Science.gov

Sample records for aided surface representation

  1. Computer aided surface representation

    SciTech Connect

    Barnhill, R.E.

    1989-02-09

    The central research problem of this project is the effective representation and display of surfaces, interpolating to given information, in three or more dimensions. In a typical problem, we wish to create a surface from some discrete information. If this information is itself on another surface, the problem is to determine a surface defined on a surface,'' which is discussed below. Often, properties of an already constructed surface are desired: such geometry processing'' is described below. The Summary of Proposed Research from our original proposal describes the aims of this research project. This Summary and the Table of Contents from the original proposal are enclosed as an Appendix to this Progress Report. The broad sweep from constructive mathematics through algorithms and computer graphics displays is utilized in the research. The wide range of activity, directed in both theory and applications, makes this project unique. Last month in the first Ardent Titan delivered in the State of Arizona came to our group, funded by the DOE and Arizona State University. Although the Titan is a commercial product, its newness requires our close collaboration with Ardent to maximize results. During the past year, four faculty members and several graduate research assistants have worked on this DOE project. The gaining of new professionals is an important aspect of this project. A listing of the students and their topics is given in the Appendix. The most significant publication during the past year is the book, Curves and Surfaces for Computer Aided Geometric Design, by Dr. Gerald Farin. This 300 page volume helps fill a considerable gap in the subject and includes many new results on Bernstein-Bezier curves and surfaces.

  2. Computer aided surface representation

    SciTech Connect

    Barnhill, R.E.

    1990-02-19

    The central research problem of this project is the effective representation, computation, and display of surfaces interpolating to information in three or more dimensions. If the given information is located on another surface, then the problem is to construct a surface defined on a surface''. Sometimes properties of an already defined surface are desired, which is geometry processing''. Visualization of multivariate surfaces is possible by means of contouring higher dimensional surfaces. These problems and more are discussed below. The broad sweep from constructive mathematics through computational algorithms to computer graphics illustrations is utilized in this research. The breadth and depth of this research activity makes this research project unique.

  3. Computer aided surface representation

    SciTech Connect

    Barnhill, R.E.

    1991-04-02

    Modern computing resources permit the generation of large amounts of numerical data. These large data sets, if left in numerical form, can be overwhelming. Such large data sets are usually discrete points from some underlying physical phenomenon. Because we need to evaluate the phenomenon at places where we don't have data, a continuous representation (a surface'') is required. A simple example is a weather map obtained from a discrete set of weather stations. (For more examples including multi-dimensional ones, see the article by Dr. Rosemary Chang in the enclosed IRIS Universe). In order to create a scientific structure encompassing the data, we construct an interpolating mathematical surface which can evaluate at arbitrary locations. We can also display and analyze the results via interactive computer graphics. In our research we construct a very wide variety of surfaces for applied geometry problems that have sound theoretical foundations. However, our surfaces have the distinguishing feature that they are constructed to solve short or long term practical problems. This DOE-funded project has developed the premiere research team in the subject of constructing surfaces (3D and higher dimensional) that provide smooth representations of real scientific and engineering information, including state of the art computer graphics visualizations. However, our main contribution is in the development of fundamental constructive mathematical methods and visualization techniques which can be incorporated into a wide variety of applications. This project combines constructive mathematics, algorithms, and computer graphics, all applied to real problems. The project is a unique resource, considered by our peers to be a de facto national center for this type of research.

  4. Computer aided surface representation

    SciTech Connect

    Barnhill, R E

    1987-11-01

    The aims of this research are the creation of new surface forms and the determination of geometric and physical properties of surfaces. The full sweep from constructive mathematics through the implementation of algorithms and the interactive computer graphics display of surfaces is utilized. Both three-dimensional and multi- dimensional surfaces are considered. Particular emphasis is given to the scientific computing solution of Department of Energy problems. The methods that we have developed and that we are proposing to develop allow applications such as: Producing smooth contour maps from measured data, such as weather maps. Modeling the heat distribution inside a furnace from sample measurements. Terrain modeling based on satellite pictures. The investigation of new surface forms includes the topics of triangular interpolants, multivariate interpolation, surfaces defined on surfaces and monotone and/or convex surfaces. The geometric and physical properties considered include contours, the intersection of surfaces, curvatures as a interrogation tool, and numerical integration.

  5. Computer aided surface representation. Progress report, June 1, 1988--May 31, 1989

    SciTech Connect

    Barnhill, R.E.

    1989-02-09

    The central research problem of this project is the effective representation and display of surfaces, interpolating to given information, in three or more dimensions. In a typical problem, we wish to create a surface from some discrete information. If this information is itself on another surface, the problem is to determine a ``surface defined on a surface,`` which is discussed below. Often, properties of an already constructed surface are desired: such ``geometry processing`` is described below. The Summary of Proposed Research from our original proposal describes the aims of this research project. This Summary and the Table of Contents from the original proposal are enclosed as an Appendix to this Progress Report. The broad sweep from constructive mathematics through algorithms and computer graphics displays is utilized in the research. The wide range of activity, directed in both theory and applications, makes this project unique. Last month in the first Ardent Titan delivered in the State of Arizona came to our group, funded by the DOE and Arizona State University. Although the Titan is a commercial product, its newness requires our close collaboration with Ardent to maximize results. During the past year, four faculty members and several graduate research assistants have worked on this DOE project. The gaining of new professionals is an important aspect of this project. A listing of the students and their topics is given in the Appendix. The most significant publication during the past year is the book, Curves and Surfaces for Computer Aided Geometric Design, by Dr. Gerald Farin. This 300 page volume helps fill a considerable gap in the subject and includes many new results on Bernstein-Bezier curves and surfaces.

  6. Computer aided surface representation. Progress report, June 1, 1989--May 31, 1990

    SciTech Connect

    Barnhill, R.E.

    1990-02-19

    The central research problem of this project is the effective representation, computation, and display of surfaces interpolating to information in three or more dimensions. If the given information is located on another surface, then the problem is to construct a ``surface defined on a surface``. Sometimes properties of an already defined surface are desired, which is ``geometry processing``. Visualization of multivariate surfaces is possible by means of contouring higher dimensional surfaces. These problems and more are discussed below. The broad sweep from constructive mathematics through computational algorithms to computer graphics illustrations is utilized in this research. The breadth and depth of this research activity makes this research project unique.

  7. Social representation of AIDS among Zambian adolescents.

    PubMed

    Joffe, Hélène; Bettega, Nadia

    2003-09-01

    This study explores shared thinking about HIV/AIDS among Zambian adolescents. With high numbers affected, the question is how this group represents its risk. Social representations of the origin, spread and risk of HIV/AIDS were gleaned via 60 semistructured interviews with urban 15 to 20 year olds. A systematic analysis revealed a shared picture: AIDS was linked to the West, God and teenage girls; its spread lay beyond the control of adolescent boys and men; and the personal sense of vulnerability was low. The results are discussed in light of their corroboration of the finding that social representations of danger can be identity protective, yet also system justifying. The potential transfer of such findings to psychological theory and to health campaigns is considered.

  8. Computer representation of molecular surfaces

    SciTech Connect

    Max, N.L.

    1981-07-06

    This review article surveys recent work on computer representation of molecular surfaces. Several different algorithms are discussed for producing vector or raster drawings of space-filling models formed as the union of spheres. Other smoother surfaces are also considered.

  9. Social representations, risk behaviors and AIDS.

    PubMed

    Camargo, Brigido Vizeu; Bousfield, Andréa Barbará S

    2009-11-01

    This study's interest relies on adolescents' social representations of unprotected sex, more precisely on the relationship between the attitude towards the preservative and the reason attribution for its non use. 1386 secondary school students took part in the study, in the Brazilian cities of Florianópolis, Itajaí and Balneário Camboriú. In order to verify reasons attributed by the students, we focused on the sample that had sexual experiences without using the condom during last year. Data was analyzed with software ALCESTE, which showed three different classes of explanations for the non use of the preservative: the moment of the intercourse (unpredictable and incontrollable), trust in the partner and the option of the contraceptive pill, instead of the preservatives, in avoiding pregnancy. The students' attitudes towards the preservative are less favourable among those who maintain sexual intercourse with known people. The results revealed two representations of AIDS: one of trust in the partner and another of the experience with sex and the preservative--the first one gives sense to the adolescents' experiences with known sexual partners and the second, with less known sexual partners.

  10. Computing Visible-Surface Representations,

    DTIC Science & Technology

    1985-03-01

    Terzopoulos N00014-75-C-0643 9. PERFORMING ORGANIZATION NAME AMC ADDRESS 10. PROGRAM ELEMENT. PROJECT, TASK Artificial Inteligence Laboratory AREA A...Massachusetts Institute of lechnolog,. Support lbr the laboratory’s Artificial Intelligence research is provided in part by the Advanced Rtccarcl Proj...dynamically maintaining visible surface representations. Whether the intention is to model human vision or to design competent artificial vision systems

  11. Can AIDS stigma be reduced to poverty stigma? Exploring Zimbabwean children's representations of poverty and AIDS

    PubMed Central

    Campbell, C; Skovdal, M; Mupambireyi, Z; Madanhire, C; Robertson, L; Nyamukapa, C A; Gregson, S

    2012-01-01

    Objective We use children's drawings to investigate social stigmatization of AIDS-affected and poverty-affected children by their peers, in the light of suggestions that the stigmatization of AIDS-affected children might derive more from the poverty experienced by these children than from their association with AIDS. Methods A qualitative study, in rural Zimbabwe, used draw-and-write techniques to elicit children's (10–12 years) representations of AIDS-affected children (n= 30) and poverty-affected children (n= 33) in 2009 and 2010 respectively. Results Representations of children affected by AIDS and by poverty differed significantly. The main problems facing AIDS-affected children were said to be the psychosocial humiliations of AIDS stigma and children's distress about sick relatives. Contrastingly, poverty-affected children were depicted as suffering from physical and material neglect and deprivation. Children affected by AIDS were described as caregivers of parents whom illness prevented from working. This translated into admiration and respect for children's active contribution to household survival. Poverty-affected children were often portrayed as more passive victims of their guardians' inability or unwillingness to work or to prioritize their children's needs, with these children having fewer opportunities to exercise agency in response to their plight. Conclusions The nature of children's stigmatization of their AIDS-affected peers may often be quite distinct from poverty stigma, in relation to the nature of suffering (primarily psychosocial and material respectively), the opportunities for agency offered by each affliction, and the opportunities each condition offers for affected children to earn the respect of their peers and community. We conclude that the particular nature of AIDS stigma offers greater opportunities for stigma reduction than poverty stigma. PMID:21985490

  12. [Social representations of health education in a time of AIDS].

    PubMed

    Teixeira, Elizabeth; de Oliveira, Denize Cristina

    2014-01-01

    This is a qualitative and descriptive study, which aimed at identifying and analyzing social representations of health education to HIV patients among health professionals. The setting included three healthcare DST/HIV/AIDS services in Belém-PA, Brazil, and 37 health professionals participated in the study. Data collection was conducted in 2012-2013 on the basis of in-depth interviews and analysis was made on Alceste 4.0 software. Final results indicated that health education can be comprehended in light of categories: educational action; sine qua non: education and training at work, and unit structure; teaching-learning process. Conclusions show that social representations are set as guidance-information for precaution-prevention and that they come forth along continuous and emerging action flow, bringing about permanent health education to ensure healthcare services in full.

  13. Workshop on Aircraft Surface Representation for Aerodynamic Computation

    NASA Technical Reports Server (NTRS)

    Gregory, T. J. (Editor); Ashbaugh, J. (Editor)

    1980-01-01

    Papers and discussions on surface representation and its integration with aerodynamics, computers, graphics, wind tunnel model fabrication, and flow field grid generation are presented. Surface definition is emphasized.

  14. Data handling and representation of freeform surfaces

    NASA Astrophysics Data System (ADS)

    Steinkopf, Ralf; Dick, Lars; Kopf, Tino; Gebhardt, Andreas; Risse, Stefan; Eberhardt, Ramona

    2011-10-01

    Freeform surfaces enable innovative optics. They are not limited by axis symmetry and hence they are almost free in design. They are used to reduce the installation space and enhance the performance of optical elements. State of the art optical design tools are computing with powerful algorithms to simulate freeform surfaces. Even new mathematical approaches are under development /1/. In consequence, new optical designs /2/ are pushing the development of manufacturing processes consequently and novel types of datasets have to proceed through the process chain /3/. The complexity of these data is the huge challenge for the data handling. Because of the asymmetrical and 3-dimensional surfaces of freeforms, large data volumes have to be created, trimmed, extended and fitted. All these processes must be performed without losing the accuracy of the original design data. Additionally, manifold types of geometries results in different kinds of mathematical representations of freeform surfaces and furthermore the used CAD/CAM tools are dealing with a set of spatial transport formats. These are all reasons why manufacture-oriented approaches for the freeform data handling are not yet sufficiently developed. This paper suggests a classification of freeform surfaces based on the manufacturing methods which are offered by diamond machining. The different manufacturing technologies, ranging from servo-turning to shaping, require a differentiated approach for the data handling process. The usage of analytical descriptions in form of splines and polynomials as well as the application of discrete descriptions like point clouds is shown in relation to the previously made classification. Advantages and disadvantages of freeform representations are discussed. Aspects of the data handling in between different process steps are pointed out and suitable exchange formats for freeform data are proposed. The described approach offers the possibility for efficient data handling from optical

  15. [Social representations on HIV/AIDS among adolescentes: implications for nursing care].

    PubMed

    Thiengo, Maria Aparecida; de Oliveira, Denize Cristina; Rodrigues, Benedita Maria Rêgo Deusdará

    2005-03-01

    With the objective of discussing the implications of the social representations of HIV/AIDS for the interpersonal relations and the practices for protection among adolescents, 15 semidirective interviews were carried out with adolescents, both with and without HIV, assisted at a Hospital School in Rio de Janeiro. The software ALCESTE 4.5 was used for the data analysis. It was observed that the social representation of AIDS is structured around cognitions connected to prevention, revealing a contradiction between the knowledge and the practices reported by the group. It is suggested that the nursing practices should be directed towards the reduction of the distance between practices, representations and scientific knowledge.

  16. Using Molecular Representations to Aid Student Understanding of Stereochemical Concepts

    ERIC Educational Resources Information Center

    Abraham, Michael; Varghese, Valsamma; Tang, Hui

    2010-01-01

    Stereochemistry is an important topic in organic chemistry. It is also a difficult topic for students to learn. This study investigated the relative effectiveness on students' understanding of three kinds of molecular representations of stereochemistry concepts. Instructional activities compared the use of either: (i) computer-based molecular…

  17. Rubber airplane: Constraint-based component-modeling for knowledge representation in computer-aided conceptual design

    NASA Technical Reports Server (NTRS)

    Kolb, Mark A.

    1990-01-01

    Viewgraphs on Rubber Airplane: Constraint-based Component-Modeling for Knowledge Representation in Computer Aided Conceptual Design are presented. Topics covered include: computer aided design; object oriented programming; airfoil design; surveillance aircraft; commercial aircraft; aircraft design; and launch vehicles.

  18. [Social representations of HIV/AIDS among healthcare professionals in benchmark services].

    PubMed

    Dantas, Mariana de Sousa; Abrão, Fátima Maria da Silva; de Freitas, Clara Maria Silvestre Monteiro; de Oliveira, Denize Cristina

    2014-12-01

    This study was based on exploratory research and a qualitative approach within the framework of the Social Representations Theory. It aims to capture the social representations of healthcare providers in relation to HIV/AIDS by describing their structure.The Free Evocations technique was applied on 86 professionals of HIV/AIDS benchmark services in Recife, Pernambuco, Brazil, from 2011 to 2013. Analysis using EVOC 2005 software showed that the possible central core is prejudice in a negative attitude dimension; in the contrast zone, chronic disease translates living with the disease. In the first periphery, treatment and disease in a clinical/biometric conception; in the second periphery, death has a imagistic and negative nature. Positive and negative elements were observed, allowing healthcare personnel to construct meaning attributed to the phenomenon and reflect on their practices.

  19. Commentary on Joffe (1996) AIDS research and prevention: a social representation approach.

    PubMed

    Fife-Schaw, C

    1997-03-01

    Hélène Joffe's (1996) article provides us with a well-presented argument detailing the failings of Knowledge, Attitude, Belief and Practice (KABP) approaches in the domain of AIDS/HIV prevention behaviours and argues that the Theory of Social Representations (Moscovici, 1984) offers a useful alternative perspective. In this commentary I would like to expand on some of the issues she raises and to counter-argue that the case for adopting social representations theory as an alternative to KABP approaches has yet to be made convincingly. To do this I will first consider the problems surrounding traditional KABP approaches, then discuss social representations theory as an alternative and consider alternatives on the way.

  20. It's harder for boys? Children's representations of their HIV/AIDS-affected peers in Zimbabwe

    PubMed Central

    LeRoux-Rutledge, Emily; Guerlain, Madeleine A.; Andersen, Louise B.; Madanhire, Claudius; Mutsikiwa, Alice; Nyamukapa, Constance; Skovdal, Morten; Gregson, Simon; Campbell, Catherine

    2015-01-01

    ABSTRACT This study examines whether children in rural Zimbabwe have differing representations of their HIV/AIDS-affected peers based on the gender of those peers. A group of 128 children (58 boys, 70 girls) aged 10–14 participated in a draw-and-write exercise, in which they were asked to tell the story of either an HIV/AIDS-affected girl child, or an HIV/AIDS-affected boy child. Stories were inductively thematically coded, and then a post hoc statistical analysis was conducted to see if there were differences in the themes that emerged in stories about girls versus stories about boys. The results showed that boys were more often depicted as materially deprived, without adult and teacher support, and heavily burdened with household duties. Further research is needed to determine whether the perceptions of the children in this study point to a series of overlooked challenges facing HIV/AIDS-affected boys, or to a culture of gender inequality facing HIV/AIDS-affected girls – which pays more attention to male suffering than to female suffering. PMID:26615976

  1. It's harder for boys? Children's representations of their HIV/AIDS-affected peers in Zimbabwe.

    PubMed

    LeRoux-Rutledge, Emily; Guerlain, Madeleine A; Andersen, Louise B; Madanhire, Claudius; Mutsikiwa, Alice; Nyamukapa, Constance; Skovdal, Morten; Gregson, Simon; Campbell, Catherine

    2015-01-01

    This study examines whether children in rural Zimbabwe have differing representations of their HIV/AIDS-affected peers based on the gender of those peers. A group of 128 children (58 boys, 70 girls) aged 10-14 participated in a draw-and-write exercise, in which they were asked to tell the story of either an HIV/AIDS-affected girl child, or an HIV/AIDS-affected boy child. Stories were inductively thematically coded, and then a post hoc statistical analysis was conducted to see if there were differences in the themes that emerged in stories about girls versus stories about boys. The results showed that boys were more often depicted as materially deprived, without adult and teacher support, and heavily burdened with household duties. Further research is needed to determine whether the perceptions of the children in this study point to a series of overlooked challenges facing HIV/AIDS-affected boys, or to a culture of gender inequality facing HIV/AIDS-affected girls - which pays more attention to male suffering than to female suffering.

  2. Aspect-Aided Dynamic Non-Negative Sparse Representation-Based Microwave Image Classification

    PubMed Central

    Zhang, Xinzheng; Yang, Qiuyue; Liu, Miaomiao; Jia, Yunjian; Liu, Shujun; Li, Guojun

    2016-01-01

    Classification of target microwave images is an important application in much areas such as security, surveillance, etc. With respect to the task of microwave image classification, a recognition algorithm based on aspect-aided dynamic non-negative least square (ADNNLS) sparse representation is proposed. Firstly, an aspect sector is determined, the center of which is the estimated aspect angle of the testing sample. The training samples in the aspect sector are divided into active atoms and inactive atoms by smooth self-representative learning. Secondly, for each testing sample, the corresponding active atoms are selected dynamically, thereby establishing dynamic dictionary. Thirdly, the testing sample is represented with ℓ1-regularized non-negative sparse representation under the corresponding dynamic dictionary. Finally, the class label of the testing sample is identified by use of the minimum reconstruction error. Verification of the proposed algorithm was conducted using the Moving and Stationary Target Acquisition and Recognition (MSTAR) database which was acquired by synthetic aperture radar. Experiment results validated that the proposed approach was able to capture the local aspect characteristics of microwave images effectively, thereby improving the classification performance. PMID:27598172

  3. Aspect-Aided Dynamic Non-Negative Sparse Representation-Based Microwave Image Classification.

    PubMed

    Zhang, Xinzheng; Yang, Qiuyue; Liu, Miaomiao; Jia, Yunjian; Liu, Shujun; Li, Guojun

    2016-09-02

    Classification of target microwave images is an important application in much areas such as security, surveillance, etc. With respect to the task of microwave image classification, a recognition algorithm based on aspect-aided dynamic non-negative least square (ADNNLS) sparse representation is proposed. Firstly, an aspect sector is determined, the center of which is the estimated aspect angle of the testing sample. The training samples in the aspect sector are divided into active atoms and inactive atoms by smooth self-representative learning. Secondly, for each testing sample, the corresponding active atoms are selected dynamically, thereby establishing dynamic dictionary. Thirdly, the testing sample is represented with ℓ 1 -regularized non-negative sparse representation under the corresponding dynamic dictionary. Finally, the class label of the testing sample is identified by use of the minimum reconstruction error. Verification of the proposed algorithm was conducted using the Moving and Stationary Target Acquisition and Recognition (MSTAR) database which was acquired by synthetic aperture radar. Experiment results validated that the proposed approach was able to capture the local aspect characteristics of microwave images effectively, thereby improving the classification performance.

  4. Efficient free-form surface representation with application in orthodontics

    NASA Astrophysics Data System (ADS)

    Yamany, Sameh M.; El-Bialy, Ahmed M.

    1999-03-01

    Orthodontics is the branch of dentistry concerned with the study of growth of the craniofacial complex. The detection and correction of malocclusion and other dental abnormalities is one of the most important and critical phases of orthodontic diagnosis. This paper introduces a system that can assist in automatic orthodontics diagnosis. The system can be used to classify skeletal and dental malocclusion from a limited number of measurements. This system is not intended to deal with several cases but is aimed at cases more likely to be encountered in epidemiological studies. Prior to the measurement of the orthodontics parameters, the position of the teeth in the jaw model must be detected. A new free-form surface representation is adopted for the efficient and accurate segmentation and separation of teeth from a scanned jaw model. THe new representation encodes the curvature and surface normal information into a 2D image. Image segmentation tools are then sued to extract structures of high/low curvature. By iteratively removing these structures, individual teeth surfaces are obtained.

  5. [Between the fear of HIV contamination and the symbolic representations of AIDS: the specter of contemporary despair].

    PubMed

    Meneghin, P

    1996-12-01

    Lack of knowledge and misinformations on HIV/AIDS are predictors of emotional responses as fear of contagion, homophobia, avoidance and excessive precautions. Fear of contagion is an affective stress response to the neurocognitive activity that leads to a perceived threat of AIDS in connection with the symbolic meanings os illness. Focused interviews were conducted with an opportunistic sample of 31 young people to know the affective responses and behaviors after blood screening for HIV antibody testing. The findings confirm the relationship of symbolic representation of illness as mystery, death, punishment and sexuality to fear of contagion and mitic conception of AIDS.

  6. Optimized Fourier representations for three-dimensional magnetic surfaces

    SciTech Connect

    Hirshman, S.P.; Meier, H.K.

    1984-11-01

    The selection of an optimal parametric angle theta describing a closed magnetic flux surface is considered with regard to accelerating the convergence rate of the Fourier series for the Cartesian coordinates x(theta,phi) identical with R - R/sub 0/ and y(theta,phi) identical with Z - Z/sub 0/. Geometric criteria are developed based on the Hamiltonian invariants of Keplerian orbits. These criteria relate the rate of curve traversal (tangential speed) to the curvature (normal acceleration) so as to provide increased angular resolution in regions of largest curvature. They are, however, limited to either convex or starlike domains and do not provide rapid convergence for complex domains with alternating convex and concave regions. A generally applicable constraint criterion, based directly on minimizing the width of the x and y Fourier spectra, is also derived. A variational principle is given for implementing these constraints numerically. Application to the representation of three-dimensional magnetic flux surfaces is discussed.

  7. 30 years later: Social Representations about AIDS and sexual practices of rural towns residents.

    PubMed

    Furtado, Francisca Marina de Souza Freire; Santos, José Anderson Galdino; Loredanna, Stedile; Araújo, Eunice; Saldanha, Ana Alayde Werba; Silva, Josevânia da

    2016-06-01

    In the 30 years of the AIDS pandemic in Brazil, it is recognized the HIV virus internalization of the phenomenon as a challenge to care and current health policies. In this sense, it aimed to verify sex practices and social representations that rural towns residents have about the disease. Attended by 789 people, men and women, between 18 and 90 years old, residents in 41 towns with fewer than 11,000 inhabitants in the state of Paraiba / Brazil. Data were collected by a questionnaire and the free association of words test. The results showed low concern about disease, perception of invulnerability to HIV infection and not using condoms during sexual intercourse, and confidence in the major reason related partner. Also showed endure derogatory and stereotypical representations, revealing that still persist in rural areas, beliefs and representations concerning the beginning of the epidemic. From these findings, it is possible to point out deficiencies in the care provided by the health services in these localities, which may result in increased vulnerability of this population to diseases, so there is the need to intensify information campaigns and intervention. The results reveal the existence of three different types of modes of learning health literacy skills in informal context: : i) learning that takes place in action, in achieving daily tasks; ii) learning processes that result from problem solving; iii) learning that occurs in an unplanned manner, resulting from accidental circumstances and, in some cases, devoid of intentionality. Nos 30 anos da pandemia da Aids no Brasil, reconhece-se o fenômeno da interiorização do vírus HIV como um desafio ao cuidado e às politicas de saúde atuais. Neste sentido, objetivou-se conhecer práticas sexuais e as representações sociais que residentes de cidades rurais têm acerca da doença. Participaram 789 pessoas, homens e mulheres, entre 18 e 90 anos de idade, residentes em 41 cidades com menos de 11.000 habitantes

  8. Social representation of hearing aids: cross-cultural study in India, Iran, Portugal, and the United Kingdom

    PubMed Central

    Manchaiah, Vinaya; Danermark, Berth; Vinay; Ahmadi, Tayebeh; Tomé, David; Krishna, Rajalakshmi; Germundsson, Per

    2015-01-01

    Background The current study was aimed at understanding the social representation of hearing aids in India, Iran, Portugal, and the United Kingdom. We also compared these results to explore the cross-cultural differences and similarities among these countries. Methods The study involved a cross-sectional design, and the data were collected from four different countries using the snowball sampling method. Data were analyzed using a content analysis to identify the most-similar categories of responses reported, a co-occurrences analysis to see which of these categories are reported commonly, and a chi-square analysis to study if there was any association between positive, neutral, and negative connotations among participants in different countries. Results The current study revealed four different social representations of hearing aids from India, Iran, Portugal, and the United Kingdom, and also a global index. Conclusion The study results provide very useful insights into how hearing aids are represented in the society. These findings may have important implications for public education and also for manufacturers from the viewpoint of designing and marketing hearing aids in different countries. PMID:26504376

  9. Computer-aided design of bevel gear tooth surfaces

    NASA Technical Reports Server (NTRS)

    Shuo, Hung Chang; Huston, Ronald L.; Coy, John J.

    1989-01-01

    This paper presents a computer-aided design procedure for generating bevel gears. The development is based on examining a perfectly plastic, cone-shaped gear blank rolling over a cutting tooth on a plane crown rack. The resulting impression on the plastic gear blank is the envelope of the cutting tooth. This impression and envelope thus form a conjugate tooth surface. Equations are presented for the locus of points on the tooth surface. The same procedures are then extended to simulate the generation of a spiral bevel gear. The corresponding governing equations are presented.

  10. Computer aided design of bevel gear tooth surfaces

    NASA Technical Reports Server (NTRS)

    Chang, S. H.; Huston, R. L.; Coy, J. J.

    1989-01-01

    This paper presents a computer-aided design procedure for generating bevel gears. The development is based on examining a perfectly plastic, cone-shaped gear blank rolling over a cutting tooth on a plane crown rack. The resulting impression on the plastic gear blank is the envelope of the cutting tooth. This impression and envelope thus form a conjugate tooth surface. Equations are presented for the locus of points on the tooth surface. The same procedures are then extended to simulate the generation of a spiral bevel gear. The corresponding governing equations are presented.

  11. Competing or co-existing? Representations of HIV/AIDS by white women teachers in post-apartheid South Africa.

    PubMed

    de Kock, Lauren; Wills, Jane

    2007-11-01

    This study explores the social representations of HIV and AIDS that circulate among white women teachers in South Africa, a group whose personal risk of the disease is low but who have a major role to play in shaping attitudes to HIV/AIDS among children and young people. The study examines how white women talk about the origin and causes of the spread of HIV in South Africa and their personal and community risk. This was explored through 25 semi-structured interviews and two focus groups with white female teachers in Johannesburg. A thematic analysis of the in-depth interviews revealed a shared private understanding of the disease, wherein the women distanced themselves by anchoring it in the context of racist cultural stereotypes of black sexuality and vulnerability. In contrast, the focus group discussions revealed a type of public talk in which HIV/AIDS is anchored in the contemporary cultural images of the new South Africa and the spirit of ubuntu or togetherness. These contradictory views reflect the racial tensions and social contexts of South Africa and which shape HIV/AIDS discourses. The findings suggest that more needs to be done to create a genuine understanding of HIV and AIDS within contemporary South African contexts.

  12. [Vulnerability of women in common-law marriage to becoming infected with HIV/AIDS: a study of social representations].

    PubMed

    Rodrigues, Larissa Silva Abreu; Paiva, Mirian Santos; de Oliveira, Jeane Freitas; da Nóbrega, Sheva Maia

    2012-04-01

    This article discusses the social representations of women living in common-law marriage in terms of their vulnerability to becoming infected with HIV/AIDS. Data were obtained through the free association of words, and consisted of an excerpt of a study founded on the Social Representations Theory developed with HIV-negative women living in the state capital and cities in the interior of Bahia. The correspondence factor analysis showed significance for the variables: origin, education level and time spent in common-law marriage. Their acceptance of marital affairs emerged as a vulnerability factor for respondents with one to five years spent in common-law marriage, living in cities in the interior. Women from the capital, with 6-10 years spent in common-law marriage, reported monogamy as a form of prevention. Women with a longer common-law marriage who had completed only a primary education reported feeling invulnerable, which was the opposite of those with one to five years in common-law marriage with a secondary education. Results show there is a need for more interventions aiming to denaturalize the socio-cultural coercions that generate representations and make women in common-law marriages more vulnerable to AIDS.

  13. Improving the representation of agricultural management in land surface models

    NASA Astrophysics Data System (ADS)

    Sacks, William J.

    To gain a better understanding of processes affecting crop yield, as well as two-way feedbacks between agricultural management and climate, a number of groups have recently incorporated croplands into regional and global land surface models. However, many aspects of agricultural management are still treated in a rudimentary way in these models. For my doctoral research, I have aimed to improve the representation of two key agricultural processes in land surface models: crop phenology and irrigation. In addition, I have investigated the effects of these processes on both crop yields and climate. First, I assembled a dataset of global crop planting and harvesting dates for nineteen crops. I also investigated climatic and non-climatic factors that drive planting date decisions around the world. Second, I investigated trends and variability in crop planting dates and development progress across the U.S. I showed a trend to earlier planting of corn and soybeans, along with a trend to a longer crop growth period, and particularly a lengthening reproductive period in corn. In addition, I showed that growing degree days are a good predictor of the length of the vegetative period in corn, but less so for the reproductive period. Third, I used these observed trends along with the Agro-IBIS model to explore the implications of changes in crop phenology for both crop yields and fluxes of water and energy. I estimated that the trend to longer-season corn cultivars over the last three decades can account for 26% of the observed yield trend in the U.S. In addition, I found that earlier planting and longer-season cultivars shift the seasonality of water and energy fluxes, and have a small effect on annual-average fluxes. Finally, I investigated the effects of irrigation on climate, finding that this effect is significant in some large regions of the globe. Although the global-average temperature change was small, the large regional changes are important for both crop yields and

  14. The Neural Representation of Consonant-Vowel Transitions in Adults Who Wear Hearing Aids

    PubMed Central

    Tremblay, Kelly L.; Kalstein, Laura; Billings, Cuttis J.; Souza, Pamela E.

    2006-01-01

    Hearing aids help compensate for disorders of the ear by amplifying sound; however, their effectiveness also depends on the central auditory system's ability to represent and integrate spectral and temporal information delivered by the hearing aid. The authors report that the neural detection of time-varying acoustic cues contained in speech can be recorded in adult hearing aid users using the acoustic change complex (ACC). Seven adults (50–76 years) with mild to severe sensorineural hearing participated in the study. When presented with 2 identifiable consonant-vowel (CV) syllables (“shee” and “see”), the neural detection of CV transitions (as indicated by the presence of a P1-N1-P2 response) was different for each speech sound. More specifically, the latency of the evoked neural response coincided in time with the onset of the vowel, similar to the latency patterns the authors previously reported in normal-hearing listeners. PMID:16959736

  15. Triangulation algorithms for the representation of molecular surface properties

    NASA Astrophysics Data System (ADS)

    Heiden, Wolfgang; Schlenkrich, Michael; Brickmann, Jürgen

    1990-09-01

    A triangulation algorithm for a dotted surface (i.e. a surface defined by point coordinates in three dimensions) is given. The individual triangles are generated on the basis of a hierarchy of strategies according to increasing surface complexity. While for small molecules an elementary algorithm is sufficient to triangulate the surface, large molecules-like proteins-generally need all steps of the hierarchy. Although this program has been developed with the aim of triangulating molecular surfaces, it can in principle be applied to any surface defined by 3D point coordinates.

  16. Representations and Metrics for Time-Varying Terrain Surfaces

    DTIC Science & Technology

    2013-08-06

    12 4.1 Development of the Surface Probability Function ( SPF ) Octree...15 5.2 SPF Terrain Model...terrain model and <….>. ..................................... 11 Figure 8: Visualization of our SPF Octree data structure using a sphere test surface

  17. AIDS

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/000594.htm HIV/AIDS To use the sharing features on this page, ... immunodeficiency virus (HIV) is the virus that causes AIDS. When a person becomes infected with HIV, the ...

  18. Energy Monitoring and Targeting as diagnosis; Applying work analysis to adapt a statistical change detection strategy using representation aiding

    NASA Astrophysics Data System (ADS)

    Hilliard, Antony

    Energy Monitoring and Targeting is a well-established business process that develops information about utility energy consumption in a business or institution. While M&T has persisted as a worthwhile energy conservation support activity, it has not been widely adopted. This dissertation explains M&T challenges in terms of diagnosing and controlling energy consumption, informed by a naturalistic field study of M&T work. A Cognitive Work Analysis of M&T identifies structures that diagnosis can search, information flows un-supported in canonical support tools, and opportunities to extend the most popular tool for MM&T: Cumulative Sum of Residuals (CUSUM) charts. A design application outlines how CUSUM charts were augmented with a more contemporary statistical change detection strategy, Recursive Parameter Estimates, modified to better suit the M&T task using Representation Aiding principles. The design was experimentally evaluated in a controlled M&T synthetic task, and was shown to significantly improve diagnosis performance.

  19. Surface dependent representations for illumination insensitive image comparison.

    PubMed

    Osadchy, Margarita; Jacobs, David W; Lindenbaum, Michael

    2007-01-01

    We consider the problem of matching images to tell whether they come from the same scene viewed under different lighting conditions. We show that the surface characteristics determine the type of image comparison method that should be used. Previous work has shown the effectiveness of comparing the image gradient direction for surfaces with material properties that change rapidly in one direction. We show analytically that two other widely used methods, normalized correlation of small windows and comparison of multiscale oriented filters, essentially compute the same thing. Then, we show that for surfaces whose properties change more slowly, comparison of the output of whitening filters is most effective. This suggests that a combination of these strategies should be employed to compare general objects. We discuss indications that Gabor jets use such a mixed strategy effectively, and we propose a new mixed strategy. We validate our results on synthetic and real images.

  20. Enhancing the Representation of Subgrid Land Surface Characteristics in Land Surface Models

    SciTech Connect

    Ke, Yinghai; Leung, Lai-Yung R.; Huang, Maoyi; Li, Hongyi

    2013-09-27

    Land surface heterogeneity has long been recognized and increasingly incorporated in the land surface modelling. In most existing land surface models, the spatial variability of surface cover is represented as subgrid composition of multiple surface cover types. In this study, we developed a new subgrid classification method (SGC) that accounts for the topographic variability of the vegetation cover. Each model grid cell was represented with a number of elevation classes and each elevation class was further described by a number of vegetation types. The numbers of elevation classes and vegetation types were variable and optimized for each model grid so that the spatial variability of both elevation and vegetation can be reasonably explained given a pre-determined total number of classes. The subgrid structure of the Community Land Model (CLM) was used as an example to illustrate the newly developed method in this study. With similar computational burden as the current subgrid vegetation representation in CLM, the new method is able to explain at least 80% of the total subgrid PFTs and greatly reduced the variations of elevation within each subgrid class compared to the baseline method where a single elevation class is assigned to each subgrid PFT. The new method was also evaluated against two other subgrid methods (SGC1 and SGC2) that assigned fixed numbers of elevation and vegetation classes for each model grid with different perspectives of surface cover classification. Implemented at five model resolutions (0.1°, 0.25°, 0.5°, 1.0° and 2.0°) with three maximum-allowed total number of classes N_class of 24, 18 and 12 representing different computational burdens over the North America (NA) continent, the new method showed variable performances compared to the SGC1 and SGC2 methods. However, the advantage of the SGC method over the other two methods clearly emerged at coarser model resolutions and with moderate computational intensity (N_class = 18) as it

  1. Enhancing the flexibility and adaptability of the DARC structural representation for computer-aided drug design.

    PubMed

    Sobel, Y; Vizet, P; Chemtob, S; Barbieux, F; Mercier, C

    1998-01-01

    Noticeable progress has been achieved in the determination of dynamic topochromatic variables for the structural representation of compounds and their situation in a given population. These independent structural variables can be further combined into more complex variables. Their contributions to the evolution of an associated property can therefore be evaluated with certainty. The risk of having correlated variables is avoided while the structural description remains exhaustive. In order to enhance the interpretative ability of the QSAR model, one or several physicochemical properties can be taken with these structural parameters as explanatory variables. Typically, partition coefficients, 3-D and quantum mechanical data are used for this purpose. The structural aspects not taken into account by the physicochemical parameters are reflected in the remaining topochromatic variables. The use of these new concepts is presented in a study of carbazole mutagenicity. The model explains 99% of the total variance with one external property and four additional topochromatic variables. The modulation of the heat of formation of an intermediate by two topochromatic variables suggests a much more precise interpretation than a simple combination of the usual external variables.

  2. Novel mixture model for the representation of potential energy surfaces

    NASA Astrophysics Data System (ADS)

    Pham, Tien Lam; Kino, Hiori; Terakura, Kiyoyuki; Miyake, Takashi; Dam, Hieu Chi

    2016-10-01

    We demonstrate that knowledge of chemical physics on a materials system can be automatically extracted from first-principles calculations using a data mining technique; this information can then be utilized to construct a simple empirical atomic potential model. By using unsupervised learning of the generative Gaussian mixture model, physically meaningful patterns of atomic local chemical environments can be detected automatically. Based on the obtained information regarding these atomic patterns, we propose a chemical-structure-dependent linear mixture model for estimating the atomic potential energy. Our experiments show that the proposed mixture model significantly improves the accuracy of the prediction of the potential energy surface for complex systems that possess a large diversity in their local structures.

  3. Improved analytical flux surface representation and calculation models for poloidal asymmetries

    NASA Astrophysics Data System (ADS)

    Collart, T. G.; Stacey, W. M.

    2016-05-01

    An orthogonalized flux-surface aligned curvilinear coordinate system has been developed from an up-down asymmetric variation of the "Miller" flux-surface equilibrium model. It is found that the new orthogonalized "asymmetric Miller" model representation of equilibrium flux surfaces provides a more accurate match than various other representations of DIII-D [J. L. Luxon, Nucl. Fusion 42, 614-633 (2002)] discharges to flux surfaces calculated using the DIII-D Equilibrium Fitting tokamak equilibrium reconstruction code. The continuity and momentum balance equations were used to develop a system of equations relating asymmetries in plasma velocities, densities, and electrostatic potential in this curvilinear system, and detailed calculations of poloidal asymmetries were performed for a DIII-D discharge.

  4. Representation of 3-D surface orientation by velocity and disparity gradient cues in area MT.

    PubMed

    Sanada, Takahisa M; Nguyenkim, Jerry D; Deangelis, Gregory C

    2012-04-01

    Neural coding of the three-dimensional (3-D) orientation of planar surface patches may be an important intermediate step in constructing representations of complex 3-D surface structure. Spatial gradients of binocular disparity, image velocity, and texture provide potent cues to the 3-D orientation (tilt and slant) of planar surfaces. Previous studies have described neurons in both dorsal and ventral stream areas that are selective for surface tilt based on one or more of these gradient cues. However, relatively little is known about whether single neurons provide consistent information about surface orientation from multiple gradient cues. Moreover, it is unclear how neural responses to combinations of surface orientation cues are related to responses to the individual cues. We measured responses of middle temporal (MT) neurons to random dot stimuli that simulated planar surfaces at a variety of tilts and slants. Four cue conditions were tested: disparity, velocity, and texture gradients alone, as well as all three gradient cues combined. Many neurons showed robust tuning for surface tilt based on disparity and velocity gradients, with relatively little selectivity for texture gradients. Some neurons showed consistent tilt preferences for disparity and velocity cues, whereas others showed large discrepancies. Responses to the combined stimulus were generally well described as a weighted linear sum of responses to the individual cues, even when disparity and velocity preferences were discrepant. These findings suggest that area MT contains a rudimentary representation of 3-D surface orientation based on multiple cues, with single neurons implementing a simple cue integration rule.

  5. Two-Layer Variable Infiltration Capacity Land Surface Representation for General Circulation Models

    NASA Technical Reports Server (NTRS)

    Xu, L.

    1994-01-01

    A simple two-layer variable infiltration capacity (VIC-2L) land surface model suitable for incorporation in general circulation models (GCMs) is described. The model consists of a two-layer characterization of the soil within a GCM grid cell, and uses an aerodynamic representation of latent and sensible heat fluxes at the land surface. The effects of GCM spatial subgrid variability of soil moisture and a hydrologically realistic runoff mechanism are represented in the soil layers. The model was tested using long-term hydrologic and climatalogical data for Kings Creek, Kansas to estimate and validate the hydrological parameters. Surface flux data from three First International Satellite Land Surface Climatology Project Field Experiments (FIFE) intensive field compaigns in the summer and fall of 1987 in central Kansas, and from the Anglo-Brazilian Amazonian Climate Observation Study (ABRACOS) in Brazil were used to validate the mode-simulated surface energy fluxes and surface temperature.

  6. Is land surface processes representation a possible weak link in current Regional Climate Models?

    NASA Astrophysics Data System (ADS)

    Davin, Edouard L.; Maisonnave, Eric; Seneviratne, Sonia I.

    2016-07-01

    The representation of land surface processes and fluxes in climate models critically affects the simulation of near-surface climate over land. Here we present an evaluation of COSMO-CLM2, a model which couples the COSMO-CLM Regional Climate Model to the Community Land Model (CLM4.0). CLM4.0 provides a more detailed representation of land processes compared to the native land surface scheme in COSMO-CLM. We perform historical reanalysis-driven simulations over Europe with COSMO-CLM2 following the EURO-CORDEX intercomparison protocol. We then evaluate simulations performed with COSMO-CLM2, the standard COSMO-CLM and other EURO-CORDEX RCMs against various observational datasets of temperature, precipitation and surface fluxes. Overall, the results indicate that COSMO-CLM2 outperforms both the standard COSMO-CLM and the other EURO-CORDEX models in simulating sensible, latent and surface radiative fluxes as well as 2-meter temperature across different seasons and regions. The performance improvement is particularly strong for turbulent fluxes and for daily maximum temperatures and more modest for daily minimum temperature, suggesting that land surface processes affect daytime even more than nighttime conditions. COSMO-CLM2 also alleviates a long-standing issue of overestimation of interannual summer temperature variability present in most EURO-CORDEX RCMs. Finally, we show that several factors contribute to these improvements, including the representation of evapotranspiration, radiative fluxes and ground heat flux. Overall, these results demonstrate that land processes represent a key area of development to tackle current deficiencies in RCMs.

  7. Molecular dynamics-based triangulation algorithm of free-form parametric surfaces for computer-aided engineering

    NASA Astrophysics Data System (ADS)

    Zheleznyakova, A. L.

    2015-05-01

    A new computational approach for automated triangulation of Computer-Aided Design (CAD) surface models, applicable to various CFD (Computational Fluid Dynamics) problems of practical interest is proposed. The complex shaped product configurations are represented by a set of Non-Uniform Rational B-Splines (NURBS) surface patches. The suggested technique is based on the molecular dynamics method. The main idea of the approach is that the mesh nodes are considered as similarly charged interacting particles which move within the region to be meshed under the influence of internal (such as particle-particle interaction forces) and external forces as well as optional additional forces. Moreover, the particles experience a medium resistance due to which the system comes to equilibrium within a relatively short period of time. The proposed 3D surface mesh generation algorithm uses a parametric NURBS representation as initial definition of the domain boundary. This method first distributes the interacting nodes into optimal locations in the parametric domain of the NURBS surface patch using molecular dynamics simulation. Then, the well-shaped triangles can be created after connecting the nodes by Delaunay triangulation. Finally, the mapping from parametric space to 3D physical space is performed. Since the presented interactive algorithm allows to control the distance between a pair of nodes depending on the curvature of the NURBS surface, the method generates high quality triangular mesh. The algorithm enables to produce uniform mesh, as well as anisotropic adaptive mesh with refinement in the large gradient regions. The mesh generation approach has the abilities to preserve the representation accuracy of the input geometry model, create a close relationship between geometry modeling and grid generation process, be automated to a large degree. Some examples are considered in order to illustrate the method's ability to generate a surface mesh for a complicated CAD model.

  8. Robust Representation of Integrated Surface-subsurface Hydrology at Watershed Scales

    NASA Astrophysics Data System (ADS)

    Painter, S. L.; Tang, G.; Collier, N.; Jan, A.; Karra, S.

    2015-12-01

    A representation of integrated surface-subsurface hydrology is the central component to process-rich watershed models that are emerging as alternatives to traditional reduced complexity models. These physically based systems are important for assessing potential impacts of climate change and human activities on groundwater-dependent ecosystems and water supply and quality. Integrated surface-subsurface models typically couple three-dimensional solutions for variably saturated flow in the subsurface with the kinematic- or diffusion-wave equation for surface flows. The computational scheme for coupling the surface and subsurface systems is key to the robustness, computational performance, and ease-of-implementation of the integrated system. A new, robust approach for coupling the subsurface and surface systems is developed from the assumption that the vertical gradient in head is negligible at the surface. This tight-coupling assumption allows the surface flow system to be incorporated directly into the subsurface system; effects of surface flow and surface water accumulation are represented as modifications to the subsurface flow and accumulation terms but are not triggered until the subsurface pressure reaches a threshold value corresponding to the appearance of water on the surface. The new approach has been implemented in the highly parallel PFLOTRAN (www.pflotran.org) code. Several synthetic examples and three-dimensional examples from the Walker Branch Watershed in Oak Ridge TN demonstrate the utility and robustness of the new approach using unstructured computational meshes. Representation of solute transport in the new approach is also discussed. Notice: This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC0500OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid

  9. An analysis of the accuracy of an initial value representation surface hopping wave function in the interaction and asymptotic regions.

    PubMed

    Sergeev, Alexey; Herman, Michael F

    2006-07-14

    The behavior of an initial value representation surface hopping wave function is examined. Since this method is an initial value representation for the semiclassical solution of the time independent Schrodinger equation for nonadiabatic problems, it has computational advantages over the primitive surface hopping wave function. The primitive wave function has been shown to provide transition probabilities that accurately compare with quantum results for model problems. The analysis presented in this work shows that the multistate initial value representation surface hopping wave function should approach the primitive result in asymptotic regions and provide transition probabilities with the same level of accuracy for scattering problems as the primitive method.

  10. Quantification of the errors associated with the representation of surface emissivity in the RRTMG_LW

    NASA Astrophysics Data System (ADS)

    Cheng, Hongze; Chen, Xiuhong; Huang, Xianglei

    2016-09-01

    Recent studies have shown that representation of surface spectral emissivity has a non-negligible impact on the polar radiation budget and on simulated climate. This fact motivates the inclusion of surface spectral emissivity into the radiative transfer scheme employed in the climate models. Using a line-by-line radiative transfer model, LBLRTM, as a benchmark, we quantify the errors due to the approximation of surface spectral emissivity in the RRTMG_LW, a radiation scheme widely used by climate models and numerical forecast models. Error quantifications are done using representative sounding profiles in the tropics, mid-latitude summer, sub-arctic winter and Sahara desert interfaced with either ocean or desert spectral emissivities. Though including surface emissivity causes little difference in broadband outgoing longwave radiation, it can cause noticeable differences in longwave radiative cooling rate from surface to 700 hPa. Compared to the benchmark, the largest deviation in radiative cooling rate usually happens at the lowest atmospheric layers next to the surface, ranging from -0.23 K/day to 0.19 K/day with the largest fractional difference being -16.22%. The discrepancies caused solely by the representation of surface emissivity are confined at the lowest atmospheric layer. Using the emissivity at the diffusive angle or the hemispherically averaged emissivity can affect the calculation accuracy, especially for strongly anisotropic surface emission. The band-by-band contribution to the discrepancies between the RRTMG_LW and benchmark reveals compensating errors among the bands used in the RRTMG_LW.

  11. Wearing the T-shirt: an exploration of the ideological underpinnings of visual representations of the African body with HIV or AIDS.

    PubMed

    Bates, Annwen E

    2007-04-01

    The article takes a hermeneutic approach to exploring a selection of visual representations of the African body in relation to the issue of HIV and AIDS in Africa. In particular, it argues that the trope of 'deficiency' ('lack'), wherein Africa is constructed as dirty, degenerate, decaying and dying, continues in visual representations aimed at a northern or UK audience. In contrast, examples of public health material aimed at a South African audience present a postcolonial counter-discourse where the African body is empowered rather than deficient. These two assumptions and their accompanying visuals parallel two differing narratives about HIV and AIDS in Africa. The article explores the ideological underpinnings of those narratives in four sections: 1) Paper-thin facts presents certain attitudes about Africa and the African body that have come into currency in relation to colonialism; 2) A matter of mor(t)ality examines the relationship between morality and the mortality of the African body; 3) The legacies endure analyses selected images aimed at a potential donor, UK audience with reference to the ideologies proposed in the previous sections; and 4) Wearing the T-shirt engages with the proposed counter-discourse and its visual representations, as evident in a selection of South African public health material.

  12. Noah-MP-Crop: Enhancing cropland representation in the community land surface modeling system

    NASA Astrophysics Data System (ADS)

    Liu, X.; Chen, F.; Barlage, M. J.; Zhou, G.; Niyogi, D.

    2015-12-01

    Croplands are important in land-atmosphere interactions and in modifying local and regional weather and climate. Despite their importance, croplands are poorly represented in the current version of the coupled Weather Research and Forecasting (WRF)/ Noah land-surface modeling system, resulting in significant surface temperature and humidity biases across agriculture- dominated regions of the United States. This study aims to improve the WRF weather forecasting and regional climate simulations during the crop growing season by enhancing the representation of cropland in the Noah-MP land model. We introduced dynamic crop growth parameterization into Noah-MP and evaluated the enhanced model (Noah-MP-Crop) at both the field and regional scales with multiple crop biomass datasets, surface fluxes and soil moisture/temperature observations. We also integrated a detailed cropland cover map into WRF, enabling the model to simulate corn and soybean field across the U.S. Great Plains. Results show marked improvement in the Noah-MP-Crop performance in simulating leaf area index (LAI), crop biomass, soil temperature, and surface fluxes. Enhanced cropland representation is not only crucial for improving weather forecasting but can also help assess potential impacts of weather variability on regional hydrometeorology and crop yields. In addition to its applications to WRF, Noah-MP-Crop can be applied in high-spatial-resolution regional crop yield modeling and drought assessments

  13. A schema for knowledge representation and its implementation in a computer-aided design and manufacturing system

    SciTech Connect

    Tamir, D.E.

    1989-01-01

    Modularity in the design and implementation of expert systems relies upon cooperation among the expert systems and communication of knowledge between them. A prerequisite for an effective modular approach is some standard for knowledge representation to be used by the developers of the different modules. In this work the author presents a schema for knowledge representation, and apply this schema in the design of a rule-based expert system. He also implements a cooperative expert system using the proposed knowledge representation method. A knowledge representation schema is a formal specification of the internal, conceptual, and external components of a knowledge base, each specified in a separate schema. The internal schema defines the structure of a knowledge base, the conceptual schema defines the concepts, and the external schema formalizes the pragmatics of a knowledge base. The schema is the basis for standardizing knowledge representation systems and it is used in the various phases of design and specification of the knowledge base. A new model of knowledge representation based on a pattern recognition interpretation of implications is developed. This model implements the concept of linguistic variables and can, therefore, emulate human reasoning with linguistic imprecision. The test case for the proposed schema of knowledge representation is a system is a cooperative expert system composed of two expert systems. This system applies a pattern recognition interpretation of a generalized one-variable implication with linguistic variables.

  14. Sorting of Single Biomolecules based on Fourier Polar Representation of Surface Enhanced Raman Spectra

    PubMed Central

    Leray, Aymeric; Brulé, Thibault; Buret, Mickael; Colas des Francs, Gérard; Bouhelier, Alexandre; Dereux, Alain; Finot, Eric

    2016-01-01

    Surface enhanced Raman scattering (SERS) spectroscopy becomes increasingly used in biosensors for its capacity to detect and identify single molecules. In practice, a large number of SERS spectra are acquired and reliable ranking methods are thus essential for analysing all these data. Supervised classification strategies, which are the most effective methods, are usually applied but they require pre-determined models or classes. In this work, we propose to sort SERS spectra in unknown groups with an alternative strategy called Fourier polar representation. This non-fitting method based on simple Fourier sine and cosine transforms produces a fast and graphical representation for sorting SERS spectra with quantitative information. The reliability of this method was first investigated theoretically and numerically. Then, its performances were tested on two concrete biological examples: first with single amino-acid molecule (cysteine) and then with a mixture of three distinct odorous molecules. The benefits of this Fourier polar representation were highlighted and compared to the well-established statistical principal component analysis method. PMID:26833130

  15. Sorting of Single Biomolecules based on Fourier Polar Representation of Surface Enhanced Raman Spectra

    NASA Astrophysics Data System (ADS)

    Leray, Aymeric; Brulé, Thibault; Buret, Mickael; Colas Des Francs, Gérard; Bouhelier, Alexandre; Dereux, Alain; Finot, Eric

    2016-02-01

    Surface enhanced Raman scattering (SERS) spectroscopy becomes increasingly used in biosensors for its capacity to detect and identify single molecules. In practice, a large number of SERS spectra are acquired and reliable ranking methods are thus essential for analysing all these data. Supervised classification strategies, which are the most effective methods, are usually applied but they require pre-determined models or classes. In this work, we propose to sort SERS spectra in unknown groups with an alternative strategy called Fourier polar representation. This non-fitting method based on simple Fourier sine and cosine transforms produces a fast and graphical representation for sorting SERS spectra with quantitative information. The reliability of this method was first investigated theoretically and numerically. Then, its performances were tested on two concrete biological examples: first with single amino-acid molecule (cysteine) and then with a mixture of three distinct odorous molecules. The benefits of this Fourier polar representation were highlighted and compared to the well-established statistical principal component analysis method.

  16. Mediating social representations using a cartoon narrative in the context of HIV/AIDS: the AmaQhawe Family Project in South Africa.

    PubMed

    Petersen, Inge; Mason, Andy; Bhana, Arvin; Bell, Carl C; McKay, Mary

    2006-03-01

    Using findings from the formative evaluation of the adaptation of the Collaborative HIV/AIDS Adolescent Mental Health Programme (CHAMP) family-based intervention in South Africa, known as the 'AmaQhawe Family Project', the potential role of 'micro-media' using a cartoon narrative for promoting health-enhancing behaviour change is explored. In particular, the cartoon narrative was found to be a useful medium for informing the development and diffusion of health-enhancing social representations that shape the potential for health-related behaviour change.

  17. Aluminum runway surface as possible aid to aircraft braking

    NASA Technical Reports Server (NTRS)

    Miller, C. D.; Pinkel, I. I.

    1973-01-01

    Several concepts are described for use singly or in combination to improve aircraft braking. All involve a thin layer of aluminum covering all or part of the runway. Advantage would derive from faster heat conduction from the tire-runway interface. Heating of tread surface with consequent softening and loss of friction coefficient should be reduced. Equations are developed indicating that at least 99 percent of friction heat should flow into the aluminum. Preliminary test results indicate a coefficient of sliding friction of 1.4, with predictably slight heating of tread. Elimination of conventional brakes is at least a remote possibility.

  18. A finite element surface impedance representation for steady-state problems

    NASA Technical Reports Server (NTRS)

    Kalinowski, A. J.

    1986-01-01

    A procedure for determining the scattered pressure field resulting from a monochromatic harmonic wave that is incident upon a layer energy absorbing structure is treated. The situation where the structure is modeled with finite elements and the surrounding acoustic medium (water or air) is represented with either acoustic finite elements, or some type of boundary integral formulation, is considered. Finite element modeling problems arise when the construction of the structure, at the fluid structure interface, are nonhomogeneous and in particular, when the inhomogeneities are small relative to the acoustic wave length. An approximate procedure is presented for replacing the detailed microscopic representation of the layered surface configuration with an equivalent simple surface impedance finite element, which is especially designed to work only at limited frequencies. An example problem is presented using NASTRAN. However, the procedure is general enough to adapt to practically any finite element code having a steady state option.

  19. Multivariate Tensor-based Morphometry on Surfaces: Application to Mapping Ventricular Abnormalities in HIV/AIDS

    PubMed Central

    Wang, Yalin; Zhang, Jie; Gutman, Boris; Chan, Tony F.; Becker, James T.; Aizenstein, Howard J.; Lopez, Oscar L.; Tamburo, Robert J.; Toga, Arthur W.; Thompson, Paul M.

    2010-01-01

    Here we developed a new method, called multivariate tensor-based surface morphometry (TBM), and applied it to study lateral ventricular surface differences associated with HIV/AIDS. Using concepts from differential geometry and the theory of differential forms, we created mathematical structures known as holomorphic one-forms, to obtain an efficient and accurate conformal parameterization of the lateral ventricular surfaces in the brain. The new meshing approach also provides a natural way to register anatomical surfaces across subjects, and improves on prior methods as it handles surfaces that branch and join at complex 3D junctions. To analyze anatomical differences, we computed new statistics from the Riemannian surface metrics - these retain multivariate information on local surface geometry. We applied this framework to analyze lateral ventricular surface morphometry in 3D MRI data from 11 subjects with HIV/AIDS and 8 healthy controls. Our method detected a 3D profile of surface abnormalities even in this small sample. Multivariate statistics on the local tensors gave better effect sizes for detecting group differences, relative to other TBM-based methods including analysis of the Jacobian determinant, the largest and smallest eigenvalues of the surface metric, and the pair of eigenvalues of the Jacobian matrix. The resulting analysis pipeline may improve the power of surface-based morphometry studies of the brain. PMID:19900560

  20. On the representation of the stability region in oscillation problems with the aid of the Hurwitz determinants

    NASA Technical Reports Server (NTRS)

    Sponder, E W

    1952-01-01

    This report concerns the use of the Hurwitz determinants in defining boundaries of regions where oscillatory phenomena are to be stable or unstable. A simplification is suggested as an aid in reducing the computations usually required, although it is emphasized that point checks in the various regions defined are required using the complete set of Hurwitz determinants or some other complete stability determination.

  1. Do stigma, blame and stereotyping contribute to unsafe sexual behaviour? A test of claims about the spread of HIV/AIDS arising from social representation theory and the AIDS risk reduction model.

    PubMed

    Riley, Gerard Anthony; Baah-Odoom, Dinah

    2010-08-01

    In the context of social representation theory and the AIDS risk reduction model, it has been claimed that stigmatizing, blaming and stereotyping attitudes make people feel less at risk of contracting HIV/AIDS, and that this, in turn, results in them taking fewer precautions in their sexual behaviour. Previous research has failed to provide convincing evidence to support these claims. The present study provided a test of the claims that addressed some of the methodological issues identified in the earlier research. A sample of 460 young people from Ghana, ranging in age from 15 to 28 years (mean=18), completed a questionnaire that measured the relevant constructs. The results supported the claims in relation to stigmatizing and intended sexual risk behaviour, but not stigmatizing and actual sexual risk behaviour. Although the latter two were correlated, this was not mediated by reduced perceptions of vulnerability. Claims in relation to blaming and stereotyping were not supported. Contrary to expectation, specific blaming and stereotyping attitudes that constructed HIV/AIDS as a sexual disease were associated with safer intended sexual behaviour, and this relationship was mediated by feeling at greater risk.

  2. Evaluation of the Surface Representation of the Greenland Ice Sheet in a General Circulation Model

    NASA Technical Reports Server (NTRS)

    Cullather, Richard I.; Nowicki, Sophie M. J.; Zhao, Bin; Suarez, Max J.

    2014-01-01

    Simulated surface conditions of the Goddard Earth Observing System model, version 5 (GEOS 5) atmospheric general circulation model (AGCM) are examined for the contemporary Greenland Ice Sheet (GrIS). A surface parameterization that explicitly models surface processes including snow compaction, meltwater percolation and refreezing, and surface albedo is found to remedy an erroneous deficit in the annual net surface energy flux and provide an adequate representation of surface mass balance (SMB) in an evaluation using simulations at two spatial resolutions. The simulated 1980-2008 GrIS SMB average is 24.7+/-4.5 cm yr(- 1) water-equivalent (w.e.) at.5 degree model grid spacing, and 18.2+/-3.3 cm yr(- 1) w.e. for 2 degree grid spacing. The spatial variability and seasonal cycle of the simulation compare favorably to recent studies using regional climate models, while results from 2 degree integrations reproduce the primary features of the SMB field. In comparison to historical glaciological observations, the coarser resolution model overestimates accumulation in the southern areas of the GrIS, while the overall SMB is underestimated. These changes relate to the sensitivity of accumulation and melt to the resolution of topography. The GEOS-5 SMB fields contrast with available corresponding atmospheric models simulations from the Coupled Model Intercomparison Project (CMIP5). It is found that only a few of the CMIP5 AGCMs examined provide significant summertime runoff, a dominant feature of the GrIS seasonal cycle. This is a condition that will need to be remedied if potential contributions to future eustatic change from polar ice sheets are to be examined with GCMs.

  3. Surface and semantic processing of cellular transport representations by high school students with low and high prior knowledge

    NASA Astrophysics Data System (ADS)

    Cook, Michelle Patrick

    The purpose of this study was to examine the influence of prior knowledge of cell transport processes on how students viewed and interpreted visual representations related to that topic. The participants were high school students (n=65) enrolled in Advanced Placement biology. Prior knowledge was assessed using a modified version of the Diffusion and Osmosis Diagnostic Test (Odom & Barrow, 1995). Eye movements were measured to reveal how students distribute their visual attention as they perceive and interpret graphics; in addition, interviews and questionnaires were employed to provide more interpretive data sources. The first manuscript of the study investigates the relationship between prior knowledge and students' ability to perceive salient features and interpret graphic representations of cellular transport. The results from eye tracking data, interviews, and questionnaire responses were triangulated and revealed differences in how high and low prior knowledge students attended to and interpreted various features of the graphic representations. Without adequate domain knowledge, low prior knowledge students focused on surface features of the graphics to build an understanding of the concepts represented. High prior knowledge students, with more abundant and better organized domain knowledge, were more likely to attend to thematically relevant content in the graphics and construct deeper understandings. The second manuscript of the study examines the influence of prior knowledge on how students transitioned among the macroscopic and molecular representations of selected graphics. Eye tracking and sequential analysis results indicated that high prior knowledge students transitioned more frequently between the molecular representations, where as low prior knowledge students transitioned more frequently between the macroscopic representations. In addition, low prior knowledge students transitioned more frequently between macroscopic and molecular representations

  4. Towards a more detailed representation of the energy balance in a coupled land surface model

    NASA Astrophysics Data System (ADS)

    Ryder, J.; Polcher, J.; Luyssaert, S.

    2012-04-01

    factors), age and height of vegetation within the surface tile. There will be the implementation of more than one canopy vegetation layer to simulate the effects of scalar gradients within the canopy for determining, more accurately, the net sensible and latent heat fluxes that are passed to the atmosphere. The model will include representation of characteristics such as in-canopy transport, coupling with sensible heat flux from the soil, a multilayer radiation budget and stomatal resistance, and interaction with the bare soil flux within the canopy space (and also with snow pack). We present how the implicit coupling approach of Polcher et al. (1998) and Best et al. (2004) is to be extended to a multilayer scenario, present initial sensitivity studies and outline future testing scenarios and validation plans.

  5. Incorporation of groundwater pumping in a global Land Surface Model with the representation of human impacts

    NASA Astrophysics Data System (ADS)

    Pokhrel, Yadu N.; Koirala, Sujan; Yeh, Pat J.-F.; Hanasaki, Naota; Longuevergne, Laurent; Kanae, Shinjiro; Oki, Taikan

    2015-01-01

    Observations indicate that groundwater levels are declining in many regions around the world. Simulating such depletion of groundwater at the global scale still remains a challenge because most global Land Surface Models (LSMs) lack the physical representation of groundwater dynamics in general and well pumping in particular. Here we present an integrated hydrologic model, which explicitly simulates groundwater dynamics and pumping within a global LSM that also accounts for human activities such as irrigation and reservoir operation. The model is used to simulate global water fluxes and storages with a particular focus on groundwater withdrawal and depletion in the High Plains Aquifer (HPA) and Central Valley Aquifer (CVA). Simulated global groundwater withdrawal and depletion for the year 2000 are 570 and 330 km3 yr-1, respectively; the depletion agrees better with observations than our previous model result without groundwater representation, but may still contain certain uncertainties and is on the higher side of other estimates. Groundwater withdrawals from the HPA and CVA are ˜22 and ˜9 km3 yr-1, respectively, which are also consistent with the observations of ˜24 and ˜13 km3 yr-1. The model simulates a significant decline in total terrestrial water storage in both regions as caused mainly by groundwater storage depletion. Groundwater table declined by ˜14 cm yr-1 in the HPA during 2003-2010; the rate is even higher (˜71 cm yr-1) in the CVA. These results demonstrate the potential of the developed model to study the dynamic relationship between human water use, groundwater storage, and the entire hydrologic cycle.

  6. Anthropogenic Aerosol Effects on Sea Surface Temperatures: Mixed-Layer Ocean Experiments with Explicit Aerosol Representation

    NASA Astrophysics Data System (ADS)

    Dallafior, Tanja; Folini, Doris; Wild, Martin; Knutti, Reto

    2014-05-01

    Anthropogenic aerosols affect the Earth's radiative balance both through direct and indirect effects. These effects can lead to a reduction of the incoming solar radiation at the surface, i.e. dimming, which may lead to a change in sea surface temperatures (SST) or SST pattern. This, in turn, may affect precipitation patterns. The goal of the present work is to achieve an estimate of the equilibrium SST changes under anthropogenic aerosol forcing since industrialisation. We show preliminary results from mixed-layer ocean (MLO) experiments with explicit aerosol representation performed with ECHAM6-HAM. The (fixed) MLO heat flux into the deep ocean was derived from atmosphere only runs with fixed climatological SSTs (1961-1990 average) and present day (year 2000) aerosols and GHG burdens. Some experiments we repeated with an alternative MLO deep ocean heat flux (based on pre-industrial conditions) to test the robustness of our results with regard to this boundary condition. The maximum surface temperature responses towards anthropogenic aerosol and GHG forcing (separately and combined) were derived on a global and regional scale. The same set of experiments was performed with aerosol and GHG forcings representative of different decades over the past one and a half centuries. This allows to assess how SST patterns at equilibrium changed with changing aerosol (and GHG) forcing. Correlating SST responses with the change in downward clear-sky and all-sky shortwave radiation provides a first estimate of the response to anthropogenic aerosols. Our results show a clear contrast in hemispheric surface temperature response, as expected from the inter-hemispheric asymmetry of aerosol forcing The presented work is part of a project aiming at quantifying the effect of anthropogenic aerosol forcing on SSTs and the consequences for global precipitation patterns. Results from this study will serve as a starting point for further experiments involving a dynamic ocean model, which

  7. The Influence of Machined Surface Microgeometry on Mechanical Hydraulic Removal Mechanism at Ultrasonically Aided EDM Finishing

    NASA Astrophysics Data System (ADS)

    Ghiculescu, D.; Marinescu, N.; Ganatsios, S.; Popa, L.; Seritan, G.

    2016-11-01

    The paper deals with Finite Element Method (FEM) of mechanical-hydraulic component of material removal mechanism at electrical discharge machining aided by ultrasonics (EDM+US) finishing. The influence of two types of crater shapes - produced by commanded and relaxation pulses - is analyzed. Based on FEM results, the ratio between depth and crater diameter is correlated with the consumed power on ultrasonic chain in order to minimize the EDMed surface roughness.

  8. Integrating aerodynamic surface modeling for computational fluid dynamics with computer aided structural analysis, design, and manufacturing

    NASA Technical Reports Server (NTRS)

    Thorp, Scott A.

    1992-01-01

    This presentation will discuss the development of a NASA Geometry Exchange Specification for transferring aerodynamic surface geometry between LeRC systems and grid generation software used for computational fluid dynamics research. The proposed specification is based on a subset of the Initial Graphics Exchange Specification (IGES). The presentation will include discussion of how the NASA-IGES standard will accommodate improved computer aided design inspection methods and reverse engineering techniques currently being developed. The presentation is in viewgraph format.

  9. Intuitive representation of surface properties of biomolecules using BioBlender

    PubMed Central

    2012-01-01

    Background In living cells, proteins are in continuous motion and interaction with the surrounding medium and/or other proteins and ligands. These interactions are mediated by protein features such as electrostatic and lipophilic potentials. The availability of protein structures enables the study of their surfaces and surface characteristics, based on atomic contribution. Traditionally, these properties are calculated by physico-chemical programs and visualized as range of colors that vary according to the tool used and imposes the necessity of a legend to decrypt it. The use of color to encode both characteristics makes the simultaneous visualization almost impossible, requiring these features to be visualized in different images. In this work, we describe a novel and intuitive code for the simultaneous visualization of these properties. Methods Recent advances in 3D animation and rendering software have not yet been exploited for the representation of biomolecules in an intuitive, animated form. For our purpose we use Blender, an open-source, free, cross-platform application used professionally for 3D work. On the basis Blender, we developed BioBlender, dedicated to biological work: elaboration of protein motion with simultaneous visualization of their chemical and physical features. Electrostatic and lipophilic potentials are calculated using physico-chemical software and scripts, organized and accessed through BioBlender interface. Results A new visual code is introduced for molecular lipophilic potential: a range of optical features going from smooth-shiny for hydrophobic regions to rough-dull for hydrophilic ones. Electrostatic potential is represented as animated line particles that flow along field lines, proportional to the total charge of the protein. Conclusions Our system permits visualization of molecular features and, in the case of moving proteins, their continuous perception, calculated for each conformation during motion. Using real world tactile

  10. An investigation of constraint-based component-modeling for knowledge representation in computer-aided conceptual design

    NASA Technical Reports Server (NTRS)

    Kolb, Mark A.

    1990-01-01

    Originally, computer programs for engineering design focused on detailed geometric design. Later, computer programs for algorithmically performing the preliminary design of specific well-defined classes of objects became commonplace. However, due to the need for extreme flexibility, it appears unlikely that conventional programming techniques will prove fruitful in developing computer aids for engineering conceptual design. The use of symbolic processing techniques, such as object-oriented programming and constraint propagation, facilitate such flexibility. Object-oriented programming allows programs to be organized around the objects and behavior to be simulated, rather than around fixed sequences of function- and subroutine-calls. Constraint propagation allows declarative statements to be understood as designating multi-directional mathematical relationships among all the variables of an equation, rather than as unidirectional assignments to the variable on the left-hand side of the equation, as in conventional computer programs. The research has concentrated on applying these two techniques to the development of a general-purpose computer aid for engineering conceptual design. Object-oriented programming techniques are utilized to implement a user-extensible database of design components. The mathematical relationships which model both geometry and physics of these components are managed via constraint propagation. In addition, to this component-based hierarchy, special-purpose data structures are provided for describing component interactions and supporting state-dependent parameters. In order to investigate the utility of this approach, a number of sample design problems from the field of aerospace engineering were implemented using the prototype design tool, Rubber Airplane. The additional level of organizational structure obtained by representing design knowledge in terms of components is observed to provide greater convenience to the program user, and to

  11. Femtosecond laser induced tunable surface transformations on (111) Si aided by square grids diffraction

    SciTech Connect

    Han, Weina; Jiang, Lan; Li, Xiaowei Liu, Yang

    2015-12-21

    We report an extra freedom to modulate the femtosecond laser energy distribution to control the surface ablated structures through a copper-grid mask. Due to the reduced deposited pulse energy by changing the scanning speed or the pulse fluence, a sequential evolution of three distinctly different surface patterns with periodic distributions is formed, namely, striped ripple lines, ripple microdots, and surface modification. By changing the scanning speed, the number of the multiple dots in a lattice can be modulated. Moreover, by exploring the ablation process through the copper grid mask, it shows an abnormal enhanced ablation effect with strong dependence of the diffraction-aided fs laser ablated surface structures on polarization direction. The sensitivity shows a quasi-cosinusoid-function with a periodicity of π/2. Particularly, the connection process of striped ripple lines manifests a preferential formation direction with the laser polarization.

  12. Reconstruction of surfaces from mixed hydrocarbon and PEG components in water: responsive surfaces aid fouling release.

    PubMed

    Cho, Youngjin; Sundaram, Harihara S; Finlay, John A; Dimitriou, Michael D; Callow, Maureen E; Callow, James A; Kramer, Edward J; Ober, Christopher K

    2012-06-11

    Coatings derived from surface active block copolymers (SABCs) having a combination of hydrophobic aliphatic (linear hydrocarbon or propylene oxide-derived groups) and hydrophilic poly(ethlyene glycol) (PEG) side chains have been developed. The coatings demonstrate superior performance against protein adsorption as well as resistance to biofouling, providing an alternative to coatings containing fluorinated side chains as the hydrophobe, thus reducing the potential environmental impact. The surfaces were examined using dynamic water contact angle, captive air-bubble contact angle, atomic force microscopy, X-ray photoelectron spectroscopy, and near-edge X-ray absorption fine structure analysis. The PS(8K)-b-P(E/B)(25K)-b-PI(10K) triblock copolymer precursor (K3) initially dominated the dry surface. In contrast to previous studies with mixed fluorinated/PEG surfaces, these new materials displayed significant surface changes after exposure to water that allowed fouling resistant behavior. PEG groups buried several nanometers below the surface in the dry state were able to occupy the coating surface after placement in water. The resulting surface exhibits a very low contact angle and good antifouling properties that are very different from those of K3. The surfaces are strongly resistant to protein adsorption using bovine serum albumin as a standard protein challenge. Biofouling assays with sporelings of the green alga Ulva and cells of the diatom Navicula showed the level of adhesion was significantly reduced relative to that of a PDMS standard and that of the triblock copolymer precursor of the SABCs.

  13. Evaluation of computer-aided procedure for detecting surface water. [using ERTS-1 data

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Results from an evaluation of a computer-aided procedure for processing ERTS-1 data to detect and locate surface water are presented. The procedure was evaluated using data from a study area in the vicinity of the Lake Somerville area in Washington County, Texas. The procedure consisted of (1) selecting water training fields, (2) aggregating the training samples together and clustering them into unimodal clusters, (3) computing the mean vector and covariance matrix for each cluster, (4) classifying all of the study area into classes corresponding to the clusters using the maximum likelihood classifier, and (5) thresholding out the nonwater pixels.

  14. Efficient generation of sum-of-products representations of high-dimensional potential energy surfaces based on multimode expansions

    NASA Astrophysics Data System (ADS)

    Ziegler, Benjamin; Rauhut, Guntram

    2016-03-01

    The transformation of multi-dimensional potential energy surfaces (PESs) from a grid-based multimode representation to an analytical one is a standard procedure in quantum chemical programs. Within the framework of linear least squares fitting, a simple and highly efficient algorithm is presented, which relies on a direct product representation of the PES and a repeated use of Kronecker products. It shows the same scalings in computational cost and memory requirements as the potfit approach. In comparison to customary linear least squares fitting algorithms, this corresponds to a speed-up and memory saving by several orders of magnitude. Different fitting bases are tested, namely, polynomials, B-splines, and distributed Gaussians. Benchmark calculations are provided for the PESs of a set of small molecules.

  15. Computer-aided detection of lung nodules using outer surface features.

    PubMed

    Demir, Önder; Yılmaz Çamurcu, Ali

    2015-01-01

    In this study, a computer-aided detection (CAD) system was developed for the detection of lung nodules in computed tomography images. The CAD system consists of four phases, including two-dimensional and three-dimensional preprocessing phases. In the feature extraction phase, four different groups of features are extracted from volume of interests: morphological features, statistical and histogram features, statistical and histogram features of outer surface, and texture features of outer surface. The support vector machine algorithm is optimized using particle swarm optimization for classification. The CAD system provides 97.37% sensitivity, 86.38% selectivity, 88.97% accuracy and 2.7 false positive per scan using three groups of classification features. After the inclusion of outer surface texture features, classification results of the CAD system reaches 98.03% sensitivity, 87.71% selectivity, 90.12% accuracy and 2.45 false positive per scan. Experimental results demonstrate that outer surface texture features of nodule candidates are useful to increase sensitivity and decrease the number of false positives in the detection of lung nodules in computed tomography images.

  16. Influence of surface roughness on mechanical properties of two computer-aided design/computer-aided manufacturing (CAD/CAM) ceramic materials.

    PubMed

    Flury, S; Peutzfeldt, A; Lussi, A

    2012-01-01

    The aim of this study was to evaluate the influence of surface roughness on surface hardness (Vickers; VHN), elastic modulus (EM), and flexural strength (FLS) of two computer-aided design/computer-aided manufacturing (CAD/CAM) ceramic materials. One hundred sixty-two samples of VITABLOCS Mark II (VMII) and 162 samples of IPS Empress CAD (IPS) were ground according to six standardized protocols producing decreasing surface roughnesses (n=27/group): grinding with 1) silicon carbide (SiC) paper #80, 2) SiC paper #120, 3) SiC paper #220, 4) SiC paper #320, 5) SiC paper #500, and 6) SiC paper #1000. Surface roughness (Ra/Rz) was measured with a surface roughness meter, VHN and EM with a hardness indentation device, and FLS with a three-point bending test. To test for a correlation between surface roughness (Ra/Rz) and VHN, EM, or FLS, Spearman rank correlation coefficients were calculated. The decrease in surface roughness led to an increase in VHN from (VMII/IPS; medians) 263.7/256.5 VHN to 646.8/601.5 VHN, an increase in EM from 45.4/41.0 GPa to 66.8/58.4 GPa, and an increase in FLS from 49.5/44.3 MPa to 73.0/97.2 MPa. For both ceramic materials, Spearman rank correlation coefficients showed a strong negative correlation between surface roughness (Ra/Rz) and VHN or EM and a moderate negative correlation between Ra/Rz and FLS. In conclusion, a decrease in surface roughness generally improved the mechanical properties of the CAD/CAM ceramic materials tested. However, FLS was less influenced by surface roughness than expected.

  17. Optimal Image Stitching for Concrete Bridge Bottom Surfaces Aided by 3d Structure Lines

    NASA Astrophysics Data System (ADS)

    Liu, Yahui; Yao, Jian; Liu, Kang; Lu, Xiaohu; Xia, Menghan

    2016-06-01

    Crack detection for bridge bottom surfaces via remote sensing techniques is undergoing a revolution in the last few years. For such applications, a large amount of images, acquired with high-resolution industrial cameras close to the bottom surfaces with some mobile platform, are required to be stitched into a wide-view single composite image. The conventional idea of stitching a panorama with the affine model or the homographic model always suffers a series of serious problems due to poor texture and out-of-focus blurring introduced by depth of field. In this paper, we present a novel method to seamlessly stitch these images aided by 3D structure lines of bridge bottom surfaces, which are extracted from 3D camera data. First, we propose to initially align each image in geometry based on its rough position and orientation acquired with both a laser range finder (LRF) and a high-precision incremental encoder, and these images are divided into several groups with the rough position and orientation data. Secondly, the 3D structure lines of bridge bottom surfaces are extracted from the 3D cloud points acquired with 3D cameras, which impose additional strong constraints on geometrical alignment of structure lines in adjacent images to perform a position and orientation optimization in each group to increase the local consistency. Thirdly, a homographic refinement between groups is applied to increase the global consistency. Finally, we apply a multi-band blending algorithm to generate a large-view single composite image as seamlessly as possible, which greatly eliminates both the luminance differences and the color deviations between images and further conceals image parallax. Experimental results on a set of representative images acquired from real bridge bottom surfaces illustrate the superiority of our proposed approaches.

  18. A Global Analytical Representation of the Potential Energy Surface of the FHF(-) Anion.

    PubMed

    Cornaton, Yann; Marquardt, Roberto

    2016-08-04

    A global analytical representation of the potential energy hypersurface of the lowest adiabatic electronic state of the FHF(-) anion is derived from ab initio calculations at the coupled cluster level of theory with full single and double and perturbative triple excitations using explicitly correlated atomic basis functions. The new compact function of interatomic distances combines covalent short-range and long-range electrostatic interaction forms and assesses accurately both the lowest reaction channels between the F(-) and HF fragments, with reaction enthalpies to within 1 kJ mol(-1), as well as vibrational terms to within 1.5 cm(-1) deviation from experimental values.

  19. Critique of Macro Flow/Damage Surface Representations for Metal Matrix Composites Using Micromechanics

    NASA Technical Reports Server (NTRS)

    Lissenden, Cliff J.; Arnold, Steven M.

    1996-01-01

    Guidance for the formulation of robust, multiaxial, constitutive models for advanced materials is provided by addressing theoretical and experimental issues using micromechanics. The multiaxial response of metal matrix composites, depicted in terms of macro flow/damage surfaces, is predicted at room and elevated temperatures using an analytical micromechanical model that includes viscoplastic matrix response as well as fiber-matrix debonding. Macro flow/damage surfaces (i.e., debonding envelopes, matrix threshold surfaces, macro 'yield' surfaces, surfaces of constant inelastic strain rate, and surfaces of constant dissipation rate) are determined for silicon carbide/titanium in three stress spaces. Residual stresses are shown to offset the centers of the flow/damage surfaces from the origin and their shape is significantly altered by debonding. The results indicate which type of flow/damage surfaces should be characterized and what loadings applied to provide the most meaningful experimental data for guiding theoretical model development and verification.

  20. Surface plasmon resonance aided electrochemical immunosensor for CK-MB determination in undiluted serum samples

    PubMed Central

    Garay, Fernando; Kisiel, Greggory; Fang, Aiping; Lindner, Ernő

    2010-01-01

    This article presents a simple chronoamperometric immunosensor for the quantitative assessment of creatine kinase MB (CK-MB) in 50 µL undiluted serum samples. The immunosensor consists of gold working and counter electrodes patterned onto a glass chip by thin-film photolithography and an external Ag|AgCl reference electrode. The detection limit (DL) of the chronoamperometric method is 13 ng mL−1 (DL = 2×RMSD/S, where RMSD is the residual mean standard deviation of the measured points around a calibration curve with a slope of S). In spiked serum samples, the response was linear up to 300 ng mL−1 of CK-MB. A surface plasmon resonance (SPR) system with simultaneous electrochemical detection (EC-SPR) aided the development of the sandwich immunoassay. Real-time monitoring of the SPR signal was used to optimize the capture antibody immobilization, CK-MB and detection antibody binding, as well as to minimize the nonspecific adsorption of serum proteins to the sensor surface. The detection antibody has been labeled with alkaline phosphatase (ALP) enzyme for sensitive electrochemical detection. ALP catalyzes the hydrolysis of ascorbic acid phosphate and generates ascorbic acid, which is measured chronoamperometrically. The electrochemical immunoassay for CK-MB was less sensitive to nonspecific adsorption related interferences, had a better detection limit, and required a lower volume of sample than the SPR method. PMID:20449577

  1. Inner stationary phase point contribution of physical optic in terms of the modified edge representation line integrals (curved surfaces)

    NASA Astrophysics Data System (ADS)

    Rodriguez, Luis; Yukimasa, Koji; Shijo, Tetsu; Ando, Makoto

    2007-12-01

    The unique concept of the modified edge representation (MER) was proposed for the surface to the line integral reduction of the physical optic (PO). The equivalence between the MER line and the PO surface integration was analytically derived by using the Stokes theorem relations as well as asymptotic treatments, for the smooth scattering surfaces without inner stationary phase points (SPP). Later on, for the planar surface, the MER line integration around the inner SPP was investigated, and it was identified as the scattering geometrical optics (SGO). In this paper, findings related with the MER line integration around the inner SPP are extended to curved surfaces. The accuracy and the applicability of the SGO extraction in terms of the MER line integration are numerically investigated for different radii of curvatures of the scattering surfaces. Authors introduce a geometrical criterion for the applicability of the method. The MER line integration provides an alternative way to the stationary phase method or the classical geometrical optics for calculating SGO. In addition, this numerical result indirectly identifies the entity of the MER line integration along the periphery of the scattering illuminated region, irrespective of the position of observer, as not other than diffraction.

  2. System maintenance manual for master modeling of aerodynamic surfaces by three-dimensional explicit representation

    NASA Technical Reports Server (NTRS)

    Gibson, A. F.

    1983-01-01

    A system of computer programs has been developed to model general three-dimensional surfaces. Surfaces are modeled as sets of parametric bicubic patches. There are also capabilities to transform coordinate to compute mesh/surface intersection normals, and to format input data for a transonic potential flow analysis. A graphical display of surface models and intersection normals is available. There are additional capabilities to regulate point spacing on input curves and to compute surface intersection curves. Internal details of the implementation of this system are explained, and maintenance procedures are specified.

  3. Utilizing CLASIC observations and multiscale models to study the impact of improved Land surface representation on modeling cloud- convection

    SciTech Connect

    Niyogi, Devdutta S.

    2013-06-07

    The CLASIC experiment was conducted over the US southern great plains (SGP) in June 2007 with an objective to lead an enhanced understanding of the cumulus convection particularly as it relates to land surface conditions. This project was design to help assist with understanding the overall improvement of land atmosphere convection initiation representation of which is important for global and regional models. The study helped address one of the critical documented deficiency in the models central to the ARM objectives for cumulus convection initiation and particularly under summer time conditions. This project was guided by the scientific question building on the CLASIC theme questions: What is the effect of improved land surface representation on the ability of coupled models to simulate cumulus and convection initiation? The focus was on the US Southern Great Plains region. Since the CLASIC period was anomalously wet the strategy has been to use other periods and domains to develop the comparative assessment for the CLASIC data period, and to understand the mechanisms of the anomalous wet conditions on the tropical systems and convection over land. The data periods include the IHOP 2002 field experiment that was over roughly same domain as the CLASIC in the SGP, and some of the DOE funded Ameriflux datasets.

  4. Improving the Representation of the Nocturnal Near-Neutral Surface Layer in the Urban Environment with a Mesoscale Atmospheric Model

    NASA Astrophysics Data System (ADS)

    Husain, Syed Zahid; Bélair, Stéphane; Mailhot, Jocelyn; Leroyer, Sylvie

    2013-06-01

    A new approach to improve the representation of surface processes in the Global Environmental Multiscale (GEM) atmospheric model associated with the exchanges between the urban canopy and the atmosphere is presented. Effects of the urban canopy on the evolution of surface-layer wind, temperature, moisture, and turbulence are directly parametrized in order to allow realistic interactions between the canopy elements (i.e., roofs, roads, and walls) and the atmosphere at GEM's multiple vertical levels that are positioned inside the canopy. Surface energy budgets as implemented in the Town Energy Balance (TEB) scheme have been used to determine temperatures of the urban canopy elements for the proposed multilayer scheme. Performance of the multilayer scheme is compared against standard implementations of the TEB scheme for one nighttime intensive observation period of the Joint Urban 2003 experiment held in Oklahoma City, USA. Although the new approach is found to have a negligible impact on urban surface-layer wind profiles, it improves the prediction of near-neutral nocturnal profiles of potential temperature close to the surface. The urban heat island effect is simulated with a better accuracy by the multilayer approach. The horizontal temperature gradient across the central business district of the city along the direction of flow is also reasonably well captured by the proposed scheme.

  5. Multidirectional and Topography-based Dynamic-scale Varifold Representations with Application to Matching Developing Cortical Surfaces.

    PubMed

    Rekik, Islem; Li, Gang; Lin, Weili; Shen, Dinggang

    2016-07-15

    The human cerebral cortex is marked by great complexity as well as substantial dynamic changes during early postnatal development. To obtain a fairly comprehensive picture of its age-induced and/or disorder-related cortical changes, one needs to match cortical surfaces to one another, while maximizing their anatomical alignment. Methods that geodesically shoot surfaces into one another as currents (a distribution of oriented normals) and varifolds (a distribution of non-oriented normals) provide an elegant Riemannian framework for generic surface matching and reliable statistical analysis. However, both conventional current and varifold matching methods have two key limitations. First, they only use the normals of the surface to measure its geometry and guide the warping process, which overlooks the importance of the orientations of the inherently convoluted cortical sulcal and gyral folds. Second, the 'conversion' of a surface into a current or a varifold operates at a fixed scale under which geometric surface details will be neglected, which ignores the dynamic scales of cortical foldings. To overcome these limitations and improve varifold-based cortical surface registration, we propose two different strategies. The first strategy decomposes each cortical surface into its normal and tangent varifold representations, by integrating principal curvature direction field into the varifold matching framework, thus providing rich information of the orientation of cortical folding and better characterization of the complex cortical geometry. The second strategy explores the informative cortical geometric features to perform a dynamic-scale measurement of the cortical surface that depends on the local surface topography (e.g., principal curvature), thereby we introduce the concept of a topography-based dynamic-scale varifold. We tested the proposed varifold variants for registering 12 pairs of dynamically developing cortical surfaces from 0 to 6 months of age. Both

  6. The Representation of Arctic Soils in the Land Surface Model: The Importance of Mosses.

    NASA Astrophysics Data System (ADS)

    Beringer, Jason; Lynch, Amanda H.; Chapin, F. Stuart, III; Mack, Michelle; Bonan, Gordon B.

    2001-08-01

    Mosses dominate the surface cover in high northern latitudes and have the potential to play a key role in modifying the thermal and hydrologic regime of Arctic soils. These modifications in turn feed back to influence surface energy exchanges and hence may affect regional climate. However, mosses are poorly represented in models of the land surface. In this study the NCAR Land Surface Model (LSM) was modified in two ways. First, additional soil texture types including mosses and lichens were added to more realistically represent northern soils. Second, the LSM was also modified so that a different soil texture type could be specified for each layer. Several experiments were performed using climate data from an Arctic tundra site in 1995. The model was run for a homogeneous loam soil column and then also for columns that included moss, lichen, peat, and sand. The addition of a surface layer of moss underlain by peat and loam had a substantial impact on modeled surface processes. First, moss acted as an insulative layer producing cooler summer temperatures (6.9°C lower at 0.5 m) and warmer winter temperatures (2.3°C higher at 0.5 m) when compared with a homogenous loam soil column. Second, a soil column with a moss surface had a greater surface infiltration, leading to greater storage of soil moisture in lower layers when compared with a homogeneous loam column. Last, moss modulated the surface energy exchanges by decreasing soil heat flux (57% in July) and increasing turbulent fluxes of heat (67% in July) and moisture (15% in July). Mosses were also more effective contributors to total latent heating than was a bare loam surface. These results suggest that the addition of moss and the ability to prescribe different soil textures for different soil layers result in a more plausible distribution of heat and water within the column and that these modifications should be incorporated into regional and global climate models.

  7. A Novel Multi-Purpose Matching Representation of Local 3D Surfaces: A Rotationally Invariant, Efficient, and Highly Discriminative Approach With an Adjustable Sensitivity.

    PubMed

    Al-Osaimi, Faisal R

    2016-02-01

    In this paper, a novel approach to local 3D surface matching representation suitable for a range of 3D vision applications is introduced. Local 3D surface patches around key points on the 3D surface are represented by 2D images such that the representing 2D images enjoy certain characteristics which positively impact the matching accuracy, robustness, and speed. First, the proposed representation is complete, in the sense, there is no information loss during their computation. Second, the 3DoF 2D representations are strictly invariant to all the 3DoF rotations. To optimally avail surface information, the sensitivity of the representations to surface information is adjustable. This also provides the proposed matching representation with the means to optimally adjust to a particular class of problems/applications or an acquisition technology. Each 2D matching representation is a sequence of adjustable integral kernels, where each kernel is efficiently computed from a triple of precise 3D curves (profiles) formed by intersecting three concentric spheres with the 3D surface. Robust techniques for sampling the profiles and establishing correspondences among them were devised. Based on the proposed matching representation, two techniques for the detection of key points were presented. The first is suitable for static images, while the second is suitable for 3D videos. The approach was tested on the face recognition grand challenge v2.0, the 3D twins expression challenge, and the Bosphorus data sets, and a superior face recognition performance was achieved. In addition, the proposed approach was used in object class recognition and tested on a Kinect data set.

  8. Modeling plant, microorganisms, and mineral surface competition for soil nitrogen and phosphorus: Competition representations and ecological significance

    NASA Astrophysics Data System (ADS)

    Zhu, Q.; Riley, W. J.; Chambers, J. Q.; Tang, J.

    2014-12-01

    It is widely accepted that terrestrial ecosystem carbon dynamics are strongly coupled and controlled by soil nutrients status. Nutrient availability serves as an indicator of aboveground carbon productivity and ecosystem stability, especially when soils are infertile. In these conditions, plants have to outcompete microorganism and mineral surfaces to acquire nutrients required for photosynthesis, respiration, seed production, defense, etc. It is usually hypothesized that microbes are short-term winners but long-term losers in nutrient competition. Microbes quickly trap available soil nitrogen and phosphorous, thereby preventing nutrient inaccessibility through hydrological leaching and mineral surface adsorption. Over longer temporal scales, nutrients are released into the soil and become available for plant uptake. Despite its ecological significance, nutrient competition is either absent or over-simplified (e.g., assuming all consumers are equally competitive) in terrestrial biogeochemistry models. Here, we aim to test the representation of different competitive strategies and to investigate their ecological consequences with a newly developed biogeochemical model structure. The new model includes three major soil nutrients (ammonia, nitrate, and phosphate) and multiple consumers (plants, microbes, mineral surfaces, nitrifiers, and denitrifiers). We analyze predicted soil carbon, nitrogen, and phosphorus dynamics with three different competitive strategies: (1) plants compete poorly against microorganisms; (2) all consumers are equally competitive; and (3) an explicit Equilibrium Chemical Approximation (ECA; Tang and Riley (2013)) treatment. We find that very different ecosystem states are predicted when assuming different competitive structures, and that the ECA approach provides the best match with a large suite of observational constraints from tropical experimental and transect studies. We conclude that terrestrial biogeochemical models should represent a

  9. Binaural sonar electronic travel aid provides vibrotactile cues for landmark, reflector motion and surface texture classification.

    PubMed

    Kuc, Roman

    2002-10-01

    Electronic travel aids (ETAs) for the blind commonly employ conventional time-of-flight sonars to provide range measurements, but their wide beams prevent accurate determination of object bearing. We describe a binaural sonar that detects objects over a wider bearing interval compared with a single transducer and also determines if the object lies to the left or right of the sonar axis in a robust manner. The sonar employs a pair of Polaroid 6500 ranging modules connected to Polaroid 7000 transducers operating simultaneously in a binaural array configuration. The sonar determines which transducer detects the echo first. An outward vergence angle between the transducers improves the first-echo detection reliability by increasing the delay between the two detected echoes, a consequence of threshold detection. We exploit this left/right detection capability in an ETA that provides vibrotactile feedback. Pager motors mount on both sides of the sonar, possibly worn on the user's wrists. The motor on the same side as the reflecting object vibrates with speed inversely related to range. As the sonar or object moves, vibration patterns provide landmark, motion and texture cues. Orienting the sonar at 45 degrees relative to the travel direction and passing a right-angle corner produces a characteristic vibrational pattern. When pointing the sonar at a moving object, such as a fluttering flag, the motors alternate in a manner to give the user a perception of the object motion. When the sonar translates or rotates to scan a foliage surface, the vibrational patterns are related to the surface scatterer distribution, allowing the user to identify the foliage.

  10. Representation and future projection for surface wind speed over the Euro-Mediterranean region from ENSEMBLES to MED-CORDEX.

    NASA Astrophysics Data System (ADS)

    Dell'Aquila, Alessandro; Calmanti, Sandro

    2014-05-01

    Wind speed has been clearly identified as one of the key climate variables over the Greater Mediterranean region. Interactions with stakeholders, especially in the energy, health and tourism sector, has highlighted the need for more in depth understanding of wind modelling capacities climatological time scale over regions characterised by a complex orography such as Mediterranean region. Regional climate models have a large potential for enhancing the quality of climate projections in the presence of complex orography and in the proximity of coastal areas. Subsequently, we will give here a brief overview of the skill of regional wind simulations in providing reliable representation of surface wind speed in the present climate and consistent projections in future climate scenarios. We start from the regional simulations presented in the EU FP6 ENSEMBLES project and we compare their skill against the more recent results obtained in the framework of MED-CORDEX initiative. The role of an increased horizontal resolution to critically improve the representation of wind speed will be here highlighted.

  11. The development and evaluation of new runoff parameterization representations coupled with Noah Land Surface Model

    NASA Astrophysics Data System (ADS)

    Zheng, Z.; Zhang, W.; Xu, J.

    2011-12-01

    As a key component of the global water cycle, runoff plays an important role in earth climate system by affecting the land surface water and energy balance. Realistic runoff parameterization within land surface model (LSM) is significant for accurate land surface modeling and numerical weather and climate prediction. Hence, optimization and refinement of runoff formulation in LSM can further improve model predictive capability of surface-to-atmosphere fluxes which influences the complex interactions between the land surface and atmosphere. Moreover, the performance of runoff simulation in LSM would essential to drought and flood prediction and warning. In this study, a new runoff parameterization named XXT (Xin'anjiang x TOPMODEL) was developed by introducing the water table depth into the soil moisture storage capacity distribution curve (SMSCC) from Xin'anjiang model for surface runoff calculation improvement and then integrating with a TOPMODEL-based groundwater scheme. Several studies had already found a strong correlation between the water table depth and land surface processes. In this runoff parameterization, the dynamic variation of surface and subsurface runoff calculation is connected in a systematic way through the change of water table depth. The XXT runoff parameterization was calibrated and validated with datasets both from observation and Weather Research & Forecasting model (WRF) outputs, the results with high Nash-efficiency coefficient indicated that it has reliable capability of runoff simulation in different climate regions. After model test, the XXT runoff parameterization is coupled with the unified Noah LSM 3.2 instead of simple water balance model (SWB) in order to alleviate the runoff simulating bias which may lead to poor energy partition and evaporation. The impact of XXT is investigated through application of a whole year (1998) simulation at surface flux site of Champaign, Illinois (40.01°N, 88.37°W). The results show that Noah

  12. A novel representation of chalk hydrology in a land surface model

    NASA Astrophysics Data System (ADS)

    Rahman, Mostaquimur; Rosolem, Rafael

    2016-04-01

    Unconfined chalk aquifers contain a significant portion of water in the United Kingdom. In order to optimize the assessment and management practices of water resources in the region, modelling and monitoring of soil moisture in the unsaturated zone of the chalk aquifers are of utmost importance. However, efficient simulation of soil moisture in such aquifers is difficult mainly due to the fractured nature of chalk, which creates high-velocity preferential flow paths in the unsaturated zone. In this study, the Joint UK Land Environment Simulator (JULES) is applied on a study area encompassing the Kennet catchment in Southern England. The fluxes and states of the coupled water and energy cycles are simulated for 10 consecutive years (2001-2010). We hypothesize that explicit representation for the soil-chalk layers and the inclusion of preferential flow in the fractured chalk aquifers improves the reproduction of the hydrological processes in JULES. In order to test this hypothesis, we propose a new parametrization for preferential flow in JULES. This parametrization explicitly describes the flow of water in soil matrices and preferential flow paths using a simplified approach which can be beneficial for large-scale hydrometeorological applications. We also define the overlaying soil properties obtained from the Harmonized World Soil Database (HWSD) in the model. Our simulation results are compared across spatial scales with measured soil moisture and river discharge, indicating the importance of accounting for the physical properties of the medium while simulating hydrological processes in the chalk aquifers.

  13. 4D Hyperspherical Harmonic (HyperSPHARM) Representation of Surface Anatomy: A Holistic Treatment of Multiple Disconnected Anatomical Structures

    PubMed Central

    Hosseinbor, A. Pasha; Chung, Moo K.; Koay, Cheng Guan; Schaefer, Stacey M.; van Reekum, Carien M.; Schmitz, Lara Peschke; Sutterer, Matt; Alexander, Andrew L.; Davidson, Richard J.

    2015-01-01

    Image-based parcellation of the brain often leads to multiple disconnected anatomical structures, which pose significant challenges for analyses of morphological shapes. Existing shape models, such as the widely used spherical harmonic (SPHARM) representation, assume topological invariance, so are unable to simultaneously parameterize multiple disjoint structures. In such a situation, SPHARM has to be applied separately to each individual structure. We present a novel surface parameterization technique using 4D hyperspherical harmonics in representing multiple disjoint objects as a single analytic function, terming it HyperSPHARM. The underlying idea behind Hyper-SPHARM is to stereographically project an entire collection of disjoint 3D objects onto the 4D hypersphere and subsequently simultaneously parameterize them with the 4D hyperspherical harmonics. Hence, HyperSPHARM allows for a holistic treatment of multiple disjoint objects, unlike SPHARM. In an imaging dataset of healthy adult human brains, we apply HyperSPHARM to the hippocampi and amygdalae. The HyperSPHARM representations are employed as a data smoothing technique, while the HyperSPHARM coefficients are utilized in a support vector machine setting for object classification. HyperSPHARM yields nearly identical results as SPHARM, as will be shown in the paper. Its key advantage over SPHARM lies computationally; Hyper-SPHARM possess greater computational efficiency than SPHARM because it can parameterize multiple disjoint structures using much fewer basis functions and stereographic projection obviates SPHARM's burdensome surface flattening. In addition, HyperSPHARM can handle any type of topology, unlike SPHARM, whose analysis is confined to topologically invariant structures. PMID:25828650

  14. A justification for a nonadiabatic surface hopping Herman-Kluk semiclassical initial value representation of the time evolution operator.

    PubMed

    Wu, Yinghua; Herman, Michael F

    2006-10-21

    A justification is given for the validity of a nonadiabatic surface hopping Herman-Kluk (HK) semiclassical initial value representation (SC-IVR) method. The method is based on a propagator that combines the single surface HK SC-IVR method [J. Chem. Phys. 84, 326 (1986)] and Herman's nonadiabatic semiclassical surface hopping theory [J. Chem. Phys. 103, 8081 (1995)], which was originally developed using the primitive semiclassical Van Vleck propagator. We show that the nonadiabatic HK SC-IVR propagator satisfies the time-dependent Schrodinger equation to the first order of variant Planck's over 2pi and the error is O(variant Planck's over 2pi(2)). As a required lemma, we show that the stationary phase approximation, under current assumptions, has an error term variant Planck's over 2pi(1) order higher than the leading term. Our derivation suggests some changes to the previous development, and it is shown that the numerical accuracy in applications to Tully's three model systems in low energies is improved.

  15. Virtual volume resection using multi-resolution triangular representation of B-spline surfaces.

    PubMed

    Ruskó, László; Mátéka, Ilona; Kriston, András

    2013-08-01

    Computer assisted analysis of organs has an important role in clinical diagnosis and therapy planning. As well as the visualization, the manipulation of 3-dimensional (3D) objects are key features of medical image processing tools. The goal of this work was to develop an efficient and easy to use tool that allows the physician to partition a segmented organ into its segments or lobes. The proposed tool allows the user to define a cutting surface by drawing some traces on 2D sections of a 3D object, cut the object into two pieces with a smooth surface that fits the input traces, and iterate the process until the object is partitioned at the desired level. The tool is based on an algorithm that interpolates the user-defined traces with B-spline surface and computes a binary cutting volume that represents the different sides of the surface. The computation of the cutting volume is based on the multi-resolution triangulation of the B-spline surface. The proposed algorithm was integrated into an open-source medical image processing framework. Using the tool, the user can select the object to be partitioned (e.g. segmented liver), define the cutting surface based on the corresponding medical image (medical image visualizing the internal structure of the liver), cut the selected object, and iterate the process. In case of liver segment separation, the cuts can be performed according to a predefined sequence, which makes it possible to label the temporary as well as the final partitions (lobes, segments) automatically. The presented tool was evaluated for anatomical segment separation of the liver involving 14 cases and virtual liver tumor resection involving one case. The segment separation was repeated 3 different times by one physician for all cases, and the average and the standard deviation of segment volumes were computed. According to the test experiences the presented algorithm proved to be efficient and user-friendly enough to perform free form cuts for liver

  16. [The graphic representation of the temperature field of the skin surface in the orbital area].

    PubMed

    Cherednichenko, V M; Barsukov, V V

    1990-01-01

    The paper describes results of researches on the possibility of graphic presentation of a temperature field of skin surface of the orbital area. A method of liquid crystal thermography and electron thermometry was used for examination of 30 patients with practically healthy eyes. It was shown that graphic presentation of data of liquid crystal thermography and electron thermometry remarkably facilitates documentation and analysis of the results obtained.

  17. a Matrix Model Representation of the Integrable Xxz Heisenberg Chain on Random Surfaces

    NASA Astrophysics Data System (ADS)

    Ambjørn, J.; Sedrakyan, A.

    2013-11-01

    We consider integrable models, i.e. models defined by R-matrices, on random Manhattan lattices (RML). The set of random Manhattan lattices is defined as the set dual to the lattice random surfaces embedded on a regular d-dimensional lattice. As an example we formulate a random matrix model where the partition function reproduces annealed average of the XXZ Heisenberg chain over all RML. A technique is presented which reduces the random matrix integration in partition function to an integration over their eigenvalues.

  18. Large Scale Isosurface Bicubic Subdivision-Surface Wavelets for Representation and Visualization

    SciTech Connect

    Bertram, M.; Duchaineau, M.A.; Hamann, B.; Joy, K.I.

    2000-01-05

    We introduce a new subdivision-surface wavelet transform for arbitrary two-manifolds with boundary that is the first to use simple lifting-style filtering operations with bicubic precision. We also describe a conversion process for re-mapping large-scale isosurfaces to have subdivision connectivity and fair parameterizations so that the new wavelet transform can be used for compression and visualization. The main idea enabling our wavelet transform is the circular symmetrization of the filters in irregular neighborhoods, which replaces the traditional separation of filters into two 1-D passes. Our wavelet transform uses polygonal base meshes to represent surface topology, from which a Catmull-Clark-style subdivision hierarchy is generated. The details between these levels of resolution are quickly computed and compactly stored as wavelet coefficients. The isosurface conversion process begins with a contour triangulation computed using conventional techniques, which we subsequently simplify with a variant edge-collapse procedure, followed by an edge-removal process. This provides a coarse initial base mesh, which is subsequently refined, relaxed and attracted in phases to converge to the contour. The conversion is designed to produce smooth, untangled and minimally-skewed parameterizations, which improves the subsequent compression after applying the transform. We have demonstrated our conversion and transform for an isosurface obtained from a high-resolution turbulent-mixing hydrodynamics simulation, showing the potential for compression and level-of-detail visualization.

  19. Improved representations of coupled soil-canopy processes in the CABLE land surface model (Subversion revision 3432)

    NASA Astrophysics Data System (ADS)

    Haverd, Vanessa; Cuntz, Matthias; Nieradzik, Lars P.; Harman, Ian N.

    2016-09-01

    CABLE is a global land surface model, which has been used extensively in offline and coupled simulations. While CABLE performs well in comparison with other land surface models, results are impacted by decoupling of transpiration and photosynthesis fluxes under drying soil conditions, often leading to implausibly high water use efficiencies. Here, we present a solution to this problem, ensuring that modelled transpiration is always consistent with modelled photosynthesis, while introducing a parsimonious single-parameter drought response function which is coupled to root water uptake. We further improve CABLE's simulation of coupled soil-canopy processes by introducing an alternative hydrology model with a physically accurate representation of coupled energy and water fluxes at the soil-air interface, including a more realistic formulation of transfer under atmospherically stable conditions within the canopy and in the presence of leaf litter. The effects of these model developments are assessed using data from 18 stations from the global eddy covariance FLUXNET database, selected to span a large climatic range. Marked improvements are demonstrated, with root mean squared errors for monthly latent heat fluxes and water use efficiencies being reduced by 40 %. Results highlight the important roles of deep soil moisture in mediating drought response and litter in dampening soil evaporation.

  20. A potential energy surface for the process H2 + H2O yielding H + H + H2O - Ab initio calculations and analytical representation

    NASA Technical Reports Server (NTRS)

    Schwenke, David W.; Walch, Stephen P.; Taylor, Peter R.

    1991-01-01

    Extensive ab initio calculations on the ground state potential energy surface of H2 + H2O were performed using a large contracted Gaussian basis set and a high level of correlation treatment. An analytical representation of the potential energy surface was then obtained which reproduces the calculated energies with an overall root-mean-square error of only 0.64 mEh. The analytic representation explicitly includes all nine internal degrees of freedom and is also well behaved as the H2 dissociates; it thus can be used to study collision-induced dissociation or recombination of H2. The strategy used to minimize the number of energy calculations is discussed, as well as other advantages of the present method for determining the analytical representation.

  1. Automatic representation of the semantic relationships corresponding to a French surface expression

    SciTech Connect

    Zarri, G.P.

    1983-01-01

    The work presented is a preliminary study concerning the automatic translation of French natural language statements into the Reseda semantic metalanguage. The text in natural language is first (pre)processed in order to obtain its syntactic structure. The semantic parsing process begins with marking the triggers, defined as lexical units which call one or more of the predicative patterns allowed for in the metalanguage. The patterns obtained are then merged, and their case slots filled with the elements found in the surface structure according to the predictions associated with the slots. The Reseda project is concerned with the creation and practical exploitation of a system for managing a biographical database using artificial intelligence techniques. 11 references.

  2. Towards a simple representation of chalk hydrology in land surface modelling

    NASA Astrophysics Data System (ADS)

    Rahman, Mostaquimur; Rosolem, Rafael

    2017-01-01

    Modelling and monitoring of hydrological processes in the unsaturated zone of chalk, a porous medium with fractures, is important to optimize water resource assessment and management practices in the United Kingdom (UK). However, incorporating the processes governing water movement through a chalk unsaturated zone in a numerical model is complicated mainly due to the fractured nature of chalk that creates high-velocity preferential flow paths in the subsurface. In general, flow through a chalk unsaturated zone is simulated using the dual-porosity concept, which often involves calibration of a relatively large number of model parameters, potentially undermining applications to large regions. In this study, a simplified parameterization, namely the Bulk Conductivity (BC) model, is proposed for simulating hydrology in a chalk unsaturated zone. This new parameterization introduces only two additional parameters (namely the macroporosity factor and the soil wetness threshold parameter for fracture flow activation) and uses the saturated hydraulic conductivity from the chalk matrix. The BC model is implemented in the Joint UK Land Environment Simulator (JULES) and applied to a study area encompassing the Kennet catchment in the southern UK. This parameterization is further calibrated at the point scale using soil moisture profile observations. The performance of the calibrated BC model in JULES is assessed and compared against the performance of both the default JULES parameterization and the uncalibrated version of the BC model implemented in JULES. Finally, the model performance at the catchment scale is evaluated against independent data sets (e.g. runoff and latent heat flux). The results demonstrate that the inclusion of the BC model in JULES improves simulated land surface mass and energy fluxes over the chalk-dominated Kennet catchment. Therefore, the simple approach described in this study may be used to incorporate the flow processes through a chalk unsaturated

  3. Towards a Process-based Representation of Annual Crops Within the Land Surface Model JULES

    NASA Astrophysics Data System (ADS)

    van den Hoof, C.; Vidale, P.

    2008-05-01

    The purpose of this work is to introduce a generic crop structure within the Joint UK Land surface Exchange Scheme JULES (Cox, 1998) that is able to evaluate the interaction between growing crops and the environment at large scales for a wide range of atmospheric conditions. JULES was designed to simulate land surface processes in natural ecosystems. The importance of representing agricultural land within global biosphere models has been pointed out in many studies (De Noblet-Ducoudre et al., 2004; Bondeau 2005 et al.). Prior to any model development, the sensitivity of JULES to morphological and physiological differences between natural vegetation and crops has been investigated by reparameterising a natural C3 grass into a C3 crop. For a case study of fallow versus wheat at Grignon (France), the model output shows important soil water savings after crop harvest at the beginning of the summer. Owing to the lack of a rooting system, the deeper soil moisture cannot contribute anymore to the moisture flux to the atmosphere. On a shorter timescale, the harvest, and by consequence the sudden appearance of bare soil, also disrupt the energy and momentum fluxes between surface and atmosphere. Having established the sensitivity of the JULES system to a crop-like forcing, some components from the crop model SUCROS (Goudriaan and van Laar, 1994) that are relevant to the global water, energy and carbon cycles, have been introduced in JULES. The new version of JULES, denoted by JULES-SUCROS, incorporates crops and natural vegetation within a single modelling framework, without discontinuity in the photosynthesis-assimilation scheme between both vegetation types. Simulations have been performed with JULES-SUCROS for wheat at the Grignon site in current and doubled CO2 atmospheric conditions. Changing atmospheric conditions in JULES-SUCROS affects the sowing date and the length of the growing season. The results show that the positive effect of the CO2 fertilisation partly

  4. Effect of mosaic representation of vegetation in land surface schemes on simulated energy and carbon balances

    NASA Astrophysics Data System (ADS)

    Li, R.; Arora, V. K.

    2011-06-01

    Energy and carbon balance implications of representing vegetation using a composite or mosaic approach in a land surface scheme are investigated. In the composite approach the attributes of different plant functional types (PFTs) present in a grid cell are aggregated in some fashion for energy and water balance calculations. The resulting physical environmental conditions (including net radiation, soil moisture and soil temperature) are common to all PFTs and affect their ecosystem processes. In the mosaic approach energy and water balance calculations are performed separately for each PFT tile using its own vegetation attributes, so each PFT "sees" different physical environmental conditions and its carbon balance evolves somewhat differently from that in the composite approach. Simulations are performed at selected boreal, temperate and tropical locations to illustrate the differences caused by using the composite versus the mosaic approaches of representing vegetation. Differences in grid averaged primary energy fluxes are generally less than 5 % between the two approaches. Grid-averaged carbon fluxes and pool sizes can, however, differ by as much as 46 %. Simulation results suggest that differences in carbon balance between the two approaches arise primarily through differences in net radiation which directly affects net primary productivity, and thus leaf area index and vegetation biomass.

  5. Effect of mosaic representation of vegetation in land surface schemes on simulated energy and carbon balances

    NASA Astrophysics Data System (ADS)

    Li, R.; Arora, V. K.

    2012-01-01

    Energy and carbon balance implications of representing vegetation using a composite or mosaic approach in a land surface scheme are investigated. In the composite approach the attributes of different plant functional types (PFTs) present in a grid cell are aggregated in some fashion for energy and water balance calculations. The resulting physical environmental conditions (including net radiation, soil moisture and soil temperature) are common to all PFTs and affect their ecosystem processes. In the mosaic approach energy and water balance calculations are performed separately for each PFT tile using its own vegetation attributes, so each PFT "sees" different physical environmental conditions and its carbon balance evolves somewhat differently from that in the composite approach. Simulations are performed at selected boreal, temperate and tropical locations to illustrate the differences caused by using the composite versus mosaic approaches of representing vegetation. These idealized simulations use 50% fractional coverage for each of the two dominant PFTs in a grid cell. Differences in simulated grid averaged primary energy fluxes at selected sites are generally less than 5% between the two approaches. Simulated grid-averaged carbon fluxes and pool sizes at these sites can, however, differ by as much as 46%. Simulation results suggest that differences in carbon balance between the two approaches arise primarily through differences in net radiation which directly affects net primary productivity, and thus leaf area index and vegetation biomass.

  6. Compact Representation of Continuous Energy Surfaces for More Efficient Protein Design.

    PubMed

    Hallen, Mark A; Gainza, Pablo; Donald, Bruce R

    2015-05-12

    In macromolecular design, conformational energies are sensitive to small changes in atom coordinates; thus, modeling the small, continuous motions of atoms around low-energy wells confers a substantial advantage in structural accuracy. However, modeling these motions comes at the cost of a very large number of energy function calls, which form the bottleneck in the design calculations. In this work, we remove this bottleneck by consolidating all conformational energy evaluations into the pre-computation of a local polynomial expansion of the energy about the "ideal" conformation for each low-energy, "rotameric" state of each residue pair. This expansion is called "energy as polynomials in internal coordinates" (EPIC), where the internal coordinates can be side-chain dihedrals, backrub angles, and/or any other continuous degrees of freedom of a macromolecule, and any energy function can be used without adding any asymptotic complexity to the design. We demonstrate that EPIC efficiently represents the energy surface for both molecular-mechanics and quantum-mechanical energy functions, and apply it specifically to protein design for modeling both side chain and backbone degrees of freedom.

  7. Compact representation of continuous energy surfaces for more efficient protein design

    PubMed Central

    Hallen, Mark A.; Gainza, Pablo; Donald, Bruce R.

    2015-01-01

    In macromolecular design, conformational energies are sensitive to small changes in atom coordinates, so modeling the small, continuous motions of atoms around low-energy wells confers a substantial advantage in structural accuracy; however, modeling these motions comes at the cost of a very large number of energy function calls, which form the bottleneck in the design calculation. In this work, we remove this bottleneck by consolidating all conformational energy evaluations into the precomputation of a local polynomial expansion of the energy about the “ideal” conformation for each low-energy, “rotameric” state of each residue pair. This expansion is called Energy as Polynomials in Internal Coordinates (EPIC), where the internal coordinates can be sidechain dihedrals, backrub angles, and/or any other continuous degrees of freedom of a macromolecule, and any energy function can be used without adding any asymptotic complexity to the design. We demonstrate that EPIC efficiently represents the energy surface for both molecular-mechanics and quantum-mechanical energy functions, and apply it specifically to protein design to model both sidechain and backbone degrees of freedom. PMID:26089744

  8. Representation of Glossy Material Surface in Ventral Superior Temporal Sulcal Area of Common Marmosets

    PubMed Central

    Miyakawa, Naohisa; Banno, Taku; Abe, Hiroshi; Tani, Toshiki; Suzuki, Wataru; Ichinohe, Noritaka

    2017-01-01

    The common marmoset (Callithrix jacchus) is one of the smallest species of primates, with high visual recognition abilities that allow them to judge the identity and quality of food and objects in their environment. To address the cortical processing of visual information related to material surface features in marmosets, we presented a set of stimuli that have identical three-dimensional shapes (bone, torus or amorphous) but different material appearances (ceramic, glass, fur, leather, metal, stone, wood, or matte) to anesthetized marmoset, and recorded multiunit activities from an area ventral to the superior temporal sulcus (STS) using multi-shanked, and depth resolved multi-electrode array. Out of 143 visually responsive multiunits recorded from four animals, 29% had significant main effect only of the material, 3% only of the shape and 43% of both the material and the shape. Furthermore, we found neuronal cluster(s), in which most cells: (1) showed a significant main effect in material appearance; (2) the best stimulus was a glossy material (glass or metal); and (3) had reduced response to the pixel-shuffled version of the glossy material images. The location of the gloss-selective area was in agreement with previous macaque studies, showing activation in the ventral bank of STS. Our results suggest that perception of gloss is an important ability preserved across wide range of primate species. PMID:28367117

  9. Optics of the average normal cornea from general and canonical representations of its surface topography.

    PubMed

    Navarro, Rafael; González, Luis; Hernández, José L

    2006-02-01

    Generally, the analysis of corneal topography involves fitting the raw data to a parametric geometric model that includes a regular basis surface, plus some sort of polynomial expansion to adjust the more irregular residual component. So far, these parametric models have been used in their canonical form, ignoring that the observation (keratometric) coordinate system is different from corneal axes of symmetry. Here we propose, instead, to use the canonical form when the topography is referenced to the intrinsic corneal system of coordinates, defined by its principal axes of symmetry. This idea is implemented using the general expression of an ellipsoid to fit the raw data given by the instrument. Then, the position and orientation of the three orthogonal semiaxes of the ellipsoid, which define the intrinsic Cartesian system of coordinates for normal corneas, can be identified by passing to the canonical form, by standard linear algebra. This model has been first validated experimentally obtaining significantly lower values for rms fitting error as compared with previous standard models: spherical, conical, and biconical. The fitting residual was then adjusted by a Zernike polynomial expansion. The topographies of 123 corneas were analyzed obtaining their radii of curvature, conic constants, Zernike coefficients, and the direction and position of the optical axis of the ellipsoid. The results were compared with those obtained using the standard models. The general ellipsoid model provides more negative values for the conic constants and lower apex radii (more prolate shapes) than the standard models applied to the same data. If the data are analyzed using standard models, the resulting mean shape of the cornea is consistent with previous studies, but when using the ellipsoid model we find new interesting features: The mean cornea is a more prolate ellipsoid (apical power 50 D), the direction of the optical axis is about 2.3 degrees nasal, and the residual term shows

  10. Optics of the average normal cornea from general and canonical representations of its surface topography

    NASA Astrophysics Data System (ADS)

    Navarro, Rafael; González, Luis; Hernández, José L.

    2006-02-01

    Generally, the analysis of corneal topography involves fitting the raw data to a parametric geometric model that includes a regular basis surface, plus some sort of polynomial expansion to adjust the more irregular residual component. So far, these parametric models have been used in their canonical form, ignoring that the observation (keratometric) coordinate system is different from corneal axes of symmetry. Here we propose, instead, to use the canonical form when the topography is referenced to the intrinsic corneal system of coordinates, defined by its principal axes of symmetry. This idea is implemented using the general expression of an ellipsoid to fit the raw data given by the instrument. Then, the position and orientation of the three orthogonal semiaxes of the ellipsoid, which define the intrinsic Cartesian system of coordinates for normal corneas, can be identified by passing to the canonical form, by standard linear algebra. This model has been first validated experimentally obtaining significantly lower values for rms fitting error as compared with previous standard models: spherical, conical, and biconical. The fitting residual was then adjusted by a Zernike polynomial expansion. The topographies of 123 corneas were analyzed obtaining their radii of curvature, conic constants, Zernike coefficients, and the direction and position of the optical axis of the ellipsoid. The results were compared with those obtained using the standard models. The general ellipsoid model provides more negative values for the conic constants and lower apex radii (more prolate shapes) than the standard models applied to the same data. If the data are analyzed using standard models, the resulting mean shape of the cornea is consistent with previous studies, but when using the ellipsoid model we find new interesting features: The mean cornea is a more prolate ellipsoid (apical power 50 D), the direction of the optical axis is about 2.3° nasal, and the residual term shows three

  11. Use of the surface-based registration function of computer-aided design/computer-aided manufacturing software in medical simulation software for three-dimensional simulation of orthognathic surgery.

    PubMed

    Kang, Sang-Hoon; Lee, Jae-Won; Kim, Moon-Key

    2013-08-01

    Three-dimensional (3D) computed tomography image models are helpful in reproducing the maxillofacial area; however, they do not necessarily provide an accurate representation of dental occlusion and the state of the teeth. Recent efforts have focused on improvement of dental imaging by replacement of computed tomography with other detailed digital images. Unfortunately, despite the advantages of medical simulation software in dentofacial analysis, diagnosis, and surgical simulation, it lacks adequate registration tools. Following up on our previous report on orthognathic simulation surgery using computer-aided design/computer-aided manufacturing (CAD/CAM) software, we recently used the registration functions of a CAD/CAM platform in conjunction with surgical simulation software. Therefore, we would like to introduce a new technique, which involves use of the registration functions of CAD/CAM software followed by transfer of the images into medical simulation software. This technique may be applicable when using various registration function tools from different software platforms.

  12. Evaluation of land surface model representation of phenology: an analysis of model runs submitted to the NACP Interim Site Synthesis

    NASA Astrophysics Data System (ADS)

    Richardson, A. D.; Nacp Interim Site Synthesis Participants

    2010-12-01

    Phenology represents a critical intersection point between organisms and their growth environment. It is for this reason that phenology is a sensitive and robust integrator of the biological impacts of year-to-year climate variability and longer-term climate change on natural systems. However, it is perhaps equally important that phenology, by controlling the seasonal activity of vegetation on the land surface, plays a fundamental role in regulating ecosystem processes, competitive interactions, and feedbacks to the climate system. Unfortunately, the phenological sub-models implemented in most state-of-the-art ecosystem models and land surface schemes are overly simplified. We quantified model errors in the representation of the seasonal cycles of leaf area index (LAI), gross ecosystem photosynthesis (GEP), and net ecosystem exchange of CO2. Our analysis was based on site-level model runs (14 different models) submitted to the North American Carbon Program (NACP) Interim Synthesis, and long-term measurements from 10 forested (5 evergreen conifer, 5 deciduous broadleaf) sites within the AmeriFlux and Fluxnet-Canada networks. Model predictions of the seasonality of LAI and GEP were unacceptable, particularly in spring, and especially for deciduous forests. This is despite an historical emphasis on deciduous forest phenology, and the perception that controls on spring phenology are better understood than autumn phenology. Errors of up to 25 days in predicting “spring onset” transition dates were common, and errors of up to 50 days were observed. For deciduous sites, virtually every model was biased towards spring onset being too early, and autumn senescence being too late. Thus, models predicted growing seasons that were far too long for deciduous forests. For most models, errors in the seasonal representation of deciduous forest LAI were highly correlated with errors in the seasonality of both GPP and NEE, indicating the importance of getting the underlying

  13. Towards a Representation of Flexible Canopy N Stiochiometry for Land-surface Models Based on Optimality Concepts

    NASA Astrophysics Data System (ADS)

    Zaehle, S.; Caldararu, S.

    2015-12-01

    Foliar nitrogen (N) is know to acclimate to environmental conditions. One particular pertinent response is the general decline in foliar N following exposure to elevated levels of atmospheric CO2 (eCO2). Associated with reduced foliar N is an increased plant nitrogen-use efficiency, which contributes to the plants' sustained growth response to eCO2 in the absence of any counteracting litter N feedbacks. Flexible leaf N thus has important consequences for the mid- to long-term response of terrestrial ecosystems to eCO2. The current generation of land-surface models including a prognostic N cycle generally employ heuristic, and simply mass-balancing parameterisations to estimate changes in stoichiometry given altered N and carbon (C) availability. This generation generally and substantially overestimates the decline of foliar N (and thus the increase in plant nitrogen use efficiency) observed in Free Air CO2 Enrichment Experiments (FACE; Zaehle et al. 2014). In this presentation, I develop a simple, prognostic and dynamic representation of flexible foliar N for use in land-surface models by maximising the marginal gain of net assimilation with respect to the energy investment to generate foliar area and foliar N. I elucidate the underlying assumptions required to simulate the commonly observed decline in foliar N with eCO2 under different scenarios of N availability (Feng et al. 2015). References: Zaehle, Sönke, Belinda E Medlyn, Martin G De Kauwe, Anthony P Walker, Michael C Dietze, Hickler Thomas, Yiqi Luo, et al. 2014. "Evaluation of 11 Terrestrial Carbon-Nitrogen Cycle Models Against Observations From Two Temperate Free-Air CO2 Enrichment Studies." New Phytologist 202 (3): 803-22. doi:10.1111/nph.12697. Feng, Zhaozhong, Tobias RUtting, Håkan Pleijel, GORAN WALLIN, Peter B Reich, Claudia I Kammann, Paul C D Newton, Kazuhiko Kobayashi, Yunjian Luo, and Johan Uddling. 2015. "Constraints to Nitrogen Acquisition of Terrestrial Plants Under Elevated CO 2." Global

  14. Why Representations?

    ERIC Educational Resources Information Center

    Schultz, James E.; Waters, Michael S.

    2000-01-01

    Discusses representations in the context of solving a system of linear equations. Views representations (concrete, tables, graphs, algebraic, matrices) from perspectives of understanding, technology, generalization, exact versus approximate solution, and learning style. (KHR)

  15. Computer-aided design of curved surfaces with automatic model generation

    NASA Technical Reports Server (NTRS)

    Staley, S. M.; Jerard, R. B.; White, P. R.

    1980-01-01

    The design and visualization of three-dimensional objects with curved surfaces have always been difficult. The paper given below describes a computer system which facilitates both the design and visualization of such surfaces. The system enhances the design of these surfaces by virtue of various interactive techniques coupled with the application of B-Spline theory. Visualization is facilitated by including a specially built model-making machine which produces three-dimensional foam models. Thus, the system permits the designer to produce an inexpensive model of the object which is suitable for evaluation and presentation.

  16. Using reactive transport codes to provide mechanistic biogeochemistry representations in global land surface models: CLM-PFLOTRAN 1.0

    NASA Astrophysics Data System (ADS)

    Tang, G.; Yuan, F.; Bisht, G.; Hammond, G. E.; Lichtner, P. C.; Kumar, J.; Mills, R. T.; Xu, X.; Andre, B.; Hoffman, F. M.; Painter, S. L.; Thornton, P. E.

    2015-12-01

    We explore coupling to a configurable subsurface reactive transport code as a flexible and extensible approach to biogeochemistry in land surface models; our goal is to facilitate testing of alternative models and incorporation of new understanding. A reaction network with the CLM-CN decomposition, nitrification, denitrification, and plant uptake is used as an example. We implement the reactions in the open-source PFLOTRAN code, coupled with the Community Land Model (CLM), and test at Arctic, temperate, and tropical sites. To make the reaction network designed for use in explicit time stepping in CLM compatible with the implicit time stepping used in PFLOTRAN, the Monod substrate rate-limiting function with a residual concentration is used to represent the limitation of nitrogen availability on plant uptake and immobilization. To achieve accurate, efficient, and robust numerical solutions, care needs to be taken to use scaling, clipping, or log transformation to avoid negative concentrations during the Newton iterations. With a tight relative update tolerance to avoid false convergence, an accurate solution can be achieved with about 50 % more computing time than CLM in point mode site simulations using either the scaling or clipping methods. The log transformation method takes 60-100 % more computing time than CLM. The computing time increases slightly for clipping and scaling; it increases substantially for log transformation for half saturation decrease from 10-3 to 10-9 mol m-3, which normally results in decreasing nitrogen concentrations. The frequent occurrence of very low concentrations (e.g. below nanomolar) can increase the computing time for clipping or scaling by about 20 %; computing time can be doubled for log transformation. Caution needs to be taken in choosing the appropriate scaling factor because a small value caused by a negative update to a small concentration may diminish the update and result in false convergence even with very tight relative

  17. Using reactive transport codes to provide mechanistic biogeochemistry representations in global land surface models: CLM-PFLOTRAN 1.0

    DOE PAGES

    Tang, G.; Yuan, F.; Bisht, G.; ...

    2015-12-17

    We explore coupling to a configurable subsurface reactive transport code as a flexible and extensible approach to biogeochemistry in land surface models; our goal is to facilitate testing of alternative models and incorporation of new understanding. A reaction network with the CLM-CN decomposition, nitrification, denitrification, and plant uptake is used as an example. We implement the reactions in the open-source PFLOTRAN code, coupled with the Community Land Model (CLM), and test at Arctic, temperate, and tropical sites. To make the reaction network designed for use in explicit time stepping in CLM compatible with the implicit time stepping used in PFLOTRAN,more » the Monod substrate rate-limiting function with a residual concentration is used to represent the limitation of nitrogen availability on plant uptake and immobilization. To achieve accurate, efficient, and robust numerical solutions, care needs to be taken to use scaling, clipping, or log transformation to avoid negative concentrations during the Newton iterations. With a tight relative update tolerance to avoid false convergence, an accurate solution can be achieved with about 50 % more computing time than CLM in point mode site simulations using either the scaling or clipping methods. The log transformation method takes 60–100 % more computing time than CLM. The computing time increases slightly for clipping and scaling; it increases substantially for log transformation for half saturation decrease from 10−3 to 10−9 mol m−3, which normally results in decreasing nitrogen concentrations. The frequent occurrence of very low concentrations (e.g. below nanomolar) can increase the computing time for clipping or scaling by about 20 %; computing time can be doubled for log transformation. Caution needs to be taken in choosing the appropriate scaling factor because a small value caused by a negative update to a small concentration may diminish the update and result in false convergence even with very

  18. Alteration in cell surface properties of Burkholderia spp. during surfactant-aided biodegradation of petroleum hydrocarbons.

    PubMed

    Mohanty, Sagarika; Mukherji, Suparna

    2012-04-01

    Chemical surfactants may impact microbial cell surface properties, i.e., cell surface hydrophobicity (CSH) and cell surface charge, and may thus affect the uptake of components from non-aqueous phase liquids (NAPLs). This work explored the impact of Triton X-100, Igepal CA 630, and Tween 80 (at twice the critical micelle concentration, CMC) on the cell surface characteristics of Burkholderia cultures, Burkholderia cepacia (ES1, aliphatic degrader) and Burkholderia multivorans (NG1, aromatic degrader), when grown on a six-component model NAPL. In the presence of Triton X-100, NAPL biodegradation was enhanced from 21% to 60% in B. cepacia and from 18% to 53% in B. multivorans. CSH based on water contact angle (50-52°) was in the same range for both strains while zeta potential at neutral pH was -38 and -31 mV for B. cepacia and B. multivorans, respectively. In the presence of Triton X-100, their CSH increased to greater than 75° and the zeta potential decreased. This induced a change in the mode of uptake and initiated aliphatic hydrocarbon degradation by B. multivorans and increased the rate of aliphatic hydrocarbon degradation in B. cepacia. Igepal CA 630 and Tween 80 also altered the cell surface properties. For B. cepacia grown in the presence of Triton X-100 at two and five times its CMC, CSH increased significantly in the log growth phase. Growth in the presence of the chemical surfactants also affected the abundance of chemical functional groups on the cell surface. Cell surface changes had maximum impact on NAPL degradation in the presence of emulsifying surfactants, Triton X-100 and Igepal CA630.

  19. Aerodynamic heating and surface temperatures on vehicles for computer-aided design studies

    NASA Technical Reports Server (NTRS)

    Dejarnette, F. R.; Kania, L. A.; Chitty, A.

    1983-01-01

    A computer subprogram has been developed to calculate aerodynamic and radiative heating rates and to determine surface temperatures by integrating the heating rates along the trajectory of a vehicle. Convective heating rates are calculated by applying the axisymmetric analogue to inviscid surface streamlines and using relatively simple techniques to calculate laminar, transitional, or turbulent heating rates. Options are provided for the selection of gas model, transition criterion, turbulent heating method, Reynolds Analogy factor, and entropy-layer swallowing effects. Heating rates are compared to experimental data, and the time history of surface temperatures are given for a high-speed trajectory. The computer subprogram is developed for preliminary design and mission analysis where parametric studies are needed at all speeds.

  20. Survey, Representation and Analysis of a War i Complex System of Surface and Underground Fortifications in the Gresta Valley, Italy

    NASA Astrophysics Data System (ADS)

    Salvador, I.; Vitti, A.

    2011-09-01

    This work is part of a research on the use of terrestrial laser scanner, integrated with total station and GPS, for the documentation and comprehension of complex architectures in up-land sites. The research is performed in the framework of the project "Ambiente e Paesaggi dei siti di Altura Trentini" - APSAT (Environment and landscape of hill-top sites in Trentino), a multidisciplinary project focused on the evolution of hill-top anthropic system in the Trentino region, Italy. The study area is located in the Gresta Valley and this work concerns on the Nagià Grom site, fortified by the Austria-Hungarian Army during the World War I. The site has been interested by a significant restore operation of a large series of entrenches paths and fortifications in the last decade. The survey herein described has involved an area once interested by military barracks with Officers' Mess, water provision and by one of the biggest field kitchens discovered in the Trentino region. A second survey involved the tunnel connecting the ammunition depot to the artillery stations. The nature of such complex architectures, characterized by an irregular and composite 3D span leads, in general, to necessary simple surveys and representations and somehow to simplified studies too. The 3D point cloud, once filtered by the massive presence of dense vegetation, eventually constitutes a rich data set for further analyses on the spatial, geological, architectural and historical properties of the site. The analysis has been carried out on two different scales. At the architectural-scale, the comparison to historic photos has allowed to understand how the original structure of the barracks was made and to find building characters that now are lost. The on-site observation of the underground stratigraphic splices and their analysis in the 3D point cloud, e.g., spatial extension and slope, have permitted the understanding of the special excavation process guided by the practical advantage of

  1. Body-surface potential mapping to aid ablation of scar-related ventricular tachycardia.

    PubMed

    Sapp, John L; Gardner, Martin J; Parkash, Ratika; Basta, Magdy; Warren, James W; Horácek, B Milan

    2006-10-01

    We investigated whether body-surface potential mapping (BSPM) during catheter ablation of scar-related ventricular tachycardia (VT) could assist with the identification of VT exit sites. The study population consisted of 9 patients who underwent catheter ablation for VT, among whom 12 induced VTs with known exit sites were identified by entrainment criteria, pace mapping, or site of successful ablation. Paced activation was initiated at various intracardiac sites (20 +/- 4 sites per patient, a total of 180) documented by nonfluoroscopic electroanatomic mapping. During all episodes of VT and pacing, patients had a 120-lead electrocardiogram recorded, and we analyzed these electrocardiographic data--by means of a similarity coefficient (SC) calculated over 100 milliseconds after the initiation of depolarization--to assess the similarity between the BSPM sequences occurring during VTs and those induced by pacing. Based on 245 observations, the relationship between the SC and the distance of the pacing site from the VT exit site was then obtained for each individual VT by linear regression analysis: the distance D (in millimeters) from the VT exit site was related to SC by the regression equation D = slope (1 - SC2) + intercept. The parameters in this equation varied widely for the 12 VTs, but, in general, the nearer the pacing site was to the exit site, the better the goodness of match. This suggests that, although there is no universally applicable relationship between D and SC, BSPM could provide a useful adjunct to standard pace mapping, although additional processing--namely, an inverse calculation of epicardial potentials/isochrones--may be needed to reliably identify VT exit sites from body-surface electrocardiograms.

  2. System for conversion between the boundary representation model and a constructive solid geometry model of an object

    DOEpatents

    Christensen, Noel C.; Emery, James D.; Smith, Maurice L.

    1988-04-05

    A system converts from the boundary representation of an object to the constructive solid geometry representation thereof. The system converts the boundary representation of the object into elemental atomic geometrical units or I-bodies which are in the shape of stock primitives or regularized intersections of stock primitives. These elemental atomic geometrical units are then represented in symbolic form. The symbolic representations of the elemental atomic geometrical units are then assembled heuristically to form a constructive solid geometry representation of the object usable for manufacturing thereof. Artificial intelligence is used to determine the best constructive solid geometry representation from the boundary representation of the object. Heuristic criteria are adapted to the manufacturing environment for which the device is to be utilized. The surface finish, tolerance, and other information associated with each surface of the boundary representation of the object are mapped onto the constructive solid geometry representation of the object to produce an enhanced solid geometry representation, particularly useful for computer-aided manufacture of the object.

  3. System for conversion between the boundary representation model and a constructive solid geometry model of an object

    DOEpatents

    Christensen, N.C.; Emery, J.D.; Smith, M.L.

    1985-04-29

    A system converts from the boundary representation of an object to the constructive solid geometry representation thereof. The system converts the boundary representation of the object into elemental atomic geometrical units or I-bodies which are in the shape of stock primitives or regularized intersections of stock primitives. These elemental atomic geometrical units are then represented in symbolic form. The symbolic representations of the elemental atomic geometrical units are then assembled heuristically to form a constructive solid geometry representation of the object usable for manufacturing thereof. Artificial intelligence is used to determine the best constructive solid geometry representation from the boundary representation of the object. Heuristic criteria are adapted to the manufacturing environment for which the device is to be utilized. The surface finish, tolerance, and other information associated with each surface of the boundary representation of the object are mapped onto the constructive solid geometry representation of the object to produce an enhanced solid geometry representation, particularly useful for computer-aided manufacture of the object. 19 figs.

  4. User's manual for master: Modeling of aerodynamic surfaces by 3-dimensional explicit representation. [input to three dimensional computational fluid dynamics

    NASA Technical Reports Server (NTRS)

    Gibson, S. G.

    1983-01-01

    A system of computer programs was developed to model general three dimensional surfaces. Surfaces are modeled as sets of parametric bicubic patches. There are also capabilities to transform coordinates, to compute mesh/surface intersection normals, and to format input data for a transonic potential flow analysis. A graphical display of surface models and intersection normals is available. There are additional capabilities to regulate point spacing on input curves and to compute surface/surface intersection curves. Input and output data formats are described; detailed suggestions are given for user input. Instructions for execution are given, and examples are shown.

  5. An assessment of the Polar Weather Research and Forecasting (WRF) model representation of near-surface meteorological variables over West Antarctica

    NASA Astrophysics Data System (ADS)

    Deb, Pranab; Orr, Andrew; Hosking, J. Scott; Phillips, Tony; Turner, John; Bannister, Daniel; Pope, James O.; Colwell, Steve

    2016-02-01

    Despite the recent significant climatic changes observed over West Antarctica, which include large warming in central West Antarctica and accelerated ice loss, adequate validation of regional simulations of meteorological variables are rare for this region. To address this gap, results from a recent version of the Polar Weather Research and Forecasting model (Polar WRF) covering West Antarctica at a high horizontal resolution of 5 km were validated against near-surface meteorological observations. The model employed physics options that included the Mellor-Yamada-Nakanishi-Niino boundary layer scheme, the WRF Single Moment 5-Class cloud microphysics scheme, the new version of the rapid radiative transfer model for both shortwave and longwave radiation, and the Noah land surface model. Our evaluation finds this model to be a useful tool for realistically capturing the near-surface meteorological conditions. It showed high skill in simulating surface pressure (correlation ≥0.97), good skill for wind speed with better correlation at inland sites (0.7-0.8) compared to coastal sites (0.3-0.6), generally good representation of strong wind events, and good skill for temperature in winter (correlation ≥0.8). The main shortcomings of this configuration of Polar WRF are an occasional failure to properly represent transient cyclones and their influence on coastal winds, an amplified diurnal temperature cycle in summer, and a general tendency to underestimate the wind speed at inland sites in summer. Additional sensitivity studies were performed to quantify the impact of the choice of boundary layer scheme and surface boundary conditions. It is shown that the model is most sensitive to the choice of boundary layer scheme, with the representation of the temperature diurnal cycle in summer significantly improved by selecting the Mellor-Yamada-Janjic boundary layer scheme. By contrast, the model results showed little sensitivity to whether the horizontal resolution was 5 or

  6. 'The surface management system' (SuMS) database: a surface-based database to aid cortical surface reconstruction, visualization and analysis

    NASA Technical Reports Server (NTRS)

    Dickson, J.; Drury, H.; Van Essen, D. C.

    2001-01-01

    Surface reconstructions of the cerebral cortex are increasingly widely used in the analysis and visualization of cortical structure, function and connectivity. From a neuroinformatics perspective, dealing with surface-related data poses a number of challenges. These include the multiplicity of configurations in which surfaces are routinely viewed (e.g. inflated maps, spheres and flat maps), plus the diversity of experimental data that can be represented on any given surface. To address these challenges, we have developed a surface management system (SuMS) that allows automated storage and retrieval of complex surface-related datasets. SuMS provides a systematic framework for the classification, storage and retrieval of many types of surface-related data and associated volume data. Within this classification framework, it serves as a version-control system capable of handling large numbers of surface and volume datasets. With built-in database management system support, SuMS provides rapid search and retrieval capabilities across all the datasets, while also incorporating multiple security levels to regulate access. SuMS is implemented in Java and can be accessed via a Web interface (WebSuMS) or using downloaded client software. Thus, SuMS is well positioned to act as a multiplatform, multi-user 'surface request broker' for the neuroscience community.

  7. Use of the MSA products as an adequate representation of the surface albedo in the ALADIN-Belgium NWP model

    NASA Astrophysics Data System (ADS)

    Bertrand, C.; Govaerts, Y.; Clerbaux, N.; Ipe, A.; Gonzalez, L.

    2003-04-01

    Land surface albedo represents the proportion of the incoming radiative flux reflected by the surface. It is highly variable in space and time over terrestrial surfaces and plays a key role in surface-atmosphere interaction processes. In particular, it is used in numerical weather forecast and climate models to parametrize surface boundary radiative conditions. Hence, the accurate knowledge of surface albedo at the appropriate time and space scales is essential in estimating radiation balance components. Unfortunately, surface albedo in numerical models is commonly prescribed from low-resolution seasonal data sets. Such data sets are often based on limited ground-based albedo observations and information on surface and vegetation types, even though such approaches do not accurately account for the actual structural effects of the underlying surface. To account for the high spatial and temporal variability of the surface albedo, the ALADIN-Belgium NWP model has been initialized with the directional hemispherical reflectance generated by the Meteosat Surface Albedo (MSA) algorithm. The MSA product is generated every 10 days with a spatial resolution close to the 7 km mesh size of ALADIN-Belgium NWP model. A number of sensitivity forecast runs using the MSA products has shown a significant improvement of the simulated radiative fluxes with respect to simulations performed with a surface albedo derived from climatological values of soil and vegetation parameters. This finding suggests that the use of the high-resolution MSA products could also be valuable for improving model temperature forecasts.

  8. Hearing Aids

    MedlinePlus

    ... Health Info » Hearing, Ear Infections, and Deafness Hearing Aids On this page: What is a hearing aid? ... the ear through a speaker. How can hearing aids help? Hearing aids are primarily useful in improving ...

  9. Garrett County Aids AID

    ERIC Educational Resources Information Center

    Appalachia, 1975

    1975-01-01

    Garrett County, Maryland volunteered to act as a pre-overseas learning laboratory for AID (Agency for International Development) interns who practiced data collection and planning techniques with the help of local citizenry. (JC)

  10. The Effects of 3D-Representation Instruction on Composite-Solid Surface-Area Learning for Elementary School Students

    ERIC Educational Resources Information Center

    Sung, Yao-Ting; Shih, Pao-Chen; Chang, Kuo-En

    2015-01-01

    Providing instruction on spatial geometry, specifically how to calculate the surface areas of composite solids, challenges many elementary school teachers. Determining the surface areas of composite solids involves complex calculations and advanced spatial concepts. The goals of this study were to build on students' learning processes for…

  11. Forecasting surface wind speeds over offshore islands near Taiwan during tropical cyclones: Comparisons of data-driven algorithms and parametric wind representations

    NASA Astrophysics Data System (ADS)

    Wei, Chih-Chiang

    2015-03-01

    Tropical cyclones often affect the western North Pacific region. Between May and October annually, enormous flood damage is frequently caused by typhoons in Taiwan. This study adopted machine learning techniques to forecast the hourly wind speeds over offshore islands near Taiwan during tropical cyclones. To develop a highly reliable surface wind speed prediction technique, the four kernel-based support vector machines for regression (SVR) models, comprising radial basis function, linear, polynomial, and Pearson VII universal kernels were used. To ensure the accuracy of the SVR model, traditional regressions and the parametric wind representations, comprising the modified Rankine profile, Holland wind profile, and DeMaria wind profile were used to compare wind speed forecasts. The methodology was applied to two islands near Taiwan, Lanyu, and Pengjia Islets. The forecasting horizon ranged from 1 to 6 h. The results indicated that the Pearson VII SVR is the most precise of the kernel-based SVR models, regressions, and parametric wind representations. Additionally, Typhoons Nanmadol and Saola which made landfall over Taiwan during 2011 and 2012 were simulated and examined. The results showed that the Pearson VII SVR yielded more favorable results than did the regressions and Holland wind profile. In addition, we observed that Holland wind profile seems applicable to open ocean but unsuitable for areas affected by topographic effects, such as the Central Mountain Range of Taiwan.

  12. A Galerkin Approach to Define Measured Terrain Surfaces with Analytic Basis Vectors to Produce a Compact Representation

    DTIC Science & Technology

    2010-11-01

    defined herein as terrain whose surface deformation due to a single vehicle traversing the surface is negligible, such as paved roads (both asphalt ...ground vehicle reliability predictions. Current application of this work is limited to the analysis of U.S. Highways, comprised of both asphalt and...Highways that are consistent between asphalt and concrete roads b. The principle terrain characteristics are defined with analytic basis vectors

  13. Modeling surface water dynamics in the Amazon Basin using MOSART-Inundation v1.0: Impacts of geomorphological parameters and river flow representation

    DOE PAGES

    Luo, Xiangyu; Li, Hong -Yi; Leung, L. Ruby; ...

    2017-03-23

    In the Amazon Basin, floodplain inundation is a key component of surface water dynamics and plays an important role in water, energy and carbon cycles. The Model for Scale Adaptive River Transport (MOSART) was extended with a macroscale inundation scheme for representing floodplain inundation. The extended model, named MOSART-Inundation, was used to simulate surface hydrology of the entire Amazon Basin. Previous hydrologic modeling studies in the Amazon Basin identified and addressed a few challenges in simulating surface hydrology of this basin, including uncertainties of floodplain topography and channel geometry, and the representation of river flow in reaches with mild slopes.more » This study further addressed four aspects of these challenges. First, the spatial variability of vegetation-caused biases embedded in the HydroSHEDS digital elevation model (DEM) data was explicitly addressed. A vegetation height map of about 1 km resolution and a land cover dataset of about 90 m resolution were used in a DEM correction procedure that resulted in an average elevation reduction of 13.2 m for the entire basin and led to evident changes in the floodplain topography. Second, basin-wide empirical formulae for channel cross-sectional dimensions were refined for various subregions to improve the representation of spatial variability in channel geometry. Third, the channel Manning roughness coefficient was allowed to vary with the channel depth, as the effect of riverbed resistance on river flow generally declines with increasing river size. Lastly, backwater effects were accounted for to better represent river flow in mild-slope reaches. The model was evaluated against in situ streamflow records and remotely sensed Envisat altimetry data and Global Inundation Extent from Multi-Satellites (GIEMS) inundation data. In a sensitivity study, seven simulations were compared to evaluate the impacts of the five modeling aspects addressed in this study. The comparisons showed that

  14. Segmentation of Textures Defined on Flat vs. Layered Surfaces using Neural Networks: Comparison of 2D vs. 3D Representations.

    PubMed

    Oh, Sejong; Choe, Yoonsuck

    2007-08-01

    Texture boundary detection (or segmentation) is an important capability in human vision. Usually, texture segmentation is viewed as a 2D problem, as the definition of the problem itself assumes a 2D substrate. However, an interesting hypothesis emerges when we ask a question regarding the nature of textures: What are textures, and why did the ability to discriminate texture evolve or develop? A possible answer to this question is that textures naturally define physically distinct (i.e., occluded) surfaces. Hence, we can hypothesize that 2D texture segmentation may be an outgrowth of the ability to discriminate surfaces in 3D. In this paper, we conducted computational experiments with artificial neural networks to investigate the relative difficulty of learning to segment textures defined on flat 2D surfaces vs. those in 3D configurations where the boundaries are defined by occluding surfaces and their change over time due to the observer's motion. It turns out that learning is faster and more accurate in 3D, very much in line with our expectation. Furthermore, our results showed that the neural network's learned ability to segment texture in 3D transfers well into 2D texture segmentation, bolstering our initial hypothesis, and providing insights on the possible developmental origin of 2D texture segmentation function in human vision.

  15. Representing Representation

    ERIC Educational Resources Information Center

    Kuntz, Aaron M.

    2010-01-01

    What can be known and how to render what we know are perpetual quandaries met by qualitative research, complicated further by the understanding that the everyday discourses influencing our representations are often tacit, unspoken or heard so often that they seem to warrant little reflection. In this article, I offer analytic memos as a means for…

  16. HIV / AIDS

    MedlinePlus

    ... facebook share with twitter share with linkedin HIV/AIDS HIV, or human immunodeficiency virus, is the virus ... HIV/AIDS. Why Is the Study of HIV/AIDS a Priority for NIAID? Nearly 37 million people ...

  17. Hearing Aids

    MedlinePlus

    ... and Consumer Devices Consumer Products Hearing Aids Hearing Aids Share Tweet Linkedin Pin it More sharing options ... to restrict your daily activities. Properly fitted hearing aids and aural rehabilitation (techniques used to identify and ...

  18. Hearing Aids

    MedlinePlus

    ... Surgery? A Week of Healthy Breakfasts Shyness Hearing Aids KidsHealth > For Teens > Hearing Aids Print A A ... with certain types of hearing loss. How Hearing Aids Help So you went to audiologist and found ...

  19. Explicit representation of microbes, enzymes, mineral surfaces, and isotopic tracers helps explain soil organic carbon decomposition and priming

    NASA Astrophysics Data System (ADS)

    Zhu, X.; Tang, J.; Riley, W. J.; Wallenstein, M. D.; Cotrufo, M. F.

    2015-12-01

    Increased plant carbon inputs from CO2 fertilization could accelerate native soil organic carbon (SOC) decomposition through the priming effect. Although this increase in SOC turnover rate due to priming might have important consequences for SOC dynamics, there are large uncertainties in the sign and magnitude of priming, as well as large challenges in identifying underlying mechanisms. Current SOC models, mostly based on first-order decomposition representations, do no represent many important biotic and abiotic processes, including the priming effect. The incorporation of explicit biotic and abiotic interactions in modeling SOC decomposition may improve our ability to accurately predict SOC dynamics. In this study, we (1) develop a microbe-explicit SOC decomposition model to simulate SOC turnovers and priming and (2) test the model with a soil incubation experiment with 14C-labeled glucose addition. We report (1) the evolutions of modeled carbon pools, (2) the fate of 14C labeled glucose addition, (3) the model performance compared to observations, (4) the transient behavior of priming components, and (5) an analysis of the effects of carbon input magnitudes and frequencies on the priming effect. Here are some findings from our model-experiment analyses: (1) the inclusion of an extracellular oxidative metabolism (EXOMET) in addition to intracellular microbial respiration helps improve the model performance; (2) priming is dominated by intracellular microbial respiration at the beginning of incubation (~ first 5 days) but later on dominated by EXOMET, which explains observed long-term sustaining priming; (3) the varying magnitudes of glucose addition do not change the magnitude of priming per unit addition; (4) the varying frequencies of glucose addition change the magnitude of priming per unit addition, but with contrast changing patterns for non-steady-state and steady state simulations; (5) constant annual total glucose addition shift the system to another

  20. Integral representation of voltage in half-plane conductor with crack from surface by D.C. potential difference method

    NASA Astrophysics Data System (ADS)

    Akira, Sasamoto; Krutitskii, P. A.

    2012-09-01

    Non destructive testing (NDT) has been used to ensure safety in public structure and public space. D.C. potential difference method, one of the NDT, can detect crack in conductive material. According to study for material, depth of crack in metal is most important parameter to judge if the crack will lead catastrophic failure in short time. Therefore estimation of crack depth by measured voltage on surface is key process in the method. However, as authors as know, exact solution of model equation for the method that is Laplace equation with prescribed boundary condition and crack has not been known so far. In this paper we show exact expression of solution and computational results for model problem described in two space dimensional lower half-space with crack vertically propagating from the surface.

  1. A novel path generation method of onsite 5-axis surface inspection using the dual-cubic NURBS representation

    NASA Astrophysics Data System (ADS)

    Li, Wen-long; Wang, Gang; Zhang, Gang; Pang, Chang-tao; Yin, Zhou-pin

    2016-09-01

    Onsite surface inspection with a touch probe or a laser scanner is a promising technique for efficiently evaluating surface profile error. The existing work of 5-axis inspection path generation bears a serious drawback, however, as there is a drastic orientation change of the inspection axis. Such a sudden change may exceed the stringent physical limit on the speed and acceleration of the rotary motions of the machine tool. In this paper, we propose a novel path generation method for onsite 5-axis surface inspection. The accessibility cones are defined and used to generate alternative interference-free inspection directions. Then, the control points are optimally calculated to obtain the dual-cubic non-Uniform rational B-splines (NURBS) curves, which respectively determine the path points and the axis vectors in an inspection path. The generated inspection path is smooth and non-interference, which deals with the ‘mutation and shake’ problems and guarantees a stable speed and acceleration of machine tool rotary motions. Its feasibility and validity is verified by the onsite inspection experiments of impeller blade.

  2. Representation of vegetation effects on the snow-covered albedo in the Noah land surface model with multiple physics options

    NASA Astrophysics Data System (ADS)

    Park, S.; Park, S. K.

    2015-04-01

    Snow albedo plays a critical role in calculating the energy budget, but parameterization of the snow surface albedo is still under great uncertainty. It varies with snow grain size, snow cover thickness, snow age, forest shading factor and other variables. Snow albedo of forest is typically lower than that of short vegetation; thus snow albedo is dependent on the spatial distributions of characteristic land cover and on the canopy density and structure. In the Noah land surface model with multiple physics options (Noah-MP), almost all vegetation types in East Asia during winter have the minimum values of leaf area index (LAI) and stem area index (SAI), which are too low and do not consider the vegetation types. Because LAI and SAI are represented in terms of photosynthetic activeness, the vegetation effect rarely exerts on the surface albedo in winter in East Asia with only these parameters. Thus, we investigated the vegetation effects on the snow-covered albedo from observations and evaluated the model improvement by considering such effect. We found that calculation of albedo without proper reflection of the vegetation effect is mainly responsible for the large positive bias in winter. Therefore, we developed new parameters, called leaf index (LI) and stem index (SI), which properly manage the effect of vegetation structure on the winter albedo. As a result, the Noah-MP's performance in albedo has been significantly improved - RMSE is reduced by approximately 73%.

  3. Grassmannian sparse representations

    NASA Astrophysics Data System (ADS)

    Azary, Sherif; Savakis, Andreas

    2015-05-01

    We present Grassmannian sparse representations (GSR), a sparse representation Grassmann learning framework for efficient classification. Sparse representation classification offers a powerful approach for recognition in a variety of contexts. However, a major drawback of sparse representation methods is their computational performance and memory utilization for high-dimensional data. A Grassmann manifold is a space that promotes smooth surfaces where points represent subspaces and the relationship between points is defined by the mapping of an orthogonal matrix. Grassmann manifolds are well suited for computer vision problems because they promote high between-class discrimination and within-class clustering, while offering computational advantages by mapping each subspace onto a single point. The GSR framework combines Grassmannian kernels and sparse representations, including regularized least squares and least angle regression, to improve high accuracy recognition while overcoming the drawbacks of performance and dependencies on high dimensional data distributions. The effectiveness of GSR is demonstrated on computationally intensive multiview action sequences, three-dimensional action sequences, and face recognition datasets.

  4. Rapid degradation of permafrost underneath waterbodies in tundra landscapes—Toward a representation of thermokarst in land surface models

    NASA Astrophysics Data System (ADS)

    Langer, M.; Westermann, S.; Boike, J.; Kirillin, G.; Grosse, G.; Peng, S.; Krinner, G.

    2016-12-01

    Waterbodies such as lakes and ponds are abundant in vast Arctic landscapes and strongly affect the thermal state of the surrounding permafrost. In order to gain a better understanding of the impact of small- and medium-sized waterbodies on permafrost and the formation of thermokarst, a land surface model was developed that can represent the vertical and lateral thermal interactions between waterbodies and permafrost. The model was validated using temperature measurements from two typical waterbodies located within the Lena River delta in northern Siberia. Impact simulations were performed under current climate conditions as well as under a moderate and a strong climate-warming scenario. The performed simulations demonstrate that small waterbodies can rise the sediment surface temperature by more than 10°C and accelerate permafrost thaw by a factor of between 4 and 5. Up to 70% of this additional heat flux into the ground was found to be dissipated into the surrounding permafrost by lateral ground heat flux in the case of small, shallow, and isolated waterbodies. Under moderate climate warming, the lateral heat flux was found to reduce permafrost degradation underneath waterbodies by a factor of 2. Under stronger climatic warming, however, the lateral heat flux was too small to prevent rapid permafrost degradation. The lateral heat flux was also found to strongly impede the formation of thermokarst. Despite this stabilizing effect, our simulations have demonstrated that underneath shallow waterbodies (<1 m), thermokarst initiation happens 30 to 40 years earlier than in simulations without preexisting waterbody.

  5. Dynamics of H{sub 2} Eley-Rideal abstraction from W(110): Sensitivity to the representation of the molecule-surface potential

    SciTech Connect

    Pétuya, R. Larrégaray, P.; Crespos, C.; Busnengo, H. F.; Martínez, A. E.

    2014-07-14

    Dynamics of the Eley-Rideal (ER) abstraction of H{sub 2} from W(110) is analyzed by means of quasi-classical trajectory calculations. Simulations are based on two different molecule-surface potential energy surfaces (PES) constructed from Density Functional Theory results. One PES is obtained by fitting, using a Flexible Periodic London-Eyring-Polanyi-Sato (FPLEPS) functional form, and the other by interpolation through the corrugation reducing procedure (CRP). Then, the present study allows us to elucidate the ER dynamics sensitivity on the PES representation. Despite some sizable discrepancies between both H+H/W(110) PESs, the obtained projectile-energy dependence of the total ER cross sections are qualitatively very similar ensuring that the main physical ingredients are captured in both PES models. The obtained distributions of the final energy among the different molecular degrees of freedom barely depend on the PES model, being most likely determined by the reaction exothermicity. Therefore, a reasonably good agreement with the measured final vibrational state distribution is observed in spite of the pressure and material gaps between theoretical and experimental conditions.

  6. Computer-aided diagnosis of pulmonary nodules on CT scans: improvement of classification performance with nodule surface features.

    PubMed

    Way, Ted W; Sahiner, Berkman; Chan, Heang-Ping; Hadjiiski, Lubomir; Cascade, Philip N; Chughtai, Aamer; Bogot, Naama; Kazerooni, Ella

    2009-07-01

    The purpose of this work is to develop a computer-aided diagnosis (CAD) system to differentiate malignant and benign lung nodules on CT scans. A fully automated system was designed to segment the nodule from its surrounding structured background in a local volume of interest (VOI) and to extract image features for classification. Image segmentation was performed with a 3D active contour method. The initial contour was obtained as the boundary of a binary object generated by k-means clustering within the VOI and smoothed by morphological opening. A data set of 256 lung nodules (124 malignant and 132 benign) from 152 patients was used in this study. In addition to morphological and texture features, the authors designed new nodule surface features to characterize the lung nodule surface smoothness and shape irregularity. The effects of two demographic features, age and gender, as adjunct to the image features were also investigated. A linear discriminant analysis (LDA) classifier built with features from stepwise feature selection was trained using simplex optimization to select the most effective features. A two-loop leave-one-out resampling scheme was developed to reduce the optimistic bias in estimating the test performance of the CAD system. The area under the receiver operating characteristic curve, A(z), for the test cases improved significantly (p < 0.05) from 0.821 +/- 0.026 to 0.857 +/- 0.023 when the newly developed image features were included with the original morphological and texture features. A similar experiment performed on the data set restricted to primary cancers and benign nodules, excluding the metastatic cancers, also resulted in an improved test A(z), though the improvement did not reach statistical significance (p = 0.07). The two demographic features did not significantly affect the performance of the CAD system (p > 0.05) when they were added to the feature space containing the morphological, texture, and new gradient field and radius

  7. Evaluating coastal sea surface heights based on a novel sub-waveform approach using sparse representation and conditional random fields

    NASA Astrophysics Data System (ADS)

    Uebbing, Bernd; Roscher, Ribana; Kusche, Jürgen

    2016-04-01

    Satellite radar altimeters allow global monitoring of mean sea level changes over the last two decades. However, coastal regions are less well observed due to influences on the returned signal energy by land located inside the altimeter footprint. The altimeter emits a radar pulse, which is reflected at the nadir-surface and measures the two-way travel time, as well as the returned energy as a function of time, resulting in a return waveform. Over the open ocean the waveform shape corresponds to a theoretical model which can be used to infer information on range corrections, significant wave height or wind speed. However, in coastal areas the shape of the waveform is significantly influenced by return signals from land, located in the altimeter footprint, leading to peaks which tend to bias the estimated parameters. Recently, several approaches dealing with this problem have been published, including utilizing only parts of the waveform (sub-waveforms), estimating the parameters in two steps or estimating additional peak parameters. We present a new approach in estimating sub-waveforms using conditional random fields (CRF) based on spatio-temporal waveform information. The CRF piece-wise approximates the measured waveforms based on a pre-derived dictionary of theoretical waveforms for various combinations of the geophysical parameters; neighboring range gates are likely to be assigned to the same underlying sub-waveform model. Depending on the choice of hyperparameters in the CRF estimation, the classification into sub-waveforms can either be more fine or coarse resulting in multiple sub-waveform hypotheses. After the sub-waveforms have been detected, existing retracking algorithms can be applied to derive water heights or other desired geophysical parameters from particular sub-waveforms. To identify the optimal heights from the multiple hypotheses, instead of utilizing a known reference height, we apply a Dijkstra-algorithm to find the "shortest path" of all

  8. Increase of the prevalence of hepatitis B virus surface antigen related to immunodeficiency inherent in acquired immune deficiency syndrome (AIDS).

    PubMed

    Ouattara, S A; Meite, M; Aron, Y; Akran, V; Gody, M; Manlan, L K; de-The, G

    1990-01-01

    During the period from January to December 1987, 2,191 serum samples were collected from different groups of the population in the Ivory Coast (1,126 healthy people selected from the general population, 416 blood donors, 112 healthy anti-HIV carriers, 173 AIDS patients, and 364 patients suffering from icterigenic hepatitis) and tested for anti-HIV (HIV-1 and HIV-2) antibodies, HBsAg, HBeAg, delta antigen (HDAg), and anti-delta (anti-HD) antibody. Anti-HIV antibodies were found in 30 (2.6%) of the general population. 55 (13.2%) blood donors, and 93 (25.5%) patients suffering from icterigenic hepatitis. HBsAg was observed in 103 (9.1%) of the general population, 45 (10.8%) blood donors, 15 (13.4%) healthy anti-HIV carriers, 59 (34.1%) AIDS patients, and 45 (40%) icterigenous hepatitis patients. The simultaneous presence of anti-HIV and HBsAg was noted in 4 (0.4%) of the general population, 8 (2%) blood donors, 15 (13.4%) healthy anti-HIV carriers, 59 (34.1%) AIDS cases, and 36 (10%) patients suffering from icterigenic hepatitis. A high prevalence of HBeAg and serological markers of infection by the delta agent were noted in the different groups. HDAg was noted only among AIDS patients or those suffering from icterigenic hepatitis, with a higher frequency among anti-HIV carriers. Our conclusion from this study is that healthy anti-HIV carriers are no more likely to be HBsAg carriers than the HIV-seronegative subjects. However, immunodeficiency induced previously by HIV infection is likely to be responsible for the high prevalence of HBsAg among AIDS patients.

  9. Modeling dynamic high-DOF finger postures from surface EMG using nonlinear synergies in latent space representation.

    PubMed

    Ngeo, Jimson; Tamei, Tomoya; Ikeda, Kazushi; Shibata, Tomohiro

    2015-01-01

    Accurate proportional myoelectric control of the hand is important in replicating dexterous manipulation in robot prostheses and orthoses. However, this is still difficult to achieve due to the complex and high degree-of-freedom (DOF) nature present in the governing musculoskeletal system. To address this problem, we suggest using a low dimensional encoding based on nonlinear synergies to represent both the high-DOF finger joint kinematics and the coordination of muscle activities taken from surface electromyographic (EMG) signals. Generating smooth multi-finger movements using EMG inputs is then done by using a shared Gaussian Process latent variable model that learns a dynamical model between both the kinematic and EMG data represented in a shared latent space. The experimental results show that the method is able to synthesize continuous movements of a full five-finger hand model, with total dimensions as large as 69 (although highly redundant and correlated). Finally, by comparing the estimation performances when the number of EMG latent dimensions are varied, we show that these synergistic features can capture the variance, shared and specific to the observed kinematics.

  10. A new diabatic representation of the coupled potential energy surfaces for Na(3p P-2) + H2 yields Na(3s S-2) + H2 or NaH + H

    NASA Technical Reports Server (NTRS)

    Halvick, Philippe; Truhlar, Donald G.

    1992-01-01

    A diabatic representation is presented of the coupled potential-energy surfaces for Na(3p P-2) + H2 yields Na (3s S-2) + H2 or NaH + H. The representation is designed to yield, upon diagonalization, realistic values for the two lowest energy adiabatic states at both asymptotes of the chemical reaction as well as near the conical intersection in the three-body interaction region. It is economical to evaluate and portable. It is suitable for dynamics calculations on both the quenching process and the electronically nonadiabatic chemical reaction.

  11. ERTS-1 data in support of the national program of inspection of dams. [computer-aided detection and location of surface waters

    NASA Technical Reports Server (NTRS)

    Graybeal, G. E.; Hall, F. G.; Moore, B. H.; Schlosser, E. H.

    1974-01-01

    A computer-aided procedure, for use in the detection and location of areas of surface water, has been developed. The procedure was developed in support of the National Program of Inspection of Dams established by Public Law 92-367. The procedure utilizes data acquired by the unmanned Earth Resources Technology Satellite in conjunction with ancillary data in the form of topographic and highway maps, and meteorological data summaries. The procedure is divided into several distinct phases. A five-volume manual has been prepared to instruct potential users of the procedure.

  12. Graphical Description of Johnson-Neyman Outcomes for Linear and Quadratic Regression Surfaces.

    ERIC Educational Resources Information Center

    Schafer, William D.; Wang, Yuh-Yin

    A modification of the usual graphical representation of heterogeneous regressions is described that can aid in interpreting significant regions for linear or quadratic surfaces. The standard Johnson-Neyman graph is a bivariate plot with the criterion variable on the ordinate and the predictor variable on the abscissa. Regression surfaces are drawn…

  13. A vertical representation of soil carbon in the JULES land surface scheme (vn4.3_permafrost) with a focus on permafrost regions

    NASA Astrophysics Data System (ADS)

    Burke, Eleanor J.; Chadburn, Sarah E.; Ekici, Altug

    2017-02-01

    An improved representation of the carbon cycle in permafrost regions will enable more realistic projections of the future climate-carbon system. Currently JULES (the Joint UK Land Environment Simulator) - the land surface model of the UK Earth System Model (UKESM) - uses the standard four-pool RothC soil carbon model. This paper describes a new version of JULES (vn4.3_permafrost) in which the soil vertical dimension is added to the soil carbon model, with a set of four pools in every soil layer. The respiration rate in each soil layer depends on the temperature and moisture conditions in that layer. Cryoturbation/bioturbation processes, which transfer soil carbon between layers, are represented by diffusive mixing. The litter inputs and the soil respiration are both parametrized to decrease with increasing depth. The model now includes a tracer so that selected soil carbon can be labelled and tracked through a simulation. Simulations show an improvement in the large-scale horizontal and vertical distribution of soil carbon over the standard version of JULES (vn4.3). Like the standard version of JULES, the vertically discretized model is still unable to simulate enough soil carbon in the tundra regions. This is in part because JULES underestimates the plant productivity over the tundra, but also because not all of the processes relevant for the accumulation of permafrost carbon, such as peat development, are included in the model. In comparison with the standard model, the vertically discretized model shows a delay in the onset of soil respiration in the spring, resulting in an increased net uptake of carbon during this time. In order to provide a more suitable representation of permafrost carbon for quantifying the permafrost carbon feedback within UKESM, the deep soil carbon in the permafrost region (below 1 m) was initialized using the observed soil carbon. There is now a slight drift in the soil carbon ( < 0.018 % decade-1), but the change in simulated soil

  14. Hearing Aids

    MedlinePlus

    ... more in both quiet and noisy situations. Hearing aids help people who have hearing loss from damage ... your doctor. There are different kinds of hearing aids. They differ by size, their placement on or ...

  15. AIDS (image)

    MedlinePlus

    AIDS (acquired immune deficiency syndrome) is caused by HIV (human immunodeficiency virus), and is a syndrome that ... life-threatening illnesses. There is no cure for AIDS, but treatment with antiviral medicine can suppress symptoms. ...

  16. Assessment of a handheld fluorescence imaging device as a visual-aid for detection of food residues on processing surfaces

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Contamination of food with pathogenic bacteria can lead to foodborne illnesses. Food processing surfaces can serve as a medium for cross-contamination if sanitization procedures are inadequate. Ensuring that food processing surfaces are correctly cleaned and sanitized is important in the food indust...

  17. Surface modification of cellulose fiber via supramolecular assembly of biodegradable polyesters by the aid of host-guest inclusion complexation.

    PubMed

    Zhao, Qiang; Wang, Shufang; Cheng, Xinjian; Yam, Richard C M; Kong, Deling; Li, Robert K Y

    2010-05-10

    In this article, we report a novel surface modification method for cellulose fiber that is based on supramolecular assembly. Beta-cyclodextrin (beta-CD) was first covalently grafted onto the fiber surface. Then poly(epsilon-caprolactone) (PCL) oligomers having both ends capped with adamantane motifs (i.e., PCL-AD) were immobilized to the cellulose fiber surface through the host-guest inclusion complexation between beta-CD and AD motif. FTIR-ATR and XPS analyses confirmed the successful assembly of PCL-ADs, which was further supported by the increasing trend of weight gain with the concentration of CDs on the fiber surface. Contact angle and TGA measurements reflect the enhanced hydrophobicity and thermal stability of the cellulose fiber as a consequence of this modification. The morphologies of the cellulose fiber before and after the assembly process have also been compared by SEM.

  18. Graphic Representations as Tools for Decision Making.

    ERIC Educational Resources Information Center

    Howard, Judith

    2001-01-01

    Focuses on the use of graphic representations to enable students to improve their decision making skills in the social studies. Explores three visual aids used in assisting students with decision making: (1) the force field; (2) the decision tree; and (3) the decision making grid. (CMK)

  19. Crawling Aid

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The Institute for the Achievement of Human Potential developed a device known as the Vehicle for Initial Crawling (VIC); the acronym is a tribute to the crawler's inventor, Hubert "Vic" Vykukal; is an effective crawling aid. The VIC is used by brain injured children who are unable to crawl due to the problems of weight-bearing and friction, caused by gravity. It is a rounded plywood frame large enough to support the child's torso, leaving arms and legs free to move. On its underside are three aluminum discs through which air is pumped to create an air-bearing surface that has less friction than a film of oil. Upper side contains the connection to the air supply and a pair of straps which restrain the child and cause the device to move with him. VIC is used with the intent to recreate the normal neurological connection between brain and muscles. Over repetitive use of the device the child develops his arm and leg muscles as well as coordination. Children are given alternating therapy, with and without the VIC until eventually the device is no longer needed.

  20. Determination of metacrate in water samples using dispersive liquid-liquid microextraction and HPLC with the aid of response surface methodology and experimental design.

    PubMed

    Xia, Jia; Xiang, Bingren; Zhang, Wei

    2008-09-05

    An improved method for the determination of metacrate in water samples has been developed using dispersive liquid-liquid microextraction (DLLME) prior to liquid chromatography analysis. The variables of interest, such as the volume of extraction solvent and disperser solvent, salt effect, sample volume, and extraction time in the DLLME process, were optimized with the aid of response surface methodology and experimental design (RSM). Firstly, an orthogonal array design (OAD) was used to choose the significant variables for the optimization. Secondly, the significant factors were optimized by using a central composite design (CCD) and the quadratic model between the dependent and the independent variables was built. The proposed method showed good agreement between the experimental data and predictive value, and it has been successfully employed to determine metacrate in water samples. The limit of detection was 1 ng mL(-1) and, repeatability of the method, described as relative standard deviation, was 5.7% (n=5).

  1. Using reactive transport codes to provide mechanistic biogeochemistry representations in land surface models: A proof of concept with CLM-PFLOTRAN

    NASA Astrophysics Data System (ADS)

    Tang, Guoping; Yuan, Fengming; Bisht, Gautam; Hammond, Glenn; Lichtner, Peter; Kumar, Jitendra; Mills, Richard; Xu, Xiaofeng; Andre, Ben; Painter, Scott; Thornton, Peter

    2016-04-01

    We explore coupling to a configurable subsurface reactive transport code as a flexible and extensible approach to biogeochemistry in land surface models. A reaction network with the CLM-CN decomposition, nitrification, denitrification, and plant uptake similar to CLM4.5 is used as an example. We implement the reactions in the open-source PFLOTRAN code, coupled with the Community Land Model (CLM), and test at Arctic, temperate, and tropical sites. To make the reaction network designed for use in explicit time stepping in CLM compatible with the implicit time stepping used in PFLOTRAN, the Monod substrate rate-limiting function with a residual concentration is used to represent the limitation of nitrogen availability on plant uptake and immobilization. Switching from explicit to implicit methods increases numerical rigor but introduces computational challenges. Our objective is to achieve accurate, efficient, and robust numerical solutions to demonstrate the feasibility of CLM-PFLOTRAN soil biogeochemistry. Our results suggest that care needs to be taken to use scaling, clipping, or log transformation to avoid negative concentrations during the Newton iterations. With a tight relative update tolerance to avoid false convergence, an accurate solution can be achieved with about 50 {%} more computing time than CLM in point mode site simulations using either the scaling or clipping methods. The log transformation method takes 60-100 {%} more computing time than CLM. The computing time increases slightly for clipping and scaling; it increases substantially for log transformation for half saturation decrease from 10-3 to 10-9 \\unit{mol m-3}, which normally results in decreasing nitrogen concentrations. The frequent occurrence of very low concentrations (e.g. below nanomolar) can increase the computing time for clipping or scaling by about 20 {%}; computing time can be doubled for log transformation. Caution needs to be taken in choosing the appropriate scaling factor

  2. Geometric modeling for computer aided design

    NASA Technical Reports Server (NTRS)

    Schwing, James L.

    1993-01-01

    Over the past several years, it has been the primary goal of this grant to design and implement software to be used in the conceptual design of aerospace vehicles. The work carried out under this grant was performed jointly with members of the Vehicle Analysis Branch (VAB) of NASA LaRC, Computer Sciences Corp., and Vigyan Corp. This has resulted in the development of several packages and design studies. Primary among these are the interactive geometric modeling tool, the Solid Modeling Aerospace Research Tool (smart), and the integration and execution tools provided by the Environment for Application Software Integration and Execution (EASIE). In addition, it is the purpose of the personnel of this grant to provide consultation in the areas of structural design, algorithm development, and software development and implementation, particularly in the areas of computer aided design, geometric surface representation, and parallel algorithms.

  3. Détection de particules α à l'aide de charges électriques de surface

    NASA Astrophysics Data System (ADS)

    Charpak, G.; Cordurié, G.; Lewiner, J.; Morisseau, D.; Chabot, M.; Santiard, J.-C.

    La trajectoire d'une ou quelques particules α peut être visualisée en collectant sur un diélectrique les charges libérées dans un gaz le long de son trajet. La quantité de charges obtenue, sans multiplication, est faible et difficile à extraire du bruit de fond. Ce bruit de fond est dû, en particulier, aux charges ou à la polarisation résiduelles a la surface du diélectrique. Nous avons abaissé, de fçon sensible, ce niveau de charges résiduelles en les compensant avec les charges créées par une source de rayons α. La lecture des charges déposées par une seule particule est alors possible avec un dispositif de mesure électrométrique à tête tournante. The trajectory of one or a few α particles can be visualized by collecting on a dielectric the charges released in the gas by ionisation. The charge quantity obtained, without multiplication, is small and difficult to extract from the background noise. This background noise is, in particular, due to the residual charges or polarization near the surface of the dielectric. This residual surface charges have been significantly reduced by balancing them with charges created by a beam of α particles. Then, the reading of charges due to one particle can be performed with an electrometric measuring setup using a rotating head.

  4. Détection de particules α à l'aide de charges électriques de surface

    NASA Astrophysics Data System (ADS)

    Charpak, G.; Cordurié, G.; Lewiner, J.; Morisseau, D.; Chabot, M.; Santiard, J.-C.

    1993-12-01

    The trajectory of one or a few α particles can be visualized by collecting on a dielectric the charges released in the gas by ionisation. The charge quantity obtained, without multiplication, is small and difficult to extract from the background noise. This background noise is, in particular, due to the residual charges or polarization near the surface of the dielectric. This residual surface charges have been significantly reduced by balancing them with charges created by a beam of α particles. Then, the reading of charges due to one particle can be performed with an electrometric measuring setup using a rotating head. La trajectoire d'une ou quelques particules α peut être visualisée en collectant sur un diélectrique les charges libérées dans un gaz le long de son trajet. La quantité de charges obtenue, sans multiplication, est faible et difficile à extraire du bruit de fond. Ce bruit de fond est dû, en particulier, aux charges ou à la polarisation résiduelles à la surface du diélectrique. Nous avons abaissé, de façon sensible, ce niveau de charges résiduelles en les compensant avec les charges créées par une source de rayons α. La lecture des charges déposées par une seule particule est alors possible avec un dispositif de mesure électrométrique à tête tournante.

  5. Intersection of parametric surfaces using lookup tables

    NASA Technical Reports Server (NTRS)

    Hanna, S. L.; Abel, J. F.; Greenberg, D. P.

    1984-01-01

    When primitive structures in the form of parametric surfaces are combined and modified interactively to form complex intersecting surfaces, it becomes important to find the curves of intersection. One must distinguish between finding the shape of the intersection curve, which may only be useful for display purposes, and finding an accurate mathematical representation of the curve, which is important for any meaningful geometric modeling, analysis, design, or manufacturing involving the intersection. The intersection curve between two or more parametric surfaces is important in a variety of computer-aided design and manufacture areas. A few examples are shape design, analysis of groins, design of fillets, and computation of numerically controlled tooling paths. The algorithm presented here provides a mathematical representation of the intersection curve to a specified accuracy. It also provides the database that can simplify operations such as hidden-surface removal, surface rendering, profile identification, and interference or clearance computations.

  6. In vitro biocompatibility of plasma-aided surface-modified 316L stainless steel for intracoronary stents.

    PubMed

    Bayram, Cem; Mizrak, Alpay Koray; Aktürk, Selçuk; Kurşaklioğlu, Hurkan; Iyisoy, Atila; Ifran, Ahmet; Denkbaş, Emir Baki

    2010-10-01

    316L-type stainless steel is a raw material mostly used for manufacturing metallic coronary stents. The purpose of this study was to examine the chemical, wettability, cytotoxic and haemocompatibility properties of 316L stainless steel stents which were modified by plasma polymerization. Six different polymeric compounds, polyethylene glycol, 2-hydroxyethyl methacrylate, ethylenediamine, acrylic acid, hexamethyldisilane and hexamethyldisiloxane, were used in a radio frequency glow discharge plasma polymerization system. As a model antiproliferative drug, mitomycin-C was chosen for covalent coupling onto the stent surface. Modified SS 316L stents were characterized by water contact angle measurements (goniometer) and x-ray photoelectron spectroscopy. C1s binding energies showed a good correlation with the literature. Haemocompatibility tests of coated SS 316L stents showed significant latency (t-test, p < 0.05) with respect to SS 316L and control groups in each test.

  7. Hearing Aids

    MedlinePlus

    ... hair cells (outer and inner rows). When the vibrations move through this fluid, the tiny outer hair ... ear to the brain. Hearing aids intensify sound vibrations that the damaged outer hair cells have trouble ...

  8. Teaching Aids

    ERIC Educational Resources Information Center

    Barnard, W. Robert, Ed.

    1976-01-01

    Provides evaluations of several aids for teaching chemistry. Included are The Use of Chemical Abstracts, Practical Technical Writing, Infrared Spectroscopy Programs, and a film titled "You Can't Go Back." (RH)

  9. A pH dependent Raman and surface enhanced Raman spectroscopic studies of citrazinic acid aided by theoretical calculations.

    PubMed

    Sarkar, Sougata; Chowdhury, Joydeep; Dutta, Soumen; Pal, Tarasankar

    2016-12-05

    A pH dependent normal Raman scattering (NRS) and surface enhanced Raman scattering (SERS) spectral patterns of citrazinic acid (CZA), a biologically important molecule, have been investigated. The acid, with different pKa values (~4 and ~11) for the two different functional groups (-COOH and -OH groups), shows interesting range of color changes (yellow at pH~14 and brown at pH~2) with the variation in solution pH. Thus, depending upon the pH of the medium, CZA molecule can exist in various protonated and/or deprotonated forms. Here we have prescribed the existence different possible forms of CZA at different pH (Forms "C", "H" and "Dprot" at pH~14 and Forms "A", "D", and "P" at pH~2 respectively). The NRS spectra of these solutions and their respective SERS spectra over gold nanoparticles were recorded. The spectra clearly differ in their spectral profiles. For example the SERS spectra recorded with the CZA solution at pH~2 shows blue shift for different bands compared to its NRS window e.g. 406 to 450cm(-1), 616 to 632cm(-1), 1332 to 1343cm(-1) etc. Again, the most enhanced peak at ~1548cm(-1) in NRS while in the SERS window this appears at ~1580cm(-1). Similar observation was also made for CZA at pH~14. For example, the 423cm(-1) band in the NRS profile experience a blue shift and appears at ~447cm(-1) in the SERS spectrum as well as other bands at ~850, ~1067 and ~1214cm(-1) in the SERS window are markedly enhanced. It is also worth noting that the SERS spectra at the different pH also differ from each other. These spectral differences indicate the existence of various adsorptive forms of the CZA molecule depending upon the pH of the solution. Therefore based on the experimental findings we propose different possible molecular forms of CZA at different pH (acidic and alkaline) conditions. For example forms 'A', 'D' and 'P' existing in acidic pH (pH~2) and three other deprotonated forms 'C', 'H' and 'Dprot' in alkaline pH (pH~14). The DFT calculations for these

  10. A pH dependent Raman and surface enhanced Raman spectroscopic studies of citrazinic acid aided by theoretical calculations

    NASA Astrophysics Data System (ADS)

    Sarkar, Sougata; Chowdhury, Joydeep; Dutta, Soumen; Pal, Tarasankar

    2016-12-01

    A pH dependent normal Raman scattering (NRS) and surface enhanced Raman scattering (SERS) spectral patterns of citrazinic acid (CZA), a biologically important molecule, have been investigated. The acid, with different pKa values (~ 4 and ~ 11) for the two different functional groups (-COOH and -OH groups), shows interesting range of color changes (yellow at pH ~ 14 and brown at pH ~ 2) with the variation in solution pH. Thus, depending upon the pH of the medium, CZA molecule can exist in various protonated and/or deprotonated forms. Here we have prescribed the existence different possible forms of CZA at different pH (Forms "C", "H" and "Dprot" at pH ~ 14 and Forms "A", "D", and "P" at pH ~ 2 respectively). The NRS spectra of these solutions and their respective SERS spectra over gold nanoparticles were recorded. The spectra clearly differ in their spectral profiles. For example the SERS spectra recorded with the CZA solution at pH ~ 2 shows blue shift for different bands compared to its NRS window e.g. 406 to 450 cm- 1, 616 to 632 cm- 1, 1332 to 1343 cm- 1 etc. Again, the most enhanced peak at ~ 1548 cm- 1 in NRS while in the SERS window this appears at ~ 1580 cm- 1. Similar observation was also made for CZA at pH ~ 14. For example, the 423 cm- 1 band in the NRS profile experience a blue shift and appears at ~ 447 cm- 1 in the SERS spectrum as well as other bands at ~ 850, ~ 1067 and ~ 1214 cm- 1 in the SERS window are markedly enhanced. It is also worth noting that the SERS spectra at the different pH also differ from each other. These spectral differences indicate the existence of various adsorptive forms of the CZA molecule depending upon the pH of the solution. Therefore based on the experimental findings we propose different possible molecular forms of CZA at different pH (acidic and alkaline) conditions. For example forms 'A', 'D' and 'P' existing in acidic pH (pH ~ 2) and three other deprotonated forms 'C', 'H' and 'Dprot' in alkaline pH (pH ~ 14). The DFT

  11. HIV/AIDS - resources

    MedlinePlus

    Resources - HIV/AIDS ... The following organizations are good resources for information on AIDS : AIDS.gov -- www.aids.gov AIDS Info -- aidsinfo.nih.gov The Henry J. Kaiser Family Foundation -- www. ...

  12. Types of Hearing Aids

    MedlinePlus

    ... Devices Consumer Products Hearing Aids Types of Hearing Aids Share Tweet Linkedin Pin it More sharing options ... some features for hearing aids? What are hearing aids? Hearing aids are sound-amplifying devices designed to ...

  13. Understanding Representation in Design.

    ERIC Educational Resources Information Center

    Bodker, Susanne

    1998-01-01

    Discusses the design of computer applications, focusing on understanding design representations--what makes design representations work, and how, in different contexts. Examines the place of various types of representation (e.g., formal notations, models, prototypes, scenarios, and mock-ups) in design and the role of formalisms and representations…

  14. Coverage and representation of condoms in conjunction with HIV/AIDS in the Kenyan Daily Nation Newspaper from 1989-2003: a qualitative content analysis to inform health promotion.

    PubMed

    McMorrow, Shannon L; Lagerwey, Mary D; Ford, Leigh A

    HIV/AIDS has been a pressing problem in the East African country of Kenya for over 20 years. Promotion of condom use is one prevention strategy embraced in global health prevention of HIV, but use remains relatively low in Kenya. In order to better understand the socio-historic context of discourses about condoms in Kenya, this study explored how condoms were covered and represented in the Kenyan Daily Nation newspaper from 1989-2003. Qualitative content analysis was conducted for 91 items from the Daily Nation including articles, letters to the editor, columns, opinion and editorial pieces, advertisements, and cartoons. These items were systematically examined for the manner and content of manifest and latent references to condoms. Researchers found four major themes, "controversy and confusion," "we need to do more: condoms might help," "not for Kenyans or from Kenyans," and "stigmatized associations." Findings provide needed insight into the socio-cultural context surrounding condoms in Kenya that is often lacking within health promotion and HIV prevention programs.

  15. The Use of Coincident Synthetic Aperture Radar and Visible Imagery to Aid in the Analysis of Photon-Counting Lidar Data Sets Over Complex Ice/Snow Surfaces

    NASA Astrophysics Data System (ADS)

    Horan, Kimberly H.

    Qualitative and quantitative analysis of multi-sensor data is becoming increasingly useful as a method of improving our understanding of complex environments, and can be an effective tool in the arsenal to help climate scientists to predict sea level rise due to change in the mass balance of large glaciers in the Arctic and Antarctic. A novel approach to remote sensing of the continuously changing polar environment involves the use of coincident RADARSAT-2 synthetic aperture radar (SAR) imagery and Landsat 7 visible/near-infrared imagery, combined with digital elevation models (DEM) developed from Multiple Altimeter Beam Experimental Lidar (MABEL) data sets. MABEL is a scaled down model of the lidar altimeter that will eventually be flown on ICESat-2, and provides dense along-track and moderate slope (cross-track) elevation data over narrow (~198 m) aircraft transects. Because glacial terrain consists of steep slopes, crevices, glacial lakes, and outflow into the sea, accurate slope information is critical to our understanding of any changes that may be happening in the ice sheets. RADARSAT-2 operates in the C-band, at a wavelength of 5.55 cm, and was chosen partly for its ability to image the Earth under all atmospheric conditions, including clouds. The SAR images not only provide spatial context for the elevation data found using the lidar, but also offer key insights into the consistency of the snow and ice making up the glacier, giving us some idea of mean temperature and surface conditions on the ice sheet. Finally, Landsat 7 images provide us with information on the extent of the glacier, and additional understanding of the state of the glacial surface. To aid in the analysis of the three data sets, proper preparation of each data set must first be performed. For the lidar data, this required the development of a new data reduction technique, based on statistical analysis, to reduce the number of received photons to those representing only the surface return

  16. Classroom Aids

    ERIC Educational Resources Information Center

    Science Activities: Classroom Projects and Curriculum Ideas, 2007

    2007-01-01

    This article describes 6 aids for science instruction, including (1) the use of fudge to represent lava; (2) the "Living by Chemistry" program, designed to make high school chemistry more accessible to a diverse pool of students without sacrificing content; (3) NOAA and NSTA's online coral reef teaching tool, a new web-based "science toolbox" for…

  17. Floriculture Aide.

    ERIC Educational Resources Information Center

    Martin, Joyce; Looney, Era

    Designed for use in a self-paced, open-entry/open-exit vocational training program for a floriculture aide, this program guide is one of six for teachers of adult women offenders from a correctional institution. Module topic outlines and sample lesson plans are presented on eleven topics: occupational opportunities in the retail florist industry;…

  18. 30 CFR 56.18010 - First aid.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false First aid. 56.18010 Section 56.18010 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Safety Programs § 56.18010 First aid. An individual capable of providing first aid shall be available on all shifts. The individual...

  19. 30 CFR 56.18010 - First aid.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false First aid. 56.18010 Section 56.18010 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Safety Programs § 56.18010 First aid. An individual capable of providing first aid shall be available on all shifts. The individual...

  20. 30 CFR 56.18010 - First aid.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false First aid. 56.18010 Section 56.18010 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Safety Programs § 56.18010 First aid. An individual capable of providing first aid shall be available on all shifts. The individual...

  1. 30 CFR 56.18010 - First aid.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false First aid. 56.18010 Section 56.18010 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Safety Programs § 56.18010 First aid. An individual capable of providing first aid shall be available on all shifts. The individual...

  2. 30 CFR 56.18010 - First aid.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false First aid. 56.18010 Section 56.18010 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Safety Programs § 56.18010 First aid. An individual capable of providing first aid shall be available on all shifts. The individual...

  3. CAGI: Computer Aided Grid Interface. A work in progress

    NASA Technical Reports Server (NTRS)

    Soni, Bharat K.; Yu, Tzu-Yi; Vaughn, David

    1992-01-01

    Progress realized in the development of a Computer Aided Grid Interface (CAGI) software system in integrating CAD/CAM geometric system output and/or Interactive Graphics Exchange Standard (IGES) files, geometry manipulations associated with grid generation, and robust grid generation methodologies is presented. CAGI is being developed in a modular fashion and will offer fast, efficient and economical response to geometry/grid preparation, allowing the ability to upgrade basic geometry in a step-by-step fashion interactively and under permanent visual control along with minimizing the differences between the actual hardware surface descriptions and corresponding numerical analog. The computer code GENIE is used as a basis. The Non-Uniform Rational B-Splines (NURBS) representation of sculptured surfaces is utilized for surface grid redistribution. The computer aided analysis system, PATRAN, is adapted as a CAD/CAM system. The progress realized in NURBS surface grid generation, the development of IGES transformer, and geometry adaption using PATRAN will be presented along with their applicability to grid generation associated with rocket propulsion applications.

  4. Converting Boundary Representation Solid Models to Half-Space Representation Models for Monte Carlo Analysis

    SciTech Connect

    Davis JE, Eddy MJ, Sutton TM, Altomari TJ

    2007-03-01

    Solid modeling computer software systems provide for the design of three-dimensional solid models used in the design and analysis of physical components. The current state-of-the-art in solid modeling representation uses a boundary representation format in which geometry and topology are used to form three-dimensional boundaries of the solid. The geometry representation used in these systems is cubic B-spline curves and surfaces--a network of cubic B-spline functions in three-dimensional Cartesian coordinate space. Many Monte Carlo codes, however, use a geometry representation in which geometry units are specified by intersections and unions of half-spaces. This paper describes an algorithm for converting from a boundary representation to a half-space representation.

  5. XML-BASED REPRESENTATION

    SciTech Connect

    R. KELSEY

    2001-02-01

    For focused applications with limited user and use application communities, XML can be the right choice for representation. It is easy to use, maintain, and extend and enjoys wide support in commercial and research sectors. When the knowledge and information to be represented is object-based and use of that knowledge and information is a high priority, then XML-based representation should be considered. This paper discusses some of the issues involved in using XML-based representation and presents an example application that successfully uses an XML-based representation.

  6. HIV/AIDS Basics

    MedlinePlus

    ... Enter ZIP code or city Follow Act Against AIDS Act Against AIDS @talkHIV Act Against AIDS Get Email Updates on AAA Anonymous Feedback HIV/AIDS Media Infographics Syndicated Content Podcasts Slide Sets HIV/ ...

  7. It's about TIME: engendering AIDS in Africa.

    PubMed

    Brijnath, Bianca

    2007-01-01

    This paper analyses how TIME magazine represents sub-Saharan African women in its coverage of HIV/AIDS. As rates of infection escalate across the continent, researchers are increasingly emphasising the need to understand the socioeconomic and cultural contexts that make women particularly vulnerable to infection. Yet popular media representations of AIDS continue to rely on older colonial imageries of Africa as the feminised, diseased 'dark continent'. This article identifies three major themes in TIME's representation of sub-Saharan African women and HIV/AIDS: the metaphor of Africa as a woman in crisis, the construction of women as the means of transmission, and the engendered nature of the debate about the impact of international development policies. It is argued that the reliance on familiar cultural narratives often obscures the epidemiological, economic and cultural realities within which sub-Saharan women live. Not merely a consequence of unprotected sex, AIDS in sub-Saharan Africa is also the result of global economics and politics, reflecting the inequities between the West and Africa, male and female, white and black. The paper concludes with a call for further research on the role of representations of HIV/AIDS and its actual routes of transmission.

  8. Teaching AIDS.

    PubMed

    Short, R V

    1989-06-01

    This article reviews a peer group Acquired Immunodeficiency Syndrome (AIDS) educational program at a university in Australia. Studies in the US have shown that most adolescents, although sexually active, do not believe they are likely to become infected with the Human Immunodeficiency Virus, and therefore do not attempt to modify their sexual behavior. A 1st step in educating students is to introduce them to condoms and impress upon them the fact that condoms should be used at the beginning of all sexual relationships, whether homosexual or heterosexual. In this program 3rd year medical students were targeted, as they are effective communicators and disseminators of information to the rest of the student body. After class members blow up condoms, giving them a chance to handle various brands and observe the varying degrees of strength, statistical evidence about the contraceptive failure rate of condoms (0.6-14.7 per 100 women-years) is discussed. Spermicides, such as nonoxynol-9 used in conjunction with condoms, are also discussed, as are condoms for women, packaging and marketing of condoms, including those made from latex and from the caecum of sheep, the latter condoms being of questionable effectiveness in preventing transmission of the virus. The care of terminal AIDS cases and current global and national statistics on AIDS are presented. The program also includes cash prizes for the best student essays on condom use, the distribution of condoms, condom key rings and T-shirts, and a student-run safe sex stand during orientation week. All of these activities are intended to involve students and attract the interest of the undergraduate community. Questionnaires administered to students at the end of the course revealed that the lectures were received favorably. Questionnaires administered to new medical and English students attending orientation week revealed that 72% of students thought the stand was a good idea and 81% and 83%, respectively found it

  9. Inscriptions Becoming Representations in Representational Practices

    ERIC Educational Resources Information Center

    Medina, Richard; Suthers, Daniel

    2013-01-01

    We analyze the interaction of 3 students working on mathematics problems over several days in a virtual math team. Our analysis traces out how successful collaboration in a later session is contingent upon the work of prior sessions and shows how the development of representational practices is an important aspect of these participants' problem…

  10. Embedded Data Representations.

    PubMed

    Willett, Wesley; Jansen, Yvonne; Dragicevic, Pierre

    2017-01-01

    We introduce embedded data representations, the use of visual and physical representations of data that are deeply integrated with the physical spaces, objects, and entities to which the data refers. Technologies like lightweight wireless displays, mixed reality hardware, and autonomous vehicles are making it increasingly easier to display data in-context. While researchers and artists have already begun to create embedded data representations, the benefits, trade-offs, and even the language necessary to describe and compare these approaches remain unexplored. In this paper, we formalize the notion of physical data referents - the real-world entities and spaces to which data corresponds - and examine the relationship between referents and the visual and physical representations of their data. We differentiate situated representations, which display data in proximity to data referents, and embedded representations, which display data so that it spatially coincides with data referents. Drawing on examples from visualization, ubiquitous computing, and art, we explore the role of spatial indirection, scale, and interaction for embedded representations. We also examine the tradeoffs between non-situated, situated, and embedded data displays, including both visualizations and physicalizations. Based on our observations, we identify a variety of design challenges for embedded data representation, and suggest opportunities for future research and applications.

  11. Wear your hat: representational resistance in safer sex discourse.

    PubMed

    Nelson, S D

    1994-01-01

    Through an analysis of four posters used by the AIDS Action Committee of Massachusetts, this article asks how representation can effectively promote safer sex practices. The images under investigation have different targeted groups--one is aimed at African-American men, one at Latinas, and two at gay men. Using a frame-work that connects definitions of sex in the respective communities with differences surrounding gender, race, and class, the imagery is unpacked in order to expose the effects of safer sex representation. This essay then argues that the degree to which ingrained definitions of sex are challenged constitutes a determining factor in the success or failure of safer sex representations.

  12. Living on the Moon: Persona, Identity, and Metaphor in Paul Monette's "Borrowed Time: An AIDS Memoir."

    ERIC Educational Resources Information Center

    Johnson, Deryl B.

    1995-01-01

    Explores the representation of AIDS in culture through narrative structure by focusing on the critically acclaimed autobiography "Borrowed Time: An AIDS Memoir" by Paul Monette. Examines how poesies and healing represent illness and reflects upon the negotiation between identity and dominant cultural images associated with AIDS. (PA)

  13. [Multi-Scale Convergence of Cold-Land Process Representation in Land-Surface Models, Microwave Remote Sensing, and Field Observations

    NASA Technical Reports Server (NTRS)

    Shi, Jiancheng

    2005-01-01

    The cryosphere is a major component of the hydrosphere and interacts significantly with the global climate system, the geosphere, and the biosphere. Measurement of the amount of water stored in the snow pack and forecasting the rate of melt are thus essential for managing water supply and flood control systems. Snow hydrologists are confronted with the dual problems of estimating both the quantity of water held by seasonal snow packs and time of snow melt. Monitoring these snow parameters is essential for one of the objectives of the Earth Science Enterprise-understanding of the global hydrologic cycle. Measuring spatially distributed snow properties, such as snow water equivalence (SWE) and wetness, from space is a key component for improvement of our understanding of coupled atmosphere-surface processes. Through the GWEC project, we have significantly advanced our understandings and improved modeling capabilities of the microwave signatures in response to snow and underground properties.

  14. AIDS.gov

    MedlinePlus

    ... concerns. Search Services Share This Help National HIV/AIDS Strategy Check out NHAS's latest progress in the ... from AIDS.gov Read more AIDS.gov tweets AIDS.gov HIV/AIDS Basics • Federal Resources • Using New ...

  15. AIDS as social construction: text mining of AIDS-related information in the Italian press.

    PubMed

    Caputo, Andrea; Giacchetta, Agnese; Langher, Viviana

    2016-09-01

    Given the relevance of AIDS as a public health problem in the Italian context and of the role of mass media in the social construction of the phenomenon, the aim of the present study is twofold: (1) to explore the main AIDS-related themes in the Italian popular press; (2) to analyse the temporal trends of AIDS representations over the last decades. For the research, we decided to consult Italian newspaper articles produced between 1985 and 1990 and between 2005 and 2010 using the archives of the main two national newspapers (La Repubblica and Corriere della Sera), resulting in an overall sample of 446 newspaper articles. A computer-aided content analysis allowed the detection of five different thematic domains (clusters), respectively focused on: Medical care (7.47%), Family support (37.03%), Science and religion debate (27%), Social exclusion (17.6%) and Healthcare policies (10.9%). These thematic domains are conceived along two main latent dimensions (factors) which explain 72.47% of the data variance which respectively deal with: (1) Attitudes towards people with AIDS (care versus avoidance) and (2) Social mandate on AIDS (powerlessness versus control). The study results also reveal the potential evolution of representations of people with AIDS over time: from stigmatised subjects who represent a risk for the entire society within a climate of social control to people progressively symbolised as frail subjects that need to be taken care of.

  16. Acquisition and Representation of Knowledge for Distributed Command Decision Aiding

    DTIC Science & Technology

    1987-12-01

    will result when common knowledge structures and processes are used for both local and external knowledge elements (as in NTDS), we used common language ...tures of the I production system language known as OPS-5 was demonstrated in October 1984. Major weaknesses observed in the OPS-5 knowledge...including explanations), and modify rule-sets. Using the YAPS language and the MIT Flavors structures that are intrinsic to the University of Maryland Franz

  17. Function, anticipation, representation

    NASA Astrophysics Data System (ADS)

    Bickhard, Mark. H.

    2001-06-01

    Function emerges in certain kinds of far-from-equilibrium systems. One important kind of function is that of interactive anticipation, an adaptedness to temporal complexity. Interactive anticipation is the locus of the emergence of normative representational content, and, thus, of representation in general: interactive anticipation is the naturalistic core of the evolution of cognition. Higher forms of such anticipation are involved in the subsequent macro-evolutionary sequence of learning, emotions, and reflexive consciousness.

  18. Computational Geometry and Computer-Aided Design

    NASA Technical Reports Server (NTRS)

    Fay, T. H. (Compiler); Shoosmith, J. N. (Compiler)

    1985-01-01

    Extended abstracts of papers addressing the analysis, representation, and synthesis of shape information are presented. Curves and shape control, grid generation and contouring, solid modelling, surfaces, and curve intersection are specifically addressed.

  19. The sensitivity of simulated competition between different plant functional types to subgrid-scale representation of vegetation in a land surface model

    NASA Astrophysics Data System (ADS)

    Shrestha, R. K.; Arora, V. K.; Melton, J. R.

    2016-03-01

    The Canadian Land Surface Scheme coupled to the Canadian Terrestrial Ecosystem Model is used to simulate competition between the model's seven non-crop plant functional types (PFTs) for available space. Our objective is to assess if the model is successfully able to reproduce the observed mix of PFTs and their fractional coverages and to what extent the simulated competition is affected by the manner in which the subgrid-scale variability of vegetation is represented. The model can be run either in a composite (single tile) configuration, where structural vegetation attributes of PFTs are aggregated for use in grid-averaged energy and water balance calculations, or a mosaic (multiple tiles) configuration, where separate energy and water balance calculations are performed for each PFT. The model realistically simulates the fractional coverages of trees, grasses, and bare ground, as well as that of individual tree and grass PFTs and their succession patterns. Our results show that the model is not overly sensitive to the manner in which subgrid-scale variability of vegetation is represented. Of the seven sites chosen across the globe to illustrate the difference between the two configurations, the simulated fractional coverage of PFTs are generally very similar (root-mean-square difference, RMSD, < 5%) between the composite and mosaic configurations at locations characterized by low heterogeneity (e.g., Amazonia, Vancouver Island, and the Tibetan Plateau), whereas at locations characterized by high heterogeneity (e.g., India, South Sudan and California), the two configurations yield somewhat different results (RMSD > 5%).

  20. Toward Chemical Accuracy in the Description of Ion-Water Interactions through Many-Body Representations. I. Halide-Water Dimer Potential Energy Surfaces.

    PubMed

    Bajaj, Pushp; Götz, Andreas W; Paesani, Francesco

    2016-06-14

    Despite recent progress, a unified understanding of how ions affect the structure and dynamics of water across different phases remains elusive. Here, we report the development of full-dimensional many-body potential energy functions, called MB-nrg (Many-Body-energy), for molecular simulations of halide ion-water systems from the gas phase to the condensed phase. The MB-nrg potentials are derived entirely from "first-principles" calculations carried out at the F12 explicitly correlated coupled-cluster level including single, double, and perturbative triple excitations, CCSD(T)-F12, in the complete basis set limit. Building upon the functional form of the MB-pol water potential, the MB-nrg potentials are expressed through the many-body expansion of the total energy in terms of explicit contributions representing one-body, two-body, and three-body interactions, with all higher-order contributions being described by classical induction. The specific focus of this study is on the MB-nrg two-body terms representing the full-dimensional potential energy surfaces (PESs) of the corresponding H2O-X(-) dimers, with X(-)= F(-), Cl(-), Br(-), and I(-). The accuracy of the MB-nrg PESs is systematically assessed through extensive comparisons with results obtained using both ab initio models and polarizable force fields for energies, structures, and harmonic frequencies of the H2O-X(-) dimers.

  1. Contacts de langues et representations (Language Contacts and Representations).

    ERIC Educational Resources Information Center

    Matthey, Marinette, Ed.

    1997-01-01

    Essays on language contact and the image of language, entirely in French, include: "Representations 'du' contexte et representations 'en' contexte? Eleves et enseignants face a l'apprentissage de la langue" ("Representations 'of' Context or Representations 'in' Context? Students and Teachers Facing Language Learning" (Laurent…

  2. Interactivity of Visual Mathematical Representations: Factors Affecting Learning and Cognitive Processes

    ERIC Educational Resources Information Center

    Sedig, Kamran; Liang, Hai-Ning

    2006-01-01

    Computer-based mathematical cognitive tools (MCTs) are a category of external aids intended to support and enhance learning and cognitive processes of learners. MCTs often contain interactive visual mathematical representations (VMRs), where VMRs are graphical representations that encode properties and relationships of mathematical concepts. In…

  3. When Best Intentions Go Awry: The Failures of Concrete Representations to Help Solve Probability Word Problems

    ERIC Educational Resources Information Center

    Beitzel, Brian D.; Staley, Richard K.; DuBois, Nelson F.

    2011-01-01

    Previous research has cast doubt on the efficacy of utilizing external representations as an aid to solving word problems. The present study replicates previous findings that concrete representations hinder college students' ability to solve probability word problems, and extends those findings to apply to a multimedia instructional context. Our…

  4. Heart attack first aid

    MedlinePlus

    First aid - heart attack; First aid - cardiopulmonary arrest; First aid - cardiac arrest ... of patients with unstable angina/non-ST-elevation myocardial infarction (updating the 2007 guideline and replacing the 2011 ...

  5. Buying a Hearing Aid

    MedlinePlus

    ... aids typically cannot be custom-fit. What are costs and styles of hearing aids? Hearing aids vary ... and for improvement in hearing tones. Real ear measurements may also be done, which determine how much ...

  6. Neurological Complications of AIDS

    MedlinePlus

    ... Patient & Caregiver Education » Fact Sheets Neurological Complications of AIDS Fact Sheet Table of Contents (click to jump ... Where can I get more information? What is AIDS? AIDS (acquired immune deficiency syndrome) is a condition ...

  7. HIV and AIDS

    MedlinePlus

    ... dientes Video: Getting an X-ray HIV and AIDS KidsHealth > For Kids > HIV and AIDS Print A ... serious infection. continue How Many People Have HIV/AIDS? Since the discovery of the virus in 1983, ...

  8. The Sensitivity of Simulated Competition Between Different Plant Functional Types to Subgrid Scale Representation of Vegetation in a Land Surface Model

    NASA Astrophysics Data System (ADS)

    Shrestha, R. K.; Arora, V.; Melton, J. R.

    2014-12-01

    Vegetation is a dynamic component of the earth system that affects weather and climate at hourly to centennial time scales. However, most current dynamic vegetation models do not explicitly simulate competition among Plant Functional Types (PFTs). Here we use the coupled CLASS-CTEM model (Canadian Land Surface Scheme coupled to Canadian Terrestrial Ecosystem Model) to explicitly simulate competition between nine PFTs for available space using a modified version of Lotka - Volterra (LV) predator-prey equations. The nine PFTs include evergreen and deciduous needleleaf trees, evergreen and cold and drought deciduous broadleaf trees and C3 and C4 crops and grasses. The CLASS-CTEM model can be configured either in the composite (single tile) or the mosaic (multiple tiles) mode. Our results show that the model is sensitive to the chosen mode. The simulated fractional coverage of PFTs are similar between two approaches at some locations whereas at the other locations the two approaches yield different results. The simulated fractional coverage of PFTs are also compared with the available observations-based estimates. Simulated results at selected locations across the globe show that the model is able to realistically simulate the fractional coverage of tree and grass PFTs and the bare fraction, as well as the fractional coverage of individual tree and grass PFTs. Along with the observed patterns of vegetation distribution the CLASS-CTEM modelling framework is also able to simulate realistic succession patterns. Some differences remain and these are attributed to the coarse spatial resolution of the model (~3.75°) and the limited number of PFTs represented in the model.

  9. Ergogenic aids.

    PubMed

    Coyle, E F

    1984-07-01

    The catabolism of bodily fuels provides the energy for muscular work. Work output can be limited by the size of fuel reserves, the rate of their catabolism, the build-up of by-products, or the neurologic activation of muscle. A substance that favorably affects a step that is normally limiting, and thus increases work output, can be considered an ergogenic aid. The maximal amount of muscular force generated during brief contractions can be acutely increased during hypnosis and with the ingestion of a placebo or psychomotor stimulant. This effect is most obvious in subjects under laboratory conditions and is less evident in athletes who are highly motivated prior to competition. Fatigue is associated with acidosis in the working musculature when attempts are made to maximize work output during a 4 to 15-minute period. Sodium bicarbonate ingestion may act to buffer the acid produced, provided that blood flow to the muscle is adequate. Prolonged intense exercise can be maintained for approximately two hours before carbohydrate stores become depleted. Carbohydrate feedings delay fatigue during prolonged exercise, especially in subjects who display a decline in blood glucose during exercise in the fasting state. Caffeine ingestion prior to an endurance bout has been reported to allow an individual to exercise somewhat more intensely than he or she would otherwise. Its effect may be mediated by augmenting fat metabolism or by altering the perception of effort. Amphetamines may act in a similar manner. Water ingestion during prolonged exercise that results in dehydration and hyperthermia can offset fluid losses and allow an individual to better maintain work output while substantially reducing the risk of heat-related injuries.

  10. Spinorial representation of submanifolds in metric Lie groups

    NASA Astrophysics Data System (ADS)

    Bayard, Pierre; Roth, Julien; Zavala Jiménez, Berenice

    2017-04-01

    In this paper we give a spinorial representation of submanifolds of any dimension and codimension into Lie groups equipped with left invariant metrics. As applications, we get a spinorial proof of the Fundamental Theorem for submanifolds into Lie groups, we recover previously known representations of submanifolds in Rn and in the 3-dimensional Lie groups S3 and E(κ , τ) , and we get a new spinorial representation for surfaces in the 3-dimensional semi-direct products: this achieves the spinorial representations of surfaces in the 3-dimensional homogeneous spaces. We finally indicate how to recover a Weierstrass-type representation for CMC-surfaces in 3-dimensional metric Lie groups recently given by Meeks, Mira, Perez and Ros.

  11. Spacecraft Attitude Representations

    NASA Technical Reports Server (NTRS)

    Markley, F. Landis

    1999-01-01

    The direction cosine matrix or attitude matrix is the most fundamental representation of the attitude, but it is very inefficient: It has six redundant parameters, it is difficult to enforce the six (orthogonality) constraints. the four-component quaternion representation is very convenient: it has only one redundant parameter, it is easy to enforce the normalization constraint, the attitude matrix is a homogeneous quadratic function of q, quaternion kinematics are bilinear in q and m. Euler angles are extensively used: they often have a physical interpretation, they provide a natural description of some spacecraft motions (COBE, MAP), but kinematics and attitude matrix involve trigonometric functions, "gimbal lock" for certain values of the angles. Other minimum (three-parameter) representations: Gibbs vector is infinite for 180 deg rotations, but useful for analysis, Modified Rodrigues Parameters are nonsingular, no trig functions, Rotation vector phi is nonsingular, but requires trig functions.

  12. Learning network representations

    NASA Astrophysics Data System (ADS)

    Moyano, Luis G.

    2017-02-01

    In this review I present several representation learning methods, and discuss the latest advancements with emphasis in applications to network science. Representation learning is a set of techniques that has the goal of efficiently mapping data structures into convenient latent spaces. Either for dimensionality reduction or for gaining semantic content, this type of feature embeddings has demonstrated to be useful, for example, for node classification or link prediction tasks, among many other relevant applications to networks. I provide a description of the state-of-the-art of network representation learning as well as a detailed account of the connections with other fields of study such as continuous word embeddings and deep learning architectures. Finally, I provide a broad view of several applications of these techniques to networks in various domains.

  13. Umbra's system representation.

    SciTech Connect

    McDonald, Michael James

    2005-07-01

    This document describes the Umbra System representation. Umbra System representation, initially developed in the spring of 2003, is implemented in Incr/Tcl using concepts borrowed from Carnegie Mellon University's Architecture Description Language (ADL) called Acme. In the spring of 2004 through January 2005, System was converted to Umbra 4, extended slightly, and adopted as the underlying software system for a variety of Umbra applications that support Complex Systems Engineering (CSE) and Complex Adaptive Systems Engineering (CASE). System is now a standard part Of Umbra 4. While Umbra 4 also includes an XML parser for System, the XML parser and Schema are not described in this document.

  14. Database-Aided Diagnosis in Digital Mammography

    DTIC Science & Technology

    2001-07-01

    panel of radiologists consisted of Anthony C. Disher, MD, Robert C. Murchison, MD, Janis F. Owens, MD, and Carolyn R. Towler, MD. Jack I. Eisenman...Database-Aided Decisions," 1997. J. Ribas -Corbera, "Image Data Compress and Interframe Interpolation of Cinematic Sequences," 1992. M. R. Vriesenga...Cinematic Sequences" (with J. Ribas -Corbera), Journal of Visual Communication and Image Representation, Vol. 4, No. 4, December 1993, pp. 392-406. 13

  15. On volume-source representations based on the representation theorem

    NASA Astrophysics Data System (ADS)

    Ichihara, Mie; Kusakabe, Tetsuya; Kame, Nobuki; Kumagai, Hiroyuki

    2016-01-01

    We discuss different ways to characterize a moment tensor associated with an actual volume change of ΔV C , which has been represented in terms of either the stress glut or the corresponding stress-free volume change ΔV T . Eshelby's virtual operation provides a conceptual model relating ΔV C to ΔV T and the stress glut, where non-elastic processes such as phase transitions allow ΔV T to be introduced and subsequent elastic deformation of - ΔV T is assumed to produce the stress glut. While it is true that ΔV T correctly represents the moment tensor of an actual volume source with volume change ΔV C , an explanation as to why such an operation relating ΔV C to ΔV T exists has not previously been given. This study presents a comprehensive explanation of the relationship between ΔV C and ΔV T based on the representation theorem. The displacement field is represented using Green's function, which consists of two integrals over the source surface: one for displacement and the other for traction. Both integrals are necessary for representing volumetric sources, whereas the representation of seismic faults includes only the first term, as the second integral over the two adjacent fault surfaces, across which the traction balances, always vanishes. Therefore, in a seismological framework, the contribution from the second term should be included as an additional surface displacement. We show that the seismic moment tensor of a volume source is directly obtained from the actual state of the displacement and stress at the source without considering any virtual non-elastic operations. A purely mathematical procedure based on the representation theorem enables us to specify the additional imaginary displacement necessary for representing a volume source only by the displacement term, which links ΔV C to ΔV T . It also specifies the additional imaginary stress necessary for representing a moment tensor solely by the traction term, which gives the "stress glut." The

  16. The Master Hearing Aid

    PubMed Central

    Curran, James R.

    2013-01-01

    As early as the 1930s the term Master Hearing Aid (MHA) described a device used in the fitting of hearing aids. In their original form, the MHA was a desktop system that allowed for simulated or actual adjustment of hearing aid components that resulted in a changed hearing aid response. Over the years the MHA saw many embodiments and contributed to a number of rationales for the fitting of hearing aids. During these same years, the MHA was viewed by many as an inappropriate means of demonstrating hearing aids; the audio quality of the desktop systems was often superior to the hearing aids themselves. These opinions and the evolution of the MHA have molded the modern perception of hearing aids and the techniques used in the fitting of hearing aids. This article reports on a history of the MHA and its influence on the fitting of hearing aids. PMID:23686682

  17. Stationary Subdivision and Multiresolution Surface Representation

    DTIC Science & Technology

    1998-01-01

    1D #$50� " 79WB ,.% #$% ø �]��À ½ ´ % ,J1% <8...K � 8 𔃺,;-¬g ¿ � § � N3kd® � kdÅ 1D #$50<G=#$% Ô ®\\ � l � ¸0�?¡Ô ® � l � k_Å � =,�l �¨§ *� <-&L¬ ´ 1 ¸ K �0< 7 �?� K&j...F�8=,.%& ,;#$%&7C=#?81 /,!<2B%&I#$5=#y#$5�<G=#$% � *a#$509,;8 " 1D ,. .OM,!# #?<.7#? @#$50Z10

  18. Knowledge Representation in PARKA

    DTIC Science & Technology

    1990-02-01

    the color of Poodle could be restricted to being just black or white, while the color of Irish-Setter could be set to red. Note that this would allow a...sub- field of knowledge representation with considerable subtlety and a history of interesting, difficult problems (see, e.g. [10]). Winston et. al

  19. Reading Students' Representations

    ERIC Educational Resources Information Center

    Diezmann, Carmel M.; McCosker, Natalie T.

    2011-01-01

    Representations play a key role in mathematical thinking: They offer "a medium" to express mathematical knowledge or organize mathematical information and to discern mathematical relationships (e.g., relative household expenditures on a pie chart) using text, symbols, or graphics. They also furnish "tools" for mathematical processes (e.g., use of…

  20. The Problem of Representation

    ERIC Educational Resources Information Center

    Tervo, Juuso

    2012-01-01

    In "Postphysical Vision: Art Education's Challenge in an Age of Globalized Aesthetics (AMondofesto)" (2008) and "Beyond Aesthetics: Returning Force and Truth to Art and Its Education" (2009), jan jagodzinski argued for politics that go "beyond" representation--a project that radically questions visual culture…

  1. How to Get Hearing Aids

    MedlinePlus

    ... Consumer Products Hearing Aids How to get Hearing Aids Share Tweet Linkedin Pin it More sharing options ... my hearing aids? How do I get hearing aids? Before getting a hearing aid, you should consider ...

  2. Preparation of perovskite-type oxides of cobalt by the malic acid aided process and their electrocatalytic surface properties in relation to oxygen evolution

    SciTech Connect

    Tiwari, S.K.; Chartier, P.; Singh, R.N. . Electrochemical Lab.)

    1995-01-01

    The electrocatalytic properties of perovskite-type cobalt oxides (La[sub 1[minus]x]Sr[sub x]CoO[sub 3], where x = 0, 0.2, 0.4), in the form of thin films on conductive supports, were studied by cyclic voltammetry and Tafel polarization techniques. The films had conductive and satisfactory adherent properties. The oxides were synthesized by a low temperature malic acid aided method. The cyclic voltammetry showed a pair of redox peaks prior to the onset of oxygen evolution on the oxide film with nickel support, while similar peaks were absent in the same oxide film on Pt and Ti. The anodic polarization studies indicated two Tafel slopes: 57 to 64 mV/decade at low and 100 to 130 mV/decade at high overpotentials, and first-order kinetics with respect to OH[sup [minus

  3. HIV infection and AIDS.

    PubMed

    Lloyd, A

    1996-09-01

    Many of the clinical features of HIV/AIDS can be ascribed to the profound immune deficiency which develops in infected patients. The destruction of the immune system by the virus results in opportunistic infection, as well as an increased risk of autoimmune disease and malignancy. In addition, disease manifestations related to the virus itself may occur. For example, during the primary illness which occurs within weeks after first exposure to HIV, clinical symptoms occur in at least 50% of cases, typically as a mononucleosis syndrome. HIV-related complications are rarely encountered in patients with preserved immunity (i.e. CD4 T-cell counts greater than 500 cells/mm3). Recurrent mucocutaneous herpes simplex (HSV), herpes zoster (VZV), oral candidiasis and oral hairy leukoplakia occur with increasing frequency as the CD4 count drops below this level. Immune thrombocytopenia (ITP) occurs in association with HIV and often presents early in the clinical course. The risk of developing opportunistic infections and malignancies typical of AIDS increases progressively as CD4 counts fall below 200 cells/mm3. The clinical manifestations of infections associated with AIDS tend to fall into well-recognized patterns of presentation, including pneumonia, dysphagia/odynophagia, diarrhoea, neurological symptoms, fever, wasting, anaemia and visual loss. The commonest pathogens include Candida albicans, Pneumocystis carinii, Mycobacterium tuberculosis, Toxoplasma gondii, Cryptococcus neoformans, Mycobacterium avium intracellulare and cytomegalovirus. Malignant disease in patients with HIV infection also occurs in a characteristic pattern. Only two tumours are prevalent: Kaposi's sarcoma, a multifocal tumour of vascular endothelium which typically involves skin and mucosal surfaces; and non-Hodgkin's lymphoma, which is typically high grade in phenotype, often arising within the central nervous system. The principles of therapy include reduction of HIV replication by antiretroviral

  4. On the representation of many-body interactions in water

    SciTech Connect

    Medders, Gregory R.; Gotz, Andreas W.; Morales, Miguel A.; Bajaj, Pushp; Paesani, Francesco

    2015-09-09

    Our recent work has shown that the many-body expansion of the interactionenergy can be used to develop analytical representations of global potential energy surfaces (PESs) for water. In this study, the role of short- and long-range interactions at different orders is investigated by analyzing water potentials that treat the leading terms of the many-body expansion through implicit (i.e., TTM3-F and TTM4-F PESs) and explicit (i.e., WHBB and MB-pol PESs) representations. Moreover, it is found that explicit short-range representations of 2-body and 3-body interactions along with a physically correct incorporation of short- and long-range contributions are necessary for an accurate representation of the waterinteractions from the gas to the condensed phase. Likewise, a complete many-body representation of the dipole moment surface is found to be crucial to reproducing the correct intensities of the infrared spectrum of liquid water.

  5. Identifying Representational Competence with Multi-Representational Displays

    ERIC Educational Resources Information Center

    Stieff, Mike; Hegarty, Mary; Deslongchamps, Ghislain

    2011-01-01

    Increasingly, multi-representational educational technologies are being deployed in science classrooms to support science learning and the development of representational competence. Several studies have indicated that students experience significant challenges working with these multi-representational displays and prefer to use only one…

  6. Representations of SARS in the British newspapers.

    PubMed

    Washer, Peter

    2004-12-01

    In the Spring of 2003, there was a huge interest in the global news media following the emergence of a new infectious disease: severe acute respiratory syndrome (SARS). This study examines how this novel disease threat was depicted in the UK newspapers, using social representations theory and in particular existing work on social representations of HIV/AIDS and Ebola to analyse the meanings of the epidemic. It investigates the way that SARS was presented as a dangerous threat to the UK public, whilst almost immediately the threat was said to be 'contained' using the mechanism of 'othering': SARS was said to be unlikely to personally affect the UK reader because the Chinese were so different to 'us'; so 'other'. In this sense, the SARS scare, despite the remarkable speed with which it was played out in the modern global news media, resonates with the meanings attributed to other epidemics of infectious diseases throughout history. Yet this study also highlights a number of differences in the social representations of SARS compared with earlier epidemics. In particular, this study examines the phenomena of 'emerging and re-emerging infectious diseases' over the past 30 or so years and suggests that these have impacted on the faith once widely held that Western biomedicine could 'conquer' infectious disease.

  7. Standard model of knowledge representation

    NASA Astrophysics Data System (ADS)

    Yin, Wensheng

    2016-09-01

    Knowledge representation is the core of artificial intelligence research. Knowledge representation methods include predicate logic, semantic network, computer programming language, database, mathematical model, graphics language, natural language, etc. To establish the intrinsic link between various knowledge representation methods, a unified knowledge representation model is necessary. According to ontology, system theory, and control theory, a standard model of knowledge representation that reflects the change of the objective world is proposed. The model is composed of input, processing, and output. This knowledge representation method is not a contradiction to the traditional knowledge representation method. It can express knowledge in terms of multivariate and multidimensional. It can also express process knowledge, and at the same time, it has a strong ability to solve problems. In addition, the standard model of knowledge representation provides a way to solve problems of non-precision and inconsistent knowledge.

  8. 30 CFR 57.15001 - First aid materials.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false First aid materials. 57.15001 Section 57.15001 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Surface and Underground § 57.15001 First aid materials. Adequate first-aid materials, including...

  9. 30 CFR 57.15001 - First aid materials.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false First aid materials. 57.15001 Section 57.15001 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Surface and Underground § 57.15001 First aid materials. Adequate first-aid materials, including...

  10. 30 CFR 57.15001 - First aid materials.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false First aid materials. 57.15001 Section 57.15001 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Surface and Underground § 57.15001 First aid materials. Adequate first-aid materials, including...

  11. 30 CFR 57.15001 - First aid materials.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false First aid materials. 57.15001 Section 57.15001 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Surface and Underground § 57.15001 First aid materials. Adequate first-aid materials, including...

  12. 30 CFR 57.15001 - First aid materials.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false First aid materials. 57.15001 Section 57.15001 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Surface and Underground § 57.15001 First aid materials. Adequate first-aid materials, including...

  13. Representation in incremental learning

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Work focused on two areas in machine learning: representation for inductive learning and how to apply concept learning techniques to learning state preferences, which can represent search control knowledge for problem solving. Specifically, in the first area the issues of the effect of representation on learning, on how learning formalisms are biased, and how concept learning can benefit from the use of a hybrid formalism are addressed. In the second area, the issues of developing an agent to learn search control knowledge from the relative values of states, of the source of that qualitative information, and of the ability to use both quantitative and qualitative information in order to develop an effective problem-solving policy are examined.

  14. Multiple Sparse Representations Classification

    PubMed Central

    Plenge, Esben; Klein, Stefan S.; Niessen, Wiro J.; Meijering, Erik

    2015-01-01

    Sparse representations classification (SRC) is a powerful technique for pixelwise classification of images and it is increasingly being used for a wide variety of image analysis tasks. The method uses sparse representation and learned redundant dictionaries to classify image pixels. In this empirical study we propose to further leverage the redundancy of the learned dictionaries to achieve a more accurate classifier. In conventional SRC, each image pixel is associated with a small patch surrounding it. Using these patches, a dictionary is trained for each class in a supervised fashion. Commonly, redundant/overcomplete dictionaries are trained and image patches are sparsely represented by a linear combination of only a few of the dictionary elements. Given a set of trained dictionaries, a new patch is sparse coded using each of them, and subsequently assigned to the class whose dictionary yields the minimum residual energy. We propose a generalization of this scheme. The method, which we call multiple sparse representations classification (mSRC), is based on the observation that an overcomplete, class specific dictionary is capable of generating multiple accurate and independent estimates of a patch belonging to the class. So instead of finding a single sparse representation of a patch for each dictionary, we find multiple, and the corresponding residual energies provides an enhanced statistic which is used to improve classification. We demonstrate the efficacy of mSRC for three example applications: pixelwise classification of texture images, lumen segmentation in carotid artery magnetic resonance imaging (MRI), and bifurcation point detection in carotid artery MRI. We compare our method with conventional SRC, K-nearest neighbor, and support vector machine classifiers. The results show that mSRC outperforms SRC and the other reference methods. In addition, we present an extensive evaluation of the effect of the main mSRC parameters: patch size, dictionary size, and

  15. A method to convert algebraic boundary representations to CSG representations for three-dimensional solids

    SciTech Connect

    Buchele, S.F.; Ellingson, W.A.

    1997-06-01

    Recent advances in reverse engineering have focused on recovering a boundary representation (b-rep) of an object, often for integration with rapid prototyping. This boundary representation may be a 3-D point cloud, a triangulation of points, or piecewise algebraic or parametric surfaces. This paper presents work in progress to develop an algorithm to extend the current state of the art in reverse engineering of mechanical parts. This algorithm will take algebraic surface representations as input and will produce a constructive solid geometry (CSG) description that uses solid primitives such as rectangular block, pyramid, sphere, cylinder, and cone. The proposed algorithm will automatically generate a CSG solid model of a part given its algebraic b-rep, thus allowing direct input into a CAD system and subsequent CSG model generation.

  16. [Time perceptions and representations].

    PubMed

    Tordjman, S

    2015-09-01

    Representations of time and time measurements depend on subjective constructs that vary according to changes in our concepts, beliefs, societal needs and technical advances. Similarly, the past, the future and the present are subjective representations that depend on each individual's psychic time and biological time. Therefore, there is no single, one-size-fits-all time for everyone, but rather a different, subjective time for each individual. We need to acknowledge the existence of different inter-individual times but also intra-individual times, to which different functions and different rhythms are attached, depending on the system of reference. However, the construction of these time perceptions and representations is influenced by objective factors (physiological, physical and cognitive) related to neuroscience which will be presented and discussed in this article. Thus, studying representation and perception of time lies at the crossroads between neuroscience, human sciences and philosophy. Furthermore, it is possible to identify several constants among the many and various representations of time and their corresponding measures, regardless of the system of time reference. These include the notion of movements repeated in a stable rhythmic pattern involving the recurrence of the same interval of time, which enables us to define units of time of equal and invariable duration. This rhythmicity is also found at a physiological level and contributes through circadian rhythms, in particular the melatonin rhythm, to the existence of a biological time. Alterations of temporality in mental disorders will be also discussed in this article illustrated by certain developmental disorders such as autism spectrum disorders. In particular, the hypothesis will be developed that children with autism would need to create discontinuity out of continuity through stereotyped behaviors and/or interests. This discontinuity repeated at regular intervals could have been

  17. Translation between representation languages

    NASA Technical Reports Server (NTRS)

    Vanbaalen, Jeffrey

    1994-01-01

    A capability for translating between representation languages is critical for effective knowledge base reuse. A translation technology for knowledge representation languages based on the use of an interlingua for communicating knowledge is described. The interlingua-based translation process consists of three major steps: translation from the source language into a subset of the interlingua, translation between subsets of the interlingua, and translation from a subset of the interlingua into the target language. The first translation step into the interlingua can typically be specified in the form of a grammar that describes how each top-level form in the source language translates into the interlingua. In cases where the source language does not have a declarative semantics, such a grammar is also a specification of a declarative semantics for the language. A methodology for building translators that is currently under development is described. A 'translator shell' based on this methodology is also under development. The shell has been used to build translators for multiple representation languages and those translators have successfully translated nontrivial knowledge bases.

  18. Neurological Complications of AIDS

    MedlinePlus

    ... the neurological complications of AIDS. Some disorders require aggressive therapy while others are treated symptomatically. Medicines range ... certain bacterial infections, and penicillin to treat neurosyphilis. Aggressive antiretroviral therapy is used to treat AIDS dementia ...

  19. Unconsciousness - first aid

    MedlinePlus

    Loss of consciousness - first aid; Coma - first aid; Mental status change; Altered mental status ... person is unconscious and: Does not return to consciousness quickly (within a minute) Has fallen down or ...

  20. First Aid Tips

    MedlinePlus

    ... NEI for Kids > First Aid Tips All About Vision About the Eye Ask a Scientist Video Series ... Eye Health and Safety First Aid Tips Healthy Vision Tips Protective Eyewear Sports and Your Eyes Fun ...

  1. Home Health Aides

    MedlinePlus

    ... do the following: Assist clients in their daily personal tasks, such as bathing or dressing Provide basic ... social networks and communities Home health aides, unlike personal care aides , typically work for certified home health ...

  2. AIDS and Athletes.

    ERIC Educational Resources Information Center

    Calabrese, Leonard H.; Kelley, Dennis

    1989-01-01

    This article discusses the onset and progression of AIDS, its importance as a public health issue, and reducing the risk of AIDS transmission among athletes and those who work with them, including team physicians and athletic trainers. (IAH)

  3. HIV/AIDS

    MedlinePlus

    ... at risk for serious infections and certain cancers. AIDS stands for acquired immunodeficiency syndrome. It is the final stage of infection with HIV. Not everyone with HIV develops AIDS. HIV most often spreads through unprotected sex with ...

  4. HIV/AIDS

    MedlinePlus

    ... yeast infection (thrush) Shingles (herpes zoster) Progression to AIDS If you receive no treatment for your HIV ... childbirth or breast-feeding. How does HIV become AIDS? HIV destroys CD4 cells — a specific type of ...

  5. HIV/AIDS Coinfection

    MedlinePlus

    ... Laotian Mongolian Spanish Turkish Vietnamese Hindi Subscribe HIV/AIDS Coinfection Approximately 10% of the HIV-infected population ... Control and Prevention website to learn about HIV/AIDS and Viral Hepatitis guidelines and resources. Home About ...

  6. AIDS in Rural California.

    ERIC Educational Resources Information Center

    Wooten, Donald B.

    1989-01-01

    Examines the increase in AIDS patients in rural California, which is greater than that in urban areas, including AIDS population projections through 1991. Describes differences between AIDS populations in rural and urban areas and relates these to state expenditure patterns and differential needs. (DHP)

  7. A Teaching Aids Exhibition.

    ERIC Educational Resources Information Center

    Mahanja, Salah

    1985-01-01

    Describes an exhibition for the benefit of teachers of English in Arab Primary Schools, which was prepared by third-year students at the Teachers College for Arab Teachers. The exhibition included games, songs, audiovisual aids, crossword puzzles, vocabulary, spelling booklets, preposition aids, and worksheet and lesson planning aids. (SED)

  8. Difficult Decisions: AIDS.

    ERIC Educational Resources Information Center

    Slesnick, Irwin L.

    1988-01-01

    Focuses on public education about the acquired immune deficiency syndrome (AIDS) epidemic. Discusses the problems of a second epidemic of fear and anxiety. Presents several questions for classroom discussion and analysis of the public fear of AIDS. Gives some statistics highlighting misinformation about AIDS. (CW)

  9. Stroke: First Aid

    MedlinePlus

    First aid Stroke: First aid Stroke: First aid By Mayo Clinic Staff A stroke occurs when there's bleeding into your brain or when normal blood flow to ... next several hours. Seek immediate medical assistance. A stroke is a true emergency. The sooner treatment is ...

  10. Creating Motivating Job Aids.

    ERIC Educational Resources Information Center

    Tilaro, Angie; Rossett, Allison

    1993-01-01

    Explains how to create job aids that employees will be motivated to use, based on a review of pertinent literature and interviews with professionals. Topics addressed include linking motivation with job aids; Keller's ARCS (Attention, Relevance, Confidence, Satisfaction) model of motivation; and design strategies for job aids based on Keller's…

  11. HIV and AIDS

    MedlinePlus

    ... A Week of Healthy Breakfasts Shyness HIV and AIDS KidsHealth > For Teens > HIV and AIDS Print A A A What's in this article? ... in human history. HIV causes a condition called acquired immunodeficiency syndrome — better known as AIDS . HIV destroys a type ...

  12. Designing State Aid Formulas

    ERIC Educational Resources Information Center

    Zhao, Bo; Bradbury, Katharine

    2009-01-01

    This paper designs a new equalization-aid formula based on fiscal gaps of local communities. When states are in transition to a new local aid formula, the issue of whether and how to hold existing aid harmless poses a challenge. The authors show that some previous studies and the formulas derived from them give differential weights to existing and…

  13. Space Derived Health Aids (AID, Heart Monitor)

    NASA Technical Reports Server (NTRS)

    1981-01-01

    CPI's spinoff from miniaturized pace circuitry is the new heart-assist device, the AID implantable automatic pulse generator. AID pulse generator monitors the heart continuously, recognizes onset of fibrillation, then administers a corrective electrical shock. A mini- computer, a power source, and two electrodes which sense heart activity are included in the unit. An associated system was also developed. It includes an external recorder to be worn by AID patients and a physician's console to display the data stored by the recorder. System provides a record of fibrillation occurrences and the ensuing defibrillation.

  14. Discrete Minimal Surface Algebras

    NASA Astrophysics Data System (ADS)

    Arnlind, Joakim; Hoppe, Jens

    2010-05-01

    We consider discrete minimal surface algebras (DMSA) as generalized noncommutative analogues of minimal surfaces in higher dimensional spheres. These algebras appear naturally in membrane theory, where sequences of their representations are used as a regularization. After showing that the defining relations of the algebra are consistent, and that one can compute a basis of the enveloping algebra, we give several explicit examples of DMSAs in terms of subsets of sln (any semi-simple Lie algebra providing a trivial example by itself). A special class of DMSAs are Yang-Mills algebras. The representation graph is introduced to study representations of DMSAs of dimension d ≤ 4, and properties of representations are related to properties of graphs. The representation graph of a tensor product is (generically) the Cartesian product of the corresponding graphs. We provide explicit examples of irreducible representations and, for coinciding eigenvalues, classify all the unitary representations of the corresponding algebras.

  15. Some Problems of Knowledge Representation in an Authoring Environment: Exteriorization, Anomalous State Meta-Cognition and Self-Confrontation.

    ERIC Educational Resources Information Center

    McAleese, Ray

    1985-01-01

    Summarizes findings of a collection of research studies at the University of Aberdeen (Scotland) aiding fundamental understanding of knowledge representation and its applications. Issues arising when a knowledge representation system is incorporated into an authoring language are discussed, including the problems of exteriorization, metacognition,…

  16. Performance comparison of polynomial representations for optimizing optical freeform systems

    NASA Astrophysics Data System (ADS)

    Brömel, A.; Gross, H.; Ochse, D.; Lippmann, U.; Ma, C.; Zhong, Y.; Oleszko, M.

    2015-09-01

    Optical systems can benefit strongly from freeform surfaces, however the choice of the right representation isn`t an easy one. Classical representations like X-Y-polynomials, as well as Zernike-polynomials are often used for such systems, but should have some disadvantage regarding their orthogonality, resulting in worse convergence and reduced quality in final results compared to newer representations like the Q-polynomials by Forbes. Additionally the supported aperture is a circle, which can be a huge drawback in case of optical systems with rectangular aperture. In this case other representations like Chebyshev-or Legendre-polynomials come into focus. There are a larger number of possibilities; however the experience with these newer representations is rather limited. Therefore in this work the focus is on investigating the performance of four widely used representations in optimizing two ambitious systems with very different properties: Three-Mirror-Anastigmat and an anamorphic System. The chosen surface descriptions offer support for circular or rectangular aperture, as well as different grades of departure from rotational symmetry. The basic shapes are for example a conic or best-fit-sphere and the polynomial set is non-, spatial or slope-orthogonal. These surface representations were chosen to evaluate the impact of these aspects on the performance optimization of the two example systems. Freeform descriptions investigated here were XY-polynomials, Zernike in Fringe representation, Q-polynomials by Forbes, as well as 2-dimensional Chebyshev-polynomials. As a result recommendations for the right choice of freeform surface representations for practical issues in the optimization of optical systems can be given.

  17. Magnetic monopole in the loop representation

    SciTech Connect

    Leal, Lorenzo; Lopez, Alexander

    2006-01-15

    We quantize, within the Loop Representation formalism, the electromagnetic field in the presence of a static magnetic pole. It is found that the loop-dependent physical wave functionals of the quantum Maxwell theory become multivalued, through a topological phase factor depending on the solid angle subtended at the monopole by a surface bounded by the loop. It is discussed how this fact generalizes what occurs in ordinary quantum mechanics in multiply connected spaces.

  18. Knowledge, Attitudes, and Experience regarding HIV/AIDS among Older Adult Inner-City Latinos

    ERIC Educational Resources Information Center

    Hillman, Jennifer

    2008-01-01

    Although Latinos, now the largest minority group in the U.S., comprise 13% of the population, they represent 18% of all new HIV and AIDS cases. This disproportionate representation also appears among older adult Latinos. Semi-structured interviews with 45 inner-city Spanish speaking older adult Latinos provide new data regarding HIV/AIDS among…

  19. Iowa College Student Aid Commission Student and Faculty Ethnic Diversity Report, 2008

    ERIC Educational Resources Information Center

    Greiner, Keith; Girardi, Anthony G.; Griffin, Mary Beth

    2008-01-01

    This report presents results of the Iowa College Student Aid Commission's annual survey of colleges and universities in Iowa concerning racial and ethnic minority representation among students and faculty. The report summarizes trends in student enrollment, state-sponsored student financial aid, and faculty appointments by racial and ethnic…

  20. What Is HIV/AIDS?

    MedlinePlus

    ... Subscribe Translate Text Size Print What Is HIV/AIDS? Human Immunodeficiency Virus (HIV) HIV stands for human ... use the HIV Testing & Care Services Locator. GO Acquired Immunodeficiency Syndrome (AIDS) AIDS stands for acquired immunodeficiency syndrome. AIDS ...

  1. HIV, AIDS, and the Future

    MedlinePlus

    ... Navigation Bar Home Current Issue Past Issues HIV / AIDS HIV, AIDS, and the Future Past Issues / Summer 2009 Table ... and your loved ones from HIV/AIDS. The AIDS Memorial Quilt In 1987, a total of 1, ...

  2. Hearing Aid Assembly

    NASA Technical Reports Server (NTRS)

    Grugel, Richard N. (Inventor)

    2002-01-01

    Progress in hearing aids has come a long way. Yet despite such progress hearing aids are not the perfect answer to many hearing problems. Some adult ears cannot accommodate tightly fitting hearing aids. Mouth movements such as chewing, talking, and athletic or other active endeavors also lead to loosely fitting ear molds. It is well accepted that loosely fitting hearing aids are the cause of feedback noise. Since feedback noise is the most common complaint of hearing aid wearers it has been the subject of various patents. Herein a hearing aid assembly is provided eliminating feedback noise. The assembly includes the combination of a hearing aid with a headset developed to constrict feedback noise.

  3. IDSS: a novel representation for woven fabrics.

    PubMed

    Zhang, Jiahua; Baciu, George; Zheng, Dejun; Liang, Cheng; Li, Guiqing; Hu, Jinlian

    2013-03-01

    The appearance of woven fabrics is intrinsically determined by the geometric details of their meso/micro scale structure. In this paper, we propose a multiscale representation and tessellation approach for woven fabrics. We extend the Displaced Subdivision Surface (DSS) to a representation named Interlaced/Intertwisted Displacement Subdivision Surface (IDSS). IDSS maps the geometric detail, scale by scale, onto a ternary interpolatory subdivision surface that is approximated by Bezier patches. This approach is designed for woven fabric rendering on DX11 GPUs. We introduce the Woven Patch, a structure based on DirectX’s new primitive, patch, to describe an area of a woven fabric so that it can be easily implemented in the graphics pipeline using a hull shader, a tessellator and a domain shader. We can render a woven piece of fabric at 25 frames per second on a low-performance NVIDIA 8400 MG mobile GPU. This allows for large-scale representations of woven fabrics that maintain the geometric variances of real yarn and fiber.

  4. [Being a mother affected with AIDS: reliving the original sin].

    PubMed

    Pereira, M L; Chaves, E C

    1999-12-01

    This study aimed to understand the meaning of being with AIDS among HIV/AIDS mothers. It looks for to identify the emotions and the way of cope with the situation as a mother has a healthy son. This study was conducted based on the Social Representations Theory. The findings showed "to be mother" and "to have AIDS" represented as a process that does not finish in the disease itself. Also it was found that there is a polarize link between the good and the evil. Indeed, this study brought the sexuality likewise the polarized link, being AIDS linked to evil aspect. These women from this study had perceived themselves as guilty of something, as a result, they deserved the punishment that the AIDS imposed on them.

  5. Postcolonial constructions of HIV/AIDS: meaning, culture, and structure.

    PubMed

    Sastry, Shaunak; Dutta, Mohan J

    2011-01-01

    As a field of inquiry, postcolonial health communication seeks to apprehend processes implicated in the construction of "primitive" versus "modern" with respect to issues of health. In the case of HIV/AIDS, the sociocultural representations of the disease have a profound impact on how the disease is configured medically and symbolically in dominant cultural imagination. Postcolonial constructions of disease are mobilized around the political and economic interests of the dominant power structures in global spaces. In this article, a thematic analysis of the constructions of HIV/AIDS in India in the mainstream U.S. news media was conducted. A corpus of news articles from the Lexis-Nexis database was created with the keywords "HIV," "AIDS," and "India." Three themes emerged from the study: (a) India as a site of biomedical control; (b) the economic logics of HIV/AIDS; and (c) AIDS, development, and the "Third World."

  6. Conditional Simulation of Ice Surfaces With Natural Roughness as an Aid in Establishing Measurement Requirements for a Multi-Beam System for ICESat-2

    NASA Astrophysics Data System (ADS)

    Wallin, B.; Herzfeld, U. C.; Zwally, H. J.; Marshak, A.; Lirette, D.

    2008-12-01

    Observation of the mass loss of the Greenland and Antarctic Ice Sheets is a primary goal of the "Decadal Survey". For a better understanding of the processes leading to current ice loss, we need to be able to observe non-linear slope and change in slope from a single observation, and to derive accurate high-resolution DEMs suitable for elevation change monitoring and geophysical modeling and prediction. A multi-beam lidar system has been proposed as an additional or primary channel for ICESat- 2, to be launched in 2014. To assess the potential of a multi-beam channel to measure high-resolution topography, we need information on subscale roughness (ice surface roughness at a resolution higher than that of observations with the Geoscience Laser Altimeter System (GLAS) aboard ICESat-1, launched in January 2003). In this talk, we describe a mathematical approach to simulate glacier, ice stream and ice sheet surfaces that (1) are constrained by GLAS elevations at the kilometer scale, (2) have scale-dependent roughness derived from observations and (3) fractal dimension and anisotropy at each scale. We utilize Glacier Roughness Sensor (GRS) data collected in the Greenland Inland Ice, UAV laser profilometer observations and cloud simulations. Results on accuracy of elevation and slope determination are derived for two possible MB channels for ICESat-2.

  7. Optimization of Bromelain-Aided Production of Angiotensin I-Converting Enzyme Inhibitory Hydrolysates from Stone Fish Using Response Surface Methodology.

    PubMed

    Muhammad Auwal, Shehu; Zarei, Mohammad; Abdul-Hamid, Azizah; Saari, Nazamid

    2017-03-31

    The stone fish is an under-utilized sea cucumber with many nutritional and ethno-medicinal values. This study aimed to establish the conditions for its optimum hydrolysis with bromelain to generate angiotensin I-converting enzyme (ACE)-inhibitory hydrolysates. Response surface methodology (RSM) based on a central composite design was used to model and optimize the degree of hydrolysis (DH) and ACE-inhibitory activity. Process conditions including pH (4-7), temperature (40-70 °C), enzyme/substrate (E/S) ratio (0.5%-2%) and time (30-360 min) were used. A pH of 7.0, temperature of 40 °C, E/S ratio of 2% and time of 240 min were determined using a response surface model as the optimum levels to obtain the maximum ACE-inhibitory activity of 84.26% at 44.59% degree of hydrolysis. Hence, RSM can serve as an effective approach in the design of experiments to improve the antihypertensive effect of stone fish hydrolysates, which can thus be used as a value-added ingredient for various applications in the functional foods industries.

  8. Home-use cancer detecting band aid

    NASA Astrophysics Data System (ADS)

    Zalevsky, Zeev; Rudnitsky, Arkady; Sheinman, Victor; Tzoy, Andrey; Toktosunov, Aitmamat; Adashov, Arkady

    2016-03-01

    In this paper we present a novel concept in which special band aid is developed for early detection of cancer. The band aid contains an array of micro needles with small detection array connected to each needle which inspects the color of the surface of the skin versus time after being pinched with the needles. We were able to show in pre-clinical trials that the color varies differently if the skin is close to tumor tissue.

  9. An invariant shape representation using the anisotropic Helmholtz equation.

    PubMed

    Joshi, A A; Ashrafulla, S; Shattuck, D W; Damasio, H; Leahy, R M

    2012-01-01

    Analyzing geometry of sulcal curves on the human cortical surface requires a shape representation invariant to Euclidean motion. We present a novel shape representation that characterizes the shape of a curve in terms of a coordinate system based on the eigensystem of the anisotropic Helmholtz equation. This representation has many desirable properties: stability, uniqueness and invariance to scaling and isometric transformation. Under this representation, we can find a point-wise shape distance between curves as well as a bijective smooth point-to-point correspondence. When the curves are sampled irregularly, we also present a fast and accurate computational method for solving the eigensystem using a finite element formulation. This shape representation is used to find symmetries between corresponding sulcal shapes between cortical hemispheres. For this purpose, we automatically generate 26 sulcal curves for 24 subject brains and then compute their invariant shape representation. Left-right sulcal shape symmetry as measured by the shape representation's metric demonstrates the utility of the presented invariant representation for shape analysis of the cortical folding pattern.

  10. Quantifying soil evaporation and transpiration at the scale of a remote sensing pixel by extrapolating mini-lysimeter results with the aid of remote sensed surface temperatures

    NASA Astrophysics Data System (ADS)

    Voortman, B.; Bartholomeus, R.; Witte, J. M.

    2012-12-01

    Lysimeters are often used to measure evapotranspiration (Et) by changes in mass of a volume of soil. Precision lysimeters generate data of Et at a high resolution in the order of 0.02 to 0.05 mm. This resolution is often reported as the accuracy of the lysimeter, which is in fact the accuracy of the weighing device. Improper installation or design of lysimeters is often not accounted for when assessing their accuracy. In general, measurement errors due to improper environmental conditions will decrease with increasing surface area and depth of the lysimeter. This is primarily because a larger part of the lysimeter is unaffected by its boundaries and because heterogeneities in soil hydraulic properties and micro-climate are more averaged out. However, the cost of large systems make them unattractive and scientists often choose for more economical solutions, optimizing between lysimeter dimensions and costs. One of the difficulties when designing a lysimeter is controlling the boundary condition at the base of the lysimeter. In case of a freely draining lysimeter (atmospheric pressure at the bottom), the lower portion of the lysimeter must saturate to generate a hydraulic gradient in downward direction, after which the lysimeter starts to drain. In groundwater independent sites this will lead to a higher soil moisture content in the lysimeter in comparison with the surrounding soil. One could overcome this problem by using suction plates and vacuum pumps to set a suction level at the base of the lysimeter equal to the surrounding soil., In dry soils, however, suction plates may dry out beyond the air entry value of the ceramic material, which neutralizes the suction pressure. Furthermore, a sophisticated drainage system will increase the maintenance and construction cost of the lysimeter. Moisture conditions in lysimeters are difficult to control and whenever this affects the available water for rooting plants this will lead to erroneous measurements of Et. We

  11. Intentionality, Representation, and Anticipation

    NASA Astrophysics Data System (ADS)

    De Preester, Helena

    2002-09-01

    Both Brentano and Merleau-Ponty have developed an account of intentionality, which nevertheless differ profoundly in the following respect. According to Brentano, intentionality mainly is a matter of mental presentations. This marks the beginning of phenomenology's difficult relation with the nature of the intentional reference. Merleau-Ponty, on the other hand, has situated intentionality on the level of the body, a turn which has important implications for the nature of intentionality. Intentionality no longer is primarily based on having (re)presentations, but is rooted in the dynamics of the living body. To contrast those approaches enables us to make clear in what way intentionality is studied nowadays. On the one hand, intentionality is conceived of as a matter of formal-syntactical causality in cognitive science, and in particular in classical-computational theory. On the other hand, a interactivist approach offers a more Merleau-Ponty-like point of view, in which autonomy, embodiment and interaction are stressed.

  12. AIDS: acquired immunodeficiency syndrome.

    PubMed Central

    Gilmore, N. J.; Beaulieu, R.; Steben, M.; Laverdière, M.

    1983-01-01

    Acquired immunodeficiency syndrome, or AIDS, is a new illness that occurs in previously healthy individuals. It is characterized by immunodeficiency, opportunistic infections and unusual malignant diseases. Life-threatening single or multiple infections with viruses, mycobacteria, fungi or protozoa are common. A rare neoplasm, Kaposi's sarcoma, has developed in approximately one third of patients with AIDS. More than 800 cases of AIDS have been reported in North America, over 24 of them in Canada. The majority of patients are male homosexuals, although AIDS has also developed in abusers of intravenously administered drugs, Haitian immigrants, individuals with hemophilia, recipients of blood transfusions, prostitutes, and infants, spouses and partners of patients with AIDS. The cause of AIDS is unknown, but the features are consistent with an infectious process. Early diagnosis can be difficult owing to the nonspecific symptoms and signs of the infections and malignant diseases. Therefore, vigilance by physicians is of utmost importance. PMID:6342737

  13. AIDS: acquired immunodeficiency syndrome *

    PubMed Central

    Gilmore, N.J.; Beaulieu, R.; Steben, M.; Laverdière, M.

    1992-01-01

    Acquired immunodeficiency syndrome, or AIDS, is a new illness that occurs in previously healthy individuals. It is characterized by immunodeficiency, opportunistic infections and unusual malignant diseases. Life-threatening single or multiple infections with viruses, mycobacteria, fungi or protozoa are common. A rare neoplasm, Kaposi's sarcoma, has developed in approximately one third of patients with AIDS. More than 800 cases of AIDS have been reported in North America, over 24 of them in Canada. The majority of patients are male homosexuals, although AIDS has also developed in abusers of intravenously administered drugs, Haitian immigrants, individuals with hemophilia, recipients of blood transfusions, prostitutes, and infants, spouses and partners of patients with AIDS. The cause of AIDS is unknown, but the features are consistent with an infectious process. Early diagnosis can be difficult owing to the nonspecific symptoms and signs of the infections and malignant diseases. Therefore, vigilance by physicians is of the utmost importance. PMID:1544049

  14. Medical aid schemes respond to AIDS.

    PubMed

    Taylor, G

    1999-01-01

    The insurance and medical aid industries reacted strongly in the 1980s to alarmist predictions of the likely impact of HIV upon employee benefits. Actuaries and accountants moved quickly to contain the risk, and most medical aid trustees quickly implemented a total exclusion of HIV treatment from their benefits. For more than 1 decade, it was argued that HIV/AIDS is a self-inflicted illness, often categorized with other STDs. In response, healthcare providers simply bypassed insurance restrictions and compensation limits by masking patient diagnoses to reflect pneumonia or other ambiguous, yet fully reimbursable, illnesses. Now, common sense has finally prevailed as a few managed healthcare programs are stepping forward to break the impasse. The largest such program is Aid for AIDS, run by Pharmaceutical Benefit Management Ltd. for schemes within the Medscheme Group. The Group built an entirely new, secure unit off-site from their normal branches to guarantee the confidentiality of patients' records and diagnoses, while treatment guidelines have been issued to every practicing physician in the country.

  15. Experience and problem representation in statistics.

    PubMed

    Rabinowitz, Mitchell; Hogan, Tracy M

    2008-01-01

    This research investigated experience level differences in problem representation in statistics. A triad judgment task was designed so that source problems shared either surface similarity (story narrative) or structural (inferential level) features (t test, correlation, or chi-square) with the target problem. Graduate students with varying levels of experience in statistics were asked to choose which source problem "goes best" with the target problem for each triad. Given a choice between a problem that shares surface-level characteristics and one that shares inferential-level characteristics, students who had taken 0 to 4 courses in statistics tended to represent problems on the basis of surface-level features. Students who had more than 4 courses did not consistently make choices on the basis of surface-level features, nor did they consistently rely on structural features. However, all students with statistics course backgrounds noticed structural features when competition between different types of features was eliminated. The role of surface and structural features in determining problem representations is discussed.

  16. AIDS in South Africa.

    PubMed

    Ijsselmuiden, C; Evian, C; Matjilla, J; Steinberg, M; Schneider, H

    1993-01-01

    The National AIDS Convention in South Africa (NACOSA) in October 1992 was the first real attempt to address HIV/AIDS. In Soweto, government, the African National Congress, nongovernmental organizations, and organized industry and labor representatives worked for 2 days to develop a national plan of action, but it did not result in a united effort to fight AIDS. The highest HIV infection rates in South Africa are among the KwaZulu in Natal, yet the Inkatha Freedom Party did not attend NACOSA. This episode exemplifies the key obstacles for South Africa to prevent and control AIDS. Inequality of access to health care may explain why health workers did not diagnose the first AIDS case in blacks until 1985. Migrant labor, Bantu education, and uprooted communities affect the epidemiology of HIV infection. Further, political and social polarization between blacks and whites contributes to a mindset that AIDS is limited to the other race which only diminishes the personal and collective sense of susceptibility and the volition and aptitude to act. The Department of National Health and Population Development's voluntary register of anonymously reported cases of AIDS specifies 1517 cumulative AIDS cases (October 1992), but this number is low. Seroprevalence studies show between 400,000-450,000 HIV positive cases. Public hospitals cannot give AIDS patients AZT and DDI. Few communities provided community-based care. Not all hospitals honor confidentiality and patients' need for autonomy. Even though HIV testing is not mandatory, it is required sometimes, e.g., HIV testing of immigrants. AIDS Training, Information and Counselling Centers are in urban areas, but not in poor areas where the need is most acute. The government just recently developed in AIDS education package for schools, but too many people consider it improper, so it is not being used. The poor quality education provided blacks would make it useless anyhow. Lifting of the academic boycott will allow South African

  17. Music and hearing aids.

    PubMed

    Madsen, Sara M K; Moore, Brian C J

    2014-10-31

    The signal processing and fitting methods used for hearing aids have mainly been designed to optimize the intelligibility of speech. Little attention has been paid to the effectiveness of hearing aids for listening to music. Perhaps as a consequence, many hearing-aid users complain that they are not satisfied with their hearing aids when listening to music. This issue inspired the Internet-based survey presented here. The survey was designed to identify the nature and prevalence of problems associated with listening to live and reproduced music with hearing aids. Responses from 523 hearing-aid users to 21 multiple-choice questions are presented and analyzed, and the relationships between responses to questions regarding music and questions concerned with information about the respondents, their hearing aids, and their hearing loss are described. Large proportions of the respondents reported that they found their hearing aids to be helpful for listening to both live and reproduced music, although less so for the former. The survey also identified problems such as distortion, acoustic feedback, insufficient or excessive gain, unbalanced frequency response, and reduced tone quality. The results indicate that the enjoyment of listening to music with hearing aids could be improved by an increase of the input and output dynamic range, extension of the low-frequency response, and improvement of feedback cancellation and automatic gain control systems.

  18. Music and Hearing Aids

    PubMed Central

    Moore, Brian C. J.

    2014-01-01

    The signal processing and fitting methods used for hearing aids have mainly been designed to optimize the intelligibility of speech. Little attention has been paid to the effectiveness of hearing aids for listening to music. Perhaps as a consequence, many hearing-aid users complain that they are not satisfied with their hearing aids when listening to music. This issue inspired the Internet-based survey presented here. The survey was designed to identify the nature and prevalence of problems associated with listening to live and reproduced music with hearing aids. Responses from 523 hearing-aid users to 21 multiple-choice questions are presented and analyzed, and the relationships between responses to questions regarding music and questions concerned with information about the respondents, their hearing aids, and their hearing loss are described. Large proportions of the respondents reported that they found their hearing aids to be helpful for listening to both live and reproduced music, although less so for the former. The survey also identified problems such as distortion, acoustic feedback, insufficient or excessive gain, unbalanced frequency response, and reduced tone quality. The results indicate that the enjoyment of listening to music with hearing aids could be improved by an increase of the input and output dynamic range, extension of the low-frequency response, and improvement of feedback cancellation and automatic gain control systems. PMID:25361601

  19. AIDS and confidentiality.

    PubMed

    Kirkman, M B; Bell, S K

    1989-01-01

    AIDS has created many challenges for those who provide care for AIDS patients. One major challenge has been the request of many public officials for healthcare professionals to abandon the traditional view of confidentiality and to reveal AIDS patients' names. This ethical dilemma is explored and some ethical theories are presented as possible resolutions. The conclusion presented is that healthcare professionals must recognize that the power of the healthcare system over an AIDS patient is immense. Therefore, healthcare professionals must make a commitment to protect the patient's right to privacy by preventing any unauthorized disclosure at all costs.

  20. We are all people living with AIDS: myths and realities of AIDS in Brazil.

    PubMed

    Daniel, H

    1991-01-01

    Although AIDS was expected in Brazil, no serious efforts were undertaken to prevent AIDS from taking root. Irresponsible press and media coverage highlighted the spread of AIDS within the gay community of the United States, creating an aura of immunity in Brazil to what was characterized as a "foreign" disorder. When AIDS did surface in 1983, the official response was to adopt an abstract, inappropriate, and ideological "Western" model, in which only stigmatized "others" and "minorities" were at risk of HIV infection. Brazilian health authorities subsequently downplayed the significance of the sale of contaminated blood in HIV transmission, and likewise ignored the rising rates of AIDS among Brazil's one unarguable majority group: the poor. An analysis of efforts to force the "facts" of AIDS to fit a false model's predictions leads to a clearer definition of the broader context of the Brazilian epidemic: we all are people living with AIDS, precisely because we live in this age of AIDS; it is sheer folly to discriminate against persons infected by HIV and to obstruct their participation in efforts to curtail the epidemic's spread; and the necessary response to AIDS is solidarity, not because it is poetic, but because no other response will suffice.

  1. Revealing Children's Implicit Spelling Representations

    ERIC Educational Resources Information Center

    Critten, Sarah; Pine, Karen J.; Messer, David J.

    2013-01-01

    Conceptualizing the underlying representations and cognitive mechanisms of children's spelling development is a key challenge for literacy researchers. Using the Representational Redescription model (Karmiloff-Smith), Critten, Pine and Steffler (2007) demonstrated that the acquisition of phonological and morphological knowledge may be underpinned…

  2. Scientific Representation and Science Learning

    ERIC Educational Resources Information Center

    Matta, Corrado

    2014-01-01

    In this article I examine three examples of philosophical theories of scientific representation with the aim of assessing which of these is a good candidate for a philosophical theory of scientific representation in science learning. The three candidate theories are Giere's intentional approach, Suárez's inferential approach and Lynch and…

  3. Learning with Interactive Graphical Representations.

    ERIC Educational Resources Information Center

    Saljo, Roger, Ed.

    1999-01-01

    The seven articles of this theme issue deal with the use of computer-based interactive graphical representations. Studying their use will bring answers to users of static graphics in traditional paper-based media and those who plan instruction using graphical representations that allow semantically direct manipulation. (SLD)

  4. Representation of Fuzzy Symmetric Relations

    DTIC Science & Technology

    1986-03-19

    Std Z39-18 REPRESENTATION OF FUZZY SYMMETRIC RELATIONS L. Valverde Dept. de Matematiques i Estadistica Universitat Politecnica de Catalunya Avda...REPRESENTATION OF FUZZY SYMMETRIC RELATIONS L. "Valverde* Dept. de Matematiques i Estadistica Universitat Politecnica de Catalunya Avda. Diagonal, 649

  5. The Representational Value of Hats

    ERIC Educational Resources Information Center

    Watson, Jane M.; Fitzallen, Noleine E.; Wilson, Karen G.; Creed, Julie F.

    2008-01-01

    The literature that is available on the topic of representations in mathematics is vast. One commonly discussed item is graphical representations. From the history of mathematics to modern uses of technology, a variety of graphical forms are available for middle school students to use to represent mathematical ideas. The ideas range from algebraic…

  6. Symbolic representation of probabilistic worlds.

    PubMed

    Feldman, Jacob

    2012-04-01

    Symbolic representation of environmental variables is a ubiquitous and often debated component of cognitive science. Yet notwithstanding centuries of philosophical discussion, the efficacy, scope, and validity of such representation has rarely been given direct consideration from a mathematical point of view. This paper introduces a quantitative measure of the effectiveness of symbolic representation, and develops formal constraints under which such representation is in fact warranted. The effectiveness of symbolic representation hinges on the probabilistic structure of the environment that is to be represented. For arbitrary probability distributions (i.e., environments), symbolic representation is generally not warranted. But in modal environments, defined here as those that consist of mixtures of component distributions that are narrow ("spiky") relative to their spreads, symbolic representation can be shown to represent the environment with a relatively negligible loss of information. Modal environments support propositional forms, logical relations, and other familiar features of symbolic representation. Hence the assumption that our environment is, in fact, modal is a key tacit assumption underlying the use of symbols in cognitive science.

  7. Symbolic Representation of Probabilistic Worlds

    ERIC Educational Resources Information Center

    Feldman, Jacob

    2012-01-01

    Symbolic representation of environmental variables is a ubiquitous and often debated component of cognitive science. Yet notwithstanding centuries of philosophical discussion, the efficacy, scope, and validity of such representation has rarely been given direct consideration from a mathematical point of view. This paper introduces a quantitative…

  8. Structural representation of data structures

    NASA Astrophysics Data System (ADS)

    Cantoni, Virginio; Gaggia, Alessandro; Gatti, Riccardo; Lombardi, Luca

    2014-06-01

    Study of the morphology of proteins, and their 3D structure, supports investigations of their functions and represents an initial step towards protein-based drug design. The goal of this paper is to define techniques, based on the geometrical and topological structure of protein surfaces, for the detection and analysis of sites of potential protein-protein and protein-ligand interactions. Two protein representation modalities based on the Concavity Tree (CT) and the Enriched Complex Extended Gaussian Image (EC-EGI) are considered. In particular, the concavity tree, in which the interface is usually extended and roughly planar, is considered to be better suited to protein-protein interaction studies. Instead, the EGI is more suited to protein-ligand interactions, in which the small ligand molecule usually has to fit into the protein cavity. In fact, the histogram of the orientations is better suited to representing a mainly convex object and its dual matching region (the cavity). Both these data structures are open, and can be easily integrated with biochemical features.

  9. AIDS is your business.

    PubMed

    Rosen, Sydney; Simon, Jonathon; Vincent, Jeffrey R; MacLeod, William; Fox, Matthew; Thea, Donald M

    2003-02-01

    If your company operates in a developing country, AIDS is your business. While Africa has received the most attention, AIDS is also spreading swiftly in other parts of the world. Russia and Ukraine had the fastest-growing epidemics last year, and many experts believe China and India will suffer the next tidal wave of infection. Why should executives be concerned about AIDS? Because it is destroying the twin rationales of globalization strategy-cheap labor and fast-growing markets--in countries where people are heavily affected by the epidemic. Fortunately, investments in programs that prevent infection and provide treatment for employees who have HIV/AIDS are profitable for many businesses--that is, they lead to savings that outweigh the programs' costs. Due to the long latency period between HIV infection and the onset of AIDS symptoms, a company is not likely to see any of the costs of HIV/AIDS until five to ten years after an employee is infected. But executives can calculate the present value of epidemic-related costs by using the discount rate to weigh each cost according to its expected timing. That allows companies to think about expenses on HIV/AIDS prevention and treatment programs as investments rather than merely as costs. The authors found that the annual cost of AIDS to six corporations in South Africa and Botswana ranged from 0.4% to 5.9% of the wage bill. All six companies would have earned positive returns on their investments if they had provided employees with free treatment for HIV/AIDS in the form of highly active antiretroviral therapy (HAART), according to the mathematical model the authors used. The annual reduction in the AIDS "tax" would have been as much as 40.4%. The authors' conclusion? Fighting AIDS not only helps those infected; it also makes good business sense.

  10. A generalized wavelet extrema representation

    SciTech Connect

    Lu, Jian; Lades, M.

    1995-10-01

    The wavelet extrema representation originated by Stephane Mallat is a unique framework for low-level and intermediate-level (feature) processing. In this paper, we present a new form of wavelet extrema representation generalizing Mallat`s original work. The generalized wavelet extrema representation is a feature-based multiscale representation. For a particular choice of wavelet, our scheme can be interpreted as representing a signal or image by its edges, and peaks and valleys at multiple scales. Such a representation is shown to be stable -- the original signal or image can be reconstructed with very good quality. It is further shown that a signal or image can be modeled as piecewise monotonic, with all turning points between monotonic segments given by the wavelet extrema. A new projection operator is introduced to enforce piecewise inonotonicity of a signal in its reconstruction. This leads to an enhancement to previously developed algorithms in preventing artifacts in reconstructed signal.

  11. Revealing children's implicit spelling representations.

    PubMed

    Critten, Sarah; Pine, Karen J; Messer, David J

    2013-06-01

    Conceptualizing the underlying representations and cognitive mechanisms of children's spelling development is a key challenge for literacy researchers. Using the Representational Redescription model (Karmiloff-Smith), Critten, Pine and Steffler (2007) demonstrated that the acquisition of phonological and morphological knowledge may be underpinned by increasingly explicit levels of spelling representation. However, their proposal that implicit representations may underlie early 'visually based' spelling remains unresolved. Children (N = 101, aged 4-6 years) were given a recognition task (Critten et al., 2007) and a novel production task, both involving verbal justifications of why spellings are correct/incorrect, strategy use and word pattern similarity. Results for both tasks supported an implicit level of spelling characterized by the ability to correctly recognize/produce words but the inability to explain operational strategies or generalize knowledge. Explicit levels and multiple representations were also in evidence across the two tasks. Implications for cognitive mechanisms underlying spelling development are discussed.

  12. Cognition and procedure representational requirements for predictive human performance models

    NASA Technical Reports Server (NTRS)

    Corker, K.

    1992-01-01

    Models and modeling environments for human performance are becoming significant contributors to early system design and analysis procedures. Issues of levels of automation, physical environment, informational environment, and manning requirements are being addressed by such man/machine analysis systems. The research reported here investigates the close interaction between models of human cognition and models that described procedural performance. We describe a methodology for the decomposition of aircrew procedures that supports interaction with models of cognition on the basis of procedures observed; that serves to identify cockpit/avionics information sources and crew information requirements; and that provides the structure to support methods for function allocation among crew and aiding systems. Our approach is to develop an object-oriented, modular, executable software representation of the aircrew, the aircraft, and the procedures necessary to satisfy flight-phase goals. We then encode in a time-based language, taxonomies of the conceptual, relational, and procedural constraints among the cockpit avionics and control system and the aircrew. We have designed and implemented a goals/procedures hierarchic representation sufficient to describe procedural flow in the cockpit. We then execute the procedural representation in simulation software and calculate the values of the flight instruments, aircraft state variables and crew resources using the constraints available from the relationship taxonomies. The system provides a flexible, extensible, manipulative and executable representation of aircrew and procedures that is generally applicable to crew/procedure task-analysis. The representation supports developed methods of intent inference, and is extensible to include issues of information requirements and functional allocation. We are attempting to link the procedural representation to models of cognitive functions to establish several intent inference methods

  13. AIDS Fact Pack.

    ERIC Educational Resources Information Center

    Center for Population Options, Washington, DC.

    The three fact sheets presented in this document address issues surrounding adolescent sexuality and sexually transmitted diseases (STDs), especially the Acquired Immune Deficiency Syndrome (AIDS). The first fact sheet, "Young Women and AIDS: A Worldwide Perspective," suggests that since open discussions of adolescent sexuality have long been…

  14. Detecting Student Aid Fraud.

    ERIC Educational Resources Information Center

    Sheppard, Jeffrey

    1998-01-01

    Describes the varied kinds of student aid fraud found to be occurring within and outside colleges and universities, and examines implications for public policy on student aid programs. Discusses specific fraud cases and their outcomes, and makes suggestions for institutional action if student fraud is suspected. (MSE)

  15. Computer Aids to Translation.

    ERIC Educational Resources Information Center

    Krollmann, Friedrich

    1981-01-01

    Describes the structure and modes of operation of the Bundessprachenamt's (BSprA: Federal Office of Languages of the Federal Republic of Germany) terminology data bank as an aid to translation. Analyzes advantages and disadvantages of each user mode, and discusses probable developments in the immediate future of machine-aided translation. (MES)

  16. International Aid to Education

    ERIC Educational Resources Information Center

    Benavot, Aaron

    2010-01-01

    Recent evidence highlights several worrisome trends regarding aid pledges and disbursements, which have been exacerbated by the global financial crisis. First, while overall development assistance rose in 2008, after 2 years of decline, the share of all sector aid going to the education sector has remained virtually unchanged at about 12 percent…

  17. AIDS as Metaphor.

    ERIC Educational Resources Information Center

    McMillen, Liz

    1994-01-01

    Scholarly interest in Acquired Immune Deficiency Syndrome (AIDS) has spread throughout the humanities, attracting the attention of historians of medicine, political scientists, sociologists, public health scholars, and anthropologists. Most theorists hope their research will aid in policymaking or change understanding of the epidemic. (MSE)

  18. First Aid: Diaper Rash

    MedlinePlus

    ... Your 1- to 2-Year-Old First Aid: Diaper Rash KidsHealth > For Parents > First Aid: Diaper Rash A A A Diaper rash is a common skin condition in babies. ... rash is due to irritation caused by the diaper, but it can have other causes not related ...

  19. Hospital Nurse Aide. Revised.

    ERIC Educational Resources Information Center

    Iowa Univ., Iowa City. Coll. of Education.

    This report presents results of a project to revise the current 120-hour advanced nurse aide course to include all recommended minimum competencies. A three-page description of project objectives, activities, and outcomes is followed by a list of the competencies for the 75-hour nurse aide course for long-term care and for the 120-hour advanced…

  20. Preventing AIDS via Education.

    ERIC Educational Resources Information Center

    House, Reese M.; Walker, Catherine M.

    1993-01-01

    Compares the Acquired Immune Deficiency Syndrome (AIDS) epidemic to past epidemics, including social and political responses. Identifies populations at risk for human immunodeficiency virus (HIV) infection. Discusses current social and economic factors affecting AIDS education programs. Makes recommendations and identifies resources for starting…

  1. THE AIDS MYTH

    PubMed Central

    Poehlmann, Karl Horst

    1996-01-01

    AIDS is now said to threaten humanity as a modern-day scourge. However, there is a group of scientists which maintains that this scare is unwarranted. Some arguments in favour of the re-evaluation of the AIDS hypothesis are presented in this article. PMID:22556763

  2. AIDS: Children Too.

    ERIC Educational Resources Information Center

    Lejeune, Genevieve, Ed.

    1994-01-01

    This journal issue is devoted to the many problems faced by children with Acquired Immune Deficiency Syndrome (AIDS) who live in both developing and developed countries. Section 1 provides general information on the pandemic, defining AIDS and exploring the social aspects of the disease. It also addresses child health, child mortality, moral and…

  3. Aid, Development, and Education

    ERIC Educational Resources Information Center

    Klees, Steven J.

    2010-01-01

    The world faces pervasive poverty and inequality. Hundreds of billions of dollars in international aid have been given or loaned to developing countries though bilateral and multilateral mechanisms, at least, ostensibly, in order to do something about these problems. Has such aid helped? Debates around this question have been ongoing for decades,…

  4. BIBLIOGRAPHY OF TRAINING AIDS.

    ERIC Educational Resources Information Center

    MCKEONE, CHARLES J.

    THIS COMPILATION OF INSTRUCTIONAL AIDS FOR USE IN AIR-CONDITIONING AND REFRIGERATION TRAINING PROGRAMS CONTAINS LISTS OF VISUAL AND AUDIOVISUAL TRAINING AIDS AND GUEST LECTURERS AVAILABLE FROM MEMBER COMPANIES OF THE AIR-CONDITIONING AND REFRIGERATION INSTITUTE AS AN INDUSTRY SERVICE TO SCHOOL OFFICIALS INTERESTED IN CONDUCTING SUCH PROGRAMS. THE…

  5. AIDS and Chemical Dependency.

    ERIC Educational Resources Information Center

    Pohl, Melvin I.

    After defining HIV and the AIDS disease and outlining symptoms and means of infection, this fact sheet lists the ways alcohol and drugs are involved with the AIDS epidemic, noting that needle-sharing transmits the virus; that alcohol or mood-altering drugs like crack cocaine cause disinhibition, increase sex drive, encourage sex for drugs, and…

  6. First Aid: Falls

    MedlinePlus

    ... Your 1- to 2-Year-Old First Aid: Falls KidsHealth > For Parents > First Aid: Falls Print A A A en español Folleto de instructiones: Caídas (Falls) With all the running, climbing, and exploring kids ...

  7. Implantable Heart Aid

    NASA Technical Reports Server (NTRS)

    1984-01-01

    CPI's human-implantable automatic implantable defibrillator (AID) is a heart assist system, derived from NASA's space circuitry technology, that can prevent erratic heart action known as arrhythmias. Implanted AID, consisting of microcomputer power source and two electrodes for sensing heart activity, recognizes onset of ventricular fibrillation (VF) and delivers corrective electrical countershock to restore rhythmic heartbeat.

  8. Inertially Aided Robotics

    DTIC Science & Technology

    1989-12-31

    0031 dis~bti:,1 is uitsnjt( Deczmllcr 31: 1989 92-05530 2:.-: 3o : T >VE?-A ~ : Inertially Aided Robotics FINAL REPORT for Contract No. DAAHO1 -88-D-0057...1 2 Advantages of Inertially Aided Robotics ...86 iii List of Figures Figure 1 - Robot Manipulator having Joint Sensor Based Control ..................... 2

  9. Marketing Financial Aid

    ERIC Educational Resources Information Center

    Huddleston, Thomas, Jr.; Batty, Burt F.

    1978-01-01

    Student financial assistance services are becoming a major part of the institutional marketing plan as traditional college-age students decline in numbers and price competition among institutions increases. The effect of financial aid on enrollment and admissions processes is discussed along with the role of the financial aid officer. (Author/LBH)

  10. Participative AIDS Education Methods.

    ERIC Educational Resources Information Center

    Chambliss, Catherine; And Others

    Since assuring quality health care delivery to patients suffering from Acquired Immunodeficiency Syndrome (AIDS) and those who test positive for Human Immunodeficiency Virus (HIV) is a priority, development of effective staff training methods is imperative. This pilot study assessed the effect on staff attitudes of a participative AIDS/HIV staff…

  11. Innovative Teaching Aids.

    ERIC Educational Resources Information Center

    Christner, Chris

    1988-01-01

    Describes the DACUM (Developing A CurriculUM) process and how it is used at Universal Technical Institute to determine what types of training aids to produce. Indicates that examining the employment needs of industry and educational needs of students enhances programs and promotes development of innovative aids. (JOW)

  12. First Aid: Burns

    MedlinePlus

    ... Your 1- to 2-Year-Old First Aid: Burns KidsHealth > For Parents > First Aid: Burns A A A Scald burns from hot water and other liquids are the most common burns in early childhood. Because burns range from mild ...

  13. The New Merit Aid

    ERIC Educational Resources Information Center

    Dynarski, Susan

    2004-01-01

    Merit aid, a discount to college costs contingent upon academic performance, is nothing new. Colleges and private organizations have long rewarded high-achieving, college-bound high school students with scholarships. While merit aid has a long history in the private sector, it has not played a major role in the public sector. At the state level,…

  14. AIDS Epidemiological models

    NASA Astrophysics Data System (ADS)

    Rahmani, Fouad Lazhar

    2010-11-01

    The aim of this paper is to present mathematical modelling of the spread of infection in the context of the transmission of the human immunodeficiency virus (HIV) and the acquired immune deficiency syndrome (AIDS). These models are based in part on the models suggested in the field of th AIDS mathematical modelling as reported by ISHAM [6].

  15. Proceedings of the NASA Workshop on Surface Fitting

    NASA Technical Reports Server (NTRS)

    Guseman, L. F., Jr. (Principal Investigator)

    1982-01-01

    Surface fitting techniques and their utilization are addressed. Surface representation, approximation, and interpolation are discussed. Along with statistical estimation problems associated with surface fitting.

  16. AIDS in the pre-AIDS era.

    PubMed

    Huminer, D; Rosenfeld, J B; Pitlik, S D

    1987-01-01

    A search of the medical literature published since 1950 disclosed 19 cases of probable AIDS reported before the start of the current epidemic. These cases retrospectively met the Centers for Disease Control's surveillance definition of the syndrome and had a clinical course suggestive of AIDS. The reports originated from North America, Western Europe, Africa, and the Middle East. The mean age of patients was 37 years, and the ratio of male to female patients was 1.7:1. Sixteen patients had opportunistic infections(s) without Kaposi's sarcoma. The remainder had disseminated Kaposi's sarcoma. The commonest opportunistic infection was Pneumocystis carinii pneumonia. Two patients were reported to be homosexual. Three others had been living in Africa, and one patient was born in Haiti. In two instances concurrent or subsequent opportunistic infection occurred in family members. All patients died 1 month to 6 years after the initial manifestation of disease. In view of the historical data, unrecognized cases of AIDS appear to have occurred sporadically in the pre-AIDS era.

  17. Multiple Representations of Buoyancy

    NASA Astrophysics Data System (ADS)

    Oliviera, Jessica; Weglarz, Meredith; Vesenka, James

    2009-10-01

    For many students the concept of buoyancy falls under a category that can be loosely described as ``knowing it when they see it.'' Unfortunately some of the misconceptions this generates are that ``objects float because they are light'' and ``objects float because they are full of air'' [1]. Those these can some times be true, these descriptions are vague at best, and frequently can be wrong. Part of these misconceptions may stem from incomplete immersion of the object in the fluid and the vector nature of forces. We describe a demonstration/lab activity to help students make sense about relationship between the tension on and weight of an object immersed in water. The activity is in rich in multiple representations, graphical, diagrammatical as well as mathematical. A simple four question multiple choice pre/post test survey has been developed to evaluate the effectiveness of the lab activity.[4pt] [1] Bruce Harlan ``Diving Science'', www.stmatthewsschool.com/deep/pdfs/Diving%20Science.pdf

  18. Attitude Representations for Kalman Filtering

    NASA Technical Reports Server (NTRS)

    Markley, F. Landis; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    The four-component quaternion has the lowest dimensionality possible for a globally nonsingular attitude representation, it represents the attitude matrix as a homogeneous quadratic function, and its dynamic propagation equation is bilinear in the quaternion and the angular velocity. The quaternion is required to obey a unit norm constraint, though, so Kalman filters often employ a quaternion for the global attitude estimate and a three-component representation for small errors about the estimate. We consider these mixed attitude representations for both a first-order Extended Kalman filter and a second-order filter, as well for quaternion-norm-preserving attitude propagation.

  19. Representations of mechanical assembly sequences

    NASA Technical Reports Server (NTRS)

    Homem De Mello, Luiz S.; Sanderson, Arthur C.

    1991-01-01

    Five types of representations for assembly sequences are reviewed: the directed graph of feasible assembly sequences, the AND/OR graph of feasible assembly sequences, the set of establishment conditions, and two types of sets of precedence relationships. (precedence relationships between the establishment of one connection between parts and the establishment of another connection, and precedence relationships between the establishment of one connection and states of the assembly process). The mappings of one representation into the others are established. The correctness and completeness of these representations are established. The results presented are needed in the proof of correctness and completeness of algorithms for the generation of mechanical assembly sequences.

  20. HIV / AIDS and tourism.

    PubMed

    Forsythe, S

    1999-01-01

    Since it tends to be significantly affected by HIV/AIDS, the tourism sector is a likely target for HIV/AIDS interventions in many countries. The tourist industry is at particular risk from the pandemic because of the mobility of the work force, the presence of sex tourists, and the heavy reliance of many countries upon tourism revenues. Indeed, tourism is one of the largest and fastest growing industries in many countries. Some people have speculated that potential tourists' fear of AIDS could discourage them from visiting certain countries, while others have even suggested that tourism should be discouraged because the industry contributes to the spread of HIV/AIDS. When traveling, tourists often take risks that they would not take at home. They tend to drink more, use drugs more, and be generally more adventurous while on holiday. Such adventures often include taking sexual risks. When tourists have sex with prostitutes, hotel staff, and others in the local population, a bridge can be created for HIV to cross back and forth between the tourist's home country and the tourist destination. The author reviews selected studies on the relationship between HIV/AIDS and tourism. Overall, the existing literature offers no definitive evidence that AIDS has had any lasting impact upon the tourism industry anywhere in the world. Rather, promoting a healthy tourism industry and HIV/AIDS prevention are likely complementary in many ways.

  1. AIDS radio triggers.

    PubMed

    Elias, A M

    1991-07-01

    In April 1991, the Ethnic Communities' Council of NSW was granted funding under the Community AIDS Prevention and Education Program through the Department of Community Services and Health, to produce a series of 6x50 second AIDS radio triggers with a 10-second tag line for further information. The triggers are designed to disseminate culturally-sensitive information about HIV/AIDS in English, Italian, Greek, Spanish, Khmer, Turkish, Macedonian, Serbo-Croatian, Arabic, Cantonese, and Vietnamese, with the goal of increasing awareness and decreasing the degree of misinformation about HIV/AIDS among people of non-English-speaking backgrounds through radio and sound. The 6 triggers cover the denial that AIDS exists in the community, beliefs that words and feelings do not protect one from catching HIV, encouraging friends to be compassionate, compassion within the family, AIDS information for a young audience, and the provision of accurate and honest information on HIV/AIDS. The triggers are slated to be completed by the end of July 1991 and will be broadcast on all possible community, ethnic, and commercial radio networks across Australia. They will be available upon request in composite form with an information kit for use by health care professionals and community workers.

  2. Hearing AIDS and music.

    PubMed

    Chasin, Marshall; Russo, Frank A

    2004-01-01

    Historically, the primary concern for hearing aid design and fitting is optimization for speech inputs. However, increasingly other types of inputs are being investigated and this is certainly the case for music. Whether the hearing aid wearer is a musician or merely someone who likes to listen to music, the electronic and electro-acoustic parameters described can be optimized for music as well as for speech. That is, a hearing aid optimally set for music can be optimally set for speech, even though the converse is not necessarily true. Similarities and differences between speech and music as inputs to a hearing aid are described. Many of these lead to the specification of a set of optimal electro-acoustic characteristics. Parameters such as the peak input-limiting level, compression issues-both compression ratio and knee-points-and number of channels all can deleteriously affect music perception through hearing aids. In other cases, it is not clear how to set other parameters such as noise reduction and feedback control mechanisms. Regardless of the existence of a "music program,'' unless the various electro-acoustic parameters are available in a hearing aid, music fidelity will almost always be less than optimal. There are many unanswered questions and hypotheses in this area. Future research by engineers, researchers, clinicians, and musicians will aid in the clarification of these questions and their ultimate solutions.

  3. Solidarity and AIDS: introduction.

    PubMed

    Krieger, N

    1991-01-01

    Perhaps more than any other disease in recent history, AIDS has taught a cruel and crucial lesson: the constraints on our response to this epidemic are as deep as our denial, as entrenched as the inequities that permeate our society, as circumscribed as our knowledge, and as unlimited as our compassion and our commitment to human rights. Elaborating on these themes, the final three articles in this Special Section on AIDS consider three widely divergent yet intimately connected topics: AIDS in Cuba, AIDS in Brazil, and global AIDS prevention in the 1990s. Together, they caution that if we persist in treating AIDS as a problem only of "others," no country will be spared the social and economic devastation that promises to be the cost of our contempt and our folly. Solidarity is not an option; it is a necessity. Without conscious recognition of the worldwide relationship between health, human rights, and social inequalities, our attempts to abate the spread of AIDS--and to ease the suffering that follows in its wake--most surely will fall short of our goals. Finally, as we mourn our dead, we must take to heart the words of Mother Jones, and "fight like hell for living." This is the politics of survival.

  4. Hearing Aids and Music

    PubMed Central

    Chasin, Marshall; Russo, Frank A.

    2004-01-01

    Historically, the primary concern for hearing aid design and fitting is optimization for speech inputs. However, increasingly other types of inputs are being investigated and this is certainly the case for music. Whether the hearing aid wearer is a musician or merely someone who likes to listen to music, the electronic and electro-acoustic parameters described can be optimized for music as well as for speech. That is, a hearing aid optimally set for music can be optimally set for speech, even though the converse is not necessarily true. Similarities and differences between speech and music as inputs to a hearing aid are described. Many of these lead to the specification of a set of optimal electro-acoustic characteristics. Parameters such as the peak input-limiting level, compression issues—both compression ratio and knee-points—and number of channels all can deleteriously affect music perception through hearing aids. In other cases, it is not clear how to set other parameters such as noise reduction and feedback control mechanisms. Regardless of the existence of a “music program,” unless the various electro-acoustic parameters are available in a hearing aid, music fidelity will almost always be less than optimal. There are many unanswered questions and hypotheses in this area. Future research by engineers, researchers, clinicians, and musicians will aid in the clarification of these questions and their ultimate solutions. PMID:15497032

  5. Women and HIV/AIDS

    MedlinePlus

    ... AIDS email updates Enter email Submit HIV and AIDS The human immunodeficiency (IH-myoo-noh-di-FISH- ... health Pregnancy and HIV View more HIV and AIDS resources Related information Birth control methods Sexually transmitted ...

  6. HIV / AIDS: An Unequal Burden

    MedlinePlus

    ... Navigation Bar Home Current Issue Past Issues HIV / AIDS HIV / AIDS: An Unequal Burden Past Issues / Summer 2009 Table ... Victoria Cargill talks to students about HIV and AIDS at the opening of a National Library of ...

  7. HIV/AIDS and Alcohol

    MedlinePlus

    ... Psychiatric Disorders Other Substance Abuse HIV/AIDS HIV/AIDS Human immunodeficiency virus (HIV) targets the body’s immune ... and often leads to acquired immune deficiency syndrome (AIDS). Each year in the United States, between 55, ...

  8. Research Report: HIV/AIDS

    MedlinePlus

    ... Reports » HIV/AIDS » Letter from the Director HIV/AIDS Email Facebook Twitter Letter from the Director Human ... the virus that causes acquired immune deficiency syndrome (AIDS) — has been with us for three decades now. ...

  9. HIV/AIDS and Vaccines

    MedlinePlus

    ... NIAID). /* // ** // */ Prevention Research Vaccines Microbicides Related Topics on AIDS.gov Clinical Trials Immune System 101 HIV Vaccine ... Be the Generation Last revised: 12/09/2016 AIDS.gov HIV/AIDS Basics • Federal Resources • Using New ...

  10. Political dimensions of AIDS.

    PubMed

    Blewett, N

    1988-01-01

    World political aspects and the example of Australia as a national political response to AIDS are presented. Global policy on AIDS is influenced by the fact that the AIDS epidemic is the 1st to be largely predictable, that long lag times occur between intervention and measurable events, and by the prompt, professional leadership of WHO, lead by Dr. J. Mann. WHO began a Global Programme on AIDS in 1987, modelled on the responses of Canada and Australia. A world summit of Ministers of Health was convened in January 1988. These moves generated a response qualified by openness, cooperation, hope and common sense. The AIDS epidemic calls for unprecedented involvement of politicians: they must coordinate medical knowledge with community action, deal with public fear, exert strong, rational leadership and avoid quick, appealing counterproductive responses. 3 clear directions must be taken to deal with the epidemic: 1) strong research and education campaigns; 2) close contact with political colleagues, interest groups and the community; 3) a national strategy which enjoins diverse interest groups, with courage, rationality and compassion. In Australia, the AIDS response began with the unwitting infection of 3 infants by blood transfusion. A public information campaign emphasizing a penetrating TV ad campaign was instituted in 1987. Policy discussions were held in all parliamentary bodies. The AIDS epidemic demands rapid, creative responses, a break from traditions in health bureaucracy, continual scrutiny of funding procedures and administrative arrangements. In practical terms in Australia, this meant establishing a special AIDS branch within the Health Advancement Division of the Community Health Department. AIDS issues must remain depoliticized to defuse adversary politics and keep leaders in a united front.

  11. Describing Surfaces.

    DTIC Science & Technology

    1985-01-01

    constant, then it is made explicit. For example, the asymptote that marks the smooth join of the bulb and the stem of the lightbulb in Figure 1, as...illustrates the representation we are aiming at. The stem of the lightbulb is determined to be cylindrical, because it is ruled and because it is a surface...and threaded end. This distinguishes the diameters of each that are collinear with the stem axis, showing ,4 that the lightbulb is a surface of

  12. Orbital Shape Representations.

    ERIC Educational Resources Information Center

    Kikuchi, Osamu; Suzuki, Keizo

    1985-01-01

    Discusses the use of orbital shapes for instructional purposes, emphasizing that differences between polar, contour, and three-dimensional plots must be made clear to students or misconceptions will occur. Also presents three-dimensional contour surfaces for the seven 4f atomic orbitals of hydrogen and discusses their computer generation. (JN)

  13. Implantable Heart Aid

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Medrad utilized NASA's Apollo technology to develop a new device called the AID implantable automatic pulse generator which monitors the heart continuously, recognizes the onset of ventricular fibrillation and delivers a corrective electrical shock. AID pulse generator is, in effect, a miniaturized version of the defibrillator used by emergency squads and hospitals to restore rhythmic heartbeat after fibrillation, but has the unique advantage of being permanently available to the patient at risk. Once implanted, it needs no specially trained personnel or additional equipment. AID system consists of a microcomputer, a power source and two electrodes which sense heart activity.

  14. Generalized movement representation in haptic perception.

    PubMed

    Dupin, Lucile; Hayward, Vincent; Wexler, Mark

    2017-03-01

    The extraction of spatial information by touch often involves exploratory movements, with tactile and kinesthetic signals combined to construct a spatial haptic percept. However, the body has many tactile sensory surfaces that can move independently, giving rise to the source binding problem: when there are multiple tactile signals originating from sensory surfaces with multiple movements, are the tactile and kinesthetic signals bound to one another? We studied haptic signal combination by applying the tactile signal to a stationary fingertip while another body part (the other hand or a foot) or a visual target moves, and using a task that can only be done if the tactile and kinesthetic signals are combined. We found that both direction and speed of movement transfer across limbs, but only direction transfers between visual target motion and the tactile signal. In control experiments, we excluded the role of explicit reasoning or knowledge of motion kinematics in this transfer. These results demonstrate the existence of 2 motion representations in the haptic system-one of direction and another of speed or amplitude-that are both source-free or unbound from their sensory surface of origin. These representations may well underlie our flexibility in haptic perception and sensorimotor control. (PsycINFO Database Record

  15. Pulmonary complications of AIDS: radiologic features. [AIDS

    SciTech Connect

    Cohen, B.A.; Pomeranz, S.; Rabinowitz, J.G.; Rosen, M.J.; Train, J.S.; Norton, K.I.; Mendelson, D.S.

    1984-07-01

    Fifty-two patients with pulmonary complications of acquired immunodeficiency syndrome (AIDS) were studied over a 3-year period. The vast majority of the patients were homosexual; however, a significant number were intravenous drug abusers. Thirteen different organisms were noted, of which Pneumocystis carinii was by far the most common. Five patients had neoplasia. Most patients had initial abnormal chest films; however, eight patients subsequently shown to have Pneumocystis carinii pneumonia had normal chest films. A significant overlap in chest radiographic findings was noted among patients with different or multiple organisms. Lung biopsy should be an early consideration for all patients with a clinical history consistent with the pulmonary complications of AIDS. Of the 52 patients, 41 had died by the time this report was completed.

  16. An ellipsoidal representation of human hand anthropometry

    NASA Technical Reports Server (NTRS)

    Buchholz, Bryan; Armstrong, Thomas J.

    1991-01-01

    Anthropometric data concerning the heometry of the hand's surface are presently modeled as a function of gross external hand measurements; an effort is made to evaluate the accuracy with which ellipsoids describe the geometry of the hand segments. Graphical comparisons indicate that differences between the ellipsoidal approximations and the breadth and depth measurements were greatest near the joints. On the bases of the present data, a set of overlapping ellipsoids could furnish a more accurate representation of hand geometry for adaptation to ellipsoid segment-geometry employing biomechanical models.

  17. Vietnamese Document Representation and Classification

    NASA Astrophysics Data System (ADS)

    Nguyen, Giang-Son; Gao, Xiaoying; Andreae, Peter

    Vietnamese is very different from English and little research has been done on Vietnamese document classification, or indeed, on any kind of Vietnamese language processing, and only a few small corpora are available for research. We created a large Vietnamese text corpus with about 18000 documents, and manually classified them based on different criteria such as topics and styles, giving several classification tasks of different difficulty levels. This paper introduces a new syllable-based document representation at the morphological level of the language for efficient classification. We tested the representation on our corpus with different classification tasks using six classification algorithms and two feature selection techniques. Our experiments show that the new representation is effective for Vietnamese categorization, and suggest that best performance can be achieved using syllable-pair document representation, an SVM with a polynomial kernel as the learning algorithm, and using Information gain and an external dictionary for feature selection.

  18. Graphical Representation of Complex Functions.

    ERIC Educational Resources Information Center

    Renka, Robert J.

    1988-01-01

    Describes methods and software for graphing representation of a complex function of a complex variable. Includes an application of a graphical interpretation of the complex zeros of the cubic and their properties. (PK)

  19. Progress in knowledge representation research

    NASA Technical Reports Server (NTRS)

    Lum, Henry

    1985-01-01

    Brief descriptions are given of research being carried out in the field of knowledge representation. Dynamic simulation and modelling of planning systems with real-time sensor inputs; development of domain-independent knowledge representation tools which can be used in the development of application-specific expert and planning systems; and development of a space-borne very high speed integrated circuit processor are among the projects discussed.

  20. Dermatomal Organization of SI Leg Representation in Humans: Revising the Somatosensory Homunculus.

    PubMed

    Dietrich, Caroline; Blume, Kathrin R; Franz, Marcel; Huonker, Ralph; Carl, Maria; Preißler, Sandra; Hofmann, Gunther O; Miltner, Wolfgang H R; Weiss, Thomas

    2017-01-23

    Penfield and Rasmussen's homunculus is the valid map of the neural body representation of nearly each textbook of biology, physiology, and neuroscience. The somatosensory homunculus places the foot representation on the mesial surface of the postcentral gyrus followed by the representations of the lower leg and the thigh in superio-lateral direction. However, this strong homuncular organization contradicts the "dermatomal" organization of spinal nerves. We used somatosensory-evoked magnetic fields and source analysis to study the leg's neural representation in the primary somatosensory cortex (SI). We show that the representation of the back of the thigh is located inferior to the foot's representation in SI whereas the front of the thigh is located laterally to the foot's representation. This observation indicates that the localization of the leg in SI rather follows the dermatomal organization of spinal nerves than the typical map of neighboring body parts as depicted in Penfield and Rasmussen's illustration of the somatosensory homunculus.

  1. Exploring children's stigmatisation of AIDS-affected children in Zimbabwe through drawings and stories.

    PubMed

    Campbell, Catherine; Skovdal, Morten; Mupambireyi, Zivai; Gregson, Simon

    2010-09-01

    AIDS-related stigma is a major contributor to the health and psychosocial well-being of children affected by AIDS. Whilst it is often suggested that AIDS-affected children may be stigmatised by other children, to date no research focuses specifically on child-on-child stigma. Using social representations theory, we explore how Zimbabwean children represent AIDS-affected peers, examining (i) whether or not they stigmatise, (ii) the forms stigma takes, and (iii) the existence of non-stigmatising representations that might serve as resources for stigma-reduction interventions. Our interest in identifying both stigmatising and non-stigmatising representations is informed by a theory of change which accords a central role to community-level debate and dialogue in challenging and reframing stigmatising representations. In late 2008, 50 children (aged 10-12) were asked to "draw a picture of a child whose family has been affected by AIDS in any way", and to write short stories about their drawings. Thematic analysis of stories and drawings revealed frequent references to stigmatisation of AIDS-affected children--with other children refusing to play with them, generally keeping their distance and bullying them. However children also frequently showed a degree of empathy and respect for AIDS-affected children's caring roles and for their love and concern for their AIDS-infected parents. We argue that a key strategy for stigma-reduction interventions is to open up social spaces in which group members (in this case children) can identify the diverse and contradictory ways they view a stigmatised out-group, providing opportunities for them to exercise agency in collectively challenging and renegotiating negative representations. Contrary to the common view that drawings enable children to achieve greater emotional expression than written stories, our children's drawings tended to be comparatively stereotypical and normative. It was in written stories that children most

  2. Setting apart the amateur from the professional: maintaining the value of standardised representational photography.

    PubMed

    Banks, Debbie

    2014-10-01

    The purpose of this paper is to discuss the importance of standard representational photography in clinical photography and its aid in maintaining the gold standard in the medical illustration profession. it is important that professionals are aware of potential threats to good practice with many areas identified in the article.

  3. Model Manipulation and Learning: Fostering Representational Competence with Virtual and Concrete Models

    ERIC Educational Resources Information Center

    Stull, Andrew T.; Hegarty, Mary

    2016-01-01

    This study investigated the development of representational competence among organic chemistry students by using 3D (concrete and virtual) models as aids for teaching students to translate between multiple 2D diagrams. In 2 experiments, students translated between different diagrams of molecules and received verbal feedback in 1 of the following 3…

  4. How Young Children View Mathematical Representations: A Study Using Eye-Tracking Technology

    ERIC Educational Resources Information Center

    Bolden, David; Barmby, Patrick; Raine, Stephanie; Gardner, Matthew

    2015-01-01

    Background: It has been shown that mathematical representations can aid children's understanding of mathematical concepts but that children can sometimes have difficulty in interpreting them correctly. New advances in eye-tracking technology can help in this respect because it allows data to be gathered concerning children's focus of attention and…

  5. Social Representations of Cybersecurity by University Students and Implications for Instructional Design

    ERIC Educational Resources Information Center

    Pawlowski, Suzanne D.; Jung, Yoonhyuk

    2015-01-01

    Cybersecurity has become an essential topic in introductory information systems (IS) core courses. As an aid to course design, the exploratory research in this paper uses a social representations lens to elucidate the perceptions of cybersecurity and cybersecurity threats held by students. Analysis of qualitative survey data from 152 students at a…

  6. 32 CFR 516.30 - Procedures for obtaining certification and DOJ representation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Procedures for obtaining certification and DOJ representation. 516.30 Section 516.30 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY AID OF CIVIL AUTHORITIES AND PUBLIC RELATIONS LITIGATION Individual Liability § 516.30 Procedures...

  7. First Aid and Safety

    MedlinePlus

    ... First-Aid Kit Food Safety for Your Family Gun Safety Halloween Candy Hints Household Safety Checklists Household ... Climbing, and Grabbing Household Safety: Preventing Injuries From Firearms Household Safety: Preventing Injuries in the Crib Household ...

  8. HIV and AIDS

    MedlinePlus

    ... known as AIDS . HIV destroys a type of defense cell in the body called a CD4 helper ... are part of the body's immune system , the defense system that fights infections. When HIV destroys these ...

  9. AIDS: A National Dilemma.

    ERIC Educational Resources Information Center

    Issues in Science and Technology, 1987

    1987-01-01

    Contains excerpts from a special study on the AIDS epidemic by the Institute of Medicine and National Academy of Sciences. Presents an overview of the problem, outlines educational needs and public health measures, and identifies future research needs. (ML)

  10. Convulsions - first aid - slideshow

    MedlinePlus

    ... this page: //medlineplus.gov/ency/presentations/100212.htm Convulsions - first aid - series—Procedure, part 1 To use ... slide 2 out of 2 Overview When a seizure occurs, the main goal is to protect the ...

  11. First Aid: Burns

    MedlinePlus

    ... MORE ON THIS TOPIC Kitchen: Household Safety Checklist Fireworks Safety First Aid: Sunburn Firesetting Fire Safety Burns ... Being Safe in the Kitchen Finding Out About Fireworks Safety Playing With Fire? Dealing With Burns Fireworks ...

  12. Hearing Aid Tester

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Hearing aids often develop malfunctions that are not detected by the wearer. This is particularly true when the wearers are school-age children. Studies of selected groups showed that from 30 to more than 50 percent of school children were not getting adequate benefit from their hearing aids because of unrecognized malfunctions, usually low or dead batteries. This can be serious because hearing impairment retards a child's educational progress. NASA technology incorporated in the Hearing Aid Malfunction Detection Unit (HAMDU), the device pictured, is expected to provide an effective countermeasure to the childrens' hearing aid problem. A patent license has been awarded to a minority-owned firm, Hopkins International Company, a subsidiary of H. H. Aerospace Design Co., Inc., Elmford, New York. The company plans early commercial availability of its version of the device.

  13. First Aid: Croup

    MedlinePlus

    ... Development Infections Diseases & Conditions Pregnancy & Baby Nutrition & Fitness Emotions & Behavior School & Family Life First Aid & Safety Doctors & ... with each breath has a pale or bluish color around the mouth drools or has difficulty swallowing ...

  14. Computer Aided Creativity.

    ERIC Educational Resources Information Center

    Proctor, Tony

    1988-01-01

    Explores the conceptual components of a computer program designed to enhance creative thinking and reviews software that aims to stimulate creative thinking. Discusses BRAIN and ORACLE, programs intended to aid in creative problem solving. (JOW)

  15. HIV/AIDS Treatment

    MedlinePlus

    ... HIV/AIDS Influenza Malaria Respiratory Syncytial Virus (RSV) Tuberculosis Zika Virus Find a Funding Opportunity Opportunities & Announcements ... related co-infections, such as hepatitis, malaria, and tuberculosis. Treatment of HIV Infection In the early 1980s ...

  16. First Aid: Croup

    MedlinePlus

    ... difficulty swallowing becomes tired easily Think Prevention! Frequent hand washing and avoiding contact with people who have respiratory ... Aid: Coughing X-Ray Exam: Neck Why Is Hand Washing So Important? Coughing Croup Contact Us Print Resources ...

  17. HIV and AIDS

    MedlinePlus

    ... that causes the disease AIDS. HIV Hurts the Immune System People who are HIV positive have been tested ... to everyone in the world. When the person's immune system has weakened and more of the blood's T ...

  18. AIDS in Africa

    DTIC Science & Technology

    2006-03-09

    have recommended that Africans infected with HIV be treated with an antibiotic/ sulfa drug combination known as cotrimoxazole in order to prevent...response is the subject of much debate. An estimated 500,000 Africa AIDS patients were being treated with antiretroviral drugs in mid-2005, up from 150,000...whether drugs can be made widely accessible without costly health infrastructure improvements. U.S. concern over AIDS in Africa grew in the 1980s, as the

  19. Naval Tactical Decision Aids

    DTIC Science & Technology

    1989-09-01

    Strike Planning Aid ( ESPA ) . .V-14 5.4. Tactical Environmental Ship Routing (TESR) V-24 5.5. Chaff Prediction and Planning System (CHAPPS).. V-29...chapter four TDAS from TESS: NAVSAR, acAS program for search and rescue (SARjat sea; ESPA , the Environmental Strike Planning Aid; TESR, the Tactical...STATISTICS CURRENT LOCATION AND CHARACTERISTICS SATELLITE DATA CONVERSION CONSTANTS In 5.1, we give a brief history of TESS. The TDAS NAVSAR, ESPA

  20. AIDS and National Security

    DTIC Science & Technology

    2007-11-02

    the body loses its ability to fight off other infections like the flu or pneumonia that it could normally handle with ease.11 These infections are... children orphaned by AIDS in sub-Saharan Africa.32 Failing states are not able to provide care for these orphans so they are lured into crime or...four major program elements funded by USAID are primary prevention, caring for children affected by AIDS, home and community based care and treatment

  1. 30 CFR 77.1705 - First aid training program; retraining of supervisory employees; availability to all miners.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false First aid training program; retraining of..., SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Miscellaneous § 77.1705 First aid..., 1972, each operator of a surface coal mine shall conduct refresher first aid training programs...

  2. 30 CFR 77.1705 - First aid training program; retraining of supervisory employees; availability to all miners.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false First aid training program; retraining of..., SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Miscellaneous § 77.1705 First aid..., 1972, each operator of a surface coal mine shall conduct refresher first aid training programs...

  3. 30 CFR 77.1705 - First aid training program; retraining of supervisory employees; availability to all miners.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false First aid training program; retraining of..., SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Miscellaneous § 77.1705 First aid..., 1972, each operator of a surface coal mine shall conduct refresher first aid training programs...

  4. 30 CFR 77.1705 - First aid training program; retraining of supervisory employees; availability to all miners.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false First aid training program; retraining of..., SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Miscellaneous § 77.1705 First aid..., 1972, each operator of a surface coal mine shall conduct refresher first aid training programs...

  5. 30 CFR 77.1705 - First aid training program; retraining of supervisory employees; availability to all miners.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false First aid training program; retraining of..., SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Miscellaneous § 77.1705 First aid..., 1972, each operator of a surface coal mine shall conduct refresher first aid training programs...

  6. [Aids, physicians, Catholic Church].

    PubMed

    Pipino, Marica; Boldrini, Elena; Cristani, Alessandro

    2003-01-01

    The latest AIDS' congress (Barcelona) reminded the world this dramatic situation. The shown data are remarkable: 5 million people of new infected in 2001, 68 million people could die in the next 20 years because of AIDS and the biggest part of them is living in the South of the world. There are two different kind of AIDS: the AIDS of rich people (2% of infected ones), who can reach the modern therapies that changed the course of the disease now curable out of hospital, and the AIDS of poor ones, without therapies and future. The political-economic effort of Western governments, of global fund anti-AIDS and of non governmental organizations now is not able to answer to this emergency in the right way. The lacking sensibility of Western doctors and the inflexible position of Catholic Church about contraception make the situation more complicated. It's hopeful the overcoming of this position using a Catholic Church's precious concept: the distinction between "simpliciter" and "secundum quid" to agree the use of condoms in case of absolute need.

  7. Computer Code Aids Design Of Wings

    NASA Technical Reports Server (NTRS)

    Carlson, Harry W.; Darden, Christine M.

    1993-01-01

    AERO2S computer code developed to aid design engineers in selection and evaluation of aerodynamically efficient wing/canard and wing/horizontal-tail configurations that includes simple hinged-flap systems. Code rapidly estimates longitudinal aerodynamic characteristics of conceptual airplane lifting-surface arrangements. Developed in FORTRAN V on CDC 6000 computer system, and ported to MS-DOS environment.

  8. Acquisition, representation and rule generation for procedural knowledge

    NASA Technical Reports Server (NTRS)

    Ortiz, Chris; Saito, Tim; Mithal, Sachin; Loftin, R. Bowen

    1991-01-01

    Current research into the design and continuing development of a system for the acquisition of procedural knowledge, its representation in useful forms, and proposed methods for automated C Language Integrated Production System (CLIPS) rule generation is discussed. The Task Analysis and Rule Generation Tool (TARGET) is intended to permit experts, individually or collectively, to visually describe and refine procedural tasks. The system is designed to represent the acquired knowledge in the form of graphical objects with the capacity for generating production rules in CLIPS. The generated rules can then be integrated into applications such as NASA's Intelligent Computer Aided Training (ICAT) architecture. Also described are proposed methods for use in translating the graphical and intermediate knowledge representations into CLIPS rules.

  9. Comparative Evaluation of Handheld Robot-Aided Intraocular Laser Surgery

    PubMed Central

    Yang, Sungwook; MacLachlan, Robert A.; Martel, Joseph N.; Lobes, Louis A.; Riviere, Cameron N.

    2015-01-01

    This paper presents robot-aided intraocular laser surgery using a handheld robot known as Micron. The micromanipulator incorporated in Micron enables visual servoing of a laser probe, while maintaining a constant distance of the tool tip from the retinal surface. The comparative study was conducted with various control methods for evaluation of robot-aided intraocular laser surgery. PMID:27019653

  10. Representation of orientation distributions

    SciTech Connect

    Wenk, H.R.; Kocks, U.F.

    1985-01-01

    This paper illustrates the principles presented with a particular experimental texture: from the surface layer of a copper polycrystal cold-rolled to 60% reduction in thickness. Four incomplete pole figures (200, 220, 222, and 113) were determined by x-ray diffraction in reflection geometry. The measured pole figures nearly exhibited orthorhombic symmetry (as expected), which was then strictly enforced by averaging the four quadrants of the pole figure. The orientation distribution function was obtained using the expansion in spherical harmonics (with only even-order coefficients up to l = 18).

  11. Reverse engineering: algebraic boundary representations to constructive solid geometry.

    SciTech Connect

    Buchele, S. F.; Ellingson, W. A.

    1997-12-17

    Recent advances in reverse engineering have focused on recovering a boundary representation (b-rep) of an object, often for integration with rapid prototyping. This boundary representation may be a 3-D point cloud, a triangulation of points, or piecewise algebraic or parametric surfaces. This paper presents work in progress to develop an algorithm to extend the current state of the art in reverse engineering of mechanical parts. This algorithm will take algebraic surface representations as input and will produce a constructive solid geometry (CSG) description that uses solid primitives such as rectangular block, pyramid, sphere, cylinder, and cone. The proposed algorithm will automatically generate a CSG solid model of a part given its algebraic b-rep, thus allowing direct input into a CAD system and subsequent CSG model generation.

  12. Data Representations for Geographic Information Systems.

    ERIC Educational Resources Information Center

    Shaffer, Clifford A.

    1992-01-01

    Surveys the field and literature of geographic information systems (GIS) and spatial data representation as it relates to GIS. Highlights include GIS terms, data types, and operations; vector representations and raster, or grid, representations; spatial indexing; elevation data representations; large spatial databases; and problem areas and future…

  13. The Student Guide: Financial Aid.

    ERIC Educational Resources Information Center

    Department of Education, Washington, DC. Student Financial Assistance.

    This publication explains what federal student financial aid is and what types of student aid are available. Two introductory sections present: federal student aid at-a-glance (what it is, who gets it, and how to get it) and finding out about student aid. The first section presents general information on the following subjects: student…

  14. Mommy, Daddy--What's AIDS?

    ERIC Educational Resources Information Center

    National Association of Pediatric Nurse Associates and Practitioners, Cherry Hill, NJ.

    This brochure is designed to help parents answer the questions that their children may ask them about Acquired Immune Deficiency Syndrome (AIDS) and the Human Immuno Deficiency Virus (HIV), the virus that causes AIDS. It provides basic information about AIDS and HIV, as well as sources for further information, such as the National AIDS Hotline. It…

  15. The First Aid Training Picture.

    ERIC Educational Resources Information Center

    Moore, Ian

    2000-01-01

    Discusses the history of first aid training provisions in the United Kingdom with respect to the outdoor industry, what to look for in a first aid training provider, an experiential model of first aid training, and the current National Governing Body requirements for first aid training for various types of coaches and instructors. (TD)

  16. Answering Your Questions about AIDS.

    ERIC Educational Resources Information Center

    Kalichman, Seth C.

    This book focuses on AIDS education and answers 350 commonly asked questions about Human Immunodeficiency Virus (HIV) and Acquired Immune Deficiency Syndrome (AIDS) taken from questions addressed to two major urban AIDS hotlines (Milwaukee, Wisconsin, and Houston, Texas). Chapter 1, "HIV - The Virus That Causes AIDS," discusses: the HIV…

  17. Culture as shared cognitive representations.

    PubMed Central

    Romney, A K; Boyd, J P; Moore, C C; Batchelder, W H; Brazill, T J

    1996-01-01

    Culture consists of shared cognitive representations in the minds of individuals. This paper investigates the extent to which English speakers share the "same" semantic structure of English kinship terms. The semantic structure is defined as the arrangement of the terms relative to each other as represented in a metric space in which items judged more similar are placed closer to each other than items judged as less similar. The cognitive representation of the semantic structure, residing in the mind of an individual, is measured by judged similarity tasks involving comparisons among terms. Using six independent measurements, from each of 122 individuals, correspondence analysis represents the data in a common multidimensional spatial representation. Judged by a variety of statistical procedures, the individuals in our sample share virtually identical cognitive representations of the semantic structure of kinship terms. This model of culture accounts for 70-90% of the total variability in these data. We argue that our findings on kinship should generalize to all semantic domains--e.g., animals, emotions, etc. The investigation of semantic domains is important because they may reside in localized functional units in the brain, because they relate to a variety of cognitive processes, and because they have the potential to provide methods for diagnosing individual breakdowns in the structure of cognitive representations typical of such ailments as Alzheimer disease. PMID:11607678

  18. Functional and structural mapping of human cerebral cortex: solutions are in the surfaces

    NASA Technical Reports Server (NTRS)

    Van Essen, D. C.; Drury, H. A.; Joshi, S.; Miller, M. I.

    1998-01-01

    The human cerebral cortex is notorious for the depth and irregularity of its convolutions and for its variability from one individual to the next. These complexities of cortical geography have been a chronic impediment to studies of functional specialization in the cortex. In this report, we discuss ways to compensate for the convolutions by using a combination of strategies whose common denominator involves explicit reconstructions of the cortical surface. Surface-based visualization involves reconstructing cortical surfaces and displaying them, along with associated experimental data, in various complementary formats (including three-dimensional native configurations, two-dimensional slices, extensively smoothed surfaces, ellipsoidal representations, and cortical flat maps). Generating these representations for the cortex of the Visible Man leads to a surface-based atlas that has important advantages over conventional stereotaxic atlases as a substrate for displaying and analyzing large amounts of experimental data. We illustrate this by showing the relationship between functionally specialized regions and topographically organized areas in human visual cortex. Surface-based warping allows data to be mapped from individual hemispheres to a surface-based atlas while respecting surface topology, improving registration of identifiable landmarks, and minimizing unwanted distortions. Surface-based warping also can aid in comparisons between species, which we illustrate by warping a macaque flat map to match the shape of a human flat map. Collectively, these approaches will allow more refined analyses of commonalities as well as individual differences in the functional organization of primate cerebral cortex.

  19. Women and AIDS: introduction.

    PubMed

    Krieger, N; Margo, G

    1991-01-01

    Around the world, more and more women--principally poor women of color--are being diagnosed with and are dying of AIDS, the acquired immune deficiency syndrome. Yet, effective and appropriate prevention programs for women are sorely missing from the global program to control AIDS. To help us understand why this gap exists, and what we must do to close it, the three articles in this issue focus on women and AIDS. Examining the situation in such countries as Zimbabwe and South Africa, as well as in other economically underdeveloped and developed regions, the authors argue that women with the least control over their bodies and their lives are at greatest risk of acquiring AIDS. For example, the high rate of infection among women in Africa cannot be understood apart from the legacy of colonialism (including land expropriation and the forced introduction of a migrant labor system) and the insidious combination of traditional and European patriarchal values. Only by recognizing the socioeconomic and cultural determinants of both disease and sexual behavior, and only by incorporating these insights into our AIDS prevention programs, will we be able to curb the spread of this lethal disease.

  20. AIDS in Africa.

    PubMed

    Mokhobo, D

    1989-03-01

    Numerous cultural practices and attitudes in Africa represent formidable obstacles to the prevention of the further spread of acquired immunodeficiency syndrome (AIDS). Polygamy and concubinage are still widely practiced throughout Africa. In fact, sexual promiscuity on the part of males is traditionally viewed as positive--a reflection of male supremacy and male sexual prowess. The disintegration of the rural African family, brought about by urbanization, the migrant labor system, and poverty, has resulted in widespread premarital promiscuity. Contraceptive practices are perceived by many as a white conspiracy aimed at limiting the growth of the black population and thereby diminishing its political power. Condom use is particularly in disfavor. Thus, AIDS prevention campaigns urging Africans to restrict the number of sexual partners and to use condoms are unlikely to be successful. Another problem is that most Africans cannot believe that AIDS is sexually linked in that the disease does not affect the sex organs as is the case with other sexually transmitted diseases. The degree to which African governments are able to allocate resources to AIDS education will determine whether the epidemic can be controlled. Even with a massive outpouring of resources, it may be difficult to arouse public alarm about AIDS since Africans are so acclimated to living with calamities of every kind.

  1. A Unified Graphical Representation of Chemical Thermodynamics and Equilibrium

    ERIC Educational Resources Information Center

    Hanson, Robert M.

    2012-01-01

    During the years 1873-1879, J. Willard Gibbs published his now-famous set of articles that form the basis of the current perspective on chemical thermodynamics. The second article of this series, "A Method of Geometrical Representation of the Thermodynamic Properties of Substances by Means of Surfaces," published in 1873, is particularly notable…

  2. Assessing value representation in animals.

    PubMed

    San-Galli, Aurore; Bouret, Sebastien

    2015-01-01

    Among all factors modulating our motivation to perform a given action, the ability to represent its outcome is clearly the most determining. Representation of outcomes, rewards in particular, and how they guide behavior, have sparked much research. Both practically and theoretically, understanding the relationship between the representation of outcome value and the organization of goal directed behavior implies that these two processes can be assessed independently. Most of animal studies essentially used instrumental actions as a proxy for the expected goal-value. The purpose of this article is to consider alternative measures of expected outcome value in animals, which are critical to understand the behavioral and neurobiological mechanisms relating the representation of the expected outcome to the organization of the behavior oriented towards its obtention. This would be critical in the field of decision making or social interactions, where the value of multiple items must often be compared and/or shared among individuals to determine the course of actions.

  3. Representational issues in machine learning

    SciTech Connect

    Liepins, G.E.; Hilliard, M.R.

    1986-10-25

    Classifier systems are numeric machine learning systems. They are machine counterparts to the natural genetic process and learn by reproduction, crossover, and mutation. Much publicity has been attended to their ability to demonstrate significant learning from a random start and without human intervention. Less well publicized is the considerable care that must be given to the choices of parameter settings and representation. Without the proper ''nurturing environment'' genetic algorithms are apt to learn very little. This infusion of human intelligence is often discounted, but the choice of appropriate representation forms the core of much of the current genetic algorithm research. This paper will address some of the representational issues from the perspective of two current experiments, one with scheduling and the other with a simulated robot. 10 refs., 7 figs.

  4. Novice Interpretations of Visual Representations of Geosciences Data

    NASA Astrophysics Data System (ADS)

    Burkemper, L. K.; Arthurs, L.

    2013-12-01

    Past cognition research of individual's perception and comprehension of bar and line graphs are substantive enough that they have resulted in the generation of graph design principles and graph comprehension theories; however, gaps remain in our understanding of how people process visual representations of data, especially of geologic and atmospheric data. This pilot project serves to build on others' prior research and begin filling the existing gaps. The primary objectives of this pilot project include: (i) design a novel data collection protocol based on a combination of paper-based surveys, think-aloud interviews, and eye-tracking tasks to investigate student data handling skills of simple to complex visual representations of geologic and atmospheric data, (ii) demonstrate that the protocol yields results that shed light on student data handling skills, and (iii) generate preliminary findings upon which tentative but perhaps helpful recommendations on how to more effectively present these data to the non-scientist community and teach essential data handling skills. An effective protocol for the combined use of paper-based surveys, think-aloud interviews, and computer-based eye-tracking tasks for investigating cognitive processes involved in perceiving, comprehending, and interpreting visual representations of geologic and atmospheric data is instrumental to future research in this area. The outcomes of this pilot study provide the foundation upon which future more in depth and scaled up investigations can build. Furthermore, findings of this pilot project are sufficient for making, at least, tentative recommendations that can help inform (i) the design of physical attributes of visual representations of data, especially more complex representations, that may aid in improving students' data handling skills and (ii) instructional approaches that have the potential to aid students in more effectively handling visual representations of geologic and atmospheric data

  5. AIDS in Colombia.

    PubMed

    Boshell, J; Gacharná, M G; García, M; Jaramillo, L S; Márquez, G; Fergusson, M M; González, S; Prada, E Y; de Rangel, R; de Cabas, R

    1989-01-01

    Between January 1984 and December 1987 a total of 178 AIDS cases were reported to the Colombian Ministry of Health. The location of these cases suggests that the human immunodeficiency virus (HIV) is widely distributed in Colombia. Most of those afflicted (97%) have been adult males. HIV seroprevalence studies of selected population groups revealed the highest antibody prevalence (5.65% in females, 22.5% in males) among individuals involved in high-risk behaviors who participated in a free AIDS testing program. High prevalences (from 0.6% to 3.9% in females, and 14.6% to 15.9% in males) were also found in patients (primarily female prostitutes and male homosexuals) attending clinics for sexually transmitted diseases in several urban areas. The number of AIDS cases in Colombia has doubled or tripled annually since reporting began in 1984, a pattern similar to that observed worldwide.

  6. Recapture training aid.

    SciTech Connect

    Pacheco, James Edward

    2004-08-01

    The breacher's training aid described in this report was designed to simulate features of magazine and steel-plate doors. The training aid enables breachers to practice using their breaching tools on components that they may encounter when attempting to enter a facility. Two types of fixtures were designed and built: (1) a large fixture incorporates simulated hinges, hasps, lock shrouds, and pins, and (2) a small fixture simulates the cross section of magazine and steel-plate doors. The small fixture consists of steel plates on either side of a structural member, such as an I-beam. The report contains detailed descriptions and photographs of the training aids, assembly instructions, and drawings.

  7. Orthographically Influenced Abstract Phonological Representation: Evidence from Non-Rhotic Speakers

    ERIC Educational Resources Information Center

    Taft, Marcus

    2006-01-01

    It is typically assumed that when orthography is translated silently into phonology (i.e., when reading silently), the phonological representation is equivalent to the spoken form or, at least, the surface phonemic form. The research presented here demonstrates that the phonological representation is likely to be more abstract than this, and is…

  8. Cross-modal influences on representational momentum and representational gravity.

    PubMed

    Hubbard, Timothy L; Courtney, Jon R

    2010-01-01

    Effects of cross-modal information on representational momentum and on representational gravity (ie on displacement of remembered location in the direction of target motion or in the direction of gravitational attraction, respectively) were examined. In experiment 1, ascending or descending visual motion (in the picture plane) was paired with ascending or descending auditory motion (in frequency space); motion was congruent (both ascending, both descending) or incongruent (one ascending, one descending). Memory for visual location or auditory pitch was probed. Congruence resulted in larger forward displacement for auditory pitch, but did not influence forward displacement for visual location. In experiment 2, horizontal visual motion was paired with ascending, descending, or no auditory motion. Memory for visual location was displaced downward with descending or no auditory motion, and downward displacement was larger for visual motion paired with descending auditory motion than for visual motion paired with ascending auditory motion. Effects of cross-modal information on displacement suggest representational momentum and representational gravity reflect high-level processing.

  9. The Statistics of Visual Representation

    NASA Technical Reports Server (NTRS)

    Jobson, Daniel J.; Rahman, Zia-Ur; Woodell, Glenn A.

    2002-01-01

    The experience of retinex image processing has prompted us to reconsider fundamental aspects of imaging and image processing. Foremost is the idea that a good visual representation requires a non-linear transformation of the recorded (approximately linear) image data. Further, this transformation appears to converge on a specific distribution. Here we investigate the connection between numerical and visual phenomena. Specifically the questions explored are: (1) Is there a well-defined consistent statistical character associated with good visual representations? (2) Does there exist an ideal visual image? And (3) what are its statistical properties?

  10. Medieval theories of mental representation.

    PubMed

    Kemp, S

    1998-11-01

    Throughout most of the Middle ages, it was generally held that stored mental representations of perceived objects or events preserved the forms or species of such objects. This belief was consistent with a metaphor used by Plato. It was also consistent with the medieval belief that a number of cognitive processes took place in the ventricles of the brain and with the phenomenology of afterimages and imagination itself. In the 14th century, William of Ockham challenged this belief by claiming that mental representations are not stored but instead constructed in the basis of past learned experiences.

  11. AIDS and tuberculosis.

    PubMed

    Morales Suárez-Valera, M M; Llopis González, A; Ballester Calabuig, M L

    1993-03-01

    Between 1985-1989 were diagnosed 376 cases of TBC in "La Fe" hospital in Valencia. 36 of this cases also had AIDS. We have carried out a compared study among the 340 cases of TBC and the 36 cases of AIDS+TBC. In this way we have described the social and work conditions of both groups, the hospitalization, the associated pathologies, the different risk factors, the different characteristics of the disease in each group of TBC, the diagnoses methods and the treatment of each case.

  12. Momentum-space representation of the Feynman propagator in Riemann-Cartan spacetime

    SciTech Connect

    Wu, Y.-H.; Wang, C.-H.

    2010-09-15

    We first construct generalized normal coordinates by using autoparallels, instead of geodesics, in an arbitrary Riemann-Cartan spacetime. With the aid of generalized normal coordinates and their associated orthonormal frames, we obtain a momentum-space representation of the Feynman propagator for scalar fields, which is a direct generalization of Bunch and Parker's works to curved spacetime with torsion. We further derive the proper-time representation in n-dimensional Riemann-Cartan spacetime from the momentum-space representation. It leads us to obtain the renormalization of the one-loop effective Lagrangians of free scalar fields by using dimensional regularization. When the torsion tensor vanishes, our resulting momentum-space representation returns to the standard Riemannian results.

  13. Severe Weather Forecast Decision Aid

    NASA Technical Reports Server (NTRS)

    Bauman, William H., III; Wheeler, Mark M.; Short, David A.

    2005-01-01

    This report presents a 15-year climatological study of severe weather events and related severe weather atmospheric parameters. Data sources included local forecast rules, archived sounding data, Cloud-to-Ground Lightning Surveillance System (CGLSS) data, surface and upper air maps, and two severe weather event databases covering east-central Florida. The local forecast rules were used to set threat assessment thresholds for stability parameters that were derived from the sounding data. The severe weather events databases were used to identify days with reported severe weather and the CGLSS data was used to differentiate between lightning and non-lightning days. These data sets provided the foundation for analyzing the stability parameters and synoptic patterns that were used to develop an objective tool to aid in forecasting severe weather events. The period of record for the analysis was May - September, 1989 - 2003. The results indicate that there are certain synoptic patterns more prevalent on days with severe weather and some of the stability parameters are better predictors of severe weather days based on locally tuned threat values. The results also revealed the stability parameters that did not display any skill related to severe weather days. An interactive web-based Severe Weather Decision Aid was developed to assist the duty forecaster by providing a level of objective guidance based on the analysis of the stability parameters, CGLSS data, and synoptic-scale dynamics. The tool will be tested and evaluated during the 2005 warm season.

  14. Rotation-independent representations for haptic movements.

    PubMed

    Shioiri, Satoshi; Yamazaki, Takanori; Matsumiya, Kazumichi; Kuriki, Ichiro

    2013-01-01

    The existence of a common mechanism for visual and haptic representations has been reported in object perception. In contrast, representations of movements might be more specific to modalities. Referring to the vertical axis is natural for visual representations whereas a fixed reference axis might be inappropriate for haptic movements and thus also inappropriate for its representations in the brain. The present study found that visual and haptic movement representations are processed independently. A psychophysical experiment examining mental rotation revealed the well-known effect of rotation angle for visual representations whereas no such effect was found for haptic representations. We also found no interference between processes for visual and haptic movements in an experiment where different stimuli were presented simultaneously through visual and haptic modalities. These results strongly suggest that (1) there are separate representations of visual and haptic movements, and (2) the haptic process has a rotation-independent representation.

  15. Lie antialgebras: cohomology and representations

    SciTech Connect

    Ovsienko, V.

    2008-11-18

    We describe the main algebraic and geometric properties of the class of algebras introduced in [1]. We discuss their origins in symplectic geometry and associative algebra, and the notions of cohomology and representations. We formulate classification theorems and give a number of examples.

  16. Representational Momentum in Older Adults

    ERIC Educational Resources Information Center

    Piotrowski, Andrea S.; Jakobson, Lorna S.

    2011-01-01

    Humans have a tendency to perceive motion even in static images that simply "imply" movement. This tendency is so strong that our memory for actions depicted in static images is distorted in the direction of implied motion--a phenomenon known as representational momentum (RM). In the present study, we created an RM display depicting a pattern of…

  17. Correct Representation of Conformational Equilibria.

    ERIC Educational Resources Information Center

    Fulop, F.; And Others

    1983-01-01

    In representing conformational equilibria of compounds having only one chiral center, erroneous formulas showing different antipodes on the two sides of the equilibrium are rare. In contrast, with compounds having two or more chiral centers especially with saturated heterocycles, this erroneous representation occurs frequently in the chemical…

  18. Mental Representations of Social Status

    ERIC Educational Resources Information Center

    Chiao, Joan Y.; Bordeaux, Andrew R.; Ambady, Nalni

    2004-01-01

    How do people think about social status? We investigated the nature of social status and number representations using a semantic distance latency test. In Study 1, 21 college students compared words connoting different social status as well as numbers, which served as a control task. Participants were faster at comparing occupations and numbers…

  19. Representational learning for sonar ATR

    NASA Astrophysics Data System (ADS)

    Isaacs, Jason C.

    2014-06-01

    Learned representations have been shown to give hopeful results for solving a multitude of novel learning tasks, even though these tasks may be unknown when the model is being trained. A few notable examples include the techniques of topic models, deep belief networks, deep Boltzmann machines, and local discriminative Gaussians, all inspired by human learning. This self-learning of new concepts via rich generative models has emerged as a promising area of research in machine learning. Although there has been recent progress, existing computational models are still far from being able to represent, identify and learn the wide variety of possible patterns and struc- ture in real-world data. An important issue for further consideration is the use of unsupervised representations for novel underwater target recognition applications. This work will discuss and demonstrate the use of latent Dirichlet allocation and autoencoders for learning unsupervised representations of objects in sonar imagery. The objective is to make these representations more abstract and invariant to noise in the training distribution and improve performance.

  20. First aid kit

    MedlinePlus

    ... bandages (Band-Aid or similar brand); assorted sizes Aluminum finger splints Elastic (ACE) bandage for wrapping wrist, ... to reduce contamination risk Save-A-Tooth storage device in case a tooth is broken or knocked out; ... equipment, and medical supplies. In: Auerbach PS, ed. Auerbach: Wilderness Medicine . ...

  1. Machine Aids to Translation.

    ERIC Educational Resources Information Center

    Brinkmann, Karl-Heinz

    1981-01-01

    Describes the TEAM Program System of the Siemens Language Services Department, particularly the main features of its terminology data bank. Discusses criteria to which stored terminology must conform and methods of data bank utilization. Concludes by summarizing the consequences that machine-aided translation development has had for the…

  2. Good Teaching Aids.

    ERIC Educational Resources Information Center

    National Audubon Society, New York, NY.

    This set of teaching aids consists of 14 Audubon Nature Bulletins with these titles: Schoolyard Laboratories, How to Lead a Field Trip, Natural Resources in the City, Mysteries of Bird Migration, Rock Stories and How to Read Them, The Ground Water Table, The Terrarium, Some Adventures With Wild Plants Outdoors and Indoors, Plant Propagation in the…

  3. More than First Aid

    ERIC Educational Resources Information Center

    Schoessler, Sally

    2011-01-01

    The school nurse is an important member of the school team since school health services keep students in school, in the classroom, and ready to learn. Although school nurses are often seen as the people who deliver first aid at school, their role is much deeper and has such breadth that only a registered, professional nurse has the skill set to…

  4. Instructional Aide Program.

    ERIC Educational Resources Information Center

    Thomson, Henry

    The Instructional Aide Program (Shoreline Community College, Seattle, Washington) is a flexible curriculum designed to prepare students to meet the paraprofessional manpower needs of several kinds of institution. It was prepared after consultation with representatives of the schools, the YMCA, and the country park system. Other agencies still to…

  5. Management of Student Aid.

    ERIC Educational Resources Information Center

    Nevin, Jeanne, Ed.

    The principles, practices, responsibilities, and controls in student financial aid are described in this manual. It traces the flow of funds, management activities, and legal issues as they occur in the process. The emphasis is on sound management principles of a general and permanent nature rather than on specific government requirements that may…

  6. Computer Aided Manufacturing.

    ERIC Educational Resources Information Center

    Insolia, Gerard

    This document contains course outlines in computer-aided manufacturing developed for a business-industry technology resource center for firms in eastern Pennsylvania by Northampton Community College. The four units of the course cover the following: (1) introduction to computer-assisted design (CAD)/computer-assisted manufacturing (CAM); (2) CAM…

  7. Coil Welding Aid

    NASA Technical Reports Server (NTRS)

    Wiesenbach, W. T.; Clark, M. C.

    1983-01-01

    Positioner holds coil inside cylinder during tack welding. Welding aid spaces turns of coil inside cylinder and applies contact pressure while coil is tack-welded to cylinder. Device facilitates fabrication of heat exchangers and other structures by eliminating hand-positioning and clamping of individual coil turns.

  8. Parent Hearing Aid Experiences

    ERIC Educational Resources Information Center

    Munoz, Karen; Roberts, Mallory; Mullings, Day; Harward, Richard

    2012-01-01

    This study addresses parent experiences in obtaining and managing hearing aids for their young child. The purpose was to identify challenges parents encounter to determine what state agencies can do to improve parent access to amplification. Data were collected July through September of 2010; 40 parents of children ages birth to 3 years old…

  9. AIDS: The Second Decade.

    ERIC Educational Resources Information Center

    Miller, Heather G., Ed.; And Others

    This report reviews the course of the Acquired Immune Deficiency Syndrome (AIDS) epidemic and its current status, examining changing patterns of sexual behavior and intravenous drug use, the distribution of cases of human immunodeficiency virus (HIV) infection, and the results of intervention efforts under way. It also discusses prevention…

  10. Impact Aid Program.

    ERIC Educational Resources Information Center

    Office of Elementary and Secondary Education (ED), Washington, DC.

    Impact Aid is a federal formula grant program designed to assist local school districts that have lost property tax revenue due to the presence of tax-exempt federal property or that have experienced increased expenditures due to the enrollment of federally connected children. Federally connected children are those whose parents pay minimal or no…

  11. AIDS Researcher Gives Retrospective

    ERIC Educational Resources Information Center

    Hawkins, B. Denise

    2011-01-01

    Nearly 30 years ago, renowned immunologist James E.K. Hildreth, M.D., Ph.D., was compelled to start researching the virus that causes AIDS. He marveled at its enigma and was pressed into action by its ability to cut lives short and devastate communities. The disease set him on a course of medical inquiry that has included biomedical breakthroughs…

  12. Newspaper Lesson Aids.

    ERIC Educational Resources Information Center

    Communication: Journalism Education Today (C:JET), 1986

    1986-01-01

    Provides photocopy-ready lesson aids on story ideas, interviewing, inverted pyramid writing style, newswriting, sports/scavenger hunt, finding feature material, identifying feature leads, feature lead selection, evaluating feature leads, compiling survey material, cutlines, headlines, paste-up rules, advertising, final semester project, newspaper…

  13. Computer Aided Art Major.

    ERIC Educational Resources Information Center

    Gibson, Jim

    The Computer Aided Art program offered at Northern State State University (Aberdeen, South Dakota), is coordinated with the traditional art major. The program is designed to familiarize students with a wide range of art-related computer hardware and software and their applications and to prepare students for problem-solving with unfamiliar…

  14. First Aid: Dehydration

    MedlinePlus

    ... Aid: Heat Illness Sun Safety Dehydration Diarrhea Vomiting Word! Dehydration What's the Big Sweat About Dehydration? How to Be Safe When You're in the Sun What's Sweat? Dehydration Is It Important to Drink a Lot of Water? Contact Us Print Resources Send to a Friend ...

  15. Job Aids and Motivation.

    ERIC Educational Resources Information Center

    Grau, Joseph A.

    1986-01-01

    Suggests job aids have motivational benefits and discusses three ways in which they positively affect motivation: increases worker's confidence of success and amount of effort they are willing to invest in attempting tasks; increases expectancy while decreasing amount of motivation needed; and reinforces task importance. (MBR)

  16. First Aid Challenge

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2011-01-01

    This article describes a challenge wherein students will be asked to design a portable first aid kit that is normally carried in a recreational vehicle (RV), but can also be hand-carried or backpacked off road for distances of approximately 1-2 miles. This can be a very practical challenge for the students because it touches everyone. Everybody…

  17. [Post-transfusional AIDS].

    PubMed

    Azzini, M; Maccabruni, A; Marcellini, M; Michelone, G; Dei Cas, A

    1987-01-01

    Two cases of post-transfusional AIDS in two premature babies who received blood of the same seropositive donor, are reported. The risk of the susceptibility to HIV infection of these patients, in relation to the immaturity of immune system and to the transfusional treatment often necessary in premature newborns, is stressed.

  18. 30 CFR 77.1707 - First aid equipment; location; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false First aid equipment; location; minimum... OF UNDERGROUND COAL MINES Miscellaneous § 77.1707 First aid equipment; location; minimum requirements. (a) Each operator of a surface coal mine shall maintain a supply of the first aid equipment set...

  19. 30 CFR 77.1707 - First aid equipment; location; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false First aid equipment; location; minimum... OF UNDERGROUND COAL MINES Miscellaneous § 77.1707 First aid equipment; location; minimum requirements. (a) Each operator of a surface coal mine shall maintain a supply of the first aid equipment set...

  20. 30 CFR 77.1707 - First aid equipment; location; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false First aid equipment; location; minimum... OF UNDERGROUND COAL MINES Miscellaneous § 77.1707 First aid equipment; location; minimum requirements. (a) Each operator of a surface coal mine shall maintain a supply of the first aid equipment set...

  1. 30 CFR 77.1707 - First aid equipment; location; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false First aid equipment; location; minimum... OF UNDERGROUND COAL MINES Miscellaneous § 77.1707 First aid equipment; location; minimum requirements. (a) Each operator of a surface coal mine shall maintain a supply of the first aid equipment set...

  2. 30 CFR 77.1707 - First aid equipment; location; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false First aid equipment; location; minimum... OF UNDERGROUND COAL MINES Miscellaneous § 77.1707 First aid equipment; location; minimum requirements. (a) Each operator of a surface coal mine shall maintain a supply of the first aid equipment set...

  3. AIDS and society.

    PubMed

    Singh, N K

    1991-08-01

    Noting the hysteria caused by an outbreak of AIDS among intravenous drug users in the state of Manipur, India, the author discusses the social and emotional aspects of the epidemic. Local media has been Manipur's main source of information concerning the outbreak, but this information has often been misleading and has served to stir up fear and hatred of HIV carriers. Many have even begun talking about an Isolation Centre. The author, the director of a drug rehabilitation center, relates his experiences in counseling 50 intravenous drug users on the subject of AIDS. He discovered that the group had very poor knowledge about the disease. When told about AIDS, they became alarmed at the possibility of dying. 1/2 of the group swore to take revenge on those who had introduced them to drugs, but the other 1/2 showed a more positive attitude, saying that they would like to help other drug addicts. The author also describes the case history of a patient who had succeeded in staying off of drugs for 8 months. HIV screening, however, revealed that the young man was seropositive. Somehow, a local newspaper got a hold of this information and published his name as a seropositive along with the names of others. Distraught by this, the young man returned to drugs. The author stresses that revealing the names of HIV carriers serves no social purpose, and in fact, only makes the problem worse. He recommends the following for dealing with the outbreak of AIDS: 1) intensive public health education on AIDS with the aim or removing unwarranted fears; 2) education to prevent drug addiction; 3) counselling to parents of drug addicts; and 4) the establishment of Seropositive Anonymous, an organization designed to help carriers deal with their problems.

  4. Asymptotic and Fredholm representations of discrete groups

    NASA Astrophysics Data System (ADS)

    Manuilov, V. M.; Mishchenko, A. S.

    1998-10-01

    A C^*-algebra servicing the theory of asymptotic representations and its embedding into the Calkin algebra that induces an isomorphism of K_1-groups is constructed. As a consequence, it is shown that all vector bundles over the classifying space B\\pi that can be obtained by means of asymptotic representations of a discrete group \\pi can also be obtained by means of representations of the group \\pi \\times {\\mathbb Z} into the Calkin algebra. A generalization of the concept of Fredholm representation is also suggested, and it is shown that an asymptotic representation can be regarded as an asymptotic Fredholm representation.

  5. Decomposability and mental representation of French verbs

    PubMed Central

    Estivalet, Gustavo L.; Meunier, Fanny E.

    2015-01-01

    In French, regardless of stem regularity, inflectional verbal suffixes are extremely regular and paradigmatic. Considering the complexity of the French verbal system, we argue that all French verbs are polymorphemic forms that are decomposed during visual recognition independently of their stem regularity. We conducted a behavioral experiment in which we manipulated the surface and cumulative frequencies of verbal inflected forms and asked participants to perform a visual lexical decision task. We tested four types of verbs with respect to their stem variants: a. fully regular (parler “to speak,” [parl-]); b. phonological change e/E verbs with orthographic markers (répéter “to repeat,” [répét-] and [répèt-]); c. phonological change o/O verbs without orthographic markers (adorer “to adore,” [ador-] and [adOr-]); and d. idiosyncratic (boire “to drink,” [boi-] and [buv-]). For each type of verb, we contrasted four conditions, forms with high and low surface frequencies and forms with high and low cumulative frequencies. Our results showed a significant cumulative frequency effect for the fully regular and idiosyncratic verbs, indicating that different stems within idiosyncratic verbs (such as [boi-] and [buv-]) have distinct representations in the mental lexicon as different fully regular verbs. For the phonological change verbs, we found a significant cumulative frequency effect only when considering the two forms of the stem together ([répét-] and [répèt-]), suggesting that they share a single abstract and under specified phonological representation. Our results also revealed a significant surface frequency effect for all types of verbs, which may reflect the recombination of the stem lexical representation with the functional information of the suffixes. Overall, these results indicate that all inflected verbal forms in French are decomposed during visual recognition and that this process could be due to the regularities of the French

  6. A numerical study of thin flame representations

    SciTech Connect

    Rotman, D.A.; Pindera, M.Z.

    1989-08-11

    In studies of reacting flows, the flame may be viewed as a moving discontinuity endowed with certain properties; notably, it acts as a source of velocity and vorticity. Asymptotic analysis shows this to be justified provided that the flame curvature is small compared to the flame thickness. Such an approach is useful when one is interested in the hydrodynamic effects of the flame on the surrounding flowfield. In numerical models of this kind it is customary to treat the discontinuity as a collection of discrete velocity blobs. In this study, we show that the velocities associated with such a representation can be very non-smooth, particularly very near to the flame surface. As an alternative, we propose the use of a finite line source as the basic flame element. Comparisons of the two flame representations are made for several simple test cases as well as for a flame propagating through an enclosure forming the tulip shape. The results show that the use of line sources eliminates spurious fluctuations in nearfield velocities thus allowing for a more accurate calculation of flame propagation and flame-flowfield interactions. 7 refs., 15 figs.

  7. A logical foundation for representation of clinical data.

    PubMed Central

    Campbell, K E; Das, A K; Musen, M A

    1994-01-01

    OBJECTIVE: A general framework for representation of clinical data that provides a declarative semantics of terms and that allows developers to define explicitly the relationships among both terms and combinations of terms. DESIGN: Use of conceptual graphs as a standard representation of logic and of an existing standardized vocabulary, the Systematized Nomenclature of Medicine (SNOMED International), for lexical elements. Concepts such as time, anatomy, and uncertainty must be modeled explicitly in a way that allows relation of these foundational concepts to surface-level clinical descriptions in a uniform manner. RESULTS: The proposed framework was used to model a simple radiology report, which included temporal references. CONCLUSION: Formal logic provides a framework for formalizing the representation of medical concepts. Actual implementations will be required to evaluate the practicality of this approach. PMID:7719805

  8. Adaptive Peircean decision aid project summary assessments.

    SciTech Connect

    Senglaub, Michael E.

    2007-01-01

    This efforts objective was to identify and hybridize a suite of technologies enabling the development of predictive decision aids for use principally in combat environments but also in any complex information terrain. The technologies required included formal concept analysis for knowledge representation and information operations, Peircean reasoning to support hypothesis generation, Mill's's canons to begin defining information operators that support the first two technologies and co-evolutionary game theory to provide the environment/domain to assess predictions from the reasoning engines. The intended application domain is the IED problem because of its inherent evolutionary nature. While a fully functioning integrated algorithm was not achieved the hybridization and demonstration of the technologies was accomplished and demonstration of utility provided for a number of ancillary queries.

  9. Different Styles of Hearing Aids

    MedlinePlus

    ... aids available and offer some cosmetic and listening advantages. Photo courtesy of Phonak Click for larger image ... in place. These aids offer cosmetic and listening advantages and are used typically for adults. Photo courtesy ...

  10. Basic HIV/AIDS Statistics

    MedlinePlus

    ... Other regions significantly affected by HIV/AIDS include Asia and the Pacific, Latin America and the Caribbean, and Eastern Europe and Central Asia. CDC’s Global AIDS website explains what CDC is ...

  11. American Foundation for AIDS Research

    MedlinePlus

    ... More To the Ends of the Earth for AIDS Research Swedish explorer Johan Ernst Nilson has raised ... More amfAR-Funded HIV Scholars Program Featured in AIDS and Behavior Supplement amfAR has partnered with the ...

  12. Material properties derived from three-dimensional shape representations.

    PubMed

    Marlow, Phillip J; Anderson, Barton L

    2015-10-01

    Retinal image structure is due to a complex mixture of physical sources that includes the surface's 3D shape, light-reflectance and transmittance properties, and the light field. The visual system can somehow discriminate between these different sources of image structure and recover information about the objects and surfaces in the scene. There has been significant debate about the nature of the representations that are used to derive surface reflectance properties such as specularity (gloss). Specularity could be derived either directly from 2D image properties or by exploiting information that can only be derived from representations in which 3D shape has been made explicit. We recently provided evidence that 3D shape information can play a critical role in the perception of material specularity, but the shape manipulation in our prior study also significantly changed 2D image properties (Marlow, Todorović, & Anderson, 2015). Here, we held fixed all monocularly visible 2D image properties and manipulated 3D shape stereoscopically. When binocularly fused, the depicted 3D shapes induced striking transformations in the surfaces' apparent material properties, which vary from matte to 'metallic'. Our psychophysical measurements of perceived specularity reveal that 3D shape information can play a critical role in material perception for both singly-curved surfaces and more complex geometries that curve in two directions. These results provide strong evidence that the perception of material specularity can depend on physical constraints derived from representations in which three-dimensional shape has been made explicit.

  13. Spatial sensory organization and body representation in pain perception.

    PubMed

    Haggard, Patrick; Iannetti, Gian Domenico; Longo, Matthew R

    2013-02-18

    Pain is a subjective experience that protects the body. This function implies a special relation between the brain mechanisms underlying pain perception and representation of the body. All sensory systems involve the body for the trivial reason that sensory receptors are located in the body. The nociceptive system of detecting noxious stimuli comprises two classes of peripheral afferents, Aδ and C nociceptors, that cover almost the entire body surface. We review evidence from experimental studies of pain in humans and other animals suggesting that Aδ skin nociceptors project to a spatially-organised, somatotopic map in the primary somatosensory cortex. While the relation between pain perception and homeostatic regulation of bodily systems is widely acknowledged, the organization of nociceptive information into spatial maps of the body has received little attention. Importantly, the somatotopic neural organization of pain systems can shed light on pain-related plasticity and pain modulation. Finally, we show that the neural coding of noxious stimuli, and consequent experience of pain, are both strongly influenced when cognitive representations of the body are activated by viewing the body, as opposed to viewing another object - an effect we term 'visual analgesia'. We argue that pain perception involves some of the representational properties of exteroceptive senses, such as vision and touch. Pain, however, has the unique feature that the content of representation is the body itself, rather than any external object of perception. We end with some suggestions regarding how linking pain to body representation could shed light on clinical conditions, notably chronic pain.

  14. Importance of perceptual representation in the visual control of action

    NASA Astrophysics Data System (ADS)

    Loomis, Jack M.; Beall, Andrew C.; Kelly, Jonathan W.; Macuga, Kristen L.

    2005-03-01

    In recent years, many experiments have demonstrated that optic flow is sufficient for visually controlled action, with the suggestion that perceptual representations of 3-D space are superfluous. In contrast, recent research in our lab indicates that some visually controlled actions, including some thought to be based on optic flow, are indeed mediated by perceptual representations. For example, we have demonstrated that people are able to perform complex spatial behaviors, like walking, driving, and object interception, in virtual environments which are rendered visible solely by cyclopean stimulation (random-dot cinematograms). In such situations, the absence of any retinal optic flow that is correlated with the objects and surfaces within the virtual environment means that people are using stereo-based perceptual representations to perform the behavior. The fact that people can perform such behaviors without training suggests that the perceptual representations are likely the same as those used when retinal optic flow is present. Other research indicates that optic flow, whether retinal or a more abstract property of the perceptual representation, is not the basis for postural control, because postural instability is related to perceived relative motion between self and the visual surroundings rather than to optic flow, even in the abstract sense.

  15. A hierarachical data structure representation for fusing multisensor information

    SciTech Connect

    Maren, A.J.; Pap, R.M.; Harston, C.T.

    1989-12-31

    A major problem with MultiSensor Information Fusion (MSIF) is establishing the level of processing at which information should be fused. Current methodologies, whether based on fusion at the data element, segment/feature, or symbolic levels, are each inadequate for robust MSIF. Data-element fusion has problems with coregistration. Attempts to fuse information using the features of segmented data relies on a Presumed similarity between the segmentation characteristics of each data stream. Symbolic-level fusion requires too much advance processing (including object identification) to be useful. MSIF systems need to operate in real-time, must perform fusion using a variety of sensor types, and should be effective across a wide range of operating conditions or deployment environments. We address this problem through developing a new representation level which facilitates matching and information fusion. The Hierarchical Data Structure (HDS) representation, created using a multilayer, cooperative/competitive neural network, meets this need. The HDS is an intermediate representation between the raw or smoothed data stream and symbolic interpretation of the data. it represents the structural organization of the data. Fused HDSs will incorporate information from multiple sensors. Their knowledge-rich structure aids top-down scene interpretation via both model matching and knowledge-based region interpretation.

  16. A hierarachical data structure representation for fusing multisensor information

    SciTech Connect

    Maren, A.J. . Space Inst.); Pap, R.M.; Harston, C.T. )

    1989-01-01

    A major problem with MultiSensor Information Fusion (MSIF) is establishing the level of processing at which information should be fused. Current methodologies, whether based on fusion at the data element, segment/feature, or symbolic levels, are each inadequate for robust MSIF. Data-element fusion has problems with coregistration. Attempts to fuse information using the features of segmented data relies on a Presumed similarity between the segmentation characteristics of each data stream. Symbolic-level fusion requires too much advance processing (including object identification) to be useful. MSIF systems need to operate in real-time, must perform fusion using a variety of sensor types, and should be effective across a wide range of operating conditions or deployment environments. We address this problem through developing a new representation level which facilitates matching and information fusion. The Hierarchical Data Structure (HDS) representation, created using a multilayer, cooperative/competitive neural network, meets this need. The HDS is an intermediate representation between the raw or smoothed data stream and symbolic interpretation of the data. it represents the structural organization of the data. Fused HDSs will incorporate information from multiple sensors. Their knowledge-rich structure aids top-down scene interpretation via both model matching and knowledge-based region interpretation.

  17. Effect of Aerosol and Ocean Representation on Simulated Climate Responses

    NASA Astrophysics Data System (ADS)

    Dallafior, Tanja; Folini, Doris; Knutti, Reto; Wild, Martin

    2016-04-01

    It is still debated to what extent anthropogenic aerosols shaped 20th century surface temperatures, especially sea surface temperatures (SSTs), through alteration of surface solar radiation (SSR). SSTs, in turn, are crucial in the context of atmospheric circulation and ocean heat uptake. Uncertainty considering anthropogenic aerosol forcing thus translates into uncertainty regarding ocean heat uptake and, ultimately, climate responses towards anthropogenic influences. We use the global climate model ECHAM to analyse the 20th century climate response towards either anthropogenic aerosols or well-mixed greenhouse gases or both with different representations of ocean and aerosols: atmosphere-only with prescribed SSTs and interactive aerosols; mixed-layer ocean and interactive or prescribed aerosols; fully coupled with prescribed aerosols. For interactive aerosols we use the Hamburg Aerosol Module (HAM). Our results suggest that up to 15% of global ocean surfaces undergo an SSR reduction of at least -4W/m² in the year 2000, due to anthropogenic aerosols. The area affected depends on how aerosols are represented and whether clear sky or all sky SSR is considered. In MLO equilibria with interactive aerosols, anthropogenic aerosols clearly shape surface temperature response patterns. This is to a lesser degree the case for the transient fully coupled case. Additivity of global mean temperature responses towards single forcings - an assumption often made in the literature - is not fulfilled for the MLO experiments, but for the fully coupled experiments. While some of these differences can be attributed to the differing ocean representation, it is implied that differing aerosol representation may play an even more relevant role. Thus, our results corroborate not only the relevance of anthropogenic aerosols for surface temperature responses, but also highlight the relevance of choice of aerosol representation.

  18. Fermi's golden rule in the Wigner representation

    NASA Astrophysics Data System (ADS)

    Segev, Bilha

    2003-06-01

    When Fermi's golden rule (FGR) is studied in the Wigner representation, the transition rate from an initial pure state or from an initial thermal distribution into a quasicontinuum manifold of degenerate states is given by an overlap integral of Wigner functions in phase space. In the semiclassical limit the transition rate is obtained by integrating over the regions in phase space where the energy difference between the initial and final potential surfaces is equal to the available energy. The integral is weighted by the initial probability density to be at that phase-space region. The classical limit of FGR is thus both simple and intuitive. In one dimension a relation to the Landau-Zener-Stuckelberg formula is established. The multi-dimensional case is considered by induction, proving that for separable multi-dimensional systems deviations of the logarithm of the transition rate from its classical limit scale at worst linearly with the dimension.

  19. Living with AIDS: Part II.

    ERIC Educational Resources Information Center

    Daedalus: Journal of the American Academy of Arts and Sciences, 1989

    1989-01-01

    A series of articles concerning various aspects of AIDS and the dilemmas it poses for U.S. society, culture, and government are presented, in this theme issue, e.g., "Introduction to the Issue" (K. Keniston); "Prospects for the Medical Control of the AIDS Epidemic" (W. Haseltine); "Social Policy: AIDS and Intravenous Drug Use" (N. Zinberg);…

  20. Manual for Student Financial Aids.

    ERIC Educational Resources Information Center

    MacDonald, Douglas S.

    This manual was designed to provide structural guidelines for financial aid program operations and administration at the Community College of Baltimore. Topics discussed include: the philosophy of student aid at an open door college; the objectives of the student financial aid office; staff development and administrative improvement; organization,…

  1. Teachers' Aides: Tasks and Concerns

    ERIC Educational Resources Information Center

    Balderson, James H.; Nixon, Mary

    1976-01-01

    Addresses three questions: (1) What tasks do aides perform? (2) Does training make a difference in the type of tasks aides perform? (3) What are the concerns of aides? (Available from the Department of Educational Administration, The University of Alberta, Edmonton, Alberta, Canada T6G 2G5; $0.50, single copy.) (Author/IRT)

  2. Pharmacotherapeutics for the AIDS Patient.

    ERIC Educational Resources Information Center

    Fife, Kenneth H.

    1991-01-01

    Anticipated shifts in the demographics of the Acquired Immune Deficiency Syndrome (AIDS) epidemic are examined, current state-of-the-art AIDS patient management is summarized, and some unique facets of drug therapy in the AIDS patient are discussed, including adverse reactions, complex drug interactions, use of investigational drugs, and…

  3. How Do People Get AIDS?

    MedlinePlus

    ... of Healthy Breakfasts Shyness How Do People Get AIDS? KidsHealth > For Teens > How Do People Get AIDS? Print A A A en español ¿Cómo contrae alguien el SIDA? AIDS stands for acquired immunodeficiency syndrome , a disease that ...

  4. Representations of mad cow disease.

    PubMed

    Washer, Peter

    2006-01-01

    This paper examines the reporting of the story of Bovine Spongiform Encephalopathy (BSE) and its human derivative variant Creutzfeld-Jacob Disease (vCJD) in the British newspapers. Three 'snapshots' of newspaper coverage are sampled and analysed between the period 1986 and 1996 focusing on how representations of the disease evolved over the 10-year period. Social representations theory is used to elucidate how this new disease threat was conceptualised in the newspaper reporting and how it was explained to the UK public. This paper examines who or what was said to be at risk from the new disease, and whether some individuals or groups held to blame for the diseases' putative origins, the appearance of vCJD in human beings, and its spread.

  5. Time representations in social science

    PubMed Central

    Schulz, Yvan

    2012-01-01

    Time has long been a major topic of study in social science, as in other sciences or in philosophy. Social scientists have tended to focus on collective representations of time, and on the ways in which these representations shape our everyday experiences. This contribution addresses work from such disciplines as anthropology, sociology and history. It focuses on several of the main theories that have preoccupied specialists in social science, such as the alleged “acceleration” of life and overgrowth of the present in contemporary Western societies, or the distinction between so-called linear and circular conceptions of time. The presentation of these theories is accompanied by some of the critiques they have provoked, in order to enable the reader to form her or his own opinion of them. PMID:23393420

  6. Mental representations of social status.

    PubMed

    Chiao, Joan Y; Bordeaux, Andrew R; Ambady, Nalini

    2004-09-01

    How do people think about social status? We investigated the nature of social status and number representations using a semantic distance latency test. In Study 1, 21 college students compared words connoting different social status as well as numbers, which served as a control task. Participants were faster at comparing occupations and numbers that were semantically farther apart relative to those more closely related. In Study 2, we examined the semantic distance effect for a social status category, for which participants have as much knowledge of, as with numbers. We asked 15 US Navy Midshipmen to compare the social status associated with different ranks in the Navy as well as compare number magnitudes. Participants were fastest when comparing ranks far in status relative to ranks close in status. These findings reveal that humans have mental representations of social status that share properties with that of number.

  7. Berry phase in Heisenberg representation

    NASA Technical Reports Server (NTRS)

    Andreev, V. A.; Klimov, Andrei B.; Lerner, Peter B.

    1994-01-01

    We define the Berry phase for the Heisenberg operators. This definition is motivated by the calculation of the phase shifts by different techniques. These techniques are: the solution of the Heisenberg equations of motion, the solution of the Schrodinger equation in coherent-state representation, and the direct computation of the evolution operator. Our definition of the Berry phase in the Heisenberg representation is consistent with the underlying supersymmetry of the model in the following sense. The structural blocks of the Hamiltonians of supersymmetrical quantum mechanics ('superpairs') are connected by transformations which conserve the similarity in structure of the energy levels of superpairs. These transformations include transformation of phase of the creation-annihilation operators, which are generated by adiabatic cyclic evolution of the parameters of the system.

  8. Knowledge representation in fuzzy logic

    NASA Technical Reports Server (NTRS)

    Zadeh, Lotfi A.

    1989-01-01

    The author presents a summary of the basic concepts and techniques underlying the application of fuzzy logic to knowledge representation. He then describes a number of examples relating to its use as a computational system for dealing with uncertainty and imprecision in the context of knowledge, meaning, and inference. It is noted that one of the basic aims of fuzzy logic is to provide a computational framework for knowledge representation and inference in an environment of uncertainty and imprecision. In such environments, fuzzy logic is effective when the solutions need not be precise and/or it is acceptable for a conclusion to have a dispositional rather than categorical validity. The importance of fuzzy logic derives from the fact that there are many real-world applications which fit these conditions, especially in the realm of knowledge-based systems for decision-making and control.

  9. Time representations in social science.

    PubMed

    Schulz, Yvan

    2012-12-01

    Time has long been a major topic of study in social science, as in other sciences or in philosophy. Social scientists have tended to focus on collective representations of time, and on the ways in which these representations shape our everyday experiences. This contribution addresses work from such disciplines as anthropology, sociology and history. It focuses on several of the main theories that have preoccupied specialists in social science, such as the alleged "acceleration" of life and overgrowth of the present in contemporary Western societies, or the distinction between so-called linear and circular conceptions of time. The presentation of these theories is accompanied by some of the critiques they have provoked, in order to enable the reader to form her or his own opinion of them.

  10. Computer aided manipulator control

    NASA Technical Reports Server (NTRS)

    Bejczy, A. K.; Zawacki, R. L.

    1980-01-01

    This paper describes the hardware and software system of a dedicated mini- and microcomputer network developed at the JPL teleoperator project to aid the operator in real-time control of remote manipulators. The operator can be in series or in parallel with the control computer during operation. The purpose of the project is to develop, demonstrate and evaluate advanced supervisory control concepts and techniques for space applications. The paper concludes with a brief outline of future development plans and issues.

  11. Directional Hearing Aid

    NASA Technical Reports Server (NTRS)

    Jhabvala, M.; Lin, H. C.

    1989-01-01

    Hearing-aid device indicates visually whether sound is coming from left, right, back, or front. Device intended to assist individuals who are deaf in at least one ear and unable to discern naturally directions to sources of sound. Device promotes safety in street traffic, on loading docks, and in presence of sirens, alarms, and other warning sounds. Quadraphonic version of device built into pair of eyeglasses and binaural version built into visor.

  12. Domain specific software design for decision aiding

    NASA Technical Reports Server (NTRS)

    Keller, Kirby; Stanley, Kevin

    1992-01-01

    McDonnell Aircraft Company (MCAIR) is involved in many large multi-discipline design and development efforts of tactical aircraft. These involve a number of design disciplines that must be coordinated to produce an integrated design and a successful product. Our interpretation of a domain specific software design (DSSD) is that of a representation or framework that is specialized to support a limited problem domain. A DSSD is an abstract software design that is shaped by the problem characteristics. This parallels the theme of object-oriented analysis and design of letting the problem model directly drive the design. The DSSD concept extends the notion of software reusability to include representations or frameworks. It supports the entire software life cycle and specifically leads to improved prototyping capability, supports system integration, and promotes reuse of software designs and supporting frameworks. The example presented in this paper is the task network architecture or design which was developed for the MCAIR Pilot's Associate program. The task network concept supported both module development and system integration within the domain of operator decision aiding. It is presented as an instance where a software design exhibited many of the attributes associated with DSSD concept.

  13. The pathology of AIDS.

    PubMed Central

    Macher, A M

    1988-01-01

    The acquired immunodeficiency syndrome (AIDS) is a devastating new disease caused by the human immunodeficiency virus (HIV). This retrovirus causes profound immunoincompetence in its infected hosts, who are thereafter susceptible to develop myriad severe and relapsing protozoal, fungal, bacterial, viral, and arthropodal opportunistic infections, as well as unusual malignancies. The more than 50,000 patients who have developed AIDS in the United States have produced a sudden unexpected deluge of diagnostic dilemmas that are stressing laboratories of pathology everywhere. This paper describes the gross and microscopic pathology of the numerous complications in patients infected by HIV: (a) the prodromal AIDS-related complex with persistent generalized lymphadenopathy, (b) lymphoid infiltration of salivary gland and lung, including the complex of lymphoid interstitial pneumonitis-pulmonary lymphoid hyperplasia, (c) extranodal non-Hodgkin's lymphomas, (d) multifocal mucocutaneous and visceral Kaposi's sarcoma, (e) small cell undifferentiated (oat cell) carcinomas, (f) protozoal infections caused by Pneumocystis carinii, Toxoplasma gondii, Acanthamoeba, Cryptosporidium species (sp.), and Isospora belli, (g) the causes of chronic enteritis, (h) mycotic infections caused by Candida sp., Cryptococcus neoformans, Histoplasma capsulatum, Coccidioides immitis, and Sporothrix schenckii, (i) bacterial infections caused by Mycobacterium avium-intracellulare, M. tuberculosis, M. kansasii, Nocardia sp., Listeria monocytogenes, Legionella sp., Treponema pallidum, and others, (j) viral infections caused by cytomegalovirus, herpes simplex and zoster, polyomavirus (progressive multifocal leukoencephalopathy), hepatitis B, molluscum contagiosum, and papillomavirus, (k) oral hairy leukoplakia, (l) subacute encephalopathy, and (m) Norwegian scabies. PMID:2836878

  14. Migrants and HIV / AIDS.

    PubMed

    Duckett, M

    2000-06-01

    This paper outlines some of the imperatives that should drive attention to the rights of legal and illegal migrants to health, particularly in relation to HIV/AIDS. It is noted that migrants can be especially vulnerable to HIV/AIDS/sexually transmitted diseases (STDs), but they are often excluded or simply missed in many prevention and care programs. In terms of the effects of globalization, it would seem that governments are required to ensure that this state of affairs does not continue. Evidence indicates that human rights and other ethical violations are occurring and need to be urgently addressed at local, national and international levels. In view of such, it is recommended that HIV/AIDS/STD prevention and care programs for migrant populations should be developed with and guided by migrant communities, and involving substantial community mobilization. Although some progress in preventing the spread of HIV to and from migrants have been documented, and projects addressing their needs have been made accessible, the challenge of dealing more comprehensively the complex issues involved still remains.

  15. SAR Image Complex Pixel Representations

    SciTech Connect

    Doerry, Armin W.

    2015-03-01

    Complex pixel values for Synthetic Aperture Radar (SAR) images of uniform distributed clutter can be represented as either real/imaginary (also known as I/Q) values, or as Magnitude/Phase values. Generally, these component values are integers with limited number of bits. For clutter energy well below full-scale, Magnitude/Phase offers lower quantization noise than I/Q representation. Further improvement can be had with companding of the Magnitude value.

  16. Temporal Representation in Semantic Graphs

    SciTech Connect

    Levandoski, J J; Abdulla, G M

    2007-08-07

    A wide range of knowledge discovery and analysis applications, ranging from business to biological, make use of semantic graphs when modeling relationships and concepts. Most of the semantic graphs used in these applications are assumed to be static pieces of information, meaning temporal evolution of concepts and relationships are not taken into account. Guided by the need for more advanced semantic graph queries involving temporal concepts, this paper surveys the existing work involving temporal representations in semantic graphs.

  17. Spatial Representations of Taxi Drivers.

    DTIC Science & Technology

    1982-09-28

    some people have suggested that adults, when they learn a new environment, proceed through these same Piagetian Stages in their representations...East Green Street Naval Postgraduate School Pasadena, CA 91101 Monterey, CA 93940 1 Special Asst. for Education and I Dr. Robert Wisher Training (OP-O1E...Research Laborat Pensacola, FL 32508 1 Dr. Gary Poock Operations Research Department Code 55PK Naval Postgraduate School Monterey, CA 93940 1 Roger W

  18. Cooperativity and 3-D Representation

    DTIC Science & Technology

    1993-02-28

    image, to simplified mechanisms for understandingshadows and shading and to renewed interest in " isophot " models of shading. Visual searchstudies have...reversals of contrast. One such representation is the isophots of the images, the lines of equal luminance. They capture the flow field of the brightness...shading as an oriented field of isophots (or at least short oriented segments) is still at an exploratory stage. We will digitize live scenes in our

  19. 48 CFR 1480.803 - Representation process.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... enterprise to an IA CO in the IEE representation at 1452.280-4 in response to a specific solicitation under the Buy Indian Act. (c) The CO may ask the appropriate Regional Solicitor to review the enterprise's representation. (d) The IEE representation does not relieve the CO of the obligation for determining...

  20. Imitation and the Dialectic of Representation.

    ERIC Educational Resources Information Center

    Zelazo, Philip David; Lourenco, Stella Felix

    2003-01-01

    Describes a theory of the understanding and use of representations, drawing heavily on Paul Ricoeur's and James Mark Baldwin's theories. Presents this theory as construing representation as intrinsically mimetic, characterizing the development of representational understanding as internalization, and emphasizing the importance of self-reflection…

  1. Methods and Strategies: The Science Representation Continuum

    ERIC Educational Resources Information Center

    Olson, Joanne K.

    2008-01-01

    Research indicates that people more easily understand abstractions when they are preceded by concrete representations (Lawson 2002). This article describes how educators can use science representations to help students form lasting understandings of abstract concepts. A spectrum illustrating some commonly used representation types and their level…

  2. 75 FR 32273 - Representation Election Procedure

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-08

    ... 29 CFR Parts 1202 and 1206 RIN 3140-ZA00 Representation Election Procedure AGENCY: National Mediation... delaying the effective date of its rule regarding representation election procedures from June 10, 2010 to... Representation Election Procedure Rule have been made. The NMB will notify participants if there are any...

  3. Promoting Decimal Number Sense and Representational Fluency

    ERIC Educational Resources Information Center

    Suh, Jennifer M.; Johnston, Chris; Jamieson, Spencer; Mills, Michelle

    2008-01-01

    The abstract nature of mathematics requires the communication of mathematical ideas through multiple representations, such as words, symbols, pictures, objects, or actions. Building representational fluency involves using mathematical representations flexibly and being able to interpret and translate among these different models and mathematical…

  4. Neural Representations of Physics Concepts.

    PubMed

    Mason, Robert A; Just, Marcel Adam

    2016-06-01

    We used functional MRI (fMRI) to assess neural representations of physics concepts (momentum, energy, etc.) in juniors, seniors, and graduate students majoring in physics or engineering. Our goal was to identify the underlying neural dimensions of these representations. Using factor analysis to reduce the number of dimensions of activation, we obtained four physics-related factors that were mapped to sets of voxels. The four factors were interpretable as causal motion visualization, periodicity, algebraic form, and energy flow. The individual concepts were identifiable from their fMRI signatures with a mean rank accuracy of .75 using a machine-learning (multivoxel) classifier. Furthermore, there was commonality in participants' neural representation of physics; a classifier trained on data from all but one participant identified the concepts in the left-out participant (mean accuracy = .71 across all nine participant samples). The findings indicate that abstract scientific concepts acquired in an educational setting evoke activation patterns that are identifiable and common, indicating that science education builds abstract knowledge using inherent, repurposed brain systems.

  5. Topographic NMF for data representation.

    PubMed

    Xiao, Yanhui; Zhu, Zhenfeng; Zhao, Yao; Wei, Yunchao; Wei, Shikui; Li, Xuelong

    2014-10-01

    Nonnegative matrix factorization (NMF) is a useful technique to explore a parts-based representation by decomposing the original data matrix into a few parts-based basis vectors and encodings with nonnegative constraints. It has been widely used in image processing and pattern recognition tasks due to its psychological and physiological interpretation of natural data whose representation may be parts-based in human brain. However, the nonnegative constraint for matrix factorization is generally not sufficient to produce representations that are robust to local transformations. To overcome this problem, in this paper, we proposed a topographic NMF (TNMF), which imposes a topographic constraint on the encoding factor as a regularizer during matrix factorization. In essence, the topographic constraint is a two-layered network, which contains the square nonlinearity in the first layer and the square-root nonlinearity in the second layer. By pooling together the structure-correlated features belonging to the same hidden topic, the TNMF will force the encodings to be organized in a topographical map. Thus, the feature invariance can be promoted. Some experiments carried out on three standard datasets validate the effectiveness of our method in comparison to the state-of-the-art approaches.

  6. Symbol Systems and Pictorial Representations

    NASA Astrophysics Data System (ADS)

    Diederich, Joachim; Wright, Susan

    All problem-solvers are subject to the same ultimate constraints -- limitations on space, time, and materials (Minsky, 1985). He introduces two principles: (1) Economics: Every intelligence must develop symbol-systems for representing objects, causes and goals, and (2) Sparseness: Every evolving intelligence will eventually encounter certain very special ideas -- e.g., about arithmetic, causal reasoning, and economics -- because these particular ideas are very much simpler than other ideas with similar uses. An extra-terrestrial intelligence (ETI) would have developed symbol systems to express these ideas and would have the capacity of multi-modal processing. Vakoch (1998) states that ...``ETI may rely significantly on other sensory modalities (than vision). Particularly useful representations would be ones that may be intelligible through more than one sensory modality. For instance, the information used to create a three-dimensional representation of an object might be intelligible to ETI heavily reliant on either visual or tactile sensory processes.'' The cross-modal representations Vakoch (1998) describes and the symbol systems Minsky (1985) proposes are called ``metaphors'' when combined. Metaphors allow for highly efficient communication. Metaphors are compact, condensed ways of expressing an idea: words, sounds, gestures or images are used in novel ways to refer to something they do not literally denote. Due to the importance of Minsky's ``economics'' principle, it is therefore possible that a message heavily relies on metaphors.

  7. Representations of metabolic knowledge: Pathways

    SciTech Connect

    Karp, P.D.; Paley, S.M.

    1994-12-31

    The automatic generation of drawings of metabolic pathways is a challenging problem that depends intimately on exactly what information has been recorded for each pathway, and on how that information is encoded. The chief contributions of the paper are a minimized representation for biochemical pathways called the predecessor list, and inference procedures for converting the predecessor list into a pathway-graph representation that can serve as input to a pathway-drawing algorithm. The predecessor list has several advantages over the pathway graph, including its compactness and its lack of redundancy. The conversion between the two representations can be formulated as both a constraint-satisfaction problem and a logical inference problem, whose goal is to assign directions to reactions, and to determine which are the main chemical compounds in the reaction. We describe a set of production rules that solves this inference problem. We also present heuristics for inferring whether the exterior compounds that are substrates of reactions at the periphery of a pathway are side or main compounds. These techniques were evaluated on 18 metabolic pathways from the EcoCyc knowledge base.

  8. Representation

    DTIC Science & Technology

    2006-09-01

    absolutely nothing, for others familiarity or even a sense of kinship while others feel pangs of contemptuousness. The psychologist Carl Jung ...noticed this about people.1 Of the Christian cross, Jung noted that it carried a much different significance (p.81) if found after one’s name in a book...signifying their death as opposed to its placement on a building. Jung researched early Christianity and discovered that the crossbeam of its Latin

  9. On the representation of many-body interactions in water

    DOE PAGES

    Medders, Gregory R.; Gotz, Andreas W.; Morales, Miguel A.; ...

    2015-09-09

    Our recent work has shown that the many-body expansion of the interactionenergy can be used to develop analytical representations of global potential energy surfaces (PESs) for water. In this study, the role of short- and long-range interactions at different orders is investigated by analyzing water potentials that treat the leading terms of the many-body expansion through implicit (i.e., TTM3-F and TTM4-F PESs) and explicit (i.e., WHBB and MB-pol PESs) representations. Moreover, it is found that explicit short-range representations of 2-body and 3-body interactions along with a physically correct incorporation of short- and long-range contributions are necessary for an accurate representationmore » of the waterinteractions from the gas to the condensed phase. Likewise, a complete many-body representation of the dipole moment surface is found to be crucial to reproducing the correct intensities of the infrared spectrum of liquid water.« less

  10. Neural dynamics of image representation in the primary visual cortex.

    PubMed

    Yan, Xiaogang; Khambhati, Ankit; Liu, Lei; Lee, Tai Sing

    2012-01-01

    Horizontal connections in the primary visual cortex have been hypothesized to play a number of computational roles: association field for contour completion, surface interpolation, surround suppression, and saliency computation. Here, we argue that horizontal connections might also serve a critical role for computing the appropriate codes for image representation. That the early visual cortex or V1 explicitly represents the image we perceive has been a common assumption in computational theories of efficient coding (Olshausen and Field (1996)), yet such a framework for understanding the circuitry in V1 has not been seriously entertained in the neurophysiological community. In fact, a number of recent fMRI and neurophysiological studies cast doubt on the neural validity of such an isomorphic representation (Cornelissen et al., 2006; von der Heydt et al., 2003). In this study, we investigated, neurophysiologically, how V1 neurons respond to uniform color surfaces and show that spiking activities of neurons can be decomposed into three components: a bottom-up feedforward input, an articulation of color tuning and a contextual modulation signal that is inversely proportional to the distance away from the bounding contrast border. We demonstrate through computational simulations that the behaviors of a model for image representation are consistent with many aspects of our neural observations. We conclude that the hypothesis of isomorphic representation of images in V1 remains viable and this hypothesis suggests an additional new interpretation of the functional roles of horizontal connections in the primary visual cortex.

  11. Negotiated Representational Mediators: How Young Children Decide What to Include in Their Science Representations

    ERIC Educational Resources Information Center

    Danish, Joshua A.; Enyedy, Noel

    2007-01-01

    In this paper, we synthesize two bodies of work related to students' representational activities: the notions of meta-representational competence and representation as a form of practice. We report on video analyses of kindergarten and first-grade students as they create representations of pollination in a science classroom, as well as summarize…

  12. Military Representation: The Theoretical and Practical Implications of Population Representation in the American Armed Forces

    DTIC Science & Technology

    1979-10-01

    REPRESENTATION AND SOCIAL EQUITY: PAST AND PRESENT EXPERIENCES.. ............... 103 Equity in the Military Melting Pot Black Representation in the...Vietnam The Vietnam-Era Draft in Retrospect Military Representation and Social Equity under the AVF Measures of Social Equity Implications CHAPTER V...MILITARY REPRESENTATION AND SOCIAL EQUITY: THE POLICY MAZE ........ ..................... ... 183 Benefits vs. Burdens of Military Service

  13. Financial Aid Administrators' Views on Simplifying Financial Aid: NASFAA's 2008 Financial Aid Simplification Survey Report

    ERIC Educational Resources Information Center

    National Association of Student Financial Aid Administrators (NJ1), 2008

    2008-01-01

    Despite a decade of simplification efforts, students and families are often still baffled by the student aid process and cringe at the sight of financial aid application forms. Contrary to its purpose of helping students to access college, the student aid application process causes families frustration and confusion that has been cited as an…

  14. Drawing Connections Across Conceptually Related Visual Representations in Science

    NASA Astrophysics Data System (ADS)

    Hansen, Janice

    with support for structure mapping led to a lessened reliance on surface features, and a better understanding of the science concepts presented. These findings suggest that presenting diagrams serially in an effort to reduce cognitive load may not be preferable for learning if making connections across representations, and by extension across science concepts, is desired. Instead, providing simultaneous diagrams with structure mapping support may result in greater attention to the salient relationships between related visual representations as well as between the representations and the science concepts they depict.

  15. Scaffolding scientific discussion using socially relevant representations in networked multimedia

    NASA Astrophysics Data System (ADS)

    Hoadley, Christopher M.

    1999-11-01

    How do students make use of social cues when learning on the computer? This work examines how students in a middle-school science course learned through on-line peer discussion. Cognitive accounts of collaboration stress interacting with ideas, while socially situated accounts stress the interpersonal context. The design of electronic environments allows investigation into the interrelation of cognitive and social dimensions. I use on-line peer discussion to investigate how socially relevant representations in interfaces can aid learning. First, I identify some of the variables that affect individual participation in on-line discussion, including interface features. Individual participation is predicted by student attitudes towards learning from peers. Second, I describe the range of group outcomes for these on-line discussions. There is a large effect of discussion group on learning outcomes which is not reducible to group composition or gross measures of group process. Third, I characterize how students (individually) construct understanding from these group discussions. Learning in the on-line discussions is shown to be a result of sustained interaction over time, not merely encountering or expressing ideas. Experimental manipulations in the types of social cues available to students suggest that many students do use socially relevant representations to support their understanding of multiple viewpoints and science reasoning. Personalizing scientific disputes can afford reflection on the nature of scientific discovery and advance. While there are many individual differences in how social representations are used by students in learning, overall learning benefits for certain social representations can be shown. This work has profound implications for design of collaborative instructional methods, equitable access to science learning, design of instructional technology, and understanding of learning and cognition in social settings.

  16. Alternative Approach to Nuclear Data Representation

    SciTech Connect

    Pruet, J; Brown, D; Beck, B; McNabb, D P

    2005-07-27

    This paper considers an approach for representing nuclear data that is qualitatively different from the approach currently adopted by the nuclear science community. Specifically, they examine a representation in which complicated data is described through collections of distinct and self contained simple data structures. This structure-based representation is compared with the ENDF and ENDL formats, which can be roughly characterized as dictionary-based representations. A pilot data representation for replacing the format currently used at LLNL is presented. Examples are given as is a discussion of promises and shortcomings associated with moving from traditional dictionary-based formats to a structure-rich or class-like representation.

  17. Pilot decision making in a computer-aided flight management situation

    NASA Technical Reports Server (NTRS)

    Chu, Y. Y.; Rouse, W. B.

    1978-01-01

    An experimental representation of a computer-aided multi-task flight management situation has been developed. A computer aiding program was implemented to serve as a back-up decision maker. An experiment was conducted with a balanced design of several subject runs for different workload levels. This was achieved using three levels of subsystem event arrival rates, three levels of control task involvement, and three levels of availability of computer aiding. Experimental results compared quite favorably with those from a computer simulation which employed a queueing model. It was shown that the aiding had enhanced system performance as well as subjective ratings, and that the adaptive aiding policy further reduced subsystem delay.

  18. Supporting Learning and Promoting Conceptual Change with Box and AVOW Diagrams. Part 1: Representational Design and Instructional Approaches.

    ERIC Educational Resources Information Center

    Cheng, Peter C-H.; Shipstone, David M.

    2003-01-01

    Describes an approach to the teaching of electricity that uses box and AVOW diagrams, novel representations of the properties of the electric circuit that portray current, voltage, resistance, and power. The diagrams were developed as aids in learning, understanding, and problem solving and to promote conceptual change by challenging a number of…

  19. The Indian Fashion Show: Manipulating Representations of Native Attire in Museum Exhibits to Fight Stereotypes in 1942 and 1998

    ERIC Educational Resources Information Center

    Parezo, Nancy J.

    2007-01-01

    In this article, the author writes about the power of representation in the staging of a unique and highly successful series of fashion shows held in 1942. These showcases, presented more than 120 times between 1942 and 1956, aided in the appreciation of American Indian clothing and dress as a messenger of style, purpose, and identity, all…

  20. Representation learning: a review and new perspectives.

    PubMed

    Bengio, Yoshua; Courville, Aaron; Vincent, Pascal

    2013-08-01

    The success of machine learning algorithms generally depends on data representation, and we hypothesize that this is because different representations can entangle and hide more or less the different explanatory factors of variation behind the data. Although specific domain knowledge can be used to help design representations, learning with generic priors can also be used, and the quest for AI is motivating the design of more powerful representation-learning algorithms implementing such priors. This paper reviews recent work in the area of unsupervised feature learning and deep learning, covering advances in probabilistic models, autoencoders, manifold learning, and deep networks. This motivates longer term unanswered questions about the appropriate objectives for learning good representations, for computing representations (i.e., inference), and the geometrical connections between representation learning, density estimation, and manifold learning.

  1. LG based decision aid for naval tactical action officer's (TAO) workstation

    NASA Astrophysics Data System (ADS)

    Stilman, Boris; Yakhnis, Vladimir; Umanskiy, Oleg; Boyd, Ron

    2005-05-01

    In the increasingly NetCentric battlespace of the 21st century, Stilman Advanced Strategies Linguistic Geometry software has the potential to revolutionize the way that the Navy fights in two key areas: as a Tactical Decision Aid and for creating a relevant Common Operating Picture. Incorporating STILMAN's software into a prototype Tactical Action Officers (TAO) workstation as a Tactical Decision Aid (TDA) will allow warfighters to manage their assets more intelligently and effectively. This prototype workstation will be developed using human-centered design principles and will be an open, component-based architecture for combat control systems for future small surface combatants. It will integrate both uninhabited vehicles and onboard sensors and weapon systems across a squadron of small surface combatants. In addition, the hypergame representation of complex operations provides a paradigm for the presentation of a common operating picture to operators and personnel throughout the command hierarchy. In the hypergame technology there are game levels that span the range from the tactical to the global strategy level, with each level informing the others. This same principle will be applied to presenting the relevant common operating picture to operators. Each operator will receive a common operating picture that is appropriate for their level in the command hierarchy. The area covered by this operating picture and the level of detail contained within it will be dependent upon the specific tasks the operator is performing (supervisory vice tactical control) and the level of the operator (or command personnel) within the command hierarchy. Each level will inform the others to keep the picture concurrent and up-to-date.

  2. Help: first aid issues.

    PubMed

    Granitoff, N; Whitaker, I Y; Diccini, S; Goncalves, V C; Marin, H F

    1995-01-01

    First aid is the initial and immediate care given to a victim outside the hospital environment, with the purpose of assuring life and avoiding worsening conditions until he/she receives qualified assistance. Providing immediate aid to someone requires tranquility and, above all, knowledge on what has to be done or not in each situation. In addition to being treated by health professionals, the chances that a victim will receive early treatment by others are large. However, in Brazil, access to information, and the possibility of reviewing it whenever necessary, may contribute greatly to the process of assimilation of this knowledge, in addition to exercises on simulated cases. Informatics has been shown as an extremely useful tool in the development of educational software, considering its multiplicity of resources and providing for the users: motivation for an interactive experience, an individualized teaching that takes into account his/her own rhythm and desired complexity level, besides making possible the user's capacity for solving problems through simulated situations. Considering that, the number of individuals of the population prepared to act as First Aid helpers in situations of life threatening accidents or sudden illness is still very scarce. The ever increasing use of the computer as a mean of spreading information in schools, enterprises, and even households and considering the advantages of an educational software for the users regarding storage and retrieval of information when needed, we proposed the creation of an interactive teaching software. This software is being developed using Storyboard live. The methodology is the following: literature review, selection of images, development of the program, application tests. The initial selected issues are: assessment of the victim, cardiorespiratory arrest and resuscitation, airway obstruction, wounds, and hemorrhages. After utilizing the program, the user should be able to solve hypothetical

  3. AIDS and family planning.

    PubMed

    1992-01-01

    In 1991, an HIV prevention program advisor and a research/evaluation specialist for family planning programs discussed problems that affected HIV prevention and family planning services in Haiti before and after the coup of the Aristide government. Population activities began aimlessly in 1974 and HIV prevention efforts only began in 1988. After the coup, Haitians lost their newly found hope for meaningful development. All foreign assistance ended and they did not trust the army. In fact, other than essential child survival activities, no health and family planning services operated for several weeks. The situation grew worse after the economic embargo. 3 months after the coup, the US considered adding family planning assistance. Still little movement of condom, family planning, and health supplies left Port-au-Prince for the provinces which adversely affected all health related efforts. Condoms could no longer be distributed easily either in the socially marketed or US supplied condom distribution programs. Before the coup, HIV prevention and family planning programs depended on peer educators to educate the public (this approach made these programs quite successful), but the 2 experts feared that they would not return to those roles and that these programs would need to completely rebuild. Another concern was the large scale urban-rural migration making it difficult for them to continue care. Early in the AIDS epidemic, the Haitian government was on the defensive because the US considered Haitians as a high risk group so it did little to prevent HIV transmission. After 1988, HIV prevention activities in Haiti centered on raising awareness and personalizing the epidemic. The AIDS specialist noted, however, that a major obstacle to increasing knowledge is that AIDS is just 1 of many fatal diseases in Haiti. Moreover few health professionals in Haiti have ever had public health training.

  4. Should Aid Reward Performance?

    PubMed Central

    Olken, Benjamin A.; Onishi, Junko; Wong, Susan

    2014-01-01

    We report an experiment in 3,000 villages that tested whether incentives improve aid efficacy. Villages received block grants for maternal and child health and education that incorporated relative performance incentives. Subdistricts were randomized into incentives, an otherwise identical program without incentives, or control. Incentives initially improved preventative health indicators, particularly in underdeveloped areas, and spending efficiency increased. While school enrollments improved overall, incentives had no differential impact on education, and incentive health effects diminished over time. Reductions in neonatal mortality in non-incentivized areas did not persist with incentives. We find no systematic scoring manipulation nor funding reallocation toward richer areas. PMID:25485039

  5. Migration and AIDS.

    PubMed

    Decosas, J; Kane, F; Anarfi, J K; Sodji, K D; Wagner, H U

    1995-09-23

    A successful short-term solution to transmission of AIDS in Western Africa by migrants involves provision of accessible and acceptable basic health and social services to migrants at their destination. The aim is to establish a sense of security and community, which is a health requirement. When migrants are excluded from community life or victimized as carriers of HIV infections, they will be driven by basic survival needs and dysfunctional social organization, which results in the rapid spread of HIV. Closing borders and mass deportation may not be an option. The long-term solution is population policy, environmental protection, and economic development. The focus on mapping the spread of AIDS must shift to a consideration of the migrant social conditions that make them vulnerable to AIDS. The issue of migration and AIDS will be addressed at the First European Conference on Tropical Medicine in October 1995 in Hamburg, Germany. In Uganda, HIV seroprevalence rates ranged from 5.5% among the stable population to 12.4% among internal migrants moving between villages to 16.3% among migrants from other areas. A World Bank project is operating in Western Africa, which traces seasonal male migration from the Cameroon to Liberia, Senegal to Nigeria, and from the Sahel to the coast during dry seasons. National border rules may influence the routes but not the extent of migration. A major destination place is Cote d' Ivoire, which has 25% of total population comprised of migrants from other countries and one of the highest HIV prevalence rates in Western Africa. On plantations prostitutes are brought in. Each prostitute serves about 25 workers. The pattern of sexual mixing contributes to the high HIV rates. Female migration is smaller and usually concentrated in prostitution at place of destination. Illiteracy and poverty drive women migrants into the trade. Their frequent health problems are malaria, pelvic pain, menstrual irregularity, vaginal discharge, and genital

  6. HIV/AIDS eradication.

    PubMed

    Marsden, Matthew D; Zack, Jerome A

    2013-07-15

    Antiretroviral therapy can inhibit HIV replication in patients and prevent progression to AIDS. However, it is not curative. Here we provide an overview of what antiretroviral drugs do and how the virus persists during therapy in rare reservoirs, such as latently infected CD4+ T cells. We also outline several innovative methods that are currently under development to eradicate HIV from infected individuals. These strategies include gene therapy approaches intended to create an HIV-resistant immune system, and activation/elimination approaches directed towards flushing out latent virus. This latter approach could involve the use of novel chemically synthesized analogs of natural activating agents.

  7. Representation and re-presentation in litigation science.

    PubMed

    Jasanoff, Sheila

    2008-01-01

    Federal appellate courts have devised several criteria to help judges distinguish between reliable and unreliable scientific evidence. The best known are the U.S. Supreme Court's criteria offered in 1993 in Daubert v. Merrell Dow Pharmaceuticals, Inc. This article focuses on another criterion, offered by the Ninth Circuit Court of Appeals, that instructs judges to assign lower credibility to "litigation science" than to science generated before litigation. In this article I argue that the criterion-based approach to judicial screening of scientific evidence is deeply flawed. That approach buys into the faulty premise that there are external criteria, lying outside the legal process, by which judges can distinguish between good and bad science. It erroneously assumes that judges can ascertain the appropriate criteria and objectively apply them to challenged evidence before litigation unfolds, and before methodological disputes are sorted out during that process. Judicial screening does not take into account the dynamics of litigation itself, including gaming by the parties and framing by judges, as constitutive factors in the production and representation of knowledge. What is admitted through judicial screening, in other words, is not precisely what a jury would see anyway. Courts are sites of repeated re-representations of scientific knowledge. In sum, the screening approach fails to take account of the wealth of existing scholarship on the production and validation of scientific facts. An unreflective application of that approach thus puts courts at risk of relying upon a "junk science" of the nature of scientific knowledge.

  8. 49 CFR 38.125 - Mobility aid accessibility.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... mobility aid maneuverability when entering or leaving the car. (c) Car ramp or bridge plate—(1) Design load. Ramps or bridge plates 30 inches or longer shall support a load of 600 pounds, placed at the centroid of... inches shall support a load of 300 pounds. (2) Ramp surface. The ramp or bridge plate surface shall...

  9. Unitary Representations of Gauge Groups

    NASA Astrophysics Data System (ADS)

    Huerfano, Ruth Stella

    I generalize to the case of gauge groups over non-trivial principal bundles representations that I. M. Gelfand, M. I. Graev and A. M. Versik constructed for current groups. The gauge group of the principal G-bundle P over M, (G a Lie group with an euclidean structure, M a compact, connected and oriented manifold), as the smooth sections of the associated group bundle is presented and studied in chapter I. Chapter II describes the symmetric algebra associated to a Hilbert space, its Hilbert structure, a convenient exponential and a total set that later play a key role in the construction of the representation. Chapter III is concerned with the calculus needed to make the space of Lie algebra valued 1-forms a Gaussian L^2-space. This is accomplished by studying general projective systems of finitely measurable spaces and the corresponding systems of sigma -additive measures, all of these leading to the description of a promeasure, a concept modeled after Bourbaki and classical measure theory. In the case of a locally convex vector space E, the corresponding Fourier transform, family of characters and the existence of a promeasure for every quadratic form on E^' are established, so the Gaussian L^2-space associated to a real Hilbert space is constructed. Chapter III finishes by exhibiting the explicit Hilbert space isomorphism between the Gaussian L ^2-space associated to a real Hilbert space and the complexification of its symmetric algebra. In chapter IV taking as a Hilbert space H the L^2-space of the Lie algebra valued 1-forms on P, the gauge group acts on the motion group of H defining in an straight forward fashion the representation desired.

  10. The conceptual representation of number.

    PubMed

    Patson, Nikole D; George, Gerret; Warren, Tessa

    2014-01-01

    The experiments reported here investigated the format of plural conceptual representations using a picture-matching paradigm. In Experiment 1, participants read sentences that ended with a singular noun phrase (NP), a two-quantified plural NP, or a plural definite description [The parents handed the child the (two) crayon/s] and then saw a picture of one or multiple referents for the NP. Judgement times to confirm that there was overlap between the pictured object(s) and a noun in the sentence showed an interaction between the NP's number and NP-picture match. For singular NPs and two-quantified NPs, participants were reliably faster to respond "yes" to a picture that had the exact number of objects specified by the NP, but for plural definite descriptions, the effect of the number of pictured items was not reliable. Experiment 2 extended this finding to conceptual plurals. Participants read sentences biased toward either a collective (Together the men carried a box-box is interpreted as singular) or distributed (Each of the men carried a box-box is likely interpreted as plural) reading. Experiment 2 showed the same interaction between NP conceptual plurality and NP-picture match as that in Experiment 1. These results suggest that: (a) our default conceptual representations for plural definite descriptions are no more similar to images of small sets of multiple items than to images of singular items; and (b) the difference between singular and plural conceptual representations is unlikely to be simply the presence or absence of a plural feature. The results are consistent with theories in which plurality is unmarked, such that some plural NPs can refer to singular referents [e.g., Sauerland, U., Anderssen, J., & Yatsushiro, J. (2005). The plural is semantically unmarked. In S. Kepser & M. Reis (Eds.), Linguistic evidence (pp. 413-434). Berlin: de Gruyter].

  11. Epigenetic regulation of HIV, AIDS, and AIDS-related malignancies.

    PubMed

    Verma, Mukesh

    2015-01-01

    Although epigenetics is not a new field, its implications for acquired immunodeficiency syndrome (AIDS) research have not been explored fully. To develop therapeutic and preventive approaches against the human immunodeficiency virus (HIV) and AIDS, it is essential to understand the mechanisms of interaction between the virus and the host, involvement of genetic and epigenetic mechanisms, characterization of viral reservoirs, and factors influencing the latency of the virus. Both methylation of viral genes and histone modifications contribute to initiating and maintaining latency and, depending on the context, triggering viral gene repression or expression. This chapter discusses progress made at the National Institutes of Health (NIH), recommendations from the International AIDS Society Scientific Working Group on HIV Cure, and underlying epigenetic regulation. A number of epigenetic inhibitors have shown potential in treating AIDS-related malignancies. Epigenetic drugs approved by the US Food and Drug Administration and their implications for the eradication of HIV/AIDS and AIDS-related malignancies also are discussed.Past and current progress in developing treatments and understanding the molecular mechanisms of AIDS and HIV infection has greatly improved patient survival. However, increased survival has been coupled with the development of cancer at higher rates than those observed among the HIV/AIDS-negative population. During the early days of the AIDS epidemic, the most frequent AIDS-defining malignancies were Kaposi's sarcoma and non-Hodgkin lymphoma (NHL). Now, with increased survival as the result of widespread use in the developed world of highly active antiretroviral therapy (HAART), non-AIDS defining cancers (i.e., anal, skin, and lung cancers, and Hodgkin disease) are on the increase in HIV-infected populations. The current status of AIDS-related malignancies also is discussed.

  12. Argumentation-Based Collaborative Inquiry in Science Through Representational Work: Impact on Primary Students' Representational Fluency

    NASA Astrophysics Data System (ADS)

    Nichols, Kim; Gillies, Robyn; Hedberg, John

    2016-06-01

    This study explored the impact of argumentation-promoting collaborative inquiry and representational work in science on primary students' representational fluency. Two hundred sixty-six year 6 students received instruction on natural disasters with a focus on collaborative inquiry. Students in the Comparison condition received only this instruction. Students in the Explanation condition were also instructed with a focus on explanations using representations. Students in the Argumentation condition received similar instruction to the Comparison and Explanation conditions but were also instructed with a focus on argumentation using representations. Conceptual understanding and representational competencies (interpreting, explaining and constructing representations) were measured prior to and immediately following the instruction. A small group collaborative representational task was video recorded at the end of the instruction and coded for modes of knowledge-building discourse; knowledge-sharing and knowledge-construction. Higher measures of conceptual understanding, representational competencies and knowledge-construction discourse were taken together as representational fluency. Students in all conditions showed significant improvement in conceptual understanding, interpreting representations and explaining representations. Students in the Comparison and Argumentation conditions also showed significantly improved scores in constructing representations. When compared to the other conditions, the Explanation group had the highest scores in conceptual understanding and also interpreting and explaining representations. While the Argumentation group had the highest scores for constructing representations, their scores for conceptual understanding as well as interpreting and explaining representations were also high. There was no difference between the groups in knowledge-sharing discourse; however, the Argumentation group displayed the highest incidence of knowledge

  13. Visual representation of scientific information.

    PubMed

    Wong, Bang

    2011-02-15

    Great technological advances have enabled researchers to generate an enormous amount of data. Data analysis is replacing data generation as the rate-limiting step in scientific research. With this wealth of information, we have an opportunity to understand the molecular causes of human diseases. However, the unprecedented scale, resolution, and variety of data pose new analytical challenges. Visual representation of data offers insights that can lead to new understanding, whether the purpose is analysis or communication. This presentation shows how art, design, and traditional illustration can enable scientific discovery. Examples will be drawn from the Broad Institute's Data Visualization Initiative, aimed at establishing processes for creating informative visualization models.

  14. QED in the worldline representation

    NASA Astrophysics Data System (ADS)

    Schubert, Christian

    2007-06-01

    Simultaneously with inventing the modern relativistic formalism of quantum electrodynamics, Feynman presented also a first-quantized representation of QED in terms of worldline path integrals. Although this alternative formulation has been studied over the years by many authors, only during the last fifteen years it has acquired some popularity as a computational tool. I will shortly review here three very different techniques which have been developed during the last few years for the evaluation of worldline path integrals, namely (i) the "string-inspired formalism", based on the use of worldline Green functions, (ii) the numerical "worldline Monte Carlo formalism", and (iii) the semiclassical "worldline instanton" approach.

  15. Particles, Cutoffs and Inequivalent Representations

    NASA Astrophysics Data System (ADS)

    Egg, Matthias; Lam, Vincent; Oldofredi, Andrea

    2017-03-01

    We critically review the recent debate between Doreen Fraser and David Wallace on the interpretation of quantum field theory, with the aim of identifying where the core of the disagreement lies. We show that, despite appearances, their conflict does not concern the existence of particles or the occurrence of unitarily inequivalent representations. Instead, the dispute ultimately turns on the very definition of what a quantum field theory is. We further illustrate the fundamental differences between the two approaches by comparing them both to the Bohmian program in quantum field theory.

  16. Efficient Type Representation in TAL

    NASA Technical Reports Server (NTRS)

    Chen, Juan

    2009-01-01

    Certifying compilers generate proofs for low-level code that guarantee safety properties of the code. Type information is an essential part of safety proofs. But the size of type information remains a concern for certifying compilers in practice. This paper demonstrates type representation techniques in a large-scale compiler that achieves both concise type information and efficient type checking. In our 200,000-line certifying compiler, the size of type information is about 36% of the size of pure code and data for our benchmarks, the best result to the best of our knowledge. The type checking time is about 2% of the compilation time.

  17. Cognitive representation of negative numbers.

    PubMed

    Fischer, Martin H

    2003-05-01

    To understand negative numbers, must we refer to positive number representations (the phylogenetic hypothesis), or do we acquire a negative mental number line (the ontogenetic hypothesis)? In the experiment reported here, participants made lateralized button responses to indicate the larger of two digits from the range -9 to 9. Digit pairs were displayed spatially congruent or incongruent with either a phylogenetic or an ontogenetic mental number line. The pattern of decision latencies suggests that negative numbers become associated with left space, thus supporting the ontogenetic view.

  18. Representer-based analyses in the coastal upwelling system

    NASA Astrophysics Data System (ADS)

    Kurapov, A. L.; Egbert, G. D.; Allen, J. S.; Miller, R. N.

    2009-10-01

    The impact of surface velocity and SSH data assimilated in a model of wind-driven upwelling over the shelf is studied using representer and observational array mode analyses and twin experiments, utilizing new tangent linear (TL) and adjoint (ADJ) codes. Bathymetry, forcing, and initial conditions are assumed to be alongshore uniform reducing the problem to classical two-dimensional. The model error is attributed to uncertainty in the surface wind stress. The representers, analyzed in cross-shore sections, show how assimilated observations provide corrections to the wind stress and circulation fields, and give information on the structure of the multivariate prior model error covariance. Since these error covariance fields satisfy the dynamics of the TL model, they maintain dominant balances (Ekman transport, geostrophy, thermal wind). Solutions computed over a flat bottom are qualitatively similar to a known analytical solution. Representers obtained with long cross-shore decorrelation scale for the wind stress errors lx (compared to the distance to coast) exhibit the classical upwelling structure. Solutions obtained with much smaller lx show structure associated with Ekman pumping, and are nearly singular if lx is smaller than the grid resolution. The zones of maximum influence of observations are sensitive to the background ocean conditions and are not necessarily centered around the observation locations. Array mode analysis is utilized to obtain model structures (combinations of representers) that are most stably observed by a given array. This analysis reveals that for realistic measurement errors and observational configurations, surface velocities will be more effective than SSH in providing correction to the wind stress on the scales of tens of km. In the DA test with synthetic observations, the prior nonlinear solution is obtained with spatially uniform alongshore wind stress and the true solution with the wind stress sharply reduced inshore of the

  19. Knot invariants from Virasoro related representation and pretzel knots

    NASA Astrophysics Data System (ADS)

    Galakhov, D.; Melnikov, D.; Mironov, A.; Morozov, A.

    2015-10-01

    We remind the method to calculate colored Jones polynomials for the plat representations of knot diagrams from the knowledge of modular transformation (monodromies) of Virasoro conformal blocks with insertions of degenerate fields. As an illustration we use a rich family of pretzel knots, lying on a surface of arbitrary genus g, which was recently analyzed by the evolution method. Further generalizations can be to generic Virasoro modular transformations, provided by integral kernels, which can lead to the Hikami invariants.

  20. Snow complexity representation and GCM climate

    NASA Astrophysics Data System (ADS)

    Dutra, Emanuel; Viterbo, Pedro; Miranda, Pedro M. A.; Balsamo, Gianpaolo

    2010-05-01

    Accurate simulations of the snow cover strongly impact on the quality of weather and climate predictions as the solar radiation absorption at land-atmosphere interface is modified by a factor up to 4 in response to snow presence (albedo effect). In Northern latitudes and Mountainous regions snow acts also as an important energy and water reservoir and a correct representation of snow mass and snow density is crucial for temperature predictions at all time-scales, with direct consequences for soil hydrology (thermal insulation effect). Three different complexity snow schemes implemented in the ECMWF land surface scheme HTESSEL are tested within the EC-EARTH framework. The snow schemes are: 1) OLD, the original HTESSEL single bulk layer snow scheme (same as in the ERA-40 and ERA-Interim reanalysis); 2) OPER, a new snow scheme in operations since September 2009, with a liquid water reservoir and revised formulations of snow density, fractional cover and snow albedo; and 3) ML3, a multi-layer version of OPER. All three snow schemes in HTESSEL are energy- and mass- balance models. The multi-layer snow scheme, ML3, was validated in offline mode covering several spatial and temporal scales: (i) site simulations for several observation locations from the Snow Models intercomparison project-2 (SnowMip2) and (ii) global simulations driven by the meteorological forcing from the Global Soil Wetness Project-2 (GSWP2) and the ECMWF ERA-Interim re-analysis. On point locations ML3 improve snow mass simulations, while on a global scale the impacts are residual pointing to the need of coupled atmosphere simulations. The 3 schemes are compared in the framework of the atmospheric model of EC-EARTH, based on the current seasonal forecast system of ECMWF. The standard configuration runs at T159 horizontal spectral resolution with 62 vertical levels. Three member ensembles of 30 years (1979-2008) simulations, with prescribed SSTs and sea ice, were performed for each of the snow schemes