The Effects of Giving and Receiving Marginal L1 Glosses on L2 Vocabulary Learning by Upper Secondary Learners

ERIC Educational Resources Information Center

Samian, Hosein Vafadar; Foo, Thomas Chow Voon; Mohebbi, Hassan

2016-01-01

This paper reports the findings of a study that investigated the effect of giving and receiving marginal L1 glosses on L2 vocabulary learning. To that end, forty nine Iranian learners of English were assigned to three different experimental conditions including marginal L1 glosses Giver (n = 17), marginal L1 glosses Receiver (n = 17), and no…

Effect of cement space on the marginal fit of CAD-CAM-fabricated monolithic zirconia crowns.

PubMed

Kale, Ediz; Seker, Emre; Yilmaz, Burak; Özcelik, Tuncer Burak

2016-12-01

Monolithic zirconia crowns fabricated with computer-aided design and computer-aided manufacturing (CAD-CAM) have recently become a common practice for the restoration of posterior teeth. The marginal fit of monolithic zirconia crowns may be affected by different cement space parameters set in the CAD software. Information is scarce regarding the effect of cement space on the marginal fit of monolithic zirconia crowns fabricated with CAD-CAM technology. The purpose of this in vitro study was to evaluate the effect of cement space on the marginal fit of CAD-CAM-fabricated monolithic zirconia crowns before cementation. Fifteen right maxillary first molar typodont teeth with standardized anatomic preparations for complete-coverage ceramic crowns were scanned with a 3-dimensional laboratory scanner. Crowns were designed 3-dimensionally using software and then milled from presintered monolithic zirconia blocks in a computer numerical control dental milling machine. The cement space was set at 25 μm around the margins for all groups, and additional cement space starting 1 mm above the finish lines of the teeth was set at 30 μm for group 25-30, 40 μm for group 25-40, and 50 μm for group 25-50 in the CAD software. A total of 120 images (3 groups, 5 crowns per group, 8 sites per crown) were measured for vertical marginal discrepancy under a stereoscopic zoom microscope and the data were statistically analyzed with 1-way analysis of variance, followed by the Tukey honestly significant difference test (α=.05). The results showed that different cement space values had statistically significant effect on the mean vertical marginal discrepancy value of tested crowns (P<.001). The mean marginal discrepancy was 85 μm for group 25-30, 68 μm for group 25-40, and 53 μm for group 25-50. Within the limitations of this in vitro study, it was concluded that the cement space had a significant effect on the marginal fit of CAD-CAM-fabricated monolithic zirconia crowns. The marginal fit improved as the cement space decreased. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Advanced-to-Revolutionary Space Technology Options - The Responsibly Imaginable

NASA Technical Reports Server (NTRS)

Bushnell, Dennis M.

2013-01-01

Paper summarizes a spectrum of low TRL, high risk technologies and systems approaches which could massively change the cost and safety of space exploration/exploitation/industrialization. These technologies and approaches could be studied in a triage fashion, the method of evaluation wherein several prospective solutions are investigated in parallel to address the innate risk of each, with resources concentrated on the more successful as more is learned. Technology areas addressed include Fabrication, Materials, Energetics, Communications, Propulsion, Radiation Protection, ISRU and LEO access. Overall and conceptually it should be possible with serious research to enable human space exploration beyond LEO both safe and affordable with a design process having sizable positive margins. Revolutionary goals require, generally, revolutionary technologies. By far, Revolutionary Energetics is the most important, has the most leverage, of any advanced technology for space exploration applications.

Transperitoneal versus extraperitoneal robotic-assisted radical prostatectomy: which one?

PubMed

Atug, F; Thomas, R

2007-06-01

As robotic surgery has proliferated, both in its availability as well as in its popularity, there are certainly several unresolved matters in the burgeoning field of robotic radical prostatectomy. Matters that are commonly discussed at forums relating to robotic prostatectomy include training, proctoring, overcoming the learning curve, positive surgical margins, quality of life issues, etc. Among the approaches available for robotic radical prostatectomy are the trans-peritoneal (TP) and the extraperitoneal (EP) approaches. Although use of the TP approach vastly outnumbers the EP approach by a wide margin, one must not discount the need for learning the EP approach, especially in patients who could greatly benefit from this approach. The obese, those who have had intraperitoneal procedures in the past, those with ostomies (colostomy, ileostomy) should be considered candidates for the EP approach. For the beginner, it is recommended that familiarizing oneself with the TP approach may be the quickest way to get proficient with use of the robot and for getting over the learning curve, which varies from surgeon to surgeon. Once comfortable with the TP approach, one should consider the application of the EP access, when indicated. One distinct disadvantage of the EP approach is the limited space available for robotic movements. This is why one would prefer getting experience in the TP before forging into the EP approach. Certainly, adequate balloon dissection of the retroperitoneal space above the bladder is critical, as well as additional dissection with the camera in place. Another criticism of the EP approach is the fact that one may not have enough space or ability to perform a complete pelvic lymph node dissection. However, in experienced hands, one is able to do a very comparable job. Though the TP approach would continue to be the premium approach for robotic and laparoscopic radical prostatectomy, one should familiarize oneself with the EP approach since this can clearly be applied to the patient with the correct indication.

Spine detection in CT and MR using iterated marginal space learning.

PubMed

Michael Kelm, B; Wels, Michael; Kevin Zhou, S; Seifert, Sascha; Suehling, Michael; Zheng, Yefeng; Comaniciu, Dorin

2013-12-01

Examinations of the spinal column with both, Magnetic Resonance (MR) imaging and Computed Tomography (CT), often require a precise three-dimensional positioning, angulation and labeling of the spinal disks and the vertebrae. A fully automatic and robust approach is a prerequisite for an automated scan alignment as well as for the segmentation and analysis of spinal disks and vertebral bodies in Computer Aided Diagnosis (CAD) applications. In this article, we present a novel method that combines Marginal Space Learning (MSL), a recently introduced concept for efficient discriminative object detection, with a generative anatomical network that incorporates relative pose information for the detection of multiple objects. It is used to simultaneously detect and label the spinal disks. While a novel iterative version of MSL is used to quickly generate candidate detections comprising position, orientation, and scale of the disks with high sensitivity, the anatomical network selects the most likely candidates using a learned prior on the individual nine dimensional transformation spaces. Finally, we propose an optional case-adaptive segmentation approach that allows to segment the spinal disks and vertebrae in MR and CT respectively. Since the proposed approaches are learning-based, they can be trained for MR or CT alike. Experimental results based on 42 MR and 30 CT volumes show that our system not only achieves superior accuracy but also is among the fastest systems of its kind in the literature. On the MR data set the spinal disks of a whole spine are detected in 11.5s on average with 98.6% sensitivity and 0.073 false positive detections per volume. On the CT data a comparable sensitivity of 98.0% with 0.267 false positives is achieved. Detected disks are localized with an average position error of 2.4 mm/3.2 mm and angular error of 3.9°/4.5° in MR/CT, which is close to the employed hypothesis resolution of 2.1 mm and 3.3°. Copyright © 2012 Elsevier B.V. All rights reserved.

CLAss-Specific Subspace Kernel Representations and Adaptive Margin Slack Minimization for Large Scale Classification.

PubMed

Yu, Yinan; Diamantaras, Konstantinos I; McKelvey, Tomas; Kung, Sun-Yuan

2018-02-01

In kernel-based classification models, given limited computational power and storage capacity, operations over the full kernel matrix becomes prohibitive. In this paper, we propose a new supervised learning framework using kernel models for sequential data processing. The framework is based on two components that both aim at enhancing the classification capability with a subset selection scheme. The first part is a subspace projection technique in the reproducing kernel Hilbert space using a CLAss-specific Subspace Kernel representation for kernel approximation. In the second part, we propose a novel structural risk minimization algorithm called the adaptive margin slack minimization to iteratively improve the classification accuracy by an adaptive data selection. We motivate each part separately, and then integrate them into learning frameworks for large scale data. We propose two such frameworks: the memory efficient sequential processing for sequential data processing and the parallelized sequential processing for distributed computing with sequential data acquisition. We test our methods on several benchmark data sets and compared with the state-of-the-art techniques to verify the validity of the proposed techniques.

Silenced, Silence, Silent: Motherhood in the Margins

ERIC Educational Resources Information Center

Carpenter, Lorelei; Austin, Helena

2007-01-01

This project explores the experiences of women who mother children with ADHD. The authors use the metaphor of the text and the margin. The text is the "motherhood myth" that describes a particular sort of "good" mothering. The margin is the space beyond that text. This marginal space is inhabited by some or all of the mothers they spoke with, some…

Probabilities of good, marginal, and poor flying conditions for space shuttle ferry flights

NASA Technical Reports Server (NTRS)

Whiting, D. M.; Guttman, N. B.

1977-01-01

Empirical probabilities are provided for good, marginal, and poor flying weather for ferrying the Space Shuttle Orbiter from Edwards AFB, California, to Kennedy Space Center, Florida, and from Edwards AFB to Marshall Space Flight Center, Alabama. Results are given by month for each overall route plus segments of each route. The criteria for defining a day as good, marginal, or poor and the method of computing the relative frequencies and conditional probabilities for monthly reference periods are described.

The Space That Difference Makes: On Marginality, Social Justice and the Future of the Health Humanities.

PubMed

Gutierrez, Kevin J; DasGupta, Sayantani

2016-12-01

Feminist theorist and educator, bell hooks, asserts that to seek true liberation one must choose marginality. One must choose to occupy the space outside the binary between colonizer-colonized, hegemonic center-periphery, and us-them in order to create a location of possibility. This essay will reveal the practice of social justice as the navigation of the space that difference makes and argue that choosing marginality provides a framework for health humanities work towards social justice in health care. The space of the launderette that is depicted in Hanif Kureishi's 1986 film, My Beautiful Laundrette, provides an example of choosing marginality and illustrates how difference structures both real and imagined spaces, which influences how individuals ultimately perceive one another. We will draw from the work of bell hooks; political geographer, Edward Soja; and Marxist philosopher, Henri Lefebvre, to demonstrate the importance of the health humanities' position at the margin to traditional health care education.

Visioning the Centre for Place and Sustainability Studies through an embodied aesthetic wholeness

NASA Astrophysics Data System (ADS)

Sameshima, Pauline; Greenwood, David A.

2015-03-01

In the context of research universities, what kind of places and spaces can we create for ourselves that foster a holistic vision of learning and community, a vision that is responsive to the shifting social and ecological landscapes of the Anthropocene? How can these spaces simultaneously address the need to nurture both personal and cultural change? How do the frames we create enhance or limit our place-making? This paper offers one situated response to such questions as it theorizes and describes the arts integrated emergence of the Centre for Place and Sustainability Studies at Lakehead University. Drawing from critical cultural and ecological studies, we problematize creating spaces in both centers and margins, and offer an arts integrated vision of a space for diverse and evolving approaches to sustainability work: a meeting ground characterized by a commitment to parallax and embodied aesthetic wholeness.

Novel maximum-margin training algorithms for supervised neural networks.

PubMed

Ludwig, Oswaldo; Nunes, Urbano

2010-06-01

This paper proposes three novel training methods, two of them based on the backpropagation approach and a third one based on information theory for multilayer perceptron (MLP) binary classifiers. Both backpropagation methods are based on the maximal-margin (MM) principle. The first one, based on the gradient descent with adaptive learning rate algorithm (GDX) and named maximum-margin GDX (MMGDX), directly increases the margin of the MLP output-layer hyperplane. The proposed method jointly optimizes both MLP layers in a single process, backpropagating the gradient of an MM-based objective function, through the output and hidden layers, in order to create a hidden-layer space that enables a higher margin for the output-layer hyperplane, avoiding the testing of many arbitrary kernels, as occurs in case of support vector machine (SVM) training. The proposed MM-based objective function aims to stretch out the margin to its limit. An objective function based on Lp-norm is also proposed in order to take into account the idea of support vectors, however, overcoming the complexity involved in solving a constrained optimization problem, usually in SVM training. In fact, all the training methods proposed in this paper have time and space complexities O(N) while usual SVM training methods have time complexity O(N (3)) and space complexity O(N (2)) , where N is the training-data-set size. The second approach, named minimization of interclass interference (MICI), has an objective function inspired on the Fisher discriminant analysis. Such algorithm aims to create an MLP hidden output where the patterns have a desirable statistical distribution. In both training methods, the maximum area under ROC curve (AUC) is applied as stop criterion. The third approach offers a robust training framework able to take the best of each proposed training method. The main idea is to compose a neural model by using neurons extracted from three other neural networks, each one previously trained by MICI, MMGDX, and Levenberg-Marquard (LM), respectively. The resulting neural network was named assembled neural network (ASNN). Benchmark data sets of real-world problems have been used in experiments that enable a comparison with other state-of-the-art classifiers. The results provide evidence of the effectiveness of our methods regarding accuracy, AUC, and balanced error rate.

Emotional and cultural impacts of ICT on learners: A case study of Opuwo, Namibia

NASA Astrophysics Data System (ADS)

Hambira, N.; Lim, C. K.; Tan, K. L.

2017-10-01

It is believed that the integration of Information and Communication Technologies (ICT) among learners and teachers can tremendously enhance the quality of teaching and learning. Besides, the advancement of the ICT technology is also used to improve the academic performance of the learners in learning and has given space to the teachers to boost their teaching in a more effective manner. However, it is also crucial to identify the impacts on the cultural and emotional among the learners. Nonetheless, it is also difficult to imagine contemporary learning environments that are not supported by ICT since the impacts of these technological developments vary among the various communities. In this paper, the contributions are three folds: (i) to investigate the impacts in the cultural and emotional aspects from the perceptions of the teachers about the learners in disadvantaged and marginalized communities, (ii) to design an assessment instrument to survey and determine the different impacts of ICT use on learners from various communities through a set of questionnaires and (iii) to validate the assessment instrument through Cronbach's Alpha reliability testing. Then, the survey is conducted on learners from disadvantaged and marginalized communities in Opuwo, Namibia that makes it an ideal case study for the context of this research. This study made use of a quantitative approach using survey research design through the application of questionnaires to collect data. The size of the population of these community is approximately 500 teachers (from 16 schools, 2 High schools and 14 Primary) and the sample size that is taken into consideration is 42 (8.4% of approximate population). The research revealed that the use of ICT has emotional benefits as well cultural impacts on learners. Careful planning of ICT curriculum was suggested as it will be beneficial to the disadvantaged and marginalized learners.

A Collective Pursuit of Learning the Possibility to Be: The CAMP Experience Assisting Situationally Marginalized Mexican American Students to a Successful Student Identity

ERIC Educational Resources Information Center

Reyes, Reynaldo, III

2007-01-01

Many students of Mexican descent must learn how to be successful students. This study describes 5 students of Mexican descent from situationally marginalized lives who were a part of a support and retention scholarship program (College Assistance Migrant Program--CAMP). These case studies document how they perceived their learning and how they…

Similar effects of substance P on learning and memory function between hippocampus and striatal marginal division

PubMed Central

Yu, Yan; Zeng, Changchun; Shu, Siyun; Liu, Xuemei; Li, Chuhua

2014-01-01

Substance P is an endogenous neurokinin that is present in the central and peripheral nervous systems. The neuropeptide substance P and its high-affinity receptor neurokinin 1 receptor are known to play an important role in the central nervous system in inflammation, blood pressure, motor behavior and anxiety. The effects of substance P in the hippocampus and the marginal division of the striatum on memory remain poorly understood. Compared with the hippocampus as a control, immunofluorescence showed high expression of the substance P receptor, neurokinin 1, in the marginal division of the striatum of normal rats. Unilateral or bilateral injection of an antisense oligonucleotide against neurokinin 1 receptor mRNA in the rat hippocampus or marginal division of the striatum effectively reduced neurokinin 1 receptor expression. Independent of injection site, rats that received this antisense oligonucleotide showed obviously increased footshock times in a Y-maze test. These results indicate that the marginal division of the striatum plays a similar function in learning and memory to the hippocampus, which is a valuable addition to our mechanistic understanding of the learning and memory functions of the marginal division of the striatum. PMID:25206901

Impact of distance-based metric learning on classification and visualization model performance and structure-activity landscapes.

PubMed

Kireeva, Natalia V; Ovchinnikova, Svetlana I; Kuznetsov, Sergey L; Kazennov, Andrey M; Tsivadze, Aslan Yu

2014-02-01

This study concerns large margin nearest neighbors classifier and its multi-metric extension as the efficient approaches for metric learning which aimed to learn an appropriate distance/similarity function for considered case studies. In recent years, many studies in data mining and pattern recognition have demonstrated that a learned metric can significantly improve the performance in classification, clustering and retrieval tasks. The paper describes application of the metric learning approach to in silico assessment of chemical liabilities. Chemical liabilities, such as adverse effects and toxicity, play a significant role in drug discovery process, in silico assessment of chemical liabilities is an important step aimed to reduce costs and animal testing by complementing or replacing in vitro and in vivo experiments. Here, to our knowledge for the first time, a distance-based metric learning procedures have been applied for in silico assessment of chemical liabilities, the impact of metric learning on structure-activity landscapes and predictive performance of developed models has been analyzed, the learned metric was used in support vector machines. The metric learning results have been illustrated using linear and non-linear data visualization techniques in order to indicate how the change of metrics affected nearest neighbors relations and descriptor space.

Impact of distance-based metric learning on classification and visualization model performance and structure-activity landscapes

NASA Astrophysics Data System (ADS)

Kireeva, Natalia V.; Ovchinnikova, Svetlana I.; Kuznetsov, Sergey L.; Kazennov, Andrey M.; Tsivadze, Aslan Yu.

2014-02-01

This study concerns large margin nearest neighbors classifier and its multi-metric extension as the efficient approaches for metric learning which aimed to learn an appropriate distance/similarity function for considered case studies. In recent years, many studies in data mining and pattern recognition have demonstrated that a learned metric can significantly improve the performance in classification, clustering and retrieval tasks. The paper describes application of the metric learning approach to in silico assessment of chemical liabilities. Chemical liabilities, such as adverse effects and toxicity, play a significant role in drug discovery process, in silico assessment of chemical liabilities is an important step aimed to reduce costs and animal testing by complementing or replacing in vitro and in vivo experiments. Here, to our knowledge for the first time, a distance-based metric learning procedures have been applied for in silico assessment of chemical liabilities, the impact of metric learning on structure-activity landscapes and predictive performance of developed models has been analyzed, the learned metric was used in support vector machines. The metric learning results have been illustrated using linear and non-linear data visualization techniques in order to indicate how the change of metrics affected nearest neighbors relations and descriptor space.

Margin based ontology sparse vector learning algorithm and applied in biology science.

PubMed

Gao, Wei; Qudair Baig, Abdul; Ali, Haidar; Sajjad, Wasim; Reza Farahani, Mohammad

2017-01-01

In biology field, the ontology application relates to a large amount of genetic information and chemical information of molecular structure, which makes knowledge of ontology concepts convey much information. Therefore, in mathematical notation, the dimension of vector which corresponds to the ontology concept is often very large, and thus improves the higher requirements of ontology algorithm. Under this background, we consider the designing of ontology sparse vector algorithm and application in biology. In this paper, using knowledge of marginal likelihood and marginal distribution, the optimized strategy of marginal based ontology sparse vector learning algorithm is presented. Finally, the new algorithm is applied to gene ontology and plant ontology to verify its efficiency.

Constrained Metric Learning by Permutation Inducing Isometries.

PubMed

Bosveld, Joel; Mahmood, Arif; Huynh, Du Q; Noakes, Lyle

2016-01-01

The choice of metric critically affects the performance of classification and clustering algorithms. Metric learning algorithms attempt to improve performance, by learning a more appropriate metric. Unfortunately, most of the current algorithms learn a distance function which is not invariant to rigid transformations of images. Therefore, the distances between two images and their rigidly transformed pair may differ, leading to inconsistent classification or clustering results. We propose to constrain the learned metric to be invariant to the geometry preserving transformations of images that induce permutations in the feature space. The constraint that these transformations are isometries of the metric ensures consistent results and improves accuracy. Our second contribution is a dimension reduction technique that is consistent with the isometry constraints. Our third contribution is the formulation of the isometry constrained logistic discriminant metric learning (IC-LDML) algorithm, by incorporating the isometry constraints within the objective function of the LDML algorithm. The proposed algorithm is compared with the existing techniques on the publicly available labeled faces in the wild, viewpoint-invariant pedestrian recognition, and Toy Cars data sets. The IC-LDML algorithm has outperformed existing techniques for the tasks of face recognition, person identification, and object classification by a significant margin.

Analysis of System Margins on Missions Utilizing Solar Electric Propulsion

NASA Technical Reports Server (NTRS)

Oh, David Y.; Landau, Damon; Randolph, Thomas; Timmerman, Paul; Chase, James; Sims, Jon; Kowalkowski, Theresa

2008-01-01

NASA's Jet Propulsion Laboratory has conducted a study focused on the analysis of appropriate margins for deep space missions using solar electric propulsion (SEP). The purpose of this study is to understand the links between disparate system margins (power, mass, thermal, etc.) and their impact on overall mission performance and robustness. It is determined that the various sources of uncertainty and risk associated with electric propulsion mission design can be summarized into three relatively independent parameters 1) EP Power Margin, 2) Propellant Margin and 3) Duty Cycle Margin. The overall relationship between these parameters and other major sources of uncertainty is presented. A detailed trajectory analysis is conducted to examine the impact that various assumptions related to power, duty cycle, destination, and thruster performance including missed thrust periods have on overall performance. Recommendations are presented for system margins for deep space missions utilizing solar electric propulsion.

Assessment of Surgical Learning Curves in Transoral Robotic Surgery for Squamous Cell Carcinoma of the Oropharynx

PubMed Central

Albergotti, William G.; Gooding, William E.; Kubik, Mark W.; Geltzeiler, Mathew; Kim, Seungwon; Duvvuri, Umamaheswar; Ferris, Robert L.

2017-01-01

IMPORTANCE Transoral robotic surgery (TORS) is increasingly employed as a treatment option for squamous cell carcinoma of the oropharynx (OPSCC). Measures of surgical learning curves are needed particularly as clinical trials using this technology continue to evolve. OBJECTIVE To assess learning curves for the oncologic TORS surgeon and to identify the number of cases needed to identify the learning phase. DESIGN, SETTING, AND PARTICIPANTS A retrospective review of all patients who underwent TORS for OPSCC at the University of Pittsburgh Medical Center between March 2010 and March 2016. Cases were excluded for involvement of a subsite outside of the oropharynx, for nonmalignant abnormality or nonsquamous histology, unknown primary, no tumor in the main specimen, free flap reconstruction, and for an inability to define margin status. EXPOSURES Transoral robotic surgery for OPSCC. MAIN OUTCOMES AND MEASURES Primary learning measures defined by the authors include the initial and final margin status and time to resection of main surgical specimen. A cumulative sum learning curve was developed for each surgeon for each of the study variables. The inflection point of each surgeon’s curve was considered to be the point signaling the completion of the learning phase. RESULTS There were 382 transoral robotic procedures identified. Of 382 cases, 160 met our inclusion criteria: 68 for surgeon A, 37 for surgeon B, and 55 for surgeon C. Of the 160 included patients, 125 were men and 35 were women. The mean (SD) age of participants was 59.4 (9.5) years. Mean (SD) time to resection including robot set-up was 79 (36) minutes. The inflection points for the final margin status learning curves were 27 cases (surgeon A) and 25 cases (surgeon C). There was no inflection point for surgeon B for final margin status. Inflection points for mean time to resection were: 39 cases (surgeon A), 30 cases (surgeon B), and 27 cases (surgeon C). CONCLUSIONS AND RELEVANCE Using metrics of positive margin rate and time to resection of the main surgical specimen, the learning curve for TORS for OPSCC is surgeon-specific. Inflection points for most learning curves peak between 20 and 30 cases. PMID:28196200

Spiking, Bursting, and Population Dynamics in a Network of Growth Transform Neurons.

PubMed

Gangopadhyay, Ahana; Chakrabartty, Shantanu

2018-06-01

This paper investigates the dynamical properties of a network of neurons, each of which implements an asynchronous mapping based on polynomial growth transforms. In the first part of this paper, we present a geometric approach for visualizing the dynamics of the network where each of the neurons traverses a trajectory in a dual optimization space, whereas the network itself traverses a trajectory in an equivalent primal optimization space. We show that as the network learns to solve basic classification tasks, different choices of primal-dual mapping produce unique but interpretable neural dynamics like noise shaping, spiking, and bursting. While the proposed framework is general enough, in this paper, we demonstrate its use for designing support vector machines (SVMs) that exhibit noise-shaping properties similar to those of modulators, and for designing SVMs that learn to encode information using spikes and bursts. It is demonstrated that the emergent switching, spiking, and burst dynamics produced by each neuron encodes its respective margin of separation from a classification hyperplane whose parameters are encoded by the network population dynamics. We believe that the proposed growth transform neuron model and the underlying geometric framework could serve as an important tool to connect well-established machine learning algorithms like SVMs to neuromorphic principles like spiking, bursting, population encoding, and noise shaping.

Transoral robotic surgery for neurogenic tumors of the prestyloid parapharyngeal space.

PubMed

Lee, Hyoung Shin; Kim, Jinna; Lee, Hyun Jin; Koh, Yoon Woo; Choi, Eun Chang

2012-08-01

The parapharyngeal space is a difficult area for a surgical approach due to anatomical complexity. We performed a minimally invasive and precise surgical technique to remove neurogenic tumors of the prestyloid parapharyngeal space using transoral robotic instrumentation. The mass was successfully removed in the two cases with three-dimensional visualization providing an excellent view of the resection margin and the dissection plane preserving the vital structures. An adequate resection margin was acquired, and no violation of the tumor capsule occurred. No significant complications were noted. Transoral robotic surgery was feasible for neurogenic tumors of the prestyloid parapharyngeal space, providing a sufficient resection margin and delicate dissection through excellent surgical views and instrumentation. Copyright © 2012. Published by Elsevier Ireland Ltd.

Ipsilateral printing in children's mirror-writing: a cause of specific learning disabilities?

PubMed

Mather, David S

2012-09-01

Previous research has demonstrated that young children produce mirror-image letter-reversals when printing their names in a leftward direction from the midline or right margin of their writing paper. This ability is postulated to be an epiphenomenon of a symmetric, proximal (arm) stage of motor development that ontogenetically precedes lateralization of fine-motor distal (finger) control-a stage in which each arm can be controlled by either side of the brain. From this view, canonical writing in right hemi-space is contralaterally mediated by the left hemisphere and mirror-writing in left hemi-space is ipsilaterally mediated by the right hemisphere. However, evidence of right hemisphere canonical letter processing in dyslexia suggests that this is not always the case. Concordantly, an early study corrected reversals by having children print these errors canonically in left hemi-space and then rightward across the midline into right hemi-space. To further understand this behaviour, the present study investigated mirror-writing in three schools (Public, Montessori, and Waldorf) each differing in how writing is introduced. It was hypothesised that there would be no school-differences in mirror-writing if printing had been learned before school-entry and that some children would produce reversals in right hemi-space that were canonically written in left-hemi-space (inverse reversals)-the opposite of the normal pattern. The results showed that 39% of the children demonstrated these inverse reversals. It is discussed how this unexpectedly high incidence may be foundational in the development of the phonologically proficient and deficient subtypes of dyslexia, spelling-dysgraphia, and the left-hand inverted writing posture.

Living on the edge: Space use of Eurasian red squirrels in marginal high-elevation habitat

NASA Astrophysics Data System (ADS)

Romeo, Claudia; Wauters, Lucas A.; Preatoni, Damiano; Tosi, Guido; Martinoli, Adriano

2010-11-01

In marginal habitats located at the edge of a species' range, environmental conditions are frequently extreme and individuals may be subject to different selective pressures compared to central populations. These so-called edge or marginal populations tend to have lower densities and reproductive rates than populations located in more suitable habitats, but little is known about local adaptations in spacing behavior. We studied space use and social organization in a population of Eurasian red squirrels ( Sciurus vulgaris) in a high-elevation marginal habitat of dwarf mountain pine ( Pinus mugo) and compared it with spacing patterns in high-quality Scots pine ( Pinus sylvestris) forest at lower-elevation. Home ranges and core areas were larger in the marginal habitat. In both habitats, males used larger home ranges than females, but sex differences in core area size were significant only in the edge population. Patterns of core area overlap were similar in both habitats with intra-sexual territoriality among adult females and higher degrees of inter-sexual overlap, typical for the species throughout its range. However, low densities in the edge population resulted in higher female by males overlap in spring-summer, suggesting males increased home ranges and core areas during mating season to augment access to estrus females. Thus, in the marginal habitat, with low food abundance and low population densities, linked with extreme winter conditions, squirrels, especially males, used large home ranges. Finally, squirrels responded more strongly to variation in food availability (inverse relation between home range size and seed abundance), and even to fluctuations in density (inverse relation between core area size and density of animals of the same sex), in the marginal than in the high-quality habitat, suggesting high behavioral plasticity to respond to the ecological constraints in marginal habitats.

Issues for the future. Putting the jigsaw together.

PubMed

1998-07-01

Oxfam's efforts to support organizations working with disabled people in Bosnia highlight the necessity of taking into account other forms of disadvantage that increase vulnerability, such as gender, when planning interventions. When Oxfam began working in Bosnia in 1993, disability was widely perceived as a medical rather than a social development issue. An Oxfam-inspired inter-Association project set up the Lotos Resource Center to create badly needed joint social space and office space for vocational training. Realizing that it was difficult to reach women with disabilities, Oxfam representatives made home visits to encourage women to participate in activities. Oxfam also actively co-opted women to join the steering committee. This work gave Oxfam a better understanding of the fact that a diversity of needs exists for disabled men and women, for able-bodied women caring for disabled partners, and for women caring for disabled children. Lessons learned include 1) people with disabilities are not homogeneous in their needs; 2) it is essential to take positive action to involve disabled women; 3) gender and disability analysis must be inclusive and must consider different sources of marginalization or else marginalization will be reinforced; and 4) a basic rights approach provides a clear framework to understand dimensions of disadvantage within households.

From Learning to Labour to Learning for Marginality: School Segregation and Marginalization in Swedish Suburbs

ERIC Educational Resources Information Center

Beach, Dennis; Sernhede, Ove

2011-01-01

In this article, using data from ethnographic research, we try to present some glimpses of the way education is described as an experience and possibility "from below", by pupils who grow up and study in schools in the most segregated and territorially stigmatized suburbs on the outskirts of our major cities. What we feel they describe…

An Investigation of a Culturally Responsive Approach to Science Education in a Summer Program for Marginalized Youth

NASA Astrophysics Data System (ADS)

Garvin, Brittany A.

There have been numerous calls and efforts made to provide states, school districts, and communities needed financial support to increase and enhance access to and opportunities in Science, Technology, Engineering, and Math (STEM) related disciplines for marginalized populations (Tyson, Lee, & Hanson, 2007; Caldwell & Siwatu, 2003). As the challenge to better educate students of color and poor students intensifies, the need to provide equitable science learning experiences for all students aimed at scientific literacy and STEM also becomes critical. Thus the need to provide summer science enrichment programs where students engage in scientific experimentation, investigation, and critical thinking are vital to helping students who have been traditionally marginalized achieve success in school science and enter the science career pipeline. This mixed methods study examined the impact of a culturally responsive approach on student attitudes, interests in science education and STEM careers, and basic science content knowledge before and after participation in an upward bound summer program. Quantitative results indicated using a culturally responsive approach to teach science in an informal learning space significantly increases student achievement. Students receiving culturally responsive science instruction exhibited statistically significant increases in their posttest science scores compared to pretest science scores, M = 0.376, 95% CI [0.266, 0.487], t (10) = 7.610, p < 0.001. Likewise, students receiving culturally responsive science instruction had a significantly higher interest in science (M = 1.740, SD = 0.548) and STEM careers, M = 0.597, 95% CI [0.276, 0.919], p = 0.001. The qualitative data obtained in this study sought to gain a more in-depth understanding of the impact of a culturally responsive approach on students' attitudes, interests in science and STEM careers. Findings suggest providing students the opportunity to do and learn science utilizing a culturally responsive approach was much more beneficial to their overall science knowledge, as it allowed students to experience, understand, and connect to and through their science learning. Likewise, culturally responsive science instruction helped students to foster a more positive interest in science and STEM careers as it provided students the opportunity to do science in a meaningful and relevant way. Moreover, results revealed students receiving culturally responsive science instruction were able to see themselves represented in the curriculum and recognized their own strengths; as a result they were more validated and affirmed in and transformed by, their learning.

Helping Students on the Margin Succeed in Schools.

ERIC Educational Resources Information Center

Langenfeld, Michelle Schoen; Cumming, Brenda

1996-01-01

Addresses how Apple Valley High School (Minnesota) has been able to help marginal students succeed in school. The fundamental actions that contributed to the effectiveness of study-team efforts to help marginal students are discussed, and what has been learned through these efforts is considered. (GR)

Structural Margins Assessment Approach

NASA Technical Reports Server (NTRS)

Ryan, Robert S.

1988-01-01

A general approach to the structural design and verification used to determine the structural margins of the space vehicle elements under Marshall Space Flight Center (MSFC) management is described. The Space Shuttle results and organization will be used as illustrations for techniques discussed. Given also are: (1) the system analyses performed or to be performed by, and (2) element analyses performed by MSFC and its contractors. Analysis approaches and their verification will be addressed. The Shuttle procedures are general in nature and apply to other than Shuttle space vehicles.

Max-margin weight learning for medical knowledge network.

PubMed

Jiang, Jingchi; Xie, Jing; Zhao, Chao; Su, Jia; Guan, Yi; Yu, Qiubin

2018-03-01

The application of medical knowledge strongly affects the performance of intelligent diagnosis, and method of learning the weights of medical knowledge plays a substantial role in probabilistic graphical models (PGMs). The purpose of this study is to investigate a discriminative weight-learning method based on a medical knowledge network (MKN). We propose a training model called the maximum margin medical knowledge network (M 3 KN), which is strictly derived for calculating the weight of medical knowledge. Using the definition of a reasonable margin, the weight learning can be transformed into a margin optimization problem. To solve the optimization problem, we adopt a sequential minimal optimization (SMO) algorithm and the clique property of a Markov network. Ultimately, M 3 KN not only incorporates the inference ability of PGMs but also deals with high-dimensional logic knowledge. The experimental results indicate that M 3 KN obtains a higher F-measure score than the maximum likelihood learning algorithm of MKN for both Chinese Electronic Medical Records (CEMRs) and Blood Examination Records (BERs). Furthermore, the proposed approach is obviously superior to some classical machine learning algorithms for medical diagnosis. To adequately manifest the importance of domain knowledge, we numerically verify that the diagnostic accuracy of M 3 KN is gradually improved as the number of learned CEMRs increase, which contain important medical knowledge. Our experimental results show that the proposed method performs reliably for learning the weights of medical knowledge. M 3 KN outperforms other existing methods by achieving an F-measure of 0.731 for CEMRs and 0.4538 for BERs. This further illustrates that M 3 KN can facilitate the investigations of intelligent healthcare. Copyright © 2018 Elsevier B.V. All rights reserved.

Simultaneous detection of landmarks and key-frame in cardiac perfusion MRI using a joint spatial-temporal context model

NASA Astrophysics Data System (ADS)

Lu, Xiaoguang; Xue, Hui; Jolly, Marie-Pierre; Guetter, Christoph; Kellman, Peter; Hsu, Li-Yueh; Arai, Andrew; Zuehlsdorff, Sven; Littmann, Arne; Georgescu, Bogdan; Guehring, Jens

2011-03-01

Cardiac perfusion magnetic resonance imaging (MRI) has proven clinical significance in diagnosis of heart diseases. However, analysis of perfusion data is time-consuming, where automatic detection of anatomic landmarks and key-frames from perfusion MR sequences is helpful for anchoring structures and functional analysis of the heart, leading toward fully automated perfusion analysis. Learning-based object detection methods have demonstrated their capabilities to handle large variations of the object by exploring a local region, i.e., context. Conventional 2D approaches take into account spatial context only. Temporal signals in perfusion data present a strong cue for anchoring. We propose a joint context model to encode both spatial and temporal evidence. In addition, our spatial context is constructed not only based on the landmark of interest, but also the landmarks that are correlated in the neighboring anatomies. A discriminative model is learned through a probabilistic boosting tree. A marginal space learning strategy is applied to efficiently learn and search in a high dimensional parameter space. A fully automatic system is developed to simultaneously detect anatomic landmarks and key frames in both RV and LV from perfusion sequences. The proposed approach was evaluated on a database of 373 cardiac perfusion MRI sequences from 77 patients. Experimental results of a 4-fold cross validation show superior landmark detection accuracies of the proposed joint spatial-temporal approach to the 2D approach that is based on spatial context only. The key-frame identification results are promising.

Counterspaces for Women of Color in STEM Higher Education: Marginal and Central Spaces for Persistence and Success

ERIC Educational Resources Information Center

Ong, Maria; Smith, Janet M.; Ko, Lily T.

2018-01-01

Counterspaces in science, technology, engineering, and mathematics (STEM) are often considered "safe spaces" at the margins for groups outside the mainstream of STEM education. The prevailing culture and structural manifestations in STEM have traditionally privileged norms of success that favor competitive, individualistic, and solitary…

Multiple-choice tests stabilize access to marginal knowledge.

PubMed

Cantor, Allison D; Eslick, Andrea N; Marsh, Elizabeth J; Bjork, Robert A; Bjork, Elizabeth Ligon

2015-02-01

Marginal knowledge refers to knowledge that is stored in memory, but is not accessible at a given moment. For example, one might struggle to remember who wrote The Call of the Wild, even if that knowledge is stored in memory. Knowing how best to stabilize access to marginal knowledge is important, given that new learning often requires accessing and building on prior knowledge. While even a single opportunity to restudy marginal knowledge boosts its later accessibility (Berger, Hall, & Bahrick, 1999), in many situations explicit relearning opportunities are not available. Our question is whether multiple-choice tests (which by definition expose the learner to the correct answers) can also serve this function and, if so, how testing compares to restudying given that tests can be particularly powerful learning devices (Roediger & Karpicke, 2006). In four experiments, we found that multiple-choice testing had the power to stabilize access to marginal knowledge, and to do so for at least up to a week. Importantly, such tests did not need to be paired with feedback, although testing was no more powerful than studying. Overall, the results support the idea that one's knowledge base is unstable, with individual pieces of information coming in and out of reach. The present findings have implications for a key educational challenge: ensuring that students have continuing access to information they have learned.

Margined winner-take-all: New learning rule for pattern recognition.

PubMed

Fukushima, Kunihiko

2018-01-01

The neocognitron is a deep (multi-layered) convolutional neural network that can be trained to recognize visual patterns robustly. In the intermediate layers of the neocognitron, local features are extracted from input patterns. In the deepest layer, based on the features extracted in the intermediate layers, input patterns are classified into classes. A method called IntVec (interpolating-vector) is used for this purpose. This paper proposes a new learning rule called margined Winner-Take-All (mWTA) for training the deepest layer. Every time when a training pattern is presented during the learning, if the result of recognition by WTA (Winner-Take-All) is an error, a new cell is generated in the deepest layer. Here we put a certain amount of margin to the WTA. In other words, only during the learning, a certain amount of handicap is given to cells of classes other than that of the training vector, and the winner is chosen under this handicap. By introducing the margin to the WTA, we can generate a compact set of cells, with which a high recognition rate can be obtained with a small computational cost. The ability of this mWTA is demonstrated by computer simulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Influence of space size of abutment screw access channel on the amount of extruded excess cement and marginal accuracy of cement-retained single implant restorations.

PubMed

Al Amri, Mohammad D; Al-Johany, Sulieman S; Al-Qarni, Mohammed N; Al-Bakri, Ahmed S; Al-Maflehi, Nassr S; Abualsaud, Haythem S

2018-02-01

The detrimental effect of extruded excess cement on peri-implant tissue has been well documented. Although several techniques have been proposed to reduce this effect by decreasing the amount of extruded cement, how the space size of the abutment screw access channel (SAC) affects the amount of extruded cement and marginal accuracy is unclear. The purpose of this in vitro study was to evaluate the effect of the size of the unfilled space of the abutment SAC on the amount of extruded excess cement and the marginal accuracy of zirconia copings. Twelve implant replicas and corresponding standard abutments were attached and embedded in acrylic resin blocks. Computer-aided design and computer-aided manufacturing (CAD-CAM) zirconia copings with a uniform 30-μm cement space were fabricated by 1 dental technician using the standard method. The copings were temporarily cemented 3 times at different sizes of the left space of the SAC as follows: the nonspaced group (NS), in which the entire SAC was completely filled, the 1-mm-spaced group (1MMS), and the 2-mm-spaced group (2MMS). Abutments and crowns were ultrasonically cleaned, steam cleaned, and air-dried. The excess cement was collected and weighed. To measure the marginal accuracy, 20 measurements were made every 18 degrees along the coping margin at ×300 magnification and compared with the pre-cementation readings. One-way ANOVA was calculated to determine whether the amount of extruded excess cement differed among the 3 groups, and the Tukey test was applied for multiple comparisons (α=.05). The mean weights (mg) of extruded excess cement were NS (33.53 ±1.5), 1MMS (22.97 ±5.4), and 2MMS (15.17 ±5.9). Multiple comparisons showed significant differences in the amount of extruded excess cement among the 3 test groups (P<.001). The mean marginal discrepancy (μm) of the pre-cemented group (29.5 ±8.2) was significantly different (P<.01) from that of the NS (72.3 ±13.7), the 1MMS (70.1 ±19), and the 2MMS group (70.1 ±18.8). No significant differences were found in marginal accuracy among the 3 test groups (P=.942). Within the limitations of this in vitro study, leaving a 2-mm space in the SAC reduced the amount of extruded excess cement by 55% in comparison with the nonspaced abutments. However, no effect was found on the marginal accuracy of zirconia copings. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

"Simulated molecular evolution" or computer-generated artifacts?

PubMed

Darius, F; Rojas, R

1994-11-01

1. The authors define a function with value 1 for the positive examples and 0 for the negative ones. They fit a continuous function but do not deal at all with the error margin of the fit, which is almost as large as the function values they compute. 2. The term "quality" for the value of the fitted function gives the impression that some biological significance is associated with values of the fitted function strictly between 0 and 1, but there is no justification for this kind of interpretation and finding the point where the fit achieves its maximum does not make sense. 3. By neglecting the error margin the authors try to optimize the fitted function using differences in the second, third, fourth, and even fifth decimal place which have no statistical significance. 4. Even if such a fit could profit from more data points, the authors should first prove that the region of interest has some kind of smoothness, that is, that a continuous fit makes any sense at all. 5. "Simulated molecular evolution" is a misnomer. We are dealing here with random search. Since the margin of error is so large, the fitted function does not provide statistically significant information about the points in search space where strings with cleavage sites could be found. This implies that the method is a highly unreliable stochastic search in the space of strings, even if the neural network is capable of learning some simple correlations. 6. Classical statistical methods are for these kind of problems with so few data points clearly superior to the neural networks used as a "black box" by the authors, which in the way they are structured provide a model with an error margin as large as the numbers being computed.7. And finally, even if someone would provide us with a function which separates strings with cleavage sites from strings without them perfectly, so-called simulated molecular evolution would not be better than random selection.Since a perfect fit would only produce exactly ones or zeros,starting a search in a region of space where all strings in the neighborhood get the value zero would not provide any kind of directional information for new iterations. We would just skip from one point to the other in a typical random walk manner.

Techniques for Conducting Effective Concept Design and Design-to-Cost Trade Studies

NASA Technical Reports Server (NTRS)

Di Pietro, David A.

2015-01-01

Concept design plays a central role in project success as its product effectively locks the majority of system life cycle cost. Such extraordinary leverage presents a business case for conducting concept design in a credible fashion, particularly for first-of-a-kind systems that advance the state of the art and that have high design uncertainty. A key challenge, however, is to know when credible design convergence has been achieved in such systems. Using a space system example, this paper characterizes the level of convergence needed for concept design in the context of technical and programmatic resource margins available in preliminary design and highlights the importance of design and cost evaluation learning curves in determining credible convergence. It also provides techniques for selecting trade study cases that promote objective concept evaluation, help reveal unknowns, and expedite convergence within the trade space and conveys general practices for conducting effective concept design-to-cost studies.

Max-margin multiattribute learning with low-rank constraint.

PubMed

Zhang, Qiang; Chen, Lin; Li, Baoxin

2014-07-01

Attribute learning has attracted a lot of interests in recent years for its advantage of being able to model high-level concepts with a compact set of midlevel attributes. Real-world objects often demand multiple attributes for effective modeling. Most existing methods learn attributes independently without explicitly considering their intrinsic relatedness. In this paper, we propose max margin multiattribute learning with low-rank constraint, which learns a set of attributes simultaneously, using only relative ranking of the attributes for the data. By learning all the attributes simultaneously through low-rank constraint, the proposed method is able to capture their intrinsic correlation for improved learning; by requiring only relative ranking, the method avoids restrictive binary labels of attributes that are often assumed by many existing techniques. The proposed method is evaluated on both synthetic data and real visual data including a challenging video data set. Experimental results demonstrate the effectiveness of the proposed method.

Learning-related human brain activations reflecting individual finances.

PubMed

Tobler, Philippe N; Fletcher, Paul C; Bullmore, Edward T; Schultz, Wolfram

2007-04-05

A basic tenet of microeconomics suggests that the subjective value of financial gains decreases with increasing assets of individuals ("marginal utility"). Using concepts from learning theory and microeconomics, we assessed the capacity of financial rewards to elicit behavioral and neuronal changes during reward-predictive learning in participants with different financial backgrounds. Behavioral learning speed during both acquisition and extinction correlated negatively with the assets of the participants, irrespective of education and age. Correspondingly, response changes in midbrain and striatum measured with functional magnetic resonance imaging were slower during both acquisition and extinction with increasing assets and income of the participants. By contrast, asymptotic magnitudes of behavioral and neuronal responses after learning were unrelated to personal finances. The inverse relationship of behavioral and neuronal learning speed with personal finances is compatible with the general concept of decreasing marginal utility with increasing wealth.

Incidental Vocabulary Learning and Recall by Intermediate Foreign Language Students: The Influence of Marginal Glosses, Dictionary Use, and Summary Writing

ERIC Educational Resources Information Center

Ghabanchi, Zargham; Ayoubi, Elham Sadat

2012-01-01

This study is an attempt to compare the effect of four reading conditions on incidental vocabulary learning and recall of intermediate EFL learners. A sample population of 120 Iranian intermediate students read two short passages in one of four reading conditions: 1) L1 Marginal Glosses (MG1--provision of L1 translations of unknown words), 2) L2…

Learning Structured Classifiers with Dual Coordinate Ascent

DTIC Science & Technology

2010-06-01

stochastic gradient descent (SGD) [LeCun et al., 1998], and the margin infused relaxed algorithm (MIRA) [ Crammer et al., 2006]. This paper presents a...evaluate these methods on the Prague Dependency Treebank us- ing online large-margin learning tech- niques ( Crammer et al., 2003; McDonald et al., 2005...between two kinds of factors: hard constraint factors, which are used to rule out forbidden par- tial assignments by mapping them to zero potential values

Semi-Supervised Marginal Fisher Analysis for Hyperspectral Image Classification

NASA Astrophysics Data System (ADS)

Huang, H.; Liu, J.; Pan, Y.

2012-07-01

The problem of learning with both labeled and unlabeled examples arises frequently in Hyperspectral image (HSI) classification. While marginal Fisher analysis is a supervised method, which cannot be directly applied for Semi-supervised classification. In this paper, we proposed a novel method, called semi-supervised marginal Fisher analysis (SSMFA), to process HSI of natural scenes, which uses a combination of semi-supervised learning and manifold learning. In SSMFA, a new difference-based optimization objective function with unlabeled samples has been designed. SSMFA preserves the manifold structure of labeled and unlabeled samples in addition to separating labeled samples in different classes from each other. The semi-supervised method has an analytic form of the globally optimal solution, and it can be computed based on eigen decomposition. Classification experiments with a challenging HSI task demonstrate that this method outperforms current state-of-the-art HSI-classification methods.

Product Quality Modelling Based on Incremental Support Vector Machine

NASA Astrophysics Data System (ADS)

Wang, J.; Zhang, W.; Qin, B.; Shi, W.

2012-05-01

Incremental Support vector machine (ISVM) is a new learning method developed in recent years based on the foundations of statistical learning theory. It is suitable for the problem of sequentially arriving field data and has been widely used for product quality prediction and production process optimization. However, the traditional ISVM learning does not consider the quality of the incremental data which may contain noise and redundant data; it will affect the learning speed and accuracy to a great extent. In order to improve SVM training speed and accuracy, a modified incremental support vector machine (MISVM) is proposed in this paper. Firstly, the margin vectors are extracted according to the Karush-Kuhn-Tucker (KKT) condition; then the distance from the margin vectors to the final decision hyperplane is calculated to evaluate the importance of margin vectors, where the margin vectors are removed while their distance exceed the specified value; finally, the original SVs and remaining margin vectors are used to update the SVM. The proposed MISVM can not only eliminate the unimportant samples such as noise samples, but also can preserve the important samples. The MISVM has been experimented on two public data and one field data of zinc coating weight in strip hot-dip galvanizing, and the results shows that the proposed method can improve the prediction accuracy and the training speed effectively. Furthermore, it can provide the necessary decision supports and analysis tools for auto control of product quality, and also can extend to other process industries, such as chemical process and manufacturing process.

Automated Knowledge Discovery From Simulators

NASA Technical Reports Server (NTRS)

Burl, Michael; DeCoste, Dennis; Mazzoni, Dominic; Scharenbroich, Lucas; Enke, Brian; Merline, William

2007-01-01

A computational method, SimLearn, has been devised to facilitate efficient knowledge discovery from simulators. Simulators are complex computer programs used in science and engineering to model diverse phenomena such as fluid flow, gravitational interactions, coupled mechanical systems, and nuclear, chemical, and biological processes. SimLearn uses active-learning techniques to efficiently address the "landscape characterization problem." In particular, SimLearn tries to determine which regions in "input space" lead to a given output from the simulator, where "input space" refers to an abstraction of all the variables going into the simulator, e.g., initial conditions, parameters, and interaction equations. Landscape characterization can be viewed as an attempt to invert the forward mapping of the simulator and recover the inputs that produce a particular output. Given that a single simulation run can take days or weeks to complete even on a large computing cluster, SimLearn attempts to reduce costs by reducing the number of simulations needed to effect discoveries. Unlike conventional data-mining methods that are applied to static predefined datasets, SimLearn involves an iterative process in which a most informative dataset is constructed dynamically by using the simulator as an oracle. On each iteration, the algorithm models the knowledge it has gained through previous simulation trials and then chooses which simulation trials to run next. Running these trials through the simulator produces new data in the form of input-output pairs. The overall process is embodied in an algorithm that combines support vector machines (SVMs) with active learning. SVMs use learning from examples (the examples are the input-output pairs generated by running the simulator) and a principle called maximum margin to derive predictors that generalize well to new inputs. In SimLearn, the SVM plays the role of modeling the knowledge that has been gained through previous simulation trials. Active learning is used to determine which new input points would be most informative if their output were known. The selected input points are run through the simulator to generate new information that can be used to refine the SVM. The process is then repeated. SimLearn carefully balances exploration (semi-randomly searching around the input space) versus exploitation (using the current state of knowledge to conduct a tightly focused search). During each iteration, SimLearn uses not one, but an ensemble of SVMs. Each SVM in the ensemble is characterized by different hyper-parameters that control various aspects of the learned predictor - for example, whether the predictor is constrained to be very smooth (nearby points in input space lead to similar output predictions) or whether the predictor is allowed to be "bumpy." The various SVMs will have different preferences about which input points they would like to run through the simulator next. SimLearn includes a formal mechanism for balancing the ensemble SVM preferences so that a single choice can be made for the next set of trials.

Generalization in Adaptation to Stable and Unstable Dynamics

PubMed Central

Kadiallah, Abdelhamid; Franklin, David W.; Burdet, Etienne

2012-01-01

Humans skillfully manipulate objects and tools despite the inherent instability. In order to succeed at these tasks, the sensorimotor control system must build an internal representation of both the force and mechanical impedance. As it is not practical to either learn or store motor commands for every possible future action, the sensorimotor control system generalizes a control strategy for a range of movements based on learning performed over a set of movements. Here, we introduce a computational model for this learning and generalization, which specifies how to learn feedforward muscle activity in a function of the state space. Specifically, by incorporating co-activation as a function of error into the feedback command, we are able to derive an algorithm from a gradient descent minimization of motion error and effort, subject to maintaining a stability margin. This algorithm can be used to learn to coordinate any of a variety of motor primitives such as force fields, muscle synergies, physical models or artificial neural networks. This model for human learning and generalization is able to adapt to both stable and unstable dynamics, and provides a controller for generating efficient adaptive motor behavior in robots. Simulation results exhibit predictions consistent with all experiments on learning of novel dynamics requiring adaptation of force and impedance, and enable us to re-examine some of the previous interpretations of experiments on generalization. PMID:23056191

Three-dimensional marginal separation

NASA Technical Reports Server (NTRS)

Duck, Peter W.

1988-01-01

The three dimensional marginal separation of a boundary layer along a line of symmetry is considered. The key equation governing the displacement function is derived, and found to be a nonlinear integral equation in two space variables. This is solved iteratively using a pseudo-spectral approach, based partly in double Fourier space, and partly in physical space. Qualitatively, the results are similar to previously reported two dimensional results (which are also computed to test the accuracy of the numerical scheme); however quantitatively the three dimensional results are much different.

The role of substance P in the marginal division of the neostriatum in learning and memory is mediated through the neurokinin 1 receptor in rats.

PubMed

Liu, Xue-mei; Shu, Si Yun; Zeng, Chang-chun; Cai, Ye-feng; Zhang, Kui-hua; Wang, Chuan-xing; Fang, Jian

2011-10-01

Substance P (SP) is a neuropeptide that plays an important role in inflammation, respiration, pain, aggression, anxiety, and learning and memory mainly through its high affinity neurokinin 1 receptor (NK1R). The marginal division (MrD) is a pan-shaped subdivision in the caudomedial margin of the neostriatum in the mammalian brain and is known to be involved in learning and memory. We studied the expression of SP, NK1R and NK1R mRNA in the rat striatum by immunohistochemistry, immunofluorescence and in situ hybridization, and found that the levels of SP, NK1R protein and NK1R mRNA were high in the cell bodies, fibers and terminals of neurons in the neostriatum, especially in the MrD. Knocking down NK1R activity in the MrD by using an antisense oligonucleotide against NK1R mRNA inhibited learning and memory in a Y-maze behavioral test. Our results show that NK1R mediates the role of SP in the MrD in learning and memory.

Discriminative Learning of Receptive Fields from Responses to Non-Gaussian Stimulus Ensembles

PubMed Central

Meyer, Arne F.; Diepenbrock, Jan-Philipp; Happel, Max F. K.; Ohl, Frank W.; Anemüller, Jörn

2014-01-01

Analysis of sensory neurons' processing characteristics requires simultaneous measurement of presented stimuli and concurrent spike responses. The functional transformation from high-dimensional stimulus space to the binary space of spike and non-spike responses is commonly described with linear-nonlinear models, whose linear filter component describes the neuron's receptive field. From a machine learning perspective, this corresponds to the binary classification problem of discriminating spike-eliciting from non-spike-eliciting stimulus examples. The classification-based receptive field (CbRF) estimation method proposed here adapts a linear large-margin classifier to optimally predict experimental stimulus-response data and subsequently interprets learned classifier weights as the neuron's receptive field filter. Computational learning theory provides a theoretical framework for learning from data and guarantees optimality in the sense that the risk of erroneously assigning a spike-eliciting stimulus example to the non-spike class (and vice versa) is minimized. Efficacy of the CbRF method is validated with simulations and for auditory spectro-temporal receptive field (STRF) estimation from experimental recordings in the auditory midbrain of Mongolian gerbils. Acoustic stimulation is performed with frequency-modulated tone complexes that mimic properties of natural stimuli, specifically non-Gaussian amplitude distribution and higher-order correlations. Results demonstrate that the proposed approach successfully identifies correct underlying STRFs, even in cases where second-order methods based on the spike-triggered average (STA) do not. Applied to small data samples, the method is shown to converge on smaller amounts of experimental recordings and with lower estimation variance than the generalized linear model and recent information theoretic methods. Thus, CbRF estimation may prove useful for investigation of neuronal processes in response to natural stimuli and in settings where rapid adaptation is induced by experimental design. PMID:24699631

Discriminative learning of receptive fields from responses to non-Gaussian stimulus ensembles.

PubMed

Meyer, Arne F; Diepenbrock, Jan-Philipp; Happel, Max F K; Ohl, Frank W; Anemüller, Jörn

2014-01-01

Analysis of sensory neurons' processing characteristics requires simultaneous measurement of presented stimuli and concurrent spike responses. The functional transformation from high-dimensional stimulus space to the binary space of spike and non-spike responses is commonly described with linear-nonlinear models, whose linear filter component describes the neuron's receptive field. From a machine learning perspective, this corresponds to the binary classification problem of discriminating spike-eliciting from non-spike-eliciting stimulus examples. The classification-based receptive field (CbRF) estimation method proposed here adapts a linear large-margin classifier to optimally predict experimental stimulus-response data and subsequently interprets learned classifier weights as the neuron's receptive field filter. Computational learning theory provides a theoretical framework for learning from data and guarantees optimality in the sense that the risk of erroneously assigning a spike-eliciting stimulus example to the non-spike class (and vice versa) is minimized. Efficacy of the CbRF method is validated with simulations and for auditory spectro-temporal receptive field (STRF) estimation from experimental recordings in the auditory midbrain of Mongolian gerbils. Acoustic stimulation is performed with frequency-modulated tone complexes that mimic properties of natural stimuli, specifically non-Gaussian amplitude distribution and higher-order correlations. Results demonstrate that the proposed approach successfully identifies correct underlying STRFs, even in cases where second-order methods based on the spike-triggered average (STA) do not. Applied to small data samples, the method is shown to converge on smaller amounts of experimental recordings and with lower estimation variance than the generalized linear model and recent information theoretic methods. Thus, CbRF estimation may prove useful for investigation of neuronal processes in response to natural stimuli and in settings where rapid adaptation is induced by experimental design.

Identification of Abnormal System Noise Temperature Patterns in Deep Space Network Antennas Using Neural Network Trained Fuzzy Logic

NASA Technical Reports Server (NTRS)

Lu, Thomas; Pham, Timothy; Liao, Jason

2011-01-01

This paper presents the development of a fuzzy logic function trained by an artificial neural network to classify the system noise temperature (SNT) of antennas in the NASA Deep Space Network (DSN). The SNT data were classified into normal, marginal, and abnormal classes. The irregular SNT pattern was further correlated with link margin and weather data. A reasonably good correlation is detected among high SNT, low link margin and the effect of bad weather; however we also saw some unexpected non-correlations which merit further study in the future.

In Space Nuclear Power as an Enabling Technology for Deep Space Exploration

NASA Technical Reports Server (NTRS)

Sackheim, Robert L.; Houts, Michael

2000-01-01

Deep Space Exploration missions, both for scientific and Human Exploration and Development (HEDS), appear to be as weight limited today as they would have been 35 years ago. Right behind the weight constraints is the nearly equally important mission limitation of cost. Launch vehicles, upper stages and in-space propulsion systems also cost about the same today with the same efficiency as they have had for many years (excluding impact of inflation). Both these dual mission constraints combine to force either very expensive, mega systems missions or very light weight, but high risk/low margin planetary spacecraft designs, such as the recent unsuccessful attempts for an extremely low cost mission to Mars during the 1998-99 opportunity (i.e., Mars Climate Orbiter and the Mars Polar Lander). When one considers spacecraft missions to the outer heliopause or even the outer planets, the enormous weight and cost constraints will impose even more daunting concerns for mission cost, risk and the ability to establish adequate mission margins for success. This paper will discuss the benefits of using a safe in-space nuclear reactor as the basis for providing both sufficient electric power and high performance space propulsion that will greatly reduce mission risk and significantly increase weight (IMLEO) and cost margins. Weight and cost margins are increased by enabling much higher payload fractions and redundant design features for a given launch vehicle (higher payload fraction of IMLEO). The paper will also discuss and summarize the recent advances in nuclear reactor technology and safety of modern reactor designs and operating practice and experience, as well as advances in reactor coupled power generation and high performance nuclear thermal and electric propulsion technologies. It will be shown that these nuclear power and propulsion technologies are major enabling capabilities for higher reliability, higher margin and lower cost deep space missions design to reliably reach the outer planets for scientific exploration.

SABER on Orbit Performance Evaluation and Lessons Learned

NASA Astrophysics Data System (ADS)

Jensen, Scott M.; Batty, J. Clair

2004-06-01

The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument, launched into orbit December 7, 2001, utilized a miniature pulse-tube cryocooler to maintain the SABER focal plane assembly (FPA) at 75 K. The limited cooling capacity of the cryocooler necessitated the development of a new never before flown Fiber Support Technology (FiST) for supporting and thermally isolating the FPA. A very precise predictive thermal modeling effort to ensure successful operation was also needed due to the very small capacity margin of the cryocooler. A high performance thermal link that minimized the temperature difference between the FPA and the cryocooler cold block and also the mechanical dynamic loading on the fragile pulse tube was developed and space qualified. This paper presents a comparison of the thermal modeling predictions with on orbit measurements, and discusses the lessons learned concerning long term performance issues of thermal isolation systems which utilize cryocoolers for cooling focal plane assemblies (FPA's). The effect of ice deposition on the thermal blankets and other FPA cooled structures, as well as the lessons learned in dealing with this ice deposition, will also be presented.

NanTroSEIZE in 3-D: Creating a Virtual Research Experience in Undergraduate Geoscience Courses

NASA Astrophysics Data System (ADS)

Reed, D. L.; Bangs, N. L.; Moore, G. F.; Tobin, H.

2009-12-01

Marine research programs, both large and small, have increasingly added a web-based component to facilitate outreach to K-12 and the public, in general. These efforts have included, among other activities, information-rich websites, ship-to-shore communication with scientists during expeditions, blogs at sea, clips on YouTube, and information about daily shipboard activities. Our objective was to leverage a portion of the vast collection of data acquired through the NSF-MARGINS program to create a learning tool with a long lifespan for use in undergraduate geoscience courses. We have developed a web-based virtual expedition, NanTroSEIZE in 3-D, based on a seismic survey associated with the NanTroSEIZE program of NSF-MARGINS and IODP to study the properties of the plate boundary fault system in the upper limit of the seismogenic zone off Japan. The virtual voyage can be used in undergraduate classes at anytime, since it is not directly tied to the finite duration of a specific seagoing project. The website combines text, graphics, audio and video to place learning in an experiential framework as students participate on the expedition and carry out research. Students learn about the scientific background of the program, especially the critical role of international collaboration, and meet the chief scientists before joining the sea-going expedition. Students are presented with the principles of 3-D seismic imaging, data processing and interpretation while mapping and identifying the active faults that were the likely sources of devastating earthquakes and tsunamis in Japan in 1944 and 1948. They also learn about IODP drilling that began in 2007 and will extend through much of the next decade. The website is being tested in undergraduate classes in fall 2009 and will be distributed through the NSF-MARGINS website (http://www.nsf-margins.org/) and the MARGINS Mini-lesson section of the Science Education Resource Center (SERC) (http://serc.carleton.edu/margins/collection.html) in early 2010.

Isolated marginal facial nerve paresis after TMJ discopexy: a case report.

PubMed

Reychler, H; Mahy, P

2011-01-01

Isolated marginal facial nerve paresis after TMJ discopexy: a case report. This is the first report of a transient, isolated marginal facial nerve paresis after temporomandibular joint arthrotomy. The paresis seems to have resulted from a crush lesion by Backhaus forceps, placed transcutaneously during the operation to distract the intra-articular space.

Mass Properties for Space Systems Standards Development

NASA Technical Reports Server (NTRS)

Beech, Geoffrey

2013-01-01

Current Verbiage in S-120 Applies to Dry Mass. Mass Margin is difference between Required Mass and Predicted Mass. Performance Margin is difference between Predicted Performance and Required Performance. Performance estimates and corresponding margin should be based on Predicted Mass (and other inputs). Contractor Mass Margin reserved from Performance Margin. Remaining performance margin allocated according to mass partials. Compliance can be evaluated effectively by comparison of three areas (preferably on a single sheet). Basic and Predicted Mass (including historical trend). Aggregate potential changes (threats and opportunities) which gives Mass Forecast. Mass Maturity by category (Estimated/Calculated/Actual).

The Application of Margin in Life Theory in Regard to Attrition and Remediation among Emergency Medicine Residents

ERIC Educational Resources Information Center

Kalynych, Colleen J.

2010-01-01

Medical residency is a time of high stress, long hours, high case loads, fatigue, and lack of free time. Burnout rates among residents have been reported to be between 25-76%. Scant literature exists in regard to resident stress and its impact on learning and attrition during residency. The theory of margin posits that a healthy margin is…

Marginal and internal fit of CAD-CAM-fabricated composite resin and ceramic crowns scanned by 2 intraoral cameras.

PubMed

de Paula Silveira, Alessandra C; Chaves, Sacha B; Hilgert, Leandro A; Ribeiro, Ana Paula D

2017-03-01

The precision of fit of chairside computer-aided design and computer-aided manufacturing (CAD-CAM) complete crowns is affected by digital impression and restorative material. The purpose of this in vitro study was to evaluate by microcomputed tomography (μCT) the marginal and internal adaptation of composite resin and ceramic complete crowns fabricated with 2 different intraoral cameras and 2 restorative materials. Ten extracted human third molars received crown preparations. For each prepared molar, 2 digital impressions were made with different intraoral cameras of the CEREC system, Bluecam and Omnicam. Four groups were formed: LB (Lava Ultimate+Bluecam), EB (Emax+Bluecam), LO (Lava Ultimate+Omnicam), and EO (Emax+Omnicam). Before measuring the precision of fit, all crowns were stabilized with a silicone material. Each unit (crown + prepared tooth) was imaged with μCT, and marginal and internal discrepancies were analyzed. For the 2D analysis, 120 measurements were made of each crown for marginal adaptation, 20 for marginal discrepancy (MD), and 20 for absolute marginal discrepancy (AMD); and for internal adaptation, 40 for axial space (AS) and 40 for occlusal space (OS). After reconstructing the 3D images, the average internal space (AIS) was calculated by dividing the total volume of the internal space by the contact surface. Data were analyzed with 2-way ANOVA and quantile regression. Regarding marginal adaptation, no significant differences were observed among groups. For internal adaptation measured in the 2D evaluation, a significant difference was observed between LO and EO for the AS variable (Mann-Whitney test; P<.008). In assessment of AIS by the 3D reconstruction, LB presented significantly lower values than the other groups (Tukey post hoc test; P<.05). Bluecam presented lower values of AIS than Omnicam, and composite resin crowns showed less discrepancy than did ceramic crowns. The marginal adaptations assessed in all groups showed values within the clinically accepted range. Moreover, the composite resin blocks associated with the Bluecam intraoral camera demonstrated the best results for AIS compared with those of the other groups. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Terrestrial Micro Renewable Energy Applications of Space Technology

NASA Astrophysics Data System (ADS)

Komerath, N. M.; Komerath, P. P.

This paper explores the synergy between technologies intended for extraterrestrial in situ resource utilization and those for terrestrial mass-market micro renewable power generation systems. The case for a micro renewable energy architecture is presented. The obstacles hindering market success are summarized, along with opportunities from recent demonstrations suggesting that the public appetite for sophisticated technology worldwide may be underappreciated by technical researchers. Technical innovations from space research are summarized along with estimates of possible conversion efficiencies. It is argued that the cost-effectiveness of micro power generation must be viewed through the value of the first few watts of available power, rather than the marginal cost per kilowatt-hour of electric power from utility power grids. This leads to the finding that the actual target cost per unit power, and efficiency, are well within reach of space technology products. Hybrid systems integrating power extraction from multiple resources, and adaptable for multiple applications, can break through mass market price barriers. Recent work to develop learning resources and test beds as part of a Micro Renewable Energy Laboratory is summarized.

Marginal Shape Deep Learning: Applications to Pediatric Lung Field Segmentation.

PubMed

Mansoor, Awais; Cerrolaza, Juan J; Perez, Geovanny; Biggs, Elijah; Nino, Gustavo; Linguraru, Marius George

2017-02-11

Representation learning through deep learning (DL) architecture has shown tremendous potential for identification, localization, and texture classification in various medical imaging modalities. However, DL applications to segmentation of objects especially to deformable objects are rather limited and mostly restricted to pixel classification. In this work, we propose marginal shape deep learning (MaShDL), a framework that extends the application of DL to deformable shape segmentation by using deep classifiers to estimate the shape parameters. MaShDL combines the strength of statistical shape models with the automated feature learning architecture of DL. Unlike the iterative shape parameters estimation approach of classical shape models that often leads to a local minima, the proposed framework is robust to local minima optimization and illumination changes. Furthermore, since the direct application of DL framework to a multi-parameter estimation problem results in a very high complexity, our framework provides an excellent run-time performance solution by independently learning shape parameter classifiers in marginal eigenspaces in the decreasing order of variation. We evaluated MaShDL for segmenting the lung field from 314 normal and abnormal pediatric chest radiographs and obtained a mean Dice similarity coefficient of 0.927 using only the four highest modes of variation (compared to 0.888 with classical ASM 1 (p-value=0.01) using same configuration). To the best of our knowledge this is the first demonstration of using DL framework for parametrized shape learning for the delineation of deformable objects.

Marginal shape deep learning: applications to pediatric lung field segmentation

NASA Astrophysics Data System (ADS)

Mansoor, Awais; Cerrolaza, Juan J.; Perez, Geovany; Biggs, Elijah; Nino, Gustavo; Linguraru, Marius George

2017-02-01

Representation learning through deep learning (DL) architecture has shown tremendous potential for identification, local- ization, and texture classification in various medical imaging modalities. However, DL applications to segmentation of objects especially to deformable objects are rather limited and mostly restricted to pixel classification. In this work, we propose marginal shape deep learning (MaShDL), a framework that extends the application of DL to deformable shape segmentation by using deep classifiers to estimate the shape parameters. MaShDL combines the strength of statistical shape models with the automated feature learning architecture of DL. Unlike the iterative shape parameters estimation approach of classical shape models that often leads to a local minima, the proposed framework is robust to local minima optimization and illumination changes. Furthermore, since the direct application of DL framework to a multi-parameter estimation problem results in a very high complexity, our framework provides an excellent run-time performance solution by independently learning shape parameter classifiers in marginal eigenspaces in the decreasing order of variation. We evaluated MaShDL for segmenting the lung field from 314 normal and abnormal pediatric chest radiographs and obtained a mean Dice similarity coefficient of 0:927 using only the four highest modes of variation (compared to 0:888 with classical ASM1 (p-value=0:01) using same configuration). To the best of our knowledge this is the first demonstration of using DL framework for parametrized shape learning for the delineation of deformable objects.

Marginal Shape Deep Learning: Applications to Pediatric Lung Field Segmentation

PubMed Central

Mansoor, Awais; Cerrolaza, Juan J.; Perez, Geovanny; Biggs, Elijah; Nino, Gustavo; Linguraru, Marius George

2017-01-01

Representation learning through deep learning (DL) architecture has shown tremendous potential for identification, localization, and texture classification in various medical imaging modalities. However, DL applications to segmentation of objects especially to deformable objects are rather limited and mostly restricted to pixel classification. In this work, we propose marginal shape deep learning (MaShDL), a framework that extends the application of DL to deformable shape segmentation by using deep classifiers to estimate the shape parameters. MaShDL combines the strength of statistical shape models with the automated feature learning architecture of DL. Unlike the iterative shape parameters estimation approach of classical shape models that often leads to a local minima, the proposed framework is robust to local minima optimization and illumination changes. Furthermore, since the direct application of DL framework to a multi-parameter estimation problem results in a very high complexity, our framework provides an excellent run-time performance solution by independently learning shape parameter classifiers in marginal eigenspaces in the decreasing order of variation. We evaluated MaShDL for segmenting the lung field from 314 normal and abnormal pediatric chest radiographs and obtained a mean Dice similarity coefficient of 0.927 using only the four highest modes of variation (compared to 0.888 with classical ASM1 (p-value=0.01) using same configuration). To the best of our knowledge this is the first demonstration of using DL framework for parametrized shape learning for the delineation of deformable objects. PMID:28592911

The J-2X Fuel Turbopump - Design, Development, and Test

NASA Technical Reports Server (NTRS)

Tellier, James G.; Hawkins, Lakiesha V.; Shinguchi, Brian H.; Marsh, Matthew W.

2011-01-01

Pratt and Whitney Rocketdyne (PWR), a NASA subcontractor, is executing the design, development, test, and evaluation (DDT&E) of a liquid oxygen, liquid hydrogen two hundred ninety four thousand pound thrust rocket engine initially intended for the Upper Stage (US) and Earth Departure Stage (EDS) of the Constellation Program Ares-I Crew Launch Vehicle (CLV). A key element of the design approach was to base the new J-2X engine on the heritage J-2S engine with the intent of uprating the engine and incorporating SSME and RS-68 lessons learned. The J-2S engine was a design upgrade of the flight proven J-2 configuration used to put American astronauts on the moon. The J-2S Fuel Turbopump (FTP) was the first Rocketdyne-designed liquid hydrogen centrifugal pump and provided many of the early lessons learned for the Space Shuttle Main Engine High Pressure Fuel Turbopumps. This paper will discuss the design trades and analyses performed for the current J-2X FTP to increase turbine life; increase structural margins, facilitate component fabrication; expedite turbopump assembly; and increase rotordynamic stability margins. Risk mitigation tests including inducer water tests, whirligig turbine blade tests, turbine air rig tests, and workhorse gas generator tests characterized operating environments, drove design modifications, or identified performance impact. Engineering design, fabrication, analysis, and assembly activities support FTP readiness for the first J-2X engine test scheduled for July 2011.

The OSIRIS-Rex Asteroid Sample Return: Mission Operations Design

NASA Technical Reports Server (NTRS)

Gal-Edd, Jonathan; Cheuvront, Allan

2014-01-01

The OSIRIS-REx mission employs a methodical, phased approach to ensure success in meeting the missions science requirements. OSIRIS-REx launches in September 2016, with a backup launch period occurring one year later. Sampling occurs in 2019. The departure burn from Bennu occurs in March 2021. On September 24, 2023, the SRC lands at the Utah Test and Training Range (UTTR). Stardust heritage procedures are followed to transport the SRC to Johnson Space Center, where the samples are removed and delivered to the OSIRIS-REx curation facility. After a six-month preliminary examination period the mission will produce a catalog of the returned sample, allowing the worldwide community to request samples for detailed analysis.Traveling and returning a sample from an Asteroid that has not been explored before requires unique operations consideration. The Design Reference Mission (DRM) ties together space craft, instrument and operations scenarios. The project implemented lessons learned from other small body missions: APLNEAR, JPLDAWN and ESARosetta. The key lesson learned was expected the unexpected and implement planning tools early in the lifecycle. In preparation to PDR, the project changed the asteroid arrival date, to arrive one year earlier and provided additional time margin. STK is used for Mission Design and STKScheduler for instrument coverage analysis.

Differentiating Visual from Response Sequencing during Long-term Skill Learning.

PubMed

Lynch, Brighid; Beukema, Patrick; Verstynen, Timothy

2017-01-01

The dual-system model of sequence learning posits that during early learning there is an advantage for encoding sequences in sensory frames; however, it remains unclear whether this advantage extends to long-term consolidation. Using the serial RT task, we set out to distinguish the dynamics of learning sequential orders of visual cues from learning sequential responses. On each day, most participants learned a new mapping between a set of symbolic cues and responses made with one of four fingers, after which they were exposed to trial blocks of either randomly ordered cues or deterministic ordered cues (12-item sequence). Participants were randomly assigned to one of four groups (n = 15 per group): Visual sequences (same sequence of visual cues across training days), Response sequences (same order of key presses across training days), Combined (same serial order of cues and responses on all training days), and a Control group (a novel sequence each training day). Across 5 days of training, sequence-specific measures of response speed and accuracy improved faster in the Visual group than any of the other three groups, despite no group differences in explicit awareness of the sequence. The two groups that were exposed to the same visual sequence across days showed a marginal improvement in response binding that was not found in the other groups. These results indicate that there is an advantage, in terms of rate of consolidation across multiple days of training, for learning sequences of actions in a sensory representational space, rather than as motoric representations.

The Mini-Mast CSI testbed: Lessons learned

NASA Technical Reports Server (NTRS)

Tanner, Sharon E.; Belvin, W. Keith; Horta, Lucas G.; Pappa, R. S.

1993-01-01

The Mini-Mast testbed was one of the first large scale Controls-Structure-Interaction (CSI) systems used to evaluate state-of-the-art methodology in flexible structure control. Now that all the testing at Langley Research Center has been completed, a look back is warranted to evaluate the program. This paper describes some of the experiences and technology development studies by NASA, university, and industry investigators. Lessons learned are presented from three categories: the testbed development, control methods, and the operation of a guest investigator program. It is shown how structural safety margins provided a realistic environment to simulate on-orbit CSI research, even though they also reduced the research flexibility afforded to investigators. The limited dynamic coupling between the bending and torsion modes of the cantilevered test article resulted in highly successful SISO and MIMO controllers. However, until accurate models were obtained for the torque wheel actuators, sensors, filters, and the structure itself, most controllers were unstable. Controls research from this testbed should be applicable to cantilevered appendages of future large space structures.

Multi-Task Learning with Low Rank Attribute Embedding for Multi-Camera Person Re-Identification.

PubMed

Su, Chi; Yang, Fan; Zhang, Shiliang; Tian, Qi; Davis, Larry Steven; Gao, Wen

2018-05-01

We propose Multi-Task Learning with Low Rank Attribute Embedding (MTL-LORAE) to address the problem of person re-identification on multi-cameras. Re-identifications on different cameras are considered as related tasks, which allows the shared information among different tasks to be explored to improve the re-identification accuracy. The MTL-LORAE framework integrates low-level features with mid-level attributes as the descriptions for persons. To improve the accuracy of such description, we introduce the low-rank attribute embedding, which maps original binary attributes into a continuous space utilizing the correlative relationship between each pair of attributes. In this way, inaccurate attributes are rectified and missing attributes are recovered. The resulting objective function is constructed with an attribute embedding error and a quadratic loss concerning class labels. It is solved by an alternating optimization strategy. The proposed MTL-LORAE is tested on four datasets and is validated to outperform the existing methods with significant margins.

Saving Face While Geeking Out: Video Game Testing as a Justification for Learning Computer Science

ERIC Educational Resources Information Center

DiSalvo, Betsy; Guzdial, Mark; Bruckman, Amy; McKlin, Tom

2014-01-01

Why would individuals who are capable of learning opt not to? Learning is important for stability and success. It would seem rational that students in groups that are frequently underrepresented or marginalized would be motivated to learn. However, negotiation of multiple identities and self-beliefs can impact motivations to learn. For example,…

Marginal deformations of heterotic G 2 sigma models

NASA Astrophysics Data System (ADS)

Fiset, Marc-Antoine; Quigley, Callum; Svanes, Eirik Eik

2018-02-01

Recently, the infinitesimal moduli space of heterotic G 2 compactifications was described in supergravity and related to the cohomology of a target space differential. In this paper we identify the marginal deformations of the corresponding heterotic nonlinear sigma model with cohomology classes of a worldsheet BRST operator. This BRST operator is nilpotent if and only if the target space geometry satisfies the heterotic supersymmetry conditions. We relate this to the supergravity approach by showing that the corresponding cohomologies are indeed isomorphic. We work at tree-level in α' perturbation theory and study general geometries, in particular with non-vanishing torsion.

Marginally outer trapped surfaces and symmetries

NASA Astrophysics Data System (ADS)

Carrasco, Alberto; Mars, Marc

2009-05-01

We study properties of outermost marginally outer trapped surfaces in slices of space-times possessing certain symmetries, like isometries, homotheties or conformal Killings. In particular, we find restrictions on these surfaces for the vector field generating the symmetry. As an application we give a result of non-existence of outermost marginally outer trapped surfaces in accelerated Friedmann-Lemaître-Roberson-Walker spacetimes.

Engineering analysis division internal note. OFT-1 margin assessment. [results of analysis to determine space shuttle subsystem margins for orbital flight test

NASA Technical Reports Server (NTRS)

Austin, L. D., Jr.

1977-01-01

The results are documented of an analysis conducted to determine space shuttle vehicle (SSV) subsystem margins for the reference flight profile for the first orbital flight test (OFT-1). In general, the results show increased margins for the OFT-1 indicators when compared to Mission 3A resutls. The inclusion of element and wing aerodynamic variations on OFT-1, in combination with winds and systems dispersions, resulted in the forward Z (FTO1) attach load indicator exceeding specified limits. The inboard and outboard elevon hinge moment margins (9 percent and 3 percent, respectively) on OFT-1 reflect values consistent with the load relief requirements dictated by elevon hinge moment variations. All other structural load indicators for OFT-1 had margins in excess of 10 percent. The SSV first stage stagnation heating indicators for OFT-1 were about 45 percent less than for Mission 3A. The hydraulic systems demands for both missions were essentially the same. The results also show OFT-1 performance requirements from the consideration of winds and dispersions to be approximately 3,300 lbs greater than Mission 3A.

Seismic margin assessment of the Edwin I. Hatch Nuclear Plant, Unit 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barr, W.T.; Moore, D.P.; Smith, J.E.

1991-06-01

This summary presents the results and lessons learned from the seismic margin assessment (SMA) of Unit 1 of the Hatch Nuclear Plant. The primary purpose of this SMA was to assess the practicality of the EPRI SMA methodology on a BWR on a soil site such as Hatch. The major findings from the Hatch SMA are briefly described along with the lessons learned during the project implementation. The experience gained on the Hatch SMA is expected to benefit others in the performance of future SMAs. 12 refs.

Reconstructing marginality: a new model of cultural diversity in nursing.

PubMed

Southwick, Margaret; Polaschek, Nick

2014-05-01

This article presents a new model of cultural diversity in nursing that critically reconstructs the concept of marginality that underpins other models. Rather than viewing the marginal as "other," marginality is redefined as the space in between the dominant cultural reality and the cultural realities of minority groups located within a society. Members of a minority cultural group who become skilled in the difficult process of negotiating this in-between space open the possibility of transformation within nursing education and practice. This model has been applied in a study of the experience of nursing students of Pacific ethnicity in New Zealand. Subsequently, an undergraduate Pacific nursing program was developed, with greatly increased success rates in registration of Pacific nurses. This model of cultural diversity can also be used to understand nursing practice involving people from minority cultures or other socially excluded categories. Copyright 2014, SLACK Incorporated.

Evaluation of marginal and internal adaptation of hybrid and nanoceramic systems with microcomputed tomography: An in vitro study.

PubMed

Yildirim, Güler; Uzun, Ismail H; Keles, Ali

2017-08-01

The accuracy of recently introduced chairside computer-aided design and computer-aided manufacturing (CAD-CAM) blocks is not well established, and marginal integrity and internal adaptation are not known. The purpose of this in vitro study was to evaluate the marginal and internal adaptation of hybrid and nanoceramics using microcomputed tomography (μ-CT). The marginal and internal adaptation of 3 polymer-infiltrated ceramic-network (PICN) materials (Vita Enamic [VE]; Lava Ultimate [LU]; Vita Suprinity [VS]) were compared with lithium disilicate (IPS e.max.CAD, IPS). Ninety-six specimens (48 dies and 48 crowns) were prepared (n=12 each group) using a chairside CAD-CAM system. The restorations were scanned with μ-CT, with 160 measurements made for each crown, and used in 2-dimensional (2D) analysis. The marginal adaptation of marginal discrepancy (MD), absolute marginal discrepancy (AMD), internal adaptation of shoulder area (SA), axial space (AS), and occlusal space (OS) were compared using appropriate statistical analysis methods (α=.05). Cement volumes were compared using 3D analysis. The IPS blocks showed higher MD (130 μm), AMD (156 μm), SA (111 μm) (P<.05), AS (52 μm), and OS (192 μm) than the other blocks (P<.01). The adaptation values of VS were significantly lower than those of the IPS block (P<.05). The adaption values of the LU and VE blocks were significantly lower than those of others (P<.01) but were statistically similar to one another (P>.05). IPS had the largest cement space at 18 mm 3 (P<.01). The marginal and internal adaptation values were within a clinically acceptable range for all 3 hybrids and nanoceramics tested. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Dis/Locating the Margins: Gloria Anzaldua and Dynamic Feminist Learning

ERIC Educational Resources Information Center

Mahraj, Katy

2010-01-01

It is confusing to be a feminist student. Deconstruction is "de rigueur"; reconstruction less so. Awareness rises while answers recede. Feminist students seek out learning experiences that disrupt, empower, and make them feminist students not only by what they learn, but also by how they learn, by the pedagogy in which they engage. Certainly there…

Cone structure imaged with adaptive optics scanning laser ophthalmoscopy in eyes with nonneovascular age-related macular degeneration.

PubMed

Zayit-Soudry, Shiri; Duncan, Jacque L; Syed, Reema; Menghini, Moreno; Roorda, Austin J

2013-11-15

To evaluate cone spacing using adaptive optics scanning laser ophthalmoscopy (AOSLO) in eyes with nonneovascular AMD, and to correlate progression of AOSLO-derived cone measures with standard measures of macular structure. Adaptive optics scanning laser ophthalmoscopy images were obtained over 12 to 21 months from seven patients with AMD including four eyes with geographic atrophy (GA) and four eyes with drusen. Adaptive optics scanning laser ophthalmoscopy images were overlaid with color, infrared, and autofluorescence fundus photographs and spectral domain optical coherence tomography (SD-OCT) images to allow direct correlation of cone parameters with macular structure. Cone spacing was measured for each visit in selected regions including areas over drusen (n = 29), at GA margins (n = 14), and regions without drusen or GA (n = 13) and compared with normal, age-similar values. Adaptive optics scanning laser ophthalmoscopy imaging revealed continuous cone mosaics up to the GA edge and overlying drusen, although reduced cone reflectivity often resulted in hyporeflective AOSLO signals at these locations. Baseline cone spacing measures were normal in 13/13 unaffected regions, 26/28 drusen regions, and 12/14 GA margin regions. Although standard clinical measures showed progression of GA in all study eyes, cone spacing remained within normal ranges in most drusen regions and all GA margin regions. Adaptive optics scanning laser ophthalmoscopy provides adequate resolution for quantitative measurement of cone spacing at the margin of GA and over drusen in eyes with AMD. Although cone spacing was often normal at baseline and remained normal over time, these regions showed focal areas of decreased cone reflectivity. These findings may provide insight into the pathophysiology of AMD progression. (ClinicalTrials.gov number, NCT00254605).

Identifying Proactive Collaboration Strategies for Teacher Readiness for Marginalized Students

ERIC Educational Resources Information Center

Akin, Imani; Neumann, Crystal

2013-01-01

This research discusses the value of collaborating to develop strategies that enhance teacher readiness for the marginalized student and the use of qualitative data that can lead to student academic and social success. Education domains include the learning environment, technology, and building parent and community connections. This research…

Psychosocial Factors of the Literacy Classroom. A Teacher's Guide.

ERIC Educational Resources Information Center

Matuszowicz, Peter F.

This paper examines the behavioral issues associated with homelessness and marginal lifestyles. It describes classroom techniques that may be used to develop self-directed learning readiness as a tool for mitigating the psychological problems associated with the causes and outcomes of marginal living and homelessness. Discussed first are 26 issues…

Attentional Selection Can Be Predicted by Reinforcement Learning of Task-relevant Stimulus Features Weighted by Value-independent Stickiness.

PubMed

Balcarras, Matthew; Ardid, Salva; Kaping, Daniel; Everling, Stefan; Womelsdorf, Thilo

2016-02-01

Attention includes processes that evaluate stimuli relevance, select the most relevant stimulus against less relevant stimuli, and bias choice behavior toward the selected information. It is not clear how these processes interact. Here, we captured these processes in a reinforcement learning framework applied to a feature-based attention task that required macaques to learn and update the value of stimulus features while ignoring nonrelevant sensory features, locations, and action plans. We found that value-based reinforcement learning mechanisms could account for feature-based attentional selection and choice behavior but required a value-independent stickiness selection process to explain selection errors while at asymptotic behavior. By comparing different reinforcement learning schemes, we found that trial-by-trial selections were best predicted by a model that only represents expected values for the task-relevant feature dimension, with nonrelevant stimulus features and action plans having only a marginal influence on covert selections. These findings show that attentional control subprocesses can be described by (1) the reinforcement learning of feature values within a restricted feature space that excludes irrelevant feature dimensions, (2) a stochastic selection process on feature-specific value representations, and (3) value-independent stickiness toward previous feature selections akin to perseveration in the motor domain. We speculate that these three mechanisms are implemented by distinct but interacting brain circuits and that the proposed formal account of feature-based stimulus selection will be important to understand how attentional subprocesses are implemented in primate brain networks.

Equitable Learning Outcomes: Supporting Economically and Culturally Disadvantaged Students in "Formative Learning Environments"

ERIC Educational Resources Information Center

Clark, Ian

2014-01-01

The central and distinguishing thesis of social and cultural perspectives on outcome equity is that public school classrooms are culturally biased environments. Such environments disaffect children who arrive at school from the economic or cultural margin. The "formative learning environment" (FoLE) establishes and sustains legitimate…

The anatomy and histology of the bicipital tunnel of the shoulder.

PubMed

Taylor, Samuel A; Fabricant, Peter D; Bansal, Manjula; Khair, M Michael; McLawhorn, Alexander; DiCarlo, Edward F; Shorey, Mary; O'Brien, Stephen J

2015-04-01

The bicipital tunnel is the extra-articular, fibro-osseous structure that encloses the long head of the biceps tendon. Twelve cadaveric shoulder specimens underwent in situ casting of the bicipital tunnel with methyl methacrylate cement to demonstrate structural competence (n = 6) and en bloc harvest with gross and histologic evaluation (n = 6). The percentage of empty tunnel was calculated histologically by subtracting the proportion of cross-sectional area of the long head of the biceps tendon from that of the bicipital tunnel for each zone. Cement casting demonstrated that the bicipital tunnel was a closed space. Zone 1 extended from the articular margin to the distal margin of the subscapularis tendon. Zone 2 extended from the distal margin of the subscapularis tendon to the proximal margin of the pectoralis major tendon. Zone 3 was the subpectoral region. Zones 1 and 2 were both enclosed by a dense connective tissue sheath and demonstrated the presence of synovium. Zone 3 had significantly greater percentage of empty tunnel than zones 1 and 2 did (P < .01). The bicipital tunnel is a closed space with 3 distinct zones. Zones 1 and 2 have similar features, including the presence of synovium, but differ from zone 3. A significant bottleneck occurs between zone 2 and zone 3, most likely at the proximal margin of the pectoralis major tendon. The bicipital tunnel is a closed space where space-occupying lesions may produce a bicipital tunnel syndrome. Careful consideration should be given to surgical techniques that decompress both zones 1 and 2 of the bicipital tunnel. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Parental Engagement: Beyond Parental Involvement in Science Education

NASA Astrophysics Data System (ADS)

St. Louis, Kathleen

This study critically analyzes parents' complex stories of engagement in school and science education. The purpose is not to essentialize parental involvement, but rather to understand the processes of parental involvement and push forward the current discourse on the engagement of low-income minority and immigrant parents in schools and specifically science education. Employing critical grounded theory methods over a four-year span, this study had three areas of focus. First, voices of marginalized parents in the context of various spaces within the school system are examined. Using a qualitative approach, informal, formal, and research spaces were explored along with how minority parents express voice in these various spaces. Findings indicate parents drew on capital to express voice differently in different spaces, essentially authoring new spaces or the type of engagement in existing spaces. Second, the values and beliefs of traditionally marginalized people, the Discourse of mainstream society, and how they can inform a third, more transformative space for parental engagement in science are considered. The voices of low-income, marginalized parents around science and parental engagement (i.e., first space) are contrasted with the tenets of major national science policy documents (i.e., second space). Findings indicate a disparity between the pathways of engagement for low-income parents and policymakers who shape science education. Third, methodological questions of responsibility and assumption in qualitative research are explored. The author's complex struggle to make sense of her positionality, responsibilities, and assumptions as a researcher is chronicled. Findings focused on insider/outsider issues and implications for culturally sensitive research are discussed. Finally, the implications for policy, teaching, and research are discussed.

46 CFR 171.010 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... vessel operates. (k) Passenger space means a space which is provided for the accommodation and use of... this chapter. (i) Machinery space means, unless otherwise prescribed by the Commandant for unusual arrangements, the space extending from the molded base line to the margin line and between the main transverse...

46 CFR 171.010 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... vessel operates. (k) Passenger space means a space which is provided for the accommodation and use of... this chapter. (i) Machinery space means, unless otherwise prescribed by the Commandant for unusual arrangements, the space extending from the molded base line to the margin line and between the main transverse...

46 CFR 171.010 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... vessel operates. (k) Passenger space means a space which is provided for the accommodation and use of... this chapter. (i) Machinery space means, unless otherwise prescribed by the Commandant for unusual arrangements, the space extending from the molded base line to the margin line and between the main transverse...

Late Quaternary Normal Faulting and Hanging Wall Basin Evolution of the Southwestern Rift Margin from Gravity and Geology, B.C.S., MX and Exploring the Influence of Text-Figure Format on Introductory Geology Learning

ERIC Educational Resources Information Center

Busch, Melanie M. D.

2011-01-01

An array of north-striking, left-stepping, active normal faults is situated along the southwestern margin of the Gulf of California. This normal fault system is the marginal fault system of the oblique-divergent plate boundary within the Gulf of California. To better understand the role of upper-crustal processes during development of an obliquely…

Gaining Access to Economically Marginalized Rural Populations: Lessons Learned from Nonprobability Sampling

ERIC Educational Resources Information Center

Mammen, Sheila; Sano, Yoshie

2012-01-01

Poverty is a significant problem in rural America. Gaining access to economically marginalized rural populations in order to recruit individuals to participate in a research study, however, is often a challenge. This article compares three different nonprobability sampling techniques that have been used to recruit rural, low-income…

A Sports Franchise Simulation Game

ERIC Educational Resources Information Center

Surdam, David G.

2009-01-01

Students in sports economics courses might better learn the basic concepts by running their own franchise. A simple game, based on the card game War, is easy and inexpensive to implement. Students quickly grasp the importance of weighing marginal benefits, both in terms of team record and marginal revenue, against the costs of improving their…

The ABCDs of Service-Learning: Who Is Serving Whom?

ERIC Educational Resources Information Center

Lieberman, Devorah

2014-01-01

The concept of and approach to service-learning across higher education has changed dramatically over the last two and a half decades. Historically, one of the primary goals of service-learning was to prepare undergraduate students to become engaged citizens and to introduce them to the challenges experienced by individuals from marginalized or…

Organizational Learning in Schools Pursuing Social Justice: Fostering Educational Entrepreneurship and Boundary Spanning

ERIC Educational Resources Information Center

Scanlan, Martin

2011-01-01

The field of socially just educational leadership is focused on promoting improvements in the teaching and learning environment as demonstrated by student learning gains, particularly for traditionally marginalized students. The field has identified priorities (i.e., school improvement, democratic community, and social justice) and steps to pursue…

The Discourse of Language Learning Strategies: Towards an Inclusive Approach

ERIC Educational Resources Information Center

Jones, Alexander Harris

2016-01-01

This paper critiques discourse surrounding language learning strategies within Teaching English to Speakers of Other Languages (TESOL) and argues for the creation of new definitions of language learning strategies that are rooted in the socio-political and socio-economic contexts of the marginalized. Section one of this paper describes linguistic…

Correlation between radiographic findings of osteoarthritis and arthroscopic findings of articular cartilage degeneration within the patellofemoral joint.

PubMed

Kijowski, Richard; Blankenbaker, Donna; Stanton, Paul; Fine, Jason; De Smet, Arthur

2006-12-01

To correlate radiographic findings of osteoarthritis on axial knee radiographs with arthroscopic findings of articular cartilage degeneration within the patellofemoral joint in patients with chronic knee pain. The study group consisted of 104 patients with osteoarthritis of the patellofemoral joint and 30 patients of similar age with no osteoarthritis of the patellofemoral joint. All patients in the study group had an axial radiograph of the knee performed prior to arthroscopic knee surgery. At the time of arthroscopy, each articular surface of the patellofemoral joint was graded using the Noyes classification system. Two radiologists retrospectively reviewed the knee radiographs to determine the presence of marginal osteophytes, joint-space narrowing, subchondral sclerosis, and subchondral cysts. The sensitivity and specificity of the various radiographic features of osteoarthritis for the detection of articular cartilage degeneration within the patellofemoral joint were determined. The sensitivity of marginal osteophytes, joint-space narrowing, subchondral sclerosis, and subchondral cysts for the detection of articular cartilage degeneration within the patellofemoral joint was 73%, 37%, 4%, and 0% respectively. The specificity of marginal osteophytes, joint-space narrowing, subchondral sclerosis, and subchondral cysts for the detection of articular cartilage degeneration within the patellofemoral joint was 67%, 90%, 100%, and 100% respectively. Marginal osteophytes were the most sensitive radiographic feature for the detection of articular cartilage degeneration within the patellofemoral joint. Joint-space narrowing, subchondral sclerosis, and subchondral cysts were insensitive radiographic features of osteoarthritis, and rarely occurred in the absence of associated osteophyte formation.

Supervised learning with decision margins in pools of spiking neurons.

PubMed

Le Mouel, Charlotte; Harris, Kenneth D; Yger, Pierre

2014-10-01

Learning to categorise sensory inputs by generalising from a few examples whose category is precisely known is a crucial step for the brain to produce appropriate behavioural responses. At the neuronal level, this may be performed by adaptation of synaptic weights under the influence of a training signal, in order to group spiking patterns impinging on the neuron. Here we describe a framework that allows spiking neurons to perform such "supervised learning", using principles similar to the Support Vector Machine, a well-established and robust classifier. Using a hinge-loss error function, we show that requesting a margin similar to that of the SVM improves performance on linearly non-separable problems. Moreover, we show that using pools of neurons to discriminate categories can also increase the performance by sharing the load among neurons.

Heidelberg retina tomograph measurements of the optic disc and parapapillary retina for detecting glaucoma analyzed by machine learning classifiers.

PubMed

Zangwill, Linda M; Chan, Kwokleung; Bowd, Christopher; Hao, Jicuang; Lee, Te-Won; Weinreb, Robert N; Sejnowski, Terrence J; Goldbaum, Michael H

2004-09-01

To determine whether topographical measurements of the parapapillary region analyzed by machine learning classifiers can detect early to moderate glaucoma better than similarly processed measurements obtained within the disc margin and to improve methods for optimization of machine learning classifier feature selection. One eye of each of 95 patients with early to moderate glaucomatous visual field damage and of each of 135 normal subjects older than 40 years participating in the longitudinal Diagnostic Innovations in Glaucoma Study (DIGS) were included. Heidelberg Retina Tomograph (HRT; Heidelberg Engineering, Dossenheim, Germany) mean height contour was measured in 36 equal sectors, both along the disc margin and in the parapapillary region (at a mean contour line radius of 1.7 mm). Each sector was evaluated individually and in combination with other sectors. Gaussian support vector machine (SVM) learning classifiers were used to interpret HRT sector measurements along the disc margin and in the parapapillary region, to differentiate between eyes with normal and glaucomatous visual fields and to compare the results with global and regional HRT parameter measurements. The area under the receiver operating characteristic (ROC) curve was used to measure diagnostic performance of the HRT parameters and to evaluate the cross-validation strategies and forward selection and backward elimination optimization techniques that were used to generate the reduced feature sets. The area under the ROC curve for mean height contour of the 36 sectors along the disc margin was larger than that for the mean height contour in the parapapillary region (0.97 and 0.85, respectively). Of the 36 individual sectors along the disc margin, those in the inferior region between 240 degrees and 300 degrees, had the largest area under the ROC curve (0.85-0.91). With SVM Gaussian techniques, the regional parameters showed the best ability to discriminate between normal eyes and eyes with glaucomatous visual field damage, followed by the global parameters, mean height contour measures along the disc margin, and mean height contour measures in the parapapillary region. The area under the ROC curve was 0.98, 0.94, 0.93, and 0.85, respectively. Cross-validation and optimization techniques demonstrated that good discrimination (99% of peak area under the ROC curve) can be obtained with a reduced number of HRT parameters. Mean height contour measurements along the disc margin discriminated between normal and glaucomatous eyes better than measurements obtained in the parapapillary region. Copyright Association for Research in Vision and Ophthalmology

Heidelberg Retina Tomograph Measurements of the Optic Disc and Parapapillary Retina for Detecting Glaucoma Analyzed by Machine Learning Classifiers

PubMed Central

Zangwill, Linda M.; Chan, Kwokleung; Bowd, Christopher; Hao, Jicuang; Lee, Te-Won; Weinreb, Robert N.; Sejnowski, Terrence J.; Goldbaum, Michael H.

2010-01-01

Purpose To determine whether topographical measurements of the parapapillary region analyzed by machine learning classifiers can detect early to moderate glaucoma better than similarly processed measurements obtained within the disc margin and to improve methods for optimization of machine learning classifier feature selection. Methods One eye of each of 95 patients with early to moderate glaucomatous visual field damage and of each of 135 normal subjects older than 40 years participating in the longitudinal Diagnostic Innovations in Glaucoma Study (DIGS) were included. Heidelberg Retina Tomograph (HRT; Heidelberg Engineering, Dossenheim, Germany) mean height contour was measured in 36 equal sectors, both along the disc margin and in the parapapillary region (at a mean contour line radius of 1.7 mm). Each sector was evaluated individually and in combination with other sectors. Gaussian support vector machine (SVM) learning classifiers were used to interpret HRT sector measurements along the disc margin and in the parapapillary region, to differentiate between eyes with normal and glaucomatous visual fields and to compare the results with global and regional HRT parameter measurements. The area under the receiver operating characteristic (ROC) curve was used to measure diagnostic performance of the HRT parameters and to evaluate the cross-validation strategies and forward selection and backward elimination optimization techniques that were used to generate the reduced feature sets. Results The area under the ROC curve for mean height contour of the 36 sectors along the disc margin was larger than that for the mean height contour in the parapapillary region (0.97 and 0.85, respectively). Of the 36 individual sectors along the disc margin, those in the inferior region between 240° and 300°, had the largest area under the ROC curve (0.85–0.91). With SVM Gaussian techniques, the regional parameters showed the best ability to discriminate between normal eyes and eyes with glaucomatous visual field damage, followed by the global parameters, mean height contour measures along the disc margin, and mean height contour measures in the parapapillary region. The area under the ROC curve was 0.98, 0.94, 0.93, and 0.85, respectively. Cross-validation and optimization techniques demonstrated that good discrimination (99% of peak area under the ROC curve) can be obtained with a reduced number of HRT parameters. Conclusions Mean height contour measurements along the disc margin discriminated between normal and glaucomatous eyes better than measurements obtained in the parapapillary region. PMID:15326133

Spaced Learning Enhances Subsequent Recognition Memory by Reducing Neural Repetition Suppression

PubMed Central

Xue, Gui; Mei, Leilei; Chen, Chuansheng; Lu, Zhong-Lin; Poldrack, Russell; Dong, Qi

2012-01-01

Spaced learning usually leads to better recognition memory as compared with massed learning, yet the underlying neural mechanisms remain elusive. One open question is whether the spacing effect is achieved by reducing neural repetition suppression. In this fMRI study, participants were scanned while intentionally memorizing 120 novel faces, half under the massed learning condition (i.e., four consecutive repetitions with jittered interstimulus interval) and the other half under the spaced learning condition (i.e., the four repetitions were interleaved). Recognition memory tests afterward revealed a significant spacing effect: Participants recognized more items learned under the spaced learning condition than under the massed learning condition. Successful face memory encoding was associated with stronger activation in the bilateral fusiform gyrus, which showed a significant repetition suppression effect modulated by subsequent memory status and spaced learning. Specifically, remembered faces showed smaller repetition suppression than forgotten faces under both learning conditions, and spaced learning significantly reduced repetition suppression. These results suggest that spaced learning enhances recognition memory by reducing neural repetition suppression. PMID:20617892

Spaced learning enhances subsequent recognition memory by reducing neural repetition suppression.

PubMed

Xue, Gui; Mei, Leilei; Chen, Chuansheng; Lu, Zhong-Lin; Poldrack, Russell; Dong, Qi

2011-07-01

Spaced learning usually leads to better recognition memory as compared with massed learning, yet the underlying neural mechanisms remain elusive. One open question is whether the spacing effect is achieved by reducing neural repetition suppression. In this fMRI study, participants were scanned while intentionally memorizing 120 novel faces, half under the massed learning condition (i.e., four consecutive repetitions with jittered interstimulus interval) and the other half under the spaced learning condition (i.e., the four repetitions were interleaved). Recognition memory tests afterward revealed a significant spacing effect: Participants recognized more items learned under the spaced learning condition than under the massed learning condition. Successful face memory encoding was associated with stronger activation in the bilateral fusiform gyrus, which showed a significant repetition suppression effect modulated by subsequent memory status and spaced learning. Specifically, remembered faces showed smaller repetition suppression than forgotten faces under both learning conditions, and spaced learning significantly reduced repetition suppression. These results suggest that spaced learning enhances recognition memory by reducing neural repetition suppression.

Dopamine Reward Prediction Error Responses Reflect Marginal Utility

PubMed Central

Stauffer, William R.; Lak, Armin; Schultz, Wolfram

2014-01-01

Summary Background Optimal choices require an accurate neuronal representation of economic value. In economics, utility functions are mathematical representations of subjective value that can be constructed from choices under risk. Utility usually exhibits a nonlinear relationship to physical reward value that corresponds to risk attitudes and reflects the increasing or decreasing marginal utility obtained with each additional unit of reward. Accordingly, neuronal reward responses coding utility should robustly reflect this nonlinearity. Results In two monkeys, we measured utility as a function of physical reward value from meaningful choices under risk (that adhered to first- and second-order stochastic dominance). The resulting nonlinear utility functions predicted the certainty equivalents for new gambles, indicating that the functions’ shapes were meaningful. The monkeys were risk seeking (convex utility function) for low reward and risk avoiding (concave utility function) with higher amounts. Critically, the dopamine prediction error responses at the time of reward itself reflected the nonlinear utility functions measured at the time of choices. In particular, the reward response magnitude depended on the first derivative of the utility function and thus reflected the marginal utility. Furthermore, dopamine responses recorded outside of the task reflected the marginal utility of unpredicted reward. Accordingly, these responses were sufficient to train reinforcement learning models to predict the behaviorally defined expected utility of gambles. Conclusions These data suggest a neuronal manifestation of marginal utility in dopamine neurons and indicate a common neuronal basis for fundamental explanatory constructs in animal learning theory (prediction error) and economic decision theory (marginal utility). PMID:25283778

Resource Management and Contingencies in Aerospace Concurrent Engineering

NASA Technical Reports Server (NTRS)

Karpati, Gabe; Hyde, Tupper; Peabody, Hume; Garrison, Matthew

2012-01-01

significant concern in designing complex systems implementing new technologies is that while knowledge about the system is acquired incrementally, substantial financial commitments, even make-or-break decisions, must be made upfront, essentially in the unknown. One practice that helps in dealing with this dichotomy is the smart embedding of contingencies and margins in the design to serve as buffers against surprises. This issue presents itself in full force in the aerospace industry, where unprecedented systems are formulated and committed to as a matter of routine. As more and more aerospace mission concepts are generated by concurrent design laboratories, it is imperative that such laboratories apply well thought-out contingency and margin structures to their designs. The first part of this publication provides an overview of resource management techniques and standards used in the aerospace industry. That is followed by a thought provoking treatise on margin policies. The expose presents the actual flight telemetry data recorded by the thermal discipline during several recent NASA Goddard Space Flight Center missions. The margins actually achieved in flight are compared against pre-flight predictions, and the appropriateness and the ramifications of having designed with rigid margins to bounding stacked worst case conditions are assessed. The second half of the paper examines the particular issues associated with the application of contingencies and margins in the concurrent engineering environment. In closure, a discipline-by-discipline disclosure of the contingency and margin policies in use at the Integrated Design Center at NASA s Goddard Space Flight Center is made.

Thinking on the Margin: A Classroom Experiment

ERIC Educational Resources Information Center

Bangs, Joann

2009-01-01

One of the most important concepts being taught in principles classes is the idea of "thinking on the margin." It can also be one of the most difficult to get across. One of the most telling examples, according to this author, comes in trying to get students to learn the profit maximizing condition for perfectly competitive firms. She…

Re-Engaging Marginalized Youth through Digital Music Production: Performance, Audience and Evaluation

ERIC Educational Resources Information Center

Brader, Andy; Luke, Allan

2013-01-01

This article presents two case studies of marginalized youth experimenting with digital music production in flexible education settings. The cases were drawn from a 3-year study of alternative assessment in flexible learning centres for youth who have left formal schooling in Queensland, Australia. The educational issues are framed by reference to…

Fulfilling Their Dreams: Marginalized Urban Youths' Perspectives on a Culturally Sensitive Social and Emotional Learning Program

ERIC Educational Resources Information Center

Slaten, Christopher D.; Rivera, Roberto C.; Shemwell, Daniel; Elison, Zachary M.

2016-01-01

A growing body of research suggests educators need to focus on cultivating social and emotional competencies that youth will need to thrive in the new knowledge economy (Durlak, Weissberg, Dymnicki, Taylor, & Schellinger, 2011). For marginalized urban youth, in particular, few have derived programs and interventions to assist with these…

Item Difficulty in the Evaluation of Computer-Based Instruction: An Example from Neuroanatomy

ERIC Educational Resources Information Center

Chariker, Julia H.; Naaz, Farah; Pani, John R.

2012-01-01

This article reports large item effects in a study of computer-based learning of neuroanatomy. Outcome measures of the efficiency of learning, transfer of learning, and generalization of knowledge diverged by a wide margin across test items, with certain sets of items emerging as particularly difficult to master. In addition, the outcomes of…

Cultivating a Professional Ethic in Covering Marginalized Populations: Learning about the Poor through Service-Learning

ERIC Educational Resources Information Center

Motley, Phillip; Sturgill, Amanda

2014-01-01

As communications students learn to tell stories, the curriculum should teach them to cover diverse groups accurately. Scholars have studied coverage of diversity in gender, nationality, ethnicity, and race. One area that has seen less attention is economic diversity, in particular, coverage of the poor. This paper examines how service-learning…

Precise segmentation of multiple organs in CT volumes using learning-based approach and information theory.

PubMed

Lu, Chao; Zheng, Yefeng; Birkbeck, Neil; Zhang, Jingdan; Kohlberger, Timo; Tietjen, Christian; Boettger, Thomas; Duncan, James S; Zhou, S Kevin

2012-01-01

In this paper, we present a novel method by incorporating information theory into the learning-based approach for automatic and accurate pelvic organ segmentation (including the prostate, bladder and rectum). We target 3D CT volumes that are generated using different scanning protocols (e.g., contrast and non-contrast, with and without implant in the prostate, various resolution and position), and the volumes come from largely diverse sources (e.g., diseased in different organs). Three key ingredients are combined to solve this challenging segmentation problem. First, marginal space learning (MSL) is applied to efficiently and effectively localize the multiple organs in the largely diverse CT volumes. Second, learning techniques, steerable features, are applied for robust boundary detection. This enables handling of highly heterogeneous texture pattern. Third, a novel information theoretic scheme is incorporated into the boundary inference process. The incorporation of the Jensen-Shannon divergence further drives the mesh to the best fit of the image, thus improves the segmentation performance. The proposed approach is tested on a challenging dataset containing 188 volumes from diverse sources. Our approach not only produces excellent segmentation accuracy, but also runs about eighty times faster than previous state-of-the-art solutions. The proposed method can be applied to CT images to provide visual guidance to physicians during the computer-aided diagnosis, treatment planning and image-guided radiotherapy to treat cancers in pelvic region.

Models of Learning Space: Integrating Research on Space, Place and Learning in Higher Education

ERIC Educational Resources Information Center

Ellis, R. A.; Goodyear, P.

2016-01-01

Learning space research is a relatively new field of study that seeks to inform the design, evaluation and management of learning spaces. This paper reviews a dispersed and fragmented literature relevant to understanding connections between university learning spaces and student learning activities. From this review, the paper distils a number of…

Use of nonlinear design optimization techniques in the comparison of battery discharger topologies for the space platform

NASA Technical Reports Server (NTRS)

Sable, Dan M.; Cho, Bo H.; Lee, Fred C.

1990-01-01

A detailed comparison of a boost converter, a voltage-fed, autotransformer converter, and a multimodule boost converter, designed specifically for the space platform battery discharger, is performed. Computer-based nonlinear optimization techniques are used to facilitate an objective comparison. The multimodule boost converter is shown to be the optimum topology at all efficiencies. The margin is greatest at 97 percent efficiency. The multimodule, multiphase boost converter combines the advantages of high efficiency, light weight, and ample margin on the component stresses, thus ensuring high reliability.

Learning multivariate distributions by competitive assembly of marginals.

PubMed

Sánchez-Vega, Francisco; Younes, Laurent; Geman, Donald

2013-02-01

We present a new framework for learning high-dimensional multivariate probability distributions from estimated marginals. The approach is motivated by compositional models and Bayesian networks, and designed to adapt to small sample sizes. We start with a large, overlapping set of elementary statistical building blocks, or "primitives," which are low-dimensional marginal distributions learned from data. Each variable may appear in many primitives. Subsets of primitives are combined in a Lego-like fashion to construct a probabilistic graphical model; only a small fraction of the primitives will participate in any valid construction. Since primitives can be precomputed, parameter estimation and structure search are separated. Model complexity is controlled by strong biases; we adapt the primitives to the amount of training data and impose rules which restrict the merging of them into allowable compositions. The likelihood of the data decomposes into a sum of local gains, one for each primitive in the final structure. We focus on a specific subclass of networks which are binary forests. Structure optimization corresponds to an integer linear program and the maximizing composition can be computed for reasonably large numbers of variables. Performance is evaluated using both synthetic data and real datasets from natural language processing and computational biology.

The Margins as "Third Space": EAP Teacher Professionalism in Canadian Universities

ERIC Educational Resources Information Center

MacDonald, Jennifer

2016-01-01

Teachers of English for Academic Purposes (EAP) in the Canadian university setting often experience professional marginalization in terms of lack of status, clarity of mandate, or administrative home within their institutions. Despite having broadly benefited the ESL/EAL sector in Canada, traditional trait-focused professionalization efforts have…

Examining the benefits of combining two learning strategies on recall of functional information in persons with multiple sclerosis.

PubMed

Goverover, Yael; Basso, Michael; Wood, Hali; Chiaravalloti, Nancy; DeLuca, John

2011-12-01

Forgetfulness occurs commonly in people with multiple sclerosis (MS), but few treatments alleviate this problem. This study examined the combined effect of two cognitive rehabilitation strategies to improve learning and memory in MS: self-generation and spaced learning. The hypothesis was that the combination of spaced learning and self-generation would yield better learning and memory recall performance than spaced learning alone. Using a within groups design, 20 participants with MS and 18 healthy controls (HC) were presented with three tasks (learning names, appointment, and object location), each in three learning conditions (Massed, Spaced Learning, and combination of spaced and generated information). Participants were required to recall the information they learned in each of these conditions immediately and 30 min following the initial presentation. The combination of spaced learning and self-generation yielded better recall than did spaced learning alone. In turn, spaced learning resulted in better recall than the massed rehearsal condition. These findings reveal that the combination of these two learning strategies may possess utility as a cognitive rehabilitation strategy.

Teaching Tolerance Magazine, 2003.

ERIC Educational Resources Information Center

Carnes, Jim, Ed.

2003-01-01

This magazine provides teachers with classroom learning materials to help children learn to be tolerant with others. Articles in the magazine are: "A Standard to Sustain" (Mary M. Harrison); "Let's Just Play" (Janet Schmidt); "Who's Helen Keller?" (Ruth Shagoury Hubbard); "Margins of Error" (Joe Parsons);…

An Integrative Cultural Model to better situate marginalized science students in postsecondary science education

NASA Astrophysics Data System (ADS)

Labouta, Hagar Ibrahim; Adams, Jennifer Dawn; Cramb, David Thomas

2018-03-01

In this paper we reflect on the article "I am smart enough to study postsecondary science: a critical discourse analysis of latecomers' identity construction in an online forum", by Phoebe Jackson and Gale Seiler (Cult Stud Sci Educ. https://doi.org/10.1007/s11422-017-9818-0). In their article, the authors did a significant amount of qualitative analysis of a discussion on an online forum by four latecomer students with past negative experiences in science education. The students used this online forum as an out-of-class resource to develop a cultural model based on their ability to ask questions together with solidarity as a new optimistic way to position themselves in science. In this forum, we continue by discussing the identity of marginalized science students in relation to resources available in postsecondary science classes. Recent findings on a successful case of a persistent marginalized science student in spite of prior struggles and failures are introduced. Building on their model and our results, we proposed a new cultural model, emphasizing interaction between inside and outside classroom resources which can further our understanding of the identity of marginalized science students. Exploring this cultural model could better explain drop-outs or engagement of marginalized science students to their study. We, then, used this model to reflect on both current traditional and effective teaching and learning practices truncating or re-enforcing relationships of marginalized students with the learning environment. In this way, we aim to further the discussion initiated by Jackson and Seiler and offer possible frameworks for future research on the interactions between marginalized students with past low achievements and other high and mid achieving students, as well as other interactions between resources inside and outside science postsecondary classrooms.

Optimizing area under the ROC curve using semi-supervised learning

PubMed Central

Wang, Shijun; Li, Diana; Petrick, Nicholas; Sahiner, Berkman; Linguraru, Marius George; Summers, Ronald M.

2014-01-01

Receiver operating characteristic (ROC) analysis is a standard methodology to evaluate the performance of a binary classification system. The area under the ROC curve (AUC) is a performance metric that summarizes how well a classifier separates two classes. Traditional AUC optimization techniques are supervised learning methods that utilize only labeled data (i.e., the true class is known for all data) to train the classifiers. In this work, inspired by semi-supervised and transductive learning, we propose two new AUC optimization algorithms hereby referred to as semi-supervised learning receiver operating characteristic (SSLROC) algorithms, which utilize unlabeled test samples in classifier training to maximize AUC. Unlabeled samples are incorporated into the AUC optimization process, and their ranking relationships to labeled positive and negative training samples are considered as optimization constraints. The introduced test samples will cause the learned decision boundary in a multidimensional feature space to adapt not only to the distribution of labeled training data, but also to the distribution of unlabeled test data. We formulate the semi-supervised AUC optimization problem as a semi-definite programming problem based on the margin maximization theory. The proposed methods SSLROC1 (1-norm) and SSLROC2 (2-norm) were evaluated using 34 (determined by power analysis) randomly selected datasets from the University of California, Irvine machine learning repository. Wilcoxon signed rank tests showed that the proposed methods achieved significant improvement compared with state-of-the-art methods. The proposed methods were also applied to a CT colonography dataset for colonic polyp classification and showed promising results.1 PMID:25395692

Optimizing area under the ROC curve using semi-supervised learning.

PubMed

Wang, Shijun; Li, Diana; Petrick, Nicholas; Sahiner, Berkman; Linguraru, Marius George; Summers, Ronald M

2015-01-01

Receiver operating characteristic (ROC) analysis is a standard methodology to evaluate the performance of a binary classification system. The area under the ROC curve (AUC) is a performance metric that summarizes how well a classifier separates two classes. Traditional AUC optimization techniques are supervised learning methods that utilize only labeled data (i.e., the true class is known for all data) to train the classifiers. In this work, inspired by semi-supervised and transductive learning, we propose two new AUC optimization algorithms hereby referred to as semi-supervised learning receiver operating characteristic (SSLROC) algorithms, which utilize unlabeled test samples in classifier training to maximize AUC. Unlabeled samples are incorporated into the AUC optimization process, and their ranking relationships to labeled positive and negative training samples are considered as optimization constraints. The introduced test samples will cause the learned decision boundary in a multidimensional feature space to adapt not only to the distribution of labeled training data, but also to the distribution of unlabeled test data. We formulate the semi-supervised AUC optimization problem as a semi-definite programming problem based on the margin maximization theory. The proposed methods SSLROC1 (1-norm) and SSLROC2 (2-norm) were evaluated using 34 (determined by power analysis) randomly selected datasets from the University of California, Irvine machine learning repository. Wilcoxon signed rank tests showed that the proposed methods achieved significant improvement compared with state-of-the-art methods. The proposed methods were also applied to a CT colonography dataset for colonic polyp classification and showed promising results.

Replacing the CCSDS Telecommand Protocol with Next Generation Uplink

NASA Technical Reports Server (NTRS)

Kazz, Greg; Burleigh, Scott; Greenberg, Ed

2012-01-01

Better performing Forward Error Correction on the forward link along with adequate power in the data open an uplink operations trade space that enable missions to: Command to greater distances in deep space (increased uplink margin) Increase the size of the payload data (latency may be a factor) Provides space for the security header/trailer of the CCSDS Space Data Link Security Protocol Note: These higher rates could be used for relief of emergency communication margins/rates and not limited to improving top-end rate performance. A higher performance uplink could also reduce the requirements on flight emergency antenna size and/or the performance required from ground stations. Use of a selective repeat ARQ protocol may increase the uplink design requirements but the resultant development is deemed acceptable, due the factor of 4 to 8 potential increase in uplink data rate.

NAND Flash Qualification Guideline

NASA Technical Reports Server (NTRS)

Heidecker, Jason

2012-01-01

Better performing Forward Error Correction on the forward link along with adequate power in the data open an uplink operations trade space that enable missions to: Command to greater distances in deep space (increased uplink margin). Increase the size of the payload data (latency may be a factor). Provides space for the security header/trailer of the CCSDS Space Data Link Security Protocol. Note: These higher rates could be used for relief of emergency communication margins/rates and not limited to improving top-end rate performance. A higher performance uplink could also reduce the requirements on flight emergency antenna size and/or the performance required from ground stations. Use of a selective repeat ARQ protocol may increase the uplink design requirements but the resultant development is deemed acceptable, due the factor of 4 to 8 potential increase in uplink data rate.

Consider the category: The effect of spacing depends on individual learning histories.

PubMed

Slone, Lauren K; Sandhofer, Catherine M

2017-07-01

The spacing effect refers to increased retention following learning instances that are spaced out in time compared with massed together in time. By one account, the advantages of spaced learning should be independent of task particulars and previous learning experiences given that spacing effects have been demonstrated in a variety of tasks across the lifespan. However, by another account, spaced learning should be affected by previous learning because past learning affects the memory and attention processes that form the crux of the spacing effect. The current study investigated whether individuals' learning histories affect the role of spacing in category learning. We examined the effect of spacing on 24 2- to 3.5-year-old children's learning of categories organized by properties to which children's previous learning experiences have biased them to attend (i.e., shape) and properties to which children are less biased to attend (i.e., texture and color). Spaced presentations led to significantly better learning of shape categories, but not of texture or color categories, compared with massed presentations. In addition, generalized estimating equations analyses revealed positive relations between the size of children's "shape-side" productive vocabularies and their shape category learning and between the size of children's "against-the-system" productive vocabularies and their texture category learning. These results suggest that children's attention to and memory for novel object categories are strongly related to their individual word-learning histories. Moreover, children's learned attentional biases affected the types of categories for which spacing facilitated learning. These findings highlight the importance of considering how learners' previous experiences may influence future learning. Copyright © 2017 Elsevier Inc. All rights reserved.

Can the pattern of vertebral marrow oedema differentiate intervertebral disc infection from degenerative changes?

PubMed

Shrot, S; Sayah, A; Berkowitz, F

2017-07-01

To evaluate whether various patterns of bone marrow oedema could be used to discriminate between infection and degenerative change. Seventy patients with imaging features suspicious for discitis and available clinical follow-up were blindly reviewed for vertebral marrow oedema on sagittal short-tau inversion recovery (STIR) images according to the following patterns: I, vertebra oedema is adjacent to the intervertebral space and sharply-marginated; II, vertebral oedema is adjacent to the intervertebral space but not sharply marginated from normal marrow or involves the entire vertebral body; and III, vertebral oedema is distant from the endplate with intervening hypointense marrow signal. Of 45 patients with a clinical diagnosis of discitis, pattern II was the most common oedema pattern (64%). Approximately 20% and 9% of discitis patients showed patterns I and III, respectively. In patients with degenerative changes, 44% patients showed pattern I, 32% showed pattern II, and 24% showed pattern III. Pattern II had a sensitivity, specificity, and positive predictive value of 0.64, 0.68, and 0.78 for diagnosing spine infection, respectively. Although bone marrow oedema in infective discitis most often extends from the disc space and has indistinct margins, the oedema may also have sharp margins or be remote from the involved intervertebral space. Bone marrow oedema patterns of infective discitis overlap with those of degenerative disease and are not sufficiently reliable to exclude infection in cases with magnetic resonance imaging findings suggestive of discitis. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Optimizing Estimated Loss Reduction for Active Sampling in Rank Learning

DTIC Science & Technology

2008-01-01

active learning framework for SVM-based and boosting-based rank learning. Our approach suggests sampling based on maximizing the estimated loss differential over unlabeled data. Experimental results on two benchmark corpora show that the proposed model substantially reduces the labeling effort, and achieves superior performance rapidly with as much as 30% relative improvement over the margin-based sampling

Racialized Spaces in Teacher Discourse: A Critical Discourse Analysis of Place-Based Identities in Roche Bois, Mauritius

ERIC Educational Resources Information Center

Wiehe, Elsa M.

2013-01-01

This eleven-month ethnographic study puts critical discourse analysis in dialogue with postmodern conceptualizations of space and place to explore how eight educators talk about space and in the process, produce racialized spaces in Roche Bois, Mauritius. The macro-historical context of racialization of this urban marginalized community informs…

Continental margin sedimentation: From sediment transport to sequence stratigraphy

USGS Publications Warehouse

Nittrouer, Charles A.; Austin, James A.; Field, Michael E.; Kravitz, Joseph H.; Syvitski, James P. M.; Wiberg, Patricia L.

2007-01-01

This volume on continental margin sedimentation brings together an expert editorial and contributor team to create a state-of-the-art resource. Taking a global perspective, the book spans a range of timescales and content, ranging from how oceans transport particles, to how thick rock sequences are formed on continental margins.- Summarizes and integrates our understanding of sedimentary processes and strata associated with fluvial dispersal systems on continental shelves and slopes- Explores timescales ranging from particle transport at one extreme, to deep burial at the other- Insights are presented for margins in general, and with focus on a tectonically active margin (northern California) and a passive margin (New Jersey), enabling detailed examination of the intricate relationships between a wide suite of sedimentary processes and their preserved stratigraphy- Includes observational studies which document the processes and strata found on particular margins, in addition to numerical models and laboratory experimentation, which provide a quantitative basis for extrapolation in time and space of insights about continental-margin sedimentation- Provides a research resource for scientists studying modern and ancient margins, and an educational text for advanced students in sedimentology and stratigraphy

Dopamine reward prediction error responses reflect marginal utility.

PubMed

Stauffer, William R; Lak, Armin; Schultz, Wolfram

2014-11-03

Optimal choices require an accurate neuronal representation of economic value. In economics, utility functions are mathematical representations of subjective value that can be constructed from choices under risk. Utility usually exhibits a nonlinear relationship to physical reward value that corresponds to risk attitudes and reflects the increasing or decreasing marginal utility obtained with each additional unit of reward. Accordingly, neuronal reward responses coding utility should robustly reflect this nonlinearity. In two monkeys, we measured utility as a function of physical reward value from meaningful choices under risk (that adhered to first- and second-order stochastic dominance). The resulting nonlinear utility functions predicted the certainty equivalents for new gambles, indicating that the functions' shapes were meaningful. The monkeys were risk seeking (convex utility function) for low reward and risk avoiding (concave utility function) with higher amounts. Critically, the dopamine prediction error responses at the time of reward itself reflected the nonlinear utility functions measured at the time of choices. In particular, the reward response magnitude depended on the first derivative of the utility function and thus reflected the marginal utility. Furthermore, dopamine responses recorded outside of the task reflected the marginal utility of unpredicted reward. Accordingly, these responses were sufficient to train reinforcement learning models to predict the behaviorally defined expected utility of gambles. These data suggest a neuronal manifestation of marginal utility in dopamine neurons and indicate a common neuronal basis for fundamental explanatory constructs in animal learning theory (prediction error) and economic decision theory (marginal utility). Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Business Context of Space Tourism

NASA Astrophysics Data System (ADS)

Schmitt, Harrison H.

2003-01-01

Broadly speaking, two types of potential commercial activity in space can be defined. First, there are those activities that represent an expansion and improvement on services with broad existing commercial foundations such as telecommunications. The second type of potential commercial activity in space is one that may offer a type of service with few or any existing commercial foundations such as space-based remote sensing. Space tourism clearly belongs in the first category of potential commercial activity in space. Roles in cooperation with the private sector that might be considered for NASA include 1) acceleration of the ``Professional-in Space'' initiative, 2) research and technology developments related to a) a ``Tourist Destination Module'' for the Space Station, b) an ``Extra Passengers Module'' for the payload bay of the Space Shuttle, and c) a ``Passenger-rated Expendable Launch Vehicle,'' 3) definition of criteria for qualifying candidate space tourists, and 4) initiatives to protect space tourism from unreasonable tort litigation. As baseline information for establishing fees, the cost of a possible tourist flight should be fully and objectively delineated. If it is correct that the marginal cost of each Space Shuttle flight to Earth-orbit is about $100 million and the effective Shuttle payload is about 50,000 pounds, then the marginal cost would be roughly $2,000 per pound.

Other Ways of Learning: Outdoor Adventure Education and Experiential Learning in School and Youth Work. Proceedings of the European Congress for Outdoor Adventure Education and Experiential Learning (4th, Rimforsa, Sweden, September 9-13, 2000).

ERIC Educational Resources Information Center

2001

A European conference convened 90 participants from 14 countries to consider "other ways of learning," such as experiential methods and aesthetic-sensual perception, which have been marginalized by the overemphasis on instrumental rationality in our societies and schools. This proceedings presents 18 papers and paper abstracts on outdoor…

Adspots and Green Eyes: 'National' Identity in Irish TV Commercials and Other 'Marginal' Areas of Irish Television.

ERIC Educational Resources Information Center

McBride, Stephanie

This paper discusses the relationship between national identity and the so-called "marginal" areas of Irish television, i.e., advertisements, continuity announcements, and promotional trailers. The following issues are considered: (1) how these "spaces" between television programs compare in terms of use and influence to…

Global Consultation Processes: Lessons Learned from Refugee Teacher Consultation Research in Malaysia

ERIC Educational Resources Information Center

O'Neal, Colleen R.; Gosnell, Nicole M.; Ng, Wai Sheng; Clement, Jennifer; Ong, Edward

2018-01-01

The process of global consultation has received little attention despite its potential for promoting international mutual understanding with marginalized communities. This article details theory, entry, implementation, and evaluation processes for global consultation research, including lessons learned from our refugee teacher intervention. The…

Coming to Do Mathematics in the Margins

ERIC Educational Resources Information Center

Brown, Raymond; Redmond, Trevor

2015-01-01

This paper explores teacher' "identity" as two teachers talk about teaching mathematics in classrooms situated within two different contexts of learning--mainstream and alternative. Employing a form of discourse analysis framed within a participation approach to learning, this paper describes teacher identity in terms of the norms and…

Deep Correlated Holistic Metric Learning for Sketch-Based 3D Shape Retrieval.

PubMed

Dai, Guoxian; Xie, Jin; Fang, Yi

2018-07-01

How to effectively retrieve desired 3D models with simple queries is a long-standing problem in computer vision community. The model-based approach is quite straightforward but nontrivial, since people could not always have the desired 3D query model available by side. Recently, large amounts of wide-screen electronic devices are prevail in our daily lives, which makes the sketch-based 3D shape retrieval a promising candidate due to its simpleness and efficiency. The main challenge of sketch-based approach is the huge modality gap between sketch and 3D shape. In this paper, we proposed a novel deep correlated holistic metric learning (DCHML) method to mitigate the discrepancy between sketch and 3D shape domains. The proposed DCHML trains two distinct deep neural networks (one for each domain) jointly, which learns two deep nonlinear transformations to map features from both domains into a new feature space. The proposed loss, including discriminative loss and correlation loss, aims to increase the discrimination of features within each domain as well as the correlation between different domains. In the new feature space, the discriminative loss minimizes the intra-class distance of the deep transformed features and maximizes the inter-class distance of the deep transformed features to a large margin within each domain, while the correlation loss focused on mitigating the distribution discrepancy across different domains. Different from existing deep metric learning methods only with loss at the output layer, our proposed DCHML is trained with loss at both hidden layer and output layer to further improve the performance by encouraging features in the hidden layer also with desired properties. Our proposed method is evaluated on three benchmarks, including 3D Shape Retrieval Contest 2013, 2014, and 2016 benchmarks, and the experimental results demonstrate the superiority of our proposed method over the state-of-the-art methods.

Training the max-margin sequence model with the relaxed slack variables.

PubMed

Niu, Lingfeng; Wu, Jianmin; Shi, Yong

2012-09-01

Sequence models are widely used in many applications such as natural language processing, information extraction and optical character recognition, etc. We propose a new approach to train the max-margin based sequence model by relaxing the slack variables in this paper. With the canonical feature mapping definition, the relaxed problem is solved by training a multiclass Support Vector Machine (SVM). Compared with the state-of-the-art solutions for the sequence learning, the new method has the following advantages: firstly, the sequence training problem is transformed into a multiclassification problem, which is more widely studied and already has quite a few off-the-shelf training packages; secondly, this new approach reduces the complexity of training significantly and achieves comparable prediction performance compared with the existing sequence models; thirdly, when the size of training data is limited, by assigning different slack variables to different microlabel pairs, the new method can use the discriminative information more frugally and produces more reliable model; last but not least, by employing kernels in the intermediate multiclass SVM, nonlinear feature space can be easily explored. Experimental results on the task of named entity recognition, information extraction and handwritten letter recognition with the public datasets illustrate the efficiency and effectiveness of our method. Copyright © 2012 Elsevier Ltd. All rights reserved.

Crew transportation for the 1990s. I - Commercializing manned flight with today's propulsion

NASA Astrophysics Data System (ADS)

Staehle, Robert; French, J. R.

Two commercial space transport concepts that have been developed employing reusable production engines are discussed. A winged space transport (WST) launched from a Boeing 747 was sized to carry six people to low orbit. With no margin for performance growth, it is not favored for development. A vertical launch/landing space transport was designed with capabilities and propulsion similar to the WST, but launched from the ground. A small launch mass penalty is offset by improved performance margins and by eliminating carrier aircraft costs. The two-pilot plus five-passenger vehicle is designed for short-duration trips to low earth orbit, or for docking up to 10 d at an orbiting station. Market applications include space station crew rotation, equipment delivery and product return, short-duration experiments, satellite servicing, reconnaissance, and tourism. Profitable per-mission prices are projected at $10-15 million, with development costs approaching $400 million.

String Theory: exact solutions, marginal deformations and hyperbolic spaces

NASA Astrophysics Data System (ADS)

Orlando, Domenico

2006-10-01

This thesis is almost entirely devoted to studying string theory backgrounds characterized by simple geometrical and integrability properties. The archetype of this type of system is given by Wess-Zumino-Witten models, describing string propagation in a group manifold or, equivalently, a class of conformal field theories with current algebras. We study the moduli space of such models by using truly marginal deformations. Particular emphasis is placed on asymmetric deformations that, together with the CFT description, enjoy a very nice spacetime interpretation in terms of the underlying Lie algebra. Then we take a slight detour so to deal with off-shell systems. Using a renormalization-group approach we describe the relaxation towards the symmetrical equilibrium situation. In he final chapter we consider backgrounds with Ramond-Ramond field and in particular we analyze direct products of constant-curvature spaces and find solutions with hyperbolic spaces.

Finding My Voice: [Re]living, [Re]learning, and [Re]searching Becoming a Singer in a Culture of Marginalization

ERIC Educational Resources Information Center

Manovski, Miroslav Pavle

2012-01-01

Boys who sing in school are often marginalized, taunted, sometimes called "gay." What if "singer" is someone's whole identity, and that person also happens to be gay? This autoethnography (Ellis, 2004) is a story of the education and development of such a singer and how, within this context, a voice teacher with an empowering…

Marginally perceptible outcome feedback, motor learning and implicit processes.

PubMed

Masters, Rich S W; Maxwell, Jon P; Eves, Frank F

2009-09-01

Participants struck 500 golf balls to a concealed target. Outcome feedback was presented at the subjective or objective threshold of awareness of each participant or at a supraliminal threshold. Participants who received fully perceptible (supraliminal) feedback learned to strike the ball onto the target, as did participants who received feedback that was only marginally perceptible (subjective threshold). Participants who received feedback that was not perceptible (objective threshold) showed no learning. Upon transfer to a condition in which the target was unconcealed, performance increased in both the subjective and the objective threshold condition, but decreased in the supraliminal condition. In all three conditions, participants reported minimal declarative knowledge of their movements, suggesting that deliberate hypothesis testing about how best to move in order to perform the motor task successfully was disrupted by the impoverished disposition of the visual outcome feedback. It was concluded that sub-optimally perceptible visual feedback evokes implicit processes.

From the Margin to the Mainstream: The Faculty Role in Advancing Service-Learning on Community Colleges. Models, Lessons from the Field, Case Studies.

ERIC Educational Resources Information Center

Pickeral, Terry, Ed.; Peters, Karen, Ed.

Prepared as part of a project to promote service-learning activities at community colleges, this sourcebook presents essays by college faculty detailing service-learning models and strategies. Following a brief foreword, an introductory essay describes the project, indicating that it involves a team of five faculty members who have built…

Gaming out online: Black lesbian identity development and community building in Xbox Live.

PubMed

Gray, Kishonna L

2017-11-22

As gaming culture continues to marginalize women and people of color, other gamers are also highlighting the inequalities they face within digital gaming communities. While heterosexism and homophobia are commonplace within gaming culture, little is known about the actual experiences of "gaymers" and even less about "gaymers" of color. As such, this article seeks to explore lesbians of color and their experiences "gayming" out and online. Exploring identity development, community building, and connectivity via social networking, the women within this study articulate what it means to be lesbian online and how this impacts their physical and digital experiences. The private spaces within gaming culture that many marginalized groups inhabit are the few spaces that value the articulation of marginalized interests and viewpoints. Ethnographic observations reveal how supportive communities can improve resilience by mitigating the effects of stereotyping, microaggressions, and other discriminatory practices in online gaming.

Time Domain Stability Margin Assessment of the NASA Space Launch System GN&C Design for Exploration Mission One

NASA Technical Reports Server (NTRS)

Clements, Keith; Wall, John

2017-01-01

The baseline stability margins for NASA's Space Launch System (SLS) launch vehicle were generated via the classical approach of linearizing the system equations of motion and determining the gain and phase margins from the resulting frequency domain model. To improve the fidelity of the classical methods, the linear frequency domain approach can be extended by replacing static, memoryless nonlinearities with describing functions. This technique, however, does not address the time varying nature of the dynamics of a launch vehicle in flight. An alternative technique for the evaluation of the stability of the nonlinear launch vehicle dynamics along its trajectory is to incrementally adjust the gain and/or time delay in the time domain simulation until the system exhibits unstable behavior. This technique has the added benefit of providing a direct comparison between the time domain and frequency domain tools in support of simulation validation.

Time Domain Stability Margin Assessment of the NS Space Launch System GN&C Design for Exploration Mission One

NASA Technical Reports Server (NTRS)

Clements, Keith; Wall, John

2017-01-01

The baseline stability margins for NASA's Space Launch System (SLS) launch vehicle were generated via the classical approach of linearizing the system equations of motion and determining the gain and phase margins from the resulting frequency domain model. To improve the fidelity of the classical methods, the linear frequency domain approach can be extended by replacing static, memoryless nonlinearities with describing functions. This technique, however, does not address the time varying nature of the dynamics of a launch vehicle in flight. An alternative technique for the evaluation of the stability of the nonlinear launch vehicle dynamics along its trajectory is to incrementally adjust the gain and/or time delay in the time domain simulation until the system exhibits unstable behavior. This technique has the added benefit of providing a direct comparison between the time domain and frequency domain tools in support of simulation validation.

Developing Multiple Literacies in Academic English through Service-Learning and Community Engagement

ERIC Educational Resources Information Center

Askildson, Lance R.; Kelly, Annie Cahill; Mick, Connie Snyder

2013-01-01

Research on service-learning offers compelling evidence of the advances student learners make in moral development, orientation to prosocial behavior, and curricular content retention. But who are those student learners? Most studies focus on native, dominant-culture, dominant-language students serving marginalized populations. Studies of the…

Why Students Lose When "Tougher Standards" Win: A Conversation with Alfie Kohn.

ERIC Educational Resources Information Center

O'Neil, John; Tell, Carol

1999-01-01

Kohn believes the "tougher standards" movement is incompatible with personalized learning, excellence, and marginalized kids' interests. Horizontal standards that shift how teaching and learning happen in classrooms are terrific, but vertical standards using traditional pedagogy are macho and mindless. Kids need freedom to design their…

Online Learning for All Students

ERIC Educational Resources Information Center

Webb, Kathleen L.

2009-01-01

Most online learning has taken the typical classroom and extended it to a new delivery method, keeping all the essential classroom elements in place. Christensen predicts that online education will be a "disruptive" innovation--an innovation that begins by serving a marginalized group, such as the students who drop out because the…

Building Teacher Interculturality: Student Partnerships in University Classrooms

ERIC Educational Resources Information Center

Smolcic, Elizabeth; Arends, Jessica

2017-01-01

The "achievement gap" for English learners and those of marginalized groups has been documented for well over a decade. It is widely recognized that socioeconomic status, language, and the fluid construct of culture play significant roles in school learning. However, despite the dismal academic progress of students learning English in…

Redefining Practice: Challenging Academic and Institutional Traditions with Clinical Distance Learning

ERIC Educational Resources Information Center

Delgaty, Laura E.

2017-01-01

With the uptake of distance learning (DL), which has actually been marginal for most academics, teaching contexts, traditional power structures and relationships have been transformed, leaving lecturers potentially disenfranchised. Institutional and cultural change is vital, particularly changes concerning academic roles. The advent of DL has…

Spatial Strategy Use during Logo Mastery: The Impact of Cognitive Style and Development Level.

ERIC Educational Resources Information Center

Easton, Charles E.; Watson, J. Allen

1993-01-01

Tested the Watson and Busch model of how children learn LOGO programing. Investigated second- and fifth-grade students' stage of cognitive development, stylistic preferences, and strategy usage. Field-independent children showed a marginal advantage over field-dependent children in learning to program in LOGO. (MM)

Rethinking the Learning Space at Work and Beyond: The Achievement of Agency across the Boundaries of Work-Related Spaces and Environments

ERIC Educational Resources Information Center

Kersh, Natasha

2015-01-01

This paper focuses on the notion of the learning space at work and discusses the extent to which its different configurations allow employees to exercise personal agency within a range of learning spaces. Although the learning space at work is already the subject of extensive research, the continuous development of the learning society and the…

Estimates of the atmospheric parameters of M-type stars: a machine-learning perspective

NASA Astrophysics Data System (ADS)

Sarro, L. M.; Ordieres-Meré, J.; Bello-García, A.; González-Marcos, A.; Solano, E.

2018-05-01

Estimating the atmospheric parameters of M-type stars has been a difficult task due to the lack of simple diagnostics in the stellar spectra. We aim at uncovering good sets of predictive features of stellar atmospheric parameters (Teff, log (g), [M/H]) in spectra of M-type stars. We define two types of potential features (equivalent widths and integrated flux ratios) able to explain the atmospheric physical parameters. We search the space of feature sets using a genetic algorithm that evaluates solutions by their prediction performance in the framework of the BT-Settl library of stellar spectra. Thereafter, we construct eight regression models using different machine-learning techniques and compare their performances with those obtained using the classical χ2 approach and independent component analysis (ICA) coefficients. Finally, we validate the various alternatives using two sets of real spectra from the NASA Infrared Telescope Facility (IRTF) and Dwarf Archives collections. We find that the cross-validation errors are poor measures of the performance of regression models in the context of physical parameter prediction in M-type stars. For R ˜ 2000 spectra with signal-to-noise ratios typical of the IRTF and Dwarf Archives, feature selection with genetic algorithms or alternative techniques produces only marginal advantages with respect to representation spaces that are unconstrained in wavelength (full spectrum or ICA). We make available the atmospheric parameters for the two collections of observed spectra as online material.

Transfer of New Earth Science Understandings to Classroom Teaching: Lessons Learned From Teachers on the Leading Edge

NASA Astrophysics Data System (ADS)

Butler, R.; Ault, C.; Bishop, E.; Southworth-Neumeyer, T.; Magura, B.; Hedeen, C.; Groom, R.; Shay, K.; Wagner, R.

2006-05-01

Teachers on the Leading Edge (TOTLE) provided a field-based teacher professional development program that explored the active continental margin geology of the Pacific Northwest during a two-week field workshop that traversed Oregon from the Pacific Coast to the Snake River. The seventeen teachers on this journey of geological discovery experienced regional examples of subduction-margin geology and examined the critical role of geophysics in connecting geologic features with plate tectonic processes. Two examples of successful transfer of science content learning to classroom teaching are: (1) Great Earthquakes and Tsunamis. This topic was addressed through instruction on earthquake seismology; field observations of tsunami geology; examination of tsunami preparedness of a coastal community; and interactive learning activities for children at an Oregon Museum of Science and Industry (OMSI) Science Camp. Teachers at Sunnyside Environmental School in Portland developed a story line for middle school students called "The Tsunami Hotline" in which inquiries from citizens serve as launch points for studies of tsunamis, earthquakes, and active continental margin geology. OMSI Science Camps is currently developing a new summer science camp program entitled "Tsunami Field Study" for students ages 12-14, based largely on TOTLE's Great Earthquakes and Tsunamis Day. (2) The Grand Cross Section. Connecting regional geologic features with plate tectonic processes was addressed many times during the field workshop. This culminated with teachers drawing cross sections from the Juan de Fuca Ridge across the active continental margin to the accreted terranes of northeast Oregon. Several TOTLE teachers have successfully transferred this activity to their classrooms by having student teams relate earthquakes and volcanoes to plate tectonics through artistic renderings of The Grand Cross Section. Analysis of program learning transfer to classroom teaching (or lack thereof) clearly indicates the importance of pedagogical content knowledge and having teachers share their wisdom in crafting new earth science content knowledge into learning activities. These lessons and adjustments to TOTLE program goals and strategies may be valuable to other Geoscience educators seeking to prepare K-12 teachers to convey the discoveries of EarthScope's USArray and Plate Boundary Observatory experiments to their students.

"Latino Spaces Have Always Been the Most Violent": Afro-Latino Collegians' Perceptions of Colorism and Latino Intragroup Marginalization

ERIC Educational Resources Information Center

Haywood, Jasmine M.

2017-01-01

This study centers on the racialized experiences of Afro-Latino undergraduates at historically White institutions. Of particular interest, I examine how six Afro-Latino collegains experience intragroup marginalization due to colorism. The research design is undergirded by critical race theory and a critical race methodology. Participants'…

2 + 2 = 5 if 2 Is Large Enough: Rhetorical Spaces of Technology Development in Aerospace Engine Testing.

ERIC Educational Resources Information Center

Ornatowski, Cezar M.

1998-01-01

Examines the nature, extent, and rhetorical exploitation of the margins of indeterminacy in aircraft engine development and testing, focusing particularly on the role of technical documents in creating these margins and in the rhetorical transactions that transpired. Suggests the conditions and implications of these rhetorical transactions need to…

Informal and Formal Support Groups Retain Women and Minorities in Physics

NASA Astrophysics Data System (ADS)

Ong, Maria

2005-10-01

Ten U.S. minority female undergraduates who aspire to become physicists were followed over an 8-year period. Participant observation and in-depth interviews recorded the strategies they used to earn bachelor's degrees in physics or physics-related fields, and then go on to graduate school and/or careers in science. One significant strategy these women of color employed was participating in small subcommunities with other women or underrepresented ethnic minorities at the margins of their local physics community. The study found that informal peer groups offered safe spaces to counter negative experiences, to normalize their social realities, and to offer practical guidance for persevering in the field. Formal women- and minority-serving programs in physics provided foundations for community building, stronger curriculum and instruction, networking, and role models. The positive effects of informal and formal support groups on these students' experiences challenge a standard application of Pierre Bourdieu's framework of social and cultural capital. Women of color in the study initially lacked traditional capital of "acceptable" appearance, cultural background and habits, and networks that are more easily acquired by white males and are rewarded by the U.S. physics culture. However, instead of failing or leaving, as Bourdieu's theory would predict, the minority women persisted and achieved in science. The marginal communities contributed to their retention by offering safe spaces in which they could learn and share alternative ways of "accruing capital." Moreover, as these women made strides along their academic and career paths, they also engaged in social justice work in efforts to change the physics culture to be more welcoming of nontraditional members. The outcomes of the study offer empirical confirmation of the critical need for informal and institutionally supported women's and minorities' support groups to promote diversity in science.

Multiple Ordinal Regression by Maximizing the Sum of Margins

PubMed Central

Hamsici, Onur C.; Martinez, Aleix M.

2016-01-01

Human preferences are usually measured using ordinal variables. A system whose goal is to estimate the preferences of humans and their underlying decision mechanisms requires to learn the ordering of any given sample set. We consider the solution of this ordinal regression problem using a Support Vector Machine algorithm. Specifically, the goal is to learn a set of classifiers with common direction vectors and different biases correctly separating the ordered classes. Current algorithms are either required to solve a quadratic optimization problem, which is computationally expensive, or are based on maximizing the minimum margin (i.e., a fixed margin strategy) between a set of hyperplanes, which biases the solution to the closest margin. Another drawback of these strategies is that they are limited to order the classes using a single ranking variable (e.g., perceived length). In this paper, we define a multiple ordinal regression algorithm based on maximizing the sum of the margins between every consecutive class with respect to one or more rankings (e.g., perceived length and weight). We provide derivations of an efficient, easy-to-implement iterative solution using a Sequential Minimal Optimization procedure. We demonstrate the accuracy of our solutions in several datasets. In addition, we provide a key application of our algorithms in estimating human subjects’ ordinal classification of attribute associations to object categories. We show that these ordinal associations perform better than the binary one typically employed in the literature. PMID:26529784

The Single Sex Debate for Girls in Science: a Comparison Between Two Informal Science Programs on Middle School Students' STEM Identity Formation

NASA Astrophysics Data System (ADS)

Hughes, Roxanne M.; Nzekwe, Brandon; Molyneaux, Kristen J.

2013-10-01

Currently, there are policy debates regarding the efficacy and legality of single sex formal and informal education programs. This issue is particularly poignant in science education due to the historical marginalization of women in these fields. This marginalization has resulted in women being positioned as a stigmatized group within many science, technology, engineering, and mathematics (STEM) related fields. Research points to adolescence as the age where this sense of marginalization begins to develop. As a result, policy responses have utilized various frameworks such as: increased access for women, changing pedagogy to address women's learning styles, changing the language and culture of science to prevent marginalization of stigmatized groups, and finally exploring the role that individual identity plays in the marginalization of women. This study adds to the policy debate as it applies to single sex education by comparing middle school participants' STEM identity formation during two informal science learning environments (an all girls' STEM camp and a co-educational STEM camp). Additionally, this study focuses on the influence of camp activities within two informal science education programs: particularly the provision of role models and authentic STEM research activities, as means to improve STEM identity and make these fields relevant to the lives of middle school students. The results indicate that both camps improved girls' STEM identities. These findings suggest that the single sex environment is not as important to STEM identity as the pedagogy used within the program.

Learning Spaces and Pedagogy: Towards the Development of a Shared Understanding

ERIC Educational Resources Information Center

McNeil, Jane; Borg, Michaela

2018-01-01

Although there is considerable interest in learning spaces in higher education, the relationship between spaces and learning is complex and not well-understood. Despite challenges, such as the lack of comparability between studies, we need to learn more about the interaction of space design and learning. A crucial step towards this is the creation…

Controls of tectonics and sediment source locations on along-strike variations in transgressive deposits on the northern California margin

USGS Publications Warehouse

Spinelli, G.A.; Field, M.E.

2003-01-01

We identify two surfaces in the shallow subsurface on the Eel River margin offshore northern California, a lowstand erosion surface, likely formed during the last glacial maximum, and an overlying surface likely formed during the most recent transgression of the shoreline. The lowstand erosion surface, which extends from the inner shelf to near the shelfbreak and from the Eel River to Trinidad Head (???80 km), truncates underlying strata on the shelf. Above the surface, inferred transgressive coastal and estuarine sedimentary units separate it from the transgressive surface on the shelf. Early in the transgression, Eel River sediment was likely both transported down the Eel Canyon and dispersed on the slope, allowing transgressive coastal sediment from the smaller Mad River to accumulate in a recognizable deposit on the shelf. The location of coastal Mad River sediment accumulation was controlled by the location of the paleo-Mad River. Throughout the remainder of the transgression, dispersed sediment from the Eel River accumulated an average of 20 m of onlapping shelf deposits. The distribution and thickness of these transgressive marine units was strongly modified by northwest-southeast trending folds. Thick sediment packages accumulated over structural lows in the lowstand surface. The thinnest sediment accumulations (0-10 m) were deposited over structural highs along faults and uplifting anticlines. The Eel margin, an active margin with steep, high sediment-load streams, has developed a thick transgressive systems tract. On this margin sediment accumulates as rapidly as the processes of uplift and downwarp locally create and destroy accommodation space. Sequence stratigraphic models of tectonically active margins should account for variations in accommodation space along margins as well as across them. ?? 2003 Elsevier Science B.V. All rights reserved.

Antecedent topography and morphological controls on sediment accumulation and slope stability of the U.S. Atlantic margin

NASA Astrophysics Data System (ADS)

Hill, J. C.; Brothers, D. S.; Ten Brink, U. S.; Andrews, B. D.

2017-12-01

The U.S. Atlantic margin encompasses a wide variety of slope failure processes, ranging from small canyon-confined failures on the upper slope to large, open slope landslides originating in deeper water. Here we used a suite of high-resolution multibeam bathymetry and detailed multichannel seismic data coverage to investigate the relationship between modern seafloor morphology, pre-existing stratigraphy and sediment accumulation patterns. We suggest that a combination of sediment supply and antecedent margin physiography, whereby variations in margin evolution during the Miocene have influenced the modern seafloor morphology, controls both the location of slope sediment accumulation and the style of slope failure. Oversteepened margins with angular shelf breaks and steep upper slopes, referred to as oblique margins, are characterized by downslope mass transport and densely-spaced canyon formation. These margins are most likely the locus of canyon-confined failures and smaller lower slope fan-apron failures (e.g., much of the Mid-Atlantic). Sigmoidal margins with prograded slopes, a rounded shelf edge, and a low gradient slope morphology can support significant sediment accumulation across a broad area, with limited canyon development. These margins are often associated with high sediment supply and are prone to large, upper slope slab-style failures (e.g., the Hudson Apron, southwestern New England, the Currituck and Cape Fear Slide complexes). Areas with morphologies in between these two end members are characterized by limited shelf-edge accommodation space and large-scale lower slope accumulation and onlap, representing transitional stages of equilibrium slope adjustment. Large failures along these intermediate-type margins tend to develop lower on the slope where thick wedges of onlapping sediment are found (e.g., around Washington Canyon, Cape Lookout and southeastern New England). As antecedent topography and sediment loading appear to play an important role in determining the spatial distribution of submarine slope failures, other key processes that contribute to the development of overpressure (e.g., sediment compaction and fluid migration) should be examined with this in mind to improve our understanding of the geologic factors that precondition slopes for failure.

Lost in Space: Designing for Learning

ERIC Educational Resources Information Center

La Marca, Susan

2010-01-01

The design of a learning space, and the many factors that come together to create that space, impact on how we feel and behave in that space and ultimately how we learn. This paper will discuss the importance of mission statements, policy and planning in light of how we create spaces that are learning-driven, human-centred and flexible. Of…

Learning Spaces as a Strategic Priority

ERIC Educational Resources Information Center

George, Gene; Erwin, Tom; Barnes, Briony

2009-01-01

In April 2007 Butler Community College made learning spaces one of its five strategic priorities. The college had just completed a major renovation of the work spaces for the IT division and had started a project to build a student union and create informal learning spaces at the Andover campus. With learning spaces becoming a strategic priority,…

Very Similar Spacing-Effect Patterns in Very Different Learning/Practice Domains

PubMed Central

Kornmeier, Jürgen; Spitzer, Manfred; Sosic-Vasic, Zrinka

2014-01-01

Temporally distributed (“spaced”) learning can be twice as efficient as massed learning. This “spacing effect” occurs with a broad spectrum of learning materials, with humans of different ages, with non-human vertebrates and also invertebrates. This indicates, that very basic learning mechanisms are at work (“generality”). Although most studies so far focused on very narrow spacing interval ranges, there is some evidence for a non-monotonic behavior of this “spacing effect” (“nonlinearity”) with optimal spacing intervals at different time scales. In the current study we focused both the nonlinearity aspect by using a broad range of spacing intervals and the generality aspect by using very different learning/practice domains: Participants learned German-Japanese word pairs and performed visual acuity tests. For each of six groups we used a different spacing interval between learning/practice units from 7 min to 24 h in logarithmic steps. Memory retention was studied in three consecutive final tests, one, seven and 28 days after the final learning unit. For both the vocabulary learning and visual acuity performance we found a highly significant effect of the factor spacing interval on the final test performance. In the 12 h-spacing-group about 85% of the learned words stayed in memory and nearly all of the visual acuity gain was preserved. In the 24 h-spacing-group, in contrast, only about 33% of the learned words were retained and the visual acuity gain dropped to zero. The very similar patterns of results from the two very different learning/practice domains point to similar underlying mechanisms. Further, our results indicate spacing in the range of 12 hours as optimal. A second peak may be around a spacing interval of 20 min but here the data are less clear. We discuss relations between our results and basic learning at the neuronal level. PMID:24609081

Maximum Margin Clustering of Hyperspectral Data

NASA Astrophysics Data System (ADS)

Niazmardi, S.; Safari, A.; Homayouni, S.

2013-09-01

In recent decades, large margin methods such as Support Vector Machines (SVMs) are supposed to be the state-of-the-art of supervised learning methods for classification of hyperspectral data. However, the results of these algorithms mainly depend on the quality and quantity of available training data. To tackle down the problems associated with the training data, the researcher put effort into extending the capability of large margin algorithms for unsupervised learning. One of the recent proposed algorithms is Maximum Margin Clustering (MMC). The MMC is an unsupervised SVMs algorithm that simultaneously estimates both the labels and the hyperplane parameters. Nevertheless, the optimization of the MMC algorithm is a non-convex problem. Most of the existing MMC methods rely on the reformulating and the relaxing of the non-convex optimization problem as semi-definite programs (SDP), which are computationally very expensive and only can handle small data sets. Moreover, most of these algorithms are two-class classification, which cannot be used for classification of remotely sensed data. In this paper, a new MMC algorithm is used that solve the original non-convex problem using Alternative Optimization method. This algorithm is also extended for multi-class classification and its performance is evaluated. The results of the proposed algorithm show that the algorithm has acceptable results for hyperspectral data clustering.

Informal mobile learning in nurse education and practice in remote areas--a case study from rural South Africa.

PubMed

Pimmer, Christoph; Brysiewicz, Petra; Linxen, Sebastian; Walters, Fiona; Chipps, Jennifer; Gröhbiel, Urs

2014-11-01

With the proliferation of portable digital technology, mobile learning is becoming increasingly popular in nursing education and practice. Most of the research in this field has been concentrated on small-scale projects in high income countries. Very little is known about the ways in which nurses and midwives use mobile technology in remote and resource poor areas in informal learning contexts in low and middle income countries. To address this gap, this study investigates whether nurses use mobile phones as effective educational tools in marginalized and remote areas, and if so, how and why. In rural South Africa, 16 nurses who attended an advanced midwifery education program, facilitators and clinical managers were interviewed about their use of digital mobile technology for learning. Techniques of qualitative content analysis were used to examine the data. Several rich "organically-grown", learning practices were identified: mobile phone usage facilitated (1) authentic problem solving; (2) reflective practice; (3) emotional support and belongingness; (4) the realization of unpredictable teaching situations; and (5) life-long learning. It is concluded that mobile phones, and the convergence of mobile phones and social media, in particular, change learning environments. In addition, these tools are suitable to connect learners and learning distributed in marginalized areas. Finally, a few suggestions are made about how these insights from informal settings can inform the development of more systematic mobile learning formats. Copyright © 2014 Elsevier Ltd. All rights reserved.

Space: the final frontier in the learning of science?

NASA Astrophysics Data System (ADS)

Milne, Catherine

2014-03-01

In Space, relations, and the learning of science, Wolff-Michael Roth and Pei-Ling Hsu use ethnomethodology to explore high school interns learning shopwork and shoptalk in a research lab that is located in a world class facility for water quality analysis. Using interaction analysis they identify how spaces, like a research laboratory, can be structured as smart spaces to create a workflow (learning flow) so that shoptalk and shopwork can projectively organize the actions of interns even in new and unfamiliar settings. Using these findings they explore implications for the design of curriculum and learning spaces more broadly. The Forum papers of Erica Blatt and Cassie Quigley complement this analysis. Blatt expands the discussion on space as an active component of learning with an examination of teaching settings, beyond laboratory spaces, as active participants of education. Quigley examines smart spaces as authentic learning spaces while acknowledging how internship experiences all empirical elements of authentic learning including open-ended inquiry and empowerment. In this paper I synthesize these ideas and propose that a narrative structure might better support workflow, student agency and democratic decision making.

Aligning physical learning spaces with the curriculum: AMEE Guide No. 107.

PubMed

Nordquist, Jonas; Sundberg, Kristina; Laing, Andrew

2016-08-01

This Guide explores emerging issues on the alignment of learning spaces with the changing curriculum in medical education. As technology and new teaching methods have altered the nature of learning in medical education, it is necessary to re-think how physical learning spaces are aligned with the curriculum. The better alignment of learning spaces with the curriculum depends on more directly engaged leadership from faculty and the community of medical education for briefing the requirements for the design of all kinds of learning spaces. However, there is a lack of precedent and well-established processes as to how new kinds of learning spaces should be programmed. Such programmes are essential aspects of optimizing the intended experience of the curriculum. Faculty and the learning community need better tools and instruments to support their leadership role in briefing and programming. A Guide to critical concepts for exploring the alignment of curriculum and learning spaces is provided. The idea of a networked learning landscape is introduced as a way of assessing and evaluating the alignment of physical spaces to the emerging curriculum. The concept is used to explore how technology has widened the range of spaces and places in which learning happens as well as enabling new styles of learning. The networked learning landscaped is explored through four different scales within which learning is accommodated: the classroom, the building, the campus, and the city. High-level guidance on the process of briefing for the networked learning landscape is provided, to take into account the wider scale of learning spaces and the impact of technology. Key to a successful measurement process is argued to be the involvement of relevant academic stakeholders who can identify the strategic direction and purpose for the design of the learning environments in relation to the emerging demands of the curriculum.

Mortality risk prediction in burn injury: Comparison of logistic regression with machine learning approaches.

PubMed

Stylianou, Neophytos; Akbarov, Artur; Kontopantelis, Evangelos; Buchan, Iain; Dunn, Ken W

2015-08-01

Predicting mortality from burn injury has traditionally employed logistic regression models. Alternative machine learning methods have been introduced in some areas of clinical prediction as the necessary software and computational facilities have become accessible. Here we compare logistic regression and machine learning predictions of mortality from burn. An established logistic mortality model was compared to machine learning methods (artificial neural network, support vector machine, random forests and naïve Bayes) using a population-based (England & Wales) case-cohort registry. Predictive evaluation used: area under the receiver operating characteristic curve; sensitivity; specificity; positive predictive value and Youden's index. All methods had comparable discriminatory abilities, similar sensitivities, specificities and positive predictive values. Although some machine learning methods performed marginally better than logistic regression the differences were seldom statistically significant and clinically insubstantial. Random forests were marginally better for high positive predictive value and reasonable sensitivity. Neural networks yielded slightly better prediction overall. Logistic regression gives an optimal mix of performance and interpretability. The established logistic regression model of burn mortality performs well against more complex alternatives. Clinical prediction with a small set of strong, stable, independent predictors is unlikely to gain much from machine learning outside specialist research contexts. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

46 CFR 171.068 - Special considerations for Type I subdivision for vessels on short international voyages.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Location Uniform average permeability 10 (a−c) Machinery Space 85+____ v 35(b) Volume Forward of Machinery Space 95−__ v 35(b) Volume Aft of Machinery Space 95−___ v For each location specified in this table— a=volume below the margin line of all spaces that, in the full load condition, normally contain no cargo...

46 CFR 171.068 - Special considerations for Type I subdivision for vessels on short international voyages.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Location Uniform average permeability 10 (a−c) Machinery Space 85+____ v 35(b) Volume Forward of Machinery Space 95−__ v 35(b) Volume Aft of Machinery Space 95−___ v For each location specified in this table— a=volume below the margin line of all spaces that, in the full load condition, normally contain no cargo...

46 CFR 171.068 - Special considerations for Type I subdivision for vessels on short international voyages.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Location Uniform average permeability 10 (a−c) Machinery Space 85+____ v 35(b) Volume Forward of Machinery Space 95−__ v 35(b) Volume Aft of Machinery Space 95−___ v For each location specified in this table— a=volume below the margin line of all spaces that, in the full load condition, normally contain no cargo...

46 CFR 171.068 - Special considerations for Type I subdivision for vessels on short international voyages.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Location Uniform average permeability 10 (a−c) Machinery Space 85+____ v 35(b) Volume Forward of Machinery Space 95−__ v 35(b) Volume Aft of Machinery Space 95−___ v For each location specified in this table— a=volume below the margin line of all spaces that, in the full load condition, normally contain no cargo...

Deep Marginalized Sparse Denoising Auto-Encoder for Image Denoising

NASA Astrophysics Data System (ADS)

Ma, Hongqiang; Ma, Shiping; Xu, Yuelei; Zhu, Mingming

2018-01-01

Stacked Sparse Denoising Auto-Encoder (SSDA) has been successfully applied to image denoising. As a deep network, the SSDA network with powerful data feature learning ability is superior to the traditional image denoising algorithms. However, the algorithm has high computational complexity and slow convergence rate in the training. To address this limitation, we present a method of image denoising based on Deep Marginalized Sparse Denoising Auto-Encoder (DMSDA). The loss function of Sparse Denoising Auto-Encoder is marginalized so that it satisfies both sparseness and marginality. The experimental results show that the proposed algorithm can not only outperform SSDA in the convergence speed and training time, but also has better denoising performance than the current excellent denoising algorithms, including both the subjective and objective evaluation of image denoising.

Spillover stabilization and decentralized modal control of large space structures

NASA Technical Reports Server (NTRS)

Czajkowski, Eva A.; Preumont, Andre

1987-01-01

The stabilization of the neglected dynamics of the higher modes of vibration in large space structures is studied, and the influence of the structure of the plant noise intensity matrix of the Kalman-Bucy filter on the stability margin of the residual modes is shown. An optimization procedure uses information on the residual modes to minimize spillover of known residual modes while preserving robustness with respect to the unknown dynamics, and the optimum plant noise intensity matrix is selected to maximize the stability margins of the residual modes and to properly place the observer poles. Examples for both centralized and decentralized control are considered.

Transformational Bilingual Learning: Re-Engaging Marginalized Learners through Language, Culture, Community, and Identity

ERIC Educational Resources Information Center

Tulloch, Shelley; Kusugak, Adriana; Chenier, Cayla; Pilakapsi, Quluaq; Uluqsi, Gloria; Walton, Fiona

2017-01-01

The Miqqut project was a participatory action research project through which Inuit language and literacy learning was embedded in a traditional skills program. Community-based researchers tracked learners' progress through entrance, exit, and post-program interviews and questionnaires, as well as through participant observation. Results show that…

The Value of Collaborative Rounds for Teacher Professional Learning in Australia

ERIC Educational Resources Information Center

Mansfield, Caroline; Thompson, Greg

2017-01-01

Teacher professional learning (PL) is viewed by governments, bureaucracies and school systems as important for improving teaching quality and effectiveness. This new enthusiasm, however, is set against a history of professional development in schools of marginal benefit. In response to this history, education authorities are interested in PL that…

The Value of a Multicultural and Critical Pedagogy: Learning Democracy through Diversity and Dissent

ERIC Educational Resources Information Center

Cammarota, Julio

2011-01-01

In this article, the author argues that true knowledge of democracy requires learning about the values of diversity and dissent. The American brand of democratic ideology has inspired numerous movements for inclusion through the securing of rights and opportunities for marginalized populations. Multicultural education is a recent historical…

Functions, Use and Effects of Embedded Support Devices in Printed Distance Learning Materials.

ERIC Educational Resources Information Center

Martens, Rob; And Others

1996-01-01

To support distance learning, printed materials for the course are enriched with embedded support devices (ESD) such as schemes, illustrations, examples, questions, or margin texts. Results of 3 studies involving 900 Dutch university students indicated that students used and appreciated ESD, and that they led to better study results. (SLD)

Becoming Critical: A Challenge for the Global Learning Programme?

ERIC Educational Resources Information Center

Huckle, John

2017-01-01

The Global Learning Programme (GLP) in England employs a new form of networked governance to deliver education for sustainable development in schools. This article focuses on Biccum's claim that such programmes serve to sustain the prevailing neo-liberal hegemony by further marginalizing critical voices such as those drawing on Marxist and…

Blended Identities: Identity Work, Equity and Marginalization in Blended Learning

ERIC Educational Resources Information Center

Heikoop, Will

2013-01-01

This article is a theoretical study of the self-presentation strategies employed by higher education students online; it examines student identity work via profile information and avatars in a blended learning environment delivered through social networking sites and virtual worlds. It argues that students are faced with difficult choices when…

Still on the Margins: Migration, English Language Learning, and Mental Health in Immigrant Psychiatric Patients

ERIC Educational Resources Information Center

Eamer, Allyson; Fernando, Shanti; King, Alyson E.

2017-01-01

This qualitative study explores the reflexive relationships among mental illness, acculturation, and progress toward English proficiency in five adult immigrants being treated at a Canadian psychiatric hospital. The research explores the additional challenges faced by mentally ill individuals when learning a new language and the extent to which…

"Disorienting, Fun or Meaningful?": Looking beyond the Boundaries of the Museum

ERIC Educational Resources Information Center

Birmingham, Daniel

2016-01-01

A growing body of research highlights how informal science learning environments (ISLE's) can alter modes of participation in science for youth who are traditionally marginalized in science (Calabrese Barton and Tan in "J Learn Sci" 19(2):187-229, 2010). While these findings reveal successful examples of ISLE's potential to bridge…

In the Margins of Training and Learning

ERIC Educational Resources Information Center

Silvennoinen, Heikki; Nori, Hanna

2017-01-01

Purpose: The purpose of this paper is to examine the distribution of learning and training opportunities in the Finnish workforce. It will concentrate on the sectors of the workforce that lack these opportunities. Design/Methodology/Approach: The Working Conditions Barometer (WCB) data from 2008, 2009 and 2010 are used (N = 3,326) in this…

The Process and Product: Crafting Community Portraits with Young People in Flexible Learning Settings

ERIC Educational Resources Information Center

Baker, Alison M.

2016-01-01

Community-based alternative education is situated on the margins in relation to mainstream education. Young people attending these learning sites are often characterised as "disengaged learners", who have fallen through the cracks of the traditional schooling system. The aim of this project was to use participatory visual methods with…

Deepening Ecological Relationality through Critical Onto-Epistemological Inquiry: Where Transformative Learning Meets Sustainable Science

ERIC Educational Resources Information Center

Williams, Lewis

2013-01-01

Indigenous worldviews remain at the margins of education, science, and sustainability efforts. The emergence of sustainable science holds promise as a means of advancing deep sustainability and recentering Indigenous knowledge. Transformative learning's engagement with sustainable science has the potential to play an integral role in this…

Learning monopolies with delayed feedback on price expectations

NASA Astrophysics Data System (ADS)

Matsumoto, Akio; Szidarovszky, Ferenc

2015-11-01

We call the intercept of the price function with the vertical axis the maximum price and the slope of the price function the marginal price. In this paper it is assumed that a monopolistic firm has full information about the marginal price and its own cost function but is uncertain on the maximum price. However, by repeated interaction with the market, the obtained price observations give a basis for an adaptive learning process of the maximum price. It is also assumed that the price observations have fixed delays, so the learning process can be described by a delayed differential equation. In the cases of one or two delays, the asymptotic behavior of the resulting dynamic process is examined, stability conditions are derived. Three main results are demonstrated in the two delay learning processes. First, it is possible to stabilize the equilibrium which is unstable in the one delay model. Second, complex dynamics involving chaos, which is impossible in the one delay model, can emerge. Third, alternations of stability and instability (i.e., stability switches) occur repeatedly.

Rethinking the learning space at work and beyond: The achievement of agency across the boundaries of work-related spaces and environments

NASA Astrophysics Data System (ADS)

Kersh, Natasha

2015-12-01

This paper focuses on the notion of the learning space at work and discusses the extent to which its different configurations allow employees to exercise personal agency within a range of learning spaces. Although the learning space at work is already the subject of extensive research, the continuous development of the learning society and the development of new types of working spaces calls for further research to advance our knowledge and understanding of the ways that individuals exercise agency and learn in the workplace. Research findings suggest that the current perception of workplace learning is strongly related to the notion of the learning space, in which individuals and teams work, learn and develop their skills. The perception of the workplace as a site only for work-specific training is gradually changing, as workplaces are now acknowledged as sites for learning in various configurations, and as contributing to the personal development and social engagement of employees. This paper argues that personal agency is constructed in the workplace, and this process involves active interrelations between agency and three dimensions of the workplace (individual, spatial and organisational), identified through both empirical and theoretical research. The discussion is supported by data from two research projects on workplace learning in the United Kingdom. This paper thus considers how different configurations of the learning space and the boundaries between a range of work-related spaces facilitate the achievement of personal agency.

Semisupervised kernel marginal Fisher analysis for face recognition.

PubMed

Wang, Ziqiang; Sun, Xia; Sun, Lijun; Huang, Yuchun

2013-01-01

Dimensionality reduction is a key problem in face recognition due to the high-dimensionality of face image. To effectively cope with this problem, a novel dimensionality reduction algorithm called semisupervised kernel marginal Fisher analysis (SKMFA) for face recognition is proposed in this paper. SKMFA can make use of both labelled and unlabeled samples to learn the projection matrix for nonlinear dimensionality reduction. Meanwhile, it can successfully avoid the singularity problem by not calculating the matrix inverse. In addition, in order to make the nonlinear structure captured by the data-dependent kernel consistent with the intrinsic manifold structure, a manifold adaptive nonparameter kernel is incorporated into the learning process of SKMFA. Experimental results on three face image databases demonstrate the effectiveness of our proposed algorithm.

Utilizing Emergency Departments as Learning Spaces through a Post-Occupancy Evaluation

ERIC Educational Resources Information Center

Guinther, Lindsey Lawry; Carll-White, Allison

2014-01-01

This case study describes the use of an emergency department as a learning space for interior design students. Kolb's (1984; 2005) framework identifies the characteristics of experiential learning and learning spaces, serving as the bridge to unify learning styles and the learning environment. A post-occupancy evaluation was conducted with…

"Doing School": A New Unit of Analysis for Schools Serving Marginalized Students

ERIC Educational Resources Information Center

Atkinson, Helen

2009-01-01

This study asserts a new unit of analysis for school reform that goes beyond the mental representations of individuals, beyond the isolated lesson, and beyond the confines of a school building. I argue that the special case of expanding time and space as a method of engagement for marginalized students requires that the unit of analysis change to…

Derivation of improved load transformation matrices for launchers-spacecraft coupled analysis, and direct computation of margins of safety

NASA Technical Reports Server (NTRS)

Klein, M.; Reynolds, J.; Ricks, E.

1989-01-01

Load and stress recovery from transient dynamic studies are improved upon using an extended acceleration vector in the modal acceleration technique applied to structural analysis. Extension of the normal LTM (load transformation matrices) stress recovery to automatically compute margins of safety is presented with an application to the Hubble space telescope.

46 CFR 171.065 - Subdivision requirements- Type I.

Code of Federal Regulations, 2011 CFR

2011-10-01

... located above the inner bottom forward or aft of the machinery space in cubic feet. P=the volume of... volume of the machinery space and the volumes of any fuel tanks which are located above the inner bottom... and the total volume of passenger spaces above the margin line. (c) The distance A in Figure 171.065...

46 CFR 171.065 - Subdivision requirements- Type I.

Code of Federal Regulations, 2014 CFR

2014-10-01

... located above the inner bottom forward or aft of the machinery space in cubic feet. P=the volume of... volume of the machinery space and the volumes of any fuel tanks which are located above the inner bottom... and the total volume of passenger spaces above the margin line. (c) The distance A in Figure 171.065...

46 CFR 171.065 - Subdivision requirements- Type I.

Code of Federal Regulations, 2013 CFR

2013-10-01

... located above the inner bottom forward or aft of the machinery space in cubic feet. P=the volume of... volume of the machinery space and the volumes of any fuel tanks which are located above the inner bottom... and the total volume of passenger spaces above the margin line. (c) The distance A in Figure 171.065...

46 CFR 171.065 - Subdivision requirements- Type I.

Code of Federal Regulations, 2012 CFR

2012-10-01

... located above the inner bottom forward or aft of the machinery space in cubic feet. P=the volume of... volume of the machinery space and the volumes of any fuel tanks which are located above the inner bottom... and the total volume of passenger spaces above the margin line. (c) The distance A in Figure 171.065...

Classrooms of Spatial Justice: Counter-Spaces and Young Men of Color in a GED Program

ERIC Educational Resources Information Center

Schwartz, Joni

2014-01-01

This article, based on an ethnographic study of an urban General Education Development (GED) program, suggests that for some marginalized young men of color, Adult education programs are counter-spaces of spatial justice in opposition to previous negative school spaces. Framed by critical race theory (CRT) and drawing on critical geography and…

Automatic Quantification of Radiographic Wrist Joint Space Width of Patients With Rheumatoid Arthritis.

PubMed

Huo, Yinghe; Vincken, Koen L; van der Heijde, Desiree; de Hair, Maria J H; Lafeber, Floris P; Viergever, Max A

2017-11-01

Objective: Wrist joint space narrowing is a main radiographic outcome of rheumatoid arthritis (RA). Yet, automatic radiographic wrist joint space width (JSW) quantification for RA patients has not been widely investigated. The aim of this paper is to present an automatic method to quantify the JSW of three wrist joints that are least affected by bone overlapping and are frequently involved in RA. These joints are located around the scaphoid bone, viz. the multangular-navicular, capitate-navicular-lunate, and radiocarpal joints. Methods: The joint space around the scaphoid bone is detected by using consecutive searches of separate path segments, where each segment location aids in constraining the subsequent one. For joint margin delineation, first the boundary not affected by X-ray projection is extracted, followed by a backtrace process to obtain the actual joint margin. The accuracy of the quantified JSW is evaluated by comparison with the manually obtained ground truth. Results: Two of the 50 radiographs used for evaluation of the method did not yield a correct path through all three wrist joints. The delineated joint margins of the remaining 48 radiographs were used for JSW quantification. It was found that 90% of the joints had a JSW deviating less than 20% from the mean JSW of manual indications, with the mean JSW error less than 10%. Conclusion: The proposed method is able to automatically quantify the JSW of radiographic wrist joints reliably. The proposed method may aid clinical researchers to study the progression of wrist joint damage in RA studies. Objective: Wrist joint space narrowing is a main radiographic outcome of rheumatoid arthritis (RA). Yet, automatic radiographic wrist joint space width (JSW) quantification for RA patients has not been widely investigated. The aim of this paper is to present an automatic method to quantify the JSW of three wrist joints that are least affected by bone overlapping and are frequently involved in RA. These joints are located around the scaphoid bone, viz. the multangular-navicular, capitate-navicular-lunate, and radiocarpal joints. Methods: The joint space around the scaphoid bone is detected by using consecutive searches of separate path segments, where each segment location aids in constraining the subsequent one. For joint margin delineation, first the boundary not affected by X-ray projection is extracted, followed by a backtrace process to obtain the actual joint margin. The accuracy of the quantified JSW is evaluated by comparison with the manually obtained ground truth. Results: Two of the 50 radiographs used for evaluation of the method did not yield a correct path through all three wrist joints. The delineated joint margins of the remaining 48 radiographs were used for JSW quantification. It was found that 90% of the joints had a JSW deviating less than 20% from the mean JSW of manual indications, with the mean JSW error less than 10%. Conclusion: The proposed method is able to automatically quantify the JSW of radiographic wrist joints reliably. The proposed method may aid clinical researchers to study the progression of wrist joint damage in RA studies.

Exploring diversity in ensemble classification: Applications in large area land cover mapping

NASA Astrophysics Data System (ADS)

Mellor, Andrew; Boukir, Samia

2017-07-01

Ensemble classifiers, such as random forests, are now commonly applied in the field of remote sensing, and have been shown to perform better than single classifier systems, resulting in reduced generalisation error. Diversity across the members of ensemble classifiers is known to have a strong influence on classification performance - whereby classifier errors are uncorrelated and more uniformly distributed across ensemble members. The relationship between ensemble diversity and classification performance has not yet been fully explored in the fields of information science and machine learning and has never been examined in the field of remote sensing. This study is a novel exploration of ensemble diversity and its link to classification performance, applied to a multi-class canopy cover classification problem using random forests and multisource remote sensing and ancillary GIS data, across seven million hectares of diverse dry-sclerophyll dominated public forests in Victoria Australia. A particular emphasis is placed on analysing the relationship between ensemble diversity and ensemble margin - two key concepts in ensemble learning. The main novelty of our work is on boosting diversity by emphasizing the contribution of lower margin instances used in the learning process. Exploring the influence of tree pruning on diversity is also a new empirical analysis that contributes to a better understanding of ensemble performance. Results reveal insights into the trade-off between ensemble classification accuracy and diversity, and through the ensemble margin, demonstrate how inducing diversity by targeting lower margin training samples is a means of achieving better classifier performance for more difficult or rarer classes and reducing information redundancy in classification problems. Our findings inform strategies for collecting training data and designing and parameterising ensemble classifiers, such as random forests. This is particularly important in large area remote sensing applications, for which training data is costly and resource intensive to collect.

Learning Human Actions by Combining Global Dynamics and Local Appearance.

PubMed

Luo, Guan; Yang, Shuang; Tian, Guodong; Yuan, Chunfeng; Hu, Weiming; Maybank, Stephen J

2014-12-01

In this paper, we address the problem of human action recognition through combining global temporal dynamics and local visual spatio-temporal appearance features. For this purpose, in the global temporal dimension, we propose to model the motion dynamics with robust linear dynamical systems (LDSs) and use the model parameters as motion descriptors. Since LDSs live in a non-Euclidean space and the descriptors are in non-vector form, we propose a shift invariant subspace angles based distance to measure the similarity between LDSs. In the local visual dimension, we construct curved spatio-temporal cuboids along the trajectories of densely sampled feature points and describe them using histograms of oriented gradients (HOG). The distance between motion sequences is computed with the Chi-Squared histogram distance in the bag-of-words framework. Finally we perform classification using the maximum margin distance learning method by combining the global dynamic distances and the local visual distances. We evaluate our approach for action recognition on five short clips data sets, namely Weizmann, KTH, UCF sports, Hollywood2 and UCF50, as well as three long continuous data sets, namely VIRAT, ADL and CRIM13. We show competitive results as compared with current state-of-the-art methods.

Borderland Spaces for Learning Partnership: Opportunities, Benefits and Challenges

ERIC Educational Resources Information Center

Hill, Jennifer; Thomas, Greg; Diaz, Anita; Simm, David

2016-01-01

This paper uses case studies and secondary literature to critically examine how learning spaces inhabited by geographers might be used productively as borderland spaces for learning partnership. Borderland spaces are novel, challenging, permissive and liminal, destabilizing traditional power hierarchies. In these spaces, students gain confidence…

Distributing learning over time: the spacing effect in children's acquisition and generalization of science concepts.

PubMed

Vlach, Haley A; Sandhofer, Catherine M

2012-01-01

The spacing effect describes the robust finding that long-term learning is promoted when learning events are spaced out in time rather than presented in immediate succession. Studies of the spacing effect have focused on memory processes rather than for other types of learning, such as the acquisition and generalization of new concepts. In this study, early elementary school children (5- to 7-year-olds; N = 36) were presented with science lessons on 1 of 3 schedules: massed, clumped, and spaced. The results revealed that spacing lessons out in time resulted in higher generalization performance for both simple and complex concepts. Spaced learning schedules promote several types of learning, strengthening the implications of the spacing effect for educational practices and curriculum. © 2012 The Authors. Child Development © 2012 Society for Research in Child Development, Inc.

Marginal Contribution-Based Distributed Subchannel Allocation in Small Cell Networks.

PubMed

Shah, Shashi; Kittipiyakul, Somsak; Lim, Yuto; Tan, Yasuo

2018-05-10

The paper presents a game theoretic solution for distributed subchannel allocation problem in small cell networks (SCNs) analyzed under the physical interference model. The objective is to find a distributed solution that maximizes the welfare of the SCNs, defined as the total system capacity. Although the problem can be addressed through best-response (BR) dynamics, the existence of a steady-state solution, i.e., a pure strategy Nash equilibrium (NE), cannot be guaranteed. Potential games (PGs) ensure convergence to a pure strategy NE when players rationally play according to some specified learning rules. However, such a performance guarantee comes at the expense of complete knowledge of the SCNs. To overcome such requirements, properties of PGs are exploited for scalable implementations, where we utilize the concept of marginal contribution (MC) as a tool to design learning rules of players’ utility and propose the marginal contribution-based best-response (MCBR) algorithm of low computational complexity for the distributed subchannel allocation problem. Finally, we validate and evaluate the proposed scheme through simulations for various performance metrics.

Space-for-time substitution and the evolution of submarine canyons in a passive, progradational margin.

NASA Astrophysics Data System (ADS)

Micallef, Aaron; Ribó, Marta; Canals, Miquel; Puig, Pere; Lastras, Galderic; Tubau, Xavier

2013-04-01

40% of submarine canyons worldwide are located in passive margins, where they constitute preferential conduits of sediment and biodiversity hotspots. Recent studies have presented evidence that submarine canyons incising passive, progradational margins can co-evolve with the adjacent continental slope during long-term margin construction. The stages of submarine canyon initiation and their development into a mature canyon-channel system are still poorly constrained, however, which is problematic when attempting to reconstruct the development of passive continental margins. In this study we analyse multibeam echosounder and seismic reflection data from the southern Ebro margin (western Mediterranean Sea) to document the stages through which a first-order gully develops into a mature, shelf-breaching canyon and, finally, into a canyon-channel system. This morphological evolution allows the application of a space-for-time substitution approach. Initial gully growth on the continental slope takes place via incision and downslope elongation, with limited upslope head retreat. Gravity flows are the main driver of canyon evolution, whereas slope failures are the main agent of erosion; they control the extent of valley widening, promote tributary development, and their influence becomes more significant with time. Breaching of the continental shelf by a canyon results in higher water/sediment loads that enhance canyon development, particularly in the upper reaches. Connection of the canyon head with a paleo-river changes evolution dynamics significantly, promoting development of a channel and formation of depositional landforms. Morphometric analyses demonstrate that canyons develop into geometrically self-similar systems that approach steady-state and higher drainage efficiency. Canyon activity in the southern Ebro margin is pulsating and enhanced during sea level lowstands. Rapid sedimentation by extension of the palaeo-Millars River into the outermost shelf and upper slope is inferred as the source of gravity flows driving canyon evolution. Canyon morphology is shown to be maintained over the course of more than one fall and rise in sea-level. Our model of canyon evolution is applicable to other passive margins (e.g. Argentine continental margin).

Individualized Instruction in Science, Earth Space Project, Learning Activities Package.

ERIC Educational Resources Information Center

Kuczma, R. M.

Learning Activity Packages (LAP) relating to the earth and space are presented for use in sampling a new type of learning for a whole year. Eighteen topics are incorporated into five units: (1) introduction to individualized learning, (2) observation versus interpretation, (3) chemistry in the space age, (4) the space age interdisciplines, and (5)…

Qualitative differences in memory for vista and environmental spaces are caused by opaque borders, not movement or successive presentation.

PubMed

Meilinger, Tobias; Strickrodt, Marianne; Bülthoff, Heinrich H

2016-10-01

Two classes of space define our everyday experience within our surrounding environment: vista spaces, such as rooms or streets which can be perceived from one vantage point, and environmental spaces, for example, buildings and towns which are grasped from multiple views acquired during locomotion. However, theories of spatial representations often treat both spaces as equal. The present experiments show that this assumption cannot be upheld. Participants learned exactly the same layout of objects either within a single room or spread across multiple corridors. By utilizing a pointing and a placement task we tested the acquired configurational memory. In Experiment 1 retrieving memory of the object layout acquired in environmental space was affected by the distance of the traveled path and the order in which the objects were learned. In contrast, memory retrieval of objects learned in vista space was not bound to distance and relied on different ordering schemes (e.g., along the layout structure). Furthermore, spatial memory of both spaces differed with respect to the employed reference frame orientation. Environmental space memory was organized along the learning experience rather than layout intrinsic structure. In Experiment 2 participants memorized the object layout presented within the vista space room of Experiment 1 while the learning procedure emulated environmental space learning (movement, successive object presentation). Neither factor rendered similar results as found in environmental space learning. This shows that memory differences between vista and environmental space originated mainly from the spatial compartmentalization which was unique to environmental space learning. Our results suggest that transferring conclusions from findings obtained in vista space to environmental spaces and vice versa should be made with caution. Copyright © 2016 Elsevier B.V. All rights reserved.

Independent Component Analysis of Textures

NASA Technical Reports Server (NTRS)

Manduchi, Roberto; Portilla, Javier

2000-01-01

A common method for texture representation is to use the marginal probability densities over the outputs of a set of multi-orientation, multi-scale filters as a description of the texture. We propose a technique, based on Independent Components Analysis, for choosing the set of filters that yield the most informative marginals, meaning that the product over the marginals most closely approximates the joint probability density function of the filter outputs. The algorithm is implemented using a steerable filter space. Experiments involving both texture classification and synthesis show that compared to Principal Components Analysis, ICA provides superior performance for modeling of natural and synthetic textures.

Equity or Marginalization?: The High School Course-Taking of Students Labeled with a Learning Disability

ERIC Educational Resources Information Center

Shifrer, Dara; Callahan, Rebecca M.; Muller, Chandra

2013-01-01

Placement of some students into the courses needed only for high school graduation and others into those that prepare them for college constitutes academic stratification. This study uses data from the Education Longitudinal Study of 2002 to investigate whether students labeled with learning disabilities complete fewer academic courses by the end…

Quality Early Childhood Education for Disadvantaged Children: An Investigation in the MCD Schools

ERIC Educational Resources Information Center

Chopra, Neelima

2016-01-01

Schools run by Municipal Corporation of Delhi (MCD) play a pivotal role in providing early childhood education to young children belonging to marginalized sections of Delhi. However, literature review reveals that low learning outcomes are common among children attending these schools. Low levels of learning are often associated with poor quality…

Standardizing the Essential Knowledge, Skills, and Attitudes for Democratic Life: A Content Analysis of Virginia Standards of Learning and Social Studies Textbooks

ERIC Educational Resources Information Center

Scott, Wendy; Suh, Yonghee

2015-01-01

This content analysis explored how Civics and Government textbooks and the Virginia Standards of Learning for Civics and Government courses reflect citizenship outcomes, specifically deconstructing the unique needs of marginalized students. The coding frame was constructed by using themes and categories from previous literature, specifically…

Learning through Emotion: Moving the Affective in from the Margins

ERIC Educational Resources Information Center

Dunn, Julie; Stinson, Madonna

2012-01-01

In an educational environment where experiences offered to children are increasingly being shaped by testing regimes and rigid curriculum design, learning experiences can often border on the bland and the neutral, or at best, focus on positive emotions such as joy and happiness. The work which is described in this article was designed to stimulate…

Learning for Social Justice: A Cultural Historical Activity Theory Analysis of Community Leadership Empowerment in a Korean American Community Organization

ERIC Educational Resources Information Center

Kim, Junghwan

2012-01-01

Community organizations, especially those aiming at social change, play a significant role in establishing societal health and contributing to adult learning in daily communities. Their existence secures marginalized groups' involvement in society and enhances community development by building community leadership with multiple stakeholders…

Photovoice and Photodocumentary for Enhancing Community Partner Engagement and Student Learning in a Public Health Field School in Cape Town

ERIC Educational Resources Information Center

Wainwright, Megan; Bingham, Shantell; Sicwebu, Namhla

2017-01-01

Background: Field school research, which begins by considering community partners as pedagogues and thus exploring their perspectives on student learning, is uncommon. Photovoice is a method for self-expression of such marginalized voices. Purpose: Describe the photovoice to photodocumentary process and present results of its evaluation.…

Space Matters: Experiences of Managing Static Formal Learning Spaces

ERIC Educational Resources Information Center

Montgomery, Tim

2008-01-01

Managing the space in which learning takes place is subject to ongoing debate. Spatial management and movement can impact upon the construction of meaning within education and upon the dynamic of learning. It is suggested that there are now different learning goals and expectations and consequently a need for different learning environments. We…

From E-Learning Space to E-Learning Place

ERIC Educational Resources Information Center

Wahlstedt, Ari; Pekkola, Samuli; Niemela, Marketta

2008-01-01

In this paper, it is argued that e-learning environments are currently more like "buildings", i.e., learning spaces, rather than "schools", i.e., places for learning. The concepts originated from architecture and urban design, where they are used both to distinguish static spaces from inhabited places, and more importantly, as design objectives.…

Autonomous Motion Learning for Intra-Vehicular Activity Space Robot

NASA Astrophysics Data System (ADS)

Watanabe, Yutaka; Yairi, Takehisa; Machida, Kazuo

Space robots will be needed in the future space missions. So far, many types of space robots have been developed, but in particular, Intra-Vehicular Activity (IVA) space robots that support human activities should be developed to reduce human-risks in space. In this paper, we study the motion learning method of an IVA space robot with the multi-link mechanism. The advantage point is that this space robot moves using reaction force of the multi-link mechanism and contact forces from the wall as space walking of an astronaut, not to use a propulsion. The control approach is determined based on a reinforcement learning with the actor-critic algorithm. We demonstrate to clear effectiveness of this approach using a 5-link space robot model by simulation. First, we simulate that a space robot learn the motion control including contact phase in two dimensional case. Next, we simulate that a space robot learn the motion control changing base attitude in three dimensional case.

Review and Assessment of JPL's Thermal Margins

NASA Technical Reports Server (NTRS)

Siebes, G.; Kingery, C.; Farguson, C.; White, M.; Blakely, M.; Nunes, J.; Avila, A.; Man, K.; Hoffman, A.; Forgrave, J.

2012-01-01

JPL has captured its experience from over four decades of robotic space exploration into a set of design rules. These rules have gradually changed into explicit requirements and are now formally implemented and verified. Over an extended period of time, the initial understanding of intent and rationale for these rules has faded and rules are now frequently applied without further consideration. In the meantime, mission classes and their associated risk postures have evolved, coupled with resource constraints and growing design diversity, bringing into question the current "one size fits all" thermal margin approach. This paper offers a systematic review of the heat flow path from an electronic junction to the eventual heat rejection to space. This includes the identification of different regimes along this path and the associated requirements. The work resulted in a renewed understanding of the intent behind JPL requirements for hot thermal margins and a framework for relevant considerations, which in turn enables better decision making when a deviation to these requirements is considered.

The Impact of Congruency Between Preferred and Actual Learning Environments on Tenth Graders' Science Literacy in Taiwan

NASA Astrophysics Data System (ADS)

Chang, Chun-Yen; Yeh, Ting-Kuang; Lin, Chun-Yen; Chang, Yueh-Hsia; Chen, Chia-Li D.

2010-08-01

This study explored the effects of congruency between preferred and actual learning environment (PLE & ALE) perceptions on students' science literacy in terms of science concepts, attitudes toward science, and the understanding of the nature of science in an innovative curriculum of High Scope Project, namely Sci-Tech Mind and Humane Heart (STMHH). A pre-/post-treatment experiment was conducted with 34 Taiwanese tenth graders involved in this study. Participating students' preferred learning environment perception and pre-instruction scientific literacy were evaluated before the STMHH curriculum. Their perceptions toward the actual STMHH learning environment and post-instruction scientific literacy were also examined after the STMHH. Students were categorized into two groups; "preferred alignment with actual learning environment" (PAA) and "preferred discordant with actual learning environment" (PDA), according to their PLEI and ALEI scores. The results of this study revealed that most of the students in this study preferred learning in a classroom environment where student-centered and teacher-centered learning environments coexisted. Furthermore, the ANCOVA analysis showed marginally statistically significant difference between groups in terms of students' post-test scores on scientific literacy with the students' pre-test scores as the covariate. As a pilot study with a small sample size aiming to probe the research direction of this problem, the result of marginally statistically significant and approaching large sized effect magnitude is likely to implicate that the congruency between preferred and actual learning environments on students' scientific literacy is noteworthy. Future study of this nature appears to merit further replications and investigations.

Distinct iron isotopic signatures and supply from marine sediment dissolution.

PubMed

Homoky, William B; John, Seth G; Conway, Tim M; Mills, Rachel A

2013-01-01

Oceanic iron inputs must be traced and quantified to learn how they affect primary productivity and climate. Chemical reduction of iron in continental margin sediments provides a substantial dissolved flux to the oceans, which is isotopically lighter than the crust, and so may be distinguished in seawater from other sources, such as wind-blown dust. However, heavy iron isotopes measured in seawater have recently led to the proposition of another source of dissolved iron from 'non-reductive' dissolution of continental margins. Here we present the first pore water iron isotope data from a passive-tectonic and semi-arid ocean margin (South Africa), which reveals a smaller and isotopically heavier flux of dissolved iron to seawater than active-tectonic and dysoxic continental margins. These data provide in situ evidence of non-reductive iron dissolution from a continental margin, and further show that geological and hydro-climatic factors may affect the amount and isotopic composition of iron entering the ocean.

Distinct iron isotopic signatures and supply from marine sediment dissolution

PubMed Central

Homoky, William B.; John, Seth G.; Conway, Tim M.; Mills, Rachel A.

2013-01-01

Oceanic iron inputs must be traced and quantified to learn how they affect primary productivity and climate. Chemical reduction of iron in continental margin sediments provides a substantial dissolved flux to the oceans, which is isotopically lighter than the crust, and so may be distinguished in seawater from other sources, such as wind-blown dust. However, heavy iron isotopes measured in seawater have recently led to the proposition of another source of dissolved iron from ‘non-reductive’ dissolution of continental margins. Here we present the first pore water iron isotope data from a passive-tectonic and semi-arid ocean margin (South Africa), which reveals a smaller and isotopically heavier flux of dissolved iron to seawater than active-tectonic and dysoxic continental margins. These data provide in situ evidence of non-reductive iron dissolution from a continental margin, and further show that geological and hydro-climatic factors may affect the amount and isotopic composition of iron entering the ocean. PMID:23868399

Identification of Predictive Cis-Regulatory Elements Using a Discriminative Objective Function and a Dynamic Search Space

PubMed Central

Karnik, Rahul; Beer, Michael A.

2015-01-01

The generation of genomic binding or accessibility data from massively parallel sequencing technologies such as ChIP-seq and DNase-seq continues to accelerate. Yet state-of-the-art computational approaches for the identification of DNA binding motifs often yield motifs of weak predictive power. Here we present a novel computational algorithm called MotifSpec, designed to find predictive motifs, in contrast to over-represented sequence elements. The key distinguishing feature of this algorithm is that it uses a dynamic search space and a learned threshold to find discriminative motifs in combination with the modeling of motifs using a full PWM (position weight matrix) rather than k-mer words or regular expressions. We demonstrate that our approach finds motifs corresponding to known binding specificities in several mammalian ChIP-seq datasets, and that our PWMs classify the ChIP-seq signals with accuracy comparable to, or marginally better than motifs from the best existing algorithms. In other datasets, our algorithm identifies novel motifs where other methods fail. Finally, we apply this algorithm to detect motifs from expression datasets in C. elegans using a dynamic expression similarity metric rather than fixed expression clusters, and find novel predictive motifs. PMID:26465884

Identification of Predictive Cis-Regulatory Elements Using a Discriminative Objective Function and a Dynamic Search Space.

PubMed

Karnik, Rahul; Beer, Michael A

2015-01-01

The generation of genomic binding or accessibility data from massively parallel sequencing technologies such as ChIP-seq and DNase-seq continues to accelerate. Yet state-of-the-art computational approaches for the identification of DNA binding motifs often yield motifs of weak predictive power. Here we present a novel computational algorithm called MotifSpec, designed to find predictive motifs, in contrast to over-represented sequence elements. The key distinguishing feature of this algorithm is that it uses a dynamic search space and a learned threshold to find discriminative motifs in combination with the modeling of motifs using a full PWM (position weight matrix) rather than k-mer words or regular expressions. We demonstrate that our approach finds motifs corresponding to known binding specificities in several mammalian ChIP-seq datasets, and that our PWMs classify the ChIP-seq signals with accuracy comparable to, or marginally better than motifs from the best existing algorithms. In other datasets, our algorithm identifies novel motifs where other methods fail. Finally, we apply this algorithm to detect motifs from expression datasets in C. elegans using a dynamic expression similarity metric rather than fixed expression clusters, and find novel predictive motifs.

Solo Life to Second Life: The Design of Physical and Virtual Learning Spaces Inspired by the Drama Classroom

ERIC Educational Resources Information Center

Nicholls, Jennifer; Philip, Robyn

2012-01-01

This paper explores the design of virtual and physical learning spaces developed for students of drama and theatre studies. What can we learn from the traditional drama workshop that will inform the design of drama and theatre spaces created in technology-mediated learning environments? The authors examine four examples of spaces created for…

Ambience in Social Learning: Student Engagement with New Designs for Learning Spaces

ERIC Educational Resources Information Center

Crook, Charles; Mitchell, Gemma

2012-01-01

An imperative to develop the social experience of learning has led to the design of informal learning spaces within libraries. Yet little is known about how these spaces are used by students or how students perceive them. Field work in one such space is reported. The general private study practice of undergraduates was captured through audio…

Embedded Managers in Informal Learning Spaces

ERIC Educational Resources Information Center

Raisin, Victoria; Fennewald, Joseph

2016-01-01

Many universities have decided to invest in updating their informal learning spaces. One decision to be made in planning the space is how to staff it. The researchers carried out a qualitative case study to better understand the perspective of learning space managers who work in offices within their assigned space. The research generated six…

Mapping Next Generation Learning Spaces as a Designed Quality Enhancement Process

ERIC Educational Resources Information Center

Leonard, Simon N.; Fitzgerald, Robert N.; Bacon, Matt; Munnerley, Danny

2017-01-01

The learning spaces of higher education are changing with collaborative, agile and technology-enabled spaces ever more popular. Despite the massive investment required to create these new spaces, current quality systems are poorly placed to account for the value they create. Such learning spaces are typically popular with students but the impact…

Inter-Labeler and Intra-Labeler Variability of Condition Severity Classification Models Using Active and Passive Learning Methods

PubMed Central

Nissim, Nir; Shahar, Yuval; Boland, Mary Regina; Tatonetti, Nicholas P; Elovici, Yuval; Hripcsak, George; Moskovitch, Robert

2018-01-01

Background and Objectives Labeling instances by domain experts for classification is often time consuming and expensive. To reduce such labeling efforts, we had proposed the application of active learning (AL) methods, introduced our CAESAR-ALE framework for classifying the severity of clinical conditions, and shown its significant reduction of labeling efforts. The use of any of three AL methods (one well known [SVM-Margin], and two that we introduced [Exploitation and Combination_XA]) significantly reduced (by 48% to 64%) condition labeling efforts, compared to standard passive (random instance-selection) SVM learning. Furthermore, our new AL methods achieved maximal accuracy using 12% fewer labeled cases than the SVM-Margin AL method. However, because labelers have varying levels of expertise, a major issue associated with learning methods, and AL methods in particular, is how to best to use the labeling provided by a committee of labelers. First, we wanted to know, based on the labelers’ learning curves, whether using AL methods (versus standard passive learning methods) has an effect on the Intra-labeler variability (within the learning curve of each labeler) and inter-labeler variability (among the learning curves of different labelers). Then, we wanted to examine the effect of learning (either passively or actively) from the labels created by the majority consensus of a group of labelers. Methods We used our CAESAR-ALE framework for classifying the severity of clinical conditions, the three AL methods and the passive learning method, as mentioned above, to induce the classifications models. We used a dataset of 516 clinical conditions and their severity labeling, represented by features aggregated from the medical records of 1.9 million patients treated at Columbia University Medical Center. We analyzed the variance of the classification performance within (intra-labeler), and especially among (inter-labeler) the classification models that were induced by using the labels provided by seven labelers. We also compared the performance of the passive and active learning models when using the consensus label. Results The AL methods produced, for the models induced from each labeler, smoother Intra-labeler learning curves during the training phase, compared to the models produced when using the passive learning method. The mean standard deviation of the learning curves of the three AL methods over all labelers (mean: 0.0379; range: [0.0182 to 0.0496]), was significantly lower (p = 0.049) than the Intra-labeler standard deviation when using the passive learning method (mean: 0.0484; range: [0.0275 to 0.0724). Using the AL methods resulted in a lower mean Inter-labeler AUC standard deviation among the AUC values of the labelers’ different models during the training phase, compared to the variance of the induced models’ AUC values when using passive learning. The Inter-labeler AUC standard deviation, using the passive learning method (0.039), was almost twice as high as the Inter-labeler standard deviation using our two new AL methods (0.02 and 0.019, respectively). The SVM-Margin AL method resulted in an Inter-labeler standard deviation (0.029) that was higher by almost 50% than that of our two AL methods. The difference in the inter-labeler standard deviation between the passive learning method and the SVM-Margin learning method was significant (p = 0.042). The difference between the SVM-Margin and Exploitation method was insignificant (p = 0.29), as was the difference between the Combination_XA and Exploitation methods (p = 0.67). Finally, using the consensus label led to a learning curve that had a higher mean intra-labeler variance, but resulted eventually in an AUC that was at least as high as the AUC achieved using the gold standard label and that was always higher than the expected mean AUC of a randomly selected labeler, regardless of the choice of learning method (including a passive learning method). Using a paired t-test, the difference between the intra-labeler AUC standard deviation when using the consensus label, versus that value when using the other two labeling strategies, was significant only when using the passive learning method (p = 0.014), but not when using any of the three AL methods. Conclusions The use of AL methods, (a) reduces intra-labeler variability in the performance of the induced models during the training phase, and thus reduces the risk of halting the process at a local minimum that is significantly different in performance from the rest of the learned models; and (b) reduces Inter-labeler performance variance, and thus reduces the dependence on the use of a particular labeler. In addition, the use of a consensus label, agreed upon by a rather uneven group of labelers, might be at least as good as using the gold standard labeler, who might not be available, and certainly better than randomly selecting one of the group’s individual labelers. Finally, using the AL methods when provided by the consensus label reduced the intra-labeler AUC variance during the learning phase, compared to using passive learning. PMID:28456512

Inter-labeler and intra-labeler variability of condition severity classification models using active and passive learning methods.

PubMed

Nissim, Nir; Shahar, Yuval; Elovici, Yuval; Hripcsak, George; Moskovitch, Robert

2017-09-01

Labeling instances by domain experts for classification is often time consuming and expensive. To reduce such labeling efforts, we had proposed the application of active learning (AL) methods, introduced our CAESAR-ALE framework for classifying the severity of clinical conditions, and shown its significant reduction of labeling efforts. The use of any of three AL methods (one well known [SVM-Margin], and two that we introduced [Exploitation and Combination_XA]) significantly reduced (by 48% to 64%) condition labeling efforts, compared to standard passive (random instance-selection) SVM learning. Furthermore, our new AL methods achieved maximal accuracy using 12% fewer labeled cases than the SVM-Margin AL method. However, because labelers have varying levels of expertise, a major issue associated with learning methods, and AL methods in particular, is how to best to use the labeling provided by a committee of labelers. First, we wanted to know, based on the labelers' learning curves, whether using AL methods (versus standard passive learning methods) has an effect on the Intra-labeler variability (within the learning curve of each labeler) and inter-labeler variability (among the learning curves of different labelers). Then, we wanted to examine the effect of learning (either passively or actively) from the labels created by the majority consensus of a group of labelers. We used our CAESAR-ALE framework for classifying the severity of clinical conditions, the three AL methods and the passive learning method, as mentioned above, to induce the classifications models. We used a dataset of 516 clinical conditions and their severity labeling, represented by features aggregated from the medical records of 1.9 million patients treated at Columbia University Medical Center. We analyzed the variance of the classification performance within (intra-labeler), and especially among (inter-labeler) the classification models that were induced by using the labels provided by seven labelers. We also compared the performance of the passive and active learning models when using the consensus label. The AL methods: produced, for the models induced from each labeler, smoother Intra-labeler learning curves during the training phase, compared to the models produced when using the passive learning method. The mean standard deviation of the learning curves of the three AL methods over all labelers (mean: 0.0379; range: [0.0182 to 0.0496]), was significantly lower (p=0.049) than the Intra-labeler standard deviation when using the passive learning method (mean: 0.0484; range: [0.0275-0.0724). Using the AL methods resulted in a lower mean Inter-labeler AUC standard deviation among the AUC values of the labelers' different models during the training phase, compared to the variance of the induced models' AUC values when using passive learning. The Inter-labeler AUC standard deviation, using the passive learning method (0.039), was almost twice as high as the Inter-labeler standard deviation using our two new AL methods (0.02 and 0.019, respectively). The SVM-Margin AL method resulted in an Inter-labeler standard deviation (0.029) that was higher by almost 50% than that of our two AL methods The difference in the inter-labeler standard deviation between the passive learning method and the SVM-Margin learning method was significant (p=0.042). The difference between the SVM-Margin and Exploitation method was insignificant (p=0.29), as was the difference between the Combination_XA and Exploitation methods (p=0.67). Finally, using the consensus label led to a learning curve that had a higher mean intra-labeler variance, but resulted eventually in an AUC that was at least as high as the AUC achieved using the gold standard label and that was always higher than the expected mean AUC of a randomly selected labeler, regardless of the choice of learning method (including a passive learning method). Using a paired t-test, the difference between the intra-labeler AUC standard deviation when using the consensus label, versus that value when using the other two labeling strategies, was significant only when using the passive learning method (p=0.014), but not when using any of the three AL methods. The use of AL methods, (a) reduces intra-labeler variability in the performance of the induced models during the training phase, and thus reduces the risk of halting the process at a local minimum that is significantly different in performance from the rest of the learned models; and (b) reduces Inter-labeler performance variance, and thus reduces the dependence on the use of a particular labeler. In addition, the use of a consensus label, agreed upon by a rather uneven group of labelers, might be at least as good as using the gold standard labeler, who might not be available, and certainly better than randomly selecting one of the group's individual labelers. Finally, using the AL methods: when provided by the consensus label reduced the intra-labeler AUC variance during the learning phase, compared to using passive learning. Copyright © 2017 Elsevier B.V. All rights reserved.

Successive and discrete spaced conditioning in active avoidance learning in young and aged zebrafish.

PubMed

Yang, Peng; Kajiwara, Riki; Tonoki, Ayako; Itoh, Motoyuki

2018-05-01

We designed an automated device to study active avoidance learning abilities of zebrafish. Open source tools were used for the device control, statistical computing, and graphic outputs of data. Using the system, we developed active avoidance tests to examine the effects of trial spacing and aging on learning. Seven-month-old fish showed stronger avoidance behavior as measured by color preference index with discrete spaced training as compared to successive spaced training. Fifteen-month-old fish showed a similar trend, but with reduced cognitive abilities compared with 7-month-old fish. Further, in 7-month-old fish, an increase in learning ability during trials was observed with discrete, but not successive, spaced training. In contrast, 15-month-old fish did not show increase in learning ability during trials. Therefore, these data suggest that discrete spacing is more effective for learning than successive spacing, with the zebrafish active avoidance paradigm, and that the time course analysis of active avoidance using discrete spaced training is useful to detect age-related learning impairment. Copyright © 2017 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

In vivo classification of human skin burns using machine learning and quantitative features captured by optical coherence tomography

NASA Astrophysics Data System (ADS)

Singla, Neeru; Srivastava, Vishal; Singh Mehta, Dalip

2018-02-01

We report the first fully automated detection of human skin burn injuries in vivo, with the goal of automatic surgical margin assessment based on optical coherence tomography (OCT) images. Our proposed automated procedure entails building a machine-learning-based classifier by extracting quantitative features from normal and burn tissue images recorded by OCT. In this study, 56 samples (28 normal, 28 burned) were imaged by OCT and eight features were extracted. A linear model classifier was trained using 34 samples and 22 samples were used to test the model. Sensitivity of 91.6% and specificity of 90% were obtained. Our results demonstrate the capability of a computer-aided technique for accurately and automatically identifying burn tissue resection margins during surgical treatment.

Forward Skirt Structural Testing on the Space Launch System (SLS) Program

NASA Technical Reports Server (NTRS)

Lohrer, J. D.; Wright, R. D.

2016-01-01

Structural testing was performed to evaluate heritage forward skirts from the Space Shuttle program for use on the NASA Space Launch System (SLS) program. Testing was needed because SLS ascent loads are 35% higher than Space Shuttle loads. Objectives of testing were to determine margins of safety, demonstrate reliability, and validate analytical models. Testing combined with analysis was able to show heritage forward skirts were acceptable to use on the SLS program.

Representative Model of the Learning Process in Virtual Spaces Supported by ICT

ERIC Educational Resources Information Center

Capacho, José

2014-01-01

This paper shows the results of research activities for building the representative model of the learning process in virtual spaces (e-Learning). The formal basis of the model are supported in the analysis of models of learning assessment in virtual spaces and specifically in Dembo´s teaching learning model, the systemic approach to evaluating…

Matching Instructors and Spaces of Learning: The Impact of Space on Behavioral, Affective and Cognitive Learning

ERIC Educational Resources Information Center

McArthur, John A.

2015-01-01

This study examined the extent to which instructional proxemics--the physical space of the learning environment--impacts student behavioral, affective, and cognitive learning. Participants included 234 college students enrolled in 15 sections of public speaking. Each section was assigned to a study learning environment and an instructor, ensuring…

Learning through Social Spaces: Migrant Women and Lifelong Learning in Post-Colonial London

ERIC Educational Resources Information Center

Jackson, Sue

2010-01-01

This article shows how migrant women engage in learning through social spaces. It argues that such spaces are little recognised, and that there are multiple ways in which migrant women construct and negotiate their informal learning through socialising with other women in different informal modes. Additionally, the article shows how learning is…

Improving and Evaluating Nested Sampling Algorithm for Marginal Likelihood Estimation

NASA Astrophysics Data System (ADS)

Ye, M.; Zeng, X.; Wu, J.; Wang, D.; Liu, J.

2016-12-01

With the growing impacts of climate change and human activities on the cycle of water resources, an increasing number of researches focus on the quantification of modeling uncertainty. Bayesian model averaging (BMA) provides a popular framework for quantifying conceptual model and parameter uncertainty. The ensemble prediction is generated by combining each plausible model's prediction, and each model is attached with a model weight which is determined by model's prior weight and marginal likelihood. Thus, the estimation of model's marginal likelihood is crucial for reliable and accurate BMA prediction. Nested sampling estimator (NSE) is a new proposed method for marginal likelihood estimation. The process of NSE is accomplished by searching the parameters' space from low likelihood area to high likelihood area gradually, and this evolution is finished iteratively via local sampling procedure. Thus, the efficiency of NSE is dominated by the strength of local sampling procedure. Currently, Metropolis-Hasting (M-H) algorithm is often used for local sampling. However, M-H is not an efficient sampling algorithm for high-dimensional or complicated parameter space. For improving the efficiency of NSE, it could be ideal to incorporate the robust and efficient sampling algorithm - DREAMzs into the local sampling of NSE. The comparison results demonstrated that the improved NSE could improve the efficiency of marginal likelihood estimation significantly. However, both improved and original NSEs suffer from heavy instability. In addition, the heavy computation cost of huge number of model executions is overcome by using an adaptive sparse grid surrogates.

Practical Methodology for the Inclusion of Nonlinear Slosh Damping in the Stability Analysis of Liquid-Propelled Space Vehicles

NASA Technical Reports Server (NTRS)

Ottander, John A.; Hall, Robert A.; Powers, J. F.

2018-01-01

A method is presented that allows for the prediction of the magnitude of limit cycles due to adverse control-slosh interaction in liquid propelled space vehicles using non-linear slosh damping. Such a method is an alternative to the industry practice of assuming linear damping and relying on: mechanical slosh baffles to achieve desired stability margins; accepting minimal slosh stability margins; or time domain non-linear analysis to accept time periods of poor stability. Sinusoidal input describing functional analysis is used to develop a relationship between the non-linear slosh damping and an equivalent linear damping at a given slosh amplitude. In addition, a more accurate analytical prediction of the danger zone for slosh mass locations in a vehicle under proportional and derivative attitude control is presented. This method is used in the control-slosh stability analysis of the NASA Space Launch System.

Assessment of Marginal Adaptation and Sealing Ability of Root Canal Sealers: An in vitro Study.

PubMed

Remy, Vimal; Krishnan, Vineesh; Job, Tisson V; Ravisankar, Madhavankutty S; Raj, C V Renjith; John, Seena

2017-12-01

This study aims to compare the marginal adaptation and sealing ability [mineral trioxide aggregate (MTA)-Fillapex, AH Plus, Endofill sealers] of root canal sealers. In the present study, the inclusion criteria include 45 single-rooted extracted mandibular premolar teeth, with single canal and complete root formation. The sectioning of the samples was done at the cementoenamel junction using a low-speed diamond disc. Step-back technique was used to prepare root canals manually. The MTA-Fillapex, AH Plus, and Endofill sealers were the three experimental sealer groups to which 45 teeth were distributed. Under scanning electron microscope (SEM), marginal gap at sealer and root dentin interface were examined at coronal and apical halves of root canal. Among the three maximum marginal adaptations were seen with AH Plus sealer (4.10 ± 0.10) which is followed by Endofill sealer (1.44 ± 0.18) and MTA-Fillapex sealer (0.80 ± 0.22). Between the coronal and apical marginal adaptation, significant statistical difference (p = 0.001) was seen in AH Plus sealer. When a Mann-Whitney U-test was done on MTA-Fillapex sealer vs AH Plus sealer and AH Plus sealer vs Endofill sealer, there was a statistically significant difference (p < 0.05) found between the above two groups at coronal and apical third. The present study proves that AH Plus sealer has a better marginal adaptation when compared with other sealers used. For sealing space of crown wall and main cone in root canal treatment, sealers play an important role. The other advantages of sealers are that they are used to fill voids and irregularities in root channel, secondary, lateral channels, and space between applied gutta-percha cones and also act as tripper during filling.

The Role of Nonclassroom Spaces in Living-Learning Communities

ERIC Educational Resources Information Center

Altimare, Emily; Sheridan, David M.

2016-01-01

A body of research suggests that learning communities provide a range of academic benefits by increasing social connectedness. Researchers have also hypothesized that informal learning spaces--nonclassroom spaces (NCSs)--can facilitate learning by supporting social connectedness. This study uses qualitative methods to explore the way nonclassroom…

e-Learning versus lecture-based courses in ECG interpretation for undergraduate medical students: a randomized noninferiority study.

PubMed

Montassier, Emmanuel; Hardouin, Jean-Benoît; Segard, Julien; Batard, Eric; Potel, Gilles; Planchon, Bernard; Trochu, Jean-Noël; Pottier, Pierre

2016-04-01

An ECG is pivotal for the diagnosis of coronary heart disease. Previous studies have reported deficiencies in ECG interpretation skills that have been responsible for misdiagnosis. However, the optimal way to acquire ECG interpretation skills is still under discussion. Thus, our objective was to compare the effectiveness of e-learning and lecture-based courses for learning ECG interpretation skills in a large randomized study. We conducted a prospective, randomized, controlled, noninferiority study. Participants were recruited from among fifth-year medical students and were assigned to the e-learning group or the lecture-based group using a computer-generated random allocation sequence. The e-learning and lecture-based groups were compared on a score of effectiveness, comparing the 95% unilateral confidence interval (95% UCI) of the score of effectiveness with the mean effectiveness in the lecture-based group, adjusted for a noninferiority margin. Ninety-eight students were enrolled. As compared with the lecture-based course, e-learning was noninferior with regard to the postcourse test score (15.1; 95% UCI 14.2; +∞), which can be compared with 12.5 [the mean effectiveness in the lecture-based group (15.0) minus the noninferiority margin (2.5)]. Furthermore, there was a significant increase in the test score points in both the e-learning and lecture-based groups during the study period (both P<0.0001). Our randomized study showed that the e-learning course is an effective tool for the acquisition of ECG interpretation skills by medical students. These preliminary results should be confirmed with further multicenter studies before the implementation of e-learning courses for learning ECG interpretation skills during medical school.

Experimental Investigation of Centrifugal Compressor Stabilization Techniques

NASA Technical Reports Server (NTRS)

Skoch, Gary J.

2003-01-01

Results from a series of experiments to investigate techniques for extending the stable flow range of a centrifugal compressor are reported. The research was conducted in a high-speed centrifugal compressor at the NASA Glenn Research Center. The stabilizing effect of steadily flowing air-streams injected into the vaneless region of a vane-island diffuser through the shroud surface is described. Parametric variations of injection angle, injection flow rate, number of injectors, injector spacing, and injection versus bleed were investigated for a range of impeller speeds and tip clearances. Both the compressor discharge and an external source were used for the injection air supply. The stabilizing effect of flow obstructions created by tubes that were inserted into the diffuser vaneless space through the shroud was also investigated. Tube immersion into the vaneless space was varied in the flow obstruction experiments. Results from testing done at impeller design speed and tip clearance are presented. Surge margin improved by 1.7 points using injection air that was supplied from within the compressor. Externally supplied injection air was used to return the compressor to stable operation after being throttled into surge. The tubes, which were capped to prevent mass flux, provided 9.3 points of additional surge margin over the baseline surge margin of 11.7 points.

Style of extensional tectonism during rifting, Red Sea and Gulf of Aden

USGS Publications Warehouse

Bohannon, R.G.

1989-01-01

Geologic and geophysical studies from the Arabian continental margin in the southern Red Sea and LANDSAT analysis of the northern Somalia margin in the Gulf of Aden suggest that the early continental rifts were long narrow features that formed by extension on closely spaced normal faults above moderate- to shallow-dipping detachments with break-away zones defining one rift flank and root zones under the opposing rift flank. The rift flanks presently form the opposing continental margins across each ocean basin. The detachment on the Arabian margin dips gently to the west, with a breakaway zone now eroded above the deeply dissected terrain of the Arabian escarpment. A model is proposed in which upper crustal breakup occurs on large detachment faults that have a distinct polarity. -from Author

Transition from magma dominant to magma poor rifting along the Nova Scotia Continental Margin

NASA Astrophysics Data System (ADS)

Lau, K. H.; Louden, K. E.; Nedimović, M. R.; Whitehead, M.; Farkas, A.; Watremez, L.; Dehler, S. A.

2011-12-01

Passive margins have been characterized as magma-dominant (volcanic) or magma-poor (non-volcanic). However, the conditions under which margins might switch states are not well understood as they typically have been studied as end member examples in isolation to each other. The Nova Scotia (NS) continental margin, however, offers an opportunity to study the nature of such a transition between the magma-dominant US East Coast margin to the south and the magma-poor Newfoundland margin to the north within a single rift segment. This transition is evidenced by a clear along-strike reduction in features characteristic of syn-rift volcanism from south-to-north along the NS margin, such as the weakening of the East Coast Magnetic Anomaly (ECMA) and the coincident disappearance of seaward dipping reflector sequences (SDRS) on multichannel seismic (MCS) reflection profiles. Results from recent industry MCS profiles along and across the margin suggest a potentially narrow magma-dominant to magma-poor along-strike transition between the southern and the central NS margin. Such a transition is broadly consistent with results of several widely-spaced, across-strike ocean bottom seismometer (OBS) wide-angle profiles. In the southern region, the crustal structure exhibits a narrow (~120-km wide) ocean-continent transition (OCT) with a high velocity (7.2 km/s) lower crust, interpreted as a gabbro-rich underplated melt, beneath the SDRS and the ECMA, similar to crustal models across the US East Coast. In contrast, profiles across the central and northern margin contain a much wider OCT (150-200-km wide) underlain by a low velocity mantle layer (7.3-7.9 km/s), interpreted as partially serpentinized olivine, which is similar to the magma-poor Newfoundland margin to the north. However, the central-to-northern OBS profiles also exhibit significant variations within the OCT and the along-strike continuity of these OCT structures is not yet clear. In November 2010, we acquired, in the OCTOPUS survey, wide-angle seismic data along a 240-km-long margin parallel profile extending from the central to the northern margin segments along an existing industry MCS profile (Ion/GX Technology NovaSPAN 5100). Twenty OBSs at 10-km spacing were analysed. A preliminary p-wave velocity model along the profile indicates that the cross-strike structures are continuous within the OCT. However, a substantial anisotropy in velocity (~8% lower parallel to the margin) is observed within the OCT. This result is consistent with an interpretation of partially serpentinized mantle that flowed perpendicular to the margin during its extension. In addition, along strike variations are also observed along the profile, which suggest a higher degree of volcanism and a thinner layer of serpentinized mantle to the southwest. These results provide a framework for future studies to the southwest to further investigate the transition to a magma-dominant regime towards the US East Coast.

Visualizing Queer Spaces: LGBTQ Students and the Traditionally Heterogendered Institution

ERIC Educational Resources Information Center

Pryor, Jonathan T.

2018-01-01

As colleges and universities have increased campus programs, LGBTQ students continue to experience marginalization within the very spaces intended to support them. This study explored how LGBTQ college students experienced campus climate at a Midwest Urban Public (MUP) institution through a framework of the traditionally heterogendered institution…

Microgravity

NASA Image and Video Library

1995-03-02

Astronaut Wendy B. Lawrence, flight engineer and mission specialist for STS-67, scribbles notes on the margin of a checklist while monitoring an experiment on the Space Shuttle Endeavour's mid-deck. The experiment is the Protein Crystal Growth (PCG), which takes up locker space near the Commercial Materials Dispersion Apparatus Instruments Technology Associates Experiment (CMIX).

Heterotopias of Homelessness: Citizenship on the Margins

ERIC Educational Resources Information Center

Mendel, Maria

2011-01-01

The concept of heterotopia challenges political theory, which has often focused on utopic thinking. Foucault describes a heterotopia as a heterogenous space that juxtaposes in a single real place several spaces, several sites that are in themselves incompatible. Streets, squares and parks form heterotopias when their utopic purity as public space…

High School Equivalency as Counter-Space

ERIC Educational Resources Information Center

Schwartz, Joni

2014-01-01

This chapter is based on the findings of an ethnographic study of an urban General Education Development (GED®) program and suggests that, for some marginalized African American and other young men of color, adult education programs are counter-spaces (Yosso, Ceja, Smith, & Solorzano, [Yosso, T., 2009]) of spatial justice in opposition to…

Learning Space Service Design

ERIC Educational Resources Information Center

Felix, Elliot

2011-01-01

Much progress has been made in creating informal learning spaces that incorporate technology and flexibly support a variety of activities. This progress has been principally in designing the right combination of furniture, technology, and space. However, colleges and universities do not design services within learning spaces with nearly the same…

Influence of dynamic topography on landscape evolution and passive continental margin stratigraphy

NASA Astrophysics Data System (ADS)

Ding, Xuesong; Salles, Tristan; Flament, Nicolas; Rey, Patrice

2017-04-01

Quantifying the interaction between surface processes and tectonics/deep Earth processes is one important aspect of landscape evolution modelling. Both observations and results from numerical modelling indicate that dynamic topography - a surface expression of time-varying mantle convection - plays a significant role in shaping landscape through geological time. Recent research suggests that dynamic topography also has non-negligible effects on stratigraphic architecture by modifying accommodation space available for sedimentation. In addition, dynamic topography influences the sediment supply to continental margins. We use Badlands to investigate the evolution of a continental-scale landscape in response to transient dynamic uplift or subsidence, and to model the stratigraphic development on passive continental margins in response to sea-level change, thermal subsidence and dynamic topography. We consider a circularly symmetric landscape consisting of a plateau surrounded by a gently sloping continental plain and a continental margin, and a linear wave of dynamic topography. We analyze the evolution of river catchments, of longitudinal river profiles and of the χ values to evaluate the dynamic response of drainage systems to dynamic topography. We calculate the amount of cumulative erosion and deposition, and sediment flux at shoreline position, as a function of precipitation rate and erodibility coefficient. We compute the stratal stacking pattern and Wheeler diagram on vertical cross-sections at the continental margin. Our results indicate that dynamic topography 1) has a considerable influence on drainage reorganization; 2) contributes to shoreline migration and the distribution of depositional packages by modifying the accommodation space; 3) affects sediment supply to the continental margin. Transient dynamic topography contributes to the migration of drainage divides and to the migration of the mainstream in a drainage basin. The dynamic uplift (respectively subsidence) of the source area results in an increase (respectively decrease) of sediment supply, while the dynamic uplift (respectively subsidence) of the continental margin leads to a decrease (respectively increase) in sedimentation.

The Promise of Equality Schools: Improving Learning of Marginal Students.

ERIC Educational Resources Information Center

Ghory, Ward; Sinclair, Robert

Public schools are responsible for ensuring that all citizens are prepared for success. An analysis of the needs of high risk students and the introduction of the idea of an "Equality School" are described in this report. Research suggests that too many young people, many of whom come from minority groups, are forced to live and learn on…

At the Margins of Internationalization: An Analysis of Journal Articles on College Student Development, Learning, and Experiences, 1998-2011

ERIC Educational Resources Information Center

Renn, Kristen A.; Brazelton, G. Blue; Holmes, Joshua M.

2014-01-01

Although international attention to understanding college student development, learning, and experiences has increased, leading higher education journals do not seem to have kept pace. We examined 8 higher education and student affairs journals (5 from the US, 3 from Europe) from 1998 to 2011. We found overall that 5% of articles addressed…

Learning from Harvey Milk: The Limits and Opportunities of One Hero to Teach about LGBTQ People and Issues

ERIC Educational Resources Information Center

Donahue, David M.

2014-01-01

Highlighting a hero is a common response to including the history of marginalized people in the curriculum. Harvey Milk is becoming that hero as social studies curriculum responds to calls for including LGBTQ people. By studying Milk, what might young people learn about LGBTQ people, issues, and movements? What opportunities and limitations exist…

An Investigation of the Effects of Authentic Science Experiences Among Urban High School Students

NASA Astrophysics Data System (ADS)

Chapman, Angela

Providing equitable learning opportunities for all students has been a persistent issue for some time. This is evident by the science achievement gap that still exists between male and female students as well as between White and many non-White student populations (NCES, 2007, 2009, 2009b) and an underrepresentation of female, African-American, Hispanic, and Native Americans in many science, technology, engineering, and mathematics (STEM) related careers (NCES, 2009b). In addition to gender and ethnicity, socioeconomic status and linguistic differences are also factors that can marginalize students in the science classroom. One factor attributed to the achievement gap and low participation in STEM career is equitable access to resources including textbooks, laboratory equipment, qualified science teachers, and type of instruction. Extensive literature supports authentic science as one way of improving science learning. However, the majority of students do not have access to this type of resource. Additionally, extensive literature posits that culturally relevant pedagogy is one way of improving education. This study examines students' participation in an authentic science experience and argues that this is one way of providing culturally relevant pedagogy in science classrooms. The purpose of this study was to better understand how marginalized students were affected by their participation in an authentic science experience, within the context of an algae biofuel project. Accordingly, an interpretivist approach was taken. Data were collected from pre/post surveys and tests, semi-structured interviews, student journals, and classroom observations. Data analysis used a mixed methods approach. The data from this study were analyzed to better understand whether students perceived the experience to be one of authentic science, as well as how students science identities, perceptions about who can do science, attitudes toward science, and learning of science practices were affected by participation in an authentic science experience. Findings indicated that participation in an authentic science experience has a positive effect on science identities, scientist perceptions, science attitudes, and learning of science and is one approach to mitigating the effects of marginalization in the science classroom. Additional findings indicated that a relationship between the authenticity of the experience and the outcomes (science identity, perceptions about who can do science, science attitudes, and learning of science). This study provides empirical evidence to support authentic science learning as a means of improving students' learning, attitudes, and identities with respect to science. This study endorses authentic science experiences for all students, marginalized included. This has implications for how we prepare future and support current science teachers. In addition, this study shows how this model can be used to effectively implement science, technology, engineering, and mathematics (STEM) education.

Promoting Equity and Student Learning: Rigor in Undergraduate Academic Experiences

ERIC Educational Resources Information Center

Bowman, Nicholas A.; Culver, K. C.

2018-01-01

This chapter discusses rigor through an examination of academic experiences that promote college outcomes for all students, particularly for those from marginalized backgrounds or with lower academic preparation.

Leading the Transition from Classrooms to Learning Spaces

ERIC Educational Resources Information Center

Oblinger, Diana

2005-01-01

A number of factors are prompting higher education's interest in learning spaces: the need to renovate existing space or accommodate additional students, pedagogical advances, a better understanding of learners, and, in some cases, curricular reform. Moving from classrooms to learning spaces involves a conceptual shift as well as a commitment to…

The Online Classroom: A Thorough Depiction of Distance Learning Spaces

ERIC Educational Resources Information Center

McKenna, Kelly

2018-01-01

This study investigated the online higher education learning space of a doctoral program offered at a distance. It explored the learning space, the stakeholders, utilization, and creators of the space. Developing a successful online classroom experience that incorporates an engaging environment and dynamic community setting conducive to learning…

Making the Case for Space: The Effect of Learning Spaces on Teaching and Learning

ERIC Educational Resources Information Center

Byers, Terry; Imms, Wesley; Hartnell-Young, Elizabeth

2014-01-01

An explanatory, mixed method study examined the impact of learning spaces on teachers' pedagogy, student engagement and student learning outcomes in a technology-rich school setting. Its quasi-experimental design allowed examination of differences in these variables between two settings--'traditional' classrooms, and 'new generation learning…

Informal Learning Spaces and Their Impact on Learning in Higher Education: Framing New Narratives of Participation

ERIC Educational Resources Information Center

Deed, Craig; Alterator, Scott

2017-01-01

Evaluating informal learning spaces in higher education institutions needs to respond to the complex conceptual orientation underpinning their intention and design. This article outlines a model of participatory analysis that accounts for the conceptual complexity, lived experience and broad intentions of informal learning space. Further, the…

Psychology of Learning Spaces: Impact on Teaching and Learning

ERIC Educational Resources Information Center

Granito, Vincent J.; Santana, Mary E.

2016-01-01

New research is emerging that focuses on the role the physical classroom space plays in the teaching-learning dynamic. The purpose of this exploratory research is to describe the students' and instructors' perspectives of how the classroom space and environment impact teaching and learning. Focus groups were utilized with data points coming from…

Instructors as Architects-Designing Learning Spaces for Discussion-Based Online Courses

ERIC Educational Resources Information Center

Wang, Yu-Mei; Chen, Derthanq Victor

2011-01-01

Online learning space design becomes a significant issue with the proliferation of online learning in higher education. Never before has the instructor been given such a privilege in building and molding the learning space to fulfill his/her instructional aspirations. However, enormous challenges are present to the instructor in taking advantage…

Learning Spaces Framework: Learning in an Online World

ERIC Educational Resources Information Center

Ministerial Council on Education, Employment, Training and Youth Affairs (NJ1), 2008

2008-01-01

"Contemporary learning--learning in an online world" describes the integrated nature of the highly technological world in which young people live and learn. A key priority is to design learning spaces that integrate technologies: engaging students in ways not previously possible; creating new learning and teaching possibilities;…

Researching Children's Understanding of Safety: An Auto-Driven Visual Approach

ERIC Educational Resources Information Center

Agbenyega, Joseph S.

2011-01-01

Safe learning spaces allow children to explore their environment in an open and inquiring way, whereas unsafe spaces constrain, frustrate and disengage children from experiencing the fullness of their learning spaces. This study explores how children make sense of safe and unsafe learning spaces, and how this understanding affects the ways they…

Academic Library Spaces: Advancing Student Success and Helping Students Thrive

ERIC Educational Resources Information Center

Spencer, Mary Ellen; Watstein, Sarah Barbara

2017-01-01

Are today's academic libraries really designed for learning? Do library spaces impact student learning? Intending to spark broader and more informed dialogue about the relationship between the quality of learning and the quality of academic library spaces in higher education, the authors consider the concept of space as service; student learning…

The Case for a Learning Space Performance Rating System

ERIC Educational Resources Information Center

Felix, Elliot; Brown, Malcolm

2011-01-01

Learning spaces are mission-critical for colleges and universities. Yet institutions lack a commonly accepted set of standards for learning spaces, lack a way to measure how well they work through a third-party certification, and lack a substantive way to compare their spaces to peer and aspirant institutions. Inspired by the success of…

RAVEN Theory Manual

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alfonsi, Andrea; Rabiti, Cristian; Mandelli, Diego

2016-06-01

RAVEN is a software framework able to perform parametric and stochastic analysis based on the response of complex system codes. The initial development was aimed at providing dynamic risk analysis capabilities to the thermohydraulic code RELAP-7, currently under development at Idaho National Laboratory (INL). Although the initial goal has been fully accomplished, RAVEN is now a multi-purpose stochastic and uncertainty quantification platform, capable of communicating with any system code. In fact, the provided Application Programming Interfaces (APIs) allow RAVEN to interact with any code as long as all the parameters that need to be perturbed are accessible by input filesmore » or via python interfaces. RAVEN is capable of investigating system response and explore input space using various sampling schemes such as Monte Carlo, grid, or Latin hypercube. However, RAVEN strength lies in its system feature discovery capabilities such as: constructing limit surfaces, separating regions of the input space leading to system failure, and using dynamic supervised learning techniques. The development of RAVEN started in 2012 when, within the Nuclear Energy Advanced Modeling and Simulation (NEAMS) program, the need to provide a modern risk evaluation framework arose. RAVEN’s principal assignment is to provide the necessary software and algorithms in order to employ the concepts developed by the Risk Informed Safety Margin Characterization (RISMC) program. RISMC is one of the pathways defined within the Light Water Reactor Sustainability (LWRS) program. In the RISMC approach, the goal is not just to identify the frequency of an event potentially leading to a system failure, but the proximity (or lack thereof) to key safety-related events. Hence, the approach is interested in identifying and increasing the safety margins related to those events. A safety margin is a numerical value quantifying the probability that a safety metric (e.g. peak pressure in a pipe) is exceeded under certain conditions. Most of the capabilities, implemented having RELAP-7 as a principal focus, are easily deployable to other system codes. For this reason, several side activates have been employed (e.g. RELAP5-3D, any MOOSE-based App, etc.) or are currently ongoing for coupling RAVEN with several different software. The aim of this document is to provide a set of commented examples that can help the user to become familiar with the RAVEN code usage.« less

The Impact of Space on Students' Perceptions of the Value and Quality of Their Learning Experience: A Case Study of the Collaborative Learning Forum

ERIC Educational Resources Information Center

Robertson, Greg; Baumann, Christoph; Bilgin, Ayse A.; Bulger, David; Coutts, Pamela M.; Engel, Roger M.; Giuriato, Rosemary; Gudlaugsdottir, Sigurbjorg; Rigney, Curtis; Tomossy, George F.

2012-01-01

Universities in Australia and worldwide, are building a new generation of learning and teaching spaces which are designed to encourage and support active and collaborative modes of learning and teaching. However, there is little evidence to show that students will recognise the contribution these spaces make to their learning. Temple (2008) argued…

The Politics of Place: Official, Intermediate and Community Discourses in Depopulated Rural Areas of Central Spain. The Case of the Riaza River Valley (Segovia, Spain)

ERIC Educational Resources Information Center

Paniagua, Angel

2009-01-01

This paper provides theoretical and methodological arguments to study the politics of space in small marginal and depopulated areas of Spain. The case for research is the Riaza river valley in the province of Segovia. Usually the analysis of rural space (and the geographical space in general) provides opposing presentations: vertical, between…

The right time to learn: mechanisms and optimization of spaced learning

PubMed Central

Smolen, Paul; Zhang, Yili; Byrne, John H.

2016-01-01

For many types of learning, spaced training, which involves repeated long inter-trial intervals, leads to more robust memory formation than does massed training, which involves short or no intervals. Several cognitive theories have been proposed to explain this superiority, but only recently have data begun to delineate the underlying cellular and molecular mechanisms of spaced training, and we review these theories and data here. Computational models of the implicated signalling cascades have predicted that spaced training with irregular inter-trial intervals can enhance learning. This strategy of using models to predict optimal spaced training protocols, combined with pharmacotherapy, suggests novel ways to rescue impaired synaptic plasticity and learning. PMID:26806627

Orion Flight Performance Design Trades

NASA Technical Reports Server (NTRS)

Jackson, Mark C.; Straube, Timothy

2010-01-01

A significant portion of the Orion pre-PDR design effort has focused on balancing mass with performance. High level performance metrics include abort success rates, lunar surface coverage, landing accuracy and touchdown loads. These metrics may be converted to parameters that affect mass, such as ballast for stabilizing the abort vehicle, propellant to achieve increased lunar coverage or extended missions, or ballast to increase the lift-to-drag ratio to improve entry and landing performance. The Orion Flight Dynamics team was tasked to perform analyses to evaluate many of these trades. These analyses not only provide insight into the physics of each particular trade but, in aggregate, they illustrate the processes used by Orion to balance performance and mass margins, and thereby make design decisions. Lessons learned can be gleaned from a review of these studies which will be useful to other spacecraft system designers. These lessons fall into several categories, including: appropriate application of Monte Carlo analysis in design trades, managing margin in a highly mass-constrained environment, and the use of requirements to balance margin between subsystems and components. This paper provides a review of some of the trades and analyses conducted by the Flight Dynamics team, as well as systems engineering lessons learned.

Self-supervised learning as an enabling technology for future space exploration robots: ISS experiments on monocular distance learning

NASA Astrophysics Data System (ADS)

van Hecke, Kevin; de Croon, Guido C. H. E.; Hennes, Daniel; Setterfield, Timothy P.; Saenz-Otero, Alvar; Izzo, Dario

2017-11-01

Although machine learning holds an enormous promise for autonomous space robots, it is currently not employed because of the inherent uncertain outcome of learning processes. In this article we investigate a learning mechanism, Self-Supervised Learning (SSL), which is very reliable and hence an important candidate for real-world deployment even on safety-critical systems such as space robots. To demonstrate this reliability, we introduce a novel SSL setup that allows a stereo vision equipped robot to cope with the failure of one of its cameras. The setup learns to estimate average depth using a monocular image, by using the stereo vision depths from the past as trusted ground truth. We present preliminary results from an experiment on the International Space Station (ISS) performed with the MIT/NASA SPHERES VERTIGO satellite. The presented experiments were performed on October 8th, 2015 on board the ISS. The main goals were (1) data gathering, and (2) navigation based on stereo vision. First the astronaut Kimiya Yui moved the satellite around the Japanese Experiment Module to gather stereo vision data for learning. Subsequently, the satellite freely explored the space in the module based on its (trusted) stereo vision system and a pre-programmed exploration behavior, while simultaneously performing the self-supervised learning of monocular depth estimation on board. The two main goals were successfully achieved, representing the first online learning robotic experiments in space. These results lay the groundwork for a follow-up experiment in which the satellite will use the learned single-camera depth estimation for autonomous exploration in the ISS, and are an advancement towards future space robots that continuously improve their navigation capabilities over time, even in harsh and completely unknown space environments.

18 CFR 385.2003 - Specifications (Rule 2003).

Code of Federal Regulations, 2011 CFR

2011-04-01

... governing timeliness, a document filed via the Internet will be deemed to have been received by the... other word or data processing equipment; (2) Have double-spaced lines with left margins not less than 11/2 inch wide, except that any tariff or rate filing may be single-spaced; (3) Have indented and...

Fishing in Puddles: Place and Space in Performance Research

ERIC Educational Resources Information Center

Piasecka, Shelley

2014-01-01

This article examines the significance of place and space from a Performance Studies and Social Studies perspective. In terms of the social sciences, I draw upon the formal, symbolic and marginal articulation of place. Hetherington suggests that certain places act as focal point for the establishment of social identities, citing city-centre…

Hierarchical structure in sharply divided phase space for the piecewise linear map

NASA Astrophysics Data System (ADS)

Akaishi, Akira; Aoki, Kazuki; Shudo, Akira

2017-05-01

We have studied a two-dimensional piecewise linear map to examine how the hierarchical structure of stable regions affects the slow dynamics in Hamiltonian systems. In the phase space there are infinitely many stable regions, each of which is polygonal-shaped, and the rest is occupied by chaotic orbits. By using symbolic representation of stable regions, a procedure to compute the edges of the polygons is presented. The stable regions are hierarchically distributed in phase space and the edges of the stable regions show the marginal instability. The cumulative distribution of the recurrence time obeys a power law as ˜t-2 , the same as the one for the system with phase space, which is composed of a single stable region and chaotic components. By studying the symbol sequence of recurrence trajectories, we show that the hierarchical structure of stable regions has no significant effect on the power-law exponent and that only the marginal instability on the boundary of stable regions is responsible for determining the exponent. We also discuss the relevance of the hierarchical structure to those in more generic chaotic systems.

Individualized Instruction in Science, Time-Space-Matter, Learning Activity Packages.

ERIC Educational Resources Information Center

Kuczma, R. M.

Learning Activity Packages (LAP) relating to time, space, and matter are presented for use in sampling a new type of learning for a whole year. Besides the unit on introduction to individualized learning, 11 major topics are incorporated into three other units: (1) observation of the physical world, (2) space and exploration for environmental…

System Guidelines for EMC Safety-Critical Circuits: Design, Selection, and Margin Demonstration

NASA Technical Reports Server (NTRS)

Lawton, R. M.

1996-01-01

Demonstration of required safety margins on critical electrical/electronic circuits in large complex systems has become an implementation and cost problem. These margins are the difference between the activation level of the circuit and the electrical noise on the circuit in the actual operating environment. This document discusses the origin of the requirement and gives a detailed process flow for the identification of the system electromagnetic compatibility (EMC) critical circuit list. The process flow discusses the roles of engineering disciplines such as systems engineering, safety, and EMC. Design and analysis guidelines are provided to assist the designer in assuring the system design has a high probability of meeting the margin requirements. Examples of approaches used on actual programs (Skylab and Space Shuttle Solid Rocket Booster) are provided to show how variations of the approach can be used successfully.

Teaching on the Margins: Tutors, Discourse and Pedagogy in Work-Based Learning for Young People

ERIC Educational Resources Information Center

Thompson, Ron

2010-01-01

This paper presents research findings on practitioners working with young people on Entry to Employment (E2E) programmes in the north of England. E2E continues a long tradition of work-related learning for unemployed school leavers for whom other forms of education or training are deemed unsuitable, and is part of the UK government's strategy for…

Regional Workshop on Inclusive Education: "Getting All Children into School and Helping Them Learn" (Bangkok, Thailand, October 19-21, 2004). Final Report

ERIC Educational Resources Information Center

Online Submission, 2005

2005-01-01

Inclusive education addresses the learning needs of all children with a specific focus on those who are vulnerable to marginalization and exclusion. It calls for all children to participate in schooling and be treated equally. The workshop explores the fundamental elements for inclusive education within the framework of Education for All (EFA)…

A Comparative Analysis of a Game-Based Mobile Learning Model in Low-Socioeconomic Communities of India

ERIC Educational Resources Information Center

Kim, Paul; Buckner, Elizabeth; Kim, Hyunkyung; Makany, Tamas; Taleja, Neha; Parikh, Vallabhi

2012-01-01

This study explores the effectiveness of a game-based mobile learning model for children living in underdeveloped regions with significant contextual variations. Data for this study came from a total of 210 children between the ages of 6-14 years old from six marginalized communities in India. The findings reveal that children with little or no…

Developing the Potential of Low Ability Personnel. Final Report for Period 15 June 1974 to 15 June 1975.

ERIC Educational Resources Information Center

Jealous, Fred S.; And Others

The project was an empirical exploration to determine the scope of the learning capacity of marginal Army personnel (those with low scores on Army general ability and aptitude tests), to observe the longitudinal effects of long term, self-managed learning strategies, and to determine the proficiency levels that these men could reach as a result of…

Mobile Game Based Learning: Can It Enhance Learning of Marginalized Peer Educators?

ERIC Educational Resources Information Center

Roy, Anupama; Sharples, Mike

2015-01-01

This paper describes an investigatory project to pilot an SMS based game to enhance the training of peer educators of MSM (Males having Sex with Males) groups in India. The objective of this research was to increase the efficacy of the MSM peer educators by bridging the gap between the training needs and their real life experiences. An SMS based…

Creating a Learning Space in Problem-Based Learning

ERIC Educational Resources Information Center

Hmelo-Silver, Cindy E.

2013-01-01

An important aspect of PBL problems is the affordances that they hold for engaging students in discussion of important content knowledge. In this paper, I argue that one can analyze a problem in terms of a deep problem space and a broader learning space to identify the conceptual ideas for potential engagement. The problem space refers to the…

Towards a Theory of Learning for Naming Rehabilitation: Retrieval Practice and Spacing Effects

PubMed Central

Schwartz, Myrna F.; Rawson, Katherine A.; Traut, Hilary; Verkuilen, Jay

2016-01-01

Purpose The purpose of this article was to examine how different types of learning experiences affect naming impairment in aphasia. Methods In 4 people with aphasia with naming impairment, we compared the benefits of naming treatment that emphasized retrieval practice (practice retrieving target names from long-term memory) with errorless learning (repetition training, which preempts retrieval practice) according to different schedules of learning. The design was within subjects. Items were administered for multiple training trials for retrieval practice or repetition in a spaced schedule (an item's trials were separated by multiple unrelated trials) or massed schedule (1 trial intervened between an item's trials). In the spaced condition, we studied 3 magnitudes of spacing to evaluate the impact of effortful retrieval during training on the ultimate benefits conferred by retrieval practice naming treatment. The primary outcome was performance on a retention test of naming after 1 day, with a follow-up test after 1 week. Results Group analyses revealed that retrieval practice outperformed errorless learning, and spaced learning outperformed massed learning at retention test and at follow-up. Increases in spacing in the retrieval practice condition yielded more robust learning of retrieved information. Conclusion This study delineates the importance of retrieval practice and spacing for treating naming impairment in aphasia. PMID:27716858

Errorless learning and spaced retrieval: how do these methods fare in healthy and clinical populations?

PubMed

Haslam, Catherine; Hodder, Kathryn I; Yates, Philip J

2011-04-01

While errorless learning and spaced retrieval have both proved effective in helping many patients with acquired brain injury (ABI) and dementia learn novel information, it is not clear which of these principles we should apply to target treatment most effectively. To address this issue we conducted a systematic comparison of these principles in three experiments, comparing their effectiveness in healthy controls (N = 60), patients with ABI (N = 30), and patients with dementia (N = 15). Participants were asked to learn face-name associations, and the relative effectiveness of the principles over and above trial-and-error learning was investigated. The results were remarkably consistent across experiments: Both errorless learning and spaced retrieval produced greater accuracy in name recall than did trial-and-error learning, but recall under conditions of spaced retrieval was significantly better than that under errorless learning. We discuss the implications of these findings and suggest that spaced retrieval may be the stronger memory rehabilitation principle when it comes to learning face-name associations in people with mild to moderate memory impairment.

NASA's Spaceliner Investment Area Technology Activities

NASA Technical Reports Server (NTRS)

Hueter, Uwe; Lyles, Garry M. (Technical Monitor)

2001-01-01

NASA's has established long term goals for access-to-space. The third generation launch systems are to be fully reusable and operational around 2025. The goals for the third generation launch system are to significantly reduce cost and improve safety over current conditions. The Advanced Space Transportation Program Office (ASTP) at the NASA's Marshall Space Flight Center in Huntsville, AL has the agency lead to develop space transportation technologies. Within ASTP, under the Spaceliner Investment Area, third generation technologies are being pursued in the areas of propulsion, airframes, integrated vehicle health management (IVHM), avionics, power, operations, and range. The ASTP program will mature these technologies through both ground and flight system testing. The Spaceliner Investment Area plans to mature vehicle technologies to reduce the implementation risks for future commercially developed reusable launch vehicles (RLV). The plan is to substantially increase the design and operating margins of the third generation RLV (the Space Shuttle is the first generation) by incorporating advanced technologies in propulsion, materials, structures, thermal protection systems, avionics, and power. Advancements in design tools and better characterization of the operational environment will allow improvements in design margins. Improvements in operational efficiencies will be provided through use of advanced integrated health management, operations, and range technologies. The increase in margins will allow components to operate well below their design points resulting in improved component operating life, reliability, and safety which in turn reduces both maintenance and refurbishment costs. These technologies have the potential of enabling horizontal takeoff by reducing the takeoff weight and achieving the goal of airline-like operation. These factors in conjunction with increased flight rates from an expanding market will result in significant improvements in safety and reductions in operational costs of future vehicles. The paper describes current status, future plans and technologies that are being matured by the Spaceliner Investment Area under the Advanced Space Transportation Program Office.

Why It Is Hard to Make Use of New Learning Spaces: A Script Perspective

ERIC Educational Resources Information Center

Kollar, Ingo; Pilz, Florian; Fischer, Frank

2014-01-01

The authors argue that a script perspective can lead to a better understanding of learning in new learning spaces. Scripts can be understood as flexible, individual memory structures guiding our understanding and actions, but also as instructional interventions that help students use the affordances offered in new learning spaces. In study 1 (N =…

A Qualitative Study of Learning Spaces at a Midwest Elementary School and Its Relationship to Student Attitudes about Reading

ERIC Educational Resources Information Center

Limpert, Stefanie Marie

2017-01-01

This study investigated the relationship between flexible learning environments and student attitudes about reading. Flexible learning environments are spaces wherein learners can choose from different seating or standing options, locations within the learning space, and the size group with which to work. This allows the learner to find the…

The Role of Margin in Link Design and Optimization

NASA Technical Reports Server (NTRS)

Cheung, K.

2015-01-01

Link analysis is a system engineering process in the design, development, and operation of communication systems and networks. Link models that are mathematical abstractions representing the useful signal power and the undesirable noise and attenuation effects (including weather effects if the signal path transverses through the atmosphere) that are integrated into the link budget calculation that provides the estimates of signal power and noise power at the receiver. Then the link margin is applied which attempts to counteract the fluctuations of the signal and noise power to ensure reliable data delivery from transmitter to receiver. (Link margin is dictated by the link margin policy or requirements.) A simple link budgeting approach assumes link parameters to be deterministic values typically adopted a rule-of-thumb policy of 3 dB link margin. This policy works for most S- and X-band links due to their insensitivity to weather effects. But for higher frequency links like Ka-band, Ku-band, and optical communication links, it is unclear if a 3 dB link margin would guarantee link closure. Statistical link analysis that adopted the 2-sigma or 3-sigma link margin incorporates link uncertainties in the sigma calculation. (The Deep Space Network (DSN) link margin policies are 2-sigma for downlink and 3-sigma for uplink.) The link reliability can therefore be quantified statistically even for higher frequency links. However in the current statistical link analysis approach, link reliability is only expressed as the likelihood of exceeding the signal-to-noise ratio (SNR) threshold that corresponds to a given bit-error-rate (BER) or frame-error-rate (FER) requirement. The method does not provide the true BER or FER estimate of the link with margin, or the required signalto-noise ratio (SNR) that would meet the BER or FER requirement in the statistical sense. In this paper, we perform in-depth analysis on the relationship between BER/FER requirement, operating SNR, and coding performance curve, in the case when the channel coherence time of link fluctuation is comparable or larger than the time duration of a codeword. We compute the "true" SNR design point that would meet the BER/FER requirement by taking into account the fluctuation of signal power and noise power at the receiver, and the shape of the coding performance curve. This analysis yields a number of valuable insights on the design choices of coding scheme and link margin for the reliable data delivery of a communication system - space and ground. We illustrate the aforementioned analysis using a number of standard NASA error-correcting codes.

Efficiency of goal-oriented communicating agents in different graph topologies: A study with Internet crawlers

NASA Astrophysics Data System (ADS)

Lőrincz, András; Lázár, Katalin A.; Palotai, Zsolt

2007-05-01

To what extent does the communication make a goal-oriented community efficient in different topologies? In order to gain insight into this problem, we study the influence of learning method as well as that of the topology of the environment on the communication efficiency of crawlers in quest of novel information in different topics on the Internet. Individual crawlers employ selective learning, function approximation-based reinforcement learning (RL), and their combination. Selective learning, in effect, modifies the starting URL lists of the crawlers, whilst RL alters the URL orderings. Real data have been collected from the web and scale-free worlds, scale-free small world (SFSW), and random world environments (RWEs) have been created by link reorganization. In our previous experiments [ Zs. Palotai, Cs. Farkas, A. Lőrincz, Is selection optimal in scale-free small worlds?, ComPlexUs 3 (2006) 158-168], the crawlers searched for novel, genuine documents and direct communication was not possible. Herein, our finding is reproduced: selective learning performs the best and RL the worst in SFSW, whereas the combined, i.e., selective learning coupled with RL is the best-by a slight margin-in scale-free worlds. This effect is demonstrated to be more pronounced when the crawlers search for different topic-specific documents: the relative performance of the combined learning algorithm improves in all worlds, i.e., in SFSW, in SFW, and in RWE. If the tasks are more complex and the work sharing is enforced by the environment then the combined learning algorithm becomes at least equal, even superior to both the selective and the RL algorithms in most cases, irrespective of the efficiency of communication. Furthermore, communication improves the performance by a large margin and adaptive communication is advantageous in the majority of the cases.

Classification and recognition of dynamical models: the role of phase, independent components, kernels and optimal transport.

PubMed

Bissacco, Alessandro; Chiuso, Alessandro; Soatto, Stefano

2007-11-01

We address the problem of performing decision tasks, and in particular classification and recognition, in the space of dynamical models in order to compare time series of data. Motivated by the application of recognition of human motion in image sequences, we consider a class of models that include linear dynamics, both stable and marginally stable (periodic), both minimum and non-minimum phase, driven by non-Gaussian processes. This requires extending existing learning and system identification algorithms to handle periodic modes and nonminimum phase behavior, while taking into account higher-order statistics of the data. Once a model is identified, we define a kernel-based cord distance between models that includes their dynamics, their initial conditions as well as input distribution. This is made possible by a novel kernel defined between two arbitrary (non-Gaussian) distributions, which is computed by efficiently solving an optimal transport problem. We validate our choice of models, inference algorithm, and distance on the tasks of human motion synthesis (sample paths of the learned models), and recognition (nearest-neighbor classification in the computed distance). However, our work can be applied more broadly where one needs to compare historical data while taking into account periodic trends, non-minimum phase behavior, and non-Gaussian input distributions.

Wave-Ice interaction in the Marginal Ice Zone: Toward a Wave-Ocean-Ice Coupled Modeling System

DTIC Science & Technology

2015-09-30

MIZ using WW3 (3 frequency bins, ice retreat in August and ice advance in October); Blue (solid): Based on observations near Antarctica by Meylan...1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Wave- Ice interaction in the Marginal Ice Zone: Toward a...Wave-Ocean- Ice Coupled Modeling System W. E. Rogers Naval Research Laboratory, Code 7322 Stennis Space Center, MS 39529 phone: (228) 688-4727

Structural design/margin assessment

NASA Technical Reports Server (NTRS)

Ryan, R. S.

1993-01-01

Determining structural design inputs and the structural margins following design completion is one of the major activities in space exploration. The end result is a statement of these margins as stability, safety factors on ultimate and yield stresses, fracture limits (fracture control), fatigue lifetime, reuse criteria, operational criteria and procedures, stability factors, deflections, clearance, handling criteria, etc. The process is normally called a load cycle and is time consuming, very complex, and involves much more than structures. The key to successful structural design is the proper implementation of the process. It depends on many factors: leadership and management of the process, adequate analysis and testing tools, data basing, communications, people skills, and training. This process and the various factors involved are discussed.

Lithologic, age group, magnetopolarity, and geochemical maps of the Springerville Volcanic Field, east-central Arizona

USGS Publications Warehouse

Condit, Christopher D.; Crumpler, Larry S.; Aubele, Jayne C.

1999-01-01

The Springerville volcanic field is one of the many late Pliocene to Holocene, mostly basaltic, volcanic fields present near the Colorado Plateau margin (fig. 1, in pamphlet). The field overlies the lithospheric transition zone between the Colorado Plateau and the Basin and Range Province (Condit and others, 1989b). Establishing relations in time, space, and composition of the rocks of these plateau-margin fields offers the possibility to integrate more fully into a regional synthesis the detailed geochemistry of these fields now being examined (for example, Perry and others, 1987; Fitton and others, 1988; Menzies and others, 1991). The work also provides baseline information for understanding mantle properties and processes at different depths and locations. Because the Springerville field is the southernmost of the plateau-margin fields, and because it contains both tholeiitic and alkalic rocks (tables 1 and 2, in pamphlet), it is a particularly important location for establishing these patterns in time, space, and composition. Our four thematic maps of the Springerville field were compiled by using digital mapping techniques so that associated petrologic and chemical data could be conveniently included in a geographic information system for one of the plateau-margin fields. Parts of these maps have been included in Condit (1995), a stand-alone Macintosh2 computer program that takes advantage of their digital format.

Design of Learning Spaces: Emotional and Cognitive Effects of Learning Environments in Relation to Child Development

ERIC Educational Resources Information Center

Arndt, Petra A.

2012-01-01

The design of learning spaces is rightly gaining more and more pedagogical attention, as they influence the learning climate and learning results in multiple ways. General structural characteristics influence the willingness to learn through emotional well-being and a sense of security. Specific structural characteristics influence cognitive…

Developing Dialogic Learning Space: The Case of Online Undergraduate Research Journals

ERIC Educational Resources Information Center

Walkington, Helen

2012-01-01

This paper explores the learning spaces associated with two geography undergraduate research journals. Wikis provide dedicated spaces for postgraduate reviewers to collaboratively develop constructive feedback to authors creating a supportive online learning environment. In becoming published authors, undergraduates reported that they gained not…

Claiming the Cultural Space of the Classroom: Issues of Ethics and Social Justice

ERIC Educational Resources Information Center

Kirshner, David

2011-01-01

Issues of social justice are accorded scant space in the professional scope of most teachers. The purview of ideologues and do-gooders, social justice would seem to have little to do with practical, everyday teaching of subject matter content. This marginalization of social justice is supported by a traditionally individualist psychology that…

Accounting for heterogeneity of public lands in hedonic property models

Treesearch

Charlotte Ham; Patricia A. Champ; John B. Loomis; Robin M. Reich

2012-01-01

Open space lands, national forests in particular, are usually treated as homogeneous entities in hedonic price studies. Failure to account for the heterogeneous nature of public open spaces may result in inappropriate inferences about the benefits of proximate location to such lands. In this study the hedonic price method is used to estimate the marginal values for...

Organic Activists: Undocumented Youth Creating Spaces of Acompañamiento

ERIC Educational Resources Information Center

Nuñez-Janes, Mariela; Ovalle, Mario

2016-01-01

Our research brings attention to undocumented youth activism as a space controlled by marginalized youth. We discuss the case study of a youth-led grassroots group in Texas to explore how undocumented youth engage a pedagogy of acompañamiento through activism. We worked with undocumented youth activists as allies over the past seven years and…

Exploration of joint redundancy but not task space variability facilitates supervised motor learning.

PubMed

Singh, Puneet; Jana, Sumitash; Ghosal, Ashitava; Murthy, Aditya

2016-12-13

The number of joints and muscles in a human arm is more than what is required for reaching to a desired point in 3D space. Although previous studies have emphasized how such redundancy and the associated flexibility may play an important role in path planning, control of noise, and optimization of motion, whether and how redundancy might promote motor learning has not been investigated. In this work, we quantify redundancy space and investigate its significance and effect on motor learning. We propose that a larger redundancy space leads to faster learning across subjects. We observed this pattern in subjects learning novel kinematics (visuomotor adaptation) and dynamics (force-field adaptation). Interestingly, we also observed differences in the redundancy space between the dominant hand and nondominant hand that explained differences in the learning of dynamics. Taken together, these results provide support for the hypothesis that redundancy aids in motor learning and that the redundant component of motor variability is not noise.

Exploration of joint redundancy but not task space variability facilitates supervised motor learning

PubMed Central

Singh, Puneet; Jana, Sumitash; Ghosal, Ashitava; Murthy, Aditya

2016-01-01

The number of joints and muscles in a human arm is more than what is required for reaching to a desired point in 3D space. Although previous studies have emphasized how such redundancy and the associated flexibility may play an important role in path planning, control of noise, and optimization of motion, whether and how redundancy might promote motor learning has not been investigated. In this work, we quantify redundancy space and investigate its significance and effect on motor learning. We propose that a larger redundancy space leads to faster learning across subjects. We observed this pattern in subjects learning novel kinematics (visuomotor adaptation) and dynamics (force-field adaptation). Interestingly, we also observed differences in the redundancy space between the dominant hand and nondominant hand that explained differences in the learning of dynamics. Taken together, these results provide support for the hypothesis that redundancy aids in motor learning and that the redundant component of motor variability is not noise. PMID:27911808

Launch Vehicle Propulsion Life Cycle Cost Lessons Learned

NASA Technical Reports Server (NTRS)

Zapata, Edgar; Rhodes, Russell E.; Robinson, John W.

2010-01-01

This paper will review lessons learned for space transportation systems from the viewpoint of the NASA, Industry and academia Space Propulsion Synergy Team (SPST). The paper provides the basic idea and history of "lessons learned". Recommendations that are extremely relevant to NASA's future investments in research, program development and operations are"'provided. Lastly, a novel and useful approach to documenting lessons learned is recommended, so as to most effectively guide future NASA investments. Applying lessons learned can significantly improve access to space for cargo or people by focusing limited funds on the right areas and needs for improvement. Many NASA human space flight initiatives have faltered, been re-directed or been outright canceled since the birth of the Space Shuttle program. The reasons given at the time have been seemingly unique. It will be shown that there are common threads as lessons learned in many a past initiative.

Lessons Learned and Technical Standards: A Logical Marriage for Future Space Systems Design

NASA Technical Reports Server (NTRS)

Gill, Paul S.; Garcia, Danny; Vaughan, William W.; Parker, Nelson C. (Technical Monitor)

2002-01-01

A comprehensive database of engineering lessons learned that corresponds with relevant technical standards will be a valuable asset to those engaged in studies on future space vehicle developments, especially for structures, materials, propulsion, control, operations and associated elements. In addition, this will enable the capturing of technology developments applicable to the design, development, and operation of future space vehicles as planned in the Space Launch Initiative. Using the time-honored tradition of passing on lessons learned while utilizing the newest information technology, NASA has launched an intensive effort to link lessons learned acquired through various Internet databases with applicable technical standards. This paper will discuss the importance of lessons learned, the difficulty in finding relevant lessons learned while engaged in a space vehicle development, and the new NASA effort to relate them to technical standards that can help alleviate this difficulty.

Albert Einstein and LD: an evaluation of the evidence.

PubMed

Thomas, M

2000-01-01

Historical figures suspected of having learning disabilities are often subjected to retrospective diagnoses. One such figure is Albert Einstein. Several organizations that promote the interests of individuals with learning disabilities claim that Einstein had a learning disability. A review of biographical sources, however, provides little or no evidence to support this claim. The claim derives its force not from evidence but from a powerful belief--that the greatest among us suffer from some impairment--and from an equally powerful desire to enhance the status of a marginalized group by including within it exceptional individuals.

The Forgetful Professor and the Space Biology Adventure

NASA Technical Reports Server (NTRS)

Massa, Gioia D.; Jones, Wanda; Munoz, Angela; Santora, Joshua

2014-01-01

This video was created as one of the products of the 2013 ISS Faculty Fellows Summer Program. Our High School science teacher faculty fellows developed this video as an elementary/middle school education component. The video shows a forgetful professor who is trying to remember something, and along the journey she learns more about the space station, space station related plant science, and the Kennedy Space Center. She learns about the Veggie hardware, LED lighting for plant growth, the rotating garden concept, and generally about space exploration and the space station. Lastly she learns about the space shuttle Atlantis.

Help! (Not-So-Good Materials for Learning to Read).

ERIC Educational Resources Information Center

Venema, Minke S.

1995-01-01

Many primary adult reading materials used in literacy education reinforce the marginalization of the efforts and intelligence of women. Such representations undermine both female learners and tutors in a field heavily populated by women. (SK)

A novel double fine guide sensor design on space telescope

NASA Astrophysics Data System (ADS)

Zhang, Xu-xu; Yin, Da-yi

2018-02-01

To get high precision attitude for space telescope, a double marginal FOV (field of view) FGS (Fine Guide Sensor) is proposed. It is composed of two large area APS CMOS sensors and both share the same lens in main light of sight. More star vectors can be get by two FGS and be used for high precision attitude determination. To improve star identification speed, the vector cross product in inter-star angles for small marginal FOV different from traditional way is elaborated and parallel processing method is applied to pyramid algorithm. The star vectors from two sensors are then used to attitude fusion with traditional QUEST algorithm. The simulation results show that the system can get high accuracy three axis attitudes and the scheme is feasibility.

Community-based participatory research in Little Haiti: challenges and lessons learned.

PubMed

Kobetz, Erin; Menard, Janelle; Diem, Joshua; Barton, Betsy; Blanco, Jenny; Pierre, Larry; Auguste, Pascale D; Etienne, Marie; Brewster, Cheryl

2009-01-01

Community-based participatory research (CBPR) is an effective methodology for developing relevant interventions with socially marginalized communities. However, implementing CBPR methods is challenging for several reasons. This paper presents challenges encountered in the context of an ongoing CBPR initiative in Little Haiti in Miami, Florida, and describes the solutions used to address them. We sought to describe the challenges faced and lessons learned while conducting CBPR in Little Haiti. Community-academic partnerships were created to guide the creation of culturally relevant cancer interventions and research. Historical distrust of research, cultural constructions of health and illness, and literacy issues are key considerations when developing partnerships with Haitian and other marginalized, immigrant communities. Partnerships are fostered over time through demonstrated mutual commitment to improving health and building community capacity. Communities must play an active role throughout the research process to ensure that studies are culturally relevant, and ensuing intervention, sustainable.

Support Vector Machines for Differential Prediction

PubMed Central

Kuusisto, Finn; Santos Costa, Vitor; Nassif, Houssam; Burnside, Elizabeth; Page, David; Shavlik, Jude

2015-01-01

Machine learning is continually being applied to a growing set of fields, including the social sciences, business, and medicine. Some fields present problems that are not easily addressed using standard machine learning approaches and, in particular, there is growing interest in differential prediction. In this type of task we are interested in producing a classifier that specifically characterizes a subgroup of interest by maximizing the difference in predictive performance for some outcome between subgroups in a population. We discuss adapting maximum margin classifiers for differential prediction. We first introduce multiple approaches that do not affect the key properties of maximum margin classifiers, but which also do not directly attempt to optimize a standard measure of differential prediction. We next propose a model that directly optimizes a standard measure in this field, the uplift measure. We evaluate our models on real data from two medical applications and show excellent results. PMID:26158123

Support Vector Machines for Differential Prediction.

PubMed

Kuusisto, Finn; Santos Costa, Vitor; Nassif, Houssam; Burnside, Elizabeth; Page, David; Shavlik, Jude

Machine learning is continually being applied to a growing set of fields, including the social sciences, business, and medicine. Some fields present problems that are not easily addressed using standard machine learning approaches and, in particular, there is growing interest in differential prediction . In this type of task we are interested in producing a classifier that specifically characterizes a subgroup of interest by maximizing the difference in predictive performance for some outcome between subgroups in a population. We discuss adapting maximum margin classifiers for differential prediction. We first introduce multiple approaches that do not affect the key properties of maximum margin classifiers, but which also do not directly attempt to optimize a standard measure of differential prediction. We next propose a model that directly optimizes a standard measure in this field, the uplift measure. We evaluate our models on real data from two medical applications and show excellent results.

The Spacing Effect and Metacognitive Control

ERIC Educational Resources Information Center

Mulligan, Neil W.; Peterson, Daniel J.

2014-01-01

Research suggests that spaced learning, compared with massed learning, results in superior long-term retention (the spacing effect). Son (2010) identified a potentially important moderator of the spacing effect: metacognitive control. Specifically, when participants chose massed restudy but were instead forced to space the restudy, the spacing…

Learning Behaviors and Learning Spaces

ERIC Educational Resources Information Center

Bennett, Scott

2011-01-01

What specific learning behaviors are important to students and faculty members? Does the campus provide spaces that foster these behaviors? Where are those spaces? Asking these three questions at six colleges and universities reveals notable differences in the ways students and faculty members answer them. Student and faculty member answers also…

Learning Spaces and Pedagogic Change: Envisioned, Enacted and Experienced

ERIC Educational Resources Information Center

Mulcahy, Dianne; Cleveland, Ben; Aberton, Helen

2015-01-01

Building on work in how spaces of learning can contribute to the broader policy agenda of achieving pedagogic change, this article takes as its context the Building the Education Revolution infrastructure programme in Australia. Deploying a sociomaterial approach to researching learning spaces and pedagogic change and drawing on data from…

Competencies for Information Professionals in Learning Labs and Makerspaces

ERIC Educational Resources Information Center

Koh, Kyungwon; Abbas, June

2015-01-01

An increasing number of libraries and museums provide transformative learning spaces, often called "Learning Labs" and "Makerspaces." These spaces invite users to explore traditional and digital media, interact with mentors and peers, and engage in creative projects. For these spaces and programs to be sustainable, it is…

Asymmetrical booster ascent guidance and control system design study. Volume 1: Summary. [space shuttle development

NASA Technical Reports Server (NTRS)

Williams, F. E.; Lemon, R. S.; Jaggers, R. F.; Wilson, J. L.

1974-01-01

Dynamics and control, stability, and guidance analyses are summarized for the asymmetrical booster ascent guidance and control system design studies, performed in conjunction with space shuttle planning. The mathematical models developed for use in rigid body and flexible body versions of the NASA JSC space shuttle functional simulator are briefly discussed, along with information on the following: (1) space shuttle stability analysis using equations of motion for both pitch and lateral axes; (2) the computer program used to obtain stability margin; and (3) the guidance equations developed for the space shuttle powered flight phases.

Geologic controls on submarine slope failure along the central U.S. Atlantic margin: Insights from the Currituck Slide Complex

USGS Publications Warehouse

Hill, Jenna C.; Brothers, Daniel S.; Craig, Bradley K.; ten Brink, Uri S.; Chaytor, Jason D.; Flores, Claudia

2017-01-01

Multiple styles of failure, ranging from densely spaced, mass transport driven canyons to the large, slab-type slope failure of the Currituck Slide, characterize adjacent sections of the central U.S. Atlantic margin that appear to be defined by variations in geologic framework. Here we use regionally extensive, deep penetration multichannel seismic (MCS) profiles to reconstruct the influence of the antecedent margin physiography on sediment accumulation along the central U.S. Atlantic continental shelf-edge, slope, and uppermost rise from the Miocene to Present. These data are combined with high-resolution sparker MCS reflection profiles and multibeam bathymetry data across the Currituck Slide Complex. Pre-Neogene allostratigraphic horizons beneath the slope are generally characterized by low gradients and convex downslope profiles. This is followed by the development of thick, prograded deltaic clinoforms during the middle Miocene. Along-strike variations in morphology of a regional unconformity at the top of this middle Miocene unit appear to have set the stage for differing styles of mass transport along the margin. Areas north and south of the Currituck Slide are characterized by oblique margin morphology, defined by an angular shelf-edge and a relatively steep (> 8°), concave slope profile. Upper slope sediment bypass, closely spaced submarine canyons, and small, localized landslides confined to canyon heads and sidewalls characterize these sectors of the margin. In contrast, the Currituck region is defined by a sigmoidal geometry, with a rounded shelf-edge rollover and gentler slope gradient (< 6°). Thick (> 800 m), regionally continuous stratified slope deposits suggest the low gradient Currituck region was a primary depocenter for fluvial inputs during multiple sea level lowstands. These results imply that the rounded, gentle slope physiography developed during the middle Miocene allowed for a relatively high rate of subsequent sediment accumulation, thus providing a mechanism for compaction–induced overpressure that preconditioned the Currituck region for failure. Detailed examination of the regional geological framework illustrates the importance of both sediment supply and antecedent slope physiography in the development of large, potentially unstable depocenters along passive margins.

The Exclusionary Circle Game: A Tool to Promote Critical Dialogue About HIV Stigma and Social Justice.

PubMed

Wong, Josephine Pui; Li, Alan Tai

2015-01-01

The Exclusionary Circle Game was a learning tool developed for an intervention study to address stigma associated with human immunodeficiency virus (HIV) infection and social exclusion. The objectives of The Exclusionary Circle Game were to enhance collective resonance and empathy, promote critical reflection and dialogue, and motivate collective action to address social exclusion. The game began with all participants being inside a circle. Each participant was randomly given one color-coded card. Each card color represented a character with a specific lived experience associated with racism, patriarchy, homophobia, transphobia, HIV stigma, and so on. Participants holding a marginalized status card were asked to leave the circle in sequence and go to designated spaces. Eventually, only one half of the participants were left in the circle. Participants then debriefed about their experiences within the entire group. The game has been used, beyond the intervention study, at research conferences with positive feedback. In this article, we detail the processes, strengths, and possibility of using this game for empowerment education.

Quantifying the Evolution of Melt Ponds in the Marginal Ice Zone Using High Resolution Optical Imagery and Neural Networks

NASA Astrophysics Data System (ADS)

Ortiz, M.; Pinales, J. C.; Graber, H. C.; Wilkinson, J.; Lund, B.

2016-02-01

Melt ponds on sea ice play a significant and complex role on the thermodynamics in the Marginal Ice Zone (MIZ). Ponding reduces the sea ice's ability to reflect sunlight, and in consequence, exacerbates the albedo positive feedback cycle. In order to understand how melt ponds work and their effect on the heat uptake of sea ice, we must quantify ponds through their seasonal evolution first. A semi-supervised neural network three-class learning scheme using a gradient descent with momentum and adaptive learning rate backpropagation function is applied to classify melt ponds/melt areas in the Beaufort Sea region. The network uses high resolution panchromatic satellite images from the MEDEA program, which are collocated with autonomous platform arrays from the Marginal Ice Zone Program, including ice mass-balance buoys, arctic weather stations and wave buoys. The goal of the study is to capture the spatial variation of melt onset and freeze-up of the ponds within the MIZ, and gather ponding statistics such as size and concentration. The innovation of this work comes from training the neural network as the melt ponds evolve over time; making the machine learning algorithm time-dependent, which has not been previously done. We will achieve this by analyzing the image histograms through quantification of the minima and maxima intensity changes as well as linking textural variation information of the imagery. We will compare the evolution of the melt ponds against several different array sites on the sea ice to explore if there are spatial differences among the separated platforms in the MIZ.

Making long-term memories in minutes: a spaced learning pattern from memory research in education

PubMed Central

Kelley, Paul; Whatson, Terry

2013-01-01

Memory systems select from environmental stimuli those to encode permanently. Repeated stimuli separated by timed spaces without stimuli can initiate Long-Term Potentiation (LTP) and long-term memory (LTM) encoding. These processes occur in time scales of minutes, and have been demonstrated in many species. This study reports on using a specific timed pattern of three repeated stimuli separated by 10 min spaces drawn from both behavioral and laboratory studies of LTP and LTM encoding. A technique was developed based on this pattern to test whether encoding complex information into LTM in students was possible using the pattern within a very short time scale. In an educational context, stimuli were periods of highly compressed instruction, and spaces were created through 10 min distractor activities. Spaced Learning in this form was used as the only means of instruction for a national curriculum Biology course, and led to very rapid LTM encoding as measured by the high-stakes test for the course. Remarkably, learning at a greatly increased speed and in a pattern that included deliberate distraction produced significantly higher scores than random answers (p < 0.00001) and scores were not significantly different for experimental groups (one hour spaced learning) and control groups (four months teaching). Thus learning per hour of instruction, as measured by the test, was significantly higher for the spaced learning groups (p < 0.00001). In a third condition, spaced learning was used to replace the end of course review for one of two examinations. Results showed significantly higher outcomes for the course using spaced learning (p < 0.0005). The implications of these findings and further areas for research are briefly considered. PMID:24093012

Memory Boost from Spaced-Out Learning.

ERIC Educational Resources Information Center

Bower, B.

1987-01-01

Discusses what learning conditions promote memory stamina. Reviews study findings which suggested that spacing of practice during rote learning of a foreign language vocabulary can produce lasting memories. (ML)

A comparison of the marginal vertical discrepancies of zirconium and metal ceramic posterior fixed dental prostheses before and after cementation.

PubMed

Gonzalo, Esther; Suárez, Maria J; Serrano, Benjamin; Lozano, Jose F L

2009-12-01

Marginal discrepancies of zirconia posterior fixed dental prostheses (FDPs) fabricated using various systems have been assessed to determine the quality of the restorations and facilitate clinical use; however, studies are limited and results are ambiguous because of the sample sizes and measurement methods. The purpose of this in vitro study was to compare changes in marginal fit of posterior fixed dental prostheses of 3 zirconia systems manufactured using CAD/CAM technology and metal ceramic posterior fixed dental protheses fabricated with the conventional lost-wax technique, before and after cementation. Forty standardized master steel dies with 2 abutments simulating first mandibular premolars were fabricated to receive a posterior 3-unit FDP (from first molar to first premolar) and divided into 4 groups (n=10): Lava All-Ceramic System, Procera Bridge Zirconia, VITA In-Ceram 2000 YZ, and metal ceramic (control group). All FDPs were prepared for an internal space of 50 microm. The external marginal gap of the restorations was investigated by measuring 30 points in the middle of the buccal and lingual surfaces; therefore, 60 measurements per abutment were recorded. Measurements were made with an image analysis program on the master steel model before and after conventional cementation with a glass ionomer agent (Ketac Cem Easymix). The data obtained were statistically analyzed using 1-way ANOVA, Duncan's multiple range post hoc test, and Student's paired t test (alpha=.05). No significant differences in the vertical marginal fit before and after cementation were recorded for the analyzed groups. The marginal discrepancy of Procera abutments before and after cementation (9 +/-10 microm and 12 +/-9 microm, respectively) was less than that of the other groups. Significant differences (P=.001) were observed in marginal adaptation between Procera Bridge Zirconia and the other groups. The results of this study showed that cementation did not cause a significant increase in the vertical marginal discrepancies of the FDPs and that an internal space of 50 mum provided a high precision of fit of the restorations. The accuracy of fit achieved for the 3 zirconium oxide groups analyzed was within the range of clinical acceptance, and the discrepancies were lower than in the metal ceramic group. Procera Bridge Zirconia showed the lowest vertical discrepancies.

Are You Still Typing?

ERIC Educational Resources Information Center

Smith, Irene; Yoder, Sharon

1996-01-01

Discusses word processing and desktop publishing and offers suggestions for creating documents that look more professional, including proportional type size, spacing, the use of punctuation marks, italics, tabs and margins, and paragraph styles. (LRW)

Learning redundant motor tasks with and without overlapping dimensions: facilitation and interference effects.

PubMed

Ranganathan, Rajiv; Wieser, Jon; Mosier, Kristine M; Mussa-Ivaldi, Ferdinando A; Scheidt, Robert A

2014-06-11

Prior learning of a motor skill creates motor memories that can facilitate or interfere with learning of new, but related, motor skills. One hypothesis of motor learning posits that for a sensorimotor task with redundant degrees of freedom, the nervous system learns the geometric structure of the task and improves performance by selectively operating within that task space. We tested this hypothesis by examining if transfer of learning between two tasks depends on shared dimensionality between their respective task spaces. Human participants wore a data glove and learned to manipulate a computer cursor by moving their fingers. Separate groups of participants learned two tasks: a prior task that was unique to each group and a criterion task that was common to all groups. We manipulated the mapping between finger motions and cursor positions in the prior task to define task spaces that either shared or did not share the task space dimensions (x-y axes) of the criterion task. We found that if the prior task shared task dimensions with the criterion task, there was an initial facilitation in criterion task performance. However, if the prior task did not share task dimensions with the criterion task, there was prolonged interference in learning the criterion task due to participants finding inefficient task solutions. These results show that the nervous system learns the task space through practice, and that the degree of shared task space dimensionality influences the extent to which prior experience transfers to subsequent learning of related motor skills. Copyright © 2014 the authors 0270-6474/14/348289-11$15.00/0.

Spaced Retrieval: Absolute Spacing Enhances Learning Regardless of Relative Spacing

ERIC Educational Resources Information Center

Karpicke, Jeffrey D.; Bauernschmidt, Althea

2011-01-01

Repeated retrieval enhances long-term retention, and spaced repetition also enhances retention. A question with practical and theoretical significance is whether there are particular schedules of spaced retrieval (e.g., gradually expanding the interval between tests) that produce the best learning. In the present experiment, subjects studied and…

The Implementation and Evaluation of a New Learning Space: A Pilot Study

ERIC Educational Resources Information Center

Wilson, Gail; Randall, Marcus

2012-01-01

A dramatic, pedagogical shift has occurred in recent years in educational environments in higher education, supported largely by the use of ubiquitous technologies. Increasingly, emphasis is being placed on the design of new learning spaces, often referred to as "Next Generation Learning Spaces" (NGLS) and their impact on pedagogy. The…

Space: The Final Frontier in the Learning of Science?

ERIC Educational Resources Information Center

Milne, Catherine

2014-01-01

In "Space", relations, and the learning of science", Wolff-Michael Roth and Pei-Ling Hsu use ethnomethodology to explore high school interns learning shopwork and shoptalk in a research lab that is located in a world class facility for water quality analysis. Using interaction analysis they identify how spaces, like a research…

Designing Informal Learning Spaces Using Student Perspectives

ERIC Educational Resources Information Center

Riddle, Matthew David; Souter, Kay

2012-01-01

This article describes the design of informal learning spaces at an Australian university that support students in the generation of knowledge. Recent learning space design projects at La Trobe have been informed by a number of pre-existing projects, including a small research project on student use of technologies, a national project on learning…

Spaced Learning Enhances Subsequent Recognition Memory by Reducing Neural Repetition Suppression

ERIC Educational Resources Information Center

Xue, Gui; Mei, Leilei; Chen, Chuansheng; Lu, Zhong-Lin; Poldrack, Russell; Dong, Qi

2011-01-01

Spaced learning usually leads to better recognition memory as compared with massed learning, yet the underlying neural mechanisms remain elusive. One open question is whether the spacing effect is achieved by reducing neural repetition suppression. In this fMRI study, participants were scanned while intentionally memorizing 120 novel faces, half…

Social Work Learning Spaces: The Social Work Studio

ERIC Educational Resources Information Center

Zufferey, Carole; King, Sue

2016-01-01

This paper explores the contribution of a physical learning space to student engagement in social work education. Drawing on a constructivist methodology, this paper examines the findings of a survey conducted with students and staff in a social work and human service programme about their experiences of a Social Work Studio learning space. The…

From Commons to Classroom: The Evolution of Learning Spaces in Academic Libraries

ERIC Educational Resources Information Center

Karasic, Victoria

2016-01-01

Over the past two decades, academic library spaces have evolved to meet the changing teaching and learning needs of diverse campus communities. The Information Commons combines the physical and virtual in an informal library space, whereas the recent Active Learning Classroom creates a more formal setting for collaboration. As scholarship has…

The Influence of Hierarchy and Layout Geometry in the Design of Learning Spaces

ERIC Educational Resources Information Center

Smith, Charlie

2017-01-01

For a number of years, higher education has moved away from didactic teaching toward collaborative and self-directed learning. This paper discusses how the configuration and spatial geometry of learning spaces influences engagement and interaction, with a particular focus on hierarchies between people within the space. Layouts, presented as…

The Cube and the Poppy Flower: Participatory Approaches for Designing Technology-Enhanced Learning Spaces

ERIC Educational Resources Information Center

Casanova, Diogo; Mitchell, Paul

2017-01-01

This paper presents an alternative method for learning space design that is driven by user input. An exploratory study was undertaken at an English university with the aim of redesigning technology-enhanced learning spaces. Two provocative concepts were presented through participatory design workshops during which students and teachers reflected…

Space and Consequences: The Impact of Different Formal Learning Spaces on Instructor and Student Behavior

ERIC Educational Resources Information Center

Brooks, D. Christopher

2012-01-01

This article presents the results of a quasi-experimental research project investigating the impact of two different formal learning spaces--a traditional classroom and a technologically enhanced active learning classroom--on instructor behavior, classroom activities, and levels of on-task student behavior at the University of Minnesota. Using…

Makerspaces in Informal Settings

ERIC Educational Resources Information Center

Brown, Ryan A.; Antink-Meyer, Allison

2017-01-01

The maker movement, with its focus on-hands on learning through creating with familiar materials, has seen growth in both formal and informal learning spaces. This article examines three informal learning spaces that have redesigned their space (or a portion of it) to accommodate several tenets of the maker movement and in various ways have become…

Is spacing really the “friend of induction”?

PubMed Central

Verkoeijen, Peter P. J. L.; Bouwmeester, Samantha

2014-01-01

Inductive learning takes place when people learn a new concept or category by observing a variety of exemplars. Kornell and Bjork (2008) asked participants to learn new painting styles either by presenting different paintings of the same artist consecutively (massed presentation) or by mixing paintings of different artists (spaced presentation). In their second experiment, Kornell and Bjork (2008) showed with a final style recognition test, that spacing resulted in better inductive learning than massing. Also, by using this style recognition test, they ruled out the possibility that spacing merely resulted in a better memory for the labels of the newly learned painting styles. The findings from Kornell and Bjork’s (2008) second experiment are important because they show that the benefit of spaced learning generalizes to complex learning tasks and outcomes, and that it is not confined to rote memory learning. However, the findings from Kornell and Bjork’s (2008) second experiment have never been replicated. In the present study we performed an exact and high-powered replication of Kornell and Bjork’s (2008) second experiment with a Web-based sample. Such a replication contributes to establish the reliability of the original finding and hence to more conclusive evidence of the spacing effect in inductive learning. The findings from the present replication attempt revealed a medium-sized advantage of spacing over massing in inductive learning, which was comparable to the original effect in the experiment by Kornell and Bjork (2008). Also, the 95% confidence intervals (CI) of the effect sizes from both experiments overlapped considerably. Hence, the findings from the present replication experiment and the original experiment clearly reinforce each other. PMID:24744742

Exploring a "Space" for Emergent Learning to Occur: Encouraging Creativity and Innovation in the Workplace

ERIC Educational Resources Information Center

Armson, Genevieve

2009-01-01

This research set out to explore perceptions about the concept of an emergent learning space within private organisations, as the current literature on learning does not adequately differentiate between organised learning and emergent learning. The research objectives explored the existence of, and perceived level of organisational encouragement…

Temporal BYY encoding, Markovian state spaces, and space dimension determination.

PubMed

Xu, Lei

2004-09-01

As a complementary to those temporal coding approaches of the current major stream, this paper aims at the Markovian state space temporal models from the perspective of the temporal Bayesian Ying-Yang (BYY) learning with both new insights and new results on not only the discrete state featured Hidden Markov model and extensions but also the continuous state featured linear state spaces and extensions, especially with a new learning mechanism that makes selection of the state number or the dimension of state space either automatically during adaptive learning or subsequently after learning via model selection criteria obtained from this mechanism. Experiments are demonstrated to show how the proposed approach works.

History and Evolution of Active Learning Spaces

ERIC Educational Resources Information Center

Beichner, Robert J.

2014-01-01

This chapter examines active learning spaces as they have developed over the years. Consistently well-designed classrooms can facilitate active learning even though the details of implementing pedagogies may differ.

Marginal Iodine Deficiency Affects Dendritic Spine Development by Disturbing the Function of Rac1 Signaling Pathway on Cytoskeleton.

PubMed

Min, Hui; Dong, Jing; Wang, Yi; Wang, Yuan; Yu, Ye; Shan, Zhongyan; Xi, Qi; Teng, Weiping; Chen, Jie

2017-01-01

Iodine deficiency (ID)-induced thyroid hormone (TH) insufficient during development leads to impairments of brain function, such as learning and memory. Marginal ID has been defined as subtle insufficiency of TH, characterized as low thyroxine (T 4 ) levels, whether marginal ID potentially had adverse effects on the development of hippocampus and the underlying mechanisms remain unclear. Thus, in the present study, we established Wistar rat models with ID diet during pregnancy and lactation. The effects of marginal ID on long-term potentiation (LTP) were investigated in the hippocampal CA1 region. To study the development of dendritic spines in pyramidal cells, Golgi-Cox staining was conducted on postnatal day (PN) 7, PN14, PN21, and PN28. The activation of Rac1 signaling pathway, which is essential for dendritic spine development by regulating actin cytoskeleton, was also investigated. Our results showed that marginal ID slightly reduced the field-excitatory postsynaptic potential (f-EPSP) slope and the population spike (PS) amplitude. Besides, the density of dendritic spines during the critical period of rat postnatal development was mildly decreased, and we found no significant change of spine morphology in marginal ID group. We also observed decreased activation of the Rac1 signaling pathway in pups subjected to maternal marginal ID. Our study may support the hypothesis that decreased T 4 induced by marginal ID results in slight impairments of LTP and leads to mild damage of dendritic spine development, which may be due to abnormal regulation of Rac1 signaling pathway on cytoskeleton.

Positive contraction mappings for classical and quantum Schrödinger systems

NASA Astrophysics Data System (ADS)

Georgiou, Tryphon T.; Pavon, Michele

2015-03-01

The classical Schrödinger bridge seeks the most likely probability law for a diffusion process, in path space, that matches marginals at two end points in time; the likelihood is quantified by the relative entropy between the sought law and a prior. Jamison proved that the new law is obtained through a multiplicative functional transformation of the prior. This transformation is characterised by an automorphism on the space of endpoints probability measures, which has been studied by Fortet, Beurling, and others. A similar question can be raised for processes evolving in a discrete time and space as well as for processes defined over non-commutative probability spaces. The present paper builds on earlier work by Pavon and Ticozzi and begins by establishing solutions to Schrödinger systems for Markov chains. Our approach is based on the Hilbert metric and shows that the solution to the Schrödinger bridge is provided by the fixed point of a contractive map. We approach, in a similar manner, the steering of a quantum system across a quantum channel. We are able to establish existence of quantum transitions that are multiplicative functional transformations of a given Kraus map for the cases where the marginals are either uniform or pure states. As in the Markov chain case, and for uniform density matrices, the solution of the quantum bridge can be constructed from the fixed point of a certain contractive map. For arbitrary marginal densities, extensive numerical simulations indicate that iteration of a similar map leads to fixed points from which we can construct a quantum bridge. For this general case, however, a proof of convergence remains elusive.

Robust control with structured perturbations

NASA Technical Reports Server (NTRS)

Keel, Leehyun

1988-01-01

Two important problems in the area of control systems design and analysis are discussed. The first is the robust stability using characteristic polynomial, which is treated first in characteristic polynomial coefficient space with respect to perturbations in the coefficients of the characteristic polynomial, and then for a control system containing perturbed parameters in the transfer function description of the plant. In coefficient space, a simple expression is first given for the l(sup 2) stability margin for both monic and non-monic cases. Following this, a method is extended to reveal much larger stability region. This result has been extended to the parameter space so that one can determine the stability margin, in terms of ranges of parameter variations, of the closed loop system when the nominal stabilizing controller is given. The stability margin can be enlarged by a choice of better stabilizing controller. The second problem describes the lower order stabilization problem, the motivation of the problem is as follows. Even though the wide range of stabilizing controller design methodologies is available in both the state space and transfer function domains, all of these methods produce unnecessarily high order controllers. In practice, the stabilization is only one of many requirements to be satisfied. Therefore, if the order of a stabilizing controller is excessively high, one can normally expect to have a even higher order controller on the completion of design such as inclusion of dynamic response requirements, etc. Therefore, it is reasonable to have a lowest possible order stabilizing controller first and then adjust the controller to meet additional requirements. The algorithm for designing a lower order stabilizing controller is given. The algorithm does not necessarily produce the minimum order controller; however, the algorithm is theoretically logical and some simulation results show that the algorithm works in general.

Shelf-geometry response to changes in relative sea level on a mixed carbonate siliciclastic shelf in the Guyana Basin

NASA Astrophysics Data System (ADS)

Campbell, A. Ewan

2005-04-01

Differences in the shelf-margin geometry for various depositional regimes show how siliciclastic and carbonate margins respond differently to changes in accommodation space. During the Cenozoic, sequences of carbonate and siliciclastic sediment were deposited in the Guyana Basin on the passive continental margin of NE South America. Study of the sequence geometries reveal significantly different geometric responses to changes in relative sea level of intervals dominated by carbonates to intervals dominated by siliciclastics. Using the geometrical shelf break as a reference point, aggradation and progradation rates for the carbonate and siliciclastic depositional systems were measured. In siliciclastics, the lateral position of the margin remains roughly stationary with relative sea-level rises in the order of 30 m/My. At higher rates the margin retreats at lower rates it progrades. Carbonate margins remain stationary or slightly progradational even with relative sea-level rises of up to 100 m/My, the fastest rates observed in this study. This illustrates the strong tendency of carbonate platforms to stack their margins and keep up with relative rises in sea level, rather than gradually retreat landward as do siliciclastics. This observation may explain why carbonate platforms preferentially try to defend a margin prior to ultimate backstepping. The high aggradation potential of carbonate margins also gives onlap and downlap termination patterns on seismic profiles where carbonate platforms develop on sloping siliciclastic shelves. The resulting unconformities are a result of differences in sediment dispersal between the two systems and not necessarily from changes of relative sea level.

Preferred-Actual Learning Environment "Spaces" and Earth Science Outcomes in Taiwan

ERIC Educational Resources Information Center

Chang, Chun-Yen; Hsiao, Chien-Hua; Barufaldi, James P.

2006-01-01

This study examines the possibilities of differential impacts on students' earth science learning outcomes between different preferred-actual learning environment spaces by using a newly developed ESCLEI (Earth Science Classroom Learning Environment Instrument). The instrument emphasizes three simultaneously important classroom components:…

The composition and structure of volcanic rifted continental margins in the North Atlantic: Further insight from shear waves

NASA Astrophysics Data System (ADS)

Eccles, Jennifer D.; White, Robert S.; Christie, Philip A. F.

2011-07-01

Imaging challenges caused by highly attenuative flood basalt sequences have resulted in the understanding of volcanic rifted continental margins lagging behind that of non-volcanic rifted and convergent margins. Massive volcanism occurred during break-up at 70% of the passive margins bordering the Atlantic Ocean, the causes and dynamics of which are still debated. This paper shows results from traveltime tomography of compressional and converted shear wave arrivals recorded on 170 four-component ocean bottom seismometers along two North Atlantic continental margin profiles. This traveltime tomography was performed using two different approaches. The first, a flexible layer-based parameterisation, enables the quality control of traveltime picks and investigation of the crustal structure. The second, with a regularised grid-based parameterisation, requires correction of converted shear wave traveltimes to effective symmetric raypaths and allows exploration of the model space via Monte Carlo analyses. The velocity models indicate high lower-crustal velocities and sharp transitions in both velocity and Vp/Vs ratios across the continent-ocean transition. The velocities are consistent with established mixing trends between felsic continental crust and high magnesium mafic rock on both margins. Interpretation of the high quality seismic reflection profile on the Faroes margin confirms that this mixing is through crustal intrusion. Converted shear wave data also provide constraints on the sub-basalt lithology on the Faroes margin, which is interpreted as a pre-break-up Mesozoic to Paleocene sedimentary system intruded by sills.

Attention control learning in the decision space using state estimation

NASA Astrophysics Data System (ADS)

Gharaee, Zahra; Fatehi, Alireza; Mirian, Maryam S.; Nili Ahmadabadi, Majid

2016-05-01

The main goal of this paper is modelling attention while using it in efficient path planning of mobile robots. The key challenge in concurrently aiming these two goals is how to make an optimal, or near-optimal, decision in spite of time and processing power limitations, which inherently exist in a typical multi-sensor real-world robotic application. To efficiently recognise the environment under these two limitations, attention of an intelligent agent is controlled by employing the reinforcement learning framework. We propose an estimation method using estimated mixture-of-experts task and attention learning in perceptual space. An agent learns how to employ its sensory resources, and when to stop observing, by estimating its perceptual space. In this paper, static estimation of the state space in a learning task problem, which is examined in the WebotsTM simulator, is performed. Simulation results show that a robot learns how to achieve an optimal policy with a controlled cost by estimating the state space instead of continually updating sensory information.

Designing for expansive science learning and identification across settings

NASA Astrophysics Data System (ADS)

Stromholt, Shelley; Bell, Philip

2017-10-01

In this study, we present a case for designing expansive science learning environments in relation to neoliberal instantiations of standards-based implementation projects in education. Using ethnographic and design-based research methods, we examine how the design of coordinated learning across settings can engage youth from non-dominant communities in scientific and engineering practices, resulting in learning experiences that are more relevant to youth and their communities. Analyses highlight: (a) transformative moments of identification for one fifth-grade student across school and non-school settings; (b) the disruption of societal, racial stereotypes on the capabilities of and expectations for marginalized youth; and (c) how youth recognized themselves as members of their community and agents of social change by engaging in personally consequential science investigations and learning.

NASA’s Universe of Learning: Providing a Direct Connection to NASA Science for Learners of all Ages with ViewSpace

NASA Astrophysics Data System (ADS)

Lawton, Brandon L.; Rhue, Timothy; Smith, Denise A.; Squires, Gordon K.; Biferno, Anya A.; Lestition, Kathleen; Cominsky, Lynn R.; Godfrey, John; Lee, Janice C.; Manning, Colleen

2018-06-01

NASA's Universe of Learning creates and delivers science-driven, audience-driven resources and experiences designed to engage and immerse learners of all ages and backgrounds in exploring the universe for themselves. The project is the result of a unique partnership between the Space Telescope Science Institute, Caltech/IPAC, Jet Propulsion Laboratory, Smithsonian Astrophysical Observatory, and Sonoma State University, and is one of 27 competitively-selected cooperative agreements within the NASA Science Mission Directorate STEM Activation program. The NASA's Universe of Learning team draws upon cutting-edge science and works closely with Subject Matter Experts (scientists and engineers) from across the NASA Astrophysics Physics of the Cosmos, Cosmic Origins, and Exoplanet Exploration themes. As one example, NASA’s Universe of Learning program is uniquely able to provide informal learning venues with a direct connection to the science of NASA astrophysics via the ViewSpace platform. ViewSpace is a modular multimedia exhibit where people explore the latest discoveries in our quest to understand the universe. Hours of awe-inspiring video content connect users’ lives with an understanding of our planet and the wonders of the universe. This experience is rooted in informal learning, astronomy, and earth science. Scientists and educators are intimately involved in the production of ViewSpace material. ViewSpace engages visitors of varying backgrounds and experience at museums, science centers, planetariums, and libraries across the United States. In addition to creating content, the Universe of Learning team is updating the ViewSpace platform to provide for additional functionality, including the introduction of digital interactives to make ViewSpace a multi-modal learning experience. During this presentation we will share the ViewSpace platform, explain how Subject Matter Experts are critical in creating content for ViewSpace, and how we are addressing audience needs and using evaluation to support a dedicated user base across the country.

Effect of urban noise to the acoustical performance of the secondary school’s learning spaces - A case study in Batu Pahat.

NASA Astrophysics Data System (ADS)

Tong, Y. G.; Abu Bakar, H.; Mohd. Sari, K. A.; Ewon, U.; Labeni, M. N.; Fauzan, N. F. A.

2017-11-01

Classrooms and laboratories are important spaces that use for teaching and learning process in the school. Therefore, good acoustical performances of these spaces are essential to ensure the speech or message from the teacher can be delivered to the students effectively and clearly. The aims of this study is to determine the acoustical performance of the teaching and learning spaces in public school that situated near to the traffic roads. The acoustical performance of the classrooms and laboratories at Sekolah Menengah Kebangsaan Convent Batu Pahat was evaluated in this study. The reverberation time and ambient noise of these learning spaces which are the main parameters for classroom design criteria were evaluated. Field measurements were carried out inside six classrooms and four laboratories unoccupied furnished according to the international standards. The acoustical performances of the tested learning spaces were poor where the noise criteria and reverberation times inside the measured classrooms and laboratories were higher than recommended values.

Developing Probabilistic Safety Performance Margins for Unknown and Underappreciated Risks

NASA Technical Reports Server (NTRS)

Benjamin, Allan; Dezfuli, Homayoon; Everett, Chris

2015-01-01

Probabilistic safety requirements currently formulated or proposed for space systems, nuclear reactor systems, nuclear weapon systems, and other types of systems that have a low-probability potential for high-consequence accidents depend on showing that the probability of such accidents is below a specified safety threshold or goal. Verification of compliance depends heavily upon synthetic modeling techniques such as PRA. To determine whether or not a system meets its probabilistic requirements, it is necessary to consider whether there are significant risks that are not fully considered in the PRA either because they are not known at the time or because their importance is not fully understood. The ultimate objective is to establish a reasonable margin to account for the difference between known risks and actual risks in attempting to validate compliance with a probabilistic safety threshold or goal. In this paper, we examine data accumulated over the past 60 years from the space program, from nuclear reactor experience, from aircraft systems, and from human reliability experience to formulate guidelines for estimating probabilistic margins to account for risks that are initially unknown or underappreciated. The formulation includes a review of the safety literature to identify the principal causes of such risks.

Tracking the Stages of Learning: Concept Maps as Representations of Liminal Space

ERIC Educational Resources Information Center

Cuthell, John; Preston, Christina

2012-01-01

The concept of liminal space has recently been applied to ways of learning: the learning journey through this space encounters difficulties and misunderstandings, that are resolved as knowledge is mastered. Since 1992 the MirandaNet Fellowship, a growing international community of educators, has investigated the ways in which this relates to the…

Investigating Learning Space for Research Workspaces in Higher Education in Malaysia

ERIC Educational Resources Information Center

Yusof, Norhafezah; Hashim, Rosna Awang; Kian, Chan Kok

2016-01-01

Purpose: The purpose of this paper is to investigate learning space for research workspaces in Higher Education Institutions (HEIs) in Malaysia based on the evaluations by experts and university research workers on a practical model for creating an effective research learning space. It examines expert analyses of the notion of a suitable research…

The Challenges of Establishing Social Learning Spaces at a Johannesburg University Student Residence: Student Views

ERIC Educational Resources Information Center

Agherdien, Najma; Petersen, Nadine

2016-01-01

This article reports on two cycles of a Participatory Action Research (PAR) study on student experiences of the process of establishing social learning spaces in a Johannesburg university student residence. We draw on Wenger's (2009) notion of "social learning spaces" to explore the manner in which students mediate their social and…

Learning Bridges: A Role for Mobile Technologies in Education

ERIC Educational Resources Information Center

Vavoula, Giasemi; Sharples, Mike; Lonsdale, Peter; Rudman, Paul; Meek, Julia

2007-01-01

MyArtSpace is a service for children to spread their learning between schools and museums using mobile phones linked to a personal Web space. Using MyArtSpace as an example, the authors discuss the possibilities for mobile technology to form bridges between formal and informal learning. They also offer guidelines for designing such bridges.…

Advanced Learning Space as an Asset for Students with Disabilities

ERIC Educational Resources Information Center

Císarová, Klára; Lamr, Marián; Vitvarová, Jana

2015-01-01

The paper describes an e-learning system called Advanced Learning Space that was developed at the Technical University of Liberec. The system provides a personalized virtual work space and promotes communication among students and their teachers. The core of the system is a module that can be used to automatically record, store and playback…

Learning Spaces in Academic Libraries--A Review of the Evolving Trends

ERIC Educational Resources Information Center

Turner, Arlee; Welch, Bernadette; Reynolds, Sue

2013-01-01

This paper presents a review of the professional discourse regarding the evolution of information and learning spaces in academic libraries, particularly in the first decade of the twenty-first century. It investigates the evolution of academic libraries and the development of learning spaces focusing on the use of the terms which have evolved…

A Study Exploring Learners' Informal Learning Space Behaviors, Attitudes, and Preferences

ERIC Educational Resources Information Center

Harrop, Deborah; Turpin, Bea

2013-01-01

What makes a successful informal learning space is a topic in need of further research. The body of discourse on informal space design is drawn from learning theory, placemaking, and architecture, with a need for understanding of the synergy between the three. Findings from a longitudinal, quantitative, and qualitative study at Sheffield Hallam…

Ultrasonography of the rumen of dairy cows

PubMed Central

2013-01-01

Background This study describes the ultrasonographic findings of the rumen in 45 healthy dairy cows. Results The cows were scanned on both sides using a 5.0 MHz transducer. The dorsal visible margin of the rumen ran parallel to the lung from cranioventral to caudodorsal. It was furthest from the dorsal midline at the 9th intercostal space (48.3 ± 9.24 cm) and closest at the 12th intercostal space (22.4 ± 3.27 cm). The longitudinal groove, which could be clearly identified at all examination sites because it appeared as a triangular notch, formed the ventral margin of the dorsal sac of the rumen. The dorsal sac of the rumen was largest at the caudal flank (40.3 ± 6.33 cm), where it was adjacent to the abdominal wall. The ventral sac of the rumen extended across the ventral midline into the right hemiabdomen and its ventral margin had a largely horizontal craniocaudal course. The height of the ventral sac of the rumen exceeded that of the dorsal sac at all examination sites; the maximum height was measured at the 12th intercostal space (62.6 ± 9.53 cm). The dorsal gas cap, characterised ultrasonographically by typical reverberation artifacts, was visible in all cows from the 12th intercostal space to the caudal flank. It was largest at the 12th intercostal space (20.5 ± 7.03 cm). The transition from the gas cap to the fibre mat was marked by the abrupt cessation of the reverberation artifacts. It was not possible to differentiate a fibre mat and a ventral fluid phase. The rumen could be imaged from the right side in 21 cows (47%). Conclusions Ultrasonography is well suited for the detailed examination of the rumen of cows. The reference values obtained from this study add to the diagnostic tools that are available for the assessment of bovine patients. PMID:23497545

Maximum margin semi-supervised learning with irrelevant data.

PubMed

Yang, Haiqin; Huang, Kaizhu; King, Irwin; Lyu, Michael R

2015-10-01

Semi-supervised learning (SSL) is a typical learning paradigms training a model from both labeled and unlabeled data. The traditional SSL models usually assume unlabeled data are relevant to the labeled data, i.e., following the same distributions of the targeted labeled data. In this paper, we address a different, yet formidable scenario in semi-supervised classification, where the unlabeled data may contain irrelevant data to the labeled data. To tackle this problem, we develop a maximum margin model, named tri-class support vector machine (3C-SVM), to utilize the available training data, while seeking a hyperplane for separating the targeted data well. Our 3C-SVM exhibits several characteristics and advantages. First, it does not need any prior knowledge and explicit assumption on the data relatedness. On the contrary, it can relieve the effect of irrelevant unlabeled data based on the logistic principle and maximum entropy principle. That is, 3C-SVM approaches an ideal classifier. This classifier relies heavily on labeled data and is confident on the relevant data lying far away from the decision hyperplane, while maximally ignoring the irrelevant data, which are hardly distinguished. Second, theoretical analysis is provided to prove that in what condition, the irrelevant data can help to seek the hyperplane. Third, 3C-SVM is a generalized model that unifies several popular maximum margin models, including standard SVMs, Semi-supervised SVMs (S(3)VMs), and SVMs learned from the universum (U-SVMs) as its special cases. More importantly, we deploy a concave-convex produce to solve the proposed 3C-SVM, transforming the original mixed integer programming, to a semi-definite programming relaxation, and finally to a sequence of quadratic programming subproblems, which yields the same worst case time complexity as that of S(3)VMs. Finally, we demonstrate the effectiveness and efficiency of our proposed 3C-SVM through systematical experimental comparisons. Copyright © 2015 Elsevier Ltd. All rights reserved.

Identity and the Role of the State.

ERIC Educational Resources Information Center

Harvey, Luli

1997-01-01

Examples of marginalized nonformal learning in Britain that is driven by a search for alternative value systems include initiatives among Kurdish refugees, Blacks seeking identity through black studies, women sharing their stories, the resurgence of Irish culture, and the green movement. (SK)

Active and Passive Technology Integration: A Novel Approach for Managing Technology's Influence on Learning Experiences in Context-Aware Learning Spaces

ERIC Educational Resources Information Center

Laine, Teemu H.; Nygren, Eeva

2016-01-01

Technology integration is the process of overcoming different barriers that hinder efficient utilisation of learning technologies. The authors divide technology integration into two components based on technology's role in the integration process. In active integration, the technology integrates learning resources into a learning space, making it…

Galileo 1989 VEEGA trajectory design. [Venus-Earth-Earth-Gravity-Assist

NASA Technical Reports Server (NTRS)

D'Amario, Louis A.; Byrnes, Dennis V.; Johannesen, Jennie R.; Nolan, Brian G.

1989-01-01

The new baseline for the Galileo Mission is a 1989 Venus-earth-earth gravity-assist (VEEGA) trajectory, which utilizes three gravity-assist planetary flybys in order to reduce launch energy requirements significantly compared to other earth-Jupiter transfer modes. The launch period occurs during October-November 1989. The total flight time is about 6 years, with November 1995 as the most likely choice for arrival at Jupiter. Optimal 1989 VEEGA trajectories have been generated for a wide range of earth launch dates and Jupiter arrival dates. Launch/arrival space contour plots are presented for various trajectory parameters, including propellant margin, which is used to measure mission performance. The accessible region of the launch/arrival space is defined by propellant margin and launch energy constraints; the available launch period is approximately 1.5 months long.

Effects of Expanding and Equal Spacing on Second Language Vocabulary Learning: Does Gradually Increasing Spacing Increase Vocabulary Learning?

ERIC Educational Resources Information Center

Nakata, Tatsuya

2015-01-01

Although expanding spacing is often regarded as the most effective practice schedule, studies comparing equal and expanding spacing have yielded mixed results. The present study set out to examine whether the amount of spacing and the retention interval may influence the effects of expanding and equal spacing on second language (L2) vocabulary…

A Space-Based Learning Service for Schools Worldwide

NASA Astrophysics Data System (ADS)

White, Norman A.; Gibson, Alan

2002-01-01

This paper outlines a scheme for international collaboration to enrich the use of space in school education, to improve students' learning about science and related subjects and to enhance the continuity of science-related studies after the age of 16. Guidelines are presented for the design of an on-line learning service to provide schools worldwide with:- interactive curriculum-related learning resources for teaching about space and through - access to a purpose-designed education satellite or satellites; - opportunities for hands-on work by students in out-of-school hours; - news about space developments to attract, widen and deepen initial interest among teachers - support services to enable teachers to make effective use of the learning service. The Learning Service is the product of almost twenty years of experience by a significant number of UK schools in experimenting with, and in using, satellites and space to aid learning; and over four years of study and development by the SpaceLink Learning Foundation - a private-sector, not- for-profit UK registered charity, which is dedicated to help in increasing both the supply of scientists and engineers and the public understanding of science. This initiative provides scope for, and could benefit from, the involvement of relevant/interested organisations drawn from different countries. The Foundation would be ready, from its UK base, to be among such a group of initiating organisations.

Designing new collaborative learning spaces in clinical environments: experiences from a children's hospital in Australia.

PubMed

Bines, Julie E; Jamieson, Peter

2013-09-01

Hospitals are complex places that provide a rich learning environment for students, staff, patients and their families, professional groups and the community. The "new" Royal Children's Hospital opened in late 2011. Its mission is focused on improving health and well-being of children and adolescents through leadership in healthcare, research and education. Addressing the need to create "responsive learning environments" aligned with the shift to student-centred pedagogy, two distinct learning environments were developed within the new Royal Children's Hospital; (i) a dedicated education precinct providing a suite of physical environments to promote a more active, collaborative and social learning experience for education and training programs conducted on the Royal Children's Hospital campus and (ii) a suite of learning spaces embedded within clinical areas so that learning becomes an integral part of the daily activities of this busy Hospital environment. The aim of this article is to present the overarching educational principles that lead the design of these learning spaces and describe the opportunities and obstacles encountered in the development of collaborative learning spaces within a large hospital development.

Anthropogenic impacts on continental margins: New frontiers and engagement arena for global sustainability research and action

NASA Astrophysics Data System (ADS)

Liu, K. K.; Glavovic, B.; Limburg, K.; Emeis, K. C.; Thomas, H.; Kremer, H.; Avril, B.; Zhang, J.; Mulholland, M. R.; Glaser, M.; Swaney, D. P.

2014-12-01

There is an urgent need to design and implement transformative governance strategies that safeguard Earth's life-support systems essential for long-term human well-being. From a series of meetings of the Continental Margins Working Group co-sponsored by IMBER and LOICZ of IGBP, we conclude that the greatest urgency exists at the ocean-land interface - the continental margins or the Margin - which extends from coastlands over continental shelves and slopes bordering the deep ocean. The Margin is enduring quadruple squeeze from (i) Population growth and rising demands for resources; (ii) Ecosystem degradation and loss; (iii) Rising CO2, climate change and alteration of marine biogeochemistry and ecosystems; and (iv) Rapid and irreversible changes in social-ecological systems. Some areas of the Margin that are subject to the greatest pressures (e.g. the Arctic) are also those for which knowledge of fundamental processes remains most limited. Aside from improving our basic understanding of the nature and variability of the Margin, priority issues include: (i) investment reform to prevent lethal but profitable activities; (ii) risk reduction; and (iii) jurisdiction, equity and fiscal responsibility. However, governance deficits or mismatches are particularly pronounced at the ocean-edge of the Margin and the prevailing Law of the Sea is incapable of resolving these challenges. The "gold rush" of accelerating demands for space and resources, and variability in how this domain is regulated, move the Margin to the forefront of global sustainability research and action. We outline a research strategy in 3 engagement arenas: (a) knowledge and understanding of dynamic Margin processes; (b) development, innovation and risk at the Margin; and (c) governance for sustainability on the Margin. The goals are (1) to better understand Margin social-ecological systems, including their physical and biogeochemical components; (2) to develop practical guidance for sustainable development and use of resources; (3) to design governance regimes to stem unsustainable practices; (4) to investigate how to enable equitable sharing of costs and benefits from sustainable use of resources; and (5) to evaluate alternative research approaches and partnerships that address the challenges faced on the Margin.

The spacing effect in intentional and incidental free recall by children and adults: Limits on the automaticity hypothesis.

PubMed

Toppino, Thomas C; Fearnow-Kenney, Melodie D; Kiepert, Marissa H; Teremula, Amanda C

2009-04-01

Preschoolers, elementary school children, and college students exhibited a spacing effect in the free recall of pictures when learning was intentional. When learning was incidental and a shallow processing task requiring little semantic processing was used during list presentation, young adults still exhibited a spacing effect, but children consistently failed to do so. Children, however, did manifest a spacing effect in incidental learning when an elaborate semantic processing task was used. These results limit the hypothesis that the spacing effect in free recall occurs automatically and constrain theoretical accounts of why the spacing between repetitions affects recall performance.

Creating Safe Spaces for Music Learning

ERIC Educational Resources Information Center

Hendricks, Karin S.; Smith, Tawnya D.; Stanuch, Jennifer

2014-01-01

This article offers a practical model for fostering emotionally safe learning environments that instill in music students a positive sense of self-belief, freedom, and purpose. The authors examine the implications for music educators of creating effective learning environments and present recommendations for creating a safe space for learning,…

Applications of Support Vector Machine (SVM) Learning in Cancer Genomics

PubMed Central

HUANG, SHUJUN; CAI, NIANGUANG; PACHECO, PEDRO PENZUTI; NARANDES, SHAVIRA; WANG, YANG; XU, WAYNE

2017-01-01

Machine learning with maximization (support) of separating margin (vector), called support vector machine (SVM) learning, is a powerful classification tool that has been used for cancer genomic classification or subtyping. Today, as advancements in high-throughput technologies lead to production of large amounts of genomic and epigenomic data, the classification feature of SVMs is expanding its use in cancer genomics, leading to the discovery of new biomarkers, new drug targets, and a better understanding of cancer driver genes. Herein we reviewed the recent progress of SVMs in cancer genomic studies. We intend to comprehend the strength of the SVM learning and its future perspective in cancer genomic applications. PMID:29275361

Exploring the Use of Online Space in an Elementary School

ERIC Educational Resources Information Center

Lye, Sze Yee; Abas, Suriati; Tay, Lee Yong; Saban, Fadilah

2012-01-01

This paper analysed how three teacher-researchers of Singapore's elementary school used online space extensively in Grade 2-Grade 4 classrooms. Such online space, made possible by free and readily available web 2.0 and open source applications, was meant to complement the physical learning space as such space can allow learning activities, which…

Lessons Learned JSC Micro-Wireless Instrumentation Systems on Space Shuttle and International Space Station CANEUS 2006

NASA Technical Reports Server (NTRS)

Studor, George

2007-01-01

A viewgraph presentation on lessons learned from NASA Johnson Space Center's micro-wireless instrumentation is shown. The topics include: 1) Background, Rationale and Vision; 2) NASA JSC/Structural Engineering Approach & History; 3) Orbiter Wing Leading Edge Impact Detection System; 4) WLEIDS Confidence and Micro-WIS Lessons Learned; and 5) Current Projects and Recommendations.

Developing Learning Spaces in Higher Education: An Evaluation of Experimental Spaces at the University of Leicester

ERIC Educational Resources Information Center

Wood, Phil; Warwick, Paul; Cox, Derek

2012-01-01

Consideration of the physical environment in which learning takes place has become a growing area of academic interest over the past decade. This study focuses on the experiences and perceptions of academic staff and students who used three refurbished, and innovative, learning spaces at the University of Leicester. The results suggest that the…

Construction and Evaluation of an Integrated Formal/Informal Learning Environment for Foreign Language Learning across Real and Virtual Spaces

ERIC Educational Resources Information Center

Waragai, Ikumi; Ohta, Tatsuya; Kurabayashi, Shuichi; Kiyoki, Yasushi; Sato, Yukiko; Brückner, Stefan

2017-01-01

This paper presents the prototype of a foreign language learning space, based on the construction of an integrated formal/informal learning environment. Before the background of the continued innovation of information technology that places conventional learning styles and educational methods into new contexts based on new value-standards,…

Robust Stability Analysis of the Space Launch System Control Design: A Singular Value Approach

NASA Technical Reports Server (NTRS)

Pei, Jing; Newsome, Jerry R.

2015-01-01

Classical stability analysis consists of breaking the feedback loops one at a time and determining separately how much gain or phase variations would destabilize the stable nominal feedback system. For typical launch vehicle control design, classical control techniques are generally employed. In addition to stability margins, frequency domain Monte Carlo methods are used to evaluate the robustness of the design. However, such techniques were developed for Single-Input-Single-Output (SISO) systems and do not take into consideration the off-diagonal terms in the transfer function matrix of Multi-Input-Multi-Output (MIMO) systems. Robust stability analysis techniques such as H(sub infinity) and mu are applicable to MIMO systems but have not been adopted as standard practices within the launch vehicle controls community. This paper took advantage of a simple singular-value-based MIMO stability margin evaluation method based on work done by Mukhopadhyay and Newsom and applied it to the SLS high-fidelity dynamics model. The method computes a simultaneous multi-loop gain and phase margin that could be related back to classical margins. The results presented in this paper suggest that for the SLS system, traditional SISO stability margins are similar to the MIMO margins. This additional level of verification provides confidence in the robustness of the control design.

Logistical Support for the Heavy-Light Mix,

DTIC Science & Technology

1988-01-20

determination to learn from history. While the physical ability to support this force is marginal, the logistical procedures, concepts of support, and a...others. £ They emphasized arni-or and mechanized in 4 antry which could keep pace with the tanks. 2 -- t. - - - - *i . h -I. -o, ., . i. . -. rJIPT...Army received a costly review of the combined arms lessons learned during WW II. In June. 1950, the North Korean Army launched an all-out attack into

Negotiating Afrikaner Subjectivity from the Post-Apartheid Margins: One Student's Subject Positions in the Discursively Constructed Classroom Space at an Elite English High School

ERIC Educational Resources Information Center

Ferreira, Ana

2014-01-01

The contemporary South African subject English classroom is a complex space requiring ongoing attention to issues of cultural and linguistic diversity, and frequently manifesting the need to work across historically constructed differences in race, ethnicity and socioeconomic status. This article reports on one aspect of a broader research…

Guidelines and Metrics for Assessing Space System Cost Estimates

DTIC Science & Technology

2008-01-01

analysis time, reuse tooling, models , mechanical ground-support equipment [MGSE]) High mass margin ( simplifying assumptions used to bound solution...engineering environment changes High reuse of architecture, design , tools, code, test scripts, and commercial real- time operating systems Simplified life...Coronal Explorer TWTA traveling wave tube amplifier USAF U.S. Air Force USCM Unmanned Space Vehicle Cost Model USN U.S. Navy UV ultraviolet UVOT UV

44 CFR 60.22 - Planning considerations for flood-prone areas.

Code of Federal Regulations, 2012 CFR

2012-10-01

... community shall consider— (1) Preservation of the flood-prone areas for open space purposes; (2) Relocation... debris, to provide an added margin of safety against floods having a magnitude greater than the base...

44 CFR 60.22 - Planning considerations for flood-prone areas.

Code of Federal Regulations, 2013 CFR

2013-10-01

... community shall consider— (1) Preservation of the flood-prone areas for open space purposes; (2) Relocation... debris, to provide an added margin of safety against floods having a magnitude greater than the base...

44 CFR 60.22 - Planning considerations for flood-prone areas.

Code of Federal Regulations, 2014 CFR

2014-10-01

... community shall consider— (1) Preservation of the flood-prone areas for open space purposes; (2) Relocation... debris, to provide an added margin of safety against floods having a magnitude greater than the base...

Impact of technology-infused interactive learning environments on college professors' instructional decisions and practices

NASA Astrophysics Data System (ADS)

Kuda Malwathumullage, Chamathca Priyanwada

Recent advancements in instructional technology and interactive learning space designs have transformed how undergraduate classrooms are envisioned and conducted today. Large number of research studies have documented the impact of instructional technology and interactive learning spaces on elevated student learning gains, positive attitudes, and increased student engagement in undergraduate classrooms across nation. These research findings combined with the movement towards student-centered instructional strategies have motivated college professors to explore the unfamiliar territories of instructional technology and interactive learning spaces. Only a limited number of research studies that explored college professors' perspective on instructional technology and interactive learning space use in undergraduate classrooms exist in the education research literature. Since college professors are an essential factor in undergraduate students' academic success, investigating how college professors perceive and utilize instructional technology and interactive learning environments can provide insights into designing effective professional development programs for college professors across undergraduate institutions. Therefore, the purpose of this study was to investigate college professors' pedagogical reasoning behind incorporating different types of instructional technologies and teaching strategies to foster student learning in technology-infused interactive learning environments. Furthermore, this study explored the extent to which college professors' instructional decisions and practices are affected by teaching in an interactive learning space along with their overall perception of instructional technology and interactive learning spaces. Four college professors from a large public Midwestern university who taught undergraduate science courses in a classroom based on the 'SCALE-UP model' participated in this study. Major data sources included classroom observations, interviews and questionnaires. An enumerative approach and the constant comparative method were utilized to analyze the data. According to the results obtained, all the participating college professors of this study employed a variety of instructional technologies and learning space features to actively engage their students in classroom activities. Participants were largely influenced by the instructional technology and the learning space features at lesson planning and execution stages whereas this influence was less notable at the student assessment stage. Overall, college professors perceive technology-infused interactive learning environments to be advantageous in terms of enabling flexibility and creativity along with easy facilitation of classroom activities. However, they felt challenged when designing effective classroom activities and preferred continuous professional development support. Overall, college professors' pedagogical decision making process, their perceived benefits and challenges seemed to be interrelated and centered on the learners and the learning process. Primary implication of this study is to implement effective professional development programs for college professors which enable them to familiarize themselves with student-centered pedagogy and effective classroom activity design along with the novel trends in learning space design and instructional technologies. Furthermore, higher education institutions need to devise incentives and recognition measures to appreciate college professors' contributions to advance scholarship of teaching and learning.

Student Perceptions of a 21st Century Learning Space

ERIC Educational Resources Information Center

Adedokun, Omolola A.; Henke, Jacqueline N.; Parker, Loran Carleton; Burgess, Wilella D.

2017-01-01

Higher education institutions are increasingly building or remodeling classrooms to be flexible spaces that support learner-centered instruction. However, little is known about the actual impact of these spaces on student outcomes. Using a mixed method design, this study examined student perceptions of a flexible learning space on student learning…

Electrical, Electronic and Electromechanical (EEE) Parts in the New Space Paradigm: When is Better the Enemy of Good Enough?

NASA Technical Reports Server (NTRS)

La Bel, Kenneth A.; Sampson, Michael J.

2016-01-01

As the space business rapidly evolves to accommodate a lower cost model of development and operation via concepts such as commercial space and small spacecraft (aka, CubeSats), traditional EEE parts screening and qualification methods are being scrutinized under a risk-reward trade space. In this presentation, two basic concepts will be the overarching theme: 1) The movement from complete risk aversion EEE parts methods to managing and/or accepting risk via alternate approaches; and, 2) A discussion of over-design focusing on both electrical design performance and bounding margins.

Electrical, Electronic and Electromechanical (EEE) Parts in the New Space Paradigm: When is Better the Enemy of Good Enough?

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; Sampson, Michael J.

2016-01-01

As the space business rapidly evolves to accommodate a lower cost model of development and operation via concepts such as commercial space and small spacecraft (aka, CubeSats), traditional EEE parts screening and qualification methods are being scrutinized under a risk-reward trade space. In this presentation, two basic concepts will be the overarching theme: 1) The movement from complete risk aversion EEE parts methods to managing and or accepting risk via alternate approaches; and, 2) A discussion of over-design focusing on both electrical design performance and bounding margins.

Reward maximization justifies the transition from sensory selection at childhood to sensory integration at adulthood.

PubMed

Daee, Pedram; Mirian, Maryam S; Ahmadabadi, Majid Nili

2014-01-01

In a multisensory task, human adults integrate information from different sensory modalities--behaviorally in an optimal Bayesian fashion--while children mostly rely on a single sensor modality for decision making. The reason behind this change of behavior over age and the process behind learning the required statistics for optimal integration are still unclear and have not been justified by the conventional Bayesian modeling. We propose an interactive multisensory learning framework without making any prior assumptions about the sensory models. In this framework, learning in every modality and in their joint space is done in parallel using a single-step reinforcement learning method. A simple statistical test on confidence intervals on the mean of reward distributions is used to select the most informative source of information among the individual modalities and the joint space. Analyses of the method and the simulation results on a multimodal localization task show that the learning system autonomously starts with sensory selection and gradually switches to sensory integration. This is because, relying more on modalities--i.e. selection--at early learning steps (childhood) is more rewarding than favoring decisions learned in the joint space since, smaller state-space in modalities results in faster learning in every individual modality. In contrast, after gaining sufficient experiences (adulthood), the quality of learning in the joint space matures while learning in modalities suffers from insufficient accuracy due to perceptual aliasing. It results in tighter confidence interval for the joint space and consequently causes a smooth shift from selection to integration. It suggests that sensory selection and integration are emergent behavior and both are outputs of a single reward maximization process; i.e. the transition is not a preprogrammed phenomenon.

Gradient-based adaptation of general gaussian kernels.

PubMed

Glasmachers, Tobias; Igel, Christian

2005-10-01

Gradient-based optimizing of gaussian kernel functions is considered. The gradient for the adaptation of scaling and rotation of the input space is computed to achieve invariance against linear transformations. This is done by using the exponential map as a parameterization of the kernel parameter manifold. By restricting the optimization to a constant trace subspace, the kernel size can be controlled. This is, for example, useful to prevent overfitting when minimizing radius-margin generalization performance measures. The concepts are demonstrated by training hard margin support vector machines on toy data.

Semi-supervised learning via regularized boosting working on multiple semi-supervised assumptions.

PubMed

Chen, Ke; Wang, Shihai

2011-01-01

Semi-supervised learning concerns the problem of learning in the presence of labeled and unlabeled data. Several boosting algorithms have been extended to semi-supervised learning with various strategies. To our knowledge, however, none of them takes all three semi-supervised assumptions, i.e., smoothness, cluster, and manifold assumptions, together into account during boosting learning. In this paper, we propose a novel cost functional consisting of the margin cost on labeled data and the regularization penalty on unlabeled data based on three fundamental semi-supervised assumptions. Thus, minimizing our proposed cost functional with a greedy yet stagewise functional optimization procedure leads to a generic boosting framework for semi-supervised learning. Extensive experiments demonstrate that our algorithm yields favorite results for benchmark and real-world classification tasks in comparison to state-of-the-art semi-supervised learning algorithms, including newly developed boosting algorithms. Finally, we discuss relevant issues and relate our algorithm to the previous work.

Designing and Instructing Hybrid Open Learning Spaces Model to Support Lifelong Learning Engagement

ERIC Educational Resources Information Center

Crawford, Caroline M.

2016-01-01

With a focus upon open and lifelong learning understanding, the real world delineation between formalized higher education graduate school efforts and professional career position lines may be suggested as being blurred. This case study offers an analysis of one university instructor's efforts towards developing hybrid learning spaces that…

Virtual Learning Spaces in the Web: An Agent-Based Architecture of Personalized Collaborative Learning Environment.

ERIC Educational Resources Information Center

Nunez Esquer, Gustavo; Sheremetov, Leonid

This paper reports on the results and future research work within the paradigm of Configurable Collaborative Distance Learning, called Espacios Virtuales de Apredizaje (EVA). The paper focuses on: (1) description of the main concepts, including virtual learning spaces for knowledge, collaboration, consulting, and experimentation, a…

Supporting Self-Regulated Personalised Learning through Competence-Based Knowledge Space Theory

ERIC Educational Resources Information Center

Steiner, Christina M.; Nussbaumer, Alexander; Albert, Dietrich

2009-01-01

This article presents two current research trends in e-learning that at first sight appear to compete. Competence-Based Knowledge Space Theory (CBKST) provides a knowledge representation framework which, since its invention by Doignon & Falmagne, has been successfully applied in various e-learning systems (for example, Adaptive Learning with…

Leveraging Faculty Reflective Practice to Understand Active Learning Spaces: Flashbacks and Re-Captures

ERIC Educational Resources Information Center

Ramsay, Crystal M.; Guo, Xiuyan; Pursel, Barton K.

2017-01-01

Although learning spaces research is not new, research approaches that target the specific teaching and learning experiences of faculty and students who occupy active learning classrooms (ALCs) is nascent. We report on two novels data collection approaches: Flashbacks and Re-Captures. Both leverage faculty reflective practice and provide windows…

Learning in the Liminal Space: A Semiotic Approach to Threshold Concepts

ERIC Educational Resources Information Center

Land, Ray; Rattray, Julie; Vivian, Peter

2014-01-01

The threshold concepts approach to student learning and curriculum design now informs an empirical research base comprising over 170 disciplinary and professional contexts. It draws extensively on the notion of troublesomeness in a "liminal" space of learning. The latter is a transformative state in the process of learning in which there…

Learning in Discussion Forums: An Analysis of Knowledge Construction in a Gaming Affinity Space

ERIC Educational Resources Information Center

Davis, Don; Marone, Vittorio

2016-01-01

In the learning sciences and game studies communities, there has been an increasing interest in the potential of game-related "paratexts" and "surrounds" in supporting learning, such as online discussion forums and gaming affinity spaces. While there have been studies identifying how learning occurs in such communities, little…

Constructing Learning Spaces? Videoconferencing at Local Learning Centres in Sweden

ERIC Educational Resources Information Center

Logdlund, Ulrik

2010-01-01

This article explores videoconferencing in the context of local learning centres in Sweden. The practice is described as a "learning space" in which adult learners construct socio-spatial relations. The study goes beyond a sociological apprehension of actors and opposes the idea of the material as neutral, passive and conformed by…

Marginal Structural Models with Counterfactual Effect Modifiers.

PubMed

Zheng, Wenjing; Luo, Zhehui; van der Laan, Mark J

2018-06-08

In health and social sciences, research questions often involve systematic assessment of the modification of treatment causal effect by patient characteristics. In longitudinal settings, time-varying or post-intervention effect modifiers are also of interest. In this work, we investigate the robust and efficient estimation of the Counterfactual-History-Adjusted Marginal Structural Model (van der Laan MJ, Petersen M. Statistical learning of origin-specific statically optimal individualized treatment rules. Int J Biostat. 2007;3), which models the conditional intervention-specific mean outcome given a counterfactual modifier history in an ideal experiment. We establish the semiparametric efficiency theory for these models, and present a substitution-based, semiparametric efficient and doubly robust estimator using the targeted maximum likelihood estimation methodology (TMLE, e.g. van der Laan MJ, Rubin DB. Targeted maximum likelihood learning. Int J Biostat. 2006;2, van der Laan MJ, Rose S. Targeted learning: causal inference for observational and experimental data, 1st ed. Springer Series in Statistics. Springer, 2011). To facilitate implementation in applications where the effect modifier is high dimensional, our third contribution is a projected influence function (and the corresponding projected TMLE estimator), which retains most of the robustness of its efficient peer and can be easily implemented in applications where the use of the efficient influence function becomes taxing. We compare the projected TMLE estimator with an Inverse Probability of Treatment Weighted estimator (e.g. Robins JM. Marginal structural models. In: Proceedings of the American Statistical Association. Section on Bayesian Statistical Science, 1-10. 1997a, Hernan MA, Brumback B, Robins JM. Marginal structural models to estimate the causal effect of zidovudine on the survival of HIV-positive men. 2000;11:561-570), and a non-targeted G-computation estimator (Robins JM. A new approach to causal inference in mortality studies with sustained exposure periods - application to control of the healthy worker survivor effect. Math Modell. 1986;7:1393-1512.). The comparative performance of these estimators is assessed in a simulation study. The use of the projected TMLE estimator is illustrated in a secondary data analysis for the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) trial where effect modifiers are subject to missing at random.

Semisupervised Support Vector Machines With Tangent Space Intrinsic Manifold Regularization.

PubMed

Sun, Shiliang; Xie, Xijiong

2016-09-01

Semisupervised learning has been an active research topic in machine learning and data mining. One main reason is that labeling examples is expensive and time-consuming, while there are large numbers of unlabeled examples available in many practical problems. So far, Laplacian regularization has been widely used in semisupervised learning. In this paper, we propose a new regularization method called tangent space intrinsic manifold regularization. It is intrinsic to data manifold and favors linear functions on the manifold. Fundamental elements involved in the formulation of the regularization are local tangent space representations, which are estimated by local principal component analysis, and the connections that relate adjacent tangent spaces. Simultaneously, we explore its application to semisupervised classification and propose two new learning algorithms called tangent space intrinsic manifold regularized support vector machines (TiSVMs) and tangent space intrinsic manifold regularized twin SVMs (TiTSVMs). They effectively integrate the tangent space intrinsic manifold regularization consideration. The optimization of TiSVMs can be solved by a standard quadratic programming, while the optimization of TiTSVMs can be solved by a pair of standard quadratic programmings. The experimental results of semisupervised classification problems show the effectiveness of the proposed semisupervised learning algorithms.

Learning in the model space for cognitive fault diagnosis.

PubMed

Chen, Huanhuan; Tino, Peter; Rodan, Ali; Yao, Xin

2014-01-01

The emergence of large sensor networks has facilitated the collection of large amounts of real-time data to monitor and control complex engineering systems. However, in many cases the collected data may be incomplete or inconsistent, while the underlying environment may be time-varying or unformulated. In this paper, we develop an innovative cognitive fault diagnosis framework that tackles the above challenges. This framework investigates fault diagnosis in the model space instead of the signal space. Learning in the model space is implemented by fitting a series of models using a series of signal segments selected with a sliding window. By investigating the learning techniques in the fitted model space, faulty models can be discriminated from healthy models using a one-class learning algorithm. The framework enables us to construct a fault library when unknown faults occur, which can be regarded as cognitive fault isolation. This paper also theoretically investigates how to measure the pairwise distance between two models in the model space and incorporates the model distance into the learning algorithm in the model space. The results on three benchmark applications and one simulated model for the Barcelona water distribution network confirm the effectiveness of the proposed framework.

Which Space? Whose Space? An Experience in Involving Students and Teachers in Space Design

ERIC Educational Resources Information Center

Casanova, Diogo; Di Napoli, Roberto; Leijon, Marie

2018-01-01

To date, learning spaces in higher education have been designed with little engagement on the part of their most important users: students and teachers. In this paper, we present the results of research carried out in a UK university. The research aimed to understand how students and teachers conceptualise learning spaces when they are given the…

RAVEN User Manual

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mandelli, Diego; Rabiti, Cristian; Cogliati, Joshua Joseph

2015-10-01

RAVEN is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. The initial development was aimed to provide dynamic risk analysis capabilities to the Thermo-Hydraulic code RELAP-7, currently under development at the Idaho National Laboratory (INL). Although the initial goal has been fully accomplished, RAVEN is now a multi-purpose probabilistic and uncertainty quantification platform, capable to agnostically communicate with any system code. This agnosticism includes providing Application Programming Interfaces (APIs). These APIs are used to allow RAVEN to interact with any code as long as all the parameters that need tomore » be perturbed are accessible by inputs files or via python interfaces. RAVEN is capable of investigating the system response, and investigating the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. The development of RAVEN has started in 2012, when, within the Nuclear Energy Advanced Modeling and Simulation (NEAMS) program, the need to provide a modern risk evaluation framework became stronger. RAVEN principal assignment is to provide the necessary software and algorithms in order to employ the concept developed by the Risk Informed Safety Margin Characterization (RISMC) program. RISMC is one of the pathways defined within the Light Water Reactor Sustainability (LWRS) program. In the RISMC approach, the goal is not just the individuation of the frequency of an event potentially leading to a system failure, but the closeness (or not) to key safety-related events. Hence, the approach is interested in identifying and increasing the safety margins related to those events. A safety margin is a numerical value quantifying the probability that a safety metric (e.g. for an important process such as peak pressure in a pipe) is exceeded under certain conditions. The initial development of RAVEN has been focused on providing dynamic risk assessment capability to RELAP-7, currently under development at the INL and, likely, future replacement of the RELAP5-3D code. Most the capabilities that have been implemented having RELAP-7 as principal focus are easily deployable for other system codes. For this reason, several side activaties are currently ongoing for coupling RAVEN with software such as RELAP5-3D, etc. The aim of this document is the explanation of the input requirements, focalizing on the input structure.« less

RAVEN User Manual

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mandelli, Diego; Rabiti, Cristian; Cogliati, Joshua Joseph

2016-02-01

RAVEN is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. The initial development was aimed to provide dynamic risk analysis capabilities to the Thermo-Hydraulic code RELAP-7, currently under development at the Idaho National Laboratory (INL). Although the initial goal has been fully accomplished, RAVEN is now a multi-purpose probabilistic and uncertainty quantification platform, capable to agnostically communicate with any system code. This agnosticism includes providing Application Programming Interfaces (APIs). These APIs are used to allow RAVEN to interact with any code as long as all the parameters that need tomore » be perturbed are accessible by input files or via python interfaces. RAVEN is capable of investigating the system response, and investigating the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. The development of RAVEN started in 2012, when, within the Nuclear Energy Advanced Modeling and Simulation (NEAMS) program, the need to provide a modern risk evaluation framework became stronger. RAVEN principal assignment is to provide the necessary software and algorithms in order to employ the concept developed by the Risk Informed Safety Margin Characterization (RISMC) program. RISMC is one of the pathways defined within the Light Water Reactor Sustainability (LWRS) program. In the RISMC approach, the goal is not just the individuation of the frequency of an event potentially leading to a system failure, but the closeness (or not) to key safety-related events. Hence, the approach is interested in identifying and increasing the safety margins related to those events. A safety margin is a numerical value quantifying the probability that a safety metric (e.g. for an important process such as peak pressure in a pipe) is exceeded under certain conditions. The initial development of RAVEN has been focused on providing dynamic risk assessment capability to RELAP-7, currently under development at the INL and, likely, future replacement of the RELAP5-3D code. Most the capabilities that have been implemented having RELAP-7 as principal focus are easily deployable for other system codes. For this reason, several side activates are currently ongoing for coupling RAVEN with software such as RELAP5-3D, etc. The aim of this document is the explanation of the input requirements, focusing on the input structure.« less

RAVEN User Manual

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mandelli, Diego; Rabiti, Cristian; Cogliati, Joshua Joseph

2017-03-01

RAVEN is a generic software framework to perform parametric and probabilistic analy- sis based on the response of complex system codes. The initial development was aimed to provide dynamic risk analysis capabilities to the Thermo-Hydraulic code RELAP-7, currently under development at the Idaho National Laboratory (INL). Although the initial goal has been fully accomplished, RAVEN is now a multi-purpose probabilistic and uncer- tainty quantification platform, capable to agnostically communicate with any system code. This agnosticism includes providing Application Programming Interfaces (APIs). These APIs are used to allow RAVEN to interact with any code as long as all the parameters thatmore » need to be perturbed are accessible by inputs files or via python interfaces. RAVEN is capable of investigating the system response, and investigating the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused to- ward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. The development of RAVEN has started in 2012, when, within the Nuclear Energy Advanced Modeling and Simulation (NEAMS) program, the need to provide a modern risk evaluation framework became stronger. RAVEN principal assignment is to provide the necessary software and algorithms in order to employ the concept developed by the Risk Informed Safety Margin Characterization (RISMC) program. RISMC is one of the pathways defined within the Light Water Reactor Sustainability (LWRS) program. In the RISMC approach, the goal is not just the individuation of the frequency of an event potentially leading to a system failure, but the closeness (or not) to key safety-related events. Hence, the approach is in- terested in identifying and increasing the safety margins related to those events. A safety margin is a numerical value quantifying the probability that a safety metric (e.g. for an important process such as peak pressure in a pipe) is exceeded under certain conditions. The initial development of RAVEN has been focused on providing dynamic risk assess- ment capability to RELAP-7, currently under develop-ment at the INL and, likely, future replacement of the RELAP5-3D code. Most the capabilities that have been implemented having RELAP-7 as principal focus are easily deployable for other system codes. For this reason, several side activates are currently ongoing for coupling RAVEN with soft- ware such as RELAP5-3D, etc. The aim of this document is the explaination of the input requirements, focalizing on the input structure.« less

In vitro marginal fit of three all-ceramic crown systems.

PubMed

Yeo, In-Sung; Yang, Jae-Ho; Lee, Jai-Bong

2003-11-01

Studies on marginal discrepancies of single restorations using various systems and materials have resulted in statistical inferences that are ambiguous because of small sample sizes and limited numbers of measurements per specimen. The purpose of this study was to compare the marginal adaptation of single anterior restorations made using different systems. The in vitro marginal discrepancies of 3 different all-ceramic crown systems (Celay In-Ceram, conventional In-Ceram, and IPS Empress 2 layering technique), and a control group of metal ceramic restorations were evaluated and compared by measuring the gap dimension between the crowns and the prepared tooth at the marginal opening. The crowns were made for 1 extracted maxillary central incisor prepared with a 1-mm shoulder margin and 6-degree tapered walls by milling. Thirty crowns per system were fabricated. Crown measurements were recorded with an optical microscope, with an accuracy of +/-0.1 microm, at 50 points spaced approximately 400 microm along the circumferential margin. The criterion of 120 microm was used as the maximum clinically acceptable marginal gap. Mean gap dimensions and standard deviations were calculated for marginal opening. The data were analyzed with a 1-way analysis of variance (alpha=.05). Mean gap dimensions and standard deviations at the marginal opening for the incisor crowns were 87 +/- 34 microm for control, 83 +/- 33 microm for Celay In-Ceram, 112 +/- 55 microm for conventional In-Ceram, and 46 +/- 16 microm for the IPS Empress 2 layering technique. Significant differences were found among the crown groups (P<.05). Compared with the control group, the IPS Empress 2 group had significantly smaller marginal discrepancies (P<.05), and the conventional In-Ceram group exhibited significantly greater marginal discrepancies (P<.05). There was no significant difference between the Celay In-Ceram and the control group. Within the limitations of this study, the marginal discrepancies were all within the clinically acceptable standard set at 120 microm. However, the IPS Empress 2 system showed the smallest and most homogeneous gap dimension, whereas the conventional In-Ceram system presented the largest and more variable gap dimension compared with the metal ceramic (control) restoration.

Marginal adaptation of composite resins under two adhesive techniques.

PubMed

Dačić, Stefan; Veselinović, Aleksandar M; Mitić, Aleksandar; Nikolić, Marija; Cenić, Milica; Dačić-Simonović, Dragica

2016-11-01

In the present research, different adhesive techniques were used to set up fillings with composite resins. After the application of etch and rinse or self etch adhesive technique, marginal adaptation of composite fillings was estimated by the length of margins without gaps, and by the microretention of resin in enamel and dentin. The study material consisted of 40 extracted teeth. Twenty Class V cavities were treated with 35% phosphorous acid and restored after rinsing by Adper Single Bond 2 and Filtek Ultimate-ASB/FU 3M ESPE composite system. The remaining 20 cavities were restored by Adper Easy One-AEO/FU 3M ESPE composite system. Marginal adaptation of composite fillings was examined using a scanning electron microscope (SEM). The etch and rinse adhesive technique showed a significantly higher percentage of margin length without gaps (in enamel: 92.5%, in dentin: 57.3%), compared with the self-etch technique with lower percentage of margin length without gaps, in enamel 70.4% (p < .001), and in dentin-22.6% (p < .05). In the first technique, microretention was composed of adhesive and hybrid layers as well as resin tugs in interprismatic spaces of enamel, while the dentin microretention was composed of adhesive and hybrid layers with resin tugs in dentin canals. In the second technique, resin tugs were rarely seen and a microgap was dominant along the border of restoration margins. The SEM analysis showed a better marginal adaptation of composite resin to enamel and dentin with better microretention when the etch and rinse adhesive procedure was applied. © 2016 Wiley Periodicals, Inc.

How category learning affects object representations: Not all morphspaces stretch alike

PubMed Central

Folstein, Jonathan R.; Gauthier, Isabel; Palmeri, Thomas J.

2012-01-01

How does learning to categorize objects affect how we visually perceive them? Behavioral, neurophysiological, and neuroimaging studies have tested the degree to which category learning influences object representations, with conflicting results. Some studies find that objects become more visually discriminable along dimensions relevant to previously learned categories, while others find no such effect. One critical factor we explore here lies in the structure of the morphspaces used in different studies. Studies finding no increase in discriminability often use “blended” morphspaces, with morphparents lying at corners of the space. By contrast, studies finding increases in discriminability use “factorial” morphspaces, defined by separate morphlines forming axes of the space. Using the same four morphparents, we created both factorial and blended morphspaces matched in pairwise discriminability. Category learning caused a selective increase in discriminability along the relevant dimension of the factorial space, but not in the blended space, and led to the creation of functional dimensions in the factorial space, but not in the blended space. These findings demonstrate that not all morphspaces stretch alike: Only some morphspaces support enhanced discriminability to relevant object dimensions following category learning. Our results have important implications for interpreting neuroimaging studies reporting little or no effect of category learning on object representations in the visual system: Those studies may have been limited by their use of blended morphspaces. PMID:22746950

Mental space travel: damage to posterior parietal cortex prevents egocentric navigation and reexperiencing of remote spatial memories.

PubMed

Ciaramelli, Elisa; Rosenbaum, R Shayna; Solcz, Stephanie; Levine, Brian; Moscovitch, Morris

2010-05-01

The ability to navigate in a familiar environment depends on both an intact mental representation of allocentric spatial information and the integrity of systems supporting complementary egocentric representations. Although the hippocampus has been implicated in learning new allocentric spatial information, converging evidence suggests that the posterior parietal cortex (PPC) might support egocentric representations. To date, however, few studies have examined long-standing egocentric representations of environments learned long ago. Here we tested 7 patients with focal lesions in PPC and 12 normal controls in remote spatial memory tasks, including 2 tasks reportedly reliant on allocentric representations (distance and proximity judgments) and 2 tasks reportedly reliant on egocentric representations (landmark sequencing and route navigation; see Rosenbaum, Ziegler, Winocur, Grady, & Moscovitch, 2004). Patients were unimpaired in distance and proximity judgments. In contrast, they all failed in route navigation, and left-lesioned patients also showed marginally impaired performance in landmark sequencing. Patients' subjective experience associated with navigation was impoverished and disembodied compared with that of the controls. These results suggest that PPC is crucial for accessing remote spatial memories within an egocentric reference frame that enables both navigation and reexperiencing. Additionally, PPC was found to be necessary to implement specific aspects of allocentric navigation with high demands on spontaneous retrieval. PsycINFO Database Record (c) 2010 APA, all rights reserved.

Entering Communities: Social Justice Oriented Disaster Response Counseling

ERIC Educational Resources Information Center

West-Olatunji, Cirecie; Goodman, Rachael D.

2011-01-01

Counselors need to learn how to effectively and respectfully enter into communities hit by disasters and create collaborative partnerships with community members. Using critical consciousness theory, the authors describe a humanistic, culturally responsive approach to disaster response counseling for marginalized individuals and communities and…

Shared Bases of Influence within a College

ERIC Educational Resources Information Center

Simplicio, Joseph S. C.

2009-01-01

This article discusses several strategies for building varied bases of influence within a college setting. These strategies include, providing opportunities for success, advocating and implementing good ideas, interacting with individuals on both the personal and non-personal levels, establishing support among marginal individuals, learning to…

Learning new vocabulary in German: the effects of inferring word meanings, type of feedback, and time of test.

PubMed

Carpenter, Shana K; Sachs, Riebana E; Martin, Beth; Schmidt, Kristian; Looft, Ruxandra

2012-02-01

In the present study, introductory-level German students read a simplified story and learned the meanings of new German words by reading English translations in marginal glosses versus trying to infer (i.e., guess) their translations. Students who inferred translations were given feedback in English or in German, or no feedback at all. Although immediate retention of new vocabulary was better for students who used marginal glosses, students who inferred word meanings and then received English feedback forgot fewer translations over time. Plausible but inaccurate inferences (i.e., those that made sense in the context) were more likely to be corrected by students who received English feedback as compared with German feedback, providing support for the beneficial effects of mediating information. Implausible inaccurate inferences, however, were more likely to be corrected on the delayed vocabulary test by students who received German feedback as compared with English feedback, possibly because of the additional contextual support provided by German feedback.

Alignment achieved? The learning landscape and curricula in health profession education.

PubMed

Nordquist, Jonas

2016-01-01

The overall aim of this review is to map the area around the topic of the relationship between physical space and learning and to then draw further potential implications from this for the specific area of health profession education. The nature of the review is a scoping review following a 5-step-model by Arksey & O'Malley. The charting of the data has been conducted with the help of the networked learning landscape framework from Nordquist and Laing. The majority of the research studies on classroom-scale level have focused on how technology may enable active learning. There are no identified research studies on the building-scale level. Hence, the alignment of curricula and physical learning spaces has scarcely been addressed in research from other sectors. In order to 'create a field', conclusions from both case studies and research in related areas must be identified and taken into account to provide insights into health profession education. Four areas have been identified as having potential for future development in health profession education: (i) active involvement of faculty members in the early stages of physical space development; (ii) further development of the assessment strategies for evaluating how physical space impacts learning; (iii) exploration of how informal spaces are being developed in other sectors; and (iv) initiating research projects in HPE to study how informal spaces impact on students' learning. Potentially, the results of this scoping review will result in better future research questions and better-designed studies in this new and upcoming academic field of aligning physical learning spaces and curricula in health profession education. © 2015 John Wiley & Sons Ltd.

Holding Firm: Power, Push-Back, and Opportunities in Navigating the Liminal Space of Critical Qualitative Health Research.

PubMed

Hart, Corinne; Poole, Jennifer M; Facey, Marcia E; Parsons, Janet A

2017-10-01

Critical qualitative health researchers typically occupy and navigate liminal academic spaces and statuses, with one foot planted in the arts and social sciences and the other in biomedical science. We are at once marginalized and empowered, and this liminality presents both challenges and opportunities. In this article, we draw on our experiences of being (often the lone) critical qualitative health scholars on thesis advisory committees and dissertation examinations, as well as our experiences of publishing and securing funding, to illuminate how power and knowledge relations create conditions that shape the nature of our roles. We share strategies we have developed for standing our theoretical and methodological ground. We discuss how we use the power of our liminality to hold firm, push back, and push forward, to ensure that critical qualitative research is not further relegated to the margins and its quality and integrity sustained.

Affinity Spaces and 21st Century Learning

ERIC Educational Resources Information Center

Gee, James Paul

2017-01-01

This article discusses video games as "attractors" to "affinity spaces." It argues that affinity spaces are key sites today where people teach and learn 21st Century skills. While affinity spaces are proliferating on the Internet as interest-and-passion-driven sites devoted to a common set of endeavors, they are not new, just…

A Model for E-Education: Extended Teaching Spaces and Extended Learning Spaces

ERIC Educational Resources Information Center

Jung, Insung; Latchem, Colin

2011-01-01

The paper proposes a model for e-education in instruction, training, initiation and induction based upon the concept of extended teaching spaces involving execution, facilitation and liberation, and extended learning spaces used for acquisition, application and construction cemented by dialogue and reflection. The proposed model is based upon…

The Geodetic Signature of the Earthquake Cycle at Subduction Zones: Model Constraints on the Deep Processes

NASA Astrophysics Data System (ADS)

Govers, R.; Furlong, K. P.; van de Wiel, L.; Herman, M. W.; Broerse, T.

2018-03-01

Recent megathrust events in Tohoku (Japan), Maule (Chile), and Sumatra (Indonesia) were well recorded. Much has been learned about the dominant physical processes in megathrust zones: (partial) locking of the plate interface, detailed coseismic slip, relocking, afterslip, viscoelastic mantle relaxation, and interseismic loading. These and older observations show complex spatial and temporal patterns in crustal deformation and displacement, and significant differences among different margins. A key question is whether these differences reflect variations in the underlying processes, like differences in locking, or the margin geometry, or whether they are a consequence of the stage in the earthquake cycle of the margin. Quantitative models can connect these plate boundary processes to surficial and far-field observations. We use relatively simple, cyclic geodynamic models to isolate the first-order geodetic signature of the megathrust cycle. Coseismic and subsequent slip on the subduction interface is dynamically (and consistently) driven. A review of global preseismic, coseismic, and postseismic geodetic observations, and of their fit to the model predictions, indicates that similar physical processes are active at different margins. Most of the observed variability between the individual margins appears to be controlled by their different stages in the earthquake cycle. The modeling results also provide a possible explanation for observations of tensile faulting aftershocks and tensile cracking of the overriding plate, which are puzzling in the context of convergence/compression. From the inversion of our synthetic GNSS velocities we find that geodetic observations may incorrectly suggest weak locking of some margins, for example, the west Aleutian margin.

Learning characteristics of a space-time neural network as a tether skiprope observer

NASA Technical Reports Server (NTRS)

Lea, Robert N.; Villarreal, James A.; Jani, Yashvant; Copeland, Charles

1993-01-01

The Software Technology Laboratory at the Johnson Space Center is testing a Space Time Neural Network (STNN) for observing tether oscillations present during retrieval of a tethered satellite. Proper identification of tether oscillations, known as 'skiprope' motion, is vital to safe retrieval of the tethered satellite. Our studies indicate that STNN has certain learning characteristics that must be understood properly to utilize this type of neural network for the tethered satellite problem. We present our findings on the learning characteristics including a learning rate versus momentum performance table.

Applying the Rule Space Model to Develop a Learning Progression for Thermochemistry

NASA Astrophysics Data System (ADS)

Chen, Fu; Zhang, Shanshan; Guo, Yanfang; Xin, Tao

2017-12-01

We used the Rule Space Model, a cognitive diagnostic model, to measure the learning progression for thermochemistry for senior high school students. We extracted five attributes and proposed their hierarchical relationships to model the construct of thermochemistry at four levels using a hypothesized learning progression. For this study, we developed 24 test items addressing the attributes of exothermic and endothermic reactions, chemical bonds and heat quantity change, reaction heat and enthalpy, thermochemical equations, and Hess's law. The test was administered to a sample base of 694 senior high school students taught in 3 schools across 2 cities. Results based on the Rule Space Model analysis indicated that (1) the test items developed by the Rule Space Model were of high psychometric quality for good analysis of difficulties, discriminations, reliabilities, and validities; (2) the Rule Space Model analysis classified the students into seven different attribute mastery patterns; and (3) the initial hypothesized learning progression was modified by the attribute mastery patterns and the learning paths to be more precise and detailed.

The cultural production of "science" and "scientist" in high school physics: Girls' access, participation, and resistance

NASA Astrophysics Data System (ADS)

Carlone, Heidi Berenson

2000-10-01

For over three decades, the gender gap in science and science education has received attention from teachers, policy makers, and scholars of various disciplines. During this time, feminist scholars have posited many reasons why the gender gap in science and science education exists. Early feminist discourse focused on girls' "deficits," while more recent work has begun to consider the problems with science and school science in the quest for a more gender inclusive science. Specifically, feminist scholars advocate a transformation of both how students learn science and the science curriculum that students are expected to learn. This study was designed to examine more deeply this call for a changed science curriculum and its implications for girls' participation, interest, and scientist identities. If we reinvisioned ways to "do" science, "learn" science, and "be a scientist" in school science, would girls come to see science as something interesting and worth pursuing further? This question framed my ethnographic investigation. I examined the culturally produced meanings of "science" and "scientist" in two high school physics classrooms (one traditional and one non-traditional class framed around real-world themes), how these meanings reproduced and contested larger sociohistorical (and prototypical) meanings of science and scientist, and how girls participated within and against these meanings. The results complicate the assumption that a classroom that enacts a non-traditional curriculum is "better" for girls. This study explained how each classroom challenged sociohistorical legacies of school science in various "spaces of possibility" and how prototypical meanings pushed the potential of these spaces to the margins. Girls in the traditional physics class generally embraced prototypical meanings because they could easily access "good student" identities. Girls in the non-traditional class, though attracted to alternative practices, struggled with the conflicting promoted student identities that did not allow them easy access to "good student" identities. In neither class were girls' perceptions of what it meant to do science and be a scientist challenged. And, in neither class did girls connect to a legitimate scientist identity. These findings leave unanswered the question of whether changes in pedagogy and curriculum alone will produce more gender fair school science.

Tutor versus computer: a prospective comparison of interactive tutorial and computer-assisted instruction in radiology education.

PubMed

Lieberman, Gillian; Abramson, Richard; Volkan, Kevin; McArdle, Patricia J

2002-01-01

This study compared the educational effectiveness of an interactive tutorial with that of interactive computer-assisted instruction (CAI) and determined the effects of personal preference, learning style, and level of training. Fifty-four medical students and four radiology residents were prospectively, randomly assigned to receive instruction from different sections of an interactive tutorial and an interactive CAI module. Participants took tests of factual knowledge at the beginning and end of the instruction and a test of visual diagnosis at the end. They completed questionnaires to evaluate their preferred learning styles objectively and to elicit their subjective attitudes toward the two formats. Mean test scores of the tutorial and CAI groups were compared by means of analysis of covariance and two-tailed repeated-measures F test. Both the tutorial and CAI groups demonstrated significant improvement in posttest scores (P < .01 and P < .01, respectively) with the tutorial group's mean posttest score marginally but significantly higher (32.84 vs 28.13, P < .001). There were no significant interaction effects with participants' year of training (P = .845), objectively evaluated preferred learning style (P = .312), subjectively elicited attitude toward learning with CAI (P = .703), or visual diagnosis score (tutorial, 7.61; CD-ROM, 7.75; P = .79). Interactive tutorial and optimal CAI are both effective instructional formats. The tutorial was marginally but significantly more effective at teaching factual knowledge, an effect unrelated to students' year of training, learning style, or stated enjoyment of CAI. The superiority of the tutorial is expected to increase when it is compared with commercially expedient CAI modules.

Critical Approaches to Lifelong Education

NASA Astrophysics Data System (ADS)

Preston, Rosemary

1999-11-01

This paper argues that contemporary interest in lifelong learning can be seen as an artefact of the market. It points out how the attractive vocabulary associated with personal development and empowerment often masks other economic and social purposes. Bearing in mind the social function of education, the author compares the strategies for the promotion of lifelong learning designed for those in "included social categories" with the policies designed for those in marginal and excluded positions. It concludes by challenging its own position by citing positive learner experience in each case.

Metacognition and the Spacing Effect: The Role of Repetition, Feedback, and Instruction on Judgments of Learning for Massed and Spaced Rehearsal

ERIC Educational Resources Information Center

Logan, Jessica M.; Castel, Alan D.; Haber, Sara; Viehman, Emily J.

2012-01-01

Although memory performance benefits from the spacing of information at encoding, judgments of learning (JOLs) are often not sensitive to the benefits of spacing. The present research examines how practice, feedback, and instruction influence JOLs for spaced and massed items. In Experiment 1, in which JOLs were made after the presentation of each…

Instances selection algorithm by ensemble margin

NASA Astrophysics Data System (ADS)

Saidi, Meryem; Bechar, Mohammed El Amine; Settouti, Nesma; Chikh, Mohamed Amine

2018-05-01

The main limit of data mining algorithms is their inability to deal with the huge amount of available data in a reasonable processing time. A solution of producing fast and accurate results is instances and features selection. This process eliminates noisy or redundant data in order to reduce the storage and computational cost without performances degradation. In this paper, a new instance selection approach called Ensemble Margin Instance Selection (EMIS) algorithm is proposed. This approach is based on the ensemble margin. To evaluate our approach, we have conducted several experiments on different real-world classification problems from UCI Machine learning repository. The pixel-based image segmentation is a field where the storage requirement and computational cost of applied model become higher. To solve these limitations we conduct a study based on the application of EMIS and other instance selection techniques for the segmentation and automatic recognition of white blood cells WBC (nucleus and cytoplasm) in cytological images.

Resident Space Object Characterization and Behavior Understanding via Machine Learning and Ontology-based Bayesian Networks

NASA Astrophysics Data System (ADS)

Furfaro, R.; Linares, R.; Gaylor, D.; Jah, M.; Walls, R.

2016-09-01

In this paper, we present an end-to-end approach that employs machine learning techniques and Ontology-based Bayesian Networks (BN) to characterize the behavior of resident space objects. State-of-the-Art machine learning architectures (e.g. Extreme Learning Machines, Convolutional Deep Networks) are trained on physical models to learn the Resident Space Object (RSO) features in the vectorized energy and momentum states and parameters. The mapping from measurements to vectorized energy and momentum states and parameters enables behavior characterization via clustering in the features space and subsequent RSO classification. Additionally, Space Object Behavioral Ontologies (SOBO) are employed to define and capture the domain knowledge-base (KB) and BNs are constructed from the SOBO in a semi-automatic fashion to execute probabilistic reasoning over conclusions drawn from trained classifiers and/or directly from processed data. Such an approach enables integrating machine learning classifiers and probabilistic reasoning to support higher-level decision making for space domain awareness applications. The innovation here is to use these methods (which have enjoyed great success in other domains) in synergy so that it enables a "from data to discovery" paradigm by facilitating the linkage and fusion of large and disparate sources of information via a Big Data Science and Analytics framework.

Space Weather in the Machine Learning Era: A Multidisciplinary Approach

NASA Astrophysics Data System (ADS)

Camporeale, E.; Wing, S.; Johnson, J.; Jackman, C. M.; McGranaghan, R.

2018-01-01

The workshop entitled Space Weather: A Multidisciplinary Approach took place at the Lorentz Center, University of Leiden, Netherlands, on 25-29 September 2017. The aim of this workshop was to bring together members of the Space Weather, Mathematics, Statistics, and Computer Science communities to address the use of advanced techniques such as Machine Learning, Information Theory, and Deep Learning, to better understand the Sun-Earth system and to improve space weather forecasting. Although individual efforts have been made toward this goal, the community consensus is that establishing interdisciplinary collaborations is the most promising strategy for fully utilizing the potential of these advanced techniques in solving Space Weather-related problems.

A comparison of pay-as-bid and marginal pricing in electricity markets

NASA Astrophysics Data System (ADS)

Ren, Yongjun

This thesis investigates the behaviour of electricity markets under marginal and pay-as-bid pricing. Marginal pricing is believed to yield the maximum social welfare and is currently implemented by most electricity markets. However, in view of recent electricity market failures, pay-as-bid has been extensively discussed as a possible alternative to marginal pricing. In this research, marginal and pay-as-bid pricing have been analyzed in electricity markets with both perfect and imperfect competition. The perfect competition case is studied under both exact and uncertain system marginal cost prediction. The comparison of the two pricing methods is conducted through two steps: (i) identify the best offer strategy of the generating companies (gencos); (ii) analyze the market performance under these optimum genco strategies. The analysis results together with numerical simulations show that pay-as-bid and marginal pricing are equivalent in a perfect market with exact system marginal cost prediction. In perfect markets with uncertain demand prediction, the two pricing methods are also equivalent but in an expected value sense. If we compare from the perspective of second order statistics, all market performance measures exhibit much lower values under pay-as-bid than under marginal pricing. The risk of deviating from the mean is therefore much higher under marginal pricing than under pay-as-bid. In an imperfect competition market with exact demand prediction, the research shows that pay-as-bid pricing yields lower consumer payments and lower genco profits. This research provides quantitative evidence that challenges some common claims about pay-as-bid pricing. One is that under pay-as-bid, participants would soon learn how to offer so as to obtain the same or higher profits than what they would have obtained under marginal pricing. This research however shows that, under pay-as-bid, participants can at best earn the same profit or expected profit as under marginal pricing. A second common claim refuted by this research is that pay-as-bid does not provide correct price signals if there is a scarcity of generation resources. We show that pay-as-bid does provide a price signal with such characteristics and furthermore argue that the price signal under marginal pricing with gaming may not necessarily be correct since it would then not reflect a lack of generation capacity but a desire to increase profit.

Glacial climate driven sedimentation overwhelms tectonics in the battle for control of margin architecture: Southeast Alaska, St. Elias Orogeny

NASA Astrophysics Data System (ADS)

Gulick, S. P.; Jaeger, J. M.; Willems, B.; Powell, R. D.; Lowe, L. A.

2006-12-01

The interplay of tectonic and climatic processes is fundamental to the development of mountain belts and the ensuing patterns of deformation and erosion. Of equal significance is the interaction of tectonic and climatic processes in the development of orogenic sedimentary basins, or in the case of a coastal mountain belt, in the growth of a continental margin. The Chugach-St. Elias Orogeny, which is driven by the collision of the Yakutat microplate with North America in southeast Alaska, has generated the highest coastal relief in the world. The combined forces of tectonic uplift and glacial erosion have resulted in the accumulation of over 5 km of sediment to form the continental shelf and the creation of the Surveyor Fan that is over 2 km thick proximally. High-resolution GI-gun seismic data allow for detailed examination of the margin architecture off the Bering Glacier within the leading edge of the Yakutat block. The deformation and growth of the margin appears to have first undergone a tectonically dominated phase followed more recently by a glacially dominated phase. During the tectonically dominated period a broad anticline-syncline system helped create accommodation space and the margin both shallowed and widened to its current 50 km width. Based on ties with industry well cuttings, the dominance switched sometime between 0.75 and 1.25 Ma to being completely controlled by glacial advance-retreat patterns. The mappable glacial sequences are undeformed by the underlying anticlines and display several notable features: 1) erosional bases that can often be mapped across the entire shelf, terminating at the shelf edge, 2) little evidence for terminal or retreat moraines on the shelf suggesting very rapid and single phase retreat of the glacier, 3) incomplete glacial sequences due to erosion by later advances, and 4) minimal creation of accommodation space. We investigate the cause of the switch to glacial dominance, the mechanisms and causes of the potentially extremely rapid glacial retreats, and the geodynamics of these glacial advances with respect to the development of margin architecture.

Evaluating marginal likelihood with thermodynamic integration method and comparison with several other numerical methods

DOE PAGES

Liu, Peigui; Elshall, Ahmed S.; Ye, Ming; ...

2016-02-05

Evaluating marginal likelihood is the most critical and computationally expensive task, when conducting Bayesian model averaging to quantify parametric and model uncertainties. The evaluation is commonly done by using Laplace approximations to evaluate semianalytical expressions of the marginal likelihood or by using Monte Carlo (MC) methods to evaluate arithmetic or harmonic mean of a joint likelihood function. This study introduces a new MC method, i.e., thermodynamic integration, which has not been attempted in environmental modeling. Instead of using samples only from prior parameter space (as in arithmetic mean evaluation) or posterior parameter space (as in harmonic mean evaluation), the thermodynamicmore » integration method uses samples generated gradually from the prior to posterior parameter space. This is done through a path sampling that conducts Markov chain Monte Carlo simulation with different power coefficient values applied to the joint likelihood function. The thermodynamic integration method is evaluated using three analytical functions by comparing the method with two variants of the Laplace approximation method and three MC methods, including the nested sampling method that is recently introduced into environmental modeling. The thermodynamic integration method outperforms the other methods in terms of their accuracy, convergence, and consistency. The thermodynamic integration method is also applied to a synthetic case of groundwater modeling with four alternative models. The application shows that model probabilities obtained using the thermodynamic integration method improves predictive performance of Bayesian model averaging. As a result, the thermodynamic integration method is mathematically rigorous, and its MC implementation is computationally general for a wide range of environmental problems.« less

Revealing nonclassicality beyond Gaussian states via a single marginal distribution

PubMed Central

Park, Jiyong; Lu, Yao; Lee, Jaehak; Shen, Yangchao; Zhang, Kuan; Zhang, Shuaining; Zubairy, Muhammad Suhail; Kim, Kihwan; Nha, Hyunchul

2017-01-01

A standard method to obtain information on a quantum state is to measure marginal distributions along many different axes in phase space, which forms a basis of quantum-state tomography. We theoretically propose and experimentally demonstrate a general framework to manifest nonclassicality by observing a single marginal distribution only, which provides a unique insight into nonclassicality and a practical applicability to various quantum systems. Our approach maps the 1D marginal distribution into a factorized 2D distribution by multiplying the measured distribution or the vacuum-state distribution along an orthogonal axis. The resulting fictitious Wigner function becomes unphysical only for a nonclassical state; thus the negativity of the corresponding density operator provides evidence of nonclassicality. Furthermore, the negativity measured this way yields a lower bound for entanglement potential—a measure of entanglement generated using a nonclassical state with a beam-splitter setting that is a prototypical model to produce continuous-variable (CV) entangled states. Our approach detects both Gaussian and non-Gaussian nonclassical states in a reliable and efficient manner. Remarkably, it works regardless of measurement axis for all non-Gaussian states in finite-dimensional Fock space of any size, also extending to infinite-dimensional states of experimental relevance for CV quantum informatics. We experimentally illustrate the power of our criterion for motional states of a trapped ion, confirming their nonclassicality in a measurement-axis–independent manner. We also address an extension of our approach combined with phase-shift operations, which leads to a stronger test of nonclassicality, that is, detection of genuine non-Gaussianity under a CV measurement. PMID:28077456

Revealing nonclassicality beyond Gaussian states via a single marginal distribution.

PubMed

Park, Jiyong; Lu, Yao; Lee, Jaehak; Shen, Yangchao; Zhang, Kuan; Zhang, Shuaining; Zubairy, Muhammad Suhail; Kim, Kihwan; Nha, Hyunchul

2017-01-31

A standard method to obtain information on a quantum state is to measure marginal distributions along many different axes in phase space, which forms a basis of quantum-state tomography. We theoretically propose and experimentally demonstrate a general framework to manifest nonclassicality by observing a single marginal distribution only, which provides a unique insight into nonclassicality and a practical applicability to various quantum systems. Our approach maps the 1D marginal distribution into a factorized 2D distribution by multiplying the measured distribution or the vacuum-state distribution along an orthogonal axis. The resulting fictitious Wigner function becomes unphysical only for a nonclassical state; thus the negativity of the corresponding density operator provides evidence of nonclassicality. Furthermore, the negativity measured this way yields a lower bound for entanglement potential-a measure of entanglement generated using a nonclassical state with a beam-splitter setting that is a prototypical model to produce continuous-variable (CV) entangled states. Our approach detects both Gaussian and non-Gaussian nonclassical states in a reliable and efficient manner. Remarkably, it works regardless of measurement axis for all non-Gaussian states in finite-dimensional Fock space of any size, also extending to infinite-dimensional states of experimental relevance for CV quantum informatics. We experimentally illustrate the power of our criterion for motional states of a trapped ion, confirming their nonclassicality in a measurement-axis-independent manner. We also address an extension of our approach combined with phase-shift operations, which leads to a stronger test of nonclassicality, that is, detection of genuine non-Gaussianity under a CV measurement.

Experimental Design for the Evaluation of Detection Techniques of Hidden Corrosion Beneath the Thermal Protective System of the Space Shuttle Orbiter

NASA Technical Reports Server (NTRS)

Kammerer, Catherine C.; Jacoby, Joseph A.; Lomness, Janice K.; Hintze, Paul E.; Russell, Richard W.

2007-01-01

The United States Space Operational Space Shuttle Fleet Consists of three shuttles with an average age of 19.7 years. Shuttles are exposed to corrosive conditions while undergoing final closeout for missions at the launch pad and extreme conditions during ascent, orbit, and descent that may accelerate the corrosion process. Structural corrosion under TPS could progress undetected (without tile removal) and eventually result in reduction in structural capability sufficient to create negative margins of . safety and ultimate loss of local structural capability.

Receiver design, performance analysis, and evaluation for space-borne laser altimeters and space-to-space laser ranging systems

NASA Technical Reports Server (NTRS)

Davidson, Frederic M.; Field, Christopher T.; Sun, Xiaoli

1996-01-01

We report here the design and the performance measurements of the breadboard receiver of the Geoscience Laser Altimeter System (GLAS). The measured ranging accuracy was better than 2 cm and 10 cm for 5 ns and 30 ns wide received laser pulses under the expected received signal level, which agreed well with the theoretical analysis. The measured receiver sensitivity or the link margin was also consistent with the theory. The effects of the waveform digitizer sample rate and resolution were also measured.

Applications of Support Vector Machine (SVM) Learning in Cancer Genomics.

PubMed

Huang, Shujun; Cai, Nianguang; Pacheco, Pedro Penzuti; Narrandes, Shavira; Wang, Yang; Xu, Wayne

2018-01-01

Machine learning with maximization (support) of separating margin (vector), called support vector machine (SVM) learning, is a powerful classification tool that has been used for cancer genomic classification or subtyping. Today, as advancements in high-throughput technologies lead to production of large amounts of genomic and epigenomic data, the classification feature of SVMs is expanding its use in cancer genomics, leading to the discovery of new biomarkers, new drug targets, and a better understanding of cancer driver genes. Herein we reviewed the recent progress of SVMs in cancer genomic studies. We intend to comprehend the strength of the SVM learning and its future perspective in cancer genomic applications. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Societal Trends and the Curriculum.

ERIC Educational Resources Information Center

Ediger, Marlow

Curriculum becomes increasingly relevant as it is based on what exists in society and what the implications are for student learning. The growing emphasis upon scripted teacher-proof programs and regimented student tasks has marginalized time for purposeful thinking and meaningful dialogue. This loss is significant because reflection supports…

Imagination for Re-Engagement from the Margins of Education

ERIC Educational Resources Information Center

Bland, Derek

2012-01-01

For marginalised secondary school students, mainstream education may no longer appear to be an inviting place. While proposed solutions to problems of disengagement and marginalisation appear to concentrate on finding ways to coerce students back to mainstream education through, for example, "learning or earning" legislation, this…

Deweyan Democratic Learning Communities and Student Marginalization

ERIC Educational Resources Information Center

Harbour, Clifford P.; Ebie, Gwyn

2011-01-01

Community colleges have long been recognized as enrolling a disproportionate share of first-generation college students, low-income students, women, and students of color. Additionally, community colleges have significant enrollments of students who identify as immigrants; lesbian, gay, bisexual, and transgender (LGBT); and disabled. Many of these…

Developing a Conceptual Framework for Student Learning during International Community Engagement

ERIC Educational Resources Information Center

Pink, Matthew A.; Taouk, Youssef; Guinea, Stephen; Bunch, Katie; Flowers, Karen; Nightingale, Karen

2016-01-01

University-community engagement often involves students engaging with people who experience multiple forms of disadvantage or marginalization. This is particularly true when universities work with communities in developing nations. Participation in these projects can be challenging for students. Assumptions about themselves, their professional…

American Youth in the 1980s.

ERIC Educational Resources Information Center

Starr, Jerold M.

1986-01-01

Youth today remains marginal to the primary institutions of American life. They no longer have opportunities within the family to develop skills, exercise responsibilities, or learn adult roles. Youths spend long periods of the day segregated in schools; longer periods in passive entertainment. Alienation results in political apathy, mental…

Student Effort, Consistency, and Online Performance

ERIC Educational Resources Information Center

Patron, Hilde; Lopez, Salvador

2011-01-01

This paper examines how student effort, consistency, motivation, and marginal learning, influence student grades in an online course. We use data from eleven Microeconomics courses taught online for a total of 212 students. Our findings show that consistency, or less time variation, is a statistically significant explanatory variable, whereas…

Andragogy--A Mantra for US/Iraqi Cross-Cultural Dialogue

ERIC Educational Resources Information Center

Mahdi, Ghada S.; Bright, Larry K.

2010-01-01

Andragogical precepts provide rich opportunities for building cultural bridges, particularly among people in times of strife. Encouraging adults to share their experiences and insights in a learning community of unconditional positive regard can build understanding, hope, and peace among people experiencing conflict and marginalization. An…

Using NASA and the Space Program to Help High School and College Students Learn Chemistry.

ERIC Educational Resources Information Center

Kelter, Paul B.; And Others

1987-01-01

Discusses some of the chemical concepts that the United States Space Program illustrates. Describes ways to use the space program to motivate students to learn chemistry and its relationship to the world. Provides examples of classroom applications to environmental chemistry and biochemistry in studying the operation of the space shuttle. (TW)

19 CFR 144.32 - Statement of quantity; charges and liens.

Code of Federal Regulations, 2013 CFR

2013-04-01

... shall have indicated thereon, preferably in the lower part of the left-hand margin if there is no space... statement shall indicate: (1) The quantity (i.e., the number of outer containers, or tons, etc.) in the...

19 CFR 144.32 - Statement of quantity; charges and liens.

Code of Federal Regulations, 2014 CFR

2014-04-01

... shall have indicated thereon, preferably in the lower part of the left-hand margin if there is no space... statement shall indicate: (1) The quantity (i.e., the number of outer containers, or tons, etc.) in the...

19 CFR 144.32 - Statement of quantity; charges and liens.

Code of Federal Regulations, 2012 CFR

2012-04-01

... shall have indicated thereon, preferably in the lower part of the left-hand margin if there is no space... statement shall indicate: (1) The quantity (i.e., the number of outer containers, or tons, etc.) in the...

The Critical Importance of Retrieval--and Spacing--for Learning.

PubMed

Soderstrom, Nicholas C; Kerr, Tyson K; Bjork, Robert A

2016-02-01

We examined the impact of repeated testing and repeated studying on long-term learning. In Experiment 1, we replicated Karpicke and Roediger's (2008) influential results showing that once information can be recalled, repeated testing on that information enhances learning, whereas restudying that information does not. We then examined whether the apparent ineffectiveness of restudying might be attributable to the spacing differences between items that were inherent in the between-subjects design employed by Karpicke and Roediger. When we controlled for these spacing differences by manipulating the various learning conditions within subjects in Experiment 2, we found that both repeated testing and restudying improved learning, and that learners' awareness of the relative mnemonic benefits of these strategies was enhanced. These findings contribute to understanding how two important factors in learning-test-induced retrieval processes and spacing-can interact, and they illustrate that such interactions can play out differently in between-subjects and within-subjects experimental designs. © The Author(s) 2015.

Geomorphology and Neogene tectonic evolution of the Palomares continental margin (Western Mediterranean)

NASA Astrophysics Data System (ADS)

Gómez de la Peña, Laura; Gràcia, Eulàlia; Muñoz, Araceli; Acosta, Juan; Gómez-Ballesteros, María; R. Ranero, César; Uchupi, Elazar

2016-10-01

The Palomares continental margin is located in the southeastern part of Spain. The margin main structure was formed during Miocene times, and it is currently part of the wide deformation zone characterizing the region between the Iberian and African plates, where no well-defined plate boundary occurs. The convergence between these two plates is here accommodated by several structures, including the left lateral strike-slip Palomares Fault. The region is characterized by sparse, low to moderate magnitude (Mw < 5.2) shallow instrumental earthquakes, although large historical events have also occurred. To understand the recent tectonic history of the margin we analyze new high-resolution multibeam bathymetry data and re-processed three multichannel seismic reflection profiles crossing the main structures. The analysis of seafloor morphology and associated subsurface structure provides new insights of the active tectonic features of the area. In contrast to other segments of the southeastern Iberian margin, the Palomares margin contains numerous large and comparatively closely spaced canyons with heads that reach near the coast. The margin relief is also characterized by the presence of three prominent igneous submarine ridges that include the Aguilas, Abubacer and Maimonides highs. Erosive processes evidenced by a number of scars, slope failures, gullies and canyon incisions shape the present-day relief of the Palomares margin. Seismic images reveal the deep structure distinguishing between Miocene structures related to the formation of the margin and currently active features, some of which may reactivate inherited structures. The structure of the margin started with an extensional phase accompanied by volcanic accretion during the Serravallian, followed by a compressional pulse that started during the Latemost Tortonian. Nowadays, tectonic activity offshore is subdued and limited to few, minor faults, in comparison with the activity recorded onshore. The deep Algero-Balearic Basin is affected by surficial processes, associated to halokinesis of Messinian evaporites.

Learning Theory Expertise in the Design of Learning Spaces: Who Needs a Seat at the Table?

ERIC Educational Resources Information Center

Rook, Michael M.; Choi, Koun; McDonald, Scott P.

2015-01-01

This study highlights the impact of including stakeholders with expertise in learning theory in a learning space design process. We present the decision-making process during the design of the Krause Innovation Studio on the campus of the Pennsylvania State University to draw a distinction between the architect and faculty member's decision-making…

A Case Study in Master Planning the Learning Landscape Hub Concepts for the University at Buffalo

ERIC Educational Resources Information Center

Dugdale, Shirley; Torino, Roger; Felix, Elliot

2009-01-01

This case study describes concepts for three types of learning spaces that grew out of a Learning Landscape planning process. The process was part of a master plan study for the three campuses of the University at Buffalo. It involved research into user needs and aspirations about future pedagogy, development of learning space strategy,…

Design of Learning Spaces in 3D Virtual Worlds: An Empirical Investigation of "Second Life"

ERIC Educational Resources Information Center

Minocha, Shailey; Reeves, Ahmad John

2010-01-01

"Second Life" (SL) is a three-dimensional (3D) virtual world, and educational institutions are adopting SL to support their teaching and learning. Although the question of how 3D learning spaces should be designed to support student learning and engagement has been raised among SL educators and designers, there is hardly any guidance or…

The Importance of Place for Learning about Peace: Residential Summer Camps as Transformative Thinking Spaces

ERIC Educational Resources Information Center

Dahl, Tove I.

2009-01-01

Do camps provide a particular kind of thinking space where learning that lasts is facilitated? The argument is built around the concept of transformative learning that involves understanding who we are or wish to be and how we grow accordingly. The nature of such learning is explored through its conceptual relationship with changes in attitudes…

Eco-Dialogical Learning and Translanguaging in Open-Ended 3D Virtual Learning Environments: Where Place, Time, and Objects Matter

ERIC Educational Resources Information Center

Zheng, Dongping; Schmidt, Matthew; Hu, Ying; Liu, Min; Hsu, Jesse

2017-01-01

The purpose of this research was to explore the relationships between design, learning, and translanguaging in a 3D collaborative virtual learning environment for adolescent learners of Chinese and English. We designed an open-ended space congruent with ecological and dialogical perspectives on second language acquisition. In such a space,…

Environmental Monitoring Networks Optimization Using Advanced Active Learning Algorithms

NASA Astrophysics Data System (ADS)

Kanevski, Mikhail; Volpi, Michele; Copa, Loris

2010-05-01

The problem of environmental monitoring networks optimization (MNO) belongs to one of the basic and fundamental tasks in spatio-temporal data collection, analysis, and modeling. There are several approaches to this problem, which can be considered as a design or redesign of monitoring network by applying some optimization criteria. The most developed and widespread methods are based on geostatistics (family of kriging models, conditional stochastic simulations). In geostatistics the variance is mainly used as an optimization criterion which has some advantages and drawbacks. In the present research we study an application of advanced techniques following from the statistical learning theory (SLT) - support vector machines (SVM) and the optimization of monitoring networks when dealing with a classification problem (data are discrete values/classes: hydrogeological units, soil types, pollution decision levels, etc.) is considered. SVM is a universal nonlinear modeling tool for classification problems in high dimensional spaces. The SVM solution is maximizing the decision boundary between classes and has a good generalization property for noisy data. The sparse solution of SVM is based on support vectors - data which contribute to the solution with nonzero weights. Fundamentally the MNO for classification problems can be considered as a task of selecting new measurement points which increase the quality of spatial classification and reduce the testing error (error on new independent measurements). In SLT this is a typical problem of active learning - a selection of the new unlabelled points which efficiently reduce the testing error. A classical approach (margin sampling) to active learning is to sample the points closest to the classification boundary. This solution is suboptimal when points (or generally the dataset) are redundant for the same class. In the present research we propose and study two new advanced methods of active learning adapted to the solution of MNO problem: 1) hierarchical top-down clustering in an input space in order to remove redundancy when data are clustered, and 2) a general method (independent on classifier) which gives posterior probabilities that can be used to define the classifier confidence and corresponding proposals for new measurement points. The basic ideas and procedures are explained by applying simulated data sets. The real case study deals with the analysis and mapping of soil types, which is a multi-class classification problem. Maps of soil types are important for the analysis and 3D modeling of heavy metals migration in soil and prediction risk mapping. The results obtained demonstrate the high quality of SVM mapping and efficiency of monitoring network optimization by using active learning approaches. The research was partly supported by SNSF projects No. 200021-126505 and 200020-121835.

Adaptive/learning control of large space structures - System identification techniques. [for multi-configuration flexible spacecraft

NASA Technical Reports Server (NTRS)

Thau, F. E.; Montgomery, R. C.

1980-01-01

Techniques developed for the control of aircraft under changing operating conditions are used to develop a learning control system structure for a multi-configuration, flexible space vehicle. A configuration identification subsystem that is to be used with a learning algorithm and a memory and control process subsystem is developed. Adaptive gain adjustments can be achieved by this learning approach without prestoring of large blocks of parameter data and without dither signal inputs which will be suppressed during operations for which they are not compatible. The Space Shuttle Solar Electric Propulsion (SEP) experiment is used as a sample problem for the testing of adaptive/learning control system algorithms.

Radiographic signs of pathology determining removal of an impacted mandibular third molar assessed in a panoramic image or CBCT

PubMed Central

Schropp, Lars; Spin-Neto, Rubens; Wenzel, Ann

2017-01-01

Objectives: To (1) compare pathological findings related to the mandibular third molar in panoramic images (PAN) and CBCT; (2) estimate the frequency of removals if pathological findings were indicative; and (3) assess factors in PAN associated with resorption and marginal bone loss at the second molar as observed in CBCT. Methods: 379 mandibular third molars were examined with PAN and CBCT. Four observers registered resorption and marginal bone loss at the second molar and increased periodontal space at the third molar in both imaging modalities. Agreement between PAN and CBCT, frequency of removals based on pathological findings in either of the two modalities and interobserver reproducibility was calculated. Logistic regression analyses assessed factors in PAN, which could predict marginal bone loss and resorption observed in CBCT. Results: Agreement between PAN and CBCT: resorption 54–74%; marginal bone loss 66–85%; and increased periodontal space 92–97%. Removals based on CBCT and PAN: 58–71% and 36–65%. Interobserver percentage accordance and kappa values ranged from 57 to 98% and 0.10–0.91 for PAN and 61–97% and 0.22–0.78 for CBCT, respectively. Mesioangulated/horizontally positioned third molars were associated with marginal bone loss [odds ratio (OR) = 7.0–31.3; p < 0.001] and resorption (OR = 2.9–35.6; p < 0.001) in CBCT. Overprojection between the third and the second molars in PAN predicted resorption observed in CBCT (OR = 5.6–21.2; p < 0.001). Conclusions: Pathology associated with the third molar is more often observed in CBCT than in PAN. More third molars would be removed if pathological findings are based on CBCT. Mesioangulated/horizontally positioned third molars overprojecting the cervical/root part of the second molar in PAN are strongly associated with pathology observed in CBCT. PMID:27681861

Radiographic signs of pathology determining removal of an impacted mandibular third molar assessed in a panoramic image or CBCT.

PubMed

Matzen, Louise H; Schropp, Lars; Spin-Neto, Rubens; Wenzel, Ann

2017-01-01

To (1) compare pathological findings related to the mandibular third molar in panoramic images (PAN) and CBCT; (2) estimate the frequency of removals if pathological findings were indicative; and (3) assess factors in PAN associated with resorption and marginal bone loss at the second molar as observed in CBCT. 379 mandibular third molars were examined with PAN and CBCT. Four observers registered resorption and marginal bone loss at the second molar and increased periodontal space at the third molar in both imaging modalities. Agreement between PAN and CBCT, frequency of removals based on pathological findings in either of the two modalities and interobserver reproducibility was calculated. Logistic regression analyses assessed factors in PAN, which could predict marginal bone loss and resorption observed in CBCT. Agreement between PAN and CBCT: resorption 54-74%; marginal bone loss 66-85%; and increased periodontal space 92-97%. Removals based on CBCT and PAN: 58-71% and 36-65%. Interobserver percentage accordance and kappa values ranged from 57 to 98% and 0.10-0.91 for PAN and 61-97% and 0.22-0.78 for CBCT, respectively. Mesioangulated/horizontally positioned third molars were associated with marginal bone loss [odds ratio (OR) = 7.0-31.3; p < 0.001] and resorption (OR = 2.9-35.6; p < 0.001) in CBCT. Overprojection between the third and the second molars in PAN predicted resorption observed in CBCT (OR = 5.6-21.2; p < 0.001). Pathology associated with the third molar is more often observed in CBCT than in PAN. More third molars would be removed if pathological findings are based on CBCT. Mesioangulated/horizontally positioned third molars overprojecting the cervical/root part of the second molar in PAN are strongly associated with pathology observed in CBCT.

Quantification of Collagen Ultrastructure after Penetrating Keratoplasty – Implications for Corneal Biomechanics

PubMed Central

Gardner, Steven J.; Kamma-Lorger, Christina S.; Hayes, Sally; Nielsen, Kim; Hjortdal, Jesper; Sorensen, Thomas; Terrill, Nicholas J.; Meek, Keith M.

2013-01-01

Purpose To quantify long-term changes in stromal collagen ultrastructure following penetrating keratoplasty (PK), and evaluate their possible implications for corneal biomechanics. Methods A pair of 16 mm post-mortem corneo-scleral buttons was obtained from a patient receiving bilateral penetrating keratoplasty 12 (left)/28 (right) years previously. Small-angle x-ray scattering quantified collagen fibril spacing, diameter and spatial order at 0.5 mm or 0.25 mm intervals along linear scans across the graft margin. Corresponding control data was collected from two corneo-scleral buttons with no history of refractive surgery. Wide-angle x-ray scattering quantified collagen fibril orientation at 0.25 mm (horizontal)×0.25 mm (vertical) intervals across both PK specimens. Quantification of orientation changes in the graft margin were verified by equivalent analysis of data from a 13 year post-operative right PK specimen obtained from a second patient in a previous study, and comparison made with new and published data from normal corneas. Results Marked changes to normal fibril alignment, in favour of tangentially oriented collagen, were observed around the entire graft margin in all PK specimens. The total number of meridional fibrils in the wound margin was observed to decrease by up to 40%, with the number of tangentially oriented fibrils increasing by up to 46%. As a result, in some locations the number of fibrils aligned parallel to the wound outnumbered those spanning it by up to five times. Localised increases in fibril spacing and diameter, with an accompanying reduction in matrix order, were also evident. Conclusions Abnormal collagen fibril size and spatial order within the PK graft margin are indicative of incomplete stromal wound remodelling and the long term persistence of fibrotic scar tissue. Lasting changes in collagen fibril orientation in and around PK wounds may alter corneal biomechanics and compromise the integrity of the graft-host interface in the long term. PMID:23861866

Research-Informed Principles for (Re)Designing Teaching and Learning Spaces

ERIC Educational Resources Information Center

Finkelstein, Adam; Ferris, Jennie; Weston, Cynthia; Winer, Laura

2016-01-01

Designing physical learning environments that connect to indicators of effective educational practice reflects a university's pedagogical commitment to student success. This article describes an approach to teaching and learning space design based on research-informed pedagogical principles successfully implemented at our university. It then…

Time Domain Stability Margin Assessment Method

NASA Technical Reports Server (NTRS)

Clements, Keith

2017-01-01

The baseline stability margins for NASA's Space Launch System (SLS) launch vehicle were generated via the classical approach of linearizing the system equations of motion and determining the gain and phase margins from the resulting frequency domain model. To improve the fidelity of the classical methods, the linear frequency domain approach can be extended by replacing static, memoryless nonlinearities with describing functions. This technique, however, does not address the time varying nature of the dynamics of a launch vehicle in flight. An alternative technique for the evaluation of the stability of the nonlinear launch vehicle dynamics along its trajectory is to incrementally adjust the gain and/or time delay in the time domain simulation until the system exhibits unstable behavior. This technique has the added benefit of providing a direct comparison between the time domain and frequency domain tools in support of simulation validation.

Time-Domain Stability Margin Assessment

NASA Technical Reports Server (NTRS)

Clements, Keith

2016-01-01

The baseline stability margins for NASA's Space Launch System (SLS) launch vehicle were generated via the classical approach of linearizing the system equations of motion and determining the gain and phase margins from the resulting frequency domain model. To improve the fidelity of the classical methods, the linear frequency domain approach can be extended by replacing static, memoryless nonlinearities with describing functions. This technique, however, does not address the time varying nature of the dynamics of a launch vehicle in flight. An alternative technique for the evaluation of the stability of the nonlinear launch vehicle dynamics along its trajectory is to incrementally adjust the gain and/or time delay in the time domain simulation until the system exhibits unstable behavior. This technique has the added benefit of providing a direct comparison between the time domain and frequency domain tools in support of simulation validation.

The Da Vinci Xi and robotic radical prostatectomy-an evolution in learning and technique.

PubMed

Goonewardene, S S; Cahill, D

2017-06-01

The da Vinci Xi robot has been introduced as the successor to the Si platform. The promise of the Xi is to open the door to new surgical procedures. For robotic-assisted radical prostatectomy (RARP)/pelvic surgery, the potential is better vision and longer instruments. How has the Xi impacted on operative and pathological parameters as indicators of surgical performance? This is a comparison of an initial series of 42 RARPs with the Xi system in 2015 with a series using the Si system immediately before Xi uptake in the same calendar year, and an Si series by the same surgeon synchronously as the Xi series using operative time, blood loss, and positive margins as surrogates of surgical performance. Subjectively and objectively, there is a learning curve to Xi uptake in longer operative times but no impact on T2 positive margins which are the most reflective single measure of RARP outcomes. Subjectively, the vision of the Xi is inferior to the Si system, and the integrated diathermy system and automated setup are quirky. All require experience to overcome. There is a learning curve to progress from the Si to Xi da Vinci surgical platforms, but this does not negatively impact the outcome.

Super learning to hedge against incorrect inference from arbitrary parametric assumptions in marginal structural modeling.

PubMed

Neugebauer, Romain; Fireman, Bruce; Roy, Jason A; Raebel, Marsha A; Nichols, Gregory A; O'Connor, Patrick J

2013-08-01

Clinical trials are unlikely to ever be launched for many comparative effectiveness research (CER) questions. Inferences from hypothetical randomized trials may however be emulated with marginal structural modeling (MSM) using observational data, but success in adjusting for time-dependent confounding and selection bias typically relies on parametric modeling assumptions. If these assumptions are violated, inferences from MSM may be inaccurate. In this article, we motivate the application of a data-adaptive estimation approach called super learning (SL) to avoid reliance on arbitrary parametric assumptions in CER. Using the electronic health records data from adults with new-onset type 2 diabetes, we implemented MSM with inverse probability weighting (IPW) estimation to evaluate the effect of three oral antidiabetic therapies on the worsening of glomerular filtration rate. Inferences from IPW estimation were noticeably sensitive to the parametric assumptions about the associations between both the exposure and censoring processes and the main suspected source of confounding, that is, time-dependent measurements of hemoglobin A1c. SL was successfully implemented to harness flexible confounding and selection bias adjustment from existing machine learning algorithms. Erroneous IPW inference about clinical effectiveness because of arbitrary and incorrect modeling decisions may be avoided with SL. Copyright © 2013 Elsevier Inc. All rights reserved.

Lessons Learned From the Development, Operation, and Review of Mechanical Systems on the Space Shuttle, International Space Station, and Payloads

NASA Technical Reports Server (NTRS)

Dinsel, Alison; Jermstad, Wayne; Robertson, Brandan

2006-01-01

The Mechanical Design and Analysis Branch at the Johnson Space Center (JSC) is responsible for the technical oversight of over 30 mechanical systems flying on the Space Shuttle Orbiter and the International Space Station (ISS). The branch also has the responsibility for reviewing all mechanical systems on all Space Shuttle and International Space Station payloads, as part of the payload safety review process, through the Mechanical Systems Working Group (MSWG). These responsibilities give the branch unique insight into a large number of mechanical systems, and problems encountered during their design, testing, and operation. This paper contains narrative descriptions of lessons learned from some of the major problems worked on by the branch during the last two years. The problems are grouped into common categories and lessons learned are stated.

The learning curve of laparoscopic treatment of rectal cancer does not increase morbidity.

PubMed

Luján, Juan; Gonzalez, Antonio; Abrisqueta, Jesús; Hernandez, Quiteria; Valero, Graciela; Abellán, Israel; Frutos, María Dolores; Parrilla, Pascual

2014-01-01

The treatment of rectal cancer via laparoscopy is controversial due to its technical complexity. Several randomized prospective studies have demonstrated clear advantages for the patient with similar oncological results to those of open surgery, although during the learning of this surgical technique there may be an increase in complications and a worse prognosis. Our aim is to analyze how the learning curve for rectal cancer via laparoscopy influences intra- and postoperative results and oncological markers. A retrospective review was conducted of the first 120 patients undergoing laparoscopic surgery for rectal neoplasia. The operations were performed by the same surgical team with a wide experience in the treatment of open colorectal cancer and qualified to perform advanced laparoscopic surgery. We analyzed sex, ASA, tumour location, neoadjuvant treatment, surgical technique, operating time, conversion, postoperative complications, length of hospital stay, number of lymph nodes, stage and involvement of margins. Significant differences were observed with regard to surgical time (224 min in the first group, 204 min in the second group), with a higher rate of conversion in the first group (22.5%) than in the second (11.3%). No significant differences were noted for rate of conservative sphincter surgery, length of hospital stay, post-surgical complications, number of affected/isolated lymph nodes or affected circumferential and distal margins. It is possible to learn this complex surgical technique without compromising the patient's safety and oncological outcome. Copyright © 2013 AEC. Published by Elsevier Espana. All rights reserved.

Learning Spaces in Higher Education: An Under-Researched Topic

ERIC Educational Resources Information Center

Temple, Paul

2008-01-01

The connections between the design and use of space in higher education, and the production of teaching and learning, and of research, are not well understood. This paper reports on a literature review on these topics, and shows that higher education spaces can be considered in various ways: in terms of campus design, in terms of how space can…

Collaborating with Users to Design Learning Spaces: Playing Nicely in the Sandbox

ERIC Educational Resources Information Center

Weaver, Barbara

2009-01-01

What should a campus do when it needs more learning spaces but can't construct new buildings? Dr. Benjamin Sill's first task when he became the director of Clemson University's general engineering program was to find space for classrooms and for the advising program. His search ended in the old YMCA building (Holtzendorff Hall), where space was…

Personal Spaces in Public Repositories as a Facilitator for Open Educational Resource Usage

ERIC Educational Resources Information Center

Cohen, Anat; Reisman, Sorel; Sperling, Barbra Bied

2015-01-01

Learning object repositories are a shared, open and public space; however, the possibility and ability of personal expression in an open, global, public space is crucial. The aim of this study is to explore personal spaces in a big learning object repository as a facilitator for adoption of Open Educational Resources (OER) into teaching practices…

Spaced Learning: The Design, Feasibility and Optimisation of SMART Spaces. Evaluation Report and Executive Summary

ERIC Educational Resources Information Center

O'Hare, Liam; Stark, Patrick; McGuinness, Carol; Biggart, Andy; Thurston, Allen

2017-01-01

This report describes the development and pilot evaluation of SMART Spaces. This programme aims to boost GCSE science outcomes by applying the principle that information is more easily learnt when it is repeated multiple times, with time passing between the repetitions. This approach is known as "spaced learning" and is contrasted with a…

From Marginality to the Mainstream: Learning from Action Research for Sustainable Development

ERIC Educational Resources Information Center

Liddy, Mags

2012-01-01

Education for sustainable development establishes the need for change within education; in particular, teacher education is recognised as a priority for reorientation towards sustainability needs. The Ubuntu Network is an action research programme, focusing on supporting teacher educators to explore the integration of development education and…

Musical Parenting and Music Education: Integrating Research and Practice

ERIC Educational Resources Information Center

Ilari, Beatriz

2018-01-01

Although teachers work constantly with parents, discussions concerning parental roles in children's music learning are often left at the margins in music teacher training programs. The aim of this article is to offer a review of musical parenting research from an ecological perspective. Bronfenbrenner's bioecological theory of human development is…

McEducation Marginalized: Multiverse of Learning-Living in Grassroots Commons

ERIC Educational Resources Information Center

Prakash, Madhu Suri; Stuchul, Dana; Madhu, Suri; Stuchul, Dana

2004-01-01

Fast food explored both as metaphor and social reality help us challenge the assumptions about education as a universal good transformed into a universal human right. Relations between education, development, and "one world" discourses expose the incommensurability of Western liberal ideals with diverse cosmo-visions now flourishing among…

Invisible Racism: Male, Hegemonic Whiteness in Higher Education

ERIC Educational Resources Information Center

Cabrera, Nolan L.

2009-01-01

Within the study of higher education, the issue of racial diversity tends to focus on either the universalistic impacts of enacting diverse learning environments or the social marginalization of students of color within these institutions. Generally absent from these discussions is how White students experience multicultural campus environments as…

Foreign Language Aptitude Theory: Yesterday, Today and Tomorrow

ERIC Educational Resources Information Center

Wen, Zhisheng; Biedron, Adriana; Skehan, Peter

2017-01-01

Foreign language (FL) aptitude generally refers to a specific talent for learning a foreign or second language (L2). After experiencing a long period of marginalized interest, FL aptitude research in recent years has witnessed renewed enthusiasm across the disciplines of educational psychology, second language acquisition (SLA) and cognitive…

The Investment Case for Education and Equity

ERIC Educational Resources Information Center

Wils, Annababette; Bonnet, Gabrielle

2015-01-01

Education is in crisis worldwide. Millions of children, especially the most marginalized, are excluded from school. Many millions more attend school, but they do not learn basic reading and math skills. In addition, international funding for education is on the decline. "The Investment Case for Education and Equity" explains the global…

Mental Health in Schools: Moving in New Directions

ERIC Educational Resources Information Center

Adelman, Howard S.; Taylor, Linda

2012-01-01

Current approaches to mental health in school tend to overemphasize individually prescribed treatment to the detriment of prevention programs. Moreover, they are implemented as another fragmented set of interventions, and this contributes to the continuing marginalization of student and learning supports. Finally, when the focus is on individuals'…

Developing Culturally Responsive Mathematics Teachers: Secondary Teachers' Evolving Conceptions of Knowing Students

ERIC Educational Resources Information Center

Parker, Frieda; Bartell, Tonya Gau; Novak, Jodie D.

2017-01-01

Research advances in teaching, learning, curriculum, and assessment have not changed the continued underperformance of marginalized students in mathematics education. Culturally responsive teaching is a means of addressing the needs of these students. It is sometimes challenging, however, to convince secondary mathematics teachers about the…

"I Can't Relate": Refusing Identification Demands in Teaching and Learning

ERIC Educational Resources Information Center

Barnard, Ian

2016-01-01

In literature, composition, and other areas of English Studies, relateability can be an important tool to inscribe marginalized subjects as academic citizens. However, its larger arc reproduces ethnocentric and individualistic ideologies at the national and personal levels that foreclose the true understanding of and engagement with Otherness that…

"Becoming" Learners/Teachers in Nomadic Space

ERIC Educational Resources Information Center

Gorodetsky, Malka; Barak, Judith

2016-01-01

This paper suggests a conjunction between the learning space of educational edge community (EEC) and the Deleuzeguattarian thought regarding the nature of teachers' "becoming." It attends to the emerging subjectivities of teachers/learners within an EEC, a nomadic, open, and smooth space of learning. It is suggested that autonomous…

14 CFR 33.62 - Stress analysis.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.62 Stress analysis. A stress analysis must be performed on each turbine engine showing the design safety margin of each turbine...

14 CFR 33.62 - Stress analysis.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.62 Stress analysis. A stress analysis must be performed on each turbine engine showing the design safety margin of each turbine...

19 CFR 144.32 - Statement of quantity; charges and liens.

Code of Federal Regulations, 2011 CFR

2011-04-01

... shall have indicated thereon, preferably in the lower part of the left-hand margin if there is no space... a portion of an original lot has been transferred to a new owner in accordance with subpart C of...

19 CFR 144.32 - Statement of quantity; charges and liens.

Code of Federal Regulations, 2010 CFR

2010-04-01

... shall have indicated thereon, preferably in the lower part of the left-hand margin if there is no space... a portion of an original lot has been transferred to a new owner in accordance with subpart C of...

A Three-Stage Colonel Blotto Game with Applications to Cyber-Physical Security

DTIC Science & Technology

2014-03-15

joint measure over the space Ri. Let µi ∈ ℘(Ri) be the strategy of Player i. Then, we let Prk #µi denote the marginal of µi on the k th battlefield. A...solely on the marginal distributions ( Prk #µ1,Pr k #µ2). The resources available to the players and the number of battlefields are common knowledge...Ri) → 2℘(Ri) denote a set-valued map (correspon- dence), defined as Ψi(µi) := { µ̃i ∈ ℘(Ri) : supp(µ̃i) = supp(µi) and Prk #µ̃i = Pr k #µi for all k

Performance and Motivation in a Middle School Flipped Learning Course

ERIC Educational Resources Information Center

Winter, Joshua W.

2018-01-01

Flipped learning is a teaching approach that promotes collaboration by using technology to 'flip' traditional instruction. Content is delivered outside of class in the individual space (online) and the group space (classroom) is used to engage in collaborative activities. Flipped learning shifts the teacher's role toward facilitation. Research on…

Redesigning Learning Spaces: What Do Teachers Want for Future Classrooms?

ERIC Educational Resources Information Center

Pedro, Neuza

2017-01-01

The concepts of future classrooms, multimedia labs or active learning space has recently gained prominence in educational research. Evidence-based research has found that well-designed primary school classrooms can boost students' learning. Also, schools' principals, teachers and students are requesting for more flexible, reconfigurable and modern…

Listening to Students: Make Learning Spaces Your Own

ERIC Educational Resources Information Center

Shouder, Tim; Inglis, Grant; Rossini, Alexander

2014-01-01

Today, collaborative learning and teamwork are largely achieved through remote connections that are increasingly available and powerful. Collaboration of this sort is the highlight of an award-winning film "Your Own," which the authors created in response to the question, "What makes a learning space great?" for Herman…

Composition in an Integrated Arts Program

ERIC Educational Resources Information Center

Strand, Katherine

2016-01-01

This article examines possibilities for addressing the need to relate learning in music to learning in other disciplines through developing a third space where students are invited to bring their own knowledge, imagination, and ideas to a music curriculum. The article explores the connections between third-space learning, composing, and arts…

Uncommons: Transforming Dusty Reading Rooms into Artefactual "Third Space" Library Learning Labs

ERIC Educational Resources Information Center

Schadl, Suzanne Michele; Nelson, Molly; Valencia, Kristen S.

2015-01-01

This article describes the implementation of two inexpensive social learning library laboratories for advanced students in Latin American and Chicana/o studies. Drawing on philosophical literature from these interdisciplinary areas and ethnic studies, these cases present a "third space" option for library learning called…

Human Spaceflight Conjunction Assessment: Lessons Learned

NASA Technical Reports Server (NTRS)

Smith, Jason T.

2011-01-01

This viewgraph presentation reviews the process of a human space flight conjunction assessment and lessons learned from the more than twelve years of International Space Station (ISS) operations. Also, the application of these lessons learned to a recent ISS conjunction assessment with object 84180 on July 16, 2009 is also presented.

Enhancing Learning and Retarding Forgetting: Choices and Consequences

ERIC Educational Resources Information Center

Pashler, Harold; Rohrer, Doug; Cepeda, Nicholas J.; Carpenter, Shana K.

2007-01-01

Our research on learning enhancement has been focusing on the consequences for learning and forgetting of some of the more obvious and concrete choices that arise in instruction, including: How does spacing of practice affect retention of information over significant retention intervals (up to two years)? Do spacing effects generalize beyond…

Instructional Facilities for the Information Age. An ERIC Information Analysis Product.

ERIC Educational Resources Information Center

Knirk, Frederick G.

Intended to assist educators and trainers who must make recommendations about facilities to architects and school authorities, this ERIC information analysis project summarizes research on the design of both classrooms and individualized learning spaces that will optimize learning. Six teaching/learning space topics are considered: (1) light and…

Connecting Learning Spaces Using Mobile Technology

ERIC Educational Resources Information Center

Chen, Wenli; Seow, Peter; So, Hyo-Jeong; Toh, Yancy; Looi, Chee-Kit

2010-01-01

The use of mobile technology can help extend children's learning spaces and enrich the learning experiences in their everyday lives where they move from one context to another, switching locations, social groups, technologies, and topics. When students have ubiquitous access to mobile devices with full connectivity, the in-situ use of the mobile…

EVA: Collaborative Distributed Learning Environment Based in Agents.

ERIC Educational Resources Information Center

Sheremetov, Leonid; Tellez, Rolando Quintero

In this paper, a Web-based learning environment developed within the project called Virtual Learning Spaces (EVA, in Spanish) is presented. The environment is composed of knowledge, collaboration, consulting, experimentation, and personal spaces as a collection of agents and conventional software components working over the knowledge domains. All…

EVA: An Interactive Web-Based Collaborative Learning Environment

ERIC Educational Resources Information Center

Sheremetov, Leonid; Arenas, Adolfo Guzman

2002-01-01

In this paper, a Web-based learning environment developed within the project called Virtual Learning Spaces (EVA, in Spanish) is described. The environment is composed of knowledge, collaboration, consulting and experimentation spaces as a collection of agents and conventional software components working over the knowledge domains. All user…

Space Shuttle UHF Communications Performance Evaluation

NASA Technical Reports Server (NTRS)

Hwu, Shian U.; Loh, Yin-Chung; Kroll, Quin D.; Sham, Catherine C.

2004-01-01

An extension boom is to be installed on the starboard side of the Space Shuttle Orbiter (SSO) payload bay for thermal tile inspection and repairing. As a result, the Space Shuttle payload bay Ultra High Frequency (UHF) antenna will be under the boom. This study is to evaluate the Space Shuttle UHF communication performance for antenna at a suitable new location. To insure the RF coverage performance at proposed new locations, the link margin between the UHF payload bay antenna and Extravehicular Activity (EVA) Astronauts at a range distance of 160 meters from the payload bay antenna was analyzed. The communication performance between Space Shuttle Orbiter and International Space Station (SSO-ISS) during rendezvous was also investigated. The multipath effects from payload bay structures surrounding the payload bay antenna were analyzed. The computer simulation tool based on the Geometrical Theory of Diffraction method (GTD) was used to compute the signal strengths. The total field strength was obtained by summing the direct fields from the antennas and the reflected and diffracted fields from the surrounding structures. The computed signal strengths were compared to the signal strength corresponding to the 0 dB link margin. Based on the results obtained in this study, RF coverage for SSO-EVA and SSO- ISS communication links was determined for the proposed payload bay antenna UHF locations. The RF radiation to the Orbiter Docking System (ODS) pyros, the payload bay avionics, and the Shuttle Remote Manipulator System (SRMS) from the new proposed UHF antenna location was also investigated to ensure the EMC/EMI compliances.

Developing Learning Analytics Design Knowledge in the "Middle Space": The Student Tuning Model and Align Design Framework for Learning Analytics Use

ERIC Educational Resources Information Center

Wise, Alyssa Friend; Vytasek, Jovita Maria; Hausknecht, Simone; Zhao, Yuting

2016-01-01

This paper addresses a relatively unexplored area in the field of learning analytics: how analytics are taken up and used as part of teaching and learning processes. Initial steps are taken towards developing design knowledge for this "middle space," with a focus on students as analytics users. First, a core set of challenges for…