Higher order total variation regularization for EIT reconstruction.
Gong, Bo; Schullcke, Benjamin; Krueger-Ziolek, Sabine; Zhang, Fan; Mueller-Lisse, Ullrich; Moeller, Knut
2018-01-08
Electrical impedance tomography (EIT) attempts to reveal the conductivity distribution of a domain based on the electrical boundary condition. This is an ill-posed inverse problem; its solution is very unstable. Total variation (TV) regularization is one of the techniques commonly employed to stabilize reconstructions. However, it is well known that TV regularization induces staircase effects, which are not realistic in clinical applications. To reduce such artifacts, modified TV regularization terms considering a higher order differential operator were developed in several previous studies. One of them is called total generalized variation (TGV) regularization. TGV regularization has been successively applied in image processing in a regular grid context. In this study, we adapted TGV regularization to the finite element model (FEM) framework for EIT reconstruction. Reconstructions using simulation and clinical data were performed. First results indicate that, in comparison to TV regularization, TGV regularization promotes more realistic images. Graphical abstract Reconstructed conductivity changes located on selected vertical lines. For each of the reconstructed images as well as the ground truth image, conductivity changes located along the selected left and right vertical lines are plotted. In these plots, the notation GT in the legend stands for ground truth, TV stands for total variation method, and TGV stands for total generalized variation method. Reconstructed conductivity distributions from the GREIT algorithm are also demonstrated.
Iterative image reconstruction that includes a total variation regularization for radial MRI.
Kojima, Shinya; Shinohara, Hiroyuki; Hashimoto, Takeyuki; Hirata, Masami; Ueno, Eiko
2015-07-01
This paper presents an iterative image reconstruction method for radial encodings in MRI based on a total variation (TV) regularization. The algebraic reconstruction method combined with total variation regularization (ART_TV) is implemented with a regularization parameter specifying the weight of the TV term in the optimization process. We used numerical simulations of a Shepp-Logan phantom, as well as experimental imaging of a phantom that included a rectangular-wave chart, to evaluate the performance of ART_TV, and to compare it with that of the Fourier transform (FT) method. The trade-off between spatial resolution and signal-to-noise ratio (SNR) was investigated for different values of the regularization parameter by experiments on a phantom and a commercially available MRI system. ART_TV was inferior to the FT with respect to the evaluation of the modulation transfer function (MTF), especially at high frequencies; however, it outperformed the FT with regard to the SNR. In accordance with the results of SNR measurement, visual impression suggested that the image quality of ART_TV was better than that of the FT for reconstruction of a noisy image of a kiwi fruit. In conclusion, ART_TV provides radial MRI with improved image quality for low-SNR data; however, the regularization parameter in ART_TV is a critical factor for obtaining improvement over the FT.
A generalized Condat's algorithm of 1D total variation regularization
NASA Astrophysics Data System (ADS)
Makovetskii, Artyom; Voronin, Sergei; Kober, Vitaly
2017-09-01
A common way for solving the denosing problem is to utilize the total variation (TV) regularization. Many efficient numerical algorithms have been developed for solving the TV regularization problem. Condat described a fast direct algorithm to compute the processed 1D signal. Also there exists a direct algorithm with a linear time for 1D TV denoising referred to as the taut string algorithm. The Condat's algorithm is based on a dual problem to the 1D TV regularization. In this paper, we propose a variant of the Condat's algorithm based on the direct 1D TV regularization problem. The usage of the Condat's algorithm with the taut string approach leads to a clear geometric description of the extremal function. Computer simulation results are provided to illustrate the performance of the proposed algorithm for restoration of degraded signals.
Sanders, Toby; Gelb, Anne; Platte, Rodrigo B.; ...
2017-01-03
Over the last decade or so, reconstruction methods using ℓ 1 regularization, often categorized as compressed sensing (CS) algorithms, have significantly improved the capabilities of high fidelity imaging in electron tomography. The most popular ℓ 1 regularization approach within electron tomography has been total variation (TV) regularization. In addition to reducing unwanted noise, TV regularization encourages a piecewise constant solution with sparse boundary regions. In this paper we propose an alternative ℓ 1 regularization approach for electron tomography based on higher order total variation (HOTV). Like TV, the HOTV approach promotes solutions with sparse boundary regions. In smooth regions however,more » the solution is not limited to piecewise constant behavior. We demonstrate that this allows for more accurate reconstruction of a broader class of images – even those for which TV was designed for – particularly when dealing with pragmatic tomographic sampling patterns and very fine image features. In conclusion, we develop results for an electron tomography data set as well as a phantom example, and we also make comparisons with discrete tomography approaches.« less
NASA Astrophysics Data System (ADS)
Zhong, Qiu-Xiang; Wu, Chuan-Sheng; Shu, Qiao-Ling; Liu, Ryan Wen
2018-04-01
Image deblurring under impulse noise is a typical ill-posed problem which requires regularization methods to guarantee high-quality imaging. L1-norm data-fidelity term and total variation (TV) regularizer have been combined to contribute the popular regularization method. However, the TV-regularized variational image deblurring model often suffers from the staircase-like artifacts leading to image quality degradation. To enhance image quality, the detailpreserving total generalized variation (TGV) was introduced to replace TV to eliminate the undesirable artifacts. The resulting nonconvex optimization problem was effectively solved using the alternating direction method of multipliers (ADMM). In addition, an automatic method for selecting spatially adapted regularization parameters was proposed to further improve deblurring performance. Our proposed image deblurring framework is able to remove blurring and impulse noise effects while maintaining the image edge details. Comprehensive experiments have been conducted to demonstrate the superior performance of our proposed method over several state-of-the-art image deblurring methods.
Low Dose CT Reconstruction via Edge-preserving Total Variation Regularization
Tian, Zhen; Jia, Xun; Yuan, Kehong; Pan, Tinsu; Jiang, Steve B.
2014-01-01
High radiation dose in CT scans increases a lifetime risk of cancer and has become a major clinical concern. Recently, iterative reconstruction algorithms with Total Variation (TV) regularization have been developed to reconstruct CT images from highly undersampled data acquired at low mAs levels in order to reduce the imaging dose. Nonetheless, the low contrast structures tend to be smoothed out by the TV regularization, posing a great challenge for the TV method. To solve this problem, in this work we develop an iterative CT reconstruction algorithm with edge-preserving TV regularization to reconstruct CT images from highly undersampled data obtained at low mAs levels. The CT image is reconstructed by minimizing an energy consisting of an edge-preserving TV norm and a data fidelity term posed by the x-ray projections. The edge-preserving TV term is proposed to preferentially perform smoothing only on non-edge part of the image in order to better preserve the edges, which is realized by introducing a penalty weight to the original total variation norm. During the reconstruction process, the pixels at edges would be gradually identified and given small penalty weight. Our iterative algorithm is implemented on GPU to improve its speed. We test our reconstruction algorithm on a digital NCAT phantom, a physical chest phantom, and a Catphan phantom. Reconstruction results from a conventional FBP algorithm and a TV regularization method without edge preserving penalty are also presented for comparison purpose. The experimental results illustrate that both TV-based algorithm and our edge-preserving TV algorithm outperform the conventional FBP algorithm in suppressing the streaking artifacts and image noise under the low dose context. Our edge-preserving algorithm is superior to the TV-based algorithm in that it can preserve more information of low contrast structures and therefore maintain acceptable spatial resolution. PMID:21860076
Selection of regularization parameter in total variation image restoration.
Liao, Haiyong; Li, Fang; Ng, Michael K
2009-11-01
We consider and study total variation (TV) image restoration. In the literature there are several regularization parameter selection methods for Tikhonov regularization problems (e.g., the discrepancy principle and the generalized cross-validation method). However, to our knowledge, these selection methods have not been applied to TV regularization problems. The main aim of this paper is to develop a fast TV image restoration method with an automatic selection of the regularization parameter scheme to restore blurred and noisy images. The method exploits the generalized cross-validation (GCV) technique to determine inexpensively how much regularization to use in each restoration step. By updating the regularization parameter in each iteration, the restored image can be obtained. Our experimental results for testing different kinds of noise show that the visual quality and SNRs of images restored by the proposed method is promising. We also demonstrate that the method is efficient, as it can restore images of size 256 x 256 in approximately 20 s in the MATLAB computing environment.
NASA Astrophysics Data System (ADS)
Bai, Bing
2012-03-01
There has been a lot of work on total variation (TV) regularized tomographic image reconstruction recently. Many of them use gradient-based optimization algorithms with a differentiable approximation of the TV functional. In this paper we apply TV regularization in Positron Emission Tomography (PET) image reconstruction. We reconstruct the PET image in a Bayesian framework, using Poisson noise model and TV prior functional. The original optimization problem is transformed to an equivalent problem with inequality constraints by adding auxiliary variables. Then we use an interior point method with logarithmic barrier functions to solve the constrained optimization problem. In this method, a series of points approaching the solution from inside the feasible region are found by solving a sequence of subproblems characterized by an increasing positive parameter. We use preconditioned conjugate gradient (PCG) algorithm to solve the subproblems directly. The nonnegativity constraint is enforced by bend line search. The exact expression of the TV functional is used in our calculations. Simulation results show that the algorithm converges fast and the convergence is insensitive to the values of the regularization and reconstruction parameters.
Gopi, Varun P; Palanisamy, P; Wahid, Khan A; Babyn, Paul; Cooper, David
2013-01-01
Micro-computed tomography (micro-CT) plays an important role in pre-clinical imaging. The radiation from micro-CT can result in excess radiation exposure to the specimen under test, hence the reduction of radiation from micro-CT is essential. The proposed research focused on analyzing and testing an alternating direction augmented Lagrangian (ADAL) algorithm to recover images from random projections using total variation (TV) regularization. The use of TV regularization in compressed sensing problems makes the recovered image quality sharper by preserving the edges or boundaries more accurately. In this work TV regularization problem is addressed by ADAL which is a variant of the classic augmented Lagrangian method for structured optimization. The per-iteration computational complexity of the algorithm is two fast Fourier transforms, two matrix vector multiplications and a linear time shrinkage operation. Comparison of experimental results indicate that the proposed algorithm is stable, efficient and competitive with the existing algorithms for solving TV regularization problems. Copyright © 2013 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Gong, Changfei; Zeng, Dong; Bian, Zhaoying; Huang, Jing; Zhang, Xinyu; Zhang, Hua; Lu, Lijun; Feng, Qianjin; Liang, Zhengrong; Ma, Jianhua
2016-03-01
Dynamic myocardial perfusion computed tomography (MPCT) is a promising technique for diagnosis and risk stratification of coronary artery disease by assessing the myocardial perfusion hemodynamic maps (MPHM). Meanwhile, the repeated scanning of the same region results in a relatively large radiation dose to patients potentially. In this work, we present a robust MPCT deconvolution algorithm with adaptive-weighted tensor total variation regularization to estimate residue function accurately under the low-dose context, which is termed `MPD-AwTTV'. More specifically, the AwTTV regularization takes into account the anisotropic edge property of the MPCT images compared with the conventional total variation (TV) regularization, which can mitigate the drawbacks of TV regularization. Subsequently, an effective iterative algorithm was adopted to minimize the associative objective function. Experimental results on a modified XCAT phantom demonstrated that the present MPD-AwTTV algorithm outperforms and is superior to other existing deconvolution algorithms in terms of noise-induced artifacts suppression, edge details preservation and accurate MPHM estimation.
NASA Astrophysics Data System (ADS)
Hintermüller, Michael; Holler, Martin; Papafitsoros, Kostas
2018-06-01
In this work, we introduce a function space setting for a wide class of structural/weighted total variation (TV) regularization methods motivated by their applications in inverse problems. In particular, we consider a regularizer that is the appropriate lower semi-continuous envelope (relaxation) of a suitable TV type functional initially defined for sufficiently smooth functions. We study examples where this relaxation can be expressed explicitly, and we also provide refinements for weighted TV for a wide range of weights. Since an integral characterization of the relaxation in function space is, in general, not always available, we show that, for a rather general linear inverse problems setting, instead of the classical Tikhonov regularization problem, one can equivalently solve a saddle-point problem where no a priori knowledge of an explicit formulation of the structural TV functional is needed. In particular, motivated by concrete applications, we deduce corresponding results for linear inverse problems with norm and Poisson log-likelihood data discrepancy terms. Finally, we provide proof-of-concept numerical examples where we solve the saddle-point problem for weighted TV denoising as well as for MR guided PET image reconstruction.
NASA Astrophysics Data System (ADS)
Huang, Zhenghua; Zhang, Tianxu; Deng, Lihua; Fang, Hao; Li, Qian
2015-12-01
Total variation(TV) based on regularization has been proven as a popular and effective model for image restoration, because of its ability of edge preserved. However, as the TV favors a piece-wise constant solution, the processing results in the flat regions of the image are easily produced "staircase effects", and the amplitude of the edges will be underestimated; the underlying cause of the problem is that the regularization parameter can not be changeable with spatial local information of image. In this paper, we propose a novel Scatter-matrix eigenvalues-based TV(SMETV) regularization with image blind restoration algorithm for deblurring medical images. The spatial information in different image regions is incorporated into regularization by using the edge indicator called difference eigenvalue to distinguish edges from flat areas. The proposed algorithm can effectively reduce the noise in flat regions as well as preserve the edge and detailed information. Moreover, it becomes more robust with the change of the regularization parameter. Extensive experiments demonstrate that the proposed approach produces results superior to most methods in both visual image quality and quantitative measures.
A spatially adaptive total variation regularization method for electrical resistance tomography
NASA Astrophysics Data System (ADS)
Song, Xizi; Xu, Yanbin; Dong, Feng
2015-12-01
The total variation (TV) regularization method has been used to solve the ill-posed inverse problem of electrical resistance tomography (ERT), owing to its good ability to preserve edges. However, the quality of the reconstructed images, especially in the flat region, is often degraded by noise. To optimize the regularization term and the regularization factor according to the spatial feature and to improve the resolution of reconstructed images, a spatially adaptive total variation (SATV) regularization method is proposed. A kind of effective spatial feature indicator named difference curvature is used to identify which region is a flat or edge region. According to different spatial features, the SATV regularization method can automatically adjust both the regularization term and regularization factor. At edge regions, the regularization term is approximate to the TV functional to preserve the edges; in flat regions, it is approximate to the first-order Tikhonov (FOT) functional to make the solution stable. Meanwhile, the adaptive regularization factor determined by the spatial feature is used to constrain the regularization strength of the SATV regularization method for different regions. Besides, a numerical scheme is adopted for the implementation of the second derivatives of difference curvature to improve the numerical stability. Several reconstruction image metrics are used to quantitatively evaluate the performance of the reconstructed results. Both simulation and experimental results indicate that, compared with the TV (mean relative error 0.288, mean correlation coefficient 0.627) and FOT (mean relative error 0.295, mean correlation coefficient 0.638) regularization methods, the proposed SATV (mean relative error 0.259, mean correlation coefficient 0.738) regularization method can endure a relatively high level of noise and improve the resolution of reconstructed images.
Total Variation with Overlapping Group Sparsity for Image Deblurring under Impulse Noise
Liu, Gang; Huang, Ting-Zhu; Liu, Jun; Lv, Xiao-Guang
2015-01-01
The total variation (TV) regularization method is an effective method for image deblurring in preserving edges. However, the TV based solutions usually have some staircase effects. In order to alleviate the staircase effects, we propose a new model for restoring blurred images under impulse noise. The model consists of an ℓ1-fidelity term and a TV with overlapping group sparsity (OGS) regularization term. Moreover, we impose a box constraint to the proposed model for getting more accurate solutions. The solving algorithm for our model is under the framework of the alternating direction method of multipliers (ADMM). We use an inner loop which is nested inside the majorization minimization (MM) iteration for the subproblem of the proposed method. Compared with other TV-based methods, numerical results illustrate that the proposed method can significantly improve the restoration quality, both in terms of peak signal-to-noise ratio (PSNR) and relative error (ReE). PMID:25874860
2016-05-01
norm does not cap - ture the geometry completely. The L1−L2 in (c) does a better job than TV while L1 in (b) and L1−0.5L2 in (d) capture the squares most...and isotropic total variation (TV) norms into a relaxed formu- lation of the two phase Mumford-Shah (MS) model for image segmentation. We show...results exceeding those obtained by the MS model when using the standard TV norm to regular- ize partition boundaries. In particular, examples illustrating
Zeng, Dong; Gao, Yuanyuan; Huang, Jing; Bian, Zhaoying; Zhang, Hua; Lu, Lijun; Ma, Jianhua
2016-10-01
Multienergy computed tomography (MECT) allows identifying and differentiating different materials through simultaneous capture of multiple sets of energy-selective data belonging to specific energy windows. However, because sufficient photon counts are not available in each energy window compared with that in the whole energy window, the MECT images reconstructed by the analytical approach often suffer from poor signal-to-noise and strong streak artifacts. To address the particular challenge, this work presents a penalized weighted least-squares (PWLS) scheme by incorporating the new concept of structure tensor total variation (STV) regularization, which is henceforth referred to as 'PWLS-STV' for simplicity. Specifically, the STV regularization is derived by penalizing higher-order derivatives of the desired MECT images. Thus it could provide more robust measures of image variation, which can eliminate the patchy artifacts often observed in total variation (TV) regularization. Subsequently, an alternating optimization algorithm was adopted to minimize the objective function. Extensive experiments with a digital XCAT phantom and meat specimen clearly demonstrate that the present PWLS-STV algorithm can achieve more gains than the existing TV-based algorithms and the conventional filtered backpeojection (FBP) algorithm in terms of both quantitative and visual quality evaluations. Copyright © 2016 Elsevier Ltd. All rights reserved.
Hessian-based norm regularization for image restoration with biomedical applications.
Lefkimmiatis, Stamatios; Bourquard, Aurélien; Unser, Michael
2012-03-01
We present nonquadratic Hessian-based regularization methods that can be effectively used for image restoration problems in a variational framework. Motivated by the great success of the total-variation (TV) functional, we extend it to also include second-order differential operators. Specifically, we derive second-order regularizers that involve matrix norms of the Hessian operator. The definition of these functionals is based on an alternative interpretation of TV that relies on mixed norms of directional derivatives. We show that the resulting regularizers retain some of the most favorable properties of TV, i.e., convexity, homogeneity, rotation, and translation invariance, while dealing effectively with the staircase effect. We further develop an efficient minimization scheme for the corresponding objective functions. The proposed algorithm is of the iteratively reweighted least-square type and results from a majorization-minimization approach. It relies on a problem-specific preconditioned conjugate gradient method, which makes the overall minimization scheme very attractive since it can be applied effectively to large images in a reasonable computational time. We validate the overall proposed regularization framework through deblurring experiments under additive Gaussian noise on standard and biomedical images.
Noisy image magnification with total variation regularization and order-changed dictionary learning
NASA Astrophysics Data System (ADS)
Xu, Jian; Chang, Zhiguo; Fan, Jiulun; Zhao, Xiaoqiang; Wu, Xiaomin; Wang, Yanzi
2015-12-01
Noisy low resolution (LR) images are always obtained in real applications, but many existing image magnification algorithms can not get good result from a noisy LR image. We propose a two-step image magnification algorithm to solve this problem. The proposed algorithm takes the advantages of both regularization-based method and learning-based method. The first step is based on total variation (TV) regularization and the second step is based on sparse representation. In the first step, we add a constraint on the TV regularization model to magnify the LR image and at the same time to suppress the noise in it. In the second step, we propose an order-changed dictionary training algorithm to train the dictionaries which is dominated by texture details. Experimental results demonstrate that the proposed algorithm performs better than many other algorithms when the noise is not serious. The proposed algorithm can also provide better visual quality on natural LR images.
NASA Astrophysics Data System (ADS)
Krauze, W.; Makowski, P.; Kujawińska, M.
2015-06-01
Standard tomographic algorithms applied to optical limited-angle tomography result in the reconstructions that have highly anisotropic resolution and thus special algorithms are developed. State of the art approaches utilize the Total Variation (TV) minimization technique. These methods give very good results but are applicable to piecewise constant structures only. In this paper, we propose a novel algorithm for 3D limited-angle tomography - Total Variation Iterative Constraint method (TVIC) which enhances the applicability of the TV regularization to non-piecewise constant samples, like biological cells. This approach consists of two parts. First, the TV minimization is used as a strong regularizer to create a sharp-edged image converted to a 3D binary mask which is then iteratively applied in the tomographic reconstruction as a constraint in the object domain. In the present work we test the method on a synthetic object designed to mimic basic structures of a living cell. For simplicity, the test reconstructions were performed within the straight-line propagation model (SIRT3D solver from the ASTRA Tomography Toolbox), but the strategy is general enough to supplement any algorithm for tomographic reconstruction that supports arbitrary geometries of plane-wave projection acquisition. This includes optical diffraction tomography solvers. The obtained reconstructions present resolution uniformity and general shape accuracy expected from the TV regularization based solvers, but keeping the smooth internal structures of the object at the same time. Comparison between three different patterns of object illumination arrangement show very small impact of the projection acquisition geometry on the image quality.
Debatin, Maurice; Hesser, Jürgen
2015-01-01
Reducing the amount of time for data acquisition and reconstruction in industrial CT decreases the operation time of the X-ray machine and therefore increases the sales. This can be achieved by reducing both, the dose and the pulse length of the CT system and the number of projections for the reconstruction, respectively. In this paper, a novel generalized Anisotropic Total Variation regularization for under-sampled, low-dose iterative CT reconstruction is discussed and compared to the standard methods, Total Variation, Adaptive weighted Total Variation and Filtered Backprojection. The novel regularization function uses a priori information about the Gradient Magnitude Distribution of the scanned object for the reconstruction. We provide a general parameterization scheme and evaluate the efficiency of our new algorithm for different noise levels and different number of projection views. When noise is not present, error-free reconstructions are achievable for AwTV and GATV from 40 projections. In cases where noise is simulated, our strategy achieves a Relative Root Mean Square Error that is up to 11 times lower than Total Variation-based and up to 4 times lower than AwTV-based iterative statistical reconstruction (e.g. for a SNR of 223 and 40 projections). To obtain the same reconstruction quality as achieved by Total Variation, the projection number and the pulse length, and the acquisition time and the dose respectively can be reduced by a factor of approximately 3.5, when AwTV is used and a factor of approximately 6.7, when our proposed algorithm is used.
Mixed Gaussian-Impulse Noise Image Restoration Via Total Variation
2012-05-01
deblurring under impulse noise ,” J. Math. Imaging Vis., vol. 36, pp. 46–53, January 2010. [5] B. Li, Q. Liu, J. Xu, and X. Luo, “A new method for removing......Several Total Variation (TV) regularization methods have recently been proposed to address denoising under mixed Gaussian and impulse noise . While
NASA Astrophysics Data System (ADS)
Zhao, Jin; Han-Ming, Zhang; Bin, Yan; Lei, Li; Lin-Yuan, Wang; Ai-Long, Cai
2016-03-01
Sparse-view x-ray computed tomography (CT) imaging is an interesting topic in CT field and can efficiently decrease radiation dose. Compared with spatial reconstruction, a Fourier-based algorithm has advantages in reconstruction speed and memory usage. A novel Fourier-based iterative reconstruction technique that utilizes non-uniform fast Fourier transform (NUFFT) is presented in this work along with advanced total variation (TV) regularization for a fan sparse-view CT. The proposition of a selective matrix contributes to improve reconstruction quality. The new method employs the NUFFT and its adjoin to iterate back and forth between the Fourier and image space. The performance of the proposed algorithm is demonstrated through a series of digital simulations and experimental phantom studies. Results of the proposed algorithm are compared with those of existing TV-regularized techniques based on compressed sensing method, as well as basic algebraic reconstruction technique. Compared with the existing TV-regularized techniques, the proposed Fourier-based technique significantly improves convergence rate and reduces memory allocation, respectively. Projected supported by the National High Technology Research and Development Program of China (Grant No. 2012AA011603) and the National Natural Science Foundation of China (Grant No. 61372172).
Total variation-based method for radar coincidence imaging with model mismatch for extended target
NASA Astrophysics Data System (ADS)
Cao, Kaicheng; Zhou, Xiaoli; Cheng, Yongqiang; Fan, Bo; Qin, Yuliang
2017-11-01
Originating from traditional optical coincidence imaging, radar coincidence imaging (RCI) is a staring/forward-looking imaging technique. In RCI, the reference matrix must be computed precisely to reconstruct the image as preferred; unfortunately, such precision is almost impossible due to the existence of model mismatch in practical applications. Although some conventional sparse recovery algorithms are proposed to solve the model-mismatch problem, they are inapplicable to nonsparse targets. We therefore sought to derive the signal model of RCI with model mismatch by replacing the sparsity constraint item with total variation (TV) regularization in the sparse total least squares optimization problem; in this manner, we obtain the objective function of RCI with model mismatch for an extended target. A more robust and efficient algorithm called TV-TLS is proposed, in which the objective function is divided into two parts and the perturbation matrix and scattering coefficients are updated alternately. Moreover, due to the ability of TV regularization to recover sparse signal or image with sparse gradient, TV-TLS method is also applicable to sparse recovering. Results of numerical experiments demonstrate that, for uniform extended targets, sparse targets, and real extended targets, the algorithm can achieve preferred imaging performance both in suppressing noise and in adapting to model mismatch.
Limited data tomographic image reconstruction via dual formulation of total variation minimization
NASA Astrophysics Data System (ADS)
Jang, Kwang Eun; Sung, Younghun; Lee, Kangeui; Lee, Jongha; Cho, Seungryong
2011-03-01
The X-ray mammography is the primary imaging modality for breast cancer screening. For the dense breast, however, the mammogram is usually difficult to read due to tissue overlap problem caused by the superposition of normal tissues. The digital breast tomosynthesis (DBT) that measures several low dose projections over a limited angle range may be an alternative modality for breast imaging, since it allows the visualization of the cross-sectional information of breast. The DBT, however, may suffer from the aliasing artifact and the severe noise corruption. To overcome these problems, a total variation (TV) regularized statistical reconstruction algorithm is presented. Inspired by the dual formulation of TV minimization in denoising and deblurring problems, we derived a gradient-type algorithm based on statistical model of X-ray tomography. The objective function is comprised of a data fidelity term derived from the statistical model and a TV regularization term. The gradient of the objective function can be easily calculated using simple operations in terms of auxiliary variables. After a descending step, the data fidelity term is renewed in each iteration. Since the proposed algorithm can be implemented without sophisticated operations such as matrix inverse, it provides an efficient way to include the TV regularization in the statistical reconstruction method, which results in a fast and robust estimation for low dose projections over the limited angle range. Initial tests with an experimental DBT system confirmed our finding.
Compressed sensing with gradient total variation for low-dose CBCT reconstruction
NASA Astrophysics Data System (ADS)
Seo, Chang-Woo; Cha, Bo Kyung; Jeon, Seongchae; Huh, Young; Park, Justin C.; Lee, Byeonghun; Baek, Junghee; Kim, Eunyoung
2015-06-01
This paper describes the improvement of convergence speed with gradient total variation (GTV) in compressed sensing (CS) for low-dose cone-beam computed tomography (CBCT) reconstruction. We derive a fast algorithm for the constrained total variation (TV)-based a minimum number of noisy projections. To achieve this task we combine the GTV with a TV-norm regularization term to promote an accelerated sparsity in the X-ray attenuation characteristics of the human body. The GTV is derived from a TV and enforces more efficient computationally and faster in convergence until a desired solution is achieved. The numerical algorithm is simple and derives relatively fast convergence. We apply a gradient projection algorithm that seeks a solution iteratively in the direction of the projected gradient while enforcing a non-negatively of the found solution. In comparison with the Feldkamp, Davis, and Kress (FDK) and conventional TV algorithms, the proposed GTV algorithm showed convergence in ≤18 iterations, whereas the original TV algorithm needs at least 34 iterations in reducing 50% of the projections compared with the FDK algorithm in order to reconstruct the chest phantom images. Future investigation includes improving imaging quality, particularly regarding X-ray cone-beam scatter, and motion artifacts of CBCT reconstruction.
Applications of compressed sensing image reconstruction to sparse view phase tomography
NASA Astrophysics Data System (ADS)
Ueda, Ryosuke; Kudo, Hiroyuki; Dong, Jian
2017-10-01
X-ray phase CT has a potential to give the higher contrast in soft tissue observations. To shorten the measure- ment time, sparse-view CT data acquisition has been attracting the attention. This paper applies two major compressed sensing (CS) approaches to image reconstruction in the x-ray sparse-view phase tomography. The first CS approach is the standard Total Variation (TV) regularization. The major drawbacks of TV regularization are a patchy artifact and loss in smooth intensity changes due to the piecewise constant nature of image model. The second CS method is a relatively new approach of CS which uses a nonlinear smoothing filter to design the regularization term. The nonlinear filter based CS is expected to reduce the major artifact in the TV regular- ization. The both cost functions can be minimized by the very fast iterative reconstruction method. However, in the past research activities, it is not clearly demonstrated how much image quality difference occurs between the TV regularization and the nonlinear filter based CS in x-ray phase CT applications. We clarify the issue by applying the two CS applications to the case of x-ray phase tomography. We provide results with numerically simulated data, which demonstrates that the nonlinear filter based CS outperforms the TV regularization in terms of textures and smooth intensity changes.
Image superresolution by midfrequency sparse representation and total variation regularization
NASA Astrophysics Data System (ADS)
Xu, Jian; Chang, Zhiguo; Fan, Jiulun; Zhao, Xiaoqiang; Wu, Xiaomin; Wang, Yanzi
2015-01-01
Machine learning has provided many good tools for superresolution, whereas existing methods still need to be improved in many aspects. On one hand, the memory and time cost should be reduced. On the other hand, the step edges of the results obtained by the existing methods are not clear enough. We do the following work. First, we propose a method to extract the midfrequency features for dictionary learning. This method brings the benefit of a reduction of the memory and time complexity without sacrificing the performance. Second, we propose a detailed wiping-off total variation (DWO-TV) regularization model to reconstruct the sharp step edges. This model adds a novel constraint on the downsampling version of the high-resolution image to wipe off the details and artifacts and sharpen the step edges. Finally, step edges produced by the DWO-TV regularization and the details provided by learning are fused. Experimental results show that the proposed method offers a desirable compromise between low time and memory cost and the reconstruction quality.
Total generalized variation-regularized variational model for single image dehazing
NASA Astrophysics Data System (ADS)
Shu, Qiao-Ling; Wu, Chuan-Sheng; Zhong, Qiu-Xiang; Liu, Ryan Wen
2018-04-01
Imaging quality is often significantly degraded under hazy weather condition. The purpose of this paper is to recover the latent sharp image from its hazy version. It is well known that the accurate estimation of depth information could assist in improving dehazing performance. In this paper, a detail-preserving variational model was proposed to simultaneously estimate haze-free image and depth map. In particular, the total variation (TV) and total generalized variation (TGV) regularizers were introduced to restrain haze-free image and depth map, respectively. The resulting nonsmooth optimization problem was efficiently solved using the alternating direction method of multipliers (ADMM). Comprehensive experiments have been conducted on realistic datasets to compare our proposed method with several state-of-the-art dehazing methods. Results have illustrated the superior performance of the proposed method in terms of visual quality evaluation.
Parallel algorithm of real-time infrared image restoration based on total variation theory
NASA Astrophysics Data System (ADS)
Zhu, Ran; Li, Miao; Long, Yunli; Zeng, Yaoyuan; An, Wei
2015-10-01
Image restoration is a necessary preprocessing step for infrared remote sensing applications. Traditional methods allow us to remove the noise but penalize too much the gradients corresponding to edges. Image restoration techniques based on variational approaches can solve this over-smoothing problem for the merits of their well-defined mathematical modeling of the restore procedure. The total variation (TV) of infrared image is introduced as a L1 regularization term added to the objective energy functional. It converts the restoration process to an optimization problem of functional involving a fidelity term to the image data plus a regularization term. Infrared image restoration technology with TV-L1 model exploits the remote sensing data obtained sufficiently and preserves information at edges caused by clouds. Numerical implementation algorithm is presented in detail. Analysis indicates that the structure of this algorithm can be easily implemented in parallelization. Therefore a parallel implementation of the TV-L1 filter based on multicore architecture with shared memory is proposed for infrared real-time remote sensing systems. Massive computation of image data is performed in parallel by cooperating threads running simultaneously on multiple cores. Several groups of synthetic infrared image data are used to validate the feasibility and effectiveness of the proposed parallel algorithm. Quantitative analysis of measuring the restored image quality compared to input image is presented. Experiment results show that the TV-L1 filter can restore the varying background image reasonably, and that its performance can achieve the requirement of real-time image processing.
Total variation superiorized conjugate gradient method for image reconstruction
NASA Astrophysics Data System (ADS)
Zibetti, Marcelo V. W.; Lin, Chuan; Herman, Gabor T.
2018-03-01
The conjugate gradient (CG) method is commonly used for the relatively-rapid solution of least squares problems. In image reconstruction, the problem can be ill-posed and also contaminated by noise; due to this, approaches such as regularization should be utilized. Total variation (TV) is a useful regularization penalty, frequently utilized in image reconstruction for generating images with sharp edges. When a non-quadratic norm is selected for regularization, as is the case for TV, then it is no longer possible to use CG. Non-linear CG is an alternative, but it does not share the efficiency that CG shows with least squares and methods such as fast iterative shrinkage-thresholding algorithms (FISTA) are preferred for problems with TV norm. A different approach to including prior information is superiorization. In this paper it is shown that the conjugate gradient method can be superiorized. Five different CG variants are proposed, including preconditioned CG. The CG methods superiorized by the total variation norm are presented and their performance in image reconstruction is demonstrated. It is illustrated that some of the proposed variants of the superiorized CG method can produce reconstructions of superior quality to those produced by FISTA and in less computational time, due to the speed of the original CG for least squares problems. In the Appendix we examine the behavior of one of the superiorized CG methods (we call it S-CG); one of its input parameters is a positive number ɛ. It is proved that, for any given ɛ that is greater than the half-squared-residual for the least squares solution, S-CG terminates in a finite number of steps with an output for which the half-squared-residual is less than or equal to ɛ. Importantly, it is also the case that the output will have a lower value of TV than what would be provided by unsuperiorized CG for the same value ɛ of the half-squared residual.
NASA Astrophysics Data System (ADS)
Lohvithee, Manasavee; Biguri, Ander; Soleimani, Manuchehr
2017-12-01
There are a number of powerful total variation (TV) regularization methods that have great promise in limited data cone-beam CT reconstruction with an enhancement of image quality. These promising TV methods require careful selection of the image reconstruction parameters, for which there are no well-established criteria. This paper presents a comprehensive evaluation of parameter selection in a number of major TV-based reconstruction algorithms. An appropriate way of selecting the values for each individual parameter has been suggested. Finally, a new adaptive-weighted projection-controlled steepest descent (AwPCSD) algorithm is presented, which implements the edge-preserving function for CBCT reconstruction with limited data. The proposed algorithm shows significant robustness compared to three other existing algorithms: ASD-POCS, AwASD-POCS and PCSD. The proposed AwPCSD algorithm is able to preserve the edges of the reconstructed images better with fewer sensitive parameters to tune.
Nonsmooth, nonconvex regularizers applied to linear electromagnetic inverse problems
NASA Astrophysics Data System (ADS)
Hidalgo-Silva, H.; Gomez-Trevino, E.
2017-12-01
Tikhonov's regularization method is the standard technique applied to obtain models of the subsurface conductivity distribution from electric or electromagnetic measurements by solving UT (m) = | F (m) - d |2 + λ P(m). The second term correspond to the stabilizing functional, with P (m) = | ∇ m |2 the usual approach, and λ the regularization parameter. Due to the roughness penalizer inclusion, the model developed by Tikhonov's algorithm tends to smear discontinuities, a feature that may be undesirable. An important requirement for the regularizer is to allow the recovery of edges, and smooth the homogeneous parts. As is well known, Total Variation (TV) is now the standard approach to meet this requirement. Recently, Wang et.al. proved convergence for alternating direction method of multipliers in nonconvex, nonsmooth optimization. In this work we present a study of several algorithms for model recovering of Geosounding data based on Infimal Convolution, and also on hybrid, TV and second order TV and nonsmooth, nonconvex regularizers, observing their performance on synthetic and real data. The algorithms are based on Bregman iteration and Split Bregman method, and the geosounding method is the low-induction numbers magnetic dipoles. Non-smooth regularizers are considered using the Legendre-Fenchel transform.
Total-variation based velocity inversion with Bregmanized operator splitting algorithm
NASA Astrophysics Data System (ADS)
Zand, Toktam; Gholami, Ali
2018-04-01
Many problems in applied geophysics can be formulated as a linear inverse problem. The associated problems, however, are large-scale and ill-conditioned. Therefore, regularization techniques are needed to be employed for solving them and generating a stable and acceptable solution. We consider numerical methods for solving such problems in this paper. In order to tackle the ill-conditioning of the problem we use blockiness as a prior information of the subsurface parameters and formulate the problem as a constrained total variation (TV) regularization. The Bregmanized operator splitting (BOS) algorithm as a combination of the Bregman iteration and the proximal forward backward operator splitting method is developed to solve the arranged problem. Two main advantages of this new algorithm are that no matrix inversion is required and that a discrepancy stopping criterion is used to stop the iterations, which allow efficient solution of large-scale problems. The high performance of the proposed TV regularization method is demonstrated using two different experiments: 1) velocity inversion from (synthetic) seismic data which is based on Born approximation, 2) computing interval velocities from RMS velocities via Dix formula. Numerical examples are presented to verify the feasibility of the proposed method for high-resolution velocity inversion.
Computerized tomography with total variation and with shearlets
NASA Astrophysics Data System (ADS)
Garduño, Edgar; Herman, Gabor T.
2017-04-01
To reduce the x-ray dose in computerized tomography (CT), many constrained optimization approaches have been proposed aiming at minimizing a regularizing function that measures a lack of consistency with some prior knowledge about the object that is being imaged, subject to a (predetermined) level of consistency with the detected attenuation of x-rays. One commonly investigated regularizing function is total variation (TV), while other publications advocate the use of some type of multiscale geometric transform in the definition of the regularizing function, a particular recent choice for this is the shearlet transform. Proponents of the shearlet transform in the regularizing function claim that the reconstructions so obtained are better than those produced using TV for texture preservation (but may be worse for noise reduction). In this paper we report results related to this claim. In our reported experiments using simulated CT data collection of the head, reconstructions whose shearlet transform has a small ℓ 1-norm are not more efficacious than reconstructions that have a small TV value. Our experiments for making such comparisons use the recently-developed superiorization methodology for both regularizing functions. Superiorization is an automated procedure for turning an iterative algorithm for producing images that satisfy a primary criterion (such as consistency with the observed measurements) into its superiorized version that will produce results that, according to the primary criterion are as good as those produced by the original algorithm, but in addition are superior to them according to a secondary (regularizing) criterion. The method presented for superiorization involving the ℓ 1-norm of the shearlet transform is novel and is quite general: It can be used for any regularizing function that is defined as the ℓ 1-norm of a transform specified by the application of a matrix. Because in the previous literature the split Bregman algorithm is used for similar purposes, a section is included comparing the results of the superiorization algorithm with the split Bregman algorithm.
Median prior constrained TV algorithm for sparse view low-dose CT reconstruction.
Liu, Yi; Shangguan, Hong; Zhang, Quan; Zhu, Hongqing; Shu, Huazhong; Gui, Zhiguo
2015-05-01
It is known that lowering the X-ray tube current (mAs) or tube voltage (kVp) and simultaneously reducing the total number of X-ray views (sparse view) is an effective means to achieve low-dose in computed tomography (CT) scan. However, the associated image quality by the conventional filtered back-projection (FBP) usually degrades due to the excessive quantum noise. Although sparse-view CT reconstruction algorithm via total variation (TV), in the scanning protocol of reducing X-ray tube current, has been demonstrated to be able to result in significant radiation dose reduction while maintain image quality, noticeable patchy artifacts still exist in reconstructed images. In this study, to address the problem of patchy artifacts, we proposed a median prior constrained TV regularization to retain the image quality by introducing an auxiliary vector m in register with the object. Specifically, the approximate action of m is to draw, in each iteration, an object voxel toward its own local median, aiming to improve low-dose image quality with sparse-view projection measurements. Subsequently, an alternating optimization algorithm is adopted to optimize the associative objective function. We refer to the median prior constrained TV regularization as "TV_MP" for simplicity. Experimental results on digital phantoms and clinical phantom demonstrated that the proposed TV_MP with appropriate control parameters can not only ensure a higher signal to noise ratio (SNR) of the reconstructed image, but also its resolution compared with the original TV method. Copyright © 2015 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Chen, Yingxuan; Yin, Fang-Fang; Zhang, Yawei; Zhang, You; Ren, Lei
2018-04-01
Purpose: compressed sensing reconstruction using total variation (TV) tends to over-smooth the edge information by uniformly penalizing the image gradient. The goal of this study is to develop a novel prior contour based TV (PCTV) method to enhance the edge information in compressed sensing reconstruction for CBCT. Methods: the edge information is extracted from prior planning-CT via edge detection. Prior CT is first registered with on-board CBCT reconstructed with TV method through rigid or deformable registration. The edge contours in prior-CT is then mapped to CBCT and used as the weight map for TV regularization to enhance edge information in CBCT reconstruction. The PCTV method was evaluated using extended-cardiac-torso (XCAT) phantom, physical CatPhan phantom and brain patient data. Results were compared with both TV and edge preserving TV (EPTV) methods which are commonly used for limited projection CBCT reconstruction. Relative error was used to calculate pixel value difference and edge cross correlation was defined as the similarity of edge information between reconstructed images and ground truth in the quantitative evaluation. Results: compared to TV and EPTV, PCTV enhanced the edge information of bone, lung vessels and tumor in XCAT reconstruction and complex bony structures in brain patient CBCT. In XCAT study using 45 half-fan CBCT projections, compared with ground truth, relative errors were 1.5%, 0.7% and 0.3% and edge cross correlations were 0.66, 0.72 and 0.78 for TV, EPTV and PCTV, respectively. PCTV is more robust to the projection number reduction. Edge enhancement was reduced slightly with noisy projections but PCTV was still superior to other methods. PCTV can maintain resolution while reducing the noise in the low mAs CatPhan reconstruction. Low contrast edges were preserved better with PCTV compared with TV and EPTV. Conclusion: PCTV preserved edge information as well as reduced streak artifacts and noise in low dose CBCT reconstruction. PCTV is superior to TV and EPTV methods in edge enhancement, which can potentially improve the localization accuracy in radiation therapy.
Moving object detection via low-rank total variation regularization
NASA Astrophysics Data System (ADS)
Wang, Pengcheng; Chen, Qian; Shao, Na
2016-09-01
Moving object detection is a challenging task in video surveillance. Recently proposed Robust Principal Component Analysis (RPCA) can recover the outlier patterns from the low-rank data under some mild conditions. However, the l-penalty in RPCA doesn't work well in moving object detection because the irrepresentable condition is often not satisfied. In this paper, a method based on total variation (TV) regularization scheme is proposed. In our model, image sequences captured with a static camera are highly related, which can be described using a low-rank matrix. Meanwhile, the low-rank matrix can absorb background motion, e.g. periodic and random perturbation. The foreground objects in the sequence are usually sparsely distributed and drifting continuously, and can be treated as group outliers from the highly-related background scenes. Instead of l-penalty, we exploit the total variation of the foreground. By minimizing the total variation energy, the outliers tend to collapse and finally converge to be the exact moving objects. The TV-penalty is superior to the l-penalty especially when the outlier is in the majority for some pixels, and our method can estimate the outlier explicitly with less bias but higher variance. To solve the problem, a joint optimization function is formulated and can be effectively solved through the inexact Augmented Lagrange Multiplier (ALM) method. We evaluate our method along with several state-of-the-art approaches in MATLAB. Both qualitative and quantitative results demonstrate that our proposed method works effectively on a large range of complex scenarios.
Accurate sparse-projection image reconstruction via nonlocal TV regularization.
Zhang, Yi; Zhang, Weihua; Zhou, Jiliu
2014-01-01
Sparse-projection image reconstruction is a useful approach to lower the radiation dose; however, the incompleteness of projection data will cause degeneration of imaging quality. As a typical compressive sensing method, total variation has obtained great attention on this problem. Suffering from the theoretical imperfection, total variation will produce blocky effect on smooth regions and blur edges. To overcome this problem, in this paper, we introduce the nonlocal total variation into sparse-projection image reconstruction and formulate the minimization problem with new nonlocal total variation norm. The qualitative and quantitative analyses of numerical as well as clinical results demonstrate the validity of the proposed method. Comparing to other existing methods, our method more efficiently suppresses artifacts caused by low-rank reconstruction and reserves structure information better.
Cai, Ailong; Wang, Linyuan; Zhang, Hanming; Yan, Bin; Li, Lei; Xi, Xiaoqi; Li, Jianxin
2014-01-01
Linear scan computed tomography (CT) is a promising imaging configuration with high scanning efficiency while the data set is under-sampled and angularly limited for which high quality image reconstruction is challenging. In this work, an edge guided total variation minimization reconstruction (EGTVM) algorithm is developed in dealing with this problem. The proposed method is modeled on the combination of total variation (TV) regularization and iterative edge detection strategy. In the proposed method, the edge weights of intermediate reconstructions are incorporated into the TV objective function. The optimization is efficiently solved by applying alternating direction method of multipliers. A prudential and conservative edge detection strategy proposed in this paper can obtain the true edges while restricting the errors within an acceptable degree. Based on the comparison on both simulation studies and real CT data set reconstructions, EGTVM provides comparable or even better quality compared to the non-edge guided reconstruction and adaptive steepest descent-projection onto convex sets method. With the utilization of weighted alternating direction TV minimization and edge detection, EGTVM achieves fast and robust convergence and reconstructs high quality image when applied in linear scan CT with under-sampled data set.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, L; Tan, S; Lu, W
Purpose: To propose a new variational method which couples image restoration with tumor segmentation for PET images using multiple regularizations. Methods: Partial volume effect (PVE) is a major degrading factor impacting tumor segmentation accuracy in PET imaging. The existing segmentation methods usually need to take prior calibrations to compensate PVE and they are highly system-dependent. Taking into account that image restoration and segmentation can promote each other and they are tightly coupled, we proposed a variational method to solve the two problems together. Our method integrated total variation (TV) semi-blind deconvolution and Mumford-Shah (MS) segmentation. The TV norm was usedmore » on edges to protect the edge information, and the L{sub 2} norm was used to avoid staircase effect in the no-edge area. The blur kernel was constrained to the Gaussian model parameterized by its variance and we assumed that the variances in the X-Y and Z directions are different. The energy functional was iteratively optimized by an alternate minimization algorithm. Segmentation performance was tested on eleven patients with non-Hodgkin’s lymphoma, and evaluated by Dice similarity index (DSI) and classification error (CE). For comparison, seven other widely used methods were also tested and evaluated. Results: The combination of TV and L{sub 2} regularizations effectively improved the segmentation accuracy. The average DSI increased by around 0.1 than using either the TV or the L{sub 2} norm. The proposed method was obviously superior to other tested methods. It has an average DSI and CE of 0.80 and 0.41, while the FCM method — the second best one — has only an average DSI and CE of 0.66 and 0.64. Conclusion: Coupling image restoration and segmentation can handle PVE and thus improves tumor segmentation accuracy in PET. Alternate use of TV and L2 regularizations can further improve the performance of the algorithm. This work was supported in part by National Natural Science Foundation of China (NNSFC), under Grant No.61375018, and Fundamental Research Funds for the Central Universities, under Grant No. 2012QN086. Wei Lu was supported in part by the National Institutes of Health (NIH) Grant No. R01 CA172638.« less
X-Ray Phase Imaging for Breast Cancer Detection
2010-09-01
regularization seeks the minimum- norm , least squares solution for phase retrieval. The retrieval result with Tikhonov regularization is still unsatisfactory...of norm , that can effectively reflect the accuracy of the retrieved data as an image, if ‖δ Ik+1−δ Ik‖ is less than a predefined threshold value β...pointed out that the proper norm for images is the total variation (TV) norm , which is the L1 norm of the gradient of the image function, and not the
Fractional-order TV-L2 model for image denoising
NASA Astrophysics Data System (ADS)
Chen, Dali; Sun, Shenshen; Zhang, Congrong; Chen, YangQuan; Xue, Dingyu
2013-10-01
This paper proposes a new fractional order total variation (TV) denoising method, which provides a much more elegant and effective way of treating problems of the algorithm implementation, ill-posed inverse, regularization parameter selection and blocky effect. Two fractional order TV-L2 models are constructed for image denoising. The majorization-minimization (MM) algorithm is used to decompose these two complex fractional TV optimization problems into a set of linear optimization problems which can be solved by the conjugate gradient algorithm. The final adaptive numerical procedure is given. Finally, we report experimental results which show that the proposed methodology avoids the blocky effect and achieves state-of-the-art performance. In addition, two medical image processing experiments are presented to demonstrate the validity of the proposed methodology.
NASA Astrophysics Data System (ADS)
Zeng, Dong; Bian, Zhaoying; Gong, Changfei; Huang, Jing; He, Ji; Zhang, Hua; Lu, Lijun; Feng, Qianjin; Liang, Zhengrong; Ma, Jianhua
2016-03-01
Multienergy computed tomography (MECT) has the potential to simultaneously offer multiple sets of energy- selective data belonging to specific energy windows. However, because sufficient photon counts are not available in the specific energy windows compared with that in the whole energy window, the MECT images reconstructed by the analytical approach often suffer from poor signal-to-noise (SNR) and strong streak artifacts. To eliminate this drawback, in this work we present a penalized weighted least-squares (PWLS) scheme by incorporating the new concept of structure tensor total variation (STV) regularization to improve the MECT images quality from low-milliampere-seconds (low-mAs) data acquisitions. Henceforth the present scheme is referred to as `PWLS- STV' for simplicity. Specifically, the STV regularization is derived by penalizing the eigenvalues of the structure tensor of every point in the MECT images. Thus it can provide more robust measures of image variation, which can eliminate the patchy artifacts often observed in total variation regularization. Subsequently, an alternating optimization algorithm was adopted to minimize the objective function. Experiments with a digital XCAT phantom clearly demonstrate that the present PWLS-STV algorithm can achieve more gains than the existing TV-based algorithms and the conventional filtered backpeojection (FBP) algorithm in terms of noise-induced artifacts suppression, resolution preservation, and material decomposition assessment.
GPU-accelerated regularized iterative reconstruction for few-view cone beam CT
DOE Office of Scientific and Technical Information (OSTI.GOV)
Matenine, Dmitri, E-mail: dmitri.matenine.1@ulaval.ca; Goussard, Yves, E-mail: yves.goussard@polymtl.ca; Després, Philippe, E-mail: philippe.despres@phy.ulaval.ca
2015-04-15
Purpose: The present work proposes an iterative reconstruction technique designed for x-ray transmission computed tomography (CT). The main objective is to provide a model-based solution to the cone-beam CT reconstruction problem, yielding accurate low-dose images via few-views acquisitions in clinically acceptable time frames. Methods: The proposed technique combines a modified ordered subsets convex (OSC) algorithm and the total variation minimization (TV) regularization technique and is called OSC-TV. The number of subsets of each OSC iteration follows a reduction pattern in order to ensure the best performance of the regularization method. Considering the high computational cost of the algorithm, it ismore » implemented on a graphics processing unit, using parallelization to accelerate computations. Results: The reconstructions were performed on computer-simulated as well as human pelvic cone-beam CT projection data and image quality was assessed. In terms of convergence and image quality, OSC-TV performs well in reconstruction of low-dose cone-beam CT data obtained via a few-view acquisition protocol. It compares favorably to the few-view TV-regularized projections onto convex sets (POCS-TV) algorithm. It also appears to be a viable alternative to full-dataset filtered backprojection. Execution times are of 1–2 min and are compatible with the typical clinical workflow for nonreal-time applications. Conclusions: Considering the image quality and execution times, this method may be useful for reconstruction of low-dose clinical acquisitions. It may be of particular benefit to patients who undergo multiple acquisitions by reducing the overall imaging radiation dose and associated risks.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bildhauer, Michael, E-mail: bibi@math.uni-sb.de; Fuchs, Martin, E-mail: fuchs@math.uni-sb.de
2012-12-15
We discuss several variants of the TV-regularization model used in image recovery. The proposed alternatives are either of nearly linear growth or even of linear growth, but with some weak ellipticity properties. The main feature of the paper is the investigation of the analytic properties of the corresponding solutions.
Nonlocal variational model and filter algorithm to remove multiplicative noise
NASA Astrophysics Data System (ADS)
Chen, Dai-Qiang; Zhang, Hui; Cheng, Li-Zhi
2010-07-01
The nonlocal (NL) means filter proposed by Buades, Coll, and Morel (SIAM Multiscale Model. Simul. 4(2), 490-530, 2005), which makes full use of the redundancy information in images, has shown to be very efficient for image denoising with Gauss noise added. On the basis of the NL method and a striver to minimize the conditional mean-square error, we design a NL means filter to remove multiplicative noise, and combining the NL filter to regularity method, we propose a NL total variational (TV) model and present a fast iterated algorithm for it. Experiments demonstrate that our algorithm is better than TV method; it is superior in preserving small structures and textures and can obtain an improvement in peak signal-to-noise ratio.
A MAP blind image deconvolution algorithm with bandwidth over-constrained
NASA Astrophysics Data System (ADS)
Ren, Zhilei; Liu, Jin; Liang, Yonghui; He, Yulong
2018-03-01
We demonstrate a maximum a posteriori (MAP) blind image deconvolution algorithm with bandwidth over-constrained and total variation (TV) regularization to recover a clear image from the AO corrected images. The point spread functions (PSFs) are estimated by bandwidth limited less than the cutoff frequency of the optical system. Our algorithm performs well in avoiding noise magnification. The performance is demonstrated on simulated data.
Preconditioned Alternating Projection Algorithms for Maximum a Posteriori ECT Reconstruction
Krol, Andrzej; Li, Si; Shen, Lixin; Xu, Yuesheng
2012-01-01
We propose a preconditioned alternating projection algorithm (PAPA) for solving the maximum a posteriori (MAP) emission computed tomography (ECT) reconstruction problem. Specifically, we formulate the reconstruction problem as a constrained convex optimization problem with the total variation (TV) regularization. We then characterize the solution of the constrained convex optimization problem and show that it satisfies a system of fixed-point equations defined in terms of two proximity operators raised from the convex functions that define the TV-norm and the constrain involved in the problem. The characterization (of the solution) via the proximity operators that define two projection operators naturally leads to an alternating projection algorithm for finding the solution. For efficient numerical computation, we introduce to the alternating projection algorithm a preconditioning matrix (the EM-preconditioner) for the dense system matrix involved in the optimization problem. We prove theoretically convergence of the preconditioned alternating projection algorithm. In numerical experiments, performance of our algorithms, with an appropriately selected preconditioning matrix, is compared with performance of the conventional MAP expectation-maximization (MAP-EM) algorithm with TV regularizer (EM-TV) and that of the recently developed nested EM-TV algorithm for ECT reconstruction. Based on the numerical experiments performed in this work, we observe that the alternating projection algorithm with the EM-preconditioner outperforms significantly the EM-TV in all aspects including the convergence speed, the noise in the reconstructed images and the image quality. It also outperforms the nested EM-TV in the convergence speed while providing comparable image quality. PMID:23271835
Preconditioned alternating projection algorithms for maximum a posteriori ECT reconstruction
NASA Astrophysics Data System (ADS)
Krol, Andrzej; Li, Si; Shen, Lixin; Xu, Yuesheng
2012-11-01
We propose a preconditioned alternating projection algorithm (PAPA) for solving the maximum a posteriori (MAP) emission computed tomography (ECT) reconstruction problem. Specifically, we formulate the reconstruction problem as a constrained convex optimization problem with the total variation (TV) regularization. We then characterize the solution of the constrained convex optimization problem and show that it satisfies a system of fixed-point equations defined in terms of two proximity operators raised from the convex functions that define the TV-norm and the constraint involved in the problem. The characterization (of the solution) via the proximity operators that define two projection operators naturally leads to an alternating projection algorithm for finding the solution. For efficient numerical computation, we introduce to the alternating projection algorithm a preconditioning matrix (the EM-preconditioner) for the dense system matrix involved in the optimization problem. We prove theoretically convergence of the PAPA. In numerical experiments, performance of our algorithms, with an appropriately selected preconditioning matrix, is compared with performance of the conventional MAP expectation-maximization (MAP-EM) algorithm with TV regularizer (EM-TV) and that of the recently developed nested EM-TV algorithm for ECT reconstruction. Based on the numerical experiments performed in this work, we observe that the alternating projection algorithm with the EM-preconditioner outperforms significantly the EM-TV in all aspects including the convergence speed, the noise in the reconstructed images and the image quality. It also outperforms the nested EM-TV in the convergence speed while providing comparable image quality.
SparseBeads data: benchmarking sparsity-regularized computed tomography
NASA Astrophysics Data System (ADS)
Jørgensen, Jakob S.; Coban, Sophia B.; Lionheart, William R. B.; McDonald, Samuel A.; Withers, Philip J.
2017-12-01
Sparsity regularization (SR) such as total variation (TV) minimization allows accurate image reconstruction in x-ray computed tomography (CT) from fewer projections than analytical methods. Exactly how few projections suffice and how this number may depend on the image remain poorly understood. Compressive sensing connects the critical number of projections to the image sparsity, but does not cover CT, however empirical results suggest a similar connection. The present work establishes for real CT data a connection between gradient sparsity and the sufficient number of projections for accurate TV-regularized reconstruction. A collection of 48 x-ray CT datasets called SparseBeads was designed for benchmarking SR reconstruction algorithms. Beadpacks comprising glass beads of five different sizes as well as mixtures were scanned in a micro-CT scanner to provide structured datasets with variable image sparsity levels, number of projections and noise levels to allow the systematic assessment of parameters affecting performance of SR reconstruction algorithms6. Using the SparseBeads data, TV-regularized reconstruction quality was assessed as a function of numbers of projections and gradient sparsity. The critical number of projections for satisfactory TV-regularized reconstruction increased almost linearly with the gradient sparsity. This establishes a quantitative guideline from which one may predict how few projections to acquire based on expected sample sparsity level as an aid in planning of dose- or time-critical experiments. The results are expected to hold for samples of similar characteristics, i.e. consisting of few, distinct phases with relatively simple structure. Such cases are plentiful in porous media, composite materials, foams, as well as non-destructive testing and metrology. For samples of other characteristics the proposed methodology may be used to investigate similar relations.
A mixed-order nonlinear diffusion compressed sensing MR image reconstruction.
Joy, Ajin; Paul, Joseph Suresh
2018-03-07
Avoid formation of staircase artifacts in nonlinear diffusion-based MR image reconstruction without compromising computational speed. Whereas second-order diffusion encourages the evolution of pixel neighborhood with uniform intensities, fourth-order diffusion considers smooth region to be not necessarily a uniform intensity region but also a planar region. Therefore, a controlled application of fourth-order diffusivity function is used to encourage second-order diffusion to reconstruct the smooth regions of the image as a plane rather than a group of blocks, while not being strong enough to introduce the undesirable speckle effect. Proposed method is compared with second- and fourth-order nonlinear diffusion reconstruction, total variation (TV), total generalized variation, and higher degree TV using in vivo data sets for different undersampling levels with application to dictionary learning-based reconstruction. It is observed that the proposed technique preserves sharp boundaries in the image while preventing the formation of staircase artifacts in the regions of smoothly varying pixel intensities. It also shows reduced error measures compared with second-order nonlinear diffusion reconstruction or TV and converges faster than TV-based methods. Because nonlinear diffusion is known to be an effective alternative to TV for edge-preserving reconstruction, the crucial aspect of staircase artifact removal is addressed. Reconstruction is found to be stable for the experimentally determined range of fourth-order regularization parameter, and therefore not does not introduce a parameter search. Hence, the computational simplicity of second-order diffusion is retained. © 2018 International Society for Magnetic Resonance in Medicine.
Estimation of Noise Properties for TV-regularized Image Reconstruction in Computed Tomography
Sánchez, Adrian A.
2016-01-01
A method for predicting the image covariance resulting from total-variation-penalized iterative image reconstruction (TV-penalized IIR) is presented and demonstrated in a variety of contexts. The method is validated against the sample covariance from statistical noise realizations for a small image using a variety of comparison metrics. Potential applications for the covariance approximation include investigation of image properties such as object- and signal-dependence of noise, and noise stationarity. These applications are demonstrated, along with the construction of image pixel variance maps for two-dimensional 128 × 128 pixel images. Methods for extending the proposed covariance approximation to larger images and improving computational efficiency are discussed. Future work will apply the developed methodology to the construction of task-based image quality metrics such as the Hotelling observer detectability for TV-based IIR. PMID:26308968
Estimation of noise properties for TV-regularized image reconstruction in computed tomography.
Sánchez, Adrian A
2015-09-21
A method for predicting the image covariance resulting from total-variation-penalized iterative image reconstruction (TV-penalized IIR) is presented and demonstrated in a variety of contexts. The method is validated against the sample covariance from statistical noise realizations for a small image using a variety of comparison metrics. Potential applications for the covariance approximation include investigation of image properties such as object- and signal-dependence of noise, and noise stationarity. These applications are demonstrated, along with the construction of image pixel variance maps for two-dimensional 128 × 128 pixel images. Methods for extending the proposed covariance approximation to larger images and improving computational efficiency are discussed. Future work will apply the developed methodology to the construction of task-based image quality metrics such as the Hotelling observer detectability for TV-based IIR.
Estimation of noise properties for TV-regularized image reconstruction in computed tomography
NASA Astrophysics Data System (ADS)
Sánchez, Adrian A.
2015-09-01
A method for predicting the image covariance resulting from total-variation-penalized iterative image reconstruction (TV-penalized IIR) is presented and demonstrated in a variety of contexts. The method is validated against the sample covariance from statistical noise realizations for a small image using a variety of comparison metrics. Potential applications for the covariance approximation include investigation of image properties such as object- and signal-dependence of noise, and noise stationarity. These applications are demonstrated, along with the construction of image pixel variance maps for two-dimensional 128× 128 pixel images. Methods for extending the proposed covariance approximation to larger images and improving computational efficiency are discussed. Future work will apply the developed methodology to the construction of task-based image quality metrics such as the Hotelling observer detectability for TV-based IIR.
Li, Laquan; Wang, Jian; Lu, Wei; Tan, Shan
2016-01-01
Accurate tumor segmentation from PET images is crucial in many radiation oncology applications. Among others, partial volume effect (PVE) is recognized as one of the most important factors degrading imaging quality and segmentation accuracy in PET. Taking into account that image restoration and tumor segmentation are tightly coupled and can promote each other, we proposed a variational method to solve both problems simultaneously in this study. The proposed method integrated total variation (TV) semi-blind de-convolution and Mumford-Shah segmentation with multiple regularizations. Unlike many existing energy minimization methods using either TV or L2 regularization, the proposed method employed TV regularization over tumor edges to preserve edge information, and L2 regularization inside tumor regions to preserve the smooth change of the metabolic uptake in a PET image. The blur kernel was modeled as anisotropic Gaussian to address the resolution difference in transverse and axial directions commonly seen in a clinic PET scanner. The energy functional was rephrased using the Γ-convergence approximation and was iteratively optimized using the alternating minimization (AM) algorithm. The performance of the proposed method was validated on a physical phantom and two clinic datasets with non-Hodgkin’s lymphoma and esophageal cancer, respectively. Experimental results demonstrated that the proposed method had high performance for simultaneous image restoration, tumor segmentation and scanner blur kernel estimation. Particularly, the recovery coefficients (RC) of the restored images of the proposed method in the phantom study were close to 1, indicating an efficient recovery of the original blurred images; for segmentation the proposed method achieved average dice similarity indexes (DSIs) of 0.79 and 0.80 for two clinic datasets, respectively; and the relative errors of the estimated blur kernel widths were less than 19% in the transversal direction and 7% in the axial direction. PMID:28603407
Hessian Schatten-norm regularization for linear inverse problems.
Lefkimmiatis, Stamatios; Ward, John Paul; Unser, Michael
2013-05-01
We introduce a novel family of invariant, convex, and non-quadratic functionals that we employ to derive regularized solutions of ill-posed linear inverse imaging problems. The proposed regularizers involve the Schatten norms of the Hessian matrix, which are computed at every pixel of the image. They can be viewed as second-order extensions of the popular total-variation (TV) semi-norm since they satisfy the same invariance properties. Meanwhile, by taking advantage of second-order derivatives, they avoid the staircase effect, a common artifact of TV-based reconstructions, and perform well for a wide range of applications. To solve the corresponding optimization problems, we propose an algorithm that is based on a primal-dual formulation. A fundamental ingredient of this algorithm is the projection of matrices onto Schatten norm balls of arbitrary radius. This operation is performed efficiently based on a direct link we provide between vector projections onto lq norm balls and matrix projections onto Schatten norm balls. Finally, we demonstrate the effectiveness of the proposed methods through experimental results on several inverse imaging problems with real and simulated data.
An iterative algorithm for L1-TV constrained regularization in image restoration
NASA Astrophysics Data System (ADS)
Chen, K.; Loli Piccolomini, E.; Zama, F.
2015-11-01
We consider the problem of restoring blurred images affected by impulsive noise. The adopted method restores the images by solving a sequence of constrained minimization problems where the data fidelity function is the ℓ1 norm of the residual and the constraint, chosen as the image Total Variation, is automatically adapted to improve the quality of the restored images. Although this approach is general, we report here the case of vectorial images where the blurring model involves contributions from the different image channels (cross channel blur). A computationally convenient extension of the Total Variation function to vectorial images is used and the results reported show that this approach is efficient for recovering nearly optimal images.
On epicardial potential reconstruction using regularization schemes with the L1-norm data term.
Shou, Guofa; Xia, Ling; Liu, Feng; Jiang, Mingfeng; Crozier, Stuart
2011-01-07
The electrocardiographic (ECG) inverse problem is ill-posed and usually solved by regularization schemes. These regularization methods, such as the Tikhonov method, are often based on the L2-norm data and constraint terms. However, L2-norm-based methods inherently provide smoothed inverse solutions that are sensitive to measurement errors, and also lack the capability of localizing and distinguishing multiple proximal cardiac electrical sources. This paper presents alternative regularization schemes employing the L1-norm data term for the reconstruction of epicardial potentials (EPs) from measured body surface potentials (BSPs). During numerical implementation, the iteratively reweighted norm algorithm was applied to solve the L1-norm-related schemes, and measurement noises were considered in the BSP data. The proposed L1-norm data term-based regularization schemes (with L1 and L2 penalty terms of the normal derivative constraint (labelled as L1TV and L1L2)) were compared with the L2-norm data terms (Tikhonov with zero-order and normal derivative constraints, labelled as ZOT and FOT, and the total variation method labelled as L2TV). The studies demonstrated that, with averaged measurement noise, the inverse solutions provided by the L1L2 and FOT algorithms have less relative error values. However, when larger noise occurred in some electrodes (for example, signal lost during measurement), the L1TV and L1L2 methods can obtain more accurate EPs in a robust manner. Therefore the L1-norm data term-based solutions are generally less perturbed by measurement noises, suggesting that the new regularization scheme is promising for providing practical ECG inverse solutions.
The Total Variation Regularized L1 Model for Multiscale Decomposition
2006-01-01
L1 fidelity term, and presented impressive and successful applications of the TV-L1 model to impulsive noise removal and outlier identification. She...used to filter 1D signal [3], to remove impulsive (salt-n- pepper) noise [35], to extract textures from natural images [45], to remove varying...34, 35, 36] discovery of the usefulness of this model for removing impul- sive noise , Chan and Esedoglu’s [17] further analysis of this model, and a
Generalized Scalar-on-Image Regression Models via Total Variation.
Wang, Xiao; Zhu, Hongtu
2017-01-01
The use of imaging markers to predict clinical outcomes can have a great impact in public health. The aim of this paper is to develop a class of generalized scalar-on-image regression models via total variation (GSIRM-TV), in the sense of generalized linear models, for scalar response and imaging predictor with the presence of scalar covariates. A key novelty of GSIRM-TV is that it is assumed that the slope function (or image) of GSIRM-TV belongs to the space of bounded total variation in order to explicitly account for the piecewise smooth nature of most imaging data. We develop an efficient penalized total variation optimization to estimate the unknown slope function and other parameters. We also establish nonasymptotic error bounds on the excess risk. These bounds are explicitly specified in terms of sample size, image size, and image smoothness. Our simulations demonstrate a superior performance of GSIRM-TV against many existing approaches. We apply GSIRM-TV to the analysis of hippocampus data obtained from the Alzheimers Disease Neuroimaging Initiative (ADNI) dataset.
A second order derivative scheme based on Bregman algorithm class
NASA Astrophysics Data System (ADS)
Campagna, Rosanna; Crisci, Serena; Cuomo, Salvatore; Galletti, Ardelio; Marcellino, Livia
2016-10-01
The algorithms based on the Bregman iterative regularization are known for efficiently solving convex constraint optimization problems. In this paper, we introduce a second order derivative scheme for the class of Bregman algorithms. Its properties of convergence and stability are investigated by means of numerical evidences. Moreover, we apply the proposed scheme to an isotropic Total Variation (TV) problem arising out of the Magnetic Resonance Image (MRI) denoising. Experimental results confirm that our algorithm has good performance in terms of denoising quality, effectiveness and robustness.
s-SMOOTH: Sparsity and Smoothness Enhanced EEG Brain Tomography
Li, Ying; Qin, Jing; Hsin, Yue-Loong; Osher, Stanley; Liu, Wentai
2016-01-01
EEG source imaging enables us to reconstruct current density in the brain from the electrical measurements with excellent temporal resolution (~ ms). The corresponding EEG inverse problem is an ill-posed one that has infinitely many solutions. This is due to the fact that the number of EEG sensors is usually much smaller than that of the potential dipole locations, as well as noise contamination in the recorded signals. To obtain a unique solution, regularizations can be incorporated to impose additional constraints on the solution. An appropriate choice of regularization is critically important for the reconstruction accuracy of a brain image. In this paper, we propose a novel Sparsity and SMOOthness enhanced brain TomograpHy (s-SMOOTH) method to improve the reconstruction accuracy by integrating two recently proposed regularization techniques: Total Generalized Variation (TGV) regularization and ℓ1−2 regularization. TGV is able to preserve the source edge and recover the spatial distribution of the source intensity with high accuracy. Compared to the relevant total variation (TV) regularization, TGV enhances the smoothness of the image and reduces staircasing artifacts. The traditional TGV defined on a 2D image has been widely used in the image processing field. In order to handle 3D EEG source images, we propose a voxel-based Total Generalized Variation (vTGV) regularization that extends the definition of second-order TGV from 2D planar images to 3D irregular surfaces such as cortex surface. In addition, the ℓ1−2 regularization is utilized to promote sparsity on the current density itself. We demonstrate that ℓ1−2 regularization is able to enhance sparsity and accelerate computations than ℓ1 regularization. The proposed model is solved by an efficient and robust algorithm based on the difference of convex functions algorithm (DCA) and the alternating direction method of multipliers (ADMM). Numerical experiments using synthetic data demonstrate the advantages of the proposed method over other state-of-the-art methods in terms of total reconstruction accuracy, localization accuracy and focalization degree. The application to the source localization of event-related potential data further demonstrates the performance of the proposed method in real-world scenarios. PMID:27965529
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, Si; Xu, Yuesheng, E-mail: yxu06@syr.edu; Zhang, Jiahan
Purpose: The authors have recently developed a preconditioned alternating projection algorithm (PAPA) with total variation (TV) regularizer for solving the penalized-likelihood optimization model for single-photon emission computed tomography (SPECT) reconstruction. This algorithm belongs to a novel class of fixed-point proximity methods. The goal of this work is to investigate how PAPA performs while dealing with realistic noisy SPECT data, to compare its performance with more conventional methods, and to address issues with TV artifacts by proposing a novel form of the algorithm invoking high-order TV regularization, denoted as HOTV-PAPA, which has been explored and studied extensively in the present work.more » Methods: Using Monte Carlo methods, the authors simulate noisy SPECT data from two water cylinders; one contains lumpy “warm” background and “hot” lesions of various sizes with Gaussian activity distribution, and the other is a reference cylinder without hot lesions. The authors study the performance of HOTV-PAPA and compare it with PAPA using first-order TV regularization (TV-PAPA), the Panin–Zeng–Gullberg one-step-late method with TV regularization (TV-OSL), and an expectation–maximization algorithm with Gaussian postfilter (GPF-EM). The authors select penalty-weights (hyperparameters) by qualitatively balancing the trade-off between resolution and image noise separately for TV-PAPA and TV-OSL. However, the authors arrived at the same penalty-weight value for both of them. The authors set the first penalty-weight in HOTV-PAPA equal to the optimal penalty-weight found for TV-PAPA. The second penalty-weight needed for HOTV-PAPA is tuned by balancing resolution and the severity of staircase artifacts. The authors adjust the Gaussian postfilter to approximately match the local point spread function of GPF-EM and HOTV-PAPA. The authors examine hot lesion detectability, study local spatial resolution, analyze background noise properties, estimate mean square errors (MSEs), and report the convergence speed and computation time. Results: HOTV-PAPA yields the best signal-to-noise ratio, followed by TV-PAPA and TV-OSL/GPF-EM. The local spatial resolution of HOTV-PAPA is somewhat worse than that of TV-PAPA and TV-OSL. Images reconstructed using HOTV-PAPA have the lowest local noise power spectrum (LNPS) amplitudes, followed by TV-PAPA, TV-OSL, and GPF-EM. The LNPS peak of GPF-EM is shifted toward higher spatial frequencies than those for the three other methods. The PAPA-type methods exhibit much lower ensemble noise, ensemble voxel variance, and image roughness. HOTV-PAPA performs best in these categories. Whereas images reconstructed using both TV-PAPA and TV-OSL are degraded by severe staircase artifacts; HOTV-PAPA substantially reduces such artifacts. It also converges faster than the other three methods and exhibits the lowest overall reconstruction error level, as measured by MSE. Conclusions: For high-noise simulated SPECT data, HOTV-PAPA outperforms TV-PAPA, GPF-EM, and TV-OSL in terms of hot lesion detectability, noise suppression, MSE, and computational efficiency. Unlike TV-PAPA and TV-OSL, HOTV-PAPA does not create sizable staircase artifacts. Moreover, HOTV-PAPA effectively suppresses noise, with only limited loss of local spatial resolution. Of the four methods, HOTV-PAPA shows the best lesion detectability, thanks to its superior noise suppression. HOTV-PAPA shows promise for clinically useful reconstructions of low-dose SPECT data.« less
Li, Si; Zhang, Jiahan; Krol, Andrzej; Schmidtlein, C. Ross; Vogelsang, Levon; Shen, Lixin; Lipson, Edward; Feiglin, David; Xu, Yuesheng
2015-01-01
Purpose: The authors have recently developed a preconditioned alternating projection algorithm (PAPA) with total variation (TV) regularizer for solving the penalized-likelihood optimization model for single-photon emission computed tomography (SPECT) reconstruction. This algorithm belongs to a novel class of fixed-point proximity methods. The goal of this work is to investigate how PAPA performs while dealing with realistic noisy SPECT data, to compare its performance with more conventional methods, and to address issues with TV artifacts by proposing a novel form of the algorithm invoking high-order TV regularization, denoted as HOTV-PAPA, which has been explored and studied extensively in the present work. Methods: Using Monte Carlo methods, the authors simulate noisy SPECT data from two water cylinders; one contains lumpy “warm” background and “hot” lesions of various sizes with Gaussian activity distribution, and the other is a reference cylinder without hot lesions. The authors study the performance of HOTV-PAPA and compare it with PAPA using first-order TV regularization (TV-PAPA), the Panin–Zeng–Gullberg one-step-late method with TV regularization (TV-OSL), and an expectation–maximization algorithm with Gaussian postfilter (GPF-EM). The authors select penalty-weights (hyperparameters) by qualitatively balancing the trade-off between resolution and image noise separately for TV-PAPA and TV-OSL. However, the authors arrived at the same penalty-weight value for both of them. The authors set the first penalty-weight in HOTV-PAPA equal to the optimal penalty-weight found for TV-PAPA. The second penalty-weight needed for HOTV-PAPA is tuned by balancing resolution and the severity of staircase artifacts. The authors adjust the Gaussian postfilter to approximately match the local point spread function of GPF-EM and HOTV-PAPA. The authors examine hot lesion detectability, study local spatial resolution, analyze background noise properties, estimate mean square errors (MSEs), and report the convergence speed and computation time. Results: HOTV-PAPA yields the best signal-to-noise ratio, followed by TV-PAPA and TV-OSL/GPF-EM. The local spatial resolution of HOTV-PAPA is somewhat worse than that of TV-PAPA and TV-OSL. Images reconstructed using HOTV-PAPA have the lowest local noise power spectrum (LNPS) amplitudes, followed by TV-PAPA, TV-OSL, and GPF-EM. The LNPS peak of GPF-EM is shifted toward higher spatial frequencies than those for the three other methods. The PAPA-type methods exhibit much lower ensemble noise, ensemble voxel variance, and image roughness. HOTV-PAPA performs best in these categories. Whereas images reconstructed using both TV-PAPA and TV-OSL are degraded by severe staircase artifacts; HOTV-PAPA substantially reduces such artifacts. It also converges faster than the other three methods and exhibits the lowest overall reconstruction error level, as measured by MSE. Conclusions: For high-noise simulated SPECT data, HOTV-PAPA outperforms TV-PAPA, GPF-EM, and TV-OSL in terms of hot lesion detectability, noise suppression, MSE, and computational efficiency. Unlike TV-PAPA and TV-OSL, HOTV-PAPA does not create sizable staircase artifacts. Moreover, HOTV-PAPA effectively suppresses noise, with only limited loss of local spatial resolution. Of the four methods, HOTV-PAPA shows the best lesion detectability, thanks to its superior noise suppression. HOTV-PAPA shows promise for clinically useful reconstructions of low-dose SPECT data. PMID:26233214
Image super-resolution via adaptive filtering and regularization
NASA Astrophysics Data System (ADS)
Ren, Jingbo; Wu, Hao; Dong, Weisheng; Shi, Guangming
2014-11-01
Image super-resolution (SR) is widely used in the fields of civil and military, especially for the low-resolution remote sensing images limited by the sensor. Single-image SR refers to the task of restoring a high-resolution (HR) image from the low-resolution image coupled with some prior knowledge as a regularization term. One classic method regularizes image by total variation (TV) and/or wavelet or some other transform which introduce some artifacts. To compress these shortages, a new framework for single image SR is proposed by utilizing an adaptive filter before regularization. The key of our model is that the adaptive filter is used to remove the spatial relevance among pixels first and then only the high frequency (HF) part, which is sparser in TV and transform domain, is considered as the regularization term. Concretely, through transforming the original model, the SR question can be solved by two alternate iteration sub-problems. Before each iteration, the adaptive filter should be updated to estimate the initial HF. A high quality HF part and HR image can be obtained by solving the first and second sub-problem, respectively. In experimental part, a set of remote sensing images captured by Landsat satellites are tested to demonstrate the effectiveness of the proposed framework. Experimental results show the outstanding performance of the proposed method in quantitative evaluation and visual fidelity compared with the state-of-the-art methods.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Akiyama, Kazunori; Fish, Vincent L.; Doeleman, Sheperd S.
We propose a new imaging technique for radio and optical/infrared interferometry. The proposed technique reconstructs the image from the visibility amplitude and closure phase, which are standard data products of short-millimeter very long baseline interferometers such as the Event Horizon Telescope (EHT) and optical/infrared interferometers, by utilizing two regularization functions: the ℓ {sub 1}-norm and total variation (TV) of the brightness distribution. In the proposed method, optimal regularization parameters, which represent the sparseness and effective spatial resolution of the image, are derived from data themselves using cross-validation (CV). As an application of this technique, we present simulated observations of M87more » with the EHT based on four physically motivated models. We confirm that ℓ {sub 1} + TV regularization can achieve an optimal resolution of ∼20%–30% of the diffraction limit λ / D {sub max}, which is the nominal spatial resolution of a radio interferometer. With the proposed technique, the EHT can robustly and reasonably achieve super-resolution sufficient to clearly resolve the black hole shadow. These results make it promising for the EHT to provide an unprecedented view of the event-horizon-scale structure in the vicinity of the supermassive black hole in M87 and also the Galactic center Sgr A*.« less
Color TV: total variation methods for restoration of vector-valued images.
Blomgren, P; Chan, T F
1998-01-01
We propose a new definition of the total variation (TV) norm for vector-valued functions that can be applied to restore color and other vector-valued images. The new TV norm has the desirable properties of 1) not penalizing discontinuities (edges) in the image, 2) being rotationally invariant in the image space, and 3) reducing to the usual TV norm in the scalar case. Some numerical experiments on denoising simple color images in red-green-blue (RGB) color space are presented.
47 CFR 76.614 - Cable television system regular monitoring.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 47 Telecommunication 4 2013-10-01 2013-10-01 false Cable television system regular monitoring. 76... system regular monitoring. Cable television operators transmitting carriers in the frequency bands 108-137 and 225-400 MHz shall provide for a program of regular monitoring for signal leakage by...
47 CFR 76.614 - Cable television system regular monitoring.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 47 Telecommunication 4 2012-10-01 2012-10-01 false Cable television system regular monitoring. 76... system regular monitoring. Cable television operators transmitting carriers in the frequency bands 108-137 and 225-400 MHz shall provide for a program of regular monitoring for signal leakage by...
47 CFR 76.614 - Cable television system regular monitoring.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 47 Telecommunication 4 2014-10-01 2014-10-01 false Cable television system regular monitoring. 76... system regular monitoring. Cable television operators transmitting carriers in the frequency bands 108-137 and 225-400 MHz shall provide for a program of regular monitoring for signal leakage by...
Low-illumination image denoising method for wide-area search of nighttime sea surface
NASA Astrophysics Data System (ADS)
Song, Ming-zhu; Qu, Hong-song; Zhang, Gui-xiang; Tao, Shu-ping; Jin, Guang
2018-05-01
In order to suppress complex mixing noise in low-illumination images for wide-area search of nighttime sea surface, a model based on total variation (TV) and split Bregman is proposed in this paper. A fidelity term based on L1 norm and a fidelity term based on L2 norm are designed considering the difference between various noise types, and the regularization mixed first-order TV and second-order TV are designed to balance the influence of details information such as texture and edge for sea surface image. The final detection result is obtained by using the high-frequency component solved from L1 norm and the low-frequency component solved from L2 norm through wavelet transform. The experimental results show that the proposed denoising model has perfect denoising performance for artificially degraded and low-illumination images, and the result of image quality assessment index for the denoising image is superior to that of the contrastive models.
Athavale, Prashant; Xu, Robert; Radau, Perry; Nachman, Adrian; Wright, Graham A
2015-07-01
Images consist of structures of varying scales: large scale structures such as flat regions, and small scale structures such as noise, textures, and rapidly oscillatory patterns. In the hierarchical (BV, L(2)) image decomposition, Tadmor, et al. (2004) start with extracting coarse scale structures from a given image, and successively extract finer structures from the residuals in each step of the iterative decomposition. We propose to begin instead by extracting the finest structures from the given image and then proceed to extract increasingly coarser structures. In most images, noise could be considered as a fine scale structure. Thus, starting the image decomposition with finer scales, rather than large scales, leads to fast denoising. We note that our approach turns out to be equivalent to the nonstationary regularization in Scherzer and Weickert (2000). The continuous limit of this procedure leads to a time-scaled version of total variation flow. Motivated by specific clinical applications, we introduce an image depending weight in the regularization functional, and study the corresponding weighted TV flow. We show that the edge-preserving property of the multiscale representation of an input image obtained with the weighted TV flow can be enhanced and localized by appropriate choice of the weight. We use this in developing an efficient and edge-preserving denoising algorithm with control on speed and localization properties. We examine analytical properties of the weighted TV flow that give precise information about the denoising speed and the rate of change of energy of the images. An additional contribution of the paper is to use the images obtained at different scales for robust multiscale registration. We show that the inherently multiscale nature of the weighted TV flow improved performance for registration of noisy cardiac MRI images, compared to other methods such as bilateral or Gaussian filtering. A clinical application of the multiscale registration algorithm is also demonstrated for aligning viability assessment magnetic resonance (MR) images from 8 patients with previous myocardial infarctions. Copyright © 2015. Published by Elsevier B.V.
Blind motion image deblurring using nonconvex higher-order total variation model
NASA Astrophysics Data System (ADS)
Li, Weihong; Chen, Rui; Xu, Shangwen; Gong, Weiguo
2016-09-01
We propose a nonconvex higher-order total variation (TV) method for blind motion image deblurring. First, we introduce a nonconvex higher-order TV differential operator to define a new model of the blind motion image deblurring, which can effectively eliminate the staircase effect of the deblurred image; meanwhile, we employ an image sparse prior to improve the edge recovery quality. Second, to improve the accuracy of the estimated motion blur kernel, we use L1 norm and H1 norm as the blur kernel regularization term, considering the sparsity and smoothing of the motion blur kernel. Third, because it is difficult to solve the numerically computational complexity problem of the proposed model owing to the intrinsic nonconvexity, we propose a binary iterative strategy, which incorporates a reweighted minimization approximating scheme in the outer iteration, and a split Bregman algorithm in the inner iteration. And we also discuss the convergence of the proposed binary iterative strategy. Last, we conduct extensive experiments on both synthetic and real-world degraded images. The results demonstrate that the proposed method outperforms the previous representative methods in both quality of visual perception and quantitative measurement.
Canales-Rodríguez, Erick J.; Caruyer, Emmanuel; Aja-Fernández, Santiago; Radua, Joaquim; Yurramendi Mendizabal, Jesús M.; Iturria-Medina, Yasser; Melie-García, Lester; Alemán-Gómez, Yasser; Thiran, Jean-Philippe; Sarró, Salvador; Pomarol-Clotet, Edith; Salvador, Raymond
2015-01-01
Spherical deconvolution (SD) methods are widely used to estimate the intra-voxel white-matter fiber orientations from diffusion MRI data. However, while some of these methods assume a zero-mean Gaussian distribution for the underlying noise, its real distribution is known to be non-Gaussian and to depend on many factors such as the number of coils and the methodology used to combine multichannel MRI signals. Indeed, the two prevailing methods for multichannel signal combination lead to noise patterns better described by Rician and noncentral Chi distributions. Here we develop a Robust and Unbiased Model-BAsed Spherical Deconvolution (RUMBA-SD) technique, intended to deal with realistic MRI noise, based on a Richardson-Lucy (RL) algorithm adapted to Rician and noncentral Chi likelihood models. To quantify the benefits of using proper noise models, RUMBA-SD was compared with dRL-SD, a well-established method based on the RL algorithm for Gaussian noise. Another aim of the study was to quantify the impact of including a total variation (TV) spatial regularization term in the estimation framework. To do this, we developed TV spatially-regularized versions of both RUMBA-SD and dRL-SD algorithms. The evaluation was performed by comparing various quality metrics on 132 three-dimensional synthetic phantoms involving different inter-fiber angles and volume fractions, which were contaminated with noise mimicking patterns generated by data processing in multichannel scanners. The results demonstrate that the inclusion of proper likelihood models leads to an increased ability to resolve fiber crossings with smaller inter-fiber angles and to better detect non-dominant fibers. The inclusion of TV regularization dramatically improved the resolution power of both techniques. The above findings were also verified in human brain data. PMID:26470024
Total variation optimization for imaging through turbid media with transmission matrix
NASA Astrophysics Data System (ADS)
Gong, Changmei; Shao, Xiaopeng; Wu, Tengfei; Liu, Jietao; Zhang, Jianqi
2016-12-01
With the transmission matrix (TM) of the whole optical system measured, the image of the object behind a turbid medium can be recovered from its speckle field by means of an image reconstruction algorithm. Instead of Tikhonov regularization algorithm (TRA), the total variation minimization by augmented Lagrangian and alternating direction algorithms (TVAL3) is introduced to recover object images. As a total variation (TV)-based approach, TVAL3 allows to effectively damp more noise and preserve more edges compared with TRA, thus providing more outstanding image quality. Different levels of detector noise and TM-measurement noise are successively added to analyze the antinoise performance of these two algorithms. Simulation results show that TVAL3 is able to recover more details and suppress more noise than TRA under different noise levels, thus providing much more excellent image quality. Furthermore, whether it be detector noise or TM-measurement noise, the reconstruction images obtained by TVAL3 at SNR=15 dB are far superior to those by TRA at SNR=50 dB.
Accelerated 1 H MRSI using randomly undersampled spiral-based k-space trajectories.
Chatnuntawech, Itthi; Gagoski, Borjan; Bilgic, Berkin; Cauley, Stephen F; Setsompop, Kawin; Adalsteinsson, Elfar
2014-07-30
To develop and evaluate the performance of an acquisition and reconstruction method for accelerated MR spectroscopic imaging (MRSI) through undersampling of spiral trajectories. A randomly undersampled spiral acquisition and sensitivity encoding (SENSE) with total variation (TV) regularization, random SENSE+TV, is developed and evaluated on single-slice numerical phantom, in vivo single-slice MRSI, and in vivo three-dimensional (3D)-MRSI at 3 Tesla. Random SENSE+TV was compared with five alternative methods for accelerated MRSI. For the in vivo single-slice MRSI, random SENSE+TV yields up to 2.7 and 2 times reduction in root-mean-square error (RMSE) of reconstructed N-acetyl aspartate (NAA), creatine, and choline maps, compared with the denoised fully sampled and uniformly undersampled SENSE+TV methods with the same acquisition time, respectively. For the in vivo 3D-MRSI, random SENSE+TV yields up to 1.6 times reduction in RMSE, compared with uniform SENSE+TV. Furthermore, by using random SENSE+TV, we have demonstrated on the in vivo single-slice and 3D-MRSI that acceleration factors of 4.5 and 4 are achievable with the same quality as the fully sampled data, as measured by RMSE of reconstructed NAA map, respectively. With the same scan time, random SENSE+TV yields lower RMSEs of metabolite maps than other methods evaluated. Random SENSE+TV achieves up to 4.5-fold acceleration with comparable data quality as the fully sampled acquisition. Magn Reson Med, 2014. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.
Computed inverse resonance imaging for magnetic susceptibility map reconstruction.
Chen, Zikuan; Calhoun, Vince
2012-01-01
This article reports a computed inverse magnetic resonance imaging (CIMRI) model for reconstructing the magnetic susceptibility source from MRI data using a 2-step computational approach. The forward T2*-weighted MRI (T2*MRI) process is broken down into 2 steps: (1) from magnetic susceptibility source to field map establishment via magnetization in the main field and (2) from field map to MR image formation by intravoxel dephasing average. The proposed CIMRI model includes 2 inverse steps to reverse the T2*MRI procedure: field map calculation from MR-phase image and susceptibility source calculation from the field map. The inverse step from field map to susceptibility map is a 3-dimensional ill-posed deconvolution problem, which can be solved with 3 kinds of approaches: the Tikhonov-regularized matrix inverse, inverse filtering with a truncated filter, and total variation (TV) iteration. By numerical simulation, we validate the CIMRI model by comparing the reconstructed susceptibility maps for a predefined susceptibility source. Numerical simulations of CIMRI show that the split Bregman TV iteration solver can reconstruct the susceptibility map from an MR-phase image with high fidelity (spatial correlation ≈ 0.99). The split Bregman TV iteration solver includes noise reduction, edge preservation, and image energy conservation. For applications to brain susceptibility reconstruction, it is important to calibrate the TV iteration program by selecting suitable values of the regularization parameter. The proposed CIMRI model can reconstruct the magnetic susceptibility source of T2*MRI by 2 computational steps: calculating the field map from the phase image and reconstructing the susceptibility map from the field map. The crux of CIMRI lies in an ill-posed 3-dimensional deconvolution problem, which can be effectively solved by the split Bregman TV iteration algorithm.
Computed inverse MRI for magnetic susceptibility map reconstruction
Chen, Zikuan; Calhoun, Vince
2015-01-01
Objective This paper reports on a computed inverse magnetic resonance imaging (CIMRI) model for reconstructing the magnetic susceptibility source from MRI data using a two-step computational approach. Methods The forward T2*-weighted MRI (T2*MRI) process is decomposed into two steps: 1) from magnetic susceptibility source to fieldmap establishment via magnetization in a main field, and 2) from fieldmap to MR image formation by intravoxel dephasing average. The proposed CIMRI model includes two inverse steps to reverse the T2*MRI procedure: fieldmap calculation from MR phase image and susceptibility source calculation from the fieldmap. The inverse step from fieldmap to susceptibility map is a 3D ill-posed deconvolution problem, which can be solved by three kinds of approaches: Tikhonov-regularized matrix inverse, inverse filtering with a truncated filter, and total variation (TV) iteration. By numerical simulation, we validate the CIMRI model by comparing the reconstructed susceptibility maps for a predefined susceptibility source. Results Numerical simulations of CIMRI show that the split Bregman TV iteration solver can reconstruct the susceptibility map from a MR phase image with high fidelity (spatial correlation≈0.99). The split Bregman TV iteration solver includes noise reduction, edge preservation, and image energy conservation. For applications to brain susceptibility reconstruction, it is important to calibrate the TV iteration program by selecting suitable values of the regularization parameter. Conclusions The proposed CIMRI model can reconstruct the magnetic susceptibility source of T2*MRI by two computational steps: calculating the fieldmap from the phase image and reconstructing the susceptibility map from the fieldmap. The crux of CIMRI lies in an ill-posed 3D deconvolution problem, which can be effectively solved by the split Bregman TV iteration algorithm. PMID:22446372
NASA Astrophysics Data System (ADS)
Zhang, Wenkun; Zhang, Hanming; Wang, Linyuan; Cai, Ailong; Li, Lei; Yan, Bin
2018-02-01
Limited angle computed tomography (CT) reconstruction is widely performed in medical diagnosis and industrial testing because of the size of objects, engine/armor inspection requirements, and limited scan flexibility. Limited angle reconstruction necessitates usage of optimization-based methods that utilize additional sparse priors. However, most of conventional methods solely exploit sparsity priors of spatial domains. When CT projection suffers from serious data deficiency or various noises, obtaining reconstruction images that meet the requirement of quality becomes difficult and challenging. To solve this problem, this paper developed an adaptive reconstruction method for limited angle CT problem. The proposed method simultaneously uses spatial and Radon domain regularization model based on total variation (TV) and data-driven tight frame. Data-driven tight frame being derived from wavelet transformation aims at exploiting sparsity priors of sinogram in Radon domain. Unlike existing works that utilize pre-constructed sparse transformation, the framelets of the data-driven regularization model can be adaptively learned from the latest projection data in the process of iterative reconstruction to provide optimal sparse approximations for given sinogram. At the same time, an effective alternating direction method is designed to solve the simultaneous spatial and Radon domain regularization model. The experiments for both simulation and real data demonstrate that the proposed algorithm shows better performance in artifacts depression and details preservation than the algorithms solely using regularization model of spatial domain. Quantitative evaluations for the results also indicate that the proposed algorithm applying learning strategy performs better than the dual domains algorithms without learning regularization model
NASA Astrophysics Data System (ADS)
Shen, Zhengwei; Cheng, Lishuang
2017-09-01
Total variation (TV)-based image deblurring method can bring on staircase artifacts in the homogenous region of the latent images recovered from the degraded images while a wavelet/frame-based image deblurring method will lead to spurious noise spikes and pseudo-Gibbs artifacts in the vicinity of discontinuities of the latent images. To suppress these artifacts efficiently, we propose a nonconvex composite wavelet/frame and TV-based image deblurring model. In this model, the wavelet/frame and the TV-based methods may complement each other, which are verified by theoretical analysis and experimental results. To further improve the quality of the latent images, nonconvex penalty function is used to be the regularization terms of the model, which may induce a stronger sparse solution and will more accurately estimate the relative large gradient or wavelet/frame coefficients of the latent images. In addition, by choosing a suitable parameter to the nonconvex penalty function, the subproblem that splits by the alternative direction method of multipliers algorithm from the proposed model can be guaranteed to be a convex optimization problem; hence, each subproblem can converge to a global optimum. The mean doubly augmented Lagrangian and the isotropic split Bregman algorithms are used to solve these convex subproblems where the designed proximal operator is used to reduce the computational complexity of the algorithms. Extensive numerical experiments indicate that the proposed model and algorithms are comparable to other state-of-the-art model and methods.
A fast 4D cone beam CT reconstruction method based on the OSC-TV algorithm.
Mascolo-Fortin, Julia; Matenine, Dmitri; Archambault, Louis; Després, Philippe
2018-01-01
Four-dimensional cone beam computed tomography allows for temporally resolved imaging with useful applications in radiotherapy, but raises particular challenges in terms of image quality and computation time. The purpose of this work is to develop a fast and accurate 4D algorithm by adapting a GPU-accelerated ordered subsets convex algorithm (OSC), combined with the total variation minimization regularization technique (TV). Different initialization schemes were studied to adapt the OSC-TV algorithm to 4D reconstruction: each respiratory phase was initialized either with a 3D reconstruction or a blank image. Reconstruction algorithms were tested on a dynamic numerical phantom and on a clinical dataset. 4D iterations were implemented for a cluster of 8 GPUs. All developed methods allowed for an adequate visualization of the respiratory movement and compared favorably to the McKinnon-Bates and adaptive steepest descent projection onto convex sets algorithms, while the 4D reconstructions initialized from a prior 3D reconstruction led to better overall image quality. The most suitable adaptation of OSC-TV to 4D CBCT was found to be a combination of a prior FDK reconstruction and a 4D OSC-TV reconstruction with a reconstruction time of 4.5 minutes. This relatively short reconstruction time could facilitate a clinical use.
A TVSCAD approach for image deblurring with impulsive noise
NASA Astrophysics Data System (ADS)
Gu, Guoyong; Jiang, Suhong; Yang, Junfeng
2017-12-01
We consider image deblurring problem in the presence of impulsive noise. It is known that total variation (TV) regularization with L1-norm penalized data fitting (TVL1 for short) works reasonably well only when the level of impulsive noise is relatively low. For high level impulsive noise, TVL1 works poorly. The reason is that all data, both corrupted and noise free, are equally penalized in data fitting, leading to insurmountable difficulty in balancing regularization and data fitting. In this paper, we propose to combine TV regularization with nonconvex smoothly clipped absolute deviation (SCAD) penalty for data fitting (TVSCAD for short). Our motivation is simply that data fitting should be enforced only when an observed data is not severely corrupted, while for those data more likely to be severely corrupted, less or even null penalization should be enforced. A difference of convex functions algorithm is adopted to solve the nonconvex TVSCAD model, resulting in solving a sequence of TVL1-equivalent problems, each of which can then be solved efficiently by the alternating direction method of multipliers. Theoretically, we establish global convergence to a critical point of the nonconvex objective function. The R-linear and at-least-sublinear convergence rate results are derived for the cases of anisotropic and isotropic TV, respectively. Numerically, experimental results are given to show that the TVSCAD approach improves those of the TVL1 significantly, especially for cases with high level impulsive noise, and is comparable with the recently proposed iteratively corrected TVL1 method (Bai et al 2016 Inverse Problems 32 085004).
47 CFR 76.614 - Cable television system regular monitoring.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 4 2011-10-01 2011-10-01 false Cable television system regular monitoring. 76.614 Section 76.614 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Technical Standards § 76.614 Cable television...
Sparsity-based acoustic inversion in cross-sectional multiscale optoacoustic imaging.
Han, Yiyong; Tzoumas, Stratis; Nunes, Antonio; Ntziachristos, Vasilis; Rosenthal, Amir
2015-09-01
With recent advancement in hardware of optoacoustic imaging systems, highly detailed cross-sectional images may be acquired at a single laser shot, thus eliminating motion artifacts. Nonetheless, other sources of artifacts remain due to signal distortion or out-of-plane signals. The purpose of image reconstruction algorithms is to obtain the most accurate images from noisy, distorted projection data. In this paper, the authors use the model-based approach for acoustic inversion, combined with a sparsity-based inversion procedure. Specifically, a cost function is used that includes the L1 norm of the image in sparse representation and a total variation (TV) term. The optimization problem is solved by a numerically efficient implementation of a nonlinear gradient descent algorithm. TV-L1 model-based inversion is tested in the cross section geometry for numerically generated data as well as for in vivo experimental data from an adult mouse. In all cases, model-based TV-L1 inversion showed a better performance over the conventional Tikhonov regularization, TV inversion, and L1 inversion. In the numerical examples, the images reconstructed with TV-L1 inversion were quantitatively more similar to the originating images. In the experimental examples, TV-L1 inversion yielded sharper images and weaker streak artifact. The results herein show that TV-L1 inversion is capable of improving the quality of highly detailed, multiscale optoacoustic images obtained in vivo using cross-sectional imaging systems. As a result of its high fidelity, model-based TV-L1 inversion may be considered as the new standard for image reconstruction in cross-sectional imaging.
Chen, Bo; Bian, Zhaoying; Zhou, Xiaohui; Chen, Wensheng; Ma, Jianhua; Liang, Zhengrong
2018-04-12
Total variation (TV) minimization for the sparse-view x-ray computer tomography (CT) reconstruction has been widely explored to reduce radiation dose. However, due to the piecewise constant assumption for the TV model, the reconstructed images often suffer from over-smoothness on the image edges. To mitigate this drawback of TV minimization, we present a Mumford-Shah total variation (MSTV) minimization algorithm in this paper. The presented MSTV model is derived by integrating TV minimization and Mumford-Shah segmentation. Subsequently, a penalized weighted least-squares (PWLS) scheme with MSTV is developed for the sparse-view CT reconstruction. For simplicity, the proposed algorithm is named as 'PWLS-MSTV.' To evaluate the performance of the present PWLS-MSTV algorithm, both qualitative and quantitative studies were conducted by using a digital XCAT phantom and a physical phantom. Experimental results show that the present PWLS-MSTV algorithm has noticeable gains over the existing algorithms in terms of noise reduction, contrast-to-ratio measure and edge-preservation.
ERIC Educational Resources Information Center
Perrow, Maxwell Vermilyea
The aim of this study was to provide quantitative measurement of the degree of identification, or lack of identification, that takes place between the viewers of television and the television roles they like and view regularly and those they dislike and view infrequently. Participants in the study were asked to keep a Television Viewing Diary and…
Evaluation of the OSC-TV iterative reconstruction algorithm for cone-beam optical CT
DOE Office of Scientific and Technical Information (OSTI.GOV)
Matenine, Dmitri, E-mail: dmitri.matenine.1@ulaval.ca; Mascolo-Fortin, Julia, E-mail: julia.mascolo-fortin.1@ulaval.ca; Goussard, Yves, E-mail: yves.goussard@polymtl.ca
Purpose: The present work evaluates an iterative reconstruction approach, namely, the ordered subsets convex (OSC) algorithm with regularization via total variation (TV) minimization in the field of cone-beam optical computed tomography (optical CT). One of the uses of optical CT is gel-based 3D dosimetry for radiation therapy, where it is employed to map dose distributions in radiosensitive gels. Model-based iterative reconstruction may improve optical CT image quality and contribute to a wider use of optical CT in clinical gel dosimetry. Methods: This algorithm was evaluated using experimental data acquired by a cone-beam optical CT system, as well as complementary numericalmore » simulations. A fast GPU implementation of OSC-TV was used to achieve reconstruction times comparable to those of conventional filtered backprojection. Images obtained via OSC-TV were compared with the corresponding filtered backprojections. Spatial resolution and uniformity phantoms were scanned and respective reconstructions were subject to evaluation of the modulation transfer function, image uniformity, and accuracy. The artifacts due to refraction and total signal loss from opaque objects were also studied. Results: The cone-beam optical CT data reconstructions showed that OSC-TV outperforms filtered backprojection in terms of image quality, thanks to a model-based simulation of the photon attenuation process. It was shown to significantly improve the image spatial resolution and reduce image noise. The accuracy of the estimation of linear attenuation coefficients remained similar to that obtained via filtered backprojection. Certain image artifacts due to opaque objects were reduced. Nevertheless, the common artifact due to the gel container walls could not be eliminated. Conclusions: The use of iterative reconstruction improves cone-beam optical CT image quality in many ways. The comparisons between OSC-TV and filtered backprojection presented in this paper demonstrate that OSC-TV can potentially improve the rendering of spatial features and reduce cone-beam optical CT artifacts.« less
Evaluation of the OSC-TV iterative reconstruction algorithm for cone-beam optical CT.
Matenine, Dmitri; Mascolo-Fortin, Julia; Goussard, Yves; Després, Philippe
2015-11-01
The present work evaluates an iterative reconstruction approach, namely, the ordered subsets convex (OSC) algorithm with regularization via total variation (TV) minimization in the field of cone-beam optical computed tomography (optical CT). One of the uses of optical CT is gel-based 3D dosimetry for radiation therapy, where it is employed to map dose distributions in radiosensitive gels. Model-based iterative reconstruction may improve optical CT image quality and contribute to a wider use of optical CT in clinical gel dosimetry. This algorithm was evaluated using experimental data acquired by a cone-beam optical CT system, as well as complementary numerical simulations. A fast GPU implementation of OSC-TV was used to achieve reconstruction times comparable to those of conventional filtered backprojection. Images obtained via OSC-TV were compared with the corresponding filtered backprojections. Spatial resolution and uniformity phantoms were scanned and respective reconstructions were subject to evaluation of the modulation transfer function, image uniformity, and accuracy. The artifacts due to refraction and total signal loss from opaque objects were also studied. The cone-beam optical CT data reconstructions showed that OSC-TV outperforms filtered backprojection in terms of image quality, thanks to a model-based simulation of the photon attenuation process. It was shown to significantly improve the image spatial resolution and reduce image noise. The accuracy of the estimation of linear attenuation coefficients remained similar to that obtained via filtered backprojection. Certain image artifacts due to opaque objects were reduced. Nevertheless, the common artifact due to the gel container walls could not be eliminated. The use of iterative reconstruction improves cone-beam optical CT image quality in many ways. The comparisons between OSC-TV and filtered backprojection presented in this paper demonstrate that OSC-TV can potentially improve the rendering of spatial features and reduce cone-beam optical CT artifacts.
Zhang, Cheng; Zhang, Tao; Zheng, Jian; Li, Ming; Lu, Yanfei; You, Jiali; Guan, Yihui
2015-01-01
In recent years, X-ray computed tomography (CT) is becoming widely used to reveal patient's anatomical information. However, the side effect of radiation, relating to genetic or cancerous diseases, has caused great public concern. The problem is how to minimize radiation dose significantly while maintaining image quality. As a practical application of compressed sensing theory, one category of methods takes total variation (TV) minimization as the sparse constraint, which makes it possible and effective to get a reconstruction image of high quality in the undersampling situation. On the other hand, a preliminary attempt of low-dose CT reconstruction based on dictionary learning seems to be another effective choice. But some critical parameters, such as the regularization parameter, cannot be determined by detecting datasets. In this paper, we propose a reweighted objective function that contributes to a numerical calculation model of the regularization parameter. A number of experiments demonstrate that this strategy performs well with better reconstruction images and saving of a large amount of time.
Towards adjoint-based inversion for rheological parameters in nonlinear viscous mantle flow
NASA Astrophysics Data System (ADS)
Worthen, Jennifer; Stadler, Georg; Petra, Noemi; Gurnis, Michael; Ghattas, Omar
2014-09-01
We address the problem of inferring mantle rheological parameter fields from surface velocity observations and instantaneous nonlinear mantle flow models. We formulate this inverse problem as an infinite-dimensional nonlinear least squares optimization problem governed by nonlinear Stokes equations. We provide expressions for the gradient of the cost functional of this optimization problem with respect to two spatially-varying rheological parameter fields: the viscosity prefactor and the exponent of the second invariant of the strain rate tensor. Adjoint (linearized) Stokes equations, which are characterized by a 4th order anisotropic viscosity tensor, facilitates efficient computation of the gradient. A quasi-Newton method for the solution of this optimization problem is presented, which requires the repeated solution of both nonlinear forward Stokes and linearized adjoint Stokes equations. For the solution of the nonlinear Stokes equations, we find that Newton’s method is significantly more efficient than a Picard fixed point method. Spectral analysis of the inverse operator given by the Hessian of the optimization problem reveals that the numerical eigenvalues collapse rapidly to zero, suggesting a high degree of ill-posedness of the inverse problem. To overcome this ill-posedness, we employ Tikhonov regularization (favoring smooth parameter fields) or total variation (TV) regularization (favoring piecewise-smooth parameter fields). Solution of two- and three-dimensional finite element-based model inverse problems show that a constant parameter in the constitutive law can be recovered well from surface velocity observations. Inverting for a spatially-varying parameter field leads to its reasonable recovery, in particular close to the surface. When inferring two spatially varying parameter fields, only an effective viscosity field and the total viscous dissipation are recoverable. Finally, a model of a subducting plate shows that a localized weak zone at the plate boundary can be partially recovered, especially with TV regularization.
Fernandes, Rômulo Araújo; Júnior, Ismael Forte Freitas; Cardoso, Jefferson Rosa; Vaz Ronque, Enio Ricardo; Loch, Mathias Roberto; de Oliveira, Arli Ramos
2008-09-23
The belief that adolescents engaged in sports increase their overall physical activity level while simultaneously decreasing physical inactivity has been the foundation of many intervention programs in developing countries. The aim of this study was to analyze the association between regular participation in sports and both active behaviors and TV viewing during leisure time. A total of 1752 Brazilian adolescents (812 = male and 940 = female) participated in this study. Regular participation in sports, as well as active behaviors (exemplified by walking or cycling) and TV viewing during leisure time were assessed by means of a questionnaire. The chi-square test analyzed the association between sports practice and leisure time behaviors, and the Poisson regression with robust variance indicated the magnitude of these associations. The prevalence of regular participation in sports was 14.8% (95% confidence interval 13.2% to 16.5%). After adjustment for all confounders, participation in sports was associated with, at the highest frequency, cycling (PR = 2.55 [1.80-3.60]) and walking (PR = 2.69 [1.98-3.64]) during leisure time. However, there was not an association between the participation in sports and frequency of TV viewing (PR = 1.28 [0.81-2.02]). This study presented data indicating that the regular participation in sports is positively associated with a higher frequency of physically active behaviors during leisure time. However, the results did not support the hypothesis that the engagement in sports necessarily decreases leisure time spent in TV viewing.
Bias correction for magnetic resonance images via joint entropy regularization.
Wang, Shanshan; Xia, Yong; Dong, Pei; Luo, Jianhua; Huang, Qiu; Feng, Dagan; Li, Yuanxiang
2014-01-01
Due to the imperfections of the radio frequency (RF) coil or object-dependent electrodynamic interactions, magnetic resonance (MR) images often suffer from a smooth and biologically meaningless bias field, which causes severe troubles for subsequent processing and quantitative analysis. To effectively restore the original signal, this paper simultaneously exploits the spatial and gradient features of the corrupted MR images for bias correction via the joint entropy regularization. With both isotropic and anisotropic total variation (TV) considered, two nonparametric bias correction algorithms have been proposed, namely IsoTVBiasC and AniTVBiasC. These two methods have been applied to simulated images under various noise levels and bias field corruption and also tested on real MR data. The test results show that the proposed two methods can effectively remove the bias field and also present comparable performance compared to the state-of-the-art methods.
Linear functional minimization for inverse modeling
Barajas-Solano, David A.; Wohlberg, Brendt Egon; Vesselinov, Velimir Valentinov; ...
2015-06-01
In this paper, we present a novel inverse modeling strategy to estimate spatially distributed parameters of nonlinear models. The maximum a posteriori (MAP) estimators of these parameters are based on a likelihood functional, which contains spatially discrete measurements of the system parameters and spatiotemporally discrete measurements of the transient system states. The piecewise continuity prior for the parameters is expressed via Total Variation (TV) regularization. The MAP estimator is computed by minimizing a nonquadratic objective equipped with the TV operator. We apply this inversion algorithm to estimate hydraulic conductivity of a synthetic confined aquifer from measurements of conductivity and hydraulicmore » head. The synthetic conductivity field is composed of a low-conductivity heterogeneous intrusion into a high-conductivity heterogeneous medium. Our algorithm accurately reconstructs the location, orientation, and extent of the intrusion from the steady-state data only. Finally, addition of transient measurements of hydraulic head improves the parameter estimation, accurately reconstructing the conductivity field in the vicinity of observation locations.« less
Statistical Interior Tomography
Xu, Qiong; Wang, Ge; Sieren, Jered; Hoffman, Eric A.
2011-01-01
This paper presents a statistical interior tomography (SIT) approach making use of compressed sensing (CS) theory. With the projection data modeled by the Poisson distribution, an objective function with a total variation (TV) regularization term is formulated in the maximization of a posteriori (MAP) framework to solve the interior problem. An alternating minimization method is used to optimize the objective function with an initial image from the direct inversion of the truncated Hilbert transform. The proposed SIT approach is extensively evaluated with both numerical and real datasets. The results demonstrate that SIT is robust with respect to data noise and down-sampling, and has better resolution and less bias than its deterministic counterpart in the case of low count data. PMID:21233044
The 1985 ARI Survey of Army Recruits: Tabular Description of NPS (active) Army Accessions. Volume 1
1987-04-01
T261 -- WATCH TV PROG:NBA BASKETBALL DO YOU WATCH ANY OF THE FOLLOWING PROGRAMS OR PROGRAMMING TYPES ON REGULAR TV STATIONS? .- NBA BASKETBALL . 1...327 261 WATCH TV PROG:NBA BASKETBALL 328-329 T262 WATCH TV PROG:COLLEGE BASKETBALL 330-331 T263 WATCH TV PROG:NHL HOCKEY 332-333 T264 WlATCH TV...T262 -- WATCH TV PROG:COLLEGE BASKETBALL DO YOU WATCH ANY OF THE FOLLOWING PROGRAMS OR PROGRAMMING TYPES ON REGULAR TV STATIONS? - COLLEGE BASKETBALL . 1
Associations between watching TV during family meals and dietary intake among adolescents.
Feldman, Shira; Eisenberg, Marla E; Neumark-Sztainer, Dianne; Story, Mary
2007-01-01
To examine associations between watching television during family meals and dietary intake among adolescents. Cross-sectional study using survey data from a diverse sample of adolescents. Data were collected from a school-based survey during the 1998-1999 school year. Middle and high school students (N = 4746) from 31 public schools in the Minneapolis-St. Paul area. Response rate was 81.5%. Intake of fruits, total vegetables, dark green/yellow vegetables, calcium-rich food, grains, soft drinks, fried food, snack food, calories, family meal frequency, and watching television during meals. General linear modeling comparing dietary intake across 3 groups. 33.5% of boys and 30.9% of girls reported watching television during family meals. Adolescents watching television were found to have lower intakes of vegetables, dark green/yellow vegetables, calcium-rich food, and grains and higher intakes of soft drinks compared to adolescents not watching television during meals. However, watching television during family meals was associated with a more healthful diet than not eating regular family meals. Watching television during family meals was associated with poorer dietary quality among adolescents. Health care providers should work with families and adolescents to promote family meals, emphasizing turning the TV off at meals.
Liu, Yan; Ma, Jianhua; Fan, Yi; Liang, Zhengrong
2012-01-01
Previous studies have shown that by minimizing the total variation (TV) of the to-be-estimated image with some data and other constraints, a piecewise-smooth X-ray computed tomography (CT) can be reconstructed from sparse-view projection data without introducing noticeable artifacts. However, due to the piecewise constant assumption for the image, a conventional TV minimization algorithm often suffers from over-smoothness on the edges of the resulting image. To mitigate this drawback, we present an adaptive-weighted TV (AwTV) minimization algorithm in this paper. The presented AwTV model is derived by considering the anisotropic edge property among neighboring image voxels, where the associated weights are expressed as an exponential function and can be adaptively adjusted by the local image-intensity gradient for the purpose of preserving the edge details. Inspired by the previously-reported TV-POCS (projection onto convex sets) implementation, a similar AwTV-POCS implementation was developed to minimize the AwTV subject to data and other constraints for the purpose of sparse-view low-dose CT image reconstruction. To evaluate the presented AwTV-POCS algorithm, both qualitative and quantitative studies were performed by computer simulations and phantom experiments. The results show that the presented AwTV-POCS algorithm can yield images with several noticeable gains, in terms of noise-resolution tradeoff plots and full width at half maximum values, as compared to the corresponding conventional TV-POCS algorithm. PMID:23154621
Liu, Yan; Ma, Jianhua; Fan, Yi; Liang, Zhengrong
2012-12-07
Previous studies have shown that by minimizing the total variation (TV) of the to-be-estimated image with some data and other constraints, piecewise-smooth x-ray computed tomography (CT) can be reconstructed from sparse-view projection data without introducing notable artifacts. However, due to the piecewise constant assumption for the image, a conventional TV minimization algorithm often suffers from over-smoothness on the edges of the resulting image. To mitigate this drawback, we present an adaptive-weighted TV (AwTV) minimization algorithm in this paper. The presented AwTV model is derived by considering the anisotropic edge property among neighboring image voxels, where the associated weights are expressed as an exponential function and can be adaptively adjusted by the local image-intensity gradient for the purpose of preserving the edge details. Inspired by the previously reported TV-POCS (projection onto convex sets) implementation, a similar AwTV-POCS implementation was developed to minimize the AwTV subject to data and other constraints for the purpose of sparse-view low-dose CT image reconstruction. To evaluate the presented AwTV-POCS algorithm, both qualitative and quantitative studies were performed by computer simulations and phantom experiments. The results show that the presented AwTV-POCS algorithm can yield images with several notable gains, in terms of noise-resolution tradeoff plots and full-width at half-maximum values, as compared to the corresponding conventional TV-POCS algorithm.
NASA Astrophysics Data System (ADS)
Du, Yi; Wang, Xiangang; Xiang, Xincheng; Wei, Zhouping
2016-12-01
Optical computed tomography (optical-CT) is a high-resolution, fast, and easily accessible readout modality for gel dosimeters. This paper evaluates a hybrid iterative image reconstruction algorithm for optical-CT gel dosimeter imaging, namely, the simultaneous algebraic reconstruction technique (SART) integrated with ordered subsets (OS) iteration and total variation (TV) minimization regularization. The mathematical theory and implementation workflow of the algorithm are detailed. Experiments on two different optical-CT scanners were performed for cross-platform validation. For algorithm evaluation, the iterative convergence is first shown, and peak-to-noise-ratio (PNR) and contrast-to-noise ratio (CNR) results are given with the cone-beam filtered backprojection (FDK) algorithm and the FDK results followed by median filtering (mFDK) as reference. The effect on spatial gradients and reconstruction artefacts is also investigated. The PNR curve illustrates that the results of SART + OS + TV finally converges to that of FDK but with less noise, which implies that the dose-OD calibration method for FDK is also applicable to the proposed algorithm. The CNR in selected regions-of-interest (ROIs) of SART + OS + TV results is almost double that of FDK and 50% higher than that of mFDK. The artefacts in SART + OS + TV results are still visible, but have been much suppressed with little spatial gradient loss. Based on the assessment, we can conclude that this hybrid SART + OS + TV algorithm outperforms both FDK and mFDK in denoising, preserving spatial dose gradients and reducing artefacts, and its effectiveness and efficiency are platform independent.
Zhang, Cheng; Zhang, Tao; Li, Ming; Lu, Yanfei; You, Jiali; Guan, Yihui
2015-01-01
In recent years, X-ray computed tomography (CT) is becoming widely used to reveal patient's anatomical information. However, the side effect of radiation, relating to genetic or cancerous diseases, has caused great public concern. The problem is how to minimize radiation dose significantly while maintaining image quality. As a practical application of compressed sensing theory, one category of methods takes total variation (TV) minimization as the sparse constraint, which makes it possible and effective to get a reconstruction image of high quality in the undersampling situation. On the other hand, a preliminary attempt of low-dose CT reconstruction based on dictionary learning seems to be another effective choice. But some critical parameters, such as the regularization parameter, cannot be determined by detecting datasets. In this paper, we propose a reweighted objective function that contributes to a numerical calculation model of the regularization parameter. A number of experiments demonstrate that this strategy performs well with better reconstruction images and saving of a large amount of time. PMID:26550024
Violence on Canadian Television Networks
Paquette, Guy
2004-01-01
Introduction Over the past twenty years, the question of the effects of violence on television has figured prominently in public opinion and hundreds of studies have been devoted to this subject. Many researchers have determined that violence has a negative impact on behavior. The public, broadcasters and political figures all support the idea of reducing the total amount of violence on television - in particular in shows for children. A thousand programs aired between 1993 and 2001 on major non-specialty television networks in Canada were analyzed: TVA, TQS, as well as CTV and Global, private French and English networks, as well as the English CBC Radio and French Radio-Canada for the public networks. Method The methodology consists of a classic analysis of content where an act of violence constitutes a unit of analysis. Results The data collected revealed that the amount of violence has increased regularly since 1993 despite the stated willingness on the part of broadcasters to produce programs with less violence. The total number of violent acts, as well as the number of violent acts per hour, is increasing. Private networks deliver three times more violence than public networks. Researchers have also noted that a high proportion of violence occurs in programs airing before 21:00 hours, thereby exposing a large number of children to this violence. Conclusion Psychological violence is taking on a more significant role in Canadian Television. PMID:19030148
Violence on canadian television networks.
Paquette, Guy
2004-02-01
Over the past twenty years, the question of the effects of violence on television has figured prominently in public opinion and hundreds of studies have been devoted to this subject. Many researchers have determined that violence has a negative impact on behavior. The public, broadcasters and political figures all support the idea of reducing the total amount of violence on television - in particular in shows for children. A thousand programs aired between 1993 and 2001 on major non-specialty television networks in Canada were analyzed: TVA, TQS, as well as CTV and Global, private French and English networks, as well as the English CBC Radio and French Radio-Canada for the public networks. The methodology consists of a classic analysis of content where an act of violence constitutes a unit of analysis. The data collected revealed that the amount of violence has increased regularly since 1993 despite the stated willingness on the part of broadcasters to produce programs with less violence. The total number of violent acts, as well as the number of violent acts per hour, is increasing. Private networks deliver three times more violence than public networks. Researchers have also noted that a high proportion of violence occurs in programs airing before 21:00 hours, thereby exposing a large number of children to this violence. Psychological violence is taking on a more significant role in Canadian Television.
Suntans and Sun Protection in Australian Teen Media: 1999 To 2000
ERIC Educational Resources Information Center
McDermott, Liane J.; Lowe, John B.; Stanton, Warren R.; Clavarino, Alexandra M.
2005-01-01
In this study, the portrayal of tanned skin and sun protection in magazines, television programs, and movies popular with Australian adolescents were analyzed. Images of models in magazines (n = 1,791), regular/supporting characters in television programs (n = 867), and regular/supporting characters in cinema movies (n = 2,836) for the 12-month…
TVs in the bedrooms of children: does it impact health and behavior?
Sisson, Susan B; Broyles, Stephanie T; Newton, Robert L; Baker, Birgitta L; Chernausek, Steven D
2011-02-01
To (1) determine socio-demographic characteristics associated with a TV in the bedroom (BTV) and (2) examine relationship of BTV, independent of total viewing time, with social and behavioral characteristics. Children 6-17 years from the 2007 US National Survey of Children's Health were included (n=48,687). BTV, daily TV viewing time, demographic, behavioral and social outcomes (community involvement, social skills, health habits and status, and family) were examined using logistic regression, and adjusted for total viewing time. Overall prevalence of BTV was 49.3% in American children. Older age, non-Hispanic Black (71.3%), Hispanics (56.3%), higher level of poverty (>56.2%), non two-parent biological family structure (>62.6%), Midwest (47.1%), Northeast (46.7%), South Atlantic (56.4%) and South Central (59.8%) region of the country were associated with higher odds of BTV. Female gender (52.7%) and residence in Alaska (33.0%) were associated with lower prevalence of BTV. BTV was associated with higher prevalence of exhibiting problematic social behaviors (29%) and overweight status (44%). BTV was significantly associated with lower prevalence of regular family meals (13%), engagement in school (16%), participation in extracurricular activities (31%), regularly sleeping enough (20%), and participation in community service (25%) after adjustment for total viewing time. BTV appears associated with more social and behavioral indices than previously reported, in addition to total viewing time. Copyright © 2010 Elsevier Inc. All rights reserved.
Does TV viewing during family meals make a difference in adolescent substance use?
Eisenberg, Marla E; Neumark-Sztainer, Dianne; Feldman, Shira
2009-06-01
Family meals are important to adolescent health, but relatively little is known about TV viewing during family meals. The present paper examines the role that TV viewing during family meals may have on substance use behaviors among adolescents. A diverse sample of 806 Minnesota high school students (mean age 17.2 years) provided survey data in 2003-2004 regarding family meal frequency, substance use behavior and general family connectedness. General linear modeling was used to compare substance use across three family meal/TV categories in a cross-sectional analysis. 28.6% of participants ate regular family meals without TV, and 27.5% had regular family meals while watching TV. Significant differences in cigarette smoking, alcohol and marijuana use were found for females reporting regular family meals versus no regular family meals, but did not differ significantly by TV viewing. No significant differences were found across groups of males. Results from this study indicate that TV viewing during family meals does not appear to attenuate the previously observed protective relationship between family meals and substance use for females. Benefits of family meals may be derived simply from having adolescents at home during mealtimes.
Low Dose PET Image Reconstruction with Total Variation Using Alternating Direction Method.
Yu, Xingjian; Wang, Chenye; Hu, Hongjie; Liu, Huafeng
2016-01-01
In this paper, a total variation (TV) minimization strategy is proposed to overcome the problem of sparse spatial resolution and large amounts of noise in low dose positron emission tomography (PET) imaging reconstruction. Two types of objective function were established based on two statistical models of measured PET data, least-square (LS) TV for the Gaussian distribution and Poisson-TV for the Poisson distribution. To efficiently obtain high quality reconstructed images, the alternating direction method (ADM) is used to solve these objective functions. As compared with the iterative shrinkage/thresholding (IST) based algorithms, the proposed ADM can make full use of the TV constraint and its convergence rate is faster. The performance of the proposed approach is validated through comparisons with the expectation-maximization (EM) method using synthetic and experimental biological data. In the comparisons, the results of both LS-TV and Poisson-TV are taken into consideration to find which models are more suitable for PET imaging, in particular low-dose PET. To evaluate the results quantitatively, we computed bias, variance, and the contrast recovery coefficient (CRC) and drew profiles of the reconstructed images produced by the different methods. The results show that both Poisson-TV and LS-TV can provide a high visual quality at a low dose level. The bias and variance of the proposed LS-TV and Poisson-TV methods are 20% to 74% less at all counting levels than those of the EM method. Poisson-TV gives the best performance in terms of high-accuracy reconstruction with the lowest bias and variance as compared to the ground truth (14.3% less bias and 21.9% less variance). In contrast, LS-TV gives the best performance in terms of the high contrast of the reconstruction with the highest CRC.
Low Dose PET Image Reconstruction with Total Variation Using Alternating Direction Method
Yu, Xingjian; Wang, Chenye; Hu, Hongjie; Liu, Huafeng
2016-01-01
In this paper, a total variation (TV) minimization strategy is proposed to overcome the problem of sparse spatial resolution and large amounts of noise in low dose positron emission tomography (PET) imaging reconstruction. Two types of objective function were established based on two statistical models of measured PET data, least-square (LS) TV for the Gaussian distribution and Poisson-TV for the Poisson distribution. To efficiently obtain high quality reconstructed images, the alternating direction method (ADM) is used to solve these objective functions. As compared with the iterative shrinkage/thresholding (IST) based algorithms, the proposed ADM can make full use of the TV constraint and its convergence rate is faster. The performance of the proposed approach is validated through comparisons with the expectation-maximization (EM) method using synthetic and experimental biological data. In the comparisons, the results of both LS-TV and Poisson-TV are taken into consideration to find which models are more suitable for PET imaging, in particular low-dose PET. To evaluate the results quantitatively, we computed bias, variance, and the contrast recovery coefficient (CRC) and drew profiles of the reconstructed images produced by the different methods. The results show that both Poisson-TV and LS-TV can provide a high visual quality at a low dose level. The bias and variance of the proposed LS-TV and Poisson-TV methods are 20% to 74% less at all counting levels than those of the EM method. Poisson-TV gives the best performance in terms of high-accuracy reconstruction with the lowest bias and variance as compared to the ground truth (14.3% less bias and 21.9% less variance). In contrast, LS-TV gives the best performance in terms of the high contrast of the reconstruction with the highest CRC. PMID:28005929
Structure-adaptive CBCT reconstruction using weighted total variation and Hessian penalties
Shi, Qi; Sun, Nanbo; Sun, Tao; Wang, Jing; Tan, Shan
2016-01-01
The exposure of normal tissues to high radiation during cone-beam CT (CBCT) imaging increases the risk of cancer and genetic defects. Statistical iterative algorithms with the total variation (TV) penalty have been widely used for low dose CBCT reconstruction, with state-of-the-art performance in suppressing noise and preserving edges. However, TV is a first-order penalty and sometimes leads to the so-called staircase effect, particularly over regions with smooth intensity transition in the reconstruction images. A second-order penalty known as the Hessian penalty was recently used to replace TV to suppress the staircase effect in CBCT reconstruction at the cost of slightly blurring object edges. In this study, we proposed a new penalty, the TV-H, which combines TV and Hessian penalties for CBCT reconstruction in a structure-adaptive way. The TV-H penalty automatically differentiates the edges, gradual transition and uniform local regions within an image using the voxel gradient, and adaptively weights TV and Hessian according to the local image structures in the reconstruction process. Our proposed penalty retains the benefits of TV, including noise suppression and edge preservation. It also maintains the structures in regions with gradual intensity transition more successfully. A majorization-minimization (MM) approach was designed to optimize the objective energy function constructed with the TV-H penalty. The MM approach employed a quadratic upper bound of the original objective function, and the original optimization problem was changed to a series of quadratic optimization problems, which could be efficiently solved using the Gauss-Seidel update strategy. We tested the reconstruction algorithm on two simulated digital phantoms and two physical phantoms. Our experiments indicated that the TV-H penalty visually and quantitatively outperformed both TV and Hessian penalties. PMID:27699100
Structure-adaptive CBCT reconstruction using weighted total variation and Hessian penalties.
Shi, Qi; Sun, Nanbo; Sun, Tao; Wang, Jing; Tan, Shan
2016-09-01
The exposure of normal tissues to high radiation during cone-beam CT (CBCT) imaging increases the risk of cancer and genetic defects. Statistical iterative algorithms with the total variation (TV) penalty have been widely used for low dose CBCT reconstruction, with state-of-the-art performance in suppressing noise and preserving edges. However, TV is a first-order penalty and sometimes leads to the so-called staircase effect, particularly over regions with smooth intensity transition in the reconstruction images. A second-order penalty known as the Hessian penalty was recently used to replace TV to suppress the staircase effect in CBCT reconstruction at the cost of slightly blurring object edges. In this study, we proposed a new penalty, the TV-H, which combines TV and Hessian penalties for CBCT reconstruction in a structure-adaptive way. The TV-H penalty automatically differentiates the edges, gradual transition and uniform local regions within an image using the voxel gradient, and adaptively weights TV and Hessian according to the local image structures in the reconstruction process. Our proposed penalty retains the benefits of TV, including noise suppression and edge preservation. It also maintains the structures in regions with gradual intensity transition more successfully. A majorization-minimization (MM) approach was designed to optimize the objective energy function constructed with the TV-H penalty. The MM approach employed a quadratic upper bound of the original objective function, and the original optimization problem was changed to a series of quadratic optimization problems, which could be efficiently solved using the Gauss-Seidel update strategy. We tested the reconstruction algorithm on two simulated digital phantoms and two physical phantoms. Our experiments indicated that the TV-H penalty visually and quantitatively outperformed both TV and Hessian penalties.
NASA Astrophysics Data System (ADS)
Humphries, T.; Winn, J.; Faridani, A.
2017-08-01
Recent work in CT image reconstruction has seen increasing interest in the use of total variation (TV) and related penalties to regularize problems involving reconstruction from undersampled or incomplete data. Superiorization is a recently proposed heuristic which provides an automatic procedure to ‘superiorize’ an iterative image reconstruction algorithm with respect to a chosen objective function, such as TV. Under certain conditions, the superiorized algorithm is guaranteed to find a solution that is as satisfactory as any found by the original algorithm with respect to satisfying the constraints of the problem; this solution is also expected to be superior with respect to the chosen objective. Most work on superiorization has used reconstruction algorithms which assume a linear measurement model, which in the case of CT corresponds to data generated from a monoenergetic x-ray beam. Many CT systems generate x-rays from a polyenergetic spectrum, however, in which the measured data represent an integral of object attenuation over all energies in the spectrum. This inconsistency with the linear model produces the well-known beam hardening artifacts, which impair analysis of CT images. In this work we superiorize an iterative algorithm for reconstruction from polyenergetic data, using both TV and an anisotropic TV (ATV) penalty. We apply the superiorized algorithm in numerical phantom experiments modeling both sparse-view and limited-angle scenarios. In our experiments, the superiorized algorithm successfully finds solutions which are as constraints-compatible as those found by the original algorithm, with significantly reduced TV and ATV values. The superiorized algorithm thus produces images with greatly reduced sparse-view and limited angle artifacts, which are also largely free of the beam hardening artifacts that would be present if a superiorized version of a monoenergetic algorithm were used.
Televised Dance: Evaluation of Three Approaches.
ERIC Educational Resources Information Center
Oglesbee, Frank W.
A study was conducted to determine whether dance-trained, television-trained, and regular television viewing audiences would evaluate different approaches to televising dance differently. Three versions of a dance performance were videotaped: (1) version A, a one-camera, one-shot recording; (2) version B, a two-camera, real-time-edited approach,…
Helping Parents Reduce Children's Television Viewing
ERIC Educational Resources Information Center
Jason, Leonard A.; Fries, Michael
2004-01-01
Parents and educators around the country are concerned about the amount of time children watch television. Part of this concern stems from the fact that a considerable amount of violence is regularly portrayed on television. In addition, those youngsters who watch an excessive amount of television have little time for developing other interests…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lee, Ho; Xing Lei; Lee, Rena
2012-05-15
Purpose: X-ray scatter incurred to detectors degrades the quality of cone-beam computed tomography (CBCT) and represents a problem in volumetric image guided and adaptive radiation therapy. Several methods using a beam blocker for the estimation and subtraction of scatter have been proposed. However, due to missing information resulting from the obstruction of the blocker, such methods require dual scanning or dynamically moving blocker to obtain a complete volumetric image. Here, we propose a half beam blocker-based approach, in conjunction with a total variation (TV) regularized Feldkamp-Davis-Kress (FDK) algorithm, to correct scatter-induced artifacts by simultaneously acquiring image and scatter information frommore » a single-rotation CBCT scan. Methods: A half beam blocker, comprising lead strips, is used to simultaneously acquire image data on one side of the projection data and scatter data on the other half side. One-dimensional cubic B-Spline interpolation/extrapolation is applied to derive patient specific scatter information by using the scatter distributions on strips. The estimated scatter is subtracted from the projection image acquired at the opposite view. With scatter-corrected projections where this subtraction is completed, the FDK algorithm based on a cosine weighting function is performed to reconstruct CBCT volume. To suppress the noise in the reconstructed CBCT images produced by geometric errors between two opposed projections and interpolated scatter information, total variation regularization is applied by a minimization using a steepest gradient descent optimization method. The experimental studies using Catphan504 and anthropomorphic phantoms were carried out to evaluate the performance of the proposed scheme. Results: The scatter-induced shading artifacts were markedly suppressed in CBCT using the proposed scheme. Compared with CBCT without a blocker, the nonuniformity value was reduced from 39.3% to 3.1%. The root mean square error relative to values inside the regions of interest selected from a benchmark scatter free image was reduced from 50 to 11.3. The TV regularization also led to a better contrast-to-noise ratio. Conclusions: An asymmetric half beam blocker-based FDK acquisition and reconstruction technique has been established. The proposed scheme enables simultaneous detection of patient specific scatter and complete volumetric CBCT reconstruction without additional requirements such as prior images, dual scans, or moving strips.« less
Anderson, Sarah E; Sacker, Amanda; Whitaker, Robert C; Kelly, Yvonne
2017-01-01
Objective To examine, in a population-based cohort of three-year-old children, the association between self-regulation and exposure to the household routines of regular bedtime, regular mealtime, and limits on watching television/video; and to determine whether self-regulation and these routines predict the risk of obesity at age 11. Methods Analyses included 10 955 children in the nationally-representative UK Millennium Cohort Study. When children were age 3, parents reported whether children had a regular bedtime and mealtime and the amount of television/video watched. Emotional and cognitive self-regulation at age 3 were assessed by parent-report with the Child Social Behaviour Questionnaire. Children’s height and weight were measured at age 11 and obesity was defined using the International Obesity Task Force (IOTF) criteria. Results At age 3, 41% of children always had a regular bedtime, 47% always had a regular mealtime, and 23% were limited to ≤1 hour television/video daily. At age 11, 6.2% of children were obese. All three household routines were significantly associated with better emotional self-regulation, but not better cognitive self-regulation. In a multi-variable logistic regression model including emotional and cognitive self-regulation, all routines, and controlling for sociodemographic covariates, a 1 unit difference in emotional self-regulation at age 3 was associated with an OR (95% CI) for obesity of 1.38 (1.11, 1.71) at age 11, and inconsistent bedtimes with an OR (95% CI) for obesity of 1.87 (1.39, 2.51) at age 11. There was no evidence that emotional self-regulation mediated the relationship between regular bedtimes and later obesity. Cognitive self-regulation was not associated with later obesity. Conclusions Three-year-old children who had regular bedtimes, mealtimes, and limits on their television/video time had better emotional self-regulation. Lack of a regular bedtime and poorer emotional self-regulation at age 3 were independent predictors of obesity at age 11. PMID:28435162
47 CFR 74.763 - Time of operation.
Code of Federal Regulations, 2010 CFR
2010-10-01
..., AUXILIARY, SPECIAL BROADCAST AND OTHER PROGRAM DISTRIBUTIONAL SERVICES Low Power TV, TV Translator, and TV Booster Stations § 74.763 Time of operation. (a) A low power TV, TV translator, or TV booster station is not required to adhere to any regular schedule of operation. However, the licensee of a TV translator...
Vehicle Detection of Aerial Image Using TV-L1 Texture Decomposition
NASA Astrophysics Data System (ADS)
Wang, Y.; Wang, G.; Li, Y.; Huang, Y.
2016-06-01
Vehicle detection from high-resolution aerial image facilitates the study of the public traveling behavior on a large scale. In the context of road, a simple and effective algorithm is proposed to extract the texture-salient vehicle among the pavement surface. Texturally speaking, the majority of pavement surface changes a little except for the neighborhood of vehicles and edges. Within a certain distance away from the given vector of the road network, the aerial image is decomposed into a smoothly-varying cartoon part and an oscillatory details of textural part. The variational model of Total Variation regularization term and L1 fidelity term (TV-L1) is adopted to obtain the salient texture of vehicles and the cartoon surface of pavement. To eliminate the noise of texture decomposition, regions of pavement surface are refined by seed growing and morphological operation. Based on the shape saliency analysis of the central objects in those regions, vehicles are detected as the objects of rectangular shape saliency. The proposed algorithm is tested with a diverse set of aerial images that are acquired at various resolution and scenarios around China. Experimental results demonstrate that the proposed algorithm can detect vehicles at the rate of 71.5% and the false alarm rate of 21.5%, and that the speed is 39.13 seconds for a 4656 x 3496 aerial image. It is promising for large-scale transportation management and planning.
Trends in exposure to televised prescription drug advertising, 2003-2011.
Kornfield, Rachel; Alexander, G Caleb; Qato, Dima M; Kim, Yoonsang; Hirsch, Jan D; Emery, Sherry L
2015-05-01
TV accounts for more than half of pharmaceutical direct-to-consumer advertising (DTCA) spending in the U.S. The purpose of this study is to quantify average household exposure to branded and non-branded (help-seeking) televised prescription drug advertisements and describe variation over time and according to medication indication and geography. In 2013, Nielsen TV ratings were compiled for prescription pharmaceutical advertising that aired between 2003 and 2011 for the top 75 U.S. media markets. All advertisements were coded as branded or help-seeking. Advertisements were further coded for one of eight prevalent indications (allergies, arthritis, asthma, erectile dysfunction, high cholesterol, smoking cessation, depression, and sleep disorder) or as "other." Televised DTCA exposure increased from 2003 to 2007 and then declined 43% by 2011, to 111 monthly prescription drug advertisements per household. The examined indications were associated with varying amounts and patterns of exposure, with greatest declines among medications for allergies and sleep disorders. Help-seeking advertisements comprised 10% of total exposure, with substantial variation by indication. Considerations of DTCA's effects on health care should take into account the shifting concentration of advertising across indications. Copyright © 2015 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.
Trends in Exposure to Televised Prescription Drug Advertising, 2003–2011
Kornfield, Rachel; Alexander, G. Caleb; Qato, Dima M.; Kim, Yoonsang; Hirsch, Jan D.; Emery, Sherry L.
2015-01-01
Introduction TV accounts for over half of pharmaceutical direct-to-consumer advertising (DTCA) spending in the U.S. The purpose of this study is to quantify average household exposure to branded and non-branded (help-seeking) televised prescription drug advertisements and describe variation over time and according to medication indication and geography. Methods In 2013, Nielsen TV ratings were compiled for prescription pharmaceutical advertising that aired between 2003 and 2011 for the top 75 U.S. media markets. All advertisements were coded as branded or help-seeking. Advertisements were further coded for one of eight prevalent indications (allergies, arthritis, asthma, erectile dysfunction, high cholesterol, smoking cessation, depression, and sleep disorder) or as “other.” Results Televised DTCA exposure increased from 2003 to 2007 and then declined 43% by 2011, to 111 monthly prescription drug advertisements per household. The examined indications were associated with varying amounts and patterns of exposure, with greatest declines among medications for allergies and sleep disorders. Help-seeking advertisements comprised 10% of total exposure, with substantial variation by indication. Conclusions Considerations of DTCA's effects on health care should take into account the shifting concentration of advertising across indications. PMID:25891057
Choi, Kihwan; Li, Ruijiang; Nam, Haewon; Xing, Lei
2014-06-21
As a solution to iterative CT image reconstruction, first-order methods are prominent for the large-scale capability and the fast convergence rate [Formula: see text]. In practice, the CT system matrix with a large condition number may lead to slow convergence speed despite the theoretically promising upper bound. The aim of this study is to develop a Fourier-based scaling technique to enhance the convergence speed of first-order methods applied to CT image reconstruction. Instead of working in the projection domain, we transform the projection data and construct a data fidelity model in Fourier space. Inspired by the filtered backprojection formalism, the data are appropriately weighted in Fourier space. We formulate an optimization problem based on weighted least-squares in the Fourier space and total-variation (TV) regularization in image space for parallel-beam, fan-beam and cone-beam CT geometry. To achieve the maximum computational speed, the optimization problem is solved using a fast iterative shrinkage-thresholding algorithm with backtracking line search and GPU implementation of projection/backprojection. The performance of the proposed algorithm is demonstrated through a series of digital simulation and experimental phantom studies. The results are compared with the existing TV regularized techniques based on statistics-based weighted least-squares as well as basic algebraic reconstruction technique. The proposed Fourier-based compressed sensing (CS) method significantly improves both the image quality and the convergence rate compared to the existing CS techniques.
Blind source deconvolution for deep Earth seismology
NASA Astrophysics Data System (ADS)
Stefan, W.; Renaut, R.; Garnero, E. J.; Lay, T.
2007-12-01
We present an approach to automatically estimate an empirical source characterization of deep earthquakes recorded teleseismically and subsequently remove the source from the recordings by applying regularized deconvolution. A principle goal in this work is to effectively deblur the seismograms, resulting in more impulsive and narrower pulses, permitting better constraints in high resolution waveform analyses. Our method consists of two stages: (1) we first estimate the empirical source by automatically registering traces to their 1st principal component with a weighting scheme based on their deviation from this shape, we then use this shape as an estimation of the earthquake source. (2) We compare different deconvolution techniques to remove the source characteristic from the trace. In particular Total Variation (TV) regularized deconvolution is used which utilizes the fact that most natural signals have an underlying spareness in an appropriate basis, in this case, impulsive onsets of seismic arrivals. We show several examples of deep focus Fiji-Tonga region earthquakes for the phases S and ScS, comparing source responses for the separate phases. TV deconvolution is compared to the water level deconvolution, Tikenov deconvolution, and L1 norm deconvolution, for both data and synthetics. This approach significantly improves our ability to study subtle waveform features that are commonly masked by either noise or the earthquake source. Eliminating source complexities improves our ability to resolve deep mantle triplications, waveform complexities associated with possible double crossings of the post-perovskite phase transition, as well as increasing stability in waveform analyses used for deep mantle anisotropy measurements.
SU-F-18C-13: Low-Dose X-Ray CT Reconstruction Using a Hybrid First-Order Method
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, L; Lin, W; Jin, M
2014-06-15
Purpose: To develop a novel reconstruction method for X-ray CT that can lead to accurate reconstruction at significantly reduced dose levels combining low X-ray incident intensity and few views of projection data. Methods: The noise nature of the projection data at low X-ray incident intensity was modeled and accounted by the weighted least-squares (WLS) criterion. The total variation (TV) penalty was used to mitigate artifacts caused by few views of data. The first order primal-dual (FOPD) algorithm was used to minimize TV in image domain, which avoided the difficulty of the non-smooth objective function. The TV penalized WLS reconstruction wasmore » achieved by alternated FOPD TV minimization and projection onto convex sets (POCS) for data fidelity constraints. The proposed FOPD-POCS method was evaluated using the FORBILD jaw phantom and the real cadaver head CT data. Results: The quantitative measures, root mean square error (RMSE) and contrast-to-noise ratio (CNR), demonstrate the superior denoising capability of WLS over LS-based TV iterative reconstruction. The improvement of RMSE (WLS vs. LS) is 15%∼21% and that of CNR is 17%∼72% when the incident counts per ray are ranged from 1×10{sup 5} to 1×10{sup 3}. In addition, the TV regularization can accurately reconstruct images from about 50 views of the jaw phantom. The FOPD-POCS reconstruction reveals more structural details and suffers fewer artifacts in both the phantom and real head images. The FOPD-POCS method also shows fast convergence at low X-ray incident intensity. Conclusion: The new hybrid FOPD-POCS method, based on TV penalized WLS, yields excellent image quality when the incident X-ray intensity is low and the projection views are limited. The reconstruction is computationally efficient since the FOPD minimization of TV is applied only in the image domain. The characteristics of FOPD-POCS can be exploited to significantly reduce radiation dose of X-ray CT without compromising accuracy for diagnosis or treatment planning.« less
Television News as Drama: An International Perspective.
ERIC Educational Resources Information Center
Breen, Myles P.
An observer can identify a trend in television news presentation style toward the dramatic, not only in the sets and the personnel, but more importantly in the choice of what is deemed newsworthy. A thesis is proposed by many suggesting that television is a regular ritual of many viewers of which news is a minor part and that television's first…
Nonlinear PP and PS joint inversion based on the exact Zoeppritz equations: a two-stage procedure
NASA Astrophysics Data System (ADS)
Zhi, Lixia; Chen, Shuangquan; Song, Baoshan; Li, Xiang-yang
2018-04-01
S-velocity and density are very important parameters in distinguishing lithology and estimating other petrophysical properties. A reliable estimate of S-velocity and density is very difficult to obtain, even from long-offset gather data. Joint inversion of PP and PS data provides a promising strategy for stabilizing and improving the results of inversion in estimating elastic parameters and density. For 2D or 3D inversion, the trace-by-trace strategy is still the most widely used method although it often suffers from a lack of clarity because of its high efficiency, which is due to parallel computing. This paper describes a two-stage inversion method for nonlinear PP and PS joint inversion based on the exact Zoeppritz equations. There are several advantages for our proposed methods as follows: (1) Thanks to the exact Zoeppritz equation, our joint inversion method is applicable for wide angle amplitude-versus-angle inversion; (2) The use of both P- and S-wave information can further enhance the stability and accuracy of parameter estimation, especially for the S-velocity and density; (3) The two-stage inversion procedure proposed in this paper can achieve a good compromise between efficiency and precision. On the one hand, the trace-by-trace strategy used in the first stage can be processed in parallel so that it has high computational efficiency. On the other hand, to deal with the indistinctness of and undesired disturbances to the inversion results obtained from the first stage, we apply the second stage—total variation (TV) regularization. By enforcing spatial and temporal constraints, the TV regularization stage deblurs the inversion results and leads to parameter estimation with greater precision. Notably, the computation consumption of the TV regularization stage can be ignored compared to the first stage because it is solved using the fast split Bregman iterations. Numerical examples using a well log and the Marmousi II model show that the proposed joint inversion is a reliable method capable of accurately estimating the density parameter as well as P-wave velocity and S-wave velocity, even when the seismic data is noisy with signal-to-noise ratio of 5.
Iterative Nonlocal Total Variation Regularization Method for Image Restoration
Xu, Huanyu; Sun, Quansen; Luo, Nan; Cao, Guo; Xia, Deshen
2013-01-01
In this paper, a Bregman iteration based total variation image restoration algorithm is proposed. Based on the Bregman iteration, the algorithm splits the original total variation problem into sub-problems that are easy to solve. Moreover, non-local regularization is introduced into the proposed algorithm, and a method to choose the non-local filter parameter locally and adaptively is proposed. Experiment results show that the proposed algorithms outperform some other regularization methods. PMID:23776560
Research on compressive sensing reconstruction algorithm based on total variation model
NASA Astrophysics Data System (ADS)
Gao, Yu-xuan; Sun, Huayan; Zhang, Tinghua; Du, Lin
2017-12-01
Compressed sensing for breakthrough Nyquist sampling theorem provides a strong theoretical , making compressive sampling for image signals be carried out simultaneously. In traditional imaging procedures using compressed sensing theory, not only can it reduces the storage space, but also can reduce the demand for detector resolution greatly. Using the sparsity of image signal, by solving the mathematical model of inverse reconfiguration, realize the super-resolution imaging. Reconstruction algorithm is the most critical part of compression perception, to a large extent determine the accuracy of the reconstruction of the image.The reconstruction algorithm based on the total variation (TV) model is more suitable for the compression reconstruction of the two-dimensional image, and the better edge information can be obtained. In order to verify the performance of the algorithm, Simulation Analysis the reconstruction result in different coding mode of the reconstruction algorithm based on the TV reconstruction algorithm. The reconstruction effect of the reconfigurable algorithm based on TV based on the different coding methods is analyzed to verify the stability of the algorithm. This paper compares and analyzes the typical reconstruction algorithm in the same coding mode. On the basis of the minimum total variation algorithm, the Augmented Lagrangian function term is added and the optimal value is solved by the alternating direction method.Experimental results show that the reconstruction algorithm is compared with the traditional classical algorithm based on TV has great advantages, under the low measurement rate can be quickly and accurately recovers target image.
Can Television Enhance Children's Mathematical Problem Solving?
ERIC Educational Resources Information Center
Fisch, Shalom M.; And Others
1994-01-01
A summative evaluation of "Square One TV," an educational mathematics series produced by the Children's Television Workshop, shows that children who regularly viewed the program showed significant improvement in solving unfamiliar, complex mathematical problems, and viewers showed improvement in their mathematical problem-solving ability…
Novel crystal timing calibration method based on total variation
NASA Astrophysics Data System (ADS)
Yu, Xingjian; Isobe, Takashi; Watanabe, Mitsuo; Liu, Huafeng
2016-11-01
A novel crystal timing calibration method based on total variation (TV), abbreviated as ‘TV merge’, has been developed for a high-resolution positron emission tomography (PET) system. The proposed method was developed for a system with a large number of crystals, it can provide timing calibration at the crystal level. In the proposed method, the timing calibration process was formulated as a linear problem. To robustly optimize the timing resolution, a TV constraint was added to the linear equation. Moreover, to solve the computer memory problem associated with the calculation of the timing calibration factors for systems with a large number of crystals, the merge component was used for obtaining the crystal level timing calibration values. Compared with other conventional methods, the data measured from a standard cylindrical phantom filled with a radioisotope solution was sufficient for performing a high-precision crystal-level timing calibration. In this paper, both simulation and experimental studies were performed to demonstrate the effectiveness and robustness of the TV merge method. We compare the timing resolutions of a 22Na point source, which was located in the field of view (FOV) of the brain PET system, with various calibration techniques. After implementing the TV merge method, the timing resolution improved from 3.34 ns at full width at half maximum (FWHM) to 2.31 ns FWHM.
Wang, Jin; Zhang, Chen; Wang, Yuanyuan
2017-05-30
In photoacoustic tomography (PAT), total variation (TV) based iteration algorithm is reported to have a good performance in PAT image reconstruction. However, classical TV based algorithm fails to preserve the edges and texture details of the image because it is not sensitive to the direction of the image. Therefore, it is of great significance to develop a new PAT reconstruction algorithm to effectively solve the drawback of TV. In this paper, a directional total variation with adaptive directivity (DDTV) model-based PAT image reconstruction algorithm, which weightedly sums the image gradients based on the spatially varying directivity pattern of the image is proposed to overcome the shortcomings of TV. The orientation field of the image is adaptively estimated through a gradient-based approach. The image gradients are weighted at every pixel based on both its anisotropic direction and another parameter, which evaluates the estimated orientation field reliability. An efficient algorithm is derived to solve the iteration problem associated with DDTV and possessing directivity of the image adaptively updated for each iteration step. Several texture images with various directivity patterns are chosen as the phantoms for the numerical simulations. The 180-, 90- and 30-view circular scans are conducted. Results obtained show that the DDTV-based PAT reconstructed algorithm outperforms the filtered back-projection method (FBP) and TV algorithms in the quality of reconstructed images with the peak signal-to-noise rations (PSNR) exceeding those of TV and FBP by about 10 and 18 dB, respectively, for all cases. The Shepp-Logan phantom is studied with further discussion of multimode scanning, convergence speed, robustness and universality aspects. In-vitro experiments are performed for both the sparse-view circular scanning and linear scanning. The results further prove the effectiveness of the DDTV, which shows better results than that of the TV with sharper image edges and clearer texture details. Both numerical simulation and in vitro experiments confirm that the DDTV provides a significant quality improvement of PAT reconstructed images for various directivity patterns.
Short-Term Effects of Televised Aggression on Children's Behavior.
ERIC Educational Resources Information Center
Liebert, Robert M.; Baron, Robert A.
Recently collected data appear to warrant advancing some tentative conslusions concerning the short-term effects of violence in television on children: 1) children are exposed to a substantial amount of violent content on television, and they can remember and learn from such exposure; 2) correlational studies have disclosed a regular association…
Ramani, Sathish; Liu, Zhihao; Rosen, Jeffrey; Nielsen, Jon-Fredrik; Fessler, Jeffrey A.
2012-01-01
Regularized iterative reconstruction algorithms for imaging inverse problems require selection of appropriate regularization parameter values. We focus on the challenging problem of tuning regularization parameters for nonlinear algorithms for the case of additive (possibly complex) Gaussian noise. Generalized cross-validation (GCV) and (weighted) mean-squared error (MSE) approaches (based on Stein's Unbiased Risk Estimate— SURE) need the Jacobian matrix of the nonlinear reconstruction operator (representative of the iterative algorithm) with respect to the data. We derive the desired Jacobian matrix for two types of nonlinear iterative algorithms: a fast variant of the standard iterative reweighted least-squares method and the contemporary split-Bregman algorithm, both of which can accommodate a wide variety of analysis- and synthesis-type regularizers. The proposed approach iteratively computes two weighted SURE-type measures: Predicted-SURE and Projected-SURE (that require knowledge of noise variance σ2), and GCV (that does not need σ2) for these algorithms. We apply the methods to image restoration and to magnetic resonance image (MRI) reconstruction using total variation (TV) and an analysis-type ℓ1-regularization. We demonstrate through simulations and experiments with real data that minimizing Predicted-SURE and Projected-SURE consistently lead to near-MSE-optimal reconstructions. We also observed that minimizing GCV yields reconstruction results that are near-MSE-optimal for image restoration and slightly sub-optimal for MRI. Theoretical derivations in this work related to Jacobian matrix evaluations can be extended, in principle, to other types of regularizers and reconstruction algorithms. PMID:22531764
47 CFR 76.614 - Cable television system regular monitoring.
Code of Federal Regulations, 2010 CFR
2010-10-01
...-137 and 225-400 MHz shall provide for a program of regular monitoring for signal leakage by... in these bands of 20 uV/m or greater at a distance of 3 meters. During regular monitoring, any leakage source which produces a field strength of 20 uV/m or greater at a distance of 3 meters in the...
Structured Sparse Principal Components Analysis With the TV-Elastic Net Penalty.
de Pierrefeu, Amicie; Lofstedt, Tommy; Hadj-Selem, Fouad; Dubois, Mathieu; Jardri, Renaud; Fovet, Thomas; Ciuciu, Philippe; Frouin, Vincent; Duchesnay, Edouard
2018-02-01
Principal component analysis (PCA) is an exploratory tool widely used in data analysis to uncover the dominant patterns of variability within a population. Despite its ability to represent a data set in a low-dimensional space, PCA's interpretability remains limited. Indeed, the components produced by PCA are often noisy or exhibit no visually meaningful patterns. Furthermore, the fact that the components are usually non-sparse may also impede interpretation, unless arbitrary thresholding is applied. However, in neuroimaging, it is essential to uncover clinically interpretable phenotypic markers that would account for the main variability in the brain images of a population. Recently, some alternatives to the standard PCA approach, such as sparse PCA (SPCA), have been proposed, their aim being to limit the density of the components. Nonetheless, sparsity alone does not entirely solve the interpretability problem in neuroimaging, since it may yield scattered and unstable components. We hypothesized that the incorporation of prior information regarding the structure of the data may lead to improved relevance and interpretability of brain patterns. We therefore present a simple extension of the popular PCA framework that adds structured sparsity penalties on the loading vectors in order to identify the few stable regions in the brain images that capture most of the variability. Such structured sparsity can be obtained by combining, e.g., and total variation (TV) penalties, where the TV regularization encodes information on the underlying structure of the data. This paper presents the structured SPCA (denoted SPCA-TV) optimization framework and its resolution. We demonstrate SPCA-TV's effectiveness and versatility on three different data sets. It can be applied to any kind of structured data, such as, e.g., -dimensional array images or meshes of cortical surfaces. The gains of SPCA-TV over unstructured approaches (such as SPCA and ElasticNet PCA) or structured approach (such as GraphNet PCA) are significant, since SPCA-TV reveals the variability within a data set in the form of intelligible brain patterns that are easier to interpret and more stable across different samples.
Simultaneous deblurring and iterative reconstruction of CBCT for image guided brain radiosurgery.
Hashemi, SayedMasoud; Song, William Y; Sahgal, Arjun; Lee, Young; Huynh, Christopher; Grouza, Vladimir; Nordström, Håkan; Eriksson, Markus; Dorenlot, Antoine; Régis, Jean Marie; Mainprize, James G; Ruschin, Mark
2017-04-07
One of the limiting factors in cone-beam CT (CBCT) image quality is system blur, caused by detector response, x-ray source focal spot size, azimuthal blurring, and reconstruction algorithm. In this work, we develop a novel iterative reconstruction algorithm that improves spatial resolution by explicitly accounting for image unsharpness caused by different factors in the reconstruction formulation. While the model-based iterative reconstruction techniques use prior information about the detector response and x-ray source, our proposed technique uses a simple measurable blurring model. In our reconstruction algorithm, denoted as simultaneous deblurring and iterative reconstruction (SDIR), the blur kernel can be estimated using the modulation transfer function (MTF) slice of the CatPhan phantom or any other MTF phantom, such as wire phantoms. The proposed image reconstruction formulation includes two regularization terms: (1) total variation (TV) and (2) nonlocal regularization, solved with a split Bregman augmented Lagrangian iterative method. The SDIR formulation preserves edges, eases the parameter adjustments to achieve both high spatial resolution and low noise variances, and reduces the staircase effect caused by regular TV-penalized iterative algorithms. The proposed algorithm is optimized for a point-of-care head CBCT unit for image-guided radiosurgery and is tested with CatPhan phantom, an anthropomorphic head phantom, and 6 clinical brain stereotactic radiosurgery cases. Our experiments indicate that SDIR outperforms the conventional filtered back projection and TV penalized simultaneous algebraic reconstruction technique methods (represented by adaptive steepest-descent POCS algorithm, ASD-POCS) in terms of MTF and line pair resolution, and retains the favorable properties of the standard TV-based iterative reconstruction algorithms in improving the contrast and reducing the reconstruction artifacts. It improves the visibility of the high contrast details in bony areas and the brain soft-tissue. For example, the results show the ventricles and some brain folds become visible in SDIR reconstructed images and the contrast of the visible lesions is effectively improved. The line-pair resolution was improved from 12 line-pair/cm in FBP to 14 line-pair/cm in SDIR. Adjusting the parameters of the ASD-POCS to achieve 14 line-pair/cm caused the noise variance to be higher than the SDIR. Using these parameters for ASD-POCS, the MTF of FBP and ASD-POCS were very close and equal to 0.7 mm -1 which was increased to 1.2 mm -1 by SDIR, at half maximum.
Simultaneous deblurring and iterative reconstruction of CBCT for image guided brain radiosurgery
NASA Astrophysics Data System (ADS)
Hashemi, SayedMasoud; Song, William Y.; Sahgal, Arjun; Lee, Young; Huynh, Christopher; Grouza, Vladimir; Nordström, Håkan; Eriksson, Markus; Dorenlot, Antoine; Régis, Jean Marie; Mainprize, James G.; Ruschin, Mark
2017-04-01
One of the limiting factors in cone-beam CT (CBCT) image quality is system blur, caused by detector response, x-ray source focal spot size, azimuthal blurring, and reconstruction algorithm. In this work, we develop a novel iterative reconstruction algorithm that improves spatial resolution by explicitly accounting for image unsharpness caused by different factors in the reconstruction formulation. While the model-based iterative reconstruction techniques use prior information about the detector response and x-ray source, our proposed technique uses a simple measurable blurring model. In our reconstruction algorithm, denoted as simultaneous deblurring and iterative reconstruction (SDIR), the blur kernel can be estimated using the modulation transfer function (MTF) slice of the CatPhan phantom or any other MTF phantom, such as wire phantoms. The proposed image reconstruction formulation includes two regularization terms: (1) total variation (TV) and (2) nonlocal regularization, solved with a split Bregman augmented Lagrangian iterative method. The SDIR formulation preserves edges, eases the parameter adjustments to achieve both high spatial resolution and low noise variances, and reduces the staircase effect caused by regular TV-penalized iterative algorithms. The proposed algorithm is optimized for a point-of-care head CBCT unit for image-guided radiosurgery and is tested with CatPhan phantom, an anthropomorphic head phantom, and 6 clinical brain stereotactic radiosurgery cases. Our experiments indicate that SDIR outperforms the conventional filtered back projection and TV penalized simultaneous algebraic reconstruction technique methods (represented by adaptive steepest-descent POCS algorithm, ASD-POCS) in terms of MTF and line pair resolution, and retains the favorable properties of the standard TV-based iterative reconstruction algorithms in improving the contrast and reducing the reconstruction artifacts. It improves the visibility of the high contrast details in bony areas and the brain soft-tissue. For example, the results show the ventricles and some brain folds become visible in SDIR reconstructed images and the contrast of the visible lesions is effectively improved. The line-pair resolution was improved from 12 line-pair/cm in FBP to 14 line-pair/cm in SDIR. Adjusting the parameters of the ASD-POCS to achieve 14 line-pair/cm caused the noise variance to be higher than the SDIR. Using these parameters for ASD-POCS, the MTF of FBP and ASD-POCS were very close and equal to 0.7 mm-1 which was increased to 1.2 mm-1 by SDIR, at half maximum.
Jiang, Xiaolei; Zhang, Li; Zhang, Ran; Yin, Hongxia; Wang, Zhenchang
2015-01-01
X-ray grating interferometry offers a novel framework for the study of weakly absorbing samples. Three kinds of information, that is, the attenuation, differential phase contrast (DPC), and dark-field images, can be obtained after a single scanning, providing additional and complementary information to the conventional attenuation image. Phase shifts of X-rays are measured by the DPC method; hence, DPC-CT reconstructs refraction indexes rather than attenuation coefficients. In this work, we propose an explicit filtering based low-dose differential phase reconstruction algorithm, which enables reconstruction from reduced scanning without artifacts. The algorithm adopts a differential algebraic reconstruction technique (DART) with the explicit filtering based sparse regularization rather than the commonly used total variation (TV) method. Both the numerical simulation and the biological sample experiment demonstrate the feasibility of the proposed algorithm.
Zhang, Li; Zhang, Ran; Yin, Hongxia; Wang, Zhenchang
2015-01-01
X-ray grating interferometry offers a novel framework for the study of weakly absorbing samples. Three kinds of information, that is, the attenuation, differential phase contrast (DPC), and dark-field images, can be obtained after a single scanning, providing additional and complementary information to the conventional attenuation image. Phase shifts of X-rays are measured by the DPC method; hence, DPC-CT reconstructs refraction indexes rather than attenuation coefficients. In this work, we propose an explicit filtering based low-dose differential phase reconstruction algorithm, which enables reconstruction from reduced scanning without artifacts. The algorithm adopts a differential algebraic reconstruction technique (DART) with the explicit filtering based sparse regularization rather than the commonly used total variation (TV) method. Both the numerical simulation and the biological sample experiment demonstrate the feasibility of the proposed algorithm. PMID:26089971
NASA Astrophysics Data System (ADS)
Peng, Chengtao; Qiu, Bensheng; Zhang, Cheng; Ma, Changyu; Yuan, Gang; Li, Ming
2017-07-01
Over the years, the X-ray computed tomography (CT) has been successfully used in clinical diagnosis. However, when the body of the patient to be examined contains metal objects, the image reconstructed would be polluted by severe metal artifacts, which affect the doctor's diagnosis of disease. In this work, we proposed a dynamic re-weighted total variation (DRWTV) technique combined with the statistic iterative reconstruction (SIR) method to reduce the artifacts. The DRWTV method is based on the total variation (TV) and re-weighted total variation (RWTV) techniques, but it provides a sparser representation than TV and protects the tissue details better than RWTV. Besides, the DRWTV can suppress the artifacts and noise, and the SIR convergence speed is also accelerated. The performance of the algorithm is tested on both simulated phantom dataset and clinical dataset, which are the teeth phantom with two metal implants and the skull with three metal implants, respectively. The proposed algorithm (SIR-DRWTV) is compared with two traditional iterative algorithms, which are SIR and SIR constrained by RWTV regulation (SIR-RWTV). The results show that the proposed algorithm has the best performance in reducing metal artifacts and protecting tissue details.
Suntans and sun protection in Australian teen media: 1999 to 2000.
McDermott, Liane J; Lowe, John B; Stanton, Warren R; Clavarino, Alexandra M
2005-08-01
In this study, the portrayal of tanned skin and sun protection in magazines, television programs, and movies popular with Australian adolescents were analyzed. Images of models in magazines (n = 1,791), regular/supporting characters in television programs (n = 867), and regular/supporting characters in cinema movies (n = 2,836)for the 12-month period August 1999 to July 2000 were coded and analyzed. A light tan was the most predominant tan level, and protective clothing was the most common sun protection measure displayed across all forms of media. There were significant associations between gender and tan levels in the television and movie samples. Although it is important to monitor the portrayal of tan levels and sun protection measures in media targeting adolescents, overall, the authors' findings revealed a media environment generally supportive of sun protection objectives.
Taniguchi-Tabata, Ayano; Mizutani, Shinsuke; Yamane-Takeuchi, Mayu; Kataoka, Kota; Azuma, Tetsuji; Tomofuji, Takaaki; Iwasaki, Yoshiaki; Morita, Manabu
2017-01-01
The aim of this study was to investigate the associations between dental knowledge, the source of dental knowledge and oral health behavior in a group of students at a university in Japan. A total of 2,220 university students (1,276 males, 944 females) volunteered to undergo an oral examination and answer a questionnaire. The questionnaire assessed dental knowledge, the source of dental knowledge and oral health behavior (e.g., daily frequency of tooth brushing, use of dental floss and regular dental checkups). The odds ratio and 95% confidence interval for oral health behavior based on dental knowledge and source of dental knowledge were calculated using logistic regression models. Of the participants, 1,266 (57.0%) students obtained dental knowledge from dental clinics, followed by school (39.2%) and television (29.1%). Logistic regression analyses indicated that use of dental floss was significantly associated with source of dental knowledge from dental clinics (P = 0.006). Receiving regular dental checkups was significantly associated with source of dental knowledge; the positive source was dental clinic (P < 0.001) and the negative sources were school (P = 0.004) and television (P = 0.018). Dental clinic was the most common source of dental knowledge and associated with better oral health behavior among the Japanese university students in this study. PMID:28594914
ERIC Educational Resources Information Center
Flanagan, Bill
Competition between cable television systems (CATV) and regular broadcast stations concerns pay-TV and distant signal importation. The pay-TV that CATV provides competes with the networks by "siphoning" away sports and feature films, while the distant signals that CATV imports to a local market "fragment" the local audience and…
A New Pansharpening Method Based on Spatial and Spectral Sparsity Priors.
He, Xiyan; Condat, Laurent; Bioucas-Diaz, Jose; Chanussot, Jocelyn; Xia, Junshi
2014-06-27
The development of multisensor systems in recent years has led to great increase in the amount of available remote sensing data. Image fusion techniques aim at inferring high quality images of a given area from degraded versions of the same area obtained by multiple sensors. This paper focuses on pansharpening, which is the inference of a high spatial resolution multispectral image from two degraded versions with complementary spectral and spatial resolution characteristics: a) a low spatial resolution multispectral image; and b) a high spatial resolution panchromatic image. We introduce a new variational model based on spatial and spectral sparsity priors for the fusion. In the spectral domain we encourage low-rank structure, whereas in the spatial domain we promote sparsity on the local differences. Given the fact that both panchromatic and multispectral images are integrations of the underlying continuous spectra using different channel responses, we propose to exploit appropriate regularizations based on both spatial and spectral links between panchromatic and the fused multispectral images. A weighted version of the vector Total Variation (TV) norm of the data matrix is employed to align the spatial information of the fused image with that of the panchromatic image. With regard to spectral information, two different types of regularization are proposed to promote a soft constraint on the linear dependence between the panchromatic and the fused multispectral images. The first one estimates directly the linear coefficients from the observed panchromatic and low resolution multispectral images by Linear Regression (LR) while the second one employs the Principal Component Pursuit (PCP) to obtain a robust recovery of the underlying low-rank structure. We also show that the two regularizers are strongly related. The basic idea of both regularizers is that the fused image should have low-rank and preserve edge locations. We use a variation of the recently proposed Split Augmented Lagrangian Shrinkage (SALSA) algorithm to effectively solve the proposed variational formulations. Experimental results on simulated and real remote sensing images show the effectiveness of the proposed pansharpening method compared to the state-of-the-art.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kim, H; Chen, J; Pouliot, J
2015-06-15
Purpose: Compressed sensing (CS) has been used for CT (4DCT/CBCT) reconstruction with few projections to reduce dose of radiation. Total-variation (TV) in L1-minimization (min.) with local information is the prevalent technique in CS, while it can be prone to noise. To address the problem, this work proposes to apply a new image processing technique, called non-local TV (NLTV), to CS based CT reconstruction, and incorporate reweighted L1-norm into it for more precise reconstruction. Methods: TV minimizes intensity variations by considering two local neighboring voxels, which can be prone to noise, possibly damaging the reconstructed CT image. NLTV, contrarily, utilizes moremore » global information by computing a weight function of current voxel relative to surrounding search area. In fact, it might be challenging to obtain an optimal solution due to difficulty in defining the weight function with appropriate parameters. Introducing reweighted L1-min., designed for approximation to ideal L0-min., can reduce the dependence on defining the weight function, therefore improving accuracy of the solution. This work implemented the NLTV combined with reweighted L1-min. by Split Bregman Iterative method. For evaluation, a noisy digital phantom and a pelvic CT images are employed to compare the quality of images reconstructed by TV, NLTV and reweighted NLTV. Results: In both cases, conventional and reweighted NLTV outperform TV min. in signal-to-noise ratio (SNR) and root-mean squared errors of the reconstructed images. Relative to conventional NLTV, NLTV with reweighted L1-norm was able to slightly improve SNR, while greatly increasing the contrast between tissues due to additional iterative reweighting process. Conclusion: NLTV min. can provide more precise compressed sensing based CT image reconstruction by incorporating the reweighted L1-norm, while maintaining greater robustness to the noise effect than TV min.« less
NASA Astrophysics Data System (ADS)
Vatankhah, Saeed; Renaut, Rosemary A.; Ardestani, Vahid E.
2018-04-01
We present a fast algorithm for the total variation regularization of the 3-D gravity inverse problem. Through imposition of the total variation regularization, subsurface structures presenting with sharp discontinuities are preserved better than when using a conventional minimum-structure inversion. The associated problem formulation for the regularization is nonlinear but can be solved using an iteratively reweighted least-squares algorithm. For small-scale problems the regularized least-squares problem at each iteration can be solved using the generalized singular value decomposition. This is not feasible for large-scale, or even moderate-scale, problems. Instead we introduce the use of a randomized generalized singular value decomposition in order to reduce the dimensions of the problem and provide an effective and efficient solution technique. For further efficiency an alternating direction algorithm is used to implement the total variation weighting operator within the iteratively reweighted least-squares algorithm. Presented results for synthetic examples demonstrate that the novel randomized decomposition provides good accuracy for reduced computational and memory demands as compared to use of classical approaches.
A limited-angle CT reconstruction method based on anisotropic TV minimization.
Chen, Zhiqiang; Jin, Xin; Li, Liang; Wang, Ge
2013-04-07
This paper presents a compressed sensing (CS)-inspired reconstruction method for limited-angle computed tomography (CT). Currently, CS-inspired CT reconstructions are often performed by minimizing the total variation (TV) of a CT image subject to data consistency. A key to obtaining high image quality is to optimize the balance between TV-based smoothing and data fidelity. In the case of the limited-angle CT problem, the strength of data consistency is angularly varying. For example, given a parallel beam of x-rays, information extracted in the Fourier domain is mostly orthogonal to the direction of x-rays, while little is probed otherwise. However, the TV minimization process is isotropic, suggesting that it is unfit for limited-angle CT. Here we introduce an anisotropic TV minimization method to address this challenge. The advantage of our approach is demonstrated in numerical simulation with both phantom and real CT images, relative to the TV-based reconstruction.
ERIC Educational Resources Information Center
Munushian, Jack
In 1972, the University of Southern California School of Engineering established a 4-channel interactive instructional television network. It was designed to allow employees of participating industries to take regular university science and engineering courses and special continuing education courses at or near their work locations. Final progress…
The 1984 ARI Survey of Army Recruits: Tabular Description of NPS Army Reserve Accessions. Volume 2
1986-05-01
12 PROB. 0.1867 I 186 T261 — NATCH TV PROG’NBA BASKETBALL NARK ONE LETTER FOR EACH OF THE FOLLOWING PROGRAMS OR PROGRAMMING TYPES ON TV: NBA ...Major league baseball — regular seaaon games 105. Major league baaaball playoffs 106. World Series 107. NBA baaketball 106. College basketball 109...BASEBALL PLAYOFFS HATCH TV PROG:WORLD SERIES HATCH TV PROG:NBA BASKETBALL HATCH TV PROG:COLLEGE BASKETBALL HATCH TV PROG:NHL HOCKEY HATCH TV
NASA Astrophysics Data System (ADS)
Almasganj, Mohammad; Adabi, Saba; Fatemizadeh, Emad; Xu, Qiuyun; Sadeghi, Hamid; Daveluy, Steven; Nasiriavanaki, Mohammadreza
2017-03-01
Optical Coherence Tomography (OCT) has a great potential to elicit clinically useful information from tissues due to its high axial and transversal resolution. In practice, an OCT setup cannot reach to its theoretical resolution due to imperfections of its components, which make its images blurry. The blurriness is different alongside regions of image; thus, they cannot be modeled by a unique point spread function (PSF). In this paper, we investigate the use of solid phantoms to estimate the PSF of each sub-region of imaging system. We then utilize Lucy-Richardson, Hybr and total variation (TV) based iterative deconvolution methods for mitigating occurred spatially variant blurriness. It is shown that the TV based method will suppress the so-called speckle noise in OCT images better than the two other approaches. The performance of proposed algorithm is tested on various samples, including several skin tissues besides the test image blurred with synthetic PSF-map, demonstrating qualitatively and quantitatively the advantage of TV based deconvolution method using spatially-variant PSF for enhancing image quality.
Self-Directed English Language Learning through Watching English Television Drama in China
ERIC Educational Resources Information Center
Wang, Danping
2012-01-01
This paper presents a case study of a group of Chinese ESL learners in China, who study English by immersing themselves regularly and rigorously in English television drama. A self-directed learning pedagogy has been developed and discussed, which seems to have signposted an effective and economic way for ESL learners to improve linguistic,…
Physical Attractiveness Stereotyping on American Television Programs: A Content Analysis.
ERIC Educational Resources Information Center
Downs, A. Chris; Harrison, Sheila K.
The frequencies of specific types of verbal attractiveness stereotypes portrayed on television commercials and regular programs were determined in two studies. In the first, the 4,294 commercials aired between 8 and 10 p.m. on the 3 major networks were observed during a 7-day period in the spring of 1982. Statements related to attractiveness were…
Psychosocial Factors and Enrollment in a Televised Smoking Cessation Program.
ERIC Educational Resources Information Center
Kviz, Frederick J.; And Others
1991-01-01
Interviews with random samples of 641 registrants for a smoking cessation program on Chicago television news and 2,398 smokers who regularly viewed the news determined that registration was associated with (1) recognition of the need to change behavior; (2) high expectation for quitting; (3) concern about the burden of lung cancer on significant…
EDUCATIONAL TELEVISION IN THE SMALL SCHOOL.
ERIC Educational Resources Information Center
LEDFORD, LOWELL E.
HENSLEY ELEMENTARY SCHOOL, CONSISTING OF 72 STUDENTS AND 3 TEACHERS, HAS INCORPORATED 12 EDUCATIONAL TELEVISION PROGRAMS AS A REGULAR PART OF THE CURRICULUM IN THE FIRST 6 GRADES. GRADES 1 AND 2 VIEWED PROGRAMS IN SCIENCE, SPEECH, ART, MUSIC, AND STORY TIME. GRADES 3 AND 4 VIEWED SERIES IN MUSIC, SCIENCE, ART, AND SPEECH, WHILE GRADES 5 AND 6 WERE…
Graph cuts for curvature based image denoising.
Bae, Egil; Shi, Juan; Tai, Xue-Cheng
2011-05-01
Minimization of total variation (TV) is a well-known method for image denoising. Recently, the relationship between TV minimization problems and binary MRF models has been much explored. This has resulted in some very efficient combinatorial optimization algorithms for the TV minimization problem in the discrete setting via graph cuts. To overcome limitations, such as staircasing effects, of the relatively simple TV model, variational models based upon higher order derivatives have been proposed. The Euler's elastica model is one such higher order model of central importance, which minimizes the curvature of all level lines in the image. Traditional numerical methods for minimizing the energy in such higher order models are complicated and computationally complex. In this paper, we will present an efficient minimization algorithm based upon graph cuts for minimizing the energy in the Euler's elastica model, by simplifying the problem to that of solving a sequence of easy graph representable problems. This sequence has connections to the gradient flow of the energy function, and converges to a minimum point. The numerical experiments show that our new approach is more effective in maintaining smooth visual results while preserving sharp features better than TV models.
[Extracurricular activities of adolescents useful for smoking prevention programs. OCTOPUS team].
López González, M L; López, T; Comas Fuentes, A; Herrero Puente, P; González Blázquez, J; Cueto Espinar, A; Thomas, H; Douglas, J; Markham, W; Charlton, A; de Vries, H; Leijs, I; Mester, I; Ausems, M
1999-01-01
The cigarette smoking habit continues to be prevalent to a greater degree than would be desirable among teenagers. Innovative prevention programs are needed. This descriptive cross-sectional study sets out the behavior variables related to the cigarette smoking habit and the extracurricular activities in which teenagers are most frequently involved which are useful for setting out extracurricular prevention programs. The data was collected by means of a questionnaire validated in a representative sample of school age youths (ages 10-11 and 13-14) from Asturias. The variables entailed in cigarette smoking were analyzed using the regression method. The starting smoker percentage is 14.5%-42.5%, regular smokers totaling 1.1% and 12.4%, respectively. Two models were constructed with the variables significantly related to smoking behavior, which are properly classified into smoker/non-smoker by 98.85% and 91.39% of the children, by ages. The environmental variables (availability of cigarettes and alcoholic beverages and regular visits to places entailing risk) are the major aspects comprising the model. The most common extracurricular activities are: watching TV, reading and listening to music and watching or playing sports. The findings provide keys to planning extracurricular activities tailored to fit in with the activities most popular among teens: TV commercials and ads on music media (CD's, tapes, etc.) and printed information mailed directly to teens at their homes, with messages conveyed by opinion-leaders among teens in the fields of sports, music and television.
The 1984 ARI Survey of Army Recruits: Tabular Description of NPS (active) Army Accessions. Volume 1
1986-05-01
WATCH TV PROG MJR LEAG BASEBALL PLAYOFFS 232-233 WATCH TV PROG WORLD SERIES 23<«-235 WATCH TV PROG NBA BASKETBALL 236-237 WATCH TV PROG COLLEGE...PROG:NBA BASKETBALL DO YOU ’^ATCH ANY OF THE FOLLOWING PROGRAMS OR PROGRAMMING TYPES ON TV? - NBA BASKETBALL , 1 - REGULARLY TURN ON THE TV TO WATCH...107. NBA basketball 108. College basketball 109. NHL hockey 110. Professional wrestling 111. Car r.ices 112. Golf tournaments 113. Tennis
Takács, Bence
2013-04-14
Young people are more and more inactive, which has numerous well-known negative effects on their health. Several studies indicate that inactive lifestyle disposes people to sit in front of the television, which increases aggression and decreases the willingness of reading. There is also a strong link between inactivity and an increase of body mass, deterioration of anthropometric parameters, and deviant behaviour. The aim of the study was to find out, on the basis of two cross-sectional surveys, the changes occurred within eight years in the free-time activity of Hungarian young people aged between 15 and 19 years. Data obtained from two surveys conducted by the National Institute for Family and Social Policy, Hungary in 2000 and 2008 including 1780 and 2018 young people, respectively, were analysed and compared. The number of young people regularly involved in sport activity increased significantly, while their media-consumption failed to decrease. Physically active young people are more health-conscious, but regular sporting activity did not expel smoking, which was associated with a sedentary lifestyle and television watching. These data reveal new responses of a new generation; watching television still takes the largest part of their free time activity, but use of computers, and participation in social activities are not necessarily increase sedentary lifestyle and deviant habits. Internet has positive effects on the regularity of their physical activity.
Vulnerability to the impact of temperature variability on mortality in 31 major Chinese cities.
Yang, Jun; Zhou, Maigeng; Li, Mengmeng; Liu, Xiaobo; Yin, Peng; Sun, Qinghua; Wang, Jun; Wu, Haixia; Wang, Boguang; Liu, Qiyong
2018-08-01
Few studies have analyzed the health effects of temperature variability (TV) accounting for both interday and intraday variations in ambient temperature. In this study, TV was defined as the standard deviations of the daily minimum and maximum temperature during different exposure days. Distributed lag non-linear Poisson regression model was used to examine the city-specific effect of TV on mortality in 31 Chinese municipalities and provincial capital cities. The national estimate was pooled through a meta-analysis based on the restricted maximum likelihood estimation. To assess effect modification on TV-mortality association by individual characteristics, stratified analyses were further fitted. Potential effect modification by city characteristics was performed through a meta-regression analysis. In total, 259 million permanent residents and 4,481,090 non-accidental deaths were covered in this study. The effect estimates of TV on mortality were generally increased by longer exposure days. A 1 °C increase in TV at 0-7 days' exposure was associated with a 0.60% (95% CI: 0.25-0.94%), 0.65% (0.24-1.05%), 0.82% (0.29-1.36%), 0.86% (0.42-1.31%), 0.98% (0.57-1.39%) and 0.54% (-0.11-1.20%) increase in non-accidental, cardiovascular, IHD, stroke, respiratory and COPD mortalities, respectively. Those with lower levels of educational attainment were significantly susceptible to TV. Cities with dense population, higher mean temperatures, and relative humidity and lower diurnal temperature ranges also had higher mortality risks caused by TV. This study demonstrated that TV had considerable health effects. An early warning system to alert residents about large temperature variations is recommended, which may have a significant impact on the community awareness and public health. Copyright © 2018 Elsevier Ltd. All rights reserved.
Wilkin, Holley A; Ball-Rokeach, Sandra J
2011-04-01
Health issues disproportionately affect Latinos, but variations within this ethnic group may mean that some Latinos are harder to reach with health messages than others. This paper introduces a methodology grounded in communication infrastructure theory to better target 'hard-to-reach' audiences. A random digit dialing telephone survey of 739 Latinos living in two Los Angeles communities was conducted. The relationships between health access difficulties and connections to an integrated storytelling network as well as individual health communication source connections were explored. Findings suggest that Latinos who are connected to an integrated storytelling network report marginally greater ease finding healthcare, despite not being any more likely to have insurance or a regular place for healthcare. Latinos who have health access problems tended to rely more upon Spanish-language television for health information. In addition, those without healthcare access problems are more likely to indicate that they use health professionals, the Internet, mainstream TV and printed materials like health pamphlets for health information. The theoretical and methodological contributions of this work, its major findings, implications, limitations and policy guidelines are discussed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhang, Wenkun; Zhang, Hanming; Li, Lei
2016-08-15
X-ray computed tomography (CT) is a powerful and common inspection technique used for the industrial non-destructive testing. However, large-sized and heavily absorbing objects cause the formation of artifacts because of either the lack of specimen penetration in specific directions or the acquisition of data from only a limited angular range of views. Although the sparse optimization-based methods, such as the total variation (TV) minimization method, can suppress artifacts to some extent, reconstructing the images such that they converge to accurate values remains difficult because of the deficiency in continuous angular data and inconsistency in the projections. To address this problem,more » we use the idea of regional enhancement of the true values and suppression of the illusory artifacts outside the region to develop an efficient iterative algorithm. This algorithm is based on the combination of regional enhancement of the true values and TV minimization for the limited angular reconstruction. In this algorithm, the segmentation approach is introduced to distinguish the regions of different image knowledge and generate the support mask of the image. A new regularization term, which contains the support knowledge to enhance the true values of the image, is incorporated into the objective function. Then, the proposed optimization model is solved by variable splitting and the alternating direction method efficiently. A compensation approach is also designed to extract useful information from the initial projections and thus reduce false segmentation result and correct the segmentation support and the segmented image. The results obtained from comparing both simulation studies and real CT data set reconstructions indicate that the proposed algorithm generates a more accurate image than do the other reconstruction methods. The experimental results show that this algorithm can produce high-quality reconstructed images for the limited angular reconstruction and suppress the illusory artifacts caused by the deficiency in valid data.« less
NASA Astrophysics Data System (ADS)
Zhang, Wenkun; Zhang, Hanming; Li, Lei; Wang, Linyuan; Cai, Ailong; Li, Zhongguo; Yan, Bin
2016-08-01
X-ray computed tomography (CT) is a powerful and common inspection technique used for the industrial non-destructive testing. However, large-sized and heavily absorbing objects cause the formation of artifacts because of either the lack of specimen penetration in specific directions or the acquisition of data from only a limited angular range of views. Although the sparse optimization-based methods, such as the total variation (TV) minimization method, can suppress artifacts to some extent, reconstructing the images such that they converge to accurate values remains difficult because of the deficiency in continuous angular data and inconsistency in the projections. To address this problem, we use the idea of regional enhancement of the true values and suppression of the illusory artifacts outside the region to develop an efficient iterative algorithm. This algorithm is based on the combination of regional enhancement of the true values and TV minimization for the limited angular reconstruction. In this algorithm, the segmentation approach is introduced to distinguish the regions of different image knowledge and generate the support mask of the image. A new regularization term, which contains the support knowledge to enhance the true values of the image, is incorporated into the objective function. Then, the proposed optimization model is solved by variable splitting and the alternating direction method efficiently. A compensation approach is also designed to extract useful information from the initial projections and thus reduce false segmentation result and correct the segmentation support and the segmented image. The results obtained from comparing both simulation studies and real CT data set reconstructions indicate that the proposed algorithm generates a more accurate image than do the other reconstruction methods. The experimental results show that this algorithm can produce high-quality reconstructed images for the limited angular reconstruction and suppress the illusory artifacts caused by the deficiency in valid data.
Xu, Q; Yang, D; Tan, J; Anastasio, M
2012-06-01
To improve image quality and reduce imaging dose in CBCT for radiation therapy applications and to realize near real-time image reconstruction based on use of a fast convergence iterative algorithm and acceleration by multi-GPUs. An iterative image reconstruction that sought to minimize a weighted least squares cost function that employed total variation (TV) regularization was employed to mitigate projection data incompleteness and noise. To achieve rapid 3D image reconstruction (< 1 min), a highly optimized multiple-GPU implementation of the algorithm was developed. The convergence rate and reconstruction accuracy were evaluated using a modified 3D Shepp-Logan digital phantom and a Catphan-600 physical phantom. The reconstructed images were compared with the clinical FDK reconstruction results. Digital phantom studies showed that only 15 iterations and 60 iterations are needed to achieve algorithm convergence for 360-view and 60-view cases, respectively. The RMSE was reduced to 10-4 and 10-2, respectively, by using 15 iterations for each case. Our algorithm required 5.4s to complete one iteration for the 60-view case using one Tesla C2075 GPU. The few-view study indicated that our iterative algorithm has great potential to reduce the imaging dose and preserve good image quality. For the physical Catphan studies, the images obtained from the iterative algorithm possessed better spatial resolution and higher SNRs than those obtained from by use of a clinical FDK reconstruction algorithm. We have developed a fast convergence iterative algorithm for CBCT image reconstruction. The developed algorithm yielded images with better spatial resolution and higher SNR than those produced by a commercial FDK tool. In addition, from the few-view study, the iterative algorithm has shown great potential for significantly reducing imaging dose. We expect that the developed reconstruction approach will facilitate applications including IGART and patient daily CBCT-based treatment localization. © 2012 American Association of Physicists in Medicine.
Family structure as a predictor of screen time among youth.
McMillan, Rachel; McIsaac, Michael; Janssen, Ian
2015-01-01
The family plays a central role in the development of health-related behaviors among youth. The objective of this study was to determine whether non-traditional parental structure and shared custody arrangements predict how much time youth spend watching television, using a computer recreationally, and playing video games. Participants were a nationally representative sample of Canadian youth (N = 26,068) in grades 6-10 who participated in the 2009/10 Health Behaviour in School-aged Children Survey. Screen time in youth from single parent and reconstituted families, with or without regular visitation with their non-residential parent, was compared to that of youth from traditional dual-parent families. Multiple imputation was used to account for missing data. After multiple imputation, the relative odds of being in the highest television, computer use, video game, and total screen time quartiles were not different in boys and girls from non-traditional families by comparison to boys and girls from traditional dual-parent families. In conclusion, parental structure and child custody arrangements did not have a meaningful impact on screen time among youth.
The extent and nature of alcohol advertising on Australian television.
Pettigrew, Simone; Roberts, Michele; Pescud, Melanie; Chapman, Kathy; Quester, Pascale; Miller, Caroline
2012-09-01
Current alcohol guidelines in Australia recommend minimising alcohol consumption, especially among minors. This study investigated (i) the extent to which children and the general population are exposed to television advertisements that endorse alcohol consumption and (ii) the themes used in these advertisements. A content analysis was conducted on alcohol advertisements aired over two months in major Australian cities. The advertisements were coded according to the products that were promoted, the themes that were employed, and the time of exposure. Advertising placement expenditure was also captured. In total, 2810 alcohol advertisements were aired, representing one in 10 beverage advertisements. Advertisement placement expenditure for alcohol products in the five cities over the two months was $15.8 million. Around half of all alcohol advertisements appeared during children's popular viewing times. The most common themes used were humour, friendship/mateship and value for money. Children and adults are regularly exposed to advertisements that depict alcohol consumption as fun, social and inexpensive. Such messages may reinforce existing alcohol-related cultural norms that prevent many Australians from meeting current intake guidelines. © 2012 Australasian Professional Society on Alcohol and other Drugs.
TV watching, soap opera and happiness.
Lu, L; Argyle, M
1993-09-01
One hundred and fourteen subjects reported the amount of time they spent watching television in general, and soap opera in particular. They also completed scales measuring happiness and other personality variables, such as extraversion and cooperativeness. In the multiple regression analysis, having controlled for the demographic variables, watching TV was related to unhappiness, whereas watching soap opera was related to happiness. Discriminant analysis showed that females, higher happiness and extraversion distinguished regular soap watchers (who nevertheless watched little TV in general) from irregular soap watchers (who nevertheless watched a lot of TV in general).
45 CFR 96.131 - Treatment services for pregnant women.
Code of Federal Regulations, 2013 CFR
2013-10-01
... (radio/television), regular advertisements in local/regional print media, posters placed in targeted... community based organizations, health care providers, and social service agencies. (c) The State shall in...
45 CFR 96.131 - Treatment services for pregnant women.
Code of Federal Regulations, 2014 CFR
2014-10-01
... (radio/television), regular advertisements in local/regional print media, posters placed in targeted... community based organizations, health care providers, and social service agencies. (c) The State shall in...
45 CFR 96.131 - Treatment services for pregnant women.
Code of Federal Regulations, 2012 CFR
2012-10-01
... (radio/television), regular advertisements in local/regional print media, posters placed in targeted... community based organizations, health care providers, and social service agencies. (c) The State shall in...
45 CFR 96.131 - Treatment services for pregnant women.
Code of Federal Regulations, 2011 CFR
2011-10-01
... (radio/television), regular advertisements in local/regional print media, posters placed in targeted... community based organizations, health care providers, and social service agencies. (c) The State shall in...
45 CFR 96.131 - Treatment services for pregnant women.
Code of Federal Regulations, 2010 CFR
2010-10-01
... (radio/television), regular advertisements in local/regional print media, posters placed in targeted... community based organizations, health care providers, and social service agencies. (c) The State shall in...
A sequential solution for anisotropic total variation image denoising with interval constraints
NASA Astrophysics Data System (ADS)
Xu, Jingyan; Noo, Frédéric
2017-09-01
We show that two problems involving the anisotropic total variation (TV) and interval constraints on the unknown variables admit, under some conditions, a simple sequential solution. Problem 1 is a constrained TV penalized image denoising problem; problem 2 is a constrained fused lasso signal approximator. The sequential solution entails finding first the solution to the unconstrained problem, and then applying a thresholding to satisfy the constraints. If the interval constraints are uniform, this sequential solution solves problem 1. If the interval constraints furthermore contain zero, the sequential solution solves problem 2. Here uniform interval constraints refer to all unknowns being constrained to the same interval. A typical example of application is image denoising in x-ray CT, where the image intensities are non-negative as they physically represent linear attenuation coefficient in the patient body. Our results are simple yet seem unknown; we establish them using the Karush-Kuhn-Tucker conditions for constrained convex optimization.
A compressed sensing based approach on Discrete Algebraic Reconstruction Technique.
Demircan-Tureyen, Ezgi; Kamasak, Mustafa E
2015-01-01
Discrete tomography (DT) techniques are capable of computing better results, even using less number of projections than the continuous tomography techniques. Discrete Algebraic Reconstruction Technique (DART) is an iterative reconstruction method proposed to achieve this goal by exploiting a prior knowledge on the gray levels and assuming that the scanned object is composed from a few different densities. In this paper, DART method is combined with an initial total variation minimization (TvMin) phase to ensure a better initial guess and extended with a segmentation procedure in which the threshold values are estimated from a finite set of candidates to minimize both the projection error and the total variation (TV) simultaneously. The accuracy and the robustness of the algorithm is compared with the original DART by the simulation experiments which are done under (1) limited number of projections, (2) limited view problem and (3) noisy projections conditions.
Total Variation Denoising and Support Localization of the Gradient
NASA Astrophysics Data System (ADS)
Chambolle, A.; Duval, V.; Peyré, G.; Poon, C.
2016-10-01
This paper describes the geometrical properties of the solutions to the total variation denoising method. A folklore statement is that this method is able to restore sharp edges, but at the same time, might introduce some staircasing (i.e. “fake” edges) in flat areas. Quite surprisingly, put aside numerical evidences, almost no theoretical result are available to backup these claims. The first contribution of this paper is a precise mathematical definition of the “extended support” (associated to the noise-free image) of TV denoising. This is intuitively the region which is unstable and will suffer from the staircasing effect. Our main result shows that the TV denoising method indeed restores a piece-wise constant image outside a small tube surrounding the extended support. Furthermore, the radius of this tube shrinks toward zero as the noise level vanishes and in some cases, an upper bound on the convergence rate is given.
Children's Television: An Analysis of Programming and Advertising.
ERIC Educational Resources Information Center
Barcus, F. Earle; Wolkin, Rachel
The studies reported in this book are content analyses of children's television and attendant advertising. Following an introductory statement, chapters present data about children's commercial television on the weekends, children's commercial television after school, and the seasonal variations in television advertising to children. A concluding…
36 CFR 705.1 - Scope and purpose of this part.
Code of Federal Regulations, 2014 CFR
2014-07-01
..., COMPILATION, AND DISTRIBUTION OF NEWS TRANSMISSIONS UNDER THE PROVISIONS OF THE AMERICAN TELEVISION AND RADIO... consisting of regularly scheduled newscasts or on-the-spot coverage of news events. ...
36 CFR 705.1 - Scope and purpose of this part.
Code of Federal Regulations, 2010 CFR
2010-07-01
..., COMPILATION, AND DISTRIBUTION OF NEWS TRANSMISSIONS UNDER THE PROVISIONS OF THE AMERICAN TELEVISION AND RADIO... consisting of regularly scheduled newscasts or on-the-spot coverage of news events. ...
36 CFR 705.1 - Scope and purpose of this part.
Code of Federal Regulations, 2012 CFR
2012-07-01
..., COMPILATION, AND DISTRIBUTION OF NEWS TRANSMISSIONS UNDER THE PROVISIONS OF THE AMERICAN TELEVISION AND RADIO... consisting of regularly scheduled newscasts or on-the-spot coverage of news events. ...
36 CFR 705.1 - Scope and purpose of this part.
Code of Federal Regulations, 2011 CFR
2011-07-01
..., COMPILATION, AND DISTRIBUTION OF NEWS TRANSMISSIONS UNDER THE PROVISIONS OF THE AMERICAN TELEVISION AND RADIO... consisting of regularly scheduled newscasts or on-the-spot coverage of news events. ...
Accelerated high-resolution photoacoustic tomography via compressed sensing
NASA Astrophysics Data System (ADS)
Arridge, Simon; Beard, Paul; Betcke, Marta; Cox, Ben; Huynh, Nam; Lucka, Felix; Ogunlade, Olumide; Zhang, Edward
2016-12-01
Current 3D photoacoustic tomography (PAT) systems offer either high image quality or high frame rates but are not able to deliver high spatial and temporal resolution simultaneously, which limits their ability to image dynamic processes in living tissue (4D PAT). A particular example is the planar Fabry-Pérot (FP) photoacoustic scanner, which yields high-resolution 3D images but takes several minutes to sequentially map the incident photoacoustic field on the 2D sensor plane, point-by-point. However, as the spatio-temporal complexity of many absorbing tissue structures is rather low, the data recorded in such a conventional, regularly sampled fashion is often highly redundant. We demonstrate that combining model-based, variational image reconstruction methods using spatial sparsity constraints with the development of novel PAT acquisition systems capable of sub-sampling the acoustic wave field can dramatically increase the acquisition speed while maintaining a good spatial resolution: first, we describe and model two general spatial sub-sampling schemes. Then, we discuss how to implement them using the FP interferometer and demonstrate the potential of these novel compressed sensing PAT devices through simulated data from a realistic numerical phantom and through measured data from a dynamic experimental phantom as well as from in vivo experiments. Our results show that images with good spatial resolution and contrast can be obtained from highly sub-sampled PAT data if variational image reconstruction techniques that describe the tissues structures with suitable sparsity-constraints are used. In particular, we examine the use of total variation (TV) regularization enhanced by Bregman iterations. These novel reconstruction strategies offer new opportunities to dramatically increase the acquisition speed of photoacoustic scanners that employ point-by-point sequential scanning as well as reducing the channel count of parallelized schemes that use detector arrays.
Code of Federal Regulations, 2010 CFR
2010-07-01
... DISTRIBUTION OF NEWS TRANSMISSIONS UNDER THE PROVISIONS OF THE AMERICAN TELEVISION AND RADIO ARCHIVES ACT § 705... program which consists of a regularly scheduled newscast or on-the-spot coverage of news events, to...
36 CFR § 705.1 - Scope and purpose of this part.
Code of Federal Regulations, 2013 CFR
2013-07-01
..., COMPILATION, AND DISTRIBUTION OF NEWS TRANSMISSIONS UNDER THE PROVISIONS OF THE AMERICAN TELEVISION AND RADIO... consisting of regularly scheduled newscasts or on-the-spot coverage of news events. ...
Code of Federal Regulations, 2011 CFR
2011-07-01
... DISTRIBUTION OF NEWS TRANSMISSIONS UNDER THE PROVISIONS OF THE AMERICAN TELEVISION AND RADIO ARCHIVES ACT § 705... program which consists of a regularly scheduled newscast or on-the-spot coverage of news events, to...
Code of Federal Regulations, 2014 CFR
2014-07-01
... DISTRIBUTION OF NEWS TRANSMISSIONS UNDER THE PROVISIONS OF THE AMERICAN TELEVISION AND RADIO ARCHIVES ACT § 705... program which consists of a regularly scheduled newscast or on-the-spot coverage of news events, to...
Code of Federal Regulations, 2012 CFR
2012-07-01
... DISTRIBUTION OF NEWS TRANSMISSIONS UNDER THE PROVISIONS OF THE AMERICAN TELEVISION AND RADIO ARCHIVES ACT § 705... program which consists of a regularly scheduled newscast or on-the-spot coverage of news events, to...
Code of Federal Regulations, 2013 CFR
2013-07-01
... DISTRIBUTION OF NEWS TRANSMISSIONS UNDER THE PROVISIONS OF THE AMERICAN TELEVISION AND RADIO ARCHIVES ACT § 705... program which consists of a regularly scheduled newscast or on-the-spot coverage of news events, to...
Food advertising during children's television programming on broadcast and cable channels.
Stitt, Carmen; Kunkel, Dale
2008-11-01
The rise in the number of overweight and obese children in the United States is recognized as a serious health threat. Among the factors contributing to this increase is the preponderance of food marketing on television targeted at children. Previous content analysis studies have identified patterns of food product types that are commonly associated with unhealthy diets, but few have attempted to independently evaluate the nutritional quality of advertised foods. This study identifies the nature and extent of food marketing messages presented during children's television programs, while also classifying the products advertised using a U.S. Department of Health and Human Services consumer food rating scheme. The findings indicate that food advertising accounts for nearly half of all commercial messages on children's programs. An average hour includes 11 food ads that account for 4:25 of total ad time. Broadcast channels deliver more food advertising than cable channels, although the types of food products marketed on both channels are highly similar. The overwhelming majority of foods ads directed to children are for high-calorie, low nutrient food products that should not be part of a regular diet. These data provide a baseline for evaluating anticipated future industry efforts at reform, such as attempts to comply with a recent Institute of Medicine (2006) policy recommendation that food marketing to children should be balanced between more healthy and less healthy food products within two years time.
Integrating Mass Media Instruction: "Connecting" NIE and TV Programs for the 21st Century.
ERIC Educational Resources Information Center
Shapley, Barbara
More high school students watch television regularly than read newspapers. Newspapers in Education coordinators should be involved in teaching their students critical viewing skills. The essential concepts that students need to learn are to: (1) understand what mass media and popular culture mean; (2) understand how the media shape attitudes and…
3D and 4D magnetic susceptibility tomography based on complex MR images
Chen, Zikuan; Calhoun, Vince D
2014-11-11
Magnetic susceptibility is the physical property for T2*-weighted magnetic resonance imaging (T2*MRI). The invention relates to methods for reconstructing an internal distribution (3D map) of magnetic susceptibility values, .chi. (x,y,z), of an object, from 3D T2*MRI phase images, by using Computed Inverse Magnetic Resonance Imaging (CIMRI) tomography. The CIMRI technique solves the inverse problem of the 3D convolution by executing a 3D Total Variation (TV) regularized iterative convolution scheme, using a split Bregman iteration algorithm. The reconstruction of .chi. (x,y,z) can be designed for low-pass, band-pass, and high-pass features by using a convolution kernel that is modified from the standard dipole kernel. Multiple reconstructions can be implemented in parallel, and averaging the reconstructions can suppress noise. 4D dynamic magnetic susceptibility tomography can be implemented by reconstructing a 3D susceptibility volume from a 3D phase volume by performing 3D CIMRI magnetic susceptibility tomography at each snapshot time.
Nagarajan, Rajakumar; Iqbal, Zohaib; Burns, Brian; Wilson, Neil E; Sarma, Manoj K; Margolis, Daniel A; Reiter, Robert E; Raman, Steven S; Thomas, M Albert
2015-11-01
The overlap of metabolites is a major limitation in one-dimensional (1D) spectral-based single-voxel MRS and multivoxel-based MRSI. By combining echo planar spectroscopic imaging (EPSI) with a two-dimensional (2D) J-resolved spectroscopic (JPRESS) sequence, 2D spectra can be recorded in multiple locations in a single slice of prostate using four-dimensional (4D) echo planar J-resolved spectroscopic imaging (EP-JRESI). The goal of the present work was to validate two different non-linear reconstruction methods independently using compressed sensing-based 4D EP-JRESI in prostate cancer (PCa): maximum entropy (MaxEnt) and total variation (TV). Twenty-two patients with PCa with a mean age of 63.8 years (range, 46-79 years) were investigated in this study. A 4D non-uniformly undersampled (NUS) EP-JRESI sequence was implemented on a Siemens 3-T MRI scanner. The NUS data were reconstructed using two non-linear reconstruction methods, namely MaxEnt and TV. Using both TV and MaxEnt reconstruction methods, the following observations were made in cancerous compared with non-cancerous locations: (i) higher mean (choline + creatine)/citrate metabolite ratios; (ii) increased levels of (choline + creatine)/spermine and (choline + creatine)/myo-inositol; and (iii) decreased levels of (choline + creatine)/(glutamine + glutamate). We have shown that it is possible to accelerate the 4D EP-JRESI sequence by four times and that the data can be reliably reconstructed using the TV and MaxEnt methods. The total acquisition duration was less than 13 min and we were able to detect and quantify several metabolites. Copyright © 2015 John Wiley & Sons, Ltd.
Wu, Junfeng; Dai, Fang; Hu, Gang; Mou, Xuanqin
2018-04-18
Excessive radiation exposure in computed tomography (CT) scans increases the chance of developing cancer and has become a major clinical concern. Recently, statistical iterative reconstruction (SIR) with l0-norm dictionary learning regularization has been developed to reconstruct CT images from the low dose and few-view dataset in order to reduce radiation dose. Nonetheless, the sparse regularization term adopted in this approach is l0-norm, which cannot guarantee the global convergence of the proposed algorithm. To address this problem, in this study we introduced the l1-norm dictionary learning penalty into SIR framework for low dose CT image reconstruction, and developed an alternating minimization algorithm to minimize the associated objective function, which transforms CT image reconstruction problem into a sparse coding subproblem and an image updating subproblem. During the image updating process, an efficient model function approach based on balancing principle is applied to choose the regularization parameters. The proposed alternating minimization algorithm was evaluated first using real projection data of a sheep lung CT perfusion and then using numerical simulation based on sheep lung CT image and chest image. Both visual assessment and quantitative comparison using terms of root mean square error (RMSE) and structural similarity (SSIM) index demonstrated that the new image reconstruction algorithm yielded similar performance with l0-norm dictionary learning penalty and outperformed the conventional filtered backprojection (FBP) and total variation (TV) minimization algorithms.
3D first-arrival traveltime tomography with modified total variation regularization
NASA Astrophysics Data System (ADS)
Jiang, Wenbin; Zhang, Jie
2018-02-01
Three-dimensional (3D) seismic surveys have become a major tool in the exploration and exploitation of hydrocarbons. 3D seismic first-arrival traveltime tomography is a robust method for near-surface velocity estimation. A common approach for stabilizing the ill-posed inverse problem is to apply Tikhonov regularization to the inversion. However, the Tikhonov regularization method recovers smooth local structures while blurring the sharp features in the model solution. We present a 3D first-arrival traveltime tomography method with modified total variation (MTV) regularization to preserve sharp velocity contrasts and improve the accuracy of velocity inversion. To solve the minimization problem of the new traveltime tomography method, we decouple the original optimization problem into two following subproblems: a standard traveltime tomography problem with the traditional Tikhonov regularization and a L2 total variation problem. We apply the conjugate gradient method and split-Bregman iterative method to solve these two subproblems, respectively. Our synthetic examples show that the new method produces higher resolution models than the conventional traveltime tomography with Tikhonov regularization. We apply the technique to field data. The stacking section shows significant improvements with static corrections from the MTV traveltime tomography.
The 1984 ARI Survey of Army Recruits: Tabular Description of NPS (active) Army Accessions. Volume 2
1986-05-01
YOU WATCH ANY OF THE FOLLOWING PROGRAMS OR PROGRAMMING TYPES ON TV? - NBA BASKETBALL 1 - REGULARLY TURN ON THE TV TO WATCH IT 2 - SOMETIMES WATCH IT...league baseball — regular season games 105. Major league baseball playoffs 106. World Series 107. NBA basketball 108. College basketball 109...LAG BASEBALL PLAYOFFS WORLD SERIES MBA BASKETBALL COLLEGE BASKETBALL NHL HOCKEY PROFESSIONAL WRESTLING CAR RACES 154 156 158- 160 162- 164
Introduction of Total Variation Regularization into Filtered Backprojection Algorithm
NASA Astrophysics Data System (ADS)
Raczyński, L.; Wiślicki, W.; Klimaszewski, K.; Krzemień, W.; Kowalski, P.; Shopa, R. Y.; Białas, P.; Curceanu, C.; Czerwiński, E.; Dulski, K.; Gajos, A.; Głowacz, B.; Gorgol, M.; Hiesmayr, B.; Jasińska, B.; Kisielewska-Kamińska, D.; Korcyl, G.; Kozik, T.; Krawczyk, N.; Kubicz, E.; Mohammed, M.; Pawlik-Niedźwiecka, M.; Niedźwiecki, S.; Pałka, M.; Rudy, Z.; Sharma, N. G.; Sharma, S.; Silarski, M.; Skurzok, M.; Wieczorek, A.; Zgardzińska, B.; Zieliński, M.; Moskal, P.
In this paper we extend the state-of-the-art filtered backprojection (FBP) method with application of the concept of Total Variation regularization. We compare the performance of the new algorithm with the most common form of regularizing in the FBP image reconstruction via apodizing functions. The methods are validated in terms of cross-correlation coefficient between reconstructed and real image of radioactive tracer distribution using standard Derenzo-type phantom. We demonstrate that the proposed approach results in higher cross-correlation values with respect to the standard FBP method.
Baust, Maximilian; Weinmann, Andreas; Wieczorek, Matthias; Lasser, Tobias; Storath, Martin; Navab, Nassir
2016-08-01
In this paper, we consider combined TV denoising and diffusion tensor fitting in DTI using the affine-invariant Riemannian metric on the space of diffusion tensors. Instead of first fitting the diffusion tensors, and then denoising them, we define a suitable TV type energy functional which incorporates the measured DWIs (using an inverse problem setup) and which measures the nearness of neighboring tensors in the manifold. To approach this functional, we propose generalized forward- backward splitting algorithms which combine an explicit and several implicit steps performed on a decomposition of the functional. We validate the performance of the derived algorithms on synthetic and real DTI data. In particular, we work on real 3D data. To our knowledge, the present paper describes the first approach to TV regularization in a combined manifold and inverse problem setup.
An l1-TV algorithm for deconvolution with salt and pepper noise
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wohlberg, Brendt; Rodriguez, Paul
2008-01-01
There has recently been considerable interest in applying Total Variation with an {ell}{sup 1} data fidelity term to the denoising of images subject to salt and pepper noise, but the extension of this formulation to more general problems, such as deconvolution, has received little attention, most probably because most efficient algorithms for {ell}{sup 1}-TV denoising can not handle more general inverse problems. We apply the Iteratively Reweighted Norm algorithm to this problem, and compare performance with an alternative algorithm based on the Mumford-Shah functional.
A content analysis of children's television advertising: focus on food and oral health.
Morgan, Maria; Fairchild, Ruth; Phillips, Andrea; Stewart, Kate; Hunter, Lindsay
2009-06-01
To analyse the nature and content of advertising during children's popular television viewing times with the specific aims of (i) identifying the proportion of advertising time devoted to confectionery and potentially cariogenic products (those which readily give rise to dental caries, more commonly known as tooth decay); and (ii) determining whether there is a variation in the advertisement of confectionery and other high-sugar products within children's school holiday time v. outside holiday time.MethodIn five separate one-week periods, the output of the four most popular British children's commercial television channels was video-recorded during the most popular viewing times for children. In total, 503 h of television were recorded and analysed. Analysis of the recordings revealed that 16.4 % of advertising time was devoted to food products; 6.3 % of all advertising time was devoted to potentially cariogenic products. Sugared cereals were the most commonly advertised high-sugar product, followed by sweetened dairy products and confectionery (chi2 = 6524.8, df = 4, P < 0.001). The advertisement of confectionery and high-sugar foods appeared to be influenced by school holidays. Health-care professionals should be aware of the shift away from the advertisement of confectionery towards the promotion of foods that might be considered healthier but contain large amounts of hidden sugar.
NASA Astrophysics Data System (ADS)
Yong, Peng; Liao, Wenyuan; Huang, Jianping; Li, Zhenchuan
2018-04-01
Full waveform inversion is an effective tool for recovering the properties of the Earth from seismograms. However, it suffers from local minima caused mainly by the limited accuracy of the starting model and the lack of a low-frequency component in the seismic data. Because of the high velocity contrast between salt and sediment, the relation between the waveform and velocity perturbation is strongly nonlinear. Therefore, salt inversion can easily get trapped in the local minima. Since the velocity of salt is nearly constant, we can make the most of this characteristic with total variation regularization to mitigate the local minima. In this paper, we develop an adaptive primal dual hybrid gradient method to implement total variation regularization by projecting the solution onto a total variation norm constrained convex set, through which the total variation norm constraint is satisfied at every model iteration. The smooth background velocities are first inverted and the perturbations are gradually obtained by successively relaxing the total variation norm constraints. Numerical experiment of the projection of the BP model onto the intersection of the total variation norm and box constraints has demonstrated the accuracy and efficiency of our adaptive primal dual hybrid gradient method. A workflow is designed to recover complex salt structures in the BP 2004 model and the 2D SEG/EAGE salt model, starting from a linear gradient model without using low-frequency data below 3 Hz. The salt inversion processes demonstrate that wavefield reconstruction inversion with a total variation norm and box constraints is able to overcome local minima and inverts the complex salt velocity layer by layer.
Liu, Yan; Ma, Jianhua; Zhang, Hao; Wang, Jing; Liang, Zhengrong
2014-01-01
Background The negative effects of X-ray exposure, such as inducing genetic and cancerous diseases, has arisen more attentions. Objective This paper aims to investigate a penalized re-weighted least-square (PRWLS) strategy for low-mAs X-ray computed tomography image reconstruction by incorporating an adaptive weighted total variation (AwTV) penalty term and a noise variance model of projection data. Methods An AwTV penalty is introduced in the objective function by considering both piecewise constant property and local nearby intensity similarity of the desired image. Furthermore, the weight of data fidelity term in the objective function is determined by our recent study on modeling variance estimation of projection data in the presence of electronic background noise. Results The presented AwTV-PRWLS algorithm can achieve the highest full-width-at-half-maximum (FWHM) measurement, for data conditions of (1) full-view 10mA acquisition and (2) sparse-view 80mA acquisition. In comparison between the AwTV/TV-PRWLS strategies and the previous reported AwTV/TV-projection onto convex sets (AwTV/TV-POCS) approaches, the former can gain in terms of FWHM for data condition (1), but cannot gain for the data condition (2). Conclusions In the case of full-view 10mA projection data, the presented AwTV-PRWLS shows potential improvement. However, in the case of sparse-view 80mA projection data, the AwTV/TV-POCS shows advantage over the PRWLS strategies. PMID:25080113
High quality 4D cone-beam CT reconstruction using motion-compensated total variation regularization
NASA Astrophysics Data System (ADS)
Zhang, Hua; Ma, Jianhua; Bian, Zhaoying; Zeng, Dong; Feng, Qianjin; Chen, Wufan
2017-04-01
Four dimensional cone-beam computed tomography (4D-CBCT) has great potential clinical value because of its ability to describe tumor and organ motion. But the challenge in 4D-CBCT reconstruction is the limited number of projections at each phase, which result in a reconstruction full of noise and streak artifacts with the conventional analytical algorithms. To address this problem, in this paper, we propose a motion compensated total variation regularization approach which tries to fully explore the temporal coherence of the spatial structures among the 4D-CBCT phases. In this work, we additionally conduct motion estimation/motion compensation (ME/MC) on the 4D-CBCT volume by using inter-phase deformation vector fields (DVFs). The motion compensated 4D-CBCT volume is then viewed as a pseudo-static sequence, of which the regularization function was imposed on. The regularization used in this work is the 3D spatial total variation minimization combined with 1D temporal total variation minimization. We subsequently construct a cost function for a reconstruction pass, and minimize this cost function using a variable splitting algorithm. Simulation and real patient data were used to evaluate the proposed algorithm. Results show that the introduction of additional temporal correlation along the phase direction can improve the 4D-CBCT image quality.
NASA Astrophysics Data System (ADS)
Choi, Sunghoon; Lee, Haenghwa; Lee, Donghoon; Choi, Seungyeon; Shin, Jungwook; Jang, Woojin; Seo, Chang-Woo; Kim, Hee-Joung
2017-03-01
A compressed-sensing (CS) technique has been rapidly applied in medical imaging field for retrieving volumetric data from highly under-sampled projections. Among many variant forms, CS technique based on a total-variation (TV) regularization strategy shows fairly reasonable results in cone-beam geometry. In this study, we implemented the TV-based CS image reconstruction strategy in our prototype chest digital tomosynthesis (CDT) R/F system. Due to the iterative nature of time consuming processes in solving a cost function, we took advantage of parallel computing using graphics processing units (GPU) by the compute unified device architecture (CUDA) programming to accelerate our algorithm. In order to compare the algorithmic performance of our proposed CS algorithm, conventional filtered back-projection (FBP) and simultaneous algebraic reconstruction technique (SART) reconstruction schemes were also studied. The results indicated that the CS produced better contrast-to-noise ratios (CNRs) in the physical phantom images (Teflon region-of-interest) by factors of 3.91 and 1.93 than FBP and SART images, respectively. The resulted human chest phantom images including lung nodules with different diameters also showed better visual appearance in the CS images. Our proposed GPU-accelerated CS reconstruction scheme could produce volumetric data up to 80 times than CPU programming. Total elapsed time for producing 50 coronal planes with 1024×1024 image matrix using 41 projection views were 216.74 seconds for proposed CS algorithms on our GPU programming, which could match the clinically feasible time ( 3 min). Consequently, our results demonstrated that the proposed CS method showed a potential of additional dose reduction in digital tomosynthesis with reasonable image quality in a fast time.
Huang, Hsuan-Ming; Hsiao, Ing-Tsung
2016-01-01
In recent years, there has been increased interest in low-dose X-ray cone beam computed tomography (CBCT) in many fields, including dentistry, guided radiotherapy and small animal imaging. Despite reducing the radiation dose, low-dose CBCT has not gained widespread acceptance in routine clinical practice. In addition to performing more evaluation studies, developing a fast and high-quality reconstruction algorithm is required. In this work, we propose an iterative reconstruction method that accelerates ordered-subsets (OS) reconstruction using a power factor. Furthermore, we combine it with the total-variation (TV) minimization method. Both simulation and phantom studies were conducted to evaluate the performance of the proposed method. Results show that the proposed method can accelerate conventional OS methods, greatly increase the convergence speed in early iterations. Moreover, applying the TV minimization to the power acceleration scheme can further improve the image quality while preserving the fast convergence rate.
Huang, Hsuan-Ming; Hsiao, Ing-Tsung
2016-01-01
In recent years, there has been increased interest in low-dose X-ray cone beam computed tomography (CBCT) in many fields, including dentistry, guided radiotherapy and small animal imaging. Despite reducing the radiation dose, low-dose CBCT has not gained widespread acceptance in routine clinical practice. In addition to performing more evaluation studies, developing a fast and high-quality reconstruction algorithm is required. In this work, we propose an iterative reconstruction method that accelerates ordered-subsets (OS) reconstruction using a power factor. Furthermore, we combine it with the total-variation (TV) minimization method. Both simulation and phantom studies were conducted to evaluate the performance of the proposed method. Results show that the proposed method can accelerate conventional OS methods, greatly increase the convergence speed in early iterations. Moreover, applying the TV minimization to the power acceleration scheme can further improve the image quality while preserving the fast convergence rate. PMID:27073853
Telling stories about abortion: abortion-related plots in American film and television, 1916-2013.
Sisson, Gretchen; Kimport, Katrina
2014-05-01
Popular discourse on abortion in film and television assumes that abortions are under- and misrepresented. Research indicates that such representations influence public perception of abortion care and may play a role in the production of social myths around abortion, with consequences for women's experience of abortion. To date, abortion plotlines in American film and television have not been systematically tracked and analyzed. A comprehensive online search was conducted to identify all representations of pregnancy decision making and abortion in American film and television through January 2013. Search results were coded for year, pregnancy decision and mortality outcome. A total of 310 plotlines were identified, with an overall upward trend over time in the number of representations of abortion decision making. Of these plotlines, 173 (55.8%) resulted in abortion, 80 (25.8%) in parenting, 13 (4.2%) in adoption and 21 (6.7%) in pregnancy loss, and 16 (5.1%) were unresolved. A total of 13.5% (n=42) of stories ended with the death of the woman who considered an abortion, whether or not she obtained one. Abortion-related plotlines occur more frequently than popular discourse assumes. Year-to-year variation in frequency suggests an interactive relationship between media representations, cultural attitudes and policies around abortion regulation, consistent with cultural theory of the relationship between media products and social beliefs. Patterns of outcomes and rates of mortality are not representative of real experience and may contribute to social myths around abortion. The narrative linking of pregnancy termination with mortality is of particular note, supporting the social myth associating abortion with death. This analysis empirically describes the number of abortion-related plotlines in American film and television. It contributes to the systematic evaluation of the portrayal of abortion in popular culture and provides abortion care professionals and advocates with an initial accurate window into cultural stories being told about abortion. Copyright © 2014 Elsevier Inc. All rights reserved.
Sparse magnetic resonance imaging reconstruction using the bregman iteration
NASA Astrophysics Data System (ADS)
Lee, Dong-Hoon; Hong, Cheol-Pyo; Lee, Man-Woo
2013-01-01
Magnetic resonance imaging (MRI) reconstruction needs many samples that are sequentially sampled by using phase encoding gradients in a MRI system. It is directly connected to the scan time for the MRI system and takes a long time. Therefore, many researchers have studied ways to reduce the scan time, especially, compressed sensing (CS), which is used for sparse images and reconstruction for fewer sampling datasets when the k-space is not fully sampled. Recently, an iterative technique based on the bregman method was developed for denoising. The bregman iteration method improves on total variation (TV) regularization by gradually recovering the fine-scale structures that are usually lost in TV regularization. In this study, we studied sparse sampling image reconstruction using the bregman iteration for a low-field MRI system to improve its temporal resolution and to validate its usefulness. The image was obtained with a 0.32 T MRI scanner (Magfinder II, SCIMEDIX, Korea) with a phantom and an in-vivo human brain in a head coil. We applied random k-space sampling, and we determined the sampling ratios by using half the fully sampled k-space. The bregman iteration was used to generate the final images based on the reduced data. We also calculated the root-mean-square-error (RMSE) values from error images that were obtained using various numbers of bregman iterations. Our reconstructed images using the bregman iteration for sparse sampling images showed good results compared with the original images. Moreover, the RMSE values showed that the sparse reconstructed phantom and the human images converged to the original images. We confirmed the feasibility of sparse sampling image reconstruction methods using the bregman iteration with a low-field MRI system and obtained good results. Although our results used half the sampling ratio, this method will be helpful in increasing the temporal resolution at low-field MRI systems.
NASA Astrophysics Data System (ADS)
Dong, Jian; Kudo, Hiroyuki
2017-03-01
Compressed sensing (CS) is attracting growing concerns in sparse-view computed tomography (CT) image reconstruction. The most standard approach of CS is total variation (TV) minimization. However, images reconstructed by TV usually suffer from distortions, especially in reconstruction of practical CT images, in forms of patchy artifacts, improper serrate edges and loss of image textures. Most existing CS approaches including TV achieve image quality improvement by applying linear transforms to object image, but linear transforms usually fail to take discontinuities into account, such as edges and image textures, which is considered to be the key reason for image distortions. Actually, discussions on nonlinear filter based image processing has a long history, leading us to clarify that the nonlinear filters yield better results compared to linear filters in image processing task such as denoising. Median root prior was first utilized by Alenius as nonlinear transform in CT image reconstruction, with significant gains obtained. Subsequently, Zhang developed the application of nonlocal means-based CS. A fact is gradually becoming clear that the nonlinear transform based CS has superiority in improving image quality compared with the linear transform based CS. However, it has not been clearly concluded in any previous paper within the scope of our knowledge. In this work, we investigated the image quality differences between the conventional TV minimization and nonlinear sparsifying transform based CS, as well as image quality differences among different nonlinear sparisying transform based CSs in sparse-view CT image reconstruction. Additionally, we accelerated the implementation of nonlinear sparsifying transform based CS algorithm.
Cooper, Crystale Purvis; Gelb, Cynthia A; Jameson, Heather; Macario, Everly; Jorgensen, Cynthia M; Seeff, Laura
2005-10-01
Screen for Life: National Colorectal Cancer Action Campaign (SFL) is a federally funded campaign to promote understanding of colorectal cancer and the importance of regular screening for adults aged 50 years and older. SFL uses a variety of communication strategies, including television public service announcements (PSAs). SFL materials are developed using the Health Communication Process endorsed by the U.S. Department of Health and Human Services, which has four stages: (a) planning and strategy development; (b) developing and pretesting concepts, messages, and materials; (c) implementing the program; and (d) assessing effectiveness and making refinements. This article describes SFL's application of this process to develop television PSAs in English and Spanish.
Dialectical Features of Black Characters in Situation Comedies on Television.
ERIC Educational Resources Information Center
Fine, Marlene G.; Anderson, Carolyn
1980-01-01
Three prime time television situation comedies with primarily Black casts were studied for frequency and variations in use of Black English Vernacular (BEV). It is suggested that homogenization of BEV on American television reflects the attitude that BEV is not a legitimate language choice. (GC)
32 CFR 705.7 - Radio and television.
Code of Federal Regulations, 2014 CFR
2014-07-01
... extra expense involved. A strict accounting of the additional expenses incurred and charged to the production company must be maintained by the designated project officer. A copy of this accounting will be...) Not in competition with the regular employment of professional performers. (2) The public affairs...
32 CFR 705.7 - Radio and television.
Code of Federal Regulations, 2013 CFR
2013-07-01
... extra expense involved. A strict accounting of the additional expenses incurred and charged to the production company must be maintained by the designated project officer. A copy of this accounting will be...) Not in competition with the regular employment of professional performers. (2) The public affairs...
Monochromatic-beam-based dynamic X-ray microtomography based on OSEM-TV algorithm.
Xu, Liang; Chen, Rongchang; Yang, Yiming; Deng, Biao; Du, Guohao; Xie, Honglan; Xiao, Tiqiao
2017-01-01
Monochromatic-beam-based dynamic X-ray computed microtomography (CT) was developed to observe evolution of microstructure inside samples. However, the low flux density results in low efficiency in data collection. To increase efficiency, reducing the number of projections should be a practical solution. However, it has disadvantages of low image reconstruction quality using the traditional filtered back projection (FBP) algorithm. In this study, an iterative reconstruction method using an ordered subset expectation maximization-total variation (OSEM-TV) algorithm was employed to address and solve this problem. The simulated results demonstrated that normalized mean square error of the image slices reconstructed by the OSEM-TV algorithm was about 1/4 of that by FBP. Experimental results also demonstrated that the density resolution of OSEM-TV was high enough to resolve different materials with the number of projections less than 100. As a result, with the introduction of OSEM-TV, the monochromatic-beam-based dynamic X-ray microtomography is potentially practicable for the quantitative and non-destructive analysis to the evolution of microstructure with acceptable efficiency in data collection and reconstructed image quality.
The Right Tools for the Right Jobs.
ERIC Educational Resources Information Center
Barbalich, Andrea, Ed.
1995-01-01
A chart shows the best campus public relations uses for 17 communication techniques: face-to-face contact; phone call, regular mail; electronic mail; special events; a speech; press release; press kit; press conference; television and radio public service announcements; video news releases; promotions and posters; advertising; newsletter;…
An iterative shrinkage approach to total-variation image restoration.
Michailovich, Oleg V
2011-05-01
The problem of restoration of digital images from their degraded measurements plays a central role in a multitude of practically important applications. A particularly challenging instance of this problem occurs in the case when the degradation phenomenon is modeled by an ill-conditioned operator. In such a situation, the presence of noise makes it impossible to recover a valuable approximation of the image of interest without using some a priori information about its properties. Such a priori information--commonly referred to as simply priors--is essential for image restoration, rendering it stable and robust to noise. Moreover, using the priors makes the recovered images exhibit some plausible features of their original counterpart. Particularly, if the original image is known to be a piecewise smooth function, one of the standard priors used in this case is defined by the Rudin-Osher-Fatemi model, which results in total variation (TV) based image restoration. The current arsenal of algorithms for TV-based image restoration is vast. In this present paper, a different approach to the solution of the problem is proposed based upon the method of iterative shrinkage (aka iterated thresholding). In the proposed method, the TV-based image restoration is performed through a recursive application of two simple procedures, viz. linear filtering and soft thresholding. Therefore, the method can be identified as belonging to the group of first-order algorithms which are efficient in dealing with images of relatively large sizes. Another valuable feature of the proposed method consists in its working directly with the TV functional, rather then with its smoothed versions. Moreover, the method provides a single solution for both isotropic and anisotropic definitions of the TV functional, thereby establishing a useful connection between the two formulae. Finally, a number of standard examples of image deblurring are demonstrated, in which the proposed method can provide restoration results of superior quality as compared to the case of sparse-wavelet deconvolution.
Improving IMRT delivery efficiency with reweighted L1-minimization for inverse planning
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kim, Hojin; Becker, Stephen; Lee, Rena
2013-07-15
Purpose: This study presents an improved technique to further simplify the fluence-map in intensity modulated radiation therapy (IMRT) inverse planning, thereby reducing plan complexity and improving delivery efficiency, while maintaining the plan quality.Methods: First-order total-variation (TV) minimization (min.) based on L1-norm has been proposed to reduce the complexity of fluence-map in IMRT by generating sparse fluence-map variations. However, with stronger dose sparing to the critical structures, the inevitable increase in the fluence-map complexity can lead to inefficient dose delivery. Theoretically, L0-min. is the ideal solution for the sparse signal recovery problem, yet practically intractable due to its nonconvexity of themore » objective function. As an alternative, the authors use the iteratively reweighted L1-min. technique to incorporate the benefits of the L0-norm into the tractability of L1-min. The weight multiplied to each element is inversely related to the magnitude of the corresponding element, which is iteratively updated by the reweighting process. The proposed penalizing process combined with TV min. further improves sparsity in the fluence-map variations, hence ultimately enhancing the delivery efficiency. To validate the proposed method, this work compares three treatment plans obtained from quadratic min. (generally used in clinic IMRT), conventional TV min., and our proposed reweighted TV min. techniques, implemented by a large-scale L1-solver (template for first-order conic solver), for five patient clinical data. Criteria such as conformation number (CN), modulation index (MI), and estimated treatment time are employed to assess the relationship between the plan quality and delivery efficiency.Results: The proposed method yields simpler fluence-maps than the quadratic and conventional TV based techniques. To attain a given CN and dose sparing to the critical organs for 5 clinical cases, the proposed method reduces the number of segments by 10-15 and 30-35, relative to TV min. and quadratic min. based plans, while MIs decreases by about 20%-30% and 40%-60% over the plans by two existing techniques, respectively. With such conditions, the total treatment time of the plans obtained from our proposed method can be reduced by 12-30 s and 30-80 s mainly due to greatly shorter multileaf collimator (MLC) traveling time in IMRT step-and-shoot delivery.Conclusions: The reweighted L1-minimization technique provides a promising solution to simplify the fluence-map variations in IMRT inverse planning. It improves the delivery efficiency by reducing the entire segments and treatment time, while maintaining the plan quality in terms of target conformity and critical structure sparing.« less
Comparison of Weather Shows in Eastern Europe
NASA Astrophysics Data System (ADS)
Najman, M.
2009-09-01
Comparison of Weather Shows in Eastern Europe Television weather shows in Eastern Europe have in most cases in the high graphical standard. There is though a wast difference in duration and information content in the weather shows. There are few signs and regularities by which we can see the character of the weather show. The main differences are mainly caused by the income structure of the TV station. Either it is a fully privately funded TV relying on the TV commercials income. Or it is a public service TV station funded mainly by the national budget or fixed fee structure/tax. There are wast differences in duration and even a graphical presentation of the weather. Next important aspect is a supplier of the weather information and /or the processor. Shortly we can say, that when the TV show is produced by the national met office, the TV show consists of more scientific terms, synoptic maps, satellite imagery, etc. If the supplier is the private meteorological company, the weather show is more user-friendly, laical with less scientific terms. We are experiencing a massive shift in public weather knowledge and demand for information. In the past, weather shows consisted only of maps with weather icons. In todaýs world, even the laic weather shows consist partly of numerical weather model outputs - they are of course designed to be understandable and graphically attractive. Outputs of the numerical weather models used to be only a part of daily life of a professional meteorologist, today they are common part of life of regular people. Video samples are a part of this presentation.
SU-G-BRA-11: Tumor Tracking in An Iterative Volume of Interest Based 4D CBCT Reconstruction
DOE Office of Scientific and Technical Information (OSTI.GOV)
Martin, R; Pan, T; Ahmad, M
2016-06-15
Purpose: 4D CBCT can allow evaluation of tumor motion immediately prior to radiation therapy, but suffers from heavy artifacts that limit its ability to track tumors. Various iterative and compressed sensing reconstructions have been proposed to reduce these artifacts, but are costly time-wise and can degrade the image quality of bony anatomy for alignment with regularization. We have previously proposed an iterative volume of interest (I4D VOI) method which minimizes reconstruction time and maintains image quality of bony anatomy by focusing a 4D reconstruction within a VOI. The purpose of this study is to test the tumor tracking accuracy ofmore » this method compared to existing methods. Methods: Long scan (8–10 mins) CBCT data with corresponding RPM data was collected for 12 lung cancer patients. The full data set was sorted into 8 phases and reconstructed using FDK cone beam reconstruction to serve as a gold standard. The data was reduced in way that maintains a normal breathing pattern and used to reconstruct 4D images using FDK, low and high regularization TV minimization (λ=2,10), and the proposed I4D VOI method with PTVs used for the VOI. Tumor trajectories were found using rigid registration within the VOI for each reconstruction and compared to the gold standard. Results: The root mean square error (RMSE) values were 2.70mm for FDK, 2.50mm for low regularization TV, 1.48mm for high regularization TV, and 2.34mm for I4D VOI. Streak artifacts in I4D VOI were reduced compared to FDK and images were less blurred than TV reconstructed images. Conclusion: I4D VOI performed at least as well as existing methods in tumor tracking, with the exception of high regularization TV minimization. These results along with the reconstruction time and outside VOI image quality advantages suggest I4D VOI to be an improvement over existing methods. Funding support provided by CPRIT grant RP110562-P2-01.« less
NASA Astrophysics Data System (ADS)
Qian, Tingting; Wang, Lianlian; Lu, Guanghua
2017-07-01
Radar correlated imaging (RCI) introduces the optical correlated imaging technology to traditional microwave imaging, which has raised widespread concern recently. Conventional RCI methods neglect the structural information of complex extended target, which makes the quality of recovery result not really perfect, thus a novel combination of negative exponential restraint and total variation (NER-TV) algorithm for extended target imaging is proposed in this paper. The sparsity is measured by a sequential order one negative exponential function, then the 2D total variation technique is introduced to design a novel optimization problem for extended target imaging. And the proven alternating direction method of multipliers is applied to solve the new problem. Experimental results show that the proposed algorithm could realize high resolution imaging efficiently for extended target.
Fast magnetic resonance imaging based on high degree total variation
NASA Astrophysics Data System (ADS)
Wang, Sujie; Lu, Liangliang; Zheng, Junbao; Jiang, Mingfeng
2018-04-01
In order to eliminating the artifacts and "staircase effect" of total variation in Compressive Sensing MRI, high degree total variation model is proposed for dynamic MRI reconstruction. the high degree total variation regularization term is used as a constraint to reconstruct the magnetic resonance image, and the iterative weighted MM algorithm is proposed to solve the convex optimization problem of the reconstructed MR image model, In addtion, one set of cardiac magnetic resonance data is used to verify the proposed algorithm for MRI. The results show that the high degree total variation method has a better reconstruction effect than the total variation and the total generalized variation, which can obtain higher reconstruction SNR and better structural similarity.
Confronting Ambiguity in Science
ERIC Educational Resources Information Center
Emery, Katherine; Harlow, Danielle; Whitmer, Ali; Gaines, Steven
2015-01-01
People are regularly confronted with environmental and science-related issues presented to them in newspapers, on television, or even in their own doctor's office. Often the information they use to inform their decisions on matters of science may be ambiguous and contradictory. This article presents an activity that investigates how students deal…
Ferreira, Nathália Luíza; Claro, Rafael Moreira; Lopes, Aline Cristine Souza
2015-12-01
This study aimed to analyze the consumption of high-sugar foods by Brazilian schoolchildren and to identify associated factors, based on data from the National School Health Survey (PeNSE 2012). Consumption of these foods was classified as: do not consume sweets and soft drinks regularly; consume sweets or soft drinks regularly; and consume sweets and soft drinks regularly. Its association with sociodemographic information, eating habits, and family contexts were investigated via multiple ordinal regressions. Regular consumption of sweets and/or soft drinks was reported by 19.2% and 36.1% of adolescents, respectively, and higher prevalence was associated with female gender, age 14-15 years, higher maternal education, not living with the mother and father, not eating meals with the parents, eating while watching TV, and longer TV time. Nearly one-fifth of adolescents regularly consumed sweets and soft drinks, which was associated with socio-demographic and behavioral factors that should be targeted in order to improve their food consumption.
Composite SAR imaging using sequential joint sparsity
NASA Astrophysics Data System (ADS)
Sanders, Toby; Gelb, Anne; Platte, Rodrigo B.
2017-06-01
This paper investigates accurate and efficient ℓ1 regularization methods for generating synthetic aperture radar (SAR) images. Although ℓ1 regularization algorithms are already employed in SAR imaging, practical and efficient implementation in terms of real time imaging remain a challenge. Here we demonstrate that fast numerical operators can be used to robustly implement ℓ1 regularization methods that are as or more efficient than traditional approaches such as back projection, while providing superior image quality. In particular, we develop a sequential joint sparsity model for composite SAR imaging which naturally combines the joint sparsity methodology with composite SAR. Our technique, which can be implemented using standard, fractional, or higher order total variation regularization, is able to reduce the effects of speckle and other noisy artifacts with little additional computational cost. Finally we show that generalizing total variation regularization to non-integer and higher orders provides improved flexibility and robustness for SAR imaging.
Prevalence of obesity and associated risk factors among adolescents in Ankara, Turkey.
Ercan, Sırma; Dallar, Yıldız Bilge; Önen, Serdar; Engiz, Özlem
2012-12-01
The purpose of this study was to investigate the prevalence of and the risk factors associated with obesity among adolescents in Ankara, Turkey. The study was conducted in 26 schools in Ankara during the time period from September 2010 to March 2011. A total of 8848 adolescents aged 11-18 years were chosen using a population-based stratified cluster sampling method. Body mass index (BMI) of the participants was compared with the BMI references for Turkish children and adolescents to estimate the prevalence of overweight and obesity. A standardized questionnaire aiming to determine the sociodemographic characteristics, computer use, television (TV) watching, physical activity, and presence of obesity in the family was applied to the study group. The results showed that the overall prevalence of obesity among adolescents was 7.7% (8.4 % for females and 7.0% for males). It was observed that BMI increased as computer use increased. A greater proportion of the overweight and obese adolescents watched TV and use computer for more than 2 hours/day as compared to their normal-weight counterparts. The normal-weight subjects were found to show a higher participation in regular physical activity. Obesity prevalence among the families of obese adolescents was 56.5%. The prevalence of adolescent obesity in Ankara, Turkey is lower as compared to many European countries and to the United States. Computer use, watching TV, physical activity and family factors are important risk factors for obesity.
Prevalence of Obesity and Associated Risk Factors Among Adolescents in Ankara, Turkey
Ercan, Sırma; Dallar, Yıldız Bilge; Önen, Serdar; Engiz, Özlem
2012-01-01
Objective: The purpose of this study was to investigate the prevalence of and the risk factors associated with obesity among adolescents in Ankara, Turkey. Methods: The study was conducted in 26 schools in Ankara during the time period from September 2010 to March 2011. A total of 8848 adolescents aged 11-18 years were chosen using a population-based stratified cluster sampling method. Body mass index (BMI) of the participants was compared with the BMI references for Turkish children and adolescents to estimate the prevalence of overweight and obesity. A standardized questionnaire aiming to determine the sociodemographic characteristics, computer use, television (TV) watching, physical activity, and presence of obesity in the family was applied to the study group. Results: The results showed that the overall prevalence of obesity among adolescents was 7.7% (8.4 % for females and 7.0% for males). It was observed that BMI increased as computer use increased. A greater proportion of the overweight and obese adolescents watched TV and use computer for more than 2 hours/day as compared to their normal-weight counterparts. The normal-weight subjects were found to show a higher participation in regular physical activity. Obesity prevalence among the families of obese adolescents was 56.5%. Conclusions: The prevalence of adolescent obesity in Ankara, Turkey is lower as compared to many European countries and to the United States. Computer use, watching TV, physical activity and family factors are important risk factors for obesity. Conflict of interest:None declared. PMID:23149433
Childhood and Adolescent Television Viewing and Antisocial Behavior in Early Adulthood
Robertson, Lindsay A.; McAnally, Helena M.
2013-01-01
OBJECTIVE: To investigate whether excessive television viewing throughout childhood and adolescence is associated with increased antisocial behavior in early adulthood. METHODS: We assessed a birth cohort of 1037 individuals born in Dunedin, New Zealand, in 1972–1973, at regular intervals from birth to age 26 years. We used regression analysis to investigate the associations between television viewing hours from ages 5 to 15 years and criminal convictions, violent convictions, diagnosis of antisocial personality disorder, and aggressive personality traits in early adulthood. RESULTS: Young adults who had spent more time watching television during childhood and adolescence were significantly more likely to have a criminal conviction, a diagnosis of antisocial personality disorder, and more aggressive personality traits compared with those who viewed less television. The associations were statistically significant after controlling for sex IQ, socioeconomic status, previous antisocial behavior, and parental control. The associations were similar for both sexes, indicating that the relationship between television viewing and antisocial behavior is similar for male and female viewers. CONCLUSIONS: Excessive television viewing in childhood and adolescence is associated with increased antisocial behavior in early adulthood. The findings are consistent with a causal association and support the American Academy of Pediatrics recommendation that children should watch no more than 1 to 2 hours of television each day. PMID:23420910
ERIC Educational Resources Information Center
Spires, Todd
2008-01-01
Soccer, or football as it is called in the rest of the world, is the most popular and fastest-growing global sport, with an estimated 240 million people regularly playing what Brazilian star Pele called "the beautiful game." Millions, worldwide, watch it on television. In 2006, the average viewership for each match of the month-long World Cup was…
Minimize Subjective Theory, Maximize Authentic Experience in the Teaching of French Civilization.
ERIC Educational Resources Information Center
Corredor, Eva L.
A program developed to teach French civilization and modern France at the U.S. Naval Academy (Annapolis, Maryland) was designed to take advantage of readily available, relatively sophisticated technology for classroom instruction. The hardware used includes a satellite earth station that receives regular television broadcasts from France, a…
NASA Astrophysics Data System (ADS)
Apiñaniz, Estibaliz; Mendioroz, Arantza; Salazar, Agustín; Celorrio, Ricardo
2010-09-01
We analyze the ability of the Tikhonov regularization to retrieve different shapes of in-depth thermal conductivity profiles, usually encountered in hardened materials, from surface temperature data. Exponential, oscillating, and sigmoidal profiles are studied. By performing theoretical experiments with added white noises, the influence of the order of the Tikhonov functional and of the parameters that need to be tuned to carry out the inversion are investigated. The analysis shows that the Tikhonov regularization is very well suited to reconstruct smooth profiles but fails when the conductivity exhibits steep slopes. We check a natural alternative regularization, the total variation functional, which gives much better results for sigmoidal profiles. Accordingly, a strategy to deal with real data is proposed in which we introduce this total variation regularization. This regularization is applied to the inversion of real data corresponding to a case hardened AISI1018 steel plate, giving much better anticorrelation of the retrieved conductivity with microindentation test data than the Tikhonov regularization. The results suggest that this is a promising way to improve the reliability of local inversion methods.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dong, Xue; Niu, Tianye; Zhu, Lei, E-mail: leizhu@gatech.edu
2014-05-15
Purpose: Dual-energy CT (DECT) is being increasingly used for its capability of material decomposition and energy-selective imaging. A generic problem of DECT, however, is that the decomposition process is unstable in the sense that the relative magnitude of decomposed signals is reduced due to signal cancellation while the image noise is accumulating from the two CT images of independent scans. Direct image decomposition, therefore, leads to severe degradation of signal-to-noise ratio on the resultant images. Existing noise suppression techniques are typically implemented in DECT with the procedures of reconstruction and decomposition performed independently, which do not explore the statistical propertiesmore » of decomposed images during the reconstruction for noise reduction. In this work, the authors propose an iterative approach that combines the reconstruction and the signal decomposition procedures to minimize the DECT image noise without noticeable loss of resolution. Methods: The proposed algorithm is formulated as an optimization problem, which balances the data fidelity and total variation of decomposed images in one framework, and the decomposition step is carried out iteratively together with reconstruction. The noise in the CT images from the proposed algorithm becomes well correlated even though the noise of the raw projections is independent on the two CT scans. Due to this feature, the proposed algorithm avoids noise accumulation during the decomposition process. The authors evaluate the method performance on noise suppression and spatial resolution using phantom studies and compare the algorithm with conventional denoising approaches as well as combined iterative reconstruction methods with different forms of regularization. Results: On the Catphan©600 phantom, the proposed method outperforms the existing denoising methods on preserving spatial resolution at the same level of noise suppression, i.e., a reduction of noise standard deviation by one order of magnitude. This improvement is mainly attributed to the high noise correlation in the CT images reconstructed by the proposed algorithm. Iterative reconstruction using different regularization, including quadratic orq-generalized Gaussian Markov random field regularization, achieves similar noise suppression from high noise correlation. However, the proposed TV regularization obtains a better edge preserving performance. Studies of electron density measurement also show that our method reduces the average estimation error from 9.5% to 7.1%. On the anthropomorphic head phantom, the proposed method suppresses the noise standard deviation of the decomposed images by a factor of ∼14 without blurring the fine structures in the sinus area. Conclusions: The authors propose a practical method for DECT imaging reconstruction, which combines the image reconstruction and material decomposition into one optimization framework. Compared to the existing approaches, our method achieves a superior performance on DECT imaging with respect to decomposition accuracy, noise reduction, and spatial resolution.« less
Borghese, Michael M; Tremblay, Mark S; Leduc, Genevieve; Boyer, Charles; Bélanger, Priscilla; LeBlanc, Allana G; Francis, Claire; Chaput, Jean-Philippe
2014-08-01
The relationships among sedentary time, television viewing time, and dietary patterns in children are not fully understood. The aim of this paper was to determine which of self-reported television viewing time or objectively measured sedentary time is a better correlate of the frequency of consumption of healthy and unhealthy foods. A cross-sectional study was conducted of 9- to 11-year-old children (n = 523; 57.1% female) from Ottawa, Ontario, Canada. Accelerometers were used to determine total sedentary time, and questionnaires were used to determine the number of hours of television watching and the frequency of consumption of foods per week. Television viewing was negatively associated with the frequency of consumption of fruits, vegetables, and green vegetables, and positively associated with the frequency of consumption of sweets, soft drinks, diet soft drinks, pastries, potato chips, French fries, fruit juices, ice cream, fried foods, and fast food. Except for diet soft drinks and fruit juices, these associations were independent of covariates, including sedentary time. Total sedentary time was negatively associated with the frequency of consumption of sports drinks, independent of covariates, including television viewing. In combined sedentary time and television viewing analyses, children watching >2 h of television per day consumed several unhealthy food items more frequently than did children watching ≤2 h of television, regardless of sedentary time. In conclusion, this paper provides evidence to suggest that television viewing time is more strongly associated with unhealthy dietary patterns than is total sedentary time. Future research should focus on reducing television viewing time, as a means of improving dietary patterns and potentially reducing childhood obesity.
Grauerholz, E; King, A
1997-04-01
This study explores the explicit and implicit messages of sexual harassment that viewers receive when viewing prime-time television in the US. A content analysis of 48 hours of prime-time television reveals that sexual harassment on television is both highly visible and invisible. Sexual harassment is rendered visible simply by its prominence in these programs. Incidents involving quid-pro-quo harassment and environmental harassment occur with regularity on television. Furthermore, about 84% of the shows studied contained at least one incident of sexual harassment; yet these acts of sexual harassment remained largely invisible because none of the behaviors were labeled as sexual harassment. These incidents are presented in humorous ways, and victims are generally unharmed and very effective at ending the harassment. Although such programs may actually reflect the reality of many women's lives in terms of prevalence of sexual harassment, they perpetuate several myths about sexual harassment, such as that sexual harassment is not serious and that victims should be able to handle the situations themselves.
ERIC Educational Resources Information Center
Powell, R. J.
Television viewing habits of 12 to 14 year olds in Australia were studied, and an attempt was made to correlate amount of viewing time and choice of programs with these children's intelligence and personality. Average viewing time per night was three hours and 40 minutes. A large variation was found in the time at which children ceased viewing.…
A note on convergence of solutions of total variation regularized linear inverse problems
NASA Astrophysics Data System (ADS)
Iglesias, José A.; Mercier, Gwenael; Scherzer, Otmar
2018-05-01
In a recent paper by Chambolle et al (2017 Inverse Problems 33 015002) it was proven that if the subgradient of the total variation at the noise free data is not empty, the level-sets of the total variation denoised solutions converge to the level-sets of the noise free data with respect to the Hausdorff distance. The condition on the subgradient corresponds to the source condition introduced by Burger and Osher (2007 Multiscale Model. Simul. 6 365–95), who proved convergence rates results with respect to the Bregman distance under this condition. We generalize the result of Chambolle et al to total variation regularization of general linear inverse problems under such a source condition. As particular applications we present denoising in bounded and unbounded, convex and non convex domains, deblurring and inversion of the circular Radon transform. In all these examples the convergence result applies. Moreover, we illustrate the convergence behavior through numerical examples.
Jodkowska, Maria; Tabak, Izabela; Oblacińska, Anna; Stalmach, Magdalena
2013-01-01
1. To estimate the time spent in sedentary behaviour (watching TV, using the computer, doing homework). 2. To assess the link between the total time spent on watching TV, using the computer, doing homework and dietary habits, physical activity, parental practices and body mass. Cross-sectional study was conducted in Poland in 2008 among 13-year olds (n=600). They self-reported their time of TV viewing, computer use and homework. Their dietary behaviours, physical activity (MVPA) and parenting practices were also self-reported. Height and weight were measured by school nurses. Descriptive statistics and correlation were used in this analysis. The mean time spent watching television in school days was 2.3 hours for girls and 2.2 for boys. Boys spent significantly more time using the computer than girls - respectively 1.8 and 1.5 hours, while girls took longer doing homework - respectively 1.7 and 1.3 hours. Mean screen time was about 4 hours in school days and about 6 hours during weekend, statistically longer for boys in weekdays. Screen time was positively associated with intake of sweets, chips, soft drinks, "fast food" and meals consumption during TV, and negatively with regularity of meals and parental supervision. There was no correlation between screen time with physical activity and body mass. Sedentary behaviours and physical activity are not competing behaviours in Polish teenagers, but their relationship with unhealthy dietary patterns may lead to development of obesity. Good parental practices, both mother's and father's supervision seems to be crucial for screen time limitation in their children. Parents should become aware that relevant lifestyle monitoring of their children is a crucial element of health education in prevention of civilization diseases. This is a task for both healthcare workers and educational staff.
Symbolic Capital in a Virtual Heterosexual Market: Abbreviation and Insertion in Italian iTV SMS
ERIC Educational Resources Information Center
Herring, Susan C.; Zelenkauskaite, Asta
2009-01-01
This study analyzes gender variation in nonstandard typography--specifically, abbreviations and insertions--in mobile phone text messages (SMS) posted to a public Italian interactive television (iTV) program. All broadcast SMS were collected for a period of 2 days from the Web archive for the iTV program, and the frequency and distribution of…
Nielsen Television '73; A Look at the Medium.
ERIC Educational Resources Information Center
Nielsen (A.C.) Co., Chicago, IL.
The latest (1973) edition of Nielsen Television presents data on the television audience. Major findings are graphically summarized and data are presented for: number of stations receivable by household; households equipped with TV sets; United States TV households with color television; total United States households using television by time of…
Moving People from Science Adjacent to Science Doers with Twitch.tv
NASA Astrophysics Data System (ADS)
Gay, Pamela L.; CosmoQuest
2017-10-01
The CosmoQuest community is testing the ability to attract people from playing online videogames to doing fully online citizen science by engaging people through the Twitch.tv streaming platform. Twitch.tv launched in 2011 as an online platform for video gamers to stream their gameplay while providing narrative. In its six years of regular growth, the platform has added support for people playing non-video games, and for those participating in non-game activities. As part of their expansion, in April 2017, Twitch.tv hosted a science week during which they streamed the Cosmos series and allowed different feeds provide real-time commentary. They also hosted panel discussions on a variety of science topics. CosmoQuest participated in this event and used it as a jumping off point for beginning to interact with Twitch.tv community members online. With CosmoQuest’s beta launch of Image Detectives, they expanded their use of this streaming platform to include regular “office hours”, during which team members did science with CosmoQuest’s online projects, took questions from community members, and otherwise promoted the CosmoQuest community. This presentation examines this case study, and looks at how well different kinds of Twitter engagements attracted audiences, the conversion rate from viewer to subscriber, and at how effectively CosmoQuest was able to migrate users from viewing citizen science on Twitch.tv to participating in citizen science on CosmoQuest.org.This project was supported through NASA cooperative agreement NNX17AD20A.
Sharing the Good News: A Rural Approach to Publicizing Community College Library Services.
ERIC Educational Resources Information Center
Rothlisberg, Allen P.
The Northland Pioneer College (NPC) Library staff has developed a media blitz strategy to publicize its services in rural Arizona. This strategy regularly draws upon a database of newspapers, radio stations, and cable television outlets in the area. Each week a different public service announcement is developed and sent out to agencies on the…
How To Be Stupid: The Teachings of Channel One.
ERIC Educational Resources Information Center
Miller, Mark Crispin
The news on Channel One, with its impression of vague anxiety, looks and sounds like regular television news, only more so. In either case, the news is just "filler"--its real function is not journalistic but commercial, meant to lead into advertisements (ads). Mass advertising tends to assume that its audience will not be studying it…
Students Enrolled in the TV College, General Extension Division Fall 1965.
ERIC Educational Resources Information Center
Stecklein, John E.; And Others
In 1964 the University of Minnesota initiated a three-year TV College as an experiment in offering courses to more freshmen and sophomores without compromising quality. The four courses offered in 1964 and the nine in 1965 were taught by regular University faculty and carried full resident credit. They were supplemented by weekly discussion…
The Gratifications of Grazing: Why Flippers Flip.
ERIC Educational Resources Information Center
Walker, James R.; Bellamy, Robert V., Jr.
An exploratory study focused on usage patterns of television remote control devices (RCDs), examining how and why individuals use television RCDs to "graze." The study identified the gratifications obtained from RCD use and evaluated their relative importance in accounting for variations in RCD use. Subjects were 455 undergraduates in…
Image Reconstruction from Under sampled Fourier Data Using the Polynomial Annihilation Transform
DOE Office of Scientific and Technical Information (OSTI.GOV)
Archibald, Richard K.; Gelb, Anne; Platte, Rodrigo
Fourier samples are collected in a variety of applications including magnetic resonance imaging and synthetic aperture radar. The data are typically under-sampled and noisy. In recent years, l 1 regularization has received considerable attention in designing image reconstruction algorithms from under-sampled and noisy Fourier data. The underlying image is assumed to have some sparsity features, that is, some measurable features of the image have sparse representation. The reconstruction algorithm is typically designed to solve a convex optimization problem, which consists of a fidelity term penalized by one or more l 1 regularization terms. The Split Bregman Algorithm provides a fastmore » explicit solution for the case when TV is used for the l1l1 regularization terms. Due to its numerical efficiency, it has been widely adopted for a variety of applications. A well known drawback in using TV as an l 1 regularization term is that the reconstructed image will tend to default to a piecewise constant image. This issue has been addressed in several ways. Recently, the polynomial annihilation edge detection method was used to generate a higher order sparsifying transform, and was coined the “polynomial annihilation (PA) transform.” This paper adapts the Split Bregman Algorithm for the case when the PA transform is used as the l 1 regularization term. In so doing, we achieve a more accurate image reconstruction method from under-sampled and noisy Fourier data. Our new method compares favorably to the TV Split Bregman Algorithm, as well as to the popular TGV combined with shearlet approach.« less
Evaluation of social marketing of oral rehydration therapy.
Koul, P B; Murali, M V; Gupta, P; Sharma, P P
1991-09-01
Attempts, at social marketing of oral rehydration therapy (ORT) through television, in changing the knowledge and practice of mothers with regard to its use was assessed. One hundred and eighty seven consecutive mothers (38 excluded due to non use of ORT) were administered a preplanned questionnaire to assess their socio-economic profile, educational status, concept of diarrhea and correct use of ORT. Fifty nine mothers who watched these programmes on TV regularly formed the study group. These were compared with 90 mothers who had gained such knowledge from non-television sources. The correct application of knowledge of ORT was significantly better in study group compared with control group. The educational status of mothers had a positive impact on motivation to use ORT at home in the study group. Mass media campaigns through "TV spots" is an effective way of improving knowledge of mothers on ORT in a developing country.
Confessions of an Accidental E/POnomer, from in Front of the Camera and Behind the Pixels
NASA Astrophysics Data System (ADS)
Durda, Daniel D.
2015-11-01
The various techniques, styles, and venues for popularizing the research outputs from our planetary science community reflect the diversity of the community itself. While some are eloquent public speakers or gifted writers, other colleagues are regularly sought for television appearances or for artwork to illustrate press releases. Whatever the method or medium, the collection of experiences we have had in ‘getting the word out’ represents a valuable resource pool of ideas and lessons learned from which we can all learn and improve. I will share some of my experiences from working with a number of television productions and magazine editors, with some thoughts on contemporary television production styles. I will also discuss life as both a planetary scientist and digital artist and share some resources that are ready, willing, and quite able to help tell the visual story of your research.
The medical geochemistry of dusts, soils, and other Earth materials: Chapter 7
Plumlee, Geoffrey S.; Ziegler, Thomas L.
2003-01-01
A quick scan of newspapers, television, science magazines, or the internet on any given day has a fairly high likelihood of encountering stories (accompanied by headlines such as those above) regarding human health concerns linked to dusts, soils, or other Earth materials. Many such concerns have been recognized and studied for decades, but new concerns arise regularly.
ERIC Educational Resources Information Center
Gold, Alexandra
2016-01-01
When Alexandra Gold described her composition course: one that situates feminist and queer theory as a lens through which to view, analyze, and discuss contemporary television, a male acquaintance responded by saying he would not pay for that class. Another female acquaintance assured Gold that although she had loved a similar class at her Ivy…
Villani, A M; Egan, T; Keogh, J B; Clifton, P M
2015-08-01
There is evidence suggesting that the nutritional content of recipes promoted by celebrity chefs or television cooking programmes contradict healthy eating guidelines. This study aims to investigate people's attitudes and beliefs about popular television cooking programmes and celebrity chefs. Males and females who watch television cooking programmes were recruited to participate in a self-administered online questionnaire (22-items) which included multiple-choice and rank order questions. A total of n = 207 participants undertook the questionnaire with fully completed questionnaires available for n = 150 participants (Males, n = 22; Females, n = 128; aged 38.4 ± 14 years). The majority of respondents watch ≤30 minutes of television cooking programming per day (total responses, n = 153/207; 74%) with almost three-quarters (total responses, n = 130/175; 74%) having attempted a recipe. New cooking ideas (total responses, n = 81/175; 46%) and entertainment (total responses, n = 64/175; 36.5%) were the two main reasons participants gave for watching these programmes. Significantly more respondents believed recipes use excessive amounts of unhealthy fat, sugar or salt (unhealthy: 24%; healthy: 7%; P < 0.0001). Almost half of all respondents (total responses, n = 67/151; 44%) believed these programmes have no impact on their habitual diet. Our results suggest television cooking programmes and celebrity chefs are unlikely to impact habitual dietary intake; rather, vicarious viewing and entertainment appear important factors relating to why people watch these programmes. However results generated from the present study are descriptive and subjective and further investigation into the impact of television cooking programmes and celebrity chefs on behavioural change requires attention. Further investigation including a systematic investigation into the dietary quality of recipes promoted by celebrity chefs against national healthy eating benchmarks is also warranted. Copyright © 2015 Elsevier Ltd. All rights reserved.
Kanda, Hideyuki; Okamura, Tomonori; Turin, Tanvir Chowdhury; Hayakawa, Takehito; Kadowaki, Takashi; Ueshima, Hirotsugu
2006-06-01
Japanese serial television dramas are becoming very popular overseas, particularly in other Asian countries. Exposure to smoking scenes in movies and television dramas has been known to trigger initiation of habitual smoking in young people. Smoking scenes in Japanese dramas may affect the smoking behavior of many young Asians. We examined smoking scenes and smoking-related items in serial television dramas targeting young audiences in Japan during the same season in two consecutive years. Fourteen television dramas targeting the young audience broadcast between July and September in 2001 and 2002 were analyzed. A total of 136 h 42 min of television programs were divided into unit scenes of 3 min (a total of 2734 unit scenes). All the unit scenes were reviewed for smoking scenes and smoking-related items. Of the 2734 3-min unit scenes, 205 (7.5%) were actual smoking scenes and 387 (14.2%) depicted smoking environments with the presence of smoking-related items, such as ash trays. In 185 unit scenes (90.2% of total smoking scenes), actors were shown smoking. Actresses were less frequently shown smoking (9.8% of total smoking scenes). Smoking characters in dramas were in the 20-49 age group in 193 unit scenes (94.1% of total smoking scenes). In 96 unit scenes (46.8% of total smoking scenes), at least one non-smoker was present in the smoking scenes. The smoking locations were mainly indoors, including offices, restaurants and homes (122 unit scenes, 59.6%). The most common smoking-related items shown were ash trays (in 45.5% of smoking-item-related scenes) and cigarettes (in 30.2% of smoking-item-related scenes). Only 3 unit scenes (0.1 % of all scenes) promoted smoking prohibition. This was a descriptive study to examine the nature of smoking scenes observed in Japanese television dramas from a public health perspective.
Adaptive regularization of the NL-means: application to image and video denoising.
Sutour, Camille; Deledalle, Charles-Alban; Aujol, Jean-François
2014-08-01
Image denoising is a central problem in image processing and it is often a necessary step prior to higher level analysis such as segmentation, reconstruction, or super-resolution. The nonlocal means (NL-means) perform denoising by exploiting the natural redundancy of patterns inside an image; they perform a weighted average of pixels whose neighborhoods (patches) are close to each other. This reduces significantly the noise while preserving most of the image content. While it performs well on flat areas and textures, it suffers from two opposite drawbacks: it might over-smooth low-contrasted areas or leave a residual noise around edges and singular structures. Denoising can also be performed by total variation minimization-the Rudin, Osher and Fatemi model-which leads to restore regular images, but it is prone to over-smooth textures, staircasing effects, and contrast losses. We introduce in this paper a variational approach that corrects the over-smoothing and reduces the residual noise of the NL-means by adaptively regularizing nonlocal methods with the total variation. The proposed regularized NL-means algorithm combines these methods and reduces both of their respective defaults by minimizing an adaptive total variation with a nonlocal data fidelity term. Besides, this model adapts to different noise statistics and a fast solution can be obtained in the general case of the exponential family. We develop this model for image denoising and we adapt it to video denoising with 3D patches.
Use of consumer survey data to target cessation messages to smokers through mass media.
Nelson, David E; Gallogly, Meg; Pederson, Linda L; Barry, Matthew; McGoldrick, Daniel; Maibach, Edward W
2008-03-01
We identified the mass media channels that reach the most cigarette smokers in an attempt to more effectively target smoking cessation messages. Reach estimates and index scores for smokers were taken from 2002-2003 ConsumerStyles and HealthStyles national surveys of adults (N=11660) to estimate overall and demographic-specific exposure measures for television, radio, newspapers, and magazines. Smokers viewed more television, listened to more radio, and read fewer magazines and newspapers than did nonsmokers. Nearly one third of smokers were regular daytime or late-night television viewers. Selected cable television networks (USA, Lifetime, and Discovery Channel) and selected radio genres, such as classic rock and country, had high reach and were cost-efficient channels for targeting smokers. Certain mass media channels offer efficient opportunities to target smoking cessation messages so they reach relatively large audiences of smokers at relatively low cost. The approach used in this study can be applied to other types of health risk factors to improve health communication planning and increase efficiency of program media expenditures.
Brzozowska, Inga; Sikorska, Iwona
2016-01-01
The literature review regarding potential effects of screen media on cognitive development among children under 3 years old, is presented. In this article, cognitive aspects of development include acquisition of language, attention, learning and later school performance. The constant increase of children's access to television is noted, indicating that 60% of infants and toddlers watch TV regularly for 1-2 hours per day. The review included 40 articles and book chapters of significant such as Anderson, Barr, Christakis, Zimmerman, Meltzoff, Courage, Setliff, Troseth. The data was selected from electronic databases of scientific publications: Psychology & Behavioral Sciences Collection, Social Sciences Full Text (H.W. Wilson) and Humanities Full Text (H.W. Wilson) available in Poland. Cited articles provide evidence of the negative impact of exposure to television, media and video on the cognitive functioning of children under 3 years old. The potential impact of watching TV for difficulties in ability to focus attention appears as a core danger. Furthermore, studies suggest a possible connection between early exposure to television and ADHD as well as difficulties with language acquisition, learning and poorer school results.
Dixon, Helen G; Scully, Maree L; Wakefield, Melanie A; White, Victoria M; Crawford, David A
2007-10-01
Television (TV) food advertising has attracted criticism for its potential role in promoting unhealthy dietary practices among children. Content analyses indicate junk food advertising is prevalent on Australian children's TV; healthy eating is rarely promoted. This paper presents (a) a cross-sectional survey examining associations between children's regular TV viewing habits and their food-related attitudes and behaviour; and (b) an experiment assessing the impact of varying combinations of TV advertisements (ads) for unhealthy and healthy foods on children's dietary knowledge, attitudes and intentions. The experimental conditions simulated possible models for regulating food ads on children's TV. Participants were 919 grade five and six students from schools in Melbourne, Australia. The survey showed that heavier TV use and more frequent commercial TV viewing were independently associated with more positive attitudes toward junk food; heavier TV use was also independently associated with higher reported junk food consumption. The experiment found that ads for nutritious foods promote selected positive attitudes and beliefs concerning these foods. Findings are discussed in light of methodological issues in media effects research and their implications for policy and practice. It is concluded that changing the food advertising environment on children's TV to one where nutritious foods are promoted and junk foods are relatively unrepresented would help to normalize and reinforce healthy eating.
New second order Mumford-Shah model based on Γ-convergence approximation for image processing
NASA Astrophysics Data System (ADS)
Duan, Jinming; Lu, Wenqi; Pan, Zhenkuan; Bai, Li
2016-05-01
In this paper, a second order variational model named the Mumford-Shah total generalized variation (MSTGV) is proposed for simultaneously image denoising and segmentation, which combines the original Γ-convergence approximated Mumford-Shah model with the second order total generalized variation (TGV). For image denoising, the proposed MSTGV can eliminate both the staircase artefact associated with the first order total variation and the edge blurring effect associated with the quadratic H1 regularization or the second order bounded Hessian regularization. For image segmentation, the MSTGV can obtain clear and continuous boundaries of objects in the image. To improve computational efficiency, the implementation of the MSTGV does not directly solve its high order nonlinear partial differential equations and instead exploits the efficient split Bregman algorithm. The algorithm benefits from the fast Fourier transform, analytical generalized soft thresholding equation, and Gauss-Seidel iteration. Extensive experiments are conducted to demonstrate the effectiveness and efficiency of the proposed model.
Michielsen, Koen; Nuyts, Johan; Cockmartin, Lesley; Marshall, Nicholas; Bosmans, Hilde
2016-12-01
In this work, the authors design and validate a model observer that can detect groups of microcalcifications in a four-alternative forced choice experiment and use it to optimize a smoothing prior for detectability of microcalcifications. A channelized Hotelling observer (CHO) with eight Laguerre-Gauss channels was designed to detect groups of five microcalcifications in a background of acrylic spheres by adding the CHO log-likelihood ratios calculated at the expected locations of the five calcifications. This model observer is then applied to optimize the detectability of the microcalcifications as a function of the smoothing prior. The authors examine the quadratic and total variation (TV) priors, and a combination of both. A selection of these reconstructions was then evaluated by human observers to validate the correct working of the model observer. The authors found a clear maximum for the detectability of microcalcification when using the total variation prior with weight β TV = 35. Detectability only varied over a small range for the quadratic and combined quadratic-TV priors when weight β Q of the quadratic prior was changed by two orders of magnitude. Spearman correlation with human observers was good except for the highest value of β for the quadratic and TV priors. Excluding those, the authors found ρ = 0.93 when comparing detection fractions, and ρ = 0.86 for the fitted detection threshold diameter. The authors successfully designed a model observer that was able to predict human performance over a large range of settings of the smoothing prior, except for the highest values of β which were outside the useful range for good image quality. Since detectability only depends weakly on the strength of the combined prior, it is not possible to pick an optimal smoothness based only on this criterion. On the other hand, such choice can now be made based on other criteria without worrying about calcification detectability.
ERIC Educational Resources Information Center
Gatti, Bernardete A.
1988-01-01
Yearly in Sao Paulo (Brazil), official external examinations allow students outside the regular school system to obtain a certificate of education equivalent to grade 8 or 11. A television program that prepares candidates for the examinations and other forms of preparation are compared, using data collected for three years. (TJH)
Farrelly, Matthew C; Davis, Kevin C; Nonnemaker, James M; Kamyab, Kian; Jackson, Christine
2011-07-01
To understand the relative effectiveness of television advertisements that differ in their thematic focus and portrayals of negative emotions and/or graphic images in promoting calls to a smokers' quitline. Regression analysis is used to explain variation in quarterly media market-level per smoker calls to the New York State Smokers' Quitline from 2001 to 2009. The primary independent variable is quarterly market-level delivery of television advertisements measured by target audience rating points (TARPs). Advertisements were characterised by their overall objective--promoting cessation, highlighting the dangers of secondhand smoke (SHS) or other--and by their portrayals of strong negative emotions and graphic images. Per smoker call volume is positively correlated with total TARPs (p<0.001), and cessation advertisements are more effective than SHS advertisements in promoting quitline call volume. Advertisements with graphic images only or neither strong negative emotions nor graphic images are associated with higher call volume with similar effect sizes. Call volume was not significantly associated with the number of TARPs for advertisements with strong negative emotions only (p=0.71) or with both graphic images and strong emotions (p=0.09). Exposure to television advertisements is strongly associated with quitline call volume, and both cessation and SHS advertisements can be effective. The use of strong negative emotions in advertisements may be effective in promoting smoking cessation in the population but does not appear to influence quitline call volume. Further research is needed to understand the role of negative emotions in promoting calls to quitlines and cessation more broadly among the majority of smokers who do not call quitlines.
Sparsity-based acoustic inversion in cross-sectional multiscale optoacoustic imaging
DOE Office of Scientific and Technical Information (OSTI.GOV)
Han, Yiyong; Tzoumas, Stratis; Nunes, Antonio
2015-09-15
Purpose: With recent advancement in hardware of optoacoustic imaging systems, highly detailed cross-sectional images may be acquired at a single laser shot, thus eliminating motion artifacts. Nonetheless, other sources of artifacts remain due to signal distortion or out-of-plane signals. The purpose of image reconstruction algorithms is to obtain the most accurate images from noisy, distorted projection data. Methods: In this paper, the authors use the model-based approach for acoustic inversion, combined with a sparsity-based inversion procedure. Specifically, a cost function is used that includes the L1 norm of the image in sparse representation and a total variation (TV) term. Themore » optimization problem is solved by a numerically efficient implementation of a nonlinear gradient descent algorithm. TV–L1 model-based inversion is tested in the cross section geometry for numerically generated data as well as for in vivo experimental data from an adult mouse. Results: In all cases, model-based TV–L1 inversion showed a better performance over the conventional Tikhonov regularization, TV inversion, and L1 inversion. In the numerical examples, the images reconstructed with TV–L1 inversion were quantitatively more similar to the originating images. In the experimental examples, TV–L1 inversion yielded sharper images and weaker streak artifact. Conclusions: The results herein show that TV–L1 inversion is capable of improving the quality of highly detailed, multiscale optoacoustic images obtained in vivo using cross-sectional imaging systems. As a result of its high fidelity, model-based TV–L1 inversion may be considered as the new standard for image reconstruction in cross-sectional imaging.« less
Zeng, Dong; Gong, Changfei; Bian, Zhaoying; Huang, Jing; Zhang, Xinyu; Zhang, Hua; Lu, Lijun; Niu, Shanzhou; Zhang, Zhang; Liang, Zhengrong; Feng, Qianjin; Chen, Wufan; Ma, Jianhua
2016-11-21
Dynamic myocardial perfusion computed tomography (MPCT) is a promising technique for quick diagnosis and risk stratification of coronary artery disease. However, one major drawback of dynamic MPCT imaging is the heavy radiation dose to patients due to its dynamic image acquisition protocol. In this work, to address this issue, we present a robust dynamic MPCT deconvolution algorithm via adaptive-weighted tensor total variation (AwTTV) regularization for accurate residue function estimation with low-mA s data acquisitions. For simplicity, the presented method is termed 'MPD-AwTTV'. More specifically, the gains of the AwTTV regularization over the original tensor total variation regularization are from the anisotropic edge property of the sequential MPCT images. To minimize the associative objective function we propose an efficient iterative optimization strategy with fast convergence rate in the framework of an iterative shrinkage/thresholding algorithm. We validate and evaluate the presented algorithm using both digital XCAT phantom and preclinical porcine data. The preliminary experimental results have demonstrated that the presented MPD-AwTTV deconvolution algorithm can achieve remarkable gains in noise-induced artifact suppression, edge detail preservation, and accurate flow-scaled residue function and MPHM estimation as compared with the other existing deconvolution algorithms in digital phantom studies, and similar gains can be obtained in the porcine data experiment.
NASA Astrophysics Data System (ADS)
Zeng, Dong; Gong, Changfei; Bian, Zhaoying; Huang, Jing; Zhang, Xinyu; Zhang, Hua; Lu, Lijun; Niu, Shanzhou; Zhang, Zhang; Liang, Zhengrong; Feng, Qianjin; Chen, Wufan; Ma, Jianhua
2016-11-01
Dynamic myocardial perfusion computed tomography (MPCT) is a promising technique for quick diagnosis and risk stratification of coronary artery disease. However, one major drawback of dynamic MPCT imaging is the heavy radiation dose to patients due to its dynamic image acquisition protocol. In this work, to address this issue, we present a robust dynamic MPCT deconvolution algorithm via adaptive-weighted tensor total variation (AwTTV) regularization for accurate residue function estimation with low-mA s data acquisitions. For simplicity, the presented method is termed ‘MPD-AwTTV’. More specifically, the gains of the AwTTV regularization over the original tensor total variation regularization are from the anisotropic edge property of the sequential MPCT images. To minimize the associative objective function we propose an efficient iterative optimization strategy with fast convergence rate in the framework of an iterative shrinkage/thresholding algorithm. We validate and evaluate the presented algorithm using both digital XCAT phantom and preclinical porcine data. The preliminary experimental results have demonstrated that the presented MPD-AwTTV deconvolution algorithm can achieve remarkable gains in noise-induced artifact suppression, edge detail preservation, and accurate flow-scaled residue function and MPHM estimation as compared with the other existing deconvolution algorithms in digital phantom studies, and similar gains can be obtained in the porcine data experiment.
Proceedings of the Symposium on Cable Television.
ERIC Educational Resources Information Center
Society of Motion Picture and Television Engineers, Inc., New York, NY.
The papers given at a symposium on cable television (CATV) are collected in this volume. The chairman of the symposium notes that "the phrase 'cable television' is not totally pertinent since we are talking about a wired-city concept that may encompass many services other than television." He prefers the term "broadband communications network,"…
Powell, Lisa M; Szczypka, Glen; Chaloupka, Frank J
2010-09-01
To examine the trends in food advertising seen by American children and adolescents. Trend analysis of children's and adolescents' exposure to food advertising in 2003, 2005, and 2007, including separate analyses by race. Children aged 2 to 5 years and 6 to 11 years and adolescents aged 12 to 17 years. Television ratings. Exposure to total food advertising and advertising by food category. Between 2003 and 2007 daily average exposure to food ads fell by 13.7% and 3.7% among young children aged 2 to 5 and 6 to 11 years, respectively, but increased by 3.7% among adolescents aged 12 to 17 years. Exposure to sweets ads fell 41%, 29.3%, and 12.1%, respectively, for 2- to 5-, 6- to 11-, and 12- to 17-year-olds and beverage ads were down by about 27% to 30% across these age groups, with substantial decreases in exposure to ads for the most heavily advertised sugar-sweetened beverages-fruit drinks and regular soft drinks. Exposure to fast food ads increased by 4.7%, 12.2%, and 20.4% among children aged 2 to 5, 6 to 11, and 12 to 17 years, respectively, between 2003 and 2007. The racial gap in exposure to food advertising grew between 2003 and 2007, particularly for fast food ads. A number of positive changes have occurred in children's exposure to food advertising. Continued monitoring of food advertising exposure along with nutritional analyses is needed to further assess self-regulatory pledges.
Investigation of cone-beam CT image quality trade-off for image-guided radiation therapy
NASA Astrophysics Data System (ADS)
Bian, Junguo; Sharp, Gregory C.; Park, Yang-Kyun; Ouyang, Jinsong; Bortfeld, Thomas; El Fakhri, Georges
2016-05-01
It is well-known that projections acquired over an angular range slightly over 180° (so-called short scan) are sufficient for fan-beam reconstruction. However, due to practical imaging conditions (projection data and reconstruction image discretization, physical factors, and data noise), the short-scan reconstructions may have different appearances and properties from the full-scan (scans over 360°) reconstructions. Nevertheless, short-scan configurations have been used in applications such as cone-beam CT (CBCT) for head-neck-cancer image-guided radiation therapy (IGRT) that only requires a small field of view due to the potential reduced imaging time and dose. In this work, we studied the image quality trade-off for full, short, and full/short scan configurations with both conventional filtered-backprojection (FBP) reconstruction and iterative reconstruction algorithms based on total-variation (TV) minimization for head-neck-cancer IGRT. Anthropomorphic and Catphan phantoms were scanned at different exposure levels with a clinical scanner used in IGRT. Both visualization- and numerical-metric-based evaluation studies were performed. The results indicate that the optimal exposure level and number of views are in the middle range for both FBP and TV-based iterative algorithms and the optimization is object-dependent and task-dependent. The optimal view numbers decrease with the total exposure levels for both FBP and TV-based algorithms. The results also indicate there are slight differences between FBP and TV-based iterative algorithms for the image quality trade-off: FBP seems to be more in favor of larger number of views while the TV-based algorithm is more robust to different data conditions (number of views and exposure levels) than the FBP algorithm. The studies can provide a general guideline for image-quality optimization for CBCT used in IGRT and other applications.
Investigation of cone-beam CT image quality trade-off for image-guided radiation therapy.
Bian, Junguo; Sharp, Gregory C; Park, Yang-Kyun; Ouyang, Jinsong; Bortfeld, Thomas; El Fakhri, Georges
2016-05-07
It is well-known that projections acquired over an angular range slightly over 180° (so-called short scan) are sufficient for fan-beam reconstruction. However, due to practical imaging conditions (projection data and reconstruction image discretization, physical factors, and data noise), the short-scan reconstructions may have different appearances and properties from the full-scan (scans over 360°) reconstructions. Nevertheless, short-scan configurations have been used in applications such as cone-beam CT (CBCT) for head-neck-cancer image-guided radiation therapy (IGRT) that only requires a small field of view due to the potential reduced imaging time and dose. In this work, we studied the image quality trade-off for full, short, and full/short scan configurations with both conventional filtered-backprojection (FBP) reconstruction and iterative reconstruction algorithms based on total-variation (TV) minimization for head-neck-cancer IGRT. Anthropomorphic and Catphan phantoms were scanned at different exposure levels with a clinical scanner used in IGRT. Both visualization- and numerical-metric-based evaluation studies were performed. The results indicate that the optimal exposure level and number of views are in the middle range for both FBP and TV-based iterative algorithms and the optimization is object-dependent and task-dependent. The optimal view numbers decrease with the total exposure levels for both FBP and TV-based algorithms. The results also indicate there are slight differences between FBP and TV-based iterative algorithms for the image quality trade-off: FBP seems to be more in favor of larger number of views while the TV-based algorithm is more robust to different data conditions (number of views and exposure levels) than the FBP algorithm. The studies can provide a general guideline for image-quality optimization for CBCT used in IGRT and other applications.
Correction of aeroheating-induced intensity nonuniformity in infrared images
NASA Astrophysics Data System (ADS)
Liu, Li; Yan, Luxin; Zhao, Hui; Dai, Xiaobing; Zhang, Tianxu
2016-05-01
Aeroheating-induced intensity nonuniformity effects severely influence the effective performance of an infrared (IR) imaging system in high-speed flight. In this paper, we propose a new approach to the correction of intensity nonuniformity in IR images. The basic assumption is that the low-frequency intensity bias is additive and smoothly varying so that it can be modeled as a bivariate polynomial and estimated by using an isotropic total variation (TV) model. A half quadratic penalty method is applied to the isotropic form of TV discretization. And an alternating minimization algorithm is adopted for solving the optimization model. The experimental results of simulated and real aerothermal images show that the proposed correction method can effectively improve IR image quality.
NASA Astrophysics Data System (ADS)
Schuster, Thomas; Hofmann, Bernd; Kaltenbacher, Barbara
2012-10-01
Inverse problems can usually be modelled as operator equations in infinite-dimensional spaces with a forward operator acting between Hilbert or Banach spaces—a formulation which quite often also serves as the basis for defining and analyzing solution methods. The additional amount of structure and geometric interpretability provided by the concept of an inner product has rendered these methods amenable to a convergence analysis, a fact which has led to a rigorous and comprehensive study of regularization methods in Hilbert spaces over the last three decades. However, for numerous problems such as x-ray diffractometry, certain inverse scattering problems and a number of parameter identification problems in PDEs, the reasons for using a Hilbert space setting seem to be based on conventions rather than an appropriate and realistic model choice, so often a Banach space setting would be closer to reality. Furthermore, non-Hilbertian regularization and data fidelity terms incorporating a priori information on solution and noise, such as general Lp-norms, TV-type norms, or the Kullback-Leibler divergence, have recently become very popular. These facts have motivated intensive investigations on regularization methods in Banach spaces, a topic which has emerged as a highly active research field within the area of inverse problems. Meanwhile some of the most well-known regularization approaches, such as Tikhonov-type methods requiring the solution of extremal problems, and iterative ones like the Landweber method, the Gauss-Newton method, as well as the approximate inverse method, have been investigated for linear and nonlinear operator equations in Banach spaces. Convergence with rates has been proven and conditions on the solution smoothness and on the structure of nonlinearity have been formulated. Still, beyond the existing results a large number of challenging open questions have arisen, due to the more involved handling of general Banach spaces and the larger variety of concrete instances with special properties. The aim of this special section is to provide a forum for highly topical ongoing work in the area of regularization in Banach spaces, its numerics and its applications. Indeed, we have been lucky enough to obtain a number of excellent papers both from colleagues who have previously been contributing to this topic and from researchers entering the field due to its relevance in practical inverse problems. We would like to thank all contributers for enabling us to present a high quality collection of papers on topics ranging from various aspects of regularization via efficient numerical solution to applications in PDE models. We give a brief overview of the contributions included in this issue (here ordered alphabetically by first author). In their paper, Iterative regularization with general penalty term—theory and application to L1 and TV regularization, Radu Bot and Torsten Hein provide an extension of the Landweber iteration for linear operator equations in Banach space to general operators in place of the inverse duality mapping, which corresponds to the use of general regularization functionals in variational regularization. The L∞ topology in data space corresponds to the frequently occuring situation of uniformly distributed data noise. A numerically efficient solution of the resulting Tikhonov regularization problem via a Moreau-Yosida appriximation and a semismooth Newton method, along with a δ-free regularization parameter choice rule, is the topic of the paper L∞ fitting for inverse problems with uniform noise by Christian Clason. Extension of convergence rates results from classical source conditions to their generalization via variational inequalities with a priori and a posteriori stopping rules is the main contribution of the paper Regularization of linear ill-posed problems by the augmented Lagrangian method and variational inequalities by Klaus Frick and Markus Grasmair, again in the context of some iterative method. A powerful tool for proving convergence rates of Tikhonov type but also other regularization methods in Banach spaces are assumptions of the type of variational inequalities that combine conditions on solution smoothness (i.e., source conditions in the Hilbert space case) and nonlinearity of the forward operator. In Parameter choice in Banach space regularization under variational inequalities, Bernd Hofmann and Peter Mathé provide results with general error measures and especially study the question of regularization parameter choice. Daijun Jiang, Hui Feng, and Jun Zou consider an application of Banach space ideas in the context of an application problem in their paper Convergence rates of Tikhonov regularizations for parameter identifiation in a parabolic-elliptic system, namely the identification of a distributed diffusion coefficient in a coupled elliptic-parabolic system. In particular, they show convergence rates of Lp-H1 (variational) regularization for the application under consideration via the use and verification of certain source and nonlinearity conditions. In computational practice, the Lp norm with p close to one is often used as a substitute for the actually sparsity promoting L1 norm. In Norm sensitivity of sparsity regularization with respect to p, Kamil S Kazimierski, Peter Maass and Robin Strehlow consider the question of how sensitive the Tikhonov regularized solution is with respect to p. They do so by computing the derivative via the implicit function theorem, particularly at the crucial value, p=1. Another iterative regularization method in Banach space is considered by Qinian Jin and Linda Stals in Nonstationary iterated Tikhonov regularization for ill-posed problems in Banach spaces. Using a variational formulation and under some smoothness and convexity assumption on the preimage space, they extend the convergence analysis of the well-known iterative Tikhonov method for linear problems in Hilbert space to a more general Banach space framework. Systems of linear or nonlinear operators can be efficiently treated by cyclic iterations, thus several variants of gradient and Newton-type Kaczmarz methods have already been studied in the Hilbert space setting. Antonio Leitão and M Marques Alves in their paper On Landweber---Kaczmarz methods for regularizing systems of ill-posed equations in Banach spaces carry out an extension to Banach spaces for the fundamental Landweber version. The impact of perturbations in the evaluation of the forward operator and its derivative on the convergence behaviour of regularization methods is a practically and highly relevant issue. It is treated in the paper Convergence rates analysis of Tikhonov regularization for nonlinear ill-posed problems with noisy operators by Shuai Lu and Jens Flemming for variational regularization of nonlinear problems in Banach spaces. In The approximate inverse in action: IV. Semi-discrete equations in a Banach space setting, Thomas Schuster, Andreas Rieder and Frank Schöpfer extend the concept of approximate inverse to the practically and highly relevant situation of finitely many measurements and a general smooth and convex Banach space as preimage space. They devise two approaches for computing the reconstruction kernels required in the method and provide convergence and regularization results. Frank Werner and Thorsten Hohage in Convergence rates in expectation for Tikhonov-type regularization of inverse problems with Poisson data prove convergence rates results for variational regularization with general convex regularization term and the Kullback-Leibler distance as data fidelity term by combining a new result on Poisson distributed data with a deterministic rates analysis. Finally, we would like to thank the Inverse Problems team, especially Joanna Evangelides and Chris Wileman, for their extraordinary smooth and productive cooperation, as well as Alfred K Louis for his kind support of our initiative.
Gao, Yang; Bian, Zhaoying; Huang, Jing; Zhang, Yunwan; Niu, Shanzhou; Feng, Qianjin; Chen, Wufan; Liang, Zhengrong; Ma, Jianhua
2014-06-16
To realize low-dose imaging in X-ray computed tomography (CT) examination, lowering milliampere-seconds (low-mAs) or reducing the required number of projection views (sparse-view) per rotation around the body has been widely studied as an easy and effective approach. In this study, we are focusing on low-dose CT image reconstruction from the sinograms acquired with a combined low-mAs and sparse-view protocol and propose a two-step image reconstruction strategy. Specifically, to suppress significant statistical noise in the noisy and insufficient sinograms, an adaptive sinogram restoration (ASR) method is first proposed with consideration of the statistical property of sinogram data, and then to further acquire a high-quality image, a total variation based projection onto convex sets (TV-POCS) method is adopted with a slight modification. For simplicity, the present reconstruction strategy was termed as "ASR-TV-POCS." To evaluate the present ASR-TV-POCS method, both qualitative and quantitative studies were performed on a physical phantom. Experimental results have demonstrated that the present ASR-TV-POCS method can achieve promising gains over other existing methods in terms of the noise reduction, contrast-to-noise ratio, and edge detail preservation.
Parent-Child Communication about Television: A View from the Parent's Perspective.
ERIC Educational Resources Information Center
Gantz, Walter; Weaver, James B., III
This study examined both general and specific parent-child television viewing experiences together with any interactions related to television viewing whether the child has watched television with a parent or alone. A total of 384 telephone interviews of parents (57% female, 43% male) with children at home between the ages of 6 and 18 were…
East Europe Report Economic and Industrial Affairs No. 2390
1983-04-22
Discussed (B-. GIilan, et al .; BORBA , 7 Mar 83) ......................... 89 -b - ALBANIA DEVELOPMENTS IN COLOR TELEVISION BROADCASTING Tirana BASHKIMI...experiment- al work was carried on with limited and irregular schedules. The beginning of regular programming coincided with the 6th party congress in...upheav- als . But the practice of permanent revolution has set back for a long time even such a huge country, with a great cultural heritage, enormous
Adolescent exposure to food advertising on television.
Powell, Lisa M; Szczypka, Glen; Chaloupka, Frank J
2007-10-01
Television viewing is hypothesized to contribute to obesity among children and adolescents through several mechanisms that include the displacement of physical activity, snacking while watching TV, and the influence of food advertising. This study drew on television ratings to examine the distribution of food advertising exposure among adolescents aged 12 through 17 based on 170 top-rated shows across network, cable and syndicated TV stations over the 9-month period from September 2003 to May 2004. A total of 238,353 30-second equivalent advertisements on the top-rated shows were assessed. Each advertisement was weighted by its rating to measure actual exposure to advertisements. The results showed that among total nonprogram content time, food-related products accounted for roughly one fifth of advertising exposure. Excluding TV promotions and public service announcements, as a proportion of all product advertising, total food-related advertising made up 26% of advertised products viewed by adolescents. By race, the proportion of advertising exposure to food products was 14% greater for African-American versus white adolescents and total exposure to food advertising would be even larger for African-American teens given that, on average, they watched more TV. Fast food was the most frequently viewed food product category comprising 23% of all food-related advertisements among adolescents. Food ads made up just over one quarter of TV ads viewed by adolescents with the most commonly viewed products of fast food, sweets, and beverage products well within the reach of their own purchasing power.
5 CFR 550.1307 - Authority to regularize paychecks.
Code of Federal Regulations, 2010 CFR
2010-01-01
... an agency's plan to reduce or eliminate variation in the amount of firefighters' biweekly paychecks... period to pay period. Such a plan must provide that the total pay any firefighter would otherwise receive... PAY ADMINISTRATION (GENERAL) Firefighter Pay § 550.1307 Authority to regularize paychecks. Upon a...
5 CFR 550.1307 - Authority to regularize paychecks.
Code of Federal Regulations, 2014 CFR
2014-01-01
... an agency's plan to reduce or eliminate variation in the amount of firefighters' biweekly paychecks... period to pay period. Such a plan must provide that the total pay any firefighter would otherwise receive... PAY ADMINISTRATION (GENERAL) Firefighter Pay § 550.1307 Authority to regularize paychecks. Upon a...
5 CFR 550.1307 - Authority to regularize paychecks.
Code of Federal Regulations, 2011 CFR
2011-01-01
... an agency's plan to reduce or eliminate variation in the amount of firefighters' biweekly paychecks... period to pay period. Such a plan must provide that the total pay any firefighter would otherwise receive... PAY ADMINISTRATION (GENERAL) Firefighter Pay § 550.1307 Authority to regularize paychecks. Upon a...
5 CFR 550.1307 - Authority to regularize paychecks.
Code of Federal Regulations, 2012 CFR
2012-01-01
... an agency's plan to reduce or eliminate variation in the amount of firefighters' biweekly paychecks... period to pay period. Such a plan must provide that the total pay any firefighter would otherwise receive... PAY ADMINISTRATION (GENERAL) Firefighter Pay § 550.1307 Authority to regularize paychecks. Upon a...
5 CFR 550.1307 - Authority to regularize paychecks.
Code of Federal Regulations, 2013 CFR
2013-01-01
... an agency's plan to reduce or eliminate variation in the amount of firefighters' biweekly paychecks... period to pay period. Such a plan must provide that the total pay any firefighter would otherwise receive... PAY ADMINISTRATION (GENERAL) Firefighter Pay § 550.1307 Authority to regularize paychecks. Upon a...
Numerical Differentiation of Noisy, Nonsmooth Data
Chartrand, Rick
2011-01-01
We consider the problem of differentiating a function specified by noisy data. Regularizing the differentiation process avoids the noise amplification of finite-difference methods. We use total-variation regularization, which allows for discontinuous solutions. The resulting simple algorithm accurately differentiates noisy functions, including those which have a discontinuous derivative.
Adolescent Television Viewing and Belief in Vampires
ERIC Educational Resources Information Center
Williams, Emyr; Robbins, Mandy; Picton, Laura
2006-01-01
A total of 1133 13-15-year-old pupils in six secondary schools in South Wales were invited to complete questions concerning vampire belief and amount of television watching. The data demonstrate that belief in vampires was positively associated with higher levels of television watching.
Chestnutt, I G; Ashraf, F J
2002-06-01
The study aimed to examine the nature, content and duration of advertisements broadcast during children's television; determine the proportion of advertisements promoting food; identify the potential of the food advertised to be detrimental to oral health; and to compare the nature and content of advertisements aimed at children with those transmitted during evening 'primetime' television. Children's and primetime television, broadcast on a main independent terrestrial channel in South Wales were video recorded, 237 and 42 hours being analysed in total. Analysis of the recording resulted in a total of 3,236 commercials, of which 2,345 were broadcast during children's television and 891 in primetime. During children's TV, 62.5% of advertising time was devoted to foodstuffs, significantly greater (P< 0.001) than the 18.4% of time spent advertising foods during primetime. Of the time spent advertising foods, during children's television 73.4% was devoted to products deemed potentially detrimental to oral health (primarily high in sugar), compared to 18.6% similarly categorised during evening television. Commercials for products which have the potential to adversely affect oral health constitute a large proportion of advertising time during children's television. Current codes of the Independent Television Commission governing advertising directed at children should be reviewed.
Physical activity, obesity and cardiovascular diseases.
Lakka, T A; Bouchard, C
2005-01-01
Sedentary lifestyle and overweight are major public health, clinical, and economical problems in modern societies. The worldwide epidemic of excess weight is due to imbalance between physical activity and dietary energy intake. Sedentary lifestyle, unhealthy diet, and consequent overweight and obesity markedly increase the risk of cardiovascular diseases. Regular physical activity 45-60 min per day prevents unhealthy weight gain and obesity, whereas sedentary behaviors such as watching television promote them. Regular exercise can markedly reduce body weight and fat mass without dietary caloric restriction in overweight individuals. An increase in total energy expenditure appears to be the most important determinant of successful exercise-induced weight loss. The best long-term results may be achieved when physical activity produces an energy expenditure of at least 2,500 kcal/week. Yet, the optimal approach in weight reduction programs appears to be a combination of regular physical activity and caloric restriction. A minimum of 60 min, but most likely 80-90 min of moderate-intensity physical activity per day may be needed to avoid or limit weight regain in formerly overweight or obese individuals. Regular moderate intensity physical activity, a healthy diet, and avoiding unhealthy weight gain are effective and safe ways to prevent and treat cardiovascular diseases and to reduce premature mortality in all population groups. Although the efforts to promote cardiovascular health concern the whole population, particular attention should be paid to individuals who are physically inactive, have unhealthy diets or are prone to weight gain. They have the highest risk for worsening of the cardiovascular risk factor profile and for cardiovascular disease. To combat the epidemic of overweight and to improve cardiovascular health at a population level, it is important to develop strategies to increase habitual physical activity and to prevent overweight and obesity in collaboration with communities, families, schools, work sites, health care professionals, media and policymakers.
Speers, Sarah E; Harris, Jennifer L; Schwartz, Marlene B
2011-09-01
The food industry disproportionately markets to young people through product placements. Children and adolescents may be more susceptible to these disguised persuasive attempts. Quantify incidence and youth exposure to food and beverage brand appearances within shows on prime-time TV. Data on the number of food, beverage, and restaurant brand appearances within shows during prime-time programming in 2008 were purchased from Nielsen and analyzed by product category and company in 2010. Exposure to these brand appearances by children, adolescents, and adults were examined and compared with exposure to prime-time TV advertisements for the same categories and companies using additional Nielsen data. Food, beverage, and restaurant brands appeared a total of 35,000 times within prime-time TV programming examined by Nielsen in 2008. Regular soft drinks, traditional restaurants (i.e., not quickserve), and energy/sports drinks made up 60% of all brand appearances. Young people viewed relatively few of these appearances with one notable exception. Coca-Cola products were seen 198 times by the average child and 269 times by the average adolescent during prime-time shows over the year, accounting for 70% of child exposure and 61% of adolescent exposure to brand appearances. One show, American Idol, accounted for more than 95% of these exposures. Exposure of children to Coca-Cola products through traditional advertisements was much less common. Brand appearances for most food industry companies, except for Coca-Cola, are relatively rare during prime-time programming with large youth audiences. Coca-Cola has pledged to refrain from advertising to children, yet the average child views almost four Coke appearances on prime-time TV every week. This analysis reveals a substantial, potential loophole in current food industry self-regulatory pledges to advertise only better-for-you foods to children. Copyright © 2011 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.
Roseman, Mary G; Poor, Morgan; Stephenson, Tammy J
2014-01-01
Examine food in cable television programming specifically targeting 11- to 14-year-olds ("tweens"). Content analysis of food-related scenes (FRS)-in which food was shown, mentioned, and/or consumed-in 880 minutes of programming was conducted. Five days of afternoon/early evening television programs on the Disney Channel. Food references were compared with USDA MyPlate and classified according to modified Ratio of Recommended to Restricted Food Components. The authors found 331 FRS, averaging 16.6 scenes/h. Preponderance of FRS was physiological needs (40.7%), followed by display (10%), party (8.5%), social event (8%), and retail store (6.6%). Snacks dominated 41% of FRS, and breakfast, lunch, and dinner were much lower in frequency. Half of FRS was visual only, followed by verbal only. Food references were not congruent with MyPlate recommendations; 42% of food items did not fit into MyPlate food groups. Only 24% of food items were fruit or vegetables, which is considerably less than recommended by MyPlate guidelines. Using modified Ratio of Recommended to Restricted Food Components, 66% of food items scored < 1.0, signifying less nutritious. Tween television programming regularly includes non-nutritious food, which likely influences tweens' attitudes and behaviors. Television programming may consider past approaches to tobacco smoking and health messages on television. More attention is warranted regarding television programming by nutrition educators, researchers, health professionals, and industry specialists. Copyright © 2014 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.
Russell, Cristel Antonia; Buhrau, Denise
2015-01-01
Background Fast-food advertising abounds on television (TV), and programs targeting youth often display fast-food consumption but rarely with any negative consequences. Cultivation research maintains that cumulative exposure to TV influences audiences’ views of and beliefs about the real world. Thus, the amount of TV adolescents watch is likely to bias their views of the consequences of eating fast food. This research posits that this relationship varies as a function of adolescents’ actual experience with fast food. Method Two cross-sectional surveys conducted in the cultivation research tradition assess the relationship between the amount of adolescents’ regular exposure to TV and their beliefs about the risks and benefits of eating fast food. Teenage children of members of online panels reported hours of TV viewing, beliefs about the consequences of eating fast food, and their frequency of fast-food consumption. Results In both studies, beliefs about health risks of fast-food consumption vary as a function of the amount of TV watched. Heavy TV viewers have less negative and more positive beliefs about the consequences of fast-food consumption than light viewers. As direct experience with fast food increases, the relationship between TV viewing and risk perceptions weakens, but the relationship between TV viewing and positive perceptions strengthens. These moderated relationships remain when we control for physical activity (Study 1) and the density of fast-food restaurants in respondents’ geographical area (Study 2). Conclusion Given the role of TV viewing in biasing perceptions of the consequences of eating fast food, public health researchers and practitioners should carefully monitor and perhaps regulate the amount of fast-food advertising on TV and the content of TV programs. PMID:26009205
Russell, Cristel Antonia; Buhrau, Denise
2015-09-01
Fast-food advertising abounds on television (TV), and programs targeting youth often display fast-food consumption but rarely with any negative consequences. Cultivation research maintains that cumulative exposure to TV influences audiences' views of and beliefs about the real world. Thus, the amount of TV adolescents watch is likely to bias their views of the consequences of eating fast food. This research posits that this relationship varies as a function of adolescents' actual experience with fast food. Two cross-sectional surveys conducted in the cultivation research tradition assess the relationship between the amount of adolescents' regular exposure to TV and their beliefs about the risks and benefits of eating fast food. Teenage children of members of online panels reported hours of TV viewing, beliefs about the consequences of eating fast food, and their frequency of fast-food consumption. In both studies, beliefs about health risks of fast-food consumption vary as a function of the amount of TV watched. Heavy TV viewers have less negative and more positive beliefs about the consequences of fast-food consumption than light viewers. As direct experience with fast food increases, the relationship between TV viewing and risk perceptions weakens, but the relationship between TV viewing and positive perceptions strengthens. These moderated relationships remain when we control for physical activity (Study 1) and the density of fast-food restaurants in respondents' geographical area (Study 2). Given the role of TV viewing in biasing perceptions of the consequences of eating fast food, public health researchers and practitioners should carefully monitor and perhaps regulate the amount of fast-food advertising on TV and the content of TV programs. Copyright © 2015 Elsevier Ltd. All rights reserved.
Use of fictional medical television in health sciences education: a systematic review.
Hoffman, Beth L; Hoffman, Robert; Wessel, Charles B; Shensa, Ariel; Woods, Michelle S; Primack, Brian A
2018-03-01
While medical television programs are popular among health profession trainees, it is not clear to what extent these programs affect their knowledge, perceptions, and/or behaviors. Therefore, we conducted a systematic review of research evaluating associations between program exposure and outcomes. We conducted systematic literature searches in Pubmed, CINAHL, and PsycINFO. Selected studies were required to be scholarly research, involve exposure to fictionalized medical television programming by health professional students, and assess associations between exposure and outcomes. Studies were classified according to quality and factors related to population, exposure, and outcomes. Of 3541 studies identified, 13 met selection criteria. Six studies involved undergraduate medical students, one involved nursing students, two involved both medical and nursing students, two involved medical residents, one involved medical students, residents and attending physicians, and one involved graduate epidemiology students. Mean study quality according to the MERSQI was 8.27. The most commonly assessed television programs were ER and Grey's Anatomy (six each). Five studies assessed regular viewing habits, and found that fictional medical programs are popular among students and that students recall health topics from episodes. The eight studies that assessed the association with outcomes when using clips as educational tools reported high satisfaction and increased knowledge of the presented health topics. While relatively few published studies have explored influences of fictional medical television on health professional students, those conducted suggest that students often view these television programs independently and that integration of this programming into medical education is feasible and acceptable.
NASA Astrophysics Data System (ADS)
Espinoza, S.
2014-12-01
From extensive drought and heat waves to floods, tornadoes and Superstorm Sandy, extreme weather and climate events provide teachable moments to help communities prepare for and respond to related environmental, economic and health impacts. The National Environmental Education Foundation (www.neefusa.org) works with the American Meteorological Society, the media and other trusted messengers to provide weather, climate and environmental information to the public in accessible and widely used formats, whether via TV, radio or social media. NEEF will provide an overview of innovative partnerships and projects that are engaging Americans in understanding and using climate and environmental information to make the best choices in their daily lives and improve the health of their communities, including: Assessing knowledge, attitudes and behaviors: NEEF will share results from its national survey research and targeted focus groups on current attitudes and practices relating to our nation's environment. Simplifying and amplifying key messages: NEEF provides a national network of more than 350 meteorologists, radio broadcasters and journalists with the science-based information and resources they need to present climate and environmental topics to their viewers on-air, online and in community outreach. Engaging television viewers in citizen science: Eyes on Central PA, a pilot project of NEEF, Project Noah and WTAJ-TV, harnesses Project Noah's citizen science platform to collect and display photos of wildlife from WTAJ-TV viewers. NEEF and WTAJ provide regular blogs and on-air stories that highlight viewers' photos and link them to local weather conditions and climate trends. Expanding the conversation: NEEF's multimedia strategy in the Mid-Atlantic U.S. is reaching Spanish-speaking audiences with climate and environmental information through regular radio and television broadcasts. We are also exploring ways to reach other non-traditional audiences, including faith communities and sports fans, with weather, climate and preparedness information.
NASA Astrophysics Data System (ADS)
Park, Y. O.; Hong, D. K.; Cho, H. S.; Je, U. K.; Oh, J. E.; Lee, M. S.; Kim, H. J.; Lee, S. H.; Jang, W. S.; Cho, H. M.; Choi, S. I.; Koo, Y. S.
2013-09-01
In this paper, we introduce an effective imaging system for digital tomosynthesis (DTS) with a circular X-ray tube, the so-called circular-DTS (CDTS) system, and its image reconstruction algorithm based on the total-variation (TV) minimization method for low-dose, high-accuracy X-ray imaging. Here, the X-ray tube is equipped with a series of cathodes distributed around a rotating anode, and the detector remains stationary throughout the image acquisition. We considered a TV-based reconstruction algorithm that exploited the sparsity of the image with substantially high image accuracy. We implemented the algorithm for the CDTS geometry and successfully reconstructed images of high accuracy. The image characteristics were investigated quantitatively by using some figures of merit, including the universal-quality index (UQI) and the depth resolution. For selected tomographic angles of 20, 40, and 60°, the corresponding UQI values in the tomographic view were estimated to be about 0.94, 0.97, and 0.98, and the depth resolutions were about 4.6, 3.1, and 1.2 voxels in full width at half maximum (FWHM), respectively. We expect the proposed method to be applicable to developing a next-generation dental or breast X-ray imaging system.
Investigation of optimization-based reconstruction with an image-total-variation constraint in PET
NASA Astrophysics Data System (ADS)
Zhang, Zheng; Ye, Jinghan; Chen, Buxin; Perkins, Amy E.; Rose, Sean; Sidky, Emil Y.; Kao, Chien-Min; Xia, Dan; Tung, Chi-Hua; Pan, Xiaochuan
2016-08-01
Interest remains in reconstruction-algorithm research and development for possible improvement of image quality in current PET imaging and for enabling innovative PET systems to enhance existing, and facilitate new, preclinical and clinical applications. Optimization-based image reconstruction has been demonstrated in recent years of potential utility for CT imaging applications. In this work, we investigate tailoring the optimization-based techniques to image reconstruction for PET systems with standard and non-standard scan configurations. Specifically, given an image-total-variation (TV) constraint, we investigated how the selection of different data divergences and associated parameters impacts the optimization-based reconstruction of PET images. The reconstruction robustness was explored also with respect to different data conditions and activity up-takes of practical relevance. A study was conducted particularly for image reconstruction from data collected by use of a PET configuration with sparsely populated detectors. Overall, the study demonstrates the robustness of the TV-constrained, optimization-based reconstruction for considerably different data conditions in PET imaging, as well as its potential to enable PET configurations with reduced numbers of detectors. Insights gained in the study may be exploited for developing algorithms for PET-image reconstruction and for enabling PET-configuration design of practical usefulness in preclinical and clinical applications.
Pan, Po-Lin; Meng, Juan
2015-01-01
This study examined how major TV news networks covered two flu pandemics in 1976 and 2009 in terms of news frames, mortality exemplars, mortality subject attributes, vaccination, evaluation approaches, and news sources. Results showed that the first pandemic was frequently framed with the medical/scientific and political/legal issues, while the second pandemic was emphasized with the health risk issue in TV news. Both flu pandemics were regularly reported with mortality exemplars, but the focus in the first pandemic was on the flu virus threat and vaccination side effects, while the vaccination shortage was frequently revealed in the second outbreak.
ERIC Educational Resources Information Center
Milkovich, Mark; And Others
This report, the third in a series of six reports on television advertising and children, describes a study designed to determine how the massive exposure to television affects children's language development. A total of 153 children in grades K-6 were interviewed about the entertainment, informational, and advertising content of 24 programs…
Low-altitude acceleration of auroral electrons during breakup observed by a mother-daughter rocket
NASA Technical Reports Server (NTRS)
Johnstone, A. D.; Davis, T. N.
1974-01-01
By the use of a mother-daughter rocket combination and ground-based observations with television, time and space variations are resolved in particle measurements in breakup aurora. The spectral variations measured during a temporal variation in the aurora can be explained by a nearly uniform acceleration of all the electrons such as would be caused by an electric potential drop along the magnetic field lines. Many other explanations can be eliminated.
Wang, Gang; Zhao, Zhikai; Ning, Yongjie
2018-05-28
As the application of a coal mine Internet of Things (IoT), mobile measurement devices, such as intelligent mine lamps, cause moving measurement data to be increased. How to transmit these large amounts of mobile measurement data effectively has become an urgent problem. This paper presents a compressed sensing algorithm for the large amount of coal mine IoT moving measurement data based on a multi-hop network and total variation. By taking gas data in mobile measurement data as an example, two network models for the transmission of gas data flow, namely single-hop and multi-hop transmission modes, are investigated in depth, and a gas data compressed sensing collection model is built based on a multi-hop network. To utilize the sparse characteristics of gas data, the concept of total variation is introduced and a high-efficiency gas data compression and reconstruction method based on Total Variation Sparsity based on Multi-Hop (TVS-MH) is proposed. According to the simulation results, by using the proposed method, the moving measurement data flow from an underground distributed mobile network can be acquired and transmitted efficiently.
A feature refinement approach for statistical interior CT reconstruction
NASA Astrophysics Data System (ADS)
Hu, Zhanli; Zhang, Yunwan; Liu, Jianbo; Ma, Jianhua; Zheng, Hairong; Liang, Dong
2016-07-01
Interior tomography is clinically desired to reduce the radiation dose rendered to patients. In this work, a new statistical interior tomography approach for computed tomography is proposed. The developed design focuses on taking into account the statistical nature of local projection data and recovering fine structures which are lost in the conventional total-variation (TV)—minimization reconstruction. The proposed method falls within the compressed sensing framework of TV minimization, which only assumes that the interior ROI is piecewise constant or polynomial and does not need any additional prior knowledge. To integrate the statistical distribution property of projection data, the objective function is built under the criteria of penalized weighed least-square (PWLS-TV). In the implementation of the proposed method, the interior projection extrapolation based FBP reconstruction is first used as the initial guess to mitigate truncation artifacts and also provide an extended field-of-view. Moreover, an interior feature refinement step, as an important processing operation is performed after each iteration of PWLS-TV to recover the desired structure information which is lost during the TV minimization. Here, a feature descriptor is specifically designed and employed to distinguish structure from noise and noise-like artifacts. A modified steepest descent algorithm is adopted to minimize the associated objective function. The proposed method is applied to both digital phantom and in vivo Micro-CT datasets, and compared to FBP, ART-TV and PWLS-TV. The reconstruction results demonstrate that the proposed method performs better than other conventional methods in suppressing noise, reducing truncated and streak artifacts, and preserving features. The proposed approach demonstrates its potential usefulness for feature preservation of interior tomography under truncated projection measurements.
A feature refinement approach for statistical interior CT reconstruction.
Hu, Zhanli; Zhang, Yunwan; Liu, Jianbo; Ma, Jianhua; Zheng, Hairong; Liang, Dong
2016-07-21
Interior tomography is clinically desired to reduce the radiation dose rendered to patients. In this work, a new statistical interior tomography approach for computed tomography is proposed. The developed design focuses on taking into account the statistical nature of local projection data and recovering fine structures which are lost in the conventional total-variation (TV)-minimization reconstruction. The proposed method falls within the compressed sensing framework of TV minimization, which only assumes that the interior ROI is piecewise constant or polynomial and does not need any additional prior knowledge. To integrate the statistical distribution property of projection data, the objective function is built under the criteria of penalized weighed least-square (PWLS-TV). In the implementation of the proposed method, the interior projection extrapolation based FBP reconstruction is first used as the initial guess to mitigate truncation artifacts and also provide an extended field-of-view. Moreover, an interior feature refinement step, as an important processing operation is performed after each iteration of PWLS-TV to recover the desired structure information which is lost during the TV minimization. Here, a feature descriptor is specifically designed and employed to distinguish structure from noise and noise-like artifacts. A modified steepest descent algorithm is adopted to minimize the associated objective function. The proposed method is applied to both digital phantom and in vivo Micro-CT datasets, and compared to FBP, ART-TV and PWLS-TV. The reconstruction results demonstrate that the proposed method performs better than other conventional methods in suppressing noise, reducing truncated and streak artifacts, and preserving features. The proposed approach demonstrates its potential usefulness for feature preservation of interior tomography under truncated projection measurements.
47 CFR 73.621 - Noncommercial educational TV stations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... interrupt regular programming. Note: Commission interpretation of this rule, including the acceptable form... Blanking Interval and in the Visual Signal. The provisions governing VBI and visual signal...
47 CFR 73.621 - Noncommercial educational TV stations.
Code of Federal Regulations, 2010 CFR
2010-10-01
... interrupt regular programming. Note: Commission interpretation of this rule, including the acceptable form... Blanking Interval and in the Visual Signal. The provisions governing VBI and visual signal...
Content Analysis of Food Advertising in Iranian Children's Television Programs.
Amini, Maryam; Omidvar, Nasrin; Yeatman, Heather; Shariat-Jafari, Shadab; Eslami-Amirabadi, Maryam; Zahedirad, Malihe
2014-10-01
Advertisements can influence children's health related behaviors. Television advertisements are the main avenues directing commercials at children in Iran. This study aimed to explore the content of food advertisement during children's television programs in 2007-8 and to compare it with those reported in 2000. All advertisements broadcasted before, during, and after children's programs aired on two major Iran national television networks were videotaped for a period of 4 weeks during 2007-8. For each advertisement, type of product(s) and mode of presentation (s) were coded. A total of 229 television advertisements were broadcasted. Food commercials were the most frequent group (31%) across the two channels. Among the food products advertised, calorie dense foods, including chocolate, soft drinks, extruded cereals, ice cream, cookies and candies were the most frequent. The appeal mainly used in television food advertisements was "stimulation of hunger/thirst" (38.5%). The advertisements were mostly presented as animations (54%) and the messages used were mainly directed to good taste. Although the total number of food advertisements during children's television programs has decreased but the consumption of high fat, high sugar, low nutrient dense foods continues to be promoted. Policies to address the issue should be scrutinized.
Kansas Public Television Network (KPTN).
ERIC Educational Resources Information Center
Lemen, Jack A.
The plans of the Kansas Public Television Board (KPTB) for development of the Kansas Television Network are detailed for the period extending from FY 1979 to FY 1983; the proposed system is designed to serve the needs of the communities by extending existing capabilities and resources, sharing common resources, and enriching the total system.…
Audience Diversion Due to Cable Television: A Statistical Analysis of New Data.
ERIC Educational Resources Information Center
Park, Rolla Edward
A statistical analysis of new data suggests that television broadcasting will continue to prosper, despite increasing competition from cable television carrying distant signals. Data on cable and non-cable audiences in 121 counties with well defined signal choice support generalized least squares estimates of two models: total audience and…
Lessons from Television: Children's Word Learning when Viewing.
ERIC Educational Resources Information Center
Rice, Mabel L.; Woodsmall, Linda
This study investigated whether or not preschoolers can learn novel words when viewing television. A total of 61 preschool children, ages 3 and 5, were assigned to either an experimental or control group. A 15-minute television program was prepared with two different voice-over narrations. The experimental version featured 20 different novel…
An integrated process and management tools for ranking multiple emerging threats to animal health.
Del Rio Vilas, Victor J; Voller, Fay; Montibeller, Gilberto; Franco, L Alberto; Sribhashyam, Sumitra; Watson, Eamon; Hartley, Matt; Gibbens, Jane C
2013-02-01
The UK's Department for Environment, Food and Rural Affairs supports the use of systematic tools for the prioritisation of known and well defined animal diseases to facilitate long and medium term planning of surveillance and disease control activities. The recognition that emerging events were not covered by the existing disease-specific approaches led to the establishment of the Veterinary Risk Group (VRG), constituted of government officials, and supporting structures such as the Risk Management Cycle and the Emerging Threat Highlight Report (ETHiR), to facilitate the identification, reporting and assessment of emerging threats to UK's animal health. Since its inception in November 2009 to the end of February 2011, the VRG reviewed 111 threats and vulnerabilities (T&V) reported through ETHiR. In July 2010 a decision support system (DSS) based on multi-criteria-decision-analysis (MCDA) improved ETHiR to allow the systematic prioritisation of emerging T&V. The DSS allows the regular ranking of emerging T&V by calculating a set of measurement indices related to the actual impact, possible impact on public perception and level of available capabilities associated with every T&V. The systematic characterisation of the processes leading to the assessment of T&V by the VRG has led to a consistent, auditable and transparent approach to the identification and assessment of emerging risks. The regular use of MCDA to manage a portfolio of emerging risks represents a different and novel application of MCDA in a health related context. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.
Emergency department visits during an Olympic gold medal television broadcast
Redelmeier, Donald A; Vermeulen, Marian J
2011-01-01
Background Practice pattern variations are often attributed to physician decision-making with no accounting for patient preferences. Objective To test whether a mass media television broadcast unrelated to health was associated with changes in the rate and characteristics of visits for acute emergency care. Design Time-series analysis of emergency department visits for any reason. Subjects Population-based sample of all patients seeking emergency care in Ontario, Canada. Measures The broadcast day was defined as the Olympic men’s gold medal ice hockey game final. The control days were defined as the 6 Sundays before and after the broadcast day. Results A total of 99 447 visits occurred over the 7 Sundays, of which 13 990 occurred on the broadcast day. Comparing the broadcast day with control days, we found no significant difference in the hourly rate of visits before the broadcast (544 vs 537, p = 0.41) or after the broadcast (647 vs 639, p = 0.55). In contrast, we observed a significant reduction in hourly rate of visits during the broadcast (647 vs 783, p < 0.001), equal to an absolute decrease of 409 patients, a relative decrease of 17% (95% confidence interval 13–21), or about 136 fewer patients per hour. The relative decrease during the broadcast was particularly large for adult men with low triage severity. The greatest reductions were for patients with abdominal, musculoskeletal or traumatic disorders. Conclusion Mass media television broadcasts can influence patient preferences and thereby lead to a decrease in emergency department visits. PMID:21915235
Color Image Restoration Using Nonlocal Mumford-Shah Regularizers
NASA Astrophysics Data System (ADS)
Jung, Miyoun; Bresson, Xavier; Chan, Tony F.; Vese, Luminita A.
We introduce several color image restoration algorithms based on the Mumford-Shah model and nonlocal image information. The standard Ambrosio-Tortorelli and Shah models are defined to work in a small local neighborhood, which are sufficient to denoise smooth regions with sharp boundaries. However, textures are not local in nature and require semi-local/non-local information to be denoised efficiently. Inspired from recent work (NL-means of Buades, Coll, Morel and NL-TV of Gilboa, Osher), we extend the standard models of Ambrosio-Tortorelli and Shah approximations to Mumford-Shah functionals to work with nonlocal information, for better restoration of fine structures and textures. We present several applications of the proposed nonlocal MS regularizers in image processing such as color image denoising, color image deblurring in the presence of Gaussian or impulse noise, color image inpainting, and color image super-resolution. In the formulation of nonlocal variational models for the image deblurring with impulse noise, we propose an efficient preprocessing step for the computation of the weight function w. In all the applications, the proposed nonlocal regularizers produce superior results over the local ones, especially in image inpainting with large missing regions. Experimental results and comparisons between the proposed nonlocal methods and the local ones are shown.
ERIC Educational Resources Information Center
Atkin, Charles K.
This report, the second in a series of six reports on television advertising and children, presents the results from a series of experimental studies designed to test children's intentional and incidental learning from television commercials. A total of 400 elementary school students of varying socioeconomic status participated in the study, with…
ERIC Educational Resources Information Center
Tweedie, Karen, Ed.
1987-01-01
Games for use in the second-language classroom are suggested, including variations on tic-tac-toe and snakes and ladders, races, board games based on American television programs, math activities, and a classroom mystery. (MSE)
Adiposity and different types of screen time.
Falbe, Jennifer; Rosner, Bernard; Willett, Walter C; Sonneville, Kendrin R; Hu, Frank B; Field, Alison E
2013-12-01
Few prospective studies have examined separate forms of screen time in relation to adiposity. Our objective was to assess independent relations of television, electronic games (video/computer), and digital versatile disc (DVD)/videos and total screen time with change in adolescent BMI. Using data from the 2004, 2006, and 2008 waves of the ongoing Growing up Today Study II, we assessed baseline and 2-year change in reported screen time in relation to concurrent change in BMI among 4287 girls and 3505 boys aged 9 to 16 years in 2004. Gender-specific models adjusted for previous BMI, age, race/ethnicity, growth/development, months between questionnaires, and physical activity. Among girls and boys, each hour per day increase in reported television viewing was associated with a 0.09 increase in BMI (Ps < .001), and each hour per day increase in total screen time was associated with a 0.07 increase among girls and 0.05 increase among boys (Ps < .001). Among girls only, greater baseline television, games, and total screen time and change in DVDs/videos were associated with gains in BMI (Ps < .05). BMI gains associated with change in television and total screen time were stronger among overweight girls than lean girls (Ps-heterogeneity < .001). Television, which remains the steadiest source of food advertising, was most consistently associated with BMI gains. Among girls, electronic games and DVDs/videos were also related to increased BMI, possibly due to influences of product placements and advergames on diet and/or distracted eating. Adolescents, especially overweight adolescents, may benefit from reduced time with multiple types of media.
Adiposity and Different Types of Screen Time
Rosner, Bernard; Willett, Walter C.; Sonneville, Kendrin R.; Hu, Frank B.; Field, Alison E.
2013-01-01
OBJECTIVE: Few prospective studies have examined separate forms of screen time in relation to adiposity. Our objective was to assess independent relations of television, electronic games (video/computer), and digital versatile disc (DVD)/videos and total screen time with change in adolescent BMI. METHODS: Using data from the 2004, 2006, and 2008 waves of the ongoing Growing up Today Study II, we assessed baseline and 2-year change in reported screen time in relation to concurrent change in BMI among 4287 girls and 3505 boys aged 9 to 16 years in 2004. Gender-specific models adjusted for previous BMI, age, race/ethnicity, growth/development, months between questionnaires, and physical activity. RESULTS: Among girls and boys, each hour per day increase in reported television viewing was associated with a 0.09 increase in BMI (Ps < .001), and each hour per day increase in total screen time was associated with a 0.07 increase among girls and 0.05 increase among boys (Ps < .001). Among girls only, greater baseline television, games, and total screen time and change in DVDs/videos were associated with gains in BMI (Ps < .05). BMI gains associated with change in television and total screen time were stronger among overweight girls than lean girls (Ps-heterogeneity < .001). CONCLUSIONS: Television, which remains the steadiest source of food advertising, was most consistently associated with BMI gains. Among girls, electronic games and DVDs/videos were also related to increased BMI, possibly due to influences of product placements and advergames on diet and/or distracted eating. Adolescents, especially overweight adolescents, may benefit from reduced time with multiple types of media. PMID:24276840
Gordon-Salant, Sandra; Callahan, Julia S
2009-08-01
Although watching television is a common leisure activity of older adults, the ability to understand televised speech may be compromised by age-related hearing loss. Two potential assistive devices for improving television viewing are hearing aids (HAs) and closed captioning (CC), but their use and benefit by older adults with hearing loss are unknown. The primary purpose of this initial investigation was to determine if older hearing-impaired adults show improvements in understanding televised speech with the use of these two assistive devices (HAs and CC) compared with conditions without these devices. A secondary purpose was to examine the frequency of HA and CC use among a sample of older HA wearers. The investigation entailed a randomized, repeated-measures design of 15 older adults (59 to 82 yr) with bilateral sensorineural hearing losses who wore HAs. Participants viewed three types of televised programs (news, drama, and game show) that were each edited into lists of speech segments and provided an identification response. Each participant was tested in four conditions: baseline (no HA or CC), HA only, CC only, and HA + CC. Also, pilot testing with young normal-hearing listeners was conducted to establish list equivalence and stimulus intelligibility with a control group. All testing was conducted in a quiet room to simulate a living room, using a 20 in flat screen television. Questionnaires were also administered to participants to determine the frequency of HA and CC use while watching television. A significant effect of viewing condition was observed for all programs. Participants exhibited significantly better speech recognition scores in conditions with CC than those without CC (p < 0.01). Use of personal HAs did not significantly improve recognition of televised speech compared with the unaided condition. The condition effect was similar across the three different programs. Most of the participants (73%) regularly wore their HAs while watching television; very few of them (13%) had ever used CC. On average, use of CC while watching television dramatically improved speech understanding by a sample of older hearing-impaired adults compared with conditions without CC, including when HAs were worn.
Gao, Yang; Bian, Zhaoying; Huang, Jing; Zhang, Yunwan; Niu, Shanzhou; Feng, Qianjin; Chen, Wufan; Liang, Zhengrong; Ma, Jianhua
2014-01-01
To realize low-dose imaging in X-ray computed tomography (CT) examination, lowering milliampere-seconds (low-mAs) or reducing the required number of projection views (sparse-view) per rotation around the body has been widely studied as an easy and effective approach. In this study, we are focusing on low-dose CT image reconstruction from the sinograms acquired with a combined low-mAs and sparse-view protocol and propose a two-step image reconstruction strategy. Specifically, to suppress significant statistical noise in the noisy and insufficient sinograms, an adaptive sinogram restoration (ASR) method is first proposed with consideration of the statistical property of sinogram data, and then to further acquire a high-quality image, a total variation based projection onto convex sets (TV-POCS) method is adopted with a slight modification. For simplicity, the present reconstruction strategy was termed as “ASR-TV-POCS.” To evaluate the present ASR-TV-POCS method, both qualitative and quantitative studies were performed on a physical phantom. Experimental results have demonstrated that the present ASR-TV-POCS method can achieve promising gains over other existing methods in terms of the noise reduction, contrast-to-noise ratio, and edge detail preservation. PMID:24977611
Content Analysis of Food Advertising in Iranian Children's Television Programs
Amini, Maryam; Omidvar, Nasrin; Yeatman, Heather; Shariat-Jafari, Shadab; Eslami-Amirabadi, Maryam; Zahedirad, Malihe
2014-01-01
Background: Advertisements can influence children's health related behaviors. Television advertisements are the main avenues directing commercials at children in Iran. This study aimed to explore the content of food advertisement during children's television programs in 2007-8 and to compare it with those reported in 2000. Methods: All advertisements broadcasted before, during, and after children's programs aired on two major Iran national television networks were videotaped for a period of 4 weeks during 2007-8. For each advertisement, type of product(s) and mode of presentation (s) were coded. Results: A total of 229 television advertisements were broadcasted. Food commercials were the most frequent group (31%) across the two channels. Among the food products advertised, calorie dense foods, including chocolate, soft drinks, extruded cereals, ice cream, cookies and candies were the most frequent. The appeal mainly used in television food advertisements was “stimulation of hunger/thirst” (38.5%). The advertisements were mostly presented as animations (54%) and the messages used were mainly directed to good taste. Conclusion: Although the total number of food advertisements during children's television programs has decreased but the consumption of high fat, high sugar, low nutrient dense foods continues to be promoted. Policies to address the issue should be scrutinized. PMID:25400894
47 CFR 73.1570 - Modulation levels: AM, FM, TV and Class A TV aural.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 4 2011-10-01 2011-10-01 false Modulation levels: AM, FM, TV and Class A TV... levels: AM, FM, TV and Class A TV aural. (a) The percentage of modulation is to be maintained at as high... and accurate data transmission and may not, in any case, exceed 6%. (2) FM stations. The total...
The Effect of Sibling Viewing Style on Children's Interpretation of Television Content.
ERIC Educational Resources Information Center
Haefner, Margaret J.; Wartella, Ellen A.
The present study investigates the impact of sibling pairs' friendly or unfriendly viewing styles on the younger siblings' understanding of the content of television programs. A total of 19 sibling pairs were videotaped as they viewed one of two television programs. The younger child in all of the pairs was in first or second grade. Fourteen of…
ERIC Educational Resources Information Center
Atkin, Charles K.
This report, the fifth in a series of six reports on television advertising and children, describes the key content dimensions of network advertising messages presented on two comparable Saturday mornings in 1972 and 1973. A total of 470 advertisements was systematically and quantitatively analyzed along 28 variables involving the nature of…
TH-AB-BRA-02: Automated Triplet Beam Orientation Optimization for MRI-Guided Co-60 Radiotherapy
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nguyen, D; Thomas, D; Cao, M
2016-06-15
Purpose: MRI guided Co-60 provides daily and intrafractional MRI soft tissue imaging for improved target tracking and adaptive radiotherapy. To remedy the low output limitation, the system uses three Co-60 sources at 120° apart, but using all three sources in planning is considerably unintuitive. We automate the beam orientation optimization using column generation, and then solve a novel fluence map optimization (FMO) problem while regularizing the number of MLC segments. Methods: Three patients—1 prostate (PRT), 1 lung (LNG), and 1 head-and-neck boost plan (H&NBoost)—were evaluated. The beamlet dose for 180 equally spaced coplanar beams under 0.35 T magnetic field wasmore » calculated using Monte Carlo. The 60 triplets were selected utilizing the column generation algorithm. The FMO problem was formulated using an L2-norm minimization with anisotropic total variation (TV) regularization term, which allows for control over the number of MLC segments. Our Fluence Regularized and Optimized Selection of Triplets (FROST) plans were compared against the clinical treatment plans (CLN) produced by an experienced dosimetrist. Results: The mean PTV D95, D98, and D99 differ by −0.02%, +0.12%, and +0.44% of the prescription dose between planning methods, showing same PTV dose coverage. The mean PTV homogeneity (D95/D5) was at 0.9360 (FROST) and 0.9356 (CLN). R50 decreased by 0.07 with FROST. On average, FROST reduced Dmax and Dmean of OARs by 6.56% and 5.86% of the prescription dose. The manual CLN planning required iterative trial and error runs which is very time consuming, while FROST required minimal human intervention. Conclusions: MRI guided Co-60 therapy needs the output of all sources yet suffers from unintuitive and laborious manual beam selection processes. Automated triplet orientation optimization is shown essential to overcome the difficulty and improves the dosimetry. A novel FMO with regularization provides additional controls over the number of MLC segments and treatment time. Varian Medical Systems; NIH grant R01CA188300; NIH grant R43CA183390.« less
Restriction of television food advertising in South Korea: impact on advertising of food companies.
Kim, Soyoung; Lee, Youngmi; Yoon, Jihyun; Chung, Sang-Jin; Lee, Soo-Kyung; Kim, Hyogyoo
2013-03-01
The association between exposure to television (TV) food advertising and children's dietary habits has been well established in previous studies. However, the efficacy of restrictions on TV food advertising in the prevention of childhood obesity remains controversial. The South Korean government has recently enforced a regulation, termed the Special Act on Safety Management of Children's Dietary Life, which restricts TV advertising of energy-dense and nutrient-poor (EDNP) foods targeting children. This study aimed to determine the impact of this regulation by examining changes in the TV advertising practices of South Korean food companies since the scheduled enforcement date of January 2010. The total advertising budget, number of advertisement placements and gross rating points (GRPs) for advertisements on EDNP foods aired on the five representative TV channels in South Korea were compared and analyzed for the year before and after January 2010. After January 2010, the total adverting budget, number of advertisement placements and GRPs decreased during regulated hours. Even during non-regulated hours, a significant decline was noticed in the number of advertisement placements and GRPs. The total advertising budget for non-EDNP foods increased, whereas that for EDNP foods decreased at a higher rate in addition to a drop in its percentage share. These results suggest positive changes in TV advertising practices of food companies because of the regulation, thereby lowering children's exposure to TV advertising of EDNP foods and promoting a safer environment that may facilitate child health improvement in South Korea.
Shieh, Chun-Chien; Kipritidis, John; O’Brien, Ricky T; Cooper, Benjamin J; Kuncic, Zdenka; Keall, Paul J
2015-01-01
Total-variation (TV) minimization reconstructions can significantly reduce noise and streaks in thoracic four-dimensional cone-beam computed tomography (4D CBCT) images compared to the Feldkamp-Davis-Kress (FDK) algorithm currently used in practice. TV minimization reconstructions are, however, prone to over-smoothing anatomical details and are also computationally inefficient. The aim of this study is to demonstrate a proof of concept that these disadvantages can be overcome by incorporating the general knowledge of the thoracic anatomy via anatomy segmentation into the reconstruction. The proposed method, referred as the anatomical-adaptive image regularization (AAIR) method, utilizes the adaptive-steepest-descent projection-onto-convex-sets (ASD-POCS) framework, but introduces an additional anatomy segmentation step in every iteration. The anatomy segmentation information is implemented in the reconstruction using a heuristic approach to adaptively suppress over-smoothing at anatomical structures of interest. The performance of AAIR depends on parameters describing the weighting of the anatomy segmentation prior and segmentation threshold values. A sensitivity study revealed that the reconstruction outcome is not sensitive to these parameters as long as they are chosen within a suitable range. AAIR was validated using a digital phantom and a patient scan, and was compared to FDK, ASD-POCS, and the prior image constrained compressed sensing (PICCS) method. For the phantom case, AAIR reconstruction was quantitatively shown to be the most accurate as indicated by the mean absolute difference and the structural similarity index. For the patient case, AAIR resulted in the highest signal-to-noise ratio (i.e. the lowest level of noise and streaking) and the highest contrast-to-noise ratios for the tumor and the bony anatomy (i.e. the best visibility of anatomical details). Overall, AAIR was much less prone to over-smoothing anatomical details compared to ASD-POCS, and did not suffer from residual noise/streaking and motion blur migrated from the prior image as in PICCS. AAIR was also found to be more computationally efficient than both ASD-POCS and PICCS, with a reduction in computation time of over 50% compared to ASD-POCS. The use of anatomy segmentation was, for the first time, demonstrated to significantly improve image quality and computational efficiency for thoracic 4D CBCT reconstruction. Further developments are required to facilitate AAIR for practical use. PMID:25565244
Zhang, Hanming; Wang, Linyuan; Yan, Bin; Li, Lei; Cai, Ailong; Hu, Guoen
2016-01-01
Total generalized variation (TGV)-based computed tomography (CT) image reconstruction, which utilizes high-order image derivatives, is superior to total variation-based methods in terms of the preservation of edge information and the suppression of unfavorable staircase effects. However, conventional TGV regularization employs l1-based form, which is not the most direct method for maximizing sparsity prior. In this study, we propose a total generalized p-variation (TGpV) regularization model to improve the sparsity exploitation of TGV and offer efficient solutions to few-view CT image reconstruction problems. To solve the nonconvex optimization problem of the TGpV minimization model, we then present an efficient iterative algorithm based on the alternating minimization of augmented Lagrangian function. All of the resulting subproblems decoupled by variable splitting admit explicit solutions by applying alternating minimization method and generalized p-shrinkage mapping. In addition, approximate solutions that can be easily performed and quickly calculated through fast Fourier transform are derived using the proximal point method to reduce the cost of inner subproblems. The accuracy and efficiency of the simulated and real data are qualitatively and quantitatively evaluated to validate the efficiency and feasibility of the proposed method. Overall, the proposed method exhibits reasonable performance and outperforms the original TGV-based method when applied to few-view problems.
Television viewing, computer use and total screen time in Canadian youth.
Mark, Amy E; Boyce, William F; Janssen, Ian
2006-11-01
Research has linked excessive television viewing and computer use in children and adolescents to a variety of health and social problems. Current recommendations are that screen time in children and adolescents should be limited to no more than 2 h per day. To determine the percentage of Canadian youth meeting the screen time guideline recommendations. The representative study sample consisted of 6942 Canadian youth in grades 6 to 10 who participated in the 2001/2002 World Health Organization Health Behaviour in School-Aged Children survey. Only 41% of girls and 34% of boys in grades 6 to 10 watched 2 h or less of television per day. Once the time of leisure computer use was included and total daily screen time was examined, only 18% of girls and 14% of boys met the guidelines. The prevalence of those meeting the screen time guidelines was higher in girls than boys. Fewer than 20% of Canadian youth in grades 6 to 10 met the total screen time guidelines, suggesting that increased public health interventions are needed to reduce the number of leisure time hours that Canadian youth spend watching television and using the computer.
Alcohol marketing in televised English professional football: a frequency analysis.
Graham, Andrew; Adams, Jean
2014-01-01
The aim of the study was to explore the frequency of alcohol marketing (both formal commercials and otherwise) in televised top-class English professional football matches. A purposive sample of six broadcasts (total = 1101 min) of televised top-class English club football matches were identified and recorded in full. A customized coding framework was used to identify and categorize all verbal and visual alcohol references in non-commercial broadcasting. The number and the duration of all formal alcohol commercials were also noted. A mean of 111 visual references and 2 verbal references to alcohol per hour of broadcast were identified. Nearly all visual references were to beer products and were primarily simple logos or branding. The majority of verbal alcohol references were related to title-sponsorship of competitions. A total of 17 formal alcohol commercials were identified, accounting for <1% of total broadcast time. Visual alcohol references in televised top-class English football matches are common with an average of nearly two per minute. Verbal references are rare and formal alcohol commercials account for <1% of broadcast time. Restriction of all alcohol sports sponsorship, as seen for tobacco, may be justified.
An object-oriented simulator for 3D digital breast tomosynthesis imaging system.
Seyyedi, Saeed; Cengiz, Kubra; Kamasak, Mustafa; Yildirim, Isa
2013-01-01
Digital breast tomosynthesis (DBT) is an innovative imaging modality that provides 3D reconstructed images of breast to detect the breast cancer. Projections obtained with an X-ray source moving in a limited angle interval are used to reconstruct 3D image of breast. Several reconstruction algorithms are available for DBT imaging. Filtered back projection algorithm has traditionally been used to reconstruct images from projections. Iterative reconstruction algorithms such as algebraic reconstruction technique (ART) were later developed. Recently, compressed sensing based methods have been proposed in tomosynthesis imaging problem. We have developed an object-oriented simulator for 3D digital breast tomosynthesis (DBT) imaging system using C++ programming language. The simulator is capable of implementing different iterative and compressed sensing based reconstruction methods on 3D digital tomosynthesis data sets and phantom models. A user friendly graphical user interface (GUI) helps users to select and run the desired methods on the designed phantom models or real data sets. The simulator has been tested on a phantom study that simulates breast tomosynthesis imaging problem. Results obtained with various methods including algebraic reconstruction technique (ART) and total variation regularized reconstruction techniques (ART+TV) are presented. Reconstruction results of the methods are compared both visually and quantitatively by evaluating performances of the methods using mean structural similarity (MSSIM) values.
Fast and low-dose computed laminography using compressive sensing based technique
NASA Astrophysics Data System (ADS)
Abbas, Sajid; Park, Miran; Cho, Seungryong
2015-03-01
Computed laminography (CL) is well known for inspecting microstructures in the materials, weldments and soldering defects in high density packed components or multilayer printed circuit boards. The overload problem on x-ray tube and gross failure of the radio-sensitive electronics devices during a scan are among important issues in CL which needs to be addressed. The sparse-view CL can be one of the viable option to overcome such issues. In this work a numerical aluminum welding phantom was simulated to collect sparsely sampled projection data at only 40 views using a conventional CL scanning scheme i.e. oblique scan. A compressive-sensing inspired total-variation (TV) minimization algorithm was utilized to reconstruct the images. It is found that the images reconstructed using sparse view data are visually comparable with the images reconstructed using full scan data set i.e. at 360 views on regular interval. We have quantitatively confirmed that tiny structures such as copper and tungsten slags, and copper flakes in the reconstructed images from sparsely sampled data are comparable with the corresponding structure present in the fully sampled data case. A blurring effect can be seen near the edges of few pores at the bottom of the reconstructed images from sparsely sampled data, despite the overall image quality is reasonable for fast and low-dose NDT.
An Object-Oriented Simulator for 3D Digital Breast Tomosynthesis Imaging System
Cengiz, Kubra
2013-01-01
Digital breast tomosynthesis (DBT) is an innovative imaging modality that provides 3D reconstructed images of breast to detect the breast cancer. Projections obtained with an X-ray source moving in a limited angle interval are used to reconstruct 3D image of breast. Several reconstruction algorithms are available for DBT imaging. Filtered back projection algorithm has traditionally been used to reconstruct images from projections. Iterative reconstruction algorithms such as algebraic reconstruction technique (ART) were later developed. Recently, compressed sensing based methods have been proposed in tomosynthesis imaging problem. We have developed an object-oriented simulator for 3D digital breast tomosynthesis (DBT) imaging system using C++ programming language. The simulator is capable of implementing different iterative and compressed sensing based reconstruction methods on 3D digital tomosynthesis data sets and phantom models. A user friendly graphical user interface (GUI) helps users to select and run the desired methods on the designed phantom models or real data sets. The simulator has been tested on a phantom study that simulates breast tomosynthesis imaging problem. Results obtained with various methods including algebraic reconstruction technique (ART) and total variation regularized reconstruction techniques (ART+TV) are presented. Reconstruction results of the methods are compared both visually and quantitatively by evaluating performances of the methods using mean structural similarity (MSSIM) values. PMID:24371468
Fast Dictionary-Based Reconstruction for Diffusion Spectrum Imaging
Bilgic, Berkin; Chatnuntawech, Itthi; Setsompop, Kawin; Cauley, Stephen F.; Yendiki, Anastasia; Wald, Lawrence L.; Adalsteinsson, Elfar
2015-01-01
Diffusion Spectrum Imaging (DSI) reveals detailed local diffusion properties at the expense of substantially long imaging times. It is possible to accelerate acquisition by undersampling in q-space, followed by image reconstruction that exploits prior knowledge on the diffusion probability density functions (pdfs). Previously proposed methods impose this prior in the form of sparsity under wavelet and total variation (TV) transforms, or under adaptive dictionaries that are trained on example datasets to maximize the sparsity of the representation. These compressed sensing (CS) methods require full-brain processing times on the order of hours using Matlab running on a workstation. This work presents two dictionary-based reconstruction techniques that use analytical solutions, and are two orders of magnitude faster than the previously proposed dictionary-based CS approach. The first method generates a dictionary from the training data using Principal Component Analysis (PCA), and performs the reconstruction in the PCA space. The second proposed method applies reconstruction using pseudoinverse with Tikhonov regularization with respect to a dictionary. This dictionary can either be obtained using the K-SVD algorithm, or it can simply be the training dataset of pdfs without any training. All of the proposed methods achieve reconstruction times on the order of seconds per imaging slice, and have reconstruction quality comparable to that of dictionary-based CS algorithm. PMID:23846466
Hargrave, Catriona; Deegan, Timothy; Bednarz, Tomasz; Poulsen, Michael; Harden, Fiona; Mengersen, Kerrie
2018-05-17
To describe a Bayesian network (BN) and complementary visualization tool that aim to support decision-making during online cone-beam computed tomography (CBCT)-based image-guided radiotherapy (IGRT) for prostate cancer patients. The BN was created to represent relationships between observed prostate, proximal seminal vesicle (PSV), bladder and rectum volume variations, an image feature alignment score (FAS TV _ OAR ), delivered dose, and treatment plan compliance (TPC). Variables influencing tumor volume (TV) targeting accuracy such as intrafraction motion, and contouring and couch shift errors were also represented. A score of overall TPC (FAS global ) and factors such as image quality were used to inform the BN output node providing advice about proceeding with treatment. The BN was quantified using conditional probabilities generated from published studies, FAS TV _ OAR /global modeling, and a survey of IGRT decision-making practices. A new IGRT visualization tool (IGRT REV ), in the form of Mollweide projection plots, was developed to provide a global summary of residual errors after online CBCT-planning CT registration. Sensitivity and scenario analyses were undertaken to evaluate the performance of the BN and the relative influence of the network variables on TPC and the decision to proceed with treatment. The IGRT REV plots were evaluated in conjunction with the BN scenario testing, using additional test data generated from retrospective CBCT-planning CT soft-tissue registrations for 13/36 patients whose data were used in the FAS TV _ OAR /global modeling. Modeling of the TV targeting errors resulted in a very low probability of corrected distances between the CBCT and planning CT prostate or PSV volumes being within their thresholds. Strength of influence evaluation with and without the BN TV targeting error nodes indicated that rectum- and bladder-related network variables had the highest relative importance. When the TV targeting error nodes were excluded from the BN, TPC was sensitive to observed PSV and rectum variations while the decision to treat was sensitive to observed prostate and PSV variations. When root nodes were set so the PSV and rectum variations exceeded thresholds, the probability of low TPC increased to 40%. Prostate and PSV variations exceeding thresholds increased the likelihood of repositioning or repeating patient preparation to 43%. Scenario testing using the test data from 13 patients, demonstrated two cases where the BN provided increased high TPC probabilities, despite some of the prostate and PSV volume variation metrics not being within tolerance. The IGRT REV tool was effective in highlighting and quantifying where TV and OAR variations occurred, supporting the BN recommendation to reposition the patient or repeat their bladder and bowel preparation. In another case, the IGRT REV tool was also effective in highlighting where PSV volume variation significantly exceeded tolerance when the BN had indicated to proceed with treatment. This study has demonstrated that both the BN and IGRT REV plots are effective tools for inclusion in a decision support system for online CBCT-based IGRT for prostate cancer patients. Alternate approaches to modeling TV targeting errors need to be explored as well as extension of the BN to support offline IGRT decisions related to adaptive radiotherapy. © 2018 American Association of Physicists in Medicine.
Information management for clinicians.
Mehta, Neil B; Martin, Stephen A; Maypole, Jack; Andrews, Rebecca
2016-08-01
Clinicians are bombarded with information daily by social media, mainstream television news, e-mail, and print and online reports. They usually do not have much control over these information streams and thus are passive recipients, which means they get more noise than signal. Accessing, absorbing, organizing, storing, and retrieving useful medical information can improve patient care. The authors outline how to create a personalized stream of relevant information that can be scanned regularly and saved so that it is readily accessible. Copyright © 2016 Cleveland Clinic.
Seo, Dong-Chul; Torabi, Mohammad R; Jiang, Nan; Fernandez-Rojas, Xinia; Park, Bock-Hee
2009-01-01
This study examined cultural influence on personal and behavioral correlates of lack of regular physical activity (PA) among college students in four countries, i.e., the United States, Costa Rica, India, and South Korea. Public universities were randomly chosen among the four countries. A total of 4,685 students participated in the study during the 2006-2007 academic year with a response rate of 90.1%. The vast majority of the questions on the instrument were adopted from the Youth Risk Behavior Survey and the Behavioral Risk Factor Surveillance System questionnaires. The instrument was translated into Spanish and Korean and then back-translated into English to check accuracy of the translation. Low fruit consumption was a culture-universal predictor of lack of regular PA. Gender, perceived body weight, vegetable consumption, and cigarette smoking were culture-specific predictors, indicating PA might be a transversal value. Body mass index, binge drinking, and TV/video watching were not associated with lack of regular PA in any of the four countries. While PA is valued across different segments of many cultures, given the several culture-specific predictors, PA appears to be more transversal than universal. Therefore, culturally sensitive interventions are necessary to promote PA among young adults.
Should image rotation be addressed during routine cone-beam CT quality assurance?
NASA Astrophysics Data System (ADS)
Ayan, Ahmet S.; Lin, Haibo; Yeager, Caitlyn; Deville, Curtiland; McDonough, James; Zhu, Timothy C.; Anderson, Nathan; Bar Ad, Voichita; Lu, Hsiao-Ming; Both, Stefan
2013-02-01
The purpose of this study is to investigate whether quality assurance (QA) for cone-beam computed tomography (CBCT) image rotation is necessary in order to ensure the accuracy of CBCT based image-guided radiation therapy (IGRT) and adaptive radiotherapy (ART). Misregistration of angular coordinates during CBCT acquisition may lead to a rotated reconstructed image. If target localization is performed based on this image, an under- or over-dosage of the target volume (TV) and organs at risk (OARs) may occur. Therefore, patient CT image sets were rotated by 1° up to 3° and the treatment plans were recalculated to quantify changes in dose-volume histograms. A computer code in C++ was written to model the TV displacement and overlap area of an ellipse shape at the target and dose prescription levels corresponding to the image rotation. We investigated clinical scenarios in IGRT and ART in order to study the implications of image rotation on dose distributions for: (1) lateral TV and isocenter (SBRT), (2) central TV and isocenter (IMRT), (3) lateral TV and isocenter (IMRT). Mathematical analysis showed the dose coverage of TV depends on its shape, size, location, and orientation relative to the isocenter. Evaluation of three first scenario for θ = 1° showed variations in TV D95 in the context of IGRT and ART when compared to the original plan were within 2.7 ± 2.6% and 7.7 ± 6.9% respectively while variations in the second and third scenarios were less significant (<0.5%) for the angular range evaluated. However a larger degree of variation was found in terms of minimum and maximum doses for target and OARs. The rotation of CBCT image data sets may have significant dosimetric consequences in IGRT and ART. The TV's location relative to isocenter and shape determine the extent of alterations in dose indicators. Our findings suggest that a CBCT QA criterion of 1° would be a reasonable action level to ensure accurate dose delivery.
Shafer, Paul R; Davis, Kevin C; Patel, Deesha; Rodes, Robert; Beistle, Diane
2016-02-17
In 2012, the US Centers for Disease Control and Prevention (CDC) launched Tips From Former Smokers (Tips), the first federally funded national tobacco education campaign. In 2013, a follow-up Tips campaign aired on national cable television networks, radio, and other channels, with supporting digital advertising to drive traffic to the Tips campaign website. The objective of this study was to use geographic and temporal variability in 2013 Tips campaign television media doses and ad tagging to evaluate changes in traffic to the campaign website in response to specific doses of campaign media. Linear regression models were used to estimate the dose-response relationship between weekly market-level television gross rating points (GRPs) and weekly Web traffic to the Tips campaign website. This relationship was measured using unique visitors, total visits, and page views as outcomes. Ad GRP effects were estimated separately for ads tagged with the Tips campaign website URL and 1-800-QUIT-NOW. In the average media market, an increase of 100 television GRPs per week for ads tagged with the Tips campaign website URL was associated with an increase of 650 unique visitors (P<.001), 769 total visits (P<.001), and 1255 total page views (P<.001) per week. The associations between GRPs for ads tagged with 1-800-QUIT-NOW and each Web traffic measure were also statistically significant (P<.001), but smaller in magnitude. Based on these findings, we estimate that the 16-week 2013 Tips television campaign generated approximately 660,000 unique visitors, 900,000 total visits, and 1,390,000 page views for the Tips campaign website. These findings can help campaign planners forecast the likely impact of targeted advertising efforts on consumers' use of campaign-specific websites.
Ruggieri, M; Fumarola, A; Straniero, A; Maiuolo, A; Coletta, I; Veltri, A; Di Fiore, A; Trimboli, P; Gargiulo, P; Genderini, M; D'Armiento, M
2008-09-01
Actually, thyroid volume >25 ml, obtained by preoperative ultrasound evaluation, is a very important exclusion criteria for minimally invasive thyroidectomy. So far, among different imaging techniques, two-dimensional ultrasonography has become the more accepted method for the assessment of thyroid volume (US-TV). The aims of this study were: (1) to estimate the preoperative thyroid volume in patients undergoing minimally invasive total thyroidectomy using a mathematical formula and (2) to verify its validity by comparing it with the postsurgical TV (PS-TV). In 53 patients who underwent minimally invasive total thyroidectomy (from January 2003 to December 2007), US-TV, obtained by ellipsoid volume formula, was compared to PS-TV determined by the Archimedes' principle. A mathematical formula able to predict the TV from the US-TV was applied in 34 cases in the last 2 years. Mean US-TV (14.4 +/- 5.9 ml) was significantly lower than mean PS-TV (21.7 +/- 10.3 ml). This underestimation was related to gland multinodularity and/or nodular involvement of the isthmus. A mathematical formula to reduce US-TV underestimation and predict the real TV was developed using a linear model. Mean predicted TV (16.8 +/- 3.7 ml) perfectly matched mean PS-TV, underestimating PS-TV in 19% of cases. We verified the accuracy of this mathematical model in patients' eligibility for minimally invasive total thyroidectomy, and we demonstrated that a predicted TV <25 ml was confirmed post-surgery in 94% of cases. We demonstrated that using a linear model, it is possible to predict from US the PS-TV with high accuracy. In fact, the mean predicted TV perfectly matched the mean PS-TV in all cases. In particular, the percentage of cases in which the predicted TV perfectly matched the PS-TV increases from 23%, estimated by US, to 43%. Moreover, the percentage of TV underestimation was reduced from 77% to 19%, as well as the range of the disagreement from up to 200% to 80%. This study shows that two-dimensional US can provide the accurate estimation of thyroid volume but that it can be improved by a mathematical model. This may contribute to a more appropriate surgical management of thyroid diseases.
Messages of distinction: the HIV/AIDS media campaign in Thailand.
Lyttleton, C
1996-03-01
In predominantly rural Thailand, television is a primary source of HIV/AIDS knowledge. Since 1990, HIV/AIDS warning messages have been aired regularly and repeatedly on television as part of the national strategy to minimize transmission of HIV. The education and prevention messages chosen do more than suggest measures to avoid infection. Within a logic of risk, these messages also define characteristics of people who are signified as threatening agents of infection. In Thailand, prostitutes and drug users are portrayed as the feared Other. Because commercial sex is so widespread, the demarcation of prostitutes as a high risk group signals a diffuse threat not easily subject to conceptual distancing. It is the pervasive and often fear-based associations born of the media material that, in large part, establish the basis for emergent practice when thoughts or actions are triggered by consideration of HIV/AIDS.
NASA Astrophysics Data System (ADS)
Han, Hao; Gao, Hao; Xing, Lei
2017-08-01
Excessive radiation exposure is still a major concern in 4D cone-beam computed tomography (4D-CBCT) due to its prolonged scanning duration. Radiation dose can be effectively reduced by either under-sampling the x-ray projections or reducing the x-ray flux. However, 4D-CBCT reconstruction under such low-dose protocols is prone to image artifacts and noise. In this work, we propose a novel joint regularization-based iterative reconstruction method for low-dose 4D-CBCT. To tackle the under-sampling problem, we employ spatiotemporal tensor framelet (STF) regularization to take advantage of the spatiotemporal coherence of the patient anatomy in 4D images. To simultaneously suppress the image noise caused by photon starvation, we also incorporate spatiotemporal nonlocal total variation (SNTV) regularization to make use of the nonlocal self-recursiveness of anatomical structures in the spatial and temporal domains. Under the joint STF-SNTV regularization, the proposed iterative reconstruction approach is evaluated first using two digital phantoms and then using physical experiment data in the low-dose context of both under-sampled and noisy projections. Compared with existing approaches via either STF or SNTV regularization alone, the presented hybrid approach achieves improved image quality, and is particularly effective for the reconstruction of low-dose 4D-CBCT data that are not only sparse but noisy.
Conductivity map from scanning tunneling potentiometry.
Zhang, Hao; Li, Xianqi; Chen, Yunmei; Durand, Corentin; Li, An-Ping; Zhang, X-G
2016-08-01
We present a novel method for extracting two-dimensional (2D) conductivity profiles from large electrochemical potential datasets acquired by scanning tunneling potentiometry of a 2D conductor. The method consists of a data preprocessing procedure to reduce/eliminate noise and a numerical conductivity reconstruction. The preprocessing procedure employs an inverse consistent image registration method to align the forward and backward scans of the same line for each image line followed by a total variation (TV) based image restoration method to obtain a (nearly) noise-free potential from the aligned scans. The preprocessed potential is then used for numerical conductivity reconstruction, based on a TV model solved by accelerated alternating direction method of multiplier. The method is demonstrated on a measurement of the grain boundary of a monolayer graphene, yielding a nearly 10:1 ratio for the grain boundary resistivity over bulk resistivity.
Impact of television on the quality of sleep in preschool children.
Brockmann, Pablo E; Diaz, Blanca; Damiani, Felipe; Villarroel, Luis; Núñez, Felipe; Bruni, Oliviero
2016-04-01
We aimed to investigate the impact of different habits concerning television (TV) use and the time of day in which TV is watched on the sleep quality of young children. Parents of 100 healthy children (58% boys, mean age of 2.7 ± 1.5 years) attending a routine health check completed the Sleep Disturbance Scale for Children (SDSC) and a questionnaire concerning TV and electronic media use. Children were divided into those with a normal (SDSC-) or abnormal (SDSC+) questionnaire score. TV viewing habits were compared between groups. The total sleep time and total TV viewing time were not different between groups. A TV set was inside each child's bedroom in 51% of participants. Children with a TV in their bedroom showed significantly higher scores in the "sleep terrors," "nightmares," "sleep talking," and "tired when waking up" responses of the SDSC (P = 0.02, 0.01, 0.01, and 0.01, respectively). Children with a TV in their room had an odds ratio (95% confidence interval) of 3.29 (1.08-9.99) for having an abnormal SDSC. Evening TV viewers had significantly higher SDSC scores compared with those who watched TV earlier during the day (P = 0.04). The presence of a TV set in the child's bedroom was associated with significant reductions in the quality of young children's sleep. Evening exposure to TV was associated with significantly worse sleep quality. Copyright © 2015 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Kazantsev, Daniil; Jørgensen, Jakob S.; Andersen, Martin S.; Lionheart, William R. B.; Lee, Peter D.; Withers, Philip J.
2018-06-01
Rapid developments in photon-counting and energy-discriminating detectors have the potential to provide an additional spectral dimension to conventional x-ray grayscale imaging. Reconstructed spectroscopic tomographic data can be used to distinguish individual materials by characteristic absorption peaks. The acquired energy-binned data, however, suffer from low signal-to-noise ratio, acquisition artifacts, and frequently angular undersampled conditions. New regularized iterative reconstruction methods have the potential to produce higher quality images and since energy channels are mutually correlated it can be advantageous to exploit this additional knowledge. In this paper, we propose a novel method which jointly reconstructs all energy channels while imposing a strong structural correlation. The core of the proposed algorithm is to employ a variational framework of parallel level sets to encourage joint smoothing directions. In particular, the method selects reference channels from which to propagate structure in an adaptive and stochastic way while preferring channels with a high data signal-to-noise ratio. The method is compared with current state-of-the-art multi-channel reconstruction techniques including channel-wise total variation and correlative total nuclear variation regularization. Realistic simulation experiments demonstrate the performance improvements achievable by using correlative regularization methods.
Antismoking television advertising and socioeconomic variations in calls to Quitline.
Siahpush, Mohammad; Wakefield, Melanie; Spittal, Matt; Durkin, Sarah
2007-04-01
To assess the socioeconomic variations in call rates to the Quitline (Victoria, Australia) and in the impact of anti-tobacco television advertising on call rates. The outcome measure was the number of calls to the Quitline in Victoria for each week for each socioeconomic group for the period January 2001 to March 2004. Socioeconomic status (SES) was derived from the caller's postcode using the Index of Socioeconomic Disadvantage provided by the Australian Bureau of Statistics. The exposure measure was weekly Target Audience Rating Points (TARPs, a standard measure of television advertising weight) for anti-tobacco advertising broadcast in Victoria over the same period. Negative binomial regression was used to examine the interaction of SES and TARPs in their effect on the number of Quitline calls. SES and call rates were positively associated. Adjusted call rate was 57% (95% CI 45% to 69%) higher in the highest than the lowest SES quintile. SES differences in call rates were stable over time. In the study period, the effect of the presence or increasing levels of antismoking TARPs on call rates did not vary across categories of SES. In the study period, different SES groups had a similar level of responsiveness to antismoking television advertisements, at least as measured by the rate of calls to the Quitline. However, the present media campaigns are not likely to diminish SES differences in call rates, and more needs to be done to encourage disadvantaged groups to call the Quitline.
Antismoking television advertising and socioeconomic variations in calls to Quitline
Siahpush, Mohammad; Wakefield, Melanie; Spittal, Matt; Durkin, Sarah
2007-01-01
Objective To assess the socioeconomic variations in call rates to the Quitline (Victoria, Australia) and in the impact of anti‐tobacco television advertising on call rates. Design The outcome measure was the number of calls to the Quitline in Victoria for each week for each socioeconomic group for the period January 2001 to March 2004. Socioeconomic status (SES) was derived from the caller's postcode using the Index of Socioeconomic Disadvantage provided by the Australian Bureau of Statistics. The exposure measure was weekly Target Audience Rating Points (TARPs, a standard measure of television advertising weight) for anti‐tobacco advertising broadcast in Victoria over the same period. Negative binomial regression was used to examine the interaction of SES and TARPs in their effect on the number of Quitline calls. Results SES and call rates were positively associated. Adjusted call rate was 57% (95% CI 45% to 69%) higher in the highest than the lowest SES quintile. SES differences in call rates were stable over time. In the study period, the effect of the presence or increasing levels of antismoking TARPs on call rates did not vary across categories of SES. Conclusions In the study period, different SES groups had a similar level of responsiveness to antismoking television advertisements, at least as measured by the rate of calls to the Quitline. However, the present media campaigns are not likely to diminish SES differences in call rates, and more needs to be done to encourage disadvantaged groups to call the Quitline. PMID:17372288
Accelerated Edge-Preserving Image Restoration Without Boundary Artifacts
Matakos, Antonios; Ramani, Sathish; Fessler, Jeffrey A.
2013-01-01
To reduce blur in noisy images, regularized image restoration methods have been proposed that use non-quadratic regularizers (like l1 regularization or total-variation) that suppress noise while preserving edges in the image. Most of these methods assume a circulant blur (periodic convolution with a blurring kernel) that can lead to wraparound artifacts along the boundaries of the image due to the implied periodicity of the circulant model. Using a non-circulant model could prevent these artifacts at the cost of increased computational complexity. In this work we propose to use a circulant blur model combined with a masking operator that prevents wraparound artifacts. The resulting model is non-circulant, so we propose an efficient algorithm using variable splitting and augmented Lagrangian (AL) strategies. Our variable splitting scheme, when combined with the AL framework and alternating minimization, leads to simple linear systems that can be solved non-iteratively using FFTs, eliminating the need for more expensive CG-type solvers. The proposed method can also efficiently tackle a variety of convex regularizers including edge-preserving (e.g., total-variation) and sparsity promoting (e.g., l1 norm) regularizers. Simulation results show fast convergence of the proposed method, along with improved image quality at the boundaries where the circulant model is inaccurate. PMID:23372080
Benefits of an exercise wellness program after spinal cord injury.
Crane, Deborah A; Hoffman, Jeanne M; Reyes, Maria R
2017-03-01
To describe the initial benefits of a structured group exercise program on exercise frequency and intensity, perceived health, pain, mood, and television watching habits. Pre-test/post-test. Eighty-nine persons with SCI participated voluntarily in a no-cost, twice weekly physical therapy group exercise class over 3 months. Forty-five persons completed pre- and post-participation interviews on exercise frequency and intensity, perceived health, pain, mood, sleep, and television watching habits. Mean participant age of the respondents was 43.82 years. 49% had AIS C or D injuries, 24% had AIS A,B paraplegia, 9% had AIS A,B C1-C4 and 18% had AIS A,B C5-C8. 75.6% of participants were male and 84.4% had a traumatic etiology as the cause of their SCI. There was a significant improvement in days of strenuous and moderate exercise as well as health state. There was an average decrease in pain scores, depression scores, number of hours spent watching television, and days/week of mild exercise. Participation in structured, small group exercise as a component of a wellness program after SCI shows promise for improving regular exercise participation and health state, but benefits may also occur across other areas of health and function including mood, pain, and hours spent watching television. Further follow-up is needed to determine whether improvements can be maintained after program completion and across all neurological levels.
Sequentially reweighted TV minimization for CT metal artifact reduction.
Zhang, Xiaomeng; Xing, Lei
2013-07-01
Metal artifact reduction has long been an important topic in x-ray CT image reconstruction. In this work, the authors propose an iterative method that sequentially minimizes a reweighted total variation (TV) of the image and produces substantially artifact-reduced reconstructions. A sequentially reweighted TV minimization algorithm is proposed to fully exploit the sparseness of image gradients (IG). The authors first formulate a constrained optimization model that minimizes a weighted TV of the image, subject to the constraint that the estimated projection data are within a specified tolerance of the available projection measurements, with image non-negativity enforced. The authors then solve a sequence of weighted TV minimization problems where weights used for the next iteration are computed from the current solution. Using the complete projection data, the algorithm first reconstructs an image from which a binary metal image can be extracted. Forward projection of the binary image identifies metal traces in the projection space. The metal-free background image is then reconstructed from the metal-trace-excluded projection data by employing a different set of weights. Each minimization problem is solved using a gradient method that alternates projection-onto-convex-sets and steepest descent. A series of simulation and experimental studies are performed to evaluate the proposed approach. Our study shows that the sequentially reweighted scheme, by altering a single parameter in the weighting function, flexibly controls the sparsity of the IG and reconstructs artifacts-free images in a two-stage process. It successfully produces images with significantly reduced streak artifacts, suppressed noise and well-preserved contrast and edge properties. The sequentially reweighed TV minimization provides a systematic approach for suppressing CT metal artifacts. The technique can also be generalized to other "missing data" problems in CT image reconstruction.
Fast alternating projection methods for constrained tomographic reconstruction
Liu, Li; Han, Yongxin
2017-01-01
The alternating projection algorithms are easy to implement and effective for large-scale complex optimization problems, such as constrained reconstruction of X-ray computed tomography (CT). A typical method is to use projection onto convex sets (POCS) for data fidelity, nonnegative constraints combined with total variation (TV) minimization (so called TV-POCS) for sparse-view CT reconstruction. However, this type of method relies on empirically selected parameters for satisfactory reconstruction and is generally slow and lack of convergence analysis. In this work, we use a convex feasibility set approach to address the problems associated with TV-POCS and propose a framework using full sequential alternating projections or POCS (FS-POCS) to find the solution in the intersection of convex constraints of bounded TV function, bounded data fidelity error and non-negativity. The rationale behind FS-POCS is that the mathematically optimal solution of the constrained objective function may not be the physically optimal solution. The breakdown of constrained reconstruction into an intersection of several feasible sets can lead to faster convergence and better quantification of reconstruction parameters in a physical meaningful way than that in an empirical way of trial-and-error. In addition, for large-scale optimization problems, first order methods are usually used. Not only is the condition for convergence of gradient-based methods derived, but also a primal-dual hybrid gradient (PDHG) method is used for fast convergence of bounded TV. The newly proposed FS-POCS is evaluated and compared with TV-POCS and another convex feasibility projection method (CPTV) using both digital phantom and pseudo-real CT data to show its superior performance on reconstruction speed, image quality and quantification. PMID:28253298
Staff Development Resources, 1990-91.
ERIC Educational Resources Information Center
South Carolina State Dept. of Education, Columbia. Office of Instructional Technology.
This staff development resource guide provides listings of instructional television and radio broadcasts related to major areas of the Total Teaching Act in South Carolina's Program for Effective Teaching (PET). Television program topics include: administration; adult education; the arts; career education; certificate-renewal credit courses;…
Hirpara, Darshna G; Gajera, H P; Hirapara, Jaydeep G; Golakiya, B A
2017-11-01
Trichoderma is one of the most exploited biocontrol agent for the management of plant diseases. Twenty strains of Trichoderma (six of T. harzianum, four of T. viride, three of T. virens, three of T. koningii, each one of T. hamatum, T. reesei, T. parceramosum and Trichoderma spp.) subjected to in vitro antagonism up to 12days after inoculation against Sclerotium rolfsii Sacc. causing stem rot in groundnut. A new concept was developed to determine inhibition coefficient representing pathogen biology and biocontrol related biophysical variables. Results explained differential inhibition coefficient of test pathogen by Trichoderma antagonists. The inhibition coefficient of test pathogen was examined highest (91.13%) by T. virens NBAII Tvs12 followed by T. virens MTCC 794 (89.33%) and T. koningii MTCC 796 (62.39%). Microscopic study confirmed biocontrol mechanism as mycoparasitism for Tvs12 and antibiosis for T. koningii MTCC 796. The sclerotial biogenesis of test pathogen was elevated during weak antagonism and diminished in interactions with strong antagonists. The inhibition coefficient of S. rolfsii was significantly negatively correlated with sclerotia formation and lipid peroxidation during the antagonism. Trichoderma strains were screened for fungicides (carbendazim and tebuconazole, thiram and mancozeb) and abiotic stress (drought and salt) tolerance. Results indicated that T. koningii MTCC 796 efficiently grew better than the other strains with maximum radial growth under adverse conditions. The genetic variability among the Trichoderma was determined using 34 gene specific markers which amplified 146 alleles. The SSR similarities explained substantial diversity (15 to 87%) across Trichoderma strains and pathogen S. rolfsii. Principal coordinates analysis (PCA) were comparable to the cluster analysis and first three most informative PC components explained 64.45% of the total variation. In PCA, potent antagonists appear to be distinct from other strains. Five SSR markers T1F/T1R (311) , TvCTT56f/TvCTT56r (387) , TvGAT18f/TvGAT18r (364) , TvCA39f/TvCA39r (196) and TvAG29f/TvAG29r (418) found to be unique to distinguish best antagonist strain Tvs12. However, MTCC 796 was examined most stress tolerant strain with better inhibition coefficient which might be useful to control the disease under adverse conditions or as a part of integrated pest management. Copyright © 2017. Published by Elsevier B.V.
Reality television predicts both positive and negative outcomes for adolescent girls.
Ferguson, Christopher J; Salmond, Kimberlee; Modi, Kamla
2013-06-01
To assess the influence of media, specifically reality television, on adolescent behavior. A total of 1141 preteen and adolescent girls (age range 11-17) answered questions related to their reality television viewing, personality, self-esteem, relational aggression, appearance focus, and desire for fame. Our results indicated that the influence of reality television on adolescent behavior is complex and potentially related to the adolescents' intended uses and gratifications for using reality television. Reality television viewing was positively related to increased self-esteem and expectations of respect in dating relationships. However, watching reality television also was related to an increased focus on appearance and willingness to compromise other values for fame. Reality television viewing did not predict relational aggression. The potential influences of reality television use on adolescent girls are both positive and negative, defying easy categorization. Copyright © 2013 Mosby, Inc. All rights reserved.
Relationships between use of television during meals and children's food consumption patterns.
Coon, K A; Goldberg, J; Rogers, B L; Tucker, K L
2001-01-01
We examined relationships between the presence of television during meals and children's food consumption patterns to test whether children's overall food consumption patterns, including foods not normally advertised, vary systematically with the extent to which television is part of normal mealtime routines. Ninety-one parent-child pairs from suburbs adjacent to Washington, DC, recruited via advertisements and word of mouth, participated. Children were in the fourth, fifth, or sixth grades. Socioeconomic data and information on television use were collected during survey interviews. Three nonconsecutive 24-hour dietary recalls, conducted with each child, were used to construct nutrient and food intake outcome variables. Independent sample t tests were used to compare mean food and nutrient intakes of children from families in which the television was usually on during 2 or more meals (n = 41) to those of children from families in which the television was either never on or only on during one meal (n = 50). Multiple linear regression models, controlling for socioeconomic factors and other covariates, were used to test strength of associations between television and children's consumption of food groups and nutrients. Children from families with high television use derived, on average, 6% more of their total daily energy intake from meats; 5% more from pizza, salty snacks, and soda; and nearly 5% less of their energy intake from fruits, vegetables, and juices than did children from families with low television use. Associations between television and children's consumption of food groups remained statistically significant in multiple linear regression models that controlled for socioeconomic factors and other covariates. Children from high television families derived less of their total energy from carbohydrate and consumed twice as much caffeine as children from low television families. There continued to be a significant association between television and children's consumption of caffeine when these relationships were tested in multiple linear regression models. The dietary patterns of children from families in which television viewing is a normal part of meal routines may include fewer fruits and vegetables and more pizzas, snack foods, and sodas than the dietary patterns of children from families in which television viewing and eating are separate activities.
Impact of tobacco control policies and mass media campaigns on monthly adult smoking prevalence.
Wakefield, Melanie A; Durkin, Sarah; Spittal, Matthew J; Siahpush, Mohammad; Scollo, Michelle; Simpson, Julie A; Chapman, Simon; White, Victoria; Hill, David
2008-08-01
We sought to assess the impact of several tobacco control policies and televised antismoking advertising on adult smoking prevalence. We used a population survey in which smoking prevalence was measured each month from 1995 through 2006. Time-series analysis assessed the effect on smoking prevalence of televised antismoking advertising (with gross audience rating points [GRPs] per month), cigarette costliness, monthly sales of nicotine replacement therapy (NRT) and bupropion, and smoke-free restaurant laws. Increases in cigarette costliness and exposure to tobacco control media campaigns significantly reduced smoking prevalence. We found a 0.3-percentage-point reduction in smoking prevalence by either exposing the population to televised antismoking ads an average of almost 4 times per month (390 GRPs) or by increasing the costliness of a pack of cigarettes by 0.03% of gross average weekly earnings. Monthly sales of NRT and bupropion, exposure to NRT advertising, and smoke-free restaurant laws had no detectable impact on smoking prevalence. Increases in the real price of cigarettes and tobacco control mass media campaigns broadcast at sufficient exposure levels and at regular intervals are critical for reducing population smoking prevalence.
Impact of Tobacco Control Policies and Mass Media Campaigns on Monthly Adult Smoking Prevalence
Wakefield, Melanie A.; Durkin, Sarah; Spittal, Matthew J.; Siahpush, Mohammad; Scollo, Michelle; Simpson, Julie A.; Chapman, Simon; White, Victoria; Hill, David
2008-01-01
Objectives. We sought to assess the impact of several tobacco control policies and televised antismoking advertising on adult smoking prevalence. Methods. We used a population survey in which smoking prevalence was measured each month from 1995 through 2006. Time-series analysis assessed the effect on smoking prevalence of televised antismoking advertising (with gross audience rating points [GRPs] per month), cigarette costliness, monthly sales of nicotine replacement therapy (NRT) and bupropion, and smoke-free restaurant laws. Results. Increases in cigarette costliness and exposure to tobacco control media campaigns significantly reduced smoking prevalence. We found a 0.3-percentage-point reduction in smoking prevalence by either exposing the population to televised antismoking ads an average of almost 4 times per month (390 GRPs) or by increasing the costliness of a pack of cigarettes by 0.03% of gross average weekly earnings. Monthly sales of NRT and bupropion, exposure to NRT advertising, and smoke-free restaurant laws had no detectable impact on smoking prevalence. Conclusions. Increases in the real price of cigarettes and tobacco control mass media campaigns broadcast at sufficient exposure levels and at regular intervals are critical for reducing population smoking prevalence. PMID:18556601
NASA Astrophysics Data System (ADS)
Mitsuhashi, Tetsuo
1990-08-01
HDTV (known as Hi-Vision in Japan), with its ability to provide through high- definition pictures on a large screen display advanced psychological effects such as sensations of reality and a visual impact unobtainable in conventional television, is the television system of the next generation. In Japan, daily one-hour experimental broadcasting was initiated in June 1989 using the BS-2 broadcast satellite, and regular service is scheduled to begin via the BS-3 satellite to be launched in 1990. To this end, a home-use receiver using VLSIs has already been developed. Moreover, HDTV is currently being applied in such diverse areas as film production, printing and publishing, medicine, and art museums. The HDTV system handles approximately five times the information of conventional television. As a result, a large screen display capable of maintaining stable resolution greater than twice that of conventional displays is essential to the full realization of HDTV's vast potential. This paper will first discuss HDTV's basic parameters, concentrating on the psychovisual effects, and explain some preferable display characteristics from this psychovisual point of view. It will then discuss the technical problems in developing such a display, and final ly describe the current state of HDTV display development.
Direct effects of food cues seen during TV viewing on energy intake in young women.
van Nee, Roselinde L; Larsen, Junilla K; Fisher, Jennifer O
2016-06-01
Few studies have examined direct effects of food cues presented within television (TV) programs on eating behavior in adults. This research experimentally determined whether exposure to food cues in TV programs affects energy intake during TV viewing among young women, independently from food cues presented in TV advertisements. The experiment involved a 2 (TV program with or without food cues) by 2 (TV advertisements with or without food cues) between-participants design. While watching TV, participants could freely eat peanut chocolate candies and crisps (potato chips). Participants were 121 young women (mean age = 19.6 years; mean BMI = 22.5). Participants who watched a TV program with food cues tended to have a lower total energy intake and ate significantly less peanut chocolate candies than participants who watched the same TV program without food cues. This effect was particularly pronounced among participants with a higher BMI. Food advertisements did not affect energy intake. Findings may indicate that subtle continuous food cues during TV programs could make young females more aware of their own eating and/or weight, leading to reduced intake of particularly sweet snack foods during TV viewing. Considering the non-significant trend for the effect of the TV program with food cues on total energy intake, findings should be replicated to provide possible tools for prevention campaigns using food cue reminders to watch one's intake. Copyright © 2016 Elsevier Ltd. All rights reserved.
Jucker, Jean-Luc; Thornborrow, Tracey; Beierholm, Ulrik; Burt, D Michael; Barton, Robert A; Evans, Elizabeth H; Jamieson, Mark A; Tovée, Martin J; Boothroyd, Lynda G
2017-08-16
Television consumption influences perceptions of attractive female body size. However, cross-cultural research examining media influence on body ideals is typically confounded by differences in the availability of reliable and diverse foodstuffs. 112 participants were recruited from 3 Nicaraguan villages that differed in television consumption and nutritional status, such that the contribution of both factors could be revealed. Participants completed a female figure preference task, reported their television consumption, and responded to several measures assessing nutritional status. Communities with higher television consumption and/or higher nutritional status preferred thinner female bodies than communities with lower television consumption and/or lower nutritional status. Bayesian mixed models estimated the plausible range of effects for television consumption, nutritional status, and other relevant variables on individual preferences. The model explained all meaningful differences between our low-nutrition villages, and television consumption, after sex, was the most likely of these predictors to contribute to variation in preferences (probability mass >95% when modelling only variables with zero-order associations with preferences, but only 90% when modelling all possible predictors). In contrast, we found no likely link with nutritional status. We thus found evidence that where media access and nutritional status are confounded, media is the more likely predictor of body ideals.
NASA Astrophysics Data System (ADS)
Li, Dongming; Zhang, Lijuan; Wang, Ting; Liu, Huan; Yang, Jinhua; Chen, Guifen
2016-11-01
To improve the adaptive optics (AO) image's quality, we study the AO image restoration algorithm based on wavefront reconstruction technology and adaptive total variation (TV) method in this paper. Firstly, the wavefront reconstruction using Zernike polynomial is used for initial estimated for the point spread function (PSF). Then, we develop our proposed iterative solutions for AO images restoration, addressing the joint deconvolution issue. The image restoration experiments are performed to verify the image restoration effect of our proposed algorithm. The experimental results show that, compared with the RL-IBD algorithm and Wiener-IBD algorithm, we can see that GMG measures (for real AO image) from our algorithm are increased by 36.92%, and 27.44% respectively, and the computation time are decreased by 7.2%, and 3.4% respectively, and its estimation accuracy is significantly improved.
Wijndaele, Katrien; Brage, Søren; Besson, Hervé; Khaw, Kay-Tee; Sharp, Stephen J.; Luben, Robert; Bhaniani, Amit; Wareham, Nicholas J.; Ekelund, Ulf
2011-01-01
Background Although television viewing time is detrimentally associated with intermediate cardiovascular risk factors, the relationship with incident total (i.e. combined fatal and non-fatal) cardiovascular disease (CVD), non-fatal CVD and coronary heart disease is largely unknown. This study examined whether television viewing time is associated with these three outcomes, independently of physical activity energy expenditure and other confounding variables. Methodology/Principal Findings A population-based cohort of 12,608 men and women (aged 61.4±9.0), free from stroke, myocardial infarction and cancer at baseline in 1998–2000 were followed up until 2007 (6.9±1.9 years). Participants self-reported education, smoking, alcohol use, antihypertensive, lipid lowering and antidepressant medication, disease history, total energy intake, sleep duration, physical activity and television viewing. BMI, waist circumference, blood pressure, triglycerides, HDL cholesterol and glycated haemoglobin (HbA1c) were measured by standardized procedures; a clustered metabolic risk score was constructed. Every one hour/day increase in television viewing was associated with an increased hazard for total (HR = 1.06, 95%CI = 1.03–1.08; 2,620 cases), non-fatal CVD (HR = 1.06, 95%CI = 1.03–1.09; 2,134 cases), and coronary heart disease (HR = 1.08, 95%CI = 1.03–1.13; 940 cases), independent of gender, age, education, smoking, alcohol, medication, diabetes status, CVD family history, sleep duration and physical activity energy expenditure. Energy intake, BMI, waist circumference, blood pressure, triglycerides, HDL cholesterol, HbA1c and the clustered metabolic risk score only partially mediated these associations. Conclusions These results indicate that the most prevalent leisure time (sedentary) behaviour, television viewing, independently contributes to increased CVD risk. Recommendations on reducing television viewing time should be considered. PMID:21647437
Serial-to-parallel color-TV converter
NASA Technical Reports Server (NTRS)
Doak, T. W.; Merwin, R. B.; Zuckswert, S. E.; Sepper, W.
1976-01-01
Solid analog-to-digital converter eliminates flicker and problems with time base stability and gain variation in sequential color TV cameras. Device includes 3-bit delta modulator; two-field memory; timing, switching, and sync network; and three 3-bit delta demodulators
Gordon-Salant, Sandra; Callahan, Julia S.
2010-01-01
Objectives Although watching television is a common leisure activity of older adults, the ability to understand televised speech may be compromised by age-related hearing loss. Two potential assistive devices for improving television viewing are hearing aids and closed captioning, but their use and benefit by older adults with hearing loss are unknown. The primary purpose of this initial investigation was to determine if older hearing-impaired adults show improvements in understanding televised speech with the use of these two assistive devices (hearing aids and closed captioning) compared to conditions without these devices. A secondary purpose was to examine the frequency of hearing aid use and closed captioning use among a sample of older hearing aid wearers. Design The investigation entailed a randomized, repeated-measures design of 15 older adults (59–82 years) with bilateral sensorineural hearing losses who wore hearing aids. Participants viewed three types of televised programs (news, drama, game show) that were each edited into lists of speech segments, and provided an identification response. Each participant was tested in four conditions: baseline (no hearing aids or closed captioning), hearing aids only, closed captioning only, and hearing aids + closed captioning. Pilot testing with young normal-hearing listeners was conducted also to establish list equivalence and stimulus intelligibility with a control group. All testing was conducted in a quiet room to simulate a living room, using a 19-in flat screen television. Questionnaires were also administered to participants to determine frequency of hearing aid use and closed captioning use while watching television. Results A significant effect of viewing condition was observed for all programs. Participants exhibited significantly better speech recognition scores in conditions with closed captioning than those without closed captioning (p<.01). Use of personal hearing aids did not significantly improve recognition of televised speech compared to the unaided condition. The condition effect was similar across the three different programs. Most of the participants (73%) regularly wore their hearing aids while watching television; very few of them (13%) had ever used closed captioning. Conclusions On average, use of closed captioning while watching television dramatically improved speech understanding by a sample of older hearing-impaired adults compared to conditions without closed captioning, including when hearing aids were worn. PMID:19444122
Children's violent television viewing: are parents monitoring?
Cheng, Tina L; Brenner, Ruth A; Wright, Joseph L; Sachs, Hari Cheryl; Moyer, Patricia; Rao, Malla R
2004-07-01
Violent media exposure has been associated with aggressive behavior, and it has been suggested that child health professionals counsel families on limiting exposure. Effective violence prevention counseling requires an understanding of norms regarding parental attitudes, practices, and influencing factors. Both theories of reasoned action and planned behavior emphasize that subjective norms and attitudes affect people's perceptions and intended behavior. Few data exist on violent television viewing and monitoring from a cross-section of families. By understanding the spectrum of parental attitudes, community-sensitive interventions for violence prevention can be developed. The objective of this study was to assess attitudes about and monitoring of violent television viewing from the perspective of parents. An anonymous self-report assisted survey was administered to a convenience sample of parents/guardians who visited child health providers at 3 sites: an urban children's hospital clinic, an urban managed care clinic, and a suburban private practice. The parent questionnaire included questions on child-rearing attitudes and practices and sociodemographic information. A total of 1004 adults who accompanied children for health visits were recruited for the study; 922 surveys were completed (participation rate: 92%). A total of 830 (90%) respondents were parents and had complete child data. Of the 830 respondents, 677 had questions on television viewing included in the survey and were the focus of this analysis. Seventy-five percent of families reported that their youngest child watched television. Of these, 53% reported always limiting violent television viewing, although 73% believed that their children viewed television violence at least 1 time a week. Among television viewers, 81% reported usually or always limiting viewing of sexual content on television and 45% reported usually or always watching television with their youngest child. Among children who watched television, parents reported that they spent an average of 2.6 hours per day watching television. Limitation of television violence was associated with female parents and younger children. There was variability in attitudes and practices regarding television violence viewing and monitoring among parents. Attitudes and practices varied on the basis of the age of the child and the gender of the parent.
Campos, Daniel; Hernández-Torres, Juan José; Agil, Ahmad; Comino, Mariano; López, Juan Carlos; Macías, Victoria
2016-01-01
Introduction We aimed to assess longitudinal changes in television (TV) food advertising during 2013 compared to 2007, measuring children's exposure to healthy and unhealthy advertisements, after the new European and Spanish Public Health laws published in 2011. Material and methods Two thematic channels for children (TC), and 2 generalist channels (GC) for all ages were recorded, between April and May 2013, on 2 week and 2 weekend days. Food advertisements were classified as core (CFA) (nutrient dense, low energy), non-core (NCFA) (unbalanced energy profile or high in energy), or others (OFA) (supermarkets and special food). Results One thousand two hundred sixty-three food advertisements were recorded (TC: 579/GC: 684) in 2013. NCFA were the most shown (54.9%) in the regular full day TV programming (p < 0.001). In 2013, children watching GC had a higher relative risk of being exposed to fast food advertisements than when watching TC (RR = 2.133, 95% CI: 1.398–3.255); CFA were broadcast most frequently in 2013 (GC: 23.7%; and TC: 47.2%) vs. 2007 (TC: 22.9%) (p < 0.001). The proportion of broadcasting between NCFA/CFA and OFA food advertisements in children's peak time slots was higher on TC (203/162) during 2013 than on GC (189/140), and significantly higher than that shown on TC in 2007 (180/36, p < 0.001). Conclusions Broadcasting of unhealthy TV food advertising on TC is lower today than six years ago; but, children's exposure to TV advertising of unhealthy food is worrying in Spain, and there is more exposure to unhealthy than healthy food by TV. Watching GC in 2013 had higher risk of being exposed to fast food advertisements than watching TC. PMID:27478462
Campos, Daniel; Hernández-Torres, Juan José; Agil, Ahmad; Comino, Mariano; López, Juan Carlos; Macías, Victoria; Campoy, Cristina
2016-08-01
We aimed to assess longitudinal changes in television (TV) food advertising during 2013 compared to 2007, measuring children's exposure to healthy and unhealthy advertisements, after the new European and Spanish Public Health laws published in 2011. Two thematic channels for children (TC), and 2 generalist channels (GC) for all ages were recorded, between April and May 2013, on 2 week and 2 weekend days. Food advertisements were classified as core (CFA) (nutrient dense, low energy), non-core (NCFA) (unbalanced energy profile or high in energy), or others (OFA) (supermarkets and special food). One thousand two hundred sixty-three food advertisements were recorded (TC: 579/GC: 684) in 2013. NCFA were the most shown (54.9%) in the regular full day TV programming (p < 0.001). In 2013, children watching GC had a higher relative risk of being exposed to fast food advertisements than when watching TC (RR = 2.133, 95% CI: 1.398-3.255); CFA were broadcast most frequently in 2013 (GC: 23.7%; and TC: 47.2%) vs. 2007 (TC: 22.9%) (p < 0.001). The proportion of broadcasting between NCFA/CFA and OFA food advertisements in children's peak time slots was higher on TC (203/162) during 2013 than on GC (189/140), and significantly higher than that shown on TC in 2007 (180/36, p < 0.001). Broadcasting of unhealthy TV food advertising on TC is lower today than six years ago; but, children's exposure to TV advertising of unhealthy food is worrying in Spain, and there is more exposure to unhealthy than healthy food by TV. Watching GC in 2013 had higher risk of being exposed to fast food advertisements than watching TC.
Sukumaran, Aparna; Diwakar, Madankumar P; Shastry, Shivakumar M
2012-05-01
This study was conducted to examine the nature, content, and duration of advertisements broadcasted during children's Tamil television channels and to determine the extent to which television advertising changes during school holiday and non-holiday periods and between prime time and non-prime time broadcast. Television broadcasts on two main children's Tamil television channels were video-recorded over 16 days between 17.00-19.00 hours (non-prime time) and 19.00-21.00 hours (prime time). For each commercial, the type of product advertised, as well as the duration (in seconds), was recorded. Advertisements were categorized as 'food' and 'non-food'. The former category was further subdivided into 'sugar-rich foods' and 'other foods'. The sugar-rich foods were further categorized as liquid, solid and sticky, and slowly dissolving sugars. Commercials related to the promotion of oral health products and non-food products were also recorded. Among the total of 128 h of television programmes recorded, advertising accounted for 10.15% (13.01 hours). The advertisement of sugar-rich food products, non-food and oral hygiene products occupied 50.36%, 38.41% and 1.90%, respectively, of the total advertising time. Solid and sticky products made up 100% of advertisements in this category on Chithiram television channel, compared with 62.5% of advertisements on Chutti television channel. It was concluded that the advertising of sugar-rich foods, particularly solid and sticky food products, was broadcasted more in Chithiram television channel, during school holidays and during prime time. © 2011 The Authors. International Journal of Paediatric Dentistry © 2011 BSPD, IAPD and Blackwell Publishing Ltd.
Psychological distress, television viewing, and physical activity in children aged 4 to 12 years.
Hamer, Mark; Stamatakis, Emmanuel; Mishra, Gita
2009-05-01
Sedentary behavior and physical activity may be independent risk factors for psychological distress in adolescents, although there is no existing information for children. We examined the cross-sectional association between psychological distress, television and screen entertainment time, and physical activity levels among a representative sample of children aged 4 to 12 years from the 2003 Scottish Health Survey. Participants were 1486 boys and girls (mean age: 8.5 +/- 2.3 years). Parents answered on behalf of children who were required to be present. The parents completed the Strengths and Difficulties Questionnaire and information on television and screen entertainment time, physical activity, and dietary intake of their children. An abnormally high Strengths and Difficulties Questionnaire total difficulties score (20-40) was found in 4.2% of the sample. Approximately 25% of the children were exposed to television and screen entertainment at least 3 hours/day. In general linear models, television and screen entertainment time per week and physical activity levels were independently associated with the Strengths and Difficulties Questionnaire total difficulties score after adjustment for age, gender, area deprivation level, single-parent status, medical conditions, and various dietary intake indicators. There was also an additive interaction effect showing that the combination of high television and screen entertainment time and low physical activity was associated with the highest Strengths and Difficulties Questionnaire score. Higher television and screen entertainment exposure (>2.7 hours/day) alone resulted in a 24% increase in the Strengths and Difficulties Questionnaire score in comparison with lower television and screen entertainment exposure (<1.6 hours/day), although when combined with low physical activity this resulted in a 46% increase. Higher levels of television and screen entertainment time and low physical activity levels interact to increase psychological distress in young children.
NASA Astrophysics Data System (ADS)
Cai, Ailong; Li, Lei; Zheng, Zhizhong; Zhang, Hanming; Wang, Linyuan; Hu, Guoen; Yan, Bin
2018-02-01
In medical imaging many conventional regularization methods, such as total variation or total generalized variation, impose strong prior assumptions which can only account for very limited classes of images. A more reasonable sparse representation frame for images is still badly needed. Visually understandable images contain meaningful patterns, and combinations or collections of these patterns can be utilized to form some sparse and redundant representations which promise to facilitate image reconstructions. In this work, we propose and study block matching sparsity regularization (BMSR) and devise an optimization program using BMSR for computed tomography (CT) image reconstruction for an incomplete projection set. The program is built as a constrained optimization, minimizing the L1-norm of the coefficients of the image in the transformed domain subject to data observation and positivity of the image itself. To solve the program efficiently, a practical method based on the proximal point algorithm is developed and analyzed. In order to accelerate the convergence rate, a practical strategy for tuning the BMSR parameter is proposed and applied. The experimental results for various settings, including real CT scanning, have verified the proposed reconstruction method showing promising capabilities over conventional regularization.
Children's Television Commercials; A Content Analysis.
ERIC Educational Resources Information Center
Winick, Charles; And Others
The purpose of the study described in this book was to determine the content parameter of television commercials addressed to children. A total of 236 commercials were collected from advertising agencies representing cereals, candy, drinks, foods for meals, restaurants, cookies, miscellaneous, cakes, ice cream, vitamins, and crunchy snacks. Each…
Food appearances in children's television programmes in Iceland.
Olafsdottir, Steingerdur; Berg, Christina
2017-11-01
Exposure to advertisements cannot fully explain the associations between young children's dietary intake and the time they spend in front of the television. It is therefore of importance to study television content other than advertisements in this aspect. The present study aimed to examine the nature and extent of verbal and visual appearances of foods and beverages in children's television programmes on Icelandic public service television. A total of 27 h of children's programmes (domestic and internationally produced) were watched. All verbal and visual appearances of foods and beverages were coded, as well as the context in which the foods/beverages were discussed or appeared. Children's programmes on Icelandic public service television. Two food groups were of special interest for their importance from a public health perspective: high-calorie and low-nutrient (HCLN) foods and fruits and vegetables (F&V). The χ 2 test and logistic regression were performed to analyse if the occurrence of the two groups was associated with the context where foods/beverages appeared. Of the 125 different programmes, a food or beverage appeared in 86 %. Of the total food appearances (n 599), HCLN foods accounted for 26 % and F&V for 23 %. HCLN foods were presented as desirable by appearing more frequently with child characters (P<0·01) than F&V. Public service television has the potential to improve the way food and eating is presented in children's programmes, as young childhood is a critical period for founding healthy habits for later life.
Determinants of Network News Coverage of the Oil Industry during the Late 1970s.
ERIC Educational Resources Information Center
Erfle, Stephen; McMillan, Henry
1989-01-01
Examines which firms and products best predict media coverage of the oil industry. Reports that price variations in testing oil and gasoline correlate with the extent of news coverage provided by network television. (MM)
Roberts, B C; Solomon, L B; Mercer, G; Reynolds, K J; Thewlis, D; Perilli, E
2018-04-01
To study, in end-stage knee osteoarthritis (OA) patients, relationships between indices of in vivo dynamic knee joint loads obtained pre-operatively using gait analysis, static knee alignment, and the subchondral trabecular bone (STB) microarchitecture of their excised tibial plateau quantified with 3D micro-CT. Twenty-five knee OA patients scheduled for total knee arthroplasty underwent pre-operative gait analysis. Mechanical axis deviation (MAD) was determined radiographically. Following surgery, excised tibial plateaus were micro-CT-scanned and STB microarchitecture analysed in four subregions (anteromedial, posteromedial, anterolateral, posterolateral). Regional differences in STB microarchitecture and relationships between joint loading and microarchitecture were examined. STB microarchitecture differed among subregions (P < 0.001), anteromedially exhibiting highest bone volume fraction (BV/TV) and lowest structure model index (SMI). Anteromedial BV/TV and SMI correlated strongest with the peak external rotation moment (ERM; r = -0.74, r = 0.67, P < 0.01), despite ERM being the lowest (by factor of 10) of the moments considered, with majority of ERM measures below accuracy thresholds; medial-to-lateral BV/TV ratios correlated with ERM, MAD, knee adduction moment (KAM) and internal rotation moment (|r|-range: 0.54-0.74). When controlling for walking speed, KAM and MAD, the ERM explained additional 11-30% of the variations in anteromedial BV/TV and medial-to-lateral BV/TV ratio (R 2 = 0.59, R 2 = 0.69, P < 0.01). This preliminary study suggests significant associations between tibial plateau STB microarchitecture and knee joint loading indices in end-stage knee OA patients. Particularly, anteromedial BV/TV correlates strongest with ERM, whereas medial-to-lateral BV/TV ratio correlates strongest with indicators of medial-to-lateral joint loading (MAD, KAM) and rotational moments. However, associations with ERM should be interpreted with caution. Copyright © 2018 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.
Instructional Television: Visual Production Techniques and Learning Comprehension.
ERIC Educational Resources Information Center
Silbergleid, Michael Ian
The purpose of this study was to determine if increasing levels of complexity in visual production techniques would increase the viewer's learning comprehension and the degree of likeness expressed for a college level instructional television program. A total of 119 mass communications students at the University of Alabama participated in the…
Magnetic Resonance-Based Electrical Property Tomography (MR- EPT) for Prostate Cancer Grade Imaging
2014-07-01
TV 2D 5 10 15 2 4 6 8 10 12 14 i 5 10 15 2 4 6 8 10 12 14 Figure 10. Prostate-like gelatin phantom with one inclusion (5mm, play dough ...magnitude image (TSE) and reconstructions. 11 c) Multiple Inclusions Two 5 mm diameter inclusions ( play dough to provide significant conductivity...reconstruction, 2D inverse reconstruction with Total Variation, 3D inverse reconstruction 10 b) Single inclusion A single 5 mm diameter inclusion ( play
CNV-TV: a robust method to discover copy number variation from short sequencing reads.
Duan, Junbo; Zhang, Ji-Gang; Deng, Hong-Wen; Wang, Yu-Ping
2013-05-02
Copy number variation (CNV) is an important structural variation (SV) in human genome. Various studies have shown that CNVs are associated with complex diseases. Traditional CNV detection methods such as fluorescence in situ hybridization (FISH) and array comparative genomic hybridization (aCGH) suffer from low resolution. The next generation sequencing (NGS) technique promises a higher resolution detection of CNVs and several methods were recently proposed for realizing such a promise. However, the performances of these methods are not robust under some conditions, e.g., some of them may fail to detect CNVs of short sizes. There has been a strong demand for reliable detection of CNVs from high resolution NGS data. A novel and robust method to detect CNV from short sequencing reads is proposed in this study. The detection of CNV is modeled as a change-point detection from the read depth (RD) signal derived from the NGS, which is fitted with a total variation (TV) penalized least squares model. The performance (e.g., sensitivity and specificity) of the proposed approach are evaluated by comparison with several recently published methods on both simulated and real data from the 1000 Genomes Project. The experimental results showed that both the true positive rate and false positive rate of the proposed detection method do not change significantly for CNVs with different copy numbers and lengthes, when compared with several existing methods. Therefore, our proposed approach results in a more reliable detection of CNVs than the existing methods.
Zhang, Hanming; Wang, Linyuan; Yan, Bin; Li, Lei; Cai, Ailong; Hu, Guoen
2016-01-01
Total generalized variation (TGV)-based computed tomography (CT) image reconstruction, which utilizes high-order image derivatives, is superior to total variation-based methods in terms of the preservation of edge information and the suppression of unfavorable staircase effects. However, conventional TGV regularization employs l1-based form, which is not the most direct method for maximizing sparsity prior. In this study, we propose a total generalized p-variation (TGpV) regularization model to improve the sparsity exploitation of TGV and offer efficient solutions to few-view CT image reconstruction problems. To solve the nonconvex optimization problem of the TGpV minimization model, we then present an efficient iterative algorithm based on the alternating minimization of augmented Lagrangian function. All of the resulting subproblems decoupled by variable splitting admit explicit solutions by applying alternating minimization method and generalized p-shrinkage mapping. In addition, approximate solutions that can be easily performed and quickly calculated through fast Fourier transform are derived using the proximal point method to reduce the cost of inner subproblems. The accuracy and efficiency of the simulated and real data are qualitatively and quantitatively evaluated to validate the efficiency and feasibility of the proposed method. Overall, the proposed method exhibits reasonable performance and outperforms the original TGV-based method when applied to few-view problems. PMID:26901410
Falbe, Jennifer; Willett, Walter C; Rosner, Bernard; Gortmaker, Steve L; Sonneville, Kendrin R; Field, Alison E
2014-10-01
Youth spend more time with screens than any activity except sleeping. Screen time is a risk factor for obesity, possibly because of the influence of food and beverage advertising on diet. We sought to assess longitudinal relations of screen time [ie, television, electronic games, digital versatile discs (DVDs)/videos, and total screen time] with the 2-y changes in consumption of foods of low nutritional quality (FLNQ) that are commonly advertised on screens [ie, sugar-sweetened beverages, fast food, sweets, salty snacks, and the sum of these foods (total FLNQ)] and fruit and vegetables. With the use of 2004, 2006, and 2008 waves of the Growing Up Today Study II, which consisted of a cohort of 6002 female and 4917 male adolescents aged 9-16 y in 2004, we assessed screen time (change and baseline) in relation to the 2-y dietary changes. Regression models included 4604 girls and 3668 boys with complete screen time and diet data on ≥2 consecutive questionnaires. Each hour-per-day increase in television, electronic games, and DVDs/videos was associated with increased intake of total FLNQ (range: 0.10-0.28 servings/d; P < 0.05). Each hour-per-day increase in total screen time predicted increased intakes of sugar-sweetened beverages, fast food, sweets, and salty snacks (range: 0.02-0.06 servings/d; P < 0.001) and decreased intakes of fruit and vegetables (range: -0.05 to -0.02 servings/d; P < 0.05). Greater screen time at baseline (except electronic games in boys) was associated with subsequent increased intake of total FLNQ, and greater screen time at baseline (except DVDs/videos) was associated with decreased intake of fruit and vegetables (P < 0.05). Across sex and food groups and in sensitivity analyses, television was most consistently associated with dietary changes. Increases in screen time were associated with increased consumption of foods and beverages of low nutritional quality and decreased consumption of fruit and vegetables. Our results caution against excessive use of screen media, especially television, in youth. © 2014 American Society for Nutrition.
[Metabolic functions and sport].
Riviere, Daniel
2004-01-01
Current epidemiological studies emphasize the increased of metabolic diseases of the adults, such as obesity, type-2 diabetes and metabolic syndromes. Even more worrying is the rising prevalence of obesity in children. It is due more to sedentariness, caused more by inactivity (television, video, games, etc.) than by overeating. Many studies have shown that regular physical activities benefit various bodily functions including metabolism. After dealing with the major benefits of physical exercise on some adult metabolic disorders, we focus on the prime role played by physical activity in combating the public health problem of childhood obesity.
Media use as a reason for meal skipping and fast eating in secondary school children.
Van den Bulck, J; Eggermont, S
2006-04-01
This study examined self-reported meal skipping and eating faster than usual with the goal of watching television or playing computer games. Respondents reported their media use and indicated how often they skipped a meal to watch a favourite television programme or to play a computer game, and how often they ate faster than usual in order to watch television or play a computer game. Respondents were 2546 adolescents of 13 (first year of secondary school) and 16 years (fourth year of secondary school) of age. About one respondent in 10 skipped at least one meal every week for either television viewing or computer game playing. Weekly meal skipping for television viewing occurs more regularly in boys and first-year students, but particularly in teenagers who view 5 h or more daily (15% of the sample). The category of teenagers who play computer games four times a week or more (25.3% of the sample) is at increased risk of meal skipping; those who play more than four times a week are 10 times more likely weekly to skip a meal. A quarter of the adolescents eat faster at least once a week to be able to watch television or play a computer game. Regardless of gender and school year, teenagers' risk of eating faster progressively increases with their use of the media. Those who watch 4 h or more daily are about seven times more likely to skip a meal for television and those who play computer games at least four times a week are nine times more likely weekly to skip a meal. Unhealthy eating habits can be a side effect of heavy or excessive media use. Teenagers' use of television or game computers during nonworking or out-of-school hours partly displaces the amount of time that needs to be spent at meals. Practitioners and educators may try to encourage or restore a pattern of healthful meal consumption habits by reducing the amount of media use, and by supporting parental rule-making regarding children's eating habits and media use.
SU-D-206-03: Segmentation Assisted Fast Iterative Reconstruction Method for Cone-Beam CT
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wu, P; Mao, T; Gong, S
2016-06-15
Purpose: Total Variation (TV) based iterative reconstruction (IR) methods enable accurate CT image reconstruction from low-dose measurements with sparse projection acquisition, due to the sparsifiable feature of most CT images using gradient operator. However, conventional solutions require large amount of iterations to generate a decent reconstructed image. One major reason is that the expected piecewise constant property is not taken into consideration at the optimization starting point. In this work, we propose an iterative reconstruction method for cone-beam CT (CBCT) using image segmentation to guide the optimization path more efficiently on the regularization term at the beginning of the optimizationmore » trajectory. Methods: Our method applies general knowledge that one tissue component in the CT image contains relatively uniform distribution of CT number. This general knowledge is incorporated into the proposed reconstruction using image segmentation technique to generate the piecewise constant template on the first-pass low-quality CT image reconstructed using analytical algorithm. The template image is applied as an initial value into the optimization process. Results: The proposed method is evaluated on the Shepp-Logan phantom of low and high noise levels, and a head patient. The number of iterations is reduced by overall 40%. Moreover, our proposed method tends to generate a smoother reconstructed image with the same TV value. Conclusion: We propose a computationally efficient iterative reconstruction method for CBCT imaging. Our method achieves a better optimization trajectory and a faster convergence behavior. It does not rely on prior information and can be readily incorporated into existing iterative reconstruction framework. Our method is thus practical and attractive as a general solution to CBCT iterative reconstruction. This work is supported by the Zhejiang Provincial Natural Science Foundation of China (Grant No. LR16F010001), National High-tech R&D Program for Young Scientists by the Ministry of Science and Technology of China (Grant No. 2015AA020917).« less
Shading correction assisted iterative cone-beam CT reconstruction
NASA Astrophysics Data System (ADS)
Yang, Chunlin; Wu, Pengwei; Gong, Shutao; Wang, Jing; Lyu, Qihui; Tang, Xiangyang; Niu, Tianye
2017-11-01
Recent advances in total variation (TV) technology enable accurate CT image reconstruction from highly under-sampled and noisy projection data. The standard iterative reconstruction algorithms, which work well in conventional CT imaging, fail to perform as expected in cone beam CT (CBCT) applications, wherein the non-ideal physics issues, including scatter and beam hardening, are more severe. These physics issues result in large areas of shading artifacts and cause deterioration to the piecewise constant property assumed in reconstructed images. To overcome this obstacle, we incorporate a shading correction scheme into low-dose CBCT reconstruction and propose a clinically acceptable and stable three-dimensional iterative reconstruction method that is referred to as the shading correction assisted iterative reconstruction. In the proposed method, we modify the TV regularization term by adding a shading compensation image to the reconstructed image to compensate for the shading artifacts while leaving the data fidelity term intact. This compensation image is generated empirically, using image segmentation and low-pass filtering, and updated in the iterative process whenever necessary. When the compensation image is determined, the objective function is minimized using the fast iterative shrinkage-thresholding algorithm accelerated on a graphic processing unit. The proposed method is evaluated using CBCT projection data of the Catphan© 600 phantom and two pelvis patients. Compared with the iterative reconstruction without shading correction, the proposed method reduces the overall CT number error from around 200 HU to be around 25 HU and increases the spatial uniformity by a factor of 20 percent, given the same number of sparsely sampled projections. A clinically acceptable and stable iterative reconstruction algorithm for CBCT is proposed in this paper. Differing from the existing algorithms, this algorithm incorporates a shading correction scheme into the low-dose CBCT reconstruction and achieves more stable optimization path and more clinically acceptable reconstructed image. The method proposed by us does not rely on prior information and thus is practically attractive to the applications of low-dose CBCT imaging in the clinic.
Physical activity in prevention and treatment of the metabolic syndrome.
Lakka, Timo A; Laaksonen, David E
2007-02-01
Randomised controlled trials have shown that exercise training has a mild or moderate favourable effect on many metabolic and cardiovascular risk factors that constitute or are related to the metabolic syndrome (MetS). Epidemiological studies suggest that regular physical activity prevents type 2 diabetes, cardiovascular disease, and premature mortality in large part through these risk factors. Although randomized controlled trials with the prevention or treatment of the MetS as the main outcome have not been published, several large randomized controlled trials provide strong evidence that favourable lifestyle changes, including regular physical activity, are effective in the prevention of type 2 diabetes in individuals who are overweight and have impaired glucose tolerance. Compliance with the current recommendations to increase the total volume of moderate-intensity physical activity and to maintain good cardiorespiratory and muscular fitness appears to markedly decrease the likelihood of developing the MetS, especially in high-risk groups. Walking is the most common form of physical activity--it improves health in many ways and is generally safe. Therefore, brisk walking for at least 30 min daily can be recommended as the principal form of physical activity at the population level. If there are no contraindications, more vigorous physical exercise or resistance training should also be considered to obtain additional health benefits. Unstructured and low-intensity physical activity may also decrease the likelihood of developing the MetS, especially when substituted for sedentary behaviours such as watching television. The measurement of maximal oxygen consumption may provide an efficient means to target even individuals with relatively few metabolic risk factors who may benefit from more intensive intervention.
Davis, Kevin C; Patel, Deesha; Rodes, Robert; Beistle, Diane
2016-01-01
Background In 2012, the US Centers for Disease Control and Prevention (CDC) launched Tips From Former Smokers (Tips), the first federally funded national tobacco education campaign. In 2013, a follow-up Tips campaign aired on national cable television networks, radio, and other channels, with supporting digital advertising to drive traffic to the Tips campaign website. Objective The objective of this study was to use geographic and temporal variability in 2013 Tips campaign television media doses and ad tagging to evaluate changes in traffic to the campaign website in response to specific doses of campaign media. Methods Linear regression models were used to estimate the dose-response relationship between weekly market-level television gross rating points (GRPs) and weekly Web traffic to the Tips campaign website. This relationship was measured using unique visitors, total visits, and page views as outcomes. Ad GRP effects were estimated separately for ads tagged with the Tips campaign website URL and 1-800-QUIT-NOW. Results In the average media market, an increase of 100 television GRPs per week for ads tagged with the Tips campaign website URL was associated with an increase of 650 unique visitors (P<.001), 769 total visits (P<.001), and 1255 total page views (P<.001) per week. The associations between GRPs for ads tagged with 1-800-QUIT-NOW and each Web traffic measure were also statistically significant (P<.001), but smaller in magnitude. Conclusions Based on these findings, we estimate that the 16-week 2013 Tips television campaign generated approximately 660,000 unique visitors, 900,000 total visits, and 1,390,000 page views for the Tips campaign website. These findings can help campaign planners forecast the likely impact of targeted advertising efforts on consumers’ use of campaign-specific websites. PMID:26887959
Pérez-Ciordia, Ignacio; Catalán Fabo, Francisca; Zalacain Nicolay, Fernando; Barriendo Antoñanzas, Maite; Solaegui Diaz de Guereñu, Ramón; Guillén Grima, Francisco
2003-01-01
The demand placed on both hospital as well as extrahospital emergency care units currently continues to increase at a growing rate. This study has a twofold objective: the quantification and study of the personal characteristics of the users who are demanding emergency care and assessing whether televised soccer games have any bearing on the utilization of emergency care services. A longitudinal descriptive study (9,723 users demanding care) and study of cases and controls (1,284 users demanding care) according to whether or not a soccer game was being televised by means of a logistic regression model. The associations were quantified by means of the odds ratio (OR). Those dealt with by telephone or in infirmaries were not included in the study. A total 10.6% of the demand involved home visits, 4.8% of this total having been sent to hospital. A total 13.3% of the demand corresponds to individuals visiting from other healthcare districts, a total of 65 being overusers of emergency care (8 or more visits). The month of August (32.3%). Sundays (44.56%) and the 12:00 p.m.-2:00 p.m. timeframe (8.38%) are the times when the greatest demand for care occurs, the differences being statistically significant. Televised soccer games were associated to a 19.8% (p < 0.001) rise in demand as compared to the control period. A high degree of use of the extrahospital emergency care units has been found to exist, a major part of the demand being concentrated at highly specific points in time. A major degree of care is provided to those visiting from outside their own healthcare districts. Television soccer game broadcasts is associated with the greater utilization of the emergency care services.
Physical activity and television watching in relation to semen quality in young men.
Gaskins, Audrey Jane; Mendiola, Jaime; Afeiche, Myriam; Jørgensen, Niels; Swan, Shanna H; Chavarro, Jorge E
2015-02-01
Semen quality appears to have declined over the past decades but reasons for this decline are unresolved. The concurrent increase in sedentary behaviour may be a contributing factor. The objective of this study was to evaluate the relationship of physical activity and television (TV) watching with sperm parameters in a population of young, healthy men. Men aged 18-22 years (n=189) from the Rochester Young Men's Study (2009-2010) participated in this analysis. Physical activity (h/week of moderate and vigorous exercise) and TV watching (h/week of TV, video or DVD watching) over the past 3 months were assessed via questionnaire. Semen quality was assessed by sperm concentration, motility, morphology and total sperm count. Sperm concentration and total sperm count were directly related to physical activity after multivariable adjustment (p-trend=0.01 and 0.04); men in the highest quartile of moderate-to-vigorous activity (≥15 h/week) had 73% (95% CI 15% to 160%) higher sperm concentration than men in the lowest quartile (<5 h/week). TV watching was inversely associated with sperm concentration and total sperm count in multivariable analyses (p-trend=0.05 and 0.06); men in the highest quartile of TV watching (>20 h/week) had 44% (95% CI 15 to 63%) lower sperm concentration than men in the lowest quartile (0 h/week). These measures of physical and leisure time activities were not significantly associated with sperm motility or morphology. In this population of healthy men, higher moderate-to-vigorous activity and less TV watching were significantly associated with higher total sperm count and sperm concentration. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Catalogue of Main Characteristics of Pulsations of 173 Semi-Regular Stars
NASA Astrophysics Data System (ADS)
Chinarova, L. L.; Andronov, I. L.
2000-12-01
The characteristics of brightness variations of 173 semi-regular stars are tabulated: the moments and brightness of the extrema; the effective periods, amplitudes and significance obtained by using different methods: a) the periodogram analysis (harmonic least squares t) with prewhitening to determine characteristics and significance of waves with 3 periods; b) the wavelet analysis to determine characteristics of statistically significant waves; ) the "running parabola" scalegram analysis to determine the optimal filter half - width for smoothing. The characteristics may be used for more precise classification of semi-regular variables. Characteristics of the 6509 extrema of 147 stars are listed. The electronic version is available via http://ila.webjump.om. The observations for the analysis have been taken from the AFOEV and VSOLJ databases (with a duration up to 94 years) for the stars: AQ, EH, EK, RS, RU, RV, ST, TV, TY, TZ, UX, VX And; GY, PX, S, V, V844 Aql; V, Z Aqr; T Ari; AG, RS, S, UU, Z Aur; RV, RW, RX, RZ, U, V, WY Boo; T Cae; RR, RS, RY, S, ST, U Cam; RT Cap; PZ, SV, UX, V393, V465, WZ Cas; T, Y Cen; AR, RU, RW, RX, SS, TY, W Cep; T Cet; RS, RT, T, X Cnc; RR, RS, TT CrB; V, Y Cvn; AA, AF, AI, AV, AW, BC, RS, RU, RV, RW, RZ, TT, V460, W Cyg; EU, U Del; RS, RY, S, TX, UX, WZ Dra; SY, Z Eri; IS, NQ, RS, SW, TU, TV, Y Gem; DE, MZ, RR, ST, SX, UU, X Her; FF, RT, U, V, W, Y Hya; RS Lac; RY, SX Leo; RX, S Lep; U, W LMi; Y, EG, R, SZ Lyr; RV, SW, X Mon; V759 Oph; BQ, FX, GT, RT, W Ori; AF, AK, SV, TX Peg; AD, BU, DY, FZ, RS, RU, S, SU, SY, T, UZ, W, XX Per; R Pic; RT, RW, Z Psc; BM Sco; S Sct; FG Ser; X Sge; AB, TT, W, Y Tau; W Tri; RX, RY, RZ, ST,SV, V, Y, Z UMa; R, V UMi; RT, SS, SW Vir; RU Vul.
NASA Astrophysics Data System (ADS)
Kim, Chang-Won; Kim, Jong-Hyo
2011-03-01
Perfusion CT (PCT) examinations are getting more frequently used for diagnosis of acute brain diseases such as hemorrhage and infarction, because the functional map images it produces such as regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), and mean transit time (MTT) may provide critical information in the emergency work-up of patient care. However, a typical PCT scans the same slices several tens of times after injection of contrast agent, which leads to much increased radiation dose and is inevitability of growing concern for radiation-induced cancer risk. Reducing the number of views in projection in combination of TV minimization reconstruction technique is being regarded as an option for radiation reduction. However, reconstruction artifacts due to insufficient number of X-ray projections become problematic especially when high contrast enhancement signals are present or patient's motion occurred. In this study, we present a novel reconstruction technique using contrast-adaptive TpV minimization that can reduce reconstruction artifacts effectively by using different p-norms in high contrast and low contrast objects. In the proposed method, high contrast components are first reconstructed using thresholded projection data and low p-norm total variation to reflect sparseness in both projection and reconstruction spaces. Next, projection data are modified to contain only low contrast objects by creating projection data of reconstructed high contrast components and subtracting them from original projection data. Then, the low contrast projection data are reconstructed by using relatively high p-norm TV minimization technique, and are combined with the reconstructed high contrast component images to produce final reconstructed images. The proposed algorithm was applied to numerical phantom and a clinical data set of brain PCT exam, and the resultant images were compared with those using filtered back projection (FBP) and conventional TV reconstruction algorithm. Our results show the potential of the proposed algorithm for image quality improvement, which in turn may lead to dose reduction.
Niederdeppe, Jeff
2014-01-01
Cultivation theory and research has been criticized for its failure to consider variation in effects by genre, employ appropriate third-variable controls, and determine causal direction. Recent studies, controlling for a variety of demographic characteristics and media use variables, have found that exposure to local television (TV) newscasts is associated with a variety of problematic “real-world” beliefs. However, many of these studies have not adequately assessed causal direction. Redressing this limitation, we analyzed data from a two-wave national representative survey which permitted tests of lagged association between overall TV viewing, local TV news viewing, and fatalistic beliefs about cancer prevention. We first replicated the original cultivation effect and found a positive association between overall TV viewing at time 1 and increased fatalistic beliefs about cancer prevention at time 2. Analyses also provided evidence that local TV news viewing at time 1 predicts increased fatalistic beliefs about cancer prevention at time 2. There was little evidence for reverse causation in predicting changes in overall TV viewing or local TV news viewing. The paper concludes with a discussion of theoretical and practical implications of these findings. PMID:25605981
... up something pre-made, sit down together to eat it. Turn off the TV and try to tune out the ringing phone. If it's impossible to do every night, schedule a regular weekly family dinner night that accommodates kids' schedules. Make it something ...
Home Data Banks Turn British On
ERIC Educational Resources Information Center
Science News, 1978
1978-01-01
Describes the operation and numerous capabilities of a British computerized data retrieval system named Prestel. It provides access, through the regular telephone network and a TV screen, to computer-based information supplied by many companies, agencies and commercial outlets. (GA)
Teychenne, Megan; Ball, Kylie; Salmon, Jo
2012-01-20
Socio-economically disadvantaged women are at a greater risk of spending excess time engaged in television viewing, a behavior linked to several adverse health outcomes. However, the factors which explain socio-economic differences in television viewing are unknown. This study aimed to investigate the contribution of intrapersonal, social and environmental factors to mediating socio-economic (educational) inequalities in women's television viewing. Cross-sectional data were provided by 1,554 women (aged 18-65) who participated in the 'Socio-economic Status and Activity in Women study' of 2004. Based on an ecological framework, women self-reported their socio-economic position (highest education level), television viewing, as well as a number of potential intrapersonal (enjoyment of television viewing, preference for leisure-time sedentary behavior, depression, stress, weight status), social (social participation, interpersonal trust, social cohesion, social support for physical activity from friends and from family) and physical activity environmental factors (safety, aesthetics, distance to places of interest, and distance to physical activity facilities). Multiple mediating analyses showed that two intrapersonal factors (enjoyment of television viewing and weight status) and two social factors (social cohesion and social support from friends for physical activity) partly explained the educational inequalities in women's television viewing. No physical activity environmental factors mediated educational variations in television viewing. Acknowledging the cross-sectional nature of this study, these findings suggest that health promotion interventions aimed at reducing educational inequalities in television viewing should focus on intrapersonal and social strategies, particularly providing enjoyable alternatives to television viewing, weight-loss/management information, increasing social cohesion in the neighborhood and promoting friend support for activity.
Preschoolers' Recitation versus Understanding of a Televised Song.
ERIC Educational Resources Information Center
Calvert, Sandra L.; And Others
A study was conducted to determine whether children think about the verbal messages embedded in songs, or merely sing the words without thinking about them. A total of 48 preschool girls and boys viewed a televised vignette of the song "Frere Jacques" under varying conditions of language comprehensibility, rehearsal, and repetition. The visual…
Prosocial and Antisocial Interaction on Television: Conflict and Jealousy on Prime Time.
ERIC Educational Resources Information Center
Comstock, Jamie; Strzyzewski, Krystyna
A study analyzed prime time television programs for the presence of interpersonal predicaments, specifically family conflict and situations involving jealousy, envy, and rivalry. The portrayal of these situations was evaluated according to relevant pro- and antisocial criteria. A total of 17 one-hour episodes and 24 half-hour episodes were…
Polley, Diana C; Spicer, Maria T; Knight, Ada P; Hartley, Ben L
2005-02-01
Study objectives were to describe overweight in Native-American and African-American three-generation families and to examine relationships among the individual variables of body mass index (BMI), television hours, and activity levels. Forty-four Native-American and 40 African-American families were recruited from 10 sites through community contacts at health, senior, community, and tribal centers. Ninety percent of parents and grandparents had BMIs above 25.0. Forty-two percent of African-American and 61% of Native-American children had a BMI above the 85th percentile. More than 35% of total energy was from fat. Significant correlations were observed between parent and child BMI and television hours, grandparent and child BMI, and grandparent and parent activity with child television hours. Sedentary caretakers facilitate more television viewing and less activity in children. Dietetics professionals should plan family-friendly daily physical activities, like walking, and diets lower in fat, sugar, and total energy, with higher intakes of fresh fruits and vegetables, whole grains, and low-fat dairy products for children and caretakers.
Investigation of an electronic image enhancer for radiographs
NASA Technical Reports Server (NTRS)
Vary, A.
1972-01-01
Radiographs of nuclear and aerospace components were studied with a closed-circuit television system to determine the advantages of electronic enhancement in radiographic nondestructive evaluation. The radiographic images were examined on a television monitor under various degrees of magnification and enhancement. The enhancement was accomplished by generating a video signal whose amplitude is proportional to the rate of change of density. Points, lines, edges, and other density variations that are faintly registered in the original image are rendered in sharp relief. Examples of the applications of this mode of enhancement are discussed together with the system's dynamic response and resolution.
Investigation of an electronic image enhancer for radiographs.
NASA Technical Reports Server (NTRS)
Vary, A.
1972-01-01
Radiographs of nuclear and aerospace components were studied with a closed-circuit television system to determine the advantages of electronic enhancement in radiographic nondestructive evaluation. The radiographic images were examined on a television monitor under various degrees of magnification and enhancement. The enhancement was accomplished by generating a video signal whose amplitude is proportional to the rate of change of density. Points, lines, edges, and other density variations that are faintly registered in the original image are rendered in sharp relief. Examples of the applications of this mode of enhancement are discussed together with the system's dynamic response and resolution.
NASA Astrophysics Data System (ADS)
Taubmann, O.; Haase, V.; Lauritsch, G.; Zheng, Y.; Krings, G.; Hornegger, J.; Maier, A.
2017-04-01
Time-resolved tomographic cardiac imaging using an angiographic C-arm device may support clinicians during minimally invasive therapy by enabling a thorough analysis of the heart function directly in the catheter laboratory. However, clinically feasible acquisition protocols entail a highly challenging reconstruction problem which suffers from sparse angular sampling of the trajectory. Compressed sensing theory promises that useful images can be recovered despite massive undersampling by means of sparsity-based regularization. For a multitude of reasons—most notably the desired reduction of scan time, dose and contrast agent required—it is of great interest to know just how little data is actually sufficient for a certain task. In this work, we apply a convex optimization approach based on primal-dual splitting to 4D cardiac C-arm computed tomography. We examine how the quality of spatially and temporally total-variation-regularized reconstruction degrades when using as few as 6.9+/- 1.2 projection views per heart phase. First, feasible regularization weights are determined in a numerical phantom study, demonstrating the individual benefits of both regularizers. Secondly, a task-based evaluation is performed in eight clinical patients. Semi-automatic segmentation-based volume measurements of the left ventricular blood pool performed on strongly undersampled images show a correlation of close to 99% with measurements obtained from less sparsely sampled data.
Should image rotation be addressed during routine cone-beam CT quality assurance?
Ayan, Ahmet S; Lin, Haibo; Yeager, Caitlyn; Deville, Curtiland; McDonough, James; Zhu, Timothy C; Anderson, Nathan; Bar Ad, Voichita; Lu, Hsiao-Ming; Both, Stefan
2013-02-21
The purpose of this study is to investigate whether quality assurance (QA) for cone-beam computed tomography (CBCT) image rotation is necessary in order to ensure the accuracy of CBCT based image-guided radiation therapy (IGRT) and adaptive radiotherapy (ART). Misregistration of angular coordinates during CBCT acquisition may lead to a rotated reconstructed image. If target localization is performed based on this image, an under- or over-dosage of the target volume (TV) and organs at risk (OARs) may occur. Therefore, patient CT image sets were rotated by 1° up to 3° and the treatment plans were recalculated to quantify changes in dose-volume histograms. A computer code in C++ was written to model the TV displacement and overlap area of an ellipse shape at the target and dose prescription levels corresponding to the image rotation. We investigated clinical scenarios in IGRT and ART in order to study the implications of image rotation on dose distributions for: (1) lateral TV and isocenter (SBRT), (2) central TV and isocenter (IMRT), (3) lateral TV and isocenter (IMRT). Mathematical analysis showed the dose coverage of TV depends on its shape, size, location, and orientation relative to the isocenter. Evaluation of three first scenario for θ = 1° showed variations in TV D95 in the context of IGRT and ART when compared to the original plan were within 2.7 ± 2.6% and 7.7 ± 6.9% respectively while variations in the second and third scenarios were less significant (<0.5%) for the angular range evaluated. However a larger degree of variation was found in terms of minimum and maximum doses for target and OARs. The rotation of CBCT image data sets may have significant dosimetric consequences in IGRT and ART. The TV's location relative to isocenter and shape determine the extent of alterations in dose indicators. Our findings suggest that a CBCT QA criterion of 1° would be a reasonable action level to ensure accurate dose delivery.
NASA Astrophysics Data System (ADS)
Vishnukumar, S.; Wilscy, M.
2017-12-01
In this paper, we propose a single image Super-Resolution (SR) method based on Compressive Sensing (CS) and Improved Total Variation (TV) Minimization Sparse Recovery. In the CS framework, low-resolution (LR) image is treated as the compressed version of high-resolution (HR) image. Dictionary Training and Sparse Recovery are the two phases of the method. K-Singular Value Decomposition (K-SVD) method is used for dictionary training and the dictionary represents HR image patches in a sparse manner. Here, only the interpolated version of the LR image is used for training purpose and thereby the structural self similarity inherent in the LR image is exploited. In the sparse recovery phase the sparse representation coefficients with respect to the trained dictionary for LR image patches are derived using Improved TV Minimization method. HR image can be reconstructed by the linear combination of the dictionary and the sparse coefficients. The experimental results show that the proposed method gives better results quantitatively as well as qualitatively on both natural and remote sensing images. The reconstructed images have better visual quality since edges and other sharp details are preserved.
Reconstruction of sparse-view X-ray computed tomography using adaptive iterative algorithms.
Liu, Li; Lin, Weikai; Jin, Mingwu
2015-01-01
In this paper, we propose two reconstruction algorithms for sparse-view X-ray computed tomography (CT). Treating the reconstruction problems as data fidelity constrained total variation (TV) minimization, both algorithms adapt the alternate two-stage strategy: projection onto convex sets (POCS) for data fidelity and non-negativity constraints and steepest descent for TV minimization. The novelty of this work is to determine iterative parameters automatically from data, thus avoiding tedious manual parameter tuning. In TV minimization, the step sizes of steepest descent are adaptively adjusted according to the difference from POCS update in either the projection domain or the image domain, while the step size of algebraic reconstruction technique (ART) in POCS is determined based on the data noise level. In addition, projection errors are used to compare with the error bound to decide whether to perform ART so as to reduce computational costs. The performance of the proposed methods is studied and evaluated using both simulated and physical phantom data. Our methods with automatic parameter tuning achieve similar, if not better, reconstruction performance compared to a representative two-stage algorithm. Copyright © 2014 Elsevier Ltd. All rights reserved.
Ionospheric reflection coefficient for television signals
NASA Astrophysics Data System (ADS)
From, W. R.
1984-08-01
It has been shown that the ionospherically reflected field strength for 50 MHz signals varies (statistically) in proportion to about the 18th power of f(0)E(s) at the midpoint between transmitter and receiver. This note is to point out that this observation provides support for the theory that the horizontal structure of E(s) is due to a horizontal variation in the wind shear rather than horizontal convergence of metallic ions or a horizontal variation in the metallic column content.
A Dictionary Learning Method with Total Generalized Variation for MRI Reconstruction
Lu, Hongyang; Wei, Jingbo; Wang, Yuhao; Deng, Xiaohua
2016-01-01
Reconstructing images from their noisy and incomplete measurements is always a challenge especially for medical MR image with important details and features. This work proposes a novel dictionary learning model that integrates two sparse regularization methods: the total generalized variation (TGV) approach and adaptive dictionary learning (DL). In the proposed method, the TGV selectively regularizes different image regions at different levels to avoid oil painting artifacts largely. At the same time, the dictionary learning adaptively represents the image features sparsely and effectively recovers details of images. The proposed model is solved by variable splitting technique and the alternating direction method of multiplier. Extensive simulation experimental results demonstrate that the proposed method consistently recovers MR images efficiently and outperforms the current state-of-the-art approaches in terms of higher PSNR and lower HFEN values. PMID:27110235
A Dictionary Learning Method with Total Generalized Variation for MRI Reconstruction.
Lu, Hongyang; Wei, Jingbo; Liu, Qiegen; Wang, Yuhao; Deng, Xiaohua
2016-01-01
Reconstructing images from their noisy and incomplete measurements is always a challenge especially for medical MR image with important details and features. This work proposes a novel dictionary learning model that integrates two sparse regularization methods: the total generalized variation (TGV) approach and adaptive dictionary learning (DL). In the proposed method, the TGV selectively regularizes different image regions at different levels to avoid oil painting artifacts largely. At the same time, the dictionary learning adaptively represents the image features sparsely and effectively recovers details of images. The proposed model is solved by variable splitting technique and the alternating direction method of multiplier. Extensive simulation experimental results demonstrate that the proposed method consistently recovers MR images efficiently and outperforms the current state-of-the-art approaches in terms of higher PSNR and lower HFEN values.
Brown, Vicki; Ananthapavan, Jaithri; Veerman, Lennert; Sacks, Gary; Lal, Anita; Peeters, Anna; Backholer, Kathryn; Moodie, Marjory
2018-05-15
Television (TV) advertising of food and beverages high in fat, sugar and salt (HFSS) influences food preferences and consumption. Children from lower socioeconomic position (SEP) have higher exposure to TV advertising due to more time spent watching TV. This paper sought to estimate the cost-effectiveness of legislation to restrict HFSS TV advertising until 9:30 pm, and to examine how health benefits and healthcare cost-savings differ by SEP. Cost-effectiveness modelling was undertaken (i) at the population level, and (ii) by area-level SEP. A multi-state multiple-cohort lifetable model was used to estimate obesity-related health outcomes and healthcare cost-savings over the lifetime of the 2010 Australian population. Incremental cost-effectiveness ratios (ICERs) were reported, with assumptions tested through sensitivity analyses. An intervention restricting HFSS TV advertising would cost AUD5.9M (95% UI AUD5.8M⁻AUD7M), resulting in modelled reductions in energy intake (mean 115 kJ/day) and body mass index (BMI) (mean 0.352 kg/m²). The intervention is likely to be cost-saving, with 1.4 times higher total cost-savings and 1.5 times higher health benefits in the most disadvantaged socioeconomic group (17,512 HALYs saved (95% UI 10,372⁻25,155); total cost-savings AUD126.3M (95% UI AUD58.7M⁻196.9M) over the lifetime) compared to the least disadvantaged socioeconomic group (11,321 HALYs saved (95% UI 6812⁻15,679); total cost-savings AUD90.9M (95% UI AUD44.3M⁻136.3M)). Legislation to restrict HFSS TV advertising is likely to be cost-effective, with greater health benefits and healthcare cost-savings for children with low SEP.
Children's Food and Beverage Promotion on Television to Parents.
Emond, Jennifer A; Smith, Marietta E; Mathur, Suman J; Sargent, James D; Gilbert-Diamond, Diane
2015-12-01
Nutritionally poor foods are heavily advertised to children on television. Whether those same products are also advertised to parents on television has not been systematically examined. This study is a content analysis of advertisements for children's packaged foods and beverages aired over US network, cable, and syndicated television for 1 year (2012 to 2013). The target audience of each advertisement was defined as children or parents based on advertisement content, where parent-directed advertisements included emotional appeals related to family bonding and love. Advertisement characteristics and patterns of airtime were compared across target audience, and the proportion of total airtime devoted to advertisements targeting parents was computed. Fifty-one children's food or beverage products were advertised over the study year, 25 (49%) of which were advertised directly to parents. Parent-directed advertisements more often featured nutrition and health messaging and an active lifestyle than child-directed advertisements, whereas child-directed advertisements more frequently highlighted fun and product taste. Over all products, 42.4% of total airtime was devoted to advertisements that targeted parents. The products with the most amount of airtime over the study year were ready-to-eat cereals, sugar-sweetened beverages, and children's yogurt, and the proportion of total advertisement airtime for those products devoted to parents was 24.4%, 72.8%, and 25.8%, respectively. Television advertisements for children's packaged foods and beverages frequently targeted parents with emotional appeals and messaging related to nutrition and health. Findings are of concern if exposure to such advertisements among parents may shape their beliefs about the appropriateness of nutritionally questionable children's foods and beverages. Copyright © 2015 by the American Academy of Pediatrics.
Children’s Food and Beverage Promotion on Television to Parents
Smith, Marietta E.; Mathur, Suman J.; Sargent, James D.; Gilbert-Diamond, Diane
2015-01-01
BACKGROUND: Nutritionally poor foods are heavily advertised to children on television. Whether those same products are also advertised to parents on television has not been systematically examined. METHODS: This study is a content analysis of advertisements for children’s packaged foods and beverages aired over US network, cable, and syndicated television for 1 year (2012 to 2013). The target audience of each advertisement was defined as children or parents based on advertisement content, where parent-directed advertisements included emotional appeals related to family bonding and love. Advertisement characteristics and patterns of airtime were compared across target audience, and the proportion of total airtime devoted to advertisements targeting parents was computed. RESULTS: Fifty-one children’s food or beverage products were advertised over the study year, 25 (49%) of which were advertised directly to parents. Parent-directed advertisements more often featured nutrition and health messaging and an active lifestyle than child-directed advertisements, whereas child-directed advertisements more frequently highlighted fun and product taste. Over all products, 42.4% of total airtime was devoted to advertisements that targeted parents. The products with the most amount of airtime over the study year were ready-to-eat cereals, sugar-sweetened beverages, and children’s yogurt, and the proportion of total advertisement airtime for those products devoted to parents was 24.4%, 72.8%, and 25.8%, respectively. DISCUSSION: Television advertisements for children’s packaged foods and beverages frequently targeted parents with emotional appeals and messaging related to nutrition and health. Findings are of concern if exposure to such advertisements among parents may shape their beliefs about the appropriateness of nutritionally questionable children’s foods and beverages. PMID:26553181
Veerman, Lennert; Lal, Anita; Peeters, Anna; Backholer, Kathryn; Moodie, Marjory
2018-01-01
Television (TV) advertising of food and beverages high in fat, sugar and salt (HFSS) influences food preferences and consumption. Children from lower socioeconomic position (SEP) have higher exposure to TV advertising due to more time spent watching TV. This paper sought to estimate the cost-effectiveness of legislation to restrict HFSS TV advertising until 9:30 pm, and to examine how health benefits and healthcare cost-savings differ by SEP. Cost-effectiveness modelling was undertaken (i) at the population level, and (ii) by area-level SEP. A multi-state multiple-cohort lifetable model was used to estimate obesity-related health outcomes and healthcare cost-savings over the lifetime of the 2010 Australian population. Incremental cost-effectiveness ratios (ICERs) were reported, with assumptions tested through sensitivity analyses. An intervention restricting HFSS TV advertising would cost AUD5.9M (95% UI AUD5.8M–AUD7M), resulting in modelled reductions in energy intake (mean 115 kJ/day) and body mass index (BMI) (mean 0.352 kg/m2). The intervention is likely to be cost-saving, with 1.4 times higher total cost-savings and 1.5 times higher health benefits in the most disadvantaged socioeconomic group (17,512 HALYs saved (95% UI 10,372–25,155); total cost-savings AUD126.3M (95% UI AUD58.7M–196.9M) over the lifetime) compared to the least disadvantaged socioeconomic group (11,321 HALYs saved (95% UI 6812–15,679); total cost-savings AUD90.9M (95% UI AUD44.3M–136.3M)). Legislation to restrict HFSS TV advertising is likely to be cost-effective, with greater health benefits and healthcare cost-savings for children with low SEP. PMID:29762517
Television exposure in children after a terrorist incident.
Pfefferbaum, B; Nixon, S J; Tivis, R D; Doughty, D E; Pynoos, R S; Gurwitch, R H; Foy, D W
2001-01-01
This study examined the influence of bomb-related television viewing in the context of physical and emotional exposure on posttraumatic stress symptoms--intrusion, avoidance, and arousal--in middle school students following the 1995 Oklahoma City bombing. Over 2,000 middle school students in Oklahoma City were surveyed 7 weeks after the incident. The primary outcome measures were the total posttraumatic stress symptom score and symptom cluster scores at the time of assessment. Bomb-related television viewing in the aftermath of the disaster was extensive. Both emotional and television exposure were associated with posttraumatic stress at 7 weeks. Among children with no physical or emotional exposure, the degree of television exposure was directly related to posttraumatic stress symptomatology. These findings suggest that television viewing in the aftermath of a disaster may make a small contribution to subsequent posttraumatic stress symptomatology in children or that increased television viewing may be a sign of current distress and that it should be monitored. Future research should examine further whether early symptoms predict increased television viewing and/or whether television viewing predicts subsequent symptoms.
Binge Viewing, Sleep, and the Role of Pre-Sleep Arousal
Exelmans, Liese; Van den Bulck, Jan
2017-01-01
Study Objectives: To investigate the prevalence of binge viewing, its association with sleep and examine arousal as an underlying mechanism of this association. Methods: Four hundred twenty-three adults (aged 18–25 years old, 61.9% female) completed an online survey assessing regular television viewing, binge viewing, sleep quality (Pittsburgh Sleep Quality Index), fatigue (Fatigue Assessment Scale), insomnia (Bergen Insomnia Scale), and pre-sleep arousal (Pre-Sleep Arousal Scale). Regression analyses were conducted. Mediation analysis was performed using PROCESS Macro. Results: There were 80.6% who identified themselves as a binge viewer. Among those who binge viewed (n = 341), 20.2% had binge viewed at least a few times a week during the past month. Among poor sleepers (Pittsburgh Sleep Quality Index > 5), 32.6% had a poor sleep quality associated with being a binge viewer. Higher binge viewing frequency was associated with a poorer sleep quality, increased fatigue and more symptoms of insomnia, whereas regular television viewing was not. Cognitive pre-sleep arousal fully mediated these relationships. Conclusions: New viewing styles such as binge viewing are increasingly prevalent and may pose a threat to sleep. Increased cognitive arousal functions as the mechanism explaining these effects. Measures of media exposure should take into account the user's level of engagement with media. Interventions aimed at (1) alerting viewers about excessive viewing duration and (2) reducing arousal before sleep may be useful ways to tackle sleep problems in binge viewers. Citation: Exelmans L, Van den Bulck J. Binge viewing, sleep, and the role of pre-sleep arousal. J Clin Sleep Med. 2017;13(8):1001–1008. PMID:28728618
Heritability of Lumbar Trabecular Bone Mechanical Properties in Baboons
Havill, L.M.; Allen, M.R.; Bredbenner, T.L.; Burr, D.B.; Nicolella, D.P.; Turner, C.H.; Warren, D.M.; Mahaney, M.C.
2010-01-01
Genetic effects on mechanical properties have been demonstrated in rodents, but not confirmed in primates. Our aim was to quantify the proportion of variation in vertebral trabecular bone mechanical properties that is due to the effects of genes. L3 vertebrae were collected from 110 females and 46 male baboons (6–32 years old) from a single extended pedigree. Cranio-caudally oriented trabecular bone cores were scanned with microCT then tested in monotonic compression to determine apparent ultimate stress, modulus, and toughness. Age and sex effects and heritability (h2) were assessed using maximum likelihood-based variance components methods. Additive effects of genes on residual trait variance were significant for ultimate stress (h2=0.58), toughness (h2=0.64), and BV/TV (h2=0.55). When BV/TV was accounted for, the residual variance in ultimate stress accounted for by the additive effects of genes was no longer significant. Toughness, however, showed evidence of a non-BV/TV-related genetic effect. Overall, maximum stress and modulus show strong genetic effects that are nearly entirely due to bone volume. Toughness shows strong genetic effects related to bone volume and shows additional genetic effects (accounting for 10% of the total trait variance) that are independent of bone volume. These results support continued use of bone volume as a focal trait to identify genes related to skeletal fragility, but also show that other focal traits related to toughness and variation in the organic component of bone matrix will enhance our ability to find additional genes that are particularly relevant to fatigue-related fractures. PMID:19900599
ERIC Educational Resources Information Center
Purdom, Boyd Andra
One experimental and three varied control groups (a total of 340 fourth graders) were used to investigate the effectiveness of a listening skill developmental unit produced by the Midwest Program on Airborne Television Instruction (MPATI). Results from an analysis of the effectiveness of the unit in developing skills of listening comprehension,…
Code of Federal Regulations, 2014 CFR
2014-10-01
... documents for the bandwidths of the commonly used television systems Number of lines=525; Nominal video bandwidth: 4.2 MHz, Sound carrier relative to video carrier=4.5 MHz 5M75C3F Total vision bandwidth: 5.75 MHz... 6. Composite Emissions Double-sideband, television relay Bn=2C+2M+2D Video limited to 5 MHz, audio...
Code of Federal Regulations, 2010 CFR
2010-10-01
... documents for the bandwidths of the commonly used television systems Number of lines=525; Nominal video bandwidth: 4.2 MHz, Sound carrier relative to video carrier=4.5 MHz 5M75C3F Total vision bandwidth: 5.75 MHz... 6. Composite Emissions Double-sideband, television relay Bn=2C+2M+2D Video limited to 5 MHz, audio...
Code of Federal Regulations, 2012 CFR
2012-10-01
... documents for the bandwidths of the commonly used television systems Number of lines=525; Nominal video bandwidth: 4.2 MHz, Sound carrier relative to video carrier=4.5 MHz 5M75C3F Total vision bandwidth: 5.75 MHz... 6. Composite Emissions Double-sideband, television relay Bn=2C+2M+2D Video limited to 5 MHz, audio...
Code of Federal Regulations, 2011 CFR
2011-10-01
... documents for the bandwidths of the commonly used television systems Number of lines=525; Nominal video bandwidth: 4.2 MHz, Sound carrier relative to video carrier=4.5 MHz 5M75C3F Total vision bandwidth: 5.75 MHz... 6. Composite Emissions Double-sideband, television relay Bn=2C+2M+2D Video limited to 5 MHz, audio...
Code of Federal Regulations, 2013 CFR
2013-10-01
... documents for the bandwidths of the commonly used television systems Number of lines=525; Nominal video bandwidth: 4.2 MHz, Sound carrier relative to video carrier=4.5 MHz 5M75C3F Total vision bandwidth: 5.75 MHz... 6. Composite Emissions Double-sideband, television relay Bn=2C+2M+2D Video limited to 5 MHz, audio...
Building the case for independent monitoring of food advertising on Australian television.
King, Lesley; Hebden, Lana; Grunseit, Anne; Kelly, Bridget; Chapman, Kathy
2013-12-01
To provide an independent monitoring report examining the ongoing impact of Australian self-regulatory pledges on food and drink advertising to children on commercial television. Analysis of food advertisements across comparable sample time periods in April/May 2006, 2007, 2009, 2010 and 2011. The main outcome measure comprised change in the mean rate of non-core food advertisements from 2006 to 2011. Sydney free-to-air television channels. Televised food advertisements. In 2011 the rate of non-core food advertisements was not significantly different from that in 2006 or 2010 (3·2/h v. 4·1/h and 3·1/h), although there were variations across the intervening years. The rate of fast-food advertising in 2010 was significantly higher than in 2006 (1·8/h v. 1·1/h, P < 0·001), but the same as that in 2011 (1·5/h). The frequency of non-core food advertising on Sydney television has remained essentially unchanged between 2006 and 2011, despite the implementation of two industry self-regulatory pledges. The current study illustrates the value of independent monitoring as a basic requirement of any responsive regulatory approach.
Characterization of shredded television scrap and implications for materials recovery.
Cui, Jirang; Forssberg, Eric
2007-01-01
Characterization of TV scrap was carried out by using a variety of methods, such as chemical analysis, particle size and shape analysis, liberation degree analysis, thermogravimetric analysis, sink-float test, and IR spectrometry. A comparison of TV scrap, personal computer scrap, and printed circuit board scrap shows that the content of non-ferrous metals and precious metals in TV scrap is much lower than that in personal computer scrap or printed circuit board scrap. It is expected that recycling of TV scrap will not be cost-effective by utilizing conventional manual disassembly. The result of particle shape analysis indicates that the non-ferrous metal particles in TV scrap formed as a variety of shapes; it is much more heterogeneous than that of plastics and printed circuit boards. Furthermore, the separability of TV scrap using density-based techniques was evaluated by the sink-float test. The result demonstrates that a high recovery of copper could be obtained by using an effective gravity separation process. Identification of plastics shows that the major plastic in TV scrap is high impact polystyrene. Gravity separation of plastics may encounter some challenges in separation of plastics from TV scrap because of specific density variations.
2010-01-01
Background Excessive television (TV) viewing might play an important role in the development of cardiovascular disease (CVD). The aim of this study was to examine the independent associations between TV viewing and CVD risk factors in adolescents. Methods A sample of 425 adolescents, aged 13- to 18.5-year-old, was included in this study. Body mass index (BMI), waist circumference (WC), glucose, total cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol, apolipoprotein (apo) A-1, apo B-100, and lipoprotein(a) levels were determined. A composite CVD risk score was computed based on age-, sex-, sexual maturation- and race-standardized triglycerides, HDL-cholesterol, LDL-cholesterol and glucose. TV viewing was self-reported. Results Two hundred and twenty-five adolescents (53%) who spent >3 hrs/day watching TV were considered as the "high TV viewing" group. Ninety-nine adolescents (23%) from the total sample were classified as overweight according to International age- and sex-specific BMI values. The high TV viewing group had significantly less favorable values of HDL-cholesterol, glucose, apo A1 and CVD score, independent of age, sex, sexual maturation, race and weight status. There was a significant interaction effect of TV viewing × weight status (P = 0.002) on WC, and the negative influence of TV viewing on WC persisted in the overweight group (P = 0.031) but was attenuated in non-overweight adolescents (P > 0.05). Conclusion Excessive TV viewing seems to be related to an unfavorable CVD risk factors profile in adolescence. Reducing TV viewing in overweight adolescents might be beneficial to decrease abdominal body fat. PMID:20500845
NASA Astrophysics Data System (ADS)
Yu, Haiqing; Chen, Shuhang; Chen, Yunmei; Liu, Huafeng
2017-05-01
Dynamic positron emission tomography (PET) is capable of providing both spatial and temporal information of radio tracers in vivo. In this paper, we present a novel joint estimation framework to reconstruct temporal sequences of dynamic PET images and the coefficients characterizing the system impulse response function, from which the associated parametric images of the system macro parameters for tracer kinetics can be estimated. The proposed algorithm, which combines statistical data measurement and tracer kinetic models, integrates a dictionary sparse coding (DSC) into a total variational minimization based algorithm for simultaneous reconstruction of the activity distribution and parametric map from measured emission sinograms. DSC, based on the compartmental theory, provides biologically meaningful regularization, and total variation regularization is incorporated to provide edge-preserving guidance. We rely on techniques from minimization algorithms (the alternating direction method of multipliers) to first generate the estimated activity distributions with sub-optimal kinetic parameter estimates, and then recover the parametric maps given these activity estimates. These coupled iterative steps are repeated as necessary until convergence. Experiments with synthetic, Monte Carlo generated data, and real patient data have been conducted, and the results are very promising.
Digital Signal Processing Methods for Ultrasonic Echoes.
Sinding, Kyle; Drapaca, Corina; Tittmann, Bernhard
2016-04-28
Digital signal processing has become an important component of data analysis needed in industrial applications. In particular, for ultrasonic thickness measurements the signal to noise ratio plays a major role in the accurate calculation of the arrival time. For this application a band pass filter is not sufficient since the noise level cannot be significantly decreased such that a reliable thickness measurement can be performed. This paper demonstrates the abilities of two regularization methods - total variation and Tikhonov - to filter acoustic and ultrasonic signals. Both of these methods are compared to a frequency based filtering for digitally produced signals as well as signals produced by ultrasonic transducers. This paper demonstrates the ability of the total variation and Tikhonov filters to accurately recover signals from noisy acoustic signals faster than a band pass filter. Furthermore, the total variation filter has been shown to reduce the noise of a signal significantly for signals with clear ultrasonic echoes. Signal to noise ratios have been increased over 400% by using a simple parameter optimization. While frequency based filtering is efficient for specific applications, this paper shows that the reduction of noise in ultrasonic systems can be much more efficient with regularization methods.
Li, Guang; Huang, Hailiang; Chen, Qing; Gaebler, Carl P.; Lin, Tiffany; Yuan, Amy; Rimner, Andreas; Mechalakos, James
2016-01-01
Purpose: To provide a comprehensive characterization of a novel respiratory surrogate that uses optical surface imaging (OSI) for accurate tidal volume (TV) measurement, dynamic airflow (TV′) calculation, and quantitative breathing pattern (BP) estimation during free breathing (FB), belly breathing (BB), chest breathing (CB), and breath hold (BH). Methods: Optical surface imaging, which captures all respiration-induced torso surface motion, was applied to measure respiratory TV, TV′, and BP in three common breathing patterns. Eleven healthy volunteers participated in breathing experiments with concurrent OSI-based and conventional spirometric measurements under an institutional review board approved protocol. This OSI-based technique measures dynamic TV from torso volume change (ΔVtorso = TV) in reference to full exhalation and airflow (TV′ = dTV/dt). Volume conservation, excluding exchanging air, was applied for OSI-based measurements under negligible pleural pressure variation in FB, BB, and CB. To demonstrate volume conservation, a constant TV was measured during BH while the chest and belly are moving (“pretended” respiration). To assess the accuracy of OSI-based spirometry, a conventional spirometer was used as the standard for both TV and TV′. Using OSI, BP was measured as BPOSI = ΔVchest/ΔVtorso and BP can be visualized using BPSHI = SHIchest/(SHIchest + SHIbelly), where surface height index (SHI) is defined as the mean vertical distance within a region of interest on the torso surface. A software tool was developed for OSI image processing, volume calculation, and BP visualization, and another tool was implemented for data acquisition using a Bernoulli-type spirometer. Results: The accuracy of the OSI-based spirometry is −21 ± 33 cm3 or −3.5% ± 6.3% averaged from 11 volunteers with 76 ± 28 breathing cycles on average in FB. Breathing variations between two separate acquisitions with approximate 30-min intervals are substantial: −1% ± 34% (ranging from −64% to 40%) in TV, 4% ± 20% (ranging from −50% to 26%) in breathing period (T), and −1% ± 34% (ranging from −49% to 44%) in BP. The airflow accuracy and variation (between two exercises) are −1 ± 54 cm3/s and −5% ± 30%, respectively. The slope of linear regression between OSI–TV and spirometric TV is 0.93 (R2 = 0.95) for FB, 0.96 (R2 = 0.98) for BB, and 0.95 (R2 = 0.95) for CB. The correlation between the two spirometric measurements is 0.98 ± 0.01. BP increases from BB, FB to CB, while TV increases from FB, BB, to CB. Under BH, 4% volume variation (range) on average was observed. Conclusions: The OSI-based technique provides an accurate measurement of tidal volume, airflow rate, and breathing pattern; all affect internal organ motion. This technique can be applied to various breathing patterns, including FB, BB, and CB. Substantial breathing irregularities and irreproducibility were observed and quantified with the OSI-based technique. These breathing parameters are useful to quantify breathing conditions, which could be used for effective tumor motion predictions. PMID:26936719
Chau, Josephine Y; Grunseit, Anne; Midthjell, Kristian; Holmen, Jostein; Holmen, Turid L; Bauman, Adrian E; van der Ploeg, Hidde P
2014-01-01
To examine associations of total sitting time, TV-viewing and leisure-time computer use with cardiometabolic risk biomarkers in adults. Population based cross-sectional study. Waist circumference, BMI, total cholesterol, HDL cholesterol, blood pressure, non-fasting glucose, gamma glutamyltransferase (GGT) and triglycerides were measured in 48,882 adults aged 20 years or older from the Nord-Trøndelag Health Study 2006-2008 (HUNT3). Adjusted multiple regression models were used to test for associations between these biomarkers and self-reported total sitting time, TV-viewing and leisure-time computer use in the whole sample and by cardiometabolic disease status sub-groups. In the whole sample, reporting total sitting time ≥10 h/day was associated with poorer BMI, waist circumference, total cholesterol, HDL cholesterol, diastolic blood pressure, systolic blood pressure, non-fasting glucose, GGT and triglyceride levels compared to those reporting total sitting time <4h/day (all p<0.05). TV-viewing ≥4 h/day was associated with poorer BMI, waist circumference, total cholesterol, HDL cholesterol, systolic blood pressure, GGT and triglycerides compared to TV-viewing <1h/day (all p<0.05). Leisure-time computer use ≥1 h/day was associated with poorer BMI, total cholesterol, diastolic blood pressure, GGT and triglycerides compared with those reporting no leisure-time computing. Sub-group analyses by cardiometabolic disease status showed similar patterns in participants free of cardiometabolic disease, while similar albeit non-significant patterns were observed in those with cardiometabolic disease. Total sitting time, TV-viewing and leisure-time computer use are associated with poorer cardiometabolic risk profiles in adults. Reducing sedentary behaviour throughout the day and limiting TV-viewing and leisure-time computer use may have health benefits. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
Outley, Corliss Wilson; Taddese, Abdissa
2006-04-01
To examine the number of food advertisements African American children are exposed to during children's television programming aired on predominantly African American and general television stations. A content analysis was conducted to identify and analyze the health-related content (HRC) and physical activity-related content (PARC) of food advertisements shown during children's television programming. Three sets of television advertisements from 3 stations (Black Entertainment Television, The WB [Warner Bros], and Disney Channel) served as the sample during a 1-week period in July 2005 (July 11-15), from 3 pm to 9 pm. In total, 1098 advertisements were recorded, with 256 food and beverage commercials used for this study. Results indicate that 36.3% of all commercials were based on fast food restaurants, 31.3% were for drinks, 16.8% were for candy, 13.7% were for cereals, and 2.0% were for snacks (percentages do not total 100 because of rounding). Compared with The WB and Disney Channel, Black Entertainment Television had significantly (P=.001) more food and beverage advertisements. Few HRC or PARC advertisements were shown. Of 256 food and beverage commercials, only 8.2% contained HRC and 9.4% had PARC. Also, the HRC and PARC scenes contained messages that were implied vs explicitly talking about the health or physical benefits of the product. African American children are overexposed to numerous types of food and beverage advertisements. These advertisements do not provide an adequate level of positive HRC and PARC messages. Consequently, the messages that are portrayed may undermine efforts to teach African American children about the importance of healthy living and physical activity.
Adoption and Use of Videocassette Recorders in the Third World.
ERIC Educational Resources Information Center
Straubhaar, Joseph; Boyd, Douglas A.
Videocassette recorder (VCR) acquisition and use in developing nations is largely an individual or household decision, and their rapid diffusion is influenced by several factors: price, and its variations due to government restrictions; income and income distribution; the content of broadcast television; the diversity of entertainment media…
Yousef, Said; Eapen, Valsamma; Zoubeidi, Taoufik; Mabrouk, Abdelazim
2014-08-01
Television viewing and videogame use (TV/VG) appear to be associated with some childhood behavioral problems. There are no studies addressing this problem in the United Arab Emirates. One hundred ninety-seven school children (mean age, 8.7 ± 2.1 years) were assessed. Child Behavior Checklist (CBCL) subscale scores and socio-demographic characteristics were compared between children who were involved with TV/VG more than 2 hours/day and those involved less than 2 hours/day (the recommended upper limit by The American Academy of Pediatrics). Thirty-seven percent of children who were involved with TV/VG time of more than 2 hours/day scored significantly higher on CBCL syndrome scales of withdrawn, social problems, attention problems, delinquent behavior, aggressive behavior, internalizing problems, externalizing problems and the CBCL total scores compared with their counterparts. Moreover, these children were younger in birth order and had fewer siblings. After controlling for these confounders using logistic regression, we found that TV/VG time more than 2 hours/day was positively associated with withdrawn (p = 0.008), attention problem (p = 0.037), externalizing problems (p = 0.007), and CBCL total (p = 0.014). Involvement with TV/VG for more than 2 hours/day is associated with more childhood behavioral problems. Counteracting negative effects of the over-involvement with TV/VG in children requires increased parental awareness.
Fast and low-dose computed laminography using compressive sensing based technique
DOE Office of Scientific and Technical Information (OSTI.GOV)
Abbas, Sajid, E-mail: scho@kaist.ac.kr; Park, Miran, E-mail: scho@kaist.ac.kr; Cho, Seungryong, E-mail: scho@kaist.ac.kr
2015-03-31
Computed laminography (CL) is well known for inspecting microstructures in the materials, weldments and soldering defects in high density packed components or multilayer printed circuit boards. The overload problem on x-ray tube and gross failure of the radio-sensitive electronics devices during a scan are among important issues in CL which needs to be addressed. The sparse-view CL can be one of the viable option to overcome such issues. In this work a numerical aluminum welding phantom was simulated to collect sparsely sampled projection data at only 40 views using a conventional CL scanning scheme i.e. oblique scan. A compressive-sensing inspiredmore » total-variation (TV) minimization algorithm was utilized to reconstruct the images. It is found that the images reconstructed using sparse view data are visually comparable with the images reconstructed using full scan data set i.e. at 360 views on regular interval. We have quantitatively confirmed that tiny structures such as copper and tungsten slags, and copper flakes in the reconstructed images from sparsely sampled data are comparable with the corresponding structure present in the fully sampled data case. A blurring effect can be seen near the edges of few pores at the bottom of the reconstructed images from sparsely sampled data, despite the overall image quality is reasonable for fast and low-dose NDT.« less
X-ray computed tomography using curvelet sparse regularization.
Wieczorek, Matthias; Frikel, Jürgen; Vogel, Jakob; Eggl, Elena; Kopp, Felix; Noël, Peter B; Pfeiffer, Franz; Demaret, Laurent; Lasser, Tobias
2015-04-01
Reconstruction of x-ray computed tomography (CT) data remains a mathematically challenging problem in medical imaging. Complementing the standard analytical reconstruction methods, sparse regularization is growing in importance, as it allows inclusion of prior knowledge. The paper presents a method for sparse regularization based on the curvelet frame for the application to iterative reconstruction in x-ray computed tomography. In this work, the authors present an iterative reconstruction approach based on the alternating direction method of multipliers using curvelet sparse regularization. Evaluation of the method is performed on a specifically crafted numerical phantom dataset to highlight the method's strengths. Additional evaluation is performed on two real datasets from commercial scanners with different noise characteristics, a clinical bone sample acquired in a micro-CT and a human abdomen scanned in a diagnostic CT. The results clearly illustrate that curvelet sparse regularization has characteristic strengths. In particular, it improves the restoration and resolution of highly directional, high contrast features with smooth contrast variations. The authors also compare this approach to the popular technique of total variation and to traditional filtered backprojection. The authors conclude that curvelet sparse regularization is able to improve reconstruction quality by reducing noise while preserving highly directional features.
The Effects of Television on Institutionalized Children.
ERIC Educational Resources Information Center
Sprafkin, Joyce N.; And Others
The extent to which television can be used to promote prosocial behavior is examined in this study. A total of 132 boys and girls (age range 8 to 18 years) with behavior problems serious enough to require institutional care participated in the study. The average IQ (WISC) was approximately 88. In the course of a year each of four treatments was…
ERIC Educational Resources Information Center
Atkin, Charles K.
This report, the first in a series of six reports on television advertising and children, presents the findings from a study designed to examine the impact of various advertising practices on the knowledge, attitudes, and behavior of young children. A total of 500 preschool and grade school children from both working-class and middle-class…
Toward a qualitative understanding of binge-watching behaviors: A focus group approach.
Flayelle, Maèva; Maurage, Pierre; Billieux, Joël
2017-12-01
Background and aims Binge-watching (i.e., seeing multiple episodes of the same TV series in a row) now constitutes a widespread phenomenon. However, little is known about the psychological factors underlying this behavior, as reflected by the paucity of available studies, most merely focusing on its potential harmfulness by applying the classic criteria used for other addictive disorders without exploring the uniqueness of binge-watching. This study thus aimed to take the opposite approach as a first step toward a genuine understanding of binge-watching behaviors through a qualitative analysis of the phenomenological characteristics of TV series watching. Methods A focus group of regular TV series viewers (N = 7) was established to explore a wide range of aspects related to TV series watching (e.g., motives, viewing practices, and related behaviors). Results A content analysis identified binge-watching features across three dimensions: TV series watching motivations, TV series watching engagement, and structural characteristics of TV shows. Most participants acknowledged that TV series watching can become addictive, but they all agreed having trouble recognizing themselves as truly being an "addict." Although obvious connections could be established with substance addiction criteria and symptoms, such parallelism appeared to be insufficient, as several distinctive facets emerged (e.g., positive view, transient overinvolvement, context dependency, and low everyday life impact). Discussion and conclusion The research should go beyond the classic biomedical and psychological models of addictive behaviors to account for binge-watching in order to explore its specificities and generate the first steps toward an adequate theoretical rationale for these emerging problematic behaviors.
van Grieken, Amy; Vlasblom, Eline; Wang, Lu; Beltman, Maaike; Boere-Boonekamp, Magda M; L'Hoir, Monique P
2017-01-01
Background Overweight is a major health issue, and parent-targeted interventions to promote healthy development in children are needed. Objective The study aimed to evaluate E-health4Uth Healthy Toddler, an intervention that educates parents of children aged 18 to 24 months regarding health-related behaviors, as compared with usual care. The effect of this intervention on the following primary outcomes was evaluated when the children were 36 months of age: health-related behaviors (breakfast daily, activity and outside play, sweetened beverage consumption, television (TV) viewing and computer time), body mass index (BMI), and the prevalence of overweight and obesity. Methods The BeeBOFT (acronym for breastfeeding, breakfast daily, outside playing, few sweet drinks, less TV viewing) study is a cluster randomized controlled trial involving 51 Youth Health Care (YHC) teams. In total, 1094 parents participated in the control group, and 1008 parents participated in the E-health4Uth Healthy Toddler intervention group. The intervention consisted of Web-based personalized advice given to parents who completed an eHealth module and discussion of the advice during a regular well-child visit. In this study the eHealth module was offered to parents before two regular well-child visits at 18 and 24 months of age. During the well-child visits, the parents’ personalized advice was combined with face-to-face counseling provided by the YHC professional. Parents in the control group received usual care, consisting of the regular well-child visits during which general information on child health-related behavior was provided to parents. Parents completed questionnaires regarding family characteristics and health-related behaviors when the child was 1 month (inclusion), 6 months, 14 months, and 36 months (follow-up) of age. The child’s height and weight were measured by trained health care professionals from birth through 36 months of age at fixed time points. Multilevel linear and logistic regression models were used to evaluate the primary outcomes at 36 months of age. Results At 36 months, we observed no differences between health-related behaviors of children, BMI or the percentage of children having overweight or obesity in the control and intervention group (P>.05). An analysis of the intervention effect revealed that boys benefited from eating breakfast daily, non-Dutch children spent more time being active or playing outdoors, children of low-educated parents and of overweight and obese mothers spent less time watching TV or using the computer, and children of normal weight mothers drank less sweetened beverages (P<.05) compared with the control group. Conclusions The E-health4Uth Healthy Toddler intervention resulted in small improvements in health-related behaviors among subgroups but had no significant effects with respect to the children’s BMI. We conclude that the E-health4Uth Healthy Toddler intervention may be useful for pediatric health care professionals in terms of providing parents with personalized information regarding their child’s health-related behaviors. Trial Registration Netherlands Trial Register: NTR1831; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=1831 (Archived by WebCite at http://www.webcitation.org/6mm5YFOB0) PMID:28751299
van Grieken, Amy; Vlasblom, Eline; Wang, Lu; Beltman, Maaike; Boere-Boonekamp, Magda M; L'Hoir, Monique P; Raat, Hein
2017-07-27
Overweight is a major health issue, and parent-targeted interventions to promote healthy development in children are needed. The study aimed to evaluate E-health4Uth Healthy Toddler, an intervention that educates parents of children aged 18 to 24 months regarding health-related behaviors, as compared with usual care. The effect of this intervention on the following primary outcomes was evaluated when the children were 36 months of age: health-related behaviors (breakfast daily, activity and outside play, sweetened beverage consumption, television (TV) viewing and computer time), body mass index (BMI), and the prevalence of overweight and obesity. The BeeBOFT (acronym for breastfeeding, breakfast daily, outside playing, few sweet drinks, less TV viewing) study is a cluster randomized controlled trial involving 51 Youth Health Care (YHC) teams. In total, 1094 parents participated in the control group, and 1008 parents participated in the E-health4Uth Healthy Toddler intervention group. The intervention consisted of Web-based personalized advice given to parents who completed an eHealth module and discussion of the advice during a regular well-child visit. In this study the eHealth module was offered to parents before two regular well-child visits at 18 and 24 months of age. During the well-child visits, the parents' personalized advice was combined with face-to-face counseling provided by the YHC professional. Parents in the control group received usual care, consisting of the regular well-child visits during which general information on child health-related behavior was provided to parents. Parents completed questionnaires regarding family characteristics and health-related behaviors when the child was 1 month (inclusion), 6 months, 14 months, and 36 months (follow-up) of age. The child's height and weight were measured by trained health care professionals from birth through 36 months of age at fixed time points. Multilevel linear and logistic regression models were used to evaluate the primary outcomes at 36 months of age. At 36 months, we observed no differences between health-related behaviors of children, BMI or the percentage of children having overweight or obesity in the control and intervention group (P>.05). An analysis of the intervention effect revealed that boys benefited from eating breakfast daily, non-Dutch children spent more time being active or playing outdoors, children of low-educated parents and of overweight and obese mothers spent less time watching TV or using the computer, and children of normal weight mothers drank less sweetened beverages (P<.05) compared with the control group. The E-health4Uth Healthy Toddler intervention resulted in small improvements in health-related behaviors among subgroups but had no significant effects with respect to the children's BMI. We conclude that the E-health4Uth Healthy Toddler intervention may be useful for pediatric health care professionals in terms of providing parents with personalized information regarding their child's health-related behaviors. Netherlands Trial Register: NTR1831; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=1831 (Archived by WebCite at http://www.webcitation.org/6mm5YFOB0). ©Amy van Grieken, Eline Vlasblom, Lu Wang, Maaike Beltman, Magda M Boere-Boonekamp, Monique P L'Hoir, Hein Raat. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 27.07.2017.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, L; Han, Y; Jin, M
Purpose: To develop an iterative reconstruction method for X-ray CT, in which the reconstruction can quickly converge to the desired solution with much reduced projection views. Methods: The reconstruction is formulated as a convex feasibility problem, i.e. the solution is an intersection of three convex sets: 1) data fidelity (DF) set – the L2 norm of the difference of observed projections and those from the reconstructed image is no greater than an error bound; 2) non-negativity of image voxels (NN) set; and 3) piecewise constant (PC) set - the total variation (TV) of the reconstructed image is no greater thanmore » an upper bound. The solution can be found by applying projection onto convex sets (POCS) sequentially for these three convex sets. Specifically, the algebraic reconstruction technique and setting negative voxels as zero are used for projection onto the DF and NN sets, respectively, while the projection onto the PC set is achieved by solving a standard Rudin, Osher, and Fatemi (ROF) model. The proposed method is named as full sequential POCS (FS-POCS), which is tested using the Shepp-Logan phantom and the Catphan600 phantom and compared with two similar algorithms, TV-POCS and CP-TV. Results: Using the Shepp-Logan phantom, the root mean square error (RMSE) of reconstructed images changing along with the number of iterations is used as the convergence measurement. In general, FS- POCS converges faster than TV-POCS and CP-TV, especially with fewer projection views. FS-POCS can also achieve accurate reconstruction of cone-beam CT of the Catphan600 phantom using only 54 views, comparable to that of FDK using 364 views. Conclusion: We developed an efficient iterative reconstruction for sparse-view CT using full sequential POCS. The simulation and physical phantom data demonstrated the computational efficiency and effectiveness of FS-POCS.« less
Jaichuen, Nongnuch; Vandevijvere, Stefanie; Kelly, Bridget; Vongmongkol, Vuthiphan; Phulkerd, Sirinya; Tangcharoensathien, Viroj
2018-06-15
Food advertising is a key factor which influences children's food preferences. This study assessed the rates, nutritional quality and contents of food and beverage advertising in children's, youth and family television programmes in Thailand. Free TV was recorded for two weeks in March 2014 from six to ten am and three to eight pm on weekends and three to eight pm on weekdays across all four channels; a total of 344 h recorded. Digital TV was recorded across three channels for one week for 24 h per day in October 2014; a total 504 h recorded. For Free TV, 1359 food advertisements were identified, with on average 2.9 non-core food advertisements per hour per channel. The most frequently advertised food products on free TV were sugar-sweetened drinks. The rates of advertisements containing promotional characters and premium offers were significantly higher for non-core than core foods, 1.2 versus 0.03 and 0.6 versus 0.0 per hour respectively. For Digital TV, 693 food advertisements were identified, with an average of one non-core food advertisement per hour per channel. The most frequently advertised food products on digital TV were baby and toddler milk formulae. Food and beverage advertising on Thai television is predominantly unhealthy. Therefore, the Government and related agencies should introduce and enforce policies to address this issue. Current regulations should be adapted to control both the frequency and nature of unhealthy on-air food marketing to protect the health of Thai children.
Lessons from the Hot Seat: NASA Scientists in Live Broadcast and Documentary Television (Invited)
NASA Astrophysics Data System (ADS)
Thaller, M.
2013-12-01
NASA sends hundreds of scientists a year to media training, where they are taught to stick to their talking points, resist off-topic questions, and stand up to bullying. In over 15 years of television work representing NASA, I have yet to put any of the practices I learned in these sessions into action. Honestly, in over 99% of cases, reporters and documentarians are looking for totally different things from scientists on their programs. For most TV interviews, there are two or three minutes to get a few points across (and it is *amazing* how fast that time goes), show an animation, and smile engagingly to give the impression that NASA scientists are not arrogant jerks and might even be worth some tax money. But we are never trained to do this! In this session, I'll talk about some of my television experiences (good, bad, and totally embarrassing), show some examples of the short video segments we film, and discuss why most science organizations, including NASA, aren't training their scientists to give the media what they really want.
Chamberlain, Lisa J; Wang, Yun; Robinson, Thomas N
2006-04-01
To examine children's screen media exposure and requests for advertised toys and food/drinks. Prospective cohort study. Twelve elementary schools in northern California. Eight hundred twenty-seven third grade children participated at baseline; 386 students in 6 schools were followed up for 20 months. None. Child self-reported requests for advertised toys and foods/drinks. At baseline, children's screen media time was significantly associated with concurrent requests for advertised toys (Spearman r = 0.15 [TV viewing] and r = 0.20 [total screen time]; both P<.001) and foods/drinks (Spearman r = 0.16 [TV viewing] and r = 0.18 [total screen time]; both P<.001). In prospective analysis, children's screen media time at baseline was significantly associated with their mean number of toy requests 7 to 20 months later (Spearman r = 0.21 [TV viewing] and r = 0.24 [total screen time]; both P<.001) and foods/drinks requests (Spearman r = 0.14 [TV viewing] and r = 0.16 [total screen time]; both P<.01). After adjusting for baseline requests and sociodemographic variables, the relationship between screen media exposure and future requests for advertised foods/drinks remained significant for total TV viewing and total screen media exposure. The relationship with future requests for toys remained significant for total screen media exposure. Screen media exposure is a prospective risk factor for children's requests for advertised products. Future experimental studies on children's health- and consumer-related outcomes are warranted.
SU-F-18C-14: Hessian-Based Norm Penalty for Weighted Least-Square CBCT Reconstruction
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sun, T; Sun, N; Tan, S
Purpose: To develop a Hessian-based norm penalty for cone-beam CT (CBCT) reconstruction that has a similar ability in suppressing noise as the total variation (TV) penalty while avoiding the staircase effect and better preserving low-contrast objects. Methods: We extended the TV penalty to a Hessian-based norm penalty based on the Frobenius norm of the Hessian matrix of an image for CBCT reconstruction. The objective function was constructed using the penalized weighted least-square (PWLS) principle. An effective algorithm was developed to minimize the objective function using a majorization-minimization (MM) approach. We evaluated and compared the proposed penalty with the TV penaltymore » on a CatPhan 600 phantom and an anthropomorphic head phantom, each acquired at a low-dose protocol (10mA/10ms) and a high-dose protocol (80mA/12ms). For both penalties, contrast-to-noise (CNR) in four low-contrast regions-of-interest (ROIs) and the full-width-at-half-maximum (FWHM) of two point-like objects in constructed images were calculated and compared. Results: In the experiment of CatPhan 600 phantom, the Hessian-based norm penalty has slightly higher CNRs and approximately equivalent FWHM values compared with the TV penalty. In the experiment of the anthropomorphic head phantom at the low-dose protocol, the TV penalty result has several artificial piece-wise constant areas known as the staircase effect while in the Hessian-based norm penalty the image appears smoother and more similar to that of the FDK result using the high-dose protocol. Conclusion: The proposed Hessian-based norm penalty has a similar performance in suppressing noise to the TV penalty, but has a potential advantage in suppressing the staircase effect and preserving low-contrast objects. This work was supported in part by National Natural Science Foundation of China (NNSFC), under Grant Nos. 60971112 and 61375018, and Fundamental Research Funds for the Central Universities, under Grant No. 2012QN086.« less
ERIC Educational Resources Information Center
Ng, Daniel; Supaporn, Potibut
A study investigated the trend of current U.S. television commercial informativeness by comparing the results with Alan Resnik and Bruce Stern's previous benchmark study conducted in 1977. A systematic random sampling procedure was used to select viewing dates and times of commercials from the three national networks. Ultimately, a total of 550…
ERIC Educational Resources Information Center
Wicks, Robert H.
A study examined the treatment and portrayal of political parties on Soviet and American television. The content of six newscasts of "World News Tonight" and "Vremya" during June of 1984 were analyzed qualitatively and quantitatively. The overall results suggest that 15 stories (24% of the total allotted time) pertaining…
ERIC Educational Resources Information Center
Francis, Leslie J.; Gibson, Harry M.
1993-01-01
Describes a study that was conducted to investigate the influence of age, sex, social class, and religion on total television viewing time and program preferences among a large sample of Scottish secondary school students. Four main program types are examined, i.e., soap, sport, light entertainment, and current awareness. (50 references) (LRW)
Television as a Talking Picture Book: A Prop for Language Acquisition.
ERIC Educational Resources Information Center
Lemish, Dafna; Rice, Mabel L.
This study provides longitudinal observations of young children's behaviors while viewing television in their own homes, over a time when the children were actively involved in the process of language acquisition. A total of 16 children were observed for a period ranging from 6 to 8 months. At the beginning, their ages ranged from 6 and 1/2 to 29…
Watching a food-related television show and caloric intake. A laboratory study.
Bodenlos, Jamie S; Wormuth, Bernadette M
2013-02-01
Television watching has been positively associated with overeating and obesity. How popular food-related television shows affects eating behavior has not been examined. An experimental study was conducted to examine how exposure to a food-related television program affects amount and type of food consumed in adults (N=80). Participants were randomized to watch a cooking or nature television program and were then presented with 800 total calories of chocolate covered candies, cheese curls, and carrots. Food was weighed before and after the ad libitum eating session to determine amount consumed. After controlling for dietary restraint, hunger and food preference, significantly more chocolate covered candies were consumed among individuals who watched the cooking program compared to the nature program. No significant differences between conditions were found for overall caloric intake or for cheese curl or carrot consumption. Findings suggest that watching food-related television programs may affect eating behavior and has implications for obesity prevention and intervention efforts. Copyright © 2012 Elsevier Ltd. All rights reserved.
Boyland, Emma J; Harrold, Joanne A; Kirkham, Tim C; Corker, Catherine; Cuddy, Jenna; Evans, Deborah; Dovey, Terence M; Lawton, Clare L; Blundell, John E; Halford, Jason C G
2011-07-01
Our aim was to determine if levels of television viewing (a proxy measure for habitual commercial exposure) affect children's food preference responses to television food commercials. A total of 281 children aged 6 to 13 years from northwest England viewed toy or food television commercials followed by a cartoon on 2 separate occasions; they then completed 3 food preference measures, a commercial recognition task, and a television viewing questionnaire. After viewing the food commercials, all children selected more branded and nonbranded fat-rich and carbohydrate-rich items from food preference checklists compared with after viewing the toy commercials. The food preferences of children with higher habitual levels of television viewing were more affected by food commercial exposure than those of low television viewers. After viewing food commercials, high television viewing children selected a greater number of branded food items compared with after the toy commercials as well as compared with the low television viewers. Children correctly recognized more food commercials than toy commercials. Exposure to television food commercials enhanced high television viewers' preferences for branded foods and increased reported preferences for all food items (branded and nonbranded) relative to the low television viewers. This is the first study to demonstrate that children with greater previous exposure to commercials (high television viewers) seemed to be more responsive to food promotion messages than children with lower previous advertising exposure. Copyright © 2011 by the American Academy of Pediatrics.
Bullying on Television: 1960-2010.
Petranovich, Kaitlin A; Bapty, Samantha J; Maestas, Travis S; Strasburger, Victor C
2016-10-01
Bullying is a serious issue for adolescents, with health consequences both at the time of victimization and later on in adulthood. Aggression in the media is an area that has been explored as a contributing factor to bullying behavior. This study aims to determine if the incidence of aggression in popular television shows over the past 50 years has changed. A total of 198 episodes of the most popular television shows between the years 1960 and 2010 were coded for incidents of aggression and analyzed using simple linear regression. The mean number of events per episode was 8.8. No statistically significant correlation was found between number of bullying events and the years in which they occurred. Whereas it is possible that aggression on television may have an impact on bullying behaviors, there is no evidence that the incidence of bullying on television has changed significantly in the past 5 decades. © The Author(s) 2015.
Is watching television a realistic leisure option for people with dementia?
Gústafsdóttir, Margrét
2015-01-01
Watching television is a common leisure activity, not least among older people. However, watching television may become difficult when it is disturbed by symptoms of dementia. A total of 284 questionnaires were handed out to relatives of people with dementia in Iceland, in the Memory Clinic of the University Hospital and in specialized units for people with dementia (6 day-care units and 8 units within nursing homes). The response rate was just below 58%. Watching television was shown to play a less important role in the course of the daily life of people with dementia as soon as the symptoms of the disease became evident, and it increasingly became less relevant. So, this previous leisure activity left an ever-growing void of time to fill. However, watching television may provide an important social context for contact and togetherness during the progress of the disease, as watching television with someone close to them was important for the individuals with dementia. It is not a viable option for people with dementia to watch television on their own, but they may enjoy watching television while sharing this activity with a person close to them. This may even provide quality time.
Trends in US newspaper and television coverage of tobacco.
Nelson, David E; Pederson, Linda L; Mowery, Paul; Bailey, Sarah; Sevilimedu, Varadan; London, Joel; Babb, Stephen; Pechacek, Terry
2015-01-01
The news media plays an important role in agenda setting and framing of stories about tobacco control. The purpose of this study was to examine newspaper, newswire and television coverage of tobacco issues in the USA over a 7-year period. Analyses of 2004-2010 news media surveillance system data from the US Centers for Disease Control and Prevention's Office on Smoking and Health, based on content analysis and quantitative methods. Information on extent of news coverage, and types of tobacco-related themes, were examined from articles in 10 newspapers and 2 major newswires, as well as transcripts from 6 national television networks. The overall extent of newspaper, newswire and television stories about tobacco, and level of coverage by specific media outlets, varied over time, especially for newspapers. Nevertheless, there was an average of 3 newspaper stories, 4 newswire stories, and 1 television tobacco-related story each day. Television stories were more likely to contain cessation/addiction or health effects/statistics themes and less likely to contain secondhand smoke or policy/regulation themes than newspaper/newswire stories. There was more variation in the choice of tobacco theme among individual newspapers/newswires than television media outlets. News coverage of tobacco in the USA was relatively constant from 2004 to 2010. Audiences were more likely to be exposed to different tobacco themes in newspapers/newswires than on television. Tracking information about tobacco news stories can be used by advocates, programs and others for planning and evaluation, and by researchers for hypothesis generation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Violations of the International Code of Marketing of Breast-milk Substitutes: Indonesia context.
Hidayana, Irma; Februhartanty, Judhiastuty; Parady, Vida A
2017-01-01
To measure compliance with the International Code of Marketing of Breast-milk Substitutes ('the Code') in Indonesia. The study was a cross-sectional survey using the Interagency Group on Breastfeeding Monitoring protocol. Public and private health facilities in six provinces on Java island in Indonesia. A total of 874 women (382 pregnant women and 492 breast-feeding mothers of infants below 6 months) and seventy-seven health workers were recruited from eighteen participating health facilities. The study also analysed a total of forty-four labels of breast-milk substitute products, twenty-seven television commercials for growing-up milk (for children >12 months) of nine brands and thirty-four print advertisements of fourteen brands. The study found that 20 % of the women had received advice and information on the use of breast-milk substitutes and 72 % had seen promotional materials for breast-milk substitutes. About 15 % reported receiving free samples and 16 % received gifts. Nearly a quarter of the health workers confirmed receiving visits from representatives of breast-milk substitute companies. Two health workers reported having received gifts from the companies. The most common labelling violations found were statements or visuals that discouraged breast-feeding and the absence of mention about the consideration of local climate in the expiration date. Violations of the Code by health workers, breast-milk substitute companies and their representatives were found in all provinces studied. A regular monitoring system should be in place to ensure improved compliance with and enforcement of the Code.
Predictors of screen viewing time in young Singaporean children: the GUSTO cohort.
Bernard, Jonathan Y; Padmapriya, Natarajan; Chen, Bozhi; Cai, Shirong; Tan, Kok Hian; Yap, Fabian; Shek, Lynette; Chong, Yap-Seng; Gluckman, Peter D; Godfrey, Keith M; Kramer, Michael S; Saw, Seang Mei; Müller-Riemenschneider, Falk
2017-09-05
Higher screen viewing time (SVT) in childhood has been associated with adverse health outcomes, but the predictors of SVT in early childhood are poorly understood. We examined the sociodemographic and behavioral predictors of total and device-specific SVT in a Singaporean cohort. At ages 2 and 3 years, SVT of 910 children was reported by their parents. Interviewer-administered questionnaires assessed SVT on weekdays and weekends for television, computer, and hand-held devices. Multivariable linear mixed-effect models were used to examine the associations of total and device-specific SVT at ages 2 and 3 with predictors, including children's sex, ethnicity, birth order, family income, and parental age, education, BMI, and television viewing time. At age 2, children's total SVT averaged 2.4 ± 2.2 (mean ± SD) hours/day, including 1.6 ± 1.6 and 0.7 ± 1.0 h/day for television and hand-held devices, respectively. At age 3, hand-held device SVT was 0.3 (95% CI: 0.2, 0.4) hours/day higher, while no increases were observed for other devices. SVT tracked moderately from 2 to 3 years (r = 0.49, p < 0.0001). Compared to Chinese children, Malay and Indian children spent 1.04 (0.66, 1.41) and 0.54 (0.15, 0.94) more hours/day watching screens, respectively. Other predictors of longer SVT were younger maternal age, lower maternal education, and longer parental television time. In our cohort, the main predictors of longer children's SVT were Malay and Indian ethnicity, younger maternal age, lower education and longer parental television viewing time. Our study may help target populations for future interventions in Asia, but also in other technology-centered societies. This ongoing study was first registered on July 1, 2010 on NCT01174875 as. Retrospectively registered.
Sedentary behavior and prostate cancer risk in the NIH-AARP Diet and Health Study.
Lynch, Brigid M; Friedenreich, Christine M; Kopciuk, Karen A; Hollenbeck, Albert R; Moore, Steven C; Matthews, Charles E
2014-05-01
Sedentary behavior (sitting time) has been proposed as an independent risk factor for some cancers; however, its role in the development of prostate cancer has not been determined. We examined the prospective associations of self-reported daily sitting time and daily television/video viewing time with the risk of developing or dying from prostate cancer among 170,481 men in the NIH-AARP Diet and Health Study. We estimated HRs and 95% confidence intervals (CI) using Cox proportional hazards regression. Between 1996 and 2006, there were 13,751 incident (including 1,365 advanced) prostate cancer cases identified; prostate cancer mortality (through 2008) was 669. No strong or significant association with prostate cancer risk was seen in fully adjusted models for either daily sitting or television/video time. There were some suggestions of effect modification by body mass index (BMI; interaction for television/video time and BMI, P = 0.02). For total prostate cancer risk, television/video time was associated with a slightly elevated, but nonsignificant, increase amongst obese men (HR = 1.28; 95% CI, 0.98-1.69); a null association was observed amongst overweight men (HR = 1.04; 0.89-1.22); and, for men with a normal BMI, television/video time was associated with a nonsignificant risk decrease (HR = 0.82; 95% CI, 0.66-1.01). Similar patterns were observed for total daily sitting and television/video time in advanced prostate cancer and prostate cancer mortality. Sedentary behavior seems to play a limited role in the development of prostate cancer; however, we cannot rule out potential effect modification by BMI or the impact of measurement error on results. ©2014 AACR.
Sedentary behavior and prostate cancer risk in the NIH-AARP Diet and Health Study
Lynch, Brigid M.; Friedenreich, Christine M.; Kopciuk, Karen A.; Hollenbeck, Albert R.; Moore, Steven C.; Matthews, Charles E.
2014-01-01
Sedentary behavior (sitting time) has been proposed as an independent risk factor for some cancers; however, its role in the development of prostate cancer has not been determined. We examined the prospective associations of self-reported daily sitting time and daily television/video viewing time with risk of developing or dying from prostate cancer among 170,481 men in the NIH-AARP Diet and Health Study. We estimated hazard ratios and 95% confidence intervals using Cox Proportional Hazards regression. Between 1996 and 2006 there were 13,751 incident (including 1,365 advanced) prostate cancer cases identified; prostate cancer mortality (through 2008) was 669. No strong or significant association with prostate cancer risk was seen in fully adjusted models for either daily sitting or television/video time. There was some suggestion of effect modification by body mass index (interaction for television/video time and body mass index, p = 0.02). For total prostate cancer risk, television/video time was associated with a slightly elevated, but non-significant increased amongst obese men (HR=1.28, 95%CI: 0.98, 1.69); a null association was observed amongst overweight men (HR=1.04, 0.89, 1.22); and, for men with a normal body mass index, television/video time was associated with a non-significant risk decrease (HR=0.82, 95%CI: 0.66, 1.01). Similar patterns were observed for total daily sitting and television/video time in advanced prostate cancer and prostate cancer mortality. Sedentary behavior appears to play a limited role in the development of prostate cancer, however we cannot rule out potential effect modification by body mass index or the impact of measurement error on results. PMID:24526287
Content analysis of food advertising in Turkish television.
Guran, Tulay; Turan, Serap; Akcay, Teoman; Degirmenci, Fatih; Avci, Okan; Asan, Abdulkerim; Erdil, Emre; Majid, Abdulaziz; Bereket, Abdullah
2010-07-01
Television (TV) viewing has been implicated in children's weight gain. We aimed to conduct a comprehensive content analysis of TV food advertising in Turkey. TV advertisements (ads) in the four most popular national free to air Turkish TV channels, were assessed on two weekdays and two weekend days at four time periods of the day; 0800-1200,1200-1600,1600-2000 and 2000-2400 h for each TV channel (64 h assessed for each TV channel), making a total of 256 h. Each ad was analysed for food and drink content, duration and audiovisual properties. There were 8853 TV ads and 2848 of these were related to food (32.1%). A majority of food ads included high-calorie, high-fat, high-sugar food and drink rather than core/healthy foods (81%). Chocolate and chocolate bars were the most frequently advertised food/drink product, followed by cakes, coffee, tea, candies, gum, fast food, chips, juices/carbonated beverages, margarine and ice-cream formed the highest rate of food products advertised in decreasing order. Thirty per cent of all obesogenic/unhealthy ads targeted childhood by using audiovisual techniques. The proportion of total advertisements which were for food or drink, and the proportion of food advertisements that were for unhealthy foods were both much higher at the weekend (33% vs. 30% and 84% vs. 78%, respectively). The time period between 1600 and 2000 h was the most concentrated time slot (33%) for food advertising. This study provides data for the first time on the high levels of obesogenic food advertising on Turkish TV. This should alarm policy-makers to set limits on food advertising targeted towards children especially in countries like Turkey in which childhood obesity is emerging as an important public health issue.
Qin, Chun-Yan; Zhou, Jin; Cao, Yong; Zhang, Yong; Hughes, Robert M; Wang, Bei-Xin
2014-09-01
Aquatic organisms' tolerance to water pollution is widely used to monitor and assess freshwater ecosystem health. Tolerance values (TVs) estimated based on statistical analyses of species-environment relationships are more objective than those assigned by expert opinion. Region-specific TVs are the basis for developing accurate bioassessment metrics particularly in developing countries, where both aquatic biota and their responses to human disturbances have been poorly documented. We used principal component analysis to derive a synthetic gradient for four stressor variables (total nitrogen, total phosphorus, dissolved oxygen, and % silt) based on 286 sampling sites in the Taihu Lake and Qiantang River basins (Yangtze River Delta), China. We used the scores of taxa on the first principal component (PC1), which explained 49.8% of the variance, to estimate the tolerance values (TV(r)) of 163 macroinvertebrates taxa that were collected from at least 20 sites, 81 of which were not included in the Hilsenhoff TV lists (TV(h)) of 1987. All estimates were scaled into the range of 1-10 as in TV(h). Of all the taxa with different TVs, 46.3% of TV(r) were lower and 52.4% were higher than TV(h). TV(r) were significantly (p < 0.01, Fig. 2), but weakly (r(2) = 0.34), correlated with TVh. Seven biotic metrics based on TVr were more strongly correlated with the main stressors and were more effective at discriminating references sites from impacted sites than those based on TV(h). Our results highlight the importance of developing region-specific TVs for macroinvertebrate-based bioassessment and to facilitate assessment of streams in China, particularly in the Yangtze River Delta.
Television viewing, computer use, time driving and all-cause mortality: the SUN cohort.
Basterra-Gortari, Francisco Javier; Bes-Rastrollo, Maira; Gea, Alfredo; Núñez-Córdoba, Jorge María; Toledo, Estefanía; Martínez-González, Miguel Ángel
2014-06-25
Sedentary behaviors have been directly associated with all-cause mortality. However, little is known about different types of sedentary behaviors in relation to overall mortality. Our objective was to assess the association between different sedentary behaviors and all-cause mortality. In this prospective, dynamic cohort study (the SUN Project) 13 284 Spanish university graduates with a mean age of 37 years were followed-up for a median of 8.2 years. Television, computer, and driving time were assessed at baseline. Poisson regression models were fitted to examine the association between each sedentary behavior and total mortality. All-cause mortality incidence rate ratios (IRRs) per 2 hours per day were 1.40 (95% confidence interval (CI): 1.06 to 1.84) for television viewing, 0.96 (95% CI: 0.79 to 1.18) for computer use, and 1.14 (95% CI: 0.90 to 1.44) for driving, after adjustment for age, sex, smoking status, total energy intake, Mediterranean diet adherence, body mass index, and physical activity. The risk of mortality was twofold higher for participants reporting ≥ 3 h/day of television viewing than for those reporting <1 h/d (IRR: 2.04 [95% CI 1.16 to 3.57]). Television viewing was directly associated with all-cause mortality. However, computer use and time spent driving were not significantly associated with higher mortality. Further cohort studies and trials designed to assess whether reductions in television viewing are able to reduce mortality are warranted. The lack of association between computer use or time spent driving and mortality needs further confirmation. © 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.
An adaptive DPCM algorithm for predicting contours in NTSC composite video signals
NASA Astrophysics Data System (ADS)
Cox, N. R.
An adaptive DPCM algorithm is proposed for encoding digitized National Television Systems Committee (NTSC) color video signals. This algorithm essentially predicts picture contours in the composite signal without resorting to component separation. The contour parameters (slope thresholds) are optimized using four 'typical' television frames that have been sampled at three times the color subcarrier frequency. Three variations of the basic predictor are simulated and compared quantitatively with three non-adaptive predictors of similar complexity. By incorporating a dual-word-length coder and buffer memory, high quality color pictures can be encoded at 4.0 bits/pel or 42.95 Mbit/s. The effect of channel error propagation is also investigated.
Choi, Sunghoon; Lee, Haenghwa; Lee, Donghoon; Choi, Seungyeon; Lee, Chang-Lae; Kwon, Woocheol; Shin, Jungwook; Seo, Chang-Woo; Kim, Hee-Joung
2018-05-01
This work describes the hardware and software developments of a prototype chest digital tomosynthesis (CDT) R/F system. The purpose of this study was to validate the developed system for its possible clinical application on low-dose chest tomosynthesis imaging. The prototype CDT R/F system was operated by carefully controlling the electromechanical subsystems through a synchronized interface. Once a command signal was delivered by the user, a tomosynthesis sweep started to acquire 81 projection views (PVs) in a limited angular range of ±20°. Among the full projection dataset of 81 images, several sets of 21 (quarter view) and 41 (half view) images with equally spaced angle steps were selected to represent a sparse view condition. GPU-accelerated and total-variation (TV) regularization strategy-based compressed sensing (CS) image reconstruction was implemented. The imaged objects were a flat-field using a copper filter to measure the noise power spectrum (NPS), a Catphan ® CTP682 quality assurance (QA) phantom to measure a task-based modulation transfer function (MTF T ask ) of three different cylinders' edge, and an anthropomorphic chest phantom with inserted lung nodules. The authors also verified the accelerated computing power over CPU programming by checking the elapsed time required for the CS method. The resultant absorbed and effective doses that were delivered to the chest phantom from two-view digital radiographic projections, helical computed tomography (CT), and the prototype CDT system were compared. The prototype CDT system was successfully operated, showing little geometric error with fast rise and fall times of R/F x-ray pulse less than 2 and 10 ms, respectively. The in-plane NPS presented essential symmetric patterns as predicted by the central slice theorem. The NPS images from 21 PVs were provided quite different pattern against 41 and 81 PVs due to aliased noise. The voxel variance values which summed all NPS intensities were inversely proportional to the number of PVs, and the CS method gave much lower voxel variance by the factors of 3.97-6.43 and 2.28-3.36 compared to filtered backprojection (FBP) and 20 iterations of simultaneous algebraic reconstruction technique (SART). The spatial frequencies of the f 50 at which the MTF T ask reduced to 50% were 1.50, 1.55, and 1.67 cycles/mm for FBP, SART, and CS methods, respectively, in the case of Bone 20% cylinder using 41 views. A variety of ranges of TV reconstruction parameters were implemented during the CS method and we could observe that the NPS and MTF T ask preserved best when the regularization and TV smoothing parameters α and τ were in a range of 0.001-0.1. For the chest phantom data, the signal difference to noise ratios (SDNRs) were higher in the proposed CS scheme images than in the FBP and SART, showing the enhanced rate of 1.05-1.43 for half view imaging. The total averaged reconstruction time during 20 iterations of the CS scheme was 124.68 s, which could match-up a clinically feasible time (<3 min). This computing time represented an enhanced speed 386 times greater than CPU programming. The total amounts of estimated effective doses were 0.12, 0.53 (half view), and 2.56 mSv for two-view radiographs, the prototype CDT system, and helical CT, respectively, showing 4.49 times higher than conventional radiography and 4.83 times lower than a CT exam, respectively. The current work describes the development and performance assessment of both hardware and software for tomosynthesis applications. The authors observed reasonable outcomes by showing a potential for low-dose application in CDT imaging using GPU acceleration. © 2018 American Association of Physicists in Medicine.
47 CFR 74.1203 - Interference.
Code of Federal Regulations, 2014 CFR
2014-10-01
... FM Broadcast Booster Stations § 74.1203 Interference. (a) An authorized FM translator or booster..., TV booster, FM translator or FM booster station; or (3) The direct reception by the public of the off... FM booster stations. Interference will be considered to occur whenever reception of a regularly used...
47 CFR 74.1203 - Interference.
Code of Federal Regulations, 2013 CFR
2013-10-01
... FM Broadcast Booster Stations § 74.1203 Interference. (a) An authorized FM translator or booster..., TV booster, FM translator or FM booster station; or (3) The direct reception by the public of the off... FM booster stations. Interference will be considered to occur whenever reception of a regularly used...
47 CFR 74.1203 - Interference.
Code of Federal Regulations, 2011 CFR
2011-10-01
... FM Broadcast Booster Stations § 74.1203 Interference. (a) An authorized FM translator or booster..., TV booster, FM translator or FM booster station; or (3) The direct reception by the public of the off... FM booster stations. Interference will be considered to occur whenever reception of a regularly used...
47 CFR 74.1203 - Interference.
Code of Federal Regulations, 2012 CFR
2012-10-01
... FM Broadcast Booster Stations § 74.1203 Interference. (a) An authorized FM translator or booster..., TV booster, FM translator or FM booster station; or (3) The direct reception by the public of the off... FM booster stations. Interference will be considered to occur whenever reception of a regularly used...
Food and beverage cues in UK and Irish children-television programming.
Scully, Paul; Reid, Orlaith; Macken, Alan; Healy, Mark; Saunders, Jean; Leddin, Des; Cullen, Walter; Dunne, Colum; O'Gorman, Clodagh S
2014-11-01
Increased time in which children spend watching television is a well-described contributor to paediatric obesity. This study investigated the frequency and type of food and beverage placement in children-specific television broadcasts and compared data from UK (UK) and Irish television stations. Content analysis, totalling 82.5 h, reflecting 5 weekdays of children-specific television broadcasting on UK and Irish television channels was performed. To allow comparison between UK and Irish food and beverage cues, only broadcasts between 06.00 and 11.30 were analysed. Data were coded separately by two analysts and transferred to SPSS for analyses. Food and beverage cues were coded based on type of product, product placement, product use, motivation, outcome and characters involved. A total of 1155 food and beverage cues were recorded. Sweet snacks were the most frequent food cue (13.3%), followed by sweets/candy (11.4%). Tea/coffee was the most frequent beverage cue (13.5%), followed by sugar-sweetened beverages (13.0%). The outcome of the cue was positive in 32.6%, negative in 19.8%, and neutral in 47.5% of cases. The most common motivating factor associated with each cue was celebratory/social (25.2%), followed by hunger/thirst (25.0%). Comparison of UK and Irish placements showed both to portray high levels of unhealthy food cues. However, placements for sugar-sweetened beverages were relatively low on both channels. This study provides further evidence of the prominence of unhealthy foods in children's programming. These data may provide guidance for healthcare professionals, regulators and programme makers in planning for a healthier portrayal of food and beverage in children's television. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
SPECT reconstruction with nonuniform attenuation from highly under-sampled projection data
NASA Astrophysics Data System (ADS)
Li, Cuifen; Wen, Junhai; Zhang, Kangping; Shi, Donghao; Dong, Haixiang; Li, Wenxiao; Liang, Zhengrong
2012-03-01
Single photon emission computed tomography (SPECT) is an important nuclear medicine imaging technique and has been using in clinical diagnoses. The SPECT image can reflect not only organizational structure but also functional activities of human body, therefore diseases can be found much earlier. In SPECT, the reconstruction is based on the measurement of gamma photons emitted by the radiotracer. The number of gamma photons detected is proportional to the dose of radiopharmaceutical, but the dose is limited because of patient safety. There is an upper limit in the number of gamma photons that can be detected per unit time, so it takes a long time to acquire SPECT projection data. Sometimes we just can obtain highly under-sampled projection data because of the limit of the scanning time or imaging hardware. How to reconstruct an image using highly under-sampled projection data is an interesting problem. One method is to minimize the total variation (TV) of the reconstructed image during the iterative reconstruction. In this work, we developed an OSEM-TV SPECT reconstruction algorithm, which could reconstruct the image from highly under-sampled projection data with non-uniform attenuation. Simulation results demonstrate that the OSEM-TV algorithm performs well in SPECT reconstruction with non-uniform attenuation.
Gender-Role Portrayals in Television Advertising Across the Globe.
Matthes, Jörg; Prieler, Michael; Adam, Karoline
Although there are numerous studies on gender-role portrayals in television advertising, comparative designs are clearly lacking. With content analytical data from a total of 13 Asian, American, and European countries, we study the stereotypical depiction of men and women in television advertisements. Our sample consists of 1755 ads collected in May 2014. Analyzing the gender of the primary character and voiceover, as well as the age, associated product categories, home- or work setting, and the working role of the primary character, we concluded that gender stereotypes in TV advertising can be found around the world. A multilevel model further showed that gender stereotypes were independent of a country's gender indices, including Hofstede's Masculinity Index, GLOBE's Gender Egalitarianism Index, the Gender-related Development Index, the Gender Inequality Index, and the Global Gender Gap Index. These findings suggest that gender stereotyping in television advertising does not depend on the gender equality prevalent in a country. The role of a specific culture in shaping gender stereotypes in television advertising is thus smaller than commonly thought.
Durkin, Sarah; Wakefield, Melanie; Spittal, Matt
2006-12-01
In the context of concerns about unintended "boomerang" influences of advertising, this study aimed to examine effects of nicotine replacement therapy (NRT) and Zyban advertising on youth perceptions of the ease of quitting, health risks of smoking and future intentions to smoke. 718 youth aged 14-16years were randomly allocated to view four television ads promoting either: NRT; Zyban; non-pharmaceutical cessation services (telephone Quitline); or non-cessation messages on sun protection. Questionnaire measures were administered before and after viewing ads. There were no effects of advertising exposure on perceived health effects of smoking or intentions to smoke. Compared with the sun protection ads, but not the Quitline ads, those exposed to NRT ads reported stronger perceptions about the ease of quitting, but non-susceptible non-smokers primarily drove this difference. This study suggests that exposure to NRT and Zyban advertising in an experimental context does not reliably influence youth smoking-related beliefs, especially those vulnerable to becoming regular smokers.
[Media use with developmental benefits].
Hipeli, E; Süss, D
2012-08-01
For children of school age television is still the dominant medium. TV consumption isn't only limited on the TV set, but also happens on the computer with internet access and mobile devices. Computer games take a high priority for boys. For girls reading is still an important experience space. Parents influence the media use of their children by their role model, and the rates for shared non-media experiences. Neighborhoods which aren't child-friendly can cause children's withdraw into home media spaces. Restrictions and controls are less important than the conversations that are conducted around media interests of the child and parents attention to early signs of problematic media use. Potentially irritating media content for children (such as violence or sex) can have strong effects when there's no open debate taking place in the family around these issues. Today's media diversity leads to parallel surfing and multi-tasking. In order that this doesn't influence children's cognitive development and learning negatively a culture of regular restriction to one activity, to which they devote their full attention, is required.
Marshall, S J; Biddle, S J H; Gorely, T; Cameron, N; Murdey, I
2004-10-01
To review the empirical evidence of associations between television (TV) viewing, video/computer game use and (a) body fatness, and (b) physical activity. Meta-analysis. Published English-language studies were located from computerized literature searches, bibliographies of primary studies and narrative reviews, and manual searches of personal archives. Included studies presented at least one empirical association between TV viewing, video/computer game use and body fatness or physical activity among samples of children and youth aged 3-18 y. The mean sample-weighted corrected effect size (Pearson r). Based on data from 52 independent samples, the mean sample-weighted effect size between TV viewing and body fatness was 0.066 (95% CI=0.056-0.078; total N=44,707). The sample-weighted fully corrected effect size was 0.084. Based on data from six independent samples, the mean sample-weighted effect size between video/computer game use and body fatness was 0.070 (95% CI=-0.048 to 0.188; total N=1,722). The sample-weighted fully corrected effect size was 0.128. Based on data from 39 independent samples, the mean sample-weighted effect size between TV viewing and physical activity was -0.096 (95% CI=-0.080 to -0.112; total N=141,505). The sample-weighted fully corrected effect size was -0.129. Based on data from 10 independent samples, the mean sample-weighted effect size between video/computer game use and physical activity was -0.104 (95% CI=-0.080 to -0.128; total N=119,942). The sample-weighted fully corrected effect size was -0.141. A statistically significant relationship exists between TV viewing and body fatness among children and youth although it is likely to be too small to be of substantial clinical relevance. The relationship between TV viewing and physical activity is small but negative. The strength of these relationships remains virtually unchanged even after correcting for common sources of bias known to impact study outcomes. While the total amount of time per day engaged in sedentary behavior is inevitably prohibitive of physical activity, media-based inactivity may be unfairly implicated in recent epidemiologic trends of overweight and obesity among children and youth. Relationships between sedentary behavior and health are unlikely to be explained using single markers of inactivity, such as TV viewing or video/computer game use.
Brown, Jane D; L'Engle, Kelly Ladin; Pardun, Carol J; Guo, Guang; Kenneavy, Kristin; Jackson, Christine
2006-04-01
To assess over time whether exposure to sexual content in 4 mass media (television, movies, music, and magazines) used by early adolescents predicts sexual behavior in middle adolescence. An in-home longitudinal survey of 1017 black and white adolescents from 14 middle schools in central North Carolina was conducted. Each teen was interviewed at baseline when he or she was 12 to 14 years old and again 2 years later using a computer-assisted self interview (audio computer-assisted self-interview) to ensure confidentiality. A new measure of each teen's sexual media diet (SMD) was constructed by weighting the frequency of use of 4 media by the frequency of sexual content in each television show, movie, music album, and magazine the teen used regularly. White adolescents in the top quintile of sexual media diet when 12 to 14 years old were 2.2 times more likely to have had sexual intercourse when 14 to 16 years old than those who were in the lowest SMD quintile, even after a number of other relevant factors, including baseline sexual behavior, were introduced. The relationship was not statistically significant for black adolescents after controlling for other factors that were more predictive, including parental disapproval of teen sex and perceived permissive peer sexual norms. Exposure to sexual content in music, movies, television, and magazines accelerates white adolescents' sexual activity and increases their risk of engaging in early sexual intercourse. Black teens appear more influenced by perceptions of their parents' expectations and their friends' sexual behavior than by what they see and hear in the media.
NASA Astrophysics Data System (ADS)
Gong, Changfei; Han, Ce; Gan, Guanghui; Deng, Zhenxiang; Zhou, Yongqiang; Yi, Jinling; Zheng, Xiaomin; Xie, Congying; Jin, Xiance
2017-04-01
Dynamic myocardial perfusion CT (DMP-CT) imaging provides quantitative functional information for diagnosis and risk stratification of coronary artery disease by calculating myocardial perfusion hemodynamic parameter (MPHP) maps. However, the level of radiation delivered by dynamic sequential scan protocol can be potentially high. The purpose of this work is to develop a pre-contrast normal-dose scan induced structure tensor total variation regularization based on the penalized weighted least-squares (PWLS) criteria to improve the image quality of DMP-CT with a low-mAs CT acquisition. For simplicity, the present approach was termed as ‘PWLS-ndiSTV’. Specifically, the ndiSTV regularization takes into account the spatial-temporal structure information of DMP-CT data and further exploits the higher order derivatives of the objective images to enhance denoising performance. Subsequently, an effective optimization algorithm based on the split-Bregman approach was adopted to minimize the associative objective function. Evaluations with modified dynamic XCAT phantom and preclinical porcine datasets have demonstrated that the proposed PWLS-ndiSTV approach can achieve promising gains over other existing approaches in terms of noise-induced artifacts mitigation, edge details preservation, and accurate MPHP maps calculation.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shi, Q; Cheng, P; Tan, S
2016-06-15
Purpose: To combine total variation (TV) and Hessian penalty in a structure adaptive way for cone-beam CT (CBCT) reconstruction. Methods: TV is a widely used first order penalty with good ability in suppressing noise and preserving edges but leads to the staircase effect in regions with smooth intensity transition. The second order Hessian penalty can effectively suppress the staircase effect with extra cost of blurring object edges. To take the best of both penalties we proposed a novel method to combine both for CBCT reconstruction in a structure adaptive way. The proposed method adaptively determined the weight of each penaltymore » according to the geometry of local regions. An specially-designed exponent term with image gradient involved was used to characterize the local geometry such that the weights for Hessian and TV were 1 and 0 respectively at uniform local regions and 0 and 1 at edge regions. For other local regions the weights varied from 0 to 1. The objective functional was minimized using the majorzationminimization approach. We evaluated the proposed method on a modified 3D shepp-logan and a CatPhan 600 phantom. The full-width-at-halfmaximum (FWHM) and contrast-to-noise (CNR) were calculated. Results: For 3D shepp-logan the reconstructed images using TV had an obvious staircase effect while those using the proposed method and Hessian preserved the smooth transition regions well. FWHMs of the proposed method TV and Hessian penalty were 1.75 1.61 and 3.16 respectively, indicating that both TV and the proposed method is able to preserve edges. For CatPhan 600 CNR values of the proposed method were similar to those of TV and Hessian. Conclusion: The proposed method retains favorable properties of TV like preserving edges and also has the ability in better preserving gradual transition structure as Hessian does. All methods performs similarly in suppressing noise. This work was supported in part by National Natural Science Foundation of China (NNSFC) under Grant Nos.60971112 and 61375018 grants from the Cancer Prevention and Research Institute of Texas (RP130109 and RP110562-P2) National Institute of Biomedical Imaging and Bioengineering (R01 EB020366) and a grant from the American Cancer Society (RSG-13-326-01-CCE).« less
Artifact reduction in short-scan CBCT by use of optimization-based reconstruction
Zhang, Zheng; Han, Xiao; Pearson, Erik; Pelizzari, Charles; Sidky, Emil Y; Pan, Xiaochuan
2017-01-01
Increasing interest in optimization-based reconstruction in research on, and applications of, cone-beam computed tomography (CBCT) exists because it has been shown to have to potential to reduce artifacts observed in reconstructions obtained with the Feldkamp–Davis–Kress (FDK) algorithm (or its variants), which is used extensively for image reconstruction in current CBCT applications. In this work, we carried out a study on optimization-based reconstruction for possible reduction of artifacts in FDK reconstruction specifically from short-scan CBCT data. The investigation includes a set of optimization programs such as the image-total-variation (TV)-constrained data-divergency minimization, data-weighting matrices such as the Parker weighting matrix, and objects of practical interest for demonstrating and assessing the degree of artifact reduction. Results of investigative work reveal that appropriately designed optimization-based reconstruction, including the image-TV-constrained reconstruction, can reduce significant artifacts observed in FDK reconstruction in CBCT with a short-scan configuration. PMID:27046218
Test of 3D CT reconstructions by EM + TV algorithm from undersampled data
DOE Office of Scientific and Technical Information (OSTI.GOV)
Evseev, Ivan; Ahmann, Francielle; Silva, Hamilton P. da
2013-05-06
Computerized tomography (CT) plays an important role in medical imaging for diagnosis and therapy. However, CT imaging is connected with ionization radiation exposure of patients. Therefore, the dose reduction is an essential issue in CT. In 2011, the Expectation Maximization and Total Variation Based Model for CT Reconstruction (EM+TV) was proposed. This method can reconstruct a better image using less CT projections in comparison with the usual filtered back projection (FBP) technique. Thus, it could significantly reduce the overall dose of radiation in CT. This work reports the results of an independent numerical simulation for cone beam CT geometry withmore » alternative virtual phantoms. As in the original report, the 3D CT images of 128 Multiplication-Sign 128 Multiplication-Sign 128 virtual phantoms were reconstructed. It was not possible to implement phantoms with lager dimensions because of the slowness of code execution even by the CORE i7 CPU.« less
Díaz-Ramírez, Glenda; Jiménez-Cruz, Arturo; Souto-Gallardo, Maria de las Cruces; Bacardí-Gascón, Montserrat
2013-01-01
Foods advertised were recorded in 2 television (TV) channels. The present article studies the association between products advertised and those consumed by mothers and children. A total of 365 mothers and their children were assessed. A positive correlation was observed between the food advertisements that the mothers recalled and the frequency of TV food advertisements (Rho = 0.44, P = 0.03). A positive correlation was found between the frequency of the foods advertised on TV and the consumption of these by the mothers (r = 0.73, P = 0.0001) and their children (Rho = 0.66, P = 0.0001). These results suggest that TV advertisements influence the food choices of mothers and children.
Akyamaç, Orkide; Oner-Ozkan, Bengi
2006-04-01
Need for continuity of a television program was assessed with attitude toward and recall of advertisements. The program continuity was manipulated experimentally by presenting one music video program as Top 10 (continuous) or as Regular (discontinuous) format. General attitude toward commercials and the belief in advertisement-product realism were investigated through the commercials with continuous and discontinuous formats of the same program. Data were gathered from undergraduates (23 men and 68 women) whose mean age was 20.2 yr. (SD=2.5). Analyses indicated continuity was not related to their attitude towards embedded commercials but was associated with their recall. Implications were discussed.
Energy expenditure, television viewing and obesity.
Buchowski, M S; Sun, M
1996-03-01
To measure energy expenditure (EE) of television viewing, sitting, and resting and duration of self-selected television viewing in obese and non-obese men and women. Cross-over randomized study consisting of two separate 24-h stays in a whole-room indirect calorimeter. 123 obese and non-obese healthy men and women (age: 38 +/- 9, BMI: 29.4 +/- 7.9) Rates of energy expenditure during resting (RMR), sitting (EEsit) and television viewing (EEtv) using indirect calorimetry technique on two separate 24-h stays in a whole-room indirect calorimeter. Physical activities and work of body movements during these periods using a large force platform system located inside the calorimeter. Rates of EE for television viewing, adjusted for differences in body composition were 18% higher than resting metabolic rate (RMR), but similar to rates of other sedentary activities. There were no significant differences between obese and non-obese subjects in metabolic rates during resting, television viewing, and other sedentary activities. Average time of self-selected television viewing was significantly greater in obese than in non-obese subjects and also in women than in men. EE rate for television viewing in adults is higher than RMR and similar to other sedentary activities. Obese adults choose television viewing as a form of leisure activity more often than non-obese individuals and as a result they could significantly reduce other forms of physical activities and total daily EE.
Farrelly, Matthew C; Hussin, Altijani; Bauer, Ursula E
2007-12-01
This study assessed the relative effectiveness and cost effectiveness of television, radio and print advertisements to generate calls to the New York smokers' quitline. Regression analysis was used to link total county level monthly quitline calls to television, radio and print advertising expenditures. Based on regression results, standardised measures of the relative effectiveness and cost effectiveness of expenditures were computed. There was a positive and statistically significant relation between call volume and expenditures for television (p<0.01) and radio (p<0.001) advertisements and a marginally significant effect for expenditures on newspaper advertisements (p<0.065). The largest effect was for television advertising. However, because of differences in advertising costs, for every $1000 increase in television, radio and newspaper expenditures, call volume increased by 0.1%, 5.7% and 2.8%, respectively. Television, radio and print media all effectively increased calls to the New York smokers' quitline. Although increases in expenditures for television were the most effective, their relatively high costs suggest they are not currently the most cost effective means to promote a quitline. This implies that a more efficient mix of media would place greater emphasis on radio than television. However, because the current study does not adequately assess the extent to which radio expenditures would sustain their effectiveness with substantial expenditure increases, it is not feasible to determine a more optimal mix of expenditures.
Infant gaze following during parent-infant coviewing of baby videos.
Demers, Lindsay B; Hanson, Katherine G; Kirkorian, Heather L; Pempek, Tiffany A; Anderson, Daniel R
2013-01-01
A total of 122 parent-infant dyads were observed as they watched a familiar or novel infant-directed video in a laboratory setting. Infants were between 12-15 and 18-21 months old. Infants were more likely to look toward the TV immediately following their parents' look toward the TV. This apparent social influence on infant looking at television was not solely due to the common influence of the television program on looking behavior. Moreover, infant looks that were preceded by parent looks tended to be longer in length than those that were not preceded by parent looks, suggesting that infants assign greater value to media content attended to by their parents. Thus, parental patterns of attention to television may influence early viewing behavior. © 2012 The Authors. Child Development © 2012 Society for Research in Child Development, Inc.
Time-Optimized High-Resolution Readout-Segmented Diffusion Tensor Imaging
Reishofer, Gernot; Koschutnig, Karl; Langkammer, Christian; Porter, David; Jehna, Margit; Enzinger, Christian; Keeling, Stephen; Ebner, Franz
2013-01-01
Readout-segmented echo planar imaging with 2D navigator-based reacquisition is an uprising technique enabling the sampling of high-resolution diffusion images with reduced susceptibility artifacts. However, low signal from the small voxels and long scan times hamper the clinical applicability. Therefore, we introduce a regularization algorithm based on total variation that is applied directly on the entire diffusion tensor. The spatially varying regularization parameter is determined automatically dependent on spatial variations in signal-to-noise ratio thus, avoiding over- or under-regularization. Information about the noise distribution in the diffusion tensor is extracted from the diffusion weighted images by means of complex independent component analysis. Moreover, the combination of those features enables processing of the diffusion data absolutely user independent. Tractography from in vivo data and from a software phantom demonstrate the advantage of the spatially varying regularization compared to un-regularized data with respect to parameters relevant for fiber-tracking such as Mean Fiber Length, Track Count, Volume and Voxel Count. Specifically, for in vivo data findings suggest that tractography results from the regularized diffusion tensor based on one measurement (16 min) generates results comparable to the un-regularized data with three averages (48 min). This significant reduction in scan time renders high resolution (1×1×2.5 mm3) diffusion tensor imaging of the entire brain applicable in a clinical context. PMID:24019951
Corporation for Public Broadcasting Annual Report, 1971.
ERIC Educational Resources Information Center
Corporation for Public Broadcasting, Washington, DC.
The Corporation for Public Broadcasting (CPB) continued to grow in fiscal year 1971, its third year of operation. Fourteen new public television stations began broadcasting, bringing 7.9 million more persons within receiving range, and bringing the total number of TV stations to 207. Income increased 18 per cent to $14 million due largely to more…
Associations of television viewing time with adults' well-being and vitality.
Dempsey, Paddy C; Howard, Bethany J; Lynch, Brigid M; Owen, Neville; Dunstan, David W
2014-12-01
Television (TV) viewing, a common leisure-time sedentary behaviour, is associated adversely with cardio-metabolic health, fatigue, depression and mental health. However, associations of TV viewing time with health-related quality of life attributes are less well understood. We examined associations of TV viewing time with physical well-being, mental well-being and vitality in a large population-based sample of Australian adults. The study sample comprised 4,483 men and 5,424 women (mean age 51±14years) from the Australian Diabetes, Obesity and Lifestyle study (1999-2000). Multiple linear regressions examined associations of TV viewing time (h/day) with the SF-36v1 physical and mental health component summary scores and the vitality sub-score, adjusting for leisure-time physical activity and waist circumference. Each 1-h/day increment in TV viewing time was associated with lower physical (-0.56 [95% CI: -0.77, -0.34]) and mental (-0.41 [-0.70, -0.12]) component summary scores and vitality (-0.51 [-0.81, -0.21]). Associations remained significant after adjustment for leisure-time physical activity and waist circumference. There was a gender interaction for the association of TV viewing time with vitality (significant in men only). TV viewing time is associated adversely with physical well-being, mental well-being and vitality. Further studies are required to better understand potential causal relationships and variations by gender and leisure-time physical activity. Copyright © 2014 Elsevier Inc. All rights reserved.
Ma, Deqiong; Jones, Graeme
2003-11-01
The effect of physical activity on upper limb fractures was examined in this population-based case control study with 321 age- and gender-matched pairs. Sports participation increased fracture risk in boys and decreased risk in girls. Television viewing had a deleterious dose response association with wrist and forearm fractures while light physical activity was protective. The aim of this population-based case control study was to examine the association between television, computer, and video viewing; types and levels of physical activity; and upper limb fractures in children 9-16 years of age. A total of 321 fracture cases and 321 randomly selected individually matched controls were studied. Television, computer, and video viewing and types and levels of physical activity were determined by interview-administered questionnaire. Bone strength was assessed by DXA and metacarpal morphometry. In general, sports participation increased total upper limb fracture risk in boys and decreased risk in girls. Gender-specific risk estimates were significantly different for total, contact, noncontact, and high-risk sports participation as well as four individual sports (soccer, cricket, surfing, and swimming). In multivariate analysis, time spent television, computer, and video viewing in both sexes was positively associated with wrist and forearm fracture risk (OR 1.6/category, 95% CI: 1.1-2.2), whereas days involved in light physical activity participation decreased fracture risk (OR 0.8/category, 95% CI: 0.7-1.0). Sports participation increased hand (OR 1.5/sport, 95% CI: 1.1-2.0) and upper arm (OR 29.8/sport, 95% CI: 1.7-535) fracture risk in boys only and decreased wrist and forearm fracture risk in girls only (OR 0.5/sport, 95% CI: 0.3-0.9). Adjustment for bone density and metacarpal morphometry did not alter these associations. There is gender discordance with regard to sports participation and fracture risk in children, which may reflect different approaches to sport. Importantly, television, computer, and video viewing has a dose-dependent association with wrist and forearm fractures, whereas light physical activity is protective. The mechanism is unclear but may involve bone-independent factors, or less likely, changes in bone quality not detected by DXA or metacarpal morphometry.
Borzekowski, Dina L G; Robinson, Thomas N
2005-07-01
Media can influence aspects of a child's physical, social, and cognitive development; however, the associations between a child's household media environment, media use, and academic achievement have yet to be determined. To examine relationships among a child's household media environment, media use, and academic achievement. During a single academic year, data were collected through classroom surveys and telephone interviews from an ethnically diverse sample of third grade students and their parents from 6 northern California public elementary schools. The majority of our analyses derive from spring 2000 data, including academic achievement assessed through the mathematics, reading, and language arts sections of the Stanford Achievement Test. We fit linear regression models to determine the associations between variations in household media and performance on the standardized tests, adjusting for demographic and media use variables. The household media environment is significantly associated with students' performance on the standardized tests. It was found that having a bedroom television set was significantly and negatively associated with students' test scores, while home computer access and use were positively associated with the scores. Regression models significantly predicted up to 24% of the variation in the scores. Absence of a bedroom television combined with access to a home computer was consistently associated with the highest standardized test scores. This study adds to the growing literature reporting that having a bedroom television set may be detrimental to young elementary school children. It also suggests that having and using a home computer may be associated with better academic achievement.
Analysis of medicine advertisement produced in Brazil.
Wzorek, Lorilei de Fátima; Correr, Cassyano J; Badaró Trindade, Angela C; Pontarolo, Roberto
2007-07-01
To analyze the compliance of drug advertisements with regulations in Brazil, subject to Resolution RDC No. 102/2000 since 2000, which abides by the WHO's (World Health Organization) Ethical Criteria for Medicinal Drug Promotion, published in 1988. Drug advertisements running within the period of October 2002 to October 2003 were collected and recorded. Media sources included various AM and FM radio stations, television channels, newspapers, and magazines, as well as printed material distributed in doctors' offices, hospitals, drugstores, conferences, billboards, and bus doors. All sources were located in Curitiba City, Brazil, and its surrounding area. Advertisement content was analyzed according to a conformity checklist prepared based on the legal requirements of RDC No. 102/00. A total of 827 advertisements for 517 different products, 83.91% regularly registered as medicinal drugs and 16.09% unregistered products that should be registered according to the Brazilian regulations, were recorded and collected. Approximately 74.73% of the advertisements did not comply with regulations; on average, such advertisements had 4.6 infractions each. The results of this research suggest that RDC No. 102/00 is not followed, which strengthens the need to adopt new forms of regulation to prohibit excesses of the pharmaceutical industry and to protect the population from abusive and misleading drug advertising.
Analysis of medicine advertisement produced in Brazil
Wzorek, Lorilei de Fátima; Correr, Cassyano J.; Badaró Trindade, Angela C.; Pontarolo, Roberto
Objective To analyze the compliance of drug advertisements with regulations in Brazil, subject to Resolution RDC No. 102/2000 since 2000, which abides by the WHO’s (World Health Organization) Ethical Criteria for Medicinal Drug Promotion, published in 1988. Methods Drug advertisements running within the period of October 2002 to October 2003 were collected and recorded. Media sources included various AM and FM radio stations, television channels, newspapers, and magazines, as well as printed material distributed in doctors’ offices, hospitals, drugstores, conferences, billboards, and bus doors. All sources were located in Curitiba City, Brazil, and its surrounding area. Advertisement content was analyzed according to a conformity checklist prepared based on the legal requirements of RDC No. 102/00. Results A total of 827 advertisements for 517 different products, 83.91% regularly registered as medicinal drugs and 16.09% unregistered products that should be registered according to the Brazilian regulations, were recorded and collected. Approximately 74.73% of the advertisements did not comply with regulations; on average, such advertisements had 4.6 infractions each. Conclusions The results of this research suggest that RDC No. 102/00 is not followed, which strengthens the need to adopt new forms of regulation to prohibit excesses of the pharmaceutical industry and to protect the population from abusive and misleading drug advertising. PMID:25214926
Physical activity and sedentary behaviour in European children: the IDEFICS study.
Santaliestra-Pasías, Alba Ma; Mouratidou, Theodora; Verbestel, Vera; Bammann, Karin; Molnar, Dénes; Sieri, Sabina; Siani, Alfonso; Veidebaum, Toomas; Mårild, Staffan; Lissner, Lauren; Hadjigeorgiou, Charalambos; Reisch, Lucia; De Bourdeaudhuij, Ilse; Moreno, Luis A
2014-10-01
To estimate the prevalence of physical activity and sedentary behaviours in European children, and to evaluate the relationship between media availability in personal space and physical activity in relation to total screen time. Data from the baseline IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) cross-sectional survey. Information on hours of television/digital video disk/video viewing and computer/games-console use (weekday and weekend days), media device availability in personal space, sports club membership, hours of active organized play and commuting (to and from school) were assessed via a self-reported parental questionnaire. Total screen time was defined as the sum of daily media use and subsequently dichotomized into meeting or not meeting the guidelines of the American Academy of Pediatrics. Eight survey centres (Italy, Estonia, Cyprus, Belgium, Sweden, Germany, Hungary and Spain). Children (n 15 330; 51% males) aged 2-10 years. Percentage of children engaged in total screen time for >2 h/d was higher on weekend days (52% v. 20% on weekdays) and in the older group (71% in males; 57% in females), varying by country. Children with a television set in their bedroom were more likely not to meet the screen time recommendations (OR = 1·54; 95% CI 1·60, 1·74). Approximately a third of the children failed to meet current screen time recommendations. Availability of a television set in personal space increased the risk of excess total screen time. This information could be used to identify potential targets for public health promotion actions of young population groups.
Hao, Yan; Li, Si-Jing; Zheng, Ping; Wu, Xia; Sheng, Jie; Yuan, Dong-Lan; Zhou, Qi; Wei, Wei; Duan, Ai-Hong; Wu, Qing-Qing; Lu, Dan
2018-05-25
To investigate if intraoperative ultrasounds by laparoscopic and transvaginal ultrasonography (LUS and TVS) could improve enucleating the residual fibroids following laparoscopic myomectomy (LM). From March to December 2016, 78 women with uterine fibroids underwent LM, LUS and TVS were applied to detect residual fibroids and to guide surgeons to enucleate them after the visible fibroids were removed during LM operation. The total number of residual fibroids found by LUS was 140, and the total number found by TVS was 127 following LM (P = 0.03). LUS is statistically superior to TVS in the detection of residual fibroids in the anterior wall (P = 0.004), in the detection of intramural fibroids (P = 0.002), and in the detection of fibroids with a diameter ranging from 0.5 to 1 cm (P = 0.002). According to the total number of enucleated fibroids by LM, patients were divided into three groups (Group 1: 2 to 4, Group 2: 5 to 7 and Group 3: ≥8 fibroid counts). The percentages of patients in each group with residual fibroids at the end of surgery were 22.2%, 51.9% and 66.7% respectively. Both LUS and TVS are beneficial to surgical treatment of fibroids by assisting enucleation of residual fibroids following LM, while LUS is more effective in localizing residual fibroids than TVS. Copyright © 2018 Elsevier B.V. All rights reserved.
Television, video, and computer game usage in children under 11 years of age.
Christakis, Dimitri A; Ebel, Beth E; Rivara, Frederick P; Zimmerman, Frederick J
2004-11-01
To conduct a population-based survey of television and other media usage in young children to determine (1) total media usage; (2) the proportion of children who have televisions in their bedrooms and who eat breakfast or dinner in front of the television; and (3) predictors of parental concern about the amount of television their child watches. Telephone survey administered to 1454 parents of children <11 years old derived from a diverse clinic population. The mean age of the index child was 5.05 years. Mean daily reported child media use was as follows: television (1.45 hours; SD, 1.5); videos (1.1 hours; SD, 1.30); and computer games (0.54 hours; SD, 0.96). Thirty percent of parents reported that their child ate breakfast or dinner in front of the television in the past week, and 22% were concerned about the amount of television that their child watched. In multivariate linear regression, eating breakfast or dinner in front of the television in the past week was associated with increased hours of television viewing (0.38 hours [0.21, 0.54]) and video (0.19 hours [0.04, 0.34]). Having a television in a child's bedroom was associated with increased hours of television (0.25 hours [0.07, 0.43]), video viewing (0.31 hours [0.16, 0.47]), and computer games (0.21 hours [0.10, 0.32]). In general, higher parental education was associated with decreased hours of television and video but not computer games. Older children were 2 to 3 times more likely than younger children to have a television in their bedroom and to have eaten a meal in front of it in the past week. More educated parents were less likely to report that their child had a television in their bedroom and more likely to be concerned about the amount of television their child viewed. Combined video and computer game usage exceeded television usage. Both children of low- and high-income parents are at risk for certain behaviors associated with television usage. Parents whose children watched more television were more likely to be concerned about the amount of television their child viewed.
ERIC Educational Resources Information Center
Morrison, Todd G.; Kalin, Rudolf; Morrison, Melanie A.
2004-01-01
Sociocultural theory and social comparison theory were used to account for variations in body-image evaluation and body-image investment among male and female adolescents (N = 1,543). Exposure to magazines and television programs containing idealistic body imagery as well as frequency of self-comparison to universalistic targets (e.g., fashion…
Carson, Valerie; Janssen, Ian
2012-10-01
There is evidence to suggest that excessive television viewing is an independent determinant of obesity in young people. However, the pathways between television viewing and obesity are not fully understood. Therefore, the purpose of this study was to examine whether the relationship between television and body mass index (BMI) is mediated by television snacking and junk food consumption. Results are based on 15,973 youth in grades 6-10 who participated in the Canadian 2009/2010 health behaviour in school-aged children survey (HBSC). Participants self-reported their weight and height and BMI z-scores were calculated based on World Health Organization growth standards. Participants reported the frequency of snacking while watching television and the frequency of eating junk food (sweets, soft drinks, baked goods, French fries, potato chips). Total hours per week of television were calculated. A contemporary multiple mediation analysis was used to examine associations. A modest positive relationship was observed between television viewing and BMI. The mean BMI z-score was 0.15 units higher in youth in the highest television viewing quartile by comparison with the youth in the lowest quartile. However, contrary to our hypothesis, television snacking and junk food consumption were not significant positive mediators of the television and BMI relationship. The pathways between television viewing and obesity are complicated and remain poorly understood. Future research using longitudinal or experimental designs, more precise measurement tools and formal mediation analyses is needed. This research should consider mediators related to both energy intake and expenditure. © 2012 The Authors. Pediatric Obesity © 2012 International Association for the Study of Obesity.
Bayesian denoising in digital radiography: a comparison in the dental field.
Frosio, I; Olivieri, C; Lucchese, M; Borghese, N A; Boccacci, P
2013-01-01
We compared two Bayesian denoising algorithms for digital radiographs, based on Total Variation regularization and wavelet decomposition. The comparison was performed on simulated radiographs with different photon counts and frequency content and on real dental radiographs. Four different quality indices were considered to quantify the quality of the filtered radiographs. The experimental results suggested that Total Variation is more suited to preserve fine anatomical details, whereas wavelets produce images of higher quality at global scale; they also highlighted the need for more reliable image quality indices. Copyright © 2012 Elsevier Ltd. All rights reserved.
Fahim, Germin; Toscani, Michael; Barone, Joseph A; Wang, Chris; Gandhi, Shivani
2018-01-01
The FDA's Presenting Risk Information draft guidance from May 2009 states that the time of risk versus benefit is a factor taken into consideration when evaluating audio and video direct-to-consumer (DTC) broadcasts. The objective of the study is to evaluate the proportion of risk narration on television (TV) advertisements in comparison to the actual proportion of serious adverse effects findings across select therapeutic areas. The study reviews prescription drug TV advertisements between the years 2010 and 2015 separated by therapeutic class. Indicators to assess risk versus benefit are as follows: total benefit time, total risk time, total ad time, percentage proportion of risk, and number of serious adverse effects (SAEs) listed in the package insert. The objective is establishing proportion of risk-to-benefit narration across therapeutic areas and the proportion of risk narration compared to the number of SAEs in the package insert. These outcomes will reflect whether TV advertisements abide by the "fair balance" rule and if the time spent on risk narrations is proportional to the number of SAEs across therapeutic areas. An analysis of risk versus benefit showed that there was a vast range of percentage differences in risk versus benefit narration across the products selected. The majority of the products narrated showed a 40% to 60% risk-to-benefit ratio. Six out of the 10 products evaluated communicated applicable black box warnings. There was variability among the SAE percentages presented between products. Lack of consistency exists between risks versus benefit proportions among different drug products.
Chen, Mei-Yen; Wang, Edward K; Jeng, Yi-Jong
2006-03-08
Amount of sleep is an important indicator of health and well-being in children and adolescents. Adequate sleep (AS: adequate sleep is defined as 6-8 hours per night regularly) is a critical factor in adolescent health and health-related behaviors. The present study was based on a health promotion project previously conducted on adolescents in Tao-Yuan County, Taiwan. The aim was to examine the relationship between AS during schooldays and excessive body weight, frequency of visiting doctors and health-related behaviors among Taiwanese adolescents. A cross-sectional study design, categorical and multivariate data analyses were used. The hypotheses investigated were: high frequency of AS is positively associated with lack of obesity and less frequent visits to doctors; and high frequency AS is positively associated with health-related behavior. A total of 656 boys (53.2%) and girls (46.8%), ranging in age from 13-18 years were studied between January and June 2004. Three hundred and fifty seven subjects (54%) reported that they slept less than the suggested 6-8 hours on schooldays. A significant negative association was found between low sleep and of the following health-related behaviors: (1) life appreciation; (2) taking responsibility for health; (3) adopting healthy diet; (4) effective stress management; (5) regular exercise; and (6) total AHP score. High frequency AS was associated with low frequencies of obesity after potential confounding factors were controlled. Junior high school adolescents reported significantly higher frequencies of AS than high school participants. Gender, family structure, home location and frequency of television watching or computer use were not significantly associated with AS. These findings support the proposition that AS is associated with good health status and high-frequency adoption of health-related behavior. Furthermore, these findings suggest that inadequate sleep may be a screening indicator for an unhealthy lifestyle and poor health status. The results might be useful for future research into the development of intervention strategies to assist adolescents who are not receiving enough hours of sleep.
Morgan, Elise F.; Mason, Zachary D.; Chien, Karen B.; Pfeiffer, Anthony J.; Barnes, George L.; Einhorn, Thomas A.; Gerstenfeld, Louis C.
2009-01-01
Non-invasive characterization of fracture callus structure and composition may facilitate development of surrogate measures of the regain of mechanical function. As such, quantitative computed tomography- (CT-) based analyses of fracture calluses could enable more reliable clinical assessments of bone healing. Although previous studies have used CT to quantify and predict fracture healing, it is unclear which of the many CT-derived metrics of callus structure and composition are the most predictive of callus mechanical properties. The goal of this study was to identify the changes in fracture callus structure and composition that occur over time and that are most closely related to the regain of mechanical function. Micro-computed tomography (μCT) imaging and torsion testing were performed on murine fracture calluses (n=188) at multiple post-fracture timepoints and under different experimental conditions that alter fracture healing. Total callus volume (TV), mineralized callus volume (BV), callus mineralized volume fraction (BV/TV), bone mineral content (BMC), tissue mineral density (TMD), standard deviation of mineral density (σTMD), effective polar moment of inertia (Jeff), torsional strength, and torsional rigidity were quantified. Multivariate statistical analyses, including multivariate analysis of variance, principal components analysis, and stepwise regression were used to identify differences in callus structure and composition among experimental groups and to determine which of the μCT outcome measures were the strongest predictors of mechanical properties. Although calluses varied greatly in the absolute and relative amounts of mineralized tissue (BV, BMC, and BV/TV), differences among timepoints were most strongly associated with changes in tissue mineral density. Torsional strength and rigidity were dependent on mineral density as well as the amount of mineralized tissue: TMD, BV, and σTMD explained 62% of the variation in torsional strength (p<0.001); and TMD, BMC, BV/TV, and σTMD explained 70% of the variation in torsional rigidity (p<0.001). These results indicate that fracture callus mechanical properties can be predicted by several μCT-derived measures of callus structure and composition. These findings form the basis for developing non-invasive assessments of fracture healing and for identifying biological and biomechanical mechanisms that lead to impaired or enhanced healing. PMID:19013264
Farrelly, Matthew C; Hussin, Altijani; Bauer, Ursula E
2007-01-01
Objectives This study assessed the relative effectiveness and cost effectiveness of television, radio and print advertisements to generate calls to the New York smokers' quitline. Methods Regression analysis was used to link total county level monthly quitline calls to television, radio and print advertising expenditures. Based on regression results, standardised measures of the relative effectiveness and cost effectiveness of expenditures were computed. Results There was a positive and statistically significant relation between call volume and expenditures for television (p<0.01) and radio (p<0.001) advertisements and a marginally significant effect for expenditures on newspaper advertisements (p<0.065). The largest effect was for television advertising. However, because of differences in advertising costs, for every $1000 increase in television, radio and newspaper expenditures, call volume increased by 0.1%, 5.7% and 2.8%, respectively. Conclusions Television, radio and print media all effectively increased calls to the New York smokers' quitline. Although increases in expenditures for television were the most effective, their relatively high costs suggest they are not currently the most cost effective means to promote a quitline. This implies that a more efficient mix of media would place greater emphasis on radio than television. However, because the current study does not adequately assess the extent to which radio expenditures would sustain their effectiveness with substantial expenditure increases, it is not feasible to determine a more optimal mix of expenditures. PMID:18048625
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xu, J; Tsui, B; Noo, F
Purpose: To develop a feature-preserving model based image reconstruction (MBIR) method that improves performance in pancreatic lesion classification at equal or reduced radiation dose. Methods: A set of pancreatic lesion models was created with both benign and premalignant lesion types. These two classes of lesions are distinguished by their fine internal structures; their delineation is therefore crucial to the task of pancreatic lesion classification. To reduce image noise while preserving the features of the lesions, we developed a MBIR method with curvature-based regularization. The novel regularization encourages formation of smooth surfaces that model both the exterior shape and the internalmore » features of pancreatic lesions. Given that the curvature depends on the unknown image, image reconstruction or denoising becomes a non-convex optimization problem; to address this issue an iterative-reweighting scheme was used to calculate and update the curvature using the image from the previous iteration. Evaluation was carried out with insertion of the lesion models into the pancreas of a patient CT image. Results: Visual inspection was used to compare conventional TV regularization with our curvature-based regularization. Several penalty-strengths were considered for TV regularization, all of which resulted in erasing portions of the septation (thin partition) in a premalignant lesion. At matched noise variance (50% noise reduction in the patient stomach region), the connectivity of the septation was well preserved using the proposed curvature-based method. Conclusion: The curvature-based regularization is able to reduce image noise while simultaneously preserving the lesion features. This method could potentially improve task performance for pancreatic lesion classification at equal or reduced radiation dose. The result is of high significance for longitudinal surveillance studies of patients with pancreatic cysts, which may develop into pancreatic cancer. The Senior Author receives financial support from Siemens GmbH Healthcare.« less
Powell, Lisa M; Szczypka, Glen; Chaloupka, Frank J; Braunschweig, Carol L
2007-09-01
In light of the high rates of child and adolescent obesity, we examined the nutritional content of food advertising seen by American children and adolescents. We drew samples of top-rated television shows by using ratings data to examine the nutritional content for fat, saturated fat, sugar, sodium, and fiber of food-product advertisements seen on television by both children and adolescents. Food products were examined in aggregate and by 5 separate categories that included cereal, sweets, snacks, drinks, and other food products. For 2- to 11-year-olds and 12- to 17-year-olds, respectively, a sample of 50,351 and 47,955 30-second-equivalent food-product advertisements and their related nutritional content were weighted by television ratings data to provide actual exposure measures of the nutritional content of food advertising seen by children and adolescents. Study results showed that 97.8% and 89.4% of food-product advertisements viewed by children 2 to 11 years old and adolescents 12 to 17 years old, respectively, were high in fat, sugar, or sodium. On average, 46.1% and 49.1% of total calories among the products advertised came from sugar in the advertisements seen by these respective age groups. A total of 97.6% of cereal advertisements seen by children 2 to 11 years old were for high-sugar cereals. No substantial differences were found in the nutritional content of advertisements seen by black and white children 2 to 11 years old. However, a slightly higher proportion of food advertisements in general and across all food-product categories seen by black versus white adolescents were for high-sugar products. The overwhelming majority of food-product advertisements seen on television by American children and adolescents are of poor nutritional content.
Mart, Christopher Robin; Eckhauser, Aaron Wesley; Murri, Michael; Su, Jason Thomas
2014-09-01
With surgical palliation of hypoplastic left heart syndrome (HLHS), the tricuspid valve (TV) becomes the systemic atrioventricular valve and moderate/severe TV insufficiency (TVI), an adverse risk factor for survival to Fontan, has been reported in up to 35% of patients prior to stage I palliation. Precise echocardiographic identification of the mechanism of TVI cannot be determined by two-dimensional echocardiography. Three-dimensional echocardiography (3DE) can provide significant insight into the mechanisms of TVI. It is the intent of this report to propose a systematic method on how to evaluate and display 3DE images of the TV in HLHS which has not been done previously. TV anatomy, function, and the known mechanisms of insufficiency are reviewed. We defined three regions of the TV (anterior, posterior, septal) that can help define valve "leaflets" that incorporates the many variations of TV anatomy. To determine how the surgeon views the TV, a picture of a pathologic specimen of the TV was placed on a computer screen and rotated until it was oriented as it appears during surgery, the "surgeons view." We have proposed a systematic method for evaluating and displaying the TV using 3DE which can provide significant insight into the mechanisms causing TVI in HLHS. This has the potential to improve both the surgical approach to repairing the valve and, ultimately, patient outcomes.
Mart, Christopher Robin; Eckhauser, Aaron Wesley; Murri, Michael; Su, Jason Thomas
2014-01-01
With surgical palliation of hypoplastic left heart syndrome (HLHS), the tricuspid valve (TV) becomes the systemic atrioventricular valve and moderate/severe TV insufficiency (TVI), an adverse risk factor for survival to Fontan, has been reported in up to 35% of patients prior to stage I palliation. Precise echocardiographic identification of the mechanism of TVI cannot be determined by two-dimensional echocardiography. Three-dimensional echocardiography (3DE) can provide significant insight into the mechanisms of TVI. It is the intent of this report to propose a systematic method on how to evaluate and display 3DE images of the TV in HLHS which has not been done previously. TV anatomy, function, and the known mechanisms of insufficiency are reviewed. We defined three regions of the TV (anterior, posterior, septal) that can help define valve “leaflets” that incorporates the many variations of TV anatomy. To determine how the surgeon views the TV, a picture of a pathologic specimen of the TV was placed on a computer screen and rotated until it was oriented as it appears during surgery, the “surgeons view.” We have proposed a systematic method for evaluating and displaying the TV using 3DE which can provide significant insight into the mechanisms causing TVI in HLHS. This has the potential to improve both the surgical approach to repairing the valve and, ultimately, patient outcomes. PMID:25298694
Carreira, L Miguel; Ferreira, A
2016-08-01
We characterized the anatomical morphology of the transverse venous sinus (TVS) of 69 canine adult cadavers belonging to three groups: brachycephalic (B), dolichocephalic (D) and mesaticephalic (M). In addition, we outlined its path over the skull using five classic human craniometric points (CPs): the asterion (ast), the bregma (b), the glabella (g), the stephanion (st) and the pterion (pt). The study aimed to establish anatomical differences in the TVS between groups and in the relationship between the TVS and skull. We found that TVS anatomy and its relationships to skull landmarks vary markedly between the groups, with similar anatomical arrangements in B and M. The TVS length can be ranked as M < B < D (with D being the biggest), whereas the width can be ranked as M < D < B (with B being the widest) with the right side being smaller than the left. In the B and M groups, the TVS assumes a craniocaudal trajectory that is closer to the lateral skull wall than in D, where the TVS presents a caudocranial direction. By documenting the morphological characteristics of the TVS, we can create a set of anatomical references allowing construction of a basic framework to greatly decrease the probability of TVS injury during neuronavigation procedures when supported by a good knowledge of the skull, brain anatomies and their relationships. © 2015 Blackwell Verlag GmbH.
Blind image fusion for hyperspectral imaging with the directional total variation
NASA Astrophysics Data System (ADS)
Bungert, Leon; Coomes, David A.; Ehrhardt, Matthias J.; Rasch, Jennifer; Reisenhofer, Rafael; Schönlieb, Carola-Bibiane
2018-04-01
Hyperspectral imaging is a cutting-edge type of remote sensing used for mapping vegetation properties, rock minerals and other materials. A major drawback of hyperspectral imaging devices is their intrinsic low spatial resolution. In this paper, we propose a method for increasing the spatial resolution of a hyperspectral image by fusing it with an image of higher spatial resolution that was obtained with a different imaging modality. This is accomplished by solving a variational problem in which the regularization functional is the directional total variation. To accommodate for possible mis-registrations between the two images, we consider a non-convex blind super-resolution problem where both a fused image and the corresponding convolution kernel are estimated. Using this approach, our model can realign the given images if needed. Our experimental results indicate that the non-convexity is negligible in practice and that reliable solutions can be computed using a variety of different optimization algorithms. Numerical results on real remote sensing data from plant sciences and urban monitoring show the potential of the proposed method and suggests that it is robust with respect to the regularization parameters, mis-registration and the shape of the kernel.
NASA Astrophysics Data System (ADS)
Durand, Sylvain; Frapart, Yves-Michel; Kerebel, Maud
2017-11-01
Spatial electron paramagnetic resonance imaging (EPRI) is a recent method to localize and characterize free radicals in vivo or in vitro, leading to applications in material and biomedical sciences. To improve the quality of the reconstruction obtained by EPRI, a variational method is proposed to inverse the image formation model. It is based on a least-square data-fidelity term and the total variation and Besov seminorm for the regularization term. To fully comprehend the Besov seminorm, an implementation using the curvelet transform and the L 1 norm enforcing the sparsity is proposed. It allows our model to reconstruct both image where acquisition information are missing and image with details in textured areas, thus opening possibilities to reduce acquisition times. To implement the minimization problem using the algorithm developed by Chambolle and Pock, a thorough analysis of the direct model is undertaken and the latter is inverted while avoiding the use of filtered backprojection (FBP) and of non-uniform Fourier transform. Numerical experiments are carried out on simulated data, where the proposed model outperforms both visually and quantitatively the classical model using deconvolution and FBP. Improved reconstructions on real data, acquired on an irradiated distal phalanx, were successfully obtained.
Lee, Bora; Kim, Hyogyoo; Lee, Soo-Kyung; Yoon, Jihyun; Chung, Sang-Jin
2014-10-01
The aim of this study was to determine the effect of television food advertising on participant food intake and risk of obesity. A total of 2419 children aged 11-13 years were selected from 118 elementary schools in South Korea. All participants completed a self-administered questionnaire with questions about height, weight, television viewing times, food preferences, and food intakes. To estimate actual exposure to food advertising, we asked participants to specify the times at which they usually watched television. We then collected data on the various types of food advertisement broadcast on five different television networks during those viewing times over the course of the previous 7 months. The amount of television watched and exposure to energy-dense/nutrient-poor (EDNP) food advertising were associated with an increased risk of being overweight or obese. Exposure to television advertising for EDNP food was also significantly associated with higher EDNP food preference and intake and lower fruit and vegetable intake. However, these relationships disappeared for all foods after adjusting for the overall amount of television watched. Although it was not possible to conclude that exposure to television advertising for EDNP food was associated with an increased risk of obesity, preference for EDNP foods, or overall food intake due to the strong comprehensive effects of television viewing time, there was a reason to believe the evidence of the effects of advertising in this study. Future longitudinal studies are needed to determine the exclusive effects of exposure to television advertising for EDNP food. Copyright © 2014 Elsevier Ltd. All rights reserved.
Blocky inversion of multichannel elastic impedance for elastic parameters
NASA Astrophysics Data System (ADS)
Mozayan, Davoud Karami; Gholami, Ali; Siahkoohi, Hamid Reza
2018-04-01
Petrophysical description of reservoirs requires proper knowledge of elastic parameters like P- and S-wave velocities (Vp and Vs) and density (ρ), which can be retrieved from pre-stack seismic data using the concept of elastic impedance (EI). We propose an inversion algorithm which recovers elastic parameters from pre-stack seismic data in two sequential steps. In the first step, using the multichannel blind seismic inversion method (exploited recently for recovering acoustic impedance from post-stack seismic data), high-resolution blocky EI models are obtained directly from partial angle-stacks. Using an efficient total-variation (TV) regularization, each angle-stack is inverted independently in a multichannel form without prior knowledge of the corresponding wavelet. The second step involves inversion of the resulting EI models for elastic parameters. Mathematically, under some assumptions, the EI's are linearly described by the elastic parameters in the logarithm domain. Thus a linear weighted least squares inversion is employed to perform this step. Accuracy of the concept of elastic impedance in predicting reflection coefficients at low and high angles of incidence is compared with that of exact Zoeppritz elastic impedance and the role of low frequency content in the problem is discussed. The performance of the proposed inversion method is tested using synthetic 2D data sets obtained from the Marmousi model and also 2D field data sets. The results confirm the efficiency and accuracy of the proposed method for inversion of pre-stack seismic data.
An improved robust blind motion de-blurring algorithm for remote sensing images
NASA Astrophysics Data System (ADS)
He, Yulong; Liu, Jin; Liang, Yonghui
2016-10-01
Shift-invariant motion blur can be modeled as a convolution of the true latent image and the blur kernel with additive noise. Blind motion de-blurring estimates a sharp image from a motion blurred image without the knowledge of the blur kernel. This paper proposes an improved edge-specific motion de-blurring algorithm which proved to be fit for processing remote sensing images. We find that an inaccurate blur kernel is the main factor to the low-quality restored images. To improve image quality, we do the following contributions. For the robust kernel estimation, first, we adapt the multi-scale scheme to make sure that the edge map could be constructed accurately; second, an effective salient edge selection method based on RTV (Relative Total Variation) is used to extract salient structure from texture; third, an alternative iterative method is introduced to perform kernel optimization, in this step, we adopt l1 and l0 norm as the priors to remove noise and ensure the continuity of blur kernel. For the final latent image reconstruction, an improved adaptive deconvolution algorithm based on TV-l2 model is used to recover the latent image; we control the regularization weight adaptively in different region according to the image local characteristics in order to preserve tiny details and eliminate noise and ringing artifacts. Some synthetic remote sensing images are used to test the proposed algorithm, and results demonstrate that the proposed algorithm obtains accurate blur kernel and achieves better de-blurring results.
Romero-Fernández, Ma Mar; Royo-Bordonada, Miguel Ángel; Rodríguez-Artalejo, Fernando
2013-07-01
To evaluate the nutritional quality of products advertised on television (TV) during children’s viewing time in Spain, applying the UK nutrient profile model (UKNPM). We recorded 80 h of four general TV station broadcasts during children’s time in May and June 2008, and identified all advertisements for foods and beverages. Nutritional information was obtained from the product labels or websites and from food composition tables. Each product was classified as healthy (e.g. gazpacho, a vegetable juice) or less healthy (e.g. potato crisp snacks) according to the UKNPM criteria. Four free-of-charge TV channels in Spain: two national channels and two regional ones. TV commercials of food and beverages. A total of 486 commercials were broadcast for ninety-six different products, with a mean frequency of 5?1 advertisements per product. Some 61?5% of the ninety-six products were less healthy, and the percentage was higher for foods (74?1 %). All (100 %) of the breakfast cereals and 80% of the non-alcoholic drinks and soft drinks were less healthy. Of the total sample of commercials, 59?7% were for less healthy products, a percentage that rose to 71?2% during children’s reinforced protection viewing time. Over half the commercials were for less healthy products, a proportion that rose to over two-thirds during the hours of special protection for children. This suggests that applying the UKNPM to regulate food advertising during this slot would entail the withdrawal of most food commercials in Spain. TV advertising of products with low nutritional quality should be restricted.
NASA Astrophysics Data System (ADS)
Zhao, Cong; Zhong, Yuncheng; Duan, Xinhui; Zhang, You; Huang, Xiaokun; Wang, Jing; Jin, Mingwu
2018-06-01
Four-dimensional (4D) x-ray cone-beam computed tomography (CBCT) is important for a precise radiation therapy for lung cancer. Due to the repeated use and 4D acquisition over a course of radiotherapy, the radiation dose becomes a concern. Meanwhile, the scatter contamination in CBCT deteriorates image quality for treatment tasks. In this work, we propose the use of a moving blocker (MB) during the 4D CBCT acquisition (‘4D MB’) and to combine motion-compensated reconstruction to address these two issues simultaneously. In 4D MB CBCT, the moving blocker reduces the x-ray flux passing through the patient and collects the scatter information in the blocked region at the same time. The scatter signal is estimated from the blocked region for correction. Even though the number of projection views and projection data in each view are not complete for conventional reconstruction, 4D reconstruction with a total-variation (TV) constraint and a motion-compensated temporal constraint can utilize both spatial gradient sparsity and temporal correlations among different phases to overcome the missing data problem. The feasibility simulation studies using the 4D NCAT phantom showed that 4D MB with motion-compensated reconstruction with 1/3 imaging dose reduction could produce satisfactory images and achieve 37% improvement on structural similarity (SSIM) index and 55% improvement on root mean square error (RMSE), compared to 4D reconstruction at the regular imaging dose without scatter correction. For the same 4D MB data, 4D reconstruction outperformed 3D TV reconstruction by 28% on SSIM and 34% on RMSE. A study of synthetic patient data also demonstrated the potential of 4D MB to reduce the radiation dose by 1/3 without compromising the image quality. This work paves the way for more comprehensive studies to investigate the dose reduction limit offered by this novel 4D MB method using physical phantom experiments and real patient data based on clinical relevant metrics.
Zhao, Cong; Zhong, Yuncheng; Duan, Xinhui; Zhang, You; Huang, Xiaokun; Wang, Jing; Jin, Mingwu
2018-05-03
Four-dimensional (4D) X-ray cone-beam computed tomography (CBCT) is important for a precise radiation therapy for lung cancer. Due to the repeated use and 4D acquisition over a course of radiotherapy, the radiation dose becomes a concern. Meanwhile, the scatter contamination in CBCT deteriorates image quality for treatment tasks. In this work, we propose to use a moving blocker (MB) during the 4D CBCT acquisition ("4D MB") and to combine motion-compensated reconstruction to address these two issues simultaneously. In 4D MB CBCT, the moving blocker reduces the X-ray flux passing through the patient and collects the scatter information in the blocked region at the same time. The scatter signal is estimated from the blocked region for correction. Even though the number of projection views and projection data in each view are not complete for conventional reconstruction, 4D reconstruction with a total-variation (TV) constraint and a motion-compensated temporal constraint can utilize both spatial gradient sparsity and temporal correlations among different phases to overcome the missing data problem. The feasibility simulation studies using the 4D NCAT phantom showed that 4D MB with motion-compensated reconstruction with 1/3 imaging dose reduction could produce satisfactory images and achieve 37% improvement on structural similarity (SSIM) index and 55% improvement on root mean square error (RMSE), compared to 4D reconstruction at the regular imaging dose without scatter correction. For the same 4D MB data, 4D reconstruction outperformed 3D TV reconstruction by 28% on SSIM and 34% on RMSE. A study of synthetic patient data also demonstrated the potential of 4D MB to reduce the radiation dose by 1/3 without compromising the image quality. This work paves the way for more comprehensive studies to investigate the dose reduction limit offered by this novel 4D MB method using physical phantom experiments and real patient data based on clinical relevant metrics. © 2018 Institute of Physics and Engineering in Medicine.
Smoking in contemporary German television programming.
Hanewinkel, Reiner; Wiborg, Gudrun
2007-01-01
To study the prevalence of smoking in German television in 2005. Content analysis of all programmes of the four main national channels Das Erste, ZDF RTL and Pro7 over one week between 3 pm and 12 pm. A total of 395 programmes were analysed (252 h of programming). Each programme was coded regarding whether there was one or more smoking occurrence, defined as active smoking or handling with tobacco products by a character. Smoking was portrayed in 176 (45%) of the programmes. Smoking occurrences were frequent in movies (77%), and in TV magazines (69%). Movies, films, and serials produced in Germany showed more often smoking (65%) compared with productions from abroad (48%; p = 0.051). Smoking is frequently portrayed in German TV.
Marketing fat and sugar to children on New Zealand television.
Wilson, Nick; Signal, Louise; Nicholls, Sarah; Thomson, George
2006-02-01
We aimed to determine the frequency and content of television food advertisements during children's viewing times on various New Zealand television channels. A content analysis was conducted of two free-to-air channels covering a total of 155 h of television time during children's viewing times (n = 858 food advertisements in 2005). Comparisons were made with data from 1997 and data from Australia. Compared to Australian channels, both New Zealand channels (TV3 and TV2) had significantly higher proportions of food advertisements that were classified as being "high in fat and/or sugar" (54% versus 80% and 69%, respectively). Using a more detailed classification system, 70.3% of food advertisements on the New Zealand channels were for foods "counter to improved nutrition" (95% CI: 67.1%, 73.3%) compared to those "favoring improved nutrition" at 5.1% (95% CI: 3.8%, 6.9%). The number of food advertisements per hour was higher in 2005 than in 1997 for the channel (TV2) for which there was time trend data (12.8 versus 8.0 per hour for the afternoon time slot). These findings provide further evidence that the majority of food advertising on New Zealand television is counter to nutritional guidelines. They suggest the need for further regulatory or other controls.
NASA Technical Reports Server (NTRS)
Watson, V. R.
1983-01-01
A personal computer has been used to illustrate physical phenomena and problem solution techniques in engineering classes. According to student evaluations, instruction of concepts was greatly improved through the use of these illustrations. This paper describes the class of phenomena that can be effectively illustrated, the techniques used to create these illustrations, and the techniques used to display the illustrations in regular classrooms and over an instructional TV network. The features of a personal computer required to apply these techniques are listed. The capabilities of some present personal computers are discussed and a forecast of the capabilities of future personal computers is presented.
ERIC Educational Resources Information Center
ERIC Clearinghouse on Reading and Communication Skills, Urbana, IL.
This collection of abstracts is part of a continuing series providing information on recent doctoral dissertations. The 47 titles deal with a variety of topics, including the following: (1) the effect of source variation upon children's reactions to television commercials; (2) covert observation as a means of measuring the affective states of…
Battle for Ulster. A Study of Internal Security
1987-06-01
More than twenty-three nations sent television crews, with American networks alone assigning sixteen. Over 400 journalists -were present. It=was, for...Independence. Another settlement option is in- dependence for Northern Ireland. This initiative, de- signed to outflank loyalists and- republicans mired in...One such variation is the new Anglo-Irish accord, signed in November -1985, which is perhaps the most important political initiative in the province
Water quality studies of TV station reservoir at Davangere City, Karnataka (India).
Begum, Nafeesa; Purushothama, R; Narayana, J; Kumar, K P Ravindra
2006-10-01
Studies were carried out to assess the water quality of TV station reservoir at Davangere City, Karnataka (India). The study revealed that there were variations in physico-chemical concentrations during the rainy season. Except turbidity, all the other physico-chemical characteristics were found within the permissible limits. The results were compared with the standards given by ISI for water quality.
Fit 5 Kids TV Reduction Program for Latino Preschoolers
Mendoza, Jason A.; Baranowski, Tom; Jaramillo, Sandra; Fesinmeyer, Megan D.; Haaland, Wren; Thompson, Debbe; Nicklas, Theresa A.
2015-01-01
Introduction Reducing Latino preschoolers’ TV viewing is needed to reduce their risk of obesity and other chronic diseases. This study’s objective was to evaluate the Fit 5 Kids (F5K) TV reduction program’s impact on Latino preschooler’s TV viewing. Study design Cluster RCT with randomization at the center level and N=160 participants. Setting/participants Latino children aged 3–5 years and their parents were recruited from six Head Start centers in Houston, Texas, in 2010–2012 with analyses in 2013–2014. Intervention F5K was culturally adapted for Latino preschoolers and the overall goal was to reduce TV viewing. Study staff taught F5K over 7–8 weeks during the regular Head Start day directly to intervention students. Control schools provided the usual Head Start curriculum, which did not specifically cover TV viewing. Main outcome measures Individual-level outcomes were measured prior to (Time 1) and immediately following (Time 2) the intervention. The primary outcome, TV viewing (minutes/day), was measured by validated 7-day TV diaries (parent-reported). Sedentary time was measured by accelerometers. Results Per the adjusted repeated measures linear mixed effects model for TV viewing (minutes/day), intervention children decreased from 76.2 (9.9) at Time 1 to 52.1 (10.0) at Time 2, whereas control children remained about the same from 84.2 (10.5) at Time 1 to 85.4 (10.5) at Time 2. The relative difference from Time 1 to Time 2 was –25.3 (95% CI= –45.2, –5.4) minutes for intervention versus control children (N=160, p=0.01). In a similar adjusted model, there was a relative decrease in sedentary time (minutes/day) from Time 1 to Time 2 favoring the intervention children (–9.5, 95% CI= –23.0, 4.1), although not significant at p<0.05. Conclusions F5K reduced Latino preschoolers’ TV viewing by >25 minutes daily. These findings have implications for prevention of obesity, related disorders, and health equity. PMID:26572093
Self-help treatment for insomnia through television and book: a randomized trial.
van Straten, Annemieke; Cuijpers, Pim; Smit, Filip; Spermon, Marianne; Verbeek, Ingrid
2009-01-01
Recently, a Dutch educational broadcasting company developed a 6 week self-help course for insomnia, which consists of a book and television programmes. In this study we examined its effects. 247 subjects with sleep problems were recruited through the media and randomized to the self-help treatment (n=126) or a waiting list control group (n=121). The intervention group received the book, and for 6 consecutive weeks a DVD or videotape. Subjects were assessed before and after the course. Both groups improved significantly with respect to sleep but there were no significant differences in improvements between the groups. However, the intervention group improved significantly more on secondary outcomes: the subjective evaluation of sleep quality (d=0.65), dysfunctional beliefs and attitudes about sleep (d=0.62), depressive symptoms (d=0.35), and quality of life (d=0.34). Cognitive-behavioral self-help treatment does not necessarily lead to sleep improvements but it does improve coping with insomnia. About 2% of the Dutch adult population has watched the regular broadcastings of the course after the trial ended. This huge number of viewers underlines that there is a need for this type of low cost self-help treatment.
Raptou, Elena; Papastefanou, Georgios; Mattas, Konstadinos
2017-01-01
The present study explored the influence of eating habits, body weight and television programme preference on television viewing time and domestic computer usage, after adjusting for sociodemographic characteristics and home media environment indicators. In addition, potential substitution or complementarity in screen time was investigated. Individual level data were collected via questionnaires that were administered to a random sample of 2,946 Germans. The econometric analysis employed a seemingly unrelated bivariate ordered probit model to conjointly estimate television viewing time and time engaged in domestic computer usage. Television viewing and domestic computer usage represent two independent behaviours in both genders and across all age groups. Dietary habits have a significant impact on television watching with less healthy food choices associated with increasing television viewing time. Body weight is found to be positively correlated with television screen time in both men and women, and overweight individuals have a higher propensity for heavy television viewing. Similar results were obtained for age groups where an increasing body mass index (BMI) in adults over 24 years old is more likely to be positively associated with a higher duration of television watching. With respect to dietary habits of domestic computer users, participants aged over 24 years of both genders seem to adopt more healthy dietary patterns. A downward trend in the BMI of domestic computer users was observed in women and adults aged 25-60 years. On the contrary, young domestic computer users 18-24 years old have a higher body weight than non-users. Television programme preferences also affect television screen time with clear differences to be observed between genders and across different age groups. In order to reduce total screen time, health interventions should target different types of screen viewing audiences separately.