L.S. Bauer; J. Granett
1979-01-01
Black flies have been long-time residents of Maine and cause extensive nuisance problems for people, domestic animals, and wildlife. The black fly problem has no simple solution because of the multitude of species present, the diverse and ecologically sensitive habitats in which they are found, and the problems inherent in measuring the extent of the damage they cause...
The current state, main problems and directions in improving water chemistry at NPSs
NASA Astrophysics Data System (ADS)
Tyapkov, V. F.; Sharafutdinov, R. B.
2007-05-01
An analysis of the current state of managing water-chemistry (WC) at Russian nuclear power plants with type-VVER and-RBMK reactors presently in operation is presented. The main directions for improvement of WC are shown.
ERIC Educational Resources Information Center
Draze, Dianne; Palouda, Annelise
This book presents information about 10 areas of design, with the main emphasis on graphic design. One section presents the creative problem solving process and provides practice in using this process to solve design problems. Students are given a glimpse of other areas of design, including fashion, industrial, architectural, decorative,…
ERIC Educational Resources Information Center
Idleman, Hillis K.
The module deals mainly with some of the service problems experienced by consumers, examines the causes of some problems, and suggests some solutions, attempting to present the standpoint of the producer as well as the buyer and user. The module may be presented as a semester or part semester course. Organized by expected student understandings,…
Management of sexuality problem in quadriplegia: a brief summary.
Wiwanitkit, Viroj
2010-09-01
Quadriplegia is a serious group of spinal disability. Cases with quadriplegia usually present unsatisfactory sexual life. In male, the main problem is the ability to reach orgasm deficient. In female, pregnancy problem should be noted. Management of sexuality problem in quadriplegia is of interest. In this article, the author will briefly review on this topic.
NASA Astrophysics Data System (ADS)
Chakrabarti, Aloknath; Mohapatra, Smrutiranjan
2013-09-01
Two problems of scattering of surface water waves involving a semi-infinite elastic plate and a pair of semi-infinite elastic plates, separated by a gap of finite width, floating horizontally on water of finite depth, are investigated in the present work for a two-dimensional time-harmonic case. Within the frame of linear water wave theory, the solutions of the two boundary value problems under consideration have been represented in the forms of eigenfunction expansions. Approximate values of the reflection and transmission coefficients are obtained by solving an over-determined system of linear algebraic equations in each problem. In both the problems, the method of least squares as well as the singular value decomposition have been employed and tables of numerical values of the reflection and transmission coefficients are presented for specific choices of the parameters for modelling the elastic plates. Our main aim is to check the energy balance relation in each problem which plays a very important role in the present approach of solutions of mixed boundary value problems involving Laplace equations. The main advantage of the present approach of solutions is that the results for the values of reflection and transmission coefficients obtained by using both the methods are found to satisfy the energy-balance relations associated with the respective scattering problems under consideration. The absolute values of the reflection and transmission coefficients are presented graphically against different values of the wave numbers.
Israel, Schools, and Arab Conflict in the Middle East.
ERIC Educational Resources Information Center
Parker, Franklin
This paper examines how Israel's educational system attempts to deal with major social, geographic, religious, economic, and political problems. Problems are presented in two main categories--internal and external. Internal problems include high immigration levels, religious and cultural differences among various Jewish sects and between Jews and…
Advisory Commission for the Study of Public Support for Post-Secondary Education in Maine.
ERIC Educational Resources Information Center
Maine State Advisory Commission for the Study of Public Support for Postsecondary Education, Augusta.
The Advisory Commission for the Study of Public Support for Postsecondary Education in Maine reviewed the financial problems facing Maine's private higher education institutions and the impact of increasing student costs at Maine's public institutions. The text of the state legislation creating the Commission is presented, along with a summary of…
Present status, future prospects of domestic acoustical instruments
NASA Astrophysics Data System (ADS)
Guibin, L.
1984-01-01
The product lines, specifications, and special features of China's main acoustical instrument products are described. The methods of operation nd the main problems associated with these products are discussed. Examples of the application of acoustical instruments are given. The main features of a digital signal analyzer are enumerated.
Antimicrobial drug-related problems in a neonatal intensive care unit
Nunes, Bruna Meirelly; Xavier, Tatiana Costa; Martins, Rand Randall
2017-01-01
Objective The goal was to determine the main drug-related problems in neonates who were using antimicrobials. Method This was an observational, prospective and longitudinal study. Drug-related problems were classified according to version 6.2 of the Pharmaceutical Care Network Europe Foundation classification. A descriptive analysis was performed, in which the clinical and therapeutic variables were presented as absolute and relative frequencies or as the mean and standard deviation, as appropriate. Results In total, 152 neonates with a predominance of males (58.5%), gestational age of 32.7 ± 4.2 weeks and weight of 1,903.1 ± 846.9g were included. The main diagnostic hypothesis of infection was early sepsis (66.5%), and 71.7% of the neonates had some risk factor for infection. Among the neonates, 33.6% had at least one drug-related problem. Of these, 84.8% were related to treatment effectiveness and 15.2% to adverse reactions. The main cause of drug-related problems was the selected dose, particularly for aminoglycosides and cephalosporins. Conclusion The use of antimicrobials in the neonatal intensive care is mainly associated with problems related to medication effectiveness, predominantly the prescription of subdoses of antimicrobials, especially aminoglycosides. PMID:28876403
NASA Astrophysics Data System (ADS)
Malekan, Mohammad; Barros, Felício B.
2017-12-01
Generalized or extended finite element method (G/XFEM) models the crack by enriching functions of partition of unity type with discontinuous functions that represent well the physical behavior of the problem. However, this enrichment functions are not available for all problem types. Thus, one can use numerically-built (global-local) enrichment functions to have a better approximate procedure. This paper investigates the effects of micro-defects/inhomogeneities on a main crack behavior by modeling the micro-defects/inhomogeneities in the local problem using a two-scale G/XFEM. The global-local enrichment functions are influenced by the micro-defects/inhomogeneities from the local problem and thus change the approximate solution of the global problem with the main crack. This approach is presented in detail by solving three different linear elastic fracture mechanics problems for different cases: two plane stress and a Reissner-Mindlin plate problems. The numerical results obtained with the two-scale G/XFEM are compared with the reference solutions from the analytical, numerical solution using standard G/XFEM method and ABAQUS as well, and from the literature.
Using a Model to Describe Students' Inductive Reasoning in Problem Solving
ERIC Educational Resources Information Center
Canadas, Maria C.; Castro, Encarnacion; Castro, Enrique
2009-01-01
Introduction: We present some aspects of a wider investigation (Canadas, 2007), whose main objective is to describe and characterize inductive reasoning used by Spanish students in years 9 and 10 when they work on problems that involved linear and quadratic sequences. Method: We produced a test composed of six problems with different…
Social Competence as a Mediating Factor in Reduction of Behavioral Problems
ERIC Educational Resources Information Center
Langeveld, Johannes H.; Gundersen, Knut K.; Svartdal, Frode
2012-01-01
The main purpose of the present study was to explore how social competence reduces behavioral problems. Based on previous findings, we assume that increased social competence can be regarded as a mediating factor in reducing behavior problems. All participants (children and adolescents, n = 112) received an intervention intended to increase social…
ERIC Educational Resources Information Center
Coggins, Phyllis, Ed.; And Others
This collection of speeches, presented as the 1974 Marine Occupations Conference in South Portland, Maine, provides an overview of information regarding availability and kinds of careers in, as well as the educational requirements for, marine occupations. Also reviewed are the problems of developing marine resources, such as those involving…
Seaweed cultivation: Traditional way and its reformation
NASA Astrophysics Data System (ADS)
Fei, Xiu-Geng; Bao, Ying; Lu, Shan
1999-09-01
Seaweed cultivation or phycoculture has been developed rather fast in recent years. The total production of cultivated seaweed at present is about 6250×103 tons fresh weight. The total cultivation area is estimated as 200×103 hectare. The annual total value of cultivated seaweeds has been estimated to be more than 3 billion US dollars. Phycoculture provides many job opportunities for the coastal region people, has the potential to improve marine environments and thus even induce global change. All traditional cultivation methods and techniques are based on or start from the individual plant or the cultivated seaweed population. Modern biological science and biotechnology achievements have benefited agriculture a lot, but traditional seaweed cultivation has not changed much since its founding. This is because seaweed cultivation has been quite conservative for quite a long period and has accumulated many problems requiring solution. Four main problems might be the most universal ones holding back further development of the industry. New ways of seaweed cultivation must be developed, new techniques must be perfected, and new problems solved. This paper mainly discusses the main problems of traditional seaweed cultivation at present and its possible further development and reformation in the future.
ERIC Educational Resources Information Center
Harman, Grant, Ed.; Selim, M., Ed.
This book presents articles that document the serious funding problems faced by higher education institutions and systems in the Asian and Pacific region, and explores possible strategies to address these problems. It presents an overview of the financial situation faced by higher education in the region, and then discusses two main strategies…
On alphabetic presentations of Clifford algebras and their possible applications
NASA Astrophysics Data System (ADS)
Toppan, Francesco; Verbeek, Piet W.
2009-12-01
In this paper, we address the problem of constructing a class of representations of Clifford algebras that can be named "alphabetic (re)presentations." The Clifford algebra generators are expressed as m-letter words written with a three-character or a four-character alphabet. We formulate the problem of the alphabetic presentations, deriving the main properties and some general results. At the end, we briefly discuss the motivations of this work and outline some possible applications.
ERIC Educational Resources Information Center
Maine State Dept. of Mental Health and Mental Retardation, Augusta.
This document presents uniformly collected data for the State of Maine and each of its counties on selected known risk factors for alcohol and drug abuse and the prevalence of substance abuse-related problems. A "Read Me First" section presents the state's approach to prevention. Information is provided on risk and protective factors,…
[Sensory integration: hierarchy and synchronization].
Kriukov, V I
2005-01-01
This is the first in the series of mini-reviews devoted to the basic problems and most important effects of attention in terms of neuronal modeling. We believe that the absence of the unified view on wealth of new date on attention is the main obstacle for further understanding of higher nervous activity. The present work deals with the main ground problem of reconciling two competing architectures designed to integrate the sensory information in the brain. The other mini-reviews will be concerned with the remaining five or six problems of attention, all of them to be ultimately resolved uniformly in the framework of small modification of dominant model of attention and memory.
NASA Astrophysics Data System (ADS)
Torres, V.; Quek, S.; Gaydecki, P.
2010-02-01
Aging and deterioration of the main functional parts in civil structures is one of the biggest problems that private and governmental institutions, dedicated to operate and maintain such structures, are facing now days. In the case of relatively old suspension bridges, problems emerge due to corrosion and break of wires in the main cables. Decisive information and a reliable monitoring and evaluation are factors of great relevance required to prevent significant or catastrophic damages caused to the structure, and more importantly, to people. The main challenge for the NDE methods of inspection arises in dealing with the steel wrapping barrier of the suspension cable, which main function is to shield, shape and hold the bundles. The following work, presents a study of a multi-Magnetoresistive sensors system aiming to support the monitoring and evaluation of suspension cables at some of its stages. Modelling, signal acquisition, signal processing, experiments and the initial phases of implementation are presented and discussed widely.
ERIC Educational Resources Information Center
Jones, Alice P.; Viding, Essi
2010-01-01
This paper presents a novel school-based intervention programme for children with chronic and severe emotional and behavioural difficulties. The main aim of the programme is to reduce conduct problems and to increase prosocial behaviours. The ultimate aim of such a programme is to help pupils with severe and chronic conduct problems back on track…
ERIC Educational Resources Information Center
Rué, Joan; Font, Antoni; Cebrián, Gisela
2013-01-01
There is wide agreement that problem-based learning is a key strategy to promote individual abilities for "learning how to learn". This paper presents the main contributions that reflective journals and the problem-based learning approach can make to foster professional knowledge and quality learning in higher education. Thirty-six…
Shapes of the Graphs of Fourth-Degree Polynomials in Terms of Their Coefficients
ERIC Educational Resources Information Center
Flesher, Tatyana; Holder, Eleanor
2007-01-01
One of the main problems in undergraduate research in pure mathematics is that of determining a problem that is, at once, interesting to and capable of solution by a student who has completed only the calculus sequence. It is also desirable that the problem should present something new, since novelty and originality greatly increase the enthusiasm…
Andrei Andreevich Bolibrukh's works on the analytic theory of differential equations
NASA Astrophysics Data System (ADS)
Anosov, Dmitry V.; Leksin, Vladimir P.
2011-02-01
This paper contains an account of A.A. Bolibrukh's results obtained in the new directions of research that arose in the analytic theory of differential equations as a consequence of his sensational counterexample to the Riemann-Hilbert problem. A survey of results of his students in developing topics first considered by Bolibrukh is also presented. The main focus is on the role of the reducibility/irreducibility of systems of linear differential equations and their monodromy representations. A brief synopsis of results on the multidimensional Riemann-Hilbert problem and on isomonodromic deformations of Fuchsian systems is presented, and the main methods in the modern analytic theory of differential equations are sketched. Bibliography: 69 titles.
Big data processing in the cloud - Challenges and platforms
NASA Astrophysics Data System (ADS)
Zhelev, Svetoslav; Rozeva, Anna
2017-12-01
Choosing the appropriate architecture and technologies for a big data project is a difficult task, which requires extensive knowledge in both the problem domain and in the big data landscape. The paper analyzes the main big data architectures and the most widely implemented technologies used for processing and persisting big data. Clouds provide for dynamic resource scaling, which makes them a natural fit for big data applications. Basic cloud computing service models are presented. Two architectures for processing big data are discussed, Lambda and Kappa architectures. Technologies for big data persistence are presented and analyzed. Stream processing as the most important and difficult to manage is outlined. The paper highlights main advantages of cloud and potential problems.
Challenging Aerospace Problems for Intelligent Systems
NASA Technical Reports Server (NTRS)
Krishnakumar, Kalmanje; Kanashige, John; Satyadas, A.; Clancy, Daniel (Technical Monitor)
2002-01-01
In this paper we highlight four problem domains that are well suited and challenging for intelligent system technologies. The problems are defined and an outline of a probable approach is presented. No attempt is made to define the problems as test cases. In other words, no data or set of equations that a user can code and get results are provided. The main idea behind this paper is to motivate intelligent system researchers to examine problems that will elevate intelligent system technologies and applications to a higher level.
Challenging Aerospace Problems for Intelligent Systems
NASA Technical Reports Server (NTRS)
KrishnaKumar, K.; Kanashige, J.; Satyadas, A.
2003-01-01
In this paper we highlight four problem domains that are well suited and challenging for intelligent system technologies. The problems are defined and an outline of a probable approach is presented. No attempt is made to define the problems as test cases. In other words, no data or set of equations that a user can code and get results are provided. The main idea behind this paper is to motivate intelligent system researchers to examine problems that will elevate intelligent system technologies and applications to a higher level.
A problem solving and decision making toolbox for approaching clinical problems and decisions.
Margolis, C; Jotkowitz, A; Sitter, H
2004-08-01
In this paper, we begin by presenting three real patients and then review all the practical conceptual tools that have been suggested for systematically analyzing clinical problems. Each of these conceptual tools (e.g. Evidence-Based Medicine, Clinical Practice Guidelines, Decision Analysis) deals mainly with a different type or aspect of clinical problems. We suggest that all of these conceptual tools can be thought of as belonging in the clinician's toolbox for solving clinical problems and making clinical decisions. A heuristic for guiding the clinician in using the tools is proposed. The heuristic is then used to analyze management of the three patients presented at the outset. Copyright 2004 Birkhäuser Verlag, Basel
[Aims and core contents of basic and post basic courses of nursing management].
Saiani, Luisa; Brugnolli, Anna
2006-01-01
The second part of the issue, dedicated to the nursing management offers a discussion on some of the relevant areas of debate for the organization of nursing care. A reflection on the core contents and main aims of basic and post basic (master, advanced level, specialistic degree) nursing courses is proposed in the first contribution. Then a selection of topics is presented, focusing on the main research contributions available in the literature and on the ongoing debate for the following areas: the role of communication at the inter-shift handover and the new model of bedside reporting; the problems and challenges of doctors nurses collaboration in the health care team; the problems and expectations of new nurses joining the health care team and the process of development of practical skills; the hot debate on nursing roles and level of practice and the difficulties in differentiating between elementary, specialist and advanced nursing practice; the new emerging roles: the characteristics and achievements of Nurse Consultant; the new challenges of coordinators of the health care teams with the management of the multigenerational nursing team. For each topic a definition of the problem is presented, an example of relevant study, a critical debate and suggestions for further studies and areas of research. A list of the main journals that deal with nursing management is proposed with comments on the main characteristics of each journal. A study protocol that aims at describing the outcomes of the different styles and models of organization of medical wards on patients and nurses is presented as an example of organizative research; an experience of, and a model for, participation of the nurses to health policy planning is proposed. Nurses were, asked to identify health care problems encountered in their daily practice, their causes and propose solutions at basic and policy level. The session of International Observatory explores the main problems and difficulties of the research on the organization of care, focusing more on opportunities than on the challenges and drawbacks of the available literature.
On Present State of Teaching Russian Language in Russia
ERIC Educational Resources Information Center
Tekucheva, Irina V.; Gromova, Liliya Y.
2016-01-01
The article discusses the current state of teaching Russian language, discovers the nature of philological education, outlines the main problems of the implementation of the standard in school practice, analyzes the problems of formation of universal educational actions within the context of the implementation of cognitive-communicative approach,…
Problems in Choosing Tools and Methods for Teaching Programming
ERIC Educational Resources Information Center
Vitkute-Adžgauskiene, Davia; Vidžiunas, Antanas
2012-01-01
The paper analyses the problems in selecting and integrating tools for delivering basic programming knowledge at the university level. Discussion and analysis of teaching the programming disciplines, the main principles of study programme design, requirements for teaching tools, methods and corresponding languages is presented, based on literature…
Measuring Children's Reading Development Using Leveled Texts.
ERIC Educational Resources Information Center
Paris, Scott G.
2002-01-01
Notes that the main problem with using Informal Reading Inventories (IRIs) for measuring reading growth is that running records and miscue analyses are gathered on variable levels of text that are appropriate for each child. Presents several possible solutions to the measurement problem beyond the simple profile descriptions usually reported from…
ERIC Educational Resources Information Center
Csikos, Csaba; Szitanyi, Judit; Kelemen, Rita
2012-01-01
The present study aims to investigate the effects of a design experiment developed for third-grade students in the field of mathematics word problems. The main focus of the program was developing students' knowledge about word problem solving strategies with an emphasis on the role of visual representations in mathematical modeling. The experiment…
ERIC Educational Resources Information Center
Ding, Meixia; Li, Xiaobao
2010-01-01
This study examines presentations of the distributive property (DP) in two widely used U.S. elementary text series and one main Chinese text series along three dimensions: problem contexts, typical problem types within each problem context, and variability in using the DP. In general, the two U.S. texts were found to resemble each other but to…
An overview of unconstrained free boundary problems
Figalli, Alessio; Shahgholian, Henrik
2015-01-01
In this paper, we present a survey concerning unconstrained free boundary problems of type where B1 is the unit ball, Ω is an unknown open set, F1 and F2 are elliptic operators (admitting regular solutions), and is a functions space to be specified in each case. Our main objective is to discuss a unifying approach to the optimal regularity of solutions to the above matching problems, and list several open problems in this direction. PMID:26261367
NASA Astrophysics Data System (ADS)
Guinot, Vincent
2017-11-01
The validity of flux and source term formulae used in shallow water models with porosity for urban flood simulations is assessed by solving the two-dimensional shallow water equations over computational domains representing periodic building layouts. The models under assessment are the Single Porosity (SP), the Integral Porosity (IP) and the Dual Integral Porosity (DIP) models. 9 different geometries are considered. 18 two-dimensional initial value problems and 6 two-dimensional boundary value problems are defined. This results in a set of 96 fine grid simulations. Analysing the simulation results leads to the following conclusions: (i) the DIP flux and source term models outperform those of the SP and IP models when the Riemann problem is aligned with the main street directions, (ii) all models give erroneous flux closures when is the Riemann problem is not aligned with one of the main street directions or when the main street directions are not orthogonal, (iii) the solution of the Riemann problem is self-similar in space-time when the street directions are orthogonal and the Riemann problem is aligned with one of them, (iv) a momentum balance confirms the existence of the transient momentum dissipation model presented in the DIP model, (v) none of the source term models presented so far in the literature allows all flow configurations to be accounted for(vi) future laboratory experiments aiming at the validation of flux and source term closures should focus on the high-resolution, two-dimensional monitoring of both water depth and flow velocity fields.
[Some problems of space medicine].
Gurovskiĭ, N N; Egorov, A D
1976-01-01
The paper discusses the problems to be resolved by space medicine and the main stages in the development of this branch of science, beginning with the vertical launches of rockets and ending with the flights of orbital stations. On the basis of ground-based simulation experiments and real space flights it presents a classification of the major symptomocomplexes that may occur inflight. The paper describes the main stages of adaptation to weightlessness and physiological changes in the weightless state. The paper also outlines further pathways in the development of space medicine.
Kristanto, B
1983-06-01
A review of the literature on the socioeconomic factors affecting infant and child mortality is presented, with special reference to Indonesia. Four main factors are identified: parents' education, parents' occupation, urban-rural residence, and housing conditions. The author suggests that, in fact, problems related to health and sanitation are the main causes of infant and child mortality. Also important are problems related to poverty, income, and income distribution. It is suggested that the solution is to be found in general socioeconomic development.
NASA Technical Reports Server (NTRS)
Shelton, D. H.
1975-01-01
A brief functional description of the Apollo lunar module stabilization and control subsystem is presented. Subsystem requirements definition, design, development, test results, and flight experiences are discussed. Detailed discussions are presented of problems encountered and the resulting corrective actions taken during the course of assembly-level testing, integrated vehicle checkout and test, and mission operations. Although the main experiences described are problem oriented, the subsystem has performed satisfactorily in flight.
From Web Directories to Ontologies: Natural Language Processing Challenges
NASA Astrophysics Data System (ADS)
Zaihrayeu, Ilya; Sun, Lei; Giunchiglia, Fausto; Pan, Wei; Ju, Qi; Chi, Mingmin; Huang, Xuanjing
Hierarchical classifications are used pervasively by humans as a means to organize their data and knowledge about the world. One of their main advantages is that natural language labels, used to describe their contents, are easily understood by human users. However, at the same time, this is also one of their main disadvantages as these same labels are ambiguous and very hard to be reasoned about by software agents. This fact creates an insuperable hindrance for classifications to being embedded in the Semantic Web infrastructure. This paper presents an approach to converting classifications into lightweight ontologies, and it makes the following contributions: (i) it identifies the main NLP problems related to the conversion process and shows how they are different from the classical problems of NLP; (ii) it proposes heuristic solutions to these problems, which are especially effective in this domain; and (iii) it evaluates the proposed solutions by testing them on DMoz data.
Discontinuous Mode Power Supply
NASA Technical Reports Server (NTRS)
Lagadinos, John; Poulos, Ethel
2012-01-01
A document discusses the changes made to a standard push-pull inverter circuit to avoid saturation effects in the main inverter power supply. Typically, in a standard push-pull arrangement, the unsymmetrical primary excitation causes variations in the volt second integral of each half of the excitation cycle that could lead to the establishment of DC flux density in the magnetic core, which could eventually cause saturation of the main inverter transformer. The relocation of the filter reactor normally placed across the output of the power supply solves this problem. The filter reactor was placed in series with the primary circuit of the main inverter transformer, and is presented as impedance against the sudden changes on the input current. The reactor averaged the input current in the primary circuit, avoiding saturation of the main inverter transformer. Since the implementation of the described change, the above problem has not reoccurred, and failures in the main power transistors have been avoided.
Linear Programming and Its Application to Pattern Recognition Problems
NASA Technical Reports Server (NTRS)
Omalley, M. J.
1973-01-01
Linear programming and linear programming like techniques as applied to pattern recognition problems are discussed. Three relatively recent research articles on such applications are summarized. The main results of each paper are described, indicating the theoretical tools needed to obtain them. A synopsis of the author's comments is presented with regard to the applicability or non-applicability of his methods to particular problems, including computational results wherever given.
Numerical methods in Markov chain modeling
NASA Technical Reports Server (NTRS)
Philippe, Bernard; Saad, Youcef; Stewart, William J.
1989-01-01
Several methods for computing stationary probability distributions of Markov chains are described and compared. The main linear algebra problem consists of computing an eigenvector of a sparse, usually nonsymmetric, matrix associated with a known eigenvalue. It can also be cast as a problem of solving a homogeneous singular linear system. Several methods based on combinations of Krylov subspace techniques are presented. The performance of these methods on some realistic problems are compared.
Explaining Algorithms: A New Perspective
ERIC Educational Resources Information Center
Müldner, Tomasz; Shakshuki, Elhadi
2006-01-01
This article presents a novel approach for explaining algorithms that aims to overcome various pedagogical limitations of the current visualization systems. The main idea is that at any given time, a learner is able to focus on a single problem. This problem can be explained, studied, understood, and tested, before the learner moves on to study…
Hidden algebra method (quasi-exact-solvability in quantum mechanics)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Turbiner, Alexander; Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado, Postal 70-543, 04510 Mexico, D. F.
1996-02-20
A general introduction to quasi-exactly-solvable problems of quantum mechanics is presented. Main attention is given to multidimensional quasi-exactly-solvable and exactly-solvable Schroedinger operators. Exact-solvability of the Calogero and Sutherland N-body problems ass ociated with an existence of the hidden algebra slN is discussed extensively.
Haitian Creole: Sound-System, Form-Classes, Texts.
ERIC Educational Resources Information Center
Ferere, Gerard Alphonse
A synchronic structural description is presented of Haitian Creole as spoken in the Port-au-Prince-Jacmel area, concentrating mainly on phonoloqy and morphology. Historical information and commentary are presented on diglossia and illiteracy, two intertwining sociolinguistic problems of Haiti. A detailed analysis is presented of the Creole sound…
Study and realization of an obstacle detection infrared system for automotive use
NASA Astrophysics Data System (ADS)
Alaouiamine, Mohammed
1991-08-01
The main technological options available in the field of obstacle detection are presented. Ultrasound, microwave, and infrared detection systems are reviewed. The reasons for choosing an infrared solution are outlined. The problems involved in developing an obstacle detection system in the near infrared are discussed. Weather condition effects, interference limitations due to multiple onboard sensors, and range detection influence are some of the problems studied. A collimated, mechanically scanned, and pulsed infrared beam is proposed to overcome some of these problems. Performances of a first and second prototype made using this system are presented.
Johnson, Robert F; O'Reilly, Michelle; Vostanis, Panos
2006-09-01
The theoretical cognitive model of stress and coping provides a structure to obtain and analyse maternal perceptions of caring for children with learning disabilities who present severe problem behaviours. The Family Fund database identified 18 families who met the sample criteria of children aged five years to 15 years with severe to moderate learning disability presenting severe problem behaviour. Physical aggression was reported to be the primary behavioural problem for 13 of the children. Interviews undertaken with the main carer of the child at their home were taped and transcribed. The data were analysed using grounded theory techniques which identified 'secondary stressors' for the parent. These were social isolation, conflict, limitation of lifestyle and self-blame. It is proposed that the amalgamated impact of these can weaken parents' coping resources and, therefore, may prove to be as significant to the negative association with maternal wellbeing as the problem behaviour.
Reponse Dynamique D'un Panneau Soumis a un Environnement Acoustique Reverberant
NASA Astrophysics Data System (ADS)
Nelisse, Hugues
1995-01-01
The present thesis deals with the problem of the dynamic response of a homeogenous flexible panel immersed in a reverberant field. This problem takes place in the framework of aerospace problems in which satellites substructures are submitted to high acoustic levels during the launchers lift-off. The thesis is divided in four main parts. The first one presents an integral formulation that allows to treat the case of a flexible panel placed in a rectangular room. A semi-analytical resolution is used to identify the two main physical unknowns of the problem, the acoustic pressure jump across the panel and the panel deflection. The second part is dedicated to the study of the notion of diffuse field. Through a bibliographic review, two indicators are used to characterize the sound field in the room and in the free field. Precise criterions related to the modal density of the room are discussed. Analysis and discussion on the conditions which allow the establishment of a diffuse field are also presented. In the third part, a theoretical formulation which allows to treat the problem of an unbaffled panel submitted to an acoustic excitation in the free field is presented. The singularity problem due to the use of the free-space Green's function is overcame by the use of a variational principle. A semi-analytical approach is used to solve the linear system of equations. Emphasis is put on the fact that the excitation is acoustic. The theory is validated with the help of an existing boundary element numerical code. The last part is first dedicated to a comparative study of the two developed approaches and to a phenomenological study. Studies of the effect of the structural damping on the panel vibrations are presented as well as analysis of some different approximations generally used in this type of problem.
A Social-Medical Approach to Violence in Colombia
Franco, Saul
2003-01-01
Violence is the main public health problem in Colombia. Many theoretical and methodological approaches to solving this problem have been attempted from different disciplines. My past work has focused on homicide violence from the perspective of social medicine. In this article I present the main conceptual and methodological aspects and the chief findings of my research over the past 15 years. Findings include a quantitative description of the current situation and the introduction of the category of explanatory contexts as a contribution to the study of Colombian violence. The complexity and severity of this problem demand greater theoretical discussion, more plans for action and a faster transition between the two. Social medicine may make a growing contribution to this field. PMID:14652328
A social-medical approach to violence in Colombia.
Franco, Saul
2003-12-01
Violence is the main public health problem in Colombia. Many theoretical and methodological approaches to solving this problem have been attempted from different disciplines. My past work has focused on homicide violence from the perspective of social medicine. In this article I present the main conceptual and methodological aspects and the chief findings of my research over the past 15 years. Findings include a quantitative description of the current situation and the introduction of the category of explanatory contexts as a contribution to the study of Colombian violence. The complexity and severity of this problem demand greater theoretical discussion, more plans for action and a faster transition between the two. Social medicine may make a growing contribution to this field.
Najera, J. A.
1989-01-01
Malaria has been one of the main health problems demanding the attention of WHO from the time the Organization was created. This review of the historical record analyses the different approaches to the malaria problem in the past 40 years and shows how WHO tried to fulfil its constitutional mandate. The article exposes the historical roots of the present situation and helps towards an understanding of current problems and approaches to malaria control. PMID:2670294
NASA Astrophysics Data System (ADS)
Stepanenko, V. D.
Papers are presented on a wide range of studies of atmospheric electricity, from the problem of the global atmospheric-electricity circuit to the effects of atmospheric electricity on ground-based facilities and biological objects. The main topics considered are general problems of atmospheric electricity, studies of atmospheric ions and aerosols, cloud electricity, studies of lightning-storm activity and atmospherics, and lightning protection.
The Use of Business Case Studies in Business German Classes.
ERIC Educational Resources Information Center
Schutte, Lilith
The use of business case studies, defined as sophisticated models that present practical business problems and theoretical guidelines that can be used to solve the problems, is discussed. It is suggested that the main advantages of case studies are that they are usually more interesting to read than theoretical materials and they encourage student…
Problem Solving as a Professional Development Strategy for Teachers: A Case Study with Fractions
ERIC Educational Resources Information Center
Perdomo-Díaz, Josefa; Felmer, Patricio; Randolph, Valeria; González, Guillermo
2017-01-01
In this paper we present a professional development course designed to impact on teachers' mathematical knowledge for teaching fractions. The main features of the course are the use of i) problem solving activities related with mathematical knowledge for teaching fractions ii) peer discussions and iii) monitor's interventions focused on answering…
Problem Based Learning in School of Engineering Science, Osaka University
NASA Astrophysics Data System (ADS)
Sato, Kosuke; Kosakada, Kozo; Kuboi, Ryoichi
Problem Based Leaning in School of Engineering Science, Osaka University is being achieved mainly focusing on the spontaneous setting of the project theme. The PBL program aims to promote students' wide variety of abilities ; communication skill, group discussion, presentation skill, mutual assessment of the students, and also especially research skill 3P (Plan-Perform-Publish) .
Extremal Optimization for Quadratic Unconstrained Binary Problems
NASA Astrophysics Data System (ADS)
Boettcher, S.
We present an implementation of τ-EO for quadratic unconstrained binary optimization (QUBO) problems. To this end, we transform modify QUBO from its conventional Boolean presentation into a spin glass with a random external field on each site. These fields tend to be rather large compared to the typical coupling, presenting EO with a challenging two-scale problem, exploring smaller differences in couplings effectively while sufficiently aligning with those strong external fields. However, we also find a simple solution to that problem that indicates that those external fields apparently tilt the energy landscape to a such a degree such that global minima become more easy to find than those of spin glasses without (or very small) fields. We explore the impact of the weight distribution of the QUBO formulation in the operations research literature and analyze their meaning in a spin-glass language. This is significant because QUBO problems are considered among the main contenders for NP-hard problems that could be solved efficiently on a quantum computer such as D-Wave.
Educational-research laboratory "electric circuits" on the base of digital technologies
NASA Astrophysics Data System (ADS)
Koroteyev, V. I.; Florentsev, V. V.; Florentseva, N. I.
2017-01-01
The problem of research activity of trainees' activation in the educational-research laboratory "Electric Circuits" using innovative methodological solutions and digital technologies is considered. The main task is in creation of the unified experimental research information-educational environment "Electrical Engineering". The problems arising during the developing and application of the modern software and hardware, experimental and research stands and digital control and measuring systems are presented. This paper presents the main stages of development and creation of educational-research laboratory "Electrical Circuits" at the Department of Electrical Engineering of NRNU MEPhI. The authors also consider the analogues of the described research complex offered by various educational institutions and companies. The analysis of their strengths and weaknesses, on which the advantages of the proposed solution are based, is held.
Enhance Academic Study in Vocational Education in China
ERIC Educational Resources Information Center
Sun, Ling
2010-01-01
The increase in international trade and the information technology boom led us to begin to face the previously unthinkable of academic shortage towards vocational education. The main objective of this paper is to present the problem and find ways to solve it. The main finding included lack of investment from society and high degree involvement of…
Identifying problem and compulsive gamblers.
van Es, R.
2000-01-01
OBJECTIVE: To present a meta-analysis of current research on the prevalence, identification, and treatment of problem and compulsive gamblers. QUALITY OF EVIDENCE: Problem and compulsive gambling was not a socio-scientific concern until the last two decades. Hence research on this topic is limited. The summary and analysis for this paper relied on computer searches of journal and news abstracts in addition to direct contact with organizations addressing the identification and treatment of compulsive gamblers. MAIN MESSAGE: An estimated 5% of those who gamble run into problems. About 1% of those who gamble are predicted to experience serious problems. Successful treatment of problem and compulsive gambling continues to be a challenge. Although cognitive therapy has been the favoured approach, a combination of several therapeutic approaches is advocated. CONCLUSIONS: Problem and compulsive gambling can present a real health threat. As with other addictions, treatment strategies continue to be a baffling social problem. Aware and informed physicians can have a pivotal role in the difficult process of identifying, acknowledging, and remediating problem and compulsive gambling. PMID:10907572
NASA Astrophysics Data System (ADS)
Hasuike, Takashi; Katagiri, Hideki
2010-10-01
This paper focuses on the proposition of a portfolio selection problem considering an investor's subjectivity and the sensitivity analysis for the change of subjectivity. Since this proposed problem is formulated as a random fuzzy programming problem due to both randomness and subjectivity presented by fuzzy numbers, it is not well-defined. Therefore, introducing Sharpe ratio which is one of important performance measures of portfolio models, the main problem is transformed into the standard fuzzy programming problem. Furthermore, using the sensitivity analysis for fuzziness, the analytical optimal portfolio with the sensitivity factor is obtained.
Multi-UAV Routing for Area Coverage and Remote Sensing with Minimum Time.
Avellar, Gustavo S C; Pereira, Guilherme A S; Pimenta, Luciano C A; Iscold, Paulo
2015-11-02
This paper presents a solution for the problem of minimum time coverage of ground areas using a group of unmanned air vehicles (UAVs) equipped with image sensors. The solution is divided into two parts: (i) the task modeling as a graph whose vertices are geographic coordinates determined in such a way that a single UAV would cover the area in minimum time; and (ii) the solution of a mixed integer linear programming problem, formulated according to the graph variables defined in the first part, to route the team of UAVs over the area. The main contribution of the proposed methodology, when compared with the traditional vehicle routing problem's (VRP) solutions, is the fact that our method solves some practical problems only encountered during the execution of the task with actual UAVs. In this line, one of the main contributions of the paper is that the number of UAVs used to cover the area is automatically selected by solving the optimization problem. The number of UAVs is influenced by the vehicles' maximum flight time and by the setup time, which is the time needed to prepare and launch a UAV. To illustrate the methodology, the paper presents experimental results obtained with two hand-launched, fixed-wing UAVs.
Optimal Decision Making in a Class of Uncertain Systems Based on Uncertain Variables
NASA Astrophysics Data System (ADS)
Bubnicki, Z.
2006-06-01
The paper is concerned with a class of uncertain systems described by relational knowledge representations with unknown parameters which are assumed to be values of uncertain variables characterized by a user in the form of certainty distributions. The first part presents the basic optimization problem consisting in finding the decision maximizing the certainty index that the requirement given by a user is satisfied. The main part is devoted to the description of the optimization problem with the given certainty threshold. It is shown how the approach presented in the paper may be applied to some problems for anticipatory systems.
Solution of elastic-plastic stress analysis problems by the p-version of the finite element method
NASA Technical Reports Server (NTRS)
Szabo, Barna A.; Actis, Ricardo L.; Holzer, Stefan M.
1993-01-01
The solution of small strain elastic-plastic stress analysis problems by the p-version of the finite element method is discussed. The formulation is based on the deformation theory of plasticity and the displacement method. Practical realization of controlling discretization errors for elastic-plastic problems is the main focus. Numerical examples which include comparisons between the deformation and incremental theories of plasticity under tight control of discretization errors are presented.
Long-term follow-up of women and men after unsuccessful IVF.
Filetto, Juliana N; Makuch, Maria Y
2005-10-01
The experience of 92 couples, who had unsuccessfully undergone one or more IVF cycles at a university clinic, was evaluated 3-8 years following their last failed attempt. One member of each couple completed a telephone questionnaire regarding life events during their last IVF cycle performed at the clinic and at the time of the interview. Some couples had continued further treatment and some had not. Multivariate correspondence analysis was used to analyse the data. Regarding the long-term experience of couples who had undergone further treatment, for men the main experiences were psychological problems and having adopted a child. For women, the main experiences were related to problems of self-image, psychological problems, loss of hope, and having adopted a child. These women also presented a strong association with problems in their marital relationship and with adoption. For the group that did not undergo further treatment, the women showed a strong association with considering adoption, and a less intense association with psychological problems and loss of hope. The men presented psychological problems and having adopted a child as associated variables. Comparison between men and women showed that recognizing the impossibility of conceiving a child and giving up treatment were strongly associated. Men and women who had not continued with further treatment were more affected in the long term than those who had undergone further treatment after IVF failure.
Singular Optimal Controls of Rocket Motion (Survey)
NASA Astrophysics Data System (ADS)
Kiforenko, B. N.
2017-05-01
Survey of modern state and discussion of problems of the perfection of methods of investigation of variational problems with a focus on mechanics of space flight are presented. The main attention is paid to the enhancement of the methods of solving of variational problems of rocket motion in the gravitational fields, including rocket motion in the atmosphere. These problems are directly connected with the permanently actual problem of the practical astronautics to increase the payload that is orbited by the carrier rockets in the circumplanetary orbits. An analysis of modern approaches to solving the problems of control of rockets and spacecraft motion on the trajectories with singular arcs that are optimal for the motion of the variable mass body in the medium with resistance is given. The presented results for some maneuvers can serve as an information source for decision making on designing promising rocket and space technology
[Biomedical foundation for human safety in aviation].
Ushakov, I B
2004-01-01
According to the author, preventive medical issues of providing human safety in aviation are related to the fundamental biomedical and socio-psychological problems of human beings in the present-day world. Factual material for analysis was compiled in the study performed at the State Research and Test Institute of Military Medicine. Outlined are main vectors of the future attack on the problem.
ESP Teaching at the Institutions of Higher Education in Modern Russia: Problems and Perspectives
ERIC Educational Resources Information Center
Prudnikova, Nadezhda
2013-01-01
The author analyses ESP teaching at the institutions of higher education in modern Russia, explains the main problems and suggests the ways of their solving, details the quality control system of the students' progress improvement, presents the complex approach to interactive ESP teaching and views it as an integral part of up-to-date…
NASA Technical Reports Server (NTRS)
Kussner, H G
1937-01-01
The present report deals with a number of the main problems requiring solution in the development of helicopters and concerning the lift, flying performance, stability, and drive. A complete solution is given for the stability of the helicopter with rigid blades and control surfaces. With a view to making a direct-lift propeller sufficient without the addition of auxiliary propellers, the "flapping drive" is assessed and its efficiency calculated.
Quality Criteria as the Innovative Development Vector of Higher Education
ERIC Educational Resources Information Center
Melnichuk, Marina; Varlamova, Alla
2015-01-01
The article deals with the problem of quality assessment in the field of higher education in Russia and the USA. The authors describe the solution of the problem in the modern period of reforms and globalization and the authors' analysis of the main quality assessment approaches is presented in the article. [For the complete Volume 13, Number 2…
Hidden algebra method (quasi-exact-solvability in quantum mechanics)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Turbiner, A.
1996-02-01
A general introduction to quasi-exactly-solvable problems of quantum mechanics is presented. Main attention is given to multidimensional quasi-exactly-solvable and exactly-solvable Schroedinger operators. Exact-solvability of the Calogero and Sutherland {ital N}-body problems ass ociated with an existence of the hidden algebra {ital sl}{sub {ital N}} is discussed extensively. {copyright} {ital 1996 American Institute of Physics.}
Proceedings of the China-Japan-U.S. Seminar on Mathematical Education.
ERIC Educational Resources Information Center
Zhang, Dianzhou, Ed.; And Others
This document contains the proceedings of the China-Japan-U.S. Seminar on Mathematical Education that was held in 1993 in China. The focus of the Seminar was problem solving in mathematics education. The main purposes of the seminar were: to examine the present states of problem solving in school mathematics in China, Japan, and the U.S.; to…
Djalalinia, Shirin; Kelishadi, Roya; Qorbani, Mostafa; Peykari, Niloofar; Kasaeian, Amir; Saeedi Moghaddam, Sahar; Gohari, Kimiya; Larijani, Bagher; Farzadfar, Farshad
2014-12-01
The importance of data quality whether in collection, analysis or presenting stage is a tangible and undeniable scientific fact and the main objects of researches implementation. This paper aims at explaining the main problems of the Iranian scientific papers for providing better data in the field of national and sub-national prevalence, incidence estimates and trends of obesity and overweight. To assess and evaluate papers, we systematically followed an approved standard protocol. Retrieval of studies was performed through Thomson Reuters Web of Science, PubMed, and Scopus, as well as Iranian databases including Irandoc, Scientific Information Database (SID), and IranMedex. Using GBD (Global Burden of Diseases) validated quality assessment forms to assess the quality and availability of data in papers, we considered the following four main domains: a) Quality of studies, b) Quality report of the results, c) Responsiveness of corresponding authors, and d) Diversity in study settings. We retrieved 3,253 records; of these 1,875 were from international and 1378 from national databases. After refining steps, 129 (3.97%) papers remained related to our study domain. More than 51% of relevant papers were excluded because of poor quality of studies. The number of reported total population and points of data were 22,972 and 29 for boys, and 38,985 and 47 for girls, respectively. For all measures, missing values and diversities in studies' setting limited our ability to compare and analyze the results. Moreover, we had some serious problems in contacting the corresponding authors for complementary information necessary (Receptiveness: 17.9%). As the present paper focused on the main problems of Iranian scientific papers and proposed suggestions, the results will have implications for better policy making.
An approach for multi-objective optimization of vehicle suspension system
NASA Astrophysics Data System (ADS)
Koulocheris, D.; Papaioannou, G.; Christodoulou, D.
2017-10-01
In this paper, a half car model of with nonlinear suspension systems is selected in order to study the vertical vibrations and optimize its suspension system with respect to ride comfort and road holding. A road bump was used as road profile. At first, the optimization problem is solved with the use of Genetic Algorithms with respect to 6 optimization targets. Then the k - ɛ optimization method was implemented to locate one optimum solution. Furthermore, an alternative approach is presented in this work: the previous optimization targets are separated in main and supplementary ones, depending on their importance in the analysis. The supplementary targets are not crucial to the optimization but they could enhance the main objectives. Thus, the problem was solved again using Genetic Algorithms with respect to the 3 main targets of the optimization. Having obtained the Pareto set of solutions, the k - ɛ optimality method was implemented for the 3 main targets and the supplementary ones, evaluated by the simulation of the vehicle model. The results of both cases are presented and discussed in terms of convergence of the optimization and computational time. The optimum solutions acquired from both cases are compared based on performance metrics as well.
Against Teleology in an Honors Great Books Curriculum
ERIC Educational Resources Information Center
Harlan-Haughey, Sarah
2014-01-01
Chronologically presented courses that span centuries often catalyze unwitting buy-in to unexamined narratives of progress. While useful for helping students make connections between the human past, present, and future, Great Books honors curricula like the one used at the University of Maine have a few inherent problems that require careful…
Organisation of Prevention in Primary Health Care.
ERIC Educational Resources Information Center
Council of Europe, Strasbourg (France).
This report examines the possiblities of increasing the amount of preventive work being carried out by primary care workers in European communities. Before making practical recommendations about promoting prevention, an analysis is presented of the main present day problems. These center on the environment (not only physical but also social and…
A Duality Theory for Non-convex Problems in the Calculus of Variations
NASA Astrophysics Data System (ADS)
Bouchitté, Guy; Fragalà, Ilaria
2018-07-01
We present a new duality theory for non-convex variational problems, under possibly mixed Dirichlet and Neumann boundary conditions. The dual problem reads nicely as a linear programming problem, and our main result states that there is no duality gap. Further, we provide necessary and sufficient optimality conditions, and we show that our duality principle can be reformulated as a min-max result which is quite useful for numerical implementations. As an example, we illustrate the application of our method to a celebrated free boundary problem. The results were announced in Bouchitté and Fragalà (C R Math Acad Sci Paris 353(4):375-379, 2015).
A Duality Theory for Non-convex Problems in the Calculus of Variations
NASA Astrophysics Data System (ADS)
Bouchitté, Guy; Fragalà, Ilaria
2018-02-01
We present a new duality theory for non-convex variational problems, under possibly mixed Dirichlet and Neumann boundary conditions. The dual problem reads nicely as a linear programming problem, and our main result states that there is no duality gap. Further, we provide necessary and sufficient optimality conditions, and we show that our duality principle can be reformulated as a min-max result which is quite useful for numerical implementations. As an example, we illustrate the application of our method to a celebrated free boundary problem. The results were announced in Bouchitté and Fragalà (C R Math Acad Sci Paris 353(4):375-379, 2015).
Pourmovahed, Zahra; Mazloomy Mahmoodabad, Seyed Saied; Zareei Mahmoodabadi, Hassan; Tavangar, Hossein; Yassini Ardekani, Seyed Mojtaba; Vaezi, Ali Akbar
2018-01-01
Objective: Problem-solving ability is one of the most important means of family stability that enables the families to understand their roles, functions, and performances. Self-efficacy deficiency in problem-solving runs through many families. This qualitative study was conducted to investigate and describe how couples solve problems in their families. Method: This study was conducted to detect couples' self-efficacy deficiency in problem-solving using purposive sampling method. Several deep semi-structured interviews based on McMaster model and observations were conducted by nine family therapists and psychiatrists on four couples (eight persons) living in Yazd (Iran).The interviews were performed, audio-recorded, and transcribed verbatim. The analysis was interpreted through directed content analysis methods. Results: Families in Yazd (Iran) made some attempts to solve their problems, but their efforts were not enough, and thus they suffered from self-efficacy deficiency, which included 8 categories. The main theme distilled from the data of 17 participants was self-efficacy deficiency, which included the following categories: avoidance, insolvency, interference from others, ineffective self-treatment, behavioral problems, stubbornness, superficiality, and denial. Conclusion: It is of paramount importance to identify self-efficacy deficiency in families and promote problem- solving programs to increase family stability. In the present study, the main deficiencies in problem-solving were detected.
NASA Astrophysics Data System (ADS)
Skogen, Morten D.; Eilola, Kari; Hansen, Jørgen L. S.; Meier, H. E. Markus; Molchanov, Mikhail S.; Ryabchenko, Vladimir A.
2014-04-01
A method to combine observations and an ensemble of ecological models has been used to assess eutrophication. Using downscaled forcing from two GCMs under the A1B emission scenario, an assessment of the eutrophication status was made for a control (1970-2000) and a future climate (2070-2100) period. By using validation results from a hindcast to compute individual weights between the models, an assessment of eutrophication is done using a set of threshold values. The final classification distinguishes between three categories: problem area, potential problem area, and non-problem area, in accordance with current management practice as suggested by the Oslo and Paris Commissions (OSPAR) and the Helsinki Commission (HELCOM). For the control run the assessment indicates that the Kattegat, the Danish Straits, the Gulf of Finland, the Gotland Basin as well as main parts of the Arkona Basin, the Bornholm Basin, and the Baltic proper may be classified as problem areas. The main part of the North Sea and also the Skagerrak are non-problem areas while the main parts of the Gulf of Bothnia, Gulf of Riga and the entire southeastern continental coast of the North Sea may be classified as potential problem areas. In the future climate scenarios most of the previous potential problem areas in the Baltic Sea have become problem areas, except for the Bothnian Bay where the situation remain fairly unchanged. In the North Sea there seems to be no obvious changes in eutrophication status in the projected future climate.
Application of spring tabs to elevator controls
NASA Technical Reports Server (NTRS)
Phillips, William H
1944-01-01
Equations are presented for calculating the stick-force characteristics obtained with a spring-tab type of elevator control. The main problems encountered in the design of a satisfactory elevator spring tab are to provide stick forces in the desired range, to maintain the force per g sufficiently constant throughout the speed range, to avoid undesirable "feel" of the control in ground handling or in flight at low airspeeds, and to prevent flutter. Examples are presented to show the design features of spring tabs required to solve these problems for airplanes of various sizes.
Computing Evans functions numerically via boundary-value problems
NASA Astrophysics Data System (ADS)
Barker, Blake; Nguyen, Rose; Sandstede, Björn; Ventura, Nathaniel; Wahl, Colin
2018-03-01
The Evans function has been used extensively to study spectral stability of travelling-wave solutions in spatially extended partial differential equations. To compute Evans functions numerically, several shooting methods have been developed. In this paper, an alternative scheme for the numerical computation of Evans functions is presented that relies on an appropriate boundary-value problem formulation. Convergence of the algorithm is proved, and several examples, including the computation of eigenvalues for a multi-dimensional problem, are given. The main advantage of the scheme proposed here compared with earlier methods is that the scheme is linear and scalable to large problems.
Instant World; A Report on Telecommunications in Canada.
ERIC Educational Resources Information Center
Information Canada, Ottawa (Ontario).
Telecommission, the study of the present state and future prospects of telecommunications in Canada, began in 1969. This general report focuses attention on the main issues and problems disclosed by the 40 individual Telecommission studies and presents options for consideration. Part one of the report sets out the complex background of problems…
Methodes entropiques appliquees au probleme inverse en magnetoencephalographie
NASA Astrophysics Data System (ADS)
Lapalme, Ervig
2005-07-01
This thesis is devoted to biomagnetic source localization using magnetoencephalography. This problem is known to have an infinite number of solutions. So methods are required to take into account anatomical and functional information on the solution. The work presented in this thesis uses the maximum entropy on the mean method to constrain the solution. This method originates from statistical mechanics and information theory. This thesis is divided into two main parts containing three chapters each. The first part reviews the magnetoencephalographic inverse problem: the theory needed to understand its context and the hypotheses for simplifying the problem. In the last chapter of this first part, the maximum entropy on the mean method is presented: its origins are explained and also how it is applied to our problem. The second part is the original work of this thesis presenting three articles; one of them already published and two others submitted for publication. In the first article, a biomagnetic source model is developed and applied in a theoretical con text but still demonstrating the efficiency of the method. In the second article, we go one step further towards a realistic modelization of the cerebral activation. The main priors are estimated using the magnetoencephalographic data. This method proved to be very efficient in realistic simulations. In the third article, the previous method is extended to deal with time signals thus exploiting the excellent time resolution offered by magnetoencephalography. Compared with our previous work, the temporal method is applied to real magnetoencephalographic data coming from a somatotopy experience and results agree with previous physiological knowledge about this kind of cognitive process.
Brain potentials during mental arithmetic: effects of extensive practice and problem difficulty.
Pauli, P; Lutzenberger, W; Rau, H; Birbaumer, N; Rickard, T C; Yaroush, R A; Bourne, L E
1994-07-01
Recent behavioral investigations indicate that the processes underlying mental arithmetic change systematically with practice from deliberate, conscious calculation to automatic, direct retrieval of answers from memory [Bourne, L.E.Jr. and Rickard, T.C., Mental calculation: The development of a cognitive skill, Paper presented at the Interamerican Congress of Psychology, San Jose, Costa Rica, 1991: Psychol. Rev., 95 (1988) 492-527]. Results reviewed by Moscovitch and Winocur [In: The handbook of aging and cognition, Erlbaum, Hillsdale, NJ, 1992, pp. 315-372] suggest that consciously controlled processes are more dependent on frontal lobe function than are automatic processes. It is appropriate, therefore to determine whether transitions in the locus of primary brain activity occur with practice on mental calculation. In this experiment, we examine the relationship between characteristics of event-related brain potentials (ERPs) and mental arithmetic. Single-digit mental multiplication problems varying in difficulty (problem size) were used, and subjects were trained on these problems for four sessions. Problem-size and practice effects were reliably found in behavioral measures (RT). The ERP was characterized by a pronounced late positivity after task presentation followed by a slow wave, and a negativity during response indication. These components responded differentially to the practice and problem-size manipulations. Practice mainly affected topography of the amplitude of positivity and offset latency of slow wave, and problem-size mainly offset latency of slow wave and pre-response negativity. Fronto-central positivity diminished from session to session, and the focus of positivity centered finally at centro-parietal regions.(ABSTRACT TRUNCATED AT 250 WORDS)
Narrative review: Diabetic foot and infrared thermography
NASA Astrophysics Data System (ADS)
Hernandez-Contreras, D.; Peregrina-Barreto, H.; Rangel-Magdaleno, J.; Gonzalez-Bernal, J.
2016-09-01
Diabetic foot is one of the major complications experienced by diabetic patients. An early identification and appropriate treatment of diabetic foot problems can prevent devastating consequences such as limb amputation. Several studies have demonstrated that temperature variations in the plantar region can be related to diabetic foot problems. Infrared thermography has been successfully used to detect complication related to diabetic foot, mainly because it is presented as a rapid, non-contact and non-invasive technique to visualize the temperature distribution of the feet. In this review, an overview of studies that relate foot temperature with diabetic foot problems through infrared thermography is presented. Through this research, it can be appreciated the potential of infrared thermography and the benefits that this technique present in this application. This paper also presents the different methods for thermogram analysis and the advantages and disadvantages of each one, being the asymmetric analysis the method most used so far.
Does parent-child agreement vary based on presenting problems? Results from a UK clinical sample.
Cleridou, Kalia; Patalay, Praveetha; Martin, Peter
2017-01-01
Discrepancies are often found between child and parent reports of child psychopathology, nevertheless the role of the child's presenting difficulties in relation to these is underexplored. This study investigates whether parent-child agreement on the conduct and emotional scales of the Strengths and Difficulties Questionnaire (SDQ) varied as a result of certain child characteristics, including the child's presenting problems to clinical services, age and gender. The UK-based sample consisted of 16,754 clinical records of children aged 11-17, the majority of which were female (57%) and White (76%). The dataset was provided by the Child Outcomes Research Consortium , which collects outcome measures from child services across the UK. Clinicians reported the child's presenting difficulties, and parents and children completed the SDQ. Using correlation analysis, the main findings indicated that agreement varied as a result of the child's difficulties for reports of conduct problems, and this seemed to be related to the presence or absence of externalising difficulties in the child's presentation. This was not the case for reports of emotional difficulties. In addition, agreement was higher when reporting problems not consistent with the child's presentation; for instance, agreement on conduct problems was greater for children presenting with internalising problems. Lastly, the children's age and gender did not seem to have an impact on agreement. These findings demonstrate that certain child presenting difficulties, and in particular conduct problems, may be related to informant agreement and need to be considered in clinical practice and research. Trial Registration This study was observational and as such did not require trial registration.
[Economic problems in military public health].
Petrov, G M; Moretskiĭ, A A
2000-03-01
There are discussed the problems of military treatment and prophylactic institution (TPI) functioning under conditions of market reform of Russian public health. Main marketing concepts in military health are determined and some recommendations on work improvement in TPI of the Armed Forces in the system of obligatory medical insurance are presented, granting population paid medical services. It is necessary to form a new type of director--military and medical manager.
A note on the electromagnetic irradiation in a holed spatial region: A space-time approach
NASA Astrophysics Data System (ADS)
Botelho, Luiz C. L.
2017-02-01
We study the role of the homological topological property of a space-time with holes (a multiple connected manifold) on the formal solution of the electromagnetic irradiation problem taking place on these “holed” space-times. In this paper, in addition to the main focus of study, we present as well important studies on this irradiation problem on other mathematical frameworks.
NASA Technical Reports Server (NTRS)
Whitson, D. W.
1975-01-01
An introduction to the theory of corona discharge and electrostatic phenomena is presented. The theory is mainly qualitative so that workers in the field should not have to go outside this manual for an understanding of the relevant phenomena. Some of the problems that may occur with the space shuttle in regard to electrical discharge are discussed.
Multi-UAV Routing for Area Coverage and Remote Sensing with Minimum Time
Avellar, Gustavo S. C.; Pereira, Guilherme A. S.; Pimenta, Luciano C. A.; Iscold, Paulo
2015-01-01
This paper presents a solution for the problem of minimum time coverage of ground areas using a group of unmanned air vehicles (UAVs) equipped with image sensors. The solution is divided into two parts: (i) the task modeling as a graph whose vertices are geographic coordinates determined in such a way that a single UAV would cover the area in minimum time; and (ii) the solution of a mixed integer linear programming problem, formulated according to the graph variables defined in the first part, to route the team of UAVs over the area. The main contribution of the proposed methodology, when compared with the traditional vehicle routing problem’s (VRP) solutions, is the fact that our method solves some practical problems only encountered during the execution of the task with actual UAVs. In this line, one of the main contributions of the paper is that the number of UAVs used to cover the area is automatically selected by solving the optimization problem. The number of UAVs is influenced by the vehicles’ maximum flight time and by the setup time, which is the time needed to prepare and launch a UAV. To illustrate the methodology, the paper presents experimental results obtained with two hand-launched, fixed-wing UAVs. PMID:26540055
Analysis of Feeder Bus Network Design and Scheduling Problems
Almasi, Mohammad Hadi; Karim, Mohamed Rehan
2014-01-01
A growing concern for public transit is its inability to shift passenger's mode from private to public transport. In order to overcome this problem, a more developed feeder bus network and matched schedules will play important roles. The present paper aims to review some of the studies performed on Feeder Bus Network Design and Scheduling Problem (FNDSP) based on three distinctive parts of the FNDSP setup, namely, problem description, problem characteristics, and solution approaches. The problems consist of different subproblems including data preparation, feeder bus network design, route generation, and feeder bus scheduling. Subsequently, descriptive analysis and classification of previous works are presented to highlight the main characteristics and solution methods. Finally, some of the issues and trends for future research are identified. This paper is targeted at dealing with the FNDSP to exhibit strategic and tactical goals and also contributes to the unification of the field which might be a useful complement to the few existing reviews. PMID:24526890
Pragmatic failure, mind style and characterisation in fiction about autism
2014-01-01
This article presents an analysis of different types of pragmatic failure in the interactional behaviour of the ‘autistic’ protagonists of three recent novels. Three main types of pragmatic failure occur across all three novels: problems with informativeness and relevance in conversational contributions; problems with face management resulting in unintentional impolite behaviours; and problems with the interpretation of figurative language. These problems are salient and frequent enough to contribute to the projection of distinctive mind styles, and more generally to the characterisation of the protagonists as individuals with communication and socialisation difficulties that are likely to both reflect and reinforce general perceptions of autism-spectrum disorders. It is also argued that pragmatic failure contributes to the potential defamiliarisation of ‘normal’ communication, which is presented as being fraught with obscurity, ambiguity and insincerity. PMID:29710882
Modeling and Negotiating Service Quality
NASA Astrophysics Data System (ADS)
Benbernou, Salima; Brandic, Ivona; Cappiello, Cinzia; Carro, Manuel; Comuzzi, Marco; Kertész, Attila; Kritikos, Kyriakos; Parkin, Michael; Pernici, Barbara; Plebani, Pierluigi
In this chapter the research problems of specifying and negotiating QoS and its corresponding quality documents are analyzed. For this reason, this chapter is separated into two main sections, Section 6.1 and 6.2, with each dedicated to one of the two problems, i.e., QoS specification and negotiation, respectively. Each section has a similar structure: they first introduce the problem and then, in the remaining subsections, review related work. Finally, the chapter ends with Section 6.3, which identifies research gaps and presents potential research challenges in QoS modelling, specification and negotiation.
NASA Astrophysics Data System (ADS)
Secchi, Paolo
2005-05-01
We introduce the main known results of the theory of incompressible and compressible vortex sheets. Moreover, we present recent results obtained by the author with J. F. Coulombel about supersonic compressible vortex sheets in two space dimensions. The problem is a nonlinear free boundary hyperbolic problem with two difficulties: the free boundary is characteristic and the Lopatinski condition holds only in a weak sense, yielding losses of derivatives. Under a supersonic condition that precludes violent instabilities, we prove an energy estimate for the boundary value problem obtained by linearization around an unsteady piecewise solution.
Agency problems of global budget system in Taiwan's National Health Insurance.
Yan, Yu-Hua; Yang, Chen-Wei; Fang, Shih-Chieh
2014-05-01
The main purpose of this study was to investigate the agency problem presented by the global budget system followed by hospitals in Taiwan. In this study, we examine empirically the interaction between the principal: Bureau of National Health Insurance (BNHI) and agency: medical service providers (hospitals); we also describe actual medical service provider and hospital governance conditions from a agency theory perspective. This study identified a positive correlation between aversion to agency hazard (self-interest behavior, asymmetric information, and risk hedging) and agency problem risks (disregard of medical ethics, pursuit of extra-contract profit, disregard of professionalism, and cost orientation). Agency costs refer to BNHI auditing and monitoring expenditures used to prevent hospitals from deviating from NHI policy goals. This study also found agency costs negatively moderate the relationship between agency hazards and agency problems The main contribution of this study is its use of agency theory to clarify agency problems and several potential factors caused by the NHI system. This study also contributes to the field of health policy study by clarifying the nature and importance of agency problems in the health care sector. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
An exact algorithm for optimal MAE stack filter design.
Dellamonica, Domingos; Silva, Paulo J S; Humes, Carlos; Hirata, Nina S T; Barrera, Junior
2007-02-01
We propose a new algorithm for optimal MAE stack filter design. It is based on three main ingredients. First, we show that the dual of the integer programming formulation of the filter design problem is a minimum cost network flow problem. Next, we present a decomposition principle that can be used to break this dual problem into smaller subproblems. Finally, we propose a specialization of the network Simplex algorithm based on column generation to solve these smaller subproblems. Using our method, we were able to efficiently solve instances of the filter problem with window size up to 25 pixels. To the best of our knowledge, this is the largest dimension for which this problem was ever solved exactly.
On the nullspace of TLS multi-station adjustment
NASA Astrophysics Data System (ADS)
Sterle, Oskar; Kogoj, Dušan; Stopar, Bojan; Kregar, Klemen
2018-07-01
In the article we present an analytic aspect of TLS multi-station least-squares adjustment with the main focus on the datum problem. The datum problem is, compared to previously published researches, theoretically analyzed and solved, where the solution is based on nullspace derivation of the mathematical model. The importance of datum problem solution is seen in a complete description of TLS multi-station adjustment solutions from a set of all minimally constrained least-squares solutions. On a basis of known nullspace, estimable parameters are described and the geometric interpretation of all minimally constrained least squares solutions is presented. At the end a simulated example is used to analyze the results of TLS multi-station minimally constrained and inner constrained least-squares adjustment solutions.
Survey of Materials Problems Resulting from Low-Pressure and Radiation Environment in Space
NASA Technical Reports Server (NTRS)
Lad, Robert A.
1960-01-01
On the basis of our present knowledge of the space environment, one might state that the exposure of materials to the radiation environment will present problems mainly with the impairment of the transparency of plastics and ionic solids due to ultraviolet radiation and with surface sputtering effects on emissivity and other thin film properties. The high vacuum in space will be of greater consequence in that it will render useless some members of practically all of the material classes. However, adequate solutions to most problems can be anticipated if enough information is at hand. This survey indicates that information is lacking at levels from the basic to the applied. A partial list of research areas in need of attack is included.
Solving Assembly Sequence Planning using Angle Modulated Simulated Kalman Filter
NASA Astrophysics Data System (ADS)
Mustapa, Ainizar; Yusof, Zulkifli Md.; Adam, Asrul; Muhammad, Badaruddin; Ibrahim, Zuwairie
2018-03-01
This paper presents an implementation of Simulated Kalman Filter (SKF) algorithm for optimizing an Assembly Sequence Planning (ASP) problem. The SKF search strategy contains three simple steps; predict-measure-estimate. The main objective of the ASP is to determine the sequence of component installation to shorten assembly time or save assembly costs. Initially, permutation sequence is generated to represent each agent. Each agent is then subjected to a precedence matrix constraint to produce feasible assembly sequence. Next, the Angle Modulated SKF (AMSKF) is proposed for solving ASP problem. The main idea of the angle modulated approach in solving combinatorial optimization problem is to use a function, g(x), to create a continuous signal. The performance of the proposed AMSKF is compared against previous works in solving ASP by applying BGSA, BPSO, and MSPSO. Using a case study of ASP, the results show that AMSKF outperformed all the algorithms in obtaining the best solution.
Ergonomics analyses of five joineries located in Florianópolis-SC, using the LEST Method.
Vergara, Lizandra Lupi Garcia; Garcia, Carolina Schwinden; Miranda, Felipe Vergara
2012-01-01
Considering the goal of Ergonomic Work Analysis to establish, from the point of view of workers, safe, healthy, comfortable and efficient environments, this study propose to analyze the work situation of machine operators at five joineries from Florianópolis-SC. For this, it was applied the LEST Method to evaluate the task made by the operators, considering the physical, cognitive and organizational work environment. As results, it was identified the main ergonomics problems of these workstations, presenting an ergonomic diagnosis and their implications on health and safety of workers. As result, it was concluded that the main ergonomics problems at joineries are related with noise, with constant load of weight and with the postures taken. Besides these problems, others were diagnosed, for example, the pressure for workers to comply strictly the task stipulated and also the poor training and capacity of workers.
NASA Astrophysics Data System (ADS)
Khan, F. A.; Yousaf, A.; Reindl, L. M.
2018-04-01
This paper presents a multi segment capacitive level monitoring sensor based on distributed E-fields approach Glocal. This approach has an advantage to analyze build-up problem by the local E-fields as well the fluid level monitoring by the global E-fields. The multi segment capacitive approach presented within this work addresses the main problem of unwanted parasitic capacitance generated from Copper (Cu) strips by applying active shielding concept. Polyvinyl chloride (PVC) is used for isolation and parafilm is used for creating artificial build-up on a CLS.
Study on status quo of shipbreaking sector and strategies
NASA Astrophysics Data System (ADS)
Shen, Wei; Xing, Guojing
2017-11-01
In recent years, the quantity of broken obsolete vessels tends to rise year by year in the shipbreaking sector, but breaking down obsolete vessels is one of vessel operations with high pollution and high risk, involving proper disposal of hazardous substances, bulge discarded oils and other materials, and thus causing great danger and harm. In this paper the author investigates mainly the status quo of the shipbreaking sector, comes up with the “green-shipbreaking” concept, analyzes main problems currently present in the shipbreaking sector and presents proper strategies and recommendations to deal with them.
Focusing on Main Street's Problems from Secluded Laboratory Retreats
ERIC Educational Resources Information Center
Kushner, Lawrence M.
1973-01-01
A report on the National Bureau of Standards is presented. It provides national measurement standards for some 40 physical quantities related through the laws of physics to the basic six - length, time, mass, temperature, electric current, and luminous intensity. (DF)
Technical and Economic Aspects of Low Emission Reduction in Poland
NASA Astrophysics Data System (ADS)
Dzikuć, M.; Łasiński, K.
2017-12-01
The paper presents the problem of excessive air pollution in Poland caused mainly by low emission. The emission arises in result of heating flats by means of old and energetically inefficient heating installations. In Poland and Bulgaria the inhaled air is of the worst quality out of all EU countries. The paper presents economic and technical problems related to low emission occurring during the combustion of solid fuels in local boiler houses. Furthermore, the most significant economic issues, connected with the reduction of low emission are discussed, as well as technological possibilities of efficient reduction of the amount of pollution in the atmosphere. Conclusions are presented at the end of the article.
Robust optimization modelling with applications to industry and environmental problems
NASA Astrophysics Data System (ADS)
Chaerani, Diah; Dewanto, Stanley P.; Lesmana, Eman
2017-10-01
Robust Optimization (RO) modeling is one of the existing methodology for handling data uncertainty in optimization problem. The main challenge in this RO methodology is how and when we can reformulate the robust counterpart of uncertain problems as a computationally tractable optimization problem or at least approximate the robust counterpart by a tractable problem. Due to its definition the robust counterpart highly depends on how we choose the uncertainty set. As a consequence we can meet this challenge only if this set is chosen in a suitable way. The development on RO grows fast, since 2004, a new approach of RO called Adjustable Robust Optimization (ARO) is introduced to handle uncertain problems when the decision variables must be decided as a ”wait and see” decision variables. Different than the classic Robust Optimization (RO) that models decision variables as ”here and now”. In ARO, the uncertain problems can be considered as a multistage decision problem, thus decision variables involved are now become the wait and see decision variables. In this paper we present the applications of both RO and ARO. We present briefly all results to strengthen the importance of RO and ARO in many real life problems.
NASA Technical Reports Server (NTRS)
Lustman, L.
1984-01-01
An outline for spectral methods for partial differential equations is presented. The basic spectral algorithm is defined, collocation are emphasized and the main advantage of the method, the infinite order of accuracy in problems with smooth solutions are discussed. Examples of theoretical numerical analysis of spectral calculations are presented. An application of spectral methods to transonic flow is presented. The full potential transonic equation is among the best understood among nonlinear equations.
Statistical estimation via convex optimization for trending and performance monitoring
NASA Astrophysics Data System (ADS)
Samar, Sikandar
This thesis presents an optimization-based statistical estimation approach to find unknown trends in noisy data. A Bayesian framework is used to explicitly take into account prior information about the trends via trend models and constraints. The main focus is on convex formulation of the Bayesian estimation problem, which allows efficient computation of (globally) optimal estimates. There are two main parts of this thesis. The first part formulates trend estimation in systems described by known detailed models as a convex optimization problem. Statistically optimal estimates are then obtained by maximizing a concave log-likelihood function subject to convex constraints. We consider the problem of increasing problem dimension as more measurements become available, and introduce a moving horizon framework to enable recursive estimation of the unknown trend by solving a fixed size convex optimization problem at each horizon. We also present a distributed estimation framework, based on the dual decomposition method, for a system formed by a network of complex sensors with local (convex) estimation. Two specific applications of the convex optimization-based Bayesian estimation approach are described in the second part of the thesis. Batch estimation for parametric diagnostics in a flight control simulation of a space launch vehicle is shown to detect incipient fault trends despite the natural masking properties of feedback in the guidance and control loops. Moving horizon approach is used to estimate time varying fault parameters in a detailed nonlinear simulation model of an unmanned aerial vehicle. An excellent performance is demonstrated in the presence of winds and turbulence.
Filtering techniques for efficient inversion of two-dimensional Nuclear Magnetic Resonance data
NASA Astrophysics Data System (ADS)
Bortolotti, V.; Brizi, L.; Fantazzini, P.; Landi, G.; Zama, F.
2017-10-01
The inversion of two-dimensional Nuclear Magnetic Resonance (NMR) data requires the solution of a first kind Fredholm integral equation with a two-dimensional tensor product kernel and lower bound constraints. For the solution of this ill-posed inverse problem, the recently presented 2DUPEN algorithm [V. Bortolotti et al., Inverse Problems, 33(1), 2016] uses multiparameter Tikhonov regularization with automatic choice of the regularization parameters. In this work, I2DUPEN, an improved version of 2DUPEN that implements Mean Windowing and Singular Value Decomposition filters, is deeply tested. The reconstruction problem with filtered data is formulated as a compressed weighted least squares problem with multi-parameter Tikhonov regularization. Results on synthetic and real 2D NMR data are presented with the main purpose to deeper analyze the separate and combined effects of these filtering techniques on the reconstructed 2D distribution.
A Legendre tau-spectral method for solving time-fractional heat equation with nonlocal conditions.
Bhrawy, A H; Alghamdi, M A
2014-01-01
We develop the tau-spectral method to solve the time-fractional heat equation (T-FHE) with nonlocal condition. In order to achieve highly accurate solution of this problem, the operational matrix of fractional integration (described in the Riemann-Liouville sense) for shifted Legendre polynomials is investigated in conjunction with tau-spectral scheme and the Legendre operational polynomials are used as the base function. The main advantage in using the presented scheme is that it converts the T-FHE with nonlocal condition to a system of algebraic equations that simplifies the problem. For demonstrating the validity and applicability of the developed spectral scheme, two numerical examples are presented. The logarithmic graphs of the maximum absolute errors is presented to achieve the exponential convergence of the proposed method. Comparing between our spectral method and other methods ensures that our method is more accurate than those solved similar problem.
A Legendre tau-Spectral Method for Solving Time-Fractional Heat Equation with Nonlocal Conditions
Bhrawy, A. H.; Alghamdi, M. A.
2014-01-01
We develop the tau-spectral method to solve the time-fractional heat equation (T-FHE) with nonlocal condition. In order to achieve highly accurate solution of this problem, the operational matrix of fractional integration (described in the Riemann-Liouville sense) for shifted Legendre polynomials is investigated in conjunction with tau-spectral scheme and the Legendre operational polynomials are used as the base function. The main advantage in using the presented scheme is that it converts the T-FHE with nonlocal condition to a system of algebraic equations that simplifies the problem. For demonstrating the validity and applicability of the developed spectral scheme, two numerical examples are presented. The logarithmic graphs of the maximum absolute errors is presented to achieve the exponential convergence of the proposed method. Comparing between our spectral method and other methods ensures that our method is more accurate than those solved similar problem. PMID:25057507
[Present status and sustainable development of Dendrobium officinale industry].
Wu, Yunqin; Si, Jinping
2010-08-01
To understand the present status and characteristics of Dendrobium officinale industry and to provide a rationale for the sustainable industrial development. Based on references and an on-site investigation of main Dendrobium officinale-producing enterprises and market, to analyze main existing problems and to propose suggestions for sustainable development. More than 10 provinces and regions are involved in the production around the center of Zhejiang and Yunnan provinces. These two provinces are different from each other in development pattern. Yunnan adopts a mode of companies minus farmer households but Zhejiang mainly employs a mode that a leading company establishes a production base with production, processing and marketing combined together. Zhejiang mode is characterized by high tech, high investment, high risk and high return. Existence of non-genuine species, stagnancy in development and application of varieties and techniques for quality control and a narrow channel for marketing are the key problems limiting sustainable development of the industry. The key to sustainable development of the industry is to establish a technological alliance to speed up development of common techniques and application of integrated innovations, to strengthen self-discipline and monitoring of production, and to expand sales market.
NASA Astrophysics Data System (ADS)
Provotorov, Ivan; Gasilov, Valentin; Anisimova, Nadezhda
2018-03-01
The structure of problems of high-rise construction us suggested, which includes the impact on environment, design solutions, transportation problems, financial costs for construction and operation, and others. Positive and negative aspects of high-rise construction are considered. One of the basic problems of high-rise construction is the problem of increased transport load. Construction of the subway on the basis of the concession mechanism, with the use of unmanned control of rolling stock is proposed as the most expedient solution. An evaluation of the effectiveness of this project is presented, it shows quite high performance indicators for a private investor. Main problems that the project implementation may face in conditions of lack of scientific and methodological support are outlined.
Iakimova, L D
1997-01-01
The article touches upon hygienic problems associated with mechanization and automation of major hydroelectric power stations. The authors present criteria to evaluate work conditions of the main occupations participating in the technologic process of hydroelectric power stations.
Children in an Information Age.
ERIC Educational Resources Information Center
Sendov, Blagovest
1988-01-01
Summarizes the main themes and presents recommendations of the international conference, "Children in an Information Age: Tomorrow's Problems Today," that was held in Bulgaria in 1985. Topics discussed include computer training for children; the need for well designed research; the teacher-computer relationship; artificial intelligence;…
A new approach to impulsive rendezvous near circular orbit
NASA Astrophysics Data System (ADS)
Carter, Thomas; Humi, Mayer
2012-04-01
A new approach is presented for the problem of planar optimal impulsive rendezvous of a spacecraft in an inertial frame near a circular orbit in a Newtonian gravitational field. The total characteristic velocity to be minimized is replaced by a related characteristic-value function and this related optimization problem can be solved in closed form. The solution of this problem is shown to approach the solution of the original problem in the limit as the boundary conditions approach those of a circular orbit. Using a form of primer-vector theory the problem is formulated in a way that leads to relatively easy calculation of the optimal velocity increments. A certain vector that can easily be calculated from the boundary conditions determines the number of impulses required for solution of the optimization problem and also is useful in the computation of these velocity increments. Necessary and sufficient conditions for boundary conditions to require exactly three nonsingular non-degenerate impulses for solution of the related optimal rendezvous problem, and a means of calculating these velocity increments are presented. A simple example of a three-impulse rendezvous problem is solved and the resulting trajectory is depicted. Optimal non-degenerate nonsingular two-impulse rendezvous for the related problem is found to consist of four categories of solutions depending on the four ways the primer vector locus intersects the unit circle. Necessary and sufficient conditions for each category of solutions are presented. The region of the boundary values that admit each category of solutions of the related problem are found, and in each case a closed-form solution of the optimal velocity increments is presented. Similar results are presented for the simpler optimal rendezvous that require only one-impulse. For brevity degenerate and singular solutions are not discussed in detail, but should be presented in a following study. Although this approach is thought to provide simpler computations than existing methods, its main contribution may be in establishing a new approach to the more general problem.
ERIC Educational Resources Information Center
Panaoura, Areti; Michael-Chrysanthou, Paraskevi; Gagatsis, Athanasios; Elia, Iliada; Philippou, Andreas
2017-01-01
This article focuses on exploring students' understanding of the concept of function concerning three main aspects: secondary students' ability to (1) define the concept of function and present examples of functions, (2) solve tasks which asked them to recognize and interpret the concept of function presented in different forms of representation,…
ERIC Educational Resources Information Center
Budinski, Natalija; Milinkovic, Dragica
2017-01-01
The availability of technology has a big impact on education, and that is the main reason for discussing the use of technologies in mathematical education in our paper. The availability of technology influences how mathematical contents could be presented to students. We present the benefits of learning mathematical concepts through real life…
The dimension split element-free Galerkin method for three-dimensional potential problems
NASA Astrophysics Data System (ADS)
Meng, Z. J.; Cheng, H.; Ma, L. D.; Cheng, Y. M.
2018-06-01
This paper presents the dimension split element-free Galerkin (DSEFG) method for three-dimensional potential problems, and the corresponding formulae are obtained. The main idea of the DSEFG method is that a three-dimensional potential problem can be transformed into a series of two-dimensional problems. For these two-dimensional problems, the improved moving least-squares (IMLS) approximation is applied to construct the shape function, which uses an orthogonal function system with a weight function as the basis functions. The Galerkin weak form is applied to obtain a discretized system equation, and the penalty method is employed to impose the essential boundary condition. The finite difference method is selected in the splitting direction. For the purposes of demonstration, some selected numerical examples are solved using the DSEFG method. The convergence study and error analysis of the DSEFG method are presented. The numerical examples show that the DSEFG method has greater computational precision and computational efficiency than the IEFG method.
Image quality enhancement for skin cancer optical diagnostics
NASA Astrophysics Data System (ADS)
Bliznuks, Dmitrijs; Kuzmina, Ilona; Bolocko, Katrina; Lihachev, Alexey
2017-12-01
The research presents image quality analysis and enhancement proposals in biophotonic area. The sources of image problems are reviewed and analyzed. The problems with most impact in biophotonic area are analyzed in terms of specific biophotonic task - skin cancer diagnostics. The results point out that main problem for skin cancer analysis is the skin illumination problems. Since it is often not possible to prevent illumination problems, the paper proposes image post processing algorithm - low frequency filtering. Practical results show diagnostic results improvement after using proposed filter. Along that, filter do not reduces diagnostic results' quality for images without illumination defects. Current filtering algorithm requires empirical tuning of filter parameters. Further work needed to test the algorithm in other biophotonic applications and propose automatic filter parameter selection.
Testing Task Schedulers on Linux System
NASA Astrophysics Data System (ADS)
Jelenković, Leonardo; Groš, Stjepan; Jakobović, Domagoj
Testing task schedulers on Linux operating system proves to be a challenging task. There are two main problems. The first one is to identify which properties of the scheduler to test. The second problem is how to perform it, e.g., which API to use that is sufficiently precise and in the same time supported on most platforms. This paper discusses the problems in realizing test framework for testing task schedulers and presents one potential solution. Observed behavior of the scheduler is the one used for “normal” task scheduling (SCHED_OTHER), unlike one used for real-time tasks (SCHED_FIFO, SCHED_RR).
Effective Planning of the Future of the Arctic
NASA Astrophysics Data System (ADS)
Sentsov, A.; Bolsunovskaya, Yu; Bolsunovskaya, L.
2014-08-01
The problems of the Arctic region have become the most important ones in the world. Political risks hinder the industrial development of the region. This paper addresses the problem of planning and modeling the future of this region. It presents the problems of developing a model of the future due to the ideologies and strategies of two main actors in the Arctic, the United States and the Russian Federation. The effects of a bipolar perception of the future of the region and of the whole world are shown. A model of the effective planning of the future of the Arctic region is proposed.
NSTS Orbiter auxiliary power unit turbine wheel cracking risk assessment
NASA Technical Reports Server (NTRS)
Cruse, T. A.; Mcclung, R. C.; Torng, T. Y.
1992-01-01
The present investigation of turbine-wheel cracking problems in the hydrazine-fueled APU turbine wheel of the Space Shuttle Orbiter's Main Engines has indicated the efficacy of systematic probabilistic risk assessment in flight certification and safety resolution. Nevertheless, real crack-initiation and propagation problems do not lend themselves to purely analytical studies. The high-cycle fatigue problem is noted to generally be unsuited to probabilistic modeling, due to its extremely high degree of intrinsic scatter. In the case treated, the cracks appear to trend toward crack arrest in a low cycle fatigue mode, due to a detuning of the resonance model.
Teaching helix and problems connected with helix using GeoGebra
NASA Astrophysics Data System (ADS)
Bímová, Daniela
2017-12-01
The contribution presents the dynamic applets created in GeoGebra that show the origin and main properties of a helix and it also presents some constructive problems connected with the helix. There are created the step by step algorithms of some constructions in the chosen applets. Three-dimensional applets include illustrative helix samples and spatial animations that help students better see problems concerning the helix spatially. There is mentioned the website in the contribution on which there is situated GeoGebra book dedicated to the topic "Helix" and containing the mentioned applets. The created applets and materials of the GeoGebra book "Helix" help in teaching and studying the course Constructive Geometry determined for the students of the Faculty of Mechanical Engineering of the Technical University of Liberec.
Rethinking exchange market models as optimization algorithms
NASA Astrophysics Data System (ADS)
Luquini, Evandro; Omar, Nizam
2018-02-01
The exchange market model has mainly been used to study the inequality problem. Although the human society inequality problem is very important, the exchange market models dynamics until stationary state and its capability of ranking individuals is interesting in itself. This study considers the hypothesis that the exchange market model could be understood as an optimization procedure. We present herein the implications for algorithmic optimization and also the possibility of a new family of exchange market models
ERIC Educational Resources Information Center
Berve, Nancy M., Ed.
1981-01-01
Annual reports are presented for the academic year 1980-1981 from 49 states (except Maine), the District of Columbia, and three Canadian provinces focusing on problems, issues, achievements, and other areas of interest to the postsecondary education community. Specific topics include the following: long-range plans for higher education,…
NASA Astrophysics Data System (ADS)
Jiang, Daijun; Li, Zhiyuan; Liu, Yikan; Yamamoto, Masahiro
2017-05-01
In this paper, we first establish a weak unique continuation property for time-fractional diffusion-advection equations. The proof is mainly based on the Laplace transform and the unique continuation properties for elliptic and parabolic equations. The result is weaker than its parabolic counterpart in the sense that we additionally impose the homogeneous boundary condition. As a direct application, we prove the uniqueness for an inverse problem on determining the spatial component in the source term by interior measurements. Numerically, we reformulate our inverse source problem as an optimization problem, and propose an iterative thresholding algorithm. Finally, several numerical experiments are presented to show the accuracy and efficiency of the algorithm.
[Forensic-medical diagnostics of doping cases in sports].
Khodasevich, L S; Kuzin, S G; Khodasevich, A L
2013-01-01
The present review of the literature is focused on the problem of forensic-medical diagnostics of doping cases in sports, with special reference to the main classes of pharmaceutical products forbidden for use by the International Olympic Committee. The main causes of death among the athletes as a result of using doping substances are considered. Much attention is given to adverse reactions induced by long-time intake of anabolic steroids many of which can be identified at autopsy.
Troubleshooting Computer Problems--a Teachers' Guide.
ERIC Educational Resources Information Center
Zeitz, Leigh
1995-01-01
Presents a troubleshooting flow chart for teachers and others to use when trying to figure out why their computers do not work correctly. Written mainly for Macintosh computers, the purpose of this guide is to save school technology coordinators time and to help educate teachers. (Author/LRW)
Systematic Planning for Educational Facilities.
ERIC Educational Resources Information Center
McGuffey, Carroll W.
This monograph provides a systematic approach to the problem of planning educational facilities. It first presents a conceptual framework for a general facilities planning and management system called Facilities Resource Allocation Management Evaluation System (FRAMES). The main components of FRAMES are identified as: (1) needs assessment, (2)…
SEMINAR PUBLICATION: NATIONAL CONFERENCE ON SANITARY SEWER OVERFLOWS (SSOS)
This seminar publication presents selected peer-reviewed papers from the conference. Thousands of municipalities across the nation are serviced by separate sanitary sewer systems. A chronic problem that faces many of these systems is the occurrence of SSOs, caused mainly by the i...
Simple predictive model for Early Childhood Caries of Chilean children.
Fierro Monti, Claudia; Pérez Flores, M; Brunotto, M
2014-01-01
Early Childhood Caries (ECC), in both industrialized and developing countries, is the most prevalent chronic disease in childhood and it is still a health public problem, affecting mainly populations considered as vulnerable, despite being preventable. The purpose of this study was to obtain a simple predictive model based on risk factors for improving public health strategies for ECC prevention for 3-5 year-old children. Clinical, environmental and psycho-socio-cultural data of children (n=250) aged 3-5 years, of both genders, from the Health Centers, were recorded in a Clinical History and Behavioral Survey. 24% of children presented behavioral problems (bizarre behavior was the main feature observed as behavioral problems). The variables associated to dmf ?4 were: bad children temperament (OR=2.43 [1.34, 4.40]) and home stress (OR=3.14 [1.54, 6.41]). It was observed that the model for male gender has higher accuracy for ECC (AUC= 78%, p-value=0.000) than others. Based on the results, we proposed a model where oral hygiene, sugar intake, male gender, and difficult temperament are main factors for predicting ECC. This model could be a promising tool for cost-effective early childhood caries control.
A new model of Ishikawa diagram for quality assessment
NASA Astrophysics Data System (ADS)
Liliana, Luca
2016-11-01
The paper presents the results of a study concerning the use of the Ishikawa diagram in analyzing the causes that determine errors in the evaluation of theparts precision in the machine construction field. The studied problem was"errors in the evaluation of partsprecision” and this constitutes the head of the Ishikawa diagram skeleton.All the possible, main and secondary causes that could generate the studied problem were identified. The most known Ishikawa models are 4M, 5M, 6M, the initials being in order: materials, methods, man, machines, mother nature, measurement. The paper shows the potential causes of the studied problem, which were firstly grouped in three categories, as follows: causes that lead to errors in assessing the dimensional accuracy, causes that determine errors in the evaluation of shape and position abnormalities and causes for errors in roughness evaluation. We took into account the main components of parts precision in the machine construction field. For each of the three categories of causes there were distributed potential secondary causes on groups of M (man, methods, machines, materials, environment/ medio ambiente-sp.). We opted for a new model of Ishikawa diagram, resulting from the composition of three fish skeletons corresponding to the main categories of parts accuracy.
Ectopic pregnancy in southern Iran: a statistical review of 96 cases.
Javey, H
1976-01-01
A review is presented of 96 cases of ectopic pregnacy over a 7-year period. It is noted that in recent years the incidence of this problem has increased. Inadequately diagnosed and treated pelvic inflammatory disease has been found to be the main predisposing factor (40%). The rate of extra-uterine gestation was 1:336 deliveries. In this study, previous fertility was high, and primigravidae constituted only 10.4% of the total. The effect of previous pelvic operations and pelvic infection is discussed; a statistical review of signs and symptoms is tabulated, and the management of the patient and of concomitant problems is presented.
Processes involved in solving mathematical problems
NASA Astrophysics Data System (ADS)
Shahrill, Masitah; Putri, Ratu Ilma Indra; Zulkardi, Prahmana, Rully Charitas Indra
2018-04-01
This study examines one of the instructional practices features utilized within the Year 8 mathematics lessons in Brunei Darussalam. The codes from the TIMSS 1999 Video Study were applied and strictly followed, and from the 183 mathematics problems recorded, there were 95 problems with a solution presented during the public segments of the video-recorded lesson sequences of the four sampled teachers. The analyses involved firstly, identifying the processes related to mathematical problem statements, and secondly, examining the different processes used in solving the mathematical problems for each problem publicly completed during the lessons. The findings revealed that for three of the teachers, their problem statements coded as `using procedures' ranged from 64% to 83%, while the remaining teacher had 40% of his problem statements coded as `making connections.' The processes used when solving the problems were mainly `using procedures', and none of the problems were coded as `giving results only'. Furthermore, all four teachers made use of making the relevant connections in solving the problems given to their respective students.
Neural dynamic optimization for control systems. I. Background.
Seong, C Y; Widrow, B
2001-01-01
The paper presents neural dynamic optimization (NDO) as a method of optimal feedback control for nonlinear multi-input-multi-output (MIMO) systems. The main feature of NDO is that it enables neural networks to approximate the optimal feedback solution whose existence dynamic programming (DP) justifies, thereby reducing the complexities of computation and storage problems of the classical methods such as DP. This paper mainly describes the background and motivations for the development of NDO, while the two other subsequent papers of this topic present the theory of NDO and demonstrate the method with several applications including control of autonomous vehicles and of a robot arm, respectively.
Solving quantum optimal control problems using Clebsch variables and Lin constraints
NASA Astrophysics Data System (ADS)
Delgado-Téllez, M.; Ibort, A.; Rodríguez de la Peña, T.
2018-01-01
Clebsch variables (and Lin constraints) are applied to the study of a class of optimal control problems for affine-controlled quantum systems. The optimal control problem will be modelled with controls defined on an auxiliary space where the dynamical group of the system acts freely. The reciprocity between both theories: the classical theory defined by the objective functional and the quantum system, is established by using a suitable version of Lagrange’s multipliers theorem and a geometrical interpretation of the constraints of the system as defining a subspace of horizontal curves in an associated bundle. It is shown how the solutions of the variational problem defined by the objective functional determine solutions of the quantum problem. Then a new way of obtaining explicit solutions for a family of optimal control problems for affine-controlled quantum systems (finite or infinite dimensional) is obtained. One of its main advantages, is the the use of Clebsch variables allows to compute such solutions from solutions of invariant problems that can often be computed explicitly. This procedure can be presented as an algorithm that can be applied to a large class of systems. Finally, some simple examples, spin control, a simple quantum Hamiltonian with an ‘Elroy beanie’ type classical model and a controlled one-dimensional quantum harmonic oscillator, illustrating the main features of the theory, will be discussed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Erfle, Stephen; Pound, John; Kalt, Joseph
An analysis of the response of American markets to supply crises in world oil markets is presented. It addresses four main issues: the efficiency of the operation of American oil markets during oil supply crises; the problems of both economic efficiency and social equity which arise during the American adaptation process; the propriety of the Federal government's past policy responses to these problems; and the relationship between perceptions of the problems caused by world oil crises and the real economic natures of these problems. Specifically, Chapter 1 presents a theoretical discussion of the effects of a world supply disruption onmore » the price level and supply availability of the world market oil to any consuming country including the US Chapter 2 provides a theoretical and empirical analysis of the efficiency of the adaptations of US oil product markets to higher world oil prices. Chapter 3 examines the responses of various groups of US oil firms to the alterations observed in world markets, while Chapter 4 presents a theoretical explanation for the price-lagging behavior exhibited by firms in the US oil industry. Chapter 5 addresses the nature of both real and imagined oil market problems in the US during periods of world oil market transition. (MCW)« less
[Methodology of Screening New Antibiotics: Present Status and Prospects].
Trenin, A S
2015-01-01
Due to extensive distribution of pathogen resistance to available pharmaceuticals and serious problems in the treatment of various infections and tumor diseases, the necessity of new antibiotics is urgent. The basic methodological approaches to chemical synthesis of antibiotics and screening of new antibiotics among natural products, mainly among microbial secondary metabolites, are considered in the review. Since the natural compounds are very much diverse, screening of such substances gives a good opportunity to discover antibiotics of various chemical structure and mechanism of action. Such an approach followed by chemical or biological transformation, is capable of providing the health care with new effective pharmaceuticals. The review is mainly concentrated on screening of natural products and methodological problems, such as: isolation of microbial producers from the habitats, cultivation of microorganisms producing appropriate substances, isolation and chemical characterization of microbial metabolites, identification of the biological activity of the metabolites. The main attention is paid to the problems of microbial secondary metabolism and design of new models for screening biologically active compounds. The last achievements in the field of antibiotics and most perspective approaches to future investigations are discussed. The main methodological approach to isolation and cultivation of the producers remains actual and needs constant improvement. The increase of the screening efficiency can be achieved by more rapid chemical identification of antibiotics and design of new screening models based on the biological activity detection.
A bicriteria heuristic for an elective surgery scheduling problem.
Marques, Inês; Captivo, M Eugénia; Vaz Pato, Margarida
2015-09-01
Resource rationalization and reduction of waiting lists for surgery are two main guidelines for hospital units outlined in the Portuguese National Health Plan. This work is dedicated to an elective surgery scheduling problem arising in a Lisbon public hospital. In order to increase the surgical suite's efficiency and to reduce the waiting lists for surgery, two objectives are considered: maximize surgical suite occupation and maximize the number of surgeries scheduled. This elective surgery scheduling problem consists of assigning an intervention date, an operating room and a starting time for elective surgeries selected from the hospital waiting list. Accordingly, a bicriteria surgery scheduling problem arising in the hospital under study is presented. To search for efficient solutions of the bicriteria optimization problem, the minimization of a weighted Chebyshev distance to a reference point is used. A constructive and improvement heuristic procedure specially designed to address the objectives of the problem is developed and results of computational experiments obtained with empirical data from the hospital are presented. This study shows that by using the bicriteria approach presented here it is possible to build surgical plans with very good performance levels. This method can be used within an interactive approach with the decision maker. It can also be easily adapted to other hospitals with similar scheduling conditions.
From Fake to Fiction: Young Children Learn about Writing Fiction.
ERIC Educational Resources Information Center
Taberski, Sharon
1987-01-01
Presents five strategies for helping elementary school students learn to write fiction: (1) stress topic selection; (2) use literature to teach fiction writing; (3) stress main character change or problem solving; (4) emphasize reality-based stories; and (5) encourage students to research their fiction. (SKC)
Genetic Epistemology, History of Science and Science Education.
ERIC Educational Resources Information Center
Franco, Creso; Colinvaux-de-Dominguez, Dominique
1992-01-01
Discusses Piaget's and Garcia's work that examines the common features underlying individual and historical development. Presents criticism to Piaget's position and examines the possibility of overcoming the main problems of Piaget's approach within a Piagetian framework. Looks at the consequences of the relationship between individual and…
Mapping people's views regarding the acceptability of surrogate motherhood.
Petitfils, Charlotte; Munoz Sastre, Maria Teresa; Sorum, Paul Clay; Mullet, Etienne
2017-02-01
The aims of the present study were to map French laypersons' views regarding the acceptability of maternal surrogacy and to delineate the circumstances under which surrogacy is considered, by different groups of people, as especially problematic. Participants (N = 236) were presented with a number of scenarios depicting the circumstances in which a couple has contracted with a surrogate mother and were asked to indicate the extent to which such a contract may present a moral problem. The scenarios were created by varying four factors: the type of surrogacy (traditional or gestational), the surrogate mother's level of autonomy, the family context in which the surrogate mother lives, and whether surrogacy was commercial or altruistic. Three qualitatively different personal positions were found: (a) a majority group for which surrogacy always (30%) or often (34%) presents a moral problem, (b) a minority group (14%) for which maternal surrogacy does not systematically present a moral problem, and (c) another minority group (22%) for which circumstances - mainly the mother's level of autonomy and the family context in which she lives - were completely determining.
Should psychiatrists write fiction?
Bladon, Henry
2018-04-01
This paper looks at the relationship between fiction and psychiatry. Specifically, the idea of psychiatrists as fiction writers is explored, and reference is made to various fictional texts to illustrate the problems of stigma and negative imagery. These two main areas of focus are highlighted as ones that the practice of writing fiction might address, and some potential pitfalls are discussed. The paper suggests how psychiatrists might ameliorate the present problems by incorporating their unique clinical skills and knowledge into fictional narratives. Declaration of interest None.
Numerical Analysis of Flow-Induced Vibrations in Closed Side Branches
NASA Astrophysics Data System (ADS)
KníŽat, Branislav; Troják, Michal
2011-12-01
Vibrations occuring in closed side branches connected to a main pipe are a frequent problem during pipeline system operation. At the design stage of pipeline systems, this problem is sometimes overlooked or underestimated which can later lead to the shortening of the systems life cycle or may even cause injury. The aim of this paper is a numerical analysis of the start of self-induced vibrations on the edge of a closed side branch. Calculation conditions and obtained results are presented within.
Urban simulation and gaming: Preliminary experience and perspectives, appendix F
NASA Technical Reports Server (NTRS)
Shostak, A. B.
1973-01-01
A three-month summer study of gaming, as applied to urban problems, was conducted. The results of the study are presented along with a series of recommendations aimed at guiding the warranted efforts of others to further explore the application of scientific gaming to the solution of some of America's urban problems. Three main topics are considered and are discussed in depth. These include: (1) gaming and urbanology, (2) methodology and lessons, and (3) reforms in the Cities Game.
Pyramid algorithms as models of human cognition
NASA Astrophysics Data System (ADS)
Pizlo, Zygmunt; Li, Zheng
2003-06-01
There is growing body of experimental evidence showing that human perception and cognition involves mechanisms that can be adequately modeled by pyramid algorithms. The main aspect of those mechanisms is hierarchical clustering of information: visual images, spatial relations, and states as well as transformations of a problem. In this paper we review prior psychophysical and simulation results on visual size transformation, size discrimination, speed-accuracy tradeoff, figure-ground segregation, and the traveling salesman problem. We also present our new results on graph search and on the 15-puzzle.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Singleton, Jr., Robert
This report documents the implementation of several related 1D heat flow problems in the verification package ExactPack [1]. In particular, the planar sandwich class defined in Ref. [2], as well as the classes PlanarSandwichHot, PlanarSandwichHalf, and other generalizations of the planar sandwich problem, are defined and documented here. A rather general treatment of 1D heat flow is presented, whose main results have been implemented in the class Rod1D. All planar sandwich classes are derived from the parent class Rod1D.
[Prevention and protection of workers' reproductive health].
Sivochalova, O V; Fesenko, M A; Golovaneva, G V; Morozova, T V; Fedorova, E V; Irmiakova, A R; Gromova, E Iu; Stepanian, I V; Vuĭtsik, P A
2013-01-01
The article mentiones issues of preserving and strengthening the reproductive health of women workers, dealed by researchers of the laboratory, established in 1974. It describes the developed concept of the reproductive health problems and scientific research areas, developed documents, including legislative fields, formulates main prospects of the laboratory to meet the requirements of the present moment. Noted the role of the Problem Commission "Scientific basis for the reproductive health of workers", in the work of the Scientific Council on medical and environmental issues of workers' health.
Management of a high risk epileptic patient under conscious sedation: A multidisciplinary approach
Chellathurai, Burnice Nalina Kumari; Thiagarajan, Ramakrishnan; Jayakumaran, SelvaKumar; Devadoss, Pradeep; Elavazhagan
2016-01-01
Epilepsy, characterized by the risk of recurrent seizures, is a chronic disease that afflicts about 5% of the world's population. The main dental problems associated with epileptic patients include gingival hyperplasia, minor oral injuries, tooth trauma, and prosthodontic problems, which require the dental treatment. Stress and fear are the most common triggering factors for the epilepsy in dental chair. Therefore, a more appropriate method of treating such epileptic patients may be warranted. Conscious sedation is a technique of providing good anesthesia and analgesia to patients, the main advantage of which is the patient's rapid return to presentation levels. Midazolam used as a sedative agent has anticonvulsant properties. This case report highlights a case requiring multiple dental procedures carried out in a high risk epileptic patient under conscious sedation. PMID:27041847
Maneuvering Rotorcraft Noise Prediction: A New Code for a New Problem
NASA Technical Reports Server (NTRS)
Brentner, Kenneth S.; Bres, Guillaume A.; Perez, Guillaume; Jones, Henry E.
2002-01-01
This paper presents the unique aspects of the development of an entirely new maneuver noise prediction code called PSU-WOPWOP. The main focus of the code is the aeroacoustic aspects of the maneuver noise problem, when the aeromechanical input data are provided (namely aircraft and blade motion, blade airloads). The PSU-WOPWOP noise prediction capability was developed for rotors in steady and transient maneuvering flight. Featuring an object-oriented design, the code allows great flexibility for complex rotor configuration and motion (including multiple rotors and full aircraft motion). The relative locations and number of hinges, flexures, and body motions can be arbitrarily specified to match the any specific rotorcraft. An analysis of algorithm efficiency is performed for maneuver noise prediction along with a description of the tradeoffs made specifically for the maneuvering noise problem. Noise predictions for the main rotor of a rotorcraft in steady descent, transient (arrested) descent, hover and a mild "pop-up" maneuver are demonstrated.
Continuum Thermodynamics - Part II: Applications and Examples
NASA Astrophysics Data System (ADS)
Albers, Bettina; Wilmanski, Krzysztof
The intention by writing Part II of the book on continuum thermodynamics was the deepening of some issues covered in Part I as well as a development of certain skills in dealing with practical problems of oscopic processes. However, the main motivation for this part is the presentation of main facets of thermodynamics which appear when interdisciplinary problems are considered. There are many monographs on the subjects of solid mechanics and thermomechanics, on fluid mechanics and on coupled fields but most of them cover only special problems in great details which are characteristic for the chosen field. It is rather seldom that relations between these fields are discussed. This concerns, for instance, large deformations of the skeleton of porous materials with diffusion (e.g. lungs), couplings of deformable particles with the fluid motion in suspensions, couplings of adsorption processes and chemical reactions in immiscible mixtures with diffusion, various multi-component aspects of the motion, e.g. of avalanches, such as segregation processes, etc...
Dorozhkova, I R; Freĭman, G E; Moroz, A M
2007-01-01
The paper presents the main points of the authors' own concept of the centralization of mycobacteriological service in large towns of the Russian Federation. The main points of step-by-step organizational and methodological measures required to solve this problem are described in detail. Consecutive measures to realize the proposed mycobacteriological service centralization model originated in January 2004 on a model of the Moscow Eastern Administrative District with 1380 thousand inhabitants are described.
Water resources in the next millennium
NASA Astrophysics Data System (ADS)
Wood, Warren
As pressures from an exponentially increasing population and economic expectations rise against a finite water resource, how do we address management? This was the main focus of the Dubai International Conference on Water Resources and Integrated Management in the Third Millennium in Dubai, United Arab Emirates, 2-6 February 2002. The invited forum attracted an eclectic mix of international thinkers from five continents. Presentations and discussions on hydrology policy/property rights, and management strategies focused mainly on problems of water supply, irrigation, and/or ecosystems.
An Optimization-based Atomistic-to-Continuum Coupling Method
DOE Office of Scientific and Technical Information (OSTI.GOV)
Olson, Derek; Bochev, Pavel B.; Luskin, Mitchell
2014-08-21
In this paper, we present a new optimization-based method for atomistic-to-continuum (AtC) coupling. The main idea is to cast the latter as a constrained optimization problem with virtual Dirichlet controls on the interfaces between the atomistic and continuum subdomains. The optimization objective is to minimize the error between the atomistic and continuum solutions on the overlap between the two subdomains, while the atomistic and continuum force balance equations provide the constraints. Separation, rather then blending of the atomistic and continuum problems, and their subsequent use as constraints in the optimization problem distinguishes our approach from the existing AtC formulations. Finally,more » we present and analyze the method in the context of a one-dimensional chain of atoms modeled using a linearized two-body potential with next-nearest neighbor interactions.« less
Equivalent source modeling of the core magnetic field using magsat data
NASA Technical Reports Server (NTRS)
Mayhew, M. A.; Estes, R. H.
1983-01-01
Experiments are carried out on fitting the main field using different numbers of equivalent sources arranged in equal area at fixed radii at and inside the core-mantle boundary. In fixing the radius for a given series of runs, the convergence problems that result from the extreme nonlinearity of the problem when dipole positions are allowed to vary are avoided. Results are presented from a comparison between this approach and the standard spherical harmonic approach for modeling the main field in terms of accuracy and computational efficiency. The modeling of the main field with an equivalent dipole representation is found to be comparable to the standard spherical harmonic approach in accuracy. The 32 deg dipole density (42 dipoles) corresponds approximately to an eleventh degree/order spherical harmonic expansion (143 parameters), whereas the 21 dipole density (92 dipoles) corresponds to approximately a seventeenth degree and order expansion (323 parameters). It is pointed out that fixing the dipole positions results in rapid convergence of the dipole solutions for single-epoch models.
van Assema, P; Steenbakkers, M; Rademaker, C; Brug, J
2005-06-01
As part of a course teaching household budgeting, a nutrition education intervention was provided to people with financial problems. The present study aimed at assess the effects of this intervention on the nutritional quality of their main meal and fruit intake, and to collect process information on intervention participation, reactions and opinions. For the effect study, a quasi-experimental multiple pre and post-test control group design was used. Telephone dietary recalls were conducted with 35 people in the intervention group and 39 people in the control group. Observations, personal interviews and written questionnaires were used to collect the process data. A significant reduction in saturated fat intake during the mail meal was found. Also, an intervention effect was found for fruit juice consumption, but not for daily fruit intake or vegetable intake during main meal occasions. The process data revealed some improvements that should be made to the intervention, such as providing more individualized information and tailored recipes.
Menopause, a Self Care Manual.
ERIC Educational Resources Information Center
Lopez, Maria Cristina; And Others
Written for women from the three main cultural groups in New Mexico (Native American, Hispanic, and Anglo), this pamphlet discusses the causes and symptoms, some remedies for the symptoms of menopause, and presents ideas for organizing support groups to help middle-aged women and their families deal with menopausal problems. Explanations of the…
A Survey and Empirical Study of Virtual Reference Service in Academic Libraries
ERIC Educational Resources Information Center
Mu, Xiangming; Dimitroff, Alexandra; Jordan, Jeanette; Burclaff, Natalie
2011-01-01
Virtual Reference Services (VRS) have high user satisfaction. The main problem is its low usage. We surveyed 100 academic library web sites to understand how VRS are presented. We then conducted a usability study to further test an active VRS model regarding its effectiveness.
Teacher Professional Development as a Scientific Problem in Comparative Pedagogics
ERIC Educational Resources Information Center
Avshenyuk, Natalia; Kostina, Lyudmyla
2014-01-01
Cogent argument for better understanding of the take-up of teacher professional development through understanding the definition itself has been presented. The main constituents of the definition with reference to different sources of information in psychology, philosophy and pedagogics have been analyzed. To make the research more logical, the…
Automation of University Libraries in Kerala: Status, Problems and Prospects
ERIC Educational Resources Information Center
Suku, J.; Pillai, Mini G.
2005-01-01
This paper discusses the present scenario of automation activities of university libraries in Kerala. The survey findings mainly cover various aspects of library automation such as information technology infrastructure, in-house activities, information services and their usage, manpower development, and budget. The paper briefly describes the role…
[Ocular findings in patients with Steinert myotonic dystrophy].
Markowska, Elzbieta; Zalewska, Renata; Mariak, Zofia; Wojnar, Małgorzata
2006-01-01
The authors present one of many myotonic dystrophies: Steinert myotonic dystrophy (Steinert disease), which is a disease occuring seldom, and causing a lot of problems during the diagnostic and treatment process. Genetic factors, results of the histopathology tests, main clinical symptoms, particularly ophtalmic manifestation are described in this article.
Administrative Law: The Hidden Comparative Law Course.
ERIC Educational Resources Information Center
Strauss, Peter L.
1996-01-01
Argues that the main contribution of the Administrative Law course to law students is that it presents problems which contrast with those of the standard court-centered curriculum and can illuminate other areas of law, repeatedly confronting students with doctrinal differences. Offers several examples from civil procedure, constitutional law, and…
Personalisation in Web-Based Learning Environments
ERIC Educational Resources Information Center
Santally, Mohammad Issack; Alain, Senteni
2006-01-01
It is postulated that one of the main problems with e-learning environments is their lack of personalisation. This article presents a comprehensive review of the current work in the field and proposes a framework for research in promoting personalisation in Web-based learning environments. The concepts of adaptability, adaptivity and the…
ERIC Educational Resources Information Center
Linacre, John Michael
Various methods of estimating main effects from ordinal data are presented and contrasted. Problems discussed include: (1) at what level to accumulate ordinal data into linear measures; (2) how to maintain scaling across analyses; and (3) the inevitable confounding of within cell variance with measurement error. An example shows three methods of…
A Non-Intuitionist's Approach To The Interpretation Problem Of Quantum Mechanics
NASA Astrophysics Data System (ADS)
Grelland, Hans Herlof
2005-02-01
A philosophy of physics called "linguistic empiricism" is presented and applied to the interpretation problem of quantum mechanics. This philosophical position is based on the works of Jacques Derrida. The main propositions are (i) that meaning, included the meaning attached to observations, are language-dependent and (ii) that mathematics in physics should be considered as a proper language, not necessary translatable to a more basic language of intuition and immediate experience. This has fundamental implications for quantum mechanics, which is a mathematically coherent and consistent theory; its interpretation problem is associated with its lack of physical images expressible in ordinary language.
NASA Astrophysics Data System (ADS)
Jayanthi, Aditya; Coker, Christopher
2016-11-01
In the last decade, CFD simulations have transitioned from the stage where they are used to validate the final designs to the main stream development of products driven by the simulation. However, there are still niche areas of applications liking oiling simulations, where the traditional CFD simulation times are probative to use them in product development and have to rely on experimental methods, which are expensive. In this paper a unique example of Sprocket-Chain simulation will be presented using nanoFluidx a commercial SPH code developed by FluiDyna GmbH and Altair Engineering. The grid less nature of the of SPH method has inherent advantages in the areas of application with complex geometry which pose severe challenge to classical finite volume CFD methods due to complex moving geometries, moving meshes and high resolution requirements leading to long simulation times. The simulations times using nanoFluidx can be reduced from weeks to days allowing the flexibility to run more simulation and can be in used in main stream product development. The example problem under consideration is a classical Multiphysics problem and a sequentially coupled solution of Motion Solve and nanoFluidX will be presented. This abstract is replacing DFD16-2016-000045.
Recognizing problem video game use.
Porter, Guy; Starcevic, Vladan; Berle, David; Fenech, Pauline
2010-02-01
It has been increasingly recognized that some people develop problem video game use, defined here as excessive use of video games resulting in various negative psychosocial and/or physical consequences. The main objectives of the present study were to identify individuals with problem video game use and compare them with those without problem video game use on several variables. An international, anonymous online survey was conducted, using a questionnaire with provisional criteria for problem video game use, which the authors have developed. These criteria reflect the crucial features of problem video game use: preoccupation with and loss of control over playing video games and multiple adverse consequences of this activity. A total of 1945 survey participants completed the survey. Respondents who were identified as problem video game users (n = 156, 8.0%) differed significantly from others (n = 1789) on variables that provided independent, preliminary validation of the provisional criteria for problem video game use. They played longer than planned and with greater frequency, and more often played even though they did not want to and despite believing that they should not do it. Problem video game users were more likely to play certain online role-playing games, found it easier to meet people online, had fewer friends in real life, and more often reported excessive caffeine consumption. People with problem video game use can be identified by means of a questionnaire and on the basis of the present provisional criteria, which require further validation. These findings have implications for recognition of problem video game users among individuals, especially adolescents, who present to mental health services. Mental health professionals need to acknowledge the public health significance of the multiple negative consequences of problem video game use.
Summary of the 2014 Sandia V&V Challenge Workshop
Schroeder, Benjamin B.; Hu, Kenneth T.; Mullins, Joshua Grady; ...
2016-02-19
A discussion of the five responses to the 2014 Sandia Verification and Validation (V&V) Challenge Problem, presented within this special issue, is provided hereafter. Overviews of the challenge problem workshop, workshop participants, and the problem statement are also included. Brief summations of teams' responses to the challenge problem are provided. Issues that arose throughout the responses that are deemed applicable to the general verification, validation, and uncertainty quantification (VVUQ) community are the main focal point of this paper. The discussion is oriented and organized into big picture comparison of data and model usage, VVUQ activities, and differentiating conceptual themes behindmore » the teams' VVUQ strategies. Significant differences are noted in the teams' approaches toward all VVUQ activities, and those deemed most relevant are discussed. Beyond the specific details of VVUQ implementations, thematic concepts are found to create differences among the approaches; some of the major themes are discussed. Lastly, an encapsulation of the key contributions, the lessons learned, and advice for the future are presented.« less
Hou, Shibing; Wu, Jiang; Qin, Yufei; Xu, Zhenming
2010-07-01
Electrostatic separation is an effective and environmentally friendly method for recycling waste printed circuit board (PCB) by several kinds of electrostatic separators. However, some notable problems have been detected in its applications and cannot be efficiently resolved by optimizing the separation process. Instead of the separator itself, these problems are mainly caused by some external factors such as the nonconductive powder (NP) and the superficial moisture of feeding granule mixture. These problems finally lead to an inefficient separation. In the present research, the impacts of these external factors were investigated and a robust design was built to optimize the process and to weaken the adverse impact. A most robust parameter setting (25 kv, 80 rpm) was concluded from the experimental design. In addition, some theoretical methods, including cyclone separation, were presented to eliminate these problems substantially. This will contribute to efficient electrostatic separation of waste PCB and make remarkable progress for industrial applications.
Silva, Adão; Gameiro, Atílio
2014-01-01
We present in this work a low-complexity algorithm to solve the sum rate maximization problem in multiuser MIMO broadcast channels with downlink beamforming. Our approach decouples the user selection problem from the resource allocation problem and its main goal is to create a set of quasiorthogonal users. The proposed algorithm exploits physical metrics of the wireless channels that can be easily computed in such a way that a null space projection power can be approximated efficiently. Based on the derived metrics we present a mathematical model that describes the dynamics of the user selection process which renders the user selection problem into an integer linear program. Numerical results show that our approach is highly efficient to form groups of quasiorthogonal users when compared to previously proposed algorithms in the literature. Our user selection algorithm achieves a large portion of the optimum user selection sum rate (90%) for a moderate number of active users. PMID:24574928
Finite-time H∞ control for linear continuous system with norm-bounded disturbance
NASA Astrophysics Data System (ADS)
Meng, Qingyi; Shen, Yanjun
2009-04-01
In this paper, the definition of finite-time H∞ control is presented. The system under consideration is subject to time-varying norm-bounded exogenous disturbance. The main aim of this paper is focused on the design a state feedback controller which ensures that the closed-loop system is finite-time bounded (FTB) and reduces the effect of the disturbance input on the controlled output to a prescribed level. A sufficient condition is presented for the solvability of this problem, which can be reduced to a feasibility problem involving linear matrix inequalities (LMIs). A detailed solving method is proposed for the restricted linear matrix inequalities. Finally, examples are given to show the validity of the methodology.
A first experience with a Smart bus for improving public transportation
NASA Astrophysics Data System (ADS)
Tostado, R.; Rovirosa, A.; Velázquez, J. L.; Castillo, E.; Cervantes, O.
2017-09-01
An alternative to optimize transportation services in the city of Puebla is presented. Main problems tackled to provide advanced transport applications in a Smart City, are described and some available solutions in other countries are analyzed. As a case of study, the challenges for designing and developing a mobile application oriented to users of the buses provided by Universidad de las Américas Puebla (UDLAP) are presented. Users include students, as well as faculty members and administrative employees. The application provides an innovative way of tracking, in real time, movements of the UDLAP transportation buses through the city of Puebla in Mexico. Modeling and technical implementation solved problems are presented and future steps for extending those services to the city of Puebla are also suggested.
Infrared stereo calibration for unmanned ground vehicle navigation
NASA Astrophysics Data System (ADS)
Harguess, Josh; Strange, Shawn
2014-06-01
The problem of calibrating two color cameras as a stereo pair has been heavily researched and many off-the-shelf software packages, such as Robot Operating System and OpenCV, include calibration routines that work in most cases. However, the problem of calibrating two infrared (IR) cameras for the purposes of sensor fusion and point could generation is relatively new and many challenges exist. We present a comparison of color camera and IR camera stereo calibration using data from an unmanned ground vehicle. There are two main challenges in IR stereo calibration; the calibration board (material, design, etc.) and the accuracy of calibration pattern detection. We present our analysis of these challenges along with our IR stereo calibration methodology. Finally, we present our results both visually and analytically with computed reprojection errors.
Preconditioned Mixed Spectral Element Methods for Elasticity and Stokes Problems
NASA Technical Reports Server (NTRS)
Pavarino, Luca F.
1996-01-01
Preconditioned iterative methods for the indefinite systems obtained by discretizing the linear elasticity and Stokes problems with mixed spectral elements in three dimensions are introduced and analyzed. The resulting stiffness matrices have the structure of saddle point problems with a penalty term, which is associated with the Poisson ratio for elasticity problems or with stabilization techniques for Stokes problems. The main results of this paper show that the convergence rate of the resulting algorithms is independent of the penalty parameter, the number of spectral elements Nu and mildly dependent on the spectral degree eta via the inf-sup constant. The preconditioners proposed for the whole indefinite system are block-diagonal and block-triangular. Numerical experiments presented in the final section show that these algorithms are a practical and efficient strategy for the iterative solution of the indefinite problems arising from mixed spectral element discretizations of elliptic systems.
Regularizing the r-mode Problem for Nonbarotropic Relativistic Stars
NASA Technical Reports Server (NTRS)
Lockitch, Keith H.; Andersson, Nils; Watts, Anna L.
2004-01-01
We present results for r-modes of relativistic nonbarotropic stars. We show that the main differential equation, which is formally singular at lowest order in the slow-rotation expansion, can be regularized if one considers the initial value problem rather than the normal mode problem. However, a more physically motivated way to regularize the problem is to include higher order terms. This allows us to develop a practical approach for solving the problem and we provide results that support earlier conclusions obtained for uniform density stars. In particular, we show that there will exist a single r-mode for each permissible combination of 1 and m. We discuss these results and provide some caveats regarding their usefulness for estimates of gravitational-radiation reaction timescales. The close connection between the seemingly singular relativistic r-mode problem and issues arising because of the presence of co-rotation points in differentially rotating stars is also clarified.
Shen, Peiping; Zhang, Tongli; Wang, Chunfeng
2017-01-01
This article presents a new approximation algorithm for globally solving a class of generalized fractional programming problems (P) whose objective functions are defined as an appropriate composition of ratios of affine functions. To solve this problem, the algorithm solves an equivalent optimization problem (Q) via an exploration of a suitably defined nonuniform grid. The main work of the algorithm involves checking the feasibility of linear programs associated with the interesting grid points. It is proved that the proposed algorithm is a fully polynomial time approximation scheme as the ratio terms are fixed in the objective function to problem (P), based on the computational complexity result. In contrast to existing results in literature, the algorithm does not require the assumptions on quasi-concavity or low-rank of the objective function to problem (P). Numerical results are given to illustrate the feasibility and effectiveness of the proposed algorithm.
NASA Astrophysics Data System (ADS)
Dzikuć, Maciej; Adamczyk, Janusz; Piwowar, Arkadiusz
2017-07-01
According to the report of the World Health Organization (WHO) on the list of 50 cities with the most polluted air in Europe as many as 33 are located in Poland. All the cities that are on the list exceed the maximum concentration of dust recommended by WHO at least three times. In the Lubuskie Province there is a very serious problem of maintaining good air quality. The air in Poland is among the most polluted in the European Union and this also applies to less-industrialized areas, such as Lubuskie, where the concentration levels of substances hazardous to human health and the environment are recorded as exceeded. One of the main factors affecting the poor air quality in the region is road transport. It is not just a problem near roads with heavy traffic, but also applies to the cities, where there is a large movement of cars, which are often old and do not meet current environmental standards. This article aims to identify the main sources of low emission from road transport and identify potential solutions to help reduce emission from this sector. The actions aimed at limiting low emission from road transport can bring a significant positive ecological effect. The aim of this article is to review one of the main sources of low emission in the province of Lubuskie, which is transportation. Moreover, the authors of the paper indicate the main problems associated with the emission coming from road transport and describe the possibilities for opportunities to reduce pollution from this sector. In addition, the article presents the three-scenario simulation of annual emissions from passenger cars that could take place in 2020.
Measurements of Solar Ultraviolet Radiation Exposure at Work and at Leisure in Danish Workers.
Grandahl, Kasper; Eriksen, Paul; Ibler, Kristina Sophie; Bonde, Jens Peter; Mortensen, Ole Steen
2018-03-30
Exposure to solar ultraviolet radiation is the main cause of skin cancer and may well present an occupational health and safety problem. In Denmark, skin cancer is a common disease in the general population, but detailed data on solar ultraviolet radiation exposure among outdoor workers are lacking. The aim of this study was to provide objective measurements of solar ultraviolet radiation exposure on working days and at leisure and compare levels of exposure between groups of mainly outdoor, equal-parts-outdoor-and-indoor and indoor workers. To this end, UV-B dosimeters with an aluminum gallium nitride (AlGaN) photodiode detector were used to measure the solar ultraviolet radiation exposure of 457 workers in the Danish summer season. Presented as semi-annual standard erythemal dose (SED) on working days, respectively, at leisure, the results are for mainly outdoor workers 214.2 SED and 64.8 SED, equal-parts-outdoor-and-indoor workers 131.4 SED and 64.8 SED, indoor workers 55.8 SED and 57.6 SED. The daily SED by month is significantly different (α = 0.05) between mainly outdoor, equal-parts-outdoor-and-indoor and indoor workers and across professional groups; some of which are exposed at very high levels that is roofers 361.8 SED. These findings substantiate that exposure to solar ultraviolet radiation is indeed an occupational health and safety problem in Denmark. © 2018 The Authors. Photochemistry and Photobiology published by Wiley Periodicals, Inc. on behalf of American Society for Photobiology.
Reach on sound: a key to object permanence in visually impaired children.
Fazzi, Elisa; Signorini, Sabrina Giovanna; Bomba, Monica; Luparia, Antonella; Lanners, Josée; Balottin, Umberto
2011-04-01
The capacity to reach an object presented through sound clue indicates, in the blind child, the acquisition of object permanence and gives information over his/her cognitive development. To assess cognitive development in congenitally blind children with or without multiple disabilities. Cohort study. Thirty-seven congenitally blind subjects (17 with associated multiple disabilities, 20 mainly blind) were enrolled. We used Bigelow's protocol to evaluate "reach on sound" capacity over time (at 6, 12, 18, 24, and 36 months), and a battery of clinical, neurophysiological and cognitive instruments to assess clinical features. Tasks n.1 to 5 were acquired by most of the mainly blind children by 12 months of age. Task 6 coincided with a drop in performance, and the acquisition of the subsequent tasks showed a less agehomogeneous pattern. In blind children with multiple disabilities, task acquisition rates were lower, with the curves dipping in relation to the more complex tasks. The mainly blind subjects managed to overcome Fraiberg's "conceptual problem"--i.e., they acquired the ability to attribute an external object with identity and substance even when it manifested its presence through sound only--and thus developed the ability to reach an object presented through sound. Instead, most of the blind children with multiple disabilities presented poor performances on the "reach on sound" protocol and were unable, before 36 months of age, to develop the strategies needed to resolve Fraiberg's "conceptual problem". Copyright © 2011 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Fazayeli, Saeed; Eydi, Alireza; Kamalabadi, Isa Nakhai
2017-07-01
Nowadays, organizations have to compete with different competitors in regional, national and international levels, so they have to improve their competition capabilities to survive against competitors. Undertaking activities on a global scale requires a proper distribution system which could take advantages of different transportation modes. Accordingly, the present paper addresses a location-routing problem on multimodal transportation network. The introduced problem follows four objectives simultaneously which form main contribution of the paper; determining multimodal routes between supplier and distribution centers, locating mode changing facilities, locating distribution centers, and determining product delivery tours from the distribution centers to retailers. An integer linear programming is presented for the problem, and a genetic algorithm with a new chromosome structure proposed to solve the problem. Proposed chromosome structure consists of two different parts for multimodal transportation and location-routing parts of the model. Based on published data in the literature, two numerical cases with different sizes generated and solved. Also, different cost scenarios designed to better analyze model and algorithm performance. Results show that algorithm can effectively solve large-size problems within a reasonable time which GAMS software failed to reach an optimal solution even within much longer times.
NASA Astrophysics Data System (ADS)
Fazayeli, Saeed; Eydi, Alireza; Kamalabadi, Isa Nakhai
2018-07-01
Nowadays, organizations have to compete with different competitors in regional, national and international levels, so they have to improve their competition capabilities to survive against competitors. Undertaking activities on a global scale requires a proper distribution system which could take advantages of different transportation modes. Accordingly, the present paper addresses a location-routing problem on multimodal transportation network. The introduced problem follows four objectives simultaneously which form main contribution of the paper; determining multimodal routes between supplier and distribution centers, locating mode changing facilities, locating distribution centers, and determining product delivery tours from the distribution centers to retailers. An integer linear programming is presented for the problem, and a genetic algorithm with a new chromosome structure proposed to solve the problem. Proposed chromosome structure consists of two different parts for multimodal transportation and location-routing parts of the model. Based on published data in the literature, two numerical cases with different sizes generated and solved. Also, different cost scenarios designed to better analyze model and algorithm performance. Results show that algorithm can effectively solve large-size problems within a reasonable time which GAMS software failed to reach an optimal solution even within much longer times.
Multi-Robot Coalitions Formation with Deadlines: Complexity Analysis and Solutions
2017-01-01
Multi-robot task allocation is one of the main problems to address in order to design a multi-robot system, very especially when robots form coalitions that must carry out tasks before a deadline. A lot of factors affect the performance of these systems and among them, this paper is focused on the physical interference effect, produced when two or more robots want to access the same point simultaneously. To our best knowledge, this paper presents the first formal description of multi-robot task allocation that includes a model of interference. Thanks to this description, the complexity of the allocation problem is analyzed. Moreover, the main contribution of this paper is to provide the conditions under which the optimal solution of the aforementioned allocation problem can be obtained solving an integer linear problem. The optimal results are compared to previous allocation algorithms already proposed by the first two authors of this paper and with a new method proposed in this paper. The results obtained show how the new task allocation algorithms reach up more than an 80% of the median of the optimal solution, outperforming previous auction algorithms with a huge reduction of the execution time. PMID:28118384
Multi-Robot Coalitions Formation with Deadlines: Complexity Analysis and Solutions.
Guerrero, Jose; Oliver, Gabriel; Valero, Oscar
2017-01-01
Multi-robot task allocation is one of the main problems to address in order to design a multi-robot system, very especially when robots form coalitions that must carry out tasks before a deadline. A lot of factors affect the performance of these systems and among them, this paper is focused on the physical interference effect, produced when two or more robots want to access the same point simultaneously. To our best knowledge, this paper presents the first formal description of multi-robot task allocation that includes a model of interference. Thanks to this description, the complexity of the allocation problem is analyzed. Moreover, the main contribution of this paper is to provide the conditions under which the optimal solution of the aforementioned allocation problem can be obtained solving an integer linear problem. The optimal results are compared to previous allocation algorithms already proposed by the first two authors of this paper and with a new method proposed in this paper. The results obtained show how the new task allocation algorithms reach up more than an 80% of the median of the optimal solution, outperforming previous auction algorithms with a huge reduction of the execution time.
Sensibility study in a flexible job shop scheduling problem
NASA Astrophysics Data System (ADS)
Curralo, Ana; Pereira, Ana I.; Barbosa, José; Leitão, Paulo
2013-10-01
This paper proposes the impact assessment of the jobs order in the optimal time of operations in a Flexible Job Shop Scheduling Problem. In this work a real assembly cell was studied: the AIP-PRIMECA cell at the Université de Valenciennes et du Hainaut-Cambrésis, in France, which is considered as a Flexible Job Shop problem. The problem consists in finding the machines operations schedule, taking into account the precedence constraints. The main objective is to minimize the batch makespan, i.e. the finish time of the last operation completed in the schedule. Shortly, the present study consists in evaluating if the jobs order affects the optimal time of the operations schedule. The genetic algorithm was used to solve the optimization problem. As a conclusion, it's assessed that the jobs order influence the optimal time.
Numerical approach to constructing the lunar physical libration: results of the initial stage
NASA Astrophysics Data System (ADS)
Zagidullin, A.; Petrova, N.; Nefediev, Yu.; Usanin, V.; Glushkov, M.
2015-10-01
So called "main problem" it is taken as a model to develop the numerical approach in the theory of lunar physical libration. For the chosen model, there are both a good methodological basis and results obtained at the Kazan University as an outcome of the analytic theory construction. Results of the first stage in numerical approach are presented in this report. Three main limitation are taken to describe the main problem: -independent consideration of orbital and rotational motion of the Moon; - a rigid body model for the lunar body is taken and its dynamical figure is described by inertia ellipsoid, which gives us the mass distribution inside the Moon. - only gravitational interaction with the Earth and the Sun is considered. Development of selenopotential is limited on this stage by the second harmonic only. Inclusion of the 3-rd and 4-th order harmonics is the nearest task for the next stage.The full solution of libration problem consists of removing the below specified limitations: consideration of the fine effects, caused by planet perturbations, by visco-elastic properties of the lunar body, by the presence of a two-layer lunar core, by the Earth obliquity, by ecliptic rotation, if it is taken as a reference plane.
Biotechnological possibilities for waste tyre-rubber treatment.
Holst, O; Stenberg, B; Christiansson, M
1998-01-01
Every year large amounts of spent rubber material, mainly from rubber tyres, are discarded. Of the annual total global production of rubber material, which amounts to 16-17 million tonnes, approximately 65% is used for the production of tyres. About 250 millions spent car tyres are generated yearly in USA only. This huge amount of waste rubber material is an environmental problem of great concern. Various ways to remediate the problem have been proposed. Among these are road fillings and combustion in kilns. Spent tyres, however, comprise valuable material that could be recycled if a proper technique can be developed. One way of recycling old tyres is to blend ground spent rubber with virgin material followed by vulcanization. The main obstacle to this recycling is bad adhesion between the crumb and matrix of virgin rubber material due to little formation of interfacial sulphur crosslinks. Micro-organisms able to break sulphur-sulphur and sulphur-carbon bonds can be used to devulcanize waste rubber in order to make polymer chains on the surface more flexible and facilitate increased binding upon vulcanization. Several species belonging to both Bacteria and Archaea have this ability. Mainly sulphur oxidizing species, such as different species of the genus Thiobacillus and thermoacidophiles of the order of Sulfolobales, have been studied in this context. The present paper will give a background to the problem and an overview of the biotechnological possibilities for solutions of waste rubber as an environmental problem, focusing on microbial desulphurization.
Transport synthetic acceleration for long-characteristics assembly-level transport problems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zika, M.R.; Adams, M.L.
2000-02-01
The authors apply the transport synthetic acceleration (TSA) scheme to the long-characteristics spatial discretization for the two-dimensional assembly-level transport problem. This synthetic method employs a simplified transport operator as its low-order approximation. Thus, in the acceleration step, the authors take advantage of features of the long-characteristics discretization that make it particularly well suited to assembly-level transport problems. The main contribution is to address difficulties unique to the long-characteristics discretization and produce a computationally efficient acceleration scheme. The combination of the long-characteristics discretization, opposing reflecting boundary conditions (which are present in assembly-level transport problems), and TSA presents several challenges. The authorsmore » devise methods for overcoming each of them in a computationally efficient way. Since the boundary angular data exist on different grids in the high- and low-order problems, they define restriction and prolongation operations specific to the method of long characteristics to map between the two grids. They implement the conjugate gradient (CG) method in the presence of opposing reflection boundary conditions to solve the TSA low-order equations. The CG iteration may be applied only to symmetric positive definite (SPD) matrices; they prove that the long-characteristics discretization yields an SPD matrix. They present results of the acceleration scheme on a simple test problem, a typical pressurized water reactor assembly, and a typical boiling water reactor assembly.« less
NASA Astrophysics Data System (ADS)
Wahid, Fathul; Teduh Dirgahayu, Raden; Hamzah, Almed; Setiaji, Hari
2018-03-01
The clear majority of previous studies have found that the absence of information systems to properly manage data is one of the main challenges in improving public health management. The present study offers an alternate perspective, revealing other emerging problems in cases where there are many information systems in place but without sufficient orchestration. The national government of Indonesia has been coercive in its implementation of various information systems without involving users at public health facilities, which has created many problems on the ground. The problems identified relate to the quality of the disconnected information systems currently in use, the lack of human resource development, unclear procedures, uncoordinated reports and the absence of an incentive scheme. The present study also highlights some practical implications, including the use of a more holistic perspective in designing and developing an integrated public health information infrastructure.
NASA Astrophysics Data System (ADS)
Tattoli, F.; Pierron, F.; Rotinat, R.; Casavola, C.; Pappalettere, C.
2011-01-01
One of the main problems in welding is the microstructural transformation within the area affected by the thermal history. The resulting heterogeneous microstructure within the weld nugget and the heat affected zones is often associated with changes in local material properties. The present work deals with the identification of material parameters governing the elasto—plastic behaviour of the fused and heat affected zones as well as the base material for titanium hybrid welded joints (Ti6Al4V alloy). The material parameters are identified from heterogeneous strain fields with the Virtual Fields Method. This method is based on a relevant use of the principle of virtual work and it has been shown to be useful and much less time consuming than classical finite element model updating approaches applied to similar problems. The paper will present results and discuss the problem of selection of the weld zones for the identification.
Problem-based learning in laboratory medicine resident education: a satisfaction survey.
Lepiller, Quentin; Solis, Morgane; Velay, Aurélie; Gantner, Pierre; Sueur, Charlotte; Stoll-Keller, Françoise; Barth, Heidi; Fafi-Kremer, Samira
2017-04-01
Theoretical knowledge in biology and medicine plays a substantial role in laboratory medicine resident education. In this study, we assessed the contribution of problem-based learning (PBL) to improve the training of laboratory medicine residents during their internship in the department of virology, Strasbourg University Hospital, France. We compared the residents' satisfaction regarding an educational program based on PBL and a program based on lectures and presentations. PBL induced a high level of satisfaction (100%) among residents compared to lectures and presentations (53%). The main advantages of this technique were to create a situational interest regarding virological problems, to boost the residents' motivation and to help them identify the most relevant learning objectives in virology. However, it appears pertinent to educate the residents in appropriate bibliographic research techniques prior to PBL use and to monitor their learning by regular formative assessment sessions.
STS-38 Space Shuttle mission report
NASA Technical Reports Server (NTRS)
Camp, David W.; Germany, D. M.; Nicholson, Leonard S.
1991-01-01
The STS-38 Space Shuttle Program Mission Report contains a summary of the vehicle subsystem activities on this thirty-seventh flight of the Space Shuttle and the seventh flight of the Orbiter vehicle Atlantis (OV-104). In addition to the Atlantis vehicle, the flight vehicle consisted of an External Tank (ET) (designated as ET-40/LWT-33), three Space Shuttle main engines (SSME's) (serial numbers 2019, 2022, 2027), and two Solid Rocket Boosters (SRB's), designated as BI-039. The STS-38 mission was a classified Department of Defense mission, and as much, the classified portions of the mission are not presented in this report. The sequence of events for this mission is shown. The significant problems that occurred in the Space Shuttle Orbiter subsystem during the mission are summarized and the official problem tracking list is presented. In addition, each Space Shuttle Orbiter problem is cited in the subsystem discussion.
ERIC Educational Resources Information Center
Muris, Peter
2006-01-01
Anxiety disorders are among the most prevalent psychiatric problems in children and adolescents. The present article summarizes the main evidence that has accumulated on the pathogenesis of childhood anxiety disorders during the past two decades. Various risk and vulnerability factors (e.g., genetics, behavioral inhibition, disgust sensitivity,…
ERIC Educational Resources Information Center
Zapotichna, Maria
2015-01-01
In the article the period of traditional education of aboriginal people in Canada in precolonial times has been presented. The main objectives have been defined as theoretical analysis of scientific and pedagogical literature, which highlights different aspects of the problem under research; characteristic of theoretical framework in understanding…
Citizen-Consumers, Social Markets and the Reform of Public Services
ERIC Educational Resources Information Center
Peters, Michael A.
2004-01-01
In a paper presented in July 2003 to Labour's National Policy Forum, the main policy-making body in the United Kingdom, Liam Byrne, a research associate of the Social Market Foundation, forecast the major problems that will face government in Britain in 2020. As reported in the "Guardian" (9 August 2003): "British national…
A Program for Job Related Reading Training.
ERIC Educational Resources Information Center
Fox, Lynn C.; Sticht, Thomas G.
A functional job-related reading program was developed to cope with literacy problems of Army personnel; the program involves students who work individually on instructional worksheets in six main modules, each designed to teach a specific job-related reading task. This paper presents an overview of background research for the program, which was…
ERIC Educational Resources Information Center
Martorana, S. V., Ed.; And Others
This publication contains the text of the main presentations and the highlights of discussion groups from the Ninth Annual Pennsylvania Conference on Postsecondary Occupational Education. The conference theme was "Programming Postsecondary Occupational Education." Ewald Nyquist, the first speaker, delineated the problems faced by…
Directions in Mental Health Counseling, 1992.
ERIC Educational Resources Information Center
Directions in Mental Health Counseling, 1992
1992-01-01
A collection of 12 lessons, this volume covers a wide range of concerns in mental health counseling. Each piece begins with an editorial comment, followed by an introduction which outlines the scope of the problem under consideration. The main body of each paper presents a clear, easily understood analysis of the subject under consideration. A…
Automated Management Of Documents
NASA Technical Reports Server (NTRS)
Boy, Guy
1995-01-01
Report presents main technical issues involved in computer-integrated documentation. Problems associated with automation of management and maintenance of documents analyzed from perspectives of artificial intelligence and human factors. Technologies that may prove useful in computer-integrated documentation reviewed: these include conventional approaches to indexing and retrieval of information, use of hypertext, and knowledge-based artificial-intelligence systems.
IP Addressing: Problem-Based Learning Approach on Computer Networks
ERIC Educational Resources Information Center
Jevremovic, Aleksandar; Shimic, Goran; Veinovic, Mladen; Ristic, Nenad
2017-01-01
The case study presented in this paper describes the pedagogical aspects and experience gathered while using an e-learning tool named IPA-PBL. Its main purpose is to provide additional motivation for adopting theoretical principles and procedures in a computer networks course. In the proposed model, the sequencing of activities of the learning…
Music Theatre: At the Crest of Music Education's Third Wave
ERIC Educational Resources Information Center
Legg, Robert; Green, Alex
2015-01-01
In the United Kingdom, curricular music education has seen two main waves of development and is in the process of shaping a third. Ideas from the second wave have maintained theoretical dominance to the present day, despite the concerns expressed by some about their practical implementation. This paper suggests that problems with the…
Directions in Mental Health Counseling, 1991.
ERIC Educational Resources Information Center
Directions in Mental Health Counseling, 1991
1991-01-01
A collection of 12 lessons, this volume covers a wide range of concerns in mental health counseling. Each piece begins with an editorial comment, followed by an introduction which outlines the scope of the problem under consideration. The main body of each lesson presents an analysis of the subject under consideration. A list of further sources…
African American and Afrocentric Communication Courses: A Rationale.
ERIC Educational Resources Information Center
Byrd, Marquita L.
One of the main problems with higher education is that curriculums, both past and present, objectify and marginalize the experiences of people of color and thus reduce diversity in the graduate and professional school populations. African American, Asians, Hispanics, and other minorities are studied in many college-level classes only as an…
Modern Approaches to Foreign Language Teaching: World Experience
ERIC Educational Resources Information Center
Shumskyi, Oleksandr
2016-01-01
The problem of applying communicative approach to foreign language teaching of students in non-language departments of higher education institutions in a number of countries has been analyzed in the paper. The brief overview of main historic milestones in the development of communicative approach has been presented. It has been found out that…
Teaching Energy Using an Integrated Science Approach
ERIC Educational Resources Information Center
Poggi, Valeria; Miceli, Cristina; Testa, Italo
2017-01-01
Despite its relevance to all scientific domains, the debate surrounding the teaching of energy is still open. The main point remains the problems students have in understanding some aspects of the energy concept and in applying their knowledge to the comprehension of natural phenomena. In this paper, we present a research-based interdisciplinary…
ERIC Educational Resources Information Center
McFadden, Justin R.; Roehrig, Gillian H.
2017-01-01
Background: This study presents two teacher design teams (TDTs) during a professional development experience centered on science, technology, engineering, and mathematics (STEM)-integrated curriculum development. The main activity of the study, curriculum design, was framed as a design problem in order to better understand how teachers engaged…
Student Engagement and Achievement in American Secondary Schools.
ERIC Educational Resources Information Center
Newmann, Fred M., Ed.
Findings from five main projects in the National Center on Effective Secondary Schools, which operated from December 1, 1985 to February 28, 1991, are presented. Projects investigated different aspects of engagement and achievement problems through literature reviews, analyses of existing data sets, and new studies of students and staff in 32…
Role of Mobile Technology in Promoting Campus-Wide Learning Environment
ERIC Educational Resources Information Center
Hussain, Irshad; Adeeb, Muhammad Aslam
2009-01-01
The present study examines the role of mobile technology in promoting campus-wide learning environment. Its main objectives were to a) evaluate the role of mobile technology in higher education in terms of its i). appropriateness ii). flexibility iii). Interactivity, & iv). availability & usefulness and to b). identify the problems of…
Solving Math Problems Approximately: A Developmental Perspective
Ganor-Stern, Dana
2016-01-01
Although solving arithmetic problems approximately is an important skill in everyday life, little is known about the development of this skill. Past research has shown that when children are asked to solve multi-digit multiplication problems approximately, they provide estimates that are often very far from the exact answer. This is unfortunate as computation estimation is needed in many circumstances in daily life. The present study examined 4th graders, 6th graders and adults’ ability to estimate the results of arithmetic problems relative to a reference number. A developmental pattern was observed in accuracy, speed and strategy use. With age there was a general increase in speed, and an increase in accuracy mainly for trials in which the reference number was close to the exact answer. The children tended to use the sense of magnitude strategy, which does not involve any calculation but relies mainly on an intuitive coarse sense of magnitude, while the adults used the approximated calculation strategy which involves rounding and multiplication procedures, and relies to a greater extent on calculation skills and working memory resources. Importantly, the children were less accurate than the adults, but were well above chance level. In all age groups performance was enhanced when the reference number was smaller (vs. larger) than the exact answer and when it was far (vs. close) from it, suggesting the involvement of an approximate number system. The results suggest the existence of an intuitive sense of magnitude for the results of arithmetic problems that might help children and even adults with difficulties in math. The present findings are discussed in the context of past research reporting poor estimation skills among children, and the conditions that might allow using children estimation skills in an effective manner. PMID:27171224
Computer simulation of solutions of polyharmonic equations in plane domain
NASA Astrophysics Data System (ADS)
Kazakova, A. O.
2018-05-01
A systematic study of plane problems of the theory of polyharmonic functions is presented. A method of reducing boundary problems for polyharmonic functions to the system of integral equations on the boundary of the domain is given and a numerical algorithm for simulation of solutions of this system is suggested. Particular attention is paid to the numerical solution of the main tasks when the values of the function and its derivatives are given. Test examples are considered that confirm the effectiveness and accuracy of the suggested algorithm.
Fluid mechanics of additive manufacturing of metal objects by accretion of droplets - a survey
NASA Astrophysics Data System (ADS)
Tesař, Václav
2016-03-01
Paper presents a survey of principles of additive manufacturing of metal objects by accretion of molten metal droplets, focusing on fluid-mechanical problems that deserve being investigated. The main problem is slowness of manufacturing due to necessarily small size of added droplets. Increase of droplet repetition rate calls for basic research of the phenomena that take place inside and around the droplets: ballistics of their flight, internal flowfield with heat and mass transfer, oscillation of surfaces, and the ways to elimination of satellite droplets.
A Multi-Beam Interferometer and Its Use as a Screening System in Gynecologic Cytology
NASA Astrophysics Data System (ADS)
Fujii, Ken-ichi; Suzuki, Norihito
1982-11-01
Clumps of cells remaining after the cell separation process present the greatest obstacle to the development of an automated screening system using flow cytofluorometry. There are two main problems caused by such clumps of cells. One occurs in the flow system, when the clumps block the nozzles, while the other occurs in the measuring system, when the clumps give a false fluorescence intensity. The former problem can be solved by designing the flow system appropriately, and the latter can be obviated by using a multi-beam interferometer.
Banks, H Thomas; Robbins, Danielle; Sutton, Karyn L
2013-01-01
In this paper we present new results for differentiability of delay systems with respect to initial conditions and delays. After motivating our results with a wide range of delay examples arising in biology applications, we further note the need for sensitivity functions (both traditional and generalized sensitivity functions), especially in control and estimation problems. We summarize general existence and uniqueness results before turning to our main results on differentiation with respect to delays, etc. Finally we discuss use of our results in the context of estimation problems.
Seguin, L.; Xu, Q.; Gauvin, L.; Zunzunegui, M.; Potvin, L.; Frohlich, K.
2005-01-01
Study objectives: To examine the unique impact of financial difficulties as measured by a lack of money for basic needs on the occurrence of health problems between the ages of 17 and 29 months, controlling for mother's level of education and neonatal health problems. Design and participants: Analyses were performed on the 29 month data of the Quebec longitudinal study of child development. This longitudinal study followed up a birth cohort annually. Interviews were conducted in the home with the mother in 98.8% of cases. This information was supplemented with data from birth records. At 29 months, the response rate was 94.2% of the initial sample (n = 1946). The main outcome measures were mothers' report of acute health problems, asthma episodes, and hospitalisation as well as growth delay and a composite index of health problems (acute problems, asthma attack, growth delay). Main results: Children raised in a family experiencing a serious lack of money for basic needs during the preceding year were more likely to be reported by their mothers as presenting acute health problems, a growth delay, two or more health problems, and to have been hospitalised for the first time within the past few months as compared with babies living in a family not experiencing a lack of money for basic needs regardless of the mother's level of education and of neonatal health problems. Conclusion: Financial difficulties as measured by a lack of money for basic needs have a significant and unique impact on toddlers' health. PMID:15598725
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
The main objectives of the 3rd Annual Biomass Energy Systems Conference were (1) to review the latest research findings in the clean fuels from biomass field, (2) to summarize the present engineering and economic status of Biomass Energy Systems, (3) to encourage interaction and information exchange among people working or interested in the field, and (4) to identify and discuss existing problems relating to ongoing research and explore opportunities for future research. Abstracts for each paper presented were edited separately. (DC)
Tebourski, Fethi
2004-01-01
In the present study we present the conditions offered to biotechnology development in Tunisia and we compare three main biotechnology applications which raise ethical and health problems: organ transplant, assisted reproductive techniques, and genetically modified organisms. We try to identify factors that have allowed success of the first two applications and failure of the latter. Conditions offered to biotechnology in other African countries are also discussed. PMID:15292577
Peixoto, Maria Manuela; Nobre, Pedro
2016-01-02
Empirical research suggests that emotional response during sexual activity discriminates between sexually functional and dysfunctional heterosexual men and women, with clinics presenting lower positive and higher negative affect. However, there is no evidence about the role of emotions in gay men and lesbian women with sexual problems. The present study analyzed affective states during sexual activity in homosexual and heterosexual men and women, with and without sexual problems. Participants in this study were 156 men and 168 women. A 2 (group) × 2 (sexual orientation) multivariate analysis of variance was performed. Participants completed a web-survey assessing sexual functioning and the Positive Affect-Negative Affect Scale. Findings indicated a main effect of group, with groups with sexual problems reporting significantly more negative and lower positive affect compared with men and women without sexual problems, regardless of sexual orientation. However, findings have also shown an interaction effect in the male sample with gay men, contrary to heterosexual men, reporting similar affective responses regardless of having a sexual dysfunction or not. Overall, findings emphasize the role of affective responses during sexual activity in men and women with sexual problems, suggesting the importance of addressing emotional responses in assessment and treatment of sexual problems in individuals with different sexual orientations.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mehrotra, Sanjay
2016-09-07
The support from this grant resulted in seven published papers and a technical report. Two papers are published in SIAM J. on Optimization [87, 88]; two papers are published in IEEE Transactions on Power Systems [77, 78]; one paper is published in Smart Grid [79]; one paper is published in Computational Optimization and Applications [44] and one in INFORMS J. on Computing [67]). The works in [44, 67, 87, 88] were funded primarily by this DOE grant. The applied papers in [77, 78, 79] were also supported through a subcontract from the Argonne National Lab. We start by presenting ourmore » main research results on the scenario generation problem in Sections 1–2. We present our algorithmic results on interior point methods for convex optimization problems in Section 3. We describe a new ‘central’ cutting surface algorithm developed for solving large scale convex programming problems (as is the case with our proposed research) with semi-infinite number of constraints in Section 4. In Sections 5–6 we present our work on two application problems of interest to DOE.« less
Urbanovich, P P
1975-01-01
Data are presented on the main problems of epizootology, pathological anatomy and pathogenesis of listeriosis of agricultural animals. It was shown that under natural conditions all species of agricultural animals are susceptible to the condition but ship are affected most often. Various clinico-anatomic forms of the disease are considered: nervous, septicemic, metrogenic, mixed, subclinical and latent. Domestic animals were observed to suffer predominantly from the nervous form of the disease. Basing on literature reports and his own findings, the author elucidates with greater detail problems of pathomorphology and pathogenesis of the nervous form of listeriosis and shows the importance of the neurogenic pathway in the development of listerious encephalomyelitis.
[Characteristics of calls by psychiatric patients to an emergency telephone helpline].
Gilat, I; Gil, Z E
1996-05-15
The role of the Israeli emergency telephone helpline, ERAN, was investigated by comparative analysis of calls received from 464 patients being treated psychiatrically, with calls received from 3,292 nonpatients during 1994. Findings reveal different patterns for helping relations in the 2 groups: Those being treated psychiatrically on a regular basis called ERAN more frequently, expected emotional support rather than direct help, mainly presented mental problems, and suicidal thoughts were much more prevalent among them. Those under no psychiatric treatment often called only once and presented a wider spectrum of expectations and problems. These differences indicate that the interrelations between the para-professional ERAN service and professional agents are complementary for mental patients and substitutional for other callers.
Space Shuttle SRM Ignition System. [Solid Rocket Motor
NASA Technical Reports Server (NTRS)
Bolieau, C. W.; Baker, J. S.; Folkman, S. L.
1978-01-01
This paper presents the Space Shuttle SRM Ignition System, which consists of a large solid propellant main igniter, a small solid propellant initiating igniter and an electromechanical safety and arming device containing two NASA Standard Initiators and a B-KNO3 pyrotechnic booster charge. In development motors, the igniter also has a valve through which CO2 is injected for post-firing quench of the SRM. The igniter has redundant, testable seals at all pressurized joints and three major reusable components; the case, the adapter, and the S&A device. Two development problem areas are discussed. One problem area was transverse mode combustion instability in the main igniter with maximum amplitude of 340 psi peak-to-peak at a frequency of 1500 Hz, which was reduced by a propellant grain configuration change and a change from a 2% aluminum content propellant to a formulation containing 10% aluminum. The other problem area was an excessively rapid rise of thrust in the SRM, which was reduced by reducing the igniter mass flow rate. This mass flow rate reduction was accomplished by removing portions of the grain starpoints in the head end.
Atherton, Olivia E; Schofield, Thomas J; Sitka, Angela; Conger, Rand D; Robins, Richard W
2016-04-01
Despite widespread speculation about the detrimental effect of unsupervised self-care on adolescent outcomes, little is known about which children are particularly prone to problem behaviors when left at home without adult supervision. The present research used data from a longitudinal study of 674 Mexican-origin children residing in the United States to examine the prospective effect of unsupervised self-care on conduct problems, and the moderating roles of hostile aggression and gender. Results showed that unsupervised self-care was related to increases over time in conduct problems such as lying, stealing, and bullying. However, unsupervised self-care only led to conduct problems for boys and for children with an aggressive temperament. The main and interactive effects held for both mother-reported and observational-rated hostile aggression and after controlling for potential confounds. Copyright © 2016 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.
O’Connor, Erin Eileen; Supplee, Lauren
2017-01-01
The present study identified trajectories of teacher-child relationship conflict and closeness from first through sixth grades, and associations between these trajectories and externalizing and internalizing behaviors at age 11 among low-income, urban males (N = 262). There were three main findings. Nagin cluster analyses indicated five trajectories for conflict with all children evidencing increases in conflict, and four trajectories for closeness with all children demonstrating decreases in closeness. Trajectories with higher levels of conflict and lower levels of closeness were associated with higher levels of externalizing and internalizing behavior problems at age 11. Moreover, conflictual teacher-child relationships exacerbated the effects of externalizing and internalizing behavior problems in early childhood; children with conflictual teacher-child relationships had higher levels of behavior problems in middle childhood relative to children with low conflictual teacher-child relationships. Implications of targeting teacher-child relationships as interventions to help prevent behavior problems are discussed. PMID:29170565
Jiménez-Martínez, María Dolores; Gil-Muñoz, Rocío; Gómez-Plaza, Encarna; Bautista-Ortín, Ana Belén
2018-03-30
The quality of red wine depends on the absence of compounds which may affect its safety and/or stability such as ochratoxin A, biogenic amines and some metals and trace compounds. The presence of ochratoxin A in musts and wines is due to fungal contamination of the grapes and has been classified as a possible human carcinogen. Biogenic amines are formed by the microbiological descarboxylation of the corresponding amino acid precursors during the fermentation or aging and storage, and, at high concentrations, they may induce adverse reactions in sensitive people. Trace elements may have both a nutritional and a toxic effect on health, but also can cause turbidity and stability problems. Their presence is affected mainly by natural factors such as soil mineral content and direct contact with tank surfaces and metallic tubing during winemaking. One of the best options to remove these compounds when present in excess in wine is fining. However, some fining agents commonly used may themselves present problems related with their allergenic properties or with their propensity to increase the protein content, which can cause turbidity problems. In an attempt to avoid such these problems, purified grape pomace was tested as a fining alternative since it has been seen to have a high capacity to reduce the astringency, turbidity and also the ochratoxin A content. The main aim of this work, therefore, was to study if this material can limit the presence of ochratoxin A, biogenic amines and metals and some trace elements in a Monastrell red wine, thus increasing the value and safety of this product.
Sigmarsdóttir, Margrét; Degarmo, David S; Forgatch, Marion S; Guðmundsdóttir, Edda Vikar
2013-12-01
Findings are presented from an Icelandic randomized control trial (RCT) evaluating parent management training - Oregon model (PMTO™), a parent training intervention designed to improve parenting practices and reduce child behavior problems. In a prior report from this effectiveness study that focused on child outcomes, children in the PMTO condition showed greater reductions in reported child adjustment problems relative to the comparison group. The present report focuses on observed parenting practices as the targeted outcome, with risk by treatment moderators also tested. It was hypothesized that mothers assigned to the PMTO condition would show greater gains in pre-post parenting practices relative to controls. The sample was recruited from five municipalities throughout Iceland and included 102 participating families of children with behavior problems. Cases were referred by community professionals and randomly assigned to either PMTO (n = 51) or community services usually offered (n = 51). Child age ranged from 5 to 12 years; 73% were boys. Contrary to expectations, findings showed no main effects for changes in maternal parenting. However, evaluation of risk by treatment moderators showed greater gains in parenting practices for mothers who increased in depressed mood within the PMTO group relative to their counterparts in the comparison group. This finding suggests that PMTO prevented the expected damaging effects of depression on maternal parenting. Failure to find hypothesized main effects may indicate that there were some unobserved factors regarding the measurement and a need to further adapt the global observational procedures to Icelandic culture. © 2013 The Scandinavian Psychological Associations.
Optical Fiber Sensors Based on Fiber Ring Laser Demodulation Technology
Xie, Wen-Ge; Wang, Peng-Zhao; Wang, Jian-Zhang
2018-01-01
A review for optical fiber sensors based on fiber ring laser (FRL) demodulation technology is presented. The review focuses on the principles, main structures, and the sensing performances of different kinds of optical fiber sensors based on FRLs. First of all, the theory background of the sensors has been discussed. Secondly, four different types of sensors are described and compared, which includes Mach–Zehnder interferometer (MZI) typed sensors, Fabry–Perot interferometer (FPI) typed sensors, Sagnac typed sensors, and fiber Bragg grating (FBG) typed sensors. Typical studies and main properties of each type of sensors are presented. Thirdly, a comparison of different types of sensors are made. Finally, the existing problems and future research directions are pointed out and analyzed. PMID:29419745
Optical Fiber Sensors Based on Fiber Ring Laser Demodulation Technology.
Xie, Wen-Ge; Zhang, Ya-Nan; Wang, Peng-Zhao; Wang, Jian-Zhang
2018-02-08
A review for optical fiber sensors based on fiber ring laser (FRL) demodulation technology is presented. The review focuses on the principles, main structures, and the sensing performances of different kinds of optical fiber sensors based on FRLs. First of all, the theory background of the sensors has been discussed. Secondly, four different types of sensors are described and compared, which includes Mach-Zehnder interferometer (MZI) typed sensors, Fabry-Perot interferometer (FPI) typed sensors, Sagnac typed sensors, and fiber Bragg grating (FBG) typed sensors. Typical studies and main properties of each type of sensors are presented. Thirdly, a comparison of different types of sensors are made. Finally, the existing problems and future research directions are pointed out and analyzed.
[Report SVIMEZ: population, education and the labor market and migration].
Cura Della Redazione, A
2012-01-01
SVIMEZ REPORT: Population, school, job market, migrations. The Svimez, a private non profit institution, is an association for the development of business and industries in the south of Italy, whose aim is the study of the economy of the South of Italy to propose development programs. The report on the Economy in the South of Italy is the main annual yearly report since 1974. The main indicators and the development of southern economy in several key sectors are presented and discussed, each year focusing on different specific problems. AIR has already proposed contributions on the gap between north and south to reflect on inequalities. The relationship between economy, wellbeing and health has been demonstrated. The section on school, job market and migrations is presented.
ERIC Educational Resources Information Center
National Association for Environmental Education, Miami, FL.
The Maine Environmental Priorities Project (MEPP) is a comparative risk project designed to identify, compare, and rank the most serious environmental problems facing Maine. Once the problems are analyzed and ranked according to their threat or risk to Maine's ecological health, human health, and quality of life, the project will propose…
Shielding and activation calculations around the reactor core for the MYRRHA ADS design
NASA Astrophysics Data System (ADS)
Ferrari, Anna; Mueller, Stefan; Konheiser, J.; Castelliti, D.; Sarotto, M.; Stankovskiy, A.
2017-09-01
In the frame of the FP7 European project MAXSIMA, an extensive simulation study has been done to assess the main shielding problems in view of the construction of the MYRRHA accelerator-driven system at SCK·CEN in Mol (Belgium). An innovative method based on the combined use of the two state-of-the-art Monte Carlo codes MCNPX and FLUKA has been used, with the goal to characterize complex, realistic neutron fields around the core barrel, to be used as source terms in detailed analyses of the radiation fields due to the system in operation, and of the coupled residual radiation. The main results of the shielding analysis are presented, as well as the construction of an activation database of all the key structural materials. The results evidenced a powerful way to analyse the shielding and activation problems, with direct and clear implications on the design solutions.
Schizophrenia: A Systemic Disorder
Kirkpatrick, Brian; Miller, Brian; García-Rizo, Clemente; Fernandez-Egea, Emilio
2015-01-01
The concept of schizophrenia that is most widely taught is that it is a disorder in which psychotic symptoms are the main problem, and a dysregulation of dopamine signaling is the main feature of pathophysiology. However, this concept limits clinical assessment, the treatments offered to patients, research, and the development of therapeutics. A more appropriate conceptual model is that: 1) schizophrenia is not a psychotic disorder, but a disorder of essentially every brain function in which psychosis is present; 2) it is not a brain disease, but a disorder with impairments throughout the body; 3) for many patients, neuropsychiatric problems other than psychosis contribute more to impairment in function and quality of life than does psychosis; and, 4) some conditions that are considered to be comorbid are integral parts of the illness. In conclusion, students, patients, and family members should be taught this model, along with its implications for assessment, research, and therapeutics. PMID:23518782
Numerical simulation of mechanical properties tests of tungsten mud waste geopolymer
NASA Astrophysics Data System (ADS)
Paszek, Natalia; Krystek, Małgorzata
2018-03-01
Geopolymers are believed to become in the future an environmental friendly alternative for the concrete. The low CO2 emission during the production process and the possibility of ecological management of the industrial wastes are mentioned as main advantages of geopolymers. The main drawback, causing problems with application of geopolymers as a building material is the lack of the theoretical material model. Indicated problem is being solved now by the group of scientists from the Silesian University of Technology. The series of laboratory tests are carried out within the European research project REMINE. The paper introduces the numerical analyses of tungsten mud waste geopolymer samples which have been performed in the Atena software on the basis of the laboratory tests. Numerical models of bended and compressed samples of different shapes are presented in the paper. The results obtained in Atena software were compared with results obtained in Abaqus and Mafem3D software.
Problems with German Science Education
NASA Astrophysics Data System (ADS)
Riess, Falk
The main problems of science (especially physics) teaching in Germany are students'' lack of interest and motivation in the subject, their poor understanding of scientific concepts, ideas, methods,and results, and their lack of comprehension of the social, political, and epistemological role of science. These circumstances result in a growing `scientific illiteracy'' of the population and adecline in democratic quality concerning decision making processes about scientific and technological projects. One means of improving this situation lies in the use of history and philosophy of science in science teaching. School science curricula and textbooks neglect almost completely the importance of history and philosophy of science. In this paper, the main empirical results concerning motivation and knowledge are given. Some examples from science curricula and textbooks are presented, and some of the few reform projects in Germany are listed. As a consequence a compensatory program is proposed in order to create the prerequisites for raising science education in Germany to an international standard.
New imaging algorithm in diffusion tomography
NASA Astrophysics Data System (ADS)
Klibanov, Michael V.; Lucas, Thomas R.; Frank, Robert M.
1997-08-01
A novel imaging algorithm for diffusion/optical tomography is presented for the case of the time dependent diffusion equation. Numerical tests are conducted for ranges of parameters realistic for applications to an early breast cancer diagnosis using ultrafast laser pulses. This is a perturbation-like method which works for both homogeneous a heterogeneous background media. Its main innovation lies in a new approach for a novel linearized problem (LP). Such an LP is derived and reduced to a boundary value problem for a coupled system of elliptic partial differential equations. As is well known, the solution of such a system amounts to the factorization of well conditioned, sparse matrices with few non-zero entries clustered along the diagonal, which can be done very rapidly. Thus, the main advantages of this technique are that it is fast and accurate. The authors call this approach the elliptic systems method (ESM). The ESM can be extended for other data collection schemes.
Proficiency Standards and Cut-Scores for Language Proficiency Tests.
ERIC Educational Resources Information Center
Moy, Raymond H.
1984-01-01
Discusses the problems associated with "grading on a curve," the approach often used for standard setting on language proficiency tests. Proposes four main steps presented in the setting of a non-arbitrary cut-score. These steps not only establish a proficiency standard checked by external criteria, but also check to see that the test covers the…
ERIC Educational Resources Information Center
Kenis, Anneleen; Mathijs, Erik
2012-01-01
Individual behaviour change is fast becoming a kind of "holy grail" to tackle climate change, in environmental policy, the environmental movement and academic literature. This is contested by those who claim that social structures are the main problem and who advocate collective social action. The objective of the research presented in…
Understanding Depression in Adolescents: A Dynamic Psychosocial Web of Risk and Protective Factors
ERIC Educational Resources Information Center
Kassis, Wassilis; Artz, Sibylle; White, Jennifer
2017-01-01
Background: Adolescent depression has been recognized as a complex problem that presents a global public health challenge. Left undetected and untreated, depression can significantly reduce quality of life. Objective: The main purpose of this paper is to re-visit risk and protective factors for depression in adolescents with a specific focus on…
ERIC Educational Resources Information Center
Botsoglou, Kafenia; Kakana, Domna-Mika
2003-01-01
The recent years in our country we are facing an increasingly great number of immigrant students, mainly from East European countries and the Balkans, particularly in many Greek elementary schools and kindergartens. Aim of the presented study is to sketch the problems that came out from the co-existence of students with different cultural…
The People Program--Parenting and Stress Education in an Industrial Setting.
ERIC Educational Resources Information Center
Ashley, Bart
The People Program is an educational effort being conducted at 20 worksites throughout Kentucky with more than 4,000 employee contacts. Part 1 of the People Program consists of a series of six 15-minute programs discussing problems experienced by parents of young children, and presented to them during their lunch break. Two main themes are…
ERIC Educational Resources Information Center
Froyen, Dries; Willems, Gonny; Blomert, Leo
2011-01-01
The phonological deficit theory of dyslexia assumes that degraded speech sound representations might hamper the acquisition of stable letter-speech sound associations necessary for learning to read. However, there is only scarce and mainly indirect evidence for this assumed letter-speech sound association problem. The present study aimed at…
ERIC Educational Resources Information Center
Yaacob, Yuzita; Wester, Michael; Steinberg, Stanly
2010-01-01
This paper presents a prototype of a computer learning assistant ILMEV (Interactive Learning-Mathematica Enhanced Vector calculus) package with the purpose of helping students to understand the theory and applications of integration in vector calculus. The main problem for students using Mathematica is to convert a textbook description of a…
A Study of Oral and Local History on Sportswomen with 5th Grade Students
ERIC Educational Resources Information Center
Dilek, Gulcin
2016-01-01
Problem Statement: Contrary to traditional historiography, which mainly focuses on men's experiences and ignores the women, historiography today includes all people, genders and social groups. Accordingly, school history also needs to regard female actors of the past in order to present a more gender-balanced past that makes visible not only the…
Invariance, Artifact, and the Psychological Setting of Rasch's Model: Comments on Engelhard
ERIC Educational Resources Information Center
Michell, Joel
2008-01-01
In the following, I confine my comments mainly to the issue of invariance in relation to Rasch's model for dichotomous, ability test items. "It is senseless to seek in the logical process of mathematical elaboration a psychologically significant precision that was not present in the psychological setting of the problem." (Boring, 1920)
Teaching Advanced Concepts in Computer Networks: VNUML-UM Virtualization Tool
ERIC Educational Resources Information Center
Ruiz-Martinez, A.; Pereniguez-Garcia, F.; Marin-Lopez, R.; Ruiz-Martinez, P. M.; Skarmeta-Gomez, A. F.
2013-01-01
In the teaching of computer networks the main problem that arises is the high price and limited number of network devices the students can work with in the laboratories. Nowadays, with virtualization we can overcome this limitation. In this paper, we present a methodology that allows students to learn advanced computer network concepts through…
ERIC Educational Resources Information Center
Mukan, Nataliya; Kravets, Svitlana
2015-01-01
In the article the methodology of comparative analysis of public school teachers' continuing professional development (CPD) in Great Britain, Canada and the USA has been presented. The main objectives are defined as theoretical analysis of scientific and pedagogical literature, which highlights different aspects of the problem under research;…
The Dynamics of Academic Productivity. A Seminar (Denver, Colorado, March 2, 1990).
ERIC Educational Resources Information Center
Massy, William F.; Zemsky, Robert
This report is an edited version of the transcript of a seminar held to explore the problem of increasing costs and defining productivity in higher education. The main paper, by William Massey, presents a conceptual model explaining the forces driving up costs in academic departments of institutions of higher education. Under the model there have…
Bastani, Peivand; Samadbeik, Mahnaz; Dinarvand, Rassoul; Kashefian-Naeeini, Sara; Vatankhah, Soudabeh
2018-06-05
Iranian health sector encountered many challenges in resource allocation and health service purchasing during the past decades, the aim of this study was to determine the main challenges of the present process of health service purchasing for national policymakers and other developing countries with the same setting. It was a qualitative study carried out via the complete content analysis of all relevant national documents from 2007 to 2014. In order to retrieve the related documents, we searched the official websites related to the Ministry of Health and Medical Education, four main Iranian insurance organizations, the Health Committee of the Parliament Profile, strategic vice president's site and Supreme Insurance Council. After recognition of documents, their credibility and authenticity were evaluated in terms of their publication or adjustment. For the analysis of documents, the four step-Scott method was used applying MAXQDA version 10. Findings illustrated that health service purchase challenges in the country can be classified in 6 main themes of policy-making, executive, intersectional, natural, legal and informational challenges with 26 subthemes. Furthermore, 5 themes of Basic Benefit Package, Reimbursement,Decision making, Technology and Contract are considered as the main Challenges in pharmaceutical purchasing area containing 13 relevant subthemes. It seems that according to documents, Iran has faced many structural and procedural problems with the purchase of the best health interventions. So it is highly recommended to consider consequences derived from the present challenges and try to use these evidences in their policy making process to decrease the existed problems and move to better procurement of health interventions.
Heubrock, D
2001-12-01
Münchhausen by proxy syndrome (MBPS) is a rare but dramatic variant of child abuse. In MBPS adults, mostly the mother, invent, manipulate, or produce the child's illness, and as a consequence the child has to undergo numerous diagnostic or treatment procedures. Typically, valid information about the etiology of the child's illness is withheld by the parents, and reversible symptoms vanish, when the child and the responsible adults are separated. Although valid statistical data about the epidemiology of MBPS are not available, MBPS should be considered more often than normally recognized. Neurological and neuropsychological presentations including developmental delays and learning problems appear to be common among MBPS cases so that clinical child neuropsychologists should be aware of this problem and consider MBPS at least in some of the mysterious cases that come to their attention. The present study describes a case of MBPS in which neurological and neuropsychological symptoms predominate. It presents a MBPS variant that is characterized by developmental delays and learning problems induced by unnecessary isolation at home, hospitalization, and treatment procedures. In the present case MBPS was at first suspected following neuropsychological assessment, since some of the main features of non-authenticity of symptom presentation gave cause for suspecting deceptive behavior on the mother's (and possibly also on the maternal grandmother's) side.
Seminar presentation on the economic evaluation of the space shuttle system
NASA Technical Reports Server (NTRS)
1973-01-01
The proceedings of a seminar on the economic aspects of the space shuttle system are presented. Emphasis was placed on the problems of economic analysis of large scale public investments, the state of the art of cost estimation, the statistical data base for estimating costs of new technological systems, and the role of the main economic parameters affecting the results of the analyses. An explanation of the system components of a space program and the present choice of launch vehicles, spacecraft, and instruments was conducted.
Glaucoma in juvenile xanthogranuloma.
Vendal, Zarmeena; Walton, David; Chen, Teresa
2006-01-01
Juvenile xanthogranuloma (JXG) is a benign histiocytic skin disorder mainly encountered during infancy. Approximately 10% of cases exhibit ocular manifestations leading to serious complications. Specifically, secondary glaucoma can result in severe and blinding eye disease. We present a case of a two-month-old female with JXG related glaucoma in order to demonstrate the classic presentation and the problems commonly encountered in treating this disease. The natural history, pathogenesis, and treatment of the condition are then discussed and the pertinent literature reviewed. JXG should be considered in any case of unilateral glaucoma that presents in infancy.
Applied Distributed Model Predictive Control for Energy Efficient Buildings and Ramp Metering
NASA Astrophysics Data System (ADS)
Koehler, Sarah Muraoka
Industrial large-scale control problems present an interesting algorithmic design challenge. A number of controllers must cooperate in real-time on a network of embedded hardware with limited computing power in order to maximize system efficiency while respecting constraints and despite communication delays. Model predictive control (MPC) can automatically synthesize a centralized controller which optimizes an objective function subject to a system model, constraints, and predictions of disturbance. Unfortunately, the computations required by model predictive controllers for large-scale systems often limit its industrial implementation only to medium-scale slow processes. Distributed model predictive control (DMPC) enters the picture as a way to decentralize a large-scale model predictive control problem. The main idea of DMPC is to split the computations required by the MPC problem amongst distributed processors that can compute in parallel and communicate iteratively to find a solution. Some popularly proposed solutions are distributed optimization algorithms such as dual decomposition and the alternating direction method of multipliers (ADMM). However, these algorithms ignore two practical challenges: substantial communication delays present in control systems and also problem non-convexity. This thesis presents two novel and practically effective DMPC algorithms. The first DMPC algorithm is based on a primal-dual active-set method which achieves fast convergence, making it suitable for large-scale control applications which have a large communication delay across its communication network. In particular, this algorithm is suited for MPC problems with a quadratic cost, linear dynamics, forecasted demand, and box constraints. We measure the performance of this algorithm and show that it significantly outperforms both dual decomposition and ADMM in the presence of communication delay. The second DMPC algorithm is based on an inexact interior point method which is suited for nonlinear optimization problems. The parallel computation of the algorithm exploits iterative linear algebra methods for the main linear algebra computations in the algorithm. We show that the splitting of the algorithm is flexible and can thus be applied to various distributed platform configurations. The two proposed algorithms are applied to two main energy and transportation control problems. The first application is energy efficient building control. Buildings represent 40% of energy consumption in the United States. Thus, it is significant to improve the energy efficiency of buildings. The goal is to minimize energy consumption subject to the physics of the building (e.g. heat transfer laws), the constraints of the actuators as well as the desired operating constraints (thermal comfort of the occupants), and heat load on the system. In this thesis, we describe the control systems of forced air building systems in practice. We discuss the "Trim and Respond" algorithm which is a distributed control algorithm that is used in practice, and show that it performs similarly to a one-step explicit DMPC algorithm. Then, we apply the novel distributed primal-dual active-set method and provide extensive numerical results for the building MPC problem. The second main application is the control of ramp metering signals to optimize traffic flow through a freeway system. This application is particularly important since urban congestion has more than doubled in the past few decades. The ramp metering problem is to maximize freeway throughput subject to freeway dynamics (derived from mass conservation), actuation constraints, freeway capacity constraints, and predicted traffic demand. In this thesis, we develop a hybrid model predictive controller for ramp metering that is guaranteed to be persistently feasible and stable. This contrasts to previous work on MPC for ramp metering where such guarantees are absent. We apply a smoothing method to the hybrid model predictive controller and apply the inexact interior point method to this nonlinear non-convex ramp metering problem.
A novel numerical framework for self-similarity in plasticity: Wedge indentation in single crystals
NASA Astrophysics Data System (ADS)
Juul, K. J.; Niordson, C. F.; Nielsen, K. L.; Kysar, J. W.
2018-03-01
A novel numerical framework for analyzing self-similar problems in plasticity is developed and demonstrated. Self-similar problems of this kind include processes such as stationary cracks, void growth, indentation etc. The proposed technique offers a simple and efficient method for handling this class of complex problems by avoiding issues related to traditional Lagrangian procedures. Moreover, the proposed technique allows for focusing the mesh in the region of interest. In the present paper, the technique is exploited to analyze the well-known wedge indentation problem of an elastic-viscoplastic single crystal. However, the framework may be readily adapted to any constitutive law of interest. The main focus herein is the development of the self-similar framework, while the indentation study serves primarily as verification of the technique by comparing to existing numerical and analytical studies. In this study, the three most common metal crystal structures will be investigated, namely the face-centered cubic (FCC), body-centered cubic (BCC), and hexagonal close packed (HCP) crystal structures, where the stress and slip rate fields around the moving contact point singularity are presented.
Stochastic Optimization For Water Resources Allocation
NASA Astrophysics Data System (ADS)
Yamout, G.; Hatfield, K.
2003-12-01
For more than 40 years, water resources allocation problems have been addressed using deterministic mathematical optimization. When data uncertainties exist, these methods could lead to solutions that are sub-optimal or even infeasible. While optimization models have been proposed for water resources decision-making under uncertainty, no attempts have been made to address the uncertainties in water allocation problems in an integrated approach. This paper presents an Integrated Dynamic, Multi-stage, Feedback-controlled, Linear, Stochastic, and Distributed parameter optimization approach to solve a problem of water resources allocation. It attempts to capture (1) the conflict caused by competing objectives, (2) environmental degradation produced by resource consumption, and finally (3) the uncertainty and risk generated by the inherently random nature of state and decision parameters involved in such a problem. A theoretical system is defined throughout its different elements. These elements consisting mainly of water resource components and end-users are described in terms of quantity, quality, and present and future associated risks and uncertainties. Models are identified, modified, and interfaced together to constitute an integrated water allocation optimization framework. This effort is a novel approach to confront the water allocation optimization problem while accounting for uncertainties associated with all its elements; thus resulting in a solution that correctly reflects the physical problem in hand.
Optimal Control Problems with Switching Points. Ph.D. Thesis, 1990 Final Report
NASA Technical Reports Server (NTRS)
Seywald, Hans
1991-01-01
The main idea of this report is to give an overview of the problems and difficulties that arise in solving optimal control problems with switching points. A brief discussion of existing optimality conditions is given and a numerical approach for solving the multipoint boundary value problems associated with the first-order necessary conditions of optimal control is presented. Two real-life aerospace optimization problems are treated explicitly. These are altitude maximization for a sounding rocket (Goddard Problem) in the presence of a dynamic pressure limit, and range maximization for a supersonic aircraft flying in the vertical, also in the presence of a dynamic pressure limit. In the second problem singular control appears along arcs with active dynamic pressure limit, which in the context of optimal control, represents a first-order state inequality constraint. An extension of the Generalized Legendre-Clebsch Condition to the case of singular control along state/control constrained arcs is presented and is applied to the aircraft range maximization problem stated above. A contribution to the field of Jacobi Necessary Conditions is made by giving a new proof for the non-optimality of conjugate paths in the Accessory Minimum Problem. Because of its simple and explicit character, the new proof may provide the basis for an extension of Jacobi's Necessary Condition to the case of the trajectories with interior point constraints. Finally, the result that touch points cannot occur for first-order state inequality constraints is extended to the case of vector valued control functions.
Liver transplantation in Asia: past, present and future.
Ng, Kelvin K; Lo, Chung Mau
2009-04-01
With the technical advances and improvements in perioperative management and immunosuppressants, liver transplantation is the standard treatment for patients with end-stage liver diseases. In Asia, a shortage of deceased donor liver grafts is the universal problem to be faced with in all transplant centres. Many surgical innovations are then driven to counteract this problem. This review focuses on 3 issues that denote the development of liver transplantation in Asian countries. These include living donor liver transplantation (LDLT), split liver transplantation (SLT) and liver transplantation for hepatocellular carcinoma (HCC). Minimal graft weight, types of liver graft to donate and the inclusion of the middle hepatic vein with the graft are the main issues to be established in LDLT. The rapid growth and wide dissemination of LDLT has certainly alleviated the supply-and-demand problem of liver grafts in Asia. SLT is another attractive approach. Technical expertise, donor selection and graft allocation are the main determinants for its success. Liver transplantation plays a key role in the management of HCC in Asia. LDLT would be the main strategy in this aspect. The issue of extending the selection criteria for HCC patients for LDLT is still controversial. On the whole, future developments to increase the donor pool for the expanding recipient need in Asia would involve transplantation from non-heart beating donor and ABO incompatible transplantation.
NASA Astrophysics Data System (ADS)
Macioł, Piotr; Regulski, Krzysztof
2016-08-01
We present a process of semantic meta-model development for data management in an adaptable multiscale modeling framework. The main problems in ontology design are discussed, and a solution achieved as a result of the research is presented. The main concepts concerning the application and data management background for multiscale modeling were derived from the AM3 approach—object-oriented Agile multiscale modeling methodology. The ontological description of multiscale models enables validation of semantic correctness of data interchange between submodels. We also present a possibility of using the ontological model as a supervisor in conjunction with a multiscale model controller and a knowledge base system. Multiscale modeling formal ontology (MMFO), designed for describing multiscale models' data and structures, is presented. A need for applying meta-ontology in the MMFO development process is discussed. Examples of MMFO application in describing thermo-mechanical treatment of metal alloys are discussed. Present and future applications of MMFO are described.
Dubow, E F; Tisak, J
1989-12-01
This study investigated the relation between stressful life events and adjustment in elementary school children, with particular emphasis on the potential main and stress-buffering effects of social support and social problem-solving skills. Third through fifth graders (N = 361) completed social support and social problem-solving measures. Their parents provided ratings of stress in the child's environment and ratings of the child's behavioral adjustment. Teachers provided ratings of the children's behavioral and academic adjustment. Hierarchical multiple regressions revealed significant stress-buffering effects for social support and problem-solving skills on teacher-rated behavior problems, that is, higher levels of social support and problem-solving skills moderated the relation between stressful life events and behavior problems. A similar stress-buffering effect was found for problem-solving skills on grade-point average and parent-rated behavior problems. In terms of children's competent behaviors, analyses supported a main effect model of social support and problem-solving. Possible processes accounting for the main and stress-buffering effects are discussed.
Nowakowski, Piotr
2017-02-01
Waste electrical and electronic equipment (WEEE), also known as e-waste, is one of the most important waste streams with high recycling potential. Materials used in these products are valuable, but some of them are hazardous. The urban mining approach attempts to recycle as many materials as possible, so efficiency in collection is vital. There are two main methods used to collect WEEE: stationary and mobile, each with different variants. The responsibility of WEEE organizations and waste collection companies is to assure all resources required for these activities - bins, containers, collection vehicles and staff - are available, taking into account cost minimization. Therefore, it is necessary to correctly determine the capacity of containers and number of collection vehicles for an area where WEEE need to be collected. There are two main problems encountered in collection, storage and transportation of WEEE: container loading problems and vehicle routing problems. In this study, an adaptation of these two models for packing and collecting WEEE is proposed, along with a practical implementation plan designed to be useful for collection companies' guidelines for container loading and route optimization. The solutions are presented in the case studies of real-world conditions for WEEE collection companies in Poland. Copyright © 2016 Elsevier Ltd. All rights reserved.
[Family violence and aggressive and oppositional behavior in childhood: a literature review].
Pesce, Renata
2009-01-01
This article presents a review of the world literature about two important subjects: family violence and problems of aggressive behavior and oppositional defiant disorder in childhood. We opted for publications that had used the CBCL- Child Behavior Checklist for investigating behavior problems in children. This instrument is internationally recognized for its reliability and validity, considered an efficient tool for identifying behavior problems in children. Our findings showed that marital violence predominated in the studies as kind of familiar violence able to cause problems of aggressiveness and transgression in children. Another point discussed was the lack of consensus on the terms used in the articles to refer to such behavior problems. The review showed the need for in-depth studies into this subject, mainly in the sense of thinking about prevention and health promotion in childhood and adolescence. Aggressive behavior in children tends to remain and increase over time, a fact that points to the need for strategies for preventing these problems in the school, familiar and health environments.
An optimal control strategy for collision avoidance of mobile robots in non-stationary environments
NASA Technical Reports Server (NTRS)
Kyriakopoulos, K. J.; Saridis, G. N.
1991-01-01
An optimal control formulation of the problem of collision avoidance of mobile robots in environments containing moving obstacles is presented. Collision avoidance is guaranteed if the minimum distance between the robot and the objects is nonzero. A nominal trajectory is assumed to be known from off-line planning. The main idea is to change the velocity along the nominal trajectory so that collisions are avoided. Furthermore, time consistency with the nominal plan is desirable. A numerical solution of the optimization problem is obtained. Simulation results verify the value of the proposed strategy.
Simplex-stochastic collocation method with improved scalability
NASA Astrophysics Data System (ADS)
Edeling, W. N.; Dwight, R. P.; Cinnella, P.
2016-04-01
The Simplex-Stochastic Collocation (SSC) method is a robust tool used to propagate uncertain input distributions through a computer code. However, it becomes prohibitively expensive for problems with dimensions higher than 5. The main purpose of this paper is to identify bottlenecks, and to improve upon this bad scalability. In order to do so, we propose an alternative interpolation stencil technique based upon the Set-Covering problem, and we integrate the SSC method in the High-Dimensional Model-Reduction framework. In addition, we address the issue of ill-conditioned sample matrices, and we present an analytical map to facilitate uniformly-distributed simplex sampling.
Ahmadinejad, Zahra; Alijani, Neda; Mansori, Sedigeh; Ziaee, Vahid
2014-01-01
There is a relationship between exercise and changes in immunity. So athletes are prone to different medical problems such as injuries and infections. Infection is an important medical problem which could be a reason for athletes’ absence from training. The relationship between physical activity and immune system, characteristics of different types of infections in athletes with emphasis on special clinical presentations or complications, time to return to physical activity and training and strategies to prevent development and transmission of infections in athletes or physically active people are the main topics of this review. PMID:24868426
Stabilization and control of distributed systems with time-dependent spatial domains
NASA Technical Reports Server (NTRS)
Wang, P. K. C.
1990-01-01
This paper considers the problem of the stabilization and control of distributed systems with time-dependent spatial domains. The evolution of the spatial domains with time is described by a finite-dimensional system of ordinary differential equations, while the distributed systems are described by first-order or second-order linear evolution equations defined on appropriate Hilbert spaces. First, results pertaining to the existence and uniqueness of solutions of the system equations are presented. Then, various optimal control and stabilization problems are considered. The paper concludes with some examples which illustrate the application of the main results.
Weighted cubic and biharmonic splines
NASA Astrophysics Data System (ADS)
Kvasov, Boris; Kim, Tae-Wan
2017-01-01
In this paper we discuss the design of algorithms for interpolating discrete data by using weighted cubic and biharmonic splines in such a way that the monotonicity and convexity of the data are preserved. We formulate the problem as a differential multipoint boundary value problem and consider its finite-difference approximation. Two algorithms for automatic selection of shape control parameters (weights) are presented. For weighted biharmonic splines the resulting system of linear equations can be efficiently solved by combining Gaussian elimination with successive over-relaxation method or finite-difference schemes in fractional steps. We consider basic computational aspects and illustrate main features of this original approach.
«Smart Grid» Concept As A Modern Technology For The Power Industry Development
NASA Astrophysics Data System (ADS)
Vidyaev, Igor G.; Ivashutenko, Alexandr S.; Samburskaya, Maria A.
2017-01-01
The article discusses the main problems of the power industry and energy supply to the distribution networks. One of the suggested solutions for these problems is the use of intelligent energy networks on the basis of digital reality simulation, in particular, the concept of «SMART GRID». The article presents the basic points of the concept and the peculiarities of its application at the enterprises. It was demonstrated that the use of this technology eliminates power shortage, reduces the energy intensity and improves the energy efficiency throughout the operation of an enterprise as a whole.
Ahmadinejad, Zahra; Alijani, Neda; Mansori, Sedigeh; Ziaee, Vahid
2014-03-01
There is a relationship between exercise and changes in immunity. So athletes are prone to different medical problems such as injuries and infections. Infection is an important medical problem which could be a reason for athletes' absence from training. The relationship between physical activity and immune system, characteristics of different types of infections in athletes with emphasis on special clinical presentations or complications, time to return to physical activity and training and strategies to prevent development and transmission of infections in athletes or physically active people are the main topics of this review.
Implicit Runge-Kutta Methods with Explicit Internal Stages
NASA Astrophysics Data System (ADS)
Skvortsov, L. M.
2018-03-01
The main computational costs of implicit Runge-Kutta methods are caused by solving a system of algebraic equations at every step. By introducing explicit stages, it is possible to increase the stage (or pseudo-stage) order of the method, which makes it possible to increase the accuracy and avoid reducing the order in solving stiff problems, without additional costs of solving algebraic equations. The paper presents implicit methods with an explicit first stage and one or two explicit internal stages. The results of solving test problems are compared with similar methods having no explicit internal stages.
Ben-Naim, Arieh
2012-12-21
A new approach to the problem of pressure-denaturation (PD) and solute-denaturation (SD) of proteins is presented. The problem is formulated in terms of Le Chatelier principle, and a solution is sought in terms of the Kirkwood-Buff theory of solutions. It is found that both problems have one factor in common; the excluded volumes of the folded and the unfolded forms with respect to the solvent molecules. It is shown that solvent-induced effects operating on hydrophilic groups along the protein are probably the main reason for PD. On the other hand, the SD depends on the preferential solvation of the folded and the unfolded forms with respect to solvent and co-solvent molecules.
Theoretical aspects of pressure and solute denaturation of proteins: A Kirkwood-buff-theory approach
NASA Astrophysics Data System (ADS)
Ben-Naim, Arieh
2012-12-01
A new approach to the problem of pressure-denaturation (PD) and solute-denaturation (SD) of proteins is presented. The problem is formulated in terms of Le Chatelier principle, and a solution is sought in terms of the Kirkwood-Buff theory of solutions. It is found that both problems have one factor in common; the excluded volumes of the folded and the unfolded forms with respect to the solvent molecules. It is shown that solvent-induced effects operating on hydrophilic groups along the protein are probably the main reason for PD. On the other hand, the SD depends on the preferential solvation of the folded and the unfolded forms with respect to solvent and co-solvent molecules.
The widening gap—a swedish perspective
NASA Astrophysics Data System (ADS)
Brandell, Gerd; Hemmi, Kirsti; Thunberg, Hans
2008-09-01
Transition problems from secondary to tertiary level in mathematics have been a recurrent issue in Sweden. This paper summarises the development during the last decades. Results from two recent research studies that illuminate the transition problem are presented. The first one, based on empirical data from a major Swedish technical university, characterises the widening gap, in content and in approach, between secondary school and first year university courses. The second study deals with students' encounters with mathematical proof and is based on a large investigation at another main Swedish university. We discuss the influence on the current transition problems of school reforms and of the great expansion of higher education in Sweden during the last 10 - 15 years in view of the results from the research studies.
NASA Astrophysics Data System (ADS)
Vasant, Pandian; Barsoum, Nader
2008-10-01
Many engineering, science, information technology and management optimization problems can be considered as non linear programming real world problems where the all or some of the parameters and variables involved are uncertain in nature. These can only be quantified using intelligent computational techniques such as evolutionary computation and fuzzy logic. The main objective of this research paper is to solve non linear fuzzy optimization problem where the technological coefficient in the constraints involved are fuzzy numbers which was represented by logistic membership functions by using hybrid evolutionary optimization approach. To explore the applicability of the present study a numerical example is considered to determine the production planning for the decision variables and profit of the company.
Primary Pterygium in a 7-Year-Old Boy: A Report of a Rare Case and Dilemma of its Management
Noor, Raja Azmi Mohd
2003-01-01
Primary pterygium in children is uncommon but is associated with severe visual problems. Astigmatism is the main visual problem caused by pterygium. Significant amounts of astigmatism occur long before a pterygium encroaches the visual axis. Early surgical intervention is safe and effective. It is associated with significant visual improvement in outcome. This is a case report on seven-year-old Malay boy who presented with a growth over nasal aspect of the right eye of 1 year duration. His right eye visual acuity is affected up to 6/12. The dilemma pased to early surgical interview is the high rate of recurrancean the young age group. This problem is highlighted in this case report. PMID:23386804
Primary pterygium in a 7-year-old boy: a report of a rare case and dilemma of its management.
Noor, Raja Azmi Mohd
2003-07-01
Primary pterygium in children is uncommon but is associated with severe visual problems. Astigmatism is the main visual problem caused by pterygium. Significant amounts of astigmatism occur long before a pterygium encroaches the visual axis. Early surgical intervention is safe and effective. It is associated with significant visual improvement in outcome. This is a case report on seven-year-old Malay boy who presented with a growth over nasal aspect of the right eye of 1 year duration. His right eye visual acuity is affected up to 6/12. The dilemma pased to early surgical interview is the high rate of recurrancean the young age group. This problem is highlighted in this case report.
Apollo experience report: Lunar module environmental control subsystem
NASA Technical Reports Server (NTRS)
Gillen, R. J.; Brady, J. C.; Collier, F.
1972-01-01
A functional description of the environmental control subsystem is presented. Development, tests, checkout, and flight experiences of the subsystem are discussed; and the design fabrication, and operational difficulties associated with the various components and subassemblies are recorded. Detailed information is related concerning design changes made to, and problems encountered with, the various elements of the subsystem, such as the thermal control water sublimator, the carbon dioxide sensing and control units, and the water section. The problems associated with water sterilization, water/glycol formulation, and materials compatibility are discussed. The corrective actions taken are described with the expection that this information may be of value for future subsystems. Although the main experiences described are problem oriented, the subsystem has generally performed satisfactorily in flight.
2015-12-15
UXO community . NAME Total Number: PERCENT_SUPPORTEDNAME FTE Equivalent: Total Number: Irma Shamatava 0.50 0.50 1 Resolving and Discriminating...Distinguishing an object of interest from innocuous items is the main problem that the UXO community is facing currently. This inverse problem...innocuous items is the main problem that the UXO community is facing currently. This inverse problem demands fast and accurate representation of
A hundred years with the cosmological constant
NASA Astrophysics Data System (ADS)
Grøn, Øyvind G.
2018-07-01
The main points in the history of the cosmological constant are briefly discussed. As a conceptual background, useful for teaching of physics at an elementary college and university level, Newton’s theory formulated locally in terms of the Poisson equation is presented, and it is shown how it is modified by the introduction of the cosmological constant. The different physical interpretations of the cosmological constant, as introduced by Einstein in 1917 and interpreted by Lemaître in 1934, are presented. Energy conservation in an expanding universe dominated by vacuum energy is discussed. The connection between the cosmological constant and the quantum mechanical vacuum energy is mentioned, together with the problem that a quantum mechanical calculation of the density of the vacuum energy gives a vastly too large value of the cosmological constant. The article is concluded by reviewing a solution of this problem that was presented on May 11, 2017.
Race, Ethnicity, and Eating Disorder Recognition by Peers
Sala, Margarita; Reyes-Rodríguez, Mae Lynn; Bulik, Cynthia M.; Bardone-Cone, Anna
2013-01-01
We investigated racial/ethnic stereotyping in the recognition and referral of eating disorders with 663 university students. We explored responses to problem and eating disorder recognition, and health care referral after reading a vignette concerning a patient of different race/ethnic background presenting with eating disorders. A series of three 4 × 3 ANOVAs revealed significant main effects for eating disorder across all three outcome variables. There were no significant main effects across the four different race/ethnicity conditions and no significant race by condition interactions. Lack of general eating disorder recognition and health care referral by student participants were found. PMID:24044598
Quantum key distribution with untrusted detectors
NASA Astrophysics Data System (ADS)
González, P.; Rebón, L.; Ferreira da Silva, T.; Figueroa, M.; Saavedra, C.; Curty, M.; Lima, G.; Xavier, G. B.; Nogueira, W. A. T.
2015-08-01
Side-channel attacks currently constitute the main challenge for quantum key distribution (QKD) to bridge theory with practice. So far two main approaches have been introduced to address this problem, (full) device-independent QKD and measurement-device-independent QKD. Here we present a third solution that might exceed the performance and practicality of the previous two in circumventing detector side-channel attacks, which arguably is the most hazardous part of QKD implementations. Our proposal has, however, one main requirement: the legitimate users of the system need to ensure that their labs do not leak any unwanted information to the outside. The security in the low-loss regime is guaranteed, while in the high-loss regime we already prove its robustness against some eavesdropping strategies.
A discussion on turbine design for safe operation
NASA Astrophysics Data System (ADS)
Brekke, H.
2012-11-01
The paper gives a brief description of the hydraulic design of Francis and Pelton runners. The dynamic behaviour at part load has been a major problem for low head and medium head Francis turbines. The main reason for this has been inter blade separation and unstable swirl flow in the draft tube. A description is given on the hydraulic design of X-BLADE runners to obtain stable operation on the whole range of operation by reducing the cross flow. A classical theoretical analysis is also given on the dynamic hydraulic load on Pelton buckets. Several CFD analyses of this non stationary flow have been presented during the last decade, but the velocity distribution in the jets have not been correct. Experimental research work is presented on the complexity of this problem.
Modeling and prototyping of biometric systems using dataflow programming
NASA Astrophysics Data System (ADS)
Minakova, N.; Petrov, I.
2018-01-01
The development of biometric systems is one of the labor-intensive processes. Therefore, the creation and analysis of approaches and techniques is an urgent task at present. This article presents a technique of modeling and prototyping biometric systems based on dataflow programming. The technique includes three main stages: the development of functional blocks, the creation of a dataflow graph and the generation of a prototype. A specially developed software modeling environment that implements this technique is described. As an example of the use of this technique, an example of the implementation of the iris localization subsystem is demonstrated. A variant of modification of dataflow programming is suggested to solve the problem related to the undefined order of block activation. The main advantage of the presented technique is the ability to visually display and design the model of the biometric system, the rapid creation of a working prototype and the reuse of the previously developed functional blocks.
Sea cliff erosion in the eastern part of the North Aegean coastline, Northern Greece.
Xeidakis, George S; Delimani, P K; Skias, S G
2006-01-01
The coastal zone is an area where many human activities are taking place. Erosion of the coast obstructs, in various ways, these activities creating occasionally serious socioeconomic and environmental problems. In this paper the coastal erosion problems encountered in the eastern Greek part of the North Aegean Sea Coast, a stretch of about 51 km long adjacent to the city of Alexandroupolis, are discussed. Given the observed type and location of erosion and other sea-action phenomena, the coast under study is divided in two parts/stretches. The western stretch, where the city of Alexandroupolis is presently extending, presents, mainly, cliff erosion problems and retreat of the coastline, very serious in some sections; whereas, the eastern stretch (to the east of the city) exhibits deposition and progression seawards due to the abundance of sediments supplied by Evros river delta. A classification of the coastline according to its relief, geologic material, erosion characteristics and rate, slope failure phenomena as well as the wave energy potential, is presented together with suggestions for case-appropriate mitigation and protection measures regarding the coastal erosion problems. The paper is focusing on the cliff erosion phenomena, since varying in height coastal cliffs made of soft rocks, cover the major part of the investigated coastline (western stretch).
Cognitive Control of a Simple Mental Image in Patients with Obsessive-Compulsive Disorder
ERIC Educational Resources Information Center
Kocak, Orhan Murat; Ozpolat, Aysegul Yilmaz; Atbasoglu, Cem; Cicek, Metehan
2011-01-01
The nature of obsessions has led researchers to try to determine if the main problem in obsessive-compulsive disorder (OCD) is impaired inhibitory control. Previous studies report that the effort to suppress is one of the factors that increase the frequency of obsessive thoughts. Based on these results and those of the present study that suggest…
ERIC Educational Resources Information Center
Aksu, Gökhan; Koruklu, Nermin
2015-01-01
Problem Statement: One of the main goals of education is to nurture individuals who know and improve themselves; who is well educated and have scientific perspective; who have developed communal coherency level; who are active, democratic and respectful to human rights. At the present time, according to an up to date mentality in mathematics…
ERIC Educational Resources Information Center
Van Zyl Slabbert, F., Ed.; And Others
In view of the sweeping political and social changes in South Africa, the Human Sciences Research Council and other agencies established the Co-operative Research Programme: South African Youth, a program to undertake research on the problems, challenges, and opportunities facing South African youth. This report presents the information base of…
Supervised Coursework as a Way of Improving Motivation in the Learning of Digital Electronics
ERIC Educational Resources Information Center
Rengel, R.; Martin, M. J.; Vasallo, B. G.
2012-01-01
This paper presents a series of activities and educational strategies related to the teaching of digital electronics in computer engineering. The main objective of these methodologies was to develop a final tutored coursework to be carried out by the students in small teams. This coursework was conceived as consisting of advanced problems or small…
The Breath of Life. The Problem of Poisoned Air.
ERIC Educational Resources Information Center
Carr, Donald E.
The origins and nature of air pollution, from earliest days to the present, are examined in this book. Although air pollution has been with us since the discovery of fire, it is proffered that the major culprit now is the burning of gasoline and low-grade heating oil. All other sources of air pollution are negligible. The main thesis is that only…
ERIC Educational Resources Information Center
United Nations Educational, Scientific, and Cultural Organization, Nairobi (Kenya). Regional Office of Science and Technology for Africa.
The main points on the agenda of this meeting attended by eight chief participants from seven member states of UNESCO in the African Region and several observers were: (1) presentations by participants on their experiences in the application of informatics (i.e., computer applications in information dissemination) in the region; (2) problems in…
Experience of valorization projects ISTC for laser technologies
NASA Astrophysics Data System (ADS)
Sartory, A. V.; Stepennov, D. B.; Vlasova, E. Y.; Pokrovsky, K. K.
2002-04-01
Application of the achievements of the ISTC projects is one of the main problems being solved to achieve one of the basic goals of the ISTC, namely, to adapt Russian scientists to conditions of developing market economy in Russia. The present report is aimed at rendering of promotional services for ISTC project teams in the context of the program of projects outcomes valorization.
Modeling of Economy Considering Crisis
NASA Astrophysics Data System (ADS)
Petrov, Lev F.
2009-09-01
We discuss main modeling's problems of economy dynamic processes and the reason forecast's absence of economic crisis. We present a structure of complexity level of system and models and discuss expected results concerning crisis phenomena. We formulate the basic perspective directions of the mathematical modeling of economy, including possibility of the analysis of the pre crisis, crisis and post crisis phenomena in economic systems.
Health Project Management. A Manual of Procedures for Formulating and Implementing Health Projects.
ERIC Educational Resources Information Center
Bainbridge, J.; Sapirie, S.
The manual presents 16 main steps for health project management, from project formulation through termination. The manual defines a health project as a temporary intensive effort to set up and put into operation a new or revised service that will result in the reduction of specific health or health-related problems. (Typical examples include the…
Environmental aspects of fossil fuels combustion in Poland
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sekula, R.
Combustion of fossil fuels is the main source of energy in Poland. Coal will probably remain the basic fuel for energy generation for many years. The principal problems connected with fuel utilization in Poland are presented in this study. The major pollutants and ways to reduce air pollution are also described. Data are based on the report of the Polish Academy of Sciences.
Competences Mastering Demanded by Practice as One of the Main Directions in Specialist Training
ERIC Educational Resources Information Center
Korchemny, Petr A.
2016-01-01
The relevance of the presented problems in the paper is conditioned by the fact that the process of implementation of the competence approach into the educational space of Russia is in contact with a number of theoretical inconsistencies which are directly related to understanding the formation and mastering of competences. The goal of the paper…
Translation Strategies of EFL Student Teachers: A Think Aloud Protocol-Based Case Study
ERIC Educational Resources Information Center
Aly, Mahsoub Abdul-Sadeq
2004-01-01
The main concern of the present study is to investigate the strategies followed by the EFL students in the translation process. This problem has been dealt with through answering the following two questions: 1- What are the strategies followed by the EFL student teachers in the translation process?; 2 - What are the educational implications for…
ERIC Educational Resources Information Center
Mukan, Nataliya; Myskiv, Iryna; Kravets, Svitlana
2016-01-01
In the article the theoretical framework of public school teachers' continuing professional development (CPD) in Great Britain, Canada and the USA has been presented. The main objectives have been defined as theoretical analysis of scientific and pedagogical literature, which highlights different aspects of the problem under research; presentation…
[The two ozone problems: too much in the troposphere, too little in the stratosphere].
Staehelin, J
1992-03-10
Trends analysis based on the long-term Swiss ozone measurements from Arosa and Payerne operationally performed by the Swiss Meteorological Institute are presented. These measurement include stratospheric ozone (approximately 90% of total ozone) and tropospheric ozone. The total ozone measurements from Arosa, the world longest series started at 1926, indicate, that total ozone has declined since about 1970 by approximately 5%. The ozone balloon soundings, operationally performed at Payerne since 1969 (2-3 ascents per week) show, that stratospheric ozone has decreased strongly in the last 20 years, whereas tropospheric ozone, remarkably has increased during this period. The relative change was strongest in the troposphere (more than 10% per decade, 3-4% increase per year during 1982-1988). However, on an absolute scale, changes in the stratosphere were strongest (relative decrease: 6 to 7% per decade at 20-22 km). The present scientific theories of the two ozone problems are reviewed: stratospheric ozone decrease was caused by the anthropogenic emissions of fluorochlorocarbons and other compounds mainly released from the earth surface. Tropospheric ozone has increased due to photochemical production of mainly anthropogenically emitted nitrogen oxides, volatile organic compounds and CO.
Bak, O
2001-01-01
The paper deals with the problem of diagnosing mental retardation in adults, with a focus on the numerical indicator of intellectual level (intelligence quotient). According to the present standards, the process of diagnosing mental retardation demands a comprehensive approach: an evaluation of both the intellectual level and social competence, and should be carried out by a team of experts (medical consultants, a psychologist, an educationist, etc.). The paper shows that, in the process of diagnosing, excessive attention should not be paid to the indicator of intellectual level, expressed by the intelligence quotient. According to the theory of psychological testing, this indicator is saddled with some error. Its use as the main criterion in diagnosing can lead to drawing false conclusions. The paper presents the Wechsler Adults Intelligence Scale WAIS-R(PL), which is the most common tool used by Polish psychologists in diagnosing the intellectual level. It also indicates the limitations and strong points of this test in the process of diagnosing mental retardation. The article is mainly addressed to medical doctors, as it contains information relating to the problem of measurement by tests, which is scantily dealt with during the medical studies.
Rakha, Gamal M H; Abdl-Haleem, Mounir M; Farghali, Haithem A M; Abdel-Saeed, Hitham
2015-03-01
The present study was conducted to ascertain the prevalence of common digestive problems compared to other health problems among dogs that were admitted to the teaching veterinary hospital, faculty of veterinary medicine, Cairo University, Egypt during 1 year period from January to December 2013. Also, study the effect of age, sex, breeds, and season on the distribution of digestive problems in dogs. A total of 3864 dogs included 1488 apparently healthy (included 816 males and 672 females) and 2376 diseased dogs (included 1542 males and 834 females) were registered for age, sex, breed, and the main complaint from their owners. A complete history and detailed clinical examination of each case were applied to the aids of radiographic, ultrasonographic, and endoscopic examination tools. Fecal examination was applied for each admitted case. Rapid tests for parvovirus and canine distemper virus detection were also performed. A five digestive problems were commonly recorded including vomiting, diarrhea, concurrent vomiting with diarrhea, anorexia, and constipation with a prevalence (%) of 13.6, 19.1, 10.1, 13.1, and 0.5 respectively while that of dermatological, respiratory, urinary, neurological, cardiovascular, auditory, and ocular problems was 27.9, 10.5, 3.3, 0.84, 0.4, 0.25, and 0.17 (%) respectively. This prevalence was obtained on the basis of the diseased cases. Age and breed had a significant effect on the distribution of digestive problems in dogs (p<0.001). Gender had an effect on the distribution of digestive problems with significant (p≤0.01) while season had a non-significant effect (p>0.05) on the distribution of such problems. Digestive problems were the highest recorded problems among dogs, and this was the first records for such problems among dogs in Egypt. Age, gender, and breeds had a significant effect on the distribution of the digestive problems in dogs while season had a non-significant effect on the distribution of such problems. The present data enable veterinarians in Egypt to ascertain their needs for diagnostic tools and medication that must be present at any pet clinic.
Impact of the parenting style of foster parents on the behaviour problems of foster children.
Fuentes, M J; Salas, M D; Bernedo, I M; García-Martín, M A
2015-09-01
Few studies have analysed the effects of the parenting style used by foster carers on children's behaviour problems. This study examines the role played by the quality of the emotional relationship with foster carers and the kind of discipline they use as regard internalizing and externalizing problems among foster children. Participants were 104 foster children (56 boys and 48 girls) and their respective foster families. The Child Behaviour Checklist, the Affect and Communication Scale, and the Rules and Demands Scale were completed by foster parents. A series of linear regression analyses were performed using the stepwise method. The main findings were as follows: an authoritarian parenting style explained the internalizing problems presented by foster children (11% of the variance); criticism/rejection, authoritarian parenting and permissive parenting explained externalizing problems (37% of the variance); and criticism/rejection and authoritarian parenting explained total problems (29% of the variance). These results indicate that criticism/rejection on the part of foster parents, as well as the use of inappropriate parenting styles (authoritarian and permissive), has an important effect in relation to the behaviour problems of foster children. This highlights the key role that foster carers play in terms of tackling the behaviour problems that foster children present. The findings also suggest that preparation for fostering should focus especially on ways of helping foster parents both to acquire positive parenting strategies and to avoid authoritarian and permissive parenting. © 2014 John Wiley & Sons Ltd.
A bottom-up approach to the strong CP problem
NASA Astrophysics Data System (ADS)
Diaz-Cruz, J. L.; Hollik, W. G.; Saldana-Salazar, U. J.
2018-05-01
The strong CP problem is one of many puzzles in the theoretical description of elementary particle physics that still lacks an explanation. While top-down solutions to that problem usually comprise new symmetries or fields or both, we want to present a rather bottom-up perspective. The main problem seems to be how to achieve small CP violation in the strong interactions despite the large CP violation in weak interactions. In this paper, we show that with minimal assumptions on the structure of mass (Yukawa) matrices, they do not contribute to the strong CP problem and thus we can provide a pathway to a solution of the strong CP problem within the structures of the Standard Model and no extension at the electroweak scale is needed. However, to address the flavor puzzle, models based on minimal SU(3) flavor groups leading to the proposed flavor matrices are favored. Though we refrain from an explicit UV completion of the Standard Model, we provide a simple requirement for such models not to show a strong CP problem by construction.
A novel fully automatic scheme for fiducial marker-based alignment in electron tomography.
Han, Renmin; Wang, Liansan; Liu, Zhiyong; Sun, Fei; Zhang, Fa
2015-12-01
Although the topic of fiducial marker-based alignment in electron tomography (ET) has been widely discussed for decades, alignment without human intervention remains a difficult problem. Specifically, the emergence of subtomogram averaging has increased the demand for batch processing during tomographic reconstruction; fully automatic fiducial marker-based alignment is the main technique in this process. However, the lack of an accurate method for detecting and tracking fiducial markers precludes fully automatic alignment. In this paper, we present a novel, fully automatic alignment scheme for ET. Our scheme has two main contributions: First, we present a series of algorithms to ensure a high recognition rate and precise localization during the detection of fiducial markers. Our proposed solution reduces fiducial marker detection to a sampling and classification problem and further introduces an algorithm to solve the parameter dependence of marker diameter and marker number. Second, we propose a novel algorithm to solve the tracking of fiducial markers by reducing the tracking problem to an incomplete point set registration problem. Because a global optimization of a point set registration occurs, the result of our tracking is independent of the initial image position in the tilt series, allowing for the robust tracking of fiducial markers without pre-alignment. The experimental results indicate that our method can achieve an accurate tracking, almost identical to the current best one in IMOD with half automatic scheme. Furthermore, our scheme is fully automatic, depends on fewer parameters (only requires a gross value of the marker diameter) and does not require any manual interaction, providing the possibility of automatic batch processing of electron tomographic reconstruction. Copyright © 2015 Elsevier Inc. All rights reserved.
Hendricks, Carla Tierney; Camara, Kristin; Violick Boole, Kathryn; Napoli, Maureen F; Goldstein, Richard; Ryan, Colleen M; Schneider, Jeffrey C
The prevalence and extent of cognitive-communication disorders and factors that have impact on outcomes are examined in the burn population within an inpatient rehabilitation facility. A retrospective data analysis was conducted on adults diagnosed with burn injury (n = 144). Descriptive statistics were used to identify the prevalence of cognitive-communication deficits on admission and discharge. The main outcomes were cognitive-communication ratings on discharge from inpatient rehabilitation as measured by the memory and problem-solving domains of the Functional Independence Measure (FIM) and composite score of the Functional Communication Measure (FCM). Medical, demographic and rehabilitation predictors of the main outcomes were assessed using regression analyses. On admission to inpatient rehabilitation, 79% of the total population presented with cognitive-communication impairments, and of them, 27% presented with persistent deficits on discharge. Admission FIM memory score, marital status, and age were significant predictors of discharge FIM memory score. Admission FIM problem-solving score, age, marital status, and prehospital living-with were significant predictors of discharge FIM problem-solving score. Admission FCM score and age were significant predictors of discharge FCM cognitive score. Persons with burn injuries are at risk for cognitive-communication impairments, which may persist after inpatient rehabilitation. FIM data obtained on admission can be used as a screening tool to identify these at-risk patients. Future work is needed to assess the efficacy of speech-language pathologist intervention for cognitive-communication deficits within the burn injury population.
Phase retrieval for crystalline specimens
NASA Astrophysics Data System (ADS)
Arnal, Romain A.; Millane, Rick P.
2017-09-01
The recent availability of ultra-bright and ultra-short X-rays pulses from new sources called x-ray free-electron lasers (XFELs) has introduced a new paradigm in X-ray crystallography. Called "diffraction-before-destruction," this paradigm addresses the main problems that plague crystallography using synchrotron sources. However, the phase problem of coherent diffraction imaging remains: one has to retrieve the phase of the measured diffraction amplitude in order to reconstruct the object. Fibrous and membrane proteins that crystallize in 1D and 2D crystals can now potentially be used for data collection with free-electron lasers. The crystallographic phase problem with such crystalline specimens is eased as the Fourier amplitude can be sampled more finely than at the Bragg sampling along one or two directions. Here we characterise uniqueness of the phase problem for different types of crystalline specimen. Simulated ab initio phase retrieval using iterative projection algorithms for 2D crystals is presented.
Conceptualizations of illness among relatives of patients diagnosed with schizophrenia.
Villares, Cecília C; Redko, Cristina P; Mari, Jair J
2017-06-01
Family concepts of a relative's illness are an important part of the coping process and reveal the cultural construction of the experience of illness. As part of a qualitative study conducted in the Schizophrenia Outpatient Clinic of the Department of Psychiatry, Escola Paulista de Medicina - UNIFESP, 14 relatives of eight outpatients diagnosed with schizophrenia were interviewed and invited to talk freely about their ideas and feelings concerning their relative's problem. Qualitative analysis was used to identify categories of illness representations. Three main categories were discussed, including Problema de Nervoso, Problema na Cabeça and Problema Espiritual (Problem of the Nerves, Problem in the Head and Spiritual Problem). The authors present evidence of these categories as cultural constructions, and discuss the relevance of popular notions of illness to the understanding of the course and outcome of schizophrenia, and the planning of culturally meaningful interventions.
Katsurada, Emiko; Tanimukai, Mitsue; Akazawa, Junko
2017-08-01
The present study investigates the relationships among children's history of maltreatment, attachment patterns, and behavior problems in Japanese institutionalized children. Twenty-nine children (12 boys and 17 girls) from three different institutions in the Kinki area (Western part of Japan) participated in this study. Their average age was 6. 41-years (ranging from 4 to 10). Thirteen of the children (44.8%) had history of maltreatment before they were institutionalized. Children's attachment was assessed by the Attachment Doll Play Assessment (George & Solomon, 1990, 1996, 2000). The child's main caregiver answered the Child Behavior Checklist (CBCL; Archenbach, 1991) to identify children's behavior problems. Results indicated a significant relationship between maltreatment history and attachment pattern. The relationship between attachment pattern and behavior problem was also confirmed. Implications and limitations of this study were discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.
Malina, Grzegorz
2004-12-15
The environmental problems related to the former chemical plant in Tarnowskie Gory, with respect to the Quaternary and Triassic groundwater as main receptors, are described and the eco-toxicological impact is discussed. The historical use of that site included industrial mining of ores (Ag, Pb, Zn) and use of Ba, B, Sr, Al, Cu during production of pigment. The majority of used and produced substances were toxic or hazardous. The applied technologies resulted in generation of waste which were mostly dumped without any elementary protection principles. Hydrodynamic modelling showed potential hazard to water-intakes. The variations of spatial distributions of selected contaminants within the Triassic carbonate series indicate that the chemical waste dumped in vicinity of the plant are the sources of groundwater contamination of boron. The results of soil and groundwater monitoring at the constructed landfill show significant contamination, mainly due to leaching from dumped waste, but also from infiltration of non-operating underground installations, and spills of toxic substances during the plant operation. The Quaternary aquifers are heavily contaminated due to the leaching out of chemical compounds from dumping sites. This is hazardous to the Triassic reservoirs--the main sources of potable water for the region. The characteristics of the key contaminants (As, B, Ba and Sr) are provided, including their transport, fate and toxicity. The spatial and temporal distribution of contaminants in groundwater is presented, and observed trends of groundwater quality decrease, mainly with respect to the Triassic aquifers, are discussed. The groundwater risk assessment being developed for the Tarnowskie Gory site should consider the present situation, and provide an approach towards evaluation and assessment of the required remediation measures.
NASA Astrophysics Data System (ADS)
Dubrovskii, V. G.; Zubov, A. P.; Koshelev, S. A.
2018-06-01
Presently, when the structure of energy consumption by industrial enterprises is being changed, many type PT turbine units operate with limitations imposed on their operating conditions, while type R backpressure turbines are often shut down for a long time or even removed from operation. Thus, the problem of using steam previously intended for process needs combined with the loading of the main equipment and additional generation of power and heat becomes urgent for many power stations. Three main ways for solving this problem are examined in this paper. Potential alternatives for retrofitting of cogeneration power stations (TETS) with types PT and R turbines are discussed. Each alternative solves a specific problem brought about by the actual operating conditions of a turbine at a specific TETs. The results of retrofitting of PT-80-130 turbines with an increase in the throughput capacity of the intermediate pressure cylinder (IPC) and R-50-130 turbines with installation of an additional low-pressure cylinder (LPC) are presented. The experience in operation of the retrofitted R-50-130 turbine with an unconventional arrangement where an additional LPC is installed upstream the high-pressure cylinder (HPC) rather than between the generator and HPC is also described. The experience in the upgrading of TETs with installation of bottom steam turbines driven by steam from a process steam extraction that is not demanded for is presented. Depending on the conditions at a specific TETs, a bottom steam turbine can be installed on a new foundation or in the compartment of a dismounted turbine with the use of serviceable auxiliary and heat-exchange equipment.
Connections between the Sznajd model with general confidence rules and graph theory
NASA Astrophysics Data System (ADS)
Timpanaro, André M.; Prado, Carmen P. C.
2012-10-01
The Sznajd model is a sociophysics model that is used to model opinion propagation and consensus formation in societies. Its main feature is that its rules favor bigger groups of agreeing people. In a previous work, we generalized the bounded confidence rule in order to model biases and prejudices in discrete opinion models. In that work, we applied this modification to the Sznajd model and presented some preliminary results. The present work extends what we did in that paper. We present results linking many of the properties of the mean-field fixed points, with only a few qualitative aspects of the confidence rule (the biases and prejudices modeled), finding an interesting connection with graph theory problems. More precisely, we link the existence of fixed points with the notion of strongly connected graphs and the stability of fixed points with the problem of finding the maximal independent sets of a graph. We state these results and present comparisons between the mean field and simulations in Barabási-Albert networks, followed by the main mathematical ideas and appendices with the rigorous proofs of our claims and some graph theory concepts, together with examples. We also show that there is no qualitative difference in the mean-field results if we require that a group of size q>2, instead of a pair, of agreeing agents be formed before they attempt to convince other sites (for the mean field, this would coincide with the q-voter model).
A new model for approximating RNA folding trajectories and population kinetics
NASA Astrophysics Data System (ADS)
Kirkpatrick, Bonnie; Hajiaghayi, Monir; Condon, Anne
2013-01-01
RNA participates both in functional aspects of the cell and in gene regulation. The interactions of these molecules are mediated by their secondary structure which can be viewed as a planar circle graph with arcs for all the chemical bonds between pairs of bases in the RNA sequence. The problem of predicting RNA secondary structure, specifically the chemically most probable structure, has many useful and efficient algorithms. This leaves RNA folding, the problem of predicting the dynamic behavior of RNA structure over time, as the main open problem. RNA folding is important for functional understanding because some RNA molecules change secondary structure in response to interactions with the environment. The full RNA folding model on at most O(3n) secondary structures is the gold standard. We present a new subset approximation model for the full model, give methods to analyze its accuracy and discuss the relative merits of our model as compared with a pre-existing subset approximation. The main advantage of our model is that it generates Monte Carlo folding pathways with the same probabilities with which they are generated under the full model. The pre-existing subset approximation does not have this property.
Innovative discharge geometries for diffusion-cooled gas lasers
NASA Astrophysics Data System (ADS)
Lapucci, Antonio
2004-09-01
Large area, narrow discharge gap, diffusion cooled gas lasers are nowadays a well established technology for the construction of industrial laser sources. Successful examples exist both with the slab (Rofin-Sinar) or coaxial (Trumpf) geometry. The main physical properties and the associated technical problems of the transverse large area RF discharge, adopted for the excitation of high power diffusion cooled gas lasers, are reviewed here. The main problems of this technology are related to the maintenance of a uniform and stable plasma excitation between closely spaced large-area electrodes at high power-density loading. Some practical solutions such as distributed resonance of the discharge channel proved successful in the case of square or rectangular cross-sections but hardly applicable to geometries such as that of coaxial electrodes. In this paper we present some solutions, adopted by our group, for the development of slab and annular CO2 lasers and for CO2 laser arrays with linear or circular symmetry. We will also briefly mention the difficulties encountered in the extraction of a good quality beam from an active medium with such a cross section. A problem that has also seen some interesting solutions.
Twelve tips for creating trigger images for problem-based learning cases.
Azer, Samy A
2007-03-01
A trigger is the starting point of problem-based learning (PBL) cases. It is usually in the form of 5-6 text lines that provide the key information about the main character (usually the patient), including 3-4 of patient's presenting problems. In addition to the trigger text, most programs using PBL include a visual trigger. This might be in the form of a single image, a series of images, a video clip, a cartoon, or even one of the patient's investigation results (e.g. chest X-ray, pathology report, or urine sample analysis). The main educational objectives of the trigger image are as follows: (1) to introduce the patient to the students; (2) to enhance students' observation skills; (3) to provide them with new information to add to the cues obtained from the trigger text; and (4) to stimulate students to ask questions as they develop their enquiry plan. When planned and delivered effectively, trigger images should be engaging and stimulate group discussion. Understanding the educational objectives of using trigger images and choosing appropriate images are the keys for constructing successful PBL cases. These twelve tips highlight the key steps in the successful creation of trigger images.
Normal grief and its correlates in Lubumbashi, an urban city in the Democratic Republic of Congo.
Joe, Katabwa Kabongo; Mapatano, Mala Ali; Manyonga, Tshibangu; Mwadianvita, Costa Kazadi; Valérien, Mutombo; Stanis, Wembonyama; Kavulu, Mukendi; Espérance, Kashala
2016-01-01
Grief is a universal experience faced at one time or another by most people during their lives. Response to grief and bereavement losses can lead to psychiatric disorders such as mood disorders, post traumatic responses, insomnia loss of appetite, anxiety, and depression. The aim of our study is to value in our community the physical and psychological complications of a normal grief. We conducted a cross-sectional study from March 2012 to September 2012 in Lubumbashi, Democratic Republic of Congo. Two questionnaires, the Hamilton Anxiety Scale and the Beck Depression Inventory scale were used as screening tool. A snow ball sampling method was performed and the questionnaires were administered only to those who consented to participate in the study. A total of 78 subjects were included in the study of which 87.2% were aged between 14-50 years old. The majority of the subjects were female 65.4%, and about a quarter (28%) was unemployed. The main correlates of the grief reported in the present study were being treated as witchcraft or accused to be responsible of a death (68%), being rejected by family and not being allowed to inherit (32%). Being homeless was reported in 26%. The main psychological symptoms reported were psychological distress after 1 year (65%) and related physical health problems after the death (72%). Depression and mild anxiety were the most reported disorders, with respectively 92.3% and 74.4% of the subjects. Grief in Lubumbashi is associated with a large number of psychological, social and health problems. Health problems such as gastric is, high blood pressure were often reported. Being accused of witchcraft remains the main social impact. Depression and anxiety were the most psychological problem associated with grief.
Normal grief and its correlates in Lubumbashi, an urban city in the Democratic Republic of Congo
Joe, Katabwa Kabongo; Mapatano, Mala Ali; Manyonga, Tshibangu; Mwadianvita, Costa Kazadi; Valérien, Mutombo; Stanis, Wembonyama; Kavulu, Mukendi; Espérance, Kashala
2016-01-01
Introduction Grief is a universal experience faced at one time or another by most people during their lives. Response to grief and bereavement losses can lead to psychiatric disorders such as mood disorders, post traumatic responses, insomnia loss of appetite, anxiety, and depression. The aim of our study is to value in our community the physical and psychological complications of a normal grief. Methods We conducted a cross-sectional study from March 2012 to September 2012 in Lubumbashi, Democratic Republic of Congo. Two questionnaires, the Hamilton Anxiety Scale and the Beck Depression Inventory scale were used as screening tool. A snow ball sampling method was performed and the questionnaires were administered only to those who consented to participate in the study. Results A total of 78 subjects were included in the study of which 87.2% were aged between 14-50 years old. The majority of the subjects were female 65.4%, and about a quarter (28%) was unemployed. The main correlates of the grief reported in the present study were being treated as witchcraft or accused to be responsible of a death (68%), being rejected by family and not being allowed to inherit (32%). Being homeless was reported in 26%. The main psychological symptoms reported were psychological distress after 1 year (65%) and related physical health problems after the death (72%). Depression and mild anxiety were the most reported disorders, with respectively 92.3% and 74.4% of the subjects. Conclusion Grief in Lubumbashi is associated with a large number of psychological, social and health problems. Health problems such as gastric is, high blood pressure were often reported. Being accused of witchcraft remains the main social impact. Depression and anxiety were the most psychological problem associated with grief. PMID:27583088
Application of fuzzy theories to formulation of multi-objective design problems. [for helicopters
NASA Technical Reports Server (NTRS)
Dhingra, A. K.; Rao, S. S.; Miura, H.
1988-01-01
Much of the decision making in real world takes place in an environment in which the goals, the constraints, and the consequences of possible actions are not known precisely. In order to deal with imprecision quantitatively, the tools of fuzzy set theory can by used. This paper demonstrates the effectiveness of fuzzy theories in the formulation and solution of two types of helicopter design problems involving multiple objectives. The first problem deals with the determination of optimal flight parameters to accomplish a specified mission in the presence of three competing objectives. The second problem addresses the optimal design of the main rotor of a helicopter involving eight objective functions. A method of solving these multi-objective problems using nonlinear programming techniques is presented. Results obtained using fuzzy formulation are compared with those obtained using crisp optimization techniques. The outlined procedures are expected to be useful in situations where doubt arises about the exactness of permissible values, degree of credibility, and correctness of statements and judgements.
Polynomial Size Formulations for the Distance and Capacity Constrained Vehicle Routing Problem
NASA Astrophysics Data System (ADS)
Kara, Imdat; Derya, Tusan
2011-09-01
The Distance and Capacity Constrained Vehicle Routing Problem (DCVRP) is an extension of the well known Traveling Salesman Problem (TSP). DCVRP arises in distribution and logistics problems. It would be beneficial to construct new formulations, which is the main motivation and contribution of this paper. We focused on two indexed integer programming formulations for DCVRP. One node based and one arc (flow) based formulation for DCVRP are presented. Both formulations have O(n2) binary variables and O(n2) constraints, i.e., the number of the decision variables and constraints grows with a polynomial function of the nodes of the underlying graph. It is shown that proposed arc based formulation produces better lower bound than the existing one (this refers to the Water's formulation in the paper). Finally, various problems from literature are solved with the node based and arc based formulations by using CPLEX 8.0. Preliminary computational analysis shows that, arc based formulation outperforms the node based formulation in terms of linear programming relaxation.
Do job demands and job control affect problem-solving?
Bergman, Peter N; Ahlberg, Gunnel; Johansson, Gun; Stoetzer, Ulrich; Aborg, Carl; Hallsten, Lennart; Lundberg, Ingvar
2012-01-01
The Job Demand Control model presents combinations of working conditions that may facilitate learning, the active learning hypothesis, or have detrimental effects on health, the strain hypothesis. To test the active learning hypothesis, this study analysed the effects of job demands and job control on general problem-solving strategies. A population-based sample of 4,636 individuals (55% women, 45% men) with the same job characteristics measured at two times with a three year time lag was used. Main effects of demands, skill discretion, task authority and control, and the combined effects of demands and control were analysed in logistic regressions, on four outcomes representing general problem-solving strategies. Those reporting high on skill discretion, task authority and control, as well as those reporting high demand/high control and low demand/high control job characteristics were more likely to state using problem solving strategies. Results suggest that working conditions including high levels of control may affect how individuals cope with problems and that workplace characteristics may affect behaviour in the non-work domain.
Post-Optimality Analysis In Aerospace Vehicle Design
NASA Technical Reports Server (NTRS)
Braun, Robert D.; Kroo, Ilan M.; Gage, Peter J.
1993-01-01
This analysis pertains to the applicability of optimal sensitivity information to aerospace vehicle design. An optimal sensitivity (or post-optimality) analysis refers to computations performed once the initial optimization problem is solved. These computations may be used to characterize the design space about the present solution and infer changes in this solution as a result of constraint or parameter variations, without reoptimizing the entire system. The present analysis demonstrates that post-optimality information generated through first-order computations can be used to accurately predict the effect of constraint and parameter perturbations on the optimal solution. This assessment is based on the solution of an aircraft design problem in which the post-optimality estimates are shown to be within a few percent of the true solution over the practical range of constraint and parameter variations. Through solution of a reusable, single-stage-to-orbit, launch vehicle design problem, this optimal sensitivity information is also shown to improve the efficiency of the design process, For a hierarchically decomposed problem, this computational efficiency is realized by estimating the main-problem objective gradient through optimal sep&ivity calculations, By reducing the need for finite differentiation of a re-optimized subproblem, a significant decrease in the number of objective function evaluations required to reach the optimal solution is obtained.
NASA Astrophysics Data System (ADS)
Llasat, Maria-Carmen; Queralt, Arnau
2013-04-01
The evidence of the impact of the anthropogenic activity over the climate change, as well as the consequent impacts in temperature, snow cover and sea level has been widely demonstrated (IPCC, 2007). However, the impact of climate change on natural risks is still not clear, and the degree of uncertainty is high. The main problem lays in the complexity of the factors involved in the production of natural disasters, mainly those related with the vulnerability (in the more holistic sense of the expression), that is continuously being modified. In terms of the impact of climate change on hazards, the analysis is still complicated, and this difficulty increases when meteorological hazards that combine meteorological factors with other ones (human and/or natural) are considered (i.e. floods, wet landslides, forest fires, etc.). The Advisory Council for the Sustainable Development of Catalonia (CADS) is an advisory body which gives strategic advice to the Catalan Government in the field of sustainable development. This contribution shows the main results of a recent report elaborated by the CADS that analyses the present and potential evolution of natural risks in Catalonia (NE of Iberian Peninsula) and the influence of climate change in it. The analysis is made from the point of view of sustainable development, having in mind the international approach (IPCC, 2007, 2011; UNISDR, 2009; Molin, 2009; Brauch, 2010) and with special incidence in potential problems related with security and civil protection. Conclusions identify as main problems those that will affect health (as a consequence of the increase of heat waves and temperature extremes) and water scarcity.
Genetic algorithm parameters tuning for resource-constrained project scheduling problem
NASA Astrophysics Data System (ADS)
Tian, Xingke; Yuan, Shengrui
2018-04-01
Project Scheduling Problem (RCPSP) is a kind of important scheduling problem. To achieve a certain optimal goal such as the shortest duration, the smallest cost, the resource balance and so on, it is required to arrange the start and finish of all tasks under the condition of satisfying project timing constraints and resource constraints. In theory, the problem belongs to the NP-hard problem, and the model is abundant. Many combinatorial optimization problems are special cases of RCPSP, such as job shop scheduling, flow shop scheduling and so on. At present, the genetic algorithm (GA) has been used to deal with the classical RCPSP problem and achieved remarkable results. Vast scholars have also studied the improved genetic algorithm for the RCPSP problem, which makes it to solve the RCPSP problem more efficiently and accurately. However, for the selection of the main parameters of the genetic algorithm, there is no parameter optimization in these studies. Generally, we used the empirical method, but it cannot ensure to meet the optimal parameters. In this paper, the problem was carried out, which is the blind selection of parameters in the process of solving the RCPSP problem. We made sampling analysis, the establishment of proxy model and ultimately solved the optimal parameters.
Resource Allocation Algorithms for the Next Generation Cellular Networks
NASA Astrophysics Data System (ADS)
Amzallag, David; Raz, Danny
This chapter describes recent results addressing resource allocation problems in the context of current and future cellular technologies. We present models that capture several fundamental aspects of planning and operating these networks, and develop new approximation algorithms providing provable good solutions for the corresponding optimization problems. We mainly focus on two families of problems: cell planning and cell selection. Cell planning deals with choosing a network of base stations that can provide the required coverage of the service area with respect to the traffic requirements, available capacities, interference, and the desired QoS. Cell selection is the process of determining the cell(s) that provide service to each mobile station. Optimizing these processes is an important step towards maximizing the utilization of current and future cellular networks.
An Automated Solution of the Low-Thrust Interplanetary Trajectory Problem.
Englander, Jacob A; Conway, Bruce A
2017-01-01
Preliminary design of low-thrust interplanetary missions is a highly complex process. The mission designer must choose discrete parameters such as the number of flybys, the bodies at which those flybys are performed, and in some cases the final destination. In addition, a time-history of control variables must be chosen that defines the trajectory. There are often many thousands, if not millions, of possible trajectories to be evaluated, which can be a very expensive process in terms of the number of human analyst hours required. An automated approach is therefore very desirable. This work presents such an approach by posing the mission design problem as a hybrid optimal control problem. The method is demonstrated on hypothetical missions to Mercury, the main asteroid belt, and Pluto.
Biology doesn't waste energy: that's really smart
NASA Astrophysics Data System (ADS)
Vincent, Julian F. V.; Bogatyreva, Olga; Bogatyrev, Nikolaj
2006-03-01
Biology presents us with answers to design problems that we suspect would be very useful if only we could implement them successfully. We use the Russian theory of problem solving - TRIZ - in a novel way to provide a system for analysis and technology transfer. The analysis shows that whereas technology uses energy as the main means of solving technical problems, biology uses information and structure. Biology is also strongly hierarchical. The suggestion is that smart technology in hierarchical structures can help us to design much more efficient technology. TRIZ also suggests that biological design is autonomous and can be defined by the prefix "self-" with any function. This autonomy extends to the control system, so that the sensor is commonly also the actuator, resulting in simpler systems and greater reliability.
Gang, Wei-juan; Wang, Xin; Wang, Fang; Dong, Guo-feng; Wu, Xiao-dong
2015-08-01
The national standard of "Regulations of Acupuncture-needle Manipulating Techniques" is one of the national Criteria of Acupuncturology for which a total of 22 items have been already established. In the process of formulation, a series of common and specific problems have been met. In the present paper, the authors expound these problems from 3 aspects, namely principles for formulation, methods for formulating criteria, and considerations about some problems. The formulating principles include selection and regulations of principles for technique classification and technique-related key factors. The main methods for formulating criteria are 1) taking the literature as the theoretical foundation, 2) taking the clinical practice as the supporting evidence, and 3) taking the expounded suggestions or conclusions through peer review.
Approach for counting vehicles in congested traffic flow
NASA Astrophysics Data System (ADS)
Tan, Xiaojun; Li, Jun; Liu, Wei
2005-02-01
More and more image sensors are used in intelligent transportation systems. In practice, occlusion is always a problem when counting vehicles in congested traffic. This paper tries to present an approach to solve the problem. The proposed approach consists of three main procedures. Firstly, a new algorithm of background subtraction is performed. The aim is to segment moving objects from an illumination-variant background. Secondly, object tracking is performed, where the CONDENSATION algorithm is used. This can avoid the problem of matching vehicles in successive frames. Thirdly, an inspecting procedure is executed to count the vehicles. When a bus firstly occludes a car and then the bus moves away a few frames later, the car will appear in the scene. The inspecting procedure should find the "new" car and add it as a tracking object.
An Automated Solution of the Low-Thrust Interplanetary Trajectory Problem
NASA Technical Reports Server (NTRS)
Englander, Jacob A.; Conway, Bruce
2016-01-01
Preliminary design of low-thrust interplanetary missions is a highly complex process. The mission designer must choose discrete parameters such as the number of flybys, the bodies at which those flybys are performed, and in some cases the final destination. In addition, a time-history of control variables must be chosen that defines the trajectory. There are often many thousands, if not millions, of possible trajectories to be evaluated, which can be a very expensive process in terms of the number of human analyst hours required. An automated approach is therefore very desirable. This work presents such an approach by posing the mission design problem as a hybrid optimal control problem. The method is demonstrated on hypothetical missions to Mercury, the main asteroid belt, and Pluto.
An Automated Solution of the Low-Thrust Interplanetary Trajectory Problem
Englander, Jacob A.; Conway, Bruce A.
2017-01-01
Preliminary design of low-thrust interplanetary missions is a highly complex process. The mission designer must choose discrete parameters such as the number of flybys, the bodies at which those flybys are performed, and in some cases the final destination. In addition, a time-history of control variables must be chosen that defines the trajectory. There are often many thousands, if not millions, of possible trajectories to be evaluated, which can be a very expensive process in terms of the number of human analyst hours required. An automated approach is therefore very desirable. This work presents such an approach by posing the mission design problem as a hybrid optimal control problem. The method is demonstrated on hypothetical missions to Mercury, the main asteroid belt, and Pluto. PMID:29515289
SSME turbopump technology improvements via transient rotordynamic analysis
NASA Technical Reports Server (NTRS)
Childs, D. W.
1975-01-01
The rotordynamic behavior of the high pressure oxygen turbopump and high pressure fuel pump was analyzed for the Space Shuttle Main Engine. The identification of potential rotordynamic problem areas which might arise during operation of these units prior to their testing was accomplished. Alternative procedures for correcting potential rotordynamic problems should they occur were investigated. An adequate analytic and physical understanding of the turbopump rotordynamics was developed to improve the probability of a correct diagnosis of rotordynamic problems from test data. Transient rotordynamic models were developed for both turbopumps. The transient models model the hydrodynamic forces of the turbopump seals. A linear stability analysis was performed for the turbopump rotordynamics models, which included gyroscopic effects, seal forces, speed-dependent bearing characteristics, and internal rotor damping. Results are presented and discussed.
A multilevel finite element method for Fredholm integral eigenvalue problems
NASA Astrophysics Data System (ADS)
Xie, Hehu; Zhou, Tao
2015-12-01
In this work, we proposed a multigrid finite element (MFE) method for solving the Fredholm integral eigenvalue problems. The main motivation for such studies is to compute the Karhunen-Loève expansions of random fields, which play an important role in the applications of uncertainty quantification. In our MFE framework, solving the eigenvalue problem is converted to doing a series of integral iterations and eigenvalue solving in the coarsest mesh. Then, any existing efficient integration scheme can be used for the associated integration process. The error estimates are provided, and the computational complexity is analyzed. It is noticed that the total computational work of our method is comparable with a single integration step in the finest mesh. Several numerical experiments are presented to validate the efficiency of the proposed numerical method.
UGV navigation in wireless sensor and actuator network environments
NASA Astrophysics Data System (ADS)
Zhang, Guyu; Li, Jianfeng; Duncan, Christian A.; Kanno, Jinko; Selmic, Rastko R.
2012-06-01
We consider a navigation problem in a distributed, self-organized and coordinate-free Wireless Sensor and Ac- tuator Network (WSAN). We rst present navigation algorithms that are veried using simulation results. Con- sidering more than one destination and multiple mobile Unmanned Ground Vehicles (UGVs), we introduce a distributed solution to the Multi-UGV, Multi-Destination navigation problem. The objective of the solution to this problem is to eciently allocate UGVs to dierent destinations and carry out navigation in the network en- vironment that minimizes total travel distance. The main contribution of this paper is to develop a solution that does not attempt to localize either the UGVs or the sensor and actuator nodes. Other than some connectivity as- sumptions about the communication graph, we consider that no prior information about the WSAN is available. The solution presented here is distributed, and the UGV navigation is solely based on feedback from neigh- boring sensor and actuator nodes. One special case discussed in the paper, the Single-UGV, Multi-Destination navigation problem, is essentially equivalent to the well-known and dicult Traveling Salesman Problem (TSP). Simulation results are presented that illustrate the navigation distance traveled through the network. We also introduce an experimental testbed for the realization of coordinate-free and localization-free UGV navigation. We use the Cricket platform as the sensor and actuator network and a Pioneer 3-DX robot as the UGV. The experiments illustrate the UGV navigation in a coordinate-free WSAN environment where the UGV successfully arrives at the assigned destinations.
"Piensa" twice: on the foreign language effect in decision making.
Costa, Albert; Foucart, Alice; Arnon, Inbal; Aparici, Melina; Apesteguia, Jose
2014-02-01
In this article, we assess to what extent decision making is affected by the language in which a given problem is presented (native vs. foreign). In particular, we aim to ask whether the impact of various heuristic biases in decision making is diminished when the problems are presented in a foreign language. To this end, we report four main studies in which more than 700 participants were tested on different types of individual decision making problems. In the first study, we replicated Keysar et al.'s (2012) recent observation regarding the foreign language effect on framing effects related to loss aversion. In the second section, we assessed whether the foreign language effect is present in other types of framing problems that involve psychological accounting biases rather than gain/loss dichotomies. In the third section, we studied the foreign language effect in several key aspects of the theory of decision making under risk and uncertainty. In the fourth study, we assessed the presence of a foreign language effect in the cognitive reflection test, a test that includes logical problems that do not carry emotional connotations. The absence of such an effect in this test suggests that foreign language leads to a reduction of heuristic biases in decision making across a range of decision making situations and provide also some evidence about the boundaries of the phenomenon. We explore several potential factors that may underlie the foreign language effect in decision making. Copyright © 2013 Elsevier B.V. All rights reserved.
Viewpoint Invariant Gesture Recognition and 3D Hand Pose Estimation Using RGB-D
ERIC Educational Resources Information Center
Doliotis, Paul
2013-01-01
The broad application domain of the work presented in this thesis is pattern classification with a focus on gesture recognition and 3D hand pose estimation. One of the main contributions of the proposed thesis is a novel method for 3D hand pose estimation using RGB-D. Hand pose estimation is formulated as a database retrieval problem. The proposed…
[Recent developments in intra-European migration since 1974].
Lebon, A; Falchi, G
1980-01-01
This article represents the text of a paper presented at a conference on European migration organized by the Council of Europe in Strasbourg, May 6-8, 1979. The authors examine changes in European migration since the oil crisis of 1974 and include a review of the relevant statistical data, a review of the main problems, and a summary of some possible future trends in European migration
Field-effect transistors (2nd revised and enlarged edition)
NASA Astrophysics Data System (ADS)
Bocharov, L. N.
The design, principle of operation, and principal technical characteristics of field-effect transistors produced in the USSR are described. Problems related to the use of field-effect transistors in various radioelectronic devices are examined, and tables of parameters and mean statistical characteristics are presented for the main types of field-effect transistors. Methods for calculating various circuit components are discussed and illustrated by numerical examples.
The Role and Use of E-Materials in Vocational Education and Training: The Case of Slovenia
ERIC Educational Resources Information Center
Mažgon, Jasna; Šebart, Mojca Kovac; Štefanc, Damijan
2015-01-01
In the paper some issues and problems regarding the implementation of ICT in initial vocational education and training in Slovenia are discussed. After the brief analysis of the main theoretical characteristics of ICT and e-materials, the key findings from the recent EU survey on the ICT in schools are presented and some conclusions on the basis…
[Current problems in the laboratory control of louse-borne typhus infection in Ukraine].
Klymchuk, M D
1996-01-01
Surveys designed to study spread of typhus infection (persistent form and Brill's disease), and state of laboratory diagnosis in Ukraine showed an important role the laboratory diagnosis plays in the system of epidemiological surveillance aimed at preventing epidemic typhus. Main trends of activities on perfection of the system of laboratory control of the infection under present-day conditions are outlined.
ERIC Educational Resources Information Center
Georgia State Dept. of Education, Atlanta. Office of Instructional Services.
Developing a secondary level health education program is the main focus of this guide, and concepts and supporting data pertaining to some of the major health problems facing children and youth are presented as well. The guide is divided into three sections. The first section, "Policies and Procedures," is concerned with school health policies and…
ERIC Educational Resources Information Center
Gahler, Michael; Garriga, Anna
2013-01-01
A large number of studies have shown that parental divorce is associated with psychological maladjustment in children. Less is known about whether the magnitude of this association has changed over time. This is mainly because of the lack of repeated data, containing identical measures over time. In the present article, the authors use data from…
Enhancing outpatient clinics management software by reducing patients' waiting time.
Almomani, Iman; AlSarheed, Ahlam
The Kingdom of Saudi Arabia (KSA) gives great attention to improving the quality of services provided by health care sectors including outpatient clinics. One of the main drawbacks in outpatient clinics is long waiting time for patients-which affects the level of patient satisfaction and the quality of services. This article addresses this problem by studying the Outpatient Management Software (OMS) and proposing solutions to reduce waiting times. Many hospitals around the world apply solutions to overcome the problem of long waiting times in outpatient clinics such as hospitals in the USA, China, Sri Lanka, and Taiwan. These clinics have succeeded in reducing wait times by 15%, 78%, 60% and 50%, respectively. Such solutions depend mainly on adding more human resources or changing some business or management policies. The solutions presented in this article reduce waiting times by enhancing the software used to manage outpatient clinics services. Both quantitative and qualitative methods have been used to understand current OMS and examine level of patient's satisfaction. Five main problems that may cause high or unmeasured waiting time have been identified: appointment type, ticket numbering, doctor late arrival, early arriving patient and patients' distribution list. These problems have been mapped to the corresponding OMS components. Solutions to the above problems have been introduced and evaluated analytically or by simulation experiments. Evaluation of the results shows a reduction in patient waiting time. When late doctor arrival issues are solved, this can reduce the clinic service time by up to 20%. However, solutions for early arriving patients reduces 53.3% of vital time, 20% of the clinic time and overall 30.3% of the total waiting time. Finally, well patient-distribution lists make improvements by 54.2%. Improvements introduced to the patients' waiting time will consequently affect patients' satisfaction and improve the quality of health care services. Copyright © 2016 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.
Singh, Brajesh K; Srivastava, Vineet K
2015-04-01
The main goal of this paper is to present a new approximate series solution of the multi-dimensional (heat-like) diffusion equation with time-fractional derivative in Caputo form using a semi-analytical approach: fractional-order reduced differential transform method (FRDTM). The efficiency of FRDTM is confirmed by considering four test problems of the multi-dimensional time fractional-order diffusion equation. FRDTM is a very efficient, effective and powerful mathematical tool which provides exact or very close approximate solutions for a wide range of real-world problems arising in engineering and natural sciences, modelled in terms of differential equations.
Multiply scaled constrained nonlinear equation solvers. [for nonlinear heat conduction problems
NASA Technical Reports Server (NTRS)
Padovan, Joe; Krishna, Lala
1986-01-01
To improve the numerical stability of nonlinear equation solvers, a partitioned multiply scaled constraint scheme is developed. This scheme enables hierarchical levels of control for nonlinear equation solvers. To complement the procedure, partitioned convergence checks are established along with self-adaptive partitioning schemes. Overall, such procedures greatly enhance the numerical stability of the original solvers. To demonstrate and motivate the development of the scheme, the problem of nonlinear heat conduction is considered. In this context the main emphasis is given to successive substitution-type schemes. To verify the improved numerical characteristics associated with partitioned multiply scaled solvers, results are presented for several benchmark examples.
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
2008-07-15
The Meeting papers discuss research and test reactor fuel performance, manufacturing and testing. Some of the main topics are: conversion from HEU to LEU in different reactors and corresponding problems and activities; flux performance and core lifetime analysis with HEU and LEU fuels; physics and safety characteristics; measurement of gamma field parameters in core with LEU fuel; nondestructive analysis of RERTR fuel; thermal hydraulic analysis; fuel interactions; transient analyses and thermal hydraulics for HEU and LEU cores; microstructure research reactor fuels; post irradiation analysis and performance; computer codes and other related problems.
Singh, Brajesh K.; Srivastava, Vineet K.
2015-01-01
The main goal of this paper is to present a new approximate series solution of the multi-dimensional (heat-like) diffusion equation with time-fractional derivative in Caputo form using a semi-analytical approach: fractional-order reduced differential transform method (FRDTM). The efficiency of FRDTM is confirmed by considering four test problems of the multi-dimensional time fractional-order diffusion equation. FRDTM is a very efficient, effective and powerful mathematical tool which provides exact or very close approximate solutions for a wide range of real-world problems arising in engineering and natural sciences, modelled in terms of differential equations. PMID:26064639
A Novel College Network Resource Management Method using Cloud Computing
NASA Astrophysics Data System (ADS)
Lin, Chen
At present information construction of college mainly has construction of college networks and management information system; there are many problems during the process of information. Cloud computing is development of distributed processing, parallel processing and grid computing, which make data stored on the cloud, make software and services placed in the cloud and build on top of various standards and protocols, you can get it through all kinds of equipments. This article introduces cloud computing and function of cloud computing, then analyzes the exiting problems of college network resource management, the cloud computing technology and methods are applied in the construction of college information sharing platform.
Passauer-Baierl, S; Hofinger, G
2011-09-01
The treatment of patients in the trauma room places extraordinary demands on the multidisciplinary and multiprofessional team with regard to expert qualifications and teamwork. The present study triangulates data extracted from observation, interviews and questionnaires. In general, team climate and teamwork are good, yet some problems could be identified. Not all team members-especially younger physicians and nurses-feel free to express their doubts and uncertainties. Furthermore, the treatment plan is not always clear for all team members. Absent or unclear leadership is seen as a main problem when a treatment proceeds negatively. The establishment of a team leader is therefore recommended.
NASA Technical Reports Server (NTRS)
Gadi, Jagannath; Yalamanchili, Raj; Shahid, Mohammad
1995-01-01
The need for high efficiency components has grown significantly due to the expanding role of fiber optic communications for various applications. Integrated optics is in a state of metamorphosis and there are many problems awaiting solutions. One of the main problems being the lack of a simple and efficient method of coupling single-mode fibers to thin-film devices for integrated optics. In this paper, optical coupling between a single-mode fiber and a uniform and tapered thin-film waveguide is theoretically modeled and analyzed. A novel tapered structure presented in this paper is shown to produce perfect match for power transfer.
Analysis of the discontinuous Galerkin method applied to the European option pricing problem
NASA Astrophysics Data System (ADS)
Hozman, J.
2013-12-01
In this paper we deal with a numerical solution of a one-dimensional Black-Scholes partial differential equation, an important scalar nonstationary linear convection-diffusion-reaction equation describing the pricing of European vanilla options. We present a derivation of the numerical scheme based on the space semidiscretization of the model problem by the discontinuous Galerkin method with nonsymmetric stabilization of diffusion terms and with the interior and boundary penalty. The main attention is paid to the investigation of a priori error estimates for the proposed scheme. The appended numerical experiments illustrate the theoretical results and the potency of the method, consequently.
The focal plane reception pattern calculation for a paraboloidal antenna with a nearby fence
NASA Technical Reports Server (NTRS)
Schmidt, Richard F.; Cheng, Hwai-Soon; Kao, Michael W.
1987-01-01
A computer simulation program is described which is used to estimate the effects of a proximate diffraction fence on the performance of paraboloid antennas. The computer program is written in FORTRAN. The physical problem, mathematical formulation and coordinate references are described. The main control structure of the program and the function of the individual subroutines are discussed. The Job Control Language set-up and program instruction are provided in the user's instruction to help users execute the present program. A sample problem with an appropriate output listing is made available as an illustration of the usage of the program.
Total-variation based velocity inversion with Bregmanized operator splitting algorithm
NASA Astrophysics Data System (ADS)
Zand, Toktam; Gholami, Ali
2018-04-01
Many problems in applied geophysics can be formulated as a linear inverse problem. The associated problems, however, are large-scale and ill-conditioned. Therefore, regularization techniques are needed to be employed for solving them and generating a stable and acceptable solution. We consider numerical methods for solving such problems in this paper. In order to tackle the ill-conditioning of the problem we use blockiness as a prior information of the subsurface parameters and formulate the problem as a constrained total variation (TV) regularization. The Bregmanized operator splitting (BOS) algorithm as a combination of the Bregman iteration and the proximal forward backward operator splitting method is developed to solve the arranged problem. Two main advantages of this new algorithm are that no matrix inversion is required and that a discrepancy stopping criterion is used to stop the iterations, which allow efficient solution of large-scale problems. The high performance of the proposed TV regularization method is demonstrated using two different experiments: 1) velocity inversion from (synthetic) seismic data which is based on Born approximation, 2) computing interval velocities from RMS velocities via Dix formula. Numerical examples are presented to verify the feasibility of the proposed method for high-resolution velocity inversion.
Skin problems in ostomy patients: a case-control study of risk factors.
Nybaek, Hanne; Bang Knudsen, Dorte; Nørgaard Laursen, Troels; Karlsmark, Tonny; Jemec, Gregor B E
2009-01-01
Skin complications are frequent in ostomy patients and a number of risk factors have been suggested. The data on risk factors have, however, been documented mainly in single-centre studies and the actual importance of the suggested risk factors should therefore be verified in a group of ostomy patients broadly selected from the gene-ral population. All patients with permanent ostomies living in Roskilde County, Denmark, were invited to participate in the study. A total of 338 responded and 199 agreed to participate. Forty-five percent of all patients presented a skin problem. Less than half (43%) of patients with a skin problem were aware of the skin problems, and less than 1 in 5 (16%) had sought treatment for their skin problem. Ileostomies, ostomies with leakage and ostomies in patients with body mass index >30 were associated with skin problems. In conclusion, ileostomy, leakage and obesity predisposed patients to peristomal skin problems. Other suggested risk factors appear to be weak or insignificant. Patients under-report the presence of peristomal skin problems and therefore it is suggested that they need to be assessed by a professional on a routine basis in order to avoid or better manage peristomal skin complications.
Lok, Willeke; Anteunis, Lucien J. C.; Chenault, Michelene N.; Meesters, Cor; Haggard, Mark P.
2012-01-01
Objective The present study investigates whether general practitioner (GP) consultation initiated by failing the population hearing screening at age nine months or GP consultation because of parental concern over ear/hearing problems was more important in deciding on referral and/or surgical treatment of otitis media (OM). Design A questionnaire covering the history between birth and 21 months of age was used to obtain information on referral after failing the hearing screening, GP consultations for ear/hearing problems, and subsequent referral to a specialist and possible surgical treatment at an ENT department. Setting The province of Limburg, the Netherlands. Subjects Healthy infants invited for the hearing screening at age nine months, who responded in an earlier study called PEPPER (Persistent Ear Problems, Providing Evidence for Referral, response rate 58%). Main outcome measures The odds of a child being surgically treated for OM. Results The response rate for the present questionnaire was 72%. Of all children tested, 3.9% failed the hearing screening and were referred to their GP. Of all 2619 children in this study, 18.6% visited their GP with ear/hearing problems. Children failing the hearing screening without GP consultation for ear/hearing problems were significantly more often treated surgically for OM than children passing the hearing screening but with GP consultation for ear/hearing problems. Conclusion Objectified hearing loss, i.e. failing the hearing screening, was important in the decision for surgical treatment in infants in the Netherlands. PMID:22794165
A quasi-Newton algorithm for large-scale nonlinear equations.
Huang, Linghua
2017-01-01
In this paper, the algorithm for large-scale nonlinear equations is designed by the following steps: (i) a conjugate gradient (CG) algorithm is designed as a sub-algorithm to obtain the initial points of the main algorithm, where the sub-algorithm's initial point does not have any restrictions; (ii) a quasi-Newton algorithm with the initial points given by sub-algorithm is defined as main algorithm, where a new nonmonotone line search technique is presented to get the step length [Formula: see text]. The given nonmonotone line search technique can avoid computing the Jacobian matrix. The global convergence and the [Formula: see text]-order convergent rate of the main algorithm are established under suitable conditions. Numerical results show that the proposed method is competitive with a similar method for large-scale problems.
Choosing the Right Systems Integration
NASA Astrophysics Data System (ADS)
Péči, Matúš; Važan, Pavel
2014-12-01
The paper examines systems integration and its main levels at higher levels of control. At present, the systems integration is one of the main aspects participating in the consolidation processes and financial flows of a company. Systems Integration is a complicated emotionconsuming process and it is often a problem to choose the right approach and level of integration. The research focused on four levels of integration, while each of them is characterized by specific conditions. At each level, there is a summary of recommendations and practical experience. The paper also discusses systems integration between the information and MES levels. The main part includes user-level integration where we describe an example of such integration. Finally, we list recommendations and also possible predictions of the systems integration as one of the important factors in the future.
Application of the theory of jet stream to the asteroidal belt
NASA Technical Reports Server (NTRS)
Ip, W.-H.
1975-01-01
The possibility of incorporating the resonant effect and jet stream formation process into the problems of the Hilda asteroids and Kirkwood gaps is discussed qualitatively. It appears that formation of the precursor jet streams of the resonant asteroids in the main belt would be suppressed due to the collisional perturbation effect of the ambient matter in this region. Together with the biased distribution of near-resonant asteroids, the depletion across the Kirkwood gaps could be understood. Within the context of jet stream theory the existence of Hilda asteroids outside the main belt requires the original limit of the main belt to be not much more extensive than the present value of 3.5 AU. This is suggestive of a cosmogonic origin of the observed outer limit.
Numerical simulation of damage evolution for ductile materials and mechanical properties study
NASA Astrophysics Data System (ADS)
El Amri, A.; Hanafi, I.; Haddou, M. E. Y.; Khamlichi, A.
2015-12-01
This paper presents results of a numerical modelling of ductile fracture and failure of elements made of 5182H111 aluminium alloys subjected to dynamic traction. The analysis was performed using Johnson-Cook model based on ABAQUS software. The modelling difficulty related to prediction of ductile fracture mainly arises because there is a tremendous span of length scales from the structural problem to the micro-mechanics problem governing the material separation process. This study has been used the experimental results to calibrate a simple crack propagation criteria for shell elements of which one has often been used in practical analyses. The performance of the proposed model is in general good and it is believed that the presented results and experimental-numerical calibration procedure can be of use in practical finite-element simulations.
Urben, Sébastien; Habersaat, Stéphanie; Suter, Maya; Pihet, Sandrine; De Ridder, Jill; Stéphan, Philippe
2016-12-01
The current study investigated gender differences in the main components of antisocial behavior in an at-risk versus an offender group of adolescents. One-hundred and forty-three adolescents divided into two different risk groups [at risk (n = 54) and offenders (n = 89)] were compared according to gender (111 boys and 32 girls). Externalizing symptoms were assessed with the Delinquent and Aggressive subscales of the Youth Self-report Questionnaire, internalizing problems with the Beck Anxiety Inventory and the Beck Depressive Inventory and personality traits with the Barratt-Impulsiveness Scale as well as the Youth Psychopathic Traits Inventory. Results revealed a consistent interaction pattern, with girls presenting higher levels of externalizing symptoms, more motor impulsivity and a more arrogant and deceitful interpersonal style than boys in the at-risk group. In contrast, in the offenders' group, psychopathic traits were more present in boys than in girls. Regarding internalizing problems, girls showed more depression than boys, independently of the risk group. Among offending youths, girls present equally severe externalizing problems, and problematic personality traits as boys. At-risk girls have the highest rates of difficulties across the tested domains and should therefore be specifically targeted for prevention and intervention.
Multi-Objective Approach for Energy-Aware Workflow Scheduling in Cloud Computing Environments
Kadima, Hubert; Granado, Bertrand
2013-01-01
We address the problem of scheduling workflow applications on heterogeneous computing systems like cloud computing infrastructures. In general, the cloud workflow scheduling is a complex optimization problem which requires considering different criteria so as to meet a large number of QoS (Quality of Service) requirements. Traditional research in workflow scheduling mainly focuses on the optimization constrained by time or cost without paying attention to energy consumption. The main contribution of this study is to propose a new approach for multi-objective workflow scheduling in clouds, and present the hybrid PSO algorithm to optimize the scheduling performance. Our method is based on the Dynamic Voltage and Frequency Scaling (DVFS) technique to minimize energy consumption. This technique allows processors to operate in different voltage supply levels by sacrificing clock frequencies. This multiple voltage involves a compromise between the quality of schedules and energy. Simulation results on synthetic and real-world scientific applications highlight the robust performance of the proposed approach. PMID:24319361
[Newborn with phocomelia and thrombocytopenia. Case report].
Maas, C; Arand, J; Orlikowsky, Th; Goelz, R
2002-01-01
Associated malformations and symptoms may be decisive in the differential diagnosis of neonatal phocomelia. We report on a neonate with phocomelia, petechiae and thrombocytopenia. This constellation is typical for the phocomelia-thrombocytopenia-syndrome, a variant of the thrombocytopenia-absent radius-(TAR) syndrome. During the neonatal period platelet transfusions were necessary. Relevant bleeding and development delays were not evident until the age of seven months. Cardinal symptoms of the TAR syndrome are bilaterally absent radius and neonatal thrombocytopenia. The patient presented with phocomelia of the upper extremities which occurs in only 5 - 10 % of the patients with TAR syndrome. Further abnormalities include additional bone and joint disorders and haematopoietic problems, such as thrombocytopenia. Bleeding episodes mainly occur in the first year of life, hence platelet transfusions may be necessary during this period. A new experimental approach is the Interleukin-6-mediated stimulation of thrombopoiesis. Usually platelet counts reach normal values in adults. The main problem remains a satisfactory management of various limb defects.
Multi-objective approach for energy-aware workflow scheduling in cloud computing environments.
Yassa, Sonia; Chelouah, Rachid; Kadima, Hubert; Granado, Bertrand
2013-01-01
We address the problem of scheduling workflow applications on heterogeneous computing systems like cloud computing infrastructures. In general, the cloud workflow scheduling is a complex optimization problem which requires considering different criteria so as to meet a large number of QoS (Quality of Service) requirements. Traditional research in workflow scheduling mainly focuses on the optimization constrained by time or cost without paying attention to energy consumption. The main contribution of this study is to propose a new approach for multi-objective workflow scheduling in clouds, and present the hybrid PSO algorithm to optimize the scheduling performance. Our method is based on the Dynamic Voltage and Frequency Scaling (DVFS) technique to minimize energy consumption. This technique allows processors to operate in different voltage supply levels by sacrificing clock frequencies. This multiple voltage involves a compromise between the quality of schedules and energy. Simulation results on synthetic and real-world scientific applications highlight the robust performance of the proposed approach.
NASA Astrophysics Data System (ADS)
Normatov, P.
2014-09-01
The Zeravshan River is a transboundary river whose water is mainly used for irrigation of agricultural lands of the Republic of Uzbekistan. Sufficiently rich hydropower resources in upstream of the Zeravshan River characterize the Republic of Tajikistan. Continuous monitoring of water resources condition is necessary for planning the development of this area taking into account hydropower production and irrigation needs. Water quality of Zeravshan River is currently one of the main problems in the relationship between the Republics of Uzbekistan and Tajikistan, and it frequently triggers conflict situations between the two countries. In most cases, the problem of water quality of the Zeravshan River is related to river pollution by wastewater of the Anzob Mountain-concentrating Industrial Complex (AMCC) in Tajikistan. In this paper results of research of chemical and bacteriological composition of the Zeravshan River waters are presented. The minimum impact of AMCC on quality of water of the river was experimentally established.
ODEion--a software module for structural identification of ordinary differential equations.
Gennemark, Peter; Wedelin, Dag
2014-02-01
In the systems biology field, algorithms for structural identification of ordinary differential equations (ODEs) have mainly focused on fixed model spaces like S-systems and/or on methods that require sufficiently good data so that derivatives can be accurately estimated. There is therefore a lack of methods and software that can handle more general models and realistic data. We present ODEion, a software module for structural identification of ODEs. Main characteristic features of the software are: • The model space is defined by arbitrary user-defined functions that can be nonlinear in both variables and parameters, such as for example chemical rate reactions. • ODEion implements computationally efficient algorithms that have been shown to efficiently handle sparse and noisy data. It can run a range of realistic problems that previously required a supercomputer. • ODEion is easy to use and provides SBML output. We describe the mathematical problem, the ODEion system itself, and provide several examples of how the system can be used. Available at: http://www.odeidentification.org.
Water pollution in Pakistan and its impact on public health--a review.
Azizullah, Azizullah; Khattak, Muhammad Nasir Khan; Richter, Peter; Häder, Donat-Peter
2011-02-01
Water pollution is one of the major threats to public health in Pakistan. Drinking water quality is poorly managed and monitored. Pakistan ranks at number 80 among 122 nations regarding drinking water quality. Drinking water sources, both surface and groundwater are contaminated with coliforms, toxic metals and pesticides throughout the country. Various drinking water quality parameters set by WHO are frequently violated. Human activities like improper disposal of municipal and industrial effluents and indiscriminate applications of agrochemicals in agriculture are the main factors contributing to the deterioration of water quality. Microbial and chemical pollutants are the main factors responsible exclusively or in combination for various public health problems. This review discusses a detailed layout of drinking water quality in Pakistan with special emphasis on major pollutants, sources of pollution and the consequent health problems. The data presented in this review are extracted from various studies published in national and international journals. Also reports released by the government and non-governmental organizations are included. Copyright © 2010 Elsevier Ltd. All rights reserved.
Teaching strategies in the learning of highest common factor and lowest common multiple
NASA Astrophysics Data System (ADS)
Halim, N. L. A.; Li, H.-C.; Shahrill, M.; Prahmana, R. C. I.
2017-12-01
The main purpose of this study is to improve students’ understanding of Highest Common Factor (HCF) and Lowest Common Multiple (LCM). Several alternative teaching strategies were integrated in the Year 7 lessons involving 20 students from one secondary school in Brunei Darussalam. The categories identified in the teaching strategy were the application of group work, embedding real-life problems, using presentations and the traditional drilling practice method. An open-ended survey was disseminated to collate the students’ feedback, and among the questions posed was in relation to the different types of lesson activities utilised within each of the teaching strategies. Although 55% of the students preferred the traditional drilling practice on the calculation of HCF and LCM, mainly due to the ease of the task as opposed to activities involving real-life problems, the findings also indicated that most students favour sharing their ideas in a healthy competition learning style between each other or between the groups.
Design of acoustic emission monitoring system based on VC++
NASA Astrophysics Data System (ADS)
Yu, Yang; He, Wei
2015-12-01
At present, a lot of companies at home and abroad have researched and produced a batch of specialized monitoring instruments for acoustic emission (AE). Most of them cost highly and the system function exists in less stable and less portability for the testing environment and transmission distance and other aspects. Depending on the research background and the status quo, a dual channel intelligent acoustic emission monitoring system was designed based on Microsoft Foundation Classes in Visual Studio C++ to solve some of the problems in the acoustic emission research and meet the needs of actual monitoring task. It contains several modules such as main module, acquisition module, signal parameters setting module and so on. It could give out corrosion AE waveform and signal parameters results according to the main menu selected parameters. So the needed information could be extracted from the experiments datum to solve the problem deeply. This soft system is the important part of AE detection g system.
Direction of rational use of water at livestock facilities
NASA Astrophysics Data System (ADS)
Potseluev, A. A.; Nazarov, I. V.
2017-05-01
The article notes the world water shortage problem. Against this background, Russia’s agricultural production is considered, in particular the livestock sector as the main consumer of water resources. The structure of the main technological processes at livestock facilities is given and possible technological damage is indicated in case of the lack of technological processes for servicing animals and poultry with water. The direction of rational use of water based on the introduction of new technical and technological solutions of water supply systems and means is substantiated. Constructive solutions of systems and facilities that help to reduce water consumption are presented, and as well a possible positive effect.
Space shuttle main engine high pressure fuel pump aft platform seal cavity flow analysis
NASA Technical Reports Server (NTRS)
Lowry, S. A.; Keeton, L. W.
1987-01-01
A general purpose, three-dimensional computational fluid dynamics code named PHOENICS, developed by CHAM Inc., is used to model the flow in the aft-platform seal cavity in the high pressure fuel pump of the space shuttle main engine. The model is used to predict the temperatures, velocities, and pressures in the cavity for six different sets of boundary conditions. The results are presented as input for further analysis of two known problems in the region, specifically: erratic pressures and temperatures in the adjacent coolant liner cavity and cracks in the blade shanks near the outer diameter of the aft-platform seal.
Neural dynamic optimization for control systems.II. Theory.
Seong, C Y; Widrow, B
2001-01-01
The paper presents neural dynamic optimization (NDO) as a method of optimal feedback control for nonlinear multi-input-multi-output (MIMO) systems. The main feature of NDO is that it enables neural networks to approximate the optimal feedback solution whose existence dynamic programming (DP) justifies, thereby reducing the complexities of computation and storage problems of the classical methods such as DP. This paper mainly describes the theory of NDO, while the two other companion papers of this topic explain the background for the development of NDO and demonstrate the method with several applications including control of autonomous vehicles and of a robot arm, respectively.
Quality of life in men diagnosed with anogenital warts*
de Camargo, Caio Cavassan; D'Elia, Maria Paula Barbieri; Miot, Helio Amante
2017-01-01
Anogenital warts are a worldwide public health problem. They consist of epithelial proliferations caused by HPV, whose transmission occurs mainly through sexual intercourse. In this study, we evaluated their impact on the quality of life of adult males. We interviewed 88 men in an outpatient clinic for sexually transmitted diseases at a Brazilian public institution, using the DLQI-BRA questionnaire. Most patients (81%) presented mild or no impairment of quality of life. The main dimensions affected were sex life, symptoms, and embarrassment. The low impact on quality of life may well justify the delay in seeking medical treatment, favoring the spread of the disease. PMID:29186268
[Chagas's disease and deep ecology: the anti-vectorial fight in question].
Siqueira-Batista, Rodrigo; Gomes, Andréia Patrícia; Rôças, Giselle; Cotta, Rosângela Minardi Mitre; Rubião, Eduardo Cárdenas Nogueira; Pissinatti, Alcides
2011-02-01
The inter-relations between man and the environment are among the main themes currently debated by the Brazilian public health. On such horizon, the questions concerning Chagas's disease are found to remain specially in the scope of the directed actions of control to the triatomine, the anti-vectorial fight , though already a century since its first description by Carlos Chagas, a major epidemiological problem in Latin America. Based on these considerations the present article will seek to discuss the main ecological aspects related to the American trypanosomiasis, emphasizing the control of the vectorial transmission in the context of the deep ecology.
Vu, Duy; Lomi, Alessandro; Mascia, Daniele; Pallotti, Francesca
2017-06-30
The main objective of this paper is to introduce and illustrate relational event models, a new class of statistical models for the analysis of time-stamped data with complex temporal and relational dependencies. We outline the main differences between recently proposed relational event models and more conventional network models based on the graph-theoretic formalism typically adopted in empirical studies of social networks. Our main contribution involves the definition and implementation of a marked point process extension of currently available models. According to this approach, the sequence of events of interest is decomposed into two components: (a) event time and (b) event destination. This decomposition transforms the problem of selection of event destination in relational event models into a conditional multinomial logistic regression problem. The main advantages of this formulation are the possibility of controlling for the effect of event-specific data and a significant reduction in the estimation time of currently available relational event models. We demonstrate the empirical value of the model in an analysis of interhospital patient transfers within a regional community of health care organizations. We conclude with a discussion of how the models we presented help to overcome some the limitations of statistical models for networks that are currently available. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.
Special cases of friction and applications
NASA Technical Reports Server (NTRS)
Litvin, F. L.; Coy, J. J.
1983-01-01
Two techniques for reducing friction forces are presented. The techniques are applied to the generalized problem of reducing the friction between kinematic pairs which connect a moveable link to a frame. The basic principles are: (1) Let the moveable link be supported by two bearings where the relative velocities of the link with respect to each bearing are of opposite directions. Thus the resultant force (torque) of friction acting on the link due to the bearings is approximately zero. Then, additional perturbation of motion parallel to the main motion of the moveable link will require only a very small force; (2) Let the perturbation in motion be perpendicular to the main motion. Equations are developed which explain these two methods. The results are discussed in relation to friction in geared couplings, gyroscope gimbal bearings and a rotary conveyor system. Design examples are presented.
Analysis of cavitation damage on the Space Shuttle main engine high pressure oxidizer turbopump
NASA Technical Reports Server (NTRS)
Stinebring, D. R.
1985-01-01
The performance of the Space Shuttle Main Engines (SSME) has met or exceeded specifications. However, the durability for selected components has not met the desired lifetime criteria. Thus, the High-Pressure Oxidizer Turbopump (HPOTP) has experienced cavitation erosion problems in a number of locations in the pump. An investigation was conducted, taking into account an analysis of the cavitation damage, the development of a flow model for the pump, and the recommendation of design changes which would increase the life expectancy of the unit. The present paper is concerned with the cavitation damage analysis. A model is presented which relates the heavy damage on the housing and over the inducer blades to unsteady blade surface cavitation. This cavitation occurs on the inducer blades in the wakes downstream of the pump inlet housing vanes.
Electronics for Piezoelectric Smart Structures
NASA Technical Reports Server (NTRS)
Warkentin, D. J.; Tani, J.
1997-01-01
This paper briefly presents work addressing some of the basic considerations for the electronic components used in smart structures incorporating piezoelectric elements. After general remarks on the application of piezoelectric elements to the problem of structural vibration control, three main topics are described. Work to date on the development of techniques for embedding electronic components within structural parts is presented, followed by a description of the power flow and dissipation requirements of those components. Finally current work on the development of electronic circuits for use in an 'active wall' for acoustic noise is introduced.
Laminated anisotropic reinforced plastic plates and shells
NASA Technical Reports Server (NTRS)
Korolev, V. I.
1981-01-01
Basic technical theories and engineering calculation equations for anisotropic plates and shells made of rigid reinforced plastics, mainly laminated fiberglass, are presented and discussed. Solutions are given for many problems of design of structural plates and shells, including curved sections and tanks, as well as two chapters on selection of the optimum materials, are given. Accounting for interlayer shearing and transverse separation, which are new engineering properties, are discussed. Application of the results obtained to thin three ply plates and shells wth a light elastic filler is presented and discussed.
Determination of the top quark mass circa 2013: methods, subtleties, perspectives
NASA Astrophysics Data System (ADS)
Juste, Aurelio; Mantry, Sonny; Mitov, Alexander; Penin, Alexander; Skands, Peter; Varnes, Erich; Vos, Marcel; Wimpenny, Stephen
2014-10-01
We present an up-to-date overview of the problem of top quark mass determination. We assess the need for precision in the top mass extraction in the LHC era together with the main theoretical and experimental issues arising in precision top mass determination. We collect and document existing results on top mass determination at hadron colliders and map the prospects for future precision top mass determination at e+e- colliders. We present a collection of estimates for the ultimate precision of various methods for top quark mass extraction at the LHC.
NASA Astrophysics Data System (ADS)
Raeli, Alice; Bergmann, Michel; Iollo, Angelo
2018-02-01
We consider problems governed by a linear elliptic equation with varying coefficients across internal interfaces. The solution and its normal derivative can undergo significant variations through these internal boundaries. We present a compact finite-difference scheme on a tree-based adaptive grid that can be efficiently solved using a natively parallel data structure. The main idea is to optimize the truncation error of the discretization scheme as a function of the local grid configuration to achieve second-order accuracy. Numerical illustrations are presented in two and three-dimensional configurations.
Electromagnetic topology: Characterization of internal electromagnetic coupling
NASA Technical Reports Server (NTRS)
Parmantier, J. P.; Aparicio, J. P.; Faure, F.
1991-01-01
The main principles are presented of a method dealing with the resolution of electromagnetic internal problems: Electromagnetic Topology. A very interesting way is to generalize the multiconductor transmission line network theory to the basic equation of the Electromagnetic Topology: the BLT equation. This generalization is illustrated by the treatment of an aperture as a four port junction. Analytical and experimental derivations of the scattering parameters are presented. These concepts are used to study the electromagnetic coupling in a scale model of an aircraft, and can be seen as a convenient means to test internal electromagnetic interference.
Simulation of a class of hazardous situations in the ICS «INM RAS - Baltic Sea»
NASA Astrophysics Data System (ADS)
Zakharova, Natalia; Agoshkov, Valery; Aseev, Nikita; Parmuzin, Eugene; Sheloput, Tateana; Shutyaev, Victor
2017-04-01
Development of Informational Computational Systems (ICS) for data assimilation procedures is one of multidisciplinary problems. To study and solve these problems one needs to apply modern results from different disciplines and recent developments in mathematical modeling, theory of adjoint equations and optimal control, inverse problems, numerical methods theory, numerical algebra, scientific computing and processing of satellite data. In this work the results on the ICS development for PC-ICS "INM RAS - Baltic Sea" are presented. We discuss practical problems studied by ICS. The System includes numerical model of the Baltic Sea thermodynamics, the new oil spill model describing the propagation of a slick at the Sea surface (Agoshkov, Aseev et al., 2014) and the optimal ship route calculating block (Agoshkov, Zayachkovsky et al., 2014). The ICS is based on the INMOM numerical model of the Baltic Sea thermodynamics (Zalesny et al., 2013). It is possible to calculate main hydrodynamic parameters (temperature, salinity, velocities, sea level) using user-friendly interface of the ICS. The System includes data assimilation procedures (Agoshkov, 2003, Parmuzin, Agoshkov, 2012) and one can use the block of variational assimilation of the sea surface temperature in order to obtain main hydrodynamic parameters. Main possibilities of the ICS and several numerical experiments are presented in the work. By the problem of risk control is meant a problem of determination of optimal resources quantity which are necessary for decreasing the risk to some acceptable value. Mass of oil slick is chosen as a function of control. For the realization of the random variable the quadratic "functional of cost" is introduced. It comprises cleaning costs and deviation of damage of oil pollution from its acceptable value. The problem of minimization of this functional is solved based on the methods of optimal control and the theory of adjoint equations. The solution of this problem is explicitly found. The study was supported by the Russian Foundation for Basic Research (project 16-31-00510) and by the Russian Science Foundation (project №14-11-00609). V. I. Agoshkov, Methods of Optimal Control and Adjoint Equations in Problems of Mathematical Physics. INM RAS, Moscow, 2003 (in Russian). V. B. Zalesny, A. V. Gusev, V. O. Ivchenko, R. Tamsalu, and R. Aps, Numerical model of the Baltic Sea circulation. Russ. J. Numer. Anal. Math. Modelling 28 (2013), No. 1, 85-100. V.I. Agoshkov, A.O. Zayachkovskiy, R. Aps, P. Kujala, and J. Rytkönen. Risk theory based solution to the problem of optimal vessel route // Russian Journal of Numerical Analysis and Mathematical Modelling. 2014. Volume 29, Issue 2, Pages 69-78. Agoshkov, V., Aseev, N., Aps, R., Kujala, P., Rytkönen, J., Zalesny, V. The problem of control of oil pollution risk in the Baltic Sea // Russian Journal of Numerical Analysis and Mathematical Modelling. 2014. Volume 29, Issue 2, Pages 93-105. E. I. Parmuzin and V. I. Agoshkov, Numerical solution of the variational assimilation problem for sea surface temperature in the model of the Black Sea dynamics. Russ. J. Numer. Anal. Math. Modelling 27 (2012), No. 1, 69-94. Olof Liungman and Johan Mattsson. Scientic Documentation of Seatrack Web; physical processes, algorithms and references, 2011.
Simons, Sereh M J; Cillessen, Felix H J M; Hazelzet, Jan A
2016-08-02
A problem-oriented approach is one of the possibilities to organize a medical record. The problem-oriented medical record (POMR) - a structured organization of patient information per presented medical problem- was introduced at the end of the sixties by Dr. Lawrence Weed to aid dealing with the multiplicity of patient problems. The problem list as a precondition is the centerpiece of the problem-oriented medical record (POMR) also called problem-oriented record (POR). Prior to the digital era, paper records presented a flat list of medical problems to the healthcare professional without the features that are possible with current technology. In modern EHRs a POMR based on a structured problem list can be used for clinical decision support, registries, order management, population health, and potentially other innovative functionality in the future, thereby providing a new incentive to the implementation and use of the POMR. On both 12 May 2014 and 1 June 2015 a systematic literature search was conducted. From the retrieved articles statements regarding the POMR and related to successful or non-successful implementation, were categorized. Generic determinants were extracted from these statements. In this research 38 articles were included. The literature analysis led to 12 generic determinants: clinical practice/reasoning, complete and accurate problem list, data structure/content, efficiency, functionality, interoperability, multi-disciplinary, overview of patient information, quality of care, system support, training of staff, and usability. Two main subjects can be distinguished in the determinants: the system that the problem list and POMR is integrated in and the organization using that system. The combination of the two requires a sociotechnical approach and both are equally important for successful implementation of a POMR. All the determinants have to be taken into account, but the weight given to each of the determinants depends on the organizationusing the problem list or POMR.
Natarajan, Subramanian; Bajaj, Hari C; Tayade, Rajesh J
2018-03-01
The problem of textile dye pollution has been addressed by various methods, mainly physical, chemical, biological, and acoustical. These methods mainly separate and/or remove the dye present in water. Recently, advanced oxidation processes (AOP) have been focused for removal of dye from waste water due to their advantages such as ecofriendly, economic and capable to degrade many dyes or organic pollutant present in water. Photocatalysis is one of the advance oxidation processes, mainly carried out under irradiation of light and suitable photocatalytic materials. The photocatalytic activity of the photocatalytic materials mainly depends on the band gap, surface area, and generation of electron-hole pair for degradation dyes present in water. It has been observed that the surface area plays a major role in photocatalytic degradation of dyes, by providing higher surface area, which leads to the higher adsorption of dye molecule on the surface of photocatalyst and enhances the photocatalytic activity. This present review discusses the synergic effect of adsorption of dyes on the photocatalytic efficiency of various nanostructured high surface area photocatalysts. In addition, it also provides the properties of the water polluting dyes, their mechanism and various photocatalytic materials; and their morphology used for the dye degradation under irradiation of light along with the future prospects of highly adsorptive photocatalytic material and their application in photocatalytic removal of dye from waste water. Copyright © 2017. Published by Elsevier B.V.
NASA Astrophysics Data System (ADS)
Ortega Gelabert, Olga; Zlotnik, Sergio; Afonso, Juan Carlos; Díez, Pedro
2017-04-01
The determination of the present-day physical state of the thermal and compositional structure of the Earth's lithosphere and sub-lithospheric mantle is one of the main goals in modern lithospheric research. All this data is essential to build Earth's evolution models and to reproduce many geophysical observables (e.g. elevation, gravity anomalies, travel time data, heat flow, etc) together with understanding the relationship between them. Determining the lithospheric state involves the solution of high-resolution inverse problems and, consequently, the solution of many direct models is required. The main objective of this work is to contribute to the existing inversion techniques in terms of improving the estimation of the elevation (topography) by including a dynamic component arising from sub-lithospheric mantle flow. In order to do so, we implement an efficient Reduced Order Method (ROM) built upon classic Finite Elements. ROM allows to reduce significantly the computational cost of solving a family of problems, for example all the direct models that are required in the solution of the inverse problem. The strategy of the method consists in creating a (reduced) basis of solutions, so that when a new problem has to be solved, its solution is sought within the basis instead of attempting to solve the problem itself. In order to check the Reduced Basis approach, we implemented the method in a 3D domain reproducing a portion of Earth that covers up to 400 km depth. Within the domain the Stokes equation is solved with realistic viscosities and densities. The different realizations (the family of problems) is created by varying viscosities and densities in a similar way as it would happen in an inversion problem. The Reduced Basis method is shown to be an extremely efficiently solver for the Stokes equation in this context.
Casapia, Martin; Joseph, Serene A; Gyorkos, Theresa W
2007-01-01
Background Communities of extreme poverty suffer disproportionately from a wide range of adverse outcomes, but are often neglected or underserved by organized services and research attention. In order to target the first Millennium Development Goal of eradicating extreme poverty, thereby reducing health inequalities, participatory research in these communities is needed. Therefore, the purpose of this study was to determine the priority problems and respective potential cost-effective interventions in Belen, a community of extreme poverty in the Peruvian Amazon, using a multidisciplinary and participatory focus. Methods Two multidisciplinary and participatory workshops were conducted with important stakeholders from government, non-government and community organizations, national institutes and academic institutions. In Workshop 1, participants prioritized the main health and health-related problems in the community of Belen. Problem trees were developed to show perceived causes and effects for the top six problems. In Workshop 2, following presentations describing data from recently completed field research in school and household populations of Belen, participants listed potential interventions for the priority problems, including associated barriers, enabling factors, costs and benefits. Results The top ten priority problems in Belen were identified as: 1) infant malnutrition; 2) adolescent pregnancy; 3) diarrhoea; 4) anaemia; 5) parasites; 6) lack of basic sanitation; 7) low level of education; 8) sexually transmitted diseases; 9) domestic violence; and 10) delayed school entry. Causes and effects for the top six problems, proposed interventions, and factors relating to the implementation of interventions were multidisciplinary in nature and included health, nutrition, education, social and environmental issues. Conclusion The two workshops provided valuable insight into the main health and health-related problems facing the community of Belen. The participatory focus of the workshops ensured the active involvement of important stakeholders from Belen. Based on the results of the workshops, effective and essential interventions are now being planned which will contribute to reducing health inequalities in the community. PMID:17623093
Finite difference methods for the solution of unsteady potential flows
NASA Technical Reports Server (NTRS)
Caradonna, F. X.
1985-01-01
A brief review is presented of various problems which are confronted in the development of an unsteady finite difference potential code. This review is conducted mainly in the context of what is done for a typical small disturbance and full potential methods. The issues discussed include choice of equation, linearization and conservation, differencing schemes, and algorithm development. A number of applications including unsteady three-dimensional rotor calculation, are demonstrated.
Lymphogranuloma venereum: a hidden emerging problem, Barcelona, 2011.
Vargas-Leguas, H; Garcia de Olalla, P; Arando, M; Armengol, P; Barbera, Mj; Vall, M; Vives, A; Martin-Ezquerra, G; Alsina, M; Blanco, J; Munoz, C; Caballero, E; Andreu, A; Ros, M; Gorrindo, P; Dominguez, A; Cayla, Ja
2012-01-12
From the beginning of 2007 until the end of 2011, 146 cases of lymphogranuloma venereum (LGV) were notified to the Barcelona Public Health Agency. Some 49% of them were diagnosed and reported in 2011, mainly in men who have sex with men. Almost half of them, 32 cases, were reported between July and September. This cluster represents the largest since 2004. This article presents the ongoing outbreak of LGV in Barcelona.
NASA Astrophysics Data System (ADS)
Eder, L. V.; Filimonova, I. V.; Provornaya, I. V.; Nemov, V. Yu
2017-09-01
In the article features of resource-raw development of the Russian economy for the period between 2000 and 2014 have been considered. The main features of the resource-raw development of the Russian economy at the present stage have been analyzed. The basic principles of the transition of the Russian economy to a resource-innovative development trajectory have been formulated.
Problems associated with operations and measurement in cryogenic wind tunnels
NASA Technical Reports Server (NTRS)
Blanchard, A.; Delcourt, V.; Plazanet, M.
1986-01-01
Cryogenic wind tunnel T'3 under continuous blower operation has been the object of improvements and the installation of auxiliary equipment, dealing in particular with the enlargement of the liquid nitrogen injection reservoir and the hook-up to a fast data acquisition system. Following a brief description of the installation and its functioning, we present the main experimental techniques and the instrumentation used in the cryogenic environment.
ERIC Educational Resources Information Center
Derado, Josip; Garner, Mary L.; Tran, Thu-Hang
2016-01-01
Students' abilities and interests vary dramatically in the college mathematics classroom. How do we teach all of these students effectively? In this paper, we present the Point Reward System (PRS), a new method of assessment that addresses this problem. We designed the PRS with three main goals in mind: to increase the retention rates; to keep all…
Fathelrahman, Ahmed I
2009-01-01
Background The main objective of the present study was to evaluate the agreement between questionnaire and medical records on some health and socioeconomic problems among poisoning cases. Methods Cross-sectional sample of 100 poisoning cases consecutively admitted to the Hospital Pulau Pinang, Malaysia during the period from September 2003 to February 2004 were studied. Data on health and socioeconomic problems were collected both by self-administered questionnaire and from medical records. Agreement between the two sets of data was assessed by calculating the concordance rate, Kappa (k) and PABAK. McNemar statistic was used to test differences between categories. Results Data collected by questionnaire and medical records showed excellent agreement on the "marital status"; good agreements on "chronic illness", "psychiatric illness", and "previous history of poisoning"; and fair agreements on "at least one health problem", and "boy-girl friends problem". PABAK values suggest better agreements' measures. Conclusion There were excellent to good agreements between questionnaire and medical records on the marital status and most of the health problems and fair to poor agreements on the majority of socioeconomic problems. The implications of those findings were discussed. PMID:19751526
Personality Traits, Sexual Problems, and Sexual Orientation: An Empirical Study.
Peixoto, Maria Manuela; Nobre, Pedro
2016-01-01
Personality traits, namely neuroticism, have been suggested as vulnerability factors for the development and maintenance of sexual dysfunction in heterosexual samples. However, no evidence was found regarding homosexual samples. This study aimed to analyze the differences on personality traits between heterosexual and homosexual men and women with and without sexual problems. Participants were 285 individuals (142 men, 143 women) who completed a web-based survey. Participants answered the NEO Five-Factor Inventory, the Brief Symptomatology Inventory, and questions regarding sexual problems. The groups of men and women with and without sexual problems were matched for sociodemographic variables. A 2 (Group) × 2 (Sexual Orientation) multivariate analysis of covariance was conducted separately for each gender. Results indicated a significant main effect for group and for sexual orientation in male and female samples. Men with sexual problems scored higher on neuroticism, whereas women with sexual problems scored higher on neuroticism and lower on extraversion when compared with healthy controls, regardless of sexual orientation. In addition, gay men scored higher on neuroticism and lesbian women scored higher on conscientiousness compared with the heterosexual groups. The present findings emphasize the central role of neuroticism on sexual problems in both men and women regardless of sexual orientation.
Computationally Efficient Nonlinear Bell Inequalities for Quantum Networks
NASA Astrophysics Data System (ADS)
Luo, Ming-Xing
2018-04-01
The correlations in quantum networks have attracted strong interest with new types of violations of the locality. The standard Bell inequalities cannot characterize the multipartite correlations that are generated by multiple sources. The main problem is that no computationally efficient method is available for constructing useful Bell inequalities for general quantum networks. In this work, we show a significant improvement by presenting new, explicit Bell-type inequalities for general networks including cyclic networks. These nonlinear inequalities are related to the matching problem of an equivalent unweighted bipartite graph that allows constructing a polynomial-time algorithm. For the quantum resources consisting of bipartite entangled pure states and generalized Greenberger-Horne-Zeilinger (GHZ) states, we prove the generic nonmultilocality of quantum networks with multiple independent observers using new Bell inequalities. The violations are maximal with respect to the presented Tsirelson's bound for Einstein-Podolsky-Rosen states and GHZ states. Moreover, these violations hold for Werner states or some general noisy states. Our results suggest that the presented Bell inequalities can be used to characterize experimental quantum networks.
Radiological clinical trials: Proposal of a problem-finding questionnaire to improve study success.
Valdora, Francesca; Bignotti, Bianca; Calabrese, Massimo; Houssami, Nehmat; Tagliafico, Alberto
2016-12-26
To develop a survey to help define the main problems in radiological clinical trials. Since 2006, we have managed seven different radiological clinical trials recruiting patients in academic and non-academic centres. We developed a preliminary questionnaire using a four-round Delphi approach to identify problems occurring in radiological clinical trials run at our centre. We investigated the recruitment experience, involvement of all multi-disciplinary team members and main obstacles to completing the projects. A final round of Delphi processes elucidated solutions to the identified problems. Among 19/20 (95%) respondents, 10 (53%) were young physicians (under 35 years old), and the respondents included non-faculty members, fellows, residents, and undergraduate students. Ninety-four percent (18/19) of respondents showed interest in conducting clinical trials. On a scale of 1 to 10, the problems with higher/worse scores (8-9) were related to technical or communication problems. The most frequent problems across all studies were technical problems related to clinical trial equipment, insufficient willingness to participate, obstacles to understanding the design of electronic-case report form and extra work. The developed questionnaire identified the main recurring problems in radiological clinical trials as perceived by end-users and helped define possible solutions that are mostly related to having dedicated clinical trial research staff.
Mundia, Lawrence; Mahalle, Salwa; Matzin, Rohani; Nasir Zakaria, Gamal Abdul; Abdullah, Nor Zaiham Midawati; Abdul Latif, Siti Norhedayah
2017-01-01
The purpose of the study was to identify the sociodemographic variables and social value correlates and predictors of employer-employee relationship problems in a random sample of 860 Brunei public and private sector workers of both genders. A quantitative field survey design was used and data were analyzed by correlation and logistic regression. The rationale and justification for using this approach is explained. The main sociodemographic correlates and predictors of employer-employee relationship problems in this study were educational level and the district in which the employee resided and worked. Other correlates, but not necessarily predictors, of employer-employee relationship problems were seeking help from the Bomo (traditional healer); obtaining help from online social networking; and workers with children in the family. The two best and most significant social value correlates and predictors of employer-employee relationship problems included interpersonal communications; and self-regulation and self-direction. Low scorers on the following variables were also associated with high likelihood for possessing employer-employee relationship problems: satisfaction with work achievements; and peace and security, while low scorers on work stress had lower odds of having employer-employee relationship problems. Other significant social value correlates, but not predictors of employer-employee relationship problems were self-presentation; interpersonal trust; peace and security; and general anxiety. Consistent with findings of relevant previous studies conducted elsewhere, there were the variables that correlated with and predicted employer-employee relationship problems in Brunei public and private sector workers. Having identified these, the next step, efforts and priority should be directed at addressing the presenting issues via counseling and psychotherapy with affected employees. Further research is recommended to understand better the problem and its possible solutions.
Mundia, Lawrence; Mahalle, Salwa; Matzin, Rohani; Nasir Zakaria, Gamal Abdul; Abdullah, Nor Zaiham Midawati; Abdul Latif, Siti Norhedayah
2017-01-01
The purpose of the study was to identify the sociodemographic variables and social value correlates and predictors of employer–employee relationship problems in a random sample of 860 Brunei public and private sector workers of both genders. A quantitative field survey design was used and data were analyzed by correlation and logistic regression. The rationale and justification for using this approach is explained. The main sociodemographic correlates and predictors of employer–employee relationship problems in this study were educational level and the district in which the employee resided and worked. Other correlates, but not necessarily predictors, of employer–employee relationship problems were seeking help from the Bomo (traditional healer); obtaining help from online social networking; and workers with children in the family. The two best and most significant social value correlates and predictors of employer–employee relationship problems included interpersonal communications; and self-regulation and self-direction. Low scorers on the following variables were also associated with high likelihood for possessing employer–employee relationship problems: satisfaction with work achievements; and peace and security, while low scorers on work stress had lower odds of having employer–employee relationship problems. Other significant social value correlates, but not predictors of employer–employee relationship problems were self-presentation; interpersonal trust; peace and security; and general anxiety. Consistent with findings of relevant previous studies conducted elsewhere, there were the variables that correlated with and predicted employer–employee relationship problems in Brunei public and private sector workers. Having identified these, the next step, efforts and priority should be directed at addressing the presenting issues via counseling and psychotherapy with affected employees. Further research is recommended to understand better the problem and its possible solutions. PMID:28769597
Misund, Aud R; Nerdrum, Per; Bråten, Stein; Pripp, Are Hugo; Diseth, Trond H
2013-10-31
Several studies have reported significantly higher stress levels, both short and long terms, among mothers giving preterm birth compared with mothers giving birth at term. Stress, however, is a psychological phenomenon that may present as anxiety, depression and/or trauma reactions. In this study, the long-term mental health outcomes and the prevalence of anxiety, depression and trauma reactions in women experiencing preterm birth were explored. Interactional, main effect variables and predictors were identified. Twenty-nine mothers of 35 premature children born before the 33rd week of pregnancy were assessed within 2 weeks postpartum (T0), 2 weeks after hospitalization (T1), 6 months post-term (T2), and 18 months post-term (T3). The standardized psychometric methods Impact of Event Scale (IES), General Health Questionnaire (GHQ) and State Anxiety Inventory (STAI-X1) assessed the maternal mental health outcomes. The maternal mental health problems except state anxiety decreased from T0 to T1, but remained high and stable at T3. The prevalence of posttraumatic stress reactions (PTSR) and posttraumatic stress disorder (PTSD) at T0 and T3 was 52% and 23%, respectively. We identified the time period between T0 and T1 to have a significant main effect on mental health outcomes. The predictors of higher levels of mental health problems were preeclampsia, previous psychological treatment, age, trait anxiety and infant's postnatal intraventricular haemorrhage. Bleeding in pregnancy predicted lower levels of mental health problems. The prevalence of maternal mental health problems remained high, emphasizing the importance of effective interventions.
NASA Astrophysics Data System (ADS)
Zainudin, A. F.; Hasini, H.; Fadhil, S. S. A.
2017-10-01
This paper presents a CFD analysis of the flow, velocity and temperature distribution in a 700 MW tangentially coal-fired boiler operating in Malaysia. The main objective of the analysis is to gain insights on the occurrences in the boiler so as to understand the inherent steam temperature imbalance problem. The results show that the root cause of the problem comes from the residual swirl in the horizontal pass. The deflection of the residual swirl due to the sudden reduction and expansion of the flow cross-sectional area causes velocity deviation between the left and right side of the boiler. This consequently results in flue gas temperature imbalance which has often caused tube leaks in the superheater/reheater region. Therefore, eliminating the residual swirl or restraining it from being diverted might help to alleviate the problem.
Jiang, Xiaoye; Yao, Yuan; Liu, Han; Guibas, Leonidas
2014-01-01
Modern data acquisition routinely produces massive amounts of network data. Though many methods and models have been proposed to analyze such data, the research of network data is largely disconnected with the classical theory of statistical learning and signal processing. In this paper, we present a new framework for modeling network data, which connects two seemingly different areas: network data analysis and compressed sensing. From a nonparametric perspective, we model an observed network using a large dictionary. In particular, we consider the network clique detection problem and show connections between our formulation with a new algebraic tool, namely Randon basis pursuit in homogeneous spaces. Such a connection allows us to identify rigorous recovery conditions for clique detection problems. Though this paper is mainly conceptual, we also develop practical approximation algorithms for solving empirical problems and demonstrate their usefulness on real-world datasets. PMID:25620806
Solution of internal ballistic problem for SRM with grain of complex shape during main firing phase
NASA Astrophysics Data System (ADS)
Kiryushkin, A. E.; Minkov, L. L.
2017-10-01
Solid rocket motor (SRM) internal ballistics problems are related to the problems with moving boundaries. The algorithm able to solve similar problems in axisymmetric formulation on Cartesian mesh with an arbitrary order of accuracy is considered in this paper. The base of this algorithm is the ghost point extrapolation using inverse Lax-Wendroff procedure. Level set method is used as an implicit representation of the domain boundary. As an example, the internal ballistics problem for SRM with umbrella type grain was solved during the main firing phase. In addition, flow parameters distribution in the combustion chamber was obtained for different time moments.
Flow in water-intake pump bays: A guide for utility engineers. Final report
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ettema, R.
1998-09-01
This report is intended to serve as a guide for power-plant engineers facing problems with flow conditions in pump bays in water-intake structures, especially those located alongside rivers. The guide briefly introduces the typical prevailing flow field outside of a riverside water intake. That flow field often sets the inflow conditions for pump bays located within the water intake. The monograph then presents and discusses the main flow problems associated with pump bays. The problems usually revolve around the formation of troublesome vortices. A novel feature of this monograph is the use of numerical modeling to reveal diagnostically how themore » vortices form and their sensitivities to flow conditions, such as uniformity of approach flow entering the bay and water-surface elevation relative to pump-bell submergence. The modeling was carried out using a computer code developed specially for the present project. Pump-bay layouts are discussed next. The discussion begins with a summary of the main variables influencing bay flows. The numerical model is used to determine the sensitivities of the vortices to variations in the geometric parameters. The fixes include the use of flow-control vanes and suction scoops for ensuring satisfactory flow performance in severe flow conditions; notably flows with strong cross flow and shallow flows. The monograph ends with descriptions of modeling techniques. An extensive discussion is provided on the use of numerical model for illuminating bay flows. The model is used to show how fluid viscosity affects bay flow. The effect of fluid viscosity is an important consideration in hydraulic modeling of water intakes.« less
Finding undetected protein associations in cell signaling by belief propagation.
Bailly-Bechet, M; Borgs, C; Braunstein, A; Chayes, J; Dagkessamanskaia, A; François, J-M; Zecchina, R
2011-01-11
External information propagates in the cell mainly through signaling cascades and transcriptional activation, allowing it to react to a wide spectrum of environmental changes. High-throughput experiments identify numerous molecular components of such cascades that may, however, interact through unknown partners. Some of them may be detected using data coming from the integration of a protein-protein interaction network and mRNA expression profiles. This inference problem can be mapped onto the problem of finding appropriate optimal connected subgraphs of a network defined by these datasets. The optimization procedure turns out to be computationally intractable in general. Here we present a new distributed algorithm for this task, inspired from statistical physics, and apply this scheme to alpha factor and drug perturbations data in yeast. We identify the role of the COS8 protein, a member of a gene family of previously unknown function, and validate the results by genetic experiments. The algorithm we present is specially suited for very large datasets, can run in parallel, and can be adapted to other problems in systems biology. On renowned benchmarks it outperforms other algorithms in the field.
On Target Localization Using Combined RSS and AoA Measurements
Beko, Marko; Dinis, Rui
2018-01-01
This work revises existing solutions for a problem of target localization in wireless sensor networks (WSNs), utilizing integrated measurements, namely received signal strength (RSS) and angle of arrival (AoA). The problem of RSS/AoA-based target localization became very popular in the research community recently, owing to its great applicability potential and relatively low implementation cost. Therefore, here, a comprehensive study of the state-of-the-art (SoA) solutions and their detailed analysis is presented. The beginning of this work starts by considering the SoA approaches based on convex relaxation techniques (more computationally complex in general), and it goes through other (less computationally complex) approaches, as well, such as the ones based on the generalized trust region sub-problems framework and linear least squares. Furthermore, a detailed analysis of the computational complexity of each solution is reviewed. Furthermore, an extensive set of simulation results is presented. Finally, the main conclusions are summarized, and a set of future aspects and trends that might be interesting for future research in this area is identified. PMID:29671832
Physical Principle for Generation of Randomness
NASA Technical Reports Server (NTRS)
Zak, Michail
2009-01-01
A physical principle (more precisely, a principle that incorporates mathematical models used in physics) has been conceived as the basis of a method of generating randomness in Monte Carlo simulations. The principle eliminates the need for conventional random-number generators. The Monte Carlo simulation method is among the most powerful computational methods for solving high-dimensional problems in physics, chemistry, economics, and information processing. The Monte Carlo simulation method is especially effective for solving problems in which computational complexity increases exponentially with dimensionality. The main advantage of the Monte Carlo simulation method over other methods is that the demand on computational resources becomes independent of dimensionality. As augmented by the present principle, the Monte Carlo simulation method becomes an even more powerful computational method that is especially useful for solving problems associated with dynamics of fluids, planning, scheduling, and combinatorial optimization. The present principle is based on coupling of dynamical equations with the corresponding Liouville equation. The randomness is generated by non-Lipschitz instability of dynamics triggered and controlled by feedback from the Liouville equation. (In non-Lipschitz dynamics, the derivatives of solutions of the dynamical equations are not required to be bounded.)
NASA Astrophysics Data System (ADS)
Zeng, Ming; Yang, Lijun; Qiu, Hongji; Li, Yuanfei; Peng, Lilin
2017-01-01
The wind power and PV are the key fields of clean energy development in China in recent years. However, there are still many aspects of problems in wind power and PV industries at present, such as the insufficient consumptive ability and the limitation of market competition capability. The effective leading and support of government in the aspect of policies is especially needed in order to solve these problems. Based on the analysis of main policies system of wind power and PV in our country, Spain, the United Kingdom and Germany are chosen as typical countries because of their wind power and PV industries are relatively developed. Their policies of wind power and PV industries are studied respectively from five aspects, namely macroscopic laws, development planning, administrative policies, fiscal and tax policies and price policies. Then the comparison among typical countries and China is made and the exiting problems in China's policies of wind power and PV industries are summed up. Finally, the suggestions to promote China's wind power and PV industries development are presented.
Understanding cathode flooding and dry-out for water management in air breathing PEM fuel cells
NASA Astrophysics Data System (ADS)
Paquin, Mathieu; Fréchette, Luc G.
An analysis of water management in air breathing small polymer electrolyte membrane fuel cells (PEMFCs) is presented. Comprehensive understanding of flooding and dry-out limiting phenomena is presented through a combination of analytical modeling and experimental investigations using a small PEMFC prototype. Configurations of the fuel cell with different heat and mass transfer properties are experimentally evaluated to assess the impact of thermal resistance and mass transport resistance on water balance. Manifestation of dry-out and flooding problems, as limiting phenomena, are explained through a ratio between these two resistances. Main conclusions are that decreasing the ratio between thermal and mass transport resistance under a certain point leads to flooding problems in air breathing PEMFC. Increasing this ratio leads to dry-out of the polymer electrolyte membrane. However, too high thermal resistance or too low mass transport resistance reduces the limiting current by pushing forward the dry-out problem. This work provides a framework to achieve the proper balance between thermal rejection and mass transport to optimize the maximum current density of free convection fuel cells.
Global Optimal Trajectory in Chaos and NP-Hardness
NASA Astrophysics Data System (ADS)
Latorre, Vittorio; Gao, David Yang
This paper presents an unconventional theory and method for solving general nonlinear dynamical systems. Instead of the direct iterative methods, the discretized nonlinear system is first formulated as a global optimization problem via the least squares method. A newly developed canonical duality theory shows that this nonconvex minimization problem can be solved deterministically in polynomial time if a global optimality condition is satisfied. The so-called pseudo-chaos produced by linear iterative methods are mainly due to the intrinsic numerical error accumulations. Otherwise, the global optimization problem could be NP-hard and the nonlinear system can be really chaotic. A conjecture is proposed, which reveals the connection between chaos in nonlinear dynamics and NP-hardness in computer science. The methodology and the conjecture are verified by applications to the well-known logistic equation, a forced memristive circuit and the Lorenz system. Computational results show that the canonical duality theory can be used to identify chaotic systems and to obtain realistic global optimal solutions in nonlinear dynamical systems. The method and results presented in this paper should bring some new insights into nonlinear dynamical systems and NP-hardness in computational complexity theory.
Organic and Nonorganic Feeding Disorders.
Rybak, Anna
2015-01-01
Feeding is one of the most important interactions between caregiver and child in the first few years of life and even later on in handicapped children. Feeding disorders can present as food refusal or low quantity of food intake due to behavioral issues or underlying organic conditions. This situation concerns mostly infants and children below 6 years of age; however, feeding problems can appear also later on in life. Feeding disorders are a concern for over 10-25% of parents of otherwise healthy children below 3 years of age, but only 1-5% of infants and toddlers suffer from severe feeding problems resulting in failure to thrive. In case of premature infants or neurologically disabled children, this rate is much higher. Feeding disorders may appear as an isolated problem, mainly due to negative behaviors during feeding, or as a concomitant disorder with an underlying organic disease or structural anomaly. The newest classification also includes the feeding style presented by the caregiver (responsive, controlling, indulgent or neglectful) as a separate cause of feeding disorders. © 2015 S. Karger AG, Basel.
Teaching an Old Dog an Old Trick: FREE-FIX and Free-Boundary Axisymmetric MHD Equilibrium
NASA Astrophysics Data System (ADS)
Guazzotto, Luca
2015-11-01
A common task in plasma physics research is the calculation of an axisymmetric equilibrium for tokamak modeling. The main unknown of the problem is the magnetic poloidal flux ψ. The easiest approach is to assign the shape of the plasma and only solve the equilibrium problem in the plasma / closed-field-lines region (the ``fixed-boundary approach''). Often, one may also need the vacuum fields, i.e. the equilibrium in the open-field-lines region, requiring either coil currents or ψ on some closed curve outside the plasma to be assigned (the ``free-boundary approach''). Going from one approach to the other is a textbook problem, involving the calculation of Green's functions and surface integrals in the plasma. However, no tools are readily available to perform this task. Here we present a code (FREE-FIX) to compute a boundary condition for a free-boundary equilibrium given only the corresponding fixed-boundary equilibrium. An improvement to the standard solution method, allowing for much faster calculations, is presented. Applications are discussed. PPPL fund 245139 and DOE grant G00009102.
Problems in Implementing Gifted/Talented Programs in 11 Rural Maine Schools.
ERIC Educational Resources Information Center
Hamrin, Jeannie M.
To identify promising practices, issues, and problems concerning education for the gifted in Maine, 239 classroom teachers and 14 administrators from 11 school districts geographically distributed throughout the state responded to questionnaires which profiled teacher personal characteristics and styles, described the educational setting and…
Veliz-Cuba, Alan; Aguilar, Boris; Hinkelmann, Franziska; Laubenbacher, Reinhard
2014-06-26
A key problem in the analysis of mathematical models of molecular networks is the determination of their steady states. The present paper addresses this problem for Boolean network models, an increasingly popular modeling paradigm for networks lacking detailed kinetic information. For small models, the problem can be solved by exhaustive enumeration of all state transitions. But for larger models this is not feasible, since the size of the phase space grows exponentially with the dimension of the network. The dimension of published models is growing to over 100, so that efficient methods for steady state determination are essential. Several methods have been proposed for large networks, some of them heuristic. While these methods represent a substantial improvement in scalability over exhaustive enumeration, the problem for large networks is still unsolved in general. This paper presents an algorithm that consists of two main parts. The first is a graph theoretic reduction of the wiring diagram of the network, while preserving all information about steady states. The second part formulates the determination of all steady states of a Boolean network as a problem of finding all solutions to a system of polynomial equations over the finite number system with two elements. This problem can be solved with existing computer algebra software. This algorithm compares favorably with several existing algorithms for steady state determination. One advantage is that it is not heuristic or reliant on sampling, but rather determines algorithmically and exactly all steady states of a Boolean network. The code for the algorithm, as well as the test suite of benchmark networks, is available upon request from the corresponding author. The algorithm presented in this paper reliably determines all steady states of sparse Boolean networks with up to 1000 nodes. The algorithm is effective at analyzing virtually all published models even those of moderate connectivity. The problem for large Boolean networks with high average connectivity remains an open problem.
2014-01-01
Background A key problem in the analysis of mathematical models of molecular networks is the determination of their steady states. The present paper addresses this problem for Boolean network models, an increasingly popular modeling paradigm for networks lacking detailed kinetic information. For small models, the problem can be solved by exhaustive enumeration of all state transitions. But for larger models this is not feasible, since the size of the phase space grows exponentially with the dimension of the network. The dimension of published models is growing to over 100, so that efficient methods for steady state determination are essential. Several methods have been proposed for large networks, some of them heuristic. While these methods represent a substantial improvement in scalability over exhaustive enumeration, the problem for large networks is still unsolved in general. Results This paper presents an algorithm that consists of two main parts. The first is a graph theoretic reduction of the wiring diagram of the network, while preserving all information about steady states. The second part formulates the determination of all steady states of a Boolean network as a problem of finding all solutions to a system of polynomial equations over the finite number system with two elements. This problem can be solved with existing computer algebra software. This algorithm compares favorably with several existing algorithms for steady state determination. One advantage is that it is not heuristic or reliant on sampling, but rather determines algorithmically and exactly all steady states of a Boolean network. The code for the algorithm, as well as the test suite of benchmark networks, is available upon request from the corresponding author. Conclusions The algorithm presented in this paper reliably determines all steady states of sparse Boolean networks with up to 1000 nodes. The algorithm is effective at analyzing virtually all published models even those of moderate connectivity. The problem for large Boolean networks with high average connectivity remains an open problem. PMID:24965213
1995 second modulator-klystron workshop: A modulator-klystron workshop for future linear colliders
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1996-03-01
This second workshop examined the present state of modulator design and attempted an extrapolation for future electron-positron linear colliders. These colliders are currently viewed as multikilometer-long accelerators consisting of a thousand or more RF sources with 500 to 1,000, or more, pulsed power systems. The workshop opened with two introductory talks that presented the current approaches to designing these linear colliders, the anticipated RF sources, and the design constraints for pulse power. The cost of main AC power is a major economic consideration for a future collider, consequently the workshop investigated efficient modulator designs. Techniques that effectively apply the artmore » of power conversion, from the AC mains to the RF output, and specifically, designs that generate output pulses with very fast rise times as compared to the flattop. There were six sessions that involved one or more presentations based on problems specific to the design and production of thousands of modulator-klystron stations, followed by discussion and debate on the material.« less
Clinical presentation of retinoblastoma in Alexandria: A step toward earlier diagnosis.
Soliman, Sameh E; Eldomiaty, Wesam; Goweida, Mohamed B; Dowidar, Amgad
2017-01-01
To evaluate the clinical presentation of retinoblastoma in Alexandria, Egypt, correlate the timing of accurate diagnosis with the presence of advanced disease and identify causes of delayed presentation. Retrospective noncomparative single institution study reviews demographic and clinical data of all new children with retinoblastoma presenting to Alexandria Main University ocular oncology clinic (OOC) from January 2012 to June 2014. Diagnosis time was from initial parental complaint to retinoblastoma diagnosis and referral time was from retinoblastoma diagnosis to presentation to the Alexandria OCC. Delayed Diagnosis and referral were counted if >2 weeks. Advanced presentation is defined as clinical TNMH (8th edition) staging of cT2 or cT3 (international intraocular retinoblastoma classification group D or E) in at least one eye or the presence of extra-ocular disease (cT4). Seventy eyes of 47 children were eligible: 52% unilateral, 7% with family history and 96% presented with leukocorea. Sixty-four percent of children had advanced intraocular disease and none had extra-ocular disease. Delayed presentation occurred in 58% of children and was significantly associated with advanced disease in both unilaterally and bilaterally affected children (p = 0.003, 0.002 respectively). The delay in diagnosis was more in unilateral cases while the delay in referral was more in bilateral cases. The main cause of delayed presentation in unilateral retinoblastoma was misdiagnosis (30%) while parental shopping for second medical opinion (30%) was the main cause in bilateral children. Delayed diagnosis is a problem affecting retinoblastoma management. Better medical education and training, health education and earlier screening are recommended to achieve earlier diagnosis.
Expected Power-Utility Maximization Under Incomplete Information and with Cox-Process Observations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fujimoto, Kazufumi, E-mail: m_fuji@kvj.biglobe.ne.jp; Nagai, Hideo, E-mail: nagai@sigmath.es.osaka-u.ac.jp; Runggaldier, Wolfgang J., E-mail: runggal@math.unipd.it
2013-02-15
We consider the problem of maximization of expected terminal power utility (risk sensitive criterion). The underlying market model is a regime-switching diffusion model where the regime is determined by an unobservable factor process forming a finite state Markov process. The main novelty is due to the fact that prices are observed and the portfolio is rebalanced only at random times corresponding to a Cox process where the intensity is driven by the unobserved Markovian factor process as well. This leads to a more realistic modeling for many practical situations, like in markets with liquidity restrictions; on the other hand itmore » considerably complicates the problem to the point that traditional methodologies cannot be directly applied. The approach presented here is specific to the power-utility. For log-utilities a different approach is presented in Fujimoto et al. (Preprint, 2012).« less
Failures of Imagination: Disability and the Ethics of Selective Reproduction.
Soniewicka, Marta
2015-10-01
The article addresses the problem of disability in the context of reproductive decisions based on genetic information. It poses the question of whether selective procreation should be considered as a moral obligation of prospective parents. To answer this question, a number of different ethical approaches to the problem are presented and critically analysed: the utilitarian; Julian Savulescu's principle of procreative beneficence; the rights-based. The main thesis of the article is that these approaches fail to provide any appealing principles on which reproductive decisions should be based. They constitute failures of imagination which may result in counter-intuitive moral judgments about both life with disability and genetic selection. A full appreciation of the ethical significance of recognition in procreative decisions leads to a more nuanced and morally satisfying view than other leading alternatives presented in the article. © 2015 John Wiley & Sons Ltd.
NASA Astrophysics Data System (ADS)
Staszak, Maciej
2018-03-01
Following chapter presents short introductory description of rubber and rubber industry. The main problem of rubber industry is the way of the usage of spent tires. Furthermore very important group of problems arise considering the metal and nonmetal additives which are significant component of the vulcanized rubber. The key attention is dedicated to typical ways of rubber usage in utilization and recovery of metals from spent rubber materials concentrating specifically on used tires processing. The method of recovery of rare metals from rubber tires was described. The rubber debris finds widest use in the field of waste metal solutions processing. The environmental pollution caused by metals poses serious threat to humans. Several applications of the use of waste rubber debris to remove metals from environmental waters were described. Moreover, the agriculture usage of waste tire rubber debris is described, presenting systems where the rubber material can be useful as a soil replacement.
A comparative study of upwind and MacCormack schemes for CAA benchmark problems
NASA Technical Reports Server (NTRS)
Viswanathan, K.; Sankar, L. N.
1995-01-01
In this study, upwind schemes and MacCormack schemes are evaluated as to their suitability for aeroacoustic applications. The governing equations are cast in a curvilinear coordinate system and discretized using finite volume concepts. A flux splitting procedure is used for the upwind schemes, where the signals crossing the cell faces are grouped into two categories: signals that bring information from outside into the cell, and signals that leave the cell. These signals may be computed in several ways, with the desired spatial and temporal accuracy achieved by choosing appropriate interpolating polynomials. The classical MacCormack schemes employed here are fourth order accurate in time and space. Results for categories 1, 4, and 6 of the workshop's benchmark problems are presented. Comparisons are also made with the exact solutions, where available. The main conclusions of this study are finally presented.
Pelvic fracture injuries of the female urethra.
Venn, S N; Greenwell, T J; Mundy, A R
1999-04-01
To review pelvic fracture urethral injuries in women, generally regarded as rare and thus discussed infrequently. Twelve patients (age range 7-51 years) with such injuries were reviewed; most had associated injuries, generally more severe than seen in males with urethral injuries. Patients with milder injuries, perhaps damaging just the innervation of the urethra, presented with incontinence; more severe injuries seemed to cause a longitudinal tear in the urethra but again patients presented mainly with incontinence problems. The most severe injuries were associated with complete rupture of the urethra and a distraction defect suggesting an avulsion injury. These problems were difficult to treat both reconstructively and in providing continence. Pelvic fracture urethral injuries occur in females, but less often than in males. The female urethra seems relatively resistant to injury; differing degrees of severity of pelvic trauma cause different types of urethral injury but in general, a more severe injury is needed to damage it than is necessary in males.
Sánchez-Barriga, Juan Jesús
2015-01-01
Tuberculosis (TB) is a world public health problem that still has a high morbidity and mortality rate mainly in countries with significant wealth gaps. Poverty, malnutrition, HIV infection, drug resistance, diabetes and addictions (mainly alcoholism) have been seen to contribute to the persistence of TB as an important health problem in Mexico. Death certificates associated with pulmonary tuberculosis (PTB) for 2000-2009 were obtained from the National Information System of the Secretariat of Health. Rates of mortality nationwide, by state, and by socioeconomic region were calculated. The strength of association between states where individuals resided, socioeconomic regions, and education with mortality from PTB was determined. Age-adjusted mortality rates per 100,000 inhabitants who died from PTB decreased from 4.1 to 2 between 2000 and 2009. Men (67.7%) presented higher mortality than women (32.3%). Individuals failing to complete elementary education presented a higher risk of dying from PTB (RR 1.08 [95%CI: 1.05-1.12]). The socioeconomic region and the entities with the strongest association were region 1, 5, Chiapas and Baja California. Region 1 in 2007 presented RR 7.34 (95%CI: 5.32-10.13), and region 5 in 2009 had RR 10.08 (95%CI: 6.83-14.88). In Mexico, the annual mortality rate from PTB decreased. Men presented higher mortality than women. Individuals failing to complete elementary education showed a higher risk of dying from PTB. The states and regions of Mexico that presented a stronger association with mortality from PTB were Chiapas and Baja California, region 1 and 5. Copyright © 2014 SEPAR. Published by Elsevier Espana. All rights reserved.
Resolvent-Techniques for Multiple Exercise Problems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Christensen, Sören, E-mail: christensen@math.uni-kiel.de; Lempa, Jukka, E-mail: jukka.lempa@hioa.no
2015-02-15
We study optimal multiple stopping of strong Markov processes with random refraction periods. The refraction periods are assumed to be exponentially distributed with a common rate and independent of the underlying dynamics. Our main tool is using the resolvent operator. In the first part, we reduce infinite stopping problems to ordinary ones in a general strong Markov setting. This leads to explicit solutions for wide classes of such problems. Starting from this result, we analyze problems with finitely many exercise rights and explain solution methods for some classes of problems with underlying Lévy and diffusion processes, where the optimal characteristicsmore » of the problems can be identified more explicitly. We illustrate the main results with explicit examples.« less
The Digestive System and Nutritional Considerations for Individuals with Rett Syndrome
Lotan, Meir; Zysman, Lilit
2006-01-01
Rett syndrome (RS) is a neurodevelopmental syndrome of genetic origin that mainly affects females. Individuals diagnosed with RS exhibit a variety of functional difficulties that impair their quality of life. One of the affected systems is the digestive system, where 74% of persons with RS have abnormal functioning. The affected digestive system causes this population to present an array of problems, such as gastroesophageal reflux (GER), constipation, and malnutrition, leading to failure to thrive (FTT), which resolves in reduced functional ability. Due to the severe effects of the dysfunctional digestive system of individuals with RS, this article will describe the problems common to this population, as well as propose some clinical suggestions for intervention. . PMID:17195872
[Problems and problem solving in family medicine].
Rurik, Imre
2009-08-23
The progression from panel doctor's system towards family medicine in Hungary is reviewed, including professional, educational, financial and legal background. The main barriers for further development are insufficient human resources, inadequate financial foundation, administrative overload and the present legal regulation. Hungarian observations are compared to international experiences, as well. The author concludes that changing environment needs new structure of health care system with more focus on prevention, with services provided not only by physicians and also different attitudes from the citizens. Association of practices is suggested as a new model, involving other health specialists, as well. Based on the experiences of this model, new financial incentives can be introduced as tools for possible improvement in the future.
Study of the deposition process of vinpocetine on the surface of porous silicon
NASA Astrophysics Data System (ADS)
Lenshin, A. S.; Polkovnikova, Yu. A.; Seredin, P. V.
Currently the most prospective way in pharmacotherapy is the obtaining of nanoparticles involving pharmaceutical substances. Application of porous inorganic materials on the basis of silicon is among the main features in solving of this problem. The present work is concerned with the problem of the deposition of pharmaceutical drug with nootropic activity - vinpocetine - into porous silicon. Silicon nanoparticles were obtained by electrochemical anodic etching of Si plates. The process of vinpocetine deposition was studied in dependence of the deposition time. As a result of the investigations it was found that infrared transmission spectra of porous silicon with the deposited vinpocetine revealed the absorption bands characteristic of vinpocetine substance.
The ANMLite Language and Logic for Specifying Planning Problems
NASA Technical Reports Server (NTRS)
Butler, Ricky W.; Siminiceanu, Radu I.; Munoz, Cesar A.
2007-01-01
We present the basic concepts of the ANMLite planning language. We discuss various aspects of specifying a plan in terms of constraints and checking the existence of a solution with the help of a model checker. The constructs of the ANMLite language have been kept as simple as possible in order to reduce complexity and simplify the verification problem. We illustrate the language with a specification of the space shuttle crew activity model that was constructed under the Spacecraft Autonomy for Vehicles and Habitats (SAVH) project. The main purpose of this study was to explore the implications of choosing a robust logic behind the specification of constraints, rather than simply proposing a new planning language.
A variational dynamic programming approach to robot-path planning with a distance-safety criterion
NASA Technical Reports Server (NTRS)
Suh, Suk-Hwan; Shin, Kang G.
1988-01-01
An approach to robot-path planning is developed by considering both the traveling distance and the safety of the robot. A computationally-efficient algorithm is developed to find a near-optimal path with a weighted distance-safety criterion by using a variational calculus and dynamic programming (VCDP) method. The algorithm is readily applicable to any factory environment by representing the free workspace as channels. A method for deriving these channels is also proposed. Although it is developed mainly for two-dimensional problems, this method can be easily extended to a class of three-dimensional problems. Numerical examples are presented to demonstrate the utility and power of this method.
Modal test of Shuttle engine nozzle
NASA Technical Reports Server (NTRS)
Johnston, G. D.; Coleman, A. D.
1983-01-01
A structural failure occurred on the main propulsion test stand at NSTL causing a hydrogen fire and damage to the engines to be used on the Orbiter Columbia. Scattered accelerometer measurements indicated very high response levels at 254 hertz and 311 hertz. The Engine Office at MSFC asked the Dynamics Test Branch to try and find out what caused the failure. All three nozzles were sent to Huntsville for testing. Modal test data revealed very quickly how the failure occurred in the steerhorn and also pointed out two other structural problems. A complete set of data is presented along with a narrative explanation of the steps taken to identify and verify the structural problem.
NASA Astrophysics Data System (ADS)
Flaga, Kazimierz; Furtak, Kazimierz
2015-03-01
Steel-concrete composite structures have been used in bridge engineering from decades. This is due to rational utilisation of the strength properties of the two materials. At the same time, the reinforced concrete (or prestressed) deck slab is more favourable than the orthotropic steel plate used in steel bridges (higher mass, better vibration damping, longer life). The most commonly found in practice are composite girder bridges, particularly in highway bridges of small and medium spans, but the spans may reach over 200 m. In larger spans steel truss girders are applied. Bridge composite structures are also employed in cable-stayed bridge decks of the main girder spans of the order of 600, 800 m. The aim of the article is to present the cionstruction process and strength analysis problems concerning of this type of structures. Much attention is paid to the design and calculation of the shear connectors characteristic for the discussed objects. The authors focused mainly on the issues of single composite structures. The effect of assembly states on the stresses and strains in composite members are highlighted. A separate part of problems is devoted to the influence of rheological factors, i.e. concrete shrinkage and creep, as well as thermal factors on the stresses and strains and redistribution of internal forces.
Chapter 9: The FTU Machine - Design Construction and Assembly
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pizzuto, A.; Annino, C.; Baldarelli, M.
2004-05-15
The main design features and guidelines for the construction of the 8-T cryogenically cooled Frascati Tokamak Upgrade (FTU) are presented. The main features include the very compact toroidal magnets based on the concept of the 'Bitter' type of coil with wedge-shaped turns, utilized for the first time for the Alcator A and C magnets, and the original configuration of the vacuum vessel (VV) structure, which is fully welded in order to achieve the required high strength and electric resistivity. The present toroidal limiter has been installed following several years of operation, and this installation has required the development of specificmore » remote-handling tools. The toroidal limiter consists of 12 independent sectors made of stainless steel carriers and molybdenum alloy (TZM) tiles. The main fabrication processes developed for the toroidal and poloidal coils as well as for the VV are described. It is to be noted that the assembly procedure has required very accurate machining of all the structures requiring several trials and steps. The machine has shown no problem in operating routinely at its maximum design values (8 T, 1.6 MA)« less
Psychiatric morbidities among mentally ill wives of Nepalese men working abroad.
Shakya, Dhana Ratna
2014-01-01
Husband working abroad may have not only favorable outcomes for wives and other family members but also adverse consequences, including psychological problems. Present study intended to look into psychiatric morbidity profiles of the Nepalese female psychiatric patients and the stressors related with their husband working abroad. This is a hospital-based descriptive study with convenient sampling method. Hundred consecutive female psychiatric patients, with the particular stressor, coming into the contact of the investigating team were enrolled within the study period of 12 months. The psychiatric morbidities/diagnoses were sorted out according to the International classification of disease and infirmity, 10(th) edition (ICD-10) criteria. Average age of the enrolled cases was 29 years. Nearly half of the women were illiterate or barely literate. Some other stressors, besides the one of husband working abroad were found to precipitate the illness in about 60%, main being relational and health problems. Common presenting complaints were mood, anxiety, and physical symptoms. Almost 30% of the subjects had some mental illness in their past too and similar proportion had in their blood relatives. About one-third admitted to use substances, mainly alcohol and cigarettes. The common psychiatric diagnoses were mood, anxiety, neurotic, and stress-related disorders. Nearly 10% had presented for suicide attempt. The status of husband working abroad may have adverse consequences in mental health of women. Mood affect, anxiety, and stress-related disorders are common psychiatric illness among them.
Belgian health-related data in three international databases
2011-01-01
Aims of the study This study wants to examine the availability of Belgian healthcare data in the three main international health databases: the World Health Organization European Health for All Database (WHO-HFA), the Organisation for Economic Co-operation and Development Health Data 2009 and EUROSTAT. Methods For the indicators present in the three databases, the availability of Belgian data and the source of these data were checked. Main findings The most important problem concerning the availability of Belgian health-related data in the three major international databases is the lack of recent data. Recent data are available for 27% of the indicators of the WHO-HFA database, 73% of the OECD Health Data, and for half of the Eurostat indicators. Especially recent data about health status (including mortality-based indicators) are lacking. Discussion Only the availability of the health-related data is studied in this article. The quality of the Belgian data is however also important to examine. The main problem concerning the availability of health data is the timeliness. One of the causes of this lack of (especially mortality) data is the reform of the Belgian State. Nowadays mortality data are provided by the communities. This results in a delay in the delivery of national mortality data. However several efforts are made to catch up. PMID:22958554
Determination of uranium in clinical and environmental samples by FIAS-ICPMS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Karpas, Z.; Lorber, A.; Halicz, L.
Uranium may enter the human body through ingestion or inhalation. Ingestion of uranium compounds through the diet, mainly drinking water, is a common occurrence, as these compounds are present in the biosphere. Inhalation of uranium-containing particles is mainly an occupational safety problem, but may also take place in areas where uranium compounds are abundant. The uranium concentration in urine samples may serve as an indication of the total uranium body content. A method based on flow injection and inductively coupled plasma mass spectrometry (FIAS-ICPMS) was found to be most suitable for determination of uranium in clinical samples (urine and serum),more » environmental samples (seawater, wells and carbonate rocks) and in liquids consumed by humans (drinking water and commercial beverages). Some examples of the application of the FIAS-ICPMS method are reviewed and presented here.« less
Complications of bariatric surgery: presentation and emergency management--a review.
Monkhouse, S J W; Morgan, J D T; Norton, S A
2009-05-01
The prevalence of obesity surgery is increasing rapidly in the UK as demand rises. Consequently, general surgeons on-call may be faced with the complications of such surgery and need to have an understanding about how to manage them, at least initially. Obesity surgery is mainly offered in tertiary centres but patients may present with problems to their local district hospital. This review summarises the main complications that may be encountered. A full literature search was carried out looking at articles published in the last 10 years. Keywords for search purposes included bariatric, surgery, complications, emergency and management. Complications of bariatric surgery have been extensively written about but never in a format that is designed to aid the on-call surgeon. The intricate details and rare complications have been excluded to concentrate on those symptoms and signs that are likely to be encountered by the emergency team.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Heydari, M.H., E-mail: heydari@stu.yazd.ac.ir; The Laboratory of Quantum Information Processing, Yazd University, Yazd; Hooshmandasl, M.R., E-mail: hooshmandasl@yazd.ac.ir
Because of the nonlinearity, closed-form solutions of many important stochastic functional equations are virtually impossible to obtain. Thus, numerical solutions are a viable alternative. In this paper, a new computational method based on the generalized hat basis functions together with their stochastic operational matrix of Itô-integration is proposed for solving nonlinear stochastic Itô integral equations in large intervals. In the proposed method, a new technique for computing nonlinear terms in such problems is presented. The main advantage of the proposed method is that it transforms problems under consideration into nonlinear systems of algebraic equations which can be simply solved. Errormore » analysis of the proposed method is investigated and also the efficiency of this method is shown on some concrete examples. The obtained results reveal that the proposed method is very accurate and efficient. As two useful applications, the proposed method is applied to obtain approximate solutions of the stochastic population growth models and stochastic pendulum problem.« less
Mulder, Samuel A; Wunsch, Donald C
2003-01-01
The Traveling Salesman Problem (TSP) is a very hard optimization problem in the field of operations research. It has been shown to be NP-complete, and is an often-used benchmark for new optimization techniques. One of the main challenges with this problem is that standard, non-AI heuristic approaches such as the Lin-Kernighan algorithm (LK) and the chained LK variant are currently very effective and in wide use for the common fully connected, Euclidean variant that is considered here. This paper presents an algorithm that uses adaptive resonance theory (ART) in combination with a variation of the Lin-Kernighan local optimization algorithm to solve very large instances of the TSP. The primary advantage of this algorithm over traditional LK and chained-LK approaches is the increased scalability and parallelism allowed by the divide-and-conquer clustering paradigm. Tours obtained by the algorithm are lower quality, but scaling is much better and there is a high potential for increasing performance using parallel hardware.
Problems of Mathematical Finance by Stochastic Control Methods
NASA Astrophysics Data System (ADS)
Stettner, Łukasz
The purpose of this paper is to present main ideas of mathematics of finance using the stochastic control methods. There is an interplay between stochastic control and mathematics of finance. On the one hand stochastic control is a powerful tool to study financial problems. On the other hand financial applications have stimulated development in several research subareas of stochastic control in the last two decades. We start with pricing of financial derivatives and modeling of asset prices, studying the conditions for the absence of arbitrage. Then we consider pricing of defaultable contingent claims. Investments in bonds lead us to the term structure modeling problems. Special attention is devoted to historical static portfolio analysis called Markowitz theory. We also briefly sketch dynamic portfolio problems using viscosity solutions to Hamilton-Jacobi-Bellman equation, martingale-convex analysis method or stochastic maximum principle together with backward stochastic differential equation. Finally, long time portfolio analysis for both risk neutral and risk sensitive functionals is introduced.
Present developments in theory of the solar wind
NASA Technical Reports Server (NTRS)
Parker, E. N.
1972-01-01
Current problems and developments in the theory of the large-scale expansion of the solar corona are reviewed. The outstanding question is whether the energy supply to the quiet corona is mainly thermal conduction outward from a region of active heating at its base, or mainly wave propagation outward from the base. It is suggested that the question can be settled only when the properties of the wind can be sampled over a wide range of radial distance from the sun, from far inside the orbit of earth to well beyond. It was suggested that hydromagnetic waves may drive the expansion of the active corona by direct transfer of momentum as well as energy.
Bioremediation of petroleum-contaminated soil: A Review
NASA Astrophysics Data System (ADS)
Yuniati, M. D.
2018-02-01
Petroleum is the major source of energy for various industries and daily life. Releasing petroleum into the environment whether accidentally or due to human activities is a main cause of soil pollution. Soil contaminated with petroleum has a serious hazard to human health and causes environmental problems as well. Petroleum pollutants, mainly hydrocarbon, are classified as priority pollutants. The application of microorganisms or microbial processes to remove or degrade contaminants from soil is called bioremediation. This microbiological decontamination is claimed to be an efficient, economic and versatile alternative to physicochemical treatment. This article presents an overview about bioremediation of petroleum-contaminated soil. It also includes an explanation about the types of bioremediation technologies as well as the processes.
Treating Sleep Problems in Patients with Schizophrenia.
Waite, Felicity; Myers, Elissa; Harvey, Allison G; Espie, Colin A; Startup, Helen; Sheaves, Bryony; Freeman, Daniel
2016-05-01
Sleep disturbance is increasingly recognized as a major problem for patients with schizophrenia but it is rarely the direct focus of treatment. The main recommended treatment for insomnia is cognitive behavioural therapy, which we have been evaluating for patients with current delusions and hallucinations in the context of non-affective psychosis. In this article we describe the lessons we have learned about clinical presentations of sleep problems in schizophrenia and the adaptations to intervention that we recommend for patients with current delusions and hallucinations. Twelve factors that may particularly contribute to sleep problems in schizophrenia are identified. These include delusions and hallucinations interfering with sleep, attempts to use sleep as an escape from voices, circadian rhythm disruption, insufficient daytime activity, and fear of the bed, based upon past adverse experiences. Specific adaptations for psychological treatment related to each factor are described. Our experience is that patients want help to improve their sleep; sleep problems in schizophrenia should be treated with evidence-based interventions, and that the interventions may have the added benefit of lessening the psychotic experiences. A treatment technique hierarchy is proposed for ease of translation to clinical practice.
Bekiroğlu, Sultan; Özdemir, Mehmet; Özyürek, Ercan; Arslan, Avni
2016-10-01
Model forests are nongovernmental organizations at local, regional and international level which are mainly focused on reconciling the conflicts between the stakeholders. This is an innovative approach to organization, which has been receiving more and more attraction from increasing number of countries, which gradually increased the number of model forests for the last 25 years. If these organizations reach desired levels of structure, medium, impacts and assets their contribution in sustainable forest resources management will increase ipso facto. The very first model forest of Turkey was created in Yalova Province in 2010. Yalova Province has certain fundamental problems including but not limited to; population growth and unplanned urbanization caused by industrialization, uncontrolled increase in demand for fire wood and non-wooden products of forestry resources, questionable resource management decisions adopted in the past and low-income levels of the people especially those in the rural areas. The main objective of present case study is to analyze Yalova Model Forest (YMF) so as to determine the possible problems that may occur during implementation of sustainable management for forestry resources through a planning approach with multiple stakeholders. As a result of research, it has been revealed that YMF has certain significant structural, environmental and impact-related problems. In order to ensure continuity of YMF's contribution to sustainable forestry resources management, these problems need to be addressed promptly. Copyright © 2016 Elsevier Ltd. All rights reserved.
Writing testable software requirements
DOE Office of Scientific and Technical Information (OSTI.GOV)
Knirk, D.
1997-11-01
This tutorial identifies common problems in analyzing requirements in the problem and constructing a written specification of what the software is to do. It deals with two main problem areas: identifying and describing problem requirements, and analyzing and describing behavior specifications.
Spin Rotation of Formalism for Spin Tracking
DOE Office of Scientific and Technical Information (OSTI.GOV)
Luccio,A.
The problem of which coefficients are adequate to correctly represent the spin rotation in vector spin tracking for polarized proton and deuteron beams in synchrotrons is here re-examined in the light of recent discussions. The main aim of this note is to show where some previous erroneous results originated and how to code spin rotation in a tracking code. Some analysis of a recent experiment is presented that confirm the correctness of the assumptions.
Ultrasound-guided intervention in the ankle and foot
Allen, Gina M; Watura, Roland
2016-01-01
In this comprehensive review, we discuss the main interventions performed in the foot and ankle for Achilles tendinopathy, Morton's neuromas and Plantar fasciitis as well as techniques for intra-articular and peritendinous injections. We present the different imaging techniques and injectable agents that can be used in clinical practice, trying to help the reader decide the most appropriate way of managing the patient with a problem in the ankle and foot. PMID:26537692
Well-Posedness Results for a Class of Toxicokinetic Models
2001-07-24
estimation. The main result that we establish here regarding well-posedness of solutions is based on ideas presented in [5] and [1]. Banks and Musante [5...necessary regularity required for the model to t into the second class of abstract problems discussed by Banks and Musante . Transport models for other...upon the results of Banks and Musante by achieving well-posedness for a more general class of abstract nonlinear parabolic equations. Ackleh, Banks and
MLA Exchange and Medical Libraries in India
Pathan, A. M.
1973-01-01
The paper deals with problems in obtaining single issues and complete volumes of medical periodicals through the international exchanges, mainly the Medical Library Association Exchange. It describes in detail how St. John's Medical College, Bangalore, acquires exchange material. It stresses the need to make the MLA Exchange known to those libraries which are presently unaware of its existence. Means of shipping exchange materials in the United States and Canada are also discussed. PMID:4702805
[Genetic engineering of forest woody plants].
Mashkina, O S; Butorina, A K
2003-03-01
The present state of genetic engineering (GE) of forest woody plants is considered with special reference to the materials of the International Conference "Wood, Breeding, Biotechnology and Industrial Expectations" held in France in June, 2001. Main tree species subjected to GE are listed, aims of constructing transgenic plants discussed, and methods described. Major achievements in the field are considered along with the problems associated with the employment of GE in the breeding of forest woody plants.
Wastes from paper and pulp mills
Makkonen, Osmo A. P.
1956-01-01
The disposal of wastes from paper and pulp mills—a problem of particular importance in the northern European countries of Norway, Sweden and Denmark, where wood-processing is one of the main industries—is discussed. The various types of waste produced are described, and their pollution potential is assessed, in terms of population equivalents, with special reference to the present position in Finland. The methods available for the treatment of these wastes are briefly outlined. PMID:13374536
Practical-oriented teaching of gifted youth in the field of natural sciences
NASA Astrophysics Data System (ADS)
Khalikova, F. D.; Gilmanshina, S. I.
2017-09-01
In the article it is presenteds the author’s concept of practice-oriented teaching of gifted adolescents to natural-science subjects on the example of chemistry. The main provisions of the concept are substantiated, on the basis of which individual educational trajectories have been developed. The essence of practice-oriented learning is revealed. Particular emphasis is placed on the formation of practical experience in applying theoretical knowledge to solve specific problems.
Spurious Numerical Solutions Of Differential Equations
NASA Technical Reports Server (NTRS)
Lafon, A.; Yee, H. C.
1995-01-01
Paper presents detailed study of spurious steady-state numerical solutions of differential equations that contain nonlinear source terms. Main objectives of this study are (1) to investigate how well numerical steady-state solutions of model nonlinear reaction/convection boundary-value problem mimic true steady-state solutions and (2) to relate findings of this investigation to implications for interpretation of numerical results from computational-fluid-dynamics algorithms and computer codes used to simulate reacting flows.
Globalisation, transnational policies and adult education
NASA Astrophysics Data System (ADS)
Milana, Marcella
2012-12-01
Globalisation, transnational policies and adult education - This paper examines policy documents produced by the United Nations Educational, Scientific and Cultural Organization (UNESCO) and the European Union (EU) in the field of adult education and learning. Both these entities address adult education as an explicit object of policy. This paper investigates how globalisation processes are constructed as policy problems when these transnational political agents propose adult education as a response. The author's main argument is that while UNESCO presents the provision of adult education as a means for governments worldwide to overcome disadvantages experienced by their own citizenry, the EU institutionalises learning experiences as a means for governments to sustain regional economic growth and political expansion. After reviewing the literature on globalisation to elucidate the theories that inform current understanding of contemporary economic, political, cultural and ecological changes as political problems, she presents the conceptual and methodological framework of her analysis. The author then examines the active role played by UNESCO and the EU in promoting adult education as a policy objective at transnational level, and unpacks the specific problem "representations" that are substantiated by these organisations. She argues that UNESCO and EU processes assign specific values and meanings to globalisation, and that these reflect a limited understanding of the complexity of globalisation. Finally, she considers two of the effects produced by these problem representations.
Applications of fuzzy theories to multi-objective system optimization
NASA Technical Reports Server (NTRS)
Rao, S. S.; Dhingra, A. K.
1991-01-01
Most of the computer aided design techniques developed so far deal with the optimization of a single objective function over the feasible design space. However, there often exist several engineering design problems which require a simultaneous consideration of several objective functions. This work presents several techniques of multiobjective optimization. In addition, a new formulation, based on fuzzy theories, is also introduced for the solution of multiobjective system optimization problems. The fuzzy formulation is useful in dealing with systems which are described imprecisely using fuzzy terms such as, 'sufficiently large', 'very strong', or 'satisfactory'. The proposed theory translates the imprecise linguistic statements and multiple objectives into equivalent crisp mathematical statements using fuzzy logic. The effectiveness of all the methodologies and theories presented is illustrated by formulating and solving two different engineering design problems. The first one involves the flight trajectory optimization and the main rotor design of helicopters. The second one is concerned with the integrated kinematic-dynamic synthesis of planar mechanisms. The use and effectiveness of nonlinear membership functions in fuzzy formulation is also demonstrated. The numerical results indicate that the fuzzy formulation could yield results which are qualitatively different from those provided by the crisp formulation. It is felt that the fuzzy formulation will handle real life design problems on a more rational basis.
Robustness and cognition in stabilization problem of dynamical systems based on asymptotic methods
NASA Astrophysics Data System (ADS)
Dubovik, S. A.; Kabanov, A. A.
2017-01-01
The problem of synthesis of stabilizing systems based on principles of cognitive (logical-dynamic) control for mobile objects used under uncertain conditions is considered. This direction in control theory is based on the principles of guaranteeing robust synthesis focused on worst-case scenarios of the controlled process. The guaranteeing approach is able to provide functioning of the system with the required quality and reliability only at sufficiently low disturbances and in the absence of large deviations from some regular features of the controlled process. The main tool for the analysis of large deviations and prediction of critical states here is the action functional. After the forecast is built, the choice of anti-crisis control is the supervisory control problem that optimizes the control system in a normal mode and prevents escape of the controlled process in critical states. An essential aspect of the approach presented here is the presence of a two-level (logical-dynamic) control: the input data are used not only for generating of synthesized feedback (local robust synthesis) in advance (off-line), but also to make decisions about the current (on-line) quality of stabilization in the global sense. An example of using the presented approach for the problem of development of the ship tilting prediction system is considered.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Alejaldre, C.; Blaumoser, M.; Almoguera, L.
1995-04-01
The flexible Heliac TJ-II is a medium six device (R=1.5m, [a]=0.2 m, B(0)=1.0 T) in an advanced stage of construction at Centro de Investigaciones Energeticas Medio Ambientales y Tecnologicas (CIEMAT), Madrid. The problems encountered during manufacturing so far have been solved satisfactorily. Nevertheless the narrow tolerances, which result from the compact machine design, create real challenges for all the component manufacturers. In this paper we present the present status of the project with a particular emphasis on the construction situation of the main components. 1 ref., 2 figs., 1 tab.
NASA Astrophysics Data System (ADS)
Lapteva, M. V.
Building up a specialized library collection of the Library of the Institute of Theoretical Astronomy of the Russian Academy of Sciences beginning with foundation of the Library (1924) up to the present time have been considered in their historical perspective. The main acquisition sources, stock figures, various parameters of the collection composi- tion, including information on rare foreign editions are also dealt with. The data on the existing retrieval systems and the perspectives of developing computerized problem directed reference bibliographic complexes are also considered.
An iterated local search algorithm for the team orienteering problem with variable profits
NASA Astrophysics Data System (ADS)
Gunawan, Aldy; Ng, Kien Ming; Kendall, Graham; Lai, Junhan
2018-07-01
The orienteering problem (OP) is a routing problem that has numerous applications in various domains such as logistics and tourism. The objective is to determine a subset of vertices to visit for a vehicle so that the total collected score is maximized and a given time budget is not exceeded. The extensive application of the OP has led to many different variants, including the team orienteering problem (TOP) and the team orienteering problem with time windows. The TOP extends the OP by considering multiple vehicles. In this article, the team orienteering problem with variable profits (TOPVP) is studied. The main characteristic of the TOPVP is that the amount of score collected from a visited vertex depends on the duration of stay on that vertex. A mathematical programming model for the TOPVP is first presented and an algorithm based on iterated local search (ILS) that is able to solve modified benchmark instances is then proposed. It is concluded that ILS produces solutions which are comparable to those obtained by the commercial solver CPLEX for smaller instances. For the larger instances, ILS obtains good-quality solutions that have significantly better objective value than those found by CPLEX under reasonable computational times.
Enhancements on the Convex Programming Based Powered Descent Guidance Algorithm for Mars Landing
NASA Technical Reports Server (NTRS)
Acikmese, Behcet; Blackmore, Lars; Scharf, Daniel P.; Wolf, Aron
2008-01-01
In this paper, we present enhancements on the powered descent guidance algorithm developed for Mars pinpoint landing. The guidance algorithm solves the powered descent minimum fuel trajectory optimization problem via a direct numerical method. Our main contribution is to formulate the trajectory optimization problem, which has nonconvex control constraints, as a finite dimensional convex optimization problem, specifically as a finite dimensional second order cone programming (SOCP) problem. SOCP is a subclass of convex programming, and there are efficient SOCP solvers with deterministic convergence properties. Hence, the resulting guidance algorithm can potentially be implemented onboard a spacecraft for real-time applications. Particularly, this paper discusses the algorithmic improvements obtained by: (i) Using an efficient approach to choose the optimal time-of-flight; (ii) Using a computationally inexpensive way to detect the feasibility/ infeasibility of the problem due to the thrust-to-weight constraint; (iii) Incorporating the rotation rate of the planet into the problem formulation; (iv) Developing additional constraints on the position and velocity to guarantee no-subsurface flight between the time samples of the temporal discretization; (v) Developing a fuel-limited targeting algorithm; (vi) Initial result on developing an onboard table lookup method to obtain almost fuel optimal solutions in real-time.
World Percussion Approaches in Collegiate Percussion Programs: A Mixed-Methods Study
ERIC Educational Resources Information Center
Hernly, Patrick
2012-01-01
As world percussion has grown in popularity in American colleges and universities, two main problems have emerged. The first problem is that no known source exists detailing how percussion instructors have incorporated world percussion into their collegiate teaching. A review of the literature has highlighted four main approaches to incorporating…
Misticoni, G; Marchetti, F; D'Andrea, N
1994-01-01
41 pediatricians agreed to register on a very simple form, all the cases of children affected by bronchial asthma visited in their clinic during october 1993. The data included basic information related to the therapy prescribed, its duration, a judgement on the efficacy of symptoms control and the main problems encountered with the children and their families. 237 cases were reported (mean age 4.6 year, range 2 months-13 years). 80% of children were monitored by the pediatrician; 47% had allergic reactions. The main drug used for profilaxis is ketotifen, a compound without documented efficacy; the main route for drug administration (especially during acute attacks) is by mouth, instead of by aerosol, evidencing problems in the health education on practical skills. In fact the main problems encountered by doctors are related to the communication with patients and families. This survey represents also a research model for involving health care providers and easily and quickly obtaining a useful, methodologically sound and interesting picture of everyday practice.
An investigation of reasoning by analogy in schizophrenia and autism spectrum disorder
Krawczyk, Daniel C.; Kandalaft, Michelle R.; Didehbani, Nyaz; Allen, Tandra T.; McClelland, M. Michelle; Tamminga, Carol A.; Chapman, Sandra B.
2014-01-01
Relational reasoning ability relies upon by both cognitive and social factors. We compared analogical reasoning performance in healthy controls (HC) to performance in individuals with Autism Spectrum Disorder (ASD), and individuals with schizophrenia (SZ). The experimental task required participants to find correspondences between drawings of scenes. Participants were asked to infer which item within one scene best matched a relational item within the second scene. We varied relational complexity, presence of distraction, and type of objects in the analogies (living or non-living items). We hypothesized that the cognitive differences present in SZ would reduce relational inferences relative to ASD and HC. We also hypothesized that both SZ and ASD would show lower performance on living item problems relative to HC due to lower social function scores. Overall accuracy was higher for HC relative to SZ, consistent with prior research. Across groups, higher relational complexity reduced analogical responding, as did the presence of non-living items. Separate group analyses revealed that the ASD group was less accurate at making relational inferences in problems that involved mainly non-living items and when distractors were present. The SZ group showed differences in problem type similar to the ASD group. Additionally, we found significant correlations between social cognitive ability and analogical reasoning, particularly for the SZ group. These results indicate that differences in cognitive and social abilities impact the ability to infer analogical correspondences along with numbers of relational elements and types of objects present in the problems. PMID:25191240
Statistical approach to tunneling time in attosecond experiments
NASA Astrophysics Data System (ADS)
Demir, Durmuş; Güner, Tuğrul
2017-11-01
Tunneling, transport of particles through classically forbidden regions, is a pure quantum phenomenon. It governs numerous phenomena ranging from single-molecule electronics to donor-acceptor transition reactions. The main problem is the absence of a universal method to compute tunneling time. This problem has been attacked in various ways in the literature. Here, in the present work, we show that a statistical approach to the problem, motivated by the imaginary nature of time in the forbidden regions, lead to a novel tunneling time formula which is real and subluminal (in contrast to various known time definitions implying superluminal tunneling). In addition to this, we show explicitly that the entropic time formula is in good agreement with the tunneling time measurements in laser-driven He ionization. Moreover, it sets an accurate range for long-range electron transfer reactions. The entropic time formula is general enough to extend to the photon and phonon tunneling phenomena.
NASA Astrophysics Data System (ADS)
Cardone, G.; Durante, T.; Nazarov, S. A.
2017-07-01
We consider the spectral Dirichlet problem for the Laplace operator in the plane Ω∘ with double-periodic perforation but also in the domain Ω• with a semi-infinite foreign inclusion so that the Floquet-Bloch technique and the Gelfand transform do not apply directly. We describe waves which are localized near the inclusion and propagate along it. We give a formulation of the problem with radiation conditions that provides a Fredholm operator of index zero. The main conclusion concerns the spectra σ∘ and σ• of the problems in Ω∘ and Ω•, namely we present a concrete geometry which supports the relation σ∘ ⫋σ• due to a new non-empty spectral band caused by the semi-infinite inclusion called an open waveguide in the double-periodic medium.
Vapor explosions and the blast at Mt. St. Helens
NASA Astrophysics Data System (ADS)
Sturtevant, B.; Kieffer, S. W.
In the study of geophysical phenomena, there are many problems which are of interest to fluid dynamicists, and some of these problems are suited for an investigation with the methods of shock-tube technology. The present paper is concerned with the physical basis of explosive volcanoes and some laboratory-scale experiments which have been initiated to examine the fundamental flow processes which control the eruptions. The main obejctive of the paper is to point out a few of the many problems which remain unsolved in this field. For the proper evaluation of results obtained with jets of model fluids, the behavior of gas jets has to be documented. A brief description is, therefore, provided of observations of transient jets of gases of differing density obtained in experiments using shock-tube techniques. Attention is given to a steady-flow model of the lateral blast related to the eruption of Mt. St. Helens on May 18, 1980.
Evaluation of Far-Field Boundary Conditions for the Gust Response Problem
NASA Technical Reports Server (NTRS)
Scott, James R.; Kreider, Kevin L.; Heminger, John A.
2002-01-01
This paper presents a detailed situ dy of four far-field boundary conditions used in solving the single airfoil gust response problem. The boundary conditions, examined are the partial Sommerfeld radiation condition with only radial derivatives, the full Sommerfeld radiation condition with both radial and tangential derivatives, the Bayliss-Turkel condition of order one, and the Hagstrom-Hariharan condition of order one. The main objectives of the study were to determine which far-field boundary condition was most accurate, which condition was least sensitive to changes in grid. and which condition was best overall in terms of both accuracy and efficiency. Through a systematic study of the flat plate gust response problem, it was determined that the Hagstrom-Hariharan condition was most accurate, the Bayliss-Turkel condition was least sensitive to changes in grid, and Bayliss-Turkel was best in terms of both accuracy and efficiency.
Facing the Language-Memory Problem in the Study of Autobiographical Memory.
Bartoli, Eleonora; Smorti, Andrea
2018-05-16
This paper discusses the problem of the role of language in autobiographical memory, that is barely considered in studies on autobiographical memories and narratives. As a matter of fact, most of the current studies on autobiographical memory confounded memory and narrative together. The present paper focuses on two main issues. Firstly, it debates how narratives contribute to the construction of autobiographical memories through self-other communication. Secondly, it reflects on how language and communication should be manipulated in studies about autobiographical memory. This paper is made of three sections: the first section discusses the role of language, particularly in the form of narrative, as a social tool by which autobiographical memories can be organised in a life story; the second section examines previous methods of investigation used in the study of autobiographical memories; finally, the third section proposes different methodological alternatives to overcome the problems emerging from our analysis of literature.
STS-36 Space Shuttle mission report
NASA Technical Reports Server (NTRS)
Mechelay, Joseph E.; Germany, D. M.; Nicholson, Leonard S.
1990-01-01
The STS-36 Space Shuttle Program Mission Report contains a summary of the vehicle subsystem activities on this thirty-fourth flight of the Space Shuttle and the sixth flight of the OV-104 Orbiter vehicle, Atlantis. In addition to the Atlantis vehicle, the flight vehicle consisted of an External Tank (ET) (designated as ET-33/LWT-26), three Space Shuttle main engines (SSME's) (serial numbers 2019, 2030, and 2029), and two Solid Rocket Boosters (SRB's) (designated as BI-036). The STS-36 mission was a classified Department of Defense mission, and as such, the classified portions of the mission are not discussed. The unclassified sequence of events for this mission is shown in tabular form. Summarized are the significant problems that occurred in the Orbiter subsystems during the mission. The official problem tracking list is presented. In addition, each of the Orbiter problems is cited in the subsystem discussion.
Deep Learning for ECG Classification
NASA Astrophysics Data System (ADS)
Pyakillya, B.; Kazachenko, N.; Mikhailovsky, N.
2017-10-01
The importance of ECG classification is very high now due to many current medical applications where this problem can be stated. Currently, there are many machine learning (ML) solutions which can be used for analyzing and classifying ECG data. However, the main disadvantages of these ML results is use of heuristic hand-crafted or engineered features with shallow feature learning architectures. The problem relies in the possibility not to find most appropriate features which will give high classification accuracy in this ECG problem. One of the proposing solution is to use deep learning architectures where first layers of convolutional neurons behave as feature extractors and in the end some fully-connected (FCN) layers are used for making final decision about ECG classes. In this work the deep learning architecture with 1D convolutional layers and FCN layers for ECG classification is presented and some classification results are showed.
Naturalness of Electroweak Symmetry Breaking
NASA Astrophysics Data System (ADS)
Espinosa, J. R.
2007-02-01
After revisiting the hierarchy problem of the Standard Model and its implications for the scale of New Physics, I consider the fine tuning problem of electroweak symmetry breaking in two main scenarios beyond the Standard Model: SUSY and Little Higgs models. The main conclusions are that New Physics should appear on the reach of the LHC; that some SUSY models can solve the hierarchy problem with acceptable residual fine tuning and, finally, that Little Higgs models generically suffer from large tunings, many times hidden.
Platt, R D; Griggs, R A
1993-08-01
In four experiments with 760 subjects, the present study examined Cosmides' Darwinian algorithm theory of reasoning: specifically, its explanation of facilitation on the Wason selection task. The first experiment replicated Cosmides' finding of facilitation for social contract versions of the selection task, using both her multiple-problem format and a single-problem format. Experiment 2 examined performance on Cosmides' three main social contract problems while manipulating the perspective of the subject and the presence and absence of cost-benefit information. The presence of cost-benefit information improved performance in two of the three problems while the perspective manipulation had no effect. In Experiment 3, the cost-benefit effect was replicated; and performance on one of the three problems was enhanced by the presence of explicit negatives on the NOT-P and NOT-Q cards. Experiment 4 examined the role of the deontic term "must" in the facilitation observed for two of the social contract problems. The presence of "must" led to a significant improvement in performance. The results of these experiments are strongly supportive of social contract theory in that cost-benefit information is necessary for substantial facilitation to be observed in Cosmides' problems. These findings also suggest the presence of other cues that can help guide subjects to a deontic social contract interpretation when the social contract nature of the problem is not clear.
Buy three but get only two: the smallest effect in a 2 × 2 ANOVA is always uninterpretable.
Garcia-Marques, Leonel; Garcia-Marques, Teresa; Brauer, Markus
2014-12-01
Loftus (Memory & Cognition 6:312-319, 1978) distinguished between interpretable and uninterpretable interactions. Uninterpretable interactions are ambiguous, because they may be due to two additive main effects (no interaction) and a nonlinear relationship between the (latent) outcome variable and its indicator. Interpretable interactions can only be due to the presence of a true interactive effect in the outcome variable, regardless of the relationship that it establishes with its indicator. In the present article, we first show that same problem can arise when an unmeasured mediator has a nonlinear effect on the measured outcome variable. Then we integrate Loftus's arguments with a seemingly contradictory approach to interactions suggested by Rosnow and Rosenthal (Psychological Bulletin 105:143-146, 1989). We show that entire data patterns, not just interaction effects alone, produce interpretable or noninterpretable interactions. Next, we show that the same problem of interpretability can apply to main effects. Lastly, we give concrete advice on what researchers can do to generate data patterns that provide unambiguous evidence for hypothesized interactions.
A new approach on auxiliary vehicle assignment in capacitated location routing problem
NASA Astrophysics Data System (ADS)
Bashiri, Mahdi; Rasoulinejad, Zeinab; Fallahzade, Ehsan
2016-03-01
The location routing problem (LRP) considers locating depots and vehicle routing decisions simultaneously. In classic LRP the number of customers in each route depends on the capacity of the vehicle. In this paper a capacitated LRP model with auxiliary vehicle assignment is presented in which the length of each route is not restricted by main vehicle capacity. Two kinds of vehicles are considered: main vehicles with higher capacity and fixed cost and auxiliary vehicles with lower capacity and fixed cost. The auxiliary vehicles can be added to the transportation system as an alternative strategy to cover the capacity limitations and they are just used to transfer goods from depots to vehicles and cannot serve the customers by themselves. To show the applicability of the proposed model, some numerical examples derived from the well-known instances are used. Moreover the model has been solved by some meta-heuristics for large sized instances. The results show the efficiency of the proposed model and the solution approach, considering the classic model and the exact solution approach, respectively.
The Mixed Finite Element Multigrid Method for Stokes Equations
Muzhinji, K.; Shateyi, S.; Motsa, S. S.
2015-01-01
The stable finite element discretization of the Stokes problem produces a symmetric indefinite system of linear algebraic equations. A variety of iterative solvers have been proposed for such systems in an attempt to construct efficient, fast, and robust solution techniques. This paper investigates one of such iterative solvers, the geometric multigrid solver, to find the approximate solution of the indefinite systems. The main ingredient of the multigrid method is the choice of an appropriate smoothing strategy. This study considers the application of different smoothers and compares their effects in the overall performance of the multigrid solver. We study the multigrid method with the following smoothers: distributed Gauss Seidel, inexact Uzawa, preconditioned MINRES, and Braess-Sarazin type smoothers. A comparative study of the smoothers shows that the Braess-Sarazin smoothers enhance good performance of the multigrid method. We study the problem in a two-dimensional domain using stable Hood-Taylor Q 2-Q 1 pair of finite rectangular elements. We also give the main theoretical convergence results. We present the numerical results to demonstrate the efficiency and robustness of the multigrid method and confirm the theoretical results. PMID:25945361
[Complications of double j catheters and their endourological management].
Pérez-Fentes, D
2016-10-01
The insertion of a double J catheter (DJ) has widespread, becoming a usual procedure and standard of care in urology. Despite its relative simplicity it is not free from intraoperative risks or problems during the weeks after the implant. Conversely, despite great advances in design of these catheters the ideal material has not been discovered yet, one that is perfectly biocompatible with urine and avoids completely the advent of complications. The range of problems associated with DJs is variable: from mild self-limited dysuria or hematuria to more complex situations with higher risk, such as catheter migration, complete calcification, breakage, obstruction and renal unit loss. The treatment of theses complications must combine maximal efficacy for their resolution with the least possible surgical aggression. Accordingly, the different options of endourological approach become very important and they are the cornerstone for the treatment of the complications associated with ureteral catheters. The objective of this review is to present the main complications derived from the insertion of a DJ, their diagnosis, prevention and treatment, focusing mainly in the different endourological techniques.
NASA Technical Reports Server (NTRS)
Beiting, E. J.; Luthe, J. C.
1983-01-01
This report discusses the feasibility of making temperature profile measurements in the fuel preburner of the main engine of the space shuttle (SSME) using coherent anti-Stokes Raman spectroscopy (CARS). The principal thrust of the work is to identify problems associated with making CARS measurements in high temperature gas phase hydrogen at very high pressures (approx 400 atmospheres). To this end a theoretical study was made of the characteristics of the CAR spectra of H2 as a function of temperature and pressure and the accuracy with which temperatures can be extracted from this spectra. In addition the experimental problems associated with carrying out these measurements on a SSME at NSTL were identified. A conceptual design of a CARS system suitable for this work is included. Many of the results of the calculations made in this report are plotted as a function of temperature. In the course of presenting these results, it was necessary to decide whether the number of density or the pressure should be treated as a fixed parameter.
NASA Astrophysics Data System (ADS)
Dunkel, Z.; Vincze, E.; Moring, A.
2012-04-01
The lack of water is a traditional problem of Hungarian agriculture. Two big rivers cross the territory of Hungary and times to times they produce huge floods. In the Carpathian basin a flood and a drought can occur in the same year. The general problem of Hungarian agriculture is the 'water' in two contexts, in lack of water and in surplus. Not only of the next year but of the next decades the basic question of the Hungarian planning is how the national economy can handle the increasing numbers of unexpected negative events of climate change because the growing numbers of sometimes catastrophic floods and droughts seems to be connected with global warming. Beside the 'normal floods' in the last few years the numbers of so called flash floods show increasing tendency too. The presentation summarises the 'extreme water events' of Hungarian Great Plain, and the forecast problems of Hungarian meteorology together with the National strategy in mitigation and adaptation in connection with climate change. From meteorological point of view the handling of flood and drought problem is totally different. In case of flood the stress is on the forecast, in case of drought mainly of the evaluation of the historical data mainly the short and long term evaluation of drought indices. Drought indices seem to be the simplest tools in drought analysis. The more or less well known and popular indices have been collected and compared not only with the well known simple but more complicated water balance and so called 'recursive' indices beside few ones use remotely sensed data, mainly satellite born information. The indices are classified into five groups, namely 'precipitation', 'water balance', 'soil moisture', 'recursive' and 'remote sensing' indices. For every group typical expressions are given and the possible use in the decision making and hazard risk evaluation and compensation of the farmers after the events. The meteorological elements of new Hungarian agricultural risk strategy will be shown.
Organic coal-water fuel: Problems and advances (Review)
NASA Astrophysics Data System (ADS)
Glushkov, D. O.; Strizhak, P. A.; Chernetskii, M. Yu.
2016-10-01
The study results of ignition of organic coal-water fuel (OCWF) compositions were considered. The main problems associated with investigation of these processes were identified. Historical perspectives of the development of coal-water composite fuel technologies in Russia and worldwide are presented. The advantages of the OCWF use as a power-plant fuel in comparison with the common coal-water fuels (CWF) were emphasized. The factors (component ratio, grinding degree of solid (coal) component, limiting temperature of oxidizer, properties of liquid and solid components, procedure and time of suspension preparation, etc.) affecting inertia and stability of the ignition processes of suspensions based on the products of coaland oil processing (coals of various types and metamorphism degree, filter cakes, waste motor, transformer, and turbine oils, water-oil emulsions, fuel-oil, etc.) were analyzed. The promising directions for the development of modern notions on the OCWF ignition processes were determined. The main reasons limiting active application of the OCWF in power generation were identified. Characteristics of ignition and combustion of coal-water and organic coal-water slurry fuels were compared. The effect of water in the composite coal fuels on the energy characteristics of their ignition and combustion, as well as ecological features of these processes, were elucidated. The current problems associated with pulverization of composite coal fuels in power plants, as well as the effect of characteristics of the pulverization process on the combustion parameters of fuel, were considered. The problems hindering the development of models of ignition and combustion of OCWF were analyzed. It was established that the main one was the lack of reliable experimental data on the processes of heating, evaporation, ignition, and combustion of OCWF droplets. It was concluded that the use of high-speed video recording systems and low-inertia sensors of temperature and gas concentration could help in providing the lacking experimental information.
NASA Astrophysics Data System (ADS)
Xinogalos, Stelios
The acquisition of problem-solving and programming skills in the era of knowledge society seems to be particularly important. Due to the intrinsic difficulty of acquiring such skills various educational tools have been developed. Unfortunately, most of these tools are not utilized. In this paper we present the programming microworlds Karel and objectKarel that support the procedural-imperative and Object-Oriented Programming (OOP) techniques and can be used for supporting the teaching and learning of programming in various learning contexts and audiences. The paper focuses on presenting the pedagogical features that are common to both environments and mainly on presenting the potential uses of these environments.
Application study of magnetic fluid seal in hydraulic turbine
NASA Astrophysics Data System (ADS)
Yu, Z. Y.; Zhang, W.
2012-11-01
The waterpower resources of our country are abundant, and the hydroelectric power is developed, but at present the main shaft sealing device of hydraulic turbine is easy to wear and tear and the leakage is great. The magnetic fluid seal has the advantages of no contact, no wear, self-healing, long life and so on. In this paper, the magnetic fluid seal would be used in the main shaft of hydraulic turbine, the sealing structure was built the model, meshed the geometry, applied loads and solved by using MULTIPHYSICS in ANSYS software, the influence of the various sealing structural parameters such as tooth width, height, slot width, sealing gap on the sealing property were analyzed, the magnetic fluid sealing device suitable for large-diameter shaft and sealing water was designed, the sealing problem of the hydraulic turbine main shaft was solved effectively which will bring huge economic benefits.
Krylov subspace methods - Theory, algorithms, and applications
NASA Technical Reports Server (NTRS)
Sad, Youcef
1990-01-01
Projection methods based on Krylov subspaces for solving various types of scientific problems are reviewed. The main idea of this class of methods when applied to a linear system Ax = b, is to generate in some manner an approximate solution to the original problem from the so-called Krylov subspace span. Thus, the original problem of size N is approximated by one of dimension m, typically much smaller than N. Krylov subspace methods have been very successful in solving linear systems and eigenvalue problems and are now becoming popular for solving nonlinear equations. The main ideas in Krylov subspace methods are shown and their use in solving linear systems, eigenvalue problems, parabolic partial differential equations, Liapunov matrix equations, and nonlinear system of equations are discussed.
Aloe vera as a functional ingredient in foods.
Rodríguez Rodríguez, Elena; Darias Martín, Jacinto; Díaz Romero, Carlos
2010-04-01
The main scientific discoveries on Aloe vera published mainly in the last three decades are presented in this work. After describing Aloe from a botanical point of view, the papers related with the chemical composition of different parts of the leaf of Aloe, particularly those in which the gel is described and are presented in a synthetic manner. The chemical analyses reveal that Aloe gel contains mannose polymers with some glucose and other sugars, among which the most important is Acemannan. Besides these, other components such as glycoproteins, enzymes, amino acids, vitamins, and minerals are described. Different factors also affecting the chemical composition of the gel, such as species and variety, climatic and soil conditions, cultivation methods, processing and preservation, are enumerated and discussed. On the other hand, the main therapeutic applications have been revised and the possible damaging effects of Aloe are also commented upon. A special emphasis is placed on the biologically active compounds or groups of compounds responsible for the therapeutic applications and which are their action mechanisms. The paper concludes that more research is needed to confirm the therapeutic and beneficial effects and to definitively clarify the myth surrounding Aloe vera. A general view on the problem of the commercialization and establishment of the quality and safety of Aloe products in the food industry has been offered here. The main points and European regulations that need to be considered regarding the quality control of prepared Aloe products are presented in this paper.
Vocabulary Instruction: Software Flashcards vs. Word Clouds
ERIC Educational Resources Information Center
Mansouri, Vahid
2015-01-01
When it comes to language learning, vocabulary learning is the main activity focused on. Vocabulary learning is the main problem and also the goal of new language learners. It is one of the major problems that language learners encounter during learning a new language. Krashen (1989) (cited in Tokac, 2005) points out the role of vocabulary in a…
ERIC Educational Resources Information Center
Vaessen, Anniek; Gerretsen, Patty; Blomert, Leo
2009-01-01
The double deficit hypothesis states that naming speed problems represent a second core deficit in dyslexia independent from a phonological deficit. The current study investigated the main assumptions of this hypothesis in a large sample of well-diagnosed dyslexics. The three main findings were that (a) naming speed was consistently related only…
Suicidal ideation in a community-derived sample of Spanish adolescents.
Fonseca-Pedrero, Eduardo; Inchausti, Félix; Pérez-Gutiérrez, Laura; Aritio Solana, Rebeca; Ortuño-Sierra, Javier; Sánchez-García, M ª Ángeles; Lucas-Molina, Beatriz; Domínguez, César; Foncea, David; Espinosa, Virginia; Gorría, Ana; Urbiola-Merina, Elena; Fernández, Marta; Merina Díaz, Carmen; Gutiérrez, Carmen; Aures, Marta; Campos, María S; Domínguez-Garrido, Elena; Pérez de Albéniz Iturriaga, Alicia
Suicide is a current public health problem and among the main causes of mortality in adolescents and young adults. The main goal of this study was to analyse suicidal ideation in a representative sample of Spanish adolescents. Specifically, the prevalence rates of suicide ideation, the psychometric properties of the Paykel Suicide Scale (PSS) scores, and the socio-emotional adjustment of adolescents at risk for suicide were analysed. The sample consisted of 1,664 participants (M=16.12 years, SD=1.36, range 14-19 years), selected by stratified sampling by clusters. The instruments used were the PSS, the Strengths and Difficulties Questionnaire, the Personal Wellbeing Index-School Children, and the Oviedo Infrequency Scale. The results showed that 4.1% of the sample indicated that they had tried to commit suicide in the previous year. Statistically significant differences were found according to gender but not according to age in the PSS mean scores. The analysis of the internal structure of the PSS showed that the one-dimensional model presented excellent goodness of fit indexes. This model showed measurement invariance across gender. The reliability of the scores, estimated with ordinal alpha, was 0.93. Participants who reported suicide ideation showed poorer mental health status and lower life satisfaction compared to the non-suicide ideation group. Suicidal ideation is present during adolescence and is associated with poor subjective well-being and increased emotional and behavioural problems. PSS seems to show adequate psychometric behaviour to assess suicidal ideation in adolescents. These findings have clear implications, both in health and education systems, to improve the promotion of emotional well-being and prevention of psychological and psychiatric problems in this sector of the population. Copyright © 2017 SEP y SEPB. Publicado por Elsevier España, S.L.U. All rights reserved.
Partition method and experimental validation for impact dynamics of flexible multibody system
NASA Astrophysics Data System (ADS)
Wang, J. Y.; Liu, Z. Y.; Hong, J. Z.
2018-06-01
The impact problem of a flexible multibody system is a non-smooth, high-transient, and strong-nonlinear dynamic process with variable boundary. How to model the contact/impact process accurately and efficiently is one of the main difficulties in many engineering applications. The numerical approaches being used widely in impact analysis are mainly from two fields: multibody system dynamics (MBS) and computational solid mechanics (CSM). Approaches based on MBS provide a more efficient yet less accurate analysis of the contact/impact problems, while approaches based on CSM are well suited for particularly high accuracy needs, yet require very high computational effort. To bridge the gap between accuracy and efficiency in the dynamic simulation of a flexible multibody system with contacts/impacts, a partition method is presented considering that the contact body is divided into two parts, an impact region and a non-impact region. The impact region is modeled using the finite element method to guarantee the local accuracy, while the non-impact region is modeled using the modal reduction approach to raise the global efficiency. A three-dimensional rod-plate impact experiment is designed and performed to validate the numerical results. The principle for how to partition the contact bodies is proposed: the maximum radius of the impact region can be estimated by an analytical method, and the modal truncation orders of the non-impact region can be estimated by the highest frequency of the signal measured. The simulation results using the presented method are in good agreement with the experimental results. It shows that this method is an effective formulation considering both accuracy and efficiency. Moreover, a more complicated multibody impact problem of a crank slider mechanism is investigated to strengthen this conclusion.
An algorithm for the split-feasibility problems with application to the split-equality problem.
Chuang, Chih-Sheng; Chen, Chi-Ming
2017-01-01
In this paper, we study the split-feasibility problem in Hilbert spaces by using the projected reflected gradient algorithm. As applications, we study the convex linear inverse problem and the split-equality problem in Hilbert spaces, and we give new algorithms for these problems. Finally, numerical results are given for our main results.
Bóveda Fontán, Julia; Pérula de Torres, Luis Ángel; Campiñez Navarro, Manuel; Bosch Fontcuberta, Josep M; Barragán Brun, Nieves; Prados Castillejo, Jose Antonio
2013-11-01
The motivational interview has been widely used as a clinical method to promote behavioural changes in patients, helping them to resolve their ambivalence to obtain their own motivations. In the present article, a review is made of the main meta-analyses and systematic and narrative reviews on the efficacy of the motivational interview in the primary health care environment. Copyright © 2012 Elsevier España, S.L. All rights reserved.
Numerical simulation of cavitating flows in shipbuilding
NASA Astrophysics Data System (ADS)
Bagaev, D.; Yegorov, S.; Lobachev, M.; Rudnichenko, A.; Taranov, A.
2018-05-01
The paper presents validation of numerical simulations of cavitating flows around different marine objects carried out at the Krylov State Research Centre (KSRC). Preliminary validation was done with reference to international test objects. The main part of the paper contains results of solving practical problems of ship propulsion design. The validation of numerical simulations by comparison with experimental data shows a good accuracy of the supercomputer technologies existing at Krylov State Research Centre for both hydrodynamic and cavitation characteristics prediction.
Geo-electromagnetic research aids geo-hazard mitigation
NASA Astrophysics Data System (ADS)
Chiappini, M.; Carmisciano, C.; Faggioni, O.
Some 100 Earth scientists from nine different nations recently gathered in Lerici, Italy; for the Second International Workshop on Geo-Electro-Magnetism. While this was not a thematic meeting, most of the 40 papers presented focused on applications of electromagnetic methods to natural or man-made hazards such as known faults, seismically active regions, volcanoes, landslides, and environmental or civil engineering problems. Anomaly and main field studies, both field investigations and theoretical techniques, were also well represented.
Valizadeh, Sousan; Dadkhah, Behrouz; Mohammadi, Eissa; Hassankhani, Hadi
2014-01-01
Introduction: The effect of amputation on an individual's psychological condition as well as family and social relationships is undeniable because physical disability not just affects the psycho-social adjustment, but also the mental health. When compared to normal people, such people are mostly experiencing social isolation. On the other hand, social support is known as the most powerful force to cope with stressful situations and it allows patients to withstand problems. The present study aims to explain understanding the trauma of patients and the experience of support sources during the process of adaptation to a lower limb amputation. Materials and Methods: The present study was conducted using qualitative content analysis. Participants included 20 patients with lower limb amputation due to trauma. Sampling was purposive initially and continued until data saturation. Unstructured interviews were used as the main method of data collection. Collected data were analyzed using qualitative content analysis and constant comparison methods. Results: The main theme extracted from the data was support sources. The classes include “supportive family”, “gaining friends’ support”, “gaining morale from peers”, and “assurance and satisfaction with the workplace.” Conclusion: Given the high number of physical, mental and social problems in trauma patients, identifying and strengthening support sources can be effective in their adaptation with the disease and improvement of the quality of their life. PMID:25191013
The pattern of acute poisoning in a teaching hospital, north-west Ethiopia.
Abula, Teferra; Wondmikun, Yared
2006-04-01
Poisoning by means of hazardous chemicals through ignorance, mishap or intentionally is becoming a serious health problem worldwide. Epidemiological data on this important health issue are, however, scarce in Ethiopia. The purpose of this study is to assess the pattern of acute poisonings and determine the approaches employed for the management of poisoning. The medical records of patients with acute poisonings presented to the Gondar University hospital between July 2001 and June 2004 were reviewed retrospectively. One hundred and two patients presenting to the emergency department of the hospital were due to acute poisoning; accounting for about 0.45% of emergency room admissions. Organophosphates, rat poison and alcohol were the commonly encountered poisoning agents (in about 70% of cases) mainly in adults possibly with suicidal or para-suicidal intention. The approaches employed in the management of poisoning mainly involved gastrointestinal decontamination procedures. Specific antidotes were used in a substantial number of patients. The fatality rate was 2.4%. Poisoning with suicidal intention is becoming a serious health problem particularly in adults. Pesticides are commonly used toxicants. The approaches in the management of poisoning are justifiable in some cases. However, much is to be done to improve the recording of patient-related information and record-keeping processes. Further large scale studies are required to investigate national trends of poisoning and factors associated with poisoning.
Tappura, K
2001-08-15
An adjustable-barrier dihedral angle potential was added as an extension to a novel, previously presented soft-core potential to study its contribution to the efficacy of the search of the conformational space in molecular dynamics. As opposed to the conventional soft-core potential functions, the leading principle in the design of the new soft-core potential, as well as of its extension, the soft-core and adjustable-barrier dihedral angle (SCADA) potential (referred as the SCADA potential), was to maintain the main equilibrium properties of the original force field. This qualifies the methods for a variety of a priori modeling problems without need for additional restraints typically required with the conventional soft-core potentials. In the present study, the different potential energy functions are applied to the problem of predicting loop conformations in proteins. Comparison of the performance of the soft-core and SCADA potential showed that the main hurdles for the efficient sampling of the conformational space of (loops in) proteins are related to the high-energy barriers caused by the Lennard-Jones and Coulombic energy terms, and not to the rotational barriers, although the conformational search can be further enhanced by lowering the rotational barriers of the dihedral angles. Finally, different evaluation methods were studied and a few promising criteria found to distinguish the near-native loop conformations from the wrong ones.
Evaluation of natural language processing systems: Issues and approaches
DOE Office of Scientific and Technical Information (OSTI.GOV)
Guida, G.; Mauri, G.
This paper encompasses two main topics: a broad and general analysis of the issue of performance evaluation of NLP systems and a report on a specific approach developed by the authors and experimented on a sample test case. More precisely, it first presents a brief survey of the major works in the area of NLP systems evaluation. Then, after introducing the notion of the life cycle of an NLP system, it focuses on the concept of performance evaluation and analyzes the scope and the major problems of the investigation. The tools generally used within computer science to assess the qualitymore » of a software system are briefly reviewed, and their applicability to the task of evaluation of NLP systems is discussed. Particular attention is devoted to the concepts of efficiency, correctness, reliability, and adequacy, and how all of them basically fail in capturing the peculiar features of performance evaluation of an NLP system is discussed. Two main approaches to performance evaluation are later introduced; namely, black-box- and model-based, and their most important characteristics are presented. Finally, a specific model for performance evaluation proposed by the authors is illustrated, and the results of an experiment with a sample application are reported. The paper concludes with a discussion on research perspective, open problems, and importance of performance evaluation to industrial applications.« less
NASA Technical Reports Server (NTRS)
Beck, D.; Das, B.; Dickson, C.; Douglas, B.; Long, L.; Middour, K.; Reid, S.; Uber, J.; Walsh, G.; Wang, L.
1989-01-01
This summary presents the main conclusions and results of the design studies conducted by a group of 13 students at the University of Maryland. The students, all participants in the spring 1989 course ENEE418 in the Electrical Engineering Department, met weekly in a two-hour class to discuss and evaluate design alternatives. The main problem considered was the design and control of a planar testbed simulating a free-flying space robot for applications in satellite servicing. This project grew out of the 1988 class where a dual-armed free flyer (DAFF) was designed and partially built. This year, a group of six students continued the development of the DAFF, achieving computer-controlled motion of the DAFF's arms. All fabrication and testing of the DAFF is being conducted in the Intelligent Servosystems Laboratory at the University of Maryland. While the work related to the design and development of the DAFF is the main subject of the report, it should be noted that other students in the ENEE418 class have investigated additional issues related to manipulation in space. For example, one group studied a new parallel linkage based manipulator for fine motion applications such as in assembly operations in space. They investigated the mechanism's kinematics, its reachable workspace, and precision of applying forces and torques. In yet another project, a student set out to measure and map the friction characteristics of the actuators used in the Modular Dextrous Hand, which has been recently developed in the Intelligent Servosystems Laboratory. The results are expected to help compensate for this friction, which is a highly nonlinear disturbance and presents significant problems in high-precision, low-speed operations. This summary continues with the discussion of the results obtained by the group of students who have been working on developing the DAFF testbed.
Vision and Vestibular System Dysfunction Predicts Prolonged Concussion Recovery in Children.
Master, Christina L; Master, Stephen R; Wiebe, Douglas J; Storey, Eileen P; Lockyer, Julia E; Podolak, Olivia E; Grady, Matthew F
2018-03-01
Up to one-third of children with concussion have prolonged symptoms lasting beyond 4 weeks. Vision and vestibular dysfunction is common after concussion. It is unknown whether such dysfunction predicts prolonged recovery. We sought to determine which vision or vestibular problems predict prolonged recovery in children. A retrospective cohort of pediatric patients with concussion. A subspecialty pediatric concussion program. Four hundred thirty-two patient records were abstracted. Presence of vision or vestibular dysfunction upon presentation to the subspecialty concussion program. The main outcome of interest was time to clinical recovery, defined by discharge from clinical follow-up, including resolution of acute symptoms, resumption of normal physical and cognitive activity, and normalization of physical examination findings to functional levels. Study subjects were 5 to 18 years (median = 14). A total of 378 of 432 subjects (88%) presented with vision or vestibular problems. A history of motion sickness was associated with vestibular dysfunction. Younger age, public insurance, and presence of headache were associated with later presentation for subspecialty concussion care. Vision and vestibular problems were associated within distinct clusters. Provocable symptoms with vestibulo-ocular reflex (VOR) and smooth pursuits and abnormal balance and accommodative amplitude (AA) predicted prolonged recovery time. Vision and vestibular problems predict prolonged concussion recovery in children. A history of motion sickness may be an important premorbid factor. Public insurance status may represent problems with disparities in access to concussion care. Vision assessments in concussion must include smooth pursuits, saccades, near point of convergence (NPC), and accommodative amplitude (AA). A comprehensive, multidomain assessment is essential to predict prolonged recovery time and enable active intervention with specific school accommodations and targeted rehabilitation.
Heart and Blood Vessels in Marfan Syndrome
... The most common of these problems affects the aorta, the main blood vessel carrying blood from the ... have problems in blood vessels other than the aorta. Even though heart and blood vessel problems affect ...
NASA Astrophysics Data System (ADS)
Futko, S. I.; Bondarenko, V. P.; Dolgii, L. N.
2012-05-01
We propose a method for characterizing and choosing solid mixed fuels for use as the solid-fuel charge of microthrusters of microelectromechanical systems. The method is based on the solution of the problem on the dependence of impulse responses of such a microthruster on the diameter of the outlet cross-section of its combustion chamber and the microkinetic parameters of the fuel. The variants of choosing the above fuels have been illustrated using glycidyl azide polymer/RDX as the example of a solid fuel mixture. The paper presents the characteristic criteria determining the composition of mixed fuels for the microthruster of a microelectromechanical system and considers the main types of "direct" and "inverse" problems arising in characterizing and choosing such fuels.
Study of the possibility of solving cosmological lithium problem in an accelerator experiment
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bystritsky, V. M., E-mail: bystvm@jinr.ru; Varlachev, V. A.; Dudkin, G. N.
Within the standar dmodel of Big Bang Nucleosynthesis (BBN), there is a cosmological lithium problem, which consists in a substantial difference between calculated data on the abundances of the isotopes {sup 6}Li and {sup 7}Li and those that were found from observational astronomy. An attempt at measuring the cross section for the main 6Li production reaction {sup 2}H({sup 4}He, γ){sup 6}Li induced by the interaction of {sup 4}He{sup +} ions with deuterons at collision energies less than the lower boundary of the BBN energy range was made in the present study. Upper limits on the cross sections for the reactionmore » in question were set.« less
Gestal, J J
1987-01-01
Except for infectious diseases all the main occupational hazards affecting health workers are reviewed: accidents (explosions, fires, electrical accidents, and other sources of injury); radiation (stochastic and non-stochastic effects, protective measures, and personnel most at risk); exposure to noxious chemicals, whose effects may be either local (allergic eczema) or generalised (cancer, mutations), particular attention being paid to the hazards presented by formol, ethylene oxide, cytostatics, and anaesthetic gases; drug addiction (which is more common among health workers than the general population) and psychic problems associated with promotion, shift work, and emotional stress; and assault (various types of assault suffered by health workers, its causes, and the characterisation of the most aggressive patients). PMID:3307896
Optimal motion planning for collision avoidance of mobile robots in non-stationary environments
NASA Technical Reports Server (NTRS)
Kyriakopoulos, K. J.; Saridis, G. N.
1992-01-01
An optimal control formulation of the problem of collision avoidance of mobile robots moving in general terrains containing moving obstacles is presented. A dynamic model of the mobile robot and the dynamic constraints are derived. Collision avoidance is guaranteed if the minimum distance between the robot and the object is nonzero. A nominal trajectory is assumed to be known from off-line planning. The main idea is to change the velocity along the nominal trajectory so that collisions are avoided. Time consistency with the nominal plan is desirable. A numerical solution of the optimization problem is obtained. A perturbation control type of approach is used to update the optimal plan. Simulation results verify the value of the proposed strategy.
Analytical study of sandwich structures using Euler-Bernoulli beam equation
NASA Astrophysics Data System (ADS)
Xue, Hui; Khawaja, H.
2017-01-01
This paper presents an analytical study of sandwich structures. In this study, the Euler-Bernoulli beam equation is solved analytically for a four-point bending problem. Appropriate initial and boundary conditions are specified to enclose the problem. In addition, the balance coefficient is calculated and the Rule of Mixtures is applied. The focus of this study is to determine the effective material properties and geometric features such as the moment of inertia of a sandwich beam. The effective parameters help in the development of a generic analytical correlation for complex sandwich structures from the perspective of four-point bending calculations. The main outcomes of these analytical calculations are the lateral displacements and longitudinal stresses for each particular material in the sandwich structure.
Fire-tube boiler optimization criteria and efficiency indicators rational values defining
NASA Astrophysics Data System (ADS)
Batrakov, P. A.; Mikhailov, A. G.; Ignatov, V. Yu
2018-01-01
Technical and economic calculations problems solving with the aim of identifying the opportunity to recommend the project for industrial implementation are represented in the paper. One of the main determining factors impacting boiler energy efficiency is the exhaust gases temperature, as well as the furnace volume thermal stress. Fire-tube boilers with different types of furnaces are considered in the study. The fullest analysis of the boiler performance thermal and technical indicators for the following engineering problem: Q=idem, M=idem and evaluation according to η, B is presented. The furnace with the finned ellipse profile application results in the fuel consumption decrease due to a more efficient heat exchange surface of the furnace compared to other examined ones.
Lean on Wii: physical rehabilitation with virtual reality Wii peripherals.
Anderson, Fraser; Annett, Michelle; Bischof, Walter F
2010-01-01
In recent years, a growing number of occupational therapists have integrated video game technologies, such as the Nintendo Wii, into rehabilitation programs. 'Wiihabilitation', or the use of the Wii in rehabilitation, has been successful in increasing patients' motivation and encouraging full body movement. The non-rehabilitative focus of Wii applications, however, presents a number of problems: games are too difficult for patients, they mainly target upper-body gross motor functions, and they lack support for task customization, grading, and quantitative measurements. To overcome these problems, we have designed a low-cost, virtual-reality based system. Our system, Virtual Wiihab, records performance and behavioral measurements, allows for activity customization, and uses auditory, visual, and haptic elements to provide extrinsic feedback and motivation to patients.
Laser Spot Detection Based on Reaction Diffusion.
Vázquez-Otero, Alejandro; Khikhlukha, Danila; Solano-Altamirano, J M; Dormido, Raquel; Duro, Natividad
2016-03-01
Center-location of a laser spot is a problem of interest when the laser is used for processing and performing measurements. Measurement quality depends on correctly determining the location of the laser spot. Hence, improving and proposing algorithms for the correct location of the spots are fundamental issues in laser-based measurements. In this paper we introduce a Reaction Diffusion (RD) system as the main computational framework for robustly finding laser spot centers. The method presented is compared with a conventional approach for locating laser spots, and the experimental results indicate that RD-based computation generates reliable and precise solutions. These results confirm the flexibility of the new computational paradigm based on RD systems for addressing problems that can be reduced to a set of geometric operations.
Bozsik, Csilla; Körmendi, Attila; Inántsy-Pap, Judit; Pataky, Nóra; Gádoros, Júlia; Halász, József
2013-01-01
The relationship between the type of physical aggressive behavior, callous/unemotional traits and behavioral problems was extensively studied in the literature, but no similar data exist in Hungarian adolescents. In the present study, the type of aggressive behavior was assessed in adolescents on a normative sample to study its relationship with callous/unemotional traits and behavioral problems. 223 students were participated in the study after informed consent (girls, n=106, age: 14.2±1.5 years; boys, n=117, age: 13.9±1.6 years) from primary and secondary schools in Miskolc and adjacent areas. The Reactive/Proactive Aggression Questionnaire was used to assess the level of aggressive behavior, the Inventory of Callous Unemotional Traits was used to measure callous/unemotional traits, while behavioral problems were established by the means of the Strengths and Difficulties Questionnaire. In the present non-clinical sample, the level of reactive aggression was higher than the level of proactive aggressive behavior. In boys, proactive and total aggression measures were significantly higher compared to girls. In both genders, reactive aggression was specifically associated with emotional and peer-related problems. Proactive aggression was correlated positively with callous traits in both genders, while self-reported prosocial behavior had an inverse correlation with proactive aggressive behavior in boys. Self reported conduct- and hyperactivity problems were positively correlated with both types of aggressive behavior in both genders. The strongest positive correlation was observed between self-reported conduct symptoms and both types of aggressive behavior. Callous/unemotional traits were related with proactive forms of aggression, similar to literature data. Reactive aggressive behavior was related to peer-related and emotional problems, thus our data outlined the importance of the distinction between the two main types of aggression.
NASA Astrophysics Data System (ADS)
Svensson, Andreas; Schön, Thomas B.; Lindsten, Fredrik
2018-05-01
Probabilistic (or Bayesian) modeling and learning offers interesting possibilities for systematic representation of uncertainty using probability theory. However, probabilistic learning often leads to computationally challenging problems. Some problems of this type that were previously intractable can now be solved on standard personal computers thanks to recent advances in Monte Carlo methods. In particular, for learning of unknown parameters in nonlinear state-space models, methods based on the particle filter (a Monte Carlo method) have proven very useful. A notoriously challenging problem, however, still occurs when the observations in the state-space model are highly informative, i.e. when there is very little or no measurement noise present, relative to the amount of process noise. The particle filter will then struggle in estimating one of the basic components for probabilistic learning, namely the likelihood p (data | parameters). To this end we suggest an algorithm which initially assumes that there is substantial amount of artificial measurement noise present. The variance of this noise is sequentially decreased in an adaptive fashion such that we, in the end, recover the original problem or possibly a very close approximation of it. The main component in our algorithm is a sequential Monte Carlo (SMC) sampler, which gives our proposed method a clear resemblance to the SMC2 method. Another natural link is also made to the ideas underlying the approximate Bayesian computation (ABC). We illustrate it with numerical examples, and in particular show promising results for a challenging Wiener-Hammerstein benchmark problem.
SQUID magnetometers for low-frequency applications
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ryhaenen, T.; Seppae, H.; Ilmoniemi, R.
1989-09-01
The authors present a novel formulation for SQUID operation, which enables them to evaluate and compare the sensitivity and applicability of different devices. SQUID magnetometers for low-frequency applications are analyzed, taking into account the coupling circuits and electronics. They discuss nonhysteretic and hysteretic single-junction rf SQUIDs, but the main emphasis is on the dynamics, sensitivity, and coupling considerations of dc-SQUID magnetometers. A short review of current ideas on thin-film, dc-SQUID design presents the problems in coupling and the basic limits of sensitivity. The fabrication technology of tunnel-junction devices is discussed with emphasis on how it limits critical current densities, specificmore » capacitances of junctions, minimum linewidths, conductor separations, etc. Properties of high-temperature superconductors are evaluated on the basis of recently published results on increased flux creep, low density of current carriers, and problems in fabricating reliable junctions. The optimization of electronics for different types of SQUIDs is presented. Finally, the most important low-frequency applications of SQUIDs in biomagnetism, metrology, geomagnetism, and some physics experiments demonstrate the various possibilities that state-of-the-art SQUIDs can provide.« less