Science.gov

Sample records for digital steganography focusing

  1. Steganography and Steganalysis in Digital Images

    DTIC Science & Technology

    2012-01-01

    Kalker. "Digital Watermarking and Steganography (Second Edition)", Morgan Kaufmann Publishers, ISBN: 978-0-12- 372585-1, 2007. [9] M. Kharrazi, H. T...Sencar, Memon. “Benchmarking steganographic and steganalysis techniques” Security, Steganography, and Watermarking of Multimedia Contents, 2005

  2. Digital holography-based steganography.

    PubMed

    Hamam, Habib

    2010-12-15

    A steganographic method offering a high hiding capacity is presented in which the techniques of digital holography are used to distribute information from a small secret image across the larger pixel field of a cover image. An iterative algorithm is used to design a phase-only or complex hologram from a padded version of the secret image, quantizing this data according to the carrier data bits that are available within the intended cover image. By introducing the hologram data only into low-order bits of larger amplitude cover pixels, the change in the cover image remains imperceptible to the casual observer, with a peak signal-to-noise ratio of >40 dB.

  3. A robust chaotic algorithm for digital image steganography

    NASA Astrophysics Data System (ADS)

    Ghebleh, M.; Kanso, A.

    2014-06-01

    This paper proposes a new robust chaotic algorithm for digital image steganography based on a 3-dimensional chaotic cat map and lifted discrete wavelet transforms. The irregular outputs of the cat map are used to embed a secret message in a digital cover image. Discrete wavelet transforms are used to provide robustness. Sweldens' lifting scheme is applied to ensure integer-to-integer transforms, thus improving the robustness of the algorithm. The suggested scheme is fast, efficient and flexible. Empirical results are presented to showcase the satisfactory performance of our proposed steganographic scheme in terms of its effectiveness (imperceptibility and security) and feasibility. Comparison with some existing transform domain steganographic schemes is also presented.

  4. Methodology of Spread-Spectrum Image Steganography

    DTIC Science & Technology

    1998-06-01

    ARMY RESEARCH LABORATORY Methodology of Spread-Spectrum Image Steganography by Lisa M. Marvel, Charles G. Boncelet, Jr., and Charles T. Retter...Image Steganography Lisa M. Marvel, Charles T. Retter Information Science and Technology Directorate, ARL Charles G. Boncelet, Jr. University of...Delaware, Newark, DE Approved for public release; distribution is unlimited. Abstract This report presents a new method of digital steganography

  5. Spread spectrum image steganography.

    PubMed

    Marvel, L M; Boncelet, C R; Retter, C T

    1999-01-01

    In this paper, we present a new method of digital steganography, entitled spread spectrum image steganography (SSIS). Steganography, which means "covered writing" in Greek, is the science of communicating in a hidden manner. Following a discussion of steganographic communication theory and review of existing techniques, the new method, SSIS, is introduced. This system hides and recovers a message of substantial length within digital imagery while maintaining the original image size and dynamic range. The hidden message can be recovered using appropriate keys without any knowledge of the original image. Image restoration, error-control coding, and techniques similar to spread spectrum are described, and the performance of the system is illustrated. A message embedded by this method can be in the form of text, imagery, or any other digital signal. Applications for such a data-hiding scheme include in-band captioning, covert communication, image tamperproofing, authentication, embedded control, and revision tracking.

  6. Steganography -- The New Intelligence Threat

    DTIC Science & Technology

    2004-01-01

    Information can be embedded within text files, digital music and videos, and digital photographs by simply changing bits and bytes. HOW IT WORKS...International Airport could be embedded in Brittany Spears’ latest music release in MP3 format. The wide range of steganography capabilities has been

  7. Steganography: Past, Present, Future

    SciTech Connect

    Judge, J C

    2001-12-01

    Steganography (a rough Greek translation of the term Steganography is secret writing) has been used in various forms for 2500 years. It has found use in variously in military, diplomatic, personal and intellectual property applications. Briefly stated, steganography is the term applied to any number of processes that will hide a message within an object, where the hidden message will not be apparent to an observer. This paper will explore steganography from its earliest instances through potential future application.

  8. Steganography and Cryptography Inspired Enhancement of Introductory Programming Courses

    ERIC Educational Resources Information Center

    Kortsarts, Yana; Kempner, Yulia

    2015-01-01

    Steganography is the art and science of concealing communication. The goal of steganography is to hide the very existence of information exchange by embedding messages into unsuspicious digital media covers. Cryptography, or secret writing, is the study of the methods of encryption, decryption and their use in communications protocols.…

  9. Steganography Detection Using Entropy Measures

    DTIC Science & Technology

    2012-11-16

    it with cryptography. Two other technologies that are closely related to steganography are watermarking and fingerprinting. These technologies are...and Watermarking of Multimedia Contents X, 681914 (February 26, 2008); 2 Niels Provos and Peter Honeyman, "Detecting Steganographic Content on The...Brian Chen and Gregory W. Wornell, "Quantization Index Modulation: A Class of Provably Good Methods for Digital Watermarking and Information Embedding

  10. Transparency benchmarking on audio watermarks and steganography

    NASA Astrophysics Data System (ADS)

    Kraetzer, Christian; Dittmann, Jana; Lang, Andreas

    2006-02-01

    The evaluation of transparency plays an important role in the context of watermarking and steganography algorithms. This paper introduces a general definition of the term transparency in the context of steganography, digital watermarking and attack based evaluation of digital watermarking algorithms. For this purpose the term transparency is first considered individually for each of the three application fields (steganography, digital watermarking and watermarking algorithm evaluation). From the three results a general definition for the overall context is derived in a second step. The relevance and applicability of the definition given is evaluated in practise using existing audio watermarking and steganography algorithms (which work in time, frequency and wavelet domain) as well as an attack based evaluation suite for audio watermarking benchmarking - StirMark for Audio (SMBA). For this purpose selected attacks from the SMBA suite are modified by adding transparency enhancing measures using a psychoacoustic model. The transparency and robustness of the evaluated audio watermarking algorithms by using the original and modifid attacks are compared. The results of this paper show hat transparency benchmarking will lead to new information regarding the algorithms under observation and their usage. This information can result in concrete recommendations for modification, like the ones resulting from the tests performed here.

  11. Transform domain steganography with blind source separation

    NASA Astrophysics Data System (ADS)

    Jouny, Ismail

    2015-05-01

    This paper applies blind source separation or independent component analysis for images that may contain mixtures of text, audio, or other images for steganography purposes. The paper focuses on separating mixtures in the transform domain such as Fourier domain or the Wavelet domain. The study addresses the effectiveness of steganography when using linear mixtures of multimedia components and the ability of standard blind sources separation techniques to discern hidden multimedia messages. Mixing in the space, frequency, and wavelet (scale) domains is compared. Effectiveness is measured using mean square error rate between original and recovered images.

  12. Steganography: LSB Methodology

    DTIC Science & Technology

    2012-08-02

    Watermarking , Ottawa, Canada, October 5, 2001, pages 27 – 30, 2001. [444] A. Westfeld and A. Pfitzmann. Attacks on... Watermarking and Data Hiding, SPIE multimedia systems and applications IV, Denver, CO, August 20 – 24, 2001, volume 4518, pages 275 – 280, 2001. Audio... Watermarking and Steganography, Second Edition. Burlington, MA: Morgan Kaufmann. Wayner, P. (2009). Disappearing Cryptography Information Hiding: Steganography & Watermarking , Third Edition. Burlington, MA: Morgan Kaufmann.

  13. Quantum red-green-blue image steganography

    NASA Astrophysics Data System (ADS)

    Heidari, Shahrokh; Pourarian, Mohammad Rasoul; Gheibi, Reza; Naseri, Mosayeb; Houshmand, Monireh

    One of the most considering matters in the field of quantum information processing is quantum data hiding including quantum steganography and quantum watermarking. This field is an efficient tool for protecting any kind of digital data. In this paper, three quantum color images steganography algorithms are investigated based on Least Significant Bit (LSB). The first algorithm employs only one of the image’s channels to cover secret data. The second procedure is based on LSB XORing technique, and the last algorithm utilizes two channels to cover the color image for hiding secret quantum data. The performances of the proposed schemes are analyzed by using software simulations in MATLAB environment. The analysis of PSNR, BER and Histogram graphs indicate that the presented schemes exhibit acceptable performances and also theoretical analysis demonstrates that the networks complexity of the approaches scales squarely.

  14. Steganography Detection Using Entropy Measures

    DTIC Science & Technology

    2012-08-19

    REPORT Steganography Detection Using Entropy Measures 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: There are two problems in steganalysis: (1) detecting...the existence of a hidden message and (2) decoding the message. As terrorist groups have been known to use steganography in planning their attacks...298 (Rev 8/98) Prescribed by ANSI Std. Z39.18 - Steganography Detection Using Entropy Measures Report Title ABSTRACT There are two problems in

  15. Toward a theory of Steganography

    DTIC Science & Technology

    2004-07-01

    Toward a theory of Steganography Nicholas J. Hopper CMU-CS-04-157 July 2004 School of Computer Science Carnegie Mellon University Pittsburgh, PA...DATE JUL 2004 2. REPORT TYPE 3. DATES COVERED 00-00-2004 to 00-00-2004 4. TITLE AND SUBTITLE Toward a theory of Steganography 5a. CONTRACT...THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Keywords: Steganography , Cryptography, Provable Security

  16. Fourier Phase Domain Steganography: Phase Bin Encoding Via Interpolation

    NASA Astrophysics Data System (ADS)

    Rivas, Edward

    2007-04-01

    In recent years there has been an increased interest in audio steganography and watermarking. This is due primarily to two reasons. First, an acute need to improve our national security capabilities in light of terrorist and criminal activity has driven new ideas and experimentation. Secondly, the explosive proliferation of digital media has forced the music industry to rethink how they will protect their intellectual property. Various techniques have been implemented but the phase domain remains a fertile ground for improvement due to the relative robustness to many types of distortion and immunity to the Human Auditory System. A new method for embedding data in the phase domain of the Discrete Fourier Transform of an audio signal is proposed. Focus is given to robustness and low perceptibility, while maintaining a relatively high capacity rate of up to 172 bits/s.

  17. Challenging the doctrines of JPEG steganography

    NASA Astrophysics Data System (ADS)

    Holub, Vojtech; Fridrich, Jessica

    2014-02-01

    The design of both steganography and steganalysis methods for digital images heavily relies on empirically justified principles. In steganography, the domain in which the embedding changes are executed is usually the preferred domain in which to measure the statistical impact of embedding (to construct the distortion function). Another principle almost exclusively used in steganalysis states that the most accurate detection is obtained when extracting the steganalysis features from the embedding domain. While a substantial body of prior art seems to support these two doctrines, this article challenges both principles when applied to the JPEG format. Through a series of targeted experiments on numerous older as well as current steganographic algorithms, we lay out arguments for why measuring the embedding distortion in the spatial domain can be highly beneficial for JPEG steganography. Moreover, as modern embedding algorithms avoid introducing easily detectable artifacts in the statistics of quantized DCT coefficients, we demonstrate that more accurate detection is obtained when constructing the steganalysis features in the spatial domain where the distortion function is minimized, challenging thus both established doctrines.

  18. Digital microscopy. Bringing new technology into focus.

    PubMed

    2010-06-01

    Digital microscopy enables the scanning of microscope slides so that they can be viewed, analyzed, and archived on a computer. While the technology is not yet widely accepted by pathologists, a switch to digital microscopy systems seems to be inevitable in the near future.

  19. Is image steganography natural?

    PubMed

    Martín, Alvaro; Sapiro, Guillermo; Seroussi, Gadiel

    2005-12-01

    Steganography is the art of secret communication. Its purpose is to hide the presence of information, using, for example, images as covers. We experimentally investigate if stego-images, bearing a secret message, are statistically "natural." For this purpose, we use recent results on the statistics of natural images and investigate the effect of some popular steganography techniques. We found that these fundamental statistics of natural images are, in fact, generally altered by the hidden "nonnatural" information. Frequently, the change is consistently biased in a given direction. However, for the class of natural images considered, the change generally falls within the intrinsic variability of the statistics, and, thus, does not allow for reliable detection, unless knowledge of the data hiding process is taken into account. In the latter case, significant levels of detection are demonstrated.

  20. Scope of Support Vector Machine in Steganography

    NASA Astrophysics Data System (ADS)

    Tanwar, Rohit; Malhotrab, Sona

    2017-08-01

    Steganography is a technique used for secure transmission of data. Using audio as a cover file opens path for many extra features. In order to overcome the limitations of conventional LSB technique, various variants were proposed by different authors. In order to achieve robustness, use of various optimization techniques has been tradition. In this paper the focus is put on use of Genetic Algorithm and Particle Swarm Intelligence in steganography. To list detailed scope, merits and de-merits of the two optimization techniques is the main constituent of this paper. In spite of analyzing the two techniques, the motivation and applicability of machine learning algorithm in the problem statement is also discussed. This paper will guide the path in using Support Vector Machine for optimizing the data hiding.

  1. Multi-Party Quantum Steganography

    NASA Astrophysics Data System (ADS)

    Mihara, Takashi

    2016-11-01

    Steganography has been proposed as a data hiding technique. As a derivation, quantum steganography based on quantum physics has also been proposed. In this paper, we extend the results in presented (Mihara, Phys. Lett. 379, 952 2015) and propose a multi-party quantum steganography technique that combines quantum error-correcting codes with entanglement. The proposed protocol shares an entangled state among n +1 parties and sends n secret messages, corresponding to the n parties, to the other party. With no knowledge of the other secret messages, the n parties can construct a stego message by cooperating with each other. Finally, we propose a protocol for sending qubits using the same technique.

  2. Multi-Party Quantum Steganography

    NASA Astrophysics Data System (ADS)

    Mihara, Takashi

    2017-02-01

    Steganography has been proposed as a data hiding technique. As a derivation, quantum steganography based on quantum physics has also been proposed. In this paper, we extend the results in presented (Mihara, Phys. Lett. 379, 952 2015) and propose a multi-party quantum steganography technique that combines quantum error-correcting codes with entanglement. The proposed protocol shares an entangled state among n +1 parties and sends n secret messages, corresponding to the n parties, to the other party. With no knowledge of the other secret messages, the n parties can construct a stego message by cooperating with each other. Finally, we propose a protocol for sending qubits using the same technique.

  3. Taxonomy for spatial domain LSB steganography techniques

    NASA Astrophysics Data System (ADS)

    Collins, James C.; Agaian, Sos S.

    2014-05-01

    The Least Significant Bit (LSB) embedding technique is a well-known and broadly employed method in multimedia steganography, used mainly in applications involving single bit-plane manipulations in the spatial domain [1]. The key advantages of LSB procedures are they are simple to understand, easy to implement, have high embedding capacity, and can be resistant to steganalysis attacks. Additionally, the LSB approach has spawned numerous applications and can be used as the basis of more complex techniques for multimedia data embedding. In the last several decades, hundreds of new LSB or LSB variant methods have been developed in an effort to optimize capacity while minimizing detectability, taking advantage of the overall simplicity of this method. LSB-steganalysis research has also intensified in an effort to find new or improved ways to evaluate the performance of this widely used steganographic system. This paper reviews and categorizes some of these major techniques of LSB embedding, focusing specifically on the spatial domain. Some justification for establishing and identifying promising uses of a proposed SD-LSB centric taxonomy are discussed. Specifically, we define a new taxonomy for SD-LSB embedding techniques with the goal of aiding researchers in tool classification methodologies that can lead to advances in the state-of-the-art in steganography. With a common framework to work with, researchers can begin to more concretely identify core tools and common techniques to establish common standards of practice for steganography in general. Finally, we provide a summary on some of the most common LSB embedding techniques followed by a proposed taxonomy standard for steganalysis.

  4. Steganography in arrhythmic electrocardiogram signal.

    PubMed

    Edward Jero, S; Ramu, Palaniappan; Ramakrishnan, S

    2015-08-01

    Security and privacy of patient data is a vital requirement during exchange/storage of medical information over communication network. Steganography method hides patient data into a cover signal to prevent unauthenticated accesses during data transfer. This study evaluates the performance of ECG steganography to ensure secured transmission of patient data where an abnormal ECG signal is used as cover signal. The novelty of this work is to hide patient data into two dimensional matrix of an abnormal ECG signal using Discrete Wavelet Transform and Singular Value Decomposition based steganography method. A 2D ECG is constructed according to Tompkins QRS detection algorithm. The missed R peaks are computed using RR interval during 2D conversion. The abnormal ECG signals are obtained from the MIT-BIH arrhythmia database. Metrics such as Peak Signal to Noise Ratio, Percentage Residual Difference, Kullback-Leibler distance and Bit Error Rate are used to evaluate the performance of the proposed approach.

  5. Auto-focus apparatus with digital signal processor

    NASA Astrophysics Data System (ADS)

    Li, Qi; Feng, Huajun; Xu, Zhihai

    2005-01-01

    There are two kinds of auto-focus methods in a digital imaging system: Depth from focus (DFF) and Depth from defocus (DFD). Depth from defocus is a method, which acquired distance information from blurred image. Because of necessity of establishment of defocus model and accurate calibration of imaging system, the application of DFD is confined. As a search focusing technology, Depth from focus has some advantages, such as high accuracy, robust performance, so it is adopted in our apparatus. In this paper, an auto-focus apparatus based on digital signal processor has been designed and constructed. DSP receives image series from a CMOS sensor firstly, then performs the auto-focus action with the following steps: analyzing focus measure of image, moving motorized lens and finding the best imaging position. For focus measures, the frequency spectrum functions, the gradient functions and the entropy function are analyzed in detail. In order to improve the sensitivity of focus measure curve, the weighting factor - distance between direct current component and alternating current component - was introduced into revising frequency spectrum functions. A series of focus experiments have been performed on the auto-focus apparatus, and the veracity and the reliability of the system have been proved to be excellent.

  6. Secure steganography designed for mobile platforms

    NASA Astrophysics Data System (ADS)

    Agaian, Sos S.; Cherukuri, Ravindranath; Sifuentes, Ronnie R.

    2006-05-01

    Adaptive steganography, an intelligent approach to message hiding, integrated with matrix encoding and pn-sequences serves as a promising resolution to recent security assurance concerns. Incorporating the above data hiding concepts with established cryptographic protocols in wireless communication would greatly increase the security and privacy of transmitting sensitive information. We present an algorithm which will address the following problems: 1) low embedding capacity in mobile devices due to fixed image dimensions and memory constraints, 2) compatibility between mobile and land based desktop computers, and 3) detection of stego images by widely available steganalysis software [1-3]. Consistent with the smaller available memory, processor capabilities, and limited resolution associated with mobile devices, we propose a more magnified approach to steganography by focusing adaptive efforts at the pixel level. This deeper method, in comparison to the block processing techniques commonly found in existing adaptive methods, allows an increase in capacity while still offering a desired level of security. Based on computer simulations using high resolution, natural imagery and mobile device captured images, comparisons show that the proposed method securely allows an increased amount of embedding capacity but still avoids detection by varying steganalysis techniques.

  7. Digital holographic microscopy and focusing methods based on image sharpness.

    PubMed

    İlhan, Hazar A; Doğar, Mert; Özcan, Merıç

    2014-09-01

    Digital holographic microscope allows imaging of opaque and transparent specimens without staining. A digitally recorded hologram must be reconstructed numerically at the actual depth of the object to obtain a focused image. We have developed a high-resolution digital holographic microscope for imaging amplitude and phase objects with autofocusing capability. If the actual depth of an object is not known a priori, it is estimated by comparing the sharpness of several reconstructions at different distances, which is very demanding in means of computational power when the recorded hologram is large. In this paper, we present 11 different sharpness metrics for estimating the actual focus depths of objects. The speed performance of focusing is discussed, and a scaling technique is introduced where the speed of autofocusing increases on the order of square of the scale ratio. We measured the performance of scaling on computer-generated holograms and on recorded holograms of a biological sample. We show that simulations are in good agreement with the experimental results. © 2014 The Authors Journal of Microscopy © 2014 Royal Microscopical Society.

  8. Digital Phased Array Ultrasonic Inspection system with dynamic focusing

    NASA Astrophysics Data System (ADS)

    Hwang, J. S.; Shin, H. J.; Song, S. J.; Song, T. K.

    2000-05-01

    Enhancement of the ultrasonic flaw detection and characterization is expected through the development of a high performance PAULI (Phased Array Ultrasonic Inspection) system which can provide high resolution two-dimensional (sector scan: S-scan) images. The high-resolution S-scan image renders inspection results more readable compared to the conventional A-scan and B-scan results. Therefore, it can improve inspection efficiency and reliability. In this study, the ultrasonic imaging technologies developed in medical applications were adapted to develop a digital PAULI system for nondestructive testing. To provide real-time S-scan images, the PAULI system uses 64 independent transceiver channels controlled by proper delay laws for steering and focusing the ultrasound beams along each scan lines. The PAULI system employs a novel dynamic receive focusing technique in order to optimize the lateral resolution by focusing the ultrasound wave at all imaging points. The dynamic receive focusing is achieved in real-time by digital signal processing methods. The feasibility of PAULI system is demonstrated for the NDE of steel structures.

  9. Fast focus estimation using frequency analysis in digital holography.

    PubMed

    Oh, Seungtaik; Hwang, Chi-Young; Jeong, Il Kwon; Lee, Sung-Keun; Park, Jae-Hyeung

    2014-11-17

    A novel fast frequency-based method to estimate the focus distance of digital hologram for a single object is proposed. The focus distance is computed by analyzing the distribution of intersections of smoothed-rays. The smoothed-rays are determined by the directions of energy flow which are computed from local spatial frequency spectrum based on the windowed Fourier transform. So our method uses only the intrinsic frequency information of the optical field on the hologram and therefore does not require any sequential numerical reconstructions and focus detection techniques of conventional photography, both of which are the essential parts in previous methods. To show the effectiveness of our method, numerical results and analysis are presented as well.

  10. Audio Steganography with Embedded Text

    NASA Astrophysics Data System (ADS)

    Teck Jian, Chua; Chai Wen, Chuah; Rahman, Nurul Hidayah Binti Ab.; Hamid, Isredza Rahmi Binti A.

    2017-08-01

    Audio steganography is about hiding the secret message into the audio. It is a technique uses to secure the transmission of secret information or hide their existence. It also may provide confidentiality to secret message if the message is encrypted. To date most of the steganography software such as Mp3Stego and DeepSound use block cipher such as Advanced Encryption Standard or Data Encryption Standard to encrypt the secret message. It is a good practice for security. However, the encrypted message may become too long to embed in audio and cause distortion of cover audio if the secret message is too long. Hence, there is a need to encrypt the message with stream cipher before embedding the message into the audio. This is because stream cipher provides bit by bit encryption meanwhile block cipher provide a fixed length of bits encryption which result a longer output compare to stream cipher. Hence, an audio steganography with embedding text with Rivest Cipher 4 encryption cipher is design, develop and test in this project.

  11. A Novel Strategy for Quantum Image Steganography Based on Moiré Pattern

    NASA Astrophysics Data System (ADS)

    Jiang, Nan; Wang, Luo

    2015-03-01

    Image steganography technique is widely used to realize the secrecy transmission. Although its strategies on classical computers have been extensively researched, there are few studies on such strategies on quantum computers. Therefore, in this paper, a novel, secure and keyless steganography approach for images on quantum computers is proposed based on Moiré pattern. Algorithms based on the Moiré pattern are proposed for binary image embedding and extraction. Based on the novel enhanced quantum representation of digital images (NEQR), recursive and progressively layered quantum circuits for embedding and extraction operations are designed. In the end, experiments are done to verify the validity and robustness of proposed methods, which confirms that the approach in this paper is effective in quantum image steganography strategy.

  12. Focusing through dynamic tissue with millisecond digital optical phase conjugation.

    PubMed

    Wang, Daifa; Zhou, Edward Haojiang; Brake, Joshua; Ruan, Haowen; Jang, Mooseok; Yang, Changhuei

    2015-08-20

    Digital optical phase conjugation (DOPC) is a new technique employed in wavefront shaping and phase conjugation for focusing light through or within scattering media such as biological tissues. DOPC is particularly attractive as it intrinsically achieves a high fluence reflectivity in comparison to nonlinear optical approaches. However, the slow refresh rate of liquid crystal spatial light modulators and limitations imposed by computer data transfer speeds have thus far made it difficult for DOPC to achieve a playback latency of shorter than ~200 ms and, therefore, prevented DOPC from being practically applied to thick living samples. In this paper, we report a novel DOPC system that is capable of 5.3 ms playback latency. This speed improvement of almost 2 orders of magnitude is achieved by using a digital micromirror device, field programmable gate array (FPGA) processing, and a single-shot binary phase retrieval technique. With this system, we are able to focus through 2.3 mm living mouse skin with blood flowing through it (decorrelation time ~30 ms) and demonstrate that the focus can be maintained indefinitely-an important technological milestone that has not been previously reported, to the best of our knowledge.

  13. Focusing through dynamic tissue with millisecond digital optical phase conjugation

    PubMed Central

    Wang, Daifa; Zhou, Edward Haojiang; Brake, Joshua; Ruan, Haowen; Jang, Mooseok; Yang, Changhuei

    2015-01-01

    Digital optical phase conjugation (DOPC) is a new technique employed in wavefront shaping and phase conjugation for focusing light through or within scattering media such as biological tissues. DOPC is particularly attractive as it intrinsically achieves a high fluence reflectivity in comparison to nonlinear optical approaches. However, the slow refresh rate of liquid crystal spatial light modulators and limitations imposed by computer data transfer speeds have thus far made it difficult for DOPC to achieve a playback latency of shorter than ~200 ms and, therefore, prevented DOPC from being practically applied to thick living samples. In this paper, we report a novel DOPC system that is capable of 5.3 ms playback latency. This speed improvement of almost 2 orders of magnitude is achieved by using a digital micromirror device, field programmable gate array (FPGA) processing, and a single-shot binary phase retrieval technique. With this system, we are able to focus through 2.3 mm living mouse skin with blood flowing through it (decorrelation time ~30 ms) and demonstrate that the focus can be maintained indefinitely—an important technological milestone that has not been previously reported, to the best of our knowledge. PMID:26677458

  14. A high capacity 3D steganography algorithm.

    PubMed

    Chao, Min-Wen; Lin, Chao-hung; Yu, Cheng-Wei; Lee, Tong-Yee

    2009-01-01

    In this paper, we present a very high-capacity and low-distortion 3D steganography scheme. Our steganography approach is based on a novel multilayered embedding scheme to hide secret messages in the vertices of 3D polygon models. Experimental results show that the cover model distortion is very small as the number of hiding layers ranges from 7 to 13 layers. To the best of our knowledge, this novel approach can provide much higher hiding capacity than other state-of-the-art approaches, while obeying the low distortion and security basic requirements for steganography on 3D models.

  15. Effective Electrocardiogram Steganography Based on Coefficient Alignment.

    PubMed

    Yang, Ching-Yu; Wang, Wen-Fong

    2016-03-01

    This study presents two types of data hiding methods based on coefficient alignment for electrocardiogram (ECG) signals, namely, lossy and reversible ECG steganographys. The lossy method is divided into high-quality and high-capacity ECG steganography, both of which are capable of hiding confidential patient data in ECG signals. The reversible data hiding method can not only hide secret messages but also completely restore the original ECG signal after bit extraction. Simulations confirmed that the perceived quality generated by the lossy ECG steganography methods was good, while hiding capacity was acceptable. In addition, these methods have a certain degree of robustness, which is rare in conventional ECG stegangraphy schemes. Moreover, the proposed reversible ECG steganography method can not only successfully extract hidden messages but also completely recover the original ECG data.

  16. Steganography using reversible texture synthesis.

    PubMed

    Wu, Kuo-Chen; Wang, Chung-Ming

    2015-01-01

    We propose a novel approach for steganography using a reversible texture synthesis. A texture synthesis process resamples a smaller texture image, which synthesizes a new texture image with a similar local appearance and an arbitrary size. We weave the texture synthesis process into steganography to conceal secret messages. In contrast to using an existing cover image to hide messages, our algorithm conceals the source texture image and embeds secret messages through the process of texture synthesis. This allows us to extract the secret messages and source texture from a stego synthetic texture. Our approach offers three distinct advantages. First, our scheme offers the embedding capacity that is proportional to the size of the stego texture image. Second, a steganalytic algorithm is not likely to defeat our steganographic approach. Third, the reversible capability inherited from our scheme provides functionality, which allows recovery of the source texture. Experimental results have verified that our proposed algorithm can provide various numbers of embedding capacities, produce a visually plausible texture images, and recover the source texture.

  17. Comments on "Steganography Using Reversible Texture Synthesis".

    PubMed

    Zhou, Hang; Chen, Kejiang; Zhang, Weiming; Yu, Nenghai

    2017-04-01

    Message hiding in texture image synthesis is a novel steganography approach by which we resample a smaller texture image and synthesize a new texture image with a similar local appearance and an arbitrary size. However, the mirror operation over the image boundary is flawed and is easy to attack. We propose an attacking method on this steganography, which can not only detect the stego-images but can also extract the hidden messages.

  18. A secure steganography for privacy protection in healthcare system.

    PubMed

    Liu, Jing; Tang, Guangming; Sun, Yifeng

    2013-04-01

    Private data in healthcare system require confidentiality protection while transmitting. Steganography is the art of concealing data into a cover media for conveying messages confidentially. In this paper, we propose a steganographic method which can provide private data in medical system with very secure protection. In our method, a cover image is first mapped into a 1D pixels sequence by Hilbert filling curve and then divided into non-overlapping embedding units with three consecutive pixels. We use adaptive pixel pair match (APPM) method to embed digits in the pixel value differences (PVD) of the three pixels and the base of embedded digits is dependent on the differences among the three pixels. By solving an optimization problem, minimal distortion of the pixel ternaries caused by data embedding can be obtained. The experimental results show our method is more suitable to privacy protection of healthcare system than prior steganographic works.

  19. Steganography based on pixel intensity value decomposition

    NASA Astrophysics Data System (ADS)

    Abdulla, Alan Anwar; Sellahewa, Harin; Jassim, Sabah A.

    2014-05-01

    This paper focuses on steganography based on pixel intensity value decomposition. A number of existing schemes such as binary, Fibonacci, Prime, Natural, Lucas, and Catalan-Fibonacci (CF) are evaluated in terms of payload capacity and stego quality. A new technique based on a specific representation is proposed to decompose pixel intensity values into 16 (virtual) bit-planes suitable for embedding purposes. The proposed decomposition has a desirable property whereby the sum of all bit-planes does not exceed the maximum pixel intensity value, i.e. 255. Experimental results demonstrate that the proposed technique offers an effective compromise between payload capacity and stego quality of existing embedding techniques based on pixel intensity value decomposition. Its capacity is equal to that of binary and Lucas, while it offers a higher capacity than Fibonacci, Prime, Natural, and CF when the secret bits are embedded in 1st Least Significant Bit (LSB). When the secret bits are embedded in higher bit-planes, i.e., 2nd LSB to 8th Most Significant Bit (MSB), the proposed scheme has more capacity than Natural numbers based embedding. However, from the 6th bit-plane onwards, the proposed scheme offers better stego quality. In general, the proposed decomposition scheme has less effect in terms of quality on pixel value when compared to most existing pixel intensity value decomposition techniques when embedding messages in higher bit-planes.

  20. Digitized cervical images: problems, solutions, and potential medical impact.

    PubMed

    Ferris, Daron G; Mitra, Sunanda; Nutter, Brian

    2006-01-01

    To demonstrate compression, illumination enhancement, registration, segmentation, automated classification and steganography using digitized cervical images. The Hybrid Multi-Scale Vector Quantization algorithm developed at Texas Technological University and other automated systems were used to improve digitized cervical images. We demonstrated high levels of image compression, illumination enhancement, registration, automated segmentation and classification and steganography of digitized cervical images. Digitized cervical images can be altered to facilitate research of cervical neoplasia.

  1. Mel-cepstrum-based steganalysis for VoIP steganography

    NASA Astrophysics Data System (ADS)

    Kraetzer, Christian; Dittmann, Jana

    2007-02-01

    Steganography and steganalysis in VoIP applications are important research topics as speech data is an appropriate cover to hide messages or comprehensive documents. In our paper we introduce a Mel-cepstrum based analysis known from speaker and speech recognition to perform a detection of embedded hidden messages. In particular we combine known and established audio steganalysis features with the features derived from Melcepstrum based analysis for an investigation on the improvement of the detection performance. Our main focus considers the application environment of VoIP-steganography scenarios. The evaluation of the enhanced feature space is performed for classical steganographic as well as for watermarking algorithms. With this strategy we show how general forensic approaches can detect information hiding techniques in the field of hidden communication as well as for DRM applications. For the later the detection of the presence of a potential watermark in a specific feature space can lead to new attacks or to a better design of the watermarking pattern. Following that the usefulness of Mel-cepstrum domain based features for detection is discussed in detail.

  2. Adaptive image steganography using contourlet transform

    NASA Astrophysics Data System (ADS)

    Fakhredanesh, Mohammad; Rahmati, Mohammad; Safabakhsh, Reza

    2013-10-01

    This work presents adaptive image steganography methods which locate suitable regions for embedding by contourlet transform, while embedded message bits are carried in discrete cosine transform coefficients. The first proposed method utilizes contourlet transform coefficients to select contour regions of the image. In the embedding procedure, some of the contourlet transform coefficients may change which may cause errors at the message extraction phase. We propose a novel iterative procedure to resolve such problems. In addition, we have proposed an improved version of the first method in which it uses an advanced embedding operation to boost its security. Experimental results show that the proposed base method is an imperceptible image steganography method with zero retrieval error rate. Comparisons with other steganography methods which utilize contourlet transform show that our proposed method is able to retrieve all messages perfectly, whereas the others fail. Moreover, the proposed method outperforms the ContSteg method in terms of PSNR and the higher-order statistics steganalysis method. Experimental evaluations of our methods with the well known DCT-based steganography algorithms have demonstrated that our improved method has superior performance in terms of PSNR and SSIM, and is more secure against the steganalysis attack.

  3. Digitally Oriented Materials”: Focus on Lithium Disilicate Ceramics

    PubMed Central

    Ferrari, Marco; Mangano, Francesco Guido; Sorrentino, Roberto

    2016-01-01

    The present paper was aimed at reporting the state of the art about lithium disilicate ceramics. The physical, mechanical, and optical properties of this material were reviewed as well as the manufacturing processes, the results of in vitro and in vivo investigations related to survival and success rates over time, and hints for the clinical indications in the light of the latest literature data. Due to excellent optical properties, high mechanical resistance, restorative versatility, and different manufacturing techniques, lithium disilicate can be considered to date one of the most promising dental materials in Digital Dentistry. PMID:27635140

  4. Using digital micromirror devices for focusing light through turbid media

    NASA Astrophysics Data System (ADS)

    Chandrasekaran, Sri Nivas; Ligtenberg, Hans; Steenbergen, Wiendelt; Vellekoop, Ivo M.

    2014-03-01

    The holy grail of biomedical optical imaging is to perform microscopy deep inside living tissue. Unfortunately, biological tissue scatters light, which prevents the formation of a sharp focus. However, recently it was shown that wavefront shaping can be used to focus light through and inside turbid materials. So far, most experiments used liquid crystal devices, which are too slow to match the dynamics of perfused tissue. Since DMD technology is approximately 1000 times faster, it may bring wavefront shaping to in-vivo applications. We will compare analytically the performance of different methods for focusing light through scattering media with an intensity-only light modulator.

  5. Surmounting the Effects of Lossy Compression on Steganography

    DTIC Science & Technology

    1996-10-01

    steganography is that which is stored with an accuracy far greater than necessary for the data’s use and display. Image, Postscript, and audio files are...Compression on Steganography Daniel L. Currie, III Fleet Information Warfare Center 2555 Amphibious Drive NAB Little Creek Norfolk, VA 23521-3225...and can be exploited to export sensitive information. Since images are fre- quently compressed for storage or transmission, effective steganography

  6. Creating an extended focus image of a tilted object in Fourier digital holography.

    PubMed

    Paturzo, Melania; Ferraro, Pietro

    2009-10-26

    We present a new method to numerically reconstruct images on a tilted plane by digital holography in Fourier configuration. The proposed technique is based on a quadratic deformation of spatial coordinates of the digital hologram. By this approach we demonstrate that it is possible to recover the extended focus image (EFI) of a tilted object in a single reconstruction step from the deformed hologram.

  7. Researcher’s Perspective of Substitution Method on Text Steganography

    NASA Astrophysics Data System (ADS)

    Zamir Mansor, Fawwaz; Mustapha, Aida; Azah Samsudin, Noor

    2017-08-01

    The linguistic steganography studies are still in the stage of development and empowerment practices. This paper will present several text steganography on substitution methods based on the researcher’s perspective, all scholar paper will analyse and compared. The objective of this paper is to give basic information in the substitution method of text domain steganography that has been applied by previous researchers. The typical ways of this method also will be identified in this paper to reveal the most effective method in text domain steganography. Finally, the advantage of the characteristic and drawback on these techniques in generally also presented in this paper.

  8. Steganography and encrypting based on immunochemical systems.

    PubMed

    Kim, Kyung-Woo; Bocharova, Vera; Halámek, Jan; Oh, Min-Kyu; Katz, Evgeny

    2011-05-01

    Steganography and encrypting were demonstrated with immuno-specific systems. IgG-proteins were used as invisible ink developed with complementary antibodies labeled with enzymes producing color spots. The information security was achieved by mixing the target protein-antigens used for the text encoding with masking proteins of similar composition but having different bioaffinity. Two different texts were simultaneously encoded by using two different encoding proteins in a mixture. Various encrypting techniques were exemplified with the immuno-systems used for the steganography. Future use of the developed approach for information protection and watermark-technology was proposed. Scaling down the encoded text to a micro-size is feasible with the use of nanotechnology.

  9. LSB Based Quantum Image Steganography Algorithm

    NASA Astrophysics Data System (ADS)

    Jiang, Nan; Zhao, Na; Wang, Luo

    2016-01-01

    Quantum steganography is the technique which hides a secret message into quantum covers such as quantum images. In this paper, two blind LSB steganography algorithms in the form of quantum circuits are proposed based on the novel enhanced quantum representation (NEQR) for quantum images. One algorithm is plain LSB which uses the message bits to substitute for the pixels' LSB directly. The other is block LSB which embeds a message bit into a number of pixels that belong to one image block. The extracting circuits can regain the secret message only according to the stego cover. Analysis and simulation-based experimental results demonstrate that the invisibility is good, and the balance between the capacity and the robustness can be adjusted according to the needs of applications.

  10. Real-time object tracking for moving target auto-focus in digital camera

    NASA Astrophysics Data System (ADS)

    Guan, Haike; Niinami, Norikatsu; Liu, Tong

    2015-02-01

    Focusing at a moving object accurately is difficult and important to take photo of the target successfully in a digital camera. Because the object often moves randomly and changes its shape frequently, position and distance of the target should be estimated at real-time so as to focus at the objet precisely. We propose a new method of real-time object tracking to do auto-focus for moving target in digital camera. Video stream in the camera is used for the moving target tracking. Particle filter is used to deal with problem of the target object's random movement and shape change. Color and edge features are used as measurement of the object's states. Parallel processing algorithm is developed to realize real-time particle filter object tracking easily in hardware environment of the digital camera. Movement prediction algorithm is also proposed to remove focus error caused by difference between tracking result and target object's real position when the photo is taken. Simulation and experiment results in digital camera demonstrate effectiveness of the proposed method. We embedded real-time object tracking algorithm in the digital camera. Position and distance of the moving target is obtained accurately by object tracking from the video stream. SIMD processor is applied to enforce parallel real-time processing. Processing time less than 60ms for each frame is obtained in the digital camera with its CPU of only 162MHz.

  11. Analysis of common-path incoherent digital holography using dual-focusing lens with diffraction gratings

    NASA Astrophysics Data System (ADS)

    Quan, Xiangyu; Moriyama, Asuka; Kouichi, Nitta; Matoba, Osamu; Awatsuji, Yasuhiro

    2017-04-01

    This paper provides overall analytical insights on the common-path incoherent digital holography using dual-focusing lens with diffraction gratings. Especially when one tries to seek an off-axis solution using the suggested configuration, the low temporal and spatial coherence require specific conditions on parameters of the set-up. AA mathematical explanation on the off-axis digital holography is described.

  12. Focus detection criterion for refocusing in multi-wavelength digital holography.

    PubMed

    Xu, Li; Mater, Mike; Ni, Jun

    2011-08-01

    The majority of focus detection criteria reported is based on amplitude contrast. Due to phase wrapping, phase contrast was previously reported unsuitable for focus finding tasks. By taking the advantage of multi-wavelength digital holography, we propose a new focus detection criterion based on phase contrast. Experimental results are presented to prove the feasibility of the developed criterion. Possible applications of the developed technology include inspecting machined surfaces in the auto industry.

  13. Topographic anatomy of the masseter muscle focusing on the tendinous digitation.

    PubMed

    Lee, Ju-Young; Kim, Jeong-Nam; Yoo, Ja-Young; Hu, Kyung-Seok; Kim, Hee-Jin; Song, Wu-Chul; Koh, Ki-Seok

    2012-10-01

    The masseter muscle has superficial tendons that interdigitate like a saw (tendinous digitations), but a detailed description of these tendons is lacking in anatomic textbooks and atlases. The aim of the present study was to elucidate the topographic anatomy of the masseter muscle, focusing on its tendinous digitation. Sixty-five adult faces (113 sides) were dissected. Five parameters, including the lengths, widths, and thickness of the muscle, were measured. The number and morphology of tendinous digitations were also investigated. The length and width of the masseter muscle were longer and wider in male specimens than in female specimens. The number of masseter muscle tendinous digitations was predominantly two in males and three in females. The length of the tendinous digitations tended to be about three-quarters of that of the muscle. The second tendinous digitation was the longest in male specimens, while the first tendinous digitation was the longest in females. Based on our results, the external morphology of the masseter muscle does not match that described in anatomical atlases and textbooks. These findings may be helpful as a basic reference and in the treatment of masseter muscle hypertrophy and masseter tenomyositis. Copyright © 2012 Wiley Periodicals, Inc.

  14. Automatic method for focusing biological specimens in digital lensless holographic microscopy.

    PubMed

    Trujillo, Carlos A; Garcia-Sucerquia, Jorge

    2014-05-01

    A self-focusing method applicable to digital lensless holographic microscopy is presented. The method searches for the global minimum of the area enclosing a given amount of energy in a region surrounding the object of interest. The proposed modified enclosed energy method has been tested on self-focusing experimental holograms of a paramecium specimen and a section of the head of a drosophila melanogaster fly. The presented self-focusing technique also has been contrasted with some of the already reported methods to seek the best focus image.

  15. One improved LSB steganography algorithm

    NASA Astrophysics Data System (ADS)

    Song, Bing; Zhang, Zhi-hong

    2013-03-01

    It is easy to be detected by X2 and RS steganalysis with high accuracy that using LSB algorithm to hide information in digital image. We started by selecting information embedded location and modifying the information embedded method, combined with sub-affine transformation and matrix coding method, improved the LSB algorithm and a new LSB algorithm was proposed. Experimental results show that the improved one can resist the X2 and RS steganalysis effectively.

  16. Efficient high-capacity steganography technique

    NASA Astrophysics Data System (ADS)

    Abdulla, Alan A.; Jassim, Sabah A.; Sellahewa, Harin

    2013-05-01

    Performance indicators characterizing modern steganographic techniques include capacity (i.e. the quantity of data that can be hidden in the cover medium), stego quality (i.e. artifacts visibility), security (i.e. undetectability), and strength or robustness (intended as the resistance against active attacks aimed to destroy the secret message). Fibonacci based embedding techniques have been researched and proposed in the literature to achieve efficient steganography in terms of capacity with respect to stego quality. In this paper, we investigated an innovative idea that extends Fibonacci-like steganography by bit-plane(s) mapping instead of bit-plane(s) replacement. Our proposed algorithm increases embedding capacity using bit-plane mapping to embed two bits of the secret message in three bits of a pixel of the cover, at the expense of a marginal loss in stego quality. While existing Fibonacci embedding algorithms do not use certain intensities of the cover for embedding due to the limitation imposed by the Zeckendorf theorem, our proposal solve this problem and make all intensity values candidates for embedding. Experimental results demonstrate that the proposed technique double the embedding capacity when compared to existing Fibonacci methods, and it is secure against statistical attacks such as RS, POV, and difference image histogram (DIH).

  17. Applied public-key steganography

    NASA Astrophysics Data System (ADS)

    Guillon, Pierre; Furon, Teddy; Duhamel, Pierre

    2002-04-01

    We consider the problem of hiding information in a steganographic framework, i.e. embedding a binary message within an apparently innocuous content, in order to establish a suspicion-free digital communication channel. The adversary is passive as no intentional attack is foreseen. The only threat is that she discovers the presence of a hidden communication. The main goal of this article is to find if the Scalar Costa Scheme, a recently published embedding method exploiting side information at the encoder, is suitable for that framework. We justify its use assessing its security level with respect to the Cachin's criterion. We derive a public-key stego-system following the ideas of R. Anderson and P. Petitcolas. This technique is eventually applied to PCM audio contents. Experimental performances are detailed in terms of bit-rate and Kullback-Leibler distance.

  18. Focusing light inside dynamic scattering media with millisecond digital optical phase conjugation (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Liu, Yan; Ma, Cheng; Shen, Yuecheng; Wang, Lihong V.

    2017-02-01

    Optical phase conjugation based wavefront shaping techniques are being actively developed to focus light through or inside scattering media such as biological tissue, and they promise to revolutionize optical imaging, manipulation, and therapy. The speed of digital optical phase conjugation (DOPC) has been limited by the low speeds of cameras and spatial light modulators (SLMs), preventing DOPC from being applied to thick living tissue. Recently, a fast DOPC system was developed based on a single-shot wavefront measurement method, a field programmable gate array (FPGA) for data processing, and a digital micromirror device (DMD) for fast modulation. However, this system has the following limitations. First, the reported single-shot wavefront measurement method does not work when our goal is to focus light inside, instead of through, scattering media. Second, the DMD performed binary amplitude modulation, which resulted in a lower focusing contrast compared with that of phase modulations. Third, the optical fluence threshold causing DMDs to malfunction under pulsed laser illumination is lower than that of liquid crystal based SLMs, and the system alignment is significantly complicated by the oblique reflection angle of the DMD. Here, we developed a simple but high-speed DOPC system using a ferroelectric liquid crystal based SLM (512 × 512 pixels), and focused light through three diffusers within 4.7 ms. Using focused-ultrasound-guided DOPC along with a double exposure scheme, we focused light inside a scattering medium containing two diffusers within 7.7 ms, thus achieving the fastest digital time-reversed ultrasonically encoded (TRUE) optical focusing to date.

  19. Automatic focusing in digital holography and its application to stretched holograms.

    PubMed

    Memmolo, P; Distante, C; Paturzo, M; Finizio, A; Ferraro, P; Javidi, B

    2011-05-15

    The searching and recovering of the correct reconstruction distance in digital holography (DH) can be a cumbersome and subjective procedure. Here we report on an algorithm for automatically estimating the in-focus image and recovering the correct reconstruction distance for speckle holograms. We have tested the approach in determining the reconstruction distances of stretched digital holograms. Stretching a hologram with a variable elongation parameter makes it possible to change the in-focus distance of the reconstructed image. In this way, the proposed algorithm can be verified at different distances by dispensing the recording of different holograms. Experimental results are shown with the aim of demonstrating the usefulness of the proposed method, and a comparative analysis has been performed with respect to other existing algorithms developed for DH. © 2011 Optical Society of America

  20. An image based auto-focusing algorithm for digital fundus photography.

    PubMed

    Moscaritolo, Michele; Jampel, Henry; Knezevich, Frederick; Zeimer, Ran

    2009-11-01

    In fundus photography, the task of fine focusing the image is demanding and lack of focus is quite often the cause of suboptimal photographs. The introduction of digital cameras has provided an opportunity to automate the task of focusing. We have developed a software algorithm capable of identifying best focus. The auto-focus (AF) method is based on an algorithm we developed to assess the sharpness of an image. The AF algorithm was tested in the prototype of a semi-automated nonmydriatic fundus camera designed to screen in the primary care environment for major eye diseases. A series of images was acquired in volunteers while focusing the camera on the fundus. The image with the best focus was determined by the AF algorithm and compared to the assessment of two masked readers. A set of fundus images was obtained in 26 eyes of 20 normal subjects and 42 eyes of 28 glaucoma patients. The 95% limits of agreement between the readers and the AF algorithm were -2.56 to 2.93 and -3.7 to 3.84 diopter and the bias was 0.09 and 0.71 diopter, for the two readers respectively. On average, the readers agreed with the AF algorithm on the best correction within less than 3/4 diopter. The intraobserver repeatability was 0.94 and 1.87 diopter, for the two readers respectively, indicating that the limit of agreement with the AF algorithm was determined predominantly by the repeatability of each reader. An auto-focus algorithm for digital fundus photography can identify the best focus reliably and objectively. It may improve the quality of fundus images by easing the task of the photographer.

  1. Enhancing depth of focus in tilted microfluidics channels by digital holography.

    PubMed

    Matrecano, Marcella; Paturzo, Melania; Finizio, Andrea; Ferraro, Pietro

    2013-03-15

    In this Letter we propose a method to enhance the limited depth of field (DOF) in optical imaging systems, through digital holography. The proposed approach is based on the introduction of a cubic phase plate into the diffraction integral, analogous to what occurs in white-light imaging systems. By this approach we show that it is possible to improve the DOF and to recover the extended focus image of a tilted object in a single reconstruction step. Moreover, we demonstrate the possibility of obtaining well-focused biological cells flowing into a tilted microfluidic channel.

  2. Focusing light inside dynamic scattering media with millisecond digital optical phase conjugation

    PubMed Central

    Liu, Yan; Ma, Cheng; Shen, Yuecheng; Shi, Junhui; Wang, Lihong V.

    2017-01-01

    Wavefront shaping based on digital optical phase conjugation (DOPC) focuses light through or inside scattering media, but the low speed of DOPC prevents it from being applied to thick, living biological tissue. Although a fast DOPC approach was recently developed, the reported single-shot wavefront measurement method does not work when the goal is to focus light inside, instead of through, highly scattering media. Here, using a ferroelectric liquid crystal based spatial light modulator, we develop a simpler but faster DOPC system that focuses light not only through, but also inside scattering media. By controlling 2.6 × 105 optical degrees of freedom, our system focused light through 3 mm thick moving chicken tissue, with a system latency of 3.0 ms. Using ultrasound-guided DOPC, along with a binary wavefront measurement method, our system focused light inside a scattering medium comprising moving tissue with a latency of 6.0 ms, which is one to two orders of magnitude shorter than those of previous digital wavefront shaping systems. Since the demonstrated speed approaches tissue decorrelation rates, this work is an important step toward in vivo deep-tissue non-invasive optical imaging, manipulation, and therapy. PMID:28815194

  3. Focusing light inside dynamic scattering media with millisecond digital optical phase conjugation.

    PubMed

    Liu, Yan; Ma, Cheng; Shen, Yuecheng; Shi, Junhui; Wang, Lihong V

    2017-02-01

    Wavefront shaping based on digital optical phase conjugation (DOPC) focuses light through or inside scattering media, but the low speed of DOPC prevents it from being applied to thick, living biological tissue. Although a fast DOPC approach was recently developed, the reported single-shot wavefront measurement method does not work when the goal is to focus light inside, instead of through, highly scattering media. Here, using a ferroelectric liquid crystal based spatial light modulator, we develop a simpler but faster DOPC system that focuses light not only through, but also inside scattering media. By controlling 2.6 × 10(5) optical degrees of freedom, our system focused light through 3 mm thick moving chicken tissue, with a system latency of 3.0 ms. Using ultrasound-guided DOPC, along with a binary wavefront measurement method, our system focused light inside a scattering medium comprising moving tissue with a latency of 6.0 ms, which is one to two orders of magnitude shorter than those of previous digital wavefront shaping systems. Since the demonstrated speed approaches tissue decorrelation rates, this work is an important step toward in vivo deep-tissue non-invasive optical imaging, manipulation, and therapy.

  4. Pattern based 3D image Steganography

    NASA Astrophysics Data System (ADS)

    Thiyagarajan, P.; Natarajan, V.; Aghila, G.; Prasanna Venkatesan, V.; Anitha, R.

    2013-03-01

    This paper proposes a new high capacity Steganographic scheme using 3D geometric models. The novel algorithm re-triangulates a part of a triangle mesh and embeds the secret information into newly added position of triangle meshes. Up to nine bits of secret data can be embedded into vertices of a triangle without causing any changes in the visual quality and the geometric properties of the cover image. Experimental results show that the proposed algorithm is secure, with high capacity and low distortion rate. Our algorithm also resists against uniform affine transformations such as cropping, rotation and scaling. Also, the performance of the method is compared with other existing 3D Steganography algorithms. [Figure not available: see fulltext.

  5. Hybrid distortion function for JPEG steganography

    NASA Astrophysics Data System (ADS)

    Wang, Zichi; Zhang, Xinpeng; Yin, Zhaoxia

    2016-09-01

    A hybrid distortion function for JPEG steganography exploiting block fluctuation and quantization steps is proposed. To resist multidomain steganalysis, both spatial domain and discrete cosine transformation (DCT) domain are involved in the proposed distortion function. In spatial domain, a distortion value is allotted for each 8×8 block according to block fluctuation. In DCT domain, quantization steps are employed to allot distortion values for DCT coefficients in a block. The two elements, block distortion and quantization steps, are combined together to measure the embedding risk. By employing the syndrome trellis coding to embed secret data, the embedding changes are constrained in complex regions, where modifications are hard to be detected. When compared to current state-of-the-art steganographic methods for JPEG images, the proposed method presents less detectable artifacts.

  6. State-of-the-art soft computing techniques in image steganography domain

    NASA Astrophysics Data System (ADS)

    Hussain, Hanizan Shaker; Din, Roshidi; Samad, Hafiza Abdul; Yaacub, Mohd Hanafizah; Murad, Roslinda; Rukhiyah, A.; Sabdri, Noor Maizatulshima

    2016-08-01

    This paper reviews major works of soft computing (SC) techniques in image steganography and watermarking in the last ten years, focusing on three main SC techniques, which are neural network, genetic algorithm, and fuzzy logic. The findings suggests that all these works applied SC techniques either during pre-processing, embedding or extracting stages or more than one of these stages. Therefore, the presence of SC techniques with their diverse approaches and strengths can help researchers in future work to attain excellent quality of image information hiding that comprises both imperceptibility and robustness.

  7. An optimized ultrasound digital beamformer with dynamic focusing implemented on FPGA.

    PubMed

    Almekkawy, Mohamed; Xu, Jingwei; Chirala, Mohan

    2014-01-01

    We present a resource-optimized dynamic digital beamformer for an ultrasound system based on a field-programmable gate array (FPGA). A comprehensive 64-channel receive beamformer with full dynamic focusing is embedded in the Altera Arria V FPGA chip. To improve spatial and contrast resolution, full dynamic beamforming is implemented by a novel method with resource optimization. This was conceived using the implementation of the delay summation through a bulk (coarse) delay and fractional (fine) delay. The sampling frequency is 40 MHz and the beamformer includes a 240 MHz polyphase filter that enhances the temporal resolution of the system while relaxing the Analog-to-Digital converter (ADC) bandwidth requirement. The results indicate that our 64-channel dynamic beamformer architecture is amenable for a low power FPGA-based implementation in a portable ultrasound system.

  8. Single-shot incoherent digital holography using a dual-focusing lens with diffraction gratings.

    PubMed

    Quan, Xiangyu; Matoba, Osamu; Awatsuji, Yasuhiro

    2017-02-01

    A new optical configuration of incoherent digital holography is presented to improve the quality of reconstructed images when the random polarization state of incoherent light is used. The proposed system improves the signal-to-noise ratio of the holograms by suppressing the unmodulated terms of a spatial light modulator. To generate the self-interference of a quasi-incoherent point-like source, we use a dual-focusing lens with diffraction gratings. The preliminary experimental results confirm the validity of the proposed method by reconstructing two point-like sources generated by a LED light source. When the pixel pitch of the phase-mode SLM is small enough, the off-axis hologram can be generated. The single-shot recording of the incoherent digital holography is expected.

  9. Depth of focus in digital holography using spatial partially coherent light

    NASA Astrophysics Data System (ADS)

    Binz, Kristen; Yu, Xiao; Clark, David; Kim, Myung K.

    2012-02-01

    Digital holography is a powerful, but young, imaging technology that has a vast array of applications; its strength lies in the ability to numerically focus on any plane within a sample from a single hologram and to use both amplitude and phase information from the intensity field to reconstruct the sample's 3D characteristics on a computer. The quality of many holograms, however, is compromised by speckle and other interference noise associated with the high-coherence lasers often used to illuminate the sample. Speckle noise may be diminished by lowering the coherence length of the source. In our experiments, partially coherent light was created by directing a laser beam through a rotating ground glass. We aimed to discern whether the coherence of the source could be systematically altered by changing the position of the ground glass within the focused laser beam. We anticipated that altering the coherence length would also systematically change the depth of focus. Initial results support our hypotheses.

  10. Digital focusing of OCT images based on scalar diffraction theory and information entropy

    PubMed Central

    Liu, Guozhong; Zhi, Zhongwei; Wang, Ruikang K.

    2012-01-01

    This paper describes a digital method that is capable of automatically focusing optical coherence tomography (OCT) en face images without prior knowledge of the point spread function of the imaging system. The method utilizes a scalar diffraction model to simulate wave propagation from out-of-focus scatter to the focal plane, from which the propagation distance between the out-of-focus plane and the focal plane is determined automatically via an image-definition-evaluation criterion based on information entropy theory. By use of the proposed approach, we demonstrate that the lateral resolution close to that at the focal plane can be recovered from the imaging planes outside the depth of field region with minimal loss of resolution. Fresh onion tissues and mouse fat tissues are used in the experiments to show the performance of the proposed method. PMID:23162717

  11. Quantum Image Steganography and Steganalysis Based On LSQu-Blocks Image Information Concealing Algorithm

    NASA Astrophysics Data System (ADS)

    A. AL-Salhi, Yahya E.; Lu, Songfeng

    2016-08-01

    Quantum steganography can solve some problems that are considered inefficient in image information concealing. It researches on Quantum image information concealing to have been widely exploited in recent years. Quantum image information concealing can be categorized into quantum image digital blocking, quantum image stereography, anonymity and other branches. Least significant bit (LSB) information concealing plays vital roles in the classical world because many image information concealing algorithms are designed based on it. Firstly, based on the novel enhanced quantum representation (NEQR), image uniform blocks clustering around the concrete the least significant Qu-block (LSQB) information concealing algorithm for quantum image steganography is presented. Secondly, a clustering algorithm is proposed to optimize the concealment of important data. Finally, we used Con-Steg algorithm to conceal the clustered image blocks. Information concealing located on the Fourier domain of an image can achieve the security of image information, thus we further discuss the Fourier domain LSQu-block information concealing algorithm for quantum image based on Quantum Fourier Transforms. In our algorithms, the corresponding unitary Transformations are designed to realize the aim of concealing the secret information to the least significant Qu-block representing color of the quantum cover image. Finally, the procedures of extracting the secret information are illustrated. Quantum image LSQu-block image information concealing algorithm can be applied in many fields according to different needs.

  12. Sensitive Patient Data Hiding using a ROI Reversible Steganography Scheme for DICOM Images.

    PubMed

    Mantos, Petros L K; Maglogiannis, Ilias

    2016-06-01

    The exchange of medical images over the Internet has evoked significant interest over the past few years due to the introduction of web and cloud based medical information systems. The protection of sensitive data has always been a key indicator in the performance of such systems. In this context, this work presents an algorithm developed for Digital Imaging and Communications in Medicine (DICOM) medical images, which applies secret-sharing steganography methods for ensuring the integrity of sensitive patient data as well as the important parts of the image. In the proposed algorithm, images are divided into two parts: the region of interest (ROI) and the region of non interest (RONI). Patient data and integrity hashes are positioned inside the ROI while the information (map) needed to recover the ROI before insertion is positioned in the RONI. Security of the extraction process is assured through the use of cryptography. The experimental results prove that the original (cover) images and the stego images provide an excellent visual equality result in terms of PSNR. Furthermore, they prove that the proposed scheme can be efficiently used as a steganography scheme in DICOM images with limited smooth areas.

  13. SFM Technique and Focus Stacking for Digital Documentation of Archaeological Artifacts

    NASA Astrophysics Data System (ADS)

    Clini, P.; Frapiccini, N.; Mengoni, M.; Nespeca, R.; Ruggeri, L.

    2016-06-01

    Digital documentation and high-quality 3D representation are always more requested in many disciplines and areas due to the large amount of technologies and data available for fast, detailed and quick documentation. This work aims to investigate the area of medium and small sized artefacts and presents a fast and low cost acquisition system that guarantees the creation of 3D models with an high level of detail, making the digitalization of cultural heritage a simply and fast procedure. The 3D models of the artefacts are created with the photogrammetric technique Structure From Motion that makes it possible to obtain, in addition to three-dimensional models, high-definition images for a deepened study and understanding of the artefacts. For the survey of small objects (only few centimetres) it is used a macro lens and the focus stacking, a photographic technique that consists in capturing a stack of images at different focus planes for each camera pose so that is possible to obtain a final image with a higher depth of field. The acquisition with focus stacking technique has been finally validated with an acquisition with laser triangulation scanner Minolta that demonstrates the validity compatible with the allowable error in relation to the expected precision.

  14. Fast extended focused imaging in digital holography using a graphics processing unit.

    PubMed

    Wang, Le; Zhao, Jianlin; Di, Jianglei; Jiang, Hongzhen

    2011-05-01

    We present a simple and effective method for reconstructing extended focused images in digital holography using a graphics processing unit (GPU). The Fresnel transform method is simplified by an algorithm named fast Fourier transform pruning with frequency shift. Then the pixel size consistency problem is solved by coordinate transformation and combining the subpixel resampling and the fast Fourier transform pruning with frequency shift. With the assistance of the GPU, we implemented an improved parallel version of this method, which obtained about a 300-500-fold speedup compared with central processing unit codes.

  15. Real-time, auto-focusing digital holographic microscope using graphics processors

    NASA Astrophysics Data System (ADS)

    Doğar, Mert; İlhan, Hazar A.; Özcan, Meriç

    2013-08-01

    The most significant advantage of holographic imaging is that one does not need to do focusing alignment for the scene or objects while capturing their images. To focus on a particular object recorded in a digital hologram, a post-processing on the recorded image must be performed. This post-processing, so called the reconstruction, is essentially the calculation of wave propagation in free space. If the object's optical distance to the recording plane is not known a priori, focusing methods are used to estimate this distance. However, these operations can be quite time consuming as the hologram sizes increase. When there is a time constraint on these procedures and the image resolution is high, traditional central processing units (CPUs) can no longer satisfy the desired reconstruction speeds. Then, especially for real-time operations, additional hardware accelerators are required for reconstructing high resolution holograms. To this extend, today's commercial graphic cards offer a viable solution, as the holograms can be reconstructed tens of times faster with a graphics processing unit than with the state-of-the-art CPUs. Here we present an auto-focusing megapixel-resolution digital holographic microscope (DHM) that uses a graphics processing unit (GPU) as the calculation engine. The computational power of the GPU allows the DHM to work in real-time such that the reconstruction distance is estimated unsupervised, and the post-processing of the holograms are made completely transparent to the user. We compare DHM with GPU and CPU and present experimental results showing a maximum of 70 focused reconstructions per second (frps) with 1024 × 1024 pixel holograms.

  16. Real-time, auto-focusing digital holographic microscope using graphics processors.

    PubMed

    Doğar, Mert; İlhan, Hazar A; Özcan, Meriç

    2013-08-01

    The most significant advantage of holographic imaging is that one does not need to do focusing alignment for the scene or objects while capturing their images. To focus on a particular object recorded in a digital hologram, a post-processing on the recorded image must be performed. This post-processing, so called the reconstruction, is essentially the calculation of wave propagation in free space. If the object's optical distance to the recording plane is not known a priori, focusing methods are used to estimate this distance. However, these operations can be quite time consuming as the hologram sizes increase. When there is a time constraint on these procedures and the image resolution is high, traditional central processing units (CPUs) can no longer satisfy the desired reconstruction speeds. Then, especially for real-time operations, additional hardware accelerators are required for reconstructing high resolution holograms. To this extend, today's commercial graphic cards offer a viable solution, as the holograms can be reconstructed tens of times faster with a graphics processing unit than with the state-of-the-art CPUs. Here we present an auto-focusing megapixel-resolution digital holographic microscope (DHM) that uses a graphics processing unit (GPU) as the calculation engine. The computational power of the GPU allows the DHM to work in real-time such that the reconstruction distance is estimated unsupervised, and the post-processing of the holograms are made completely transparent to the user. We compare DHM with GPU and CPU and present experimental results showing a maximum of 70 focused reconstructions per second (frps) with 1024 × 1024 pixel holograms.

  17. Quantitative analysis of 3D hydrodynamic focusing of microparticles by digital holographic microscopy

    NASA Astrophysics Data System (ADS)

    Perfetti, C.; Iorio, C. S.; El Mallahi, A.; Dubois, F.

    2014-02-01

    In the field of life sciences, the monitoring of biological samples has become a great concern to control the ecosystem evolution. However, their characterization is often time-consuming because the typical size of the organisms/particles of interest is several orders of magnitude smaller than the size of the sample under observation. Optical visualization systems require, then, high magnifications that severely limit the depth of focus and consequently decrease the sampling rate. To tackle this issue, the most straightforward technique consists in focusing the samples to fit the observation field of view by means of so-called "sheath flows". This expedient allows for increasing the overall flow rate, inversely related to the sampling time. In this article, a cost-effective 3D hydro-focusing device is presented. Several flow rates have been tested for both sample and sheath flows, and a thorough investigation of the shape of the focused streamlines conducted in order to validate the prototype design. The 3D position of the sampled micro-objects has been located by digital holographic microscopy and their distribution in cross-sections downstream the injection nozzle compared to numerical simulations. A maximum constriction—ratio between the part of the cross-sections where particles are present with and without focusing sheath flow—of 4.4 % has been observed confirming the potentiality of the technique. Also, a successful match between experiment and numerical simulation has been noted.

  18. Focusing light through scattering media by full-polarization digital optical phase conjugation

    PubMed Central

    Shen, Yuecheng; Liu, Yan; Ma, Cheng; Wang, Lihong V.

    2016-01-01

    Digital optical phase conjugation (DOPC) is an emerging technique for focusing light through or within scattering media such as biological tissue. Since DOPC systems are based on time reversal, they benefit from collecting as much information about the scattered light as possible. However, existing DOPC techniques record and subsequently phase-conjugate the scattered light in only a single polarization state, limited by the operating principle of spatial light modulators. Here, we develop the first full-polarization DOPC system which records and phase-conjugates scattered light along two orthogonal polarizations. When focusing light through thick scattering media, such as 2 mm and 4 mm thick chicken breast tissue, our full-polarization DOPC system on average doubles the focal peak-to-background ratio achieved by single-polarization DOPC systems and improves the phase conjugation fidelity. PMID:26977651

  19. Focusing light through scattering media by full-polarization digital optical phase conjugation.

    PubMed

    Shen, Yuecheng; Liu, Yan; Ma, Cheng; Wang, Lihong V

    2016-03-15

    Digital optical phase conjugation (DOPC) is an emerging technique for focusing light through or within scattering media such as biological tissue. Since DOPC systems are based on time reversal, they benefit from collecting as much information about the scattered light as possible. However, existing DOPC techniques record and subsequently phase-conjugate the scattered light in only a single-polarization state, limited by the operating principle of spatial light modulators. Here, we develop the first, to the best of our knowledge, full-polarization DOPC system that records and phase-conjugates scattered light along two orthogonal polarizations. When focusing light through thick scattering media, such as 2 mm and 4 mm-thick chicken breast tissue, our full-polarization DOPC system on average doubles the focal peak-to-background ratio achieved by single-polarization DOPC systems and improves the phase-conjugation fidelity.

  20. Temporal focusing-based multiphoton excitation microscopy via digital micromirror device.

    PubMed

    Yih, Jenq-Nan; Hu, Yvonne Yuling; Sie, Yong Da; Cheng, Li-Chung; Lien, Chi-Hsiang; Chen, Shean-Jen

    2014-06-01

    This Letter presents an enhanced temporal focusing-based multiphoton excitation (MPE) microscope in which the conventional diffraction grating is replaced by a digital micromirror device (DMD). Experimental results from imaging a thin fluorescence film show that the 4.0 μm axial resolution of the microscope is comparable with that of a setup incorporating a 600  lines/mm grating; hence, the optical sectioning ability of the proposed setup is demonstrated. Similar to a grating, the DMD diffracts illuminating light frequencies for temporal focusing; additionally, it generates arbitrary patterns. Since the DMD is placed on the image-conjugate plane of the objective lens' focal plane, the MPE pattern can be projected on the focal plane precisely.

  1. Amplifier Noise Based Optical Steganography with Coherent Detection

    NASA Astrophysics Data System (ADS)

    Wu, Ben; Chang, Matthew P.; Caldwell, Naomi R.; Caldwell, Myles E.; Prucnal, Paul R.

    2014-12-01

    We summarize the principle and experimental setup of optical steganography based on amplified spontaneous emission (ASE) noise. Using ASE noise as the signal carrier, optical steganography effectively hides a stealth channel in both the time domain and the frequency domain. Coherent detection is used at the receiver of the stealth channel. Because ASE noise has short coherence length and random phase, it only interferes with itself within a very short range. Coherent detection requires the stealth transmitter and stealth receiver to precisely match the optical delay,which generates a large key space for the stealth channel. Several methods to further improve optical steganography, signal to noise ratio, compatibility with the public channel, and applications of the stealth channel are also summarized in this review paper.

  2. Large payload quantum steganography based on cavity quantum electrodynamics

    NASA Astrophysics Data System (ADS)

    Ye, Tian-Yu; Jiang, Li-Zhen

    2013-04-01

    A large payload quantum steganography protocol based on cavity quantum electrodynamics (QED) is presented in this paper, which effectively uses the evolutionary law of atoms in cavity QED. The protocol builds up a hidden channel to transmit secret messages using entanglement swapping between one GHZ state and one Bell state in cavity QED together with the Hadamard operation. The quantum steganography protocol is insensitive to cavity decay and the thermal field. The capacity, imperceptibility and security against eavesdropping are analyzed in detail in the protocol. It turns out that the protocol not only has good imperceptibility but also possesses good security against eavesdropping. In addition, its capacity for a hidden channel achieves five bits, larger than most of the previous quantum steganography protocols.

  3. Automatic focus determination through cosine and modified cosine score in digital holography

    NASA Astrophysics Data System (ADS)

    He, Aga; Xiao, Wen; Pan, Feng

    2017-03-01

    An automatic focus determination method in digital holography that utilizes the cosine score (CS) of the inner angle between the vectors that result from adjacent axial reconstructed amplitude images is proposed. This method is based on the fact that the optical field near the focus plane contains more regular features of an object than the defocused region. Further, a modified CS (MCS) autofocusing method is proposed to extend the application range and improve the performance of the proposed method. First, a low-pass filter is designed for the object term holograms in the frequency domain. Second, the standardized Z-scores method is applied along the axis to the amplitude images reconstructed from the filtered hologram. Finally, the MCS of the standardized amplitude images is calculated by an improved cosine-like formula. Next, the focus plane is found at the minimum MCS for different types of objects. This method enables accurate focus determination for all types of objects, as well as for the image region with a slow change or small size, which offers time savings and the precise autofocusing of objects with large longitudinal volumes. The simulations and experimental results on a United States Air Force resolution chart and living cells are presented, illustrating the efficiency and potential of the methods.

  4. Continuous scanning of a time-reversed ultrasonically encoded optical focus by reflection-mode digital phase conjugation

    PubMed Central

    Suzuki, Yuta; Tay, Jian Wei; Yang, Qiang; Wang, Lihong V.

    2014-01-01

    Time-reversed ultrasonically encoded (TRUE) optical focusing in turbid media was previously implemented using both analog and digital phase conjugation. The digital approach, in addition to its large energy gain, can improve the focal intensity and resolution by iterative focusing. However, performing iterative focusing at each focal position can be time-consuming. Here, we show that by gradually moving the focal position, the TRUE focal intensity is improved, as in iterative focusing at a fixed position, and can be continuously scanned to image fluorescent targets in a shorter time. Also, our setup is the first demonstration of TRUE focusing using a digital phase conjugate mirror in reflection mode, which is more suitable for practical applications. PMID:24978506

  5. Quantum steganography with noisy quantum channels

    SciTech Connect

    Shaw, Bilal A.; Brun, Todd A.

    2011-02-15

    Steganography is the technique of hiding secret information by embedding it in a seemingly ''innocent'' message. We present protocols for hiding quantum information by disguising it as noise in a codeword of a quantum error-correcting code. The sender (Alice) swaps quantum information into the codeword and applies a random choice of unitary operation, drawing on a secret random key she shares with the receiver (Bob). Using the key, Bob can retrieve the information, but an eavesdropper (Eve) with the power to monitor the channel, but without the secret key, cannot distinguish the message from channel noise. We consider two types of protocols: one in which the hidden quantum information is stored locally in the codeword, and another in which it is embedded in the space of error syndromes. We analyze how difficult it is for Eve to detect the presence of secret messages, and estimate rates of steganographic communication and secret key consumption for specific protocols and examples of error channels. We consider both the case where there is no actual noise in the channel (so that all errors in the codeword result from the deliberate actions of Alice), and the case where the channel is noisy and not controlled by Alice and Bob.

  6. Quantum steganography with noisy quantum channels

    NASA Astrophysics Data System (ADS)

    Shaw, Bilal A.; Brun, Todd A.

    2011-02-01

    Steganography is the technique of hiding secret information by embedding it in a seemingly “innocent” message. We present protocols for hiding quantum information by disguising it as noise in a codeword of a quantum error-correcting code. The sender (Alice) swaps quantum information into the codeword and applies a random choice of unitary operation, drawing on a secret random key she shares with the receiver (Bob). Using the key, Bob can retrieve the information, but an eavesdropper (Eve) with the power to monitor the channel, but without the secret key, cannot distinguish the message from channel noise. We consider two types of protocols: one in which the hidden quantum information is stored locally in the codeword, and another in which it is embedded in the space of error syndromes. We analyze how difficult it is for Eve to detect the presence of secret messages, and estimate rates of steganographic communication and secret key consumption for specific protocols and examples of error channels. We consider both the case where there is no actual noise in the channel (so that all errors in the codeword result from the deliberate actions of Alice), and the case where the channel is noisy and not controlled by Alice and Bob.

  7. Digitally focused array ultrasonic testing technique for carbon fiber composite structures

    NASA Astrophysics Data System (ADS)

    Salchak, Y.; Zhvyrblya, V.; Sednev, D.; Lider, A.

    2016-06-01

    Composite fiber reinforced polymers are highly promising structures. At present, they are widely used in different areas such as aeronautics and nuclear industries. There is a great number of advantages of composite structures such as design flexibility, low cost per cubic inch, resistance to corrosion, lower material costs, lighter weight and improved productivity. However, composites degradation may be caused by different mechanisms such as overload, impact, overheating, creep and fatigue. Comparing to inspection of other materials some unique consideration is required for testing and analysis. Ultrasound testing is the most common method for inspection of composite structures. Digitally Focused Array Technology is considered as novel approach which enables fast and effective quantitative automatic testing. In this study new methodology of quality assurance of composite structure components based on DFA is performed.

  8. Nonlinear structured-illumination enhanced temporal focusing multiphoton excitation microscopy with a digital micromirror device

    PubMed Central

    Cheng, Li-Chung; Lien, Chi-Hsiang; Da Sie, Yong; Hu, Yvonne Yuling; Lin, Chun-Yu; Chien, Fan-Ching; Xu, Chris; Dong, Chen Yuan; Chen, Shean-Jen

    2014-01-01

    In this study, the light diffraction of temporal focusing multiphoton excitation microscopy (TFMPEM) and the excitation patterning of nonlinear structured-illumination microscopy (NSIM) can be simultaneously and accurately implemented via a single high-resolution digital micromirror device. The lateral and axial spatial resolutions of the TFMPEM are remarkably improved through the second-order NSIM and projected structured light, respectively. The experimental results demonstrate that the lateral and axial resolutions are enhanced from 397 nm to 168 nm (2.4-fold) and from 2.33 μm to 1.22 μm (1.9-fold), respectively, in full width at the half maximum. Furthermore, a three-dimensionally rendered image of a cytoskeleton cell featuring ~25 nm microtubules is improved, with other microtubules at a distance near the lateral resolution of 168 nm also able to be distinguished. PMID:25136483

  9. Nonlinear structured-illumination enhanced temporal focusing multiphoton excitation microscopy with a digital micromirror device.

    PubMed

    Cheng, Li-Chung; Lien, Chi-Hsiang; Da Sie, Yong; Hu, Yvonne Yuling; Lin, Chun-Yu; Chien, Fan-Ching; Xu, Chris; Dong, Chen Yuan; Chen, Shean-Jen

    2014-08-01

    In this study, the light diffraction of temporal focusing multiphoton excitation microscopy (TFMPEM) and the excitation patterning of nonlinear structured-illumination microscopy (NSIM) can be simultaneously and accurately implemented via a single high-resolution digital micromirror device. The lateral and axial spatial resolutions of the TFMPEM are remarkably improved through the second-order NSIM and projected structured light, respectively. The experimental results demonstrate that the lateral and axial resolutions are enhanced from 397 nm to 168 nm (2.4-fold) and from 2.33 μm to 1.22 μm (1.9-fold), respectively, in full width at the half maximum. Furthermore, a three-dimensionally rendered image of a cytoskeleton cell featuring ~25 nm microtubules is improved, with other microtubules at a distance near the lateral resolution of 168 nm also able to be distinguished.

  10. Quantum steganography and quantum error-correction

    NASA Astrophysics Data System (ADS)

    Shaw, Bilal A.

    corrects an arbitrary error on the receiver's half of the ebit as well. We prove that this code is the smallest code with a CSS structure that uses only one ebit and corrects an arbitrary single-qubit error on the sender's side. We discuss the advantages and disadvantages for each of the two codes. In the second half of this thesis we explore the yet uncharted and relatively undiscovered area of quantum steganography. Steganography is the process of hiding secret information by embedding it in an "innocent" message. We present protocols for hiding quantum information in a codeword of a quantum error-correcting code passing through a channel. Using either a shared classical secret key or shared entanglement Alice disguises her information as errors in the channel. Bob can retrieve the hidden information, but an eavesdropper (Eve) with the power to monitor the channel, but without the secret key, cannot distinguish the message from channel noise. We analyze how difficult it is for Eve to detect the presence of secret messages, and estimate rates of steganographic communication and secret key consumption for certain protocols. We also provide an example of how Alice hides quantum information in the perfect code when the underlying channel between Bob and her is the depolarizing channel. Using this scheme Alice can hide up to four stego-qubits.

  11. Understanding Americans: a focus on the transition from traditional to digital soil mapping

    NASA Astrophysics Data System (ADS)

    Miller, Bradley; Brevik, Eric; Fenton, Thomas; Homburg, Jeffrey

    2017-04-01

    The USA has had arguably the strongest and certainly the most extensive soil mapping program in the world. Yet many of the developments in digital soil mapping (DSM) occurred outside the USA from the late 1970s through the 1990s. This presentation attempts to explore why the USA has differed from many of the international trends in DSM. Much of the work on DSM in the USA has focused on the extraction of expert knowledge to formulate spatial prediction models for soil classes. Although DSM approaches are quickly evolving in American academia, the adoption of DSM methods have been slow and cautious in the National Cooperative Soil Survey (NCSS) mapping efforts. The great majority of soil maps available in the USA are digitized maps that were originally produced by traditional methods with some manual updating. Work attempting to implement more DSM techniques in the NCSS has been underway in select areas of California, Minnesota, Utah, Texas, and Wyoming. However, the only official NCSS product considered to be fully DSM-based thus far is in Essex County, Vermont. It is noteworthy that the Essex County Soil Survey map is still heavily dependent upon expert knowledge. Why the attachment to expert knowledge as opposed to data mining techniques for identifying new patterns in soil variability? We argue that this is because of the exceptional soil maps that were produced for the USA using traditional methods. Despite the limitations of traditional methods, it is difficult to improve upon the amount of field investigation and verification done to create the existing NCSS maps. Along with that comes a deep attachment to soil series as map units and all the data associated with those soil series.

  12. A digital auto-focusing method based on CCD mosaicing for aerial camera

    NASA Astrophysics Data System (ADS)

    Wang, Yan; Liu, Yang; Chen, Xing-lin

    2011-08-01

    A novel focusing method of the remote sensing camera is proposed in this paper. To evaluate the quality of the image obtained by the aerial camera, an assessing function was constructed based on the Wavelet transform. And the characteristic of the CCD mosaicing structure was taken use to solve the problem that the evaluating values can not be compared for the images captured by the aerial camera are variable. On the basis of the wavelet evaluating function, the quality of the image was assessed. Then the CCD mosaicing structure was utilized to perform auto-focusing process, a simulation was made to validate the novel method in the end. There are three major contributions in the paper. Firstly, the weights of the wavelet coefficients in the evaluating function were set according to the characteristic of the Wavelet transform and human vision system (HVS). By those, the assessing result is close to our subjective feel and insensitive to noise. Secondly, in order to make the function adaptive to images with different high-frequency components, the properties of the wavelet basis were analyzed. By comparing the evaluating effect of different images, the wavelet basis with the best effect is symlet2 and the level of decomposing is three. Finally, by making use of the CCD mosaicing structure, the problem that auto-focusing of the aerial camera can't use digital images processing directly was solved, and the region with the highest frequency component was chosen as the evaluating area so as to improve the sensitivity of the function.

  13. A Digital Image Steganography using Sierpinski Gasket Fractal and PLSB

    NASA Astrophysics Data System (ADS)

    Rupa, Ch.

    2013-09-01

    Information attacks are caused due to the weaknesses in the information security. These attacks affect the non-repudiation and integrity of the security services. In this paper, a novel security approach that can defend the message from information attacks is proposed. In this new approach the original message is encrypted by Fractal Sierpinski Gasket (FSG) cryptographic algorithm, that result is hidden into an image using penultimate and least significant bit (PLSB) embedding method. This method makes the security more robust than conventional approach. Important properties of fractals are sensitivity and self similarity. These can be exploited to produce avalanche effect. Stegoanalysis of the proposed method shows that it is resistant to various attacks and stronger than the existed steganographic approaches.

  14. A Framework for Automated Digital Forensic Reporting

    DTIC Science & Technology

    2009-03-01

    use, the report should make a note that private browsing or history erasing may have been conducted. Media reporting (still image, audio and video...provide a wealth of revealing information when examining a case. In this context, digital media is defined as digital photos, video, and audio . Digital...can then be parsed with a regular expression and mapped to the PyFlag relevant fields for inclusion in the database. For example, a steganography

  15. Government Information Focus. The Digital Divide: Understanding and Addressing the Challenge.

    ERIC Educational Resources Information Center

    Latimer, Christopher P.

    This report discusses the challenges of the Digital Divide. Part I examines the issues concerning access as it relates to schools, communities, free Internet service providers, and broadband. Part II defines technological literacy and how it pertains to the Digital Divide debate. Part III examines those who are affected by the divide and…

  16. A Practical Guide for Building a Digital Library: User-Focused Collection

    ERIC Educational Resources Information Center

    Zhu, Qin; Guevara, Sophia

    2009-01-01

    With changing user expectations, many libraries are moving toward digital content. Accessible from anywhere at any time, digital content provides users with efficient, on-demand information experiences. Accordingly, librarians are presented with challenges and opportunities to build, manage, and implement outreach strategies that promote their…

  17. A Practical Guide for Building a Digital Library: User-Focused Collection

    ERIC Educational Resources Information Center

    Zhu, Qin; Guevara, Sophia

    2009-01-01

    With changing user expectations, many libraries are moving toward digital content. Accessible from anywhere at any time, digital content provides users with efficient, on-demand information experiences. Accordingly, librarians are presented with challenges and opportunities to build, manage, and implement outreach strategies that promote their…

  18. Focus and perspective adaptive digital surgical microscope: optomechanical design and experimental implementation

    NASA Astrophysics Data System (ADS)

    Claus, Daniel; Reichert, Carsten; Herkommer, Alois

    2017-05-01

    This paper relates to the improvement of conventional surgical stereo microscopy via the application of digital recording devices and adaptive optics. The research is aimed at improving the working conditions of the surgeon during the operation, such that free head movement is possible. The depth clues known from conventional stereo microscopy in interaction with the human eye's functionality, such as convergence, disparity, angular elevation, parallax, and accommodation, are implemented in a digital recording system via adaptive optomechanical components. Two laterally moving pupil apertures have been used mimicking the digital implementation of the eye's vergence and head motion. The natural eye's accommodation is mimicked via the application of a tunable lens. Additionally, another system has been built, which enables tracking the surgeon's eye pupil through a digital displaying stereoscopic microscope to supply the necessary information for steering the recording system. The optomechanical design and experimental results for both systems, digital recording stereoscopic microscope and pupil tracking system, are shown.

  19. An efficient steganography method for hiding patient confidential information.

    PubMed

    Al-Dmour, Hayat; Al-Ani, Ahmed; Nguyen, Hung

    2014-01-01

    This paper deals with the important issue of security and confidentiality of patient information when exchanging or storing medical images. Steganography has recently been viewed as an alternative or complement to cryptography, as existing cryptographic systems are not perfect due to their vulnerability to certain types of attack. We propose in this paper a new steganography algorithm for hiding patient confidential information. It utilizes Pixel Value Differencing (PVD) to identify contrast regions in the image and a Hamming code that embeds 3 secret message bits into 4 bits of the cover image. In order to preserve the content of the region of interest (ROI), the embedding is only performed using the Region of Non-Interest (RONI).

  20. Quantum Steganography for Multi-party Covert Communication

    NASA Astrophysics Data System (ADS)

    Liu, Lin; Tang, Guang-Ming; Sun, Yi-Feng; Yan, Shu-Fan

    2016-01-01

    A novel multi-party quantum steganography protocol based on quantum secret sharing is proposed in this paper. Hidden channels are built in HBB and improved HBB quantum secret sharing protocols for secret messages transmitting, via the entanglement swapping of GHZ states and Bell measurement. Compared with the original protocol, there are only a few different GHZ sates transmitted in the proposed protocol, making the hidden channel with good imperceptibility. Moreover, the secret messages keep secure even when the hidden channel is under the attack from the dishonest participators, for the sub-secretmessages distributed randomly to different participators. With good imperceptibility and security, the capacity of proposed protocol is higher than previous multi-party quantum steganography protocol.

  1. Quantum watermarking scheme through Arnold scrambling and LSB steganography

    NASA Astrophysics Data System (ADS)

    Zhou, Ri-Gui; Hu, Wenwen; Fan, Ping

    2017-09-01

    Based on the NEQR of quantum images, a new quantum gray-scale image watermarking scheme is proposed through Arnold scrambling and least significant bit (LSB) steganography. The sizes of the carrier image and the watermark image are assumed to be 2n× 2n and n× n, respectively. Firstly, a classical n× n sized watermark image with 8-bit gray scale is expanded to a 2n× 2n sized image with 2-bit gray scale. Secondly, through the module of PA-MOD N, the expanded watermark image is scrambled to a meaningless image by the Arnold transform. Then, the expanded scrambled image is embedded into the carrier image by the steganography method of LSB. Finally, the time complexity analysis is given. The simulation experiment results show that our quantum circuit has lower time complexity, and the proposed watermarking scheme is superior to others.

  2. Cropping and noise resilient steganography algorithm using secret image sharing

    NASA Astrophysics Data System (ADS)

    Juarez-Sandoval, Oswaldo; Fierro-Radilla, Atoany; Espejel-Trujillo, Angelina; Nakano-Miyatake, Mariko; Perez-Meana, Hector

    2015-03-01

    This paper proposes an image steganography scheme, in which a secret image is hidden into a cover image using a secret image sharing (SIS) scheme. Taking advantage of the fault tolerant property of the (k,n)-threshold SIS, where using any k of n shares (k≤n), the secret data can be recovered without any ambiguity, the proposed steganography algorithm becomes resilient to cropping and impulsive noise contamination. Among many SIS schemes proposed until now, Lin and Chan's scheme is selected as SIS, due to its lossless recovery capability of a large amount of secret data. The proposed scheme is evaluated from several points of view, such as imperceptibility of the stegoimage respect to its original cover image, robustness of hidden data to cropping operation and impulsive noise contamination. The evaluation results show a high quality of the extracted secret image from the stegoimage when it suffered more than 20% cropping or high density noise contamination.

  3. The Quantum Steganography Protocol via Quantum Noisy Channels

    NASA Astrophysics Data System (ADS)

    Wei, Zhan-Hong; Chen, Xiu-Bo; Niu, Xin-Xin; Yang, Yi-Xian

    2015-08-01

    As a promising branch of quantum information hiding, Quantum steganography aims to transmit secret messages covertly in public quantum channels. But due to environment noise and decoherence, quantum states easily decay and change. Therefore, it is very meaningful to make a quantum information hiding protocol apply to quantum noisy channels. In this paper, we make the further research on a quantum steganography protocol for quantum noisy channels. The paper proved that the protocol can apply to transmit secret message covertly in quantum noisy channels, and explicity showed quantum steganography protocol. In the protocol, without publishing the cover data, legal receivers can extract the secret message with a certain probability, which make the protocol have a good secrecy. Moreover, our protocol owns the independent security, and can be used in general quantum communications. The communication, which happen in our protocol, do not need entangled states, so our protocol can be used without the limitation of entanglement resource. More importantly, the protocol apply to quantum noisy channels, and can be used widely in the future quantum communication.

  4. Degeneration of Fraunhofer diffraction on bacterial colonies due to their light focusing properties examined in the digital holographic microscope system.

    PubMed

    Buzalewicz, Igor; Liżewski, Kamil; Kujawińska, Małgorzata; Podbielska, Halina

    2013-11-04

    The degeneration of Fraunhofer diffraction conditions in the optical system with converging spherical wave illumination for bacteria species identification based on diffraction patterns is analyzed by digital holographic methods. The obtained results have shown that the colonies of analyzed bacteria species act as biological lenses with the time-dependent light focusing properties, which are characterized and monitored by means of phase retrieval from sequentially captured digital holograms. This significantly affects the location of Fraunhofer patterns observation plane, which is continuously shifted across optical axis in time.

  5. Steganography on multiple MP3 files using spread spectrum and Shamir's secret sharing

    NASA Astrophysics Data System (ADS)

    Yoeseph, N. M.; Purnomo, F. A.; Riasti, B. K.; Safiie, M. A.; Hidayat, T. N.

    2016-11-01

    The purpose of steganography is how to hide data into another media. In order to increase security of data, steganography technique is often combined with cryptography. The weakness of this combination technique is the data was centralized. Therefore, a steganography technique is develop by using combination of spread spectrum and secret sharing technique. In steganography with secret sharing, shares of data is created and hidden in several medium. Medium used to concealed shares were MP3 files. Hiding technique used was Spread Spectrum. Secret sharing scheme used was Shamir's Secret Sharing. The result showed that steganography with spread spectrum combined with Shamir's Secret Share using MP3 files as medium produce a technique that could hid data into several cover. To extract and reconstruct the data hidden in stego object, it is needed the amount of stego object which more or equal to its threshold. Furthermore, stego objects were imperceptible and robust.

  6. Controlling depth of focus in 3D image reconstructions by flexible and adaptive deformation of digital holograms.

    PubMed

    Ferraro, P; Paturzo, M; Memmolo, P; Finizio, A

    2009-09-15

    We show here that through an adaptive deformation of digital holograms it is possible to manage the depth of focus in 3D imaging reconstruction. Deformation is applied to the original hologram with the aim to put simultaneously in focus, and in one reconstructed image plane, different objects lying at different distances from the hologram plane (i.e., CCD sensor). In the same way, by adapting the deformation it is possible to extend the depth of field having a tilted object entirely in focus. We demonstrate the method in both lensless as well as in microscope configuration.

  7. Passive auto-focus for digital still cameras and camera phones: Filter-switching and low-light techniques

    NASA Astrophysics Data System (ADS)

    Gamadia, Mark Noel

    In order to gain valuable market share in the growing consumer digital still camera and camera phone market, camera manufacturers have to continually add and improve existing features to their latest product offerings. Auto-focus (AF) is one such feature, whose aim is to enable consumers to quickly take sharply focused pictures with little or no manual intervention in adjusting the camera's focus lens. While AF has been a standard feature in digital still and cell-phone cameras, consumers often complain about their cameras' slow AF performance, which may lead to missed photographic opportunities, rendering valuable moments and events with undesired out-of-focus pictures. This dissertation addresses this critical issue to advance the state-of-the-art in the digital band-pass filter, passive AF method. This method is widely used to realize AF in the camera industry, where a focus actuator is adjusted via a search algorithm to locate the in-focus position by maximizing a sharpness measure extracted from a particular frequency band of the incoming image of the scene. There are no known systematic methods for automatically deriving the parameters such as the digital pass-bands or the search step-size increments used in existing passive AF schemes. Conventional methods require time consuming experimentation and tuning in order to arrive at a set of parameters which balance AF performance in terms of speed and accuracy ultimately causing a delay in product time-to-market. This dissertation presents a new framework for determining an optimal set of passive AF parameters, named Filter- Switching AF, providing an automatic approach to achieve superior AF performance, both in good and low lighting conditions based on the following performance measures (metrics): speed (total number of iterations), accuracy (offset from truth), power consumption (total distance moved), and user experience (in-focus position overrun). Performance results using three different prototype cameras

  8. Focus and perspective adaptive digital surgical microscope: optomechanical design and experimental implementation.

    PubMed

    Claus, Daniel; Reichert, Carsten; Herkommer, Alois

    2017-05-01

    This paper relates to the improvement of conventional surgical stereo microscopy via the application of digital recording devices and adaptive optics. The research is aimed at improving the working conditions of the surgeon during the operation, such that free head movement is possible. The depth clues known from conventional stereo microscopy in interaction with the human eye’s functionality, such as convergence, disparity, angular elevation, parallax, and accommodation, are implemented in a digital recording system via adaptive optomechanical components. Two laterally moving pupil apertures have been used mimicking the digital implementation of the eye’s vergence and head motion. The natural eye’s accommodation is mimicked via the application of a tunable lens. Additionally, another system has been built, which enables tracking the surgeon’s eye pupil through a digital displaying stereoscopic microscope to supply the necessary information for steering the recording system. The optomechanical design and experimental results for both systems, digital recording stereoscopic microscope and pupil tracking system, are shown.

  9. Using High-Dimensional Image Models to Perform Highly Undetectable Steganography

    NASA Astrophysics Data System (ADS)

    Pevný, Tomáš; Filler, Tomáš; Bas, Patrick

    This paper presents a complete methodology for designing practical and highly-undetectable stegosystems for real digital media. The main design principle is to minimize a suitably-defined distortion by means of efficient coding algorithm. The distortion is defined as a weighted difference of extended state-of-the-art feature vectors already used in steganalysis. This allows us to "preserve" the model used by steganalyst and thus be undetectable even for large payloads. This framework can be efficiently implemented even when the dimensionality of the feature set used by the embedder is larger than 107. The high dimensional model is necessary to avoid known security weaknesses. Although high-dimensional models might be problem in steganalysis, we explain, why they are acceptable in steganography. As an example, we introduce HUGO, a new embedding algorithm for spatial-domain digital images and we contrast its performance with LSB matching. On the BOWS2 image database and in contrast with LSB matching, HUGO allows the embedder to hide 7× longer message with the same level of security level.

  10. Motion-free hybrid design laser beam propagation analyzer using a digital micromirror device and a variable focus liquid lens.

    PubMed

    Sheikh, Mumtaz; Riza, Nabeel A

    2010-06-01

    To the best of our knowledge, we propose the first motion-free laser beam propagation analyzer with a hybrid design using a digital micromirror device (DMD) and a liquid electronically controlled variable focus lens (ECVFL). Unlike prior analyzers that require profiling the beam at multiple locations along the light propagation axis, the proposed analyzer profiles the beam at the same plane for multiple values of the ECVFL focal length, thus eliminating beam profiler assembly motion. In addition to measuring standard Gaussian beam parameters, the analyzer can also be used to measure the M(2) beam propagation parameter of a multimode beam. Proof-of-concept beam parameter measurements with the proposed analyzer are successfully conducted for a 633 nm laser beam. Given the all-digital nature of the DMD-based profiling and all-analog motion-free nature of the ECVFL beam focus control, the proposed analyzer versus prior art promises better repeatability, speed, and reliability.

  11. The use and value of digital media for information about pregnancy and early motherhood: a focus group study.

    PubMed

    Lupton, Deborah

    2016-07-19

    Many women in countries in the global North access digital media information sources during pregnancy and the early years of motherhood. These include websites, blogs, online discussion forums, apps and social media platforms. Little previous research has sought to investigate in detail how women use the diverse range of digital media now available to them and what types of information they value. A qualitative study using focus groups was conducted to address these issues. Four focus groups were held in Sydney, Australia, including a total of 36 women who were either pregnant or had given birth in the previous three years. The participants were asked to talk about the types of digital media they used for pregnancy and parenting purposes, why they used them and in what ways they found them useful or helpful (or not). Group discussions were transcribed and thematically analysed, identifying the dominant information characteristics identified by women as valuable and useful. Nine characteristics emerged from the focus group discussions as most important to women: information that was: 1) immediate; 2) regular; 3) detailed; 4) entertaining; 5) customised; 6) practical; 7) professional; 8) reassuring; and 9) unbiased. These characteristics were valued for different purposes and needs. Digital media provided women with details when they most needed them or at times when they had opportunities to access them. The study showed that women value apps or digital platforms that are multi-functional. The findings revealed the importance of using digital information for establishing and maintaining social connections and intimate relationships with other mothers. However, participants also highly valued expert advice and expressed the desire for greater and more ready access to information and support offered by healthcare professionals. Pregnant women and those with young children place a high value on the information and support they receive from and sharing using online

  12. High capacity image steganography method based on framelet and compressive sensing

    NASA Astrophysics Data System (ADS)

    Xiao, Moyan; He, Zhibiao

    2015-12-01

    To improve the capacity and imperceptibility of image steganography, a novel high capacity and imperceptibility image steganography method based on a combination of framelet and compressive sensing (CS) is put forward. Firstly, SVD (Singular Value Decomposition) transform to measurement values obtained by compressive sensing technique to the secret data. Then the singular values in turn embed into the low frequency coarse subbands of framelet transform to the blocks of the cover image which is divided into non-overlapping blocks. Finally, use inverse framelet transforms and combine to obtain the stego image. The experimental results show that the proposed steganography method has a good performance in hiding capacity, security and imperceptibility.

  13. Modified 8×8 quantization table and Huffman encoding steganography

    NASA Astrophysics Data System (ADS)

    Guo, Yongning; Sun, Shuliang

    2014-10-01

    A new secure steganography, which is based on Huffman encoding and modified quantized discrete cosine transform (DCT) coefficients, is provided in this paper. Firstly, the cover image is segmented into 8×8 blocks and modified DCT transformation is applied on each block. Huffman encoding is applied to code the secret image before embedding. DCT coefficients are quantized by modified quantization table. Inverse DCT(IDCT) is conducted on each block. All the blocks are combined together and the steg image is finally achieved. The experiment shows that the proposed method is better than DCT and Mahender Singh's in PSNR and Capacity.

  14. Steganography and steganalysis in voice-over IP scenarios: operational aspects and first experiences with a new steganalysis tool set

    NASA Astrophysics Data System (ADS)

    Dittmann, Jana; Hesse, Danny; Hillert, Reyk

    2005-03-01

    Based on the knowledge and experiences from existing image steganalysis techniques, the overall objective of the paper is to evaluate existing audio steganography with a special focus on attacks in ad-hoc end-to-end media communications on the example of Voice over IP (VoIP) scenarios. One aspect is to understand operational requirements of recent steganographic techniques for VoIP applications. The other aspect is to elaborate possible steganalysis approaches applied to speech data. In particular we have examined existing VoIP applications with respect to their extensibility to steganographic algorithms. We have also paid attention to the part of steganalysis in PCM audio data which allows us to detect hidden communication while a running VoIP communication with the usage of the PCM codec. In our impelementation we use Jori's Voice over IP library by Jori Liesenborgs (JVOIPLIB) that provides primitives for a voice over IP communication. Finally we show first results of our prototypic implementation which extents the common VoIP scenario by the new feature of steganography. We also show the results for our PCM steganalyzer framework that is able to detect this kind of hidden communication by using a set of 13 first and second order statistics.

  15. Comparative analysis of the modified enclosed energy metric for self-focusing holograms from digital lensless holographic microscopy.

    PubMed

    Trujillo, Carlos; Garcia-Sucerquia, Jorge

    2015-06-01

    A comparative analysis of the performance of the modified enclosed energy (MEE) method for self-focusing holograms recorded with digital lensless holographic microscopy is presented. Notwithstanding the MEE analysis previously published, no extended analysis of its performance has been reported. We have tested the MEE in terms of the minimum axial distance allowed between the set of reconstructed holograms to search for the focal plane and the elapsed time to obtain the focused image. These parameters have been compared with those for some of the already reported methods in the literature. The MEE achieves better results in terms of self-focusing quality but at a higher computational cost. Despite its longer processing time, the method remains within a time frame to be technologically attractive. Modeled and experimental holograms have been utilized in this work to perform the comparative study.

  16. Digital multi-focusing from a single photograph taken with an uncalibrated conventional camera.

    PubMed

    Cao, Yang; Fang, Shuai; Wang, Zengfu

    2013-09-01

    The demand to restore all-in-focus images from defocused images and produce photographs focused at different depths is emerging in more and more cases, such as low-end hand-held cameras and surveillance cameras. In this paper, we manage to solve this challenging multi-focusing problem with a single image taken with an uncalibrated conventional camera. Different from all existing multi-focusing approaches, our method does not need to include a deconvolution process, which is quite time-consuming and will cause ringing artifacts in the focused region and low depth-of-field. This paper proposes a novel systematic approach to realize multi-focusing from a single photograph. First of all, with the optical explanation for the local smooth assumption, we present a new point-to-point defocus model. Next, the blur map of the input image, which reflects the amount of defocus blur at each pixel in the image, is estimated by two steps. 1) With the sharp edge prior, a rough blur map is obtained by estimating the blur amount at the edge regions. 2) The guided image filter is applied to propagate the blur value from the edge regions to the whole image by which a refined blur map is obtained. Thus far, we can restore the all-in-focus photograph from a defocused input. To further produce photographs focused at different depths, the depth map from the blur map must be derived. To eliminate the ambiguity over the focal plane, user interaction is introduced and a binary graph cut algorithm is used. So we introduce user interaction and use a binary graph cut algorithm to eliminate the ambiguity over the focal plane. Coupled with the camera parameters, this approach produces images focused at different depths. The performance of this new multi-focusing algorithm is evaluated both objectively and subjectively by various test images. Both results demonstrate that this algorithm produces high quality depth maps and multi-focusing results, outperforming the previous approaches.

  17. Introduction to focus issue: intrinsic and designed computation: information processing in dynamical systems--beyond the digital hegemony.

    PubMed

    Crutchfield, James P; Ditto, William L; Sinha, Sudeshna

    2010-09-01

    How dynamical systems store and process information is a fundamental question that touches a remarkably wide set of contemporary issues: from the breakdown of Moore's scaling laws--that predicted the inexorable improvement in digital circuitry--to basic philosophical problems of pattern in the natural world. It is a question that also returns one to the earliest days of the foundations of dynamical systems theory, probability theory, mathematical logic, communication theory, and theoretical computer science. We introduce the broad and rather eclectic set of articles in this Focus Issue that highlights a range of current challenges in computing and dynamical systems.

  18. Introduction to Focus Issue: Intrinsic and Designed Computation: Information Processing in Dynamical Systems-Beyond the Digital Hegemony

    NASA Astrophysics Data System (ADS)

    Crutchfield, James P.; Ditto, William L.; Sinha, Sudeshna

    2010-09-01

    How dynamical systems store and process information is a fundamental question that touches a remarkably wide set of contemporary issues: from the breakdown of Moore's scaling laws—that predicted the inexorable improvement in digital circuitry—to basic philosophical problems of pattern in the natural world. It is a question that also returns one to the earliest days of the foundations of dynamical systems theory, probability theory, mathematical logic, communication theory, and theoretical computer science. We introduce the broad and rather eclectic set of articles in this Focus Issue that highlights a range of current challenges in computing and dynamical systems.

  19. Laser Modified ZnO/CdSSe Core-Shell Nanowire Arrays for Micro-Steganography and Improved Photoconduction

    NASA Astrophysics Data System (ADS)

    Lu, Junpeng; Liu, Hongwei; Zheng, Minrui; Zhang, Hongji; Lim, Sharon Xiaodai; Tok, Eng Soon; Sow, Chorng Haur

    2014-09-01

    Arrays of ZnO/CdSSe core/shell nanowires with shells of tunable band gaps represent a class of interesting hybrid nanomaterials with unique optical and photoelectrical properties due to their type II heterojunctions and chemical compositions. In this work, we demonstrate that direct focused laser beam irradiation is able to achieve localized modification of the hybrid structure and chemical composition of the nanowire arrays. As a result, the photoresponsivity of the laser modified hybrid is improved by a factor of ~3. A 3D photodetector with improved performance is demonstrated using laser modified nanowire arrays overlaid with monolayer graphene as the top electrode. Finally, by controlling the power of the scanning focused laser beam, micropatterns with different fluorescence emissions are created on a substrate covered with nanowire arrays. Such a pattern is not apparent when imaged under normal optical microscopy but the pattern becomes readily revealed under fluorescence microscopy i.e. a form of Micro-Steganography is achieved.

  20. Laser modified ZnO/CdSSe core-shell nanowire arrays for Micro-Steganography and improved photoconduction.

    PubMed

    Lu, Junpeng; Liu, Hongwei; Zheng, Minrui; Zhang, Hongji; Lim, Sharon Xiaodai; Tok, Eng Soon; Sow, Chorng Haur

    2014-09-12

    Arrays of ZnO/CdSSe core/shell nanowires with shells of tunable band gaps represent a class of interesting hybrid nanomaterials with unique optical and photoelectrical properties due to their type II heterojunctions and chemical compositions. In this work, we demonstrate that direct focused laser beam irradiation is able to achieve localized modification of the hybrid structure and chemical composition of the nanowire arrays. As a result, the photoresponsivity of the laser modified hybrid is improved by a factor of ~3. A 3D photodetector with improved performance is demonstrated using laser modified nanowire arrays overlaid with monolayer graphene as the top electrode. Finally, by controlling the power of the scanning focused laser beam, micropatterns with different fluorescence emissions are created on a substrate covered with nanowire arrays. Such a pattern is not apparent when imaged under normal optical microscopy but the pattern becomes readily revealed under fluorescence microscopy i.e. a form of Micro-Steganography is achieved.

  1. Focus on the Journey, Not the Destination: Digital Games and Students with Disability

    ERIC Educational Resources Information Center

    Main, Susan; O'Rourke, John; Morris, Julia; Dunjey, Helen

    2016-01-01

    The way in which technologies support students with disability has been widely explored in recent times. Much of this research has focused on computer programs specifically designed to teach social and academic skills to students with disability. In the research reported in this paper we examined how students with disability could use technology…

  2. Focus on the Journey, Not the Destination: Digital Games and Students with Disability

    ERIC Educational Resources Information Center

    Main, Susan; O'Rourke, John; Morris, Julia; Dunjey, Helen

    2016-01-01

    The way in which technologies support students with disability has been widely explored in recent times. Much of this research has focused on computer programs specifically designed to teach social and academic skills to students with disability. In the research reported in this paper we examined how students with disability could use technology…

  3. Digital FDIRC: A focused differential internal reflection Cherenkov imaged by SiPM arrays

    NASA Astrophysics Data System (ADS)

    Marrocchesi, P. S.; Bagliesi, M. G.; Basti, A.; Bigongiari, G.; Bonechi, S.; Brogi, P.; Checchia, C.; Collazuol, G.; Maestro, P.; Morsani, F.; Piemonte, C.; Stolzi, F.; Suh, J. E.; Sulaj, A.

    2016-07-01

    A prototype of an Internal Reflection Cherenkov, equipped with a SiO2 (fused silica) radiator bar optically connected to a cylindrical mirror, was tested at CERN SPS in March 2015 with a beam of relativistic ions obtained from fragmentation of primary argon nuclei at energies 13, 19 and 30 GeV/n. The detector, designed to identify cosmic nuclei, features an imaging focal plane of dimensions 4 cm × 3 cm equipped with 16 arrays of NUV-SiPM (near-ultraviolet sensitive silicon photon avalanche detector) for a total of 1024 sensitive elements. The outstanding performance of the photodetectors (with negligible background in between adjacent photopeaks) allowed us to apply the technique of photon counting to the Cherenkov light collected on the focal plane. Thanks to the fine granularity of the array elements, the Cherenkov pattern was recorded together with the total number of detected photoelectrons increasing as Z2 as a function of the atomic number Z. In this paper, we report the performance of the SiPM arrays and the excellent resolution achieved by the digital Cherenkov prototype in the charge identification of the elements present in the beam.

  4. Employing the Gini coefficient to measure participation inequality in treatment-focused Digital Health Social Networks.

    PubMed

    van Mierlo, Trevor; Hyatt, Douglas; Ching, Andrew T

    2016-01-01

    Digital Health Social Networks (DHSNs) are common; however, there are few metrics that can be used to identify participation inequality. The objective of this study was to investigate whether the Gini coefficient, an economic measure of statistical dispersion traditionally used to measure income inequality, could be employed to measure DHSN inequality. Quarterly Gini coefficients were derived from four long-standing DHSNs. The combined data set included 625,736 posts that were generated from 15,181 actors over 18,671 days. The range of actors (8-2323), posts (29-28,684), and Gini coefficients (0.15-0.37) varied. Pearson correlations indicated statistically significant associations between number of actors and number of posts (0.527-0.835, p < .001), and Gini coefficients and number of posts (0.342-0.725, p < .001). However, the association between Gini coefficient and number of actors was only statistically significant for the addiction networks (0.619 and 0.276, p < .036). Linear regression models had positive but mixed R(2) results (0.333-0.527). In all four regression models, the association between Gini coefficient and posts was statistically significant (t = 3.346-7.381, p < .002). However, unlike the Pearson correlations, the association between Gini coefficient and number of actors was only statistically significant in the two mental health networks (t = -4.305 and -5.934, p < .000). The Gini coefficient is helpful in measuring shifts in DHSN inequality. However, as a standalone metric, the Gini coefficient does not indicate optimal numbers or ratios of actors to posts, or effective network engagement. Further, mixed-methods research investigating quantitative performance metrics is required.

  5. Far-field focusing of laser beam based on digital image processing techniques

    NASA Astrophysics Data System (ADS)

    Zhang, He-yong; Zhao, Shuai; Guo, Jin; Liu, Li-sheng; Tian, Yu-zhen

    2010-11-01

    In order to lead the laser beam transmit in the atmosphere convergently, an experiment of laser focus at the distance of 450m and 300m has been operated in the outdoor place. The actual manipulations are as follows: Firstly, the laser was collimated by a beam expander, then the near-parallel laser beam was transmitted with a Galileo telescope system, and the distance between the concave lens and the convex lens can be tuned through a precise displacement platform, so the focus of the system changed due to the tiny displacement of the concave lens. Secondly, the average power of the laser spot can be measured using power meter, the power is 47.67mW and the standard deviation is 0.67mW while the focal length is 450m. Thirdly, the energy distribution was found through the laser beam analyzer. The spot images were saved using the beam analyzer, then the saved image can be processed with Matlab software afterwards. The function named EDGE and Sobel operator was used in the pre-processing of the saved image, then method of median filter was used in the course of image de-noising and 53H filter was adopted in the signal analysis. The diameter of laser spot was obtained by the method above, the diameter is 5.56mm and the standard deviation is 0.24mm. The spot center excursion is 0.56mm, it is 10.43% of the total diameter of the laser spot. At last, the key factors of the energy dissipation in the focusing system can be summarized as follows: restriction of the diffraction limit, attenuation in the atmosphere, geometrical aberration of optical system, and the diffraction limit and the geometrical aberration are significant in the three factors above, so we can reduce the impact of the both factors during the design of optical system. The reliable referenced data of the system design can be acquired through the primary experiment research.

  6. Optical steganography based on amplified spontaneous emission noise.

    PubMed

    Wu, Ben; Wang, Zhenxing; Tian, Yue; Fok, Mable P; Shastri, Bhavin J; Kanoff, Daniel R; Prucnal, Paul R

    2013-01-28

    We propose and experimentally demonstrate an optical steganography method in which a data signal is transmitted using amplified spontaneous emission (ASE) noise as a carrier. The ASE serving as a carrier for the private signal has an identical frequency spectrum to the existing noise generated by the Erbium doped fiber amplifiers (EDFAs) in the transmission system. The system also carries a conventional data channel that is not private. The so-called "stealth" or private channel is well-hidden within the noise of the system. Phase modulation is used for both the stealth channel and the public channel. Using homodyne detection, the short coherence length of the ASE ensures that the stealth signal can only be recovered if the receiver closely matches the delay-length difference, which is deliberately changed in a dynamic fashion that is only known to the transmitter and its intended receiver.

  7. Improving the privacy of optical steganography with temporal phase masks.

    PubMed

    Wang, Z; Fok, M P; Xu, L; Chang, J; Prucnal, P R

    2010-03-15

    Temporal phase modulation of spread stealth signals is proposed and demonstrated to improve optical steganography transmission privacy. After phase modulation, the temporally spread stealth signal has a more complex spectral-phase-temporal relationship, such that the original temporal profile cannot be restored when only dispersion compensation is applied to the temporally spread stealth signals. Therefore, it increases the difficulty for the eavesdropper to detect and intercept the stealth channel that is hidden under a public transmission, even with a correct dispersion compensation device. The experimental results demonstrate the feasibility of this approach and display insignificant degradation in transmission performance, compared to the conventional stealth transmission without temporal phase modulation. The proposed system can also work without a clock transmission for signal synchronization. Our analysis and simulation results show that it is difficult for the adversary to detect the existence of the stealth transmission, or find the correct phase mask to recover the stealth signals.

  8. Image steganography using layered pixel-value differencing

    NASA Astrophysics Data System (ADS)

    Kim, Jaeyoung; Park, Hanhoon

    2017-02-01

    This paper proposes a layered approach to improve the embedding capacity of the existing pixel-value differencing (PVD) methods for image steganography. Specifically, one of the PVD methods is applied to embed a secret information into a cover image and the resulting image, called stego-image, is used to embed additional secret information by the same or another PVD method. This results in a double-layered stego-image. Then, another PVD method can be applied to the double-layered stego-image, resulting in a triple-layered stego-image. Likewise, multi-layered stego-images can be obtained. To successfully recover the secret information hidden in each layer, the embedding process is carefully designed. In the experiment, the proposed layered PVD method proved to be effective.

  9. Diagonal queue medical image steganography with Rabin cryptosystem.

    PubMed

    Jain, Mamta; Lenka, Saroj Kumar

    2016-03-01

    The main purpose of this work is to provide a novel and efficient method to the image steganography area of research in the field of biomedical, so that the security can be given to the very precious and confidential sensitive data of the patient and at the same time with the implication of the highly reliable algorithms will explode the high security to the precious brain information from the intruders. The patient information such as patient medical records with personal identification information of patients can be stored in both storage and transmission. This paper describes a novel methodology for hiding medical records like HIV reports, baby girl fetus, and patient's identity information inside their Brain disease medical image files viz. scan image or MRI image using the notion of obscurity with respect to a diagonal queue least significant bit substitution. Data structure queue plays a dynamic role in resource sharing between multiple communication parties and when secret medical data are transferred asynchronously (secret medical data not necessarily received at the same rate they were sent). Rabin cryptosystem is used for secret medical data writing, since it is computationally secure against a chosen-plaintext attack and shows the difficulty of integer factoring. The outcome of the cryptosystem is organized in various blocks and equally distributed sub-blocks. In steganography process, various Brain disease cover images are organized into various blocks of diagonal queues. The secret cipher blocks and sub-blocks are assigned dynamically to selected diagonal queues for embedding. The receiver gets four values of medical data plaintext corresponding to one ciphertext, so only authorized receiver can identify the correct medical data. Performance analysis was conducted using MSE, PSNR, maximum embedding capacity as well as by histogram analysis between various Brain disease stego and cover images.

  10. Fingerprinting Digital Circuits on Programmable Hardware

    DTIC Science & Technology

    2007-11-02

    signature data in image, video, and audio signals have received a great deal of attention. A spectrum of steganographic techniques for protection of...several recent techniques provide protection against all known attacks [15]. Although protection of digital audio signals emerged as a more difficult...task, at least three different techniques have been proposed [12, 16, 17]. The protection of video streams using steganography has been demonstrated

  11. Enhanced quantitative phase imaging in self-interference digital holographic microscopy using an electrically focus tunable lens

    PubMed Central

    Schubert, Robin; Vollmer, Angelika; Ketelhut, Steffi; Kemper, Björn

    2014-01-01

    Self-interference digital holographic microscopy (DHM) has been found particular suitable for simplified quantitative phase imaging of living cells. However, a main drawback of the self-interference DHM principle are scattering patterns that are induced by the coherent nature of the laser light which affect the resolution for detection of optical path length changes. We present a simple and efficient technique for the reduction of coherent disturbances in quantitative phase images. Therefore, amplitude and phase of the sample illumination are modulated by an electrically focus tunable lens. The proposed method is in particular convenient with the self-interference DHM concept. Results from the characterization of the method show that a reduction of coherence induced disturbances up to 70 percent can be achieved. Finally, the performance for enhanced quantitative imaging of living cells is demonstrated. PMID:25574433

  12. Fast volumetric imaging with patterned illumination via digital micro-mirror device-based temporal focusing multiphoton microscopy.

    PubMed

    Chang, Chia-Yuan; Hu, Yvonne Yuling; Lin, Chun-Yu; Lin, Cheng-Han; Chang, Hsin-Yu; Tsai, Sheng-Feng; Lin, Tzu-Wei; Chen, Shean-Jen

    2016-05-01

    Temporal focusing multiphoton microscopy (TFMPM) has the advantage of area excitation in an axial confinement of only a few microns; hence, it can offer fast three-dimensional (3D) multiphoton imaging. Herein, fast volumetric imaging via a developed digital micromirror device (DMD)-based TFMPM has been realized through the synchronization of an electron multiplying charge-coupled device (EMCCD) with a dynamic piezoelectric stage for axial scanning. The volumetric imaging rate can achieve 30 volumes per second according to the EMCCD frame rate of more than 400 frames per second, which allows for the 3D Brownian motion of one-micron fluorescent beads to be spatially observed. Furthermore, it is demonstrated that the dynamic HiLo structural multiphoton microscope can reject background noise by way of the fast volumetric imaging with high-speed DMD patterned illumination.

  13. Fast volumetric imaging with patterned illumination via digital micro-mirror device-based temporal focusing multiphoton microscopy

    PubMed Central

    Chang, Chia-Yuan; Hu, Yvonne Yuling; Lin, Chun-Yu; Lin, Cheng-Han; Chang, Hsin-Yu; Tsai, Sheng-Feng; Lin, Tzu-Wei; Chen, Shean-Jen

    2016-01-01

    Temporal focusing multiphoton microscopy (TFMPM) has the advantage of area excitation in an axial confinement of only a few microns; hence, it can offer fast three-dimensional (3D) multiphoton imaging. Herein, fast volumetric imaging via a developed digital micromirror device (DMD)-based TFMPM has been realized through the synchronization of an electron multiplying charge-coupled device (EMCCD) with a dynamic piezoelectric stage for axial scanning. The volumetric imaging rate can achieve 30 volumes per second according to the EMCCD frame rate of more than 400 frames per second, which allows for the 3D Brownian motion of one-micron fluorescent beads to be spatially observed. Furthermore, it is demonstrated that the dynamic HiLo structural multiphoton microscope can reject background noise by way of the fast volumetric imaging with high-speed DMD patterned illumination. PMID:27231617

  14. Enhanced quantitative phase imaging in self-interference digital holographic microscopy using an electrically focus tunable lens.

    PubMed

    Schubert, Robin; Vollmer, Angelika; Ketelhut, Steffi; Kemper, Björn

    2014-12-01

    Self-interference digital holographic microscopy (DHM) has been found particular suitable for simplified quantitative phase imaging of living cells. However, a main drawback of the self-interference DHM principle are scattering patterns that are induced by the coherent nature of the laser light which affect the resolution for detection of optical path length changes. We present a simple and efficient technique for the reduction of coherent disturbances in quantitative phase images. Therefore, amplitude and phase of the sample illumination are modulated by an electrically focus tunable lens. The proposed method is in particular convenient with the self-interference DHM concept. Results from the characterization of the method show that a reduction of coherence induced disturbances up to 70 percent can be achieved. Finally, the performance for enhanced quantitative imaging of living cells is demonstrated.

  15. Application of Genetic Algorithm and Particle Swarm Optimization techniques for improved image steganography systems

    NASA Astrophysics Data System (ADS)

    Jude Hemanth, Duraisamy; Umamaheswari, Subramaniyan; Popescu, Daniela Elena; Naaji, Antoanela

    2016-01-01

    Image steganography is one of the ever growing computational approaches which has found its application in many fields. The frequency domain techniques are highly preferred for image steganography applications. However, there are significant drawbacks associated with these techniques. In transform based approaches, the secret data is embedded in random manner in the transform coefficients of the cover image. These transform coefficients may not be optimal in terms of the stego image quality and embedding capacity. In this work, the application of Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) have been explored in the context of determining the optimal coefficients in these transforms. Frequency domain transforms such as Bandelet Transform (BT) and Finite Ridgelet Transform (FRIT) are used in combination with GA and PSO to improve the efficiency of the image steganography system.

  16. Demonstration of optical steganography transmission using temporal phase coded optical signals with spectral notch filtering.

    PubMed

    Hong, Xuezhi; Wang, Dawei; Xu, Lei; He, Sailing

    2010-06-07

    A novel approach is proposed and experimentally demonstrated for optical steganography transmission in WDM networks using temporal phase coded optical signals with spectral notch filtering. A temporal phase coded stealth channel is temporally and spectrally overlaid onto a public WDM channel. Direct detection of the public channel is achieved in the presence of the stealth channel. The interference from the public channel is suppressed by spectral notching before the detection of the optical stealth signal. The approach is shown to have good compatibility and robustness to the existing WDM network for optical steganography transmission.

  17. Steganography forensics method for detecting least significant bit replacement attack

    NASA Astrophysics Data System (ADS)

    Wang, Xiaofeng; Wei, Chengcheng; Han, Xiao

    2015-01-01

    We present an image forensics method to detect least significant bit replacement steganography attack. The proposed method provides fine-grained forensics features by using the hierarchical structure that combines pixels correlation and bit-planes correlation. This is achieved via bit-plane decomposition and difference matrices between the least significant bit-plane and each one of the others. Generated forensics features provide the susceptibility (changeability) that will be drastically altered when the cover image is embedded with data to form a stego image. We developed a statistical model based on the forensics features and used least square support vector machine as a classifier to distinguish stego images from cover images. Experimental results show that the proposed method provides the following advantages. (1) The detection rate is noticeably higher than that of some existing methods. (2) It has the expected stability. (3) It is robust for content-preserving manipulations, such as JPEG compression, adding noise, filtering, etc. (4) The proposed method provides satisfactory generalization capability.

  18. Minimizing embedding impact in steganography using trellis-coded quantization

    NASA Astrophysics Data System (ADS)

    Filler, Tomáš; Judas, Jan; Fridrich, Jessica

    2010-01-01

    In this paper, we propose a practical approach to minimizing embedding impact in steganography based on syndrome coding and trellis-coded quantization and contrast its performance with bounds derived from appropriate rate-distortion bounds. We assume that each cover element can be assigned a positive scalar expressing the impact of making an embedding change at that element (single-letter distortion). The problem is to embed a given payload with minimal possible average embedding impact. This task, which can be viewed as a generalization of matrix embedding or writing on wet paper, has been approached using heuristic and suboptimal tools in the past. Here, we propose a fast and very versatile solution to this problem that can theoretically achieve performance arbitrarily close to the bound. It is based on syndrome coding using linear convolutional codes with the optimal binary quantizer implemented using the Viterbi algorithm run in the dual domain. The complexity and memory requirements of the embedding algorithm are linear w.r.t. the number of cover elements. For practitioners, we include detailed algorithms for finding good codes and their implementation. Finally, we report extensive experimental results for a large set of relative payloads and for different distortion profiles, including the wet paper channel.

  19. Use and Users of Digital Resources: A Focus on Undergraduate Education in the Humanities and Social Sciences

    ERIC Educational Resources Information Center

    Harley, Diane; Henke, Johnathan; Lawrence, Shannon; Miller, Ian; Perciali, Irene; Nasatir, David

    2006-01-01

    The purpose of our research was (1) to map the universe of digital resources available to a subset of undergraduate educators in the humanities and social sciences, and (2) to investigate how and if available digital resources are actually being used in undergraduate teaching environments. We employed multiple methods, including surveys and focus…

  20. From Deep Freeze to Digital Migration: RIT/Eastman House Seminar Focuses on Preserving Our Photographic Heritage.

    ERIC Educational Resources Information Center

    Ross, Donald E.

    1996-01-01

    Discusses a photograph conservation seminar held in August 1996 and co-sponsored by the Rochester Institute of Technology and the George Eastman House (Rochester, New York). Highlights include assessing and improving storage conditions; possibilities of digital reconstruction; digital cameras; cataloging; and access, especially with CD-ROMs and…

  1. A Situated Practice of Ethics for Participatory Visual and Digital Methods in Public Health Research and Practice: A Focus on Digital Storytelling

    PubMed Central

    Hill, Amy L.; Flicker, Sarah

    2014-01-01

    This article explores ethical considerations related to participatory visual and digital methods for public health research and practice, through the lens of an approach known as “digital storytelling.” We begin by briefly describing the digital storytelling process and its applications to public health research and practice. Next, we explore 6 common challenges: fuzzy boundaries, recruitment and consent to participate, power of shaping, representation and harm, confidentiality, and release of materials. We discuss their complexities and offer some considerations for ethical practice. We hope this article serves as a catalyst for expanded dialogue about the need for high standards of integrity and a situated practice of ethics wherein researchers and practitioners reflexively consider ethical decision-making as part of the ongoing work of public health. PMID:23948015

  2. A situated practice of ethics for participatory visual and digital methods in public health research and practice: a focus on digital storytelling.

    PubMed

    Gubrium, Aline C; Hill, Amy L; Flicker, Sarah

    2014-09-01

    This article explores ethical considerations related to participatory visual and digital methods for public health research and practice, through the lens of an approach known as "digital storytelling." We begin by briefly describing the digital storytelling process and its applications to public health research and practice. Next, we explore 6 common challenges: fuzzy boundaries, recruitment and consent to participate, power of shaping, representation and harm, confidentiality, and release of materials. We discuss their complexities and offer some considerations for ethical practice. We hope this article serves as a catalyst for expanded dialogue about the need for high standards of integrity and a situated practice of ethics wherein researchers and practitioners reflexively consider ethical decision-making as part of the ongoing work of public health.

  3. On the Extraction of Spread-Spectrum Hidden Data in Digital Media

    DTIC Science & Technology

    2012-06-01

    hiding, information hiding, spread-spectrum embedding, steganalysis, steganography, watermarking . I. INTRODUCTION Digital data embedding in digital...Special Issue on Multimedia Watermarking , vol. 9, pp. 303-311, Sept. 2003. [3] H. S. Malvar and D. A. Florencio, “Improved spread spectrum: A new modulation...technique for robust watermarking ,” IEEE Trans. Signal Proc., vol. 51, pp. 898-905, April 2003. [4] I. J. Cox, J. Kilian, F. T. Leighton, and T

  4. Laser Modified ZnO/CdSSe Core-Shell Nanowire Arrays for Micro-Steganography and Improved Photoconduction

    PubMed Central

    Lu, Junpeng; Liu, Hongwei; Zheng, Minrui; Zhang, Hongji; Lim, Sharon Xiaodai; Tok, Eng Soon; Sow, Chorng Haur

    2014-01-01

    Arrays of ZnO/CdSSe core/shell nanowires with shells of tunable band gaps represent a class of interesting hybrid nanomaterials with unique optical and photoelectrical properties due to their type II heterojunctions and chemical compositions. In this work, we demonstrate that direct focused laser beam irradiation is able to achieve localized modification of the hybrid structure and chemical composition of the nanowire arrays. As a result, the photoresponsivity of the laser modified hybrid is improved by a factor of ~3. A 3D photodetector with improved performance is demonstrated using laser modified nanowire arrays overlaid with monolayer graphene as the top electrode. Finally, by controlling the power of the scanning focused laser beam, micropatterns with different fluorescence emissions are created on a substrate covered with nanowire arrays. Such a pattern is not apparent when imaged under normal optical microscopy but the pattern becomes readily revealed under fluorescence microscopy i.e. a form of Micro-Steganography is achieved. PMID:25213321

  5. Approaches to adaptive digital control focusing on the second order modal descriptions of large, flexible spacecraft dynamics

    NASA Technical Reports Server (NTRS)

    Johnson, C. R., Jr.

    1979-01-01

    The widespread modal analysis of flexible spacecraft and recognition of the poor a priori parameterization possible of the modal descriptions of individual structures have prompted the consideration of adaptive modal control strategies for distributed parameter systems. The current major approaches to computationally efficient adaptive digital control useful in these endeavors are explained in an original, lucid manner using modal second order structure dynamics for algorithm explication. Difficulties in extending these lumped-parameter techniques to distributed-parameter system expansion control are cited.

  6. A novel quantum LSB-based steganography method using the Gray code for colored quantum images

    NASA Astrophysics Data System (ADS)

    Heidari, Shahrokh; Farzadnia, Ehsan

    2017-10-01

    As one of the prevalent data-hiding techniques, steganography is defined as the act of concealing secret information in a cover multimedia encompassing text, image, video and audio, imperceptibly, in order to perform interaction between the sender and the receiver in which nobody except the receiver can figure out the secret data. In this approach a quantum LSB-based steganography method utilizing the Gray code for quantum RGB images is investigated. This method uses the Gray code to accommodate two secret qubits in 3 LSBs of each pixel simultaneously according to reference tables. Experimental consequences which are analyzed in MATLAB environment, exhibit that the present schema shows good performance and also it is more secure and applicable than the previous one currently found in the literature.

  7. DTCWT based high capacity steganography using coefficient replacement and adaptive scaling

    NASA Astrophysics Data System (ADS)

    Sathisha, N.; Priya, R.; Babu, K. Suresh; Raja, K. B.; Venugopal, K. R.; Patnaik, L. M.

    2013-12-01

    The steganography is used for secure communication. In this paper we propose Dual Tree Complex Wavelet Transform (DTCWT) based high capacity steganography using coefficient replacement and adaptive scaling. The DTCWT is applied on cover image and Lifting Wavelet Transform2 (LWT2) is applied on payload to convert spatial domain into transform domain. The new concept of replacing HH sub band coefficients of DTCWT of cover image by LL sub band coefficients of payload is introduced to generate intermediate stego object. The adaptive scaling factor is used based on entropy of cover image to scale down intermediate stego object coefficient values to generate final stego object. It is observed that the capacity and security are increased in the proposed algorithm compared to existing algorithms.

  8. Improved diagonal queue medical image steganography using Chaos theory, LFSR, and Rabin cryptosystem.

    PubMed

    Jain, Mamta; Kumar, Anil; Choudhary, Rishabh Charan

    2017-06-01

    In this article, we have proposed an improved diagonal queue medical image steganography for patient secret medical data transmission using chaotic standard map, linear feedback shift register, and Rabin cryptosystem, for improvement of previous technique (Jain and Lenka in Springer Brain Inform 3:39-51, 2016). The proposed algorithm comprises four stages, generation of pseudo-random sequences (pseudo-random sequences are generated by linear feedback shift register and standard chaotic map), permutation and XORing using pseudo-random sequences, encryption using Rabin cryptosystem, and steganography using the improved diagonal queues. Security analysis has been carried out. Performance analysis is observed using MSE, PSNR, maximum embedding capacity, as well as by histogram analysis between various Brain disease stego and cover images.

  9. Steganography algorithm multi pixel value differencing (MPVD) to increase message capacity and data security

    NASA Astrophysics Data System (ADS)

    Rojali, Siahaan, Ida Sri Rejeki; Soewito, Benfano

    2017-08-01

    Steganography is the art and science of hiding the secret messages so the existence of the message cannot be detected by human senses. The data concealment is using the Multi Pixel Value Differencing (MPVD) algorithm, utilizing the difference from each pixel. The development was done by using six interval tables. The objective of this algorithm is to enhance the message capacity and to maintain the data security.

  10. Focusing light through biological tissue and tissue-mimicking phantoms up to 9.6 cm in thickness with digital optical phase conjugation

    NASA Astrophysics Data System (ADS)

    Shen, Yuecheng; Liu, Yan; Ma, Cheng; Wang, Lihong V.

    2016-08-01

    Optical phase conjugation (OPC)-based wavefront shaping techniques focus light through or within scattering media, which is critically important for deep-tissue optical imaging, manipulation, and therapy. However, to date, the sample thickness in OPC experiments has been limited to only a few millimeters. Here, by using a laser with a long coherence length and an optimized digital OPC system that can safely deliver more light power, we focused 532-nm light through tissue-mimicking phantoms up to 9.6 cm thick, as well as through ex vivo chicken breast tissue up to 2.5 cm thick. Our results demonstrate that OPC can be achieved even when photons have experienced on average 1000 scattering events. The demonstrated penetration of nearly 10 cm (˜100 transport mean free paths) has never been achieved before by any optical focusing technique, and it shows the promise of OPC for deep-tissue noninvasive optical imaging, manipulation, and therapy.

  11. Enhanced information security employing orthogonal code, steganography, and joint transform correlation

    NASA Astrophysics Data System (ADS)

    Islam, M. N.; Islam, Mohammad F.; Shahrabi, Kamal

    2013-03-01

    A novel and robust technique is proposed in this paper for securing confidential information by utilizing orthogonal coding scheme, encoded steganography and nonlinear encryption through joint transform correlation. Different biometric signatures are encoded using individual orthogonal codes and then multiplexed together. The encrypted and multiplexed image is hidden inside a cover image employing a steganography technique, where one from the three least significant bits is chosen using another secret key. A color cover image is utilized which is decomposed into three color components, red, green and blue, so that three different sets of biometric signatures can be embedded into each of the color components. The color stego image is finally encrypted using multiple phase-shifted reference joint transform correlation (MRJTC) technique. The proposed encryption technique is a nonlinear process which increases the security strength significantly against any unauthorized access. The encoded steganography technique reduces the vulnerability that an intruder can retrieve any information from a given image through any steganalysis attack. Finally, the orthogonal coding scheme enhances the robustness by making the biometric information almost inaccessible without authorization.

  12. Extreme learning machine based optimal embedding location finder for image steganography.

    PubMed

    Atee, Hayfaa Abdulzahra; Ahmad, Robiah; Noor, Norliza Mohd; Rahma, Abdul Monem S; Aljeroudi, Yazan

    2017-01-01

    In image steganography, determining the optimum location for embedding the secret message precisely with minimum distortion of the host medium remains a challenging issue. Yet, an effective approach for the selection of the best embedding location with least deformation is far from being achieved. To attain this goal, we propose a novel approach for image steganography with high-performance, where extreme learning machine (ELM) algorithm is modified to create a supervised mathematical model. This ELM is first trained on a part of an image or any host medium before being tested in the regression mode. This allowed us to choose the optimal location for embedding the message with best values of the predicted evaluation metrics. Contrast, homogeneity, and other texture features are used for training on a new metric. Furthermore, the developed ELM is exploited for counter over-fitting while training. The performance of the proposed steganography approach is evaluated by computing the correlation, structural similarity (SSIM) index, fusion matrices, and mean square error (MSE). The modified ELM is found to outperform the existing approaches in terms of imperceptibility. Excellent features of the experimental results demonstrate that the proposed steganographic approach is greatly proficient for preserving the visual information of an image. An improvement in the imperceptibility as much as 28% is achieved compared to the existing state of the art methods.

  13. Extreme learning machine based optimal embedding location finder for image steganography

    PubMed Central

    Aljeroudi, Yazan

    2017-01-01

    In image steganography, determining the optimum location for embedding the secret message precisely with minimum distortion of the host medium remains a challenging issue. Yet, an effective approach for the selection of the best embedding location with least deformation is far from being achieved. To attain this goal, we propose a novel approach for image steganography with high-performance, where extreme learning machine (ELM) algorithm is modified to create a supervised mathematical model. This ELM is first trained on a part of an image or any host medium before being tested in the regression mode. This allowed us to choose the optimal location for embedding the message with best values of the predicted evaluation metrics. Contrast, homogeneity, and other texture features are used for training on a new metric. Furthermore, the developed ELM is exploited for counter over-fitting while training. The performance of the proposed steganography approach is evaluated by computing the correlation, structural similarity (SSIM) index, fusion matrices, and mean square error (MSE). The modified ELM is found to outperform the existing approaches in terms of imperceptibility. Excellent features of the experimental results demonstrate that the proposed steganographic approach is greatly proficient for preserving the visual information of an image. An improvement in the imperceptibility as much as 28% is achieved compared to the existing state of the art methods. PMID:28196080

  14. Digital video steganalysis using motion vector recovery-based features.

    PubMed

    Deng, Yu; Wu, Yunjie; Zhou, Linna

    2012-07-10

    As a novel digital video steganography, the motion vector (MV)-based steganographic algorithm leverages the MVs as the information carriers to hide the secret messages. The existing steganalyzers based on the statistical characteristics of the spatial/frequency coefficients of the video frames cannot attack the MV-based steganography. In order to detect the presence of information hidden in the MVs of video streams, we design a novel MV recovery algorithm and propose the calibration distance histogram-based statistical features for steganalysis. The support vector machine (SVM) is trained with the proposed features and used as the steganalyzer. Experimental results demonstrate that the proposed steganalyzer can effectively detect the presence of hidden messages and outperform others by the significant improvements in detection accuracy even with low embedding rates.

  15. Generating 3D and 3D-like animations of strongly uneven surface microareas of bloodstains from small series of partially out-of-focus digital SEM micrographs.

    PubMed

    Hortolà, Policarp

    2010-01-01

    When dealing with microscopic still images of some kinds of samples, the out-of-focus problem represents a particularly serious limiting factor for the subsequent generation of fully sharp 3D animations. In order to produce fully-focused 3D animations of strongly uneven surface microareas, a vertical stack of six digital secondary-electron SEM micrographs of a human bloodstain microarea was acquired. Afterwards, single combined images were generated using a macrophotography and light microscope image post-processing software. Subsequently, 3D animations of texture and topography were obtained in different formats using a combination of software tools. Finally, a 3D-like animation of a texture-topography composite was obtained in different formats using another combination of software tools. By one hand, results indicate that the use of image post-processing software not concerned primarily with electron micrographs allows to obtain, in an easy way, fully-focused images of strongly uneven surface microareas of bloodstains from small series of partially out-of-focus digital SEM micrographs. On the other hand, results also indicate that such small series of electron micrographs can be utilized for generating 3D and 3D-like animations that can subsequently be converted into different formats, by using certain user-friendly software facilities not originally designed for use in SEM, that are easily available from Internet. Although the focus of this study was on bloodstains, the methods used in it well probably are also of relevance for studying the surface microstructures of other organic or inorganic materials whose sharp displaying is difficult of obtaining from a single SEM micrograph.

  16. Vertical focusing and cell ordering in a microchannel via viscoelasticity: Applications for cell monitoring using a digital holographic microscopy

    NASA Astrophysics Data System (ADS)

    Won Seo, Kyung; Ran Ha, Young; Joon Lee, Sang

    2014-05-01

    We demonstrate sheath-free vertical concentration and positioning of cells induced by fluid viscoelasticity in a rectangular channel. The high uniformity in depth position and the reduction in cell overlap eliminate out-of-focus blurring and increase detection sensitivity. Additionally, orientational ordering of red blood cells improves the monitoring and counting performance of an optical imaging system. As a proof of concept of vertical focusing and cell ordering, we demonstrate counting and monitoring of red blood cells flowing in a microchannel using phase-contrast holographic microscopy for quantitative phase imaging.

  17. Game of Words: Prototype of a Digital Game Focusing on Oral Production (and Comprehension) through Asynchronous Interaction

    ERIC Educational Resources Information Center

    Loiseau, Mathieu; Hallal, Racha; Ballot, Pauline; Gazidedja, Ada

    2016-01-01

    In this paper, we present a learning game designed according to a strategy focusing on favouring the learners' "playful attitude". The game's modalities pertain to what we might call "guessing games". The chosen avatar of such guessing games both exists as learning and Commercial Off The Shelf (COTS) board games. We explain in…

  18. Practical steganalysis of digital images: state of the art

    NASA Astrophysics Data System (ADS)

    Fridrich, Jessica; Goljan, Miroslav

    2002-04-01

    Steganography is the art of hiding the very presence of communication by embedding secret messages into innocuous looking cover documents, such as digital images. Detection of steganography, estimation of message length, and its extraction belong to the field of steganalysis. Steganalysis has recently received a great deal of attention both from law enforcement and the media. In our paper, we classify and review current stego-detection algorithms that can be used to trace popular steganographic products. We recognize several qualitatively different approaches to practical steganalysis - visual detection, detection based on first order statistics (histogram analysis), dual statistics methods that use spatial correlations in images and higher-order statistics (RS steganalysis), universal blind detection schemes, and special cases, such as JPEG compatibility steganalysis. We also present some new results regarding our previously proposed detection of LSB embedding using sensitive dual statistics. The recent steganalytic methods indicate that the most common paradigm in image steganography - the bit-replacement or bit substitution - is inherently insecure with safe capacities far smaller than previously thought.

  19. Steganography-based access control to medical data hidden in electrocardiogram.

    PubMed

    Mai, Vu; Khalil, Ibrahim; Ibaida, Ayman

    2013-01-01

    Steganographic techniques allow secret data to be embedded inside another host data such as an image or a text file without significant changes to the quality of the host data. In this research, we demonstrate how steganography can be used as the main mechanism to build an access control model that gives data owners complete control to their sensitive cardiac health information hidden in their own Electrocardiograms. Our access control model is able to protect the privacy of users, the confidentiality of medical data, reduce storage space and make it more efficient to upload and download large amount of data.

  20. Building a Steganography Program Including How to Load, Process, and Save JPEG and PNG Files in Java

    ERIC Educational Resources Information Center

    Courtney, Mary F.; Stix, Allen

    2006-01-01

    Instructors teaching beginning programming classes are often interested in exercises that involve processing photographs (i.e., files stored as .jpeg). They may wish to offer activities such as color inversion, the color manipulation effects archived with pixel thresholding, or steganography, all of which Stevenson et al. [4] assert are sought by…

  1. Building a Steganography Program Including How to Load, Process, and Save JPEG and PNG Files in Java

    ERIC Educational Resources Information Center

    Courtney, Mary F.; Stix, Allen

    2006-01-01

    Instructors teaching beginning programming classes are often interested in exercises that involve processing photographs (i.e., files stored as .jpeg). They may wish to offer activities such as color inversion, the color manipulation effects archived with pixel thresholding, or steganography, all of which Stevenson et al. [4] assert are sought by…

  2. Detecting 2LSB steganography using extended pairs of values analysis

    NASA Astrophysics Data System (ADS)

    Khalind, Omed; Aziz, Benjamin

    2014-05-01

    In this paper, we propose an extended pairs of values analysis to detect and estimate the amount of secret messages embedded with 2LSB replacement in digital images based on chi-square attack and regularity rate in pixel values. The detection process is separated from the estimation of the hidden message length, as it is the main requirement of any steganalysis method. Hence, the detection process acts as a discrete classifier, which classifies a given set of images into stego and clean classes. The method can accurately detect 2LSB replacement even when the message length is about 10% of the total capacity, it also reaches its best performance with an accuracy of higher than 0.96 and a true positive rate of more than 0.997 when the amount of data are 20% to 100% of the total capacity. However, the method puts no assumptions neither on the image nor the secret message, as it tested with two sets of 3000 images, compressed and uncompressed, embedded with a random message for each case. This method of detection could also be used as an automated tool to analyse a bulk of images for hidden contents, which could be used by digital forensics analysts in their investigation process.

  3. An Efficient Method for Image and Audio Steganography using Least Significant Bit (LSB) Substitution

    NASA Astrophysics Data System (ADS)

    Chadha, Ankit; Satam, Neha; Sood, Rakshak; Bade, Dattatray

    2013-09-01

    In order to improve the data hiding in all types of multimedia data formats such as image and audio and to make hidden message imperceptible, a novel method for steganography is introduced in this paper. It is based on Least Significant Bit (LSB) manipulation and inclusion of redundant noise as secret key in the message. This method is applied to data hiding in images. For data hiding in audio, Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT) both are used. All the results displayed prove to be time-efficient and effective. Also the algorithm is tested for various numbers of bits. For those values of bits, Mean Square Error (MSE) and Peak-Signal-to-Noise-Ratio (PSNR) are calculated and plotted. Experimental results show that the stego-image is visually indistinguishable from the original cover-image when n<=4, because of better PSNR which is achieved by this technique. The final results obtained after steganography process does not reveal presence of any hidden message, thus qualifying the criteria of imperceptible message.

  4. Digitizing Preservation.

    ERIC Educational Resources Information Center

    Conway, Paul

    1994-01-01

    Discussion of digital imaging technology focuses on its potential use for preservation of library materials. Topics addressed include converting microfilm to digital; the high cost of conversion from paper or microfilm; quality; indexing; database management issues; incompatibility among imaging systems; longevity; cooperative pilot projects; and…

  5. Temporal phase mask encrypted optical steganography carried by amplified spontaneous emission noise.

    PubMed

    Wu, Ben; Wang, Zhenxing; Shastri, Bhavin J; Chang, Matthew P; Frost, Nicholas A; Prucnal, Paul R

    2014-01-13

    A temporal phase mask encryption method is proposed and experimentally demonstrated to improve the security of the stealth channel in an optical steganography system. The stealth channel is protected in two levels. In the first level, the data is carried by amplified spontaneous emission (ASE) noise, which cannot be detected in either the time domain or spectral domain. In the second level, even if the eavesdropper suspects the existence of the stealth channel, each data bit is covered by a fast changing phase mask. The phase mask code is always combined with the wide band noise from ASE. Without knowing the right phase mask code to recover the stealth data, the eavesdropper can only receive the noise like signal with randomized phase.

  6. A Novel Image Steganography Technique for Secured Online Transaction Using DWT and Visual Cryptography

    NASA Astrophysics Data System (ADS)

    Anitha Devi, M. D.; ShivaKumar, K. B.

    2017-08-01

    Online payment eco system is the main target especially for cyber frauds. Therefore end to end encryption is very much needed in order to maintain the integrity of secret information related to transactions carried online. With access to payment related sensitive information, which enables lot of money transactions every day, the payment infrastructure is a major target for hackers. The proposed system highlights, an ideal approach for secure online transaction for fund transfer with a unique combination of visual cryptography and Haar based discrete wavelet transform steganography technique. This combination of data hiding technique reduces the amount of information shared between consumer and online merchant needed for successful online transaction along with providing enhanced security to customer’s account details and thereby increasing customer’s confidence preventing “Identity theft” and “Phishing”. To evaluate the effectiveness of proposed algorithm Root mean square error, Peak signal to noise ratio have been used as evaluation parameters

  7. Parallel steganography framework for hiding a color image inside stereo images

    NASA Astrophysics Data System (ADS)

    Munoz-Ramirez, David O.; Ponomaryov, Volodymyr I.; Reyes-Reyes, Rogelio; Cruz-Ramos, Clara

    2017-05-01

    In this work, a robust steganography framework to hide a color image into a stereo images is proposed. The embedding algorithm is performed via Discrete Cosine Transform (DCT) and Quantization Index Modulation-Dither Modulation (QIM-DM) hiding the secret data. Additionally, the Arnold's Cat Map Transform is applied in order to scramble the secret color image, guaranteeing better security and robustness of the proposed system. Novel framework has demonstrated better performance against JPEG compression attacks among other existing approaches. Besides, the proposed algorithm is developed taking into account the parallel paradigm in order to be implemented in multi-core CPU increasing the processing speed. The results obtained by the proposed framework show high values of PSNR and SSIM, which demonstrate imperceptibility and sufficient robustness against JPEG compression attacks.

  8. A Comparison of Web-Based Library Catalogs and Museum Exhibits and Their Impacts on Actual Visits: A Focus Group Evaluation for the Colorado Digitization Project.

    ERIC Educational Resources Information Center

    Fry, Thomas K.; Lance, Keith Curry; Cox, Marti A.; Moe, Tammi

    The Colorado Digitization Project (CDP) commissioned the Library Research Service (LRS) of the Colorado State Library and the University of Denver Library and Information Science Program to evaluate user perceptions of the relative merits of the catalog (or database) and the exhibit approaches to providing access to digital information, especially…

  9. Blind steganalysis method for JPEG steganography combined with the semisupervised learning and soft margin support vector machine

    NASA Astrophysics Data System (ADS)

    Dong, Yu; Zhang, Tao; Xi, Ling

    2015-01-01

    Stego images embedded by unknown steganographic algorithms currently may not be detected by using steganalysis detectors based on binary classifier. However, it is difficult to obtain high detection accuracy by using universal steganalysis based on one-class classifier. For solving this problem, a blind detection method for JPEG steganography was proposed from the perspective of information theory. The proposed method combined the semisupervised learning and soft margin support vector machine with steganalysis detector based on one-class classifier to utilize the information in test data for improving detection performance. Reliable blind detection for JPEG steganography was realized only using cover images for training. The experimental results show that the proposed method can contribute to improving the detection accuracy of steganalysis detector based on one-class classifier and has good robustness under different source mismatch conditions.

  10. Adaptive Steganography

    DTIC Science & Technology

    2011-03-28

    project work was conducted under a no cost extension that was necessitated by the departure of some of the students on the grant. Adem Orsdemir left...Altun, Adem Orsdemir, and Junwen Mao to Orhan Bulan and the PI. 1. O. Bulan and G. Sharma, “High capacity image barcodes using color separability

  11. Camouflaging in Digital Image for Secure Communication

    NASA Astrophysics Data System (ADS)

    Jindal, B.; Singh, A. P.

    2013-06-01

    The present paper reports on a new type of camouflaging in digital image for hiding crypto-data using moderate bit alteration in the pixel. In the proposed method, cryptography is combined with steganography to provide a two layer security to the hidden data. The novelty of the algorithm proposed in the present work lies in the fact that the information about hidden bit is reflected by parity condition in one part of the image pixel. The remaining part of the image pixel is used to perform local pixel adjustment to improve the visual perception of the cover image. In order to examine the effectiveness of the proposed method, image quality measuring parameters are computed. In addition to this, security analysis is also carried by comparing the histograms of cover and stego images. This scheme provides a higher security as well as robustness to intentional as well as unintentional attacks.

  12. Final focus nomenclature

    SciTech Connect

    Erickson, R.

    1986-08-08

    The formal names and common names for all devices in the final focus system of the SLC are listed. The formal names consist of a device type designator, microprocessor designator, and a four-digit unit number. (LEW)

  13. Pedagogical Praxis Surrounding the Integration of Photography, Visual Literacy, Digital Literacy, and Educational Technology into Business Education Classrooms: A Focus Group Study

    ERIC Educational Resources Information Center

    Schlosser, Peter Allen

    2010-01-01

    This paper reports on an investigation into how Marketing and Business Education Teachers utilize and integrate educational technology into curriculum through the use of photography. The ontology of this visual, technological, and language interface is explored with an eye toward visual literacy, digital literacy, and pedagogical praxis, focusing…

  14. Pedagogical Praxis Surrounding the Integration of Photography, Visual Literacy, Digital Literacy, and Educational Technology into Business Education Classrooms: A Focus Group Study

    ERIC Educational Resources Information Center

    Schlosser, Peter Allen

    2010-01-01

    This paper reports on an investigation into how Marketing and Business Education Teachers utilize and integrate educational technology into curriculum through the use of photography. The ontology of this visual, technological, and language interface is explored with an eye toward visual literacy, digital literacy, and pedagogical praxis, focusing…

  15. Steganalysis of content-adaptive JPEG steganography based on Gauss partial derivative filter bank

    NASA Astrophysics Data System (ADS)

    Zhang, Yi; Liu, Fenlin; Yang, Chunfang; Luo, Xiangyang; Song, Xiaofeng; Lu, Jicang

    2017-01-01

    A steganalysis feature extraction method based on Gauss partial derivative filter bank is proposed in this paper to improve the detection performance for content-adaptive JPEG steganography. Considering that the embedding changes of content-adaptive steganographic schemes are performed in the texture and edge regions, the proposed method generates filtered images comprising rich texture and edge information using Gauss partial derivative filter bank, and histograms of absolute values of filtered subimages are extracted as steganalysis features. Gauss partial derivative filter bank can represent texture and edge information in multiple orientations with less computation load than conventional methods and prevent redundancy in different filtered images. These two properties are beneficial in the extraction of low-complexity sensitive features. The results of experiments conducted on three selected modern JPEG steganographic schemes-uniform embedding distortion, JPEG universal wavelet relative distortion, and side-informed UNIWARD-indicate that the proposed feature set is superior to the prior art feature sets-discrete cosine transform residual, phase aware rich model, and Gabor filter residual.

  16. Image Steganography using Karhunen-Loève Transform and Least Bit Substitution

    NASA Astrophysics Data System (ADS)

    Chadha, Ankit; Satam, Neha; Sood, Rakshak; Bade, Dattatray

    2013-10-01

    As communication channels are increasing in number, reliability of faithful communication is reducing. Hacking and tempering of data are two major issues for which security should be provided by channel. This raises the importance of steganography. In this paper, a novel method to encode the message information inside a carrier image has been described. It uses Karhunen-Lo\\`eve Transform for compression of data and Least Bit Substitution for data encryption. Compression removes redundancy and thus also provides encoding to a level. It is taken further by means of Least Bit Substitution. The algorithm used for this purpose uses pixel matrix which serves as a best tool to work on. Three different sets of images were used with three different numbers of bits to be substituted by message information. The experimental results show that algorithm is time efficient and provides high data capacity. Further, it can decrypt the original data effectively. Parameters such as carrier error and message error were calculated for each set and were compared for performance analysis.

  17. Wavelet-Based ECG Steganography for Protecting Patient Confidential Information in Point-of-Care Systems.

    PubMed

    Ibaida, Ayman; Khalil, Ibrahim

    2013-12-01

    With the growing number of aging population and a significant portion of that suffering from cardiac diseases, it is conceivable that remote ECG patient monitoring systems are expected to be widely used as point-of-care (PoC) applications in hospitals around the world. Therefore, huge amount of ECG signal collected by body sensor networks from remote patients at homes will be transmitted along with other physiological readings such as blood pressure, temperature, glucose level, etc., and diagnosed by those remote patient monitoring systems. It is utterly important that patient confidentiality is protected while data are being transmitted over the public network as well as when they are stored in hospital servers used by remote monitoring systems. In this paper, a wavelet-based steganography technique has been introduced which combines encryption and scrambling technique to protect patient confidential data. The proposed method allows ECG signal to hide its corresponding patient confidential data and other physiological information thus guaranteeing the integration between ECG and the rest. To evaluate the effectiveness of the proposed technique on the ECG signal, two distortion measurement metrics have been used: the percentage residual difference and the wavelet weighted PRD. It is found that the proposed technique provides high-security protection for patients data with low (less than 1%) distortion and ECG data remain diagnosable after watermarking (i.e., hiding patient confidential data) and as well as after watermarks (i.e., hidden data) are removed from the watermarked data.

  18. Discrete wavelet transform and singular value decomposition based ECG steganography for secured patient information transmission.

    PubMed

    Edward Jero, S; Ramu, Palaniappan; Ramakrishnan, S

    2014-10-01

    ECG Steganography provides secured transmission of secret information such as patient personal information through ECG signals. This paper proposes an approach that uses discrete wavelet transform to decompose signals and singular value decomposition (SVD) to embed the secret information into the decomposed ECG signal. The novelty of the proposed method is to embed the watermark using SVD into the two dimensional (2D) ECG image. The embedding of secret information in a selected sub band of the decomposed ECG is achieved by replacing the singular values of the decomposed cover image by the singular values of the secret data. The performance assessment of the proposed approach allows understanding the suitable sub-band to hide secret data and the signal degradation that will affect diagnosability. Performance is measured using metrics like Kullback-Leibler divergence (KL), percentage residual difference (PRD), peak signal to noise ratio (PSNR) and bit error rate (BER). A dynamic location selection approach for embedding the singular values is also discussed. The proposed approach is demonstrated on a MIT-BIH database and the observations validate that HH is the ideal sub-band to hide data. It is also observed that the signal degradation (less than 0.6%) is very less in the proposed approach even with the secret data being as large as the sub band size. So, it does not affect the diagnosability and is reliable to transmit patient information.

  19. A high-capacity steganography scheme for JPEG2000 baseline system.

    PubMed

    Zhang, Liang; Wang, Haili; Wu, Renbiao

    2009-08-01

    Hiding capacity is very important for efficient covert communications. For JPEG2000 compressed images, it is necessary to enlarge the hiding capacity because the available redundancy is very limited. In addition, the bitstream truncation makes it difficult to hide information. In this paper, a high-capacity steganography scheme is proposed for the JPEG2000 baseline system, which uses bit-plane encoding procedure twice to solve the problem due to bitstream truncation. Moreover, embedding points and their intensity are determined in a well defined quantitative manner via redundancy evaluation to increase hiding capacity. The redundancy is measured by bit, which is different from conventional methods which adjust the embedding intensity by multiplying a visual masking factor. High volumetric data is embedded into bit-planes as low as possible to keep message integrality, but at the cost of an extra bit-plane encoding procedure and slightly changed compression ratio. The proposed method can be easily integrated into the JPEG2000 image coder, and the produced stego-bitstream can be decoded normally. Simulation shows that the proposed method is feasible, effective, and secure.

  20. A novel fuzzy logic-based image steganography method to ensure medical data security.

    PubMed

    Karakış, R; Güler, I; Çapraz, I; Bilir, E

    2015-12-01

    This study aims to secure medical data by combining them into one file format using steganographic methods. The electroencephalogram (EEG) is selected as hidden data, and magnetic resonance (MR) images are also used as the cover image. In addition to the EEG, the message is composed of the doctor׳s comments and patient information in the file header of images. Two new image steganography methods that are based on fuzzy-logic and similarity are proposed to select the non-sequential least significant bits (LSB) of image pixels. The similarity values of the gray levels in the pixels are used to hide the message. The message is secured to prevent attacks by using lossless compression and symmetric encryption algorithms. The performance of stego image quality is measured by mean square of error (MSE), peak signal-to-noise ratio (PSNR), structural similarity measure (SSIM), universal quality index (UQI), and correlation coefficient (R). According to the obtained result, the proposed method ensures the confidentiality of the patient information, and increases data repository and transmission capacity of both MR images and EEG signals.

  1. A Graph Theory Practice on Transformed Image: A Random Image Steganography

    PubMed Central

    Thanikaiselvan, V.; Arulmozhivarman, P.; Subashanthini, S.; Amirtharajan, Rengarajan

    2013-01-01

    Modern day information age is enriched with the advanced network communication expertise but unfortunately at the same time encounters infinite security issues when dealing with secret and/or private information. The storage and transmission of the secret information become highly essential and have led to a deluge of research in this field. In this paper, an optimistic effort has been taken to combine graceful graph along with integer wavelet transform (IWT) to implement random image steganography for secure communication. The implementation part begins with the conversion of cover image into wavelet coefficients through IWT and is followed by embedding secret image in the randomly selected coefficients through graph theory. Finally stegoimage is obtained by applying inverse IWT. This method provides a maximum of 44 dB peak signal to noise ratio (PSNR) for 266646 bits. Thus, the proposed method gives high imperceptibility through high PSNR value and high embedding capacity in the cover image due to adaptive embedding scheme and high robustness against blind attack through graph theoretic random selection of coefficients. PMID:24453857

  2. Hiding phase-quantized biometrics: a case of steganography for reduced-complexity correlation filter classifiers

    NASA Astrophysics Data System (ADS)

    Hennings, Pablo; Savvides, Marios; Vijaya Kumar, B. V. K.

    2005-03-01

    This paper introduces an application of steganography for hiding cancelable biometric data based on quad-phase correlation filter classification. The proposed technique can perform two tasks: (1) embed an encrypted (cancelable) template for biometric recognition into a host image or (2) embed the biometric data required for remote (or later) classification, such as embedding a transformed face image into the host image, so that it can be transmitted for remote authentication or stored for later use. The novel approach is that we will encode quantized Fourier domain information of the template (or biometric) in the spatial representation of the host image. More importantly we show that we only need 2 bits per pixel in the frequency domain to represent the filter and biometric, making it compact and ideal for application of data hiding. To preserve the template (or biometric) from vulnerabilities to successful attacks, we encrypt the filter or biometric image by convolving it with a random kernel which essentially produces an image in the spatial domain which looks like white noise, so essentially both the frequency and spatial representations will have no visible exploitable structure. We also present results on reduced complexity correlation filter classification performance when using biometric images recovered from stego-images.

  3. A graph theory practice on transformed image: a random image steganography.

    PubMed

    Thanikaiselvan, V; Arulmozhivarman, P; Subashanthini, S; Amirtharajan, Rengarajan

    2013-01-01

    Modern day information age is enriched with the advanced network communication expertise but unfortunately at the same time encounters infinite security issues when dealing with secret and/or private information. The storage and transmission of the secret information become highly essential and have led to a deluge of research in this field. In this paper, an optimistic effort has been taken to combine graceful graph along with integer wavelet transform (IWT) to implement random image steganography for secure communication. The implementation part begins with the conversion of cover image into wavelet coefficients through IWT and is followed by embedding secret image in the randomly selected coefficients through graph theory. Finally stegoimage is obtained by applying inverse IWT. This method provides a maximum of 44 dB peak signal to noise ratio (PSNR) for 266646 bits. Thus, the proposed method gives high imperceptibility through high PSNR value and high embedding capacity in the cover image due to adaptive embedding scheme and high robustness against blind attack through graph theoretic random selection of coefficients.

  4. Effect of using different cover image quality to obtain robust selective embedding in steganography

    NASA Astrophysics Data System (ADS)

    Abdullah, Karwan Asaad; Al-Jawad, Naseer; Abdulla, Alan Anwer

    2014-05-01

    One of the common types of steganography is to conceal an image as a secret message in another image which normally called a cover image; the resulting image is called a stego image. The aim of this paper is to investigate the effect of using different cover image quality, and also analyse the use of different bit-plane in term of robustness against well-known active attacks such as gamma, statistical filters, and linear spatial filters. The secret messages are embedded in higher bit-plane, i.e. in other than Least Significant Bit (LSB), in order to resist active attacks. The embedding process is performed in three major steps: First, the embedding algorithm is selectively identifying useful areas (blocks) for embedding based on its lighting condition. Second, is to nominate the most useful blocks for embedding based on their entropy and average. Third, is to select the right bit-plane for embedding. This kind of block selection made the embedding process scatters the secret message(s) randomly around the cover image. Different tests have been performed for selecting a proper block size and this is related to the nature of the used cover image. Our proposed method suggests a suitable embedding bit-plane as well as the right blocks for the embedding. Experimental results demonstrate that different image quality used for the cover images will have an effect when the stego image is attacked by different active attacks. Although the secret messages are embedded in higher bit-plane, but they cannot be recognised visually within the stegos image.

  5. High-precision topography measurement through accurate in-focus plane detection with hybrid digital holographic microscope and white light interferometer module.

    PubMed

    Liżewski, Kamil; Tomczewski, Sławomir; Kozacki, Tomasz; Kostencka, Julianna

    2014-04-10

    High-precision topography measurement of micro-objects using interferometric and holographic techniques can be realized provided that the in-focus plane of an imaging system is very accurately determined. Therefore, in this paper we propose an accurate technique for in-focus plane determination, which is based on coherent and incoherent light. The proposed method consists of two major steps. First, a calibration of the imaging system with an amplitude object is performed with a common autofocusing method using coherent illumination, which allows for accurate localization of the in-focus plane position. In the second step, the position of the detected in-focus plane with respect to the imaging system is measured with white light interferometry. The obtained distance is used to accurately adjust a sample with the precision required for the measurement. The experimental validation of the proposed method is given for measurement of high-numerical-aperture microlenses with subwavelength accuracy.

  6. Electrostatically focused addressable field emission array chips (AFEA's) for high-speed massively parallel maskless digital E-beam direct write lithography and scanning electron microscopy

    DOEpatents

    Thomas, Clarence E.; Baylor, Larry R.; Voelkl, Edgar; Simpson, Michael L.; Paulus, Michael J.; Lowndes, Douglas H.; Whealton, John H.; Whitson, John C.; Wilgen, John B.

    2002-12-24

    Systems and methods are described for addressable field emission array (AFEA) chips. A method of operating an addressable field-emission array, includes: generating a plurality of electron beams from a pluralitly of emitters that compose the addressable field-emission array; and focusing at least one of the plurality of electron beams with an on-chip electrostatic focusing stack. The systems and methods provide advantages including the avoidance of space-charge blow-up.

  7. Focus stacking: Comparing commercial top-end set-ups with a semi-automatic low budget approach. A possible solution for mass digitization of type specimens

    PubMed Central

    Brecko, Jonathan; Mathys, Aurore; Dekoninck, Wouter; Leponce, Maurice; VandenSpiegel, Didier; Semal, Patrick

    2014-01-01

    Abstract In this manuscript we present a focus stacking system, composed of commercial photographic equipment. The system is inexpensive compared to high-end commercial focus stacking solutions. We tested this system and compared the results with several different software packages (CombineZP, Auto-Montage, Helicon Focus and Zerene Stacker). We tested our final stacked picture with a picture obtained from two high-end focus stacking solutions: a Leica MZ16A with DFC500 and a Leica Z6APO with DFC290. Zerene Stacker and Helicon Focus both provided satisfactory results. However, Zerene Stacker gives the user more possibilities in terms of control of the software, batch processing and retouching. The outcome of the test on high-end solutions demonstrates that our approach performs better in several ways. The resolution of the tested extended focus pictures is much higher than those from the Leica systems. The flash lighting inside the Ikea closet creates an evenly illuminated picture, without struggling with filters, diffusers, etc. The largest benefit is the price of the set-up which is approximately € 3,000, which is 8 and 10 times less than the LeicaZ6APO and LeicaMZ16A set-up respectively. Overall, this enables institutions to purchase multiple solutions or to start digitising the type collection on a large scale even with a small budget. PMID:25589866

  8. Focus stacking: Comparing commercial top-end set-ups with a semi-automatic low budget approach. A possible solution for mass digitization of type specimens.

    PubMed

    Brecko, Jonathan; Mathys, Aurore; Dekoninck, Wouter; Leponce, Maurice; VandenSpiegel, Didier; Semal, Patrick

    2014-01-01

    In this manuscript we present a focus stacking system, composed of commercial photographic equipment. The system is inexpensive compared to high-end commercial focus stacking solutions. We tested this system and compared the results with several different software packages (CombineZP, Auto-Montage, Helicon Focus and Zerene Stacker). We tested our final stacked picture with a picture obtained from two high-end focus stacking solutions: a Leica MZ16A with DFC500 and a Leica Z6APO with DFC290. Zerene Stacker and Helicon Focus both provided satisfactory results. However, Zerene Stacker gives the user more possibilities in terms of control of the software, batch processing and retouching. The outcome of the test on high-end solutions demonstrates that our approach performs better in several ways. The resolution of the tested extended focus pictures is much higher than those from the Leica systems. The flash lighting inside the Ikea closet creates an evenly illuminated picture, without struggling with filters, diffusers, etc. The largest benefit is the price of the set-up which is approximately € 3,000, which is 8 and 10 times less than the LeicaZ6APO and LeicaMZ16A set-up respectively. Overall, this enables institutions to purchase multiple solutions or to start digitising the type collection on a large scale even with a small budget.

  9. Audre's daughter: Black lesbian steganography in Dee Rees' Pariah and Audre Lorde's Zami: A New Spelling of My Name.

    PubMed

    Kang, Nancy

    2016-01-01

    This article argues that African-American director Dee Rees' critically acclaimed debut Pariah (2011) is a rewriting of lesbian poet-activist Audre Lorde's iconic "bio-mythography" Zami: A New Spelling of My Name (1982). The article examines how Rees' work creatively and subtly re-envisions Lorde's Zami by way of deeply rooted and often cleverly camouflaged patterns, resonances, and contrasts. Shared topics include naming, mother-daughter bonds, the role of clothing in identity formation, domestic abuse, queer time, and lesbian, gay, bisexual, and transgender legacy discourse construction. What emerges between the visual and written texts is a hidden language of connection--what may be termed Black lesbian steganography--which proves thought-provoking to viewers and readers alike.

  10. A review on "A Novel Technique for Image Steganography Based on Block-DCT and Huffman Encoding"

    NASA Astrophysics Data System (ADS)

    Das, Rig; Tuithung, Themrichon

    2013-03-01

    This paper reviews the embedding and extraction algorithm proposed by "A. Nag, S. Biswas, D. Sarkar and P. P. Sarkar" on "A Novel Technique for Image Steganography based on Block-DCT and Huffman Encoding" in "International Journal of Computer Science and Information Technology, Volume 2, Number 3, June 2010" [3] and shows that the Extraction of Secret Image is Not Possible for the algorithm proposed in [3]. 8 bit Cover Image of size is divided into non joint blocks and a two dimensional Discrete Cosine Transformation (2-D DCT) is performed on each of the blocks. Huffman Encoding is performed on an 8 bit Secret Image of size and each bit of the Huffman Encoded Bit Stream is embedded in the frequency domain by altering the LSB of the DCT coefficients of Cover Image blocks. The Huffman Encoded Bit Stream and Huffman Table

  11. Digital psychiatry.

    PubMed

    Tang, S; Helmeste, D

    2000-02-01

    The American managed care movement has been viewed as a big experiment and is being watched closely by the rest of the world. In the meanwhile, computer-based information technology (IT) is changing the practice of medicine, much more rapidly than managed care. A New World of digitized knowledge and information has been created. Although literature on IT in psychiatry is largely absent in peer-reviewed psychiatric journals, IT is finding its way into all aspects of medicine, particularly psychiatry. Telepsychiatry programs are becoming very popular. At the same time, medical information sites are flourishing and evolving into a new health-care industry. Patient-physician information asymmetry is decreasing as patients are gaining easy access to medical information hitherto only available to professionals. Thus, psychiatry is facing another paradigm shift, at a time when most attention has been focused on managed care. In this new digital world, knowledge and information are no longer the sole property of professionals. Value will migrate from traditional in-person office-based therapy to digital clinical products, from in-person library search and classroom didactic instruction to interactive on-line searches and distance learning. In this time of value migration, psychiatrists have to determine what their 'distinctive competence' is and where best to add value in the health-care delivery value chain. The authors assess the impact of IT on clinical psychiatry and review how clinical practice, education and research in psychiatry are expected to change in this emerging digital world.

  12. Focusing laser scanner

    NASA Technical Reports Server (NTRS)

    Callen, W. R.; Weaver, J. E.

    1979-01-01

    Economical laser scanner assembled from commercially available components, modulates and scans focused laser beam over area up to 5.1 by 5.1 cm. Scanner gives resolution comparable to that of conventional television. Device is highly applicable to area of analog and digital storage and retrieval.

  13. Digital Readiness Gaps

    ERIC Educational Resources Information Center

    Horrigan, John B.

    2016-01-01

    For many years concerns about "digital divides" centered primarily on whether people had "access" to digital technologies. Now, those worried about these issues also focus on the degree to which people succeed or struggle when they use technology to try to navigate their environments, solve problems, and make decisions. This…

  14. Will Digital Texts Succeed?

    ERIC Educational Resources Information Center

    Acker, Stephen R.

    2008-01-01

    With faculty changing instructional practices to take advantage of customizable, focused content (and digital delivery of that content), many people assume that digital distribution is the answer to bringing the costs of course content delivery in line. But the picture just isn't that simple. A wide continuum of options is available to faculty and…

  15. Digital Readiness Gaps

    ERIC Educational Resources Information Center

    Horrigan, John B.

    2016-01-01

    For many years concerns about "digital divides" centered primarily on whether people had "access" to digital technologies. Now, those worried about these issues also focus on the degree to which people succeed or struggle when they use technology to try to navigate their environments, solve problems, and make decisions. This…

  16. Digital Watermarking: From Concepts to Real-Time Video Applications

    DTIC Science & Technology

    1999-01-01

    includes still-image, video, audio , and geometry data among others-the fundamental con- cept of steganography can be transferred from the field of...used in cryptographic systems. Steganography can be defined as hiding messages in plain sight-that is, rather than encrypting the message, it is embedded...case, the classic medieval palimpsest written in invisible ink on a normal letter. Obviously, manual steganography is a rather tedious and time-consuming

  17. Digital security technology simplified.

    PubMed

    Scaglione, Bernard J

    2007-01-01

    Digital security technology is making great strides in replacing analog and other traditional security systems including CCTV card access, personal identification and alarm monitoring applications. Like any new technology, the author says, it is important to understand its benefits and limitations before purchasing and installing, to ensure its proper operation and effectiveness. This article is a primer for security directors on how digital technology works. It provides an understanding of the key components which make up the foundation for digital security systems, focusing on three key aspects of the digital security world: the security network, IP cameras and IP recorders.

  18. Digitization Best Practices

    SciTech Connect

    Xue, Fei; Holtkamp, Irma S.; Knudson, Frances L.

    2012-07-31

    This project involved performing tests and documenting results to determine best practices for digitizing older print documents. The digitization process is complicated, especially when original documents exhibit non-standard fonts and are faded. Tests focused on solutions to improve high quality scanning, increase OCR accuracy, and efficiently use embedded metadata. Results are summarized. From the test results on the right sides, we know that when we plan to digitize documents, we should balance Quantity and Quality based on our expectation, and then make final decision for the digitization process.

  19. Digital Earth

    NASA Astrophysics Data System (ADS)

    de La Beaujardiere, J.

    2001-05-01

    Digital Earth (DE) seeks to make geospatial information broadly and easily available. Vast amounts of natural and cultural information are gathered about the Earth, but it is often difficult to find needed data, to share knowledge across disciplines, and to combine information from several sources. DE defines a framework for interoperability by selecting relevant open standards from the information technology community. These standards specify the technical means by which publishers can provide or sell their data, and by which client applications can find and access data in an automated fashion. The standardized DE framework enables many types of clients--from web browsers to museum kiosks to research-grade virtual environments--to use a common geospatial information infrastructure. Digital Earth can benefit Earth system education in general, and DLESE in particular, in several ways. First, educators, students and creators of instructional material will benefit from standardized access to georeferenced data. Secondly, educational lesson plans that focus on a region or aspect of the Earth can themselves be considered geospatial information resources that could be cataloged and retrieved through DE. Finally, general public knowledge about our planet will by increased by Digital Earth.

  20. Digital Citizenship Focus Questions For Implementation

    ERIC Educational Resources Information Center

    Ribble, Mike S.; Bailey, Gerald D.

    2004-01-01

    Are you irritated at the thoughtless technology-related interruptions in public places? Are you tired of having to "police" staff and/or students who use technology inappropriately? Are you concerned that schools ban certain forms of technology in schools only to see students using and misusing it after the last school bell rings? A growing…

  1. Advanced Course in Engineering (ACE) - Cyber Security Boot Camp

    DTIC Science & Technology

    2008-04-01

    drives, classifying file systems, one-way hashes, digital signatures and steganography . 6. Steganography : data hiding in multimedia (images, audio , video...classifying steganography algorithms and tools, steganographic capacity, detection and recovery of hidden data, digital data watermarking, watermark...robustness, digital data forensics. 7. Covert Channels: Third Wave society, timing and storage channels, protocol steganography , TCP/IP covert

  2. Digital Libraries.

    ERIC Educational Resources Information Center

    Fox, Edward A.; Urs, Shalini R.

    2002-01-01

    Provides an overview of digital libraries research, practice, and literature. Highlights include new technologies; redefining roles; historical background; trends; creating digital content, including conversion; metadata; organizing digital resources; services; access; information retrieval; searching; natural language processing; visualization;…

  3. Digital Libraries.

    ERIC Educational Resources Information Center

    Fox, Edward A.; Urs, Shalini R.

    2002-01-01

    Provides an overview of digital libraries research, practice, and literature. Highlights include new technologies; redefining roles; historical background; trends; creating digital content, including conversion; metadata; organizing digital resources; services; access; information retrieval; searching; natural language processing; visualization;…

  4. Website-based PNG image steganography using the modified Vigenere Cipher, least significant bit, and dictionary based compression methods

    NASA Astrophysics Data System (ADS)

    Rojali, Salman, Afan Galih; George

    2017-08-01

    Along with the development of information technology in meeting the needs, various adverse actions and difficult to avoid are emerging. One of such action is data theft. Therefore, this study will discuss about cryptography and steganography that aims to overcome these problems. This study will use the Modification Vigenere Cipher, Least Significant Bit and Dictionary Based Compression methods. To determine the performance of study, Peak Signal to Noise Ratio (PSNR) method is used to measure objectively and Mean Opinion Score (MOS) method is used to measure subjectively, also, the performance of this study will be compared to other method such as Spread Spectrum and Pixel Value differencing. After comparing, it can be concluded that this study can provide better performance when compared to other methods (Spread Spectrum and Pixel Value Differencing) and has a range of MSE values (0.0191622-0.05275) and PSNR (60.909 to 65.306) with a hidden file size of 18 kb and has a MOS value range (4.214 to 4.722) or image quality that is approaching very good.

  5. A World of Digital Media Online.

    ERIC Educational Resources Information Center

    Amthor, Geoff

    1995-01-01

    Discussion of digital media focuses on IBM's Digital Library which integrates information storage, management, search, retrieval, and distribution technologies to help content owners provide easy access while protecting and preserving materials. Highlights include capturing digital data, and examples of the use of Digital Library at two…

  6. Digital Preservation.

    ERIC Educational Resources Information Center

    Yakel, Elizabeth

    2001-01-01

    Reviews research on digital preservation issues, including born-digital and digitally recreated documents. Discusses electronic records research; metadata and other standards; electronic mail; Web-based documents; moving images media; selection of materials for digitization, including primary sources; administrative issues; media stability…

  7. Black Men and the Digital Divide

    ERIC Educational Resources Information Center

    Conceição, Simone C. O.; Martin, Larry G.

    2016-01-01

    This chapter focuses on the role adult educators can play in assisting Black men to overcome the challenges faced in accessing and using digital technology and acquiring appropriate skills in a digital society.

  8. Black Men and the Digital Divide

    ERIC Educational Resources Information Center

    Conceição, Simone C. O.; Martin, Larry G.

    2016-01-01

    This chapter focuses on the role adult educators can play in assisting Black men to overcome the challenges faced in accessing and using digital technology and acquiring appropriate skills in a digital society.

  9. Ion focusing

    DOEpatents

    Cooks, Robert Graham; Baird, Zane; Peng, Wen-Ping

    2017-01-17

    The invention generally relates to apparatuses for focusing ions at or above ambient pressure and methods of use thereof. In certain embodiments, the invention provides an apparatus for focusing ions that includes an electrode having a cavity, at least one inlet within the electrode configured to operatively couple with an ionization source, such that discharge generated by the ionization source is injected into the cavity of the electrode, and an outlet. The cavity in the electrode is shaped such that upon application of voltage to the electrode, ions within the cavity are focused and directed to the outlet, which is positioned such that a proximal end of the outlet receives the focused ions and a distal end of the outlet is open to ambient pressure.

  10. Ion focusing

    SciTech Connect

    Cooks, Robert Graham; Baird, Zane; Peng, Wen-Ping

    2015-11-10

    The invention generally relates to apparatuses for focusing ions at or above ambient pressure and methods of use thereof. In certain embodiments, the invention provides an apparatus for focusing ions that includes an electrode having a cavity, at least one inlet within the electrode configured to operatively couple with an ionization source, such that discharge generated by the ionization source is injected into the cavity of the electrode, and an outlet. The cavity in the electrode is shaped such that upon application of voltage to the electrode, ions within the cavity are focused and directed to the outlet, which is positioned such that a proximal end of the outlet receives the focused ions and a distal end of the outlet is open to ambient pressure.

  11. Digital imaging.

    PubMed

    Daniel, Gregory B

    2009-07-01

    Medical imaging is rapidly moving toward a digital-based image system. An understanding of the principles of digital imaging is necessary to evaluate features of imaging systems and can play an important role in purchasing decisions.

  12. Digital photorefraction

    NASA Astrophysics Data System (ADS)

    Costa, Manuel F. M.; Jorge, Jorge M.

    1998-01-01

    The early evaluation of the visual status of human infants is of a critical importance. It is of utmost importance to the development of the child's visual system that she perceives clear, focused, retinal images. Furthermore if the refractive problems are not corrected in due time amblyopia may occur. Photorefraction is a non-invasive clinical tool rather convenient for application to this kind of population. A qualitative or semi-quantitative information about refractive errors, accommodation, strabismus, amblyogenic factors and some pathologies (cataracts) can the easily obtained. The photorefraction experimental setup we established using new technological breakthroughs on the fields of imaging devices, image processing and fiber optics, allows the implementation of both the isotropic and eccentric photorefraction approaches. Essentially both methods consist on delivering a light beam into the eyes. It is refracted by the ocular media, strikes the retina, focusing or not, reflects off and is collected by a camera. The system is formed by one CCD color camera and a light source. A beam splitter in front of the camera's objective allows coaxial illumination and observation. An optomechanical system also allows eccentric illumination. The light source is a flash type one and is synchronized with the camera's image acquisition. The camera's image is digitized displayed in real time. Image processing routines are applied for image's enhancement and feature extraction.

  13. Digital photorefraction

    NASA Astrophysics Data System (ADS)

    Costa, Manuel F.; Jorge, Jorge M.

    1997-12-01

    The early evaluation of the visual status of human infants is of a critical importance. It is of utmost importance to the development of the child's visual system that she perceives clear, focused, retinal images. Furthermore if the refractive problems are not corrected in due time amblyopia may occur. Photorefraction is a non-invasive clinical tool rather convenient for application to this kind of population. A qualitative or semi-quantitative information about refractive errors, accommodation, strabismus, amblyogenic factors and some pathologies (cataracts) can the easily obtained. The photorefraction experimental setup we established using new technological breakthroughs on the fields of imaging devices, image processing and fiber optics, allows the implementation of both the isotropic and eccentric photorefraction approaches. Essentially both methods consist on delivering a light beam into the eyes. It is refracted by the ocular media, strikes the retina, focusing or not, reflects off and is collected by a camera. The system is formed by one CCD color camera and a light source. A beam splitter in front of the camera's objective allows coaxial illumination and observation. An optomechanical system also allows eccentric illumination. The light source is a flash type one and is synchronized with the camera's image acquisition. The camera's image is digitized displayed in real time. Image processing routines are applied for image's enhancement and feature extraction.

  14. Sum-SINR/sum-capacity optimal multisignature spread-spectrum steganography

    NASA Astrophysics Data System (ADS)

    Wei, Lili; Pados, Dimitris A.; Batalama, Stella N.; Medley, Michael J.

    2008-04-01

    For any given digital host image or audio file (or group of hosts) and any (block) transform domain of interest, we find an orthogonal set of signatures that achieves maximum sum-signal-to-interference-plus-noise ratio (sum- SINR) spread-spectrum message embedding for any fixed embedding amplitude values. We also find the sumcapacity optimal amplitude allocation scheme for any given total distortion budget under the assumption of (colored) Gaussian transform-domain host data. The practical implication of the results is sum-SINR, sumcapacity optimal multiuser/multisignature spread-spectrum data hiding in the same medium. Theoretically, the findings establish optimality of the recently presented Gkizeli-Pados-Medley multisignature eigen-design algorithm.

  15. New Roles for New Times: Digital Curation for Preservation

    ERIC Educational Resources Information Center

    Walters, Tyler; Skinner, Katherine

    2011-01-01

    Digital curation refers to the actions people take to maintain and add value to digital information over its lifecycle, including the processes used when creating digital content. Digital preservation focuses on the "series of managed activities necessary to ensure continued access to digital materials for as long as necessary." In this…

  16. Digital Imaging.

    ERIC Educational Resources Information Center

    Howell, Les

    1996-01-01

    Defines a digital photograph as a numerical record of light electronically measured and recorded by a computer's scanner. States that most personal computers cannot do digital photography successfully and that digital pictures can be hard to manage and present a storage problem. Finds that, once the school has the hardware/software, picture…

  17. Digital Imaging.

    ERIC Educational Resources Information Center

    Howell, Les

    1996-01-01

    Defines a digital photograph as a numerical record of light electronically measured and recorded by a computer's scanner. States that most personal computers cannot do digital photography successfully and that digital pictures can be hard to manage and present a storage problem. Finds that, once the school has the hardware/software, picture…

  18. Digital Citizenship

    ERIC Educational Resources Information Center

    Isman, Aytekin; Canan Gungoren, Ozlem

    2014-01-01

    Era in which we live is known and referred as digital age.In this age technology is rapidly changed and developed. In light of these technological advances in 21st century, schools have the responsibility of training "digital citizen" as well as a good citizen. Digital citizens must have extensive skills, knowledge, Internet and …

  19. Development of a Chip/Chip/SRM platform using digital chip isoelectric focusing and LC-Chip mass spectrometry for enrichment and quantitation of low abundance protein biomarkers in human plasma

    PubMed Central

    Rafalko, Agnes; Dai, Shujia; Hancock, William S.; Karger, Barry L.; Hincapie, Marina

    2013-01-01

    Protein biomarkers are critical for diagnosis, prognosis, and treatment of disease. The transition from protein biomarker discovery to verification can be a rate limiting step in clinical development of new diagnostics. Liquid chromatography-selected reaction monitoring mass spectrometry (LC-SRM MS) is becoming an important tool for biomarker verification studies in highly complex biological samples. Analyte enrichment or sample fractionation is often necessary to reduce sample complexity and improve sensitivity of SRM for quantitation of clinically relevant biomarker candidates present at the low ng/mL range in blood. In this paper, we describe an alternative method for sample preparation for LC-SRM MS, which does not rely on availability of antibodies. This new platform is based on selective enrichment of proteotypic peptides from complex biological peptide mixtures via isoelectric focusing (IEF) on a digital ProteomeChip (dPC™) for SRM quantitation using a triple quadrupole (QQQ) instrument with an LC-Chip (Chip/Chip/SRM). To demonstrate the value of this approach, the optimization of the Chip/Chip/SRM platform was performed using prostate specific antigen (PSA) added to female plasma as a model system. The combination of immunodepletion of albumin and IgG with peptide fractionation on the dPC, followed by SRM analysis, resulted in a limit of quantitation of PSA added to female plasma at the level of ~1–2.5 ng/mL with a CV of ~13%. The optimized platform was applied to measure levels of PSA in plasma of a small cohort of male patients with prostate cancer (PCa) and healthy matched controls with concentrations ranging from 1.5 to 25 ng/mL. A good correlation (r2 = 0.9459) was observed between standard clinical ELISA tests and the SRM-based-assay. Our data demonstrate that the combination of IEF on the dPC and SRM (Chip/Chip/SRM) can be successfully applied for verification of low abundance protein biomarkers in complex samples. PMID:22098410

  20. Development of a Chip/Chip/SRM platform using digital chip isoelectric focusing and LC-Chip mass spectrometry for enrichment and quantitation of low abundance protein biomarkers in human plasma.

    PubMed

    Rafalko, Agnes; Dai, Shujia; Hancock, William S; Karger, Barry L; Hincapie, Marina

    2012-02-03

    Protein biomarkers are critical for diagnosis, prognosis, and treatment of disease. The transition from protein biomarker discovery to verification can be a rate limiting step in clinical development of new diagnostics. Liquid chromatography-selected reaction monitoring mass spectrometry (LC-SRM MS) is becoming an important tool for biomarker verification studies in highly complex biological samples. Analyte enrichment or sample fractionation is often necessary to reduce sample complexity and improve sensitivity of SRM for quantitation of clinically relevant biomarker candidates present at the low ng/mL range in blood. In this paper, we describe an alternative method for sample preparation for LC-SRM MS, which does not rely on availability of antibodies. This new platform is based on selective enrichment of proteotypic peptides from complex biological peptide mixtures via isoelectric focusing (IEF) on a digital ProteomeChip (dPC) for SRM quantitation using a triple quadrupole (QQQ) instrument with an LC-Chip (Chip/Chip/SRM). To demonstrate the value of this approach, the optimization of the Chip/Chip/SRM platform was performed using prostate specific antigen (PSA) added to female plasma as a model system. The combination of immunodepletion of albumin and IgG with peptide fractionation on the dPC, followed by SRM analysis, resulted in a limit of quantitation of PSA added to female plasma at the level of ∼1-2.5 ng/mL with a CV of ∼13%. The optimized platform was applied to measure levels of PSA in plasma of a small cohort of male patients with prostate cancer (PCa) and healthy matched controls with concentrations ranging from 1.5 to 25 ng/mL. A good correlation (r(2) = 0.9459) was observed between standard clinical ELISA tests and the SRM-based assay. Our data demonstrate that the combination of IEF on the dPC and SRM (Chip/Chip/SRM) can be successfully applied for verification of low abundance protein biomarkers in complex samples.

  1. Conceptualizing Digital Literacies and Digital Ethics for Sustainability Education

    ERIC Educational Resources Information Center

    Brown, Susan A.

    2014-01-01

    Purpose: The purpose of this paper is to discuss the need for integrating a focus on digital literacies and digital ethics into sustainability education, proposing a conceptualization of these for sustainability education. Design/methodology/approach: The paper draws on relevant literature in the field of sustainability education and in the field…

  2. Conceptualizing Digital Literacies and Digital Ethics for Sustainability Education

    ERIC Educational Resources Information Center

    Brown, Susan A.

    2014-01-01

    Purpose: The purpose of this paper is to discuss the need for integrating a focus on digital literacies and digital ethics into sustainability education, proposing a conceptualization of these for sustainability education. Design/methodology/approach: The paper draws on relevant literature in the field of sustainability education and in the field…

  3. Digital Natives or Digital Tribes?

    ERIC Educational Resources Information Center

    Watson, Ian Robert

    2013-01-01

    This research builds upon the discourse surrounding digital natives. A literature review into the digital native phenomena was undertaken and found that researchers are beginning to identify the digital native as not one cohesive group but of individuals influenced by other factors. Primary research by means of questionnaire survey of technologies…

  4. Tsunami focusing

    NASA Astrophysics Data System (ADS)

    Spillane, M. C.; Titov, V. V.; Moore, C. W.; Aydin, B.; Kanoglu, U.; Synolakis, C. E.

    2010-12-01

    Tsunamis are long waves generated by impulsive disturbances of the seafloor or coastal topography caused by earthquakes, submarine/subaerial mass failures. They evolve substantially through three dimensional - 2 spatial+1 temporal - spreading as the initial surface deformation propagates. This is referred to as its directivity and focusing. A directivity function was first defined by Ben-Menahem (1961, Bull. Seismol. Soc. Am. 51, 401-435) using the source length and the rupture velocity. Okal (2003, Pure Appl. Geophys. 160, 2189-2221) discussed the details of the analysis of Ben-Menahem (1961) and demonstrated the distinct difference between the directivity patterns of landslide and earthquake generated tsunamis. Marchuk and Titov (1989, Proc. IUGG/IOC International Tsunami Symposium, July 31 - August 3, 1989, Novosibirsk, USSR. p.11-17) described the process of tsunami focusing for a rectangular initial deformation combining positive and negative surface displacements. They showed the existence of a focusing point where abnormal tsunami wave height can be registered. Here, first, we describe and quantify numerically tsunami focusing processes for a combined positive and negative - N-wave type - strip source representing the 17 July 1998 Papua New Guinea and 17 July 2006 Java events. Specifically, considering field observations and tsunami focusing, we propose a source mechanism for the 17 July 2006 Java event. Then, we introduce a new analytical solution for a strip source propagating over a flat bottom using the linear shallow-water wave equation. The analytical solution of Carrier and Yeh (2005, Computer Modeling In Engineering & Sciences, 10(2), 113-121) appears to have two drawbacks. One, the solution involves singular complete elliptic integral of the first kind which results in a self-similar approximate solution for the far-field at large times. Two, only the propagation of Gaussian shaped finite-crest wave profiles can be modeled. Our solution is not only

  5. Adiabatic Focuser

    SciTech Connect

    Chen, P.; Oide, K.; Sessler, Andrew M.; Yu, S.S.

    1989-08-01

    Theoretical analysis is made of an intense relativistic electron beam. such as would be available from a linear collider, moving through a plasma of increasing density, but density always less than that of the beam (underdense). In this situation. the plasma electrons are expelled from the beam channel and the electrons are subject to an ever-increasing focusing force provided by the channel ions. Analysis is made on the beam radiation energy loss in the classical, the transition, and the quantum regimes. It is shown that the focuser is insensitive to the beam energy spread due to radiation loss. Furthermore, because of the different scaling behaviors in the nonclassical regimes, the radiation limit on lenses (the Oide limit) can be exceeded. The sensitivity of the system to the optic mismatch and the nonlinearity is also analyzed. Examples are given with SLC-type and TLC-type parameters.

  6. Preservation Methods for Digital Library

    ERIC Educational Resources Information Center

    Rajendran, L.; Venkatesan, M.; Kanthimathi, S.

    2005-01-01

    Going digital is the way to minimize handling of damaged materials, but the imaging process is demanding and must be done with oversight by preservation staff and with a high enough level of quality to ensure the reusability of the archival electronic file for as long as possible. This paper focuses on the scope and needs of digital preservation,…

  7. Digital Media Stories for Persuasion

    ERIC Educational Resources Information Center

    Leopold, Lisa

    2010-01-01

    Digital media story-telling (which enhances traditional oral story-telling with images, music, and text) has been a focus of recent scholarship for its potential to produce numerous educational benefits. Through digital media storytelling, students' imagination, creativity, critical thinking, writing, public speaking, and organizational or…

  8. Digital Media Stories for Persuasion

    ERIC Educational Resources Information Center

    Leopold, Lisa

    2010-01-01

    Digital media story-telling (which enhances traditional oral story-telling with images, music, and text) has been a focus of recent scholarship for its potential to produce numerous educational benefits. Through digital media storytelling, students' imagination, creativity, critical thinking, writing, public speaking, and organizational or…

  9. Digital Literacies of the Cybergirl

    ERIC Educational Resources Information Center

    Thomas, Angela

    2004-01-01

    This article explores the nexus between digital literacies and identity in the online graphical chat environment of the "palace". With a focus on the adolescent cybergirl, it examines how girls use words and images to create a digital presence, and in so doing, "write" their bodies and their selves. I discuss how the cybergirl is discursively…

  10. A better detection of 2LSB steganography via standard deviation of the extended pairs of values

    NASA Astrophysics Data System (ADS)

    Khalind, Omed; Aziz, Benjamin

    2015-05-01

    This paper proposes a modification to the Extended Pairs of Values (EPoV) method of 2LSB steganalysis in digital still images. In EPoV, the detection and the estimation of the hidden message length were performed in two separate processes as it considered the automated detection. However, the new proposed method uses the standard deviation of the EPoV to measure the amount of distortion in the stego image made by the embedding process using 2LSB replacement, which is directly proportional with the embedding rate. It is shown that it can accurately estimate the length of the hidden message and outperform the other methods of the targeted 2LSB steganalysis in the literature. The proposed method is also more consistent with the steganalysis methods in the literature by giving the amount of difference to the expected clean image. According to the experimental results, based on analysing 3000 nevercompressed images, the proposed method is more accurate than the current targeted 2LSB steganalysis methods for low embedding rates.

  11. Content-adaptive pentary steganography using the multivariate generalized Gaussian cover model

    NASA Astrophysics Data System (ADS)

    Sedighi, Vahid; Fridrich, Jessica; Cogranne, Rémi

    2015-03-01

    The vast majority of steganographic schemes for digital images stored in the raster format limit the amplitude of embedding changes to the smallest possible value. In this paper, we investigate the possibility to further improve the empirical security by allowing the embedding changes in highly textured areas to have a larger amplitude and thus embedding there a larger payload. Our approach is entirely model driven in the sense that the probabilities with which the cover pixels should be changed by a certain amount are derived from the cover model to minimize the power of an optimal statistical test. The embedding consists of two steps. First, the sender estimates the cover model parameters, the pixel variances, when modeling the pixels as a sequence of independent but not identically distributed generalized Gaussian random variables. Then, the embedding change probabilities for changing each pixel by 1 or 2, which can be transformed to costs for practical embedding using syndrome-trellis codes, are computed by solving a pair of non-linear algebraic equations. Using rich models and selection-channel-aware features, we compare the security of our scheme based on the generalized Gaussian model with pentary versions of two popular embedding algorithms: HILL and S-UNIWARD.

  12. Books Born Digital

    ERIC Educational Resources Information Center

    Eaton, Lance

    2009-01-01

    It used to be that a book was published first as a hardcover, then as a lower-cost paperback. With increasingly tech-savvy consumers demanding instantaneous access to content in various formats, that publishing protocol has in the last decade changed to one in which the book in codex form often remains the focus, but digital "extras"…

  13. Books Born Digital

    ERIC Educational Resources Information Center

    Eaton, Lance

    2009-01-01

    It used to be that a book was published first as a hardcover, then as a lower-cost paperback. With increasingly tech-savvy consumers demanding instantaneous access to content in various formats, that publishing protocol has in the last decade changed to one in which the book in codex form often remains the focus, but digital "extras"…

  14. Electrophoretic Focusing

    NASA Technical Reports Server (NTRS)

    Snyder, Robert S.

    2001-01-01

    Electrophoretic focusing is a new method of continuous flow electrophoresis that introduces precision flow control to achieve high resolution separations. The electric field is applied perpendicular to an incoming sample lamina and buffer but also perpendicular to the broad faces of the thin rectangular chamber. A uniform fluid cross-flow then enters and exits the separation chamber through the same broad faces which are porous. A balance is achieved by adjusting either the electric field or the cross-flow so the desired sample fraction with its specific migration velocity encounters an opposing flow of the same velocity. Applying an electric field transverse to the incoming sample lamina and opposing this field with a carefully configured buffer flow, a sample constituent can be selected and focused into a narrow stream for subsequent analysis. Monotonically changing either electric field or buffer cross-flow will yield a scan of all constituents of the sample. Stopping the scan increases the collection time for minor constituents to improve their analysis. Using the high voltage gradients and/or cross-flow to rapidly deflect extraneous sample through the porous screens and into either of the side (purge) chambers, the selected sample is focused in the center plane of the separation chamber and collected without contact or interaction with the separation chamber walls. Results will be presented on the separation of a range of materials including dyes, proteins, and monodisperse polystyrene latexes. Sources of sample dispersion inherent in other electrokinetic techniques will be shown to be negligible for a variety of sample concentrations, buffer properties and operating conditions.

  15. Digital Imaging

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Digital Imaging is the computer processed numerical representation of physical images. Enhancement of images results in easier interpretation. Quantitative digital image analysis by Perceptive Scientific Instruments, locates objects within an image and measures them to extract quantitative information. Applications are CAT scanners, radiography, microscopy in medicine as well as various industrial and manufacturing uses. The PSICOM 327 performs all digital image analysis functions. It is based on Jet Propulsion Laboratory technology, is accurate and cost efficient.

  16. Digital metamaterials.

    PubMed

    Della Giovampaola, Cristian; Engheta, Nader

    2014-12-01

    Balancing complexity and simplicity has played an important role in the development of many fields in science and engineering. One of the well-known and powerful examples of such balance can be found in Boolean algebra and its impact on the birth of digital electronics and the digital information age. The simplicity of using only two numbers, '0' and '1', in a binary system for describing an arbitrary quantity made the fields of digital electronics and digital signal processing powerful and ubiquitous. Here, inspired by the binary concept, we propose to develop the notion of digital metamaterials. Specifically, we investigate how one can synthesize an electromagnetic metamaterial with a desired permittivity, using as building blocks only two elemental materials, which we call 'metamaterial bits', with two distinct permittivity functions. We demonstrate, analytically and numerically, how proper spatial mixtures of such metamaterial bits lead to elemental 'metamaterial bytes' with effective material parameters that are different from the parameters of the metamaterial bits. We then apply this methodology to several design examples of optical elements, such as digital convex lenses, flat graded-index digital lenses, digital constructs for epsilon-near-zero (ENZ) supercoupling and digital hyperlenses, thus highlighting the power and simplicity of the methodology.

  17. Digital printing

    NASA Astrophysics Data System (ADS)

    Sobotka, Werner K.

    1997-02-01

    Digital printing is described as a tool to replace conventional printing machines completely. Still this goal was not reached until now with any of the digital printing technologies to be described in the paper. Productivity and costs are still the main parameters and are not really solved until now. Quality in digital printing is no problem anymore. Definition of digital printing is to transfer digital datas directly on the paper surface. This step can be carried out directly or with the use of an intermediate image carrier. Keywords in digital printing are: computer- to-press; erasable image carrier; image carrier with memory. Digital printing is also the logical development of the new digital area as it is pointed out in Nicholas Negropotes book 'Being Digital' and also the answer to networking and Internet technologies. Creating images text and color in one country and publishing the datas in another country or continent is the main advantage. Printing on demand another big advantage and last but not least personalization the last big advantage. Costs and being able to coop with this new world of prepress technology is the biggest disadvantage. Therefore the very optimistic growth rates for the next few years are really nonexistent. The development of complete new markets is too slow and the replacing of old markets is too small.

  18. Digital Humanities: What Can Libraries Offer?

    ERIC Educational Resources Information Center

    Wong, Shun Han Rebekah

    2016-01-01

    The collaborative aspect of digital humanities is one of the core values of the field. Specialists and organizations involved in digital humanities partnerships may include individual scholars focusing on a particular area, multiple scholars across disciplines, computer scientists, or digital humanities centers. Through a quantitative analysis of…

  19. Diversity, Disability, and Geographic Digital Divide

    ERIC Educational Resources Information Center

    Sumari, Melati; Carr, Erika; Ndebe-Ngovo, Manjerngie

    2006-01-01

    The phenomenon called digital divide was the focus of this paper. Diversity, disability, and geographical digital divide were relevant to this collaborative project. An extensive review of the literature was conducted for the completion of this project. The evidence for the digital divide in terms of race, level of education, and gender in the…

  20. Digital Humanities: What Can Libraries Offer?

    ERIC Educational Resources Information Center

    Wong, Shun Han Rebekah

    2016-01-01

    The collaborative aspect of digital humanities is one of the core values of the field. Specialists and organizations involved in digital humanities partnerships may include individual scholars focusing on a particular area, multiple scholars across disciplines, computer scientists, or digital humanities centers. Through a quantitative analysis of…

  1. Architectural Optimization of Digital Libraries

    NASA Technical Reports Server (NTRS)

    Biser, Aileen O.

    1998-01-01

    This work investigates performance and scaling issues relevant to large scale distributed digital libraries. Presently, performance and scaling studies focus on specific implementations of production or prototype digital libraries. Although useful information is gained to aid these designers and other researchers with insights to performance and scaling issues, the broader issues relevant to very large scale distributed libraries are not addressed. Specifically, no current studies look at the extreme or worst case possibilities in digital library implementations. A survey of digital library research issues is presented. Scaling and performance issues are mentioned frequently in the digital library literature but are generally not the focus of much of the current research. In this thesis a model for a Generic Distributed Digital Library (GDDL) and nine cases of typical user activities are defined. This model is used to facilitate some basic analysis of scaling issues. Specifically, the calculation of Internet traffic generated for different configurations of the study parameters and an estimate of the future bandwidth needed for a large scale distributed digital library implementation. This analysis demonstrates the potential impact a future distributed digital library implementation would have on the Internet traffic load and raises questions concerning the architecture decisions being made for future distributed digital library designs.

  2. Design of DPSS based fiber bragg gratings and their application in all-optical encryption, OCDMA, optical steganography, and orthogonal-division multiplexing.

    PubMed

    Djordjevic, Ivan B; Saleh, Alaa H; Küppers, Franko

    2014-05-05

    The future information infrastructure will be affected by limited bandwidth of optical networks, high energy consumption, heterogeneity of network segments, and security issues. As a solution to all problems, we advocate the use of both electrical basis functions (orthogonal prolate spheroidal basis functions) and optical basis functions, implemented as FBGs with orthogonal impulse response in addition to spatial modes. We design the Bragg gratings with orthogonal impulse responses by means of discrete layer peeling algorithm. The target impulse responses belong to the class of discrete prolate spheroidal sequences, which are mutually orthogonal regardless of the sequence order, while occupying the fixed bandwidth. We then design the corresponding encoders and decoders suitable for all-optical encryption, optical CDMA, optical steganography, and orthogonal-division multiplexing (ODM). Finally, we propose the spectral multiplexing-ODM-spatial multiplexing scheme enabling beyond 10 Pb/s serial optical transport networks.

  3. Digital Discrimination

    ERIC Educational Resources Information Center

    Blansett, Jim

    2008-01-01

    In recent years, the Internet has become a digital commons of commerce and education. However, accessibility standards have often been overlooked online, and the digital equivalents to curb-cuts and other physical accommodations have only rarely been implemented to serve those with print disabilities. (A print disability can be a learning…

  4. Digital Discrimination

    ERIC Educational Resources Information Center

    Blansett, Jim

    2008-01-01

    In recent years, the Internet has become a digital commons of commerce and education. However, accessibility standards have often been overlooked online, and the digital equivalents to curb-cuts and other physical accommodations have only rarely been implemented to serve those with print disabilities. (A print disability can be a learning…

  5. Digital TMI

    NASA Technical Reports Server (NTRS)

    Rios, Joseph

    2012-01-01

    Presenting the current status of the Digital TMI project to visiting members of the FAA Command Center. Digital TMI is an effort to store national-level traffic management initiatives in a standards-compliant manner. Work is funded by the FAA.

  6. Digital Roundup

    ERIC Educational Resources Information Center

    Horn, Michael B.

    2013-01-01

    State policy is crucial to the spread of digital-learning opportunities at the elementary and secondary level. A review of recent legislative action reveals policies that are constantly in flux and differ quite markedly from one state to another. Some have hoped for model digital-learning legislation that could handle all the various issues…

  7. Digital Ethics/Going Digital.

    ERIC Educational Resources Information Center

    Wilson, Bradley

    1996-01-01

    Finds that the recent National Press Photographers Association code of ethics can serve as a model for any photography staff. Discusses how digital imaging is becoming commonplace in classrooms, due to decreasing costs and easier software. Explains digital terminology. Concludes that time saved in the darkroom and at the printer is now spent on…

  8. Digital Ethics/Going Digital.

    ERIC Educational Resources Information Center

    Wilson, Bradley

    1996-01-01

    Finds that the recent National Press Photographers Association code of ethics can serve as a model for any photography staff. Discusses how digital imaging is becoming commonplace in classrooms, due to decreasing costs and easier software. Explains digital terminology. Concludes that time saved in the darkroom and at the printer is now spent on…

  9. Digital Assays Part II: Digital Protein and Cell Assays.

    PubMed

    Basu, Amar S

    2017-08-01

    A digital assay is one in which the sample is partitioned into many containers such that each partition contains a discrete number of biological entities (0, 1, 2, 3, . . .). A powerful technique in the biologist's toolkit, digital assays bring a new level of precision in quantifying nucleic acids, measuring proteins and their enzymatic activity, and probing single-cell genotype and phenotype. Where part I of this review focused on the fundamentals of partitioning and digital PCR, part II turns its attention to digital protein and cell assays. Digital enzyme assays measure the kinetics of single proteins with enzymatic activity. Digital enzyme-linked immunoassays (ELISAs) quantify antigenic proteins with 2 to 3 log lower detection limit than conventional ELISA, making them well suited for low-abundance biomarkers. Digital cell assays probe single-cell genotype and phenotype, including gene expression, intracellular and surface proteins, metabolic activity, cytotoxicity, and transcriptomes (scRNA-seq). These methods exploit partitioning to 1) isolate single cells or proteins, 2) detect their activity via enzymatic amplification, and 3) tag them individually by coencapsulating them with molecular barcodes. When scaled, digital assays reveal stochastic differences between proteins or cells within a population, a key to understanding biological heterogeneity. This review is intended to give a broad perspective to scientists interested in adopting digital assays into their workflows.

  10. Digital imaging in dentistry.

    PubMed

    Essen, S Donovan

    2011-01-01

    Information technology is vital to operations, marketing, accounting, finance and administration. One of the most exciting and quickly evolving technologies in the modern dental office is digital applications. The dentist is often the business manager, information technology officer and strategic planning chief for his small business. The information systems triangle applies directly to this critical manager supported by properly trained ancillary staff and good equipment. With emerging technology driving all medical disciplines and the rapid pace at which it emerges, it is vital for the contemporary practitioner to keep abreast of the newest information technology developments. This article compares the strategic and operational advantages of digital applications, specifically imaging. The focus of this paper will be on digital radiography (DR), 3D computerized tomography, digital photography and digitally-driven CAD/CAM to what are now considered obsolescing modalities and contemplates what may arrive in the future. It is the purpose of this essay to succinctly evaluate the decisions involved in the role, application and implications of employing this tool in the dental environment

  11. Digital Epidemiology

    PubMed Central

    Salathé, Marcel; Bengtsson, Linus; Bodnar, Todd J.; Brewer, Devon D.; Brownstein, John S.; Buckee, Caroline; Campbell, Ellsworth M.; Cattuto, Ciro; Khandelwal, Shashank; Mabry, Patricia L.; Vespignani, Alessandro

    2012-01-01

    Mobile, social, real-time: the ongoing revolution in the way people communicate has given rise to a new kind of epidemiology. Digital data sources, when harnessed appropriately, can provide local and timely information about disease and health dynamics in populations around the world. The rapid, unprecedented increase in the availability of relevant data from various digital sources creates considerable technical and computational challenges. PMID:22844241

  12. Are "Digital Natives" Really Digitally Competent?--A Study on Chinese Teenagers

    ERIC Educational Resources Information Center

    Li, Yan; Ranieri, Maria

    2010-01-01

    Literature review has found that despite the considerable attention focused on "digital natives", few studies have carefully investigated the characteristics of this group. The purpose of this study is to contribute to the debate on digital natives by providing a "piece of evidence" on the digital competence status of a group…

  13. Are "Digital Natives" Really Digitally Competent?--A Study on Chinese Teenagers

    ERIC Educational Resources Information Center

    Li, Yan; Ranieri, Maria

    2010-01-01

    Literature review has found that despite the considerable attention focused on "digital natives", few studies have carefully investigated the characteristics of this group. The purpose of this study is to contribute to the debate on digital natives by providing a "piece of evidence" on the digital competence status of a group…

  14. Digital radiography.

    PubMed

    Mattoon, J S

    2006-01-01

    Digital radiography has been used in human medical imaging since the 1980s with recent and rapid acceptance into the veterinary profession. Using advanced image capture and computer technology, radiographic images are viewed on a computer monitor. This is advantageous because radiographic images can be adjusted using dedicated computer software to maximize diagnostic image quality. Digital images can be accessed at computer workstations throughout the hospital, instantly retrieved from computer archives, and transmitted via the internet for consultation or case referral. Digital radiographic data can also be incorporated into a hospital information system, making record keeping an entirely paperless process. Digital image acquisition is faster when compared to conventional screen-film radiography, improving workflow and patient throughput. Digital radiography greatly reduces the need for 'retake' radiographs because of wide latitude in exposure factors. Also eliminated are costs associated with radiographic film and x-ray film development. Computed radiography, charged coupled devices, and flat panel detectors are types of digital radiography systems currently available.

  15. Digital video.

    PubMed

    Johnson, Don; Johnson, Mike

    2004-04-01

    The process of digital capture, editing, and archiving video has become an important aspect of documenting arthroscopic surgery. Recording the arthroscopic findings before and after surgery is an essential part of the patient's medical record. The hardware and software has become more reasonable to purchase, but the learning curve to master the software is steep. Digital video is captured at the time of arthroscopy to a hard disk, and written to a CD at the end of the operative procedure. The process of obtaining video of open procedures is more complex. Outside video of the procedure is recorded on digital tape with a digital video camera. The camera must be plugged into a computer to capture the video on the hard disk. Adobe Premiere software is used to edit the video and render the finished video to the hard drive. This finished video is burned onto a CD. We outline the choice of computer hardware and software for the manipulation of digital video. The techniques of backup and archiving the completed projects and files also are outlined. The uses of digital video for education and the formats that can be used in PowerPoint presentations are discussed.

  16. The Power of Digital Learning: Integrating Digital Content. The CEO Forum School Technology and Readiness Report, Year Three.

    ERIC Educational Resources Information Center

    CEO Forum on Education and Technology, Washington, DC.

    This report offers a vision for digital learning and focuses on actions that schools, teachers, students, and parents must take to integrate digital content into the curriculum to create the learning environments that develop 21st century skills. Section 1 presents a vision for digital learning. The power of digital learning is discussed in…

  17. Digital Collections, Digital Libraries & the Digitization of Cultural Heritage Information.

    ERIC Educational Resources Information Center

    Lynch, Clifford

    2002-01-01

    Discusses digital collections and digital libraries. Topics include broadband availability; digital rights protection; content, both non-profit and commercial; digitization of cultural content; sustainability; metadata harvesting protocol; infrastructure; authorship; linking multiple resources; data mining; digitization of reference works;…

  18. Digital Radiography: A Technology Overview

    NASA Astrophysics Data System (ADS)

    Arnold, Ben A.

    1982-12-01

    Digital radiography, a term hardly recognized two years ago, has grown to become the talk of the radiology community and the excitement of many commercial companies. M2st of this attention has been directed toward digital subtraction intravenous angiography), although during this same time period, a variety of digital radiography apparatus and image processing techniques have been under development. In November of 1980 at the RSNA Conference in Chicago, three commercial digital angiography systems were announced by Philips, Technicare and ADAC Corporations. During this same time period, the University of Arizona was discussing the concept of a photo electronic radiology department2, the University of Pittsburg and Stanford University were investigating line scan radiography3,4 and approximately five laboratories were carrying out clinical IV angiography with digital video systems.5-9 These developments followed basic research programs in digital electronic and computerized imaging at various locations around the world. 10-18 In the spring of 1981 we attempted to review the state of digital radiography, focusing on the various detector systems and image acquisition approaches.19 Since that time, rapid advancements in digital radiography have occurred. A major conference was held on digital radiography at Stanford UniversityzO, a new area detector system for digital radiography was announced by Fuji Film Corporation, clinical testing began on the Picker line scan digital chest unit21, and improvements were made in selenium detectors for digital radiography. Several additional companies announced digital video angiography systems, bringing the total now to approximately 15 companies worldwide. Digital video subtraction angiography is now well established as an important clinical diagnostic procedure and a variety of improvements and extensions of digital angiography systems are now ongoing. Digital acquisition and storage systems are increasing in both speed and

  19. Towards Statistically Undetectable Steganography

    DTIC Science & Technology

    2011-06-30

    objects and the objects carrying the message (stego objects). Formally, the security of a stego-system is evaluated using the Kullback- Lei bier...P™(X)), is a mean-shifted Gauss - Gauss problem.4 This property, usually called the Local Asymptotic Normality (LAN) of the detector, allows us to...by logn. 4In hypothesis testing, the problem of testing N(tio,a2) vs. N(m,a2) is called the mean-shifted Gauss - Gauss problem and its detection

  20. Digital karyotyping.

    PubMed

    Wang, Tian-Li; Maierhofer, Christine; Speicher, Michael R; Lengauer, Christoph; Vogelstein, Bert; Kinzler, Kenneth W; Velculescu, Victor E

    2002-12-10

    Alterations in the genetic content of a cell are the underlying cause of many human diseases, including cancers. We have developed a method, called digital karyotyping, that provides quantitative analysis of DNA copy number at high resolution. This approach involves the isolation and enumeration of short sequence tags from specific genomic loci. Analysis of human cancer cells by using this method identified gross chromosomal changes as well as amplifications and deletions, including regions not previously known to be altered. Foreign DNA sequences not present in the normal human genome could also be readily identified. Digital karyotyping provides a broadly applicable means for systematic detection of DNA copy number changes on a genomic scale.

  1. Digital Radiography

    NASA Technical Reports Server (NTRS)

    1986-01-01

    System One, a digital radiography system, incorporates a reusable image medium (RIM) which retains an image. No film is needed; the RIM is read with a laser scanner, and the information is used to produce a digital image on an image processor. The image is stored on an optical disc. System allows the radiologist to "dial away" unwanted images to compare views on three screens. It is compatible with existing equipment and cost efficient. It was commercialized by a Stanford researcher from energy selective technology developed under a NASA grant.

  2. Digital Tidbits

    ERIC Educational Resources Information Center

    Kumaran, Maha; Geary, Joe

    2011-01-01

    Technology has transformed libraries. There are digital libraries, electronic collections, online databases and catalogs, ebooks, downloadable books, and much more. With free technology such as social websites, newspaper collections, downloadable online calendars, clocks and sticky notes, online scheduling, online document sharing, and online…

  3. Digital books.

    PubMed

    Wink, Diane M

    2011-01-01

    In this bimonthly series, the author examines how nurse educators can use the Internet and Web-based computer technologies such as search, communication, and collaborative writing tools; social networking and social bookmarking sites; virtual worlds; and Web-based teaching and learning programs. This article describes digital books.

  4. Digital Badges

    ERIC Educational Resources Information Center

    Frederiksen, Linda

    2013-01-01

    Unlike so much of the current vocabulary in education and technology that seems to stir more confusion than clarity, most public service librarians may already have a general idea about digital badges. As visual representations of individual accomplishments, competencies or skills that are awarded by groups, institutions, or organizations, they…

  5. Digital Tidbits

    ERIC Educational Resources Information Center

    Kumaran, Maha; Geary, Joe

    2011-01-01

    Technology has transformed libraries. There are digital libraries, electronic collections, online databases and catalogs, ebooks, downloadable books, and much more. With free technology such as social websites, newspaper collections, downloadable online calendars, clocks and sticky notes, online scheduling, online document sharing, and online…

  6. Digital Batteries

    NASA Astrophysics Data System (ADS)

    Hubler, Alfred

    2009-03-01

    The energy density in conventional capacitors is limited by sparking. We present nano-capacitor arrays, where - like in laser diodes and quantum wells [1] - quantization prevents dielectric breakthrough. We show that the energy density and the power/weight ratio are very high, possibly larger than in hydrogen [2]. Digital batteries are a potential clean energy source for cars, laptops, and mobile devices. The technology is related to flash drives. However, because of the high energy density, safety is a concern. Digital batteries can be easily and safely charged and discharged. In the discharged state they pose no danger. Even if a charged digital battery were to explode, it would produce no radioactive waste, no long-term radiation, and probably could be designed to produce no noxious chemicals. We discuss methodologies to prevent shorts and other measures to make digital batteries safe. [1] H. Higuraskh, A. Toriumi, F. Yamaguchi, K. Kawamura, A. Hubler, Correlation Tunnel Device, U. S. Patent No. 5,679,961 (1997) [2] Alfred Hubler, http://server10.how-why.com/blog/

  7. Crossing the Digital Divide

    SciTech Connect

    Ken Thomas

    2011-11-01

    Nuclear utilities continue to upgrade aging instrumentation and control (I&C) systems with modern digital-based systems to address reliability and obsolescence concerns. In addition, the industry has demonstrated that these systems can be successfully developed and deployed even for highly safety-significant applications, such as reactor protection. However, three factors have retarded wide-scale implementation of digital technology for plant modernization and business innovation: *Large-scale digital upgrades entail considerable risk; *The upgrades are very costly and have not led to bottom-line business improvement, financial or otherwise; *Cyber Security concerns discourage wide-scale digital integration. A new national research program is under way that has been designed to address these industry concerns about expanding the use of digital technology. The Idaho National Laboratory (INL) has lead responsibility for the Advanced Instrumentation, Information, and Control Systems Technologies research pathway within the Light Water Reactor Sustainability (LWRS) Program. The LWRS Program is a research and development (R&D) program sponsored by the U.S. Department of Energy (DOE) and performed in close collaboration with industry R&D and improvement programs (as defined in INL’s FY2009–2013 Light Water Reactor Sustainability Research and Development Program Plan, INL/MIS08-14918). Its purpose is to provide the technical foundations for licensing and managing the long-term, safe, and economical operation of existing nuclear power plants. The DOE’s program focus is on longer-term and higher-risk/reward research that contributes to the national policy objectives of energy security and environmental security. The specific concern addressed by this program is that large-scale I&C obsolescence could become a life-limiting issue for the current nuclear operating fleet.

  8. Focusing criterion in DHM image reconstruction

    NASA Astrophysics Data System (ADS)

    Mihailescu, M.; Mihale, N.; Popescu, R. C.; Acasandrei, A.; Paun, I. A.; Dinescu, M.; Scarlat, E.

    2015-02-01

    This study is presenting the theoretical approach and the practical results of a precise activity involved in the hologram reconstruction in order to find the optimally focused image of MG63 osteoblast-like cells cultivated on polymeric flat substrates. The morphology and dynamic of the cell is investigated by digital holographic microscopy (DHM) technique. The reconstruction is digitally performed using an algorithm based on the scalar theory of diffraction in the Fresnel approximation. The quality of the 3D images of the cells is crucially depending on the focusing capability of the reconstruction chain to fit the parameters of the optical recorder, particularly the focusing value. Our proposal to find the focused image is based on the images decomposition on gray levels and their histogram analysis. More precisely the focusing criterion is based on the evaluation of the form of this distribution.

  9. Digital image watermarking: its formal model, fundamental properties and possible attacks

    NASA Astrophysics Data System (ADS)

    Nyeem, Hussain; Boles, Wageeh; Boyd, Colin

    2014-12-01

    While formal definitions and security proofs are well established in some fields like cryptography and steganography, they are not as evident in digital watermarking research. A systematic development of watermarking schemes is desirable, but at present, their development is usually informal, ad hoc, and omits the complete realization of application scenarios. This practice not only hinders the choice and use of a suitable scheme for a watermarking application, but also leads to debate about the state-of-the-art for different watermarking applications. With a view to the systematic development of watermarking schemes, we present a formal generic model for digital image watermarking. Considering possible inputs, outputs, and component functions, the initial construction of a basic watermarking model is developed further to incorporate the use of keys. On the basis of our proposed model, fundamental watermarking properties are defined and their importance exemplified for different image applications. We also define a set of possible attacks using our model showing different winning scenarios depending on the adversary capabilities. It is envisaged that with a proper consideration of watermarking properties and adversary actions in different image applications, use of the proposed model would allow a unified treatment of all practically meaningful variants of watermarking schemes.

  10. Digital karyotyping

    PubMed Central

    Wang, Tian-Li; Maierhofer, Christine; Speicher, Michael R.; Lengauer, Christoph; Vogelstein, Bert; Kinzler, Kenneth W.; Velculescu, Victor E.

    2002-01-01

    Alterations in the genetic content of a cell are the underlying cause of many human diseases, including cancers. We have developed a method, called digital karyotyping, that provides quantitative analysis of DNA copy number at high resolution. This approach involves the isolation and enumeration of short sequence tags from specific genomic loci. Analysis of human cancer cells by using this method identified gross chromosomal changes as well as amplifications and deletions, including regions not previously known to be altered. Foreign DNA sequences not present in the normal human genome could also be readily identified. Digital karyotyping provides a broadly applicable means for systematic detection of DNA copy number changes on a genomic scale. PMID:12461184

  11. Digital tachometer

    NASA Astrophysics Data System (ADS)

    Shirokov, B.

    1984-03-01

    A tachometer with digital indication was built for measuring the speed of automobile engines with only two digits in the rpm readout. It consists of a Schmitt trigger for shaping input pulses, a pulse counter, a cycle time setting multivibrator and a readout time setting multivibrator, a stabilizer, a flicker suppressor, and a capacitive transducer. The instrument operates from a 12 V battery and draws 180 mA. The transducer includes a 30 to 50 turns coil of PEL 0.5 wire wound around the conductor which connects the ignition coil to the engine distributor and its transistor is mounted on a fin-type heat sink. Tuneup of the tachometer involves matching the transducer capacitor for maximum voltage at minimum current and trimming the readout time setting multivibrator with its adjustable resistor for a 1.5 readout with a 50 Hz input signal.

  12. [Digital radiography].

    PubMed

    Haendle, J

    1983-03-01

    Digital radiography is a generally accepted term comprising all x-ray image systems producing a projected image which resembles the conventional x-ray film image, and which are linked to any type of digital image processing. Fundamental criteria of differentiation are based on the production and detection method of the x-ray image. Various systems are employed, viz. the single-detector, line-detector or fanbeam detector and the area-beam or area-detector image converters, which differ from one another mainly in the manner of conversion of the radiation produced by the x-ray tube. The article also deals with the pros and cons of the various principles, the multitude of systems employed, and the varying frequency of their use in x-ray diagnosis work.

  13. Digital Image Collections: Issues and Practice.

    ERIC Educational Resources Information Center

    Ester, Michael

    The Commission on Preservation and Access has published a number of reports on the preservation and access implications of scanning text and microfilm. This report focuses on what sets the digitization of visual collections apart from other scanning projects. Projects to digitize visual collections present their own unique set of questions and…

  14. Uniting the paper and digital worlds.

    PubMed

    Schreiner, Keri

    2008-01-01

    Digital pen and paper technologies are increasingly popular in vertical markets such as health care, but the broad market of everyday consumers remains untapped. In the past year, several developers targeting that market have focused on notetakers-whether journalists, lawyers, or students-in the hope of uniting the paper and digital worlds.

  15. Understanding Computer-Based Digital Video.

    ERIC Educational Resources Information Center

    Martindale, Trey

    2002-01-01

    Discussion of new educational media and technology focuses on producing and delivering computer-based digital video. Highlights include video standards, including international standards and aspect ratio; camera formats and features, including costs; shooting digital video; editing software; compression; and a list of informative Web sites. (LRW)

  16. Education for Digitization: How Do We Prepare?

    ERIC Educational Resources Information Center

    Perry, Claudia A.

    2005-01-01

    This paper examines the characteristics and variety of digitization training initiatives in North America and to a lesser extent, Europe, and the growing development of credit-bearing courses and programs within higher education relating to digitization, with a specific focus on librarianship. Information was collected in response to an inquiry…

  17. A Personalized Information Environment for Digital Libraries.

    ERIC Educational Resources Information Center

    Jayawardana, Champa; Hewagamage, K. Priyantha; Hirakawa, Masahito

    2001-01-01

    Discussion of digital libraries focuses on the need for personalization capabilities so users can create their own personalized information environments. Highlights include material personalization; collection personalization; active reading; personalized retrieving; personalized filtering; and a prototype system. (LRW)

  18. Stop Calling It "Digital Humanities"

    ERIC Educational Resources Information Center

    Pannapacker, William

    2013-01-01

    A persistent criticism of the digital-humanities movement is that it is elitist and exclusive because it requires the resources of a major university (faculty, infrastructure, money), and is thus more suited to campuses with a research focus. Academics and administrators at small liberal-arts colleges may read about DH and, however exciting it…

  19. Digital Telematics: Present and Future.

    ERIC Educational Resources Information Center

    Stalberg, Christian E.

    1987-01-01

    This overview of developments in international telecommunications networks focuses on their importance for developing countries and the necessary interdependence of all countries. Highlights include digital technology, telephone service, packet switching networks, communications satellites, fiber optic cables, and possible future developments.…

  20. Tweens' Characterization of Digital Technologies

    ERIC Educational Resources Information Center

    Brito, Pedro Quelhas

    2012-01-01

    The tweens are a transitional age group undergoing deep physical and psychological transformations. Based on a thirteen-focus group research design involving 103 students, and applying a tweens-centered approach, the characteristics of SMS, IM, Internet, digital photos, electronic games, and email were analyzed. Categories such as moral issues,…

  1. Tweens' Characterization of Digital Technologies

    ERIC Educational Resources Information Center

    Brito, Pedro Quelhas

    2012-01-01

    The tweens are a transitional age group undergoing deep physical and psychological transformations. Based on a thirteen-focus group research design involving 103 students, and applying a tweens-centered approach, the characteristics of SMS, IM, Internet, digital photos, electronic games, and email were analyzed. Categories such as moral issues,…

  2. Digital Telematics: Present and Future.

    ERIC Educational Resources Information Center

    Stalberg, Christian E.

    1987-01-01

    This overview of developments in international telecommunications networks focuses on their importance for developing countries and the necessary interdependence of all countries. Highlights include digital technology, telephone service, packet switching networks, communications satellites, fiber optic cables, and possible future developments.…

  3. Video Games and Digital Literacies

    ERIC Educational Resources Information Center

    Steinkuehler, Constance

    2010-01-01

    Today's youth are situated in a complex information ecology that includes video games and print texts. At the basic level, video game play itself is a form of digital literacy practice. If we widen our focus from the "individual player + technology" to the online communities that play them, we find that video games also lie at the nexus of a…

  4. Stop Calling It "Digital Humanities"

    ERIC Educational Resources Information Center

    Pannapacker, William

    2013-01-01

    A persistent criticism of the digital-humanities movement is that it is elitist and exclusive because it requires the resources of a major university (faculty, infrastructure, money), and is thus more suited to campuses with a research focus. Academics and administrators at small liberal-arts colleges may read about DH and, however exciting it…

  5. Video Games and Digital Literacies

    ERIC Educational Resources Information Center

    Steinkuehler, Constance

    2010-01-01

    Today's youth are situated in a complex information ecology that includes video games and print texts. At the basic level, video game play itself is a form of digital literacy practice. If we widen our focus from the "individual player + technology" to the online communities that play them, we find that video games also lie at the nexus of a…

  6. Educating for the 21st Century: Bringing Today's Classrooms into the Digital Age. Field Hearing of the Committee on Health, Education, Labor, and Pensions, United States Senate, One Hundred Thirteenth Congress, First Session on Examining Educating for the 21st Century, Focusing on Bringing Today's Classrooms into the Digital Age (November 22, 2013, Charlotte, NC). Senate Hearing 113-821

    ERIC Educational Resources Information Center

    US Senate, 2016

    2016-01-01

    This field hearing of the Committee on Health, Education, Labor, and Pensions, focused on discussing new ways to use technology in the classroom. The committee met on Friday, November 22, 2013, in the media room, Phillip O. Berry Academy of Technology with Hon. Kay Hagan presiding. Opening remarks by Honorable Kay R. Hagan began with her stating…

  7. Digitally Literate Teachers in Leading Edge Schools in Norway

    ERIC Educational Resources Information Center

    Almas, Aslaug Grov; Krumsvik, Rune

    2007-01-01

    This paper highlights digitally literate, in-service teachers in leading edge schools in Norway and focuses on how they, in their professional development, adapt digital literacy. Today we find a consensus among policy-makers, researchers, teacher-educators and teachers that digital literacy must be given high priority and needs to be explored…

  8. E-inclusion Process and Societal Digital Skill Development

    ERIC Educational Resources Information Center

    Vitolina, Ieva

    2015-01-01

    Nowadays, the focus shifts from information and communication technology access to skills and knowledge. Moreover, lack of digital skills is an obstacle in the process of learning new digital competences using technologies and e-learning. The objective of this research is to investigate how to facilitate students to use the acquired digital skills…

  9. Digital Library Federation: Annual Report, 1998-1999.

    ERIC Educational Resources Information Center

    Council on Library and Information Resources, Washington, DC. Digital Library Federation.

    This annual report of the Digital Library Federation describes projects initiated in response to the following program priorities: (1) focus attention on libraries of materials that are born digital, including a social science data workshop and guides to quality in visual resource imaging; (2) integrate digital materials into the fabric of…

  10. E-inclusion Process and Societal Digital Skill Development

    ERIC Educational Resources Information Center

    Vitolina, Ieva

    2015-01-01

    Nowadays, the focus shifts from information and communication technology access to skills and knowledge. Moreover, lack of digital skills is an obstacle in the process of learning new digital competences using technologies and e-learning. The objective of this research is to investigate how to facilitate students to use the acquired digital skills…

  11. The Inquiry Page: Bringing Digital Libraries to Learners.

    ERIC Educational Resources Information Center

    Bruce, Bertram C.; Bishop, Ann Peterson; Heidorn, P. Bryan; Lunsford, Karen J.; Poulakos, Steven; Won, Mihye

    2003-01-01

    Discusses digital library development, particularly a national science digital library, and describes the Inquiry Page which focuses on building a constructivist environment using Web resources, collaborative processes, and knowledge that bridges digital libraries with users in K-12 schools, museums, community groups, or other organizations. (LRW)

  12. Libraries in Today's Digital Age: The Copyright Controversy. ERIC Digest.

    ERIC Educational Resources Information Center

    Russell, Carrie

    This digest focuses on the continuing ambiguities libraries and their users face in dealing with copyright in the digital environment. In the networked digital world, the basic principles of copyright are more difficult to apply. Digital copies are easy to create, modify, and manipulate, they are extremely easy to distribute widely over networks,…

  13. Scanning for Digitization Projects

    ERIC Educational Resources Information Center

    Wentzel, Larry

    2007-01-01

    Librarians and archivists find themselves facing the prospect of digitization. Everyone is doing it, everyone needs it. Discussions rage nationally and internationally concerning what to digitize and the best means to present and retain digital objects. Digitization is the act of making something digital, expressing a physical object "in numerical…

  14. Scanning for Digitization Projects

    ERIC Educational Resources Information Center

    Wentzel, Larry

    2007-01-01

    Librarians and archivists find themselves facing the prospect of digitization. Everyone is doing it, everyone needs it. Discussions rage nationally and internationally concerning what to digitize and the best means to present and retain digital objects. Digitization is the act of making something digital, expressing a physical object "in numerical…

  15. Focused ion beam micromilling and articles therefrom

    DOEpatents

    Lamartine, B.C.; Stutz, R.A.

    1998-06-30

    An ultrahigh vacuum focused ion beam micromilling apparatus and process are disclosed. Additionally, a durable data storage medium using the micromilling process is disclosed, the durable data storage medium capable of storing, e.g., digital or alphanumeric characters as well as graphical shapes or characters. 6 figs.

  16. Focused ion beam micromilling and articles therefrom

    DOEpatents

    Lamartine, Bruce C.; Stutz, Roger A.

    1998-01-01

    An ultrahigh vacuum focused ion beam micromilling apparatus and process are isclosed. Additionally, a durable data storage medium using the micromilling process is disclosed, the durable data storage medium capable of storing, e.g., digital or alphanumeric characters as well as graphical shapes or characters.

  17. Accessible Geoscience - Digital Fieldwork

    NASA Astrophysics Data System (ADS)

    Meara, Rhian

    2017-04-01

    Accessible Geoscience is a developing field of pedagogic research aimed at widening participation in Geography, Earth and Environmental Science (GEES) subjects. These subjects are often less commonly associated with disabilities, ethnic minorities, low income socio-economic groups and females. While advancements and improvements have been made in the inclusivity of these subject areas in recent years, access and participation of disabled students remains low. While universities are legally obligated to provide reasonable adjustments to ensure accessibility, the assumed incompatibility of GEES subjects and disability often deters students from applying to study these courses at a university level. Instead of making reasonable adjustments if and when they are needed, universities should be aiming to develop teaching materials, spaces and opportunities which are accessible to all, which in turn will allow all groups to participate in the GEES subjects. With this in mind, the Swansea Geography Department wish to enhance the accessibility of our undergraduate degree by developing digital field work opportunities. In the first instance, we intend to digitise three afternoon excursions which are run as part of a 1st year undergraduate module. Each of the field trips will be digitized into English- and Welsh-medium formats. In addition, each field trip will be digitized into British Sign Language (BSL) to allow for accessibility for D/deaf and hard of hearing students. Subtitles will also be made available in each version. While the main focus of this work is to provide accessible fieldwork opportunities for students with disabilities, this work also has additional benefits. Students within the Geography Department will be able to revisit the field trips, to revise and complete associated coursework. The use of digitized field work should not replace opportunities for real field work, but its use by the full cohort of students will begin to "normalize" accessible field

  18. Research challenges in digital education.

    PubMed

    Norman, Geoff

    2014-09-01

    Simulation and other forms of digital learning will occupy a place of increasing prominence in medical education in the future. However, to maximally use the potential of these media, we must go beyond a research agenda dictated by a 'Does it work?' question to one driven by careful analysis of the nature of the task to be learned and its relation to the characteristics of the technology. Secondly, we must change the focus from the characteristics of individual devices to a broader approach to design of a digital curriculum based on current understanding of the nature of human learning.

  19. Digital structural

    USGS Publications Warehouse

    Dohm, J.M.; Anderson, R.C.; Tanaka, K.L.

    1998-01-01

    Magmatic and tectonic activity have both contributed significantly to the surface geology of Mars. Digital structural mapping techniques have now been used to classify and date centers of tectonic activity in the western equatorial region. For example, our results show a center of tectonic activity at Valles Marineris, which may be associated with uplift caused by intrusion. Such evidence may help explain, in part, the development of the large troughs and associated outflow channels and chaotic terrain. We also find a local centre of tectonic activity near the source region of Warrego Valles. Here, we suggest that the valley system may have resulted largely from intrusive-related hydrothermal activity. We hope that this work, together with the current Mars Global Surveyor mission, will lead to a better understanding of the geological processes that shaped the Martian surface.

  20. Digital demodulator

    NASA Technical Reports Server (NTRS)

    Shull, T. A. (Inventor)

    1982-01-01

    A digital demodulator for converting pulse code modulated data from phase shift key (PSK) to non return to zero (NRZ) and to biphase data is described. The demodulator is composed of standard integrated logic circuits. The key to the demodulation function is a pair of cross coupled one shot multivibrators and which with a flip-flop produce the NRZ-L is all that is required, the circuitry is greatly simplified and the 2(v) times bit rate contraint can be removed from the carrier. A flip-flop, an OR gate, and AND gate and a binary counter generate the bit rate clock (BTCK) for the NRZ-L. The remainder of the circuitry is for converting the NRZ-L and BTCK into biphase data. The device was designed for use in the space shuttle bay environment measurements.

  1. Digital Avionics

    NASA Technical Reports Server (NTRS)

    Koelbl, Terry G.; Ponchak, Denise; Lamarche, Teresa

    2002-01-01

    The field of digital avionics experienced another year of important advances in civil aviation, military systems, and space applications. As a result of the events of 9/11/2001, NASA has pursued activities to apply its aerospace technologies toward improved aviation security. Both NASA Glenn Research Center and Langley Research Center have performed flight research demonstrations using advanced datalink concepts to transmit live pictures from inside a jetliner, and to downlink the contents of the plane's 'black box' recorder in real time. The U.S. Navy and General Electric demonstrated survivable engine control (SEC) algorithms during engine ground tests at the Weapons Survivability Laboratory at China Lake. The scientists at Boeing Satellite Systems advanced the field of stellar inertial technology with the development of a new method for positioning optical star trackers on satellites.

  2. Digital Avionics

    NASA Technical Reports Server (NTRS)

    Koelbl, Terry G.; Ponchak, Denise; Lamarche, Teresa

    2003-01-01

    Digital Avionics activities played an important role in the advancements made in civil aviation, military systems, and space applications. This document profiles advances made in each of these areas by the aerospace industry, NASA centers, and the U.S. military. Emerging communication technologies covered in this document include Internet connectivity onboard aircraft, wireless broadband communication for aircraft, and a mobile router for aircraft to communicate in multiple communication networks over the course of a flight. Military technologies covered in this document include avionics for unmanned combat air vehicles and microsatellites, and head-up displays. Other technologies covered in this document include an electronic flight bag for the Boeing 777, and surveillance systems for managing airport operations.

  3. Digital Avionics

    NASA Technical Reports Server (NTRS)

    Koelbl, Terry G.; Ponchak, Denise; Lamarche, Teresa

    2002-01-01

    The field of digital avionics experienced another year of important advances in civil aviation, military systems, and space applications. As a result of the events of 9/11/2001, NASA has pursued activities to apply its aerospace technologies toward improved aviation security. Both NASA Glenn Research Center and Langley Research Center have performed flight research demonstrations using advanced datalink concepts to transmit live pictures from inside a jetliner, and to downlink the contents of the plane's 'black box' recorder in real time. The U.S. Navy and General Electric demonstrated survivable engine control (SEC) algorithms during engine ground tests at the Weapons Survivability Laboratory at China Lake. The scientists at Boeing Satellite Systems advanced the field of stellar inertial technology with the development of a new method for positioning optical star trackers on satellites.

  4. Digital demodulator

    NASA Astrophysics Data System (ADS)

    Shull, T. A.

    1982-01-01

    A digital demodulator for converting pulse code modulated data from phase shift key (PSK) to non return to zero (NRZ) and to biphase data is described. The demodulator is composed of standard integrated logic circuits. The key to the demodulation function is a pair of cross coupled one shot multivibrators and which with a flip-flop produce the NRZ-L is all that is required, the circuitry is greatly simplified and the 2(v) times bit rate contraint can be removed from the carrier. A flip-flop, an OR gate, and AND gate and a binary counter generate the bit rate clock (BTCK) for the NRZ-L. The remainder of the circuitry is for converting the NRZ-L and BTCK into biphase data. The device was designed for use in the space shuttle bay environment measurements.

  5. Digital linear actuator

    SciTech Connect

    Birchard, W.G.

    1988-06-21

    A digital actuator is described comprising: (a) digital actuator cells, each digital actuator cell having an axis of expansion and first and second end surfaces; (b) third connecting means, each for connecting the first end surface of one digital actuator cell to the second end surface of an adjacent actuator cell, the plurality of digital actuator cells being connected in series by respective ones of the third connecting means to form the digital linear actuator.

  6. The Digital Library: A Biography. Strategies and Tools for the Digital Library.

    ERIC Educational Resources Information Center

    Greenstein, Daniel; Thorin, Suzanne E.

    This report draws on the results of a survey and case studies of Digital Library Federation (DLF) members (Council on Library and Information Resources - CLIR). The survey was intended to document how DLF member libraries are focusing their digital library programs: how and under what circumstances their programs were initiated; the influences…

  7. Focus group research.

    PubMed

    Traynor, Michael

    2015-05-13

    A focus group is usually understood as a group of people brought together by a researcher to interact as a group. Focus group research explicitly uses interaction as part of its methodology. This article summarises the practice of running focus groups, explores the nature of focus group data and provides an example of focus group analysis.

  8. "Only" and Focus.

    ERIC Educational Resources Information Center

    Vallduvi, Enric

    The relationship of the word "only," one of a class of words known as scalar particles, focus adverbs, focus inducers, or focus-sensitive particles, with the "focus" of the sentence is examined. It is suggested, based on analysis of discourse structure, that this "association with focus" is not an inherent property of…

  9. Butte Digital Image Project: Shifting Focus from Collection to Community

    ERIC Educational Resources Information Center

    Pierson, Patricia

    2010-01-01

    The Butte Free Public Library was established in 1894. At that time, head librarian J. Davies published a catalog of the opening collection. Two fires and one flood later, many of the monographs from that original collection list have, remarkably, survived. Because of this, in part, the library, now known as the Butte-Silver Bow Public Library…

  10. Butte Digital Image Project: Shifting Focus from Collection to Community

    ERIC Educational Resources Information Center

    Pierson, Patricia

    2010-01-01

    The Butte Free Public Library was established in 1894. At that time, head librarian J. Davies published a catalog of the opening collection. Two fires and one flood later, many of the monographs from that original collection list have, remarkably, survived. Because of this, in part, the library, now known as the Butte-Silver Bow Public Library…

  11. Multi-digit number processing beyond the two-digit number range: a combination of sequential and parallel processes.

    PubMed

    Meyerhoff, Hauke S; Moeller, Korbinian; Debus, Kolja; Nuerk, Hans-Christoph

    2012-05-01

    Investigations of multi-digit number processing typically focus on two-digit numbers. Here, we aim to investigate the generality of results from two-digit numbers for four- and six-digit numbers. Previous studies on two-digit numbers mostly suggested a parallel processing of tens and units. In contrast, the few studies examining the processing of larger numbers suggest sequential processing of the individual constituting digits. In this study, we combined the methodological approaches of studies implying either parallel or sequential processing. Participants completed a number magnitude comparison task on two-, four-, and six-digit numbers including unit-decade compatible and incompatible differing digit pairs (e.g., 32_47, 3<4 and 2<7 vs. 37_52, 3<5 but 7>2, respectively) at all possible digit positions. Response latencies and fixation behavior indicated that sequential and parallel decomposition is not exclusive in multi-digit number processing. Instead, our results clearly suggested that sequential and parallel processing strategies seem to be combined when processing multi-digit numbers beyond the two-digit number range. To account for the results, we propose a chunking hypothesis claiming that multi-digit numbers are separated into chunks of shorter digit strings. While the different chunks are processed sequentially digits within these chunks are processed in parallel. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Digital video delivery for a digital library in computer science

    NASA Astrophysics Data System (ADS)

    Fox, Edward A.; Abdulla, Ghaleb

    1994-04-01

    With support from four NSF awards we aim to develop a prototype digital library in computer science and apply it to improve undergraduate educations. First, Project Envision, `A User- Centered Database from the Computer Science Literature,' 1991-94, deals with translation, coding standards including SGML, retrieval/previewing/presentation/browsing/linking, human-computer interaction, and construction of a partial archive using text and multimedia materials provided by ACM. Second, `Interactive Learning with a Digital Library in Computer Science,' 1993-96, supported by NSF and ACM with additional assistance from other publishers, focuses on improving learning through delivery of materials from the archive. Third, `Networked Multimedia File System with HyTime,' funded by NSF through the SUCCEED coalition, considers networking support for distributed multimedia applications and the use of HyTime for description of such applications. Fourth, equipment support comes from the Information Access Laboratory allotment of the `Interactive Accessibility: Breaking Barriers to the Power of Computing' grant funded by NSF for 1993-98. In this paper we report on plans and work with digital video relating to these projects. In particular we focus on our analysis of the requirements for a multimedia digital library in computer science and our experience with MPEG as it applies to that library.

  13. Extending the Classroom: Digital Micro-Narratives for Novice Language Learners

    ERIC Educational Resources Information Center

    Kronenberg, Felix A.

    2014-01-01

    Digital Storytelling offers many advantages for language learning, especially within a project-based framework. In this article, the use of Digital Micro-Narratives is proposed as particularly useful for second language learners at the novice level. As a sub-genre of Digital Storytelling, Digital Micro-Narratives focus more on frequently updated…

  14. Direct-to-digital holography and holovision

    DOEpatents

    Thomas, Clarence E.; Baylor, Larry R.; Hanson, Gregory R.; Rasmussen, David A.; Voelkl, Edgar; Castracane, James; Simkulet, Michelle; Clow, Lawrence

    2000-01-01

    Systems and methods for direct-to-digital holography are described. An apparatus includes a laser; a beamsplitter optically coupled to the laser; a reference beam mirror optically coupled to the beamsplitter; an object optically coupled to the beamsplitter, a focusing lens optically coupled to both the reference beam mirror and the object; and a digital recorder optically coupled to the focusing lens. A reference beam is incident upon the reference beam mirror at a non-normal angle, and the reference beam and an object beam are focused by the focusing lens at a focal plane of the digital recorder to form an image. The systems and methods provide advantages in that computer assisted holographic measurements can be made.

  15. Virtual mask digital electron beam lithography

    DOEpatents

    Baylor, L.R.; Thomas, C.E.; Voelkl, E.; Moore, J.A.; Simpson, M.L.; Paulus, M.J.

    1999-04-06

    Systems and methods for direct-to-digital holography are described. An apparatus includes a laser; a beamsplitter optically coupled to the laser; a reference beam mirror optically coupled to the beamsplitter; an object optically coupled to the beamsplitter, a focusing lens optically coupled to both the reference beam mirror and the object; and a digital recorder optically coupled to the focusing lens. A reference beam is incident upon the reference beam mirror at a non-normal angle, and the reference beam and an object beam are focused by the focusing lens at a focal plane of the digital recorder to form an image. The systems and methods provide advantages in that computer assisted holographic measurements can be made. 5 figs.

  16. Virtual mask digital electron beam lithography

    DOEpatents

    Baylor, Larry R.; Thomas, Clarence E.; Voelkl, Edgar; Moore, James A.; Simpson, Michael L.; Paulus, Michael J.

    1999-01-01

    Systems and methods for direct-to-digital holography are described. An apparatus includes a laser; a beamsplitter optically coupled to the laser; a reference beam mirror optically coupled to the beamsplitter; an object optically coupled to the beamsplitter, a focusing lens optically coupled to both the reference beam mirror and the object; and a digital recorder optically coupled to the focusing lens. A reference beam is incident upon the reference beam mirror at a non-normal angle, and the reference beam and an object beam are focused by the focusing lens at a focal plane of the digital recorder to form an image. The systems and methods provide advantages in that computer assisted holographic measurements can be made.

  17. Digital Sensor Technology

    SciTech Connect

    Ted Quinn; Jerry Mauck; Richard Bockhorst; Ken Thomas

    2013-07-01

    The nuclear industry has been slow to incorporate digital sensor technology into nuclear plant designs due to concerns with digital qualification issues. However, the benefits of digital sensor technology for nuclear plant instrumentation are substantial in terms of accuracy, reliability, availability, and maintainability. This report demonstrates these benefits in direct comparisons of digital and analog sensor applications. It also addresses the qualification issues that must be addressed in the application of digital sensor technology.

  18. High-performance digital color video camera

    NASA Astrophysics Data System (ADS)

    Parulski, Kenneth A.; D'Luna, Lionel J.; Benamati, Brian L.; Shelley, Paul R.

    1992-01-01

    Typical one-chip color cameras use analog video processing circuits. An improved digital camera architecture has been developed using a dual-slope A/D conversion technique and two full-custom CMOS digital video processing integrated circuits, the color filter array (CFA) processor and the RGB postprocessor. The system used a 768 X 484 active element interline transfer CCD with a new field-staggered 3G color filter pattern and a lenslet overlay, which doubles the sensitivity of the camera. The industrial-quality digital camera design offers improved image quality, reliability, manufacturability, while meeting aggressive size, power, and cost constraints. The CFA processor digital VLSI chip includes color filter interpolation processing, an optical black clamp, defect correction, white balance, and gain control. The RGB postprocessor digital integrated circuit includes a color correction matrix, gamma correction, 2D edge enhancement, and circuits to control the black balance, lens aperture, and focus.

  19. High-performance digital color video camera

    NASA Astrophysics Data System (ADS)

    Parulski, Kenneth A.; Benamati, Brian L.; D'Luna, Lionel J.; Shelley, Paul R.

    1991-06-01

    Typical one-chip color cameras use analog video processing circuits. An improved digital camera architecture has been developed using a dual-slope A/D conversion technique, and two full custom CMOS digital video processing ICs, the 'CFA processor' and the 'RGB post- processor.' The system uses a 768 X 484 active element interline transfer CCD with a new 'field-staggered 3G' color filter pattern and a 'lenslet' overlay, which doubles the sensitivity of the camera. The digital camera design offers improved image quality, reliability, and manufacturability, while meeting aggressive size, power, and cost constraints. The CFA processor digital VLSI chip includes color filter interpolation processing, an optical black clamp, defect correction, white balance, and gain control. The RGB post-processor digital IC includes a color correction matrix, gamma correction, two-dimensional edge-enhancement, and circuits to control the black balance, lens aperture, and focus.

  20. Photonics meet digital art

    NASA Astrophysics Data System (ADS)

    Curticapean, Dan; Israel, Kai

    2014-09-01

    The paper focuses on the work of an interdisciplinary project between photonics and digital art. The result is a poster collection dedicated to the International Year of Light 2015. In addition, an internet platform was created that presents the project. It can be accessed at http://www.magic-of-light.org/iyl2015/index.htm. From the idea to the final realization, milestones with tasks and steps will be presented in the paper. As an interdisciplinary project, students from technological degree programs were involved as well as art program students. The 2015 Anniversaries: Alhazen (1015), De Caus (1615), Fresnel (1815), Maxwell (1865), Einstein (1905), Penzias Wilson, Kao (1965) and their milestone contributions in optics and photonics will be highlighted.

  1. Experimental OAI-Based Digital Library Systems

    NASA Technical Reports Server (NTRS)

    Nelson, Michael L. (Editor); Maly, Kurt (Editor); Zubair, Mohammad (Editor); Rusch-Feja, Diann (Editor)

    2002-01-01

    The objective of Open Archives Initiative (OAI) is to develop a simple, lightweight framework to facilitate the discovery of content in distributed archives (http://www.openarchives.org). The focus of the workshop held at the 5th European Conference on Research and Advanced Technology for Digital Libraries (ECDL 2001) was to bring researchers in the area of digital libraries who are building OAI based systems so as to share their experiences, problems they are facing, and approaches they are taking to address them. The workshop consisted of invited talks from well-established researchers working in building OAI based digital library system along with short paper presentations.

  2. Focus Curriculum Manual; A Focus Dissemination Project.

    ERIC Educational Resources Information Center

    Human Resource Associates, Inc., Hastings, Minn.

    This training manual is for use in preparing staff members to use the Focus Model, which is a "school within a school" for disaffected high school students. The material is designed to be used as a resource aid following participation in an in-service workshop. Information is presented to help implement a contracting system to establish…

  3. Digital imaging overview.

    PubMed

    Carrino, John A

    2003-07-01

    Digital imaging consists of digital acquisition modalities, image, and information management systems. All modalities are available to be purchased as digital acquisition devices. Image management has been the domain for PACSs. PACSs are complex systems designed to transmit, store, and display medical images. They use and rely on many types of different information and display technologies. The initial focus for PACSs has been on solving the engineering issues associated with the transfer of large image data sets and the suitability of softcopy displays for diagnosis particular to the human visual system. For operating within a centralized radiology department, these are largely solved. However, for enterprise wide dissemination and distribution, there are still challenges in the form of expedient transfer syntaxes and image quality, but these are also being effectively addressed. Information management is the domain of the RIS. One of the goals of radiology management should encompass the development of a robust practice environment that emphasizes workflow enhancements with seamless integration of decision support tools. The concept of "person-machine" systems emphasizes taking full advantage of both human and machine capabilities with a capacity to grow and change function. As the computer capabilities increase, more jobs can be relinquished to the machine. The physician can then focus on tasks that require more complex judgment and comprehension. The goal of this human-machine hybrid is to have more power than either of its components alone. This multifaceted role will most likely be embedded in the background having agents query and retrieve context specific information to be presented to the user. As augmenters of human talent, computers can turn data into information and information into knowledge. Medical imaging is a beneficiary of the information technology developments driven by the consumer and business sectors. Although these applications of

  4. COS NUV Focus Sweep

    NASA Astrophysics Data System (ADS)

    Sahnow, David

    2017-08-01

    Program 13530 performed an NUV focus sweep during Cycle 21 in order to determine whether the COS focus has changed since it was originally measured in Program 11469 during SMOV. Nineteen NUV exposures of NGC188-41 were obtained during a single orbit while the OSM1 focus was moved over the range from -200 to +200 steps. The focus was found to be close to the initial value.

  5. Focus Intonation in Bengali

    ERIC Educational Resources Information Center

    Hasan, Md. Kamrul

    2015-01-01

    This work attempts to investigate the role of prosody in the syntax of focus in Bangla. The aim of this study is to show the intonation pattern of Bangla in emphasis and focus. In order to do that, the author has looked at the pattern of focus without-i/o as well as with the same. Do they really pose any different focus intonation pattern from…

  6. Alternating phase focused linacs

    DOEpatents

    Swenson, Donald A.

    1980-01-01

    A heavy particle linear accelerator employing rf fields for transverse and ongitudinal focusing as well as acceleration. Drift tube length and gap positions in a standing wave drift tube loaded structure are arranged so that particles are subject to acceleration and succession of focusing and defocusing forces which contain the beam without additional magnetic or electric focusing fields.

  7. Taxonomy of Challenges for Digital Forensics.

    PubMed

    Karie, Nickson M; Venter, Hein S

    2015-07-01

    Since its inception, over a decade ago, the field of digital forensics has faced numerous challenges. Despite different researchers and digital forensic practitioners having studied and analysed various known digital forensic challenges, as of 2013, there still exists a need for a formal classification of these challenges. This article therefore reviews existing research literature and highlights the various challenges that digital forensics has faced for the last 10 years. In conducting this research study, however, it was difficult for the authors to review all the existing research literature in the digital forensic domain; hence, sampling and randomization techniques were employed to facilitate the review of the gathered literature. Taxonomy of the various challenges is subsequently proposed in this paper based on our review of the literature. The taxonomy classifies the large number of digital forensic challenges into four well-defined and easily understood categories. The proposed taxonomy can be useful, for example, in future developments of automated digital forensic tools by explicitly describing processes and procedures that focus on addressing specific challenges identified in this paper. However, it should also be noted that the purpose of this paper was not to propose any solutions to the individual challenges that digital forensics face, but to serve as a survey of the state of the art of the research area.

  8. [Digital echocardiography laboratory].

    PubMed

    Trambaiolo, Paolo; Posteraro, Alfredo; Salustri, Alessandro; Amici, Elisabetta; Piaggio, Maurizio; Decanini, Cesare; Gambelli, Giancarlo

    2004-07-01

    The implementation of a digital echocardiography laboratory exists today using the DICOM (Digital Imaging Communication in Medicine) standard to acquire, store and transfer echocardiographic digital images. The components of a laboratory include: 1) digital echocardiography machines with DICOM output, 2) a switched high-speed local area network, 3) a DICOM server with abundant local storage, and 4) a software to manage image and measurement information. The aim of this article was to describe the critical components of a digital echocardiography laboratory, discuss strategies for implementation, and describe some of the pitfalls that we encountered in our own implementation of the digital third level echocardiography laboratory.

  9. Digital communications: Microwave applications

    NASA Astrophysics Data System (ADS)

    Feher, K.

    Transmission concepts and techniques of digital systems are presented; and practical state-of-the-art implementation of digital communications systems by line-of-sight microwaves is described. Particular consideration is given to statistical methods in digital transmission systems analysis, digital modulation methods, microwave amplifiers, system gain, m-ary and QAM microwave systems, correlative techniques and applications to digital radio systems, hybrid systems, digital microwave systems design, diversity and protection switching techniques, measurement techniques, and research and development trends and unsolved problems.

  10. Digital image processing.

    PubMed

    Seeram, Euclid

    2004-01-01

    Digital image processing is now commonplace in radiology, nuclear medicine and sonography. This article outlines underlying principles and concepts of digital image processing. After completing this article, readers should be able to: List the limitations of film-based imaging. Identify major components of a digital imaging system. Describe the history and application areas of digital image processing. Discuss image representation and the fundamentals of digital image processing. Outline digital image processing techniques and processing operations used in selected imaging modalities. Explain the basic concepts and visualization tools used in 3-D and virtual reality imaging. Recognize medical imaging informatics as a new area of specialization for radiologic technologists.

  11. Digital development and morphogenesis

    PubMed Central

    Sanz-Ezquerro, JJ; Tickle, C

    2003-01-01

    Signalling interactions between the polarizing region, which produces SHH, and the apical ectodermal ridge, which produces FGFs, are essential for outgrowth and patterning of vertebrate limbs. However, mechanisms that mediate translation of early positional information of cells into anatomy remain largely unknown. In particular, the molecular and cellular basis of digit morphogenesis are not fully understood, either in terms of the formation of the different digits along the antero-posterior axis or in the way digits stop growing once pattern formation has been completed. Here we will review recent data about digit development. Manipulation of morphogenetic signals during digit formation, including application of SHH interdigitally, has shown that digit primordia possess a certain plasticity, and that digit anatomy becomes irreversibly fixed during morphogenesis. The process of generation of joints and thus segmentation and formation of digit tips is also discussed. PMID:12587920

  12. Digital rectal exam

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/007069.htm Digital rectal exam To use the sharing features on this page, please enable JavaScript. A digital rectal exam is an examination of the lower ...

  13. Digital flight control research

    NASA Technical Reports Server (NTRS)

    Potter, J. E.; Stern, R. G.; Smith, T. B.; Sinha, P.

    1974-01-01

    The results of studies which were undertaken to contribute to the design of digital flight control systems, particularly for transport aircraft are presented. In addition to the overall design considerations for a digital flight control system, the following topics are discussed in detail: (1) aircraft attitude reference system design, (2) the digital computer configuration, (3) the design of a typical digital autopilot for transport aircraft, and (4) a hybrid flight simulator.

  14. Digital pathology for education.

    PubMed

    Huisman, André

    2012-01-01

    The use of digital slides for educational purposes (both for medical students and during pathology traineeships) will eventually accelerate the acceptance of digital pathology in general. This chapter describes the advantages of using digital slides especially for education. Also the requirements for using digital slides for this purpose are evaluated, including software requirements, the slide scanner and the IT infrastructure needed to provide a robust infrastructure to end users.

  15. Digital Mapping Glossary,

    DTIC Science & Technology

    A glossary has been compiled primarily for the benefit of photogrammetrists and computer scientists engaged in the development and use of semi...automatic and automatic digital mapping systems. Terms in the following categories are defined: (a) Terms with meanings in digital mapping that are...different from the meanings of these terms in conventional non-digital photogrammetry; (b) Terms with meanings in digital mapping that are different from the

  16. How digital are the Digital Humanities? An analysis of two scholarly blogging platforms.

    PubMed

    Puschmann, Cornelius; Bastos, Marco

    2015-01-01

    In this paper we compare two academic networking platforms, HASTAC and Hypotheses, to show the distinct ways in which they serve specific communities in the Digital Humanities (DH) in different national and disciplinary contexts. After providing background information on both platforms, we apply co-word analysis and topic modeling to show thematic similarities and differences between the two sites, focusing particularly on how they frame DH as a new paradigm in humanities research. We encounter a much higher ratio of posts using humanities-related terms compared to their digital counterparts, suggesting a one-way dependency of digital humanities-related terms on the corresponding unprefixed labels. The results also show that the terms digital archive, digital literacy, and digital pedagogy are relatively independent from the respective unprefixed terms, and that digital publishing, digital libraries, and digital media show considerable cross-pollination between the specialization and the general noun. The topic modeling reproduces these findings and reveals further differences between the two platforms. Our findings also indicate local differences in how the emerging field of DH is conceptualized and show dynamic topical shifts inside these respective contexts.

  17. How Digital Are the Digital Humanities? An Analysis of Two Scholarly Blogging Platforms

    PubMed Central

    Puschmann, Cornelius; Bastos, Marco

    2015-01-01

    In this paper we compare two academic networking platforms, HASTAC and Hypotheses, to show the distinct ways in which they serve specific communities in the Digital Humanities (DH) in different national and disciplinary contexts. After providing background information on both platforms, we apply co-word analysis and topic modeling to show thematic similarities and differences between the two sites, focusing particularly on how they frame DH as a new paradigm in humanities research. We encounter a much higher ratio of posts using humanities-related terms compared to their digital counterparts, suggesting a one-way dependency of digital humanities-related terms on the corresponding unprefixed labels. The results also show that the terms digital archive, digital literacy, and digital pedagogy are relatively independent from the respective unprefixed terms, and that digital publishing, digital libraries, and digital media show considerable cross-pollination between the specialization and the general noun. The topic modeling reproduces these findings and reveals further differences between the two platforms. Our findings also indicate local differences in how the emerging field of DH is conceptualized and show dynamic topical shifts inside these respective contexts. PMID:25675441

  18. Fuzzy topological digital space and digital fuzzy spline of electroencephalography during epileptic seizures

    NASA Astrophysics Data System (ADS)

    Shah, Mazlina Muzafar; Wahab, Abdul Fatah

    2017-08-01

    Epilepsy disease occurs because of there is a temporary electrical disturbance in a group of brain cells (nurons). The recording of electrical signals come from the human brain which can be collected from the scalp of the head is called Electroencephalography (EEG). EEG then considered in digital format and in fuzzy form makes it a fuzzy digital space data form. The purpose of research is to identify the area (curve and surface) in fuzzy digital space affected by inside epilepsy seizure in epileptic patient's brain. The main focus for this research is to generalize fuzzy topological digital space, definition and basic operation also the properties by using digital fuzzy set and the operations. By using fuzzy digital space, the theory of digital fuzzy spline can be introduced to replace grid data that has been use previously to get better result. As a result, the flat of EEG can be fuzzy topological digital space and this type of data can be use to interpolate the digital fuzzy spline.

  19. TELEMETRY EQUIPMENT WITH DIGITAL READING,

    DTIC Science & Technology

    Contents: Basic peculiarities of telemetry equipment with digital reading ; Elements of pulse technology applied in telemetry equipment with digital... reading ; Digital reading systems; Telemetry systems with digital reading . (Author)

  20. Mass Digitization of Books

    ERIC Educational Resources Information Center

    Coyle, Karen

    2006-01-01

    Mass digitization of the bound volumes that we generally call "books" has begun, and, thanks to the interest in Google and all that it does, it is getting widespread media attention. The Open Content Alliance (OCA), a library initiative formed after Google announced its library book digitization project, has brought library digitization projects…

  1. Reconceptualising Critical Digital Literacy

    ERIC Educational Resources Information Center

    Pangrazio, Luciana

    2016-01-01

    While it has proved a useful concept during the past 20 years, the notion of "critical digital literacy" requires rethinking in light of the fast-changing nature of young people's digital practices. This paper contrasts long-established notions of "critical digital literacy" (based primarily around the critical consumption of…

  2. Digital Language Death

    PubMed Central

    Kornai, András

    2013-01-01

    Of the approximately 7,000 languages spoken today, some 2,500 are generally considered endangered. Here we argue that this consensus figure vastly underestimates the danger of digital language death, in that less than 5% of all languages can still ascend to the digital realm. We present evidence of a massive die-off caused by the digital divide. PMID:24167559

  3. Reconceptualising Critical Digital Literacy

    ERIC Educational Resources Information Center

    Pangrazio, Luciana

    2016-01-01

    While it has proved a useful concept during the past 20 years, the notion of "critical digital literacy" requires rethinking in light of the fast-changing nature of young people's digital practices. This paper contrasts long-established notions of "critical digital literacy" (based primarily around the critical consumption of…

  4. Bridging the Digital Divide

    ERIC Educational Resources Information Center

    Clarke, Alan; Milner, Helen; Killer, Terry; Dixon, Genny

    2008-01-01

    As the Government publishes its action plan for consultation on digital inclusion, the authors consider some of the challenges and opportunities for the delivery of digital inclusion. Clarke argues that digital inclusion requires more than access to technology or the skills to use it effectively, it demands information and media literacy. Milner…

  5. Digital Ink and Notetaking

    ERIC Educational Resources Information Center

    Colwell, Kenneth E.

    2004-01-01

    Tablet PCs and graphics tablets employ digital ink technology. In this paper the author introduces the reader to digital ink technology with the aim of promoting its use in various instructional or training settings, with the goal of improving instructor-learner dialogue and student learning. The potential of digital ink for improved instructional…

  6. Digital Ink and Notetaking

    ERIC Educational Resources Information Center

    Colwell, Kenneth E.

    2004-01-01

    Tablet PCs and graphics tablets employ digital ink technology. In this paper the author introduces the reader to digital ink technology with the aim of promoting its use in various instructional or training settings, with the goal of improving instructor-learner dialogue and student learning. The potential of digital ink for improved instructional…

  7. Mass Digitization of Books

    ERIC Educational Resources Information Center

    Coyle, Karen

    2006-01-01

    Mass digitization of the bound volumes that we generally call "books" has begun, and, thanks to the interest in Google and all that it does, it is getting widespread media attention. The Open Content Alliance (OCA), a library initiative formed after Google announced its library book digitization project, has brought library digitization projects…

  8. Digital Literacy. Research Brief

    ERIC Educational Resources Information Center

    Williamson, Ronald

    2011-01-01

    21st Century students need a complex set of skills to be successful in a digital environment. Digital literacy, similar to traditional definitions of literacy, is a set of skills students use to locate, organize, understand, evaluate and create information. The difference is that it occurs in an environment where a growing set of digital tools…

  9. Bridging the Digital Divide

    ERIC Educational Resources Information Center

    Clarke, Alan; Milner, Helen; Killer, Terry; Dixon, Genny

    2008-01-01

    As the Government publishes its action plan for consultation on digital inclusion, the authors consider some of the challenges and opportunities for the delivery of digital inclusion. Clarke argues that digital inclusion requires more than access to technology or the skills to use it effectively, it demands information and media literacy. Milner…

  10. Why Map Issues? On Controversy Analysis as a Digital Method

    PubMed Central

    2015-01-01

    This article takes stock of recent efforts to implement controversy analysis as a digital method in the study of science, technology, and society (STS) and beyond and outlines a distinctive approach to address the problem of digital bias. Digital media technologies exert significant influence on the enactment of controversy in online settings, and this risks undermining the substantive focus of controversy analysis conducted by digital means. To address this problem, I propose a shift in thematic focus from controversy analysis to issue mapping. The article begins by distinguishing between three broad frameworks that currently guide the development of controversy analysis as a digital method, namely, demarcationist, discursive, and empiricist. Each has been adopted in STS, but only the last one offers a digital “move beyond impartiality.” I demonstrate this approach by analyzing issues of Internet governance with the aid of the social media platform Twitter. PMID:26336325

  11. Why Map Issues? On Controversy Analysis as a Digital Method.

    PubMed

    Marres, Noortje

    2015-09-01

    This article takes stock of recent efforts to implement controversy analysis as a digital method in the study of science, technology, and society (STS) and beyond and outlines a distinctive approach to address the problem of digital bias. Digital media technologies exert significant influence on the enactment of controversy in online settings, and this risks undermining the substantive focus of controversy analysis conducted by digital means. To address this problem, I propose a shift in thematic focus from controversy analysis to issue mapping. The article begins by distinguishing between three broad frameworks that currently guide the development of controversy analysis as a digital method, namely, demarcationist, discursive, and empiricist. Each has been adopted in STS, but only the last one offers a digital "move beyond impartiality." I demonstrate this approach by analyzing issues of Internet governance with the aid of the social media platform Twitter.

  12. Digital Architecture Planning Model

    SciTech Connect

    Oxstrand, Johanna Helene; Al Rashdan, Ahmad Yahya Mohammad; Bly, Aaron Douglas; Rice, Brandon Charles; Fitzgerald, Kirk; Wilson, Keith Leon

    2016-03-01

    As part of the U.S. Department of Energy’s Light Water Reactor Sustainability Program, the Digital Architecture (DA) Project focuses on providing a model that nuclear utilities can refer to when planning deployment of advanced technologies. The digital architecture planning model (DAPM) is the methodology for mapping power plant operational and support activities into a DA that unifies all data sources needed by the utilities to operate their plants. The DA is defined as a collection of information technology capabilities needed to support and integrate a wide spectrum of real-time digital capabilities for performance improvements of nuclear power plants. DA can be thought of as integration of the separate instrumentation and control and information systems already in place in nuclear power plants, which are brought together for the purpose of creating new levels of automation in plant work activities. A major objective in DAPM development was to survey all key areas that needed to be reviewed in order for a utility to make knowledgeable decisions regarding needs and plans to implement a DA at the plant. The development was done in two steps. First, researchers surveyed the nuclear industry in order to learn their near-term plans for adopting new advanced capabilities and implementing a network (i.e., wireless and wire) infrastructure throughout the plant, including the power block. Secondly, a literature review covering regulatory documents, industry standards, and technical research reports and articles was conducted. The objective of the review was to identify key areas to be covered by the DAPM, which included the following: 1. The need for a DA and its benefits to the plant 2. Resources required to implement the DA 3. Challenges that need to be addressed and resolved to implement the DA 4. Roles and responsibilities of the DA implementation plan. The DAPM was developed based on results from the survey and the literature review. Model development, including

  13. Collaborative learning model inquiring based on digital game

    NASA Astrophysics Data System (ADS)

    Yuan, Jiugen; Xing, Ruonan

    2012-04-01

    With the development of computer education software, digital educational game has become an important part in our life, entertainment and education. Therefore how to make full use of digital game's teaching functions and educate through entertainment has become the focus of current research. The thesis make a connection between educational game and collaborative learning, the current popular teaching model, and concludes digital game-based collaborative learning model combined with teaching practice.

  14. Digital storytelling: an innovative technological approach to nursing education.

    PubMed

    Price, Deborah M; Strodtman, Linda; Brough, Elizabeth; Lonn, Steven; Luo, Airong

    2015-01-01

    This study investigated the impact of using digital stories in promoting deeper understanding in nursing students about palliative care concepts. Students (N = 134) created a 5-minute narrated digital story utilizing VoiceThread technology that synthesized and applied knowledge that had been presented in class and course readings. Postsurvey and focus group evaluation data revealed that through the writing and sharing of digital stories, students embraced the personal and complex nature of palliative care.

  15. Digital disruption ?syndromes.

    PubMed

    Sullivan, Clair; Staib, Andrew

    2017-05-18

    The digital transformation of hospitals in Australia is occurring rapidly in order to facilitate innovation and improve efficiency. Rapid transformation can cause temporary disruption of hospital workflows and staff as processes are adapted to the new digital workflows. The aim of this paper is to outline various types of digital disruption and some strategies for effective management. A large tertiary university hospital recently underwent a rapid, successful roll-out of an integrated electronic medical record (EMR). We observed this transformation and propose several digital disruption "syndromes" to assist with understanding and management during digital transformation: digital deceleration, digital transparency, digital hypervigilance, data discordance, digital churn and post-digital 'depression'. These 'syndromes' are defined and discussed in detail. Successful management of this temporary digital disruption is important to ensure a successful transition to a digital platform.What is known about this topic? Digital disruption is defined as the changes facilitated by digital technologies that occur at a pace and magnitude that disrupt established ways of value creation, social interactions, doing business and more generally our thinking. Increasing numbers of Australian hospitals are implementing digital solutions to replace traditional paper-based systems for patient care in order to create opportunities for improved care and efficiencies. Such large scale change has the potential to create transient disruption to workflows and staff. Managing this temporary disruption effectively is an important factor in the successful implementation of an EMR.What does this paper add? A large tertiary university hospital recently underwent a successful rapid roll-out of an integrated electronic medical record (EMR) to become Australia's largest digital hospital over a 3-week period. We observed and assisted with the management of several cultural, behavioural and

  16. Digital data acquisition and processing.

    PubMed

    Naivar, Mark A; Galbraith, David W

    2015-01-05

    A flow cytometer is made up of many different subsystems that work together to measure the optical properties of individual cells within a sample. The data acquisition system (also called the data system) is one of these subsystems, and it is responsible for converting the electrical signals from the optical detectors into list-mode data. This unit describes the inner workings of the data system, and provides insight into how the instrument functions as a whole. Some of the information provided in this unit is applicable to everyday use of these instruments, and, at minimum, should make it easier for the reader to assemble a specific data system. With the considerable advancement of electronics technology, it becomes possible to build an entirely functional data system using inexpensive hobbyist-level electronics. This unit covers both analog and digital data systems, but the primary focus is on the more prevalent digital data systems of modern flow cytometric instrumentation.

  17. Focus, 2000-2001.

    ERIC Educational Resources Information Center

    Focus, 2001

    2001-01-01

    These three issues of 2000-2001 "Focus" present a collection of papers focusing on issues related to poverty. The first issue discusses child support enforcement policy and low-income families, highlighting such issues as fragile families and child wellbeing; low-income families and the child support enforcement system; child support…

  18. Microfabricated particle focusing device

    DOEpatents

    Ravula, Surendra K.; Arrington, Christian L.; Sigman, Jennifer K.; Branch, Darren W.; Brener, Igal; Clem, Paul G.; James, Conrad D.; Hill, Martyn; Boltryk, Rosemary June

    2013-04-23

    A microfabricated particle focusing device comprises an acoustic portion to preconcentrate particles over large spatial dimensions into particle streams and a dielectrophoretic portion for finer particle focusing into single-file columns. The device can be used for high throughput assays for which it is necessary to isolate and investigate small bundles of particles and single particles.

  19. FOCUS: Sustainable Mathematics Successes

    ERIC Educational Resources Information Center

    Mireles, Selina V.; Acee, Taylor W.; Gerber, Lindsey N.

    2014-01-01

    The FOCUS (Fundamentals of Conceptual Understanding and Success) Co-Requisite Model Intervention (FOCUS Intervention) for College Algebra was developed as part of the Developmental Education Demonstration Projects (DEDP) in Texas. The program was designed to use multiple services, courses, and best practices to support student completion of a…

  20. Focus, 2000-2001.

    ERIC Educational Resources Information Center

    Focus, 2001

    2001-01-01

    These three issues of 2000-2001 "Focus" present a collection of papers focusing on issues related to poverty. The first issue discusses child support enforcement policy and low-income families, highlighting such issues as fragile families and child wellbeing; low-income families and the child support enforcement system; child support…

  1. Digital Mammography and Digital Breast Tomosynthesis.

    PubMed

    Moseley, Tanya W

    2016-06-01

    Breast imaging technology has advanced significantly from the 1930s until the present. American women have a 1 in 8 chance of developing breast cancer. Mammography has been proven in multiple clinical trials to reduce breast cancer mortality. Although a mainstay of breast imaging and improved from film-screen mammography, digital mammography is not a perfect examination. Overlapping obscuring breast tissue limits mammographic interpretation. Breast digital tomosynthesis reduces and/or eliminates overlapping obscuring breast tissue. Although there are some disadvantages with digital breast tomosynthesis, this relatively lost-cost technology may be used effectively in the screening and diagnostic settings.

  2. Smartphone adapters for digital photomicrography

    PubMed Central

    Roy, Somak; Pantanowitz, Liron; Amin, Milon; Seethala, Raja R.; Ishtiaque, Ahmed; Yousem, Samuel A.; Parwani, Anil V.; Cucoranu, Ioan; Hartman, Douglas J.

    2014-01-01

    Background: Photomicrographs in Anatomic Pathology provide a means of quickly sharing information from a glass slide for consultation, education, documentation and publication. While static image acquisition historically involved the use of a permanently mounted camera unit on a microscope, such cameras may be expensive, need to be connected to a computer, and often require proprietary software to acquire and process images. Another novel approach for capturing digital microscopic images is to use smartphones coupled with the eyepiece of a microscope. Recently, several smartphone adapters have emerged that allow users to attach mobile phones to the microscope. The aim of this study was to test the utility of these various smartphone adapters. Materials and Methods: We surveyed the market for adapters to attach smartphones to the ocular lens of a conventional light microscope. Three adapters (Magnifi, Skylight and Snapzoom) were tested. We assessed the designs of these adapters and their effectiveness at acquiring static microscopic digital images. Results: All adapters facilitated the acquisition of digital microscopic images with a smartphone. The optimal adapter was dependent on the type of phone used. The Magnifi adapters for iPhone were incompatible when using a protective case. The Snapzoom adapter was easiest to use with iPhones and other smartphones even with protective cases. Conclusions: Smartphone adapters are inexpensive and easy to use for acquiring digital microscopic images. However, they require some adjustment by the user in order to optimize focus and obtain good quality images. Smartphone microscope adapters provide an economically feasible method of acquiring and sharing digital pathology photomicrographs. PMID:25191623

  3. Exploring Doctoral Students' Use of Digital Technologies: What Do They Use Them for and Why?

    ERIC Educational Resources Information Center

    Gouseti, Anastasia

    2017-01-01

    Digital technologies now form an integral feature of the university student experience and there is a range of studies that explore digital technology use within a higher education context. However, very few of these studies focus on how doctoral students engage with digital technologies. This article aims to throw light on the digital practices…

  4. Digital Collections, Digital Libraries and the Digitization of Cultural Heritage Information.

    ERIC Educational Resources Information Center

    Lynch, Clifford

    2002-01-01

    Discusses the development of digital collections and digital libraries. Topics include digitization of cultural heritage information; broadband issues; lack of compelling content; training issues; types of materials being digitized; sustainability; digital preservation; infrastructure; digital images; data mining; and future possibilities for…

  5. Digital Collections, Digital Libraries and the Digitization of Cultural Heritage Information.

    ERIC Educational Resources Information Center

    Lynch, Clifford

    2002-01-01

    Discusses the development of digital collections and digital libraries. Topics include digitization of cultural heritage information; broadband issues; lack of compelling content; training issues; types of materials being digitized; sustainability; digital preservation; infrastructure; digital images; data mining; and future possibilities for…

  6. Focused ultrasound in ophthalmology.

    PubMed

    Silverman, Ronald H

    2016-01-01

    The use of focused ultrasound to obtain diagnostically significant information about the eye goes back to the 1950s. This review describes the historical and technological development of ophthalmic ultrasound and its clinical application and impact. Ultrasound, like light, can be focused, which is crucial for formation of high-resolution, diagnostically useful images. Focused, single-element, mechanically scanned transducers are most common in ophthalmology. Specially designed transducers have been used to generate focused, high-intensity ultrasound that through thermal effects has been used to treat glaucoma (via ciliodestruction), tumors, and other pathologies. Linear and annular transducer arrays offer synthetic focusing in which precise timing of the excitation of independently addressable array elements allows formation of a converging wavefront to create a focus at one or more programmable depths. Most recently, linear array-based plane-wave ultrasound, in which the array emits an unfocused wavefront and focusing is performed solely on received data, has been demonstrated for imaging ocular anatomy and blood flow. While the history of ophthalmic ultrasound extends back over half-a-century, new and powerful technologic advances continue to be made, offering the prospect of novel diagnostic capabilities.

  7. Focused ultrasound in ophthalmology

    PubMed Central

    Silverman, Ronald H

    2016-01-01

    The use of focused ultrasound to obtain diagnostically significant information about the eye goes back to the 1950s. This review describes the historical and technological development of ophthalmic ultrasound and its clinical application and impact. Ultrasound, like light, can be focused, which is crucial for formation of high-resolution, diagnostically useful images. Focused, single-element, mechanically scanned transducers are most common in ophthalmology. Specially designed transducers have been used to generate focused, high-intensity ultrasound that through thermal effects has been used to treat glaucoma (via ciliodestruction), tumors, and other pathologies. Linear and annular transducer arrays offer synthetic focusing in which precise timing of the excitation of independently addressable array elements allows formation of a converging wavefront to create a focus at one or more programmable depths. Most recently, linear array-based plane-wave ultrasound, in which the array emits an unfocused wavefront and focusing is performed solely on received data, has been demonstrated for imaging ocular anatomy and blood flow. While the history of ophthalmic ultrasound extends back over half-a-century, new and powerful technologic advances continue to be made, offering the prospect of novel diagnostic capabilities. PMID:27757007

  8. Digital rights management for digital cinema

    NASA Astrophysics Data System (ADS)

    Kirovski, Darko; Peinado, Marcus; Petitcolas, Fabien A. P.

    2001-12-01

    There is a wide consensus among the feature film production studios that the Internet era brings a new paradigm for film distribution to cinemas worldwide. The benefits of digital cinema to both producers and cinemas are numerous: significantly lower distribution and maintenance costs, immediate access to film libraries, higher presentation quality, and strong potential for developing new business models. Despite these advantages, the studios are still reluctant to jump into the digital age. The main showstopper for digital cinema is the danger of widespread piracy. Piracy already costs Hollywood an estimated two billion dollars annually and digital cinema without proper copyright enforcement could increase this number. In this paper, we present a copyright management system that aims at providing the set of necessary security tools: standard cryptographic primitives and copyright protection mechanisms that enable a reliable and secure feature film delivery system.

  9. Play, Creativity and Digital Cultures. Routledge Research in Education

    ERIC Educational Resources Information Center

    Willett, Rebekah, Ed.; Robinson, Muriel, Ed.; Marsh, Jackie, Ed.

    2011-01-01

    Recent work on children's digital cultures has identified a range of literacies emerging through children's engagement with new media technologies. This edited collection focuses on children's digital cultures, specifically examining the role of play and creativity in learning with these new technologies. The chapters in this book were contributed…

  10. Play, Creativity and Digital Cultures. Routledge Research in Education

    ERIC Educational Resources Information Center

    Willett, Rebekah, Ed.; Robinson, Muriel, Ed.; Marsh, Jackie, Ed.

    2011-01-01

    Recent work on children's digital cultures has identified a range of literacies emerging through children's engagement with new media technologies. This edited collection focuses on children's digital cultures, specifically examining the role of play and creativity in learning with these new technologies. The chapters in this book were contributed…

  11. Digital Intermediation: An Exploration of User and Intermediary Perspectives.

    ERIC Educational Resources Information Center

    Southwick, Silvia Barcellos

    2003-01-01

    Reports on an exploratory case study of intermediation in a hospital digital library information service. Focuses on intermediation where user-intermediary communications were conducted through an asynchronous text-based digital medium. Contributions of the study are evidenced in a descriptive framework of nine categories of factors perceived as…

  12. Reference Implications of Digital Technology in a Library Photograph Collection.

    ERIC Educational Resources Information Center

    Benemann, William E.

    1994-01-01

    Describes a feasibility study which focused on converting Japanese-American evacuation and relocation photographs to digital format for improved access and preservation. Problems and issues surrounding indexing the collection, the use of Library of Congress Subject Headings and authority files, and public service issues raised by a digital image…

  13. The Nerdy Teacher: Pedagogical Identities for a Digital Age

    ERIC Educational Resources Information Center

    Hull, Glynda; Scott, John; Higgs, Jennifer

    2014-01-01

    Professional learning around digital media often focuses on tool use and neglects consideration of teachers as interested, creative producers of digital media artifacts. The best way to help teachers learn about and adapt technology in their classrooms is by immersing them in hands-on work in the same way their students use social networks and…

  14. Struggle for Social Position in Digital Media Composition

    ERIC Educational Resources Information Center

    Doerr-Stevens, Candance

    2013-01-01

    This study investigates the processes and products of multimodal and multi-authored digital media composition. Using ethnographic case study and Mediated Discourse Analysis (Norris & Jones, 2005), this study focuses specifically on the digital media composition of radio and film documentaries, examining struggle among students, media, and…

  15. Struggle for Social Position in Digital Media Composition

    ERIC Educational Resources Information Center

    Doerr-Stevens, Candance

    2013-01-01

    This study investigates the processes and products of multimodal and multi-authored digital media composition. Using ethnographic case study and Mediated Discourse Analysis (Norris & Jones, 2005), this study focuses specifically on the digital media composition of radio and film documentaries, examining struggle among students, media, and…

  16. The Nerdy Teacher: Pedagogical Identities for a Digital Age

    ERIC Educational Resources Information Center

    Hull, Glynda; Scott, John; Higgs, Jennifer

    2014-01-01

    Professional learning around digital media often focuses on tool use and neglects consideration of teachers as interested, creative producers of digital media artifacts. The best way to help teachers learn about and adapt technology in their classrooms is by immersing them in hands-on work in the same way their students use social networks and…

  17. Negotiating Digital Divides: Perspectives from the New Zealand Schooling System

    ERIC Educational Resources Information Center

    Starkey, Louise; Sylvester, Allan; Johnstone, David

    2017-01-01

    This article explores digital divides identified in research literature and considers educational policy directions that may mitigate or enhance future inequities. A review of literature identified three categories of digital divides in society; access, capability, and participation. To explore the strategic focus in schooling, data were gathered…

  18. Use of digital nerve blocks to provide anaesthetic relief.

    PubMed

    Summers, Anthony

    2011-09-01

    This article discusses the various techniques that nurses can use to perform digital nerve blocks, which are some of the most common procedures undertaken by emergency practitioners treating patients with finger injuries. In covering the advantages and disadvantages of each technique, it focuses primarily on the digits of the hand, but the techniques can also be performed on toes.

  19. Building Expertise to Support Digital Scholarship: A Global Perspective

    ERIC Educational Resources Information Center

    Lewis, Vivian; Spiro, Lisa; Wang, Xuemao; Cawthorne, Jon E.

    2015-01-01

    This report sheds light on the expertise required to support a robust and sustainable digital scholarship (DS) program. It focuses first on defining and describing the key domain knowledge, skills, competencies, and mindsets at some of the world's most prominent digital scholarship programs. It then identifies the main strategies used to build…

  20. Looking at Digital Library Usability from a Reuse Perspective.

    ERIC Educational Resources Information Center

    Sumner, Tamara; Dawe, Melissa

    The need for information systems to support the dissemination and reuse of educational resources has sparked a number of large-scale digital library efforts. This article describes usability findings from one such project--the Digital Library for Earth System Education (DLESE)--focusing on its role in the process of educational resource reuse.…

  1. Flat Focusing Mirror

    PubMed Central

    Cheng, Y. C.; Kicas, S.; Trull, J.; Peckus, M.; Cojocaru, C.; Vilaseca, R.; Drazdys, R.; Staliunas, K.

    2014-01-01

    The control of spatial propagation properties of narrow light beams such as divergence, focusing or imaging are main objectives in optics and photonics. In this letter, we propose and demonstrate experimentally a flat focusing mirror, based on an especially designed dielectric structure without any optical axis. More generally, it also enables imaging any light pattern in reflection. The flat focusing mirror with a transversal invariance can largely increase the applicability of structured photonic materials for light beam propagation control in small-dimension photonic circuits. PMID:25228358

  2. Digital imaging technology assessment: Digital document storage project

    NASA Technical Reports Server (NTRS)

    1989-01-01

    An ongoing technical assessment and requirements definition project is examining the potential role of digital imaging technology at NASA's STI facility. The focus is on the basic components of imaging technology in today's marketplace as well as the components anticipated in the near future. Presented is a requirement specification for a prototype project, an initial examination of current image processing at the STI facility, and an initial summary of image processing projects at other sites. Operational imaging systems incorporate scanners, optical storage, high resolution monitors, processing nodes, magnetic storage, jukeboxes, specialized boards, optical character recognition gear, pixel addressable printers, communications, and complex software processes.

  3. Inertial focusing in microfluidics.

    PubMed

    Martel, Joseph M; Toner, Mehmet

    2014-07-11

    When Segré and Silberberg in 1961 witnessed particles in a laminar pipe flow congregating at an annulus in the pipe, scientists were perplexed and spent decades learning why such behavior occurred, finally understanding that it was caused by previously unknown forces on particles in an inertial flow. The advent of microfluidics opened a new realm of possibilities for inertial focusing in the processing of biological fluids and cellular suspensions and created a field that is now rapidly expanding. Over the past five years, inertial focusing has enabled high-throughput, simple, and precise manipulation of bodily fluids for a myriad of applications in point-of-care and clinical diagnostics. This review describes the theoretical developments that have made the field of inertial focusing what it is today and presents the key applications that will make inertial focusing a mainstream technology in the future.

  4. Focusing corner cube

    DOEpatents

    Monjes, J.A.

    1985-09-12

    This invention retortreflects and focuses a beam of light. The invention comprises a modified corner cube reflector wherein one reflective surface is planar, a second reflective surface is spherical, and the third reflective surface may be planar or convex cylindrical.

  5. Focus: Surface Characterization.

    ERIC Educational Resources Information Center

    Winograd, Nicholas

    1985-01-01

    The 38th Annual Summer Symposium on Analytical Chemistry (June 18-20, 1985) focused on the surface characterization of catalytic and electronic materials. Highlights of the symposium are provided, including presentations that considered lasers and microscopy. (JN)

  6. Facility Focus: Food Service.

    ERIC Educational Resources Information Center

    College Planning & Management, 2002

    2002-01-01

    Describes the Hawthorn Court Community Center at Iowa State University, Ames, and the HUB-Robeson Center at Pennsylvania State University. Focuses on the food service offered in these new student-life buildings. Includes photographs. (EV)

  7. Inertial Focusing in Microfluidics

    PubMed Central

    Martel, Joseph M.; Toner, Mehmet

    2015-01-01

    When Segré and Silberberg in 1961 witnessed particles in a laminar pipe flow congregating at an annulus in the pipe, scientists were perplexed and spent decades learning why such behavior occurred, finally understanding that it was caused by previously unknown forces on particles in an inertial flow. The advent of microfluidics opened a new realm of possibilities for inertial focusing in the processing of biological fluids and cellular suspensions and created a field that is now rapidly expanding. Over the past five years, inertial focusing has enabled high-throughput, simple, and precise manipulation of bodily fluids for a myriad of applications in point-of-care and clinical diagnostics. This review describes the theoretical developments that have made the field of inertial focusing what it is today and presents the key applications that will make inertial focusing a mainstream technology in the future. PMID:24905880

  8. Focus Group Guide

    DTIC Science & Technology

    2017-07-01

    Time/Date: Unit: Session #: Focus Group Location: Number of Participants: Group Rank Makeup: Demographics (# by race, sex ): Use separate...Sexual Harassment (C) Sex Harassment Retaliation (D) Discrimination - Sex (E) Discrimination - Race (F) Discrimination - Disability (G

  9. Focus on Preservation.

    ERIC Educational Resources Information Center

    Wyly, Mary; And Others

    1985-01-01

    Three articles focus on preservation of library materials: profile of Bonnie Jo Cullison, book conservationist at Newberry Library (Chicago, Illinois); planning for preservation (administration, conservation training, microreproduction, library binding, environmental control, research and development, educating public); preservation guide for…

  10. Facility Focus: Food Service.

    ERIC Educational Resources Information Center

    College Planning & Management, 2002

    2002-01-01

    Describes the Hawthorn Court Community Center at Iowa State University, Ames, and the HUB-Robeson Center at Pennsylvania State University. Focuses on the food service offered in these new student-life buildings. Includes photographs. (EV)

  11. Final focus test beam

    SciTech Connect

    Not Available

    1991-03-01

    This report discusses the following: the Final Focus Test Beam Project; optical design; magnets; instrumentation; magnetic measurement and BPM calibration; mechanical alignment and stabilization; vacuum system; power supplies; control system; radiation shielding and personnel protection; infrastructure; and administration.

  12. High harmonics focusing undulator

    SciTech Connect

    Varfolomeev, A.A.; Hairetdinov, A.H.; Smirnov, A.V.; Khlebnikov, A.S.

    1995-12-31

    It was shown in our previous work that there exist a possibility to enhance significantly the {open_quote}natural{close_quote} focusing properties of the hybrid undulator. Here we analyze the actual undulator configurations which could provide such field structure. Numerical simulations using 2D code PANDIRA were carried out and the enhanced focusing properties of the undulator were demonstrated. The obtained results provide the solution for the beam transport in a very long (short wavelength) undulator schemes.

  13. New NLC Final Focus

    SciTech Connect

    Raimondi, P.

    2004-10-11

    A novel design of the Final Focus has recently been proposed [1] and has been adopted now for the Next Linear Collider [2]. This new design has fewer optical elements and is much shorter, nonetheless achieving better chromatic properties. In this paper, the new final focus system is briefly discussed stressing one particular characteristic of the new design--its multi TeV energy reach.

  14. Electron beam focusing system

    SciTech Connect

    Dikansky, N.; Nagaitsev, S.; Parkhomchuk, V.

    1997-09-01

    The high energy electron cooling requires a very cold electron beam. Thus, the electron beam focusing system is very important for the performance of electron cooling. A system with and without longitudinal magnetic field is presented for discussion. Interaction of electron beam with the vacuum chamber as well as with the background ions and stored antiprotons can cause the coherent electron beam instabilities. Focusing system requirements needed to suppress these instabilities are presented.

  15. Using Disruptive Technologies to Make Digital Connections: Stories of Media Use and Digital Literacy in Secondary Classrooms

    ERIC Educational Resources Information Center

    Nowell, Shanedra D.

    2014-01-01

    This study focused on ways teachers and students in an urban high school used technologies often labeled as disruptive (i.e. social media and mobile phones) as learning and relationship building tools, inside and outside the classroom. In this teacher research study, secondary teachers discussed digital literacies, the digital divide, and digital…

  16. Using Disruptive Technologies to Make Digital Connections: Stories of Media Use and Digital Literacy in Secondary Classrooms

    ERIC Educational Resources Information Center

    Nowell, Shanedra D.

    2014-01-01

    This study focused on ways teachers and students in an urban high school used technologies often labeled as disruptive (i.e. social media and mobile phones) as learning and relationship building tools, inside and outside the classroom. In this teacher research study, secondary teachers discussed digital literacies, the digital divide, and digital…

  17. Plutonium focus area

    SciTech Connect

    1996-08-01

    To ensure research and development programs focus on the most pressing environmental restoration and waste management problems at the U.S. Department of Energy (DOE), the Assistant Secretary for the Office of Environmental Management (EM) established a working group in August 1993 to implement a new approach to research and technology development. As part of this new approach, EM developed a management structure and principles that led to the creation of specific Focus Areas. These organizations were designed to focus the scientific and technical talent throughout DOE and the national scientific community on the major environmental restoration and waste management problems facing DOE. The Focus Area approach provides the framework for intersite cooperation and leveraging of resources on common problems. After the original establishment of five major Focus Areas within the Office of Technology Development (EM-50, now called the Office of Science and Technology), the Nuclear Materials Stabilization Task Group (EM-66) followed the structure already in place in EM-50 and chartered the Plutonium Focus Area (PFA). The following information outlines the scope and mission of the EM, EM-60, and EM-66 organizations as related to the PFA organizational structure.

  18. Dealing with Diversity and Digital Culture.

    ERIC Educational Resources Information Center

    Ferreiro, Soledad

    1997-01-01

    The main barriers for Latin America's participation in the digital culture are: the few people with access to technology; the technological infrastructure; lack of relevant contents in primary languages; and English as the predominant language of the global information infrastructure. Nations should focus on infrastructure, contents, and access.…

  19. Education Reform for the Digital Era

    ERIC Educational Resources Information Center

    Finn, Chester E., Ed., Jr.; Fairchild, Daniela R., Ed.

    2012-01-01

    Will the digital-learning movement repeat the mistakes of the charter-school movement? How much more successful might today's charter universe look if yesterday's proponents had focused on the policies and practices needed to ensure its quality, freedom, and resources over the long term? What mistakes might have been avoided? Damaging scandals…

  20. Educating the First Digital Generation. Educate Us

    ERIC Educational Resources Information Center

    Harwood, Paul G.; Asal, Victor

    2007-01-01

    Asal and Harwood explore how today's information technology is changing how teachers educate and are educated. Focusing on the United States, with useful insights from the classroom digital revolution in a few other places (the United Kingdom, Australia, and India), the authors investigate the impact of today's technologies on education--how they…

  1. Digitizing Historical Pictorial Collections for the Internet.

    ERIC Educational Resources Information Center

    Ostrow, Stephen E.

    This report is one in a series from the Council on Library and Information Resources that explores the issues and problems that institutions must address when undertaking digital conversion projects. The focus of this report is on projects that mean to provide widespread access over the Internet to large historical pictorial collections, using an…

  2. Evaluation of commercially available exterior digital VMDs

    SciTech Connect

    Ringler, C.E.; Hoover, C.E.

    1995-06-01

    This report discusses the testing and evaluation of thirteen commercially available exterior digital video motion detection (VMD) systems. The systems were evaluated for use in a specific outdoor application. The report focuses primarily on the testing parameters, each system`s advertised features, and the nuisance alarm and detection test results.

  3. Digital Photography--a Question of Ethics.

    ERIC Educational Resources Information Center

    Meltzer, Bonnie

    1996-01-01

    Discusses reasons for computer manipulation of photographs and the need to educate students about the ethics involving digital scanning. Focuses on ownership, copyrights, reasons for changing a photograph, reader-interpretation, and the context in which the photograph is used. Suggests a photo illustration project to teach students about these…

  4. Redefining Book Reviews for the Digital Age

    ERIC Educational Resources Information Center

    Butler, Deirdre; Leahy, Margaret; McCormack, Ciaran

    2010-01-01

    This paper describes the results of a pilot study conducted in Ireland to examine the effectiveness of an online book review project. The project focused on the production of book reviews by primary school children in the form of digital video. The videos created were uploaded to a password protected website, which was available to the schools…

  5. Redefining Book Reviews for the Digital Age

    ERIC Educational Resources Information Center

    Butler, Deirdre; Leahy, Margaret; McCormack, Ciaran

    2010-01-01

    This paper describes the results of a pilot study conducted in Ireland to examine the effectiveness of an online book review project. The project focused on the production of book reviews by primary school children in the form of digital video. The videos created were uploaded to a password protected website, which was available to the schools…

  6. Integrating Automatic Genre Analysis into Digital Libraries.

    ERIC Educational Resources Information Center

    Rauber, Andreas; Muller-Kogler, Alexander

    With the number and types of documents in digital library systems increasing, tools for automatically organizing and presenting the content have to be found. While many approaches focus on topic-based organization and structuring, hardly any system incorporates automatic structural analysis and representation. Yet, genre information…

  7. Centralized digital control of accelerators

    SciTech Connect

    Melen, R.E.

    1983-09-01

    In contrasting the title of this paper with a second paper to be presented at this conference entitled Distributed Digital Control of Accelerators, a potential reader might be led to believe that this paper will focus on systems whose computing intelligence is centered in one or more computers in a centralized location. Instead, this paper will describe the architectural evolution of SLAC's computer based accelerator control systems with respect to the distribution of their intelligence. However, the use of the word centralized in the title is appropriate because these systems are based on the use of centralized large and computationally powerful processors that are typically supported by networks of smaller distributed processors.

  8. Saving Amputated Digits

    PubMed Central

    Frykman, Gary K.; Wood, Virchel E.

    1974-01-01

    Since the advent of microsurgery in the 1960's it has become possible to sucessfully repair vessels as small as 0.5 mm in diameter, which makes the replantation of totally severed digits possible. Some centers have reported 50 to 60 percent survival of completely severed digits and up to 100 percent survival of amputated hands and of partially amputed but otherwise non-viable digits that were reattached. In view of this success, severed members should be considered as potentially replantable. The recommended indications for replantation are: (1) multiple digital amputations at or proximal to the proximal interphalangeal joint; (2) amputation of the thumb; (3) amputation of the wrist or hand; (4) partially attached digits that are non-viable without reattachment. The surviving replanted digits give functional improvement to the hand and prove cosmetically acceptable. ImagesFigure 1.Figure 2. PMID:4608643

  9. Digital work-flow

    PubMed Central

    MARSANGO, V.; BOLLERO, R.; D’OVIDIO, N.; MIRANDA, M.; BOLLERO, P.; BARLATTANI, A.

    2014-01-01

    SUMMARY Objective. The project presents a clinical case in which the digital work-flow procedure was applied for a prosthetic rehabilitation in natural teeth and implants. Materials. Digital work-flow uses patient’s photo for the aesthetic’s planning, digital smile technology for the simulation of the final restoration and real time scanning to register the two arches. Than the scanning are sent to the laboratory that proceed with CAD-CAM production. Results. Digital work-flow offers the opportunities to easily speak with laboratory and patients, gives better clinical results and demonstrated to be a less invasiveness method for the patient. Conclusion. Intra-oral scanner, digital smile design, preview using digital wax-up, CAD-CAM production, are new predictable opportunities for prosthetic team. This work-flow, compared with traditional methods, is faster, more precise and predictable. PMID:25694797

  10. Digital radiography: an overview.

    PubMed

    Parks, Edwin T; Williamson, Gail F

    2002-11-15

    Since the discovery of X-rays in 1895, film has been the primary medium for capturing, displaying, and storing radiographic images. It is a technology that dental practitioners are the most familiar and comfortable with in terms of technique and interpretation. Digital radiography is the latest advancement in dental imaging and is slowly being adopted by the dental profession. Digital imaging incorporates computer technology in the capture, display, enhancement, and storage of direct radiographic images. Digital imaging offers some distinct advantages over film, but like any emerging technology, it presents new and different challenges for the practitioner to overcome. This article presents an overview of digital imaging including basic terminology and comparisons with film-based imaging. The principles of direct and indirect digital imaging modalities, intraoral and extraoral applications, image processing, and diagnostic efficacy will be discussed. In addition, the article will provide a list of questions dentists should consider prior to purchasing digital imaging systems for their practice.

  11. Digital Natives and Digital Divide: Analysing Perspective for Emerging Pedagogy

    ERIC Educational Resources Information Center

    Onye, Uriel U.; Du, Yunfei

    2016-01-01

    This paper addresses the concepts of digital natives and digital divide from the perspective of the digital outsiders (part of digital natives). It takes a critical look at the implications of available ICT in both developed and underdeveloped countries in the fight against digital divide. The major contribution to literature is by drawing…

  12. EDITORIAL: Focus on Plasmonics FOCUS ON PLASMONICS

    NASA Astrophysics Data System (ADS)

    Bozhevolnyi, Sergey; García-Vidal, Francisco

    2008-10-01

    Plasmonics is an emerging field in optics dealing with the so-called surface plasmons whose extraordinary properties are being both analyzed from a fundamental point of view and exploited for numerous technological applications. Surface plasmons associated with surface electron density oscillations decorating metal-dielectric interfaces were discovered by Rufus Ritchie in the 1950s. Since the seventies, the subwavelength confinement of electromagnetic fields as well as their enhancement inherent to the surface plasmon excitation has been widely used for spectroscopic purposes. Recent advances in nano-fabrication, characterization and modelling techniques have allowed unique properties of these surface electromagnetic modes to be explored with respect to subwavelength field localization and waveguiding, opening the path to truly nanoscale plasmonic optical devices. This area of investigation also has interesting links with research on photonic band gap materials and the field of optical metamaterials. Nowadays, plasmonics can be seen as a mature interdisciplinary area of research in which scientists coming from different backgrounds (chemistry, physics, optics and engineering) strive to discover and exploit new and exciting phenomena associated with surface plasmons. The already made and forthcoming discoveries will have impacts in many fields of science and technology, including not only photonics and materials science but also computation, biology and medicine, among others. This focus issue of New Journal of Physics is intended to cover all the aforementioned capabilities of surface plasmons by presenting a current overview of state-of-the-art advances achieved by the leading groups in this field of research. The below list of articles represents the first contributions to the collection and further additions will appear soon. Focus on Plasmonics Contents Nanoantenna array-induced fluorescence enhancement and reduced lifetimes Reuben M Bakker, Vladimir P Drachev

  13. Digital Sensor Technology

    SciTech Connect

    Thomas, Ken D.; Quinn, Edward L.; Mauck, Jerry L.; Bockhorst, Richard M.

    2015-02-01

    The nuclear industry has been slow to incorporate digital sensor technology into nuclear plant designs due to concerns with digital qualification issues. However, the benefits of digital sensor technology for nuclear plant instrumentation are substantial in terms of accuracy and reliability. This paper, which refers to a final report issued in 2013, demonstrates these benefits in direct comparisons of digital and analog sensor applications. Improved accuracy results from the superior operating characteristics of digital sensors. These include improvements in sensor accuracy and drift and other related parameters which reduce total loop uncertainty and thereby increase safety and operating margins. An example instrument loop uncertainty calculation for a pressure sensor application is presented to illustrate these improvements. This is a side-by-side comparison of the instrument loop uncertainty for both an analog and a digital sensor in the same pressure measurement application. Similarly, improved sensor reliability is illustrated with a sample calculation for determining the probability of failure on demand, an industry standard reliability measure. This looks at equivalent analog and digital temperature sensors to draw the comparison. The results confirm substantial reliability improvement with the digital sensor, due in large part to ability to continuously monitor the health of a digital sensor such that problems can be immediately identified and corrected. This greatly reduces the likelihood of a latent failure condition of the sensor at the time of a design basis event. Notwithstanding the benefits of digital sensors, there are certain qualification issues that are inherent with digital technology and these are described in the report. One major qualification impediment for digital sensor implementation is software common cause failure (SCCF).

  14. Digital Longitudinal Tomosynthesis

    NASA Astrophysics Data System (ADS)

    Rimkus, Daniel Steven

    1985-12-01

    The purpose of this dissertation was to investigate the clinical utility of digital longitudinal tomosynthesis in radiology. By acquiring a finite group of digital images during a longitudinal tomographic exposure, and processing these images, tomographic planes, other than the fulcrum plane, can be reconstructed. This process is now termed "tomosynthesis". A prototype system utilizing this technique was developed. Both phantom and patient studies were done with this system. The phantom studies were evaluated by subjective, visual criterion and by quantitative analysis of edge sharpness and noise in the reconstructions. Two groups of patients and one volunteer were studied. The first patient group consisted of 8 patients undergoing intravenous urography (IVU). These patients had digital tomography and film tomography of the abdomen. The second patient group consisted of 4 patients with lung cancer admitted to the hospital for laser resection of endobronchial tumor. These patients had mediastinal digital tomograms to evaluate the trachea and mainstem bronchi. The knee of one volunteer was imaged by film tomography and digital tomography. The results of the phantom studies showed that the digital reconstructions accurately produced images of the desired planes. The edge sharpness of the reconstructions approached that of the acquired images. Adequate reconstructions were achieved with as few as 5 images acquired during the exposure, with the quality of the reconstructions improving as the number of images acquired increased. The IVU patients' digital studies had less contrast and spatial resolution than the film tomograms. The single renal lesion visible on the film tomograms was also visible in the digital images. The digital mediastinal studies were felt by several radiologists to be superior to a standard chest xray in evaluating the airways. The digital images of the volunteer's knee showed many of the same anatomic features as the film tomogram, but the digital

  15. Digital Systems Technical Analysis.

    DTIC Science & Technology

    1982-10-01

    criticality assessment , and configuration management methodologies for existing and new digital systems. Any recommendations concerning acceptance criteria...total removals or total failures. 5.2.1.1 Navigation Equipments q More than 30 models were investigated as possible digital units. As shown in Table 5-3...19 digital models were identified in the navigation category. Some of the models that were found to be analog are presented in Table 5-3 for

  16. Digital micro-mirror devices in digital optical microscopy

    NASA Astrophysics Data System (ADS)

    Adeyemi, Adekunle Adesanya

    In this thesis, studies on the applications of digital micro-mirror devices (DMD) to enhancement of digital optical microscope images are presented. This involves adaptation of the fast switching capability and high optical efficiency of DMD to control the spatial illumination of the specimen. The first study focuses on a method of using DMD to enhance the dynamic range of a digital optical microscope. Our adaptive feedback illumination control method generates a high dynamic range image through an algorithm that combines the DMD-to-camera pixel geometrical mapping and a feedback operation. The feedback process automatically generates an illumination pattern in an iterative fashion that spatially modulates the DMD array elements on a pixel-by-pixel level. Via experiment, we demonstrate a transmitted-light microscope system that uses precise DMD control of a DMD-based projector to enhance the dynamic range ideally by a factor of 573. Results are presented showing approximately 5 times the camera dynamic range, enabling visualization over a wide range of specimen characteristics. The second study presents a technique for programming the source of the spherical reference illumination in a digital in-line holographic microscope using DMD. The programmable point source is achieved by individually addressing the elements of a DMD to spatially control the illumination of the object located at some distance from the source of the spherical reference field. Translation of the ON-state DMD mirror element changes the spatial location of the point source and consequently generates a sequence of translated holograms of the object. The experimental results obtained through numerical reconstruction of translated holograms of Latex microspheres shows the possibility of expanding the field of view by about 263% and also extracting depth information between features in an object volume. The common challenges associated with the use of DMD in coherent and broadband illumination

  17. Digital In, Digital Out: Digital Editing with Firewire.

    ERIC Educational Resources Information Center

    Doyle, Bob; Sauer, Jeff

    1997-01-01

    Reviews linear and nonlinear digital video (DV) editing equipment and software, using the IEEE 1394 (FireWire) connector. Includes a chart listing specifications and rating eight DV editing systems, reviews two DV still-photo cameras, and previews beta DV products. (PEN)

  18. Digital In, Digital Out: Digital Editing with Firewire.

    ERIC Educational Resources Information Center

    Doyle, Bob; Sauer, Jeff

    1997-01-01

    Reviews linear and nonlinear digital video (DV) editing equipment and software, using the IEEE 1394 (FireWire) connector. Includes a chart listing specifications and rating eight DV editing systems, reviews two DV still-photo cameras, and previews beta DV products. (PEN)

  19. Exploring digital professionalism.

    PubMed

    Ellaway, Rachel H; Coral, Janet; Topps, David; Topps, Maureen

    2015-01-01

    The widespread use of digital media (both computing devices and the services they access) has blurred the boundaries between our personal and professional lives. Contemporary students are the last to remember a time before the widespread use of the Internet and they will be the first to practice in a largely e-health environment. This article explores concepts of digital professionalism and their place in contemporary medical education, and proposes a series of principles of digital professionalism to guide teaching, learning and practice in the healthcare professions. Despite the many risks and fears surrounding their use, digital media are not an intrinsic threat to medical professionalism. Professionals should maintain the capacity for deliberate, ethical, and accountable practice when using digital media. The authors describe a digital professionalism framework structured around concepts of proficiency, reputation, and responsibility. Digital professionalism can be integrated into medical education using strategies based on awareness, alignment, assessment, and accountability. These principles of digital professionalism provide a way for medical students and medical practitioners to embrace the positive aspects of digital media use while being mindful and deliberate in its use to avoid or minimize any negative consequences.

  20. Digital Electronic Still Camera

    NASA Technical Reports Server (NTRS)

    Holland, Samuel D.; Yeates, Herbert D.

    1993-01-01

    Digital electronic still camera part of electronic recording, processing, tansmitting, and displaying system. Removable hard-disk drive in camera serves as digital electronic equivalent of photographic film. Images viewed, analyzed, or transmitted quickly. Camera takes images of nearly photographic quality and stores them in digital form. Portable, hand-held, battery-powered unit designed for scientific use. Camera used in conjunction with playback unit also serving as transmitting unit if images sent to remote station. Remote station equipped to store, process, and display images. Digital image data encoded with error-correcting code at playback/transmitting unit for error-free transmission to remote station.

  1. Digital Imaging Investigations.

    ERIC Educational Resources Information Center

    Keith, Ronald L.; Saunders, David K.; Yanik, Elizabeth G.

    2003-01-01

    Explains how digital technology can be used as a tool for teaching students the skills of observation, questioning, information gathering, classifying, predicting, and hypothesis testing. (Author/SOE)

  2. Experiments in digital literacy.

    PubMed

    Eshet-Alkali, Yoram; Amichai-Hamburger, Yair

    2004-08-01

    Having digital literacy requires more than just the ability to use software or to operate a digital device; it includes a large variety of complex skills such as cognitive, motoric, sociological, and emotional that users need to have in order to use digital environments effectively. A conceptual model that was recently described by the authors suggests that digital literacy comprises five major digital skills: photo-visual skills ("reading" instructions from graphical displays), reproduction skills (utilizing digital reproduction to create new, meaningful materials from preexisting ones), branching skills (constructing knowledge from non-linear, hypertextual navigation), information skills (evaluating the quality and validity of information), and socio-emotional skills (understanding the "rules" that prevail in cyberspace and applying this understanding in online cyberspace communication). The present paper presents results from a performance-based pioneer study that investigated the application of the above digital literacy skills conceptual model among different groups of scholars. Results clearly indicate that the younger participants performed better than the older ones, with photo-visual and branching literacy tasks, whereas the older participants were found to be more literate in reproduction and information literacy tasks. Research results shed light on the cognitive skills that users utilize in performing with digital environments, and provide educators and software developers with helpful guidelines for designing better user-centered digital environments.

  3. Decontamination & decommissioning focus area

    SciTech Connect

    1996-08-01

    In January 1994, the US Department of Energy Office of Environmental Management (DOE EM) formally introduced its new approach to managing DOE`s environmental research and technology development activities. The goal of the new approach is to conduct research and development in critical areas of interest to DOE, utilizing the best talent in the Department and in the national science community. To facilitate this solutions-oriented approach, the Office of Science and Technology (EM-50, formerly the Office of Technology Development) formed five Focus AReas to stimulate the required basic research, development, and demonstration efforts to seek new, innovative cleanup methods. In February 1995, EM-50 selected the DOE Morgantown Energy Technology Center (METC) to lead implementation of one of these Focus Areas: the Decontamination and Decommissioning (D & D) Focus Area.

  4. Sagittal focusing Laue monochromator

    DOEpatents

    Zhong; Zhong , Hanson; Jonathan , Hastings; Jerome , Kao; Chi-Chang , Lenhard; Anthony , Siddons; David Peter , Zhong; Hui

    2009-03-24

    An x-ray focusing device generally includes a slide pivotable about a pivot point defined at a forward end thereof, a rail unit fixed with respect to the pivotable slide, a forward crystal for focusing x-rays disposed at the forward end of the pivotable slide and a rearward crystal for focusing x-rays movably coupled to the pivotable slide and the fixed rail unit at a distance rearward from the forward crystal. The forward and rearward crystals define reciprocal angles of incidence with respect to the pivot point, wherein pivoting of the slide about the pivot point changes the incidence angles of the forward and rearward crystals while simultaneously changing the distance between the forward and rearward crystals.

  5. NICMOS focus monitor

    NASA Astrophysics Data System (ADS)

    Schneider, Glenn

    1997-07-01

    This proposal is used to determine and monitor the optimal focus and tilt settings for all three NICMOS cameras. It is derived from SM2/NIC 7041, but is structurally quite a bit different. This proposal is built to run NIC1/2 focus sweeps on a weekly basis, and NIC3 focus sweeps twice a week during SMOV {following the "interim" runs of the 7150}. 7043 will run for as long as it is deemed necessary to keep track of the camera focii and to monitor the dewar anomaly. After the discussion on 20/3/96, this proposal is written to run 4 complete 1-week iterations starting 3 days after the last run of the 7150 {NICMOS COARSE OPTICAL ALIGNMENT, PART 2}.

  6. Uses of Digital Tools and Literacies in the English Language Arts Classroom

    ERIC Educational Resources Information Center

    Beach, Richard

    2012-01-01

    This article reviews research on English language arts teachers' use of digital tools in the classroom to remediate print literacies. Specifically, this review focuses on the affordances of digital tools to foster uses of digital literacies of informational/accessibility, collaboration knowledge construction, multimodal communication, gaming…

  7. How the Construction & Analysis of Digital Movies Support Theory-Building.

    ERIC Educational Resources Information Center

    Goldman-Segall, Ricki; Beers, Maggie; de Castell, Suzanne; Bryson, Mary; Reilly, Brian

    This paper brings together four short discussions that focus on how the construction and analysis of digital movies support theory-building, and whether that theory-building is equitable. Researches who have used digital media extensively over the last decade address how participants in studies using digital media become collaborators and…

  8. Digital Library Use: Social Practice in Design and Evaluation (SIGs DL, IA)

    ERIC Educational Resources Information Center

    Lynch, Clifford

    2000-01-01

    This proposal for a technical session presentation focused on socially-grounded approaches to understanding digital libraries; the social nature of digital libraries; and implications for the design and evaluation of digital libraries. Panelists included: Christine L. Borgman, Laura Neumann, Nancy Van House and Ann P. Bishop. (LRW)

  9. High Res at High Speed: Automated Delivery of High-Resolution Images from Digital Library Collections

    ERIC Educational Resources Information Center

    Westbrook, R. Niccole; Watkins, Sean

    2012-01-01

    As primary source materials in the library are digitized and made available online, the focus of related library services is shifting to include new and innovative methods of digital delivery via social media, digital storytelling, and community-based and consortial image repositories. Most images on the Web are not of sufficient quality for most…

  10. Uses of Digital Tools and Literacies in the English Language Arts Classroom

    ERIC Educational Resources Information Center

    Beach, Richard

    2012-01-01

    This article reviews research on English language arts teachers' use of digital tools in the classroom to remediate print literacies. Specifically, this review focuses on the affordances of digital tools to foster uses of digital literacies of informational/accessibility, collaboration knowledge construction, multimodal communication, gaming…

  11. (In)Forming: The Affordances of Digital Fabrication in Architectural Education

    ERIC Educational Resources Information Center

    Cabrinha, Mark Newell

    2010-01-01

    This research focuses on the effect of technology on the culture of architectural education through the lens of digital fabrication (CAD/CAM). As the computer was introduced into design education long before digital fabrication was accessible, design culture has prioritized image over material experience. Digital fabrication enables a material…

  12. [Application of three-dimensional digital technology in the diagnosis and treatment planning in orthodontics].

    PubMed

    Bai, Y X

    2016-06-01

    Three-dimensional(3D)digital technology has been widely used in the field of orthodontics in clinical examination, diagnosis, treatment and curative effect evaluation. 3D digital technology greatly improves the accuracy of diagnosis and treatment, and provides effective means for personalized orthodontic treatment. This review focuses on the application of 3D digital technology in the field of orthodontics.

  13. High Res at High Speed: Automated Delivery of High-Resolution Images from Digital Library Collections

    ERIC Educational Resources Information Center

    Westbrook, R. Niccole; Watkins, Sean

    2012-01-01

    As primary source materials in the library are digitized and made available online, the focus of related library services is shifting to include new and innovative methods of digital delivery via social media, digital storytelling, and community-based and consortial image repositories. Most images on the Web are not of sufficient quality for most…

  14. (In)Forming: The Affordances of Digital Fabrication in Architectural Education

    ERIC Educational Resources Information Center

    Cabrinha, Mark Newell

    2010-01-01

    This research focuses on the effect of technology on the culture of architectural education through the lens of digital fabrication (CAD/CAM). As the computer was introduced into design education long before digital fabrication was accessible, design culture has prioritized image over material experience. Digital fabrication enables a material…

  15. Institutional Shaping of Cultural Memory: Digital Library as Environment for Textual Transmission

    ERIC Educational Resources Information Center

    Dalbello, Marija

    2004-01-01

    The emerging trends in digital(ized) collection development from 1997 are examined using a sample of projects accessible through Web-based registries of the Association of Research Libraries and the Digital Library Federation. The analysis focuses on thematic repertoire, narrative structuring, underlying historiographic principles, presentation,…

  16. The Digital Atheneum: New Approaches for Preserving, Restoring and Analyzing Damaged Manuscripts.

    ERIC Educational Resources Information Center

    Brown, Michael S.; Seales, W. Brent

    There are now major efforts being undertaken throughout the world to digitize and preserve significant materials. Digital acquisition, which is the conversion of physical materials into a digital format, allows the possibility of efficient dissemination, and serves as a means of preservation. This paper presents research focused on developing new…

  17. Digital Storytelling as Arts-Inspired Inquiry for Engaging, Understanding, and Supporting Indigenous Youth

    ERIC Educational Resources Information Center

    Eglinton, Kristen Ali; Gubrium, Aline; Wexler, Lisa

    2017-01-01

    In this paper we examine digital storytelling as a mode of arts-inspired inquiry: in particular we consider digital storytelling as a powerful arts-inspired approach that can help researchers, practitioners, and communities understand and support indigenous and marginalized youth. Our two-fold focus is on: (1) a digital storytelling initiative…

  18. The Inequities of the Digital Divide: Is E-Learning a Solution?

    ERIC Educational Resources Information Center

    Journell, Wayne

    2007-01-01

    This article addresses the continuing digital divide in public education, one that defines itself largely along geographic, socioeconomic, and cultural lines. The article refutes the idea that the digital divide is dwindling due to increasing access to technology within the United States, instead focusing on digital literacy and cultural barriers…

  19. Electrolysis and isoelectric focusing

    NASA Astrophysics Data System (ADS)

    Choi, Y. S.; Lui, Roger; Yu, Xun

    1994-01-01

    This paper consists of two parts. In the first part, the authors prove the existence of steady-state solutions for a three-species electrolyte. The species are subject to both dissociation-association reactions inside the electrolyte and electrochemical reactions at the boundary electrodes. This is a common occurrence in electrolysis. In the second part, the authors investigate how to use this model to describe isoelectric focusing, which is a common technique used to separate large protein molecules. In particular, the isoelectric focusing point for a particular type of protein molecule is calculated using formal perturbation analysis.

  20. [Focused musculoskeletal sonography].

    PubMed

    Horn, Rudolf

    2015-09-16

    Even in emergent situations, focused musculoskeletal sonography must not be overlooked. It has a place in traumatology no less valuable than its place in internal medicine. It can be used to identify traumatic joint effusions, occult fractures and fissures, joint inflammation, muscle and tendon rupture; it can differentiate soft tissue swelling, locate a foreign body, or identify the location of fractures. Focused ultrasound should be performed by the attending physician directly at the patient’s bedside, in order to answer these specific questions.

  1. Academic Medical Centers as digital health catalysts.

    PubMed

    DePasse, Jacqueline W; Chen, Connie E; Sawyer, Aenor; Jethwani, Kamal; Sim, Ida

    2014-09-01

    Emerging digital technologies offer enormous potential to improve quality, reduce cost, and increase patient-centeredness in healthcare. Academic Medical Centers (AMCs) play a key role in advancing medical care through cutting-edge medical research, yet traditional models for invention, validation and commercialization at AMCs have been designed around biomedical initiatives, and are less well suited for new digital health technologies. Recently, two large bi-coastal Academic Medical Centers, the University of California, San Francisco (UCSF) through the Center for Digital Health Innovation (CDHI) and Partners Healthcare through the Center for Connected Health (CCH) have launched centers focused on digital health innovation. These centers show great promise but are also subject to significant financial, organizational, and visionary challenges. We explore these AMC initiatives, which share the following characteristics: a focus on academic research methodology; integration of digital technology in educational programming; evolving models to support "clinician innovators"; strategic academic-industry collaboration and emergence of novel revenue models. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Digital repeat analysis; setup and operation.

    PubMed

    Nol, J; Isouard, G; Mirecki, J

    2006-06-01

    Since the emergence of digital imaging, there have been questions about the necessity of continuing reject analysis programs in imaging departments to evaluate performance and quality. As a marketing strategy, most suppliers of digital technology focus on the supremacy of the technology and its ability to reduce the number of repeats, resulting in less radiation doses given to patients and increased productivity in the department. On the other hand, quality assurance radiographers and radiologists believe that repeats are mainly related to positioning skills, and repeat analysis is the main tool to plan training needs to up-skill radiographers. A comparative study between conventional and digital imaging was undertaken to compare outcomes and evaluate the need for reject analysis. However, digital technology still being at its early development stages, setting a credible reject analysis program became the major task of the study. It took the department, with the help of the suppliers of the computed radiography reader and the picture archiving and communication system, over 2 years of software enhancement to build a reliable digital repeat analysis system. The results were supportive of both philosophies; the number of repeats as a result of exposure factors was reduced dramatically; however, the percentage of repeats as a result of positioning skills was slightly on the increase for the simple reason that some rejects in the conventional system qualifying for both exposure and positioning errors were classified as exposure error. The ability of digitally adjusting dark or light images reclassified some of those images as positioning errors.

  3. Digital rights language support for evolving digital cinema requirements

    NASA Astrophysics Data System (ADS)

    Orri, Xavier; Mas, Joan-Maria; Macq, Benoit M. M.

    2003-06-01

    Digital cinema can be defined as the digital electronic distribution and display of theatrical film content or live material to the theatre. However, this simple definition does not reflect the complex mesh of balanced business relationships between the different parties involved in the worldwide cinematic distribution. Its transition from an analogue to a digital business will happen progressively, starting with only content being digitally distributed and going until an all-digital business. From these facts derive strong requirements on digital rights management (DRM) systems for digital cinema and therefore on the digital rights language supporting it. This paper explores the requirements imposed by the cinematic distribution model and by its progressive transition to digital, and the impact these have on digital rights languages. We analyze the support provided by different digital rights languages, identifying weaknesses and exploring solutions in fulfilling the requirements of the digital cinema distribution model.

  4. Focus on First Graders.

    ERIC Educational Resources Information Center

    Schwartz, Shari S.

    The result of a collaboration between the El Paso, Texas, school district and community agencies, the Focus on First Graders program provides early intervention and prevention using a comprehensive approach to providing a variety of services at the school to at-risk first graders from low income families. Teachers and parents were surveyed to…

  5. Focus on Bilingual Education.

    ERIC Educational Resources Information Center

    Mayo, Donald S., Ed.

    1982-01-01

    This collection of essays focuses on issues in bilingual education. First, Elizabeth Flynn examines different kinds of bilingual programs; efforts made towards cultural pluralism in a number of countries; national benefits to be derived from bilingualism; the needs of American ethnic groups, new immigrants, and foreign students; and the pros and…

  6. Youth Leadership. IDRA Focus.

    ERIC Educational Resources Information Center

    IDRA Newsletter, 1995

    1995-01-01

    This theme issue focuses on motivating young people to learn by providing leadership opportunities in school. "Coca-Cola Valued Youth Program: Assessing Progress" (Josie Danini Supik) examines the program's success. This program, which trains high-risk middle and high school students as tutors of younger children, has dramatically…

  7. Policy Update. IDRA Focus.

    ERIC Educational Resources Information Center

    IDRA Newsletter, 1995

    1995-01-01

    This theme issue focuses on the drastic revision of the Texas education code undertaken during the 1995 state legislative session. "Education Policy Reform: Key Points for Districts" (Albert Cortez, Mikki Symonds) outlines critical issues in the legislation that have an impact on educational quality: charter schools exempt from state…

  8. Focused on Student Success

    ERIC Educational Resources Information Center

    California Community Colleges, Chancellor's Office, 2014

    2014-01-01

    In January 2011, the California Community Colleges Board of Governors formed a task force to chart a roadmap for system-wide focus on student success. The task force identified best practices and designed evidence-based recommendations to ensure student success is a driving theme in colleges. This comprehensive plan, known as the Student Success…

  9. Instructional Technology. IDRA Focus.

    ERIC Educational Resources Information Center

    IDRA Newsletter, 1997

    1997-01-01

    This theme issue includes five articles that focus on implementing instructional technology in ways that benefit all students, including limited-English-proficient, minority, economically disadvantaged, and at-risk students. "Cruising the Web with English Language Learners" (Laura Chris Green) presents three scenarios using the World…

  10. School Reform. IDRA Focus.

    ERIC Educational Resources Information Center

    IDRA Newsletter, 1998

    1998-01-01

    This theme issue addresses school reform, focusing on accountability, attrition, public-supported private education, equitable education, and schoolwide reform. "School-Student Performance and Accountability" (Jose A. Cardenas) discusses what constitutes good performance in school; the shifting emphasis among the input, output, and…

  11. Bilingual Education. IDRA Focus.

    ERIC Educational Resources Information Center

    IDRA Newsletter, 1998

    1998-01-01

    This theme issue focuses on instructional practices, evaluation, and the state of bilingual education. "Effective Implementation of Bilingual Programs: Reflections from the Field" (Abelardo Villarreal, Adela Solis) describes the key characteristics of successful bilingual programs: vision and goals; program leadership; linkage to central…

  12. Focusing on the Invisible

    ERIC Educational Resources Information Center

    Haley, Tim R.

    2008-01-01

    This article seeks to answer the question of whether or not the design and development of an educational laboratory really changes when the focus is on nanotechnology. It explores current laboratory building trends and the added considerations for building a nanotechnology laboratory. The author leaves the reader with additional points to consider…

  13. [Focus: Family Communication].

    ERIC Educational Resources Information Center

    Barnes, Richard E., Ed.

    1977-01-01

    This issue of the "Journal of the Wisconsin Communication Association" focuses on family communication and contains the following articles: "Marital Typologies: An Alternative Approach to the Study of Communication in Enduring Relations" by Mary Anne Fitzpatrick, "Intimate Communication and the Family" by Marilyn D. LaCourt, and "A Study in…

  14. A FOCUS On Students.

    ERIC Educational Resources Information Center

    Fletcher, Susan

    1998-01-01

    William McKinley Middle School in Cedar Rapids, Iowa, has a parent volunteer program called FOCUS that targets average students who are not doing well academically. Program goals are to improve students' organizational skills, help them complete homework assignments, and reteach and preview lessons to increase understanding, so that students will…

  15. Focus on Distance Education.

    ERIC Educational Resources Information Center

    Grenzky, Janet; Maitland, Christine

    2001-01-01

    As a followup to a survey of distance education faculty, the National Education Association conducted two 3-hour focus groups with 12 higher education faculty members in June 2000. The purpose of the groups was to gain more understanding of the complexity of feelings and opinions expressed in a telephone survey conducted in March 2000. The…

  16. Focus on Godard.

    ERIC Educational Resources Information Center

    Brown, Royal S., Ed.

    This Film Focus series presents selected information about the respected and controversial French filmmaker Jean-Luc Godard and his films. Information is documented through reports of interviews, reviews, essays, and commentaries. Included are filmographies of Godard's films, beginning in 1954 and continuing through 1972. Also, there is a selected…

  17. Focus on Godard.

    ERIC Educational Resources Information Center

    Brown, Royal S., Ed.

    This Film Focus series presents selected information about the respected and controversial French filmmaker Jean-Luc Godard and his films. Information is documented through reports of interviews, reviews, essays, and commentaries. Included are filmographies of Godard's films, beginning in 1954 and continuing through 1972. Also, there is a selected…

  18. Focus on Basics, 1997.

    ERIC Educational Resources Information Center

    Focus on Basics, 1997

    1997-01-01

    Together, these four newsletters contain 36 articles devoted to adult literacy research and practice and the relationship between them. The following articles are included: "A Productive Partnership" (Richard J. Murnane, Bob Bickerton); "Welcome to 'Focus on Basics'" (Barbara Garner); "Applying Research on the Last Frontier" (Karen Backlund, Kathy…

  19. Theme: Focus on Teaching.

    ERIC Educational Resources Information Center

    Connors, James J.; And Others

    1996-01-01

    Includes "The More Things Change..." (Connors); "Students--Bored of Education?" (Earle); "Yesterday, Today and Tomorrow" (Wesch et al.); "Attitude and the Value of Environment" (Foster); "Fins, Feathers and Fur" (Crank); "Greenhouse as a Focus for Agriscience" (Hurst); and "Agricultural and Environmental Education at Milton Hershey School"…

  20. Focus on Phase Electives.

    ERIC Educational Resources Information Center

    Jones, Victor H., Ed.

    1976-01-01

    In this thematic issue, articles focus on the use of phase electives in the English classroom. Discussions include "Death in the Classroom,""Soapbox Operas in the English Classroom,""Language and History in Phase-Elective Programs,""Phase Electives and the Problem of Composition," and "Phase Electives and College Preparation.""Phase Electives Are…

  1. Focus on Grandparents.

    ERIC Educational Resources Information Center

    Murphy, Linda; Della Corte, Suzanne

    1990-01-01

    Following the birth of a handicapped child, both parent and grandparent experience similar feelings of consternation, shock, and grief. The grandparents' reaction is double, however, as they suffer not only for the newborn but for their own child's pain as well. This article focuses on dealing with grief and its stages, including numbness, denial,…

  2. ENC Focus Review.

    ERIC Educational Resources Information Center

    Thorson, Annette, Ed.

    The mission of the Eisenhower National Clearinghouse (ENC) is to identify effective curriculum resources, create high-quality professional development materials, and disseminate useful information and products to improve K-12 mathematics and science teaching and learning. This issue of "ENC Focus" contains articles related to mathematics teaching…

  3. Homework. Focus On

    ERIC Educational Resources Information Center

    Rahal, Michelle Layer

    2010-01-01

    Homework has been an integral part of the educational system for over 100 years. What likely began as simple memorization tasks has evolved into complex projects and sparked an increasingly heated debate over the purpose and value of homework assignments. This "Focus On" examines the purpose of homework, how to create homework that has value,…

  4. Equity. IDRA Focus.

    ERIC Educational Resources Information Center

    IDRA Newsletter, 1998

    1998-01-01

    This theme issue focuses on equity in children's literature, public funding for private schools, women in educational fields, female dropouts, and the relationship between school violence and family and community violence. "Violence in Our Schools" (Bradley Scott) explores reasons for school violence (media violence, isolation from…

  5. Focus on Refugees. Transcript.

    ERIC Educational Resources Information Center

    Brandel, Sarah; And Others

    This is the transcript of the "Focus on Refugees," proqram conducted by the Overseas Development Council. Remarks from the following participants are included: (1) Sarah Brandel, Associate Fellow at the Overseas Development Council; (2) Gary Perkins, Chief of Mission of the Washington Office of the United Nations High Commissioner for Refugees…

  6. Focus on Efficient Management.

    ERIC Educational Resources Information Center

    Kentucky State Dept. of Education, Frankfort. Office of Resource Management.

    Compiled as a workshop handbook, this guide presents information to help food service program administrators comply with federal regulations and evaluate and upgrade their operations. Part I discusses requirements of the National School Lunch Program, focusing on the "offer versus serve" method of service enacted in 1976 to reduce waste.…

  7. Public Engagement. IDRA Focus.

    ERIC Educational Resources Information Center

    IDRA Newsletter, 1996

    1996-01-01

    This newsletter includes six articles that examine key issues facing public schools and communities related to accountability, bilingual education, immigrant education, school finance, and school choice. In addressing these issues, articles focus on the importance of community involvement and input in local school reform efforts aimed at achieving…

  8. Immigrant Education. IDRA Focus.

    ERIC Educational Resources Information Center

    IDRA Newsletter, 1996

    1996-01-01

    This newsletter includes five articles on immigrant education that focus on successful school programs and educational policy issues. In "Immigrant Education from the Administrators' Perspective" (Pam McCollum, Juanita Garcia), three principals of south Texas secondary schools with successful immigrant programs discuss their views on the…

  9. Lifelong Learning. IDRA Focus.

    ERIC Educational Resources Information Center

    IDRA Newsletter, 1995

    1995-01-01

    This theme issue focuses on the need for adult literacy programs, as well as recent innovations in literacy education. "Adult Literacy and Leadership: Current Innovations" (Aurelio M. Montemayor) describes an adult literacy outreach program in Texas, and discusses the importance of family literacy for parents' involvement in their…

  10. Young Children. IDRA Focus.

    ERIC Educational Resources Information Center

    IDRA Newsletter, 1998

    1998-01-01

    This theme issue includes five articles that focus on educational, cognitive, and brain research with implications for early childhood educators, including those who work with limited-English-proficient, minority, and economically disadvantaged children. "Coming to Grips with Reading Instruction at the Early Grades" (Christie L. Goodman)…

  11. Neocortical focus: experimental view.

    PubMed

    Timofeev, Igor; Chauvette, Sylvain; Soltani, Sara

    2014-01-01

    All brain normal or pathological activities occur in one of the states of vigilance: wake, slow-wave sleep, or REM sleep. Neocortical seizures preferentially occur during slow-wave sleep. We provide a description of neuronal behavior and mechanisms mediating such a behavior within neocortex taking place in natural states of vigilance as well as during seizures pointing to similarities and differences exhibited during sleep and seizures. A concept of epileptic focus is described using a model of cortical undercut, because in that model, the borders of the focus are well defined. In this model, as in other models of acquired epilepsy, the main factor altering excitability is deafferentation, which upregulates neuronal excitability that promotes generation of seizures. Periods of disfacilitation recorded during slow-wave sleep further upregulate neuronal excitability. It appears that the state of neurons and neuronal network in the epileptic focus produced by deafferentation are such that seizures cannot be generated there. Instead, seizures always start around the perimeter of the undercut cortex. Therefore, we define these areas as the seizure focus. In this zone, neuronal connectivity and excitability are moderately enhanced, lowering the threshold for seizure generation.

  12. [Focus: Family Communication].

    ERIC Educational Resources Information Center

    Barnes, Richard E., Ed.

    1977-01-01

    This issue of the "Journal of the Wisconsin Communication Association" focuses on family communication and contains the following articles: "Marital Typologies: An Alternative Approach to the Study of Communication in Enduring Relations" by Mary Anne Fitzpatrick, "Intimate Communication and the Family" by Marilyn D. LaCourt, and "A Study in…

  13. Homework. Focus On

    ERIC Educational Resources Information Center

    Rahal, Michelle Layer

    2010-01-01

    Homework has been an integral part of the educational system for over 100 years. What likely began as simple memorization tasks has evolved into complex projects and sparked an increasingly heated debate over the purpose and value of homework assignments. This "Focus On" examines the purpose of homework, how to create homework that has value,…

  14. Focus on Rashomon.

    ERIC Educational Resources Information Center

    Richie, Donald S., Ed.

    This Film Focus series is a collection of reviews, essays, and commentaries on the Japanese film Rashomon. The plot consists of an attack, a rape, and a robbery, all of which probably occurred during the Middle Ages. Each character relates his own version of what happened, or might have happened, revealing the outward and inner driving forces,…

  15. Focusing educational initiatives

    NASA Technical Reports Server (NTRS)

    Parks, George K.

    1990-01-01

    The United States will soon be facing a critical shortage of aerospace scientists and engineers. To address this problem, Space Grant Colleges can assist in focusing interest in existing educational initiatives and in creating new educational opportunities, particularly for women and underrepresented minorities.

  16. Focus on the President.

    ERIC Educational Resources Information Center

    Optometric Education, 1996

    1996-01-01

    In an interview, the incoming president of the Association of Schools and Colleges of Optometry (ASCO), Thomas L. Lewis, discusses his goals for the association, the challenges facing optometric education in the next decade, cooperation between ASCO and other professional organizations in optometry, his mentors in the profession, his focus as a…

  17. Focus on the President.

    ERIC Educational Resources Information Center

    Optometric Education, 2000

    2000-01-01

    An interview with the new president of the Association of Schools and Colleges of Optometry, John Schoessler, considers issues the president wishes to focus on during his presidency, changes in optometry students over the years, people who influenced his educational ideas, and research currently being conducted at Ohio State University College of…

  18. Education Policy. IDRA Focus.

    ERIC Educational Resources Information Center

    IDRA Newsletter, 1998

    1998-01-01

    This theme issue includes five articles that focus on educational policy in the Texas legislature in relation to student retention, Internet access, and sexual harassment. "1999 Texas Legislative Session--End of an Era?" (Albert Cortez, Maria Robledo Montecel) examines educational equity issues facing legislators: school funding,…

  19. Focus: International Economics.

    ERIC Educational Resources Information Center

    Lynch, Gerald J.; Watts, Michael W.; Wentworth, Donald R.

    The "Focus" series, part of the National Council on Economic Education's (NCEE) EconomicsAmerica program, uses economics to enhance learning in subjects such as history, geography, civics, and personal finance, as well as economics. Activities are interactive, reflecting the belief that students learn best through active, highly…

  20. Theme: Focus on Teaching.

    ERIC Educational Resources Information Center

    Connors, James J.; And Others

    1996-01-01

    Includes "The More Things Change..." (Connors); "Students--Bored of Education?" (Earle); "Yesterday, Today and Tomorrow" (Wesch et al.); "Attitude and the Value of Environment" (Foster); "Fins, Feathers and Fur" (Crank); "Greenhouse as a Focus for Agriscience" (Hurst); and "Agricultural and Environmental Education at Milton Hershey School"…

  1. Flight test validation of a design procedure for digital autopilots

    NASA Technical Reports Server (NTRS)

    Bryant, W. H.

    1983-01-01

    Commercially available general aviation autopilots are currently in transition from an analogue circuit system to a computer implemented digital flight control system. Well known advantages of the digital autopilot include enhanced modes, self-test capacity, fault detection, and greater computational capacity. A digital autopilot's computational capacity can be used to full advantage by increasing the sophistication of the digital autopilot's chief function, stability and control. NASA's Langley Research Center has been pursuing the development of direct digital design tools for aircraft stabilization systems for several years. This effort has most recently been directed towards the development and realization of multi-mode digital autopilots for GA aircraft, conducted under a SPIFR-related program called the General Aviation Terminal Operations Research (GATOR) Program. This presentation focuses on the implementation and testing of a candidate multi-mode autopilot designed using these newly developed tools.

  2. Occupying the Digital Humanities

    ERIC Educational Resources Information Center

    Rice, Jeff

    2013-01-01

    This essay questions the digital humanities' dependence on interpretation and critique as strategies for reading and responding to texts. Instead, the essay proposes suggestion as a digital rhetorical practice, one that does not replace hermeneutics, but instead offers alternative ways to respond to texts. The essay uses the Occupy movement as an…

  3. Towards a Digital Future

    ERIC Educational Resources Information Center

    Thomson, Rachel

    2009-01-01

    A month ago, a French court ruled that internet access is a basic human right. Gordon Brown has said it is as crucial for people as electricity and water. Yet, 17 million Britons are still excluded from digital technology and an estimated 13 per cent of the population--some six million people--are both socially and digitally excluded. There are…

  4. Digital ureteroscopes: technology update

    PubMed Central

    Gridley, Chad M; Knudsen, Bodo E

    2017-01-01

    The field of ureteroscopy has undergone a continual evolution since the first ureteroscopes were introduced. Over the past 10 years, we have entered into the digital era of ureteroscopy with both semirigid and flexible options becoming available. The following review looks at the benefits and drawbacks of digital flexible ureteroscopes as well as the current commercially available options. PMID:28203551

  5. Digital communications study

    NASA Technical Reports Server (NTRS)

    Boorstyn, R. R.

    1973-01-01

    Research is reported dealing with problems of digital data transmission and computer communications networks. The results of four individual studies are presented which include: (1) signal processing with finite state machines, (2) signal parameter estimation from discrete-time observations, (3) digital filtering for radar signal processing applications, and (4) multiple server queues where all servers are not identical.

  6. ISDN: The Digital Difference.

    ERIC Educational Resources Information Center

    Piedmo, Greg

    1995-01-01

    Integrated services digital network (ISDN) is a dial-up digital transmission service supporting transmission of audio, video, and text data over standard copper telephone wires or fiber optic cables. Advantages of ISDN over analog transmission include the ability of one phone line to support up to three simultaneous, separate conversations (phone,…

  7. The Digital Absurd

    ERIC Educational Resources Information Center

    Hodges, Steve

    2010-01-01

    I believe that the concept of the absurd, as described in philosophy and reflected in works of drama and literature, provides an unusual and helpful perspective from which to view the emerging field of digital media. In my opinion, absurd principles can help us understand the mixed feelings we may have when engaging with digital media: joy and…

  8. Navigate the Digital Rapids

    ERIC Educational Resources Information Center

    Lindsay, Julie; Davis, Vicki

    2010-01-01

    How can teachers teach digital citizenship when the digital landscape is changing so rapidly? How can teachers teach proper online social interactions when the students are outside their classroom and thus outside their control? Will encouraging students to engage in global collaborative environments land teachers in hot water? These are the…

  9. Fundamentals of Digital Logic.

    ERIC Educational Resources Information Center

    Noell, Monica L.

    This course is designed to prepare electronics personnel for further training in digital techniques, presenting need to know information that is basic to any maintenance course on digital equipment. It consists of seven study units: (1) binary arithmetic; (2) boolean algebra; (3) logic gates; (4) logic flip-flops; (5) nonlogic circuits; (6)…

  10. Those Nifty Digital Cameras!

    ERIC Educational Resources Information Center

    Ekhaml, Leticia

    1996-01-01

    Describes digital photography--an electronic imaging technology that merges computer capabilities with traditional photography--and its uses in education. Discusses how a filmless camera works, types of filmless cameras, advantages and disadvantages, and educational applications of the consumer digital cameras. (AEF)

  11. Digital rotation measurement unit

    DOEpatents

    Sanderson, S.N.

    1983-09-30

    A digital rotation indicator is disclosed for monitoring the position of a valve member having a movable actuator. The indicator utilizes mercury switches adapted to move in cooperation with the actuator. Each of the switches produces an output as it changes state when the actuator moves. A direction detection circuit is connected to the switches to produce a first digital signal indicative of the direction of rotation of the actuator. A count pulse generating circuit is also connected to the switches to produce a second digital pulse signal having count pulses corresponding to a change of state of any of the mercury switches. A reset pulse generating circuit is provided to generate a reset pulse each time a count pulse is generated. An up/down counter is connected to receive the first digital pulse signal and the second digital pulse signal and to count the pulses of the second digital pulse signal either up or down depending upon the instantaneous digital value of the first digital signal whereby a running count indicative of the movement of the actuator is maintained.

  12. Digital Pinhole Camera

    ERIC Educational Resources Information Center

    Lancor, Rachael; Lancor, Brian

    2014-01-01

    In this article we describe how the classic pinhole camera demonstration can be adapted for use with digital cameras. Students can easily explore the effects of the size of the pinhole and its distance from the sensor on exposure time, magnification, and image quality. Instructions for constructing a digital pinhole camera and our method for…

  13. Digital Video Editing

    ERIC Educational Resources Information Center

    McConnell, Terry

    2004-01-01

    Monica Adams, head librarian at Robinson Secondary in Fairfax country, Virginia, states that librarians should have the technical knowledge to support projects related to digital video editing. The process of digital video editing and the cables, storage issues and the computer system with software is described.

  14. Digital Signature Management.

    ERIC Educational Resources Information Center

    Hassler, Vesna; Biely, Helmut

    1999-01-01

    Describes the Digital Signature Project that was developed in Austria to establish an infrastructure for applying smart card-based digital signatures in banking and electronic-commerce applications. Discusses the need to conform to international standards, an international certification infrastructure, and security features for a public directory…

  15. Music Instruction Goes Digital

    ERIC Educational Resources Information Center

    Demski, Jennifer

    2011-01-01

    Faced with meager enrollment in band, orchestra, and choir programs, schools are using digital technology to excite students about creating music on today's terms. This article discusses how music educators reinvent their profession by acknowledging and incorporating the way students interact with music today--digitally. Bill Evans, a music…

  16. Writing and Digital Media

    ERIC Educational Resources Information Center

    van Waes, Luuk, Ed.; Leijten, Marielle, Ed.; Neuwirth, Chris, Ed.

    2006-01-01

    Digital media has become an increasingly powerful force in modern society. This volume brings together outstanding European, American and Australian research in "writing and digital media" and explores its cognitive, social and cultural implications. In addition to presenting programs of original research by internationally known…

  17. Digitized synchronous demodulator

    NASA Technical Reports Server (NTRS)

    Woodhouse, Christopher E. (Inventor)

    1990-01-01

    A digitized synchronous demodulator is constructed entirely of digital components including timing logic, an accumulator, and means to digitally filter the digital output signal. Indirectly, it accepts, at its input, periodic analog signals which are converted to digital signals by traditional analog-to-digital conversion techniques. Broadly, the input digital signals are summed to one of two registers within an accumulator, based on the phase of the input signal and medicated by timing logic. At the end of a predetermined number of cycles of the inputted periodic signals, the contents of the register that accumulated samples from the negative half cycle is subtracted from the accumulated samples from the positive half cycle. The resulting difference is an accurate measurement of the narrow band amplitude of the periodic input signal during the measurement period. This measurement will not include error sources encountered in prior art synchronous demodulators using analog techniques such as offsets, charge injection errors, temperature drift, switching transients, settling time, analog to digital converter missing code, and linearity errors.

  18. Educating Digital Citizens

    ERIC Educational Resources Information Center

    Tan, Thomas

    2011-01-01

    Digital citizenship is how educators, citizens, and parents can teach where the lines of cyber safety and ethics are in the interconnected online world their students will inhabit. Aside from keeping technology users safe, digital citizenship also prepares students to survive and thrive in an environment embedded with information, communication,…

  19. Digital Signature Management.

    ERIC Educational Resources Information Center

    Hassler, Vesna; Biely, Helmut

    1999-01-01

    Describes the Digital Signature Project that was developed in Austria to establish an infrastructure for applying smart card-based digital signatures in banking and electronic-commerce applications. Discusses the need to conform to international standards, an international certification infrastructure, and security features for a public directory…

  20. Digital Libraries: An Overview.

    ERIC Educational Resources Information Center

    Schwartz, Candy

    2000-01-01

    Provides an overview of the basic components of a digital library. Highlights include library collections; metadata; services, including information seeking and retrieval, reference query fulfillment, and user training; user interaction with digital libraries, including searching, browsing, and navigation; economic support; maintenance;…