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Sample records for calculational task group

  1. The work of the ICRP dose calculational task group: Issues in implementation of the ICRP dosimetric methodology

    Energy Technology Data Exchange (ETDEWEB)

    Eckerman, K.F. [Oak Ridge National Lab., TN (United States)

    1999-01-01

    Committee 2 of the International Commission on Radiological Protection (ICRP) has had efforts underway to provide the radiation protection community with age-dependent dose coefficients, i.e.g, the dose per unit intake. The Task Group on Dose Calculations, chaired by the author, is responsible for the computation of these coefficients. The Task Group, formed in 1974 to produce ICRP Publication 30, is now international in its membership and its work load has been distributed among the institutions represented on the task group. This paper discusses: (1) recent advances in biokinetic modeling; (2) the recent changes in the dosimetric methodology; (3) the novel computational problems with some of the ICRP quantities; and (4) quality assurance issues which the Task Group has encountered. Potential future developments of the dosimetric framework which might strengthen the relationships with the emerging understanding of radiation risk will also be discussed.

  2. Biology task group

    International Nuclear Information System (INIS)

    The accomplishments of the task group studies over the past year are reviewed. The purposes of biological investigations, in the context of subseabed disposal, are: an evaluation of the dose to man; an estimation of effects on the ecosystem; and an estimation of the influence of organisms on and as barriers to radionuclide migration. To accomplish these ends, the task group adopted the following research goals: (1) acquire more data on biological accumulation of specific radionuclides, such as those of Tc, Np, Ra, and Sr; (2) acquire more data on transfer coefficients from sediment to organism; (3) Calculate mass transfer rates, construct simple models using them, and estimate collective dose commitment; (4) Identify specific pathways or transfer routes, determine the rates of transfer, and make dose limit calculations with simple models; (5) Calculate dose rates to and estimate irradiation effects on the biota as a result of waste emplacement, by reference to background irradiation calculations. (6) Examine the effect of the biota on altering sediment/water radionuclide exchange; (7) Consider the biological data required to address different accident scenarios; (8) Continue to provide the basic biological information for all of the above, and ensure that the system analysis model is based on the most realistic and up-to-date concepts of marine biologists; and (9) Ensure by way of free exchange of information that the data used in any model are the best currently available

  3. Monitor unit calculations for external photon and electron beams: Report of the AAPM Therapy Physics Committee Task Group No. 71

    International Nuclear Information System (INIS)

    A protocol is presented for the calculation of monitor units (MU) for photon and electron beams, delivered with and without beam modifiers, for constant source-surface distance (SSD) and source-axis distance (SAD) setups. This protocol was written by Task Group 71 of the Therapy Physics Committee of the American Association of Physicists in Medicine (AAPM) and has been formally approved by the AAPM for clinical use. The protocol defines the nomenclature for the dosimetric quantities used in these calculations, along with instructions for their determination and measurement. Calculations are made using the dose per MU under normalization conditions, D0′, that is determined for each user's photon and electron beams. For electron beams, the depth of normalization is taken to be the depth of maximum dose along the central axis for the same field incident on a water phantom at the same SSD, where D0′ = 1 cGy/MU. For photon beams, this task group recommends that a normalization depth of 10 cm be selected, where an energy-dependent D0′ ≤ 1 cGy/MU is required. This recommendation differs from the more common approach of a normalization depth of dm, with D0′ = 1 cGy/MU, although both systems are acceptable within the current protocol. For photon beams, the formalism includes the use of blocked fields, physical or dynamic wedges, and (static) multileaf collimation. No formalism is provided for intensity modulated radiation therapy calculations, although some general considerations and a review of current calculation techniques are included. For electron beams, the formalism provides for calculations at the standard and extended SSDs using either an effective SSD or an air-gap correction factor. Example tables and problems are included to illustrate the basic concepts within the presented formalism

  4. Calculations of two new dose metrics proposed by AAPM Task Group 111 using the measurements with standard CT dosimetry phantoms

    International Nuclear Information System (INIS)

    Purpose: AAPM Task Group 111 proposed to measure the equilibrium dose-pitch product D-careteq for scan modes involving table translation and the midpoint dose DL(0) for stationary-table modes on the central and peripheral axes of sufficiently long (e.g., at least 40 cm) phantoms. This paper presents an alternative approach to calculate both metrics using the measurements of scanning the standard computed tomographic (CT) dosimetry phantoms on CT scanners.Methods: D-careteq was calculated from CTDI100 and ε(CTDI100) (CTDI100 efficiency), and DL(0) was calculated from D-careteq and the approach to equilibrium function H(L) =DL(0)/Deq, where Deq was the equilibrium dose. CTDI100 may be directly obtained from several sources (such as medical physicist's CT scanner performance evaluation or the IMPACT CT patient dosimetry calculator), or be derived from CTDIVol using the central to peripheral CTDI100 ratio (R100). The authors have provided the required ε(CTDI100) and H(L) data in two previous papers [X. Li, D. Zhang, and B. Liu, Med. Phys. 39, 901–905 (2012); and ibid. 40, 031903 (10pp.) (2013)]. R100 was assessed for a series of GE, Siemens, Philips, and Toshiba CT scanners with multiple settings of scan field of view, tube voltage, and bowtie filter.Results: The calculated DL(0) and DL(0)/Deq in PMMA and water cylinders were consistent with the measurements on two GE CT scanners (LightSpeed 16 and VCT) by Dixon and Ballard [Med. Phys. 34, 3399–3413 (2007)], the measurements on a Siemens CT scanner (SOMATOM Spirit Power) by Descamps et al. [J. Appl. Clin. Med. Phys. 13, 293–302 (2012)], and the Monte Carlo simulations by Boone [Med. Phys. 36, 4547–4554 (2009)].Conclusions: D-careteq and DL(0) can be calculated using the alternative approach. The authors have provided the required ε(CTDI100) and H(L) data in two previous papers. R100 is presented for a majority of multidetector CT scanners currently on the market, and can be easily assessed for other CT

  5. Task reports of INFCE Working Group 6

    International Nuclear Information System (INIS)

    Task 1 Report summarizes on a country-by-country basis the data supplied by the participating states related to nuclear power forecast, spent fuel generation, AR storage capacity, AFR storage capacity, AFR storage and transport systems. Task Reports 2-5 analyse the spent fuel storage and transport situation according to reactor types. Information on the technical description of spent fuel existing storage and transport techniques and techniques under development and on costs is given. Task 6 summarizes the present legal framework for spent fuel management related to licensing, safety, environmental and physical protection, accounting and control of nuclear material by states, non-proliferation of nuclear weapons, assurances for national access to nuclear material contained in spent fuel, and protection of technology. The institutional practice for spent fuel storage and transport is described. For the period up to the year 2025 a prognosis and recommendations related to legal framework and institutional models are given. The special needs of developing countries and industrialized countries with a limited nuclear power programme with respect to spent fuel management are analysed in Task Reports 7 and 8

  6. The Decision-Making Process of a Small Task Group.

    Science.gov (United States)

    Roderick, Joan C.

    1985-01-01

    This article focuses on the following areas of group process: the nature of the task group, the steps taken to reach a decision, and the ways in which a leader can effectively manage the inevitable conflict that emerges within groups as the problem-solving process progresses. (CT)

  7. The work of the ICRP task group on internal dosimetry

    International Nuclear Information System (INIS)

    Over the last few years the task group of committee 2 of ICRP on internal dosimetry (INDOS), in conjunction with the task group on dose calculations (DOCAL), has prepared a series of publications that have given dose coefficients for intakes of radionuclides by infants, children and adults. Most recently Publication 88 has been issued that gives doses to the embryo, fetus and newborn child from intakes of radionuclides by the mother. A document is presently being completed that will give doses to the child from intakes of radionuclides in mothers' milk (Publication 94). This document, to be published early in 2005, will complete the programme of work of committee 2 on dose coefficients for members of the public. The emphasis of work on internal dosimetry by Committee 2 has turned to occupational exposure. A comprehensive revision of advice on dose assessment and monitoring for occupational intakes of radionuclides is being prepared by INDOS and DOCAL. It is intended to replace Publications 30, 54, 68 and 78 by a series of publications that will cover both dosimetry and bioassay interpretation. The first report will cover radionuclides of the 31 elements covered in the series of publications on dose coefficients for members of the public. Subsequent publications will cover additional elements. This series of publications will be accompanied by a supporting Guidance Document that will give more comprehensive advice on the interpretation of bioassay data. The development of this document will draw from work carried out in an EC supported program, IDEAS that has examined how to improve the assessment of bioassay data. (orig.)

  8. Minimal Groups Increase Young Children's Motivation and Learning on Group-Relevant Tasks

    Science.gov (United States)

    Master, Allison; Walton, Gregory M.

    2013-01-01

    Three experiments ("N" = 130) used a minimal group manipulation to show that just perceived membership in a social group boosts young children's motivation for and learning from group-relevant tasks. In Experiment 1, 4-year-old children assigned to a minimal "puzzles group" persisted longer on a challenging puzzle than children identified as the…

  9. The Emergence of Individual and Collective Leadership in Task Groups

    DEFF Research Database (Denmark)

    Paunova, Minna

    2015-01-01

    This review synthesizes conceptual and empirical research on the emergence of individual and collective leadership in task groups, and proposes avenues for leadership research. To advance multilevel study of leadership emergence, including emergence of distributed and shared leadership, the paper...... reviews research on individual leader emergence, structured around two identified theoretical mechanisms—one of leadership achievement (i.e., based on functional behaviors) and another of leadership ascription (i.e., based on nominal characteristics). These approaches compete to elucidate individual...... leader emergence in task groups as influenced by individual traits, states, and behaviors. However, current approaches to leadership in groups rely on functional achievement explanations of how collective leadership emerges, influenced by positive states and behaviors. Attention to ascription...

  10. Task group to develop list of environmental standards

    Science.gov (United States)

    A new task group designed to develop a list of existing and potential standards that are applicable to environmental contamination problems in soil, rock, and groundwater has been established by the American Society for Testing a n d Materials (ASTM) Subcommittee on Geotechnics of Waste Management. The list currently includes over 60 existing and draft ASTM standards from ASTM committees in the areas of site characterization, construction evaluation, and geosynthetics.

  11. Indiana University High Energy Physics Group, Task C

    International Nuclear Information System (INIS)

    The Indiana University Task C group is participating in the experiments GEM at the SSC and MACRO at the Gran Sasso. After an introduction to GEM in paragraph II, a detailed report is presented on the work done during the current contract period on the design of the outer region of the GEM Central Tracker. The Central Tracker Monte Carlo, which was the other significant GEM activity by the group, is included. In paragraph III is introduced MACRO and a brief status report is given. Muon Astronomy analysis done using MACRO data is also presented

  12. Multi-group calculations for fast reactors

    International Nuclear Information System (INIS)

    The paper deals with various causes of error in calculations. The first part sets out the mathematical approximations (diffusion approximation, Sn method, etc.), the numerical resolution methods (effect of integration step), the models used, and the implications of these various factors in the determination of the principal characteristics of a fast neutron reactor. The second part studies the effect on reactivity of variations of element cross-sections, using various fuels, in a reactor of rather hard spectrum. (author)

  13. MANAGING UNCERTAINTIES ASSOCIATED WITH RADIOACTIVE WASTE DISPOSAL: TASK GROUP 4 OF THE IAEA PRISM PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Seitz, R.

    2011-03-02

    It is widely recognized that the results of safety assessment calculations provide an important contribution to the safety arguments for a disposal facility, but cannot in themselves adequately demonstrate the safety of the disposal system. The safety assessment and a broader range of arguments and activities need to be considered holistically to justify radioactive waste disposal at any particular site. Many programs are therefore moving towards the production of what has become known as a Safety Case, which includes all of the different activities that are conducted to demonstrate the safety of a disposal concept. Recognizing the growing interest in the concept of a Safety Case, the International Atomic Energy Agency (IAEA) is undertaking an intercomparison and harmonization project called PRISM (Practical Illustration and use of the Safety Case Concept in the Management of Near-surface Disposal). The PRISM project is organized into four Task Groups that address key aspects of the Safety Case concept: Task Group 1 - Understanding the Safety Case; Task Group 2 - Disposal facility design; Task Group 3 - Managing waste acceptance; and Task Group 4 - Managing uncertainty. This paper addresses the work of Task Group 4, which is investigating approaches for managing the uncertainties associated with near-surface disposal of radioactive waste and their consideration in the context of the Safety Case. Emphasis is placed on identifying a wide variety of approaches that can and have been used to manage different types of uncertainties, especially non-quantitative approaches that have not received as much attention in previous IAEA projects. This paper includes discussions of the current results of work on the task on managing uncertainty, including: the different circumstances being considered, the sources/types of uncertainties being addressed and some initial proposals for approaches that can be used to manage different types of uncertainties.

  14. Managing Uncertainties Associated With Radioactive Waste Disposal: Task Group 4 Of The IAEA PRISM Project

    International Nuclear Information System (INIS)

    It is widely recognized that the results of safety assessment calculations provide an important contribution to the safety arguments for a disposal facility, but cannot in themselves adequately demonstrate the safety of the disposal system. The safety assessment and a broader range of arguments and activities need to be considered holistically to justify radioactive waste disposal at any particular site. Many programs are therefore moving towards the production of what has become known as a Safety Case, which includes all of the different activities that are conducted to demonstrate the safety of a disposal concept. Recognizing the growing interest in the concept of a Safety Case, the International Atomic Energy Agency (IAEA) is undertaking an intercomparison and harmonization project called PRISM (Practical Illustration and use of the Safety Case Concept in the Management of Near-surface Disposal). The PRISM project is organized into four Task Groups that address key aspects of the Safety Case concept: Task Group 1 - Understanding the Safety Case; Task Group 2 - Disposal facility design; Task Group 3 - Managing waste acceptance; and Task Group 4 - Managing uncertainty. This paper addresses the work of Task Group 4, which is investigating approaches for managing the uncertainties associated with near-surface disposal of radioactive waste and their consideration in the context of the Safety Case. Emphasis is placed on identifying a wide variety of approaches that can and have been used to manage different types of uncertainties, especially non-quantitative approaches that have not received as much attention in previous IAEA projects. This paper includes discussions of the current results of work on the task on managing uncertainty, including: the different circumstances being considered, the sources/types of uncertainties being addressed and some initial proposals for approaches that can be used to manage different types of uncertainties.

  15. Report of the Task Group on Behavioral Effects

    International Nuclear Information System (INIS)

    The overall objective of the Task Group on Behavioral Effects is to examine effects on the mental health of the public and the workers directly involved in the accident at TMI-2. Of particular interest are the behavioral response of the workers under stress during the accident, and the behavioral response of the population under stress during the accident. In examining effects on mental health, a distinction is to be made between short term and long term effects. Attention is also to be paid to the possible impact [on] the affected populations and workers of a variety of studies either under way or planned

  16. The work of the task group of committee 2 of ICRP on age-dependent dosimetry

    International Nuclear Information System (INIS)

    With the accident at Chernobyl and developing concern in regard to the consequences of discharging radionuclides into the environment has come increasing awareness of the need to assess radiation doses to all age groups in the population. In 1987, ICRP set up a Task Group of Committee 2 on Age-dependent Dosimetry with the responsibility for calculating internationally agreed dose coefficients for members of the public. This covered the calculation and ingestion, as well as doses to the embryo and fetus from intakes of radionuclides by the mother. This paper reviews the programme of work.(authors). 17 refs., 6 tabs

  17. Engineering task plan for steam line ramp calculations

    International Nuclear Information System (INIS)

    The purpose of this document is to provide an approved work plan to perform calculations that verify the load limits of a proposed ramp over a steam line at the back side (East side) of SY Farm in support of work package 2W-94-00812/K. The objective of this supporting document is to provide Operations with a set of checked calculations that verify the ramp over the steam line at SY Farm will support a fully loaded concrete mixer truck without affecting the steam line. The calculations will be performed by an engineers from Facility Systems and independently checked and reviewed by another engineer. The calculations may then be added to the work package. If Operations decides to make any configuration changes to the steam line or surrounding area, Operations shall have these changes documented by an Engineering Change Notice (ECN). This ECN can be done by Facility Systems or any other engineering organization at the direction of Operations

  18. Steam Generator Group Project. Task 6. Channel head decontamination

    International Nuclear Information System (INIS)

    The Steam Generator Group Project utilizes a retired-from-service pressurized-water-reactor steam generator as a test bed and source of specimens for research. An important preparatory step to primary side research activities was reduction of the radiation field in the steam generator channel head. This task report describes the channel head decontamination activities. Though not a programmatic research objective it was judged beneficial to explore the use of dilute reagent chemical decontamination techniques. These techniques presented potential for reduced personnel exposure and reduced secondary radwaste generation, over currently used abrasive blasting techniques. Two techniques with extensive laboratory research and vendors prepared to offer commercial application were tested, one on either side of the channel head. As indicated in the report, both techniques accomplished similar decontamination objectives. Neither technique damaged the generator channel head or tubing materials, as applied. This report provides details of the decontamination operations. Application system and operating conditions are described

  19. Effects of Training on Computer-Mediated Communication in Single or Mixed Gender Small Task Groups.

    Science.gov (United States)

    Savicki, Victor; Kelley, Merle; Ammon, Benjamin

    2002-01-01

    Investigates group gender composition and communication styles in small task groups involved in computer-mediated communication. Describes a study that tried to train small task groups in the use of one communication style and suggests further research in the area of communication training for online task groups. (Author/LRW)

  20. GRUCAL, a computer program for calculating macroscopic group constants

    International Nuclear Information System (INIS)

    Nuclear reactor calculations require material- and composition-dependent, energy averaged nuclear data to describe the interaction of neutrons with individual isotopes in material compositions of reactor zones. The code GRUCAL calculates these macroscopic group constants for given compositions from the material-dependent data of the group constant library GRUBA. The instructions for calculating group constants are not fixed in the program, but will be read at the actual execution time from a separate instruction file. This allows to accomodate GRUCAL to various problems or different group constant concepts. (orig.)

  1. Ability of aphasic individuals to perform numerical processing and calculation tasks

    Directory of Open Access Journals (Sweden)

    Gabriela De Luccia

    2014-03-01

    Full Text Available Objective To compare performance on EC301 battery calculation task between aphasic subjects and normal controls of the same sex, age, and education. Method Thirty-two aphasic patients who had suffered a single left hemisphere stroke were evaluated. Forty-four healthy volunteers were also selected. All subjects underwent a comprehensive arithmetic battery to assess their numerical and calculation skills. Performances on numerical processing and calculation tasks were then analyzed. Results Aphasic individuals showed changes in their ability to perform numerical processing and calculation tasks that were not observed in the healthy population. Conclusion Compared with healthy subjects of the same age and education level, individuals with aphasia had difficulty performing various tasks that involved numerical processing and calculation.

  2. Indiana University High Energy Physics Group, Task C

    International Nuclear Information System (INIS)

    The Indiana University High Energy Physics Group, Task C has been actively involved in the MACRO experiment at Gran Sasso and the SSC experiment L during the current contract year. MACRO is a large US-Italian Monopole, Astrophysics, and Cosmic Ray Observatory being built under the Gran Sasso Mountain outside of Rome. Indiana University is in charge of organizing the United States software effort. We have built a state-of-the-art two-meter spectrophotometer for the MACRO liquid scintillator. We are in charge of ERP, the Event Reconstruction Processor online trigger processor for muons and stellar collapse. We are designing an air Cerenkov array to be placed on top of the Gran Sasso. Our other activity involves participation in the SSC experiment L. As long-standing members of L we have done proposal writing and have worked on important L planning and organization matters. We are now doing development work on the L Central Tracker straw drift tubes, including gas optimization, readout, and Monte Carlos. 12 refs., 20 figs., 1 tab

  3. The ames network and the task group on WWER's

    International Nuclear Information System (INIS)

    The European Network on 'Ageing Materials Evaluation and Studies' (AMES) was created in 1993. Its main objectives are (a) to provide information and understanding on neutron irradiation effects in reactor materials in support of designers, operators, regulators and researchers and (b) to establish and discharge projects in the above areas. The Steering Committee is composed of at least one participant from each nuclear European Union country. The JRC's Institute for Advanced Materials of the European Commission plays the role of Operating Agent and Manager of the AMES Network. This paper describes the structure, objectives, and major projects of the AMES network. Particular emphasis is placed upon the work it is intended to perform within the Task Group on 'WWER's of the first AMES project (AMES1) on 'Validation of surveillance practice and mitigation methods'. EC DGXVII is addressing the question of how to facilitate contacts between EU and Russian industries in the framework of nuclear Industrial co-operation, and this project may provide a suitable starting point upon which to develop a basis for further work of mutual interest. (author)

  4. Indiana University High Energy Physics Group, Task C

    Energy Technology Data Exchange (ETDEWEB)

    Heinz, R.M.; Mufson, S.L.; Musser, J.

    1991-01-01

    The Indiana University High Energy Physics Group, Task C has been actively involved in the MACRO experiment at Gran Sasso and the SSC experiment L during the current contract year. MACRO is a large US-Italian Monopole, Astrophysics, and Cosmic Ray Observatory being built under the Gran Sasso Mountain outside of Rome. Indiana University is in charge of organizing the United States software effort. We have built a state-of-the-art two-meter spectrophotometer for the MACRO liquid scintillator. We are in charge of ERP, the Event Reconstruction Processor online trigger processor for muons and stellar collapse. We are designing an air Cerenkov array to be placed on top of the Gran Sasso. Our other activity involves participation in the SSC experiment L. As long-standing members of L we have done proposal writing and have worked on important L planning and organization matters. We are now doing development work on the L Central Tracker straw drift tubes, including gas optimization, readout, and Monte Carlos. 12 refs., 20 figs., 1 tab.

  5. Exact renormalization group as a scheme for calculations

    International Nuclear Information System (INIS)

    In this lecture I report on recent work to use exact renormalization group methods to construct a scheme for calculations in quantum field theory and classical statistical mechanics on the continuum. (orig./HSI)

  6. Benchmark calculations of 150-group cross section library for LMR's

    International Nuclear Information System (INIS)

    For the purpose of diversification of selection of cross section library for neutron calculation of LMR, the 150 multi-group cross section library was generated from ENDF-VI release. The set was then examined by analyzing measured reactivity quantities such as control rod worth, Doppler effect and sodium void effect for BFS critical assemblies that we obtained through the critical experiment plan for developing the KALIMER core design. The calculated results based on 9 group structure using the new set were also compared with those of JEF set based on the same group structure and compared with those of the same set based on 25 group structure to find the proper group structure. ENDF-VI-based set shows a small deviation in predicting measured integral quantities in comparison with the previous set and a small group effect

  7. Third Grade Students' Performance on Calculator and Calculator-Related Tasks. Technical Report No. 498.

    Science.gov (United States)

    Weaver, J. Fred

    Refinements of work with calculator algorithms previously conducted by the author are reported. Work with "chaining" and the doing/undoing property in addition and subtraction was tested with 24 third-grade students. Results indicated the need for further instruction with both ideas. Students were able to manipulate the calculator keyboard, but…

  8. Student Perceptions of Social Task Development in Online Group Project Work

    Science.gov (United States)

    Morgan, Kari; Cameron, Bruce A.; Williams, Karen C.

    2009-01-01

    This article explores student perceptions of social task development in an online group project and poses recommendations for implementation of group projects. Qualitative methods were used to analyze student perceptions of social task development in online group project. Respect, "being nice," follow the rules/follow the leader, communication,…

  9. ERP measures of math anxiety: how math anxiety affects working memory and mental calculation tasks?

    OpenAIRE

    Klados, Manousos A.; Simos, Panagiotis; Micheloyannis, Sifis; Margulies, Daniel ,; Bamidis, Panagiotis D.

    2015-01-01

    There have been several attempts to account for the impact of Mathematical Anxiety (MA) on brain activity with variable results. The present study examines the effects of MA on ERP amplitude during performance of simple arithmetic calculations and working memory tasks. Data were obtained from 32 university students as they solved four types of arithmetic problems (one- and two-digit addition and multiplication) and a working memory task comprised of three levels of difficulty (1, 2, and 3-bac...

  10. Communication on a problem solving task in cooperative learning groups

    Science.gov (United States)

    Sadler, Jo; Fawns, Rod

    1992-12-01

    There is some evidence from this study that reflectivity within cooperative learning groups develops over time. Preliminary observations suggest that Slavin's third and fourth levels of skills, those of reflection and reasoning and reconception and reformulation and Kempa and Ayob's higher levels of explanation and insight appear more advanced in groups strategically managed by teachers for such outcomes. Later analyses will permit more detailed accounts of the relationships between the teacher's management strategies, and reflection within groups of different gender composition.

  11. Calculation of the isotope cluster for polypeptides by probability grouping.

    Science.gov (United States)

    Olson, Matthew T; Yergey, Alfred L

    2009-02-01

    This paper presents a novel theoretical basis for accurately calculating the isotope cluster of polypeptides. In contrast to previous approaches to this problem, which consider exhaustive or near exhaustive combinations of isotopic species, the program, Neutron Cluster, groups probabilities to yield highly accurate information without elucidating any fine structure within a nominal mass unit. This is a fundamental difference from any previously described algorithm for calculating the isotope cluster. As a result of this difference, the accurate isotope clusters for high molecular weight polypeptides can be calculated rapidly without any pruning. When applied to isotope enriched polypeptides, the algorithm introduces "grouping error", which is described, quantified, and avoided by using probability partitioning. PMID:19026561

  12. The Role of Communication in Group Decision-Making Efficacy: A Task-Contingency Perspective.

    Science.gov (United States)

    Hirokawa, Randy Y.

    1990-01-01

    Argues importance of communication for group decision-making performance and its impact on such performance are function of three task characteristics: structure, information requirement, and evaluation demand. Identifies task circumstances in which group communication can be expected to play role in determining decision-making performance, as…

  13. Group Life in America: A Task Force Report.

    Science.gov (United States)

    Lipset, Seymour Martin

    Contents of this book include discussions of the following topics: (1) issues for the 1970s (redefining American pluralism); (2) historic pattern of change (rise and fall of repressive movements); (3) unity in the post-war era; (4) breakdown in consensus (racial equality and black militancy; demand for group rights; anti-war and other protests;…

  14. AAPM Task Group 128: Quality assurance tests for prostate brachytherapy ultrasound systems

    International Nuclear Information System (INIS)

    While ultrasound guided prostate brachytherapy has gained wide acceptance as a primary treatment tool for prostate cancer, quality assurance of the ultrasound guidance system has received very little attention. Task Group 128 of the American Association of Physicists in Medicine was created to address quality assurance requirements specific to transrectal ultrasound used for guidance of prostate brachytherapy. Accurate imaging guidance and dosimetry calculation depend upon the quality and accuracy of the ultrasound image. Therefore, a robust quality assurance program for the ultrasound system is essential. A brief review of prostate brachytherapy and ultrasound physics is provided, followed by a recommendation for elements to be included in a comprehensive test phantom. Specific test recommendations are presented, covering grayscale visibility, depth of penetration, axial and lateral resolution, distance measurement, area measurement, volume measurement, needle template/electronic grid alignment, and geometric consistency with the treatment planning computer.

  15. Perceptual grouping by similarity of surface roughness in haptics: the influence of task difficulty.

    Science.gov (United States)

    Van Aarsen, V; Overvliet, K E

    2016-08-01

    We investigated grouping by similarity of surface roughness in the context of task difficulty. We hypothesized that grouping yields a larger benefit at higher levels of task complexity, because efficient processing is more helpful when more cognitive resources are needed to execute a task. Participants searched for a patch of a different roughness as compared to the distractors in two strips of similar or dissimilar roughness values. We reasoned that if the distractors could be grouped based on similar roughness values, exploration time would be shorter and fewer errors would occur. To manipulate task complexity, we varied task difficulty (high target saliency equalling low task difficulty), and we varied the fingers used to explore the display (two fingers of one hand being more cognitive demanding than two fingers of opposite hands). We found much better performance in the easy condition as compared to the difficult condition (in both error rates and mean search slopes). Moreover, we found a larger effect for the similarity manipulation in the difficult condition as compared to the easy condition. Within the difficult condition, we found a larger effect for the one-hand condition as compared to the two-hand condition. These results show that haptic search is accelerated by the use of grouping by similarity of surface roughness, especially when the task is relatively complex. We conclude that the effect of perceptual grouping is more prominent when more cognitive resources are needed to perform a task. PMID:27010724

  16. Steam Generator Group Project: Task 10, Secondary side examination

    International Nuclear Information System (INIS)

    This report concludes an effort to examine and assess from the secondary side, the condition of the retired-from-service Surry 2A steam generator. It is includes photographs of degradation of various components or regions in a generic recirculating type steam generator. The photographic detail given in the text (and the previous report NUREG/CR-3843, PNL-5033) have not been readily available to many investigators outside the Nuclear Steam Supply Vendors and Users. The photographs include views of Inconel 600 heat exchanger tubes (0.875 diameter [nominal] x 0.050 inch wall) showing deformed and intergranularly stress-corrosion cracked U-bends, tube denting in the support plate, intergranular attack and thinning (both in the tube sheet region), support plat deformation and cracking at flow slots and in ligaments between flow holes and tube holes. In addition, photographs of tube pitting, anti-vibration bar fretting, and the sludge pile are presented. An experimental stress analysis was conducted on a distorted Row 1 tube in the region of a compressed flow slot between the 6th and 7th (top) support plates. During removal of the tube, relaxation strains were measured and residual stresses calculated. Finally a cursory metallurgical failure analysis was conducted on a broken U-bend (R1C91) to determine its mode of failure. A rotabroach boring technique was used to make multiple penetrations with minimal damage to the secondary side, at various locations on the shell

  17. Small-Group Leader Assignment: Effects Across Different Degrees of Task Interdependence

    OpenAIRE

    Basik, Kevin J.

    1997-01-01

    ABSTRACT The use of teams and work groups in organizations has become increasingly more popular in the last decade. Within each of these groups, a leadership role must be filled in order for the team to achieve its task. This study posited that the method by which the leader comes into this role may have a direct impact on the group's performance and its perceptions of the group's interpersonal processes and efficiency, satisfaction with the group, satisfaction with the group output, a...

  18. Summary report for ITER Task -- D4: Activation calculations for the stainless steel ITER design

    International Nuclear Information System (INIS)

    Detailed activation analysis for ITER has been performed as a part of ITER Task D4. The calculations have been performed for the shielding blanket (SS/water) and for the breeding blanket (LiN) options. The activation code RACC-P, which has been modified under IFER Task-D-10 for pulsed operation, has been used in this analysis. The spatial distributions of the radioactive inventory, decay heat, biological hazard potential, and the contact dose were calculated for the two designs for different operation modes and targeted fluences. A one-dimensional toroidal geometrical model has been utilized to determine the neutron fluxes in the two designs. The results are normalized for an inboard and outboard neutron wall loadings of 0.91 and 1.2 MW/M2, respectively. The point-wise distributions of the decay gamma sources have been calculated everywhere in the reactor at several times after the shutdown of the two designs and are then used in the transport code ONEDANT to calculate the biological dose everywhere in the reactor. The point-wise distributions of all the responses have also been calculated. These calculations have been performed for neutron fluences of 3.0 MWa/M2, which corresponds to the target fluence of ITER, and 0.1 MWa/M2, which is anticipated to correspond to the beginning of an extended maintenance period

  19. MUPO, Critical 43 Group Spectra Calculation for Homogeneous Reactor

    International Nuclear Information System (INIS)

    1 - Nature of physical problem solved: MUPO calculates the critical spectrum of a bare homogeneous reactor in 43 groups. This spectrum is used to evaluate condensed microscopic cross-sections. An option for this programme is to read in the library data from cards and write the binary library tape -DRAGON LIBRARY 3-. 2 - Method of solution: 3 options. Introduction of an additional absorber to account for a control poison, source iteration technique, and a buckling iteration. 3 - Restrictions on the complexity of the problem: 110 materials

  20. Small, Task-Oriented Groups: Conflict, Conflict Management, Satisfaction, and Decision Quality.

    Science.gov (United States)

    Wall, Victor D., Jr.; And Others

    1987-01-01

    Examined relationship among amount of conflict experienced, the style of its management, individual satisfaction, and decision quality of small, task-oriented groups using 129 college student subjects in 24 groups. Data suggest a curvilinear relationship between the number of conflict episodes experienced by group members and the subsequent…

  1. The Effects of Dual Task on Healthy Adults Balance Index in Age and Gender groups

    Directory of Open Access Journals (Sweden)

    Sona Abedi

    2012-10-01

    Full Text Available Background and Aim: Falls are the leading cause of accidental death among older adults. Recent studies have demonstrated that an impaired ability to maintain balance while simultaneously performing cognitive tasks is associated with increased rates of adverse outcomes, such as falls in elderly people. Because interventions designed to improve dual-task balance performance have the potential to reduce falling rate and functional decline, they are a critical health care need.Material & Methods: 60 healthy adults in four equal groups (mean age in: young men=22.1±1.9, old men =68.3±4.1, young women =22.6±1.8, old women =66.9±2.6 participated in this study. All subjects experienced four test conditions including: single- task with eyes open (O1, single- task with eyes closed (C1, dual-task with eyes open (O2 and dual-task with eyes closed (C2. Postural task in this study included standing on 8 instability level of biodex balance SD machine plate and cognitive task was backward counting by three.Results: balance index mean in older group was significantly higher in comparison with young group in all test conditions (O1 P=.000, C1 P=.003, O2 P=.000, C2 P=.000. There are not any significant differences between gender groups balance index mean, in test conditions. In Young women group O2 overall (OL, antroposterior (AP and mediolateral (ML balance indexes means were significantly higher than corresponding amounts in C2 (OL P=.014, AP P=.030, ML P=.017. In old women group C2 ML balance index mean was significantly higher than O2 ML balance index mean (P=.034. There are not significant differences between single- and dual-task conditions in other within group comparisons.Conclusion: In young men, young women and old women balance index means are different between single and dual eyes closed condition. Older adults balance index in single- and dual-task conditions is higher than young adults balance index. There is not any difference between men and

  2. The Impact of Big Five Personality Characteristics on Group Cohesion and Creative Task Performance

    OpenAIRE

    Buchanan, Laurie Birch

    1998-01-01

    One of the most prominent trends in organizations today is the use of teams to accomplish the work once assigned to individuals. Team composition variables, including the personality characteristics of team members, need to be carefully considered so that the transition of work from individuals to teams results in performance improvements. The types of tasks relegated to teams also affect performance, and it is equally important that group tasks are clearly defined. As such, the current st...

  3. Optimisation and decisions in radiological protection - A report of the work of an ICRP task group

    International Nuclear Information System (INIS)

    In 1984 the International Commission on Radiological Protection (ICRP) established a Task Group of Committee 4 to produce a report on methods for optimisation of protection other than cost-benefit analysis. As the work of the task group progressed it became clear that it would be more useful to produce a report on the entire field of application of optimisation, mainly to show how the various techniques including cost-benefit analysis could be applied appropriately to problems at different levels of complexity. This paper reports on the main ideas that have been developed by the task group. It must be emphasised that these ideas have not been endorsed by Committee 4 nor approved by the Commission so they can not yet be considered as recommendations

  4. Performance on paced serial addition tasks indicates an associative network for calculation.

    Science.gov (United States)

    Hiscock, M; Caroselli, J S; Kimball, L E; Panwar, N

    2001-06-01

    Although paced serial addition (PSA) tasks are considered to be tests of general information-processing capacity, recent work suggests that performance on such tasks is influenced by arithmetic-specific variables. We designed two visual PSA experiments to determine whether the performance of normal adults would support predictions derived from the cognitive psychology of calculation. Experiment 1 showed that mixing familiar (Arabic numeral) and less familiar (Roman numeral) stimulus formats reduced scores below the averaged scores for pure Arabic and Roman lists. The Roman-Arabic order of addends was more difficult than the Arabic-Roman order. Experiment 2, which involved only Arabic numerals as addends, showed that performance could be impaired by constraining the trial-to-trial variability of sums. The results of both experiments confirm the importance of arithmetic-specific variables in PSA and provide support for an associative network model of calculation. In addition, the findings implicate interference from extraneous addends and responses as the performance-limiting factor. PMID:11404809

  5. Summary report for MEGAPIE R+D Task Group X9: Neutronic and nuclear assessment

    International Nuclear Information System (INIS)

    The comprehensive work performed by the R+D task group X9 since the beginning of the MEGAPIE initiative is described in this summary report. The list of topics covered by this group is large and covers many of the essential aspects of an innovative system such as the MEGAPIE target. The X9 group worked on the neutronic and nuclear related aspects of the target design, as summarized in the following. The main tool in the neutronic design of a spallation neutron target is a reliable particle transport code, and nowadays the Monte Carlo technique is widely adopted in this field. There are several codes which are more or less extensively used in the nuclear physics community; at the beginning of the project a benchmark exercise was performed among several institutes using different Monte Carlo codes. The aim of the benchmark was to perform a code intercomparison by looking at the different predictions of several important quantities, as described later in the report. The benchmark results were first compiled in two separate reports. The results are critically discussed here. Based on the obtained results, and considering also other factors such as the code maintenance, the codes FLUKA and MCNPX were indicated as the most recommended ones to be used in the continuation of the X9 work. Proton and neutron fluxes in the MEGAPIE target were calculated. Detailed models of he MEGAPIE target and of the surrounding SINQ facility were developed, as well as of the present solid SINQ target. A comparison between the neutron flux with MEGAPIE and the SINQ solid target showed that the MEGAPIE target sill deliver 40% to 50% more thermal neutrons to the instruments served by SINQ as compared to the SINQ Mark 3 target. Calculations of the beam power deposition distributions are essential as input for the thermohydraulics CFD analysis of the lower target. Power deposition was calculated with FLUKA and MCNPX. The results from the two codes agree within 5%. Approximately 85% of the beam

  6. Summary report for MEGAPIE R+D Task Group X9: Neutronic and nuclear assessment

    Energy Technology Data Exchange (ETDEWEB)

    Zanini, L

    2005-12-15

    The comprehensive work performed by the R+D task group X9 since the beginning of the MEGAPIE initiative is described in this summary report. The list of topics covered by this group is large and covers many of the essential aspects of an innovative system such as the MEGAPIE target. The X9 group worked on the neutronic and nuclear related aspects of the target design, as summarized in the following. The main tool in the neutronic design of a spallation neutron target is a reliable particle transport code, and nowadays the Monte Carlo technique is widely adopted in this field. There are several codes which are more or less extensively used in the nuclear physics community; at the beginning of the project a benchmark exercise was performed among several institutes using different Monte Carlo codes. The aim of the benchmark was to perform a code intercomparison by looking at the different predictions of several important quantities, as described later in the report. The benchmark results were first compiled in two separate reports. The results are critically discussed here. Based on the obtained results, and considering also other factors such as the code maintenance, the codes FLUKA and MCNPX were indicated as the most recommended ones to be used in the continuation of the X9 work. Proton and neutron fluxes in the MEGAPIE target were calculated. Detailed models of he MEGAPIE target and of the surrounding SINQ facility were developed, as well as of the present solid SINQ target. A comparison between the neutron flux with MEGAPIE and the SINQ solid target showed that the MEGAPIE target sill deliver 40% to 50% more thermal neutrons to the instruments served by SINQ as compared to the SINQ Mark 3 target. Calculations of the beam power deposition distributions are essential as input for the thermohydraulics CFD analysis of the lower target. Power deposition was calculated with FLUKA and MCNPX. The results from the two codes agree within 5%. Approximately 85% of the beam

  7. Summary report for ITER task - D4: Activation calculations for the lithium vanadium ITER design

    International Nuclear Information System (INIS)

    Detailed activation analysis for ITER has been performed as a part of ITER Task D4. The calculations have been performed for the shielding blanket (SS/water) and for the breeding blanket (Li/V) options. The activation code RACC-P, which has been modified under ITER Task-D-10 for pulsed operation, has been used in this analysis. The spatial distributions of the radioactive inventory, decay heat, biological hazard potential, and the contact dose were calculated for the two designs for different operation modes and targeted fluences. A one-dimensional toroidal geometrical model has been utilized to determine the neutron fluxes in the two designs. The results are normalized for an inboard and outboard neutron wall loading of 0.91 and 1.2 MW/m2, respectively. The point-wise distributions of the decay gamma sources have been calculated everywhere in the reactor at several times after the shutdown of the two designs and are then used in the transport code ONEDANT to calculate the biological dose everywhere in the reactor. The point-wise distributions of all the responses have also been calculated. These calculations have been performed for neutron fluences of 3.0 MWa/m2, which corresponds to the target fluence of ITER, and 0.1 MWa/m2, which is anticipated to correspond to the beginning of the extended maintenance period. The decay heat results show that a large fraction of this energy (50 to 90%) Is produced by photons. This implies that this energy would be transported to different parts of the reactor, thus relieving the energy concentration at high intensity source locations such as the first wall. Accurate modeling for the decay gamma transport is required to produce realistic spatial distribution of the decay heat which may be used in LOCA and LOFA analyses. The results of the pulsed operation, using the new version of RACC, show large reductions in the radioactivity and the decay heat for pure pulsed operation

  8. HIV and Nurses: A Focus Group on Task Shifting in Uganda.

    Science.gov (United States)

    Spies, Lori A; Gray, Jennifer; Opollo, Jackline; Mbalinda, Scovia

    2016-01-01

    The HIV prevalence rate is 7.4% in Uganda, where the HIV-related President's Emergency Plan for AIDS Relief and United Nations millennial development goals have not been met. This is partially due to a critical shortage of nurses and other health care providers. Task shifting is a World Health Organization strategy to address the shortage of human resources for health by shifting work from one cadre of health care worker to another, often less-trained, cadre. We conducted three focus groups with nurses in Uganda to better understand perceptions of their preparation for and implementation of task shifting. The focus group included nurses from diverse work settings. Data analysis revealed that nurses were proud of the work they were doing but were challenged by the lack of consistent and appropriate support. We found a need for additional policies, regulations, and consistent preparation for nurses who work in environments with task shifting. PMID:26847378

  9. Does the medium matter? The interaction of task type and technology on group performance and member reactions.

    Science.gov (United States)

    Straus, S G; McGrath, J E

    1994-02-01

    The authors investigated the hypothesis that as group tasks pose greater requirements for member interdependence, communication media that transmit more social context cues will foster group performance and satisfaction. Seventy-two 3-person groups of undergraduate students worked in either computer-mediated or face-to-face meetings on 3 tasks with increasing levels of interdependence: an idea-generation task, an intellective task, and a judgment task. Results showed few differences between computer-mediated and face-to-face groups in the quality of the work completed but large differences in productivity favoring face-to-face groups. Analysis of productivity and of members' reactions supported the predicted interaction of tasks and media, with greater discrepancies between media conditions for tasks requiring higher levels of coordination. Results are discussed in terms of the implications of using computer-mediated communications systems for group work. PMID:8200874

  10. Sonar sound groups and increased terminal buzz duration reflect task complexity in hunting bats.

    Science.gov (United States)

    Hulgard, Katrine; Ratcliffe, John M

    2016-01-01

    More difficult tasks are generally regarded as such because they demand greater attention. Echolocators provide rare insight into this relationship because biosonar signals can be monitored. Here we show that bats produce longer terminal buzzes and more sonar sound groups during their approach to prey under presumably more difficult conditions. Specifically, we found Daubenton's bats, Myotis daubentonii, produced longer buzzes when aerial-hawking versus water-trawling prey, but that bats taking revolving air- and water-borne prey produced more sonar sound groups than did the bats when taking stationary prey. Buzz duration and sonar sound groups have been suggested to be independent means by which bats attend to would-be targets and other objects of interest. We suggest that for attacking bats both should be considered as indicators of task difficulty and that the buzz is, essentially, an extended sonar sound group. PMID:26857019

  11. Joint utility task group CGI data-base procurement history module

    International Nuclear Information System (INIS)

    The purpose of the procurement history record module of the Joint Utility Task Group's (JUTG's) commercial-grade item (CGI) data base is to assist utilities to cost effectively implement the dedication methodology provided in the Electric Power Research Institute's (EPRI's) report NP-5652, open-quotes Guidelines for the Utilization of Commercial Grade Items in Nuclear Safety-Related Applications.close quotes

  12. Indiana University high energy physics group, task C: Technical progress report, December 1, 1987-November 30, 1988

    International Nuclear Information System (INIS)

    The Indiana University High Energy Physics Group, Task C has been actively involved in the MACRO experiment at Gran Sasso during the current contract year. MACRO is a large US-Italian Monopole, Astrophysics, and Cosmic Ray Observatory being built under the Gran Sasso Mountain outside of Rome. Indiana University is in charge of the US software effort. We have been performing extensive Monte Carlo design and data analysis calculations. We are also doing development work on the MACRO liquid scintillator. We are setting up a Quality Assurance liquid scintillator laboratory in Frascati, Italy. We are producing vertical scintillator tank endplates and calibration boats in our machine shop

  13. Report of Task Group on Ex-Vessel Thermal-Hydraulics Corium/concrete interactions and combustible gas distribution in large dry containments

    International Nuclear Information System (INIS)

    The Task Group on Ex-Vessel Thermal-Hydraulics was established by the PWG 2 to address the physical processes that occur in the ex-vessel phase of severe accidents, to study their impact on containment loading and failure, and to assess the available calculation methods. This effort is part of an overall CSNI effort to come to an international understanding of the issues involved. The Task Group decided to focus its initial efforts on the Large Dry Containment used extensively to contain the consequences of postulated (design basis) accidents in Light Water Reactors (LWR). Although such containments have not been designed with explicit consideration of severe accidents, recent assessments indicate a substantial inherent capability for these accidents. The Task Group has examined the loads likely to challenge the integrity of the containment, and considered the calculation of the containment's response. This report is the outcome of this effort

  14. Cross section probability tables in multi-group transport calculations

    International Nuclear Information System (INIS)

    The use of cross section probability tables in multigroup transport calculations is presented. Emphasis is placed on how probability table parameters are generated in a multigroup cross section processor and how existing transport codes must be modifed to use them. In order to illustrate the accuracy obtained by using probability tables, results are presented for a variety of neutron and photon transport problems

  15. Advanced density matrix renormalization group method for nuclear structure calculations

    Czech Academy of Sciences Publication Activity Database

    Legeza, Ö.; Veis, Libor; Poves, A.; Dukelsky, J.

    2015-01-01

    Roč. 92, č. 5 (2015), 051303. ISSN 0556-2813 Institutional support: RVO:61388955 Keywords : INITIO QUANTUM-CHEMISTRY * GROUP ALGORITHM * SHELL-MODEL Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.733, year: 2014

  16. The Patient Specific QA of IMRT and VMAT Through the AAPM Task Group Report 119

    International Nuclear Information System (INIS)

    The aim of this study was to evaluate the patient specific quality assurance (QA) results of intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) through the AAPM Task Group Report 119. Using the treatment planning system, both IMRT and VMAT treatment plans were established. The absolute dose and relative dose for the target and OAR were measured by using an ion chamber and the bi-planar diode array, respectively. The plan evaluation was used by the Dose volume histogram (DVH) and the dose verification was implemented by compare the measured value with the calculated value. For the evaluation of plan, in case of prostate, both IMRT and VMAT were closed the goal of target and OARs. In case of H and N and Multi-target, IMRT was not reached the goal of target, but VMAT was reached the goal of target and OARs. In case of C-shape(easy), both were reached the goal of target and OARs. In case of C-shape(hard), both were reached the goal of target but not reached the goal of OARs. For the evaluation of absolute dose, in case of IMRT, the mean of relative error (%) between measured and calculated value was 1.24±2.06 and 1.4±2.9% for target and OAR, respectively. The confidence limits were 3.65% and 4.39% for target and OAR, respectively. In case of VMAT the mean of relative error was 2.06±0.64% and 2.21±0.74% for target and OAR, respectively. The confidence limits were 4.09% and 3.04% for target and OAR, respectively. For the evaluation of relative dose, in case of IMRT, the average percentage of passing gamma criteria (3mm/3%) were 98.3±1.5% and the confidence limits were 3.78%. In case of VMAT, the average percentage were 98.2±1.1% and the confidence limits were 3.95%. We performed IMRT and VMAT patient specific QA using TG-119 based procedure, all analyzed results were satisfied with acceptance criteria based on TG-119. So, the IMRT and VMAT of our institution was confirmed the accuracy.

  17. A Bayesian Group Sparse Multi-Task Regression Model for Imaging Genetics

    OpenAIRE

    Greenlaw, Keelin; Szefer, Elena; Graham, Jinko; Lesperance, Mary; Nathoo, Farouk S.

    2016-01-01

    Motivation: Recent advances in technology for brain imaging and high-throughput genotyping have motivated studies examining the influence of genetic variation on brain structure. Wang et al. (Bioinformatics, 2012) have developed an approach for the analysis of imaging genomic studies using penalized multi-task regression with regularization based on a novel group $l_{2,1}$-norm penalty which encourages structured sparsity at both the gene level and SNP level. While incorporating a number of u...

  18. Sonar sound groups and increased terminal buzz duration reflect task complexity in hunting bats

    OpenAIRE

    Katrine Hulgard; Ratcliffe, John M.

    2016-01-01

    More difficult tasks are generally regarded as such because they demand greater attention. Echolocators provide rare insight into this relationship because biosonar signals can be monitored. Here we show that bats produce longer terminal buzzes and more sonar sound groups during their approach to prey under presumably more difficult conditions. Specifically, we found Daubenton’s bats, Myotis daubentonii, produced longer buzzes when aerial-hawking versus water-trawling prey, but that bats taki...

  19. Responses to task 1 questionnaire of INFCE Working Group 6 supplied by participating states

    International Nuclear Information System (INIS)

    Responses to Task 1 Questionnaire of INFCE Working Group 6 supplied by participating states (Argentina, Australia, Austria, Belgium, Canada, Finland, France, Federal Republic of Germany, Italy, Japan, Netherlands, Portugal, Spain, Sweden, Switzerland, Turkey, USSR, United Kingdom, United States, Yugoslavia). Data and information are given on nuclear power forecast, spent fuel requirements for AR and AFR storage, current programmes for storage, future spent fuel disposition plans and transport

  20. The respiratory tract deposition model proposed by the ICRP Task Group

    International Nuclear Information System (INIS)

    The Task Group has developed a new model of the deposition of inhaled aerosols in each anatomical region of the respiratory tract. The model is used to evaluate the fraction of airborne activity that is deposited in respiratory regions having distinct retention characteristics and clearance pathways: the anterior nares, the extrathoracic airways of the naso- and oropharynx and larynx, the bronchi, the bronchioles, and the alveolated airways of the lung. Drawn from experimental data on total and regional deposition in human subjects, the model is based on extrapolation of these data by means of a detailed theoretical model of aerosol transport and deposition within the lung. The Task Group model applies to all practical conditions, and for aerosol particles and vapors from atomic size up to very coarse aerosols with an activity median aerodynamic diameter of 100 μm. The model is designed to predict regional deposition in different subjects, including adults of either sex, children of various ages, and infants, and also to account for anatomical differences among Caucasian and non-Caucasian subjects. The Task Group model represents aerosol inhalability and regional deposition in different subjects by algebraic expressions of aerosol size, breathing rates, standard lung volumes, and scaling factors for airway dimensions. 35 refs., 13 figs., 2 tabs

  1. The respiratory tract deposition model proposed by the ICRP Task Group

    International Nuclear Information System (INIS)

    The Task Group has developed a new model of the deposition of inhaled aerosols in each anatomical region of the respiratory tract. The model is used to evaluate the fraction of airborne activity that is deposited in respiratory regions having distinct retention characteristics and clearance pathways, and/or tissue sensitivity: the extrathoracic airways of the naso- and oropharynx and larynx, the bronchi, the bronchioles, and the alveolated airways of the lung. Drawn from experimental data on total and regional deposition in human subjects, the model is based on extrapolation of these data by means of a detailed theoretical model of aerosol transport and deposition within the lung. The Task Group model applies to all practical conditions, and for aerosol particles and vapours from atomic size up to very coarse aerosols with an activity median aerodynamic diameter of 100 μm. The model is designed to predict regional deposition in different subjects, including adults of either sex, children of various ages, and infants, and also to account for anatomical differences among Caucasian and non-Caucasian subjects. The Task Group model represents aerosol inhalability and regional deposition in different subjects by algebraic expressions of aerosol size, breathing rates, standard lung volumes, and scaling factors for airway dimensions. It is emphasised that the current version of the model described here is still provisional. (author)

  2. Optimal Group Size for Software Change Tasks: A Social Information Foraging Perspective.

    Science.gov (United States)

    Bhowmik, Tanmay; Niu, Nan; Wang, Wentao; Cheng, Jing-Ru C; Li, Ling; Cao, Xiongfei

    2016-08-01

    Group size is a key factor in collaborative software development and many other cybernetic applications where task assignments are important. While methods exist to estimate its value for proprietary projects, little is known about how group size affects distributed and decentralized cybernetic applications and in particular open source software (OSS) development. This paper presents a novel approach in which we frame developers' collective resolution of OSS change tasks as a social information foraging problem. This new perspective enables us to predict the optimal group size and quantify group size's effect on individual performance. We test the theory with data mined from two projects: 1) Firefox and 2) Mylyn. This paper not only uncovers the mismatch of optimal and actual group sizes, but also reveals the association of optimality with improved productivity. In addition, the social-level productivity gain is observed as project evolves. We show this paper's impact by extending the frontiers of knowledge in two areas: 1) social coding and 2) recommendation systems. PMID:25910274

  3. One-group transport theory calculation for three slabs cells

    International Nuclear Information System (INIS)

    As an idealized model of plate type fuel assemblies for nuclear reactors, three-slab cells are analysed numerically based on the exact solution of the transport equation in the one-group isotropic scattering model. From the equations describing the interface conditions, a set of regular integral equations for the coefficients of the singular eigenfunctions expansions is derived using the half-range orthogonality relations of the eigenfunctions and the recently developed method of regularization. Numerical solutions are obtained by solving this set of equations iteratively. The thermal utilization factor and thermal disadvantage factors as well as flux and current distributions are reported for the first time for various sets of parameters. The accuracy of the P sub(N) approximations is also analysed compared to the exact results. (Author)

  4. Advanced density matrix renormalization group method for nuclear structure calculations

    CERN Document Server

    Legeza, Ö; Poves, A; Dukelsky, J

    2015-01-01

    We present an efficient implementation of the Density Matrix Renormalization Group (DMRG) algorithm that includes an optimal ordering of the proton and neutron orbitals and an efficient expansion of the active space utilizing various concepts of quantum information theory. We first show how this new DMRG methodology could solve a previous $400$ KeV discrepancy in the ground state energy of $^{56}$Ni. We then report the first DMRG results in the $pf+g9/2$ shell model space for the ground $0^+$ and first $2^+$ states of $^{64}$Ge which are benchmarked with reference data obtained from Monte Carlo shell model. The corresponding correlation structure among the proton and neutron orbitals is determined in terms of the two-orbital mutual information. Based on such correlation graphs we propose several further algorithmic improvement possibilities that can be utilized in a new generation of tensor network based algorithms.

  5. Task Group on Safety Margins Action Plan (SMAP). Safety Margins Action Plan - Final Report

    International Nuclear Information System (INIS)

    . Chapter 3 looks at techniques for the deterministic calculation of safety margins and discusses the complementary probabilistic risk assessment techniques needed to generalize safety margins beyond design basis accidents. Chapter 4 examines the definition of safety margin, which is noted to take different meanings in different fields. For example, in civil engineering and applications that deal with the load-strength interference concept, safety margin describes the distance between the means of the load and strength probability density functions with regard to the standard deviation in both. However, in the nuclear industry, the term safety margin evolved to describe the goal of assuring the existence of adequate safety margin in deterministic calculations. Specifically, safety margin refers to keeping the value of a given safety variable under a pre-established safety limit in design basis accidents. Implicitly, safety margin in the nuclear industry is the distance from the safety limit to onset of damage. The SMAP task group fulfilled its first objective by adopting a methodology for quantifying safety margins that merges the deterministic and probabilistic approaches. The methodology described in Chapter 5 is consistent with the definition of safety margin commonly used in the nuclear industry. The metrics of this methodology quantify the change in safety over a range of accident sequences that extend beyond the design bases. However, the methodology is not described in this report to a level that would meet guidance document requirements. This is in part because methods and techniques needed to quantify safety margins in a global manner are evolving, and thus specific guidance rendered at this time would shortly become obsolete. This report presents the framework in sufficient detail to serve as the basis of an analysis and, thus, this report meets the second objective established for the SMAP group. A proof-of-concept application to further aid potential applicants

  6. Task Group on Non-conforming, Counterfeit, Fraudulent, and Suspect Items (TGNCFSI) - Report Review

    International Nuclear Information System (INIS)

    This presentation deals with the new task force created under the umbrella of the CNRA (NEA) to cope with the emergent and safety relevant issues of non-conforming, counterfeit, fraudulent and suspect items (NCFSI). The presentation talks about what are the causal factors and challenges faced related to these problems and what are some of the main improvements and recommendations to cope with it such as: methods for inspecting NCFSI, review regulatory requirements and to work on international groups such as the WGIP and WGOE on these issues

  7. NASA Engineering Safety Center NASA Aerospace Flight Battery Systems Working Group 2007 Proactive Task Status

    Science.gov (United States)

    Manzo, Michelle A.

    2007-01-01

    In 2007, the NASA Engineering Safety Center (NESC) chartered the NASA Aerospace Flight Battery Systems Working Group to bring forth and address critical battery-related performance/manufacturing issues for NASA and the aerospace community. A suite of tasks identifying and addressing issues related to Ni-H2 and Li-ion battery chemistries was submitted and selected for implementation. The current NESC funded are: (1) Wet Life of Ni-H2 Batteries (2) Binding Procurement (3) NASA Lithium-Ion Battery Guidelines (3a) Li-Ion Performance Assessment (3b) Li-Ion Guidelines Document (3b-i) Assessment of Applicability of Pouch Cells for Aerospace Missions (3b-ii) High Voltage Risk Assessment (3b-iii) Safe Charge Rates for Li-Ion Cells (4) Availability of Source Material for Li-Ion Cells (5) NASA Aerospace Battery Workshop This presentation provides a brief overview of the tasks in the 2007 plan and serves as an introduction to more detailed discussions on each of the specific tasks.

  8. Vectorized and multi-tasked solutions of the two-group neutron diffusion equations

    International Nuclear Information System (INIS)

    A numerical algorithm with parallelism has been employed to solve the two-group, two-dimensional [X-Y] neutron diffusion equations on a FPS-164 attached scientific processor, IBM-3090/Model 200 with vector facilities mainframe computer and a CRAY X/MP-48 supercomputer. All three machines employ vector pipelines and the latter two computers also contain respectively 2 and 4 CPUs. Utilizing a parallel numerical algorithm, the FPS-164, IBM-3090/Model 200 and CRAY X/MP-48 [using 1 CPU] execute, respectively 5.5, 1.7 and 11.6 times faster in vector versus scalar mode for pin-wise mesh. Run time reductions versus an IBM-3081/Model K for the FPS-164, IBM-3090/Model 200 and CRAY X/MP-48 [using 1 CPU], respectively are 1.0, 4.7 and 27.5. The results from the preliminary work completed for multi-tasking on 2 CPUs of the CRAY X/MP-48 indicate a speedup of about 1.62 for just the Inner iteration code segment that was multi-tasked. The theoretical speedup of 2.0 is not obtained mainly because of vector pipelines' performance degradation due to the decrease in vector lengths associated with multi-tasking the Inner iteration

  9. Harmonization of nuclear codes and standards, pacific nuclear council working and task group report

    International Nuclear Information System (INIS)

    Full text: The codes and standards, both at the national and international level, have had a major impact on the industry worldwide and served it well in maintaining the performance and safety of the nuclear reactors and facilities. The codes and standards, in general, are consensus documents and do seek public input at various levels before they are finalized and rolled out for use by the nuclear vendors, consultants, utilities and regulatory bodies. However, the extensive development of prescriptive national standards if unchecked against the global environment and trade agreements (NAFTA, WTO, etc.) can also become barriers and cause difficulties to compete in the world market. During the last decade, the national and international writing standards writing bodies have recognized these issues and are moving more towards the rationalization and harmonization of their standards with the more widely accepted generic standards. The Pacific Nuclear Council (PNC) recognized the need for harmonization of the nuclear codes and standards for its member countries and formed a Task Group to achieve its objectives. The Task Group has a number of members from the PNC member countries. In 2005 PNC further raised the importance of this activity and formed a Working Group to cover a broader scope. The Working Group (WG) mandate is to identify and analyze the different codes and standards introduced to the Pacific Basin region, in order to achieve mutual understanding, harmonization and application in each country. This o requires the WG to develop and encourage the use of reasonably consistent criteria for the design and development, engineering, procurement, fabrication, construction, testing, operations, maintenance, waste management, decommissioning and the management of the commercial nuclear power plants in the Pacific Basin so as to: Promote consistent safety, quality, environmental and management standards for nuclear energy and other peaceful applications of nuclear

  10. TASK 2.5.4 DEVELOPMENT OF AN ENERGY SAVINGS CALCULATOR

    Energy Technology Data Exchange (ETDEWEB)

    Miller, William A [ORNL; New, Joshua Ryan [ORNL; Desjarlais, Andre Omer [ORNL; Huang, Joe [Lawrence Berkeley National Laboratory (LBNL); Erdem, Ender [Lawrence Berkeley National Laboratory (LBNL); Ronnen, Levinson [Lawrence Berkeley National Laboratory (LBNL)

    2010-03-01

    California s major energy utilities and the California Energy Commission (CEC) are seeking to allocate capital that yields the greatest return on investment for energy infrastructure that meets any part of the need for reliable supplies of energy. The utilities are keenly interested in knowing the amount of electrical energy savings that would occur if cool roof color materials are adopted in the building market. To meet this need the Oak Ridge National Laboratory and the Lawrence Berkeley National Laboratory (LBNL) have been collaborating on a Public Interest Energy Research (PIER) project to develop an industry-consensus energy-savings calculator. The task was coordinated with an ongoing effort supported by the DOE to develop one calculator to achieve both the DOE and the EPA objectives for deployment of cool roof products. Recent emphasis on domestic building energy use has made the work a top priority by the Department of Energy s (DOE) Building Technologies Program. The Roof Savings Calculator (RSC) tool is designed to help building owners, manufacturers, distributors, contractors and practitioners easily run complex simulations. The latest web technologies and usability design were employed to provide an easy input interface to an annual simulation of hour-by-hour, whole-building performance using the world-class simulation tools DOE-2.1E and AtticSim. Building defaults were assigned based on the best available statistical evidence and can provide energy and cost savings after the user selects nothing more than the building location. A key goal for the tool is to promote the energy benefits of cool color tile, metal and asphalt shingle roof products and other energy saving systems. The RSC tool focuses on applications for the roof and attic; however, the code conducts a whole building simulation that puts the energy and heat flows of the roof and attic into the perspective of the whole house. An annual simulation runs in about 30 sec. In addition to cool

  11. Waste Area Grouping 2 Remedial Investigation Phase 1 Seep Task data report: Contaminant source area assessment

    International Nuclear Information System (INIS)

    This report presents the findings of the Waste Area Grouping (WAG) 2, Phase 1 Remedial Investigation (RI) Seep Task efforts during 1993 and 1994 at Oak Ridge National Laboratory (ORNL). The results presented here follow results form the first year of sampling, 1992, which are contained in the Phase 1 RI report for WAG 2 (DOE 1995a). The WAG 2 Seep Task efforts focused on contaminants in seeps, tributaries, and main streams within the White Oak Creek (WOC) watershed. This report is designed primarily as a reference for contaminants and a resource for guiding remedial decisions. Additional in-depth assessments of the Seep Task data may provide clearer understandings of contaminant transport from the different source areas in the WOC watershed. WAG 2 consists of WOC and its tributaries downstream of the ORNL main plant area, White Oak Lake, the White Oak Creek Embayment of the Clinch River, and the associated flood plains and subsurface environment. The WOC watershed encompasses ORNL and associated WAGs. WAG 2 acts as an integrator for contaminant releases from the contaminated sites at ORNL and as the conduit transporting contaminants to the Clinch River. The main objectives of the Seep Task were to identify and characterize seeps, tributaries and source areas that are responsible for the contaminant releases to the main streams in WAG 2 and to quantify their input to the total contaminant release from the watershed at White Oak Dam (WOD). Efforts focused on 90Sr, 3H, and 137Cs because these contaminants pose the greatest potential human health risk from water ingestion at WOD. Bimonthly sampling was conducted throughout the WOC watershed beginning in March 1993 and ending in August 1994. Samples were also collected for metals, anions, alkalinity, organics, and other radionuclides

  12. Mindfulness Training Improves Attentional Task Performance in Incarcerated Youth: A Group Randomized Controlled Intervention Trial

    Directory of Open Access Journals (Sweden)

    Noelle R Leonard

    2013-11-01

    Full Text Available We investigated the impact of cognitive behavioral therapy and mindfulness training (CBT/MT on attentional task performance in incarcerated adolescents. Attention is a cognitive system necessary for managing cognitive demands and regulating emotions. Yet persistent and intensive demands, such as those experienced during high-stress intervals like incarceration and the events leading to incarceration, may deplete attention resulting in cognitive failures, emotional disturbances, and impulsive behavior. We hypothesized that CBT/MT may mitigate these deleterious effects of high stress and protect against degradation in attention over the high-stress interval of incarceration. Using a group randomized controlled trial design, we randomly assigned dormitories of incarcerated youth, ages 16 to 18, to a CBT/MT intervention (youth n = 147 or an active control intervention (youth n = 117. Both arms received approximately 750 minutes of intervention in a small-group setting over a 3-5 week period. Youth in the CBT/MT arm also logged the amount of out-of-session time spent practicing MT exercises. The Attention Network Test was used to index attentional task performance at baseline and 4 months post-baseline. Overall, task performance degraded over time in all participants. The magnitude of performance degradation was significantly less in the CBT/MT vs. control arm. Further, within the CBT/MT arm, performance degraded over time in those with no outside-of-class practice time, but remained stable over time in those who practiced mindfulness exercises outside of the session meetings. Thus, these findings suggest that sufficient CBT/MT practice may protect against functional attentional impairments associated with high-stress intervals. Keywords: adolescent development, incarcerated adolescents, detained adolescents, stress, attention, mindfulness meditation.

  13. Task group of international union of radioecology 'ecosystem approach to environment protection'

    International Nuclear Information System (INIS)

    An ecosystem approach is a holistic (i.e., top-down) strategy for protection of ecosystem structures and functions from perturbations. A task group of International Union of Radioecology 'Ecosystem Approach to Environment Protection' was launched in April, 2010. This task group is preparing a report on the following topics: (1) goals of environmental protection; (2) legislation about environmental protection; (3) assessment of the Reference Animals and Plants (RAP) concept in the general context of environmental protection; (4) limitations and uncertainties of the RAPs concept; (5) justification and merits of the ecosystem approach; (6) assessing the feasibility of the ecosystem approach; (7) research and development required for the ecosystem approach; and (8) recommendations with respect to radiation protection. The topics 1, 3, 4 and 5 have been almost completely prepared, and demonstrate that the ecosystem approach is required for radiation protection of the environment. On the other hand, methods of the ecosystem approach which should be adopted for radiation protection of the environment are not clear in the current draft report. They should be specified by reviewing the Convention on Biological Diversity, fish stock management and other activities where the ecosystem approach is already adopted. (author)

  14. Studying the process of transforming a statistical inquiry-based task in the context of a teacher study group

    OpenAIRE

    Bakogianni, Dionysia

    2015-01-01

    Statistical inquiry, although beneficial for developing students' statistical thinking, constitutes a quite demanding task for the mathematics teacher. In this paper, I focus on the transformation of a statistical inquiry-based task. In the context of a study group of five secondary mathematics teachers, I investigate the various stages that the task passes through (set up phase, implementation phase, reflection) and explore factors that seem to frame the process of transformation. The emergi...

  15. The birth of NASA the work of the Space Task Group, America's first true space pioneers

    CERN Document Server

    von Ehrenfried, Dutch

    2016-01-01

    This is the story of the work of the original NASA space pioneers; men and women who were suddenly organized in 1958 from the then National Advisory Committee on Aeronautics (NACA) into the Space Task Group. A relatively small group, they developed the initial mission concept plans and procedures for the U. S. space program. Then they boldly built hardware and facilities to accomplish those missions. The group existed only three years before they were transferred to the Manned Spacecraft Center in Houston, Texas, in 1962, but their organization left a large mark on what would follow. Von Ehrenfried's personal experience with the STG at Langley uniquely positions him to describe the way the group was structured and how it reacted to the new demands of a post-Sputnik era. He artfully analyzes how the growing space program was managed and what techniques enabled it to develop so quickly from an operations perspective. The result is a fascinating window into history, amply backed up by first person documentation ...

  16. An Agent-Based Simulation for Investigating the Impact of Stereotypes on Task-Oriented Group Formation

    Science.gov (United States)

    Maghami, Mahsa; Sukthankar, Gita

    In this paper, we introduce an agent-based simulation for investigating the impact of social factors on the formation and evolution of task-oriented groups. Task-oriented groups are created explicitly to perform a task, and all members derive benefits from task completion. However, even in cases when all group members act in a way that is locally optimal for task completion, social forces that have mild effects on choice of associates can have a measurable impact on task completion performance. In this paper, we show how our simulation can be used to model the impact of stereotypes on group formation. In our simulation, stereotypes are based on observable features, learned from prior experience, and only affect an agent's link formation preferences. Even without assuming stereotypes affect the agents' willingness or ability to complete tasks, the long-term modifications that stereotypes have on the agents' social network impair the agents' ability to form groups with sufficient diversity of skills, as compared to agents who form links randomly. An interesting finding is that this effect holds even in cases where stereotype preference and skill existence are completely uncorrelated.

  17. Steam generator group project: Task 13 final report: Nondestructive examination validation

    International Nuclear Information System (INIS)

    The Steam Generator Group Project (SGGP) was a multi-task effort using the retired-from-service Surry 2A pressurized water reactor steam generator as a test bed to investigate the reliability and effectiveness of in-service nondestructive eddy current (EC) inspection equipment and procedures. The information developed provided the technical basis for recommendations for improved in- service inspection and tube plugging criteria of steam generators. This report describes the results and analysis from Task 13--NDE Validation. The primary objective of Task 13 was to validate the EC inspection to detect and size tube defects. Additional objectives were to assess the nature and severity of tube degradation from all regions of the generator and to measure the remaining integrity of degraded specimens by burst testing. More than 550 specimens were removed from the generator and included in the validation studies. The bases for selecting the specimens and the methods and procedures used for specimen removal from the generator are reported. Results from metallurgical examinations of these specimens are presented and discussed. These examinations include visual inspection of all specimens to locate and identify tube degradation, metallographic examination of selected specimens to establish defect severity and burst testing of selected specimens to establish the remaining integrity of service-degraded tubes. Statistical analysis of the combined metallurgical and EC data to determine the probability of detection (POD) and sizing accuracy are reported along with a discussion of the factors which influenced the EC results. Finally, listings of the metallurgical and corresponding EC data bases are given. 12 refs., 141 figs., 24 tabs

  18. SU-E-P-22: AAPM Task Group 263 Tackling Standardization of Nomenclature for Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Matuszak, M; Feng, M [University of Michigan, Ann Arbor, MI (United States); Moran, J [Univ Michigan Medical Center, Ann Arbor, MI (United States); Xiao, Y [Thomas Jefferson University, Philadelphia, PA (United States); Mayo, C; Miller, R [Mayo Clinic, Rochester, MN (United States); Bosch, W [Washington Univ, Saint Louis, MO (United States); Popple, R [Univ Alabama Birmingham, Birmingham, AL (United States); Marks, L [UNC School of Medicine, Chapel Hill, NC (United States); Wu, Q [Duke University Medical Center, Durham, NC (United States); Molineu, A; Martel, M [UT MD Anderson Cancer Center, Houston, TX (United States); Yock, T [Massachusetts General Hospital, Boston, MA (United States); McNutt, T [Johns Hopkins University, Severna Park, MD (United States); Brown, N [Baptist Medical Center, Jacksonville, FL (United States); Purdie, T [Princess Margaret Hospital, Toronto, ON (Canada); Yorke, E [Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Santanam, L [Washington University School of Medicine, St.louis, MO (United States); Gabriel, P [University of Pennsylvania, Philadelphia, PA (United States); Michalski, J [Washington University, Saint Louis, MO (United States); and others

    2015-06-15

    Purpose: There is growing recognition of need for increased clarity and consistency in the nomenclatures used for body and organ structures, DVH metrics, toxicity, dose and volume units, etc. Standardization has multiple benefits; e.g. facilitating data collection for clinical trials, enabling the pooling of data between institutions, making transfers (i.e. hand-offs) between centers safer, and enabling vendors to define “default” settings. Towards this goal, the American Association of Physicists in Medicine (AAPM) formed a task group (TG263) in July of 2014, operating under the Work Group on Clinical Trials to develop consensus statements. Guiding principles derived from the investigation and example nomenclatures will be presented for public feedback. Methods: We formed a multi-institutional and multi-vendor collaborative group of 39 physicists, physicians and others involved in clinical use and electronic transfer of information. Members include individuals from IROC, NRG, IHE-RO, DICOM WG-7, ASTRO and EORTC groups with overlapping interests to maximize the quality of the consensus and increase the likelihood of adoption. Surveys of group and NRG members were used to define current nomenclatures and requirements. Technical requirements of vendor systems and the proposed DICOM standards were examined. Results: There is a marked degree of inter and intra institutional variation in current approaches, resulting from inter-vendor differences in capabilities, clinic specific conceptualizations and inconsistencies. Using a consensus approach, the group defined optimal formats for the naming of targets and normal structures. A formal objective assessment of 13 existing clinically-used software packages show that all had capabilities to accommodate these recommended nomenclatures. Conclusions: A multi-stakeholder effort is making significant steps forward in developing a standard nomenclature that will work across platforms. Our current working list includes > 550

  19. SU-E-P-22: AAPM Task Group 263 Tackling Standardization of Nomenclature for Radiation Therapy

    International Nuclear Information System (INIS)

    Purpose: There is growing recognition of need for increased clarity and consistency in the nomenclatures used for body and organ structures, DVH metrics, toxicity, dose and volume units, etc. Standardization has multiple benefits; e.g. facilitating data collection for clinical trials, enabling the pooling of data between institutions, making transfers (i.e. hand-offs) between centers safer, and enabling vendors to define “default” settings. Towards this goal, the American Association of Physicists in Medicine (AAPM) formed a task group (TG263) in July of 2014, operating under the Work Group on Clinical Trials to develop consensus statements. Guiding principles derived from the investigation and example nomenclatures will be presented for public feedback. Methods: We formed a multi-institutional and multi-vendor collaborative group of 39 physicists, physicians and others involved in clinical use and electronic transfer of information. Members include individuals from IROC, NRG, IHE-RO, DICOM WG-7, ASTRO and EORTC groups with overlapping interests to maximize the quality of the consensus and increase the likelihood of adoption. Surveys of group and NRG members were used to define current nomenclatures and requirements. Technical requirements of vendor systems and the proposed DICOM standards were examined. Results: There is a marked degree of inter and intra institutional variation in current approaches, resulting from inter-vendor differences in capabilities, clinic specific conceptualizations and inconsistencies. Using a consensus approach, the group defined optimal formats for the naming of targets and normal structures. A formal objective assessment of 13 existing clinically-used software packages show that all had capabilities to accommodate these recommended nomenclatures. Conclusions: A multi-stakeholder effort is making significant steps forward in developing a standard nomenclature that will work across platforms. Our current working list includes > 550

  20. Ongoing quality control in digital radiography: Report of AAPM Imaging Physics Committee Task Group 151

    Energy Technology Data Exchange (ETDEWEB)

    Jones, A. Kyle, E-mail: kyle.jones@mdanderson.org; Geiser, William [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Heintz, Philip [Department of Radiology, University of New Mexico, Albuquerque, New Mexico 87104 (United States); Goldman, Lee [Hartford Hospital, Hartford, Connecticut 06102 (United States); Jerjian, Khachig [Hoag Memorial Hospital, Newport Beach, California 92658 (United States); Martin, Melissa [Therapy Physics, Inc., Gardena, California 90248 (United States); Peck, Donald [Henry Ford Health System, Detroit, Michigan 48202 (United States); Pfeiffer, Douglas [Boulder Community Foothills Hospital, Boulder, Colorado 80303 (United States); Ranger, Nicole [Landauer, Inc., Glenwood, Illinois 60425 (United States); Yorkston, John [Carestream Health, Inc., Rochester, New York 14615 (United States)

    2015-11-15

    Quality control (QC) in medical imaging is an ongoing process and not just a series of infrequent evaluations of medical imaging equipment. The QC process involves designing and implementing a QC program, collecting and analyzing data, investigating results that are outside the acceptance levels for the QC program, and taking corrective action to bring these results back to an acceptable level. The QC process involves key personnel in the imaging department, including the radiologist, radiologic technologist, and the qualified medical physicist (QMP). The QMP performs detailed equipment evaluations and helps with oversight of the QC program, the radiologic technologist is responsible for the day-to-day operation of the QC program. The continued need for ongoing QC in digital radiography has been highlighted in the scientific literature. The charge of this task group was to recommend consistency tests designed to be performed by a medical physicist or a radiologic technologist under the direction of a medical physicist to identify problems with an imaging system that need further evaluation by a medical physicist, including a fault tree to define actions that need to be taken when certain fault conditions are identified. The focus of this final report is the ongoing QC process, including rejected image analysis, exposure analysis, and artifact identification. These QC tasks are vital for the optimal operation of a department performing digital radiography.

  1. Ongoing quality control in digital radiography: Report of AAPM Imaging Physics Committee Task Group 151

    International Nuclear Information System (INIS)

    Quality control (QC) in medical imaging is an ongoing process and not just a series of infrequent evaluations of medical imaging equipment. The QC process involves designing and implementing a QC program, collecting and analyzing data, investigating results that are outside the acceptance levels for the QC program, and taking corrective action to bring these results back to an acceptable level. The QC process involves key personnel in the imaging department, including the radiologist, radiologic technologist, and the qualified medical physicist (QMP). The QMP performs detailed equipment evaluations and helps with oversight of the QC program, the radiologic technologist is responsible for the day-to-day operation of the QC program. The continued need for ongoing QC in digital radiography has been highlighted in the scientific literature. The charge of this task group was to recommend consistency tests designed to be performed by a medical physicist or a radiologic technologist under the direction of a medical physicist to identify problems with an imaging system that need further evaluation by a medical physicist, including a fault tree to define actions that need to be taken when certain fault conditions are identified. The focus of this final report is the ongoing QC process, including rejected image analysis, exposure analysis, and artifact identification. These QC tasks are vital for the optimal operation of a department performing digital radiography

  2. Report on Task 2 in the special working group of the International Thermonuclear Experimental Reactor (ITER)

    Energy Technology Data Exchange (ETDEWEB)

    Kishimoto, Hiroshi [Japan Atomic Energy Research Inst., Tokyo (Japan)

    1999-10-01

    Under international cooperation of four parties of U.S.A., EU, Russia, and Japan, the Engineering Design Activity (EDA) on the International Thermonuclear Experimental Reactor (ITER) began in June, 1992, the actions were finished their initial six years programs in 1998, but were not transferred to its construction. Then, an investigation on design option to intend to reduce its construction cost to it's a half was conducted by three years elongation of EDA, for which a Special Working Group (SWG) was established at the 13th ITER boards of directors. The work of this Task 2 was to evaluate some impacts to the Nuclear Fusion Development Program. The report of the Task 2 consists of five chapters, where general nuclear fusion development were discussed at a center of Tokamak. In special, on Chapter 4: Comparison with the other routes, for a modular route claimed by U.S.A., some earnest discussions were conducted by U.S.A. and other three parties, to be anxious to for U.S.A. to suggest to withdraw this work. In this report, four points of Japanese claims on security of flexibility capable of conducting advanced Tokamak research in ITER, safety proof due to positive introduction and test of low activation materials to ITER, and so forth, were all reflected. In the SWG, an opinion that the nuclear fusion program in the world was prepared to start to ITER was agreed by all members. (G.K.)

  3. Report on Task 2 in the special working group of the International Thermonuclear Experimental Reactor (ITER)

    International Nuclear Information System (INIS)

    Under international cooperation of four parties of U.S.A., EU, Russia, and Japan, the Engineering Design Activity (EDA) on the International Thermonuclear Experimental Reactor (ITER) began in June, 1992, the actions were finished their initial six years programs in 1998, but were not transferred to its construction. Then, an investigation on design option to intend to reduce its construction cost to it's a half was conducted by three years elongation of EDA, for which a Special Working Group (SWG) was established at the 13th ITER boards of directors. The work of this Task 2 was to evaluate some impacts to the Nuclear Fusion Development Program. The report of the Task 2 consists of five chapters, where general nuclear fusion development were discussed at a center of Tokamak. In special, on Chapter 4: Comparison with the other routes, for a modular route claimed by U.S.A., some earnest discussions were conducted by U.S.A. and other three parties, to be anxious to for U.S.A. to suggest to withdraw this work. In this report, four points of Japanese claims on security of flexibility capable of conducting advanced Tokamak research in ITER, safety proof due to positive introduction and test of low activation materials to ITER, and so forth, were all reflected. In the SWG, an opinion that the nuclear fusion program in the world was prepared to start to ITER was agreed by all members. (G.K.)

  4. GRUCAL: a program system for the calculation of macroscopic group constants

    International Nuclear Information System (INIS)

    Nuclear reactor calculations require material- and composition-dependent, energy-averaged neutron physical data in order to decribe the interaction between neutrons and isotopes. The multigroup cross section code GRUCAL calculates these macroscopic group constants for given material compositions from the material-dependent data of the group constant library GRUBA. The instructions for calculating group constants are not fixed in the program, but are read in from an instruction file. This makes it possible to adapt GRUCAL to various problems or different group constant concepts

  5. Biased Information Search in Homogeneous Groups: Confidence as a Moderator for the Effect of Anticipated Task Requirements

    OpenAIRE

    Kerschreiter, Rudolf; Schulz-Hardt, Stefan; Mojzisch, Andreas; Frey, Dieter

    2008-01-01

    When searching for information, groups that are homogeneous regarding their members' prediscussion decision preferences show a strong bias for information that supports rather than conflicts with the prevailing opinion (confirmation bias). The present research examined whether homogeneous groups blindly search for information confirming their beliefs irrespective of the anticipated task or whether they are sensitive to the usefulness of new information for this forthcoming task. Results of th...

  6. Radiation Protection in Brachytherapy. Report of the SEFM Task Group on Brachytherapy

    International Nuclear Information System (INIS)

    This document presents the report of the Brachytherapy Task Group of the Spanish Society of Medical Physics. It is dedicated to the radiation protection aspects involved in brachytherapy. The aim of this work is to include the more relevant aspects related to radiation protection issues that appear in clinical practice, and for the current equipment in Spain. Basically this report focuses on the typical contents associated with high dose rate brachytherapy with 192Ir and 60Co sources, and permanent seed implants with 125I, 103Pd and 131Cs, which are the most current and widespread modalities. Ophthalmic brachytherapy (COMS with 125I, 106Ru, 90Sr) is also included due to its availability in a significant number of spanish hospitals. The purpose of this report is to assist to the medical physicist community in establishing a radiation protection program for brachytherapy procedures, trying to solve some ambiguities in the application of legal requirements and recommendations in clinical practice. (Author)

  7. Examining the Impact of Novel Pre-activity Tasks on Macroskills: The Case of Group Discussion on Writing Ability

    Directory of Open Access Journals (Sweden)

    Hooshang Khoshsima

    2016-02-01

    Full Text Available The main concern of most researchers in the field of second and foreign language teaching is lessening the problems and eliminating the hinders on the way of learning a language. Writing is considered as one of the most challenging and complicated tasks for learners to perform particularly when they have to write in a second or foreign language. Numerous studies were done on the importance of the pre-writing stage and activities which are directly and indirectly related to the theme of the writing. Accordingly, the main aim of this study was to examine the effects of group discussion as a pre- activity task on writing ability. To this aim, 27 Iranian EFL learners, who were at the same level –intermediate- studying at Shokuh and Safir Institutes, Birjand, Iran were chosen randomly. Two groups- one control and one experimental group- were studied. In control group the conventional method was used in teaching writing, while in experimental group, group discussion pre-activity task was administered. After 16 sessions, the obtained data of the pretests and posttests was analyzed by SPSS software. According to the results, researcher strongly concluded that group discussion has no significant effect on writing ability of Iranian intermediate learners. This study can help teachers and syllabus designers in choosing and applying an effective pre-activity task.Keywords: writing ability, pre-activity task, group discussion, EFL learners

  8. Progress with nuclear energy agency task group on nuclear site restoration

    International Nuclear Information System (INIS)

    The Nuclear Energy Agency (NEA) Co-operative Programme for the Exchange of Scientific and Technical Information Concerning Nuclear Installation Decommissioning Projects (CPD) is a joint undertaking of a limited number of organisations, mainly from NEA member countries. The objective of the CPD is to acquire and share information from operational experience in decommissioning nuclear installations that is useful for future projects. The information exchange includes biannual meetings of the Technical Advisory Group (TAG) and supporting projects on topics. The TAG has decided to form a Task Group to review nuclear site restoration starting in March 2012 that involves nuclear operators, experts and regulators. The group is supported by the International Atomic Energy Agency (IAEA) that is leading similar work on legacy sites. Within NEA Countries, several nuclear sites are being restored for beneficial reuse. Restoration is normally considered the last activity in a sequence of decommissioning steps but increasingly the value of long-term planning and parallel remediation is being recognised. It is essential that regulators know that liabilities are well understood (well characterised) and there is adequate financial provision to carry on the remediation works. Operators are also learning that early intervention is needed to ensure prevention and minimisation of leaks and spills of radioactive and non-radioactive contaminants in order to reduce groundwater and soil contamination, thus reducing overall liabilities and ensuring protection of the environment. Early intervention needs to be guided by good practices that include adequate site characterisation, reliable conceptual models and defined goals. Currently most nuclear site restoration work takes place at the legacy nuclear sites. This work has emphasised the need for better clarity in terms of the regulatory expectations for site restoration. At other nuclear sites the drivers are less evident and there is a risk

  9. Dosimetric evaluation of a commercial 3D treatment planning system using the AAPM Task Group 23 test package.

    Science.gov (United States)

    Casanova Borca, Valeria; Pasquino, Massimo; Bresciani, Sara; Catuzzo, Paola; Ozzello, Franca; Tofani, Santi

    2005-03-01

    The accuracy of the dose calculation algorithm is one of the most critical steps in assessing the radiotherapy treatment to achieve the 5% accuracy in dose delivery, which represents the suggested limit to increase the complication-free local control of tumor. We have used the AAPM Task Group 23 (TG-23) test package for clinical photon external beam therapy to evaluate the accuracy of the new version of the PLATO TPS algorithm. The comparison between tabulated values and calculated ones has been performed for 266 and 297 dose values for the 4 and 18 MV photon beams, respectively. Dose deviations less than 2% were found in the 98.5%- and 90.6% analyzed dose points for the two considered energies, respectively. Larger deviations were obtained for both energies, in large dose gradients, such as the build-up region or near the field edges and blocks. As far as the radiological field width is concerned, 64 points were analyzed for both the energies: 53 points (83%) and 64 points (100%) were within +/-2 millimeters for the 4 and 18 MV photon beams, respectively. The results show the good accuracy of the algorithm either in simple geometry beam conditions or in complex ones, in homogeneous medium, and in the presence of inhomogeneities, for low and high energy beams. Our results fit well the data reported by several authors related to the calculation accuracy of different treatment planning systems (TPSs) (within a mean value of 0.7% and 1.2% for 4 and 18 MV respectively). The TG-23 test package can be considered a powerful instrument to evaluate dose calculation accuracy, and as such may play an important role in a quality assurance program related to the commissioning of a new TPS. PMID:15839346

  10. Harmonization of nuclear codes and standards. Pacific nuclear council working and task group report

    International Nuclear Information System (INIS)

    Nuclear codes and standards have been an integral part of the nuclear industry since its inception. As the industry came into the main stream over the 2nd half of the 20th century, a number of national and international standards were developed to support a specific nuclear reactor concept. These codes and standards have been a key component of the industry to maintain its focus on nuclear safety, reliability and quality. Both national and international standards have served the industry well in obtaining public, shareholder and regulatory acceptance. The existing suite of national and international standards is required to support the emerging nuclear renaissance. However as noted above under Pacific Nuclear Council (PNC), Manufacturing Design Evaluation Program (MDEP) and SMiRT discussions, the time has come now for the codes and standards writing bodies and the industry to take the next step to examine the relevance of existing suite in view of current needs and challenges. This review must account for the changing global environment including global supply chain and regulatory framework, resources, deregulation, free trade, and industry need for competitiveness and performance excellence. The Task Group (TG) has made limited progress in this review period as no additional information on the listing of codes and standards have been received from the members. However, TG Chair has been successful in obtaining considerable interest from some additional individuals from the member countries. It is important that PNC management seek additional participation from the member countries and asks for their active engagement in the Working Group (WG) TG activities to achieve its mandate and deliverables. The harmonization of codes and standards is a key area for the emerging nuclear renaissance and as noted by a number of international organizations (refer to MDEP action noted above) that these tasks can not be completed unless we have the right level of resources and

  11. Report of the task group on the seismic behaviour of structures: status report

    International Nuclear Information System (INIS)

    In 1995, the CSNI Committee on the Safety of Nuclear Installations) approved a new mandate for PWG-3 and the new title 'Integrity of Components and Structures'. The PWG-3 is assisted by three task groups, one of which is addressing the problem of seismic behavior of structures. Ten topics were identified: engineering characterization of seismic input, site response, soil structure interaction, identification of functions and classification of systems, structures and components, structural response and capacity evaluation (including effects of aging and degradation), component and equipment response and capacity evaluation (including effects of aging and degradation), response and capacity evaluation of distribution systems (piping, cable trays, conduit, HVAC), load combination and acceptance criteria, uncertainties (PSA and margins), plant seismic instrumentation and trip. This report summarizes the seismic issues and activities in various member countries (Canada, Czech Republic, France, Hungary, Italy, Japan, Spain, Switzerland, United Kingdom, United States) and international organizations (IAEA), provides a summary of the important issues that are of collective interest to the group members, and recommends a future programme of work to address these issues

  12. IMRT commissioning: Multiple institution planning and dosimetry comparisons, a report from AAPM Task Group 119

    International Nuclear Information System (INIS)

    AAPM Task Group 119 has produced quantitative confidence limits as baseline expectation values for IMRT commissioning. A set of test cases was developed to assess the overall accuracy of planning and delivery of IMRT treatments. Each test uses contours of targets and avoidance structures drawn within rectangular phantoms. These tests were planned, delivered, measured, and analyzed by nine facilities using a variety of IMRT planning and delivery systems. Each facility had passed the Radiological Physics Center credentialing tests for IMRT. The agreement between the planned and measured doses was determined using ion chamber dosimetry in high and low dose regions, film dosimetry on coronal planes in the phantom with all fields delivered, and planar dosimetry for each field measured perpendicular to the central axis. The planar dose distributions were assessed using gamma criteria of 3%/3 mm. The mean values and standard deviations were used to develop confidence limits for the test results using the concept confidence limit=|mean|+1.96σ. Other facilities can use the test protocol and results as a basis for comparison to this group. Locally derived confidence limits that substantially exceed these baseline values may indicate the need for improved IMRT commissioning.

  13. Recommendations for clinical electron beam dosimetry: Supplement to the recommendations of Task Group 25

    International Nuclear Information System (INIS)

    The goal of Task Group 25 (TG-25) of the Radiation Therapy Committee of the American Association of Physicists in Medicine (AAPM) was to provide a methodology and set of procedures for a medical physicist performing clinical electron beam dosimetry in the nominal energy range of 5-25 MeV. Specifically, the task group recommended procedures for acquiring basic information required for acceptance testing and treatment planning of new accelerators with therapeutic electron beams. Since the publication of the TG-25 report, significant advances have taken place in the field of electron beam dosimetry, the most significant being that primary standards laboratories around the world have shifted from calibration standards based on exposure or air kerma to standards based on absorbed dose to water. The AAPM has published a new calibration protocol, TG-51, for the calibration of high-energy photon and electron beams. The formalism and dosimetry procedures recommended in this protocol are based on the absorbed dose to water calibration coefficient of an ionization chamber at 60Co energy, ND,w60Co, together with the theoretical beam quality conversion coefficient kQ for the determination of absorbed dose to water in high-energy photon and electron beams. Task Group 70 was charged to reassess and update the recommendations in TG-25 to bring them into alignment with report TG-51 and to recommend new methodologies and procedures that would allow the practicing medical physicist to initiate and continue a high quality program in clinical electron beam dosimetry. This TG-70 report is a supplement to the TG-25 report and enhances the TG-25 report by including new topics and topics that were not covered in depth in the TG-25 report. These topics include procedures for obtaining data to commission a treatment planning computer, determining dose in irregularly shaped electron fields, and commissioning of sophisticated special procedures using high-energy electron beams. The use of

  14. Using a Random Dependent Group Contingency to Increase On-Task Behaviors of High School Students with High Incidence Disabilities

    Science.gov (United States)

    Williamson, Brenda D.; Campbell-Whatley, Gloria D.; Lo, Ya-yu

    2009-01-01

    Group contingencies have the advantages of encouraging individual students to collectively feel responsible for appropriate and inappropriate classroom behaviors and have shown effectiveness in improving students' behavior. The purpose of this study was to investigate the effects of a random dependent group contingency on the on-task behaviors of…

  15. Towards mainstreaming of biodiversity data publishing: recommendations of the GBIF Data Publishing Framework Task Group

    Directory of Open Access Journals (Sweden)

    Moritz Tom

    2011-12-01

    'data publishing framework' that can address sociocultural, technical-infrastructural, policy, political and legal constraints, as well as addressing issues of sustainability and financial support. To address these aspects of a data publishing framework - a systematic, standard approach to the formal definition and public disclosure of data - in the context of biodiversity data, the Global Biodiversity Information Facility (GBIF, the single inter-governmental body most clearly mandated to undertake such an effort convened a Data Publishing Framework Task Group. We conceive this data publishing framework as an environment conducive to ensure free and open access to world's biodiversity data. Here, we present the recommendations of that Task Group, which are intended to encourage free and open access to the worlds' biodiversity data.

  16. Comparison of multigroup and few-group calculations of fast power reactor parameters

    International Nuclear Information System (INIS)

    The basic parameters of a fast breeder reactor in two-dimensional cylindrical geometry and in multi- and few-group diffusion approximation were calculated and compared. Two different types of reactor were considered, viz., homogeneous and heterogeneous. The results can serve as a quantitative aid for the choice of the proper number of groups for the calculations of various reactor parameters with required accuracy. (author)

  17. Using Symbolic TI Calculators in Engineering Mathematics: Sample Tasks and Reflections from a Decade of Practice

    Science.gov (United States)

    Beaudin, Michel; Picard, Gilles

    2010-01-01

    Starting in September 1999, new students at ETS were required to own the TI-92 Plus or TI-89 symbolic calculator and since September 2002, the Voyage 200. Looking back at these ten years of working with a computer algebra system on every student's desk, one could ask whether the introduction of this hand-held technology has really forced teachers…

  18. NASA Battery Working Group - 2007-2008: Battery Task Summary Report

    Science.gov (United States)

    Manzo, Michelle

    2008-01-01

    This presentation provides a summary of the 2007-2008 NASA Battery Working Group efforts completed in support of the NASA Engineering Safety Center (NESC). The effort covered a series of pro-active tasks that address the following: Binding Procurements -- guidelines related to requirements for the battery system that should be considered at the time of contract award Wet Life of Ni-H2 Batteries -- issues/strategies for effective storage and impact of long-term storage on performance and life Generic Guidelines for Lithium-ion Safety, Handling and Qualification -- Standardized approaches developed and risk assessments (1) Lithium-ion Performance Assessment -- survey of manufacturers and capabilities to meet mission needs. Guidelines document generated (2) Conditions Required for using Pouch Cells in Aerospace Missions -- focus on corrosion, thermal excursions and long-term performance issues. Document defining requirements to maintain performance and life (3) High Voltage Risk Assessment -- focus on safety and abuse tolerance of battery module assemblies. Recommendations of features required for safe implementation (4) Procedure for Determination of Safe Charge Rates -- evaluation of various cell chemistries and recommendation of safe operating regimes for specific cell designs

  19. Nuclear Energy Agency task group on Radiological Characterisation for Decommissioning of Nuclear Installations

    International Nuclear Information System (INIS)

    Radiological characterisation plays a significant role in the process of decommissioning of shut-down nuclear facilities in order to ensure the protection of the environment and radiation safety. At all stages of a decommissioning programme or project, adequate radiological characterisation is of crucial importance, not least from a material and waste perspective. The radiological characterisation is a key element for planning, controlling and optimising decommissioning and dismantling activities. Experience has shown that data and information from the operation of a facility can - supplemented by recently collected and analysed data and information - be of crucial importance for decisions on waste management and for characterisation of radioactive waste. Once the dismantling has been done, some information may be hard, costly or even impossible to obtain later in the waste management process. This was the reason why the Working Party on Decommissioning and Dismantling (WPDD) of the OECD Nuclear Energy Agency (NEA) decided in late 2013 to extend the mandate of the Task Group on Radiological Characterisation and Decommissioning (TGRCD) for a second phase focusing on nuclear facility characterisation from a waste and material end-state perspective whereas the first phase focused on overall strategies of radiological characterisation. This paper gives an overview of the activities and findings within both phases up to now. (authors)

  20. Radiation dosimetry in digital breast tomosynthesis: Report of AAPM Tomosynthesis Subcommittee Task Group 223

    Energy Technology Data Exchange (ETDEWEB)

    Sechopoulos, Ioannis, E-mail: isechop@emory.edu [Departments of Radiology and Imaging Sciences, Hematology and Medical Oncology and Winship Cancer Institute, Emory University, 1701 Uppergate Drive Northeast, Suite 5018, Atlanta, Georgia 30322 (United States); Sabol, John M. [GE Healthcare, Global Diagnostic X-Ray, Mailstop W-701, 3000 North Grandview Boulevard, Waukesha, Wisconsin 53188 (United States); Berglund, Johan [Research and Development, Philips Women' s Healthcare, Solna (Sweden); Bolch, Wesley E. [J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611 (United States); Brateman, Libby [University of Florida, Gainesville, Florida 32611 (United States); Christodoulou, Emmanuel; Goodsitt, Mitchell [Department of Radiology, University of Michigan, 1500 East Medical Center Drive, Ann Arbor, Michigan 48109 (United States); Flynn, Michael [Department of Radiology, Henry Ford Health System, Radiology Research 2F, 1 Ford Place, Detroit, Michigan 48202 (United States); Geiser, William [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030-4009 (United States); Kyle Jones, A. [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Lo, Joseph Y.; Paul Segars, W. [Department of Radiology, Medical Physics Graduate Program, and Department of Biomedical Engineering, Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 (United States); Maidment, Andrew D. A. [Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104-4206 (United States); Nishino, Kazuyoshi [R and D X-ray Products Group, Shimadzu Corporation, Tokyo (Japan); Nosratieh, Anita [Biomedical Engineering Graduate Group, Department of Radiology, University of California, Davis, California 95817 (United States); and others

    2014-09-15

    The radiation dose involved in any medical imaging modality that uses ionizing radiation needs to be well understood by the medical physics and clinical community. This is especially true of screening modalities. Digital breast tomosynthesis (DBT) has recently been introduced into the clinic and is being used for screening for breast cancer in the general population. Therefore, it is important that the medical physics community have the required information to be able to understand, estimate, and communicate the radiation dose levels involved in breast tomosynthesis imaging. For this purpose, the American Association of Physicists in Medicine Task Group 223 on Dosimetry in Tomosynthesis Imaging has prepared this report that discusses dosimetry in breast imaging in general, and describes a methodology and provides the data necessary to estimate mean breast glandular dose from a tomosynthesis acquisition. In an effort to maximize familiarity with the procedures and data provided in this Report, the methodology to perform the dose estimation in DBT is based as much as possible on that used in mammography dose estimation.

  1. Code of Ethics for the American Association of Physicists in Medicine: report of Task Group 109.

    Science.gov (United States)

    Serago, Christopher F; Adnani, Nabil; Bank, Morris I; BenComo, Jose A; Duan, Jun; Fairobent, Lynne; Freedman, D Jay; Halvorsen, Per H; Hendee, William R; Herman, Michael G; Morse, Richard K; Mower, Herbert W; Pfeiffer, Douglas E; Root, William J; Sherouse, George W; Vossler, Matthew K; Wallace, Robert E; Walters, Barbara

    2009-01-01

    A comprehensive Code of Ethics for the members of the American Association of Physicists in Medicine (AAPM) is presented as the report of Task Group 109 which consolidates previous AAPM ethics policies into a unified document. The membership of the AAPM is increasingly diverse. Prior existing AAPM ethics polices were applicable specifically to medical physicists, and did not encompass other types of members such as health physicists, regulators, corporate affiliates, physicians, scientists, engineers, those in training, or other health care professionals. Prior AAPM ethics policies did not specifically address research, education, or business ethics. The Ethics Guidelines of this new Code of Ethics have four major sections: professional conduct, research ethics, education ethics, and business ethics. Some elements of each major section may be duplicated in other sections, so that readers interested in a particular aspect of the code do not need to read the entire document for all relevant information. The prior Complaint Procedure has also been incorporated into this Code of Ethics. This Code of Ethics (PP 24-A) replaces the following AAPM policies: Ethical Guidelines for Vacating a Position (PP 4-B); Ethical Guidelines for Reviewing the Work of Another Physicist (PP 5-C); Guidelines for Ethical Practice for Medical Physicists (PP 8-D); and Ethics Complaint Procedure (PP 21-A). The AAPM Board of Directors approved this Code or Ethics on July 31, 2008. PMID:19235389

  2. Clinical use of electronic portal imaging: Report of AAPM Radiation Therapy Committee Task Group 58

    International Nuclear Information System (INIS)

    AAPM Task Group 58 was created to provide materials to help the medical physicist and colleagues succeed in the clinical implementation of electronic portal imaging devices (EPIDs) in radiation oncology. This complex technology has matured over the past decade and is capable of being integrated into routine practice. However, the difficulties encountered during the specification, installation, and implementation process can be overwhelming. TG58 was charged with providing sufficient information to allow the users to overcome these difficulties and put EPIDs into routine clinical practice. In answering the charge, this report provides; comprehensive information about the physics and technology of currently available EPID systems; a detailed discussion of the steps required for successful clinical implementation, based on accumulated experience; a review of software tools available and clinical use protocols to enhance EPID utilization; and specific quality assurance requirements for initial and continuing clinical use of the systems. Specific recommendations are summarized to assist the reader with successful implementation and continuing use of an EPID

  3. Teacher management behaviors and pupil task involvement during small group laboratory activities

    Science.gov (United States)

    Beasley, Warren

    A major concern of many beginning and experienced teachers is that of classroom management and control. This article describes recent research into defining classroom management procedures that are used by high school science teachers and their relationship to pupil ontaskness. The classroom is conceptualized as a manipulable behavioral system. This construct arises directly from Barker's (1968) ecological psychology, the classroom and its occupants being conceptualized as a behavior setting. The behaviors of the teacher and the pupils are an integral part of the unit (behavior setting), which in turn coerces certain behaviors from its participants. Thus settings, and, in particular, subsettings, are seen as more important determiners of social behavior than the personality of individual teacher or pupil. The methodology employed in this research has involved the extensive use of video in naturalistic science classrooms. Tapes of both teacher and pupil behaviors were continuously and independently recorded. Intensive analysis using electronic recording instruments interfaced with the computer has allowed the collection and sophisticated analysis of the observational data. Data relating to teacher management behavior in small group settings have been analyzed and the relationships to pupil task involvement have been explored.

  4. Quality assurance of IMRT plan evaluation and dosimetric comparison using AAPM Task Group 119

    International Nuclear Information System (INIS)

    Intensity Modulation Radiotherapy (IMRT) planning demands stringent quality assurance and accurate dose determination for delivery of highly conformal dose to the patients. Generally 3-D dose distributions obtained from a treatment planning system have to be verified by dosimetric methods (Herzen J 2007). Commissioning studies are best done by defining target and normal structure shapes on CT images of the dosimetry phantom, planning the treatment, and then comparing the measured dose in the phantom to the planned dose from the computer system. These studies should mimic the types of target and structure geometries along with the target doses and dose constraints that are likely to be encountered in the clinic. IMRT commissioning procedure based on multi institution planning and dosimetry comparisons was proposed by AAPM task group 119 (Ezzell G A 2009). In order to verify our IMRT QA procedure and to establish the practical base line commissioning, we downloaded the AAPM TGI 19 test suite DICOM-RT images and structure sets to our treatment planning system (TPS) for planning and dosimetric comparison. The square slab phantom CT images of dimension 30 cm X 30 cm x 15 cm were loaded to the Eclipse (V8.6) TPS

  5. AAPM and GEC-ESTRO guidelines for image-guided robotic brachytherapy: Report of Task Group 192

    Energy Technology Data Exchange (ETDEWEB)

    Podder, Tarun K., E-mail: tarun.podder@uhhospitals.org [Department of Radiation Oncology, University Hospitals, Case Western Reserve University, Cleveland, Ohio 44122 (United States); Beaulieu, Luc [Department of Radiation Oncology, Centre Hospitalier Univ de Quebec, Quebec G1R 2J6 (Canada); Caldwell, Barrett [Schools of Industrial Engineering and Aeronautics and Astronautics, Purdue University, West Lafayette, Indiana 47907 (United States); Cormack, Robert A. [Department of Radiation Oncology, Harvard Medical School, Boston, Massachusetts 02115 (United States); Crass, Jostin B. [Department of Radiation Oncology, Vanderbilt University, Nashville, Tennessee 37232 (United States); Dicker, Adam P.; Yu, Yan [Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 (United States); Fenster, Aaron [Department of Imaging Research, Robarts Research Institute, London, Ontario N6A 5K8 (Canada); Fichtinger, Gabor [School of Computer Science, Queen’s University, Kingston, Ontario K7L 3N6 (Canada); Meltsner, Michael A. [Philips Radiation Oncology Systems, Fitchburg, Wisconsin 53711 (United States); Moerland, Marinus A. [Department of Radiotherapy, University Medical Center Utrecht, Utrecht, 3508 GA (Netherlands); Nath, Ravinder [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520 (United States); Rivard, Mark J. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States); Salcudean, Tim [Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z4 (Canada); Song, Danny Y. [Department of Radiation Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231 (United States); Thomadsen, Bruce R. [Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705 (United States)

    2014-10-15

    In the last decade, there have been significant developments into integration of robots and automation tools with brachytherapy delivery systems. These systems aim to improve the current paradigm by executing higher precision and accuracy in seed placement, improving calculation of optimal seed locations, minimizing surgical trauma, and reducing radiation exposure to medical staff. Most of the applications of this technology have been in the implantation of seeds in patients with early-stage prostate cancer. Nevertheless, the techniques apply to any clinical site where interstitial brachytherapy is appropriate. In consideration of the rapid developments in this area, the American Association of Physicists in Medicine (AAPM) commissioned Task Group 192 to review the state-of-the-art in the field of robotic interstitial brachytherapy. This is a joint Task Group with the Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology (GEC-ESTRO). All developed and reported robotic brachytherapy systems were reviewed. Commissioning and quality assurance procedures for the safe and consistent use of these systems are also provided. Manual seed placement techniques with a rigid template have an estimated in vivo accuracy of 3–6 mm. In addition to the placement accuracy, factors such as tissue deformation, needle deviation, and edema may result in a delivered dose distribution that differs from the preimplant or intraoperative plan. However, real-time needle tracking and seed identification for dynamic updating of dosimetry may improve the quality of seed implantation. The AAPM and GEC-ESTRO recommend that robotic systems should demonstrate a spatial accuracy of seed placement ≤1.0 mm in a phantom. This recommendation is based on the current performance of existing robotic brachytherapy systems and propagation of uncertainties. During clinical commissioning, tests should be conducted to ensure that this level of accuracy is achieved. These tests

  6. AAPM and GEC-ESTRO guidelines for image-guided robotic brachytherapy: Report of Task Group 192

    International Nuclear Information System (INIS)

    In the last decade, there have been significant developments into integration of robots and automation tools with brachytherapy delivery systems. These systems aim to improve the current paradigm by executing higher precision and accuracy in seed placement, improving calculation of optimal seed locations, minimizing surgical trauma, and reducing radiation exposure to medical staff. Most of the applications of this technology have been in the implantation of seeds in patients with early-stage prostate cancer. Nevertheless, the techniques apply to any clinical site where interstitial brachytherapy is appropriate. In consideration of the rapid developments in this area, the American Association of Physicists in Medicine (AAPM) commissioned Task Group 192 to review the state-of-the-art in the field of robotic interstitial brachytherapy. This is a joint Task Group with the Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology (GEC-ESTRO). All developed and reported robotic brachytherapy systems were reviewed. Commissioning and quality assurance procedures for the safe and consistent use of these systems are also provided. Manual seed placement techniques with a rigid template have an estimated in vivo accuracy of 3–6 mm. In addition to the placement accuracy, factors such as tissue deformation, needle deviation, and edema may result in a delivered dose distribution that differs from the preimplant or intraoperative plan. However, real-time needle tracking and seed identification for dynamic updating of dosimetry may improve the quality of seed implantation. The AAPM and GEC-ESTRO recommend that robotic systems should demonstrate a spatial accuracy of seed placement ≤1.0 mm in a phantom. This recommendation is based on the current performance of existing robotic brachytherapy systems and propagation of uncertainties. During clinical commissioning, tests should be conducted to ensure that this level of accuracy is achieved. These tests

  7. Role of Gestalt grouping in selective attention: Evidence from the Stroop task

    NARCIS (Netherlands)

    Lamers, M.J.M.; Roelofs, A.P.A.

    2007-01-01

    Selective attention has been intensively studied using the Stroop task. Evidence suggests that Stroop interference in a color-naming task arises partly because of visual attention sharing between color and word: Removing the target color after 150 msec reduces interference (Neumann, 1986). Moreover,

  8. Numerical Calculation of Scaling Exponents of Percolation Process in the Framework of Renormalization Group Approach

    Directory of Open Access Journals (Sweden)

    Adzhemyan L. Ts.

    2016-01-01

    Full Text Available The renormalization group theory is used to the study of the directed bond percolation (Gribov process near its second-order phase transition between absorbing and active state. We present a numerical calculation of the renormalization group functions in the ε-expansion where ε is the deviation from the upper critical dimension dc = 4. Within this procedure anomalous dimensions γ are expressed in terms of irreducible renormalized Feynman diagrams and thus the calculation of renormalization constants could be entirely skipped. The renormalization group is included by means of the R operation, and for computational purposes we choose the null momentum subtraction scheme.

  9. Numerical Calculation of Scaling Exponents of Percolation Process in the Framework of Renormalization Group Approach

    Science.gov (United States)

    Adzhemyan, L. Ts.; Hnatič, M.; Kompaniets, M.; Lučivjanský, T.; Mižišin, L.

    2016-02-01

    The renormalization group theory is used to the study of the directed bond percolation (Gribov process) near its second-order phase transition between absorbing and active state. We present a numerical calculation of the renormalization group functions in the ɛ-expansion where ɛ is the deviation from the upper critical dimension dc = 4. Within this procedure anomalous dimensions γ are expressed in terms of irreducible renormalized Feynman diagrams and thus the calculation of renormalization constants could be entirely skipped. The renormalization group is included by means of the R operation, and for computational purposes we choose the null momentum subtraction scheme.

  10. Neutronic calculations for a fast assembly by using two-group neutron albedo theory

    International Nuclear Information System (INIS)

    Under Two-Group Neutron Albedo Theory, the effective neutron multiplication factor, Keff, explicitly appears and therefore it is possible to obtain an explicit form of variation of Keff. A generalization of the two-group albedo theory can be used if a more detailed energy spectrum treatment is required. The two-group neutron albedo theory is well illustrated by the endeavor of calculating the key parameters for a fast assembly. The results obtained from diffusion approach and albedo method calculations have had excellent concordance. (author)

  11. Nuclear Data Uncertainty Propagation in Depletion Calculations Using Cross Section Uncertainties in One-group or Multi-group

    Science.gov (United States)

    Díez, C. J.; Cabellos, O.; Martínez, J. S.

    2015-01-01

    Several approaches have been developed in last decades to tackle nuclear data uncertainty propagation problems of burn-up calculations. One approach proposed was the Hybrid Method, where uncertainties in nuclear data are propagated only on the depletion part of a burn-up problem. Because only depletion is addressed, only one-group cross sections are necessary, and hence, their collapsed one-group uncertainties. This approach has been applied successfully in several advanced reactor systems like EFIT (ADS-like reactor) or ESFR (Sodium fast reactor) to assess uncertainties on the isotopic composition. However, a comparison with using multi-group energy structures was not carried out, and has to be performed in order to analyse the limitations of using one-group uncertainties.

  12. Feel like you belong: on the bidirectional link between emotional fit and group identification in task groups

    OpenAIRE

    Delvaux, Ellen; Meeussen, Loes; Mesquita, Batja

    2015-01-01

    Three studies investigated the association between members’ group identification and the emotional fit with their group. In the first study, a cross-sectional study in a large organization, we replicated earlier research by showing that group identification and emotional fit are positively associated, using a broader range of emotions and using profile correlations to measure group members’ emotional fit. In addition, in two longitudinal studies, where groups of students were followed at seve...

  13. Resonating-group calculations with a new type of cluster internal wave function

    International Nuclear Information System (INIS)

    In the resonating group method, the many-nucleon wave function is taken to be totally antisymmetric and describes the motion of nucleons grouped into clusters. A new type of cluster internal wave function that can produce improved results, especially for the cluster binding energy, is proposed. We hope to utilize this type of cluster wave function in various resonating-group scattering and reaction calculations. A preliminary study in the case of p+4He scattering yields favorable conclusions. (author)

  14. Evaluation of the accuracy of group calculations for reactor criticality perturbations

    International Nuclear Information System (INIS)

    For calculations of criticality perturbations it is necessary to use group constants which take into account not only the peculiarities of the intra-group flux but also those of the behaviour of the adjoint flux. A new method is proposed for obtaining bilinear-averaged constants of this type on the basis of the resonance characteristics of the importance function and the difference between the value of neutron importance at the group boundary and the group-averaged value (the bsup(+j) factor). A number of calculations are made for the ratios of reactivity coefficients in the BFS assemblies. Values have been obtained for the difference between the results of calculation with bilinear-averaged constants and those averaged conventionally (over flux). In many cases, this difference exceeds the experimental error. (author)

  15. Principal working group No. 1 on operating experience and human factors (PWG1). Report of the task group on reviewing the activities

    International Nuclear Information System (INIS)

    A Task Group was formed by PWG-1 in the latter part of 1999 to review the mandate of PWG1 in light of new directions and assignments from CSNI, and to prepare a report that suggests future directions of the Working Group, in harmony with directions from CSNI. This report is the response of the Task Group. Principal Working Group no.1 was organized in September 1982. The group formed its charter, which included: - reviewing periodically activities for the collection, dissemination, storage and analysis of incidents reported under the IRS; - examining annually the incidents reported during the previous year in order to select issues (either technical or human-factor-oriented) with major safety significance and report them to CSNI; - encouraging feed-back through CSNI of lessons derived from operating experience to nuclear safety research programmes, including human factors studies; - providing a forum to exchange information in the field of human factors studies; - establishing short-term task forces, when necessary to carry out information exchange, special studies or any other work within its mandate; - making recommendations to CSNI for improving and encouraging these activities. The mandate of the working group was systematically re-examined in 1994. The purpose was to determine whether changes since the formation of the original mandate would indicate some need to refocus the directions of the working group. It was concluded that the main line of work (sometimes called the core business) of PWG1, which was shown to be an efficient tool for exchanging safety-significant operating experience and lessons learned from safety-significant issues, remained as valid and necessary in 1994 as it was in 1982. Some recommendations for improvement of efficiency were made, but the core business was unchanged. Very little of the mandate needed modification. With little change over nearly 20 years, these six items have constituted the mandate of PWG1. There have been twenty

  16. The main tasks and obtained results within soil protection working group of the Danube countries

    International Nuclear Information System (INIS)

    In the frame of the Danube Countries Working Community activities was in 1993 constituted independent Soil Protection Working Group (SPWG). Its primary task is to elaborate principles and common soil protection concept in given countries accepted on the level of governments and related authorities, and also to the solution of the solution of the problems on regional levels. Final objective is to implement such concept of soil protection policy, which is able to maintain its quality and productivity potential for next generations also. Based on four years activities coordination could be significance and the SPWG relevance expressed in following topics: (1) Soil pollution and soil degradation, particularly in most pos-communistic countries has been attaining high degree, and in many locations also the threshold of ecological be arability. As reclamation and revitalization of the degraded and polluted soils require long time and considerable financial means, it is not only moral;, even also economically more effective to protect preventively than subsequent reclamation. (2) Main objective of the correct soil protection policy should be its high quality conservation also for the next generations. To this is joined also the protection not only productional, but also non-productional functions, particularly filtrational, transformational and buffering capacibility, including its role and significance, as land and environment. From, in this way considered relationships reality is resulting that the soil protection objectives are not only laws and prohibition approvement, but also active relationships harmonization between the man requirements and soil productivity potential, in order of the sustainable land resources use for the next generations. (3) Based on mentioned realities and relationships we consider the SPWG as an active gremium for elaboration of the the uniform soil protection concepts for governments and responsible organisations that in financial consequence

  17. Dosimetric effects caused by couch tops and immobilization devices: Report of AAPM Task Group 176

    Energy Technology Data Exchange (ETDEWEB)

    Olch, Arthur J., E-mail: aolch@chla.usc.edu [Radiation Oncology Department, University of Southern California and Children' s Hospital Los Angeles, Los Angeles, California 90027 (United States); Gerig, Lee [Department of Physics, Ottawa Hospital Regional Cancer Centre, Carleton University, Ottawa, Ontario K1S 5B6, Canada and Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1N 6N5 (Canada); Li, Heng [Department of Radiation Physics, UT MD Anderson Cancer Center, Houston, Texas 77030 (United States); Mihaylov, Ivaylo [Department of Radiation Oncology Department, University of Miami, Miami, Florida 33136 (United States); Morgan, Andrew [The Beacon Centre, Musgrove Park Hospital, Taunton TA1 5DA (United Kingdom)

    2014-06-15

    The dosimetric impact from devices external to the patient is a complex combination of increased skin dose, reduced tumor dose, and altered dose distribution. Although small monitor unit or dose corrections are routinely made for blocking trays, ion chamber correction factors, e.g., accounting for temperature and pressure, or tissue inhomogeneities, the dose perturbation of the treatment couch top or immobilization devices is often overlooked. These devices also increase skin dose, an effect which is also often ignored or underestimated. These concerns have grown recently due to the increased use of monolithic carbon fiber couch tops which are optimal for imaging for patient position verification but cause attenuation and increased skin dose compared to the “tennis racket” style couch top they often replace. Also, arc delivery techniques have replaced stationary gantry techniques which cause a greater fraction of the dose to be delivered from posterior angles. A host of immobilization devices are available and used to increase patient positioning reproducibility, and these also have attenuation and skin dose implications which are often ignored. This report of Task Group 176 serves to present a survey of published data that illustrates the magnitude of the dosimetric effects of a wide range of devices external to the patient. The report also provides methods for modeling couch tops in treatment planning systems so the physicist can accurately compute the dosimetric effects for indexed patient treatments. Both photon and proton beams are considered. A discussion on avoidance of high density structures during beam planning is also provided. An important aspect of this report are the recommendations the authors make to clinical physicists, treatment planning system vendors, and device vendors on how to make measurements of surface dose and attenuation and how to report these values. For the vendors, an appeal is made to work together to provide accurate couch top

  18. Clinical implementation of AAPM Task Group 32 recommendations on brachytherapy source strength specification

    International Nuclear Information System (INIS)

    Historically the strength of sealed brachytherapy sources has been described by many physical quantities, including true activity, apparent activity, and equivalent mass of radium. Recently, the AAPM Task Group 32 recommended that these quantities be replaced by a single quantity, air-kerma strength, with units of μGy m2 h-1. A set of equations has been developed for unambiguously converting source strength estimates and renormalizing published dose-rate tables, which assume traditional quantities and units, into forms consistent with air-kerma strength. For commonly used brachytherapy sources, multiplicative conversion factors for each source-strength formalism and set of units are given. To convert equivalent mass of radium to air-kerma strength requires a single multiplicative factor, 7.23 μGy m2 h-1/mgRaEq, applicable to all sources. Based upon a review of vendor source specification practices, the factors for converting source strength of 198Au, 103Pd, and 125I seeds from apparent mCi to air-kerma strength are 2.06, 1.29, and 1.27 μGy m2 h-1/mCi(apparent), respectively. These factors are independent of source geometry but depend on the nominal exposure rate constant value selected by the vendor. Conversion factors applicable to mass of radium or true activity depend upon both source geometry and radionuclide identity. Because many of these conversion factors depend upon vendor choices of physical constants and exposure rate constants, readers are cautioned to carefully review vendor source strength specification practices before adopting these values clinically. Finally, the relationships between the various source strength quantities and absorbed dose rate in the medium surrounding the source are elucidated

  19. Minutes and group memories from all NERBC/USGS-RPA power plant siting task force meetings through October, 1980. Appendix

    International Nuclear Information System (INIS)

    The New England River Basins Commission/United States Geological Survey-Resource Planning Analysis Office (NERBC/USGS-RPA) Power Plant Siting Task Force has formerly met seven times between July 1979 and August 1980. At the first meeting on July 13, 1979, the members agreed that there were many problems with the current process of selecting sites for power plants in New England, and that they would work by consensus to find solutions for these problems. At the second meeting on October 19, 1979, NERBC staff presented information on the site selection and approval processes in New England. The Task Force began a preliminary discussion of problems in these processes, and agreed that the initial scope of work of the Task Force would focus on issues in site selection. At the third meeting on January 18, 1980, the Task Force began initial discussions in three areas: imperfections in the site selection process, stakeholders in the site selection process, and principles to guide solutions to the problems in site selection. On March 7, 1980, at the fourth meeting, the Task Force continued discussions on imperfections, stakeholders, and principles. At the fifth meeting on May 2, 1980, the Task Force reached a wide range of agreements on the difficulties encountered in the site selection process and on the principles guiding problem solving in site selection. At the sixth meeting on May 29, 1980, the Task Force focused on solutions to the problems identified at earlier meetings. Groups of Task Force members constructed eight different scenarios describing alternative power plant siting processes. In July 1980, the Task Force met for the seventh time and refined the eight scenarios, paring them down to five. An attempt was made to develop two scenarios using the common elements from the five. One of these two graphic models was based on government involvement in the site selection process, and the other was based on stakeholder involvement in the process

  20. An Efficient Group Key Management Using Code for Key Calculation for Simultaneous Join/Leave: CKCS

    Directory of Open Access Journals (Sweden)

    Melisa Hajyvahabzadeh

    2012-08-01

    Full Text Available This paper presents an efficient group key management protocol, CKCS (Code for Key Calculation in Simultaneous join/leave for simultaneous join/leave in secure multicast. This protocol is based on logical key hierarchy. In this protocol, when new members join the group simultaneously, server sends only thegroup key for those new members. Then, current members and new members calculate the necessary keys by node codes and one-way hash function. A node code is a random number which is assigned to each key to help users calculate the necessary keys. Again, at leave, the server just sends the new group key to remaining members. The results show that CKCS reduces computational and communication overhead, and also message size in simultaneous join/leave.

  1. Innovative characteristics of the new dosimetric model for the human respiratory tract studied by the ICRP appointed Task Group of Committee 2

    International Nuclear Information System (INIS)

    In 1984, the ICRP appointed a Task Group of Committee 2 to review and revise, as necessary, the current lung dosimetric model. On the basis of the knowledge acquired during the past 20 years, the Task Group's approach has been to review, in depth, the morphology and physiology of the human respiratory tract, inspirability of aerosols and regional deposition of inhaled particles as functions of aerosol size and breathing parameters, clearance of deposited materials, nature and specific sites of damage to the respiratory system caused by inhaled radioactive substances. In the proposed model, clearance from the three regions of the respiratory tract (extrathoracic ET, fast-clearing thoracic Tf and slow-clearing thoracic Ts, comprising lymph nodes) is described in terms of competition between the mechanical processes moving particles, which do not depend on the substances, and those of absorption into the blood, determined solely by the material. A Task Group report will also include models for calculating radiation doses to tissues of the respiratory system following inhalation of α, β and γ emitting particulate and gaseous radionuclides. (author)

  2. Strategic development in exact calculation: Group and individual differences in four achievement subtypes

    OpenAIRE

    Wylie, Judith; Jordan, Julie-Ann; Mulhern, Gerard

    2012-01-01

    This longitudinal study sought to identify developmental changes in strategy use between 5 and 7 years of age when solving exact calculation problems. Four mathematics and reading achievement subtypes were examined at four time points. Five strategies were considered: finger counting, verbal counting, delayed retrieval, automatic retrieval, and derived fact retrieval. Results provided unique insights into children’s strategic development in exact calculation at this early stage. Group analysi...

  3. Structural integrity of welded bi-metallic components (BIMET) - Task Group 5 'Analysis'. Prediction by EAM and FEA

    International Nuclear Information System (INIS)

    Investigations in the EU BIMET project focused on two pipe segments of ferritic and austenitic steel with a special weld in between which is characterised by a multiphase transition with strongly diverging characteristics (strength mis-matching). The BIMET project is described, and some of the findings of Task Group 5 'Analysis' are presented which are based on EAM and FEA

  4. First principles calculation of material properties of group IV elements and III-V compounds

    OpenAIRE

    Malone, Brad Dean

    2012-01-01

    This thesis presents first principles calculations on the properties of group IV elements and group III-V compounds. It includes investigations into what structure a material is likely to form in, and given that structure, what are its electronic, optical, and lattice dynamical properties as well as what are the properties of defects that might be introduced into the sample. The thesis is divided as follows:Chapter 1 contains some of the conceptual foundations used in the present work. These ...

  5. Calculation and preliminary analysis of group cross sections for gadolinium and its isotopes

    International Nuclear Information System (INIS)

    Evaluated nuclear data files ENDL 78 and ENDF/B-IV and the cross section generation code FEDGROUP-R were used to produce averaged group cross sections for group systems BNAB and THSIG for gadolinium and its isotopes. Different sets of group cross sections for gadolinium (due to different evaluated data files or different processing codes) were compared and significant differences analyzed. The group capture cross sections for the isotopes of gadolinium were compared with published data. The group cross sections data sets prepared are analyzed as to what extent they can meet the requirements of cell calculations for gadolinium-loaded fuel. Some group cross section tables and cross section plots are presented. (author)

  6. Non interactive calculation of effective neutron multiplication factor by using two-group neutron albedo theory

    International Nuclear Information System (INIS)

    The effective neutron multiplication factor, Keff, explicitly appears under the neutron albedo theory. An albedo scheme can be used to determine Keff value without an iterative strategy. The albedo theory is illustrated by the endeavor of calculating Keff by using two-group neutron albedo method for spherical reflected cores. (author). 4 refs, 7 tabs

  7. One group neutron flux at a point in a cylindrical reactor cell calculated by Monte Carlo

    International Nuclear Information System (INIS)

    Mean values of the neutron flux over material regions and the neutron flux at space points in a cylindrical annular cell (one group model) have been calculated by Monte Carlo. The results are compared with those obtained by an improved collision probability method (author)

  8. Are Expert Users Always Better Searchers? Interaction of Expertise and Semantic Grouping in Hypertext Search Tasks

    Science.gov (United States)

    Salmeron, L.; Canas, J. J.; Fajardo, I.

    2005-01-01

    The facilitative effect of expertise in hypertext information retrieval (IR) tasks has been widely reported in related literature. However, recent theories of human expertise question the robustness of this result, since previous works have not fully considered the interaction between user and system characteristics. In this study, the constraint…

  9. Fairness, Teachers' Non-Task Behavior and Alumni Satisfaction: The Influence of Group Commitment

    Science.gov (United States)

    de Lara, Pablo Zoghbi Manrique

    2008-01-01

    Purpose--The purpose of this study is to examine the relationship between interactional justice, as a type of organizational justice that reflects the teachers' perceived fairness of supervisor treatment, and their non-task behavior in terms of organizational citizenship behavior (OCB) and deviant workplace behavior (DWB).…

  10. Distribution of the minimum path on percolation clusters: A renormalization group calculation

    International Nuclear Information System (INIS)

    This thesis uses the renormalization group for the research of the chemical distance or the minimal path on percolation clusters on a 2 dimensional square lattice. Our aims are to calculate analytically (iterative calculation) the fractal dimension of the minimal path. dmin., and the distributions of the minimum paths, lmin for different lattice sizes and for different starting densities (including the threshold value pc). For the distributions. We seek for an analytic form which describes them. The probability to get a minimum path for each linear size L is calculated by iterating the distribution of lmin for the basic cell of size 2*2 to the next scale sizes, using the H cell renormalization group. For the threshold value of p and for values near to pc. We confirm a scaling in the form: P(l,L) =f1/l(l/(Ldmin). L - the linear size, l - the minimum path. The distribution can be also represented in the Fourier space, so we will try to solve the renormalization group equations in this space. A numerical fitting is produced and compared to existing numerical results. In order to improve the agreement between the renormalization group and the numerical simulations, we also present attempts to generalize the renormalization group by adding more parameters, e.g. correlations between bonds in different directions or finite densities for occupation of bonds and sites. (author) 17 refs

  11. Adsorption of epoxy and hydroxyl groups on zigzag graphene nanoribbons: Insights from density functional calculations

    International Nuclear Information System (INIS)

    Graphical abstract: The highly stable carbonyl groups formed on surface may lead to the difficulty to complete GO-related materials reduction. Highlights: ► The carbonyl pair and carbonyl-hydroxyl pair are formed on ribbon surface. ► Stabilities of these pairs relative to the initial structures strongly depend on the sites. ► The O–CH bond belonging to the carbonyl-hydroxyl pair was highly dissociative. ► Magnetic and electronic properties of ribbons were well tuned by oxidized groups. - Abstract: Density functional theory calculations have been used to investigate the adsorption of epoxy and hydroxyl groups on zigzag graphene nanoribbons. Our calculations show that the adsorbed epoxy groups and both the epoxy and hydroxyl groups on a ribbon surface can be transformed to a carbonyl pair and a carbonyl–hydroxyl pair. The energy barriers of these processes are 1.13 and 0.37 eV, respectively. In contrast to the reduced GO sheets, the stabilities of the carbonyl–hydroxyl pair and the carbonyl pair, with respect to the corresponding initial configuration, strongly depend on the adsorbed sites of groups. The vacancy defect improves the adsorptions of oxygen-containing groups on the surface. Because of the adsorption of new hydroxyl groups, the O–H bond belonging to the carbonyl–hydroxyl pair was highly dissociative and led to the formation of a highly stable carbonyl group with the release of water. The magnetic and electronic properties of the zigzag graphene nanoribbons were well tuned by different oxidized groups.

  12. Verification of a Multi-group Cross Section Library for Burnup Calculation

    Energy Technology Data Exchange (ETDEWEB)

    Daing, Aung Tharn; Kim, Myung Hyun [Kyung Hee Univ., Yongin (Korea, Republic of); Joo, Hang Yu [Seoul National Univ., Seoul (Korea, Republic of)

    2013-05-15

    Despite satisfying the estimation of the neutronic parameters without depletion to some extent, it still requires detailed investigation of the behavior of a fuel with strong neutron absorber over its operating life time by nTRACER, the direct whole core calculation code with the conventional semi Predictor-Corrector method. This study is mainly focused on the verification of the newly generated multi-group library for burnup calculation by nTRACER through the analysis of its performance of depletion calculation of UO{sub 2} fuel with strong neutron absorbers such as Gadolinium. Firstly, the depletion calculation results of nTRACER are presented by comparing the evolution of k-inf and the inventories of commonly found important isotopes as a function of burnup in the cases of gadolinia(GAD)-bearing fuel pin and fuel assembly (FA) with those of MCNPX-version.2.6.0. The newly generated multi-group library for burnup calculation by nTRACER was verified through GAD-bearing fuel after the new approach of resonance treatment had been employed. Though very good agreement in the overall effect reflected on the multiplication factor of FA at BOC, the evolution of k-inf along fuel irradiation history was systematically well underestimated by nTRACER when compared to Monte Carlo results.

  13. ZZ ORYX-E/38B, Group Constant Library from ENDF/B Fission Product Data for ORIGEN Calculation

    International Nuclear Information System (INIS)

    1 - Nature of physical problem solved: Format: ORIGEN; Number of groups: 124 energy groups; Nuclides: H, He, Li, Be, B, C, N, O, F, Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Br, Kr, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, I, Xe, Cs, Ba, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po. Origin: ENDF/B-IV; Weighting spectrum: Maxwellian (1/E) fission spectrum with a one percent tolerance. ORYX-E increases the versatility of the program ORIGEN , the isotope generation and depletion code package by providing basic cross section and decay information for light element, fission-product, and actinide nuclides. This data library package results from data compiled for ORNL Chemical Technology Division's work with ORIGEN and from a 2-year effort of the cross section evaluation working group (CSEWG) fission product task force. 2 - Method of solution: The data is generated from ENDF/B-IV and is formatted for input to the ORIGEN code. Applications include calculations for waste projection, decay heat, nuclear safeguards, and fuel cycle economics. The data library is generated from the ENDF/B-IV fission product data. The capture cross section of all fission product nuclides for which capture cross section information is given (about 180 nuclides) were processed into 124 energy groups using MINX. Multigroup cross sections were generated at 0 degrees with infinite dilution and one broad thermal group. Fine group data was generated using a Maxwellian (1/E) fission spectrum with a one percent tolerance

  14. Optimization and decision making in radiological protection: a report of the work of an ICRP task group

    International Nuclear Information System (INIS)

    In 1984 the International Commission on Radiological Protection established a task group to a report on optimization of protection. This paper outlines the current state of work of the task group, with particular emphasis on the development of various techniques to assist with optimization analyses. It is shown that these quantitative techniques fit within the concept of optimization as a structured approach to problems, and that appropriate technique depends on the level of complexity of the problem. This approach is illustrated by applying a range of different techniques to the same example problem. Finally some comments are made on the application of the procedure, noting the importance of identifying responsibilities from those of individuals to those of competent authorities

  15. Preparation of 1-group nuclear data for AGR fault studies and partial investigation of the adequacy of 1-group calculations of fault transients

    International Nuclear Information System (INIS)

    A route for the preparation of 1-group nuclear data for AGR fault studies using SKARK is outlined. The route starts from an initial 2-group 3D static calculation and involves the use of pseudo-absorbers to force agreement of the initial 1-group flux with the 2-group total flux. With data prepared in this manner static 1-group and 2-group calculations for various regulating rod insertions have been compared. The 1-group calculations were found to exaggerate flux shape changes from the initial state compared to the 2-group calculations. These results are used to quantify some of the errors in using a 1-group description of AGR fault transients. (author)

  16. Getting behind the Scenes of Fleetwood Mac's "Rumours": Using a Documentary on the Making of a Music Album to Learn about Task Groups

    Science.gov (United States)

    Comer, Debra R.; Holbrook, Robert L., Jr.

    2012-01-01

    The authors present an efficient and easy-to-implement experiential exercise that reinforces for students key concepts about task groups (i.e., group cohesiveness, conflict within groups, group effectiveness, group norms, and group roles). The exercise, which uses a documentary about the making of Fleetwood Mac's "Rumours" album to demonstrate the…

  17. A metaanalysis of perceptual organization in schizophrenia, schizotypy, and other high-risk groups based on variants of the Embedded Figures Task.

    Directory of Open Access Journals (Sweden)

    Kirsten Rebecca Panton

    2016-02-01

    Full Text Available Current research on perceptual organization in schizophrenia frequently employs shapes with regularly sampled contours (fragmented stimuli, in noise fields composed of similar elements, to elicit visual abnormalities. However, perceptual organization is multi-factorial and, in earlier studies, continuous contours have also been employed in tasks assessing the ability to extract shapes from a background. We conducted a systematic review and meta-analysis of studies using closed-contour stimuli, including the Embedded Figures Test (EFT and related tasks, both in people with schizophrenia and in healthy schizotypes and relatives, considered at increased risk for psychosis. Eleven studies met the selection criteria for inclusion in the meta-analysis, including six that used a between-groups study design (i.e. perceptual organization abilities of schizophrenia/high-risk groups were compared to healthy or clinical controls, and five that treated schizophrenia symptoms or schizotypy traits and indices of perceptual organization as continuous variables. Effect sizes and heterogeneity statistics were calculated, and the risk of publication bias was explored. A significant, moderate effect for EFT performance was found with studies that compared performance of schizophrenia/high-risk groups to a healthy or patient comparison group (d = -.523, p<.001. However, significant heterogeneity was also found amongst the schizotypy, but not schizophrenia studies, as well as studies using accuracy, but not reaction time as a measure of performance. A non-significant correlation was found for the studies that examined schizophrenia symptoms or schizotypy traits as continuous variables (r = .012, p = .825. These results suggest that deficits in perceptual organization of non-fragmented stimuli are found when differences between schizophrenia/high-risk groups and comparison groups are maximized. These findings should motivate further investigation of perceptual

  18. A Metaanalysis of Perceptual Organization in Schizophrenia, Schizotypy, and Other High-Risk Groups Based on Variants of the Embedded Figures Task.

    Science.gov (United States)

    Panton, Kirsten R; Badcock, David R; Badcock, Johanna C

    2016-01-01

    Current research on perceptual organization in schizophrenia frequently employs shapes with regularly sampled contours (fragmented stimuli), in noise fields composed of similar elements, to elicit visual abnormalities. However, perceptual organization is multi-factorial and, in earlier studies, continuous contours have also been employed in tasks assessing the ability to extract shapes from a background. We conducted a systematic review and meta-analysis of studies using closed-contour stimuli, including the Embedded Figures Test (EFT) and related tasks, both in people with schizophrenia and in healthy schizotypes and relatives, considered at increased risk for psychosis. Eleven studies met the selection criteria for inclusion in the meta-analysis, including six that used a between-groups study design (i.e., perceptual organization abilities of schizophrenia/high-risk groups were compared to healthy or clinical controls), and five that treated schizophrenia symptoms or schizotypy traits and indices of perceptual organization as continuous variables. Effect sizes and heterogeneity statistics were calculated, and the risk of publication bias was explored. A significant, moderate effect for EFT performance was found with studies that compared performance of schizophrenia/high-risk groups to a healthy or patient comparison group (d = -0.523, p schizotypy, but not schizophrenia studies, as well as studies using accuracy, but not reaction time as a measure of performance. A non-significant correlation was found for the studies that examined schizophrenia symptoms or schizotypy traits as continuous variables (r = 0.012, p = 0.825). These results suggest that deficits in perceptual organization of non-fragmented stimuli are found when differences between schizophrenia/high-risk groups and comparison groups are maximized. These findings should motivate further investigation of perceptual organization abilities with closed-contour stimuli both in schizophrenia and high

  19. ZZ DLC-14 AIR, Group Constant Library of Secondary Gamma Transport in Air for ANISN Calculation

    International Nuclear Information System (INIS)

    1 - Nature of physical problem solved: Format: ANISN, DOT, MORSE (FIDO format); Number of groups: 22 neutron / 18 gamma-ray; Nuclides: air; Origin: ENDF/B for neutron cross sections, DLC-4/HPIC for gamma-ray and DLC-12/POPLIB for secondary gamma-ray production. Weighting spectrum: 1/E for neutron cross sections. The basic idea behind the distribution of this ANISN input data is to allow potential users to repeat the ANISN calculations reported in ref. (1). It is felt that it will be more economical to repeat the calculations rather than to distribute the results of the Straker-Gritzner (1) calculations. However, the cross section part of the data can actually be used in DOT or MORSE or any transport code which will accept input cross section in the FIDO format. 2 - Method of solution: The sample input data for ANISN are for a P5, S16 calculation of the transport of neutrons and secondary gamma-rays from a 12.2 to 15 MeV point neutron source in an infinite air medium. The source is actually uniformly distributed in the first interval (500 cm radius) of a spherical medium of air with radius 3005 meters. The problem is set up for calculating various 'detector responses' by means of the 'activity' option available with ANISN. This is accomplished by providing a cross section table for a 'material' which has detector responses in certain table positions. Then the inclusion of appropriate input data for 22$ and 23$ arrays causes the group fluxes to be multiplied by the group response function values to give the desired answer. The neutron detector responses calculated by this sample problem are Henderson tissue dose, Snyder-Neufeld dose, tissue kerma, and air kerma. The gamma-ray response functions calculated are Henderson tissue dose and air kerma. The neutron cross sections were first reduced from point data from ENDF/B to a 104 fine group structure with a modified version of CSP, assuming a 1/E weighting factor. The gamma-ray data were reduced from point data from DLC

  20. Report of the Fourth interim meeting of the Seabed Working Group Engineering Studies Task Group, 3-6 October 1983, at Rijks Geologische Dienst, Haarlem, The Netherlands

    International Nuclear Information System (INIS)

    This report presents the results of the fourth interim meeting of the Seabed Working Group's (SWG) Engineering Studies Task Group (ESTG). This task group is charged with determining whether the engineering technology exists to emplace waste canisters in deep ocean sediments. The fourth interim meeting, held at Rijks Geologische Dienst, Haarlem, The Netherlands, 3-6 October 1983, reviewed progress made by the various national programs since the ESTG third interim meeting (July 1982) and developed a table of requirements for processing samples for a geotechnical properties data base. Other items addressed were (1) potential methods of instrumenting penetrators to obtain in situ measurements, (2) procedures for evaluating and quantifying the disturbed zone created by an emplaced penetrator, (3) review and modification of the current draft version of the SWG Five-Year Plan, (4) review and extension of the ESTG detailed plan for penetrator tests, and (5) details of the penetrator tests scheduled for March 1984 in the Nares Abyssal Plain using the research vessel M/V TYRO. The review of the national programs indicated significant progress when measured against the integrated ESTG five-year plan which results in a joint evaluation of engineering feasibility of subseabed disposal based upon (1) a demonstration of an emplacement capability, (2) an evaluation of the zone of sediment disturbance created during emplacement, (3) the existence of acceptable emplacement models, and (4) an acceptable engineering data base. A table of geotechnical sample-processing requirements is being developed to provide guidance for the other task groups that may have the opportunity to furnish suitable geotechnical samples to the ESTG as well as to provide some measure of consistency within the ESTG for the development of the engineering data base for the SWG study areas

  1. A new model for the human alimentary tract: The work of a committee 2 task group

    International Nuclear Information System (INIS)

    The absorbed doses received from ingested radionuclides are currently calculated using the method outlined in ICRP Publication 30. It has been recognised by the ICRP that some of the assumptions used to calculate absorbed doses should be reviewed. A new physiologically based method has been developed, applicable to intakes of radionuclides in food and liquids by children and adults. All parts of the alimentary tract are included, additional sites for absorption and retention are considered and the morphometric and transit parameter values are reviewed in coordination with the ICRP Reference Man revision. Features of the new model are explained and preliminary dose estimates are presented. (author)

  2. Method for calculation of global sensitivity indices for few-group cross-section-dependent problems

    International Nuclear Information System (INIS)

    The variance based global sensitivity analysis technique is robust, has a wide range of applicability and provides accurate sensitivity information for most models. However, it requires input variables to be mutually independent. A modification to this technique that allows one to deal with input variables that are block-wise correlated and normally distributed is presented. The focus of this study is the application of the modified global sensitivity analysis technique to calculations of reactor parameters that are dependent on multigroup or few-group neutron cross-sections. The result of the sensitivity analysis is obtained in terms of the global sensitivity indices, which can be used for characterising the contribution of uncertainties from the input cross-sections or their groups to the uncertainty of the calculated reactor parameter. The main effort in this work, besides presenting the theoretical background, is in establishing a method for a practical numerical calculation of the global sensitivity indices. The implementation of the method involves the calculation of multi-dimensional integrals, which can be prohibitively expensive to compute. Numerical techniques specifically suited to the evaluation of multidimensional integrals namely Monte Carlo and sparse grids methods are used, and their efficiency is compared. The method is illustrated and tested on a two-group cross-section dependent problem. In all the cases considered the results obtained with sparse grids achieved much better accuracy while using a significantly smaller number of samples. This aspect is addressed in a mini-study and a preliminary explanation of the results obtained is given. (author)

  3. EQUIVA, Few-Group Diffusion Parameter for PWR Reflector Region by 1-D Transport Calculation

    International Nuclear Information System (INIS)

    1 - Description of program or function: EQUIVA-1 generates few-group equivalent diffusion theory parameters for pressurized water (PWR) reflector regions from the results of simple one-dimensional (slab) multigroup transport calculations. The one-dimensional 'normalized generalized equivalence theory' (NGET) method is used for this purpose. Equivalent parameters can be generated for any number of condensed energy groups and for different material regions, such as for the explicit baffle and water reflector of the radial reflector of a PWR, or for the homogenized baffle/reflector. EQUIVA-2 generates environment-insensitive equivalent diffusion theory parameters for pressurized water (PWR) reflector regions from the results of simple one-dimensional (slab) multigroup transport calculations. The one-dimensional reflector models have been implemented, namely the few-group NGET-RM method and the two-group KOEBKE-RM method. Equivalent parameters can be generated for one homogenized region only, although this region itself may be constituted by any number of component regions. 2 - Method of solution: EQUIVA-1: Analytic functions of non-symmetric real matrices are computed by means of a spectral analysis method. EQUIVA-2: Analytic functions of non-symmetric real matrices are computed by means of a spectral analysis method. Component region slab response matrices are combined using rigorous addition rules to obtain a global response matrix for a single region/node. 3 - Restrictions on the complexity of the problem: EQUIVA-1.1 is a variably dimensioned code and there is no restriction on the number of energy groups, etc. The size of the problem is restricted only by the computer core storage available. EQUIVA-2.0 is a variably dimensioned code and there is no restriction on the number of energy groups, etc. The size of the problem is restricted only by the computer core storage available

  4. A functional renormalization group approach to electronic structure calculations for systems without translational symmetry

    CERN Document Server

    Seiler, Christian

    2016-01-01

    A formalism for electronic-structure calculations is presented that is based on the functional renormalization group (FRG). The traditional FRG has been formulated for systems that exhibit a translational symmetry with an associated Fermi surface, which can provide the organization principle for the renormalization group (RG) procedure. We here advance an alternative formulation, where the RG-flow is organized in the energy-domain rather than in k-space. This has the advantage that it can also be applied to inhomogeneous matter lacking a band-structure, such as disordered metals or molecules. The energy-domain FRG ({\\epsilon}FRG) presented here accounts for Fermi-liquid corrections to quasi-particle energies and particle-hole excitations. It goes beyond the state of the art GW-BSE, because in {\\epsilon}FRG the Bethe-Salpeter equation (BSE) is solved in a self-consistent manner. An efficient implementation of the approach that has been tested against exact diagonalization calculations and calculations based on...

  5. FOURACES, MultiGroup Cross-Sections, Resonance Calculation from ENDF/B, KEDAK, UKNDL

    International Nuclear Information System (INIS)

    1 - Description of problem or function: FOURACES produces spectrum weighted, group averaged nuclear cross sections and related parameters for nuclear reactor calculations. ENDF/B-IV, ENDF/B-V, KEDAK or UKNDL libraries may be used as basic input data. The weighting function and energy group structure are arbitrary, and are specified by the user. The code can deal with single or multi-level Breit-Wigner Adler- Adler and Reich-Moore resonance formalisms, and includes a Doppler broadening option. 4. Method of solution: If the weighting function is simple enough group averaged quantities are computed from the point data and interpolation rule read from the evaluated data library using analytic formulae. Otherwise the integrations are performed using the trapezium rule. Resonance data are converted into point data using subroutines written primarily for the program CRESO (abstract NEA 0719), then Doppler broadened, and finally group averaged. 5. Restrictions on the complexity of the problem: A maximum of 256 energy groups can be dealt with

  6. The Indirect Effect of Age Group on Switch Costs via Gray Matter Volume and Task-Related Brain Activity

    Science.gov (United States)

    Steffener, Jason; Gazes, Yunglin; Habeck, Christian; Stern, Yaakov

    2016-01-01

    Healthy aging simultaneously affects brain structure, brain function, and cognition. These effects are often investigated in isolation ignoring any relationships between them. It is plausible that age related declines in cognitive performance are the result of age-related structural and functional changes. This straightforward idea is tested in within a conceptual research model of cognitive aging. The current study tested whether age-related declines in task-performance were explained by age-related differences in brain structure and brain function using a task-switching paradigm in 175 participants. Sixty-three young and 112 old participants underwent MRI scanning of brain structure and brain activation. The experimental task was an executive context dual task with switch costs in response time as the behavioral measure. A serial mediation model was applied voxel-wise throughout the brain testing all pathways between age group, gray matter volume, brain activation and increased switch costs, worsening performance. There were widespread age group differences in gray matter volume and brain activation. Switch costs also significantly differed by age group. There were brain regions demonstrating significant indirect effects of age group on switch costs via the pathway through gray matter volume and brain activation. These were in the bilateral precuneus, bilateral parietal cortex, the left precentral gyrus, cerebellum, fusiform, and occipital cortices. There were also significant indirect effects via the brain activation pathway after controlling for gray matter volume. These effects were in the cerebellum, occipital cortex, left precentral gyrus, bilateral supramarginal, bilateral parietal, precuneus, middle cingulate extending to medial superior frontal gyri and the left middle frontal gyri. There were no significant effects through the gray matter volume alone pathway. These results demonstrate that a large proportion of the age group effect on switch costs can

  7. Accuracy and calibration of integrated radiation output indicators in diagnostic radiology: A report of the AAPM Imaging Physics Committee Task Group 190

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Pei-Jan P., E-mail: Pei-Jan.Lin@vcuhealth.org [Virginia Commonwealth University Medical Center, Richmond, Virginia 23298 (United States); Schueler, Beth A. [Mayo Clinic, Rochester, Minnesota 55905 (United States); Balter, Stephen [Columbia University Medical Center, New York, New York 10032 (United States); Strauss, Keith J. [Children’s Hospital Medical Center, Cincinnati, Ohio 45229 (United States); Wunderle, Kevin A. [Cleveland Clinic Foundation, Cleveland, Ohio 44195 (United States); LaFrance, M. Terry [Baystate Health Systems, Inc., Springfield, Massachusetts 01199 (United States); Kim, Don-Soo [Children’s Hospital Boston, Boston, Massachusetts 02115 (United States); Behrman, Richard H. [Boston University Medical Center, Boston, Massachusetts 02118 (United States); Shepard, S. Jeff [University of Texas MD Anderson Cancer Center, Houston, Texas 77096 (United States); Bercha, Ishtiaq H. [Children’s Hospital Colorado, Aurora, Colorado 80045 (United States)

    2015-12-15

    Due to the proliferation of disciplines employing fluoroscopy as their primary imaging tool and the prolonged extensive use of fluoroscopy in interventional and cardiovascular angiography procedures, “dose-area-product” (DAP) meters were installed to monitor and record the radiation dose delivered to patients. In some cases, the radiation dose or the output value is calculated, rather than measured, using the pertinent radiological parameters and geometrical information. The AAPM Task Group 190 (TG-190) was established to evaluate the accuracy of the DAP meter in 2008. Since then, the term “DAP-meter” has been revised to air kerma-area product (KAP) meter. The charge of TG 190 (Accuracy and Calibration of Integrated Radiation Output Indicators in Diagnostic Radiology) has also been realigned to investigate the “Accuracy and Calibration of Integrated Radiation Output Indicators” which is reflected in the title of the task group, to include situations where the KAP may be acquired with or without the presence of a physical “meter.” To accomplish this goal, validation test protocols were developed to compare the displayed radiation output value to an external measurement. These test protocols were applied to a number of clinical systems to collect information on the accuracy of dose display values in the field.

  8. Accuracy and calibration of integrated radiation output indicators in diagnostic radiology: A report of the AAPM Imaging Physics Committee Task Group 190

    International Nuclear Information System (INIS)

    Due to the proliferation of disciplines employing fluoroscopy as their primary imaging tool and the prolonged extensive use of fluoroscopy in interventional and cardiovascular angiography procedures, “dose-area-product” (DAP) meters were installed to monitor and record the radiation dose delivered to patients. In some cases, the radiation dose or the output value is calculated, rather than measured, using the pertinent radiological parameters and geometrical information. The AAPM Task Group 190 (TG-190) was established to evaluate the accuracy of the DAP meter in 2008. Since then, the term “DAP-meter” has been revised to air kerma-area product (KAP) meter. The charge of TG 190 (Accuracy and Calibration of Integrated Radiation Output Indicators in Diagnostic Radiology) has also been realigned to investigate the “Accuracy and Calibration of Integrated Radiation Output Indicators” which is reflected in the title of the task group, to include situations where the KAP may be acquired with or without the presence of a physical “meter.” To accomplish this goal, validation test protocols were developed to compare the displayed radiation output value to an external measurement. These test protocols were applied to a number of clinical systems to collect information on the accuracy of dose display values in the field

  9. Group Tasks, Activities, Dynamics, and Interactions in Collaborative Robotics Projects with Elementary and Middle School Children

    Science.gov (United States)

    Yuen, Timothy T.; Boecking, Melanie; Stone, Jennifer; Tiger, Erin Price; Gomez, Alvaro; Guillen, Adrienne; Arreguin, Analisa

    2014-01-01

    Robotics provide the opportunity for students to bring their individual interests, perspectives and areas of expertise together in order to work collaboratively on real-world science, technology, engineering and mathematics (STEM) problems. This paper examines the nature of collaboration that manifests in groups of elementary and middle school…

  10. IEC Quality Assurance Task Group 5: UV, Temperature, and Humidity (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D.; Bath, J.; K& ouml; hl, M.; Shioda, T.

    2014-06-01

    Taskgroup 5 (TG5) is concerned with a comparative aging standard incorporating factors including ultraviolet radiation and temperature. Separate experiments are being conducted in support of a test standard via the regional sub-groups in Asia, Europe, and the United States. The authors will describe the objectives and timeline for TG5 as well as providing an update on the experiments in progress.

  11. Percolation with first-and-second neighbour bonds: a renormalization-group calculation of critical exponents

    International Nuclear Information System (INIS)

    A real-space renormalization group approach for the bond percolation problem in a square lattice with first- and second- neighbour bonds is proposed. The respective probabilities are treated, as independent variables. Two types of cells are constructed. In one of them the lattice is considered as two interpenetrating sublattices, first-neighbour bonds playing the role of intersublattice links. This allows the calculation of both critical exponents ν and γ, without resorting to any external field. Values found for the critical indices are in good agreement with data available in the literature. The phase diagram in parameter space is also obtained in each case. (Author)

  12. The report of Task Group 100 of the AAPM: Application of risk analysis methods to radiation therapy quality management.

    Science.gov (United States)

    Huq, M Saiful; Fraass, Benedick A; Dunscombe, Peter B; Gibbons, John P; Ibbott, Geoffrey S; Mundt, Arno J; Mutic, Sasa; Palta, Jatinder R; Rath, Frank; Thomadsen, Bruce R; Williamson, Jeffrey F; Yorke, Ellen D

    2016-07-01

    The increasing complexity of modern radiation therapy planning and delivery challenges traditional prescriptive quality management (QM) methods, such as many of those included in guidelines published by organizations such as the AAPM, ASTRO, ACR, ESTRO, and IAEA. These prescriptive guidelines have traditionally focused on monitoring all aspects of the functional performance of radiotherapy (RT) equipment by comparing parameters against tolerances set at strict but achievable values. Many errors that occur in radiation oncology are not due to failures in devices and software; rather they are failures in workflow and process. A systematic understanding of the likelihood and clinical impact of possible failures throughout a course of radiotherapy is needed to direct limit QM resources efficiently to produce maximum safety and quality of patient care. Task Group 100 of the AAPM has taken a broad view of these issues and has developed a framework for designing QM activities, based on estimates of the probability of identified failures and their clinical outcome through the RT planning and delivery process. The Task Group has chosen a specific radiotherapy process required for "intensity modulated radiation therapy (IMRT)" as a case study. The goal of this work is to apply modern risk-based analysis techniques to this complex RT process in order to demonstrate to the RT community that such techniques may help identify more effective and efficient ways to enhance the safety and quality of our treatment processes. The task group generated by consensus an example quality management program strategy for the IMRT process performed at the institution of one of the authors. This report describes the methodology and nomenclature developed, presents the process maps, FMEAs, fault trees, and QM programs developed, and makes suggestions on how this information could be used in the clinic. The development and implementation of risk-assessment techniques will make radiation therapy

  13. The calculation of resonance captures in a few-group approximation

    International Nuclear Information System (INIS)

    The theory of few-group treatment of resonance captures is expounded, and appropriate methods for the spatial and energy averaging of cross-sections are derived in a form suitable for machine computation - i.e. as material cross-sections which can be used directly in a neutronics code. The method treats both self and mutual shielding of resonances (the latter, interaction with other nuclides, by an approximate method), in geometries ranging from homogeneous mixtures, through regular rod arrays to clustered fuel assemblies, and includes the effect of spatial source distribution, for example between moderator and coolant in pressure tube configurations. A particular application of the method has been to the lattice calculation code WIMS, and a sample 10-group library of data for U-238 and U-235 as used in this code is included. (author)

  14. Reports of the Working Group on Precision Calculations for the Z Resonance

    International Nuclear Information System (INIS)

    This Report summarizes the results of 12 months' activities of the Working Group on Precision Calculations for the Z Resonance, run at CERN in 1994. The main goal of the Working Group was to present a update of studies on radiative corrections for Z-resonance processes, integrating all new results that had appeared since the previous Workshop on ''Z Physics at LEP 1'', held in 1989. The Report is, however, more than a mere collection of the proceedings of the three general meetings held on January 14, March 31 and June 13, 1994. Three subgroups have been working in three related fields: electroweak physics, QCD at the Z resonance and Bhabha scattering in the luminosity region. An attempt has been made to present the final reports from these subgroups in a complete and homogeneous form. The subgroups' contributions in the three fields correspondingly comprise the three main parts of the Report. (orig.)

  15. Indiana University high energy physics group, Task E. Technical progress report, December 1, 1987-June 1, 1988

    International Nuclear Information System (INIS)

    Task E of the Indiana University High Energy Physics Group was established on December 1, 1987. This progress report covers the period December 1, 1987 to June 1, 1988. Work was concentrated on the development of the Large Volume Detector (LVD) at the Gran Sasso Laboratory in Italy. Most effort was devoted to design and experimental tests for the gas recirculating and purification system of the limited streamer tubes used in particle tracking. Some time was also devoted to the valuation of competing designs for the data acquisition system of the limited streamer tubes

  16. IEC Quality Assurance Task Group 5: UV, Temperature, and Humidity (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D.; Bath, J.; Kohl, M.; Shioda, T.

    2014-03-01

    Taskgroup 5 (TG5) is concerned with a comparative aging standard incorporating factors including ultraviolet radiation, temperature, and humidity. Separate experiments are being conducted in support of a test standard via the regional sub-groups in Asia, Europe, and the United States. The authors will describe the objectives and timeline for TG5 as well as providing an update on the experiments in progress.

  17. Steam Generator Group Project: Task 9 final report, Nondestructive evaluation round robin: Volume 1, Description and summary data

    International Nuclear Information System (INIS)

    The Steam Generator Group Project (SGGP) is using the retired-from-service Surry 2A pressurized water reactor steam generator as a test bed to investigate the reliability and effectiveness of inservice nondestructive eddy current inspection equipment and procedures. The information developed will provide the technical basis for updating the Regulatory Guides governing inservice inspection and tube plugging criteria of steam generators. This report describes Task 9 of the multi-task project. The objective of Task 9 was to plan, perform and analyze results of four round robin nondestructive examinations on a subset of tubes from the Surry generator. A description of the objectives, conduct and analysis of results for each round robin is presented. Validation of inspection results will be provided by removal of specimens from the generator for destructive and out-of-generator characterization (in progress). Preliminary comparisons of the inspection results in terms of agreement among teams of defect detection and sizing are given for each round robin. The majority of indications were reported at the hot leg top of the tube sheet. The best results on detection agreement ranged between 70 and 90 percent, but reported defect sizes varied significantly between teams for all round robins. The variability in detection and sizing appears to be due to analyst interpretation of the complex eddy current signals rather than differences in inspection equipment. 5 refs., 20 figs., 33 tabs

  18. Effects of long-term practice and task complexity on brain activities when performing abacus-based mental calculations: a PET study

    International Nuclear Information System (INIS)

    The aim of this study was to examine the neural bases for the exceptional mental calculation ability possessed by Chinese abacus experts through PET imaging. We compared the different regional cerebral blood flow (rCBF) patterns using 15O-water PET in 10 abacus experts and 12 non-experts while they were performing each of the following three tasks: covert reading, simple addition, and complex contiguous addition. All data collected were analyzed using SPM2 and MNI templates. For non-experts during the tasks of simple addition, the observed activation of brain regions were associated with coordination of language (inferior frontal network) and visuospatial processing (left parietal/frontal network). Similar activation patterns but with a larger visuospatial processing involvement were observed during complex contiguous addition tasks, suggesting the recruitment of more visuospatial memory for solving the complex problems. For abacus experts, however, the brain activation patterns showed slight differences when they were performing simple and complex addition tasks, both of which involve visuospatial processing (bilateral parietal/frontal network). These findings supported the notion that the experts were completing all the calculation process on a virtual mental abacus and relying on this same computational strategy in both simple and complex tasks, which required almost no increasing brain workload for solving the latter. In conclusion, after intensive training and practice, the neural pathways in an abacus expert have been connected more effectively for performing the number encoding and retrieval that are required in abacus tasks, resulting in exceptional mental computational ability. (orig.)

  19. AAPM Task Group 108: PET and PET/CT Shielding Requirements

    International Nuclear Information System (INIS)

    The shielding of positron emission tomography (PET) and PET/CT (computed tomography) facilities presents special challenges. The 0.511 MeV annihilation photons associated with positron decay are much higher energy than other diagnostic radiations. As a result, barrier shielding may be required in floors and ceilings as well as adjacent walls. Since the patient becomes the radioactive source after the radiopharmaceutical has been administered, one has to consider the entire time that the subject remains in the clinic. In this report we present methods for estimating the shielding requirements for PET and PET/CT facilities. Information about the physical properties of the most commonly used clinical PET radionuclides is summarized, although the report primarily refers to fluorine-18. Typical PET imaging protocols are reviewed and exposure rates from patients are estimated including self-attenuation by body tissues and physical decay of the radionuclide. Examples of barrier calculations are presented for controlled and noncontrolled areas. Shielding for adjacent rooms with scintillation cameras is also discussed. Tables and graphs of estimated transmission factors for lead, steel, and concrete at 0.511 MeV are also included. Meeting the regulatory limits for uncontrolled areas can be an expensive proposition. Careful planning with the equipment vendor, facility architect, and a qualified medical physicist is necessary to produce a cost effective design while maintaining radiation safety standards

  20. AAPM Task Group 108: PET and PET/CT shielding requirements.

    Science.gov (United States)

    Madsen, Mark T; Anderson, Jon A; Halama, James R; Kleck, Jeff; Simpkin, Douglas J; Votaw, John R; Wendt, Richard E; Williams, Lawrence E; Yester, Michael V

    2006-01-01

    The shielding of positron emission tomography (PET) and PET/CT (computed tomography) facilities presents special challenges. The 0.511 MeV annihilation photons associated with positron decay are much higher energy than other diagnostic radiations. As a result, barrier shielding may be required in floors and ceilings as well as adjacent walls. Since the patient becomes the radioactive source after the radiopharmaceutical has been administered, one has to consider the entire time that the subject remains in the clinic. In this report we present methods for estimating the shielding requirements for PET and PET/CT facilities. Information about the physical properties of the most commonly used clinical PET radionuclides is summarized, although the report primarily refers to fluorine-18. Typical PET imaging protocols are reviewed and exposure rates from patients are estimated including self-attenuation by body tissues and physical decay of the radionuclide. Examples of barrier calculations are presented for controlled and noncontrolled areas. Shielding for adjacent rooms with scintillation cameras is also discussed. Tables and graphs of estimated transmission factors for lead, steel, and concrete at 0.511 MeV are also included. Meeting the regulatory limits for uncontrolled areas can be an expensive proposition. Careful planning with the equipment vendor, facility architect, and a qualified medical physicist is necessary to produce a cost effective design while maintaining radiation safety standards. PMID:16485403

  1. Calculation and Word Problem-Solving Skills in Primary Grades--Impact of Cognitive Abilities and Longitudinal Interrelations with Task-persistent Behaviour

    Science.gov (United States)

    Jõgi, Anna-Liisa; Kikas, Eve

    2016-01-01

    Background: Primary school math skills form a basis for academic success down the road. Different math skills have different antecedents and there is a reason to believe that more complex math tasks require better self-regulation. Aims: The study aimed to investigate longitudinal interrelations of calculation and problem-solving skills, and…

  2. Two Paths from the Same Place: Task Driven and Human Centered Evolution of a Group Information Surface

    Science.gov (United States)

    Russell, Daniel M.; Trimble, Jay; Wales, Roxana; Clancy, Daniel (Technical Monitor)

    2003-01-01

    This is the tale of two different implementations of a collaborative information tool, that started from the same design source. The Blueboard, developed at IBM Research, is a tool for groups to use in exchanging information in a lightweight, informal collaborative way. It began as a large display surface for walk-by use in a corporate setting and has evolved in response to task demands and user needs. At NASA, the MERBoard is being designed to support surface operations for the upcoming Mars Exploration Rover Missions. The MERBoard is a tool that was inspired by the Blueboard design, extending this design to support the collaboration requirements for viewing, annotating, linking and distributing information for the science and engineering teams that will operate two rovers on the surface of Mars. The ways in which each group transformed the system reflects not only technical requirements, but also the needs of users in each setting and embedding of the system within the larger socio-technical environment. Lessons about how task requirements, information flow requirements and work practice drive the evolution of a system are illustrated.

  3. Range Commanders Council Meteorology Group 88th Meeting: NASA Marshall Space Flight Center Task Report, 2004

    Science.gov (United States)

    Roberts, Barry C.

    2004-01-01

    Supported Return-to-Flight activities by providing surface climate data from Kennedy Space Center used primarily for ice and dew formation studies, and upper air wind analysis primarily used for ascent loads analyses. The MSFC Environments Group's Terrestrial and Planetary Environments Team documented Space Shuttle day-of-launch support activities by publishing a document in support of SSP Return-to-Flight activities entitled "Space Shuttle Program Flight Operations Support". The team also formalized the Shuttle Natural Environments Technical Panel and chaired the first special session of the SSP Natural Environments Panel meeting at KSC, November 4-7,2003.58 participants from NASA, DOD and other government agencies from across the country attended the meeting.

  4. Critical groups vs. representative person: dose calculations due to predicted releases from USEXA

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, N.L.D., E-mail: nelson.luiz@ctmsp.mar.mil.br [Centro Tecnologico da Marinha (CTM/SP), Sao Paulo, SP (Brazil); Rochedo, E.R.R., E-mail: elainerochedo@gmail.com [Instituto de Radiprotecao e Dosimetria (lRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Mazzilli, B.P., E-mail: mazzilli@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The critical group cf Centro Experimental Aramar (CEA) site was previously defined based 00 the effluents releases to the environment resulting from the facilities already operational at CEA. In this work, effective doses are calculated to members of the critical group considering the predicted potential uranium releases from the Uranium Hexafluoride Production Plant (USEXA). Basically, this work studies the behavior of the resulting doses related to the type of habit data used in the analysis and two distinct situations are considered: (a) the utilization of average values obtained from official institutions (IBGE, IEA-SP, CNEN, IAEA) and from the literature; and (b) the utilization of the 95{sup tb} percentile of the values derived from distributions fit to the obtained habit data. The first option corresponds to the way that data was used for the definition of the critical group of CEA done in former assessments, while the second one corresponds to the use of data in deterministic assessments, as recommended by ICRP to estimate doses to the so--called 'representative person' . (author)

  5. Critical groups vs. representative person: dose calculations due to predicted releases from USEXA

    International Nuclear Information System (INIS)

    The critical group cf Centro Experimental Aramar (CEA) site was previously defined based 00 the effluents releases to the environment resulting from the facilities already operational at CEA. In this work, effective doses are calculated to members of the critical group considering the predicted potential uranium releases from the Uranium Hexafluoride Production Plant (USEXA). Basically, this work studies the behavior of the resulting doses related to the type of habit data used in the analysis and two distinct situations are considered: (a) the utilization of average values obtained from official institutions (IBGE, IEA-SP, CNEN, IAEA) and from the literature; and (b) the utilization of the 95tb percentile of the values derived from distributions fit to the obtained habit data. The first option corresponds to the way that data was used for the definition of the critical group of CEA done in former assessments, while the second one corresponds to the use of data in deterministic assessments, as recommended by ICRP to estimate doses to the so--called 'representative person' . (author)

  6. Summary report for MEGAPIE R+D Task Group X4: Fluid dynamics and structure mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Smith, B. L

    2006-03-15

    The document chronicles, and draws summary conclusions from, the activities of the X4 R+D Support Group from the start of the project on January 1, 2000 to the time of the Technical Review Meeting in Mol: 27-29 June, 2005. The objectives to be accomplished were set out in a Baseline document. These were: to define the lower target flow configuration, within the geometric constraints imposed by the physical boundary conditions (geometrical confinement, lead- bismuth eutectic (LBE) inventory, pump capacities, target heat exchanger (THX) power, etc.); to identify, and evaluate, optimum target window design to minimise thermal loads and pressure drops, and to avoid hot-spots and flow instabilities; to demonstrate reliable cooling of the lower target enclosure (LTE); to demonstrate the structural integrity of the lower section of the Iiquid-metal container LMC) and its internal components, and that of the LTE; to provide best-estimate safety margins on target coolability and structural integrity under operational flow conditions; to investigate, quantify, and make recommendations regarding, abnormal target operation including possible accident scenarios). The time-scale set for MEGAPIE was always such that much of the design work needed to be carried out at the same time as the R+D support. Often, the target design was changing faster than the time required to perform the detailed computer simulations. As a consequence, many of the simulations reported or referenced in this document do not refer to the very latest target design, and in many respects the results and conclusions must be regarded as generic in nature. Nonetheless, very valuable work has been carried out by the various organisations, and better understanding of the expected temperature distributions and stress levels in the operating MEGAPIE target has been gained, and direct feed-back to the design team on various aspects of the design details has taken place as a consequence of this work. As the design

  7. Summary report for MEGAPIE R+D Task Group X4: Fluid dynamics and structure mechanics

    International Nuclear Information System (INIS)

    The document chronicles, and draws summary conclusions from, the activities of the X4 R+D Support Group from the start of the project on January 1, 2000 to the time of the Technical Review Meeting in Mol: 27-29 June, 2005. The objectives to be accomplished were set out in a Baseline document. These were: to define the lower target flow configuration, within the geometric constraints imposed by the physical boundary conditions (geometrical confinement, lead- bismuth eutectic (LBE) inventory, pump capacities, target heat exchanger (THX) power, etc.); to identify, and evaluate, optimum target window design to minimise thermal loads and pressure drops, and to avoid hot-spots and flow instabilities; to demonstrate reliable cooling of the lower target enclosure (LTE); to demonstrate the structural integrity of the lower section of the Iiquid-metal container LMC) and its internal components, and that of the LTE; to provide best-estimate safety margins on target coolability and structural integrity under operational flow conditions; to investigate, quantify, and make recommendations regarding, abnormal target operation including possible accident scenarios). The time-scale set for MEGAPIE was always such that much of the design work needed to be carried out at the same time as the R+D support. Often, the target design was changing faster than the time required to perform the detailed computer simulations. As a consequence, many of the simulations reported or referenced in this document do not refer to the very latest target design, and in many respects the results and conclusions must be regarded as generic in nature. Nonetheless, very valuable work has been carried out by the various organisations, and better understanding of the expected temperature distributions and stress levels in the operating MEGAPIE target has been gained, and direct feed-back to the design team on various aspects of the design details has taken place as a consequence of this work. As the design

  8. Waste area Grouping 2 Phase I task data report: Human health risk assessment

    International Nuclear Information System (INIS)

    This report is one of five reports issued in 1996 that provide follow- up information to the Phase 1 Remedial Investigation (RI) Report for Waste Area Grouping (WAG) 2 at Oak Ridge National Laboratory (ORNL). The five reports address areas of concern that could cause potential human health risk and ecological risk within WAG2 at ORNL. The purpose of this report is to present a summary of the human health risk assessment results based on the data collected for the WAG 2 Phase 1 RI. Estimates of risk are provided based on measured concentrations in the surface water, floodplain soil, and sediment of White Oak Creek, Melton Branch, and their tributaries. The human health risk assessment methodology used in this risk assessment is based on Risk Assessment Guidance for Superfund (RAGS). First, the data for the different media are elevated to determine usability for risk assessment. Second, through the process of selecting chemicals of potential concern (COPCs), contaminants to be considered in the risk assessment are identified for each assessment of exposure potential is performed, and exposure pathways are identified. Subsequently, exposure is estimated quantitatively, and the toxicity of each of the COPCs is determined. The results of these analyses are combined and summarized in a risk characterization

  9. Report of task group on the biological basis for dose limitation in the skin

    International Nuclear Information System (INIS)

    Researchers have drawn attention to what they consider inconsistencies in the manner in which ICRP have considered skin in relation to the effective dose equivalent. They urge that the dose to the skin should be considered routinely for inclusion in the effective dose equivalent in the context of protection of individuals and population groups. They note that even with a weighting factor of only 0.01 that the dose to the skin can be a significant contributor to the effective dose equivalent including skin for practical exposure conditions. In the case of many exposures the risk to the skin can be ignored but exposure in an uniformly contaminated cloud that might occur with 85Kr the dose to the skin could contribute 60% of the stochastic risk if included in the effective dose equivalent with a WT of 0.01. Through the years and even today the same questions about radiation effects in the skin and dosimetry keep being asked. This report collates the available data and current understanding of radiation effects on the skin, and may make it possible to estimate risks more accurately and to improve the approach to characterizing skin irradiations. 294 refs., 29 figs

  10. Extrapolating Accelerated UV Weathering Data: Perspective From PVQAT Task Group 5 (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D.; Annigoni, E.; Ballion, A.; Bokria, J.; Bruckman, L.; Burns, D.; Elliott, L.; French, R.; Fowler, S.; Gu, X.; Honeker, C.; Khonkar, H.; Kohl, M.; Krommenhoek, P.; Peret-Aebi, L.; Phillips, N.; Scott, K.; Sculati-Meillaud, F.; Shioda, T.

    2015-02-01

    Taskgroup 5 (TG5) is concerned with a accelerated aging standard incorporating factors including ultraviolet radiation, temperature, and moisture. Separate experiments are being conducted in support of a test standard via the regional sub-groups in Asia, Europe, and the United States. The authors will describe the objectives and timeline for the TG5 interlaboratory study being directed out of the USA. Qualitative preliminary data from the experiment is presented. To date, the encapsulation transmittance experiment has: replicated behaviors of fielded materials (including specimen location- and formulation additive-specific discoloration); demonstrated coupling between UV aging and temperature; demonstrated that degradation in EVA results from UV- aging; and obtained good qualitative comparison between Xe and UVA-340 sources for EVA. To date, the encapsulation adhesion experiment (using the compressive shear test to quantify strength of attachment) has demonstrated that attachment strength can decrease drastically (>50%) with age; however, early results suggest significant factor (UV, T, RH) dependence. Much remains to be learned about adhesion.

  11. Computer calculation of the Van Vleck second moment for materials with internal rotation of spin groups

    Science.gov (United States)

    Goc, Roman

    2004-09-01

    in this paper calculates the second moment for solids with rotation of different groups of spins with C 3 symmetry. Method of solution: The rotation of molecules or their parts, for example CH 3 groups, is simulated as a random walk process by rotating each individual group of spins about its symmetry axis by an angle allowed by the type of symmetry. It is not a continuous rotation, but is in the form of jumps between consecutive positions allowed by the symmetry of the rotating group. Such a model of rotation fulfills assumptions on which theoretical equations used in NMR are derived. The value of Van Vleck's second moment averaged by this rotation is evaluated. The degree of averaging depends on the number of rotational jumps simulated during calculation. This number is then expressed in terms of the frequency of rotation and finally into the temperature. As a result we obtain simulated values of the NMR second moment as a function of temperature. Restrictions on the complexity of the problem: The only restriction is the number of spins for which calculations can be performed in a reasonable amount of CPU time. This restriction is therefore a combination of the number of spins in the unit cell, number of unit cells included in the calculation, and the speed of the computer used. The tested version of the program was compiled for a maximum number of 6250 spins, arranged in 125 unit cells. There are 15 axes of rotation allowed per unit cell. Any of these restrictions can be overcome by increasing the dimensions of the appropriate arrays in the program. The dimensions given in the program are sufficient for analysis of most of the NMR data which one can find in the scientific literature. This is due to the fact that the magnetic dipole-dipole interaction decreases with the third power of distance between spins, and calculations including spins up to a distance of about 2.0 nm give a final accuracy of the second moment equal to about 1%, while experimental values are

  12. Renormalization-group investigation of a superconducting U(r)-phase transition using five loops calculations

    Science.gov (United States)

    Kalagov, G. A.; Kompaniets, M. V.; Nalimov, M. Yu.

    2016-04-01

    We have studied a Fermi system with attractive U (r)-symmetric interaction at the finite temperatures by the quantum field renormalization group (RG) method. The RG functions have been calculated in the framework of dimensional regularization and minimal subtraction scheme up to five loops. It has been found that for r ≥ 4 the RG flux leaves the system's stability region - the system undergoes a first order phase transition. To estimate the temperature of the transition to superconducting or superfluid phase the RG analysis for composite operators has been performed using three-loops approximation. The result of this analysis shows that for 3D systems estimated phase transition temperature is higher then well known theoretical estimations based on continuous phase transition formalism.

  13. Ab Initio Calculations on Halogen Bond Between N-Br and Electron-donating Groups

    Institute of Scientific and Technical Information of China (English)

    WANG Yan-hua; CHEN Xue-song; ZOU Jian-wei; YU Qing-sen

    2007-01-01

    Ab initio calculations of complexes formed between N-bromosuccinimide and a series of electron-donating groups were performed at the level of MP2/Lanl2DZ* to gain a deeper insight into the nature of the N-Br halogen stronger halogen-bonding complex than the C-Br. A comparison of neutral hydrogen bond complex series reveals that the electron-donating capacities of the atoms decrease in the order, N>O>S; O(sp3)>O(sp2), which is adequate for the C-Br halogen bonding. Interaction energies, in conjunction with the geometrical parameters show that the affinitive capacity of trihalide anions X-3 with N-bromosuccinimide are markedly lower than that of the corresponding X- with N-bromosuccinimide, even lower than those of neutral molecules with N-bromosuccinimide. AIM analyses further confirmed the above results.

  14. The density matrix renormalization group: a new approach to large-scale nuclear structure calculations

    International Nuclear Information System (INIS)

    A new approach to large-scale nuclear structure calculations, based on the density matrix renormalization group (DMRG), is described. The DMRG method, which was developed originally in the framework of low dimensional quantum lattices, has recently been extended to finite Fermi systems. Following a general description of this extended DMRG methodology, we briefly review its first application to a pairing Hamiltonian. We then discuss its application to a schematic nuclear model involving many identical nucleons constrained to move in a single large-j shell. In those cases in which exact diagonalization of the Hamiltonian is possible, the method is able to reproduce the exact result with extreme precision. Results are also presented for a model problem in which exact solution is not feasible. (Author)

  15. The effects of proportional representation and gender orientation of the task on emergent leadership behavior in mixed-gender work groups.

    Science.gov (United States)

    Karakowsky, L; Siegel, J P

    1999-08-01

    Much of the research that has examined the behavioral consequences of membership in mixed-gender work groups suggests that men are more participative and influential in task-related behavior. Drawing from elements of sociological, structural, and psychological perspectives, this study examined the effects of group gender composition and gender orientation of the group's task on patterns of emergent leadership behavior. Participants were assigned to male-dominated, female-dominated, or balanced-gender groups for the purpose of discussing and generating solutions for two business-related cases--each case emphasized either male-oriented or female-oriented expertise. The findings suggest that the proportional representation of men and women in a work group, along with the gender orientation of the group's task, can significantly influence the level of leadership behavior exhibited in group activity. PMID:10504894

  16. Optimization of multidimensional cross-section tables for few-group core calculations

    International Nuclear Information System (INIS)

    Highlights: • Optimization of tabulated cross-sections libraries for multi-group diffusion codes. • Sensitivity coefficients using perturbation theory are determined. • A non-uniform grid satisfying a given target accuracy in k-effective is built. • Satisfactory results are obtained using libraries with different accuracy level. - Abstract: Multigroup diffusion codes for three dimensional LWR core analysis use as input data pre-generated homogenized few group cross sections and discontinuity factors for certain combinations of state variables, such as temperatures or densities. The simplest way of compiling those data are tabulated libraries, where a grid covering the domain of state variables is defined and the homogenized cross sections are computed at the grid points. Then, during the core calculation, an interpolation algorithm is used to compute the cross sections from the table values. Since interpolation errors depend on the distance between the grid points, a determined refinement of the mesh is required to reach a target accuracy, which could lead to large data storage volume and a large number of lattice transport calculations. In this paper, a simple and effective procedure to optimize the distribution of grid points for tabulated libraries is presented. Optimality is considered in the sense of building a non-uniform point distribution with the minimum number of grid points for each state variable satisfying a given target accuracy in k-effective. The procedure consists of determining the sensitivity coefficients of k-effective to cross sections using perturbation theory; and estimating the interpolation errors committed with different mesh steps for each state variable. These results allow evaluating the influence of interpolation errors of each cross section on k-effective for any combination of state variables, and estimating the optimal distance between grid points

  17. Space group symmetry applied to SCF calculations with periodic boundary conditions and Gaussian orbitals

    Science.gov (United States)

    Rusakov, Alexander A.; Frisch, Michael J.; Scuseria, Gustavo E.

    2013-09-01

    Space group symmetry is exploited and implemented in density functional calculations of extended systems with periodic boundary conditions. Our scheme for reducing the number of two-electron integrals employs the entire set of operations of the space group, including glide plains and screw axes. Speedups observed for the Fock matrix formation in simple 3D systems range from 2X to 9X for the near field Coulomb part and from 3X to 8X for the Hartree-Fock-type exchange, the slowest steps of the procedure, thus leading to a substantial reduction of the computational time. The relatively small speedup factors in special cases are attributed to the highly symmetric positions atoms occupy in crystals, including the ones tested here, as well as to the choice of the smallest possible unit cells. For quasi-1D systems with most atoms staying invariant only under identity, the speedup factors often exceed one order of magnitude reaching almost 70X (near-field Coulomb) and 57X (HFx) for the largest tested (16,7) single-walled nanotube with 278 symmetry operations.

  18. Extrapolated renormalization group calculation of the surface tension in square-lattice Ising model

    International Nuclear Information System (INIS)

    By using self-dual clusters (whose sizes are characterized by the numbers b=2, 3, 4, 5) within a real space renormalization group framework, the longitudinal surface tension of the square-lattice first-neighbour 1/2-spin ferromagnetic Ising model is calculated. The exact critical temperature T sub(c) is recovered for any value of b; the exact assymptotic behaviour of the surface tension in the limit of low temperatures is analytically recovered; the approximate correlation length critical exponents monotonically tend towards the exact value ν=1 (which, at two dimensions, coincides with the surface tension critical exponent μ) for increasingly large cells; the same behaviour is remarked in what concerns the approximate values for the surface tension amplitude in the limit T→T sub(c). Four different numerical procedures are developed for extrapolating to b→infinite the renormalization group results for the surface tension, and quite satisfactory agreement is obtained with Onsager's exact expression (error varying from zero to a few percent on the whole temperature domain). Furthermore the set of RG surface tensions is compared with a set of biased surface tensions (associated to appropriate misfit seams), and find only fortuitous coincidence among them. (Author)

  19. ZZ AMZ, 70-Group 40 Isotope Multigroup Library for Fast Reactor Calculation

    International Nuclear Information System (INIS)

    1 - Description of program or function: format: EXPANDA; number of groups: 70-group library of multigroup constants; nuclides: H-1, Be-9, B-10, B-11, C-12, O-16, N-23, Mg, Al-27, Si, Ti, V, Cr, Mn-55, Fe, Ni, Cu, Ga, Zr, Nb-93, Mo, In-115, Sn, Pb, Th-232, Pa-233, U-233, U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, Am-241, and lumped fission products of U-233, U-235, Pu-239. origin: ENDF/B-IV and ENDF/B-V; weighting spectrum: Fission products inventories for BBR reactor at 360 and 600 days of irradiation were calculated and used as weighting function. AMZ is a 70-group library of multigroup constants for the fast reactor nuclear design code EXPANDA. Data is stored for three temperatures (300 K, 900 K, 2100 K) and for seven background cross sections. The following isotopes are available: H1, Be9, B10, B11, C12, O16, N23, Mg, Al27, Si, Ti, V, Cr, Mn55, Fe, Ni, Cu, Ga, Zr, Nb93, Mo, In115, Sn, Pb, Th232, Pa233, U233, U234, U235, U236, U238, Pu238, Pu239, Pu240, Pu241, Pu242, Am241, and lumped fission products of U233, U235, Pu239. 2 - Method of solution: Nuclear cross sections, transfer matrices, and self-shielding factors were generated from ENDF/B-IV data using the codes NJOY (PSR-0171) and RGENDF

  20. Indiana University High Energy Physics Group, Task E: Technical progress report, December 1, 1988--November 30, 1989

    International Nuclear Information System (INIS)

    This progress report for Task E of the Indiana University High Energy Physics Group covers the period June 1, 1988 to May 31, 1989. During this time we worked on several aspects of the development of the Large Volume Detector (LVD) at the Gran Sasso Laboratory in Italy. We finished our gas flow studies for the recirculating and purification system for the limited streamer gas and aided, on a consulting basis, our colleagues at Frascati with the technical specifications for the gas system which they plan to buy from industry. Our major efforts were devoted to design of the tracking trigger, plans for cabling of the whole detector, and learning about the L3 database system. 3 refs., 2 figs., 2 tabs

  1. Indiana University High Energy Physics Group, Task C: Technical progress report, December 1, 1988--December 31, 1989

    International Nuclear Information System (INIS)

    The Indiana University High Energy Physics Group, Task C has been actively involved in the MACRO experiment at Gran Sasso during the current contract year. MACRO is a large US-Italian Monopole, Astrophysics, and Cosmic Ray Observatory being built under the Gran Sasso Mountain outside of Rome. Indiana University is in charge of organizing the United States software effort. We have contributed to the online event display software and the data analysis software. We are also doing development work on the MACRO liquid scintillator. We have set up a Liquid Scintillator Quality Assurance Laboratory in Frascati, Italy. We are producing vertical scintillator tank end plates and calibration boats in our machine shop. We have preliminary data from a test run of one MACRO supermodule. 14 figs

  2. Characterisation, implementation and quality assurance of biokinetic models. The experience of the CONRAD Task Group 5.2

    International Nuclear Information System (INIS)

    CONRAD (Coordinated Network on Radiation Dosimetry) was an action funded by the European Commission within the 6th Framework Programme in order to link groups undertaking research relating to radiation dosimetry at workplaces. Workpackage 5 of CONRAD was dedicated to internal dosimetry. Task Group 5.2 ''Research Studies on Biokinetic Models'' dealt with the development, implementation, characterization and quality assurance of biokinetic models. The new ICRP model of the human alimentary tract (HATM), the new NCRP model for contaminated wounds, new systemic recycling models of the biokinetics of radioisotopes of polonium and plutonium presented in the scientific literature were implemented into the computer codes of five different institutions. Also new systemic biokinetic models for zirconium and molybdenum, developed on the basis of own results from stable tracer studies, were implemented. The excellent agreement among the results obtained by the different groups indicate that all the present models can be easily implemented into available software codes and that the outputs are independent of the computational approach used. It was also possible to better characterize the systemic models of plutonium by use of a partition factor expressing the relative distribution of material between skeleton and liver, and the NCRP wound model, by derivation of the exact analytical solutions for the wound retention resulting from the model formulation. (author)

  3. Application de la methode des sous-groupes au calcul Monte-Carlo multigroupe

    Science.gov (United States)

    Martin, Nicolas

    This thesis is dedicated to the development of a Monte Carlo neutron transport solver based on the subgroup (or multiband) method. In this formalism, cross sections for resonant isotopes are represented in the form of probability tables on the whole energy spectrum. This study is intended in order to test and validate this approach in lattice physics and criticality-safety applications. The probability table method seems promising since it introduces an alternative computational way between the legacy continuous-energy representation and the multigroup method. In the first case, the amount of data invoked in continuous-energy Monte Carlo calculations can be very important and tend to slow down the overall computational time. In addition, this model preserves the quality of the physical laws present in the ENDF format. Due to its cheap computational cost, the multigroup Monte Carlo way is usually at the basis of production codes in criticality-safety studies. However, the use of a multigroup representation of the cross sections implies a preliminary calculation to take into account self-shielding effects for resonant isotopes. This is generally performed by deterministic lattice codes relying on the collision probability method. Using cross-section probability tables on the whole energy range permits to directly take into account self-shielding effects and can be employed in both lattice physics and criticality-safety calculations. Several aspects have been thoroughly studied: (1) The consistent computation of probability tables with a energy grid comprising only 295 or 361 groups. The CALENDF moment approach conducted to probability tables suitable for a Monte Carlo code. (2) The combination of the probability table sampling for the energy variable with the delta-tracking rejection technique for the space variable, and its impact on the overall efficiency of the proposed Monte Carlo algorithm. (3) The derivation of a model for taking into account anisotropic

  4. Impact of obesity on pregnancy outcome in different ethnic groups: calculating population attributable fractions.

    Directory of Open Access Journals (Sweden)

    Eugene Oteng-Ntim

    Full Text Available OBJECTIVES: To quantify the proportion of adverse pregnancy outcome attributable to maternal obesity. DESIGN: Cross sectional analysis of routine obstetric dataset. SETTING: Guy's and St Thomas's NHS Foundation Trust (GSTFT. POPULATION: 23,668 women who had singleton deliveries at GSTFT between 2004 and 2008. METHODS: Logistic regression was used to estimate the association between BMI and outcome in different ethnic groups. Adjusted odds ratios, and the proportions of obese women, were used to calculate population attributable risk fractions (PAFs. MAIN OUTCOME MEASURES: (I MATERNAL OUTCOMES: diabetes, type of delivery, post-partum haemorrhage, and preterm delivery. (ii Perinatal outcomes: macrosomia, low birth weight, admission to neonatal intensive care/special care baby unit, and perinatal death. RESULTS: The prevalence of maternal obesity was 14%. Increasing BMI was independently associated with increasing risk of adverse obstetric and neonatal outcome. At the individual level, the effect of obesity on diabetes was highest in Asian women compared to white women (p for interaction = 0.03. Calculation of population attributable risk fractions demonstrated that one third of diabetes cases and one in six Caesarean sections could be avoided in this population if all obese women were of normal BMI. At the population level, the contribution of obesity to diabetes was highest for Black women (42%, and lowest for oriental women (8%. Seven percent of neonatal macrosomia in all the population, and 13% in Black mothers, were attributable to obesity. CONCLUSIONS: Preventing obesity prior to pregnancy will substantially reduce the burden of obstetric and neonatal morbidity in this population. This reduction will be higher in Black women.

  5. Nuclear group constant set FUSION-J3 for fusion reactor nuclear calculations based on JENDL-3

    International Nuclear Information System (INIS)

    Based on evaluated nuclear data file JENDL-3, published in April 1990, we produced a nuclear group constant set 'FUSION-J3' for fusion reactor nuclear calculation by ANISN code instead of GICX40 produced in 1977. The set FUSION-J3 is the coupled group constant set with neutron 125 and gamma-ray 40 group structure, and has the maximum order of 5 as Legendre expansion in scattering cross section. Forty nuclides included in FUSION-J3 can be used in fusion reactor nuclear calculations. Considering mobility in two-dimensional calculations and fixed group structure in induced activity calculation code system as the GICX40 structure, we composed also FUSION-40 group constant set with neutron 42 group and gamma-ray 21 group structure. The set FUSION-40 includes the same maximum order of the Legendre expansion and the same nuclides as FUSION-J3. From the results in experimental analysis and benchmark calculations, it became proved that JENDL-3 is at higher level of accuracy than ENDF/B-IV and -V. The set FUSION-J3 can be clear applicable to fusion reactor nuclear calculations. (author)

  6. Program system SADKO-2 for assurance of high-energy radiation transport calculation by the group constant methods

    International Nuclear Information System (INIS)

    The structure of the SADKO-2 program system, providing for calculations of radiation transport by the group methods for protons, π-mesons within the energy range from 20 MeV to 10 TeV; for neutrons-from the thermal one to 10 TeV; for photons-from 0.01 up to 15 MeV. The SADKO system containing the program for calculation of complete and twice-differential cross section of inelastic hA-interaction, the program for calculation of group microcross sections for particles with energy above 20 MeV and the program for calculation of group microcross sections for isotope mixtures. The file of the group cross sections in a predetermined format, prepared with an account of the components composition of the shielding and detector substance, constitute the result of the SADKO-2 constant system operation. 25 refs., 7 figs

  7. Dynamical mean-field theory and path integral renormalisation group calculations of strongly correlated electronic states

    International Nuclear Information System (INIS)

    The two-plane HUBBARD model, which is a model for some electronic properties of undoped YBCO superconductors as well as displays a MOTT metal-to-insulator transition and a metal-to-band insulator transition, is studied within Dynamical Mean-Field Theory using HIRSCH-FYE Monte Carlo. In order to find the different transitions and distinguish the types of insulator, we calculate the single-particle spectral densities, the self-energies and the optical conductivities. We conclude that there is a continuous transition from MOTT to band insulator. In the second part, ground state properties of a diagonally disordered HUBBARD model is studied using a generalisation of Path Integral Renormalisation Group, a variational method which can also determine low-lying excitations. In particular, the distribution of antiferromagnetic properties is investigated. We conclude that antiferromagnetism breaks down in a percolation-type transition at a critical disorder, which is not changed appreciably by the inclusion of correlation effects, when compared to earlier studies. Electronic and excitation properties at the system sizes considered turn out to primarily depend on the geometry. (orig.)

  8. Dynamical mean-field theory and path integral renormalisation group calculations of strongly correlated electronic states

    Energy Technology Data Exchange (ETDEWEB)

    Heilmann, D.B.

    2007-02-15

    The two-plane HUBBARD model, which is a model for some electronic properties of undoped YBCO superconductors as well as displays a MOTT metal-to-insulator transition and a metal-to-band insulator transition, is studied within Dynamical Mean-Field Theory using HIRSCH-FYE Monte Carlo. In order to find the different transitions and distinguish the types of insulator, we calculate the single-particle spectral densities, the self-energies and the optical conductivities. We conclude that there is a continuous transition from MOTT to band insulator. In the second part, ground state properties of a diagonally disordered HUBBARD model is studied using a generalisation of Path Integral Renormalisation Group, a variational method which can also determine low-lying excitations. In particular, the distribution of antiferromagnetic properties is investigated. We conclude that antiferromagnetism breaks down in a percolation-type transition at a critical disorder, which is not changed appreciably by the inclusion of correlation effects, when compared to earlier studies. Electronic and excitation properties at the system sizes considered turn out to primarily depend on the geometry. (orig.)

  9. HEXNEM nodal neutronics code for two dimensional multi group diffusion calculations in hexagonal geometry

    International Nuclear Information System (INIS)

    A computer code HEXNEM based on a Nodal Expansion method has been developed for solving of the neutron diffusion equation for two-dimensional hexagonal geometries. The nodal equations are derived using higher order polynomial approximations to the spatial dependence of the flux within the hexagonal node. The final equations which are cast in the form of inhomogeneous response matrix equations for each group, involve spatial moments of the node interior flux distribution and surface averaged partial currents across the faces of the node. These equations are solved using a conventional fission source iteration accelerated by coarse mesh rebalance and asymptotic source extrapolation. Numerical calculations for models of reactor cores like PFBR or VVER designs have shown accuracy of the nodal schemes to be superior to that the coarse mesh finite difference method. The higher order axial approximations in the nodal method permit the use of an axial mesh which is at least four times coarser than a typical finite difference mesh. Two benchmark problems have been solved and the results are presented. This report describes the mathematical development and numerical solution of the nodal equations, as well as the input options used in the computer code. (author)

  10. Second mission of North-Cotentin radio-ecology group. The uncertainty calculation

    International Nuclear Information System (INIS)

    The present study treats only the collective risk of ex-utero leukaemia associated with the routine releases of the nuclear industrial installations of the North Cotentin (0.0009 cases over the considered period) the uncertainty on the contribution to the collective risk of the incidents and the accidents of the nuclear installations (notably the drilling of the pipe of release in sea arisen in 1979-1980 and the fire of the waste silo on January 6. 1981, for the reprocessing plant of La Hague has not been considered. Only 45% of the risk are taken into account by the study. Every calculated value remains very inferior to the number of leukemia cases observed (4 cases observed for two expected cases) and to the risk of radioinduced leukemia any merged exposure sources, that is to say 0.84 cases. It appears thus not very probable that the nuclear installations of the North - Cotentin can explain the tendency to the excess of observed leukaemia. The limits of the study become attached for the main part to the environmental impact of the routine releases and to the lifestyles and refuses to tackle anything concerning the health radiation effects. The work made by the group does not allow to end in the harmlessness of radioactive waste, nevertheless, it gives an idea of the scale of the impacts onto the environment of the routine releases. (N.C.)

  11. Determination of monopolar heterogeneous parameters in the neutron semitransport theory and their utilization in three group reactor calculations

    International Nuclear Information System (INIS)

    A general calculation of the monopolar parameters used in the heterogeneous methods for thermal reactors especially for heavy water reactors is presented. The determination of the three group heterogeneous parameters is done using the semitransport theory. A general presentation of the connection between a three group diffusion type code and the cell calculation is made. We reffer to the cell codes used in order to determine the monopolar parameters (author)

  12. Critical operator actions: human reliability modeling and data issues. Principal Working Group No. 5 - Task 94-1. Final Task Report prepared by a Group of Experts of the NEA Committee on the Safety of Nuclear Installations

    International Nuclear Information System (INIS)

    information. The same may apply to the experiences made in the context of design and procedures improvements, based on or related to HRA. As a recognition of the importance of human interactions and of the need to exchange experiences from their treatment, Task 94-1 was initiated within PWG5 in 1994. The present report summarises the results of the work carried out by the group of experts. In Chapter 2 the specific task objectives are stated and the scope is defined. Chapter 3 contains the descriptions of the current HRA activities, including both industrial applications and research projects, in the countries participating in the task. In Chapter 4 data needs and sources for HRA are outlined and in Chapter 5 currently used analysis approaches and their limitations are discussed. Results of the HRA survey, carried out as a major part of this task, are presented in Chapter 6. Chapter 7 deals with a number of special topics in HRA, considered as particularly complex and/or difficult due to the scarceness of data. Current development tendencies are addressed with considerable detail in Chapter 8, followed by conclusions and recommendations (Chapter 9). Comprehensive references are provided at the end of each chapter. Finally, Appendices B, C, D, and F contain detailed information related to the HRA survey

  13. A Review of the Meetings of the Working Group on the Comparison of Calculational Models

    International Nuclear Information System (INIS)

    The purpose of the Calculational Model Group was to discuss the models being used to determine the consequences of sodium fuel interaction in reactor incidents and to compare the results when the codes were applied to specific test cases. This review is intended to compare and comment on the various treatments and to present the results of the comparison of predictions when the codes were applied to specific test cases. The results of the first comparison calculation by the Working Group assumed instantaneous fuel fragmentation and mixing and was reported to the 2. Specialist Meeting on SFI at Ispra. Since the Ispra meeting additional results for the original comparisons have been presented to the Working Group as new codes were introduced or developed. However one of the two test cases considered at the last meeting in April 1975 was substantially the same as the case originally considered in that instantaneous fragmentation and mixing was assumed although some of the other parameters such as the dimensions of the interacting zone and length of sodium column were different. It is therefore appropriate to consider the recent cases only. Codes used for parametric surveys indicate how the pressures, expulsion velocities and work energy depend on various assumptions. It is implicit in all the codes that at the time of initiation of the interaction the coolant is in the liquid state and heat transfer from the fragmented particles is by conduction. For UO2/Na systems it is the conductivity of the UO2 which limits the heat transfer initially. The assumption of uniform sodium temperature is made in many of the codes. This stage of the interaction has been defined as Stage A and it is considered separately from Stage B when the interacting zone has expanded sufficiently to permit vapour to be present. The mass of fuel fragmenting with time was assumed to increase with time and calculations were carried out for two cases Tf = 0 and Tf = 10 ms where Tf is the fuel

  14. Study on the surface hydroxyl group on solid breeding materials by ab-initio calculations

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Satoru; Taniguchi, Masaki [Tokyo Univ. (Japan). Faculty of Engineering

    1996-10-01

    The nature of -OH on the surface of Li{sub 2}O was analyzed with the ab-initio quantum chemical calculation technique. Calculation results showed that the stretching vibration of O-H is affected by the chemical species around the -OH. (author)

  15. Reexamining the validity and reliability of the clinical version of the Iowa gambling task: Evidence from a normal subject group

    Directory of Open Access Journals (Sweden)

    Ching-Hung eLin

    2013-05-01

    Full Text Available Over past decade, the Iowa gambling task (IGT has been utilized to test various decision deficits induced by neurological damage or psychiatric disorders. The IGT has recently been standardized for identifying 13 different neuropsychological disorders. Neuropsychological patients choose bad decks frequently, and normal subjects prefer good EV decks. However, the IGT has several validity and reliability problems. Some research groups have pointed out that the validity of IGT is influenced by the personality and emotional state of subjects. Additionally, several other studies have proposed that the prominent deck B phenomenon (PDB phenomenon – that is, normal subjects preferring bad deck B – may be the most serious problem confronting IGT validity. Specifically, deck B offers a high frequency of gains but negative EV. In the standard IGT administration, choice behavior can be understood with reference to gain-loss frequency (GLF rather than inferred future consequences (EV, the basic assumption of IGT. Furthermore, using two different criteria (basic assumption vs. professional norm results in significantly different classification results. Therefore, we recruited 72 normal subjects to test the validity and reliability of IGT. Each subject performed three runs of the computer-based clinical IGT version. The PDB phenomenon has been observed to a significant degree in the first and second stages of the clinical IGT version. Obviously, validity, reliability and the practice effect were unstable between two given stages. The present form of the clinical IGT version has only one stage, so its use should be reconsidered for examining normal decision makers; results from patient groups must also be interpreted with great care. GLF could be the main factor to be considered in establishing the constructional validity and reliability of the clinical IGT version.

  16. ANIGAM: a computer code for the automatic calculation of nuclear group data

    International Nuclear Information System (INIS)

    The computer code ANIGAM consists mainly of the well-known programmes GAM-I and ANISN as well as of a subroutine which reads the THERMOS cross section library and prepares it for ANISN. ANIGAM has been written for the automatic calculation of microscopic and macroscopic cross sections of light water reactor fuel assemblies. In a single computer run both were calculated, the cross sections representative for fuel assemblies in reactor core calculations and the cross sections of each cell type of a fuel assembly. The calculated data were delivered to EXTERMINATOR and CITATION for following diffusion or burn up calculations by an auxiliary programme. This report contains a detailed description of the computer codes and methods used in ANIGAM, a description of the subroutines, of the OVERLAY structure and an input and output description. (oririg.)

  17. Small groups, large profits: Calculating interest rates in community-managed microfinance

    DEFF Research Database (Denmark)

    Rasmussen, Ole Dahl

    2012-01-01

    Savings groups are a widely used strategy for women’s economic resilience – over 80% of members worldwide are women, and in the case described here, 72.5%. In these savings groups it is common to see the interest rate on savings reported as "20-30% annually". Using panel data from 204 groups in M...

  18. Innovative characteristics of the new dosimetric model for the human respiratory tract studied by the ICRP appointed Task Group of Committee 2

    CERN Document Server

    Melandri, C; Tarroni, G

    1991-01-01

    In 1984, the ICRP appointed a Task Group of Committee 2 to review and revise, as necessary, the current lung dosimetric model. On the basis of the knowledge acquired during the past 20 years, the Task Group's approach has been to review, in depth, the morphology and physiology of the human respiratory tract, inspirability of aerosols and regional deposition of inhaled particles as functions of aerosol size and breathing parameters, clearance of deposited materials, nature and specific sites of damage to the respiratory system caused by inhaled radioactive substances. In the proposed model, clearance from the three regions of the respiratory tract (extrathoracic ET, fast-clearing thoracic T sub f and slow-clearing thoracic T sub s , comprising lymph nodes) is described in terms of competition between the mechanical processes moving particles, which do not depend on the substances, and those of absorption into the blood, determined solely by the material. A Task Group report will also include models for calcula...

  19. Dosimetric evaluation of a commercial 3-D treatment planning system using Report 55 b AAPM Task Group 23

    International Nuclear Information System (INIS)

    A relevant part of radiotherapy treatment planning system QA concerns dose calculation verification. Report 55 by AAPM TG-23 is an instrument for performing dosimetric evaluation of treatment planning systems in case of external photon beams. It was employed by different groups in three radiotherapy departments for controlling performances of RTPS CadPlan Varian-Dosetek, versions 2.7.9, 3.0.6 and 3. 1. 1. Once the basic data of the AAPM 4 MV and 18 MV X-ray units had been converted into the CadPlan format and the AAPM units configured, the whole set of TG23 tests were carried out on three different systems. According to Report 55. comparisons between values measured by TG-23 and calculated by RTPS were made in terms of dose at selected points and radiological field width at different depths. As far as dose is concerned, 266 data were compared for 4 MV and 297 for Is MV. Ninety-five-point-nine percent of dose deviations for 4 MV and 92.6% for 18 MV are less than 2%. Most of the relevant discrepancies for both energies occur in a test case where dose has to be calculated under a long narrow block centred on the beam axis. Deviations as much as 6.1 % for 4 MV and - 7.5% for 18 MV were obsessed in points at 1 cm depth under the block. Poor results were also observed in the rectangular field 25 x 5. in points outside the field edges under collimators. As regards radiological field width. 58 out of 64 comparisons for 4 MV occurred in the range ± 2 mm. For 18 MV the biggest deviation was - 2.2 mm. The TG-23 tests demonstrated that the accuracy of the RTPS in dose calculation is good in most of the typical radiotherapy applications. Our results are better than those recently published for other RTPS. The TG-23 package turned out to be an effective instrument for QA and calculation verification. as well as being a powerful method for training purpose in configuring and using a RTPS (author.)

  20. DECOVALEX-THMC Project. Task A. Influence of near field coupled THM phenomena on the performance of a spent fuel repository. Report of Task A1: Preliminary scoping calculations

    International Nuclear Information System (INIS)

    The DECOVALEX-THMC project is an ongoing international co-operative project that was stared in 2004 to support the development of mathematical models of coupled Thermal (T), Hydrological (H), Mechanical (M) and Chemical (C) processes in geological media for siting potential nuclear fuel waste repositories. The general objective is to characterise and evaluate the coupled THMC processes in the near field and far field of a geological repository and to assess their impact on performance assessment: - during the three phases of repository development: excavation phase, operation phase and post-closure phase; - for three different rocks types: crystalline, argillaceous and tuff; - with specific focus on the issues of: Excavation Damaged Zone (EDZ), permanent property changes of rock masses, and glaciation and permafrost phenomena. The project involves a large number of research teams supported by radioactive waste management agencies or governmental regulatory bodies in Canada, China, Finland, France, Germany, Japan, Sweden and USA, who conducted advanced studies and numerical modelling of coupled THMC processes under five tasks. This report presents the definition of the first phase, Task A-1, of the Task A of the project. The task is a working example of how interaction between THMC modelling and SA analysis could be performed. Starting with the technical definition of the Task A, the report presents the results of preliminary THM calculations with a purpose of an initial appreciation of the phenomena and material properties that must be better understood in subsequent phases. Many simplifications and assumptions were introduced and the results should be considered under these assumptions. Based on the evaluation of the multiple teams' results, a few points of concern were identified that may guide the successive phases of Task A studies: 1. The predicted maximum total stress in the MX-80 bentonite could slightly exceed the 15 MPa design pressure for the container

  1. DECOVALEX-THMC Project. Task A. Influence of near field coupled THM phenomena on the performance of a spent fuel repository. Report of Task A1: Preliminary scoping calculations

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Son (ed.) [Canadian Nuclear Safety Commission (Canada); Lanru Jing (ed.) [Royal Institute of Technology, Stockholm (Sweden); Boergesson, Lennart [Clay Technology AB, Lund (Sweden); Chijimatzu, Masakazu [Hazama Corporation (Japan); Jussila, Petri [Helsinki Univ. of Technology, Helsinki (Finland); Rutqvist, Jonny [Lawrence Berkeley National Laboratory CA (United States)

    2007-02-15

    The DECOVALEX-THMC project is an ongoing international co-operative project that was stared in 2004 to support the development of mathematical models of coupled Thermal (T), Hydrological (H), Mechanical (M) and Chemical (C) processes in geological media for siting potential nuclear fuel waste repositories. The general objective is to characterise and evaluate the coupled THMC processes in the near field and far field of a geological repository and to assess their impact on performance assessment: - during the three phases of repository development: excavation phase, operation phase and post-closure phase; - for three different rocks types: crystalline, argillaceous and tuff; - with specific focus on the issues of: Excavation Damaged Zone (EDZ), permanent property changes of rock masses, and glaciation and permafrost phenomena. The project involves a large number of research teams supported by radioactive waste management agencies or governmental regulatory bodies in Canada, China, Finland, France, Germany, Japan, Sweden and USA, who conducted advanced studies and numerical modelling of coupled THMC processes under five tasks. This report presents the definition of the first phase, Task A-1, of the Task A of the project. The task is a working example of how interaction between THMC modelling and SA analysis could be performed. Starting with the technical definition of the Task A, the report presents the results of preliminary THM calculations with a purpose of an initial appreciation of the phenomena and material properties that must be better understood in subsequent phases. Many simplifications and assumptions were introduced and the results should be considered under these assumptions. Based on the evaluation of the multiple teams' results, a few points of concern were identified that may guide the successive phases of Task A studies: 1. The predicted maximum total stress in the MX-80 bentonite could slightly exceed the 15 MPa design pressure for the

  2. Resonating-group calculations with new cluster wave function for p+3,4He elastic scattering

    International Nuclear Information System (INIS)

    A new type of cluster internal wave function that can produce improved results, especially for the cluster binding energy, has been proposed. As a first application, we have carried out calculations for the case of p+3He and p+4He elastic scattering on the basis of the resonating group method with this type of wave function. The agreement of the calculated results and the experimental data is quite satisfactory. (author)

  3. JMA's regional atmospheric transport model calculations for the WMO technical task team on meteorological analyses for Fukushima Daiichi Nuclear Power Plant accident

    International Nuclear Information System (INIS)

    The World Meteorological Organization (WMO) convened a small technical task team of experts to produce a set of meteorological analyses to drive atmospheric transport, dispersion and deposition models (ATDMs) for the United Nations Scientific Committee on the Effects of Atomic Radiation's assessment of the Fukushima Daiichi Nuclear Power Plant (DNPP) accident. The Japan Meteorological Agency (JMA) collaborated with the WMO task team as the regional specialized meteorological center of the country where the accident occurred, and provided its operational 5-km resolution mesoscale (MESO) analysis and its 1-km resolution radar/rain gauge-analyzed precipitation (RAP) data. The JMA's mesoscale tracer transport model was modified to a regional ATDM for radionuclides (RATM), which included newly implemented algorithms for dry deposition, wet scavenging, and gravitational settling of radionuclide aerosol particles. Preliminary and revised calculations of the JMA-RATM were conducted according to the task team's protocol. Verification against Cesium 137 (137Cs) deposition measurements and observed air concentration time series showed that the performance of RATM with MESO data was significantly improved by the revisions to the model. The use of RAP data improved the 137Cs deposition pattern but not the time series of air concentrations at Tokai-mura compared with calculations just using the MESO data. Sensitivity tests of some of the more uncertain parameters were conducted to determine their impacts on ATDM calculations, and the dispersion and deposition of radionuclides on 15 March 2011, the period of some of the largest emissions and deposition to the land areas of Japan. The area with high deposition in the northwest of Fukushima DNPP and the hotspot in the central part of Fukushima prefecture were primarily formed by wet scavenging influenced by the orographic effect of the mountainous area in the west of the Fukushima prefecture

  4. Task-Based Learning: Student’s Perception Of Their Skill In Participating In Small Group Discussions

    Directory of Open Access Journals (Sweden)

    Sharifah Sulaiha S A

    2009-06-01

    Full Text Available IntroductionTask-based learning (TBL has been accepted asan effective tool in teaching and learning activities inmost medical schools. Many studies have lookedat competencies and learning outcomes essential forundergraduates. Among the essential competenciesare interpersonal skills and the ability to engage in agroup discussion which this study has focused on.The evidence supporting higher interpersonal skills ishowever limited because many relevant competenciesare hard to measure and require long observationalperiods. ObjectiveTo determine students’ self-perceived value of TBL inenhancing their interpersonal skills during the clinicalphase. Material and MethodsAll students’ (semesters 6-10 in the clinical schoolof International Medical University (IMU wereinvited to participate in this cross-sectional study donein December 2007 utilising a self-administeredquestionnaire with a 5-point Likert scale. It assessed thestudents’ perception on TBL sessions conducted duringtheir clinical attachments in the various disciplines.Mean-scores, standard deviations, and confidenceinterval were used.ResultsResponse rate was 62%. The results indicated thatstudents were favorable in their opinion on TBL asa suitable forum for active communication andparticipation in group discussion. The results also showthat both male and female students’ have similarperception. As for the comparison according tosemesters, this showed that students’ maturity does notinfluence their perception as well.Conclusion In conclusion, the study has shown positive students’perception on the effect of TBL on acquired skills such as interpersonal communication. Our findings areconsistent with many earlier studies which showstudents’ perception of the method of learning asimportant factor in the enhancement of theirinterpersonal skills which is fundamental to clinicalpractice. Further research is necessary; long-term andlarger scale observational studies would undoubtedly

  5. A group of neutronics calculations in the MNSR using the MCNP-4C code

    International Nuclear Information System (INIS)

    The MCNP-4C code was used to model the 3-D core configuration for the Syrian Miniature Neutron Source Reactor (MNSR). The continuous energy neutron cross sections were evaluated from ENDF/B-VI library to calculate the thermal and fast neutron fluxes in the MNSR inner and outer irradiation sites. The thermal fluxes in the MNSR inner irradiation sites were measured for the first time using the multiple foil activation method. Good agreements were noticed between the calculated and measured results. This model is used as well to calculate neutron flux spectrum in the reactor inner and outer irradiation sites and the reactor thermal power. Three 3-D neutronic models for the Syrian MNSR reactor using the MCNP-4C code were developed also to assess the possibility of fuel conversion from 89.87 % HEU fuel (UAl4-Al) to 19.75 % LEU fuel (UO2). This model is used in this paper to calculate the following reactor core physics parameters: clean cold core excess reactivity, calibration of the control rod worth and calculation its shut down margin, calibration of the top beryllium shim plate reflector, axial neutron flux distributions in the inner and outer irradiation sites and the kinetics parameters ( ιp l and βeff). (authors)

  6. Large-dimension configuration-interaction calculations of positron binding to the group-II atoms

    International Nuclear Information System (INIS)

    The configuration-interaction (CI) method is applied to the calculation of the structures of a number of positron binding systems, including e+Be, e+Mg, e+Ca, and e+Sr. These calculations were carried out in orbital spaces containing about 200 electron and 200 positron orbitals up to l=12. Despite the very large dimensions, the binding energy and annihilation rate converge slowly with l, and the final values do contain an appreciable correction obtained by extrapolating the calculation to the l→∞ limit. The binding energies were 0.00317 hartree for e+Be, 0.0170 hartree for e+Mg, 0.0189 hartree for e+Ca, and 0.0131 hartree for e+Sr

  7. The management of imaging dose during image-guided radiotherapy: Report of the AAPM Task Group 75

    International Nuclear Information System (INIS)

    Radiographic image guidance has emerged as the new paradigm for patient positioning, target localization, and external beam alignment in radiotherapy. Although widely varied in modality and method, all radiographic guidance techniques have one thing in common--they can give a significant radiation dose to the patient. As with all medical uses of ionizing radiation, the general view is that this exposure should be carefully managed. The philosophy for dose management adopted by the diagnostic imaging community is summarized by the acronym ALARA, i.e., as low as reasonably achievable. But unlike the general situation with diagnostic imaging and image-guided surgery, image-guided radiotherapy (IGRT) adds the imaging dose to an already high level of therapeutic radiation. There is furthermore an interplay between increased imaging and improved therapeutic dose conformity that suggests the possibility of optimizing rather than simply minimizing the imaging dose. For this reason, the management of imaging dose during radiotherapy is a different problem than its management during routine diagnostic or image-guided surgical procedures. The imaging dose received as part of a radiotherapy treatment has long been regarded as negligible and thus has been quantified in a fairly loose manner. On the other hand, radiation oncologists examine the therapy dose distribution in minute detail. The introduction of more intensive imaging procedures for IGRT now obligates the clinician to evaluate therapeutic and imaging doses in a more balanced manner. This task group is charged with addressing the issue of radiation dose delivered via image guidance techniques during radiotherapy. The group has developed this charge into three objectives: (1) Compile an overview of image-guidance techniques and their associated radiation dose levels, to provide the clinician using a particular set of image guidance techniques with enough data to estimate the total diagnostic dose for a specific

  8. Status Report on Activities of the Systems Assessment Task Force, OECD-NEA Expert Group on Accident Tolerant Fuels for LWRs

    Energy Technology Data Exchange (ETDEWEB)

    Bragg-Sitton, Shannon Michelle [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    The Organization for Economic Cooperation and Development /Nuclear Energy Agency (OECD/NEA) Nuclear Science Committee approved the formation of an Expert Group on Accident Tolerant Fuel (ATF) for LWRs (EGATFL) in 2014. Chaired by Kemal Pasamehmetoglu, INL Associate Laboratory Director for Nuclear Science and Technology, the mandate for the EGATFL defines work under three task forces: (1) Systems Assessment, (2) Cladding and Core Materials, and (3) Fuel Concepts. Scope for the Systems Assessment task force includes definition of evaluation metrics for ATF, technology readiness level definition, definition of illustrative scenarios for ATF evaluation, parametric studies, and selection of system codes. The Cladding and Core Materials and Fuel Concepts task forces will identify gaps and needs for modeling and experimental demonstration; define key properties of interest; identify the data necessary to perform concept evaluation under normal conditions and illustrative scenarios; identify available infrastructure (internationally) to support experimental needs; and make recommendations on priorities. Where possible, considering proprietary and other export restrictions (e.g., International Traffic in Arms Regulations), the Expert Group will facilitate the sharing of data and lessons learned across the international group membership. The Systems Assessment Task Force is chaired by Shannon Bragg-Sitton (INL), while the Cladding Task Force will be chaired by a representative from France (Marie Moatti, Electricite de France [EdF]) and the Fuels Task Force will be chaired by a representative from Japan (Masaki Kurata, Japan Atomic Energy Agency [JAEA]). This report provides an overview of the Systems Assessment Task Force charter and status of work accomplishment.

  9. Strategic Development in Exact Calculation: Group and Individual Differences in Four Achievement Subtypes

    Science.gov (United States)

    Wylie, Judith; Jordan, Julie-Ann; Mulhern, Gerry

    2012-01-01

    This longitudinal study sought to identify developmental changes in strategy use between 5 and 7 years of age when solving exact calculation problems. Four mathematics and reading achievement subtypes were examined at four time points. Five strategies were considered: finger counting, verbal counting, delayed retrieval, automatic retrieval, and…

  10. Calculation features of traffic light regulation regimesat the signal group control

    OpenAIRE

    Єресов, Володимир Іванович; Трушевський, Вячеслав Едуардович

    2014-01-01

    The differences between the existing technologies of traffic light control by phases and signal groups were determined in the paper. It was proved that the signal group control technology is more perfect and to a greater extent corresponds to the changing traffic conditions at intersections. Approach for compiling the traffic light regulation cycle structure based on the analysis of conflict of traffic and pedestrian flows, taking into account traffic volume, the number of road accidents in t...

  11. Conformational energy calculations and proton nuclear overhauser enhancements reveal a unique conformation for blood group A oligosaccharides

    International Nuclear Information System (INIS)

    The 1H NMR spectra of a series of blood group A active oligosaccharides containing from four to ten sugar residues have been completely assigned, and quantitative nuclear Overhauser enhancements (NOE) have been measured between protons separated by known distances within the pyranoside ring. The observation of NOE between anomeric protons and those of the aglycon sugar as well as small effects between protons of distant rings suggests that the oligosaccharides have well-defined conformations. Conformational energy calculations were carried out on a trisaccharide, Fuc(α-1→2)[GalNAc(α-1→3)]-Galβ-O-me, which models the nonreducing terminal fragments of the blood group A oligosaccharides. The results of calculations with three different potential energy functions which have been widely used in peptides and carbohydrates gave several minimum energy conformations. In NOE calculations from conformational models, the rotational correlation time was adjusted to fit T1's and intra-ring NOE. Comparison of calculated maps of NOE as a function of glycosidic dihedral angles showed that only a small region of conformational space was consistent with experimental data on a blood group A tetrasaccharide alditol. This conformation occurs at an energy minimum in all three energy calculations. Temperature dependence of the NOE implies that the oligosaccharides adopt single rigid conformations which do not change with temperature

  12. Calculation of the one-dimension two energy groups lambda modes, using the boundary functions method

    International Nuclear Information System (INIS)

    Using parameters and cross sections of SIMULATE-III code, a method to obtain the lambda modes was developed. In order to validate the method, eigenvalues and eigenfunctions obtained with this method were compared with those obtained using SIMULATE III and VENTURE codes. For superior order modes, the results were compared with those calculated by General Electric, for the Cofrentes Nuclear Power Plant-Spain. (author)

  13. Development of a multi-group SN transport calculation code with unstructured tetrahedral meshes

    International Nuclear Information System (INIS)

    This paper reviews the computational methods used in the MUST (Multi-group Unstructured geometry SN Transport) code for solving the multi-group Sn transport equation in general geometries and describes the status of development of MUST. MUST solves the multi-group transport equation with unstructured tetrahedral meshes for modeling complicated geometrical problems. For tetrahedral mesh generation, input generation, and output visualization, we developed a management program where the mesh generation is based on Gmsh and TetGen that are open softwares. The geometrical modeling is done with the commercial CAD softwares such as CATIA. MUST uses the discontinuous finite element method (DFEM) and two-sub cell balance methods with linear discontinuous expansion (LDEM-SCB) to spatially discretize the transport equation. We applied MUST to three neutron and gamma coupled test problems for testing MUST. (author)

  14. Extreme group index measured and calculated in 2D SOI-based photonic crystal waveguides

    DEFF Research Database (Denmark)

    Lavrinenko, Andrei; Jacobsen, Rune Shim; Fage-Pedersen, Jacob; Frandsen, Lars Hagedorn; Zsigri, Beata; Peucheret, Christophe; Borel, Peter Ingo

    2005-01-01

    lattice of air-holes in the 216-nm thick silicon layer in an SOI material. Experimental transmission spectra show a mode cut-off around 1562.5 nm for the fundamental photonic bandgap mode. In order to measure and model the group index of modes in the PCW, a time-of-flight (ToF) method is applied....

  15. Two dimensional power density calculations in two group approximation for PWR cores

    International Nuclear Information System (INIS)

    The programme module for multidimensional power density calculations is one of the most computer-time consuming part of utility oriented burnup programme. standard finite difference method is not economical in such cases. modern integral methods (finite elements, nodal expansion method) prove to be more efficient. The differences method is nevertheless widely used because of its accuracy and reliability. It is presented in the following report that the introduction of certain integral properties into standard finite differences method leads to a successful combination of both qualities: the efficiency of a 2-D finite differences programme can be increased for an order of magnitude without loss of accuracy. (author)

  16. IUCN/SSC Otter Specialist Group: Otters in Captivity Task Force (OCT – Supporting Quality Captive Otter Care Worldwide

    Directory of Open Access Journals (Sweden)

    Jan Reed-Smith

    2008-10-01

    Full Text Available Work on creating the Otters in Captivity Task Force was begun in earnest in 2007 after OSG chair Jim Conroy reiterated Claus Reuther’s earlier request that the OSG look at how we could best interface with our colleagues working with otters in captive settings. I am pleased to report that this task force, known as OCT, has made some valuable progress in establishing our goals, identifying objectives, meeting some targets, and solidifying positive working relationships with otter professionals worldwide.

  17. Calculation of the wall pressure field generated on a group of buildings by an external explosion

    International Nuclear Information System (INIS)

    The aim is to work out a three-dimensional code calculating the over-pressure distribution on any structure when an air shock wave arrives, especially in the case of a geometry providing multiple waves reflection. The computer code ZEPHIR was written under the assumption that the phenomena agree with the acoustic laws. An integral formulation leads infinite three-dimensional problems to a bidimensional one on a surface S limiting the real D. The surface S is discretized with triangular elements and replaced by the polyedron constituted by the mesh. The pressure is calculated at the barycenter of the triangular elements, with interpolation between several time-steps. The ZEPHIR code has been validated at first againt analytical solutions obtained for simple obstacle geometries. Test were performed with models of PWR buildings at a scale of 1/40, a cylinder for the reactor building and a parallelepiped for the fuel building, used adjacent or separated by a gap. Plastic explosive permits to obtain the pressure-time history of a hydrocarbon explosion at that scale. The results are in good agreement with the computation. The code ZEPHIR is characterized by a relatively cheap utilization

  18. Calculation of anisotropic few-group constants in asymptotic cells: the code ANICELL

    International Nuclear Information System (INIS)

    The theoretical background of the ANICELL computer program together with a user's manual is presented. ANICELL is a nuclear reactor neutron transport code which solves the traditional asymptotic and the so-called tilted flux transport problems in one-dimensional cylindrical geometry using linearly anisotropic scattering. The method of solution used is the first flight collision probability technique. Few-group constants including radial and axial diffusion coefficients for the cell are also prepared by the program. (author)

  19. Hierarchical Parallelisation of Functional Renormalisation Group Calculations -- hp-fRG

    OpenAIRE

    Rohe, Daniel

    2015-01-01

    The functional renormalisation group (fRG) has become a powerful and widely used method to study correlated electron systems. This often involves a high numerical effort, motivating the question in how far High Performance Computing (HPC) platforms can leverage the approach. In this work we report on a multi-level parallelisation of the underlying computational machinery and show that this can speed up the code by several orders of magnitude. This in turn can extend the applicability of the m...

  20. Calculations in two-group neutron transport theory with isotropic-and linearly anisotropic scattering

    International Nuclear Information System (INIS)

    Typical half-space problems in two-group neutron transport theory are solved numerically using the singular-eigenfunction-expansion technique, considering isotropic-and linearly anisotropic scattering. Numerical results are reported for the Albedo, Milne and Constant-Source problems in a half-space pure light-water medium using isotropic scattering data set of Metacalf and Zweifel and considering various degrees of anisotropy

  1. Building neutron cross-section dependencies for few-group reactor calculations using stepwise regression

    International Nuclear Information System (INIS)

    Approximation of few-group neutron cross-sections by functions of burnup and thermal-hydraulics parameters of a fuel cell is considered. The cross-section is written as a sum of two terms: the base cross-section, which depends only on burnup and is computed under the nominal reactor core conditions, and the deviation, which depends on burnup and thermal-hydraulics variables of the cell. A one-dimensional dependence of the base cross-section is interpolated by a cubic spline. Multi-dimensional dependencies of the deviation are approximated by a polynomial. Construction of the polynomial is performed by a best-fitting selection of the polynomial terms using the stepwise regression algorithm. The number of terms to satisfy a user-given accuracy of approximation is minimized. As an example, approximation of a set of two-group macro and micro cross-sections as functions of burnup, coolant and fuel temperature, coolant density and boron concentration is considered for a fuel pin cell of a VVER reactor. The constructed five-dimensional polynomial approximating cross-sections within 0.05% tolerance has about 20 terms for fast group cross-sections and 50 terms for thermal group cross-sections. The error of approximation is verified on the two data sets: the initial data used for approximation and the test data being computed on randomly selected points. Mean square and maximum errors are comparable for all the cross-sections for both sets of data. These results show that the initial data can be applied to control the approximation error

  2. A one-dimensional, one-group absorption-production nodal method for neutron flux and power distributions calculations

    International Nuclear Information System (INIS)

    It is presented the absorption-production nodal method for steady and dynamical calculations in one-dimension and one group energy. It was elaborated the NOD1D computer code (in FORTRAN-IV language). Calculations of neutron flux and power distributions, burnup, effective multiplication factors and critical boron concentration were made with the NOD1D code and compared with results obtained through the CITATION code, which uses the finite difference method. The nuclear constants were produced by the LEOPARD code. (M.C.K.)

  3. Reports of the working groups on precision calculations for LEP2 physics. Proceedings

    International Nuclear Information System (INIS)

    This is the report of the LEP2 Monte Carlo Workshop held at CERN from 1999 to 2000. It consists of four parts. In the first part, the most recent developments in the calculation of four-fermion processes in electron-positron collisions at LEP2 are presented, concentrating on predictions for four main reactions: W-pair production, visible photons in four-fermion events, single-W production, and Z-pair production. Based on a comparison of results within different approaches, theoretical uncertainties on these prediction are established. The second part is devoted to QCD issues, focusing on improving the understanding and the Monte Carlo simulation of multijet final states due to hard QCD processes at LEP, i.e. quark-antiquark plus multigluon and/or secondary quark production, with particular emphasis on four-jet final states and b-quark mass effects. Specific topics covered are: relevant developments in the main event generators; description and tuning of inclusive (all-flavour) jet rates; quark mass effects in the three- and four-jet rates; mass, higher-order and hadronization effects in four-jet angular and shape distributions; b-quark fragmentation and gluon splitting into b-quarks. In the third part, γγ physics is discussed. After a detailed description of the physics modelling of the most recent versions of the currently available codes, comparisons between the results of the different event generators, as well as between LEP data and the theoretical predictions are presented, together with the problem of background due to γγ processes in searches for new particles. In the last part, recent developments in the theoretical calculation of two-fermion processes are reported. The Bhabha process and the production of muon, tau, neutrino and quark pairs is covered. On the basis of comparison of various calculations, theoretical uncertainties are estimated and compared with those needed for the final LEP2 data analysis. The subjects for further study are identified

  4. Optical properties of group-3 metal hexaboride nanoparticles by first-principles calculations

    Science.gov (United States)

    Yoshio, Satoshi; Maki, Koichiro; Adachi, Kenji

    2016-06-01

    LaB6 nanoparticles are widely used as solar control materials for strong near-infrared absorption and high visible transparency. In order to elucidate the origin of this unique optical property, first-principles calculations have been made for the energy-band structure and dielectric functions of RIIIB6 (RIII = Sc, Y, La, Ac). On account of the precise assessment of the energy eigenvalues of vacant states in conduction band by employing the screened exchange method, as well as to the incorporation of the Drude term, dielectric functions and various physical properties of LaB6 have been reproduced in excellent agreement with experimental values. Systematic examinations of dielectric functions and electronic structures of the trivalent metal hexaborides have clarified the origin of the visible transparency and the near-infrared plasmon absorption of RIIIB6 nanoparticles.

  5. INDUCED EEG GAMMA OSCILLATION ALIGNMENT IMPROVES DIFFERENTIATION BETWEEN AUTISM AND ADHD GROUP RESPONSES IN A FACIAL CATEGORIZATION TASK.

    Science.gov (United States)

    Gross, Eric; El-Baz, Ayman S; Sokhadze, Guela E; Sears, Lonnie; Casanova, Manuel F; Sokhadze, Estate M

    2012-01-01

    INTRODUCTION: Children diagnosed with an autism spectrum disorder (ASD) often lack the ability to recognize and properly respond to emotional stimuli. Emotional deficits also characterize children with attention deficit/hyperactivity disorder (ADHD), in addition to exhibiting limited attention span. These abnormalities may effect a difference in the induced EEG gamma wave burst (35-45 Hz) peaked approximately 300-400 milliseconds following an emotional stimulus. Because induced gamma oscillations are not fixed at a definite point in time post-stimulus, analysis of averaged EEG data with traditional methods may result in an attenuated gamma burst power. METHODS: We used a data alignment technique to improve the averaged data, making it a better representation of the individual induced EEG gamma oscillations. A study was designed to test the response of a subject to emotional stimuli, presented in the form of emotional facial expression images. In a four part experiment, the subjects were instructed to identify gender in the first two blocks of the test, followed by differentiating between basic emotions in the final two blocks (i.e. anger vs. disgust). EEG data was collected from ASD (n=10), ADHD (n=9), and control (n=11) subjects via a 128 channel EGI system, and processed through a continuous wavelet transform and bandpass filter to isolate the gamma frequencies. A custom MATLAB code was used to align the data from individual trials between 200-600 ms post-stimulus, EEG site, and condition by maximizing the Pearson product-moment correlation coefficient between trials. The gamma power for the 400 ms window of maximum induced gamma burst was then calculated and compared between subject groups. RESULTS AND CONCLUSION: Condition (anger/disgust recognition, gender recognition) × Alignment × Group (ADHD, ASD, Controls) interaction was significant at most of parietal topographies (e.g., P3-P4, P7-P8). These interactions were better manifested in the aligned data set

  6. Accurate variational electronic structure calculations with the density matrix renormalization group

    CERN Document Server

    Wouters, Sebastian

    2014-01-01

    During the past 15 years, the density matrix renormalization group (DMRG) has become increasingly important for ab initio quantum chemistry. The underlying matrix product state (MPS) ansatz is a low-rank decomposition of the full configuration interaction tensor. The virtual dimension of the MPS controls the size of the corner of the many-body Hilbert space that can be reached. Whereas the MPS ansatz will only yield an efficient description for noncritical one-dimensional systems, it can still be used as a variational ansatz for other finite-size systems. Rather large virtual dimensions are then required. The two most important aspects to reduce the corresponding computational cost are a proper choice and ordering of the active space orbitals, and the exploitation of the symmetry group of the Hamiltonian. By taking care of both aspects, DMRG becomes an efficient replacement for exact diagonalization in quantum chemistry. DMRG and Hartree-Fock theory have an analogous structure. The former can be interpreted a...

  7. Migros-3: a code for the generation of group constants for reactor calculations from neutron nuclear data in KEDAK format

    International Nuclear Information System (INIS)

    The code MIGROS-3 was developed from MIGROS-2. The main advantage of MIGROS-3 is its compatibility with the new conventions of the latest version of the Karlsruhe nuclear data library, KEDAK-3. Moreover, to some extent refined physical models were used and numerical methods were improved. MIGROS-3 allows the calculation of microscopic group cross sections of the ABBN type from isotopic neutron data given in KEDAK-format. All group constants, necessary for diffusion-, consistent P1- and Ssub(N)-calculations can be generated. Anisotropy of elastic scattering can be taken into account up to P5. A description of the code and the underlying theory is given. The input and output description, a sample problem and the program lists are provided. (orig.)

  8. MCANG - a group data library of cumulative angular distributions of elastically scattered neutrons for Monte Carlo calculations

    International Nuclear Information System (INIS)

    A code has been written for producing group data suited to take into account the center of mass anisotropy of elastic neutron scattering in Monte Carlo calculations. The format of the generated data library is described. Up to now variants of the library based on KEDAK2 and KEDAK3/ENDL78 have been produced. One of the libraries is listed in the appendix. (author)

  9. Minimal Intervention Dentistry (MID) for managing dental caries – a review: Report of a FDI task group*

    OpenAIRE

    FRENCKEN, Jo. E.; Peters, Mathilde C.; Manton, David J.; Leal, Soraya C.; Gordan, Valeria V.; Eden, Ece

    2012-01-01

    This publication describes the history of Minimal Intervention Dentistry (MID) for managing dental caries and presents evidence for various carious lesion detection devices, for preventive measures, for restorative and non-restorative therapies as well as for repairing rather than replacing defective restorations. It is a follow-up to the FDI World Dental Federation publication on MID, of 2000. The dental profession currently is faced with an enormous task of how to manage the high burden of ...

  10. Status of degraded core issues. Synthesis paper prepared by G. Bandini in collaboration with the NEA task group on degraded core cooling

    International Nuclear Information System (INIS)

    The in-vessel evolution of a severe accident in a nuclear reactor is characterised, generally, by core uncover and heat-up, core material oxidation and melting, molten material relocation and debris behaviour in the lower plenum up to vessel failure. The in-vessel core melt progression involves a large number of physical and chemical phenomena that may depend on the severe accident sequence and the reactor type under consideration. Core melt progression has been studied in the last twenty years through many experimental works. Since then, computer codes are being developed and validated to analyse different reactor accident sequences. The experience gained from the TMI-2 accident also constitutes an important source of data. The understanding of core degradation process is necessary to evaluate initial conditions for subsequent phases of the accident (ex-vessel and within the containment), and define accident management strategies and mitigative actions for operating and advanced reactors. This synthesis paper, prepared within the Task Group on Degraded Core Cooling (TG-DCC) of PWG2, contains a brief summary of current views on the status of degraded core issues regarding light water reactors. The in-vessel fission product release and transport issue is not addressed in this paper. The areas with remaining uncertainties and the needs for further experimental investigation and model development have been identified. The early phase of core melt progression is reasonably well understood. Remaining uncertainties may be addressed on the basis of ongoing experimental activities, e.g. on core quenching, and research programs foreseen in the near future. The late phase of core melt progression is less understood. Ongoing research programs are providing additional valuable information on corium molten pool behaviour. Confirmatory research is still required. The pool crust behaviour and material relocation into the lower plenum are the areas where additional research should

  11. Cluster-Continuum Calculations of Hydration Free Energies of Anions and Group 12 Divalent Cations

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Hao-Bo [ORNL; Liang, Liyuan [ORNL; Parks, Jerry M [ORNL; Smith, Jeremy C [ORNL; Riccardi, Demian M [ORNL; Gu, Baohua [ORNL

    2013-01-01

    Understanding aqueous phase processes involving group 12 metal cations is relevant to both environmental and biological sciences. Here, quantum chemical methods and polarizable continuum models are used to compute the hydration free energies of a series of divalent group 12 metal cations (Zn2+, Cd2+, and Hg2+) together with Cu2+ and the anions OH , SH , Cl , and F . A cluster-continuum method is employed, in which gas-phase clusters of the ion and explicit solvent molecules are immersed in a dielectric continuum. Two approaches to define the size of the solute-water cluster are compared, in which the number of explicit waters used is either held constant or determined variationally as that of the most favorable hydration free energy. Results obtained with various polarizable continuum models are also presented. Each leg of the relevant thermodynamic cycle is analyzed in detail to determine how different contributions yield the observed mean signed error (MSE) and the standard deviation of the error (STDEV) between theory and experiment. The use of a constant number of water molecules for each set of ions is found to lead to predicted relative trends that benefit from error cancellation. Overall, the best results are obtained with MP2 and the Solvent Model D polarizable continuum model (SMD), with eight explicit water molecules for anions and ten for the metal cations, yielding a STDEV of 2.3 kcal/mol and MSE of 0.9 kcal/mol between theoretical to experimental hydration free energies, which range from -72.4 kcal/mol for SH to -505.9 kcal/mol for Cu2+. Using B3PW91 with DFT-D3 dispersion corrections (B3PW91-D) and SMD yields a STDEV of 3.3 kcal mol 1 and MSE of 1.6 kcal/mol, to which adding MP2 corrections from smaller divalent metal ion water molecule clusters yields very good agreement with the full MP2 results. Using B3PW91-D and SMD, with two explicit water molecules for anions and six for divalent metal cations also yields reasonable agreement with experiment

  12. Hierarchical Parallelisation of Functional Renormalisation Group Calculations -- hp-fRG

    CERN Document Server

    Rohe, Daniel

    2015-01-01

    The functional renormalisation group (fRG) has become a powerful and widely used method to study correlated electron systems. This often involves a high numerical effort, motivating the question in how far High Performance Computing (HPC) platforms can leverage the approach. In this work we report on a multi-level parallelisation of the underlying computational machinery and show that this can speed up the code by several orders of magnitude. This in turn can extend the applicability of the method to otherwise inaccessible cases. We exploit three levels of parallelisation: Distributed computing by means of Message Passing (MPI), shared-memory computing using OpenMP, and vectorisation by means of SIMD units (single-instruction-multiple-data). Results are provided for two distinct High Performance Computing (HPC) platforms, namely the IBM-based BlueGene/Q system JUQUEEN and an Intel Sandy-Bridge-based development cluster. We discuss how certain issues and obstacles were overcome in the course of adapting the co...

  13. Biological effects of inhaled radionuclides. A report of a task group of Committee 1 of the International Commission on Radiological Protection. Adopted by the Commission in May 1979

    International Nuclear Information System (INIS)

    This report focuses on various types of radionuclides that may be inhaled and deposited in the respiratory tract. One of the primary goals of this ICRP Task Group is to assess specifically the biological implications of inhaled plutonium. Because other transuranics are becoming more abundant, information on americium, curium and einsteinium is included. Data are also included from studies of polonium and of several beta-gamma emitting isotopes. The Task Group evaluated most of the data on the biological effects of inhaled radionuclides in experimental animals to identify the tissues at risk and to assess possible dose-response relationships. Few data from human cases of inhaled radionuclides are available for this assessment. The biological effects of nonradioactive air pollutants were also considered to provide the perspective that all air pollutants can have a deleterious effect on human life and to emphasize the possibility for combined or synergistic effects of nonradioactive and radioactive substances on the respiratory tract. (author)

  14. Reactivity calculations for the fuel elements of I.T.U. TRIGA MARK-II reactor by means of one-group perturbation theory

    International Nuclear Information System (INIS)

    The reactivities of the fuel elements of I.T.U. TRIGA MARK-II reactor has been calculated by using both one-group perturbation theory and a one-dimensional, two-group diffusion computer code TRIGAP. For each fuel element, reactivities calculated by both methods are compared with those measured experimentally. It is seen that the reactivity calculations made by using the one-group perturbation theory give the results with better accuracy in comparison to TRIGAP. One-group perturbation theory can be easily applied to the reactivity calculations of fuel elements of TRIGA type reactors in acceptable range (orig.)

  15. The geospace response to variable inputs from the lower atmosphere: a review of the progress made by Task Group 4 of CAWSES-II

    Science.gov (United States)

    Oberheide, Jens; Shiokawa, Kazuo; Gurubaran, Subramanian; Ward, William E.; Fujiwara, Hitoshi; Kosch, Michael J.; Makela, Jonathan J.; Takahashi, Hisao

    2015-12-01

    The advent of new satellite missions, ground-based instrumentation networks, and the development of whole atmosphere models over the past decade resulted in a paradigm shift in understanding the variability of geospace, that is, the region of the atmosphere between the stratosphere and several thousand kilometers above ground where atmosphere-ionosphere-magnetosphere interactions occur. It has now been realized that conditions in geospace are linked strongly to terrestrial weather and climate below, contradicting previous textbook knowledge that the space weather of Earth's near space environment is driven by energy injections at high latitudes connected with magnetosphere-ionosphere coupling and solar radiation variation at extreme ultraviolet wavelengths alone. The primary mechanism through which energy and momentum are transferred from the lower atmosphere is through the generation, propagation, and dissipation of atmospheric waves over a wide range of spatial and temporal scales including electrodynamic coupling through dynamo processes and plasma bubble seeding. The main task of Task Group 4 of SCOSTEP's CAWSES-II program, 2009 to 2013, was to study the geospace response to waves generated by meteorological events, their interaction with the mean flow, and their impact on the ionosphere and their relation to competing thermospheric disturbances generated by energy inputs from above, such as auroral processes at high latitudes. This paper reviews the progress made during the CAWSES-II time period, emphasizing the role of gravity waves, planetary waves and tides, and their ionospheric impacts. Specific campaign contributions from Task Group 4 are highlighted, and future research directions are discussed.

  16. ZZ DLC-2D/100G, 100 Neutron-Group Cross-Section Library by SUPERTOG Calculation for ANISN, DOT

    International Nuclear Information System (INIS)

    1 - Nature of physical problem solved: Format: ANISN, DOT or DTF-4; Number of groups: 100; Nuclides: H, D, He, He-3, Li-6, Li-7, Be-9, B-10, B-11, C-12, N-14, O-16, Na-23, Mg, Al-27, Si, Cl, K, Ca, V, Cr, Mn-55, Fe, Co-59, Ni, Cu, Cu-63, Cu-65, Nb, Mo, Ag-107, Xe-135, Cs-133, Sm-149, Eu-151, Eu-153, Gd, Dy-164, Lu-175, Lu-176, Ta-181, Ta-182, W-182, W-183, W-184, W-186, Re-185, Re-187, Au-197, Pb, Th-232, Pa-233, U-234, U-235, U-238, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, Am-241, Am-243, and Cm-244. Origin: The nuclides in DLC-2 are those which have been released as category I ENDF/B by the National Neutron Cross Section Center, Brookhaven National Laboratory. Weighting spectrum: The explicit assumption was made that the flux has the shape of a fission spectrum joined at 0.0674 MeV by a 1/E tail. Neutron transport calculations can be performed with DLC-2 data. Since the data are intended for use in multigroup discrete-ordinates or Monte Carlo transport codes which treat anisotropic scattering, possible cross section angular expansion is limited only by the options available in the particular code used. Specifically, the retrieval program manipulates DLC-2 such that it conforms to input requirements of the ANISN, DOT, or DTF-4 codes, or any computer code using data in the ANISN or DTF-4 format. The nuclides in DLC-2 are those which have been released as category I ENDF/B by the National Neutron Cross Section Center, Brookhaven National Laboratory. The library contains data for H, D, He, 3-He, 6-Li, 7-Li, 9-Be, 10-B, 11-B, 12-C, 14-N, 16-O, 23-Na, Mg, 27-Al, Si, Cl, K, Ca, V, Cr, 55-Mn, Fe, 59-Co, Ni, Cu, 63-Cu, 65-Cu, Nb, Mo, 107-Ag, 135-Xe, 133-Cs, 149-Sm, 151-Eu, 153-Eu, Gd, 164-Dy, 175-Lu, 176-Lu, 181-Ta, 182-Ta, 182-W, 183-W, 184-W, 186-W, 185-Re, 187-Re, 197-Au, Pb, 232-Th, 233-Pa, 234-U, 235-U, 238-U, 238-Pu, 239-Pu, 240-Pu, 241-Pu, 242-Pu, 241-Am, 243-Am, and 244-Cm. 2 - Method of solution: DLC-2 was generated by SUPERTOG from nuclear data in either point

  17. Spin orbit coupling for molecular ab initio density matrix renormalization group calculations: Application to g-tensors

    Energy Technology Data Exchange (ETDEWEB)

    Roemelt, Michael, E-mail: michael.roemelt@theochem.rub.de [Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, D-44780 Bochum, Germany and Max-Planck Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr (Germany)

    2015-07-28

    Spin Orbit Coupling (SOC) is introduced to molecular ab initio density matrix renormalization group (DMRG) calculations. In the presented scheme, one first approximates the electronic ground state and a number of excited states of the Born-Oppenheimer (BO) Hamiltonian with the aid of the DMRG algorithm. Owing to the spin-adaptation of the algorithm, the total spin S is a good quantum number for these states. After the non-relativistic DMRG calculation is finished, all magnetic sublevels of the calculated states are constructed explicitly, and the SOC operator is expanded in the resulting basis. To this end, spin orbit coupled energies and wavefunctions are obtained as eigenvalues and eigenfunctions of the full Hamiltonian matrix which is composed of the SOC operator matrix and the BO Hamiltonian matrix. This treatment corresponds to a quasi-degenerate perturbation theory approach and can be regarded as the molecular equivalent to atomic Russell-Saunders coupling. For the evaluation of SOC matrix elements, the full Breit-Pauli SOC Hamiltonian is approximated by the widely used spin-orbit mean field operator. This operator allows for an efficient use of the second quantized triplet replacement operators that are readily generated during the non-relativistic DMRG algorithm, together with the Wigner-Eckart theorem. With a set of spin-orbit coupled wavefunctions at hand, the molecular g-tensors are calculated following the scheme proposed by Gerloch and McMeeking. It interprets the effective molecular g-values as the slope of the energy difference between the lowest Kramers pair with respect to the strength of the applied magnetic field. Test calculations on a chemically relevant Mo complex demonstrate the capabilities of the presented method.

  18. Spin orbit coupling for molecular ab initio density matrix renormalization group calculations: Application to g-tensors

    International Nuclear Information System (INIS)

    Spin Orbit Coupling (SOC) is introduced to molecular ab initio density matrix renormalization group (DMRG) calculations. In the presented scheme, one first approximates the electronic ground state and a number of excited states of the Born-Oppenheimer (BO) Hamiltonian with the aid of the DMRG algorithm. Owing to the spin-adaptation of the algorithm, the total spin S is a good quantum number for these states. After the non-relativistic DMRG calculation is finished, all magnetic sublevels of the calculated states are constructed explicitly, and the SOC operator is expanded in the resulting basis. To this end, spin orbit coupled energies and wavefunctions are obtained as eigenvalues and eigenfunctions of the full Hamiltonian matrix which is composed of the SOC operator matrix and the BO Hamiltonian matrix. This treatment corresponds to a quasi-degenerate perturbation theory approach and can be regarded as the molecular equivalent to atomic Russell-Saunders coupling. For the evaluation of SOC matrix elements, the full Breit-Pauli SOC Hamiltonian is approximated by the widely used spin-orbit mean field operator. This operator allows for an efficient use of the second quantized triplet replacement operators that are readily generated during the non-relativistic DMRG algorithm, together with the Wigner-Eckart theorem. With a set of spin-orbit coupled wavefunctions at hand, the molecular g-tensors are calculated following the scheme proposed by Gerloch and McMeeking. It interprets the effective molecular g-values as the slope of the energy difference between the lowest Kramers pair with respect to the strength of the applied magnetic field. Test calculations on a chemically relevant Mo complex demonstrate the capabilities of the presented method

  19. Spin orbit coupling for molecular ab initio density matrix renormalization group calculations: Application to g-tensors

    Science.gov (United States)

    Roemelt, Michael

    2015-07-01

    Spin Orbit Coupling (SOC) is introduced to molecular ab initio density matrix renormalization group (DMRG) calculations. In the presented scheme, one first approximates the electronic ground state and a number of excited states of the Born-Oppenheimer (BO) Hamiltonian with the aid of the DMRG algorithm. Owing to the spin-adaptation of the algorithm, the total spin S is a good quantum number for these states. After the non-relativistic DMRG calculation is finished, all magnetic sublevels of the calculated states are constructed explicitly, and the SOC operator is expanded in the resulting basis. To this end, spin orbit coupled energies and wavefunctions are obtained as eigenvalues and eigenfunctions of the full Hamiltonian matrix which is composed of the SOC operator matrix and the BO Hamiltonian matrix. This treatment corresponds to a quasi-degenerate perturbation theory approach and can be regarded as the molecular equivalent to atomic Russell-Saunders coupling. For the evaluation of SOC matrix elements, the full Breit-Pauli SOC Hamiltonian is approximated by the widely used spin-orbit mean field operator. This operator allows for an efficient use of the second quantized triplet replacement operators that are readily generated during the non-relativistic DMRG algorithm, together with the Wigner-Eckart theorem. With a set of spin-orbit coupled wavefunctions at hand, the molecular g-tensors are calculated following the scheme proposed by Gerloch and McMeeking. It interprets the effective molecular g-values as the slope of the energy difference between the lowest Kramers pair with respect to the strength of the applied magnetic field. Test calculations on a chemically relevant Mo complex demonstrate the capabilities of the presented method.

  20. Group cross sections calculations

    International Nuclear Information System (INIS)

    Just a few methods have been developped to compute multigroup cross-sections from ENDF data. We have developped an original method in order to get accuracy and to reduce the number of discretization points in the same time; this is why we have tried to use polynomial integration. In this paper, we describe this method: in the first part, we recall some physical hypothesis generally used to solve the linear Boltzmann equation: that is the frame in which the numerical method has been developped. Polynomial methods are really powerfull only if discretization points are suitably chosen. This choice is explained in the next part of this paper. In conclusion, some numerical results are given to illustrate our method

  1. Quantification of resonance interference effect for multi-group effective cross-section in lattice physics calculation

    International Nuclear Information System (INIS)

    This paper presents the quantification of resonance interference effect for multi-group effective cross-section in lattice physics calculation. In the resonance self-shielding method based on the equivalence theory, the resonance interference effect among multiple nuclides cannot be treated directly to the multi-group effective cross-section. The continuous energy or the ultra-fine-group treatment can directly consider the effect, but the application to the fuel assembly geometry is not realistic with practical computation time. In the present study, the resonance interference effect to the multi-group effective cross-section is simply quantified by the resonance interference factor (RIF) in order to confirm the benefit for considering the effect. The RIF is generated for the typical pin-cell geometry of water moderated system. The multi-group effective cross-sections with and without RIFs are compared with the continuous energy Monte-Carlo result. As a result, the significant impact for considering the resonance interference effect is confirmed to the limited nuclide, reaction type and energy group. Fortunately, these have small effect on k-infinity because the resonance interference effect is mainly induced by the wide resonances of 238U to the other minor nuclides (e.g., 235U, 239Pu) in the limited resonance energy ranges. The results also show that the effect is small to the absorption cross-section of 238U, which is the dominant resonance nuclide in the fuel. The quantification results in the present study indicate a useful material to investigate the more advanced resonance treatment for the next generation lattice physics code. (author)

  2. METHODOLOGY AND CALCULATIONS FOR THE ASSIGNMENT OF WASTE GROUPS FOR THE LARGE UNDERGROUND WASTE STORAGE TANKS AT THE HANFORD SITE

    International Nuclear Information System (INIS)

    This document categorizes each of the large waste storage tanks into one of several categories based on each tank's waste characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement event. Revision 7 is the annual update of the calculations of the flammable gas Waste Groups for DSTs and SSTs. The Hanford Site contains 177 large underground radioactive waste storage tanks (28 double-shell tanks and 149 single-shell tanks). These tanks are categorized into one of three waste groups (A, B, and C) based on their waste and tank characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement gas release event. Assignments of waste groups to the 177 double-shell tanks and single-shell tanks, as reported in this document, are based on a Monte Carlo analysis of three criteria. The first criterion is the headspace flammable gas concentration following release of retained gas. This criterion determines whether the tank contains sufficient retained gas such that the well-mixed headspace flammable gas concentration would reach 100% of the lower flammability limit if the entire tank's retained gas were released. If the volume of retained gas is not sufficient to reach 100% of the lower flammability limit, then flammable conditions cannot be reached and the tank is classified as a waste group C tank independent of the method the gas is released. The second criterion is the energy ratio and considers whether there is sufficient supernatant on top of the saturated solids such that gas-bearing solids have the potential energy required to break up the material and release gas. Tanks that are not waste group C tanks and that have an energy ratio < 3.0 do not have sufficient potential energy to break up

  3. METHODOLOGY AND CALCULATIONS FOR THE ASSIGNMENT OF WASTE GROUPS FOR THE LARGE UNDERGROUND WASTE STORAGE TANKS AT THE HANFORD SITE

    Energy Technology Data Exchange (ETDEWEB)

    FOWLER KD

    2007-12-27

    This document categorizes each of the large waste storage tanks into one of several categories based on each tank's waste characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement event. Revision 7 is the annual update of the calculations of the flammable gas Waste Groups for DSTs and SSTs. The Hanford Site contains 177 large underground radioactive waste storage tanks (28 double-shell tanks and 149 single-shell tanks). These tanks are categorized into one of three waste groups (A, B, and C) based on their waste and tank characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement gas release event. Assignments of waste groups to the 177 double-shell tanks and single-shell tanks, as reported in this document, are based on a Monte Carlo analysis of three criteria. The first criterion is the headspace flammable gas concentration following release of retained gas. This criterion determines whether the tank contains sufficient retained gas such that the well-mixed headspace flammable gas concentration would reach 100% of the lower flammability limit if the entire tank's retained gas were released. If the volume of retained gas is not sufficient to reach 100% of the lower flammability limit, then flammable conditions cannot be reached and the tank is classified as a waste group C tank independent of the method the gas is released. The second criterion is the energy ratio and considers whether there is sufficient supernatant on top of the saturated solids such that gas-bearing solids have the potential energy required to break up the material and release gas. Tanks that are not waste group C tanks and that have an energy ratio < 3.0 do not have sufficient

  4. METHODOLOGY AND CALCULATIONS FOR THE ASSIGNMENT OF WASTE GROUPS FOR THE LARGE UNDERGROUND WASTE STORAGE TANKS AT THE HANFORD SITE

    Energy Technology Data Exchange (ETDEWEB)

    WEBER RA

    2009-01-16

    a waste group B (or A) tank identifies the potential for an induced flammable gas release hazard, the hazard only exists for specific operations that can release the retained gas in the tank at a rate and quantity that results in reaching 100% of the lower flammability limit in the tank headspace. The identification and evaluation of tank farm operations that could cause an induced flammable gas release hazard in a waste group B (or A) tank are included in other documents. The third criterion is the buoyancy ratio. This criterion addresses tanks that are not waste group C double-shell tanks and have an energy ratio {ge} 3.0. For these double-shell tanks, the buoyancy ratio considers whether the saturated solids can retain sufficient gas to exceed neutral buoyancy relative to the supernatant layer and therefore have buoyant displacement gas release events. If the buoyancy ratio is {ge} 1.0, that double-shell tank is assigned to waste group A. These tanks are considered to have a potential spontaneous buoyant displacement flammable gas release hazard in addition to a potential induced flammable gas release hazard. This document categorizes each of the large waste storage tanks into one of several categories based on each tank's waste characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement event. Revision 8 is the annual update of the calculations of the flammable gas Waste Groups for DSTs and SSTs.

  5. METHODOLOGY AND CALCULATIONS FOR THE ASSIGNMENT OF WASTE GROUPS FOR THE LARGE UNDERGROUND WASTE STORAGE TANKS AT THE HANFORD SITE

    International Nuclear Information System (INIS)

    group B (or A) tank identifies the potential for an induced flammable gas release hazard, the hazard only exists for specific operations that can release the retained gas in the tank at a rate and quantity that results in reaching 100% of the lower flammability limit in the tank headspace. The identification and evaluation of tank farm operations that could cause an induced flammable gas release hazard in a waste group B (or A) tank are included in other documents. The third criterion is the buoyancy ratio. This criterion addresses tanks that are not waste group C double-shell tanks and have an energy ratio (ge) 3.0. For these double-shell tanks, the buoyancy ratio considers whether the saturated solids can retain sufficient gas to exceed neutral buoyancy relative to the supernatant layer and therefore have buoyant displacement gas release events. If the buoyancy ratio is (ge) 1.0, that double-shell tank is assigned to waste group A. These tanks are considered to have a potential spontaneous buoyant displacement flammable gas release hazard in addition to a potential induced flammable gas release hazard. This document categorizes each of the large waste storage tanks into one of several categories based on each tank's waste characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement event. Revision 8 is the annual update of the calculations of the flammable gas Waste Groups for DSTs and SSTs

  6. Evidence-Based Interventions in School Psychology: An Illustration of Task Force Coding Criteria Using Group-Based Research Design.

    Science.gov (United States)

    Lewis-Snyder, Gretchen; Stoiber, Karen Callan; Kratochwill, Thomas R.

    2002-01-01

    Applies the criteria in the "Procedural and Coding Manual for Review of Evidence-Based Interventions," to a group-based design intervention study. In general, the application of the criteria suggested promising evidence in support of the program. Considerations for interpreting the results of the coding process are discussed with particular…

  7. Report on the joint meeting of the Division of Development and Technology Plasma/Wall Interaction and High Heat Flux Materials and Components Task Groups

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, K.L. (ed.)

    1985-10-01

    This report of the Joint Meeting of the Division of Development and Technology Plasma/Wall Interaction and High Heat Flux Materials and Components Task Groups contains contributing papers in the following areas: Plasma/Materials Interaction Program and Technical Assessment, High Heat Flux Materials and Components Program and Technical Assessment, Pumped Limiters, Ignition Devices, Program Planning Activities, Compact High Power Density Reactor Requirements, Steady State Tokamaks, and Tritium Plasma Experiments. All these areas involve the consideration of High Heat Flux on Materials and the Interaction of the Plasma with the First Wall. Many of the Test Facilities are described as well. (LSP)

  8. Division of Development and Technology Plasma/Materials Interaction and High Heat Flux Materials and Components Task Groups: Report on the joint meeting, July 9, 1986

    International Nuclear Information System (INIS)

    This paper contains a collection of viewgraphs from a joint meeting of the Division of Development and Technology Plasma/Materials Interaction and High Heat Flux Materials and Components Task Groups. A list of contributing topics is: PPPL update, ATF update, Los Alamos RFP program update, status of DIII-D, PMI graphite studies at ORNL, PMI studies for low atomic number materials, high heat flux materials issues, high heat flux testing program, particle confinement in tokamaks, helium self pumping, self-regenerating coatings technical planning activity and international collaboration update

  9. Report on the joint meeting of the Division of Development and Technology Plasma/Wall Interaction and High Heat Flux Materials and Components Task Groups

    International Nuclear Information System (INIS)

    This report of the Joint Meeting of the Division of Development and Technology Plasma/Wall Interaction and High Heat Flux Materials and Components Task Groups contains contributing papers in the following areas: Plasma/Materials Interaction Program and Technical Assessment, High Heat Flux Materials and Components Program and Technical Assessment, Pumped Limiters, Ignition Devices, Program Planning Activities, Compact High Power Density Reactor Requirements, Steady State Tokamaks, and Tritium Plasma Experiments. All these areas involve the consideration of High Heat Flux on Materials and the Interaction of the Plasma with the First Wall. Many of the Test Facilities are described as well

  10. Development of an improved method for calculating the effective delayed neutron fraction of a core using a structure with only a few collapsed energy groups

    International Nuclear Information System (INIS)

    In this study, an improved method for calculating the effective delayed neutron fraction of a core with a few collapsed energy groups has been developed. To accurately calculate the effective delayed neutron fraction of a core using the conventional method, a structure with several energy groups is needed for the fast energy region in order to reflect the difference in the fission spectra for prompt fission neutrons and delayed neutrons. On the other hand, a structure with only a few energy groups is needed for the criticality evaluation. Thus, the calculation cost increases for the effective delayed neutron fraction calculations owing to the need for a large number of energy groups. To solve this problem, in the present study, the error mechanism for the effective delayed neutron fraction calculation using a structure with only a few energy groups was studied, and it was found that the error results from the collapse of the fission spectra after the cell calculations without adjoint flux weighting. In addition, an improved method for the collapse fission spectra with an adjoint flux obtained by one-point calculation was developed. Using the proposed method, the effective delayed neutron fraction can be estimated with sufficient accuracy using a structure consisting of only a few collapsed energy groups. This result will contribute to reducing the calculation cost and/or improving the accuracy of effective delayed neutron fraction calculations. (author)

  11. The IUGS Task Group on Global Geoscience Professionalism - promoting professional skills professionalism in the teaching, research and application of geoscience for the protection and education of the public

    Science.gov (United States)

    Allington, Ruth; Fernandez-Fuentes, Isabel

    2013-04-01

    A new IUGS Task Group entitled the Task Group on Global Geoscience Professionalism was formed in 2012 and launched at a symposium at the 341GC in Brisbane on strengthening communication between fundamental and applied geosciences and between geoscientists and public. The Task Group aims to ensure that the international geoscience community is engaged in a transformation of its profession so as to embed the need for a professional skills base alongside technical and scientific skills and expertise, within a sound ethical framework in all arenas of geoscience practice. This needs to be established during training and education and reinforced as CPD throughout a career in geoscience as part of ensuring public safety and effective communication of geoscience concepts to the public. The specific objective of the Task Group on Global Geoscience Professionalism that is relevant to this poster session is: • To facilitate a more 'joined up' geoscience community fostering better appreciation by academics and teachers of the professional skills that geoscientists need in the workplace, and facilitate better communication between academic and applied communities leading to more effective application of research findings and technology to applied practitioners and development of research programmes that truly address urgent issues. Other Task Group objectives are: • To provide a specific international forum for discussion of matters of common concern and interest among geoscientists and geoscientific organizations involved in professional affairs, at the local, national and international level; • To act as a resource to IUGS on professional affairs in the geosciences as they may influence and impact "Earth Science for the Global Community" in general - both now and in the future; • To offer and provide leadership and knowledge transfer services to countries and geoscientist communities around the world seeking to introduce systems of professional governance and self

  12. The calculation of pressure vessels

    International Nuclear Information System (INIS)

    The calculation guidelines of the Arbeitsgemeinschaft Druckbehaelter (task group for pressure vessels) have been revised with the following objective: conversion to international standards (SI), adaption to the latest state of guidelines for production and testing, revision of the contents of individual regulations. Another target of the cooperating interest groups of producers, operators, and supervisory bodies was a harmonization of the approaches for calculation with other German guidelines, in particular the Technische Regeln fuer Dampfkessel (technical regulations for steam boilers). (orig./RW)

  13. Faddeev calculation of 3 alpha and alpha alpha Lambda systems using alpha alpha resonating-group method kernel

    CERN Document Server

    Fujiwara, Y; Kohno, M; Suzuki, Y; Baye, D; Sparenberg, J M

    2004-01-01

    We carry out Faddeev calculations of three-alpha (3 alpha) and two-alpha plus Lambda (alpha alpha Lambda) systems, using two-cluster resonating-group method kernels. The input includes an effective two-nucleon force for the alpha alpha resonating-group method and a new effective Lambda N force for the Lambda alpha interaction. The latter force is a simple two-range Gaussian potential for each spin-singlet and triplet state, generated from the phase-shift behavior of the quark-model hyperon-nucleon interaction, fss2, by using an inversion method based on supersymmetric quantum mechanics. Owing to the exact treatment of the Pauli-forbidden states between the clusters, the present three-cluster Faddeev formalism can describe the mutually related, alpha alpha, 3 alpha and alpha alpha Lambda systems, in terms of a unique set of the baryon-baryon interactions. For the three-range Minnesota force which describes the alpha alpha phase shifts quite accurately, the ground-state and excitation energies of 9Be Lambda are...

  14. METHODOLOGY & CALCULATIONS FOR THE ASSIGNMENT OF WASTE GROUPS FOR THE LARGE UNDERGROUND WASTE STORAGE TANKS AT THE HANFORD SITE

    Energy Technology Data Exchange (ETDEWEB)

    BARKER, S.A.

    2006-07-27

    Waste stored within tank farm double-shell tanks (DST) and single-shell tanks (SST) generates flammable gas (principally hydrogen) to varying degrees depending on the type, amount, geometry, and condition of the waste. The waste generates hydrogen through the radiolysis of water and organic compounds, thermolytic decomposition of organic compounds, and corrosion of a tank's carbon steel walls. Radiolysis and thermolytic decomposition also generates ammonia. Nonflammable gases, which act as dilutents (such as nitrous oxide), are also produced. Additional flammable gases (e.g., methane) are generated by chemical reactions between various degradation products of organic chemicals present in the tanks. Volatile and semi-volatile organic chemicals in tanks also produce organic vapors. The generated gases in tank waste are either released continuously to the tank headspace or are retained in the waste matrix. Retained gas may be released in a spontaneous or induced gas release event (GRE) that can significantly increase the flammable gas concentration in the tank headspace as described in RPP-7771. The document categorizes each of the large waste storage tanks into one of several categories based on each tank's waste characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement event. Revision 5 is the annual update of the methodology and calculations of the flammable gas Waste Groups for DSTs and SSTs.

  15. Interagency task force on the health effects of ionizing radiation: report of the work group on care and benefits

    International Nuclear Information System (INIS)

    The report examines existing systems for providing care and benefits to persons who may have been injured by radiation exposure and recommends additional guidelines for handling radiation-related claims. The benefits systems examined are Veterans' benefits, Federal Employees Compensation Act, Longshoremen's and Harbor Workers' Compensation Act, State Workers' Compensation programs, Government and private 'back-up' program, Social Security Disability Insurance (Medicare), Supplemental Security Income (Medicaid), private health insurance, government hospitals, and remedies available under the judicial system. The report recommends that the Federal Government develop guidelines to determine the likelihood of a causal relationship between a person's illness and his exposure to radiation; that Federal compensation programs and State programs develop criteria for deciding radiation exposure claims, based on those guidelines; that a national registry of radiation workers be established to maintain individual radiation exposure records; and that the Federal Government annually compile compensation claims based on radiation exposure. Appendixes list those groups of people most likely to be exposed to radiation, and the benefits available under the various compensation programs listed above

  16. Second mission of North-Cotentin radio-ecology group. The uncertainty calculation; Deuxieme mission du Groupe Radio-ecologie Nord-Cotentin. Le calcul d'incertitude

    Energy Technology Data Exchange (ETDEWEB)

    Boilley, D

    2003-03-15

    The present study treats only the collective risk of ex-utero leukaemia associated with the routine releases of the nuclear industrial installations of the North Cotentin (0.0009 cases over the considered period) the uncertainty on the contribution to the collective risk of the incidents and the accidents of the nuclear installations (notably the drilling of the pipe of release in sea arisen in 1979-1980 and the fire of the waste silo on January 6. 1981, for the reprocessing plant of La Hague has not been considered. Only 45% of the risk are taken into account by the study. Every calculated value remains very inferior to the number of leukemia cases observed (4 cases observed for two expected cases) and to the risk of radioinduced leukemia any merged exposure sources, that is to say 0.84 cases. It appears thus not very probable that the nuclear installations of the North - Cotentin can explain the tendency to the excess of observed leukaemia. The limits of the study become attached for the main part to the environmental impact of the routine releases and to the lifestyles and refuses to tackle anything concerning the health radiation effects. The work made by the group does not allow to end in the harmlessness of radioactive waste, nevertheless, it gives an idea of the scale of the impacts onto the environment of the routine releases. (N.C.)

  17. nα resonating-group calculation with a quark-model G-matrix NN interaction

    International Nuclear Information System (INIS)

    We calculate nα phase-shifts and scattering observables in the resonating-group method, using the nuclear-matter G-matrix of an SU6 quark-model NN interaction. The G-matrix is generated in the recent energy-independent procedure of the quark-model NN interaction with the continuous prescription for intermediate spectra, by assuming an appropriate Fermi momentum kF=1.2 fm-1. The nα RGM interaction kernels are evaluated with explicit treatments of the nonlocality and momentum dependence of partial-wave G-matrix components. The momentum dependence of the G-matrix components is different for each of the nucleon-exchange and interaction types. Without introducing any artificial parameters except for kF, the central and spin-orbit components of the nα Born kernel are found to have reasonable strengths under the assumption of a rigid translationally invariant shell-model wave function of the α-cluster. The characteristic behaviors of three different exchange terms, corresponding to knockout, heavy-particle pickup and nucleon-rearrangement processes, are essentially the same between the case of previous local effective NN forces and the case of nonlocal G-matrix NN interactions. (author)

  18. Crystal structure, dft calculations and herbicidal activity of a new 1,2,3-triazole derivative containing sulfonyl group

    International Nuclear Information System (INIS)

    A new 1,2,4-triazole with sulfonyl moiety was synthesized and confirmed by 1H-NMR, MS and elemental analyses. The crystal structure of the title compound 5 (C/sub 13/H/sub 14/FN/sub 3/SO/sub 2/, Mr = 295.33) was determined by single-crystal X-ray diffraction. The crystal structure of this compound is triclinic, space group P-1 with a = 7.3111(15), b = 8.8637(18), c = 11.514(2) A, alpha = 69.09(3), beta = 80.17(3), gamma = 72.08(3), V = 661.6(2) A3, Z = 2, F(000) = 308, Dc = 1.482 g/cm3, micro = 0.262 mm-1, the final R1 = 0.0292 and wR2 = 0.0848 for 1960 observed reflections with I > 2(I). A total of 4393 reflections were collected, of which 2305 were independent (Rint = 0.0223). The herbicidal activity of the triazole was moderate against rape root and barn-yard grass. Theoretical calculations of the title compound were carried out using B3LYP with the 6-31++G (d,p) basis set employing full geometry optimization and frontier orbital energies. The optimized geometric bond lengths and bond angles obtained by using DFT(B3LYP) showed the good agreement with the experimental data. (author)

  19. Calculation of the reactivity worth for TRIGA core fuel elements by means of the two-dimensional, two-group perturbation theory

    International Nuclear Information System (INIS)

    A two-dimensional, two-group perturbation theory calculation method has been proposed for the rapid and accurate calculation of the reactivity worth for TRIGA core fuel elements. The method requires shorter computation times and provides almost the same level of accuracy as a conventional direct eigenvalue calculation method using the CITATION code. Values for changes in macroscopic cross-sections and diffusion coefficients are obtained from cell calculation. The reactivity worth for each individual fuel element is calculated on the basis of the above-mentioned changes, by means of the two-group, first order perturbation method using normal and adjoint neutron fluxes calculated beforehand for a normal core. The method was applied to a 250 kW TRIGA Mark-II reactor. The results of the calculations are in agreement with the experimental values for fuel elements in the locations C3, D8, E7 and F4. The reactivity worth for the TRIGA core fuel element placed in location B2 calculated by means of this method is approximately 5% greater than that calculated by means of the CITATION code which is based on a conventional direct eigenvalue calculation method. (orig.)

  20. Interference between postural control and spatial vs. non-spatial auditory reaction time tasks in older adults.

    Science.gov (United States)

    Fuhrman, Susan I; Redfern, Mark S; Jennings, J Richard; Furman, Joseph M

    2015-01-01

    This study investigated whether spatial aspects of an information processing task influence dual-task interference. Two groups (Older/Young) of healthy adults participated in dual-task experiments. Two auditory information processing tasks included a frequency discrimination choice reaction time task (non-spatial task) and a lateralization choice reaction time task (spatial task). Postural tasks included combinations of standing with eyes open or eyes closed on either a fixed floor or a sway-referenced floor. Reaction times and postural sway via center of pressure were recorded. Baseline measures of reaction time and sway were subtracted from the corresponding dual-task results to calculate reaction time task costs and postural task costs. Reaction time task cost increased with eye closure (p = 0.01), sway-referenced flooring (p visual-spatial interference may occur in older subjects when vision is used to maintain posture. PMID:26410669

  1. ACCEPTABILITY EVALUATION FOR USING ICRP TISSUE WEIGHTING FACTORS TO CALCULATE EFFECTIVE DOSE VALUE FOR SEPARATE GENDER-AGE GROUPS OF RUSSIAN FEDERATION

    Directory of Open Access Journals (Sweden)

    L. V. Repin

    2013-01-01

    Full Text Available An article describes radiation risk factors for several gender-age population groups according to Russian statistical and medical-demographic data, evaluates the lethality rate for separate nosologic forms of malignant neoplasms based on Russian cancer registries according to the method of the International Agency for Cancer Research. Relative damage factors are calculated for the gender-age groups under consideration. The tissue weighting factors recommended by ICRP to calculate effective doses are compared with relative damage factors calculated by ICRP for the nominal population and with similar factors calculated in this work for separate population cohorts in theRussian Federation. The significance of differences and the feasibility of using tissue weighting factors adapted for the Russian population in assessing population risks in cohorts of different gender-age compositions have been assessed.

  2. The shielding design calculation of HWZPR using one-dimension transport method and ZPR-22 group cross section library

    International Nuclear Information System (INIS)

    The one-dimension SN method code ANISN and specific cross section library ZPR-22 have been used to perform the design calculation of dose rate distribution along the radial and axial direction of HWZPR shielding. Through multi-case calculations and optimization analysis works, a double slab cover structure is adopted. It is combined with the feasibility of structure and the possibility of boron concentration to be merged in paraffin for design case. The calculation results of axial direction: the core lattice distance is 18 cm; core radius R = 113 cm; reflector saving of radial direction is 25 cm; transfer leakage Dy = Dz = 244.6 cm. The calculation results of radial direction; the core lattice distance is 18 cm; critical water level 138.5 cm; reflector saving of axial direction is 20 cm; transfer leakage correction parameter Dy = 160 cm

  3. The use of WIMSD4 and LWRWIMS, READWT and FILSIX, to generate two-group data for reactor calculations

    International Nuclear Information System (INIS)

    This report brings together information describing the transfer of data between WIMS lattice calculations and JOSHUA reactor calculations. It describes the interface in considerable detail and then provides the information that a user of WIMSD4 or LWRWIMS would need to generate an interface. Two auxiliary codes, READWT and FILSIX, are used to process the interface and maintain a library of reactor code data. Input and use of these codes are specified. (author)

  4. Theoretical Calculations of Thermal Broadenings and Transition Probabilities of R, R' and B Line-Groups for Ruby

    Institute of Scientific and Technical Information of China (English)

    MA Dong-Ping; LIU Yan-Yun; CHEN Ju-Rong

    2001-01-01

    On the basis of the unified calculation of the thermal shifts of R1 line, R2 line and ground-state-splitting transition probabilities of direct and Raman processes have theoretically been calculated. The thermal broadenings of R,The theoretically predicted transition probabilities are in good agreement with the experimental ones.PACS numbers: 71.70.Ch, 78.20.Nv, 63.20.Mt, 63.20.Kr

  5. Addition of the sulfhydryl group (-SH) to the PPR78 model (predictive 1978, Peng-Robinson EOS with temperature dependent kij calculated through a group contribution method)

    International Nuclear Information System (INIS)

    In 2004, we started to develop a group contribution method aimed at estimating the temperature dependent binary interaction parameters (kij(T)) for the widely used Peng-Robinson equation of state (EOS). This model was called PPR78 (predictive 1978, Peng-Robinson EOS) because it relies on the Peng-Robinson EOS as published by Peng and Robinson in 1978 and because the addition of a group contribution method to estimate the kij makes it predictive. In our previous papers, 14 groups were defined: CH3, CH2, CH, C, CH4 (methane), C2H6 (ethane), CHaro, Caro, Cfusedaromaticrings, CH2,cyclic, CHcyclic=Ccyclic, CO2, N2, and H2S. It was thus possible to estimate the kij for any mixture containing alkanes, aromatics, naphthenes, CO2, N2, and H2S whatever the temperature. In this study, the PPR78 model is extended to systems containing thiols (also called mercaptans). To do so, the sulfhydryl group: -SH was added

  6. Radiation Protection in Brachytherapy. Report of the SEFM Task Group on Brachytherapy; Proteccion radiologica en Braquiterapia. Informe del grupo de trabajo de Braquiterapia de la SEFM

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Calatayud, J.; Corredoira Silva, E.; Crispin Contreras, V.; Eudaldo Puell, T.; Frutos Baraja, J. de; Pino Sorroche, F.; Pujades Claumarchirant, M. C.; Richart Sancho, J.

    2015-07-01

    This document presents the report of the Brachytherapy Task Group of the Spanish Society of Medical Physics. It is dedicated to the radiation protection aspects involved in brachytherapy. The aim of this work is to include the more relevant aspects related to radiation protection issues that appear in clinical practice, and for the current equipment in Spain. Basically this report focuses on the typical contents associated with high dose rate brachytherapy with {sup 1}92Ir and {sup 6}0Co sources, and permanent seed implants with {sup 1}25I, {sup 1}03Pd and {sup 1}31Cs, which are the most current and widespread modalities. Ophthalmic brachytherapy (COMS with {sup 1}25I, {sup 1}06Ru, {sup 9}0Sr) is also included due to its availability in a significant number of spanish hospitals. The purpose of this report is to assist to the medical physicist community in establishing a radiation protection program for brachytherapy procedures, trying to solve some ambiguities in the application of legal requirements and recommendations in clinical practice. (Author)

  7. ZZ VITAMIN-C/B, 171 Neutron-Group, 36 Gamma-Group Coupled Cross-Section for Fusion, LMFBR Calculations

    International Nuclear Information System (INIS)

    1 - Description of problem or function: Format: AMPX, CCCC format. Number of groups: 171 neutron, 36 gamma-ray group cross section; Nuclides: H, He, Li, Be, B, C, N, O, F, Na, Mg, Al, Si, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ag, Cd, Sn, Eu, Ta, W, Pb, Th, U, Pu, Am Origin: ENDF/B; Weighting spectrum: - Maxwellian thermal spectrum (300 K) up to 0.125 eV; - 1/E slowing down spectrum to 820.8 KeV; - fission spectrum to 10.0 MeV; - 1/E spectrum to 12.57 MeV; - velocity exponential fusion peak to 15.57 MeV - 1/E spectrum to 17.333 MeV. Gamma cross sections are flat-weighted. ZZ-VITAMIN-C/B is a data library containing 171 neutron, 36 gamma-ray group cross section data for fusion and LMFBR neutronics. The weighting function for the neutron data consists of six regions: a Maxwellian thermal spectrum (300 K) up to 0.125 eV, a 1/E slowing down spectrum to 820.8 KeV, a fission spectrum to 10.0 MeV, a 1/E spectrum to 12.57 MeV, a velocity exponential fusion peak to 15.57 MeV, and a 1/E spectrum to 17.333 MeV. The gamma cross sections are flat-weighted. The Legendre expansion order is P3. Data are available in the form of a 171 neutron group AMPX interface, a 171 neutron 36 gamma- ray production AMPX interface, and a 36 group gamma-ray interaction AMPX interface. The neutron data are also available in CCCC format as ISOTXS neutron cross section and BRKOXS self-shielding factor standard interface files. Data exists for 60 nuclides used in proposed fusion or fission/ fusion hybrid systems. 2 - Method of solution: The data has been computed from ENDF/B files using the program MINX. The Bondarenko method is employed to create group dependent resonance self-shielding factors to account for temperature and dilution effects. The fractional error tolerances were set to 0.5 percent, and 0.1 percent for integration

  8. ZZ BP-3, 104-Group Neutron Cross-Section Library for Transport Calculation. ZZ BP-6, 104 Group Neutron and Gamma-Ray Multigroup Cross-Section Library for Transport Calculation

    International Nuclear Information System (INIS)

    1 - Description of program or function: specified on ORNL-RSIC-25, shielding benchmark problems. - BP-3 (Neutron cross sections): Format: ANISN, DOT and MORSE; Number of groups: 22 neutron / 18 gamma-ray; Nuclides: air; Origin: ENDF/B; Weighting spectrum: 1/E; - BP-6 (neutron and gamma-ray cross sections): Format: ANISN, DOT and MORSE; Number of groups: 22 neutron / 18 gamma-ray; Nuclides: Borated Polyethylene (C-12, H, and B-10); Origin: ENDF/B-II. The cross section data can be used to repeat the Shielding Benchmark Problems 3.0 and 6.0 for testing against the results published in ORNL-RSIC-25. 2 - Method of solution: ZZ-BP-3 neutron cross sections from the CCC-17/05R library were processed into 104 neutron groups using the PSR-9/CSP code. The fine-group neutron cross sections were collapsed to 22 broad groups using CCC-254/ANISN with an equilibrium fission spectrum source. The resulting multigroup cross sections are P5 coefficients punched on cards in format suitable for input to ANISN, DOT, and MORSE. ZZ-BP-6 neutron and gamma-ray cross sections for 12C, H, and 10B were from ENDF/B-II data. The neutron multigroup cross sections were generated into 104 neutron groups using the PSR-13/SUPERTOG code. The fine-group neutron cross sections were collapsed to 22 broad groups using CCC-254/ANISN with an equilibrium fission spectrum source. The gamma-ray multigroup cross sections were generated using PSR-7/MUG. The neutron-gamma-ray coupling utilized yield data from the DLC-12/POPOP4 library (data sets 010101, 060101, 060301, and 05100201). The neutron-gamma-ray coupled multigroup cross-section set was generated using the SAMPLE COUPLING CODE (ASCC). The multigroup cross sections are in a 22-18 group structure with P3 coefficients punched on cards in format suitable for input to ANISN, DOT, and MORSE

  9. The influence of an energy groups number and mesh size on results of reactivity coefficients calculations for BN-600 benchmark core. Appendix 1

    International Nuclear Information System (INIS)

    This document presents the OKBM contribution to the analysis of a benchmark of BN-600 reactor hybrid core with simultaneous loading of uranium fuel and MOX fuel within the framework of the international IAEA Co-ordinated Research Project (CRP) on 'Updated Codes and Methods to Reduce the Calculational Uncertainties of the LMFR Reactivity Effects'. The purpose of the present document is the comparison of some obtained for the Phase 2 results using the different energy groups number and the different mesh point size. The CRP participants at calculation of a benchmark used different planar mesh point sizes. The axial mesh point size was not stipulated, but the mesh sizes were specified for the desired results representation. Therefore in some cases there was possible the application of rather large axial mesh size. The discrepancy in results because the different mesh point size using should be estimated. The results of some participants were obtained using the relatively small energy groups number - 6, 9, and 12. The influence of the energy group number on value of the obtained reactivity coefficients is analyzed in case of the OKBM calculations results. Besides in case of the sodium density reactivity coefficient the OKBM used method of the choice for the few group optimal division of the energy scale is shown. The probable additional uncertainties as the consequence of the baseless group division are estimated by the comparison of the group division schemes applied by different CRP participants

  10. Generation of 69-group cross section library based on JEF data for TRIGA reactor calculations and its validation by analyzing the benchmark lattices of thermal reactors - 095

    International Nuclear Information System (INIS)

    A new executable, identified as NJOY99.0 has been created to generate the 69-group cross-section library for the reactor lattice transport code WIMS. The new code incorporates modifications in the WIMSR module of NJOY to generate the 69-group library, which will be used for TRIGA reactor calculations. The basic evaluated nuclear data file JEF-2.2 was used to generate the 69-group cross-section library in WIMS format. The results for TRX-1, TRX-2, BAPL-1, BAPL-2, and BAPL-3 benchmarks obtained by using the generated 69-group cross-section library from JEF-2.2 were analyzed. The following integral parameters were considered for the validation of the 69-group library: finite medium effective multiplication factor (keff), Ratio of epithermal to thermal 238U captures (ρ28), Ratio of epithermal to thermal 235U fission (δ25), Ratio of 238U fission to 235U fission (δ28) and Ratio of 238U captures to 235U fissions (C*). The TRX and BAPL benchmark lattices were modeled with optimized inputs, which were suggested in the final report of the WIMS Library Update Project (WLUP) Stage-I by Ravnik. The calculated results of the integral parameters of TRX and BAPL Benchmark Lattices obtained by using the new version of code WIMSD-5B were found to be in good agreement with the experimental values. Besides, The TRX and BAPL calculation results showed that JEF-2.2 is reliable for thermal reactor calculations and validated the 69-group library, which will be used for the neutronic calculation of the TRIGA Mark-II research reactor at AERE, Savar, Dhaka, Bangladesh. (authors)

  11. BNAB-93 group data library Part 1: Nuclear data for the calculation of neutron and photon radiation fields

    International Nuclear Information System (INIS)

    This paper is the first in a series of publications dedicated to the description of the new Russian multigroup data set BNAB-93. The first part of this series is devoted to the description of the neutron and photon data and their formats, and to their use in calculations. (author). 12 refs, 8 tabs

  12. Report of the task group reviewing national and international activities in the area of ageing of nuclear power plant concrete structures

    International Nuclear Information System (INIS)

    After a background information on the mandate of the task group and its organisation, the longevity of nuclear power plants is first addressed: the present status of nuclear power plants in the 25 OECD Member Countries is summarised and the importance of ensuring continued safe operation of nuclear power plants described. Safety-related concrete structures (primarily containments) for several reactor concepts are briefly described as well as their materials of construction. Primary mechanisms that can produce adverse ageing of the concrete structures are described (e.g., chemical attack and corrosion of steel reinforcement). The overall performance of nuclear power plant concrete structures is described and age-related degradation incidences that have occurred are noted (e.g., corrosion of steel in water intake structures and corrosion of metal liners). National ageing management programmes of OECD Member Countries are then described with the emphasis placed on nuclear power plant safety-related concrete structures. Although the majority of these programmes are addressing components such as the reactor pressure vessel and steam generator, several national programmes have sophisticated activities that address the concrete structures (e.g., Canada, France, Japan, Switzerland, United Kingdom, and the United States). International ageing management activities are then summarised, primarily addressed under the auspices of the International Atomic Energy Agency (IAEA) (ageing management activities for concrete containment buildings) and the Commission of European Communities (CEC) (assessment of the long-term durability of reinforced and prestressed concrete structures and buildings, and steel containments in nuclear power plants). General conclusions and recommendations are provided at the end of the report

  13. A review of the NeT Task Group 1 residual stress measurement and analysis round robin on a single weld bead-on-plate specimen

    International Nuclear Information System (INIS)

    This paper reviews the European network NeT round-robin activities on measuring and simulating the residual stresses generated by laying a single weld bead on a flat austenitic steel plate. The activities are described, as are the main results obtained. From 2002 to 2010, fourteen independent sets of residual stress measurements were made using five different techniques, and subjected to detailed statistical analysis to evaluate best estimate profiles for validation of finite element predictions. In parallel, over forty finite element simulations were performed, examining a wide range of solution variables and their impact on the predicted residual stresses. This large body of work has allowed NeT Task Group 1 to develop a reliable thermal solution strategy. This is described and involves a global weld heat input calibrated against far-field thermocouples followed by derivation of detailed weld heat source characteristics by matching the weld fusion boundary profile. The accurate thermal solutions then allow the most important mechanical solution variables to be isolated and optimised. An important variable is found to be the material hardening model, with mixed isotropic-kinematic hardening being the most accurate for the AISI 316L plate material. Other solution variables, such as the welding efficiency, the mesh design and the thermal boundary conditions, are found to be of much less importance. The NeT TG1 specimen is described here in sufficient detail to serve as a benchmark for both finite element simulation and measurement of weld residual stresses. - Highlights: • NeT TG1 is the most comprehensive weld residual stress benchmark yet produced. • The large measurements database allows statistical analysis of the measured stresses. • The mean measured profiles are of great value for validating residual stress prediction techniques. • The simulations database affords a unique insight into the sensitivity of predicted residual stresses to a variety of

  14. Cliff´s Delta Calculator: A non-parametric effect size program for two groups of observations

    OpenAIRE

    Guillermo Macbeth; Eugenia Razumiejczyk; Rubén Daniel Ledesma

    2011-01-01

    The Cliff´s Delta statistic is an effect size measure that quantifies the amount of difference between two non-parametric variables beyond p-values interpretation. This measure can be understood as a useful complementary analysis for the corresponding hypothesis testing. During the last two decades the use of effect size measures has been strongly encouraged by methodologists and leading institutions of behavioral sciences. The aim of this contribution is to introduce the Cliff´s Delta Calcul...

  15. Processing and validation of JEFF-3.1.1 and ENDF/B-VII.0 group-wise cross section libraries for shielding calculations

    International Nuclear Information System (INIS)

    This paper presents a synthesis of the ENEA-Bologna Nuclear Data Group programme dedicated to generate and validate group-wise cross section libraries for shielding and radiation damage deterministic calculations in nuclear fission reactors, following the data processing methodology recommended in the ANSI/ANS-6.1.2-1999 (R2009) American Standard. The VITJEFF311.BOLIB and VITENDF70.BOLIB fine group coupled n-γ (199 n + 42 γ - VITAMIN-B6 structure) multi-purpose cross section libraries, based on the Bondarenko method for neutron resonance self-shielding and respectively on JEFF-3.1.1 and ENDF/B-VII.0 evaluated nuclear data, were produced in AMPX format using the NJOY-99.259 and the ENEA-Bologna 2007 Revision of the SCAMPI nuclear data processing systems. Two derived broad-group coupled n-γ (47 n + 20 γ - BUGLE-96 structure) working cross section libraries in FIDO-ANISN format for LWR shielding and pressure vessel dosimetry calculations, named BUGJEFF311.BOLIB and BUGENDF70.BOLIB, were generated by the revised version of SCAMPI, through problem-dependent cross section collapsing and self-shielding from the cited fine-group libraries. The validation results on the criticality safety benchmark experiments for the fine-group libraries and the preliminary validation results for the broad-group working libraries on the PCA-Replica and VENUS-3 engineering neutron shielding benchmark experiments are reported in synthesis. (authors)

  16. Comparison of measurements and calculations of fuel for different structures in the libraries of effective sections (44 groups/238 groups); Comparacion de medidas y calculos de combustibles para diversas estructuras en las librerias de secciones eficaces (44 grupos/238 grupos)

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Rivada, A.; Tore, C.

    2013-07-01

    The study was conducted for the use of the sections effective in 44 groups, based on the libraries of effective sections ENDF/b-v, for the calculation of the isotopy of the spent fuel. These effective sections have been developed to be used in the system codes SCALE for the analysis the fresh nuclear fuel as the spent and their radioactive waste.

  17. Calculation of phases of np- scattering up to Tlab=3 GeV for potentials Argonne group on the phase-function method

    CERN Document Server

    Zhaba, V I

    2016-01-01

    For calculation of the single-channel nucleon-nucleon scattering a phase-functions method has been proposed. Using a phase-functions method the following phase shifts of a np- scattering numerically for 1S0-, 1P1-, 3P0-, 3P1-, 1D2-, 3D2-, 1F3-, 3F3-, 1G4-, 3G4- states are calculated. The calculations has been performed using realistic nucleon-nucleon potentials Argonne group (Av18, Av14sscc, Av8', Av8'sscc, Av6', Av4', Av2'). Obtained phase shifts are in good agreement with the results obtained in the framework of other methods. Using the obtained phase shifts we have calculated the full cross-section np- scattering.

  18. Group additivity calculation of the standard molal thermodynamic properties of aqueous amino acids, polypeptides and unfolded proteins as a function of temperature, pressure and ionization state

    Directory of Open Access Journals (Sweden)

    J. M. Dick

    2005-10-01

    Full Text Available Thermodynamic calculation of the chemical speciation of proteins and the limits of protein metastability affords a quantitative understanding of the biogeochemical constraints on the distribution of proteins within and among different organisms and chemical environments. These calculations depend on accurate determination of the ionization states and standard molal Gibbs free energies of proteins as a function of temperature and pressure, which are not generally available. Hence, to aid predictions of the standard molal thermodynamic properties of ionized proteins as a function of temperature and pressure, calculated values are given below of the standard molal thermodynamic properties at 25°C and 1 bar and the revised Helgeson-Kirkham-Flowers equations of state parameters of the structural groups comprising amino acids, polypeptides and unfolded proteins. Group additivity and correlation algorithms were used to calculate contributions by ionized and neutral sidechain and backbone groups to the standard molal Gibbs free energy (Δ G°, enthalpy (Δ H°, entropy (S°, isobaric heat capacity (C°P, volume (V° and isothermal compressibility (κ°T of multiple reference model compounds. Experimental values of C°P, V° and κ°T at high temperature were taken from the recent literature, which ensures an internally consistent revision of the thermodynamic properties and equations of state parameters of the sidechain and backbone groups of proteins, as well as organic groups. As a result, Δ G°, Δ H°, S° C°P, V° and κ°T of unfolded proteins in any ionization state can be calculated up to T~-300°C and P~-5000 bars. In addition, the ionization states of unfolded proteins as a function of not only pH, but also temperature and pressure can be calculated by taking account of the degree of ionization of the sidechain and backbone groups present in the sequence. Calculations of this

  19. Application of the renormalization group to the calculation of the vacuum decay rate in flat and curved space-time

    Science.gov (United States)

    Metaxas, Dimitrios

    2007-02-01

    I show that an application of renormalization group arguments may lead to significant corrections to the vacuum decay rate for phase transitions in flat and curved space-time. It can also give some information regarding its dependence on the parameters of the theory, including the cosmological constant in the case of decay in curved space-time.

  20. Burnup-dependent effect of lattice-level homogenization and group condensation on calculated kinetics parameters for CANDU-type lattices

    International Nuclear Information System (INIS)

    Highlights: • CANDU-type-lattice kinetics parameters are calculated using different adjoint-weighting approximations at different burnups. • Fine-group space-dependent adjoint weighting is the most accurate method of calculating the kinetics parameters. • Two-group lattice-homogenized adjoint weighting overestimates the effective delayed-neutron fraction by approximately 5%. • Fine-group lattice-homogenized adjoint weighting overestimates the effective delayed neutron fraction only by approximately 2%. - Abstract: Modern analysis of nuclear reactor transients uses space-time reactor kinetics methods. In the Canadian nuclear industry, safety analysis calculations use almost exclusively the Improved Quasistatic (IQS) flux factorization method. The IQS method, like all methods based on flux factorization, relies on calculating effective point kinetics parameters, which dominate the time behavior of the flux, using adjoint-weighted integrals. The accuracy of the adjoint representation influences the accuracy of the effective kinetics parameters. Routine full core calculations are not performed using detailed models and transport theory, but rather using a cell-homogenized model and two-group diffusion theory. This work evaluates the effect of homogenization and group condensation at different burnups, for three fuel types: natural-uranium (NU) fuel, low-void reactivity (LVR) fuel and Advanced CANDU Reactor (ACR) fuel. Results show that the use of a two-group lattice-homogenized adjoint consistently overestimates the effective delayed neutron fraction by approximately 5% for all three fuel types and over a wide burnup range. The use of a two-group lattice-homogenized adjoint also introduces errors in the effective neutron generation time, but these are at most 1.3% (and their sign changes with burnup). Errors tend to vary with burnup by approximately 1% (of the individual parameter value). If a 69-group lattice-homogenized adjoint is used, the errors drop to

  1. Cliff´s Delta Calculator: A non-parametric effect size program for two groups of observations

    Directory of Open Access Journals (Sweden)

    Guillermo Macbeth

    2011-05-01

    Full Text Available The Cliff´s Delta statistic is an effect size measure that quantifies the amount of difference between two non-parametric variables beyond p-values interpretation. This measure can be understood as a useful complementary analysis for the corresponding hypothesis testing. During the last two decades the use of effect size measures has been strongly encouraged by methodologists and leading institutions of behavioral sciences. The aim of this contribution is to introduce the Cliff´s Delta Calculator software that performs such analysis and offers some interpretation tips. Differences and similarities with the parametric case are analysed and illustrated. The implementation of this free program is fully described and compared with other calculators. Alternative algorithmic approaches are mathematically analysed and a basic linear algebra proof of its equivalence is formally presented. Two worked examples in cognitive psychology are commented. A visual interpretation of Cliff´s Delta is suggested. Availability, installation and applications of the program are presented and discussed.

  2. Processing and validation of JEFF-3.1.1 and ENDF/B-VII.0 group-wise cross section libraries for shielding calculations

    Science.gov (United States)

    Pescarini, M.; Sinitsa, V.; Orsi, R.; Frisoni, M.

    2013-03-01

    This paper presents a synthesis of the ENEA-Bologna Nuclear Data Group programme dedicated to generate and validate group-wise cross section libraries for shielding and radiation damage deterministic calculations in nuclear fission reactors, following the data processing methodology recommended in the ANSI/ANS-6.1.2-1999 (R2009) American Standard. The VITJEFF311.BOLIB and VITENDF70.BOLIB finegroup coupled n-γ (199 n + 42 γ - VITAMIN-B6 structure) multi-purpose cross section libraries, based on the Bondarenko method for neutron resonance self-shielding and respectively on JEFF-3.1.1 and ENDF/B-VII.0 evaluated nuclear data, were produced in AMPX format using the NJOY-99.259 and the ENEA-Bologna 2007 Revision of the SCAMPI nuclear data processing systems. Two derived broad-group coupled n-γ (47 n + 20 γ - BUGLE-96 structure) working cross section libraries in FIDO-ANISN format for LWR shielding and pressure vessel dosimetry calculations, named BUGJEFF311.BOLIB and BUGENDF70.BOLIB, were generated by the revised version of SCAMPI, through problem-dependent cross section collapsing and self-shielding from the cited fine-group libraries. The validation results on the criticality safety benchmark experiments for the fine-group libraries and the preliminary validation results for the broad-group working libraries on the PCA-Replica and VENUS-3 engineering neutron shielding benchmark experiments are reported in synthesis.

  3. Processing and validation of JEFF-3.1.1 and ENDF/B-VII.0 group-wise cross section libraries for shielding calculations

    Directory of Open Access Journals (Sweden)

    Orsi R.

    2013-03-01

    Full Text Available This paper presents a synthesis of the ENEA-Bologna Nuclear Data Group programme dedicated to generate and validate group-wise cross section libraries for shielding and radiation damage deterministic calculations in nuclear fission reactors, following the data processing methodology recommended in the ANSI/ANS-6.1.2-1999 (R2009 American Standard. The VITJEFF311.BOLIB and VITENDF70.BOLIB finegroup coupled n-γ (199 n + 42 γ – VITAMIN-B6 structure multi-purpose cross section libraries, based on the Bondarenko method for neutron resonance self-shielding and respectively on JEFF-3.1.1 and ENDF/B-VII.0 evaluated nuclear data, were produced in AMPX format using the NJOY-99.259 and the ENEA-Bologna 2007 Revision of the SCAMPI nuclear data processing systems. Two derived broad-group coupled n-γ (47 n + 20 γ – BUGLE-96 structure working cross section libraries in FIDO-ANISN format for LWR shielding and pressure vessel dosimetry calculations, named BUGJEFF311.BOLIB and BUGENDF70.BOLIB, were generated by the revised version of SCAMPI, through problem-dependent cross section collapsing and self-shielding from the cited fine-group libraries. The validation results on the criticality safety benchmark experiments for the fine-group libraries and the preliminary validation results for the broad-group working libraries on the PCA-Replica and VENUS-3 engineering neutron shielding benchmark experiments are reported in synthesis.

  4. Temperature, pressure, and electrochemical constraints on protein speciation: Group additivity calculation of the standard molal thermodynamic properties of ionized unfolded proteins

    Directory of Open Access Journals (Sweden)

    J. M. Dick

    2006-01-01

    Full Text Available Thermodynamic calculations can be used to quantify environmental constraints on the speciation of proteins, such as the pH and temperature dependence of ionization state, and the relative chemical stabilities of proteins in different biogeochemical settings. These calculations depend in part on values of the standard molal Gibbs energies of proteins and their ionization reactions as a function of temperature and pressure. Because these values are not generally available, we calculated values of the standard molal thermodynamic properties at 25°C and 1 bar as well as the revised Helgeson-Kirkham-Flowers equations of state parameters of neutral and charged zwitterionic reference model compounds including aqueous amino acids, polypeptides, and unfolded proteins. The experimental calorimetric and volumetric data for these species taken from the literature were combined with group additivity algorithms to calculate the properties and parameters of neutral and ionized sidechain and backbone groups in unfolded proteins. The resulting set of group contributions enables the calculation of the standard molal Gibbs energy, enthalpy, entropy, isobaric heat capacity, volume, and isothermal compressibility of unfolded proteins in a range of proton ionization states to temperatures and pressures exceeding 100°C and 1000 bar. This approach provides a useful frame of reference for thermodynamic studies of protein folding and complexation reactions. It can also be used to assign provisional values of the net charge and Gibbs energy of ionized proteins as a function of temperature and pH. Using these values, an Eh-pH diagram for a reaction representing the speciation of extracellular proteins from Pyrococcus furiosus and Bacillus subtilis was generated. The predicted predominance limits of these proteins correspond with the different electrochemical conditions of hydrothermal vents and soils. More comprehensive calculations of this kind may reveal pervasive

  5. Solid state 1H spin-lattice relaxation and isolated-molecule and cluster electronic structure calculations in organic molecular solids: The relationship between structure and methyl group and t-butyl group rotation

    Science.gov (United States)

    Wang, Xianlong; Mallory, Frank B.; Mallory, Clelia W.; Odhner, Hosanna R.; Beckmann, Peter A.

    2014-05-01

    We report ab initio density functional theory electronic structure calculations of rotational barriers for t-butyl groups and their constituent methyl groups both in the isolated molecules and in central molecules in clusters built from the X-ray structure in four t-butyl aromatic compounds. The X-ray structures have been reported previously. We also report and interpret the temperature dependence of the solid state 1H nuclear magnetic resonance spin-lattice relaxation rate at 8.50, 22.5, and 53.0 MHz in one of the four compounds. Such experiments for the other three have been reported previously. We compare the computed barriers for methyl group and t-butyl group rotation in a central target molecule in the cluster with the activation energies determined from fitting the 1H NMR spin-lattice relaxation data. We formulate a dynamical model for the superposition of t-butyl group rotation and the rotation of the t-butyl group's constituent methyl groups. The four compounds are 2,7-di-t-butylpyrene, 1,4-di-t-butylbenzene, 2,6-di-t-butylnaphthalene, and 3-t-butylchrysene. We comment on the unusual ground state orientation of the t-butyl groups in the crystal of the pyrene and we comment on the unusually high rotational barrier of these t-butyl groups.

  6. Solid state {sup 1}H spin-lattice relaxation and isolated-molecule and cluster electronic structure calculations in organic molecular solids: The relationship between structure and methyl group and t-butyl group rotation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xianlong, E-mail: WangXianlong@uestc.edu.cn, E-mail: pbeckman@brynmawr.edu [Key Laboratory for NeuroInformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, 4 North Jianshe Rd., 2nd Section, Chengdu 610054 (China); Mallory, Frank B. [Department of Chemistry, Bryn Mawr College, 101 North Merion Ave., Bryn Mawr, Pennsylvania 19010-2899 (United States); Mallory, Clelia W. [Department of Chemistry, Bryn Mawr College, 101 North Merion Ave., Bryn Mawr, Pennsylvania 19010-2899 (United States); Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323 (United States); Odhner, Hosanna R.; Beckmann, Peter A., E-mail: WangXianlong@uestc.edu.cn, E-mail: pbeckman@brynmawr.edu [Department of Physics, Bryn Mawr College, 101 North Merion Ave., Bryn Mawr, Pennsylvania 19010-2899 (United States)

    2014-05-21

    We report ab initio density functional theory electronic structure calculations of rotational barriers for t-butyl groups and their constituent methyl groups both in the isolated molecules and in central molecules in clusters built from the X-ray structure in four t-butyl aromatic compounds. The X-ray structures have been reported previously. We also report and interpret the temperature dependence of the solid state {sup 1}H nuclear magnetic resonance spin-lattice relaxation rate at 8.50, 22.5, and 53.0 MHz in one of the four compounds. Such experiments for the other three have been reported previously. We compare the computed barriers for methyl group and t-butyl group rotation in a central target molecule in the cluster with the activation energies determined from fitting the {sup 1}H NMR spin-lattice relaxation data. We formulate a dynamical model for the superposition of t-butyl group rotation and the rotation of the t-butyl group's constituent methyl groups. The four compounds are 2,7-di-t-butylpyrene, 1,4-di-t-butylbenzene, 2,6-di-t-butylnaphthalene, and 3-t-butylchrysene. We comment on the unusual ground state orientation of the t-butyl groups in the crystal of the pyrene and we comment on the unusually high rotational barrier of these t-butyl groups.

  7. Overview on the dosimetric uncertainty analysis for photon-emitting brachytherapy sources, in the light of the AAPM Task Group No 138 and GEC-ESTRO report

    International Nuclear Information System (INIS)

    In 2011, the American Association of Physicists in Medicine (AAPM) and the Groupe Europeen de Curietherapie-European Society for Radiotherapy and Oncology (GEC-ESTRO) published a report pertaining to uncertainties in brachytherapy single-source dosimetry preceding clinical use. The International Organization for Standardization's Guide to the Expression of Uncertainty in Measurement and Technical Note 1297 by the National Institute of Standards and Technology are taken as reference standards for uncertainty formalism. Uncertainties involved in measurements or Monte Carlo methods to estimate brachytherapy dose distributions are provided with discussion of the components intrinsic to the overall dosimetric assessment. The uncertainty propagation from the primary calibration standard through transfer to the clinic for air-kerma strength is given with uncertainties in each of the brachytherapy dosimetry parameters of the AAPM TG-43 dose-calculation formalism. For low-energy and high-energy brachytherapy sources of low dose-rate and high dose-rate, a combined dosimetric uncertainty ≤5% (k = 1) is estimated, which is consistent with prior literature estimates. Recommendations are provided for clinical medical physicists, dosimetry investigators, and manufacturers of brachytherapy sources and treatment planning systems. These recommendations reflect the guidance of the AAPM and GEC-ESTRO for their members, and may also be used as guidance to manufacturers and regulatory agencies in developing good manufacturing practices for conventional brachytherapy sources used in routine clinical treatments. (authors)

  8. ZZ JFS-1, Cross-Sections Library 25-Groups ABBN and 70-Group JFS for Fast Reactor Calculation. ZZ JFS-2, 25 Group (ABBN) and 70 Group JFS Cross Sections Library for Fast Reactors. ZZ JFS-3/J2, 70 Group 30 Isotopes Cross Section Library for Fast Reactors

    International Nuclear Information System (INIS)

    1 - Description of problem or function: - JFS-V2-1: Format: ABBN energy structure; Number of groups: 25 group constants; Nuclides: Be, B-10, B-11, C, O, Na, Al, Si, Cr, Mn, Fe, Ni, Cu, Mo, Th-232, U-233, U-234, U-235, U-236, U-238, Pu-239, Pu-240, Pu-241, Pu-242, Am-241, fission products of U-235, and fission products of Pu-239. Origin: ENDF/B-IV; Weighting spectrum: The cross-section adjustment has been made by using an auxiliary equation for simultaneous evaluations for U-235, U-238, and Pu-239. - JFS-V2-2: Format: JFS energy structure; Number of groups: 70 group constants; Nuclides: Be, B-10, B-11, C, O, Na, Al, Si, Cr, Mn, Fe, Ni, Cu, Mo, Th-232, U-233, U-234, U-235, U-236, U-238, Pu-239, Pu-240, Pu-241, Pu-242, Am-241, fission products of U-235, and fission products of Pu-239. Origin: ENDF/B-IV; Weighting spectrum: The cross-section adjustment has been made by using an auxiliary equation for simultaneous evaluations for U-235, U-238, and Pu-239. - JFS-3/J2: Number of groups: 70 group constants with quarter-lethargy width; Nuclides: H-1, He-4, Be-9, B-10, B-11, C-12, N-14, O-16, Na-23, Al-27, Si, Ar, Ti, V, Cr, Mn-55, Fe, Ni, Cu, Zr, Nb-93, Mo, Eu-151, Eu-153, Gd, Gd-155, Gd-156, Gd-157, Gd-158, Gd-160, Ta-181, W, Th-228, Th-230, Th-232, Th-233, Th-234, Pa-233, U-233, U-234, U-235, U-236, U-238, Np-237, Np-239, Pu-236, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, Am-241, Am-242m, Am-242g, Am-243, Cm-242, Cm-243, Cm-244, Cm-245 and 12 LFPs for 4 mother nuclides (U-235, U-238, Pu-239 and Pu-241) and 3 burnup days (180, 1080 and 1800). Origin: JENDL-2 and ENDF/B-V; Weighting spectrum: the collision density spectrum for a typical large LMFBR core spectrum is used as the weighting function. ZZ-JFS-3/J2: To improve fast reactor group constant set JFS-3-J2 to be applicable for high burnup reactor calculation, burnup depending lumped FP group cross sections for mother fission isotopes of U-235, U-238, Pu-239 and Pu-241 have been generated by using 155 FP nuclides of JENDL-2

  9. ZZ WM-NRSM, Neutron and Gamma Group Cross-Section Library for Nuclear Rocket Shielding Calculations

    International Nuclear Information System (INIS)

    Description of problem or function: - Master Library 1: Format: ANISN-W, DOT-IIW and APPROPOS. Number of groups: 52; Nuclides: Al, Be, B, B-10, Cd, C, Cr, Co, Cu, Gd, Au, H, In-115, Fe, Pb, Li, Li-6, Li-7, Mg, Mn, Mo, Ni, Nb, N, O, Si, Ta, Ti, W, U-235, U-238, Zr. Origin: Westinghouse Astro-nuclear Laboratory. Weighting spectrum: 1/E, flux and current spectra. - Master Library 2: Format: ANISN-W, DOT-IIW and APPROPOS. Number of groups: 52; Nuclides: Al, Be, B, B-10, Cd, C, Cr, Co, Cu, Gd, Au, H, In-115, Fe, Pb, Li, Li-6, Li-7, Mg, Mn, Mo, Ni, Nb, N, O, Si, Ta, Ti, W, U-235, U-238, Zr. Origin: Westinghouse Astro-nuclear Laboratory. Weighting spectrum: 1/E, flux and current spectra. - Master Library 3: Format: APPROPOS. Number of groups: 52; Nuclides: Al, Be, B, B-10, Cd, C, Cr, Co, Cu, Gd, Au, H, In-115, Fe, Pb, Li, Li-6, Li-7, Mg, Mn, Mo, Ni, Nb, N, O, Si, Ta, Ti, W, U-235, U-238, Zr. Origin: Westinghouse Astro-nuclear Laboratory. Weighting spectrum: 1/E, flux and current spectra. - Master Library 5: Format: KAP-VI, GAMLEG-W, MAC and SCAP. Number of groups: energy points in the range of 0.01 MeV to 20.0 MeV; Nuclides: H, He, Li, Be, B, C, N, O, Na, Mg, Al, Si, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ag, Cd, In, Sn, Cs, Ba, Sm, Gd, Dy, Y, Hf, Ta, W, Au, Hg, Pb, Po, Th, Pa, U, Np, Pu. Origin: Westinghouse Astro-nuclear Laboratory. - Basic set of nuclear data (Library 6): Format: ANISN-W and DOT-IIW. Number of groups: 52; Nuclides: H, Be, B, C, U-235, U-238, N, O, Mg, Al, Si, Cr, Mn, Fe Co, Ni, Cu, Zr, Mo, Ag, In, Cd, Gd, Pb, Nb, Ti, Ta, Li-6, Li-7, B-10 W, S. Origin: Master Libraries. Weighting spectrum: decided by user. WANL-MSFC Nuclear Rocket Shielding Data Generators GAMLEG-W, APPROPOS, NAGS, SATURN and Neutron and photon Cross Section Libraries 1-6. Applications of the Data: Transport codes which use the data are ANISN-W, KAP-VI, DOT-IIW, MAC and SCAP. The transport codes, also available from RSIC, the cross section processing codes, and

  10. ZZ DLC-16 COBB, 123 Neutron-Group Cross-Section Library from ENDF/B for XSDRN Calculation

    International Nuclear Information System (INIS)

    1 - Nature of physical problem solved: Format: XSDRN; Number of groups: 123; Nuclides: H, D, He, Be-9, B-10, C-12, O-16, Na-23, Mg, Al-27, Ti, Cr, Mn-55, Fe, Ni, Cu, Cu-63, Cu-65, Nb-93, Mo, Xe-135, Sm-149, Eu-151, Eu-153, Gd, Dy-164, Lu-175, Lu-176, W-182, W-183, W-184, W-186, Re-185, Re-187, Au-197, U-233, U-234, U-235, U-236, U-238, Np-237, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, Am-241, Am-243, and Cm-244. Origin: Mainly ENDF/B; Weighting spectrum: Fast cross sections → 1/E (14 MeV to .414 eV) Thermal cross sections → 1/E (1.86 eV to 0.125 eV) → Maxwell-Boltzmann (0.125 eV to 0.0047 eV). The library is intended to be a source of evaluated data for the cross section preparation code XSDRN. It supplements, rather than replaces, the existing XSDRN master library which is distributed with the code package. The library contains data for H, D, He, 9-Be, 10-B, 12-C, 16-O, 23-Na, Mg, 27-Al, Ti, Cr, 55-Mn, Fe, Ni, Cu, 63-Cu, 65-Cu, 93-Nb, Mo, 135-Xe, 149-Sm, 151-Eu, 153-Eu, Gd, 164-Dy, 175-Lu, 176-Lu, 182-W, 183-W, 184-W, 186-W, 185-Re, 187-Re, 197-Au, 233-U, 234-U, 235-U, 236-U, 238-U, 237-Np, 238-Pu, 239-Pu, 240-Pu, 241-Pu, 242-Pu, 241-Am, 243-Am, and 244-Cm. 2 - Method of solution: The library contains ENDF/B version 2 cross sections processed through several steps (primarily by SUPERTOG) into the standard XSDRN 123-group energy structure. These steps are - (a) process fast cross sections with SUPERTOG into standard GAM-2 energy structure (14 MeV to 0.414 eV), using a 1/E weighting function, and produce a GAM-2 tape. (This step was performed by R. Q. Wright, Math Div., ORNL). (b) Process thermal cross sections with SUPERTOG into standard 30-group THERMOS energy group structure (1.86 eV to 0.0047 eV), using a Maxwell-Boltzmann distribution with temperature 293 deg.K as a weighting function for E < 0.125 eV coupled to a 1/E weighting function for E from 0.125 eV to 1.86 eV. (c) Compute room temperature free-gas kernels, using THERMOS tape-making program, and

  11. Processing and validation of JEFF-3.1.1 and ENDF/B-VII.0 group-wise cross section libraries for shielding calculations

    OpenAIRE

    Orsi R.; Sinitsa V.; Pescarini M.; Frisoni M.

    2013-01-01

    This paper presents a synthesis of the ENEA-Bologna Nuclear Data Group programme dedicated to generate and validate group-wise cross section libraries for shielding and radiation damage deterministic calculations in nuclear fission reactors, following the data processing methodology recommended in the ANSI/ANS-6.1.2-1999 (R2009) American Standard. The VITJEFF311.BOLIB and VITENDF70.BOLIB finegroup coupled n-γ (199 n + 42 γ – VITAMIN-B6 structure) multi-purpose cross section libraries, based o...

  12. Performance of a fine-grained parallel model for multi-group nodal-transport calculations in three-dimensional pin-by-pin reactor geometry

    International Nuclear Information System (INIS)

    A production code SCOPE2 was developed based on the fine-grained parallel algorithm by the red/black iterative method targeting parallel computing environments such as a PC-cluster. It can perform a depletion calculation in a few hours using a PC-cluster with the model based on a 9-group nodal-SP3 transport method in 3-dimensional pin-by-pin geometry for in-core fuel management of commercial PWRs. The present algorithm guarantees the identical convergence process as that in serial execution, which is very important from the viewpoint of quality management. The fine-mesh geometry is constructed by hierarchical decomposition with introduction of intermediate management layer as a block that is a quarter piece of a fuel assembly in radial direction. A combination of a mesh division scheme forcing even meshes on each edge and a latency-hidden communication algorithm provided simplicity and efficiency to message passing to enhance parallel performance. Inter-processor communication and parallel I/O access were realized using the MPI functions. Parallel performance was measured for depletion calculations by the 9-group nodal-SP3 transport method in 3-dimensional pin-by-pin geometry with 340 x 340 x 26 meshes for full core geometry and 170 x 170 x 26 for quarter core geometry. A PC cluster that consists of 24 Pentium-4 processors connected by the Fast Ethernet was used for the performance measurement. Calculations in full core geometry gave better speedups compared to those in quarter core geometry because of larger granularity. Fine-mesh sweep and feedback calculation parts gave almost perfect scalability since granularity is large enough, while 1-group coarse-mesh diffusion acceleration gave only around 80%. The speedup and parallel efficiency for total computation time were 22.6 and 94%, respectively, for the calculation in full core geometry with 24 processors. (authors)

  13. Guidelines by the AAPM and GEC-ESTRO on the use of innovative brachytherapy devices and applications: Report of Task Group 167.

    Science.gov (United States)

    Nath, Ravinder; Rivard, Mark J; DeWerd, Larry A; Dezarn, William A; Thompson Heaton, H; Ibbott, Geoffrey S; Meigooni, Ali S; Ouhib, Zoubir; Rusch, Thomas W; Siebert, Frank-André; Venselaar, Jack L M

    2016-06-01

    Although a multicenter, Phase III, prospective, randomized trial is the gold standard for evidence-based medicine, it is rarely used in the evaluation of innovative devices because of many practical and ethical reasons. It is usually sufficient to compare the dose distributions and dose rates for determining the equivalence of the innovative treatment modality to an existing one. Thus, quantitative evaluation of the dosimetric characteristics of innovative radiotherapy devices or applications is a critical part in which physicists should be actively involved. The physicist's role, along with physician colleagues, in this process is highlighted for innovative brachytherapy devices and applications and includes evaluation of (1) dosimetric considerations for clinical implementation (including calibrations, dose calculations, and radiobiological aspects) to comply with existing societal dosimetric prerequisites for sources in routine clinical use, (2) risks and benefits from a regulatory and safety perspective, and (3) resource assessment and preparedness. Further, it is suggested that any developed calibration methods be traceable to a primary standards dosimetry laboratory (PSDL) such as the National Institute of Standards and Technology in the U.S. or to other PSDLs located elsewhere such as in Europe. Clinical users should follow standards as approved by their country's regulatory agencies that approved such a brachytherapy device. Integration of this system into the medical source calibration infrastructure of secondary standard dosimetry laboratories such as the Accredited Dosimetry Calibration Laboratories in the U.S. is encouraged before a source is introduced into widespread routine clinical use. The American Association of Physicists in Medicine and the Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology (GEC-ESTRO) have developed guidelines for the safe and consistent application of brachytherapy using innovative devices and

  14. Steps towards a CSP yield calculation guideline: A first draft for discussion in the SolarPACES working group guiSmo

    Science.gov (United States)

    Hirsch, Tobias; Bachelier, Camille; Eck, Markus; Dersch, Jürgen; Fluri, Thomas; Giuliano, Stefano; Goebel, Olaf; Haller, Ursula; Lude, Simon; Meyer, Richard; Rau, Christoph; Schenk, Heiko; Schmidt, Norbert; Seitz, Markus; Westphal, Boris; Yildiz, Enver

    2016-05-01

    This paper provides an overview on an important step towards a SolarPACES guideline for CSP yield calculation. With the increasing number of CSP installations, standardization becomes more and more important for further reduction of costs and increase in quality. Yield calculation is a key issue throughout all phases of project development and throughout most of the involved players. Due to the need for more complex process models for CSP compared to other renewables like PV or wind, the yield calculation procedure is more demanding. Uncertainties in the process are covered by additional but partially unnecessary risk surcharges since systematic approaches for avoiding expensive redundancies in risk buffers are not available. It is the main motivation of the mentioned CSP yield calculation guideline to overcome this situation by providing a detailed methodology for yield calculation. A first comprehensive draft version has been compiled and will be subject of discussion in the SolarPACES working group guiSmo. The following sections illustrate the motivation for the guideline, the contents at a glance, as well as expected benefits for selected players.

  15. Task Group 7B: Cellular and Molecular Mechanisms of Biological Aging: The Roles of Nature, Nurture and Chance in the Maintenance of Human Healthspan

    Energy Technology Data Exchange (ETDEWEB)

    Weier, Heinz-Ulrich; Arya, Suresh; Grant, Christine; Miller, Linda; Ono, Santa Jeremy; Patil, Chris; Shay, Jerry; Topol, Eric; Torry, Michael; Weier, Heinz-Ulrich G.; Tse, Iris; Lin, Su-Ju; Miller, Richard

    2007-11-14

    The degree to which an individual organism maintains healthspan and lifespan is a function of complex interactions between genetic inheritance ('nature'), environment, including cultural inheritance (nurture) and stochastic events ('luck' or 'chance'). This task group will focus upon the role of chance because it is so poorly understood and because it appears to be of major importance in the determination of individual variations in healthspan and lifespan within species. The major factor determining variations in healthspan and lifespan between species is genetic inheritance. Broader aspects of cellular and molecular mechanisms of biological aging will also be considered, given their importance for understanding the cellular and molecular basis of successful aging. The task force will consider the cellular and molecular basis for nature, nurture and chance in healthspan and life span determination. On the basis of comparisons between identical and non-identical twins, geneticists have estimated that genes control no more than about a quarter of the inter-individual differences in lifespan (Herskind 1996). Twin studies of very old individuals, however, show substantially greater genetic contributions to Healthspan (McClearn 2004; Reed 2003). The environment clearly plays an important role in the length and the quality of life. Tobacco smoke, for example has the potential to impact upon multiple body systems in ways that appear to accelerate the rates at which those systems age (Bernhard 2007). To document the role of chance events on aging, one must rigorously control both the genetic composition of an organism and its environment. This has been done to a remarkable degree in a species of nematodes, Caenorhabditis elegans (Vanfleteren 1998). The results confirm hundreds of previous studies with a wide range of species, especially those with inbred rodents housed under apparently identical but less well controlled environments. One

  16. Differences in dual-task performance and prefrontal cortex activation between younger and older adults

    Directory of Open Access Journals (Sweden)

    Ohsugi Hironori

    2013-01-01

    Full Text Available Abstract Background The purpose of this study was to examine task-related changes in prefrontal cortex (PFC activity during a dual-task in both healthy young and older adults and compare patterns of activation between the age groups. We also sought to determine whether brain activation during a dual-task relates to executive/attentional function and how measured factors associated with both of these functions vary between older and younger adults. Results Thirty-five healthy volunteers (20 young and 15 elderly participated in this study. Near-infrared spectroscopy (NIRS was employed to measure PFC activation during a single-task (performing calculations or stepping and dual-task (performing both single-tasks at once. Cognitive function was assessed in the older patients with the Trail-making test part B (TMT-B. Major outcomes were task performance, brain activation during task (oxygenated haemoglobin: Oxy-Hb measured by NIRS, and TMT-B score. Mixed ANOVAs were used to compare task factors and age groups in task performance. Mixed ANOVAs also compared task factors, age group and time factors in task-induced changes in measured Oxy-Hb. Among the older participants, correlations between the TMT-B score and Oxy-Hb values measured in each single-task and in the dual-task were examined using a Pearson correlation coefficient. Oxy-Hb values were significantly increased in both the calculation task and the dual-task within patients in both age groups. However, the Oxy-Hb values associated with there were higher in the older group during the post-task period for the dual-task. Also, there were significant negative correlations between both task-performance accuracy and Oxy-Hb values during the dual-task and participant TMT-B scores. Conclusions Older adults demonstrated age-specific PFC activation in response to dual-task challenge. There was also a significant negative correlation between PFC activation during dual-task and executive

  17. A Metaanalysis of Perceptual Organization in Schizophrenia, Schizotypy, and Other High-Risk Groups Based on Variants of the Embedded Figures Task

    OpenAIRE

    Panton, Kirsten R.; Badcock, David R.; Badcock, Johanna C.

    2016-01-01

    Current research on perceptual organization in schizophrenia frequently employs shapes with regularly sampled contours (fragmented stimuli), in noise fields composed of similar elements, to elicit visual abnormalities. However, perceptual organization is multi-factorial and, in earlier studies, continuous contours have also been employed in tasks assessing the ability to extract shapes from a background. We conducted a systematic review and meta-analysis of studies using closed-contour stimul...

  18. Are we on a learning curve or a treadmill? The benefits of participative group goal setting become apparent as tasks become increasingly challenging over time

    NARCIS (Netherlands)

    Haslam, S.A.; Wegge, J.; Postmes, T.

    2009-01-01

    A large body of research has pointed to the utility) of individual and group goal setting as a performance enhancement strategy. However, group goal setting is more complex than individual goal setting as the group context often strengthens the desire for voice and the possibility, of resistance. In

  19. Calculation of average molecular parameters, functional groups, and a surrogate molecule for heavy fuel oils using 1H and 13C NMR spectroscopy

    KAUST Repository

    Abdul Jameel, Abdul Gani

    2016-04-22

    Heavy fuel oil (HFO) is primarily used as fuel in marine engines and in boilers to generate electricity. Nuclear Magnetic Resonance (NMR) is a powerful analytical tool for structure elucidation and in this study, 1H NMR and 13C NMR spectroscopy were used for the structural characterization of 2 HFO samples. The NMR data was combined with elemental analysis and average molecular weight to quantify average molecular parameters (AMPs), such as the number of paraffinic carbons, naphthenic carbons, aromatic hydrogens, olefinic hydrogens, etc. in the HFO samples. Recent formulae published in the literature were used for calculating various derived AMPs like aromaticity factor 〖(f〗_a), C/H ratio, average paraffinic chain length (¯n), naphthenic ring number 〖(R〗_N), aromatic ring number〖 (R〗_A), total ring number〖 (R〗_T), aromatic condensation index (φ) and aromatic condensation degree (Ω). These derived AMPs help in understanding the overall structure of the fuel. A total of 19 functional groups were defined to represent the HFO samples, and their respective concentrations were calculated by formulating balance equations that equate the concentration of the functional groups with the concentration of the AMPs. Heteroatoms like sulfur, nitrogen, and oxygen were also included in the functional groups. Surrogate molecules were finally constructed to represent the average structure of the molecules present in the HFO samples. This surrogate molecule can be used for property estimation of the HFO samples and also serve as a surrogate to represent the molecular structure for use in kinetic studies.

  20. Task A, High Energy Physics Program experiment and theory: Task B, High Energy Physics Program numerical simulation of quantum field theories. [Particle Physics Group, Physics Dept. , The Florida State Univ. , Tallahassee

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    The effort of the experimental group has been concentrated on the CERN ALEPH and FERMILAB D0 collider experiments and completion of two fixed target experiments. The BNL fixed target experiment 771 took the world's largest sample of D(1285) and E/iota(1420) events, using pion, kaon and antiproton beams. Observing the following resonances: 0[sup [minus plus

  1. The influence of carbon surface oxygen groups on Dubinin-Astakhov equation parameters calculated from CO{sub 2} adsorption isotherm

    Energy Technology Data Exchange (ETDEWEB)

    Furmaniak, Sylwester; Terzyk, Artur P; Gauden, Piotr A [N Copernicus University, Department of Chemistry, Physicochemistry of Carbon Materials Research Group, Gagarin Street 7, 87-100 Torun (Poland); Harris, Peter J F [Centre for Advanced Microscopy, University of Reading, Whiteknights, Reading RG6 6AF (United Kingdom); Kowalczyk, Piotr, E-mail: aterzyk@chem.uni.torun.p, E-mail: p.j.f.harris@rdg.ac.u [Applied Physics, RMIT University, GPO Box 2476V, Victoria 3001 (Australia)

    2010-03-03

    We present the results of a systematic study of the influence of carbon surface oxidation on Dubinin-Astakhov isotherm parameters obtained from the fitting of CO{sub 2} adsorption data. Using GCMC simulations of adsorption on realistic VPC models differing in porosity and containing the most frequently occurring carbon surface functionalities (carboxyls, hydroxyls and carbonyls) and their mixtures, it is concluded that the maximum adsorption calculated from the DA model is not strongly affected by the presence of oxygen groups. Unfortunately, the same cannot be said of the remaining two parameters of this model i.e. the heterogeneity parameter (n) and the characteristic energy of adsorption (E{sub 0}). Since from the latter the pore diameters of carbons are usually calculated, by inverse-type relationships, it is concluded that they are questionable for carbons containing surface oxides, especially carboxyls.

  2. Development of the neutron-transport code TransRay and studies on the two- and three-dimensional calculation of effective group cross sections

    International Nuclear Information System (INIS)

    Conventionally the data preparation of the neutron cross sections for reactor-core calculations pursues with 2D cell codes. Aim of this thesis was, to develop a 3D cell code, to study with this code 3D effects, and to evaluate the necessarity of a 3D data preparation of the neutron cross sections. For the calculation of the neutron transport the method of the first-collision probabilities, which are calculated with the ray-tracing method, was chosen. The mathematical algorithms were implemented in the 2D/3D cell code TransRay. For the geometry part of the program the geometry module of a Monte Carlo code was used.The ray tracing in 3D was parallelized because of the high computational time. The program TransRay was verified on 2D test problems. For a reference pressured-water reactor following 3D problems were studied: A partly immersed control rod and void (vacuum or steam) around a fuel rod as model of a steam void. All problems were for comparison calculated also with the programs HELIOS(2D) and MCNP(3D). The dependence of the multiplication factor and the averaged two-group cross section on the immersion depth of the control rod respectively of the height of the steam void were studied. The 3D-calculated two-group cross sections were compared with three conventional approximations: Linear interpolation, interpolation with flux weighting, and homogenization, At the 3D problem of the control rod it was shown that the interpolation with flux weighting is a good approximation. Therefore here a 3D data preparation is not necessary. At the test case of the single control rod, which is surrounded by the void, the three approximation for the two-group cross sections were proved as unsufficient. Therefore a 3D data preparation is necessary. The single fuel-rod cell with void can be considered as the limiting case of a reactor, in which a phase interface has been formed

  3. Effects of nuclear data library and ultra-fine group calculation for large size sodium-cooled fast reactor OECD benchmarks

    International Nuclear Information System (INIS)

    The present paper summarizes calculation results for an international benchmark proposed by the Sodium-cooled Fast Reactor core Feed-back and transient response (SFR-FT) under the framework of the Working Party on scientific issues of Reactor Systems (WPRS) of the Nuclear Energy Agency of the OECD. It focuses on the large size oxide-fueled SFR. Library effect for core performance characteristics and reactivity feedback coefficients is analyzed using sensitivity analysis. The effect of ultra-fine energy group calculation in effective cross section generation is also analyzed. The discrepancy is about 0.4% for a neutron multiplication factor by changing JENDL-4.0 with JEFF-3.1. That is about -0.1% by changing JENDL-4.0 with ENDF/B-VII.1. The main contributions to the discrepancy between JENDL-4.0 and ENDF/B-VII.1 are 240Pu capture, 238U inelastic scattering and 239Pu fission. Those to the discrepancy between JENDL-4.0 and JEFF-3.1 are 23Na inelastic scattering, 56Fe inelastic scattering, 238Pu fission, 240Pu capture, 240Pu fission, 238U inelastic scattering, 239Pu fission and 239Pu nu-value. As for the sodium void reactivity, JEFF-3.1 and ENDF/B-VII.1 underestimate by about 8% compared with JENDL-4.0. The main contributions to the discrepancy between JENDL-4.0 and ENDF/B-VII.1 and 23Na elastic scattering, 23Na inelastic scattering and 239Pu fission. That to the discrepancy between JENDL-4.0 and JEFF-3.1 is 23Na inelastic scattering. The ultra-fine energy group calculation increases the sodium void reactivity by 2%. (author)

  4. Description of Bacillus toyonensis sp. nov., a novel species of the Bacillus cereus group, and pairwise genome comparisons of the species of the group by means of ANI calculations.

    Science.gov (United States)

    Jiménez, Guillermo; Urdiain, Mercedes; Cifuentes, Ana; López-López, Aránzazu; Blanch, Anicet R; Tamames, Javier; Kämpfer, Peter; Kolstø, Anne-Brit; Ramón, Daniel; Martínez, Juan F; Codoñer, Francisco M; Rosselló-Móra, Ramon

    2013-09-01

    Strain BCT-7112(T) was isolated in 1966 in Japan from a survey designed to obtain naturally occurring microorganisms as pure cultures in the laboratory for use as probiotics in animal nutrition. This strain, which was primarily identified as Bacillus cereus var toyoi, has been in use for more than 30 years as the active ingredient of the preparation TOYOCERIN(®), an additive for use in animal nutrition (e.g. swine, poultry, cattle, rabbits and aquaculture). Despite the fact that the strain was initially classified as B. cereus, it showed significant genomic differences from the type strains of the B. cereus group that were large enough (ANI values below 92%) to allow it to be considered as a different species within the group. The polyphasic taxonomic study presented here provides sufficient discriminative parameters to classify BCT-7112(T) as a new species for which the name Bacillus toyonensis sp. nov. is proposed, with BCT-7112(T) (=CECT 876(T); =NCIMB 14858(T)) being designated as the type strain. In addition, a pairwise comparison between the available genomes of the whole B. cereus group by means of average nucleotide identity (ANI) calculations indicated that besides the eight classified species (including B. toyonensis), additional genomospecies could be detected, and most of them also had ANI values below 94%. ANI values were on the borderline of a species definition only in the cases of representatives of B. cereus versus B. thuringiensis, and B. mycoides and B. weihenstephanensis. PMID:23791203

  5. ZZ IRDF-2002, 640-Group Cross-Section Library and Spectra for Dosimetry Calculation in ENDF-6 Format. ZZ IRDF-2002-ACE, Cross-Section Library and Spectra for Dosimetry Calculation in ACE Format for Monte Carlo methods. ZZ IRDF-90, 640-Group Cross-Section Library and Spectra for Dosimetry Calculation in ENDF-6 Format. ZZ IRDF-82, 620-Group Cross-Section Library and Spectra for Dosimetry Calculation in ENDF-5 Format

    International Nuclear Information System (INIS)

    1 - Description of problem or function: - ZZ-IRDF-82: ENDF-5 Format; 620 group (SAND II) Dosimetry Library. Nuclides: Li, B, F, Na, Mg, Al, P, S, Sc, Ti, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Rh, In, I, Au, Th, U, Np, Pu, Am. - ZZ-IRDF-90: ENDF-6 Format; 640 groups extended SAND II structure. Nuclides: Li, B, F, Mg, Al, P, S, Sc, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Rh, Cd, Ir, Gd, Au, Th, U, Np, Pu, V. Damage cross section for Fe, Cr, Ni. Weighting spectrum: Maxwell spectrum, 1/E spectrum and Watt fission spectrum. - ZZ-IRDF-2002: ENDF-6 Format (pointwise cross-section data). SAND II 640 energy group structure (multigroup data). Nuclides: Li, B, F, Na, Mg, Al, P, S, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Y, Zr, Nb, Rh, Ag, In, I, La, Pr, Tm, Ta, W, Au, Hg, Pb, Th, U, Np, Pu, Am, Cd, Gd. Damage cross section for Fe, Cr, Ni, Si, GaAs displacement. Weighting spectrum: - Typical MTR spectrum used in the input of the cross-section uncertainty processing code. - Flat weighting spectrum used in converting the pointwise cross-section data to the extended SAND-II group structure. - ZZ-IRDF-2002-ACE: ACE Format (continuous energy cross-section data for Monte Carlo). Nuclides: Li, B, F, Na, Mg, Al, P, S, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Y, Zr, Nb, Rh, Ag, In, I, La, Pr, Tm, Ta, W, Au, Hg, Pb, Th, U, Np, Pu, Am, Cd, Gd. Damage cross section for Fe, Cr, Ni, Si, GaAs displacement. - (A) ZZ-IRDF-82: The 1982 version of the International Reactor Dosimetry File is composed of two different parts. The first part is made up of a collection of dosimetry Cross sections and the second part contains a collection of benchmark spectra. For ease of use in dosimetry applications both Cross sections and spectra are distributed in multigroup form. Each of these two parts is in the ENDF/B-V Format as a separate computer file. I) The dosimetry cross section library contains the following data: (1) The entire ENDF/B-V Dosimetry Library (Mod. 1) in the form of 620 group averaged Cross

  6. Report of the AAPM Task Group No. 105: Issues associated with clinical implementation of Monte Carlo-based photon and electron external beam treatment planning

    International Nuclear Information System (INIS)

    The Monte Carlo (MC) method has been shown through many research studies to calculate accurate dose distributions for clinical radiotherapy, particularly in heterogeneous patient tissues where the effects of electron transport cannot be accurately handled with conventional, deterministic dose algorithms. Despite its proven accuracy and the potential for improved dose distributions to influence treatment outcomes, the long calculation times previously associated with MC simulation rendered this method impractical for routine clinical treatment planning. However, the development of faster codes optimized for radiotherapy calculations and improvements in computer processor technology have substantially reduced calculation times to, in some instances, within minutes on a single processor. These advances have motivated several major treatment planning system vendors to embark upon the path of MC techniques. Several commercial vendors have already released or are currently in the process of releasing MC algorithms for photon and/or electron beam treatment planning. Consequently, the accessibility and use of MC treatment planning algorithms may well become widespread in the radiotherapy community. With MC simulation, dose is computed stochastically using first principles; this method is therefore quite different from conventional dose algorithms. Issues such as statistical uncertainties, the use of variance reduction techniques, the ability to account for geometric details in the accelerator treatment head simulation, and other features, are all unique components of a MC treatment planning algorithm. Successful implementation by the clinical physicist of such a system will require an understanding of the basic principles of MC techniques. The purpose of this report, while providing education and review on the use of MC simulation in radiotherapy planning, is to set out, for both users and developers, the salient issues associated with clinical implementation and

  7. Improved intertask coordination after extensive dual-task practice

    OpenAIRE

    Liepelt, R.; Strobach, T.; Frensch, P.; Schubert, T.

    2011-01-01

    This study examines whether an improved intertask coordination skill is acquired during extensive dual-task training and whether it can be transferred to a new dual-task situation. Participants practised a visual–manual task and an auditory–vocal task. These tasks were trained in two groups matched in dual-task performance measures before practice: a single-task practice group and a hybrid practice group (including single-task and dual-task practice). After practice, the single-task practice ...

  8. Handout on shielding calculation

    International Nuclear Information System (INIS)

    In order to avoid the difficulties of the radioprotection supervisors in the tasks related to shielding calculations, is presented in this paper the basic concepts of shielding theory. It also includes exercises and examples. (author)

  9. Waste area grouping 2 Phase I task data report: Ecological risk assessment and White Oak Creek watershed screening ecological risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Efroymson, R.A.; Jackson, B.L.; Jones, D.S. [and others

    1996-05-01

    This report presents an ecological risk assessment for Waste Area Grouping (WAG) 2 based on the data collected in the Phase I remedial investigation (RI). It serves as an update to the WAG 2 screening ecological risk assessment that was performed using historic data. In addition to identifying potential ecological risks in WAG 2 that may require additional data collection, this report serves to determine whether there are ecological risks of sufficient magnitude to require a removal action or some other expedited remedial process. WAG 2 consists of White Oak Creek (WOC) and its tributaries downstream of the Oak Ridge National Laboratory (ORNL) main plant area, White Oak Lake (WOL), the White Oak Creek Embayment of the Clinch River, associated flood plains, and the associated groundwater. The WOC system drains the WOC watershed, an area of approximately 16.8 km{sup 2} that includes ORNL and associated WAGs. The WOC system has been exposed to contaminants released from ORNL and associated operations since 1943 and continues to receive contaminants from adjacent WAGs.

  10. Testing WIMS-D4M cross sections and the ANL ENDF/B-V 69 group library. Results from global diffusion and Monte Carlo calculations compared with measurements in the Romanian 14-MW TRIGA reactor

    Energy Technology Data Exchange (ETDEWEB)

    Bretscher, M.M.

    1993-12-31

    The WIMS-D4 code has been modified (WIMS-D4M) to produce microscopic isotopic cross sections in ISOTXS format for use in diffusion and transport calculations. Beginning with 69-group libraries based on ENDF/B-V data, numerous cell calculations have been made to prepare a set of broad group cross sections for use in diffusion calculations. Global calculations have been made for two control rod states of the Romanian steady state TRIGA reactor with 29 fresh HEU fuel clusters. Detailed Monte Carlo calculations also have been performed for the same reactor configurations using data based on ENDF/B-V. Results from these global calculations are compared with each other and with the measured excess reactivities. Although region-averaged macroscopic principal cross sections obtained from WIMS-D4M are in good agreement with the corresponding Monte Carlo values, problems exist with the high energy (E > 10 keV) microscopic hydrogen transport cross sections.

  11. INDAR: a computer code for the calculation of critical group radiation exposure from routine discharges of radioactivity to seas and estuaries - description and users' guide

    International Nuclear Information System (INIS)

    The computer program INDAR enables detailed estimates to be made of critical group radiation exposure arising from routine discharges of radioactivity for coastal sites where the discharge is close to the shore and the shoreline is reasonably straight, and for estuarine sites where radioactivity is rapidly mixed across the width of the estuary. Important processes which can be taken into account include the turbulence generated by the discharge, the effects of a sloping sea bed and the variation with time of the lateral dispersion coefficient. The significance of the timing of discharges can also be assessed. INDAR uses physically meaningful hydrographic parameters directly. For most sites the most important exposure pathways are seafood consumption, external exposure over estuarine sediments and beaches, and the handling of fishing gear. As well as for these primary pathways, INDAR enables direct calculations to be made for some additional exposure pathways. The secondary pathways considered are seaweed consumption, swimming, the handling of materials other than fishing gear and the inhalation of activity. (author)

  12. Short-range incommensurate d-wave charge order from a two-loop renormalization group calculation of the ferm-ionic hot spot model

    Science.gov (United States)

    Freire, Hermann; de Carvalho, Vanuildo

    2015-03-01

    The two-loop renormalization group (RG) calculation is considerably extended here for a two-dimensional (2D) fermionic effective field theory model, which includes only the so-called ``hot spots'' that are connected by the spin-density-wave (SDW) ordering wavevector on a Fermi surface generated by the 2D t -t' Hubbard model at low hole doping. We compute the Callan-Symanzik RG equation up to two loops describing the flow of the single-particle Green's function, the corresponding spectral function, the Fermi velocity, and some of the most important order-parameter susceptibilities in the model at lower energies. As a result, we establish that - in addition to clearly dominant SDW correlations - an approximate (pseudospin) symmetry relating a short-range incommensurate d-wave charge order to the d-wave superconducting order indeed emerges at lower energy scales, which is in agreement with recent works available in the literature addressing the 2D spin-fermion model. We derive implications of this possible electronic phase in the ongoing attempt to describe the phenomenology of the pseudogap regime in underdoped cuprates. We acknowledge financial support from CNPq under Grant No. 245919/2012-0 and FAPEG under Grant No. 201200550050248 for this project.

  13. Report of the results of the fiscal 1997 regional consortium R and D project. Regional consortium energy field / R and D of a task adaptation type group architecture transfer robot system, TRIPTERS (first fiscal year); 1997 nendo chiiki consortium kenkyu kaihatsu jigyo. Chiiki consortium energy bun`ya / task tekigogata gun kosei hanso robot system TRIPTERS no kaihatsu kenkyu (daiichi nendo) seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The paper stated the fiscal 1997 result of the development of a task adaptation type group architecture transfer robot system (TRIPTERS) which can cope with changes in carrying task rapidly and flexibly. R and D were conducted mainly of various functional modules, the operation management technology which enables group architecture, and the basic design of a standardized transfer robot. As to the positioning, studied were the construction of the basic hardware of laser position measuring device, and the application method. Concerning the cooperative carrying, conducted were securing of positioning accuracy of matters to be carried, high speed heavy transfer control, and design of dead reckoning system. Relating to the operation management, passable areas were divided into more than one zones, and the effective path reservation method was constructed so that one and the same zone is not occupied. As to the environmental recognition/obstacle avoidance, developed were actual hour/distance acquisition equipment, and autonomous cars running according to the directions of the color sign recognition system by stereo CCD camera. Also conducted were the development of methods to recognize the distance to obstacles and to discriminate areas, the development of mobile sensor, and the basic experiment on running of the demonstration machine. 44 refs., 153 figs., 15 tabs.

  14. A dosimetric uncertainty analysis for photon-emitting brachytherapy sources: Report of AAPM Task Group No. 138 and GEC-ESTRO

    International Nuclear Information System (INIS)

    This report addresses uncertainties pertaining to brachytherapy single-source dosimetry preceding clinical use. The International Organization for Standardization (ISO) Guide to the Expression of Uncertainty in Measurement (GUM) and the National Institute of Standards and Technology (NIST) Technical Note 1297 are taken as reference standards for uncertainty formalism. Uncertainties in using detectors to measure or utilizing Monte Carlo methods to estimate brachytherapy dose distributions are provided with discussion of the components intrinsic to the overall dosimetric assessment. Uncertainties provided are based on published observations and cited when available. The uncertainty propagation from the primary calibration standard through transfer to the clinic for air-kerma strength is covered first. Uncertainties in each of the brachytherapy dosimetry parameters of the TG-43 formalism are then explored, ending with transfer to the clinic and recommended approaches. Dosimetric uncertainties during treatment delivery are considered briefly but are not included in the detailed analysis. For low- and high-energy brachytherapy sources of low dose rate and high dose rate, a combined dosimetric uncertainty <5% (k=1) is estimated, which is consistent with prior literature estimates. Recommendations are provided for clinical medical physicists, dosimetry investigators, and source and treatment planning system manufacturers. These recommendations include the use of the GUM and NIST reports, a requirement of constancy of manufacturer source design, dosimetry investigator guidelines, provision of the lowest uncertainty for patient treatment dosimetry, and the establishment of an action level based on dosimetric uncertainty. These recommendations reflect the guidance of the American Association of Physicists in Medicine (AAPM) and the Groupe Europeen de Curietherapie-European Society for Therapeutic Radiology and Oncology (GEC-ESTRO) for their members and may also be used as

  15. A dosimetric uncertainty analysis for photon-emitting brachytherapy sources: Report of AAPM Task Group No. 138 and GEC-ESTRO

    Energy Technology Data Exchange (ETDEWEB)

    DeWerd, Larry A.; Ibbott, Geoffrey S.; Meigooni, Ali S.; Mitch, Michael G.; Rivard, Mark J.; Stump, Kurt E.; Thomadsen, Bruce R.; Venselaar, Jack L. M. [Department of Medical Physics and Accredited Dosimetry Calibration Laboratory, University of Wisconsin, Madison, Wisconsin 53706 (United States); Department of Radiation Physics, M. D. Anderson Cancer Center, Houston, Texas 77030 (United States); Department of Radiation Oncology, Comprehensive Cancer Center of Nevada, Las Vegas, Nevada 89169 (United States); Ionizing Radiation Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States); Santa Maria Radiation Oncology Center, Santa Maria, California 93454 (United States); Departments of Medical Physics and Human Oncology, University of Wisconsin, Madison, Wisconsin 53706 (United States); Department of Medical Physics and Engineering, Instituut Verbeeten, 5042 SB Tilburg (Netherlands)

    2011-02-15

    This report addresses uncertainties pertaining to brachytherapy single-source dosimetry preceding clinical use. The International Organization for Standardization (ISO) Guide to the Expression of Uncertainty in Measurement (GUM) and the National Institute of Standards and Technology (NIST) Technical Note 1297 are taken as reference standards for uncertainty formalism. Uncertainties in using detectors to measure or utilizing Monte Carlo methods to estimate brachytherapy dose distributions are provided with discussion of the components intrinsic to the overall dosimetric assessment. Uncertainties provided are based on published observations and cited when available. The uncertainty propagation from the primary calibration standard through transfer to the clinic for air-kerma strength is covered first. Uncertainties in each of the brachytherapy dosimetry parameters of the TG-43 formalism are then explored, ending with transfer to the clinic and recommended approaches. Dosimetric uncertainties during treatment delivery are considered briefly but are not included in the detailed analysis. For low- and high-energy brachytherapy sources of low dose rate and high dose rate, a combined dosimetric uncertainty <5% (k=1) is estimated, which is consistent with prior literature estimates. Recommendations are provided for clinical medical physicists, dosimetry investigators, and source and treatment planning system manufacturers. These recommendations include the use of the GUM and NIST reports, a requirement of constancy of manufacturer source design, dosimetry investigator guidelines, provision of the lowest uncertainty for patient treatment dosimetry, and the establishment of an action level based on dosimetric uncertainty. These recommendations reflect the guidance of the American Association of Physicists in Medicine (AAPM) and the Groupe Europeen de Curietherapie-European Society for Therapeutic Radiology and Oncology (GEC-ESTRO) for their members and may also be used as

  16. Game Analysis of Relationships between Emotion Conflicts and Tasks Perform Conflicts in Project Group%项目团队中情感与履行任务冲突关系博弈分析

    Institute of Scientific and Technical Information of China (English)

    万涛

    2011-01-01

    针对项目团队中存在冲突影响团队有效构建与和谐发展的问题,在现有的项目团队冲突经济行为研究成果基础上引进非经济行为分析,利用博弈论构建任务履行冲突(经济行为)与情感冲突(非经济行为)的关系理论模型,实例研究表明,该理论研究符合实际运作,为构建和谐的项目团队提供了理论依据.%Conflicts in project group are important factors affecting the effective establishment and harmonious development of project group. Non - economic behavior conflicts were analysed based on the research achievement of economic behavior conflicts in the existing project group. The relationship theoretical models were set up using tasks perform conflicts ( economic behaviors) and emotion conflicts ( non - economic behaviors) by game theory. The case indicates that the result accords with the practical operation;consequently it gives a basis for theory to establish the harmonious project group.

  17. Simulating the Emergence of Task Rotation

    OpenAIRE

    Kees Zoethout; Wander Jager; Eric Molleman

    2006-01-01

    In work groups, task rotation may decrease the negative consequences of boredom and lead to a better task performance. In this paper we use multi agent simulation to study several organisation types in which task rotation may or may not emerge. By looking at the development of expertise and motivation of the different agents and their performance as a function of self-organisation, boredom, and task rotation frequency, we describe the dynamics of task rotation. The results show that systems i...

  18. Recommendations for the presentation of NMR structures of proteins and nucleic acids - IUPAC-IUBMB-IUPAB Inter-Union Task Group on the Standardization of Data Bases of Protein and Nucleic Acid Structures Determined by NMR Spectroscopy

    International Nuclear Information System (INIS)

    The recommendations presented here are designed to support easier communication of NMR data and NMR structures of proteins and nucleic acids through unified nomenclature and reporting standards. Much of this document pertains to the reporting of data in journal articles; however, in the interest of the future development of structural biology, it is desirable that the bulk of the reported information be stored in computer-accessible form and be freely accessible to the scientific community in standardized formats for data exchange. These recommendations stem from an IUPAC-IUBMB-IUPAB inter-union venture with the direct involvement of ICSU and CODATA. The Task Group has reviewed previous formal recommendations and has extended them in the light of more recent developments in the field of biomolecular NMR spectroscopy. Drafts of the recommendations presented here have been examined critically by more than 50 specialists in the field and have gone through two rounds of extensive modification to incorporate suggestions and criticisms

  19. Task A: Yale Accelerator Users Group (YAUG)

    International Nuclear Information System (INIS)

    This report discusses the following topics: Yaug collider detector program; E-791: continued study of heavy flavors at TPL; Hadroproduction of charm and beauty; Search for composite objects produced in relativistic heavy ion collisions; and high energy physics computer facility

  20. Developmental changes in using verbal self-cueing in task-switching situations: The impact of task practice and task-sequencing demands

    Directory of Open Access Journals (Sweden)

    Jutta eKray

    2013-12-01

    Full Text Available In this study we examined whether developmental changes in using verbal self-cueing for task-goal maintenance are dependent on the amount of task practice and task-sequencing demands. To measure task-goal maintenance we applied a switching paradigm in which children either performed only task A or B in single-task blocks or switched between them on every second trial in mixed-task blocks. Task-goal maintenance was determined by comparing the performance between both blocks (mixing costs. The influence of verbal self-cueing was measured by instructing children to either name the next task aloud or not to verbalize during task preparation. Task-sequencing demands were varied between groups whereas one group received spatial task cues to support keeping track of the task sequence, while the other group did not. We also varied by the amount of prior practice in task switching while one group of participants practiced task switching first, before performing the task naming in addition, and the other group did it vice versa. Results of our study investigating younger (8-10 years and older children (11-13 years revealed no age differences in beneficial effects of verbal self-cueing. In line with previous findings, children showed reduced mixing costs under task-naming instructions and under conditions of low task-sequence demands (with the presence of spatial task cues. Our results also indicated that these benefits were only obtained for those groups of children that first received practice in task switching alone with no additional verbalization instruction. These findings suggest that internal task-cueing strategies can be efficiently used in children but only if they received prior practice in the underlying task so that demands on keeping and coordinating various instructions are reduced. Moreover, children benefitted from spatial task cues for better task-goal maintenance only if no verbal task-cueing strategy was introduced first.

  1. Functionality and operation of fluoroscopic automatic brightness control/automatic dose rate control logic in modern cardiovascular and interventional angiography systems: A Report of Task Group 125 Radiography/Fluoroscopy Subcommittee, Imaging Physics Committee, Science Council

    International Nuclear Information System (INIS)

    Task Group 125 (TG 125) was charged with investigating the functionality of fluoroscopic automatic dose rate and image quality control logic in modern angiographic systems, paying specific attention to the spectral shaping filters and variations in the selected radiologic imaging parameters. The task group was also charged with describing the operational aspects of the imaging equipment for the purpose of assisting the clinical medical physicist with clinical set-up and performance evaluation. Although there are clear distinctions between the fluoroscopic operation of an angiographic system and its acquisition modes (digital cine, digital angiography, digital subtraction angiography, etc.), the scope of this work was limited to the fluoroscopic operation of the systems studied. The use of spectral shaping filters in cardiovascular and interventional angiography equipment has been shown to reduce patient dose. If the imaging control algorithm were programmed to work in conjunction with the selected spectral filter, and if the generator parameters were optimized for the selected filter, then image quality could also be improved. Although assessment of image quality was not included as part of this report, it was recognized that for fluoroscopic imaging the parameters that influence radiation output, differential absorption, and patient dose are also the same parameters that influence image quality. Therefore, this report will utilize the terminology ''automatic dose rate and image quality'' (ADRIQ) when describing the control logic in modern interventional angiographic systems and, where relevant, will describe the influence of controlled parameters on the subsequent image quality. A total of 22 angiography units were investigated by the task group and of these one each was chosen as representative of the equipment manufactured by GE Healthcare, Philips Medical Systems, Shimadzu Medical USA, and Siemens Medical Systems. All equipment, for which measurement data were

  2. Task-related functional connectivity in autism spectrum conditions: an EEG study using wavelet transform coherence

    Directory of Open Access Journals (Sweden)

    Catarino Ana

    2013-01-01

    Full Text Available Abstract Background Autism Spectrum Conditions (ASC are a set of pervasive neurodevelopmental conditions characterized by a wide range of lifelong signs and symptoms. Recent explanatory models of autism propose abnormal neural connectivity and are supported by studies showing decreased interhemispheric coherence in individuals with ASC. The first aim of this study was to test the hypothesis of reduced interhemispheric coherence in ASC, and secondly to investigate specific effects of task performance on interhemispheric coherence in ASC. Methods We analyzed electroencephalography (EEG data from 15 participants with ASC and 15 typical controls, using Wavelet Transform Coherence (WTC to calculate interhemispheric coherence during face and chair matching tasks, for EEG frequencies from 5 to 40 Hz and during the first 400 ms post-stimulus onset. Results Results demonstrate a reduction of interhemispheric coherence in the ASC group, relative to the control group, in both tasks and for all electrode pairs studied. For both tasks, group differences were generally observed after around 150 ms and at frequencies lower than 13 Hz. Regarding within-group task comparisons, while the control group presented differences in interhemispheric coherence between faces and chairs tasks at various electrode pairs (FT7-FT8, TP7-TP8, P7-P8, such differences were only seen for one electrode pair in the ASC group (T7-T8. No significant differences in EEG power spectra were observed between groups. Conclusions Interhemispheric coherence is reduced in people with ASC, in a time and frequency specific manner, during visual perception and categorization of both social and inanimate stimuli and this reduction in coherence is widely dispersed across the brain. Results of within-group task comparisons may reflect an impairment in task differentiation in people with ASC relative to typically developing individuals. Overall, the results of this research support the value of WTC

  3. Task inhibition and task repetition in task switching

    OpenAIRE

    Philipp, A; Koch, I.

    2006-01-01

    To explore the effect of exogenous processes on cognitive control, we used a cueing task-switching paradigm with two spatial judgement tasks and added an irrelevant colour attribute to the task-relevant spatial attribute of the target. The colour was not related to any specific Stimulus-Response relation in the tasks. A correlation was created between stimulus colour and task identity. This correlation was strong but imperfect in Experiment 1 and perfect in Experiment 2. As a result of the co...

  4. Cognitive Complexity of Mathematics Instructional Tasks in a Taiwanese Classroom: An Examination of Task Sources

    Science.gov (United States)

    Hsu, Hui-Yu; Silver, Edward A.

    2014-01-01

    We examined geometric calculation with number tasks used within a unit of geometry instruction in a Taiwanese classroom, identifying the source of each task used in classroom instruction and analyzing the cognitive complexity of each task with respect to 2 distinct features: diagram complexity and problem-solving complexity. We found that…

  5. 13C GIAO DFT calculation as a tool for configuration prediction of N-O group in saturated heterocyclic N-oxides

    Czech Academy of Sciences Publication Activity Database

    Pohl, Radek; Potmischil, F.; Dračínský, Martin; Vaněk, Václav; Slavětínská, Lenka; Buděšínský, Miloš

    2012-01-01

    Roč. 50, č. 6 (2012), s. 415-423. ISSN 0749-1581 R&D Projects: GA ČR GA203/09/1919 Institutional research plan: CEZ:AV0Z40550506 Keywords : NMR * 13C * 1H * saturated heterocyclic N-oxides * chemical shift calculations * DFT Subject RIV: CC - Organic Chemistry Impact factor: 1.528, year: 2012

  6. Operating and maintenance experience with computer-based systems in nuclear power plants - A report by the PWG-1 Task Group on Computer-based Systems Important to Safety

    International Nuclear Information System (INIS)

    This report was prepared by the Task Group on Computer-based Systems Important to Safety of the Principal Working Group No. 1. Canada had a leading role in this study. Operating and Maintenance Experience with Computer-based Systems in nuclear power plants is essential for improving and upgrading against potential failures. The present report summarises the observations and findings related to the use of digital technology in nuclear power plants. It also makes recommendations for future activities in Member Countries. Continued expansion of digital technology in nuclear power reactor has resulted in new safety and licensing issues, since the existing licensing review criteria were mainly based on the analogue devices used when the plants were designed. On the industry side, a consensus approach is needed to help stabilise and standardise the treatment of digital installations and upgrades while ensuring safety and reliability. On the regulatory side, new guidelines and regulatory requirements are needed to assess digital upgrades. Upgrades or new installation issues always involve potential for system failures. They are addressed specifically in the 'hazard' or 'failure' analysis, and it is in this context that they ultimately are resolved in the design and addressed in licensing. Failure Analysis is normally performed in parallel with the design, verification and validation (V and V), and implementation activities of the upgrades. Current standards and guidelines in France, U.S. and Canada recognise the importance of failure analysis in computer-based system design. Thus failure analysis is an integral part of the design and implementation process and is aimed at evaluating potential failure modes and cause of system failures. In this context, it is essential to define 'System' as the plant system affected by the upgrade, not the 'Computer' system. The identified failures would provide input to the design process in the form of design requirements or design

  7. Mobile Thread Task Manager

    Science.gov (United States)

    Clement, Bradley J.; Estlin, Tara A.; Bornstein, Benjamin J.

    2013-01-01

    The Mobile Thread Task Manager (MTTM) is being applied to parallelizing existing flight software to understand the benefits and to develop new techniques and architectural concepts for adapting software to multicore architectures. It allocates and load-balances tasks for a group of threads that migrate across processors to improve cache performance. In order to balance-load across threads, the MTTM augments a basic map-reduce strategy to draw jobs from a global queue. In a multicore processor, memory may be "homed" to the cache of a specific processor and must be accessed from that processor. The MTTB architecture wraps access to data with thread management to move threads to the home processor for that data so that the computation follows the data in an attempt to avoid L2 cache misses. Cache homing is also handled by a memory manager that translates identifiers to processor IDs where the data will be homed (according to rules defined by the user). The user can also specify the number of threads and processors separately, which is important for tuning performance for different patterns of computation and memory access. MTTM efficiently processes tasks in parallel on a multiprocessor computer. It also provides an interface to make it easier to adapt existing software to a multiprocessor environment.

  8. Numerical processing efficiency improved in children using mental abacus: ERP evidence utilizing a numerical Stroop task

    Directory of Open Access Journals (Sweden)

    Feiyan Chen

    2015-05-01

    Full Text Available This study examined whether long-term abacus-based mental calculation (AMC training improved numerical processing efficiency and at what stage of information processing the effect appeard. Thirty-three children participated in the study and were randomly assigned to two groups at primary school entry, matched for age, gender and IQ. All children went through the same curriculum except that the abacus group received a 2-hour/per week AMC training, while the control group did traditional numerical practice for a similar amount of time. After a two-year training, they were tested with a numerical Stroop task. Electroencephalographic (EEG and event related potential (ERP recording techniques were used to monitor the temporal dynamics during the task. Children were required to determine the numerical magnitude (NC task or the physical size (PC task of two numbers presented simultaneously. In the NC task, the AMC group showed faster response times but similar accuracy compared to the control group. In the PC task, the two groups exhibited the same speed and accuracy. The saliency of numerical information relative to physical information was greater in AMC group. With regards to ERP results, the AMC group displayed congruity effects both in the earlier (N1 and later (N2 and LPC (late positive component time domain, while the control group only displayed congruity effects for LPC. In the left parietal region, LPC amplitudes were larger for the AMC than the control group. Individual differences for LPC amplitudes over left parietal area showed a positive correlation with RTs in the NC task in both congruent and neutral conditions. After controlling for the N2 amplitude, this correlation also became significant in the incongruent condition. Our results suggest that AMC training can strengthen the relationship between symbolic representation and numerical magnitude so that numerical information processing becomes quicker and automatic in AMC children.

  9. Optimization: Old Dogs and New Tasks

    Science.gov (United States)

    Kaplan, Jennifer J.; Otten, Samuel

    2012-01-01

    This article introduces an optimization task with a ready-made motivating question that may be paraphrased as follows: "Are you smarter than a Welsh corgi?" The authors present the task along with descriptions of the ways in which two groups of students approached it. These group vignettes reveal as much about the nature of calculus students'…

  10. Abacus Training Affects Math and Task Switching Abilities and Modulates Their Relationships in Chinese Children.

    Science.gov (United States)

    Wang, Chunjie; Geng, Fengji; Yao, Yuan; Weng, Jian; Hu, Yuzheng; Chen, Feiyan

    2015-01-01

    Our previous work demonstrated that abacus-based mental calculation (AMC), a traditional Chinese calculation method, could help children improve their math abilities (e.g. basic arithmetical ability) and executive function (e.g. working memory). This study further examined the effects of long-term AMC training on math ability in visual-spatial domain and the task switching component of executive function. More importantly, this study investigated whether AMC training modulated the relationship between math abilities and task switching. The participants were seventy 7-year-old children who were randomly assigned into AMC and control groups at primary school entry. Children in AMC group received 2-hour AMC training every week since primary school entry. On the contrary, children in the control group had never received any AMC training. Math and task switching abilities were measured one year and three years respectively after AMC training began. The results showed that AMC children performed better than their peers on math abilities in arithmetical and visual-spatial domains. In addition, AMC group responded faster than control group in the switching task, while no group difference was found in switch cost. Most interestingly, group difference was present in the relationships between math abilities and switch cost. These results implied the effect of AMC training on math abilities as well as its relationship with executive function. PMID:26444689

  11. Calculation of demands for nuclear fuels and fuel cycle services. Description of computer model and strategies developed by Working Group 1

    International Nuclear Information System (INIS)

    Working Group 1 examined a range of reactor deployment strategies and fuel cycle options, in oder to estimate the range of nuclear fuel requirements and fuel cycle service needs which would result. The computer model, its verification in comparison with other models, the strategies to be examined through use of the model, and the range of results obtained are described

  12. An application of the renormalization group to the calculation of the vacuum decay rate in flat and curved space-time

    CERN Document Server

    Metaxas, D

    2004-01-01

    I show that an application of renormalization group arguments may lead to significant corrections to the vacuum decay rate for phase transitions in flat and curved space-time. It can also give some information regarding its dependence on the parameters of the theory, including the cosmological constant in the case of decay in curved space-time.

  13. Heats of formation of MHxCly (M = Si, P, As, Sb) compounds and main group fluorides from high level electronic structure calculations.

    Science.gov (United States)

    Vasiliu, Monica; Grant, Daniel J; Feller, David; Dixon, David A

    2012-04-12

    Atomization energies at 0 K and heats of formation at 0 and 298 K are predicted for the MH(x)Cl(y) compounds (M = Si, P, As, and Sb) and for a number of trivalent, tetravalent, and pentavalent fluorides (SbF(3), BiF(3), GeF(4), SnF(4), PbF(4), AsF(5), SbF(5)) from coupled cluster theory (CCSD(T)) calculations using correlation consistent basis sets and extrapolation to the complete basis set limit. Small-core, relativistic effective core potentials were used for the heavier elements (Ge, As, Sn, Sb, Pb, and Bi), including correlation of the outer core electrons. Additional scalar relativistic (for the lighter elements) and atomic spin-orbit corrections are included in order to achieve near chemical accuracy of ±1.5 kcal/mol. Vibrational zero point energies were computed from scaled harmonic frequencies at the second order Møller-Plesset perturbation theory (MP2) level where possible. Agreement between theory and the available experimental data is excellent. We present a revised heat of formation of the antimony atom in the gas phase. The calculated values will be of use in predicting the behavior of chemical vapor deposition systems. PMID:22397634

  14. MINOR PARAMETERS NEEDED FOR INDIVIDUAL-DOSE CALCULATIONS: Final Report for Tasks 7.1, 7.2, 8.1, 8.2, 9.1, 9.2, and 9.3

    Energy Technology Data Exchange (ETDEWEB)

    Anspaugh, L. R.; Napier, Bruce A.

    2009-10-23

    This brief report documents the selection of parameters needed to support individual-dose calculations from 131I released into the environment with gaseous effluents from the Mayak Production Association.

  15. Assessing the implications on performance when aligning customer lifetime value calculations with religious faith groups and afterlifetime values - a Socratic elenchus approach

    DEFF Research Database (Denmark)

    Hollensen, Svend; Wilson, Jonathan

    2013-01-01

    Customer Lifetime Value (CLV) is an established relationship marketing-centric approach to evaluating performance based upon the significance of a customer, and what resources should be allocated towards maintaining relations – beyond short-term transactional views. The conceptual argument...... presented in this paper contributes one very simple, yet significant argument, which is both transactional and relational. Namely, a large portion of humanity believes in a life beyond current existence – the Afterlife. Therefore, death in the psyche of such a person does not terminate benefit seeking......, and there is value in the afterlife. The aim here is to refine value-based calculations, drawing from varying religious perspectives: reincarnation, heaven, and enlightenment, amongst others. A particular focus has been given to Islamic schools of thought and practices, as a test case and in response to market...

  16. Ab initio calculation of the electronic and vibrational properties of metal-organic molecules based on cyclic C{sub 6} intercalated with some group VIII transition metals

    Energy Technology Data Exchange (ETDEWEB)

    Kuzmin, Stanislav L.; Duley, Walter W. [Department of Physics and Astronomy, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1 (Canada)

    2013-04-15

    The vibrational and electronic properties of a new class of organometallic sandwich molecules, (C{sub 6}){sub n}Me{sub n-1}, based on stacks of cyclic C{sub 6} intercalated with Fe and Ru have been studied using first principles density functional techniques (DFT). Spectral properties as well as the HOMO-LUMO gap energy in molecules containing up to eight C{sub 6} layers have been calculated. The HOMO-LUMO energy gap in these molecules is < 1 eV and decreases significantly in longer molecules. It is shown that infinite chains should have excellent metallic properties. These molecules are promising for nanoelectronic applications, due to their predicted high stability, conductivity, and magnetic properties. (copyright 2013 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Atomistic processes of Ni and Pd atoms on MgO(001) surfaces with surface-functional hydroxyl groups: ab-initio calculations

    International Nuclear Information System (INIS)

    By using ab-initio calculations based on the density functional theory, we systematically studied the adsorption and the diffusion properties of Ni and Pd (XM) atoms on hydroxylated MgO(001) [MgOhdr(001)] surfaces. The energetics of adsorption, binding, and diffusion are presented and compared with those of XM atoms on clean MgO(001). The calculated energetics showed considerably enhanced adsorption of XM on MgOhdr(001) compared to that on MgO(001). The stronger binding of XM and OH on MgO(001) indicated the favorable formation of XMOH complexes instead of XM dimers on the surface. In the case of surface diffusion, XMOH on MgO(001) was observed to diffuse via a hopping process over the surface hollow sites. The diffusion of XMOH on MgO(001) was slightly faster than that of XM atoms. Compared to the surface diffusion of PtOH on MgO(001), the surface diffusion energy barriers were in the following order, PtOH (0.89 eV) > NiOH (0.71 eV) > PdOH (0.43 eV). Therefore, the surface dynamics of Ni, Pd, and Pt on MgOhdr(001) driven thermally at temperatures relevant to the catalytic activities of metal clusters are expected to be different. The electronic structures and the charge states of XMOH on MgO(001) were analyzed further and compared with those of XM on MgO(001).

  18. Group Anonymity

    CERN Document Server

    Chertov, Oleg; 10.1007/978-3-642-14058-7_61

    2010-01-01

    In recent years the amount of digital data in the world has risen immensely. But, the more information exists, the greater is the possibility of its unwanted disclosure. Thus, the data privacy protection has become a pressing problem of the present time. The task of individual privacy-preserving is being thoroughly studied nowadays. At the same time, the problem of statistical disclosure control for collective (or group) data is still open. In this paper we propose an effective and relatively simple (wavelet-based) way to provide group anonymity in collective data. We also provide a real-life example to illustrate the method.

  19. Orientation Preferences of Backbone Secondary Amide Functional Groups in Peptide Nucleic Acid Complexes: Quantum Chemical Calculations Reveal an Intrinsic Preference of Cationic D-Amino Acid-Based Chiral PNA Analogues for the P-form

    OpenAIRE

    Topham, Christopher M.; Smith, Jeremy C.

    2006-01-01

    Geometric descriptions of nonideal interresidue hydrogen bonding and backbone-base water bridging in the minor groove are established in terms of polyamide backbone carbonyl group orientation from analyses of residue junction conformers in experimentally determined peptide nucleic acid (PNA) complexes. Two types of interresidue hydrogen bonding are identified in PNA conformers in heteroduplexes with nucleic acids that adopt A-like basepair stacking. Quantum chemical calculations on the bindin...

  20. Clinical task performance and imaging task performance compared for two different commercial electronic portal imaging systems

    International Nuclear Information System (INIS)

    Full text: This paper reports on the investigation and comparison of performance of a Varian Portal Vision system and a Siemens Beamview Plus system using the framework outlined by ICRU Report 54. Radiation Therapy EPI (Electronic Portal Imaging) systems are one of the main applications of digital imaging technology in a radiation therapy department. Radiation Therapy EPI systems may produce images of a lesser quality than the diagnostic radiology equivalent. It is therefore important to optimise the system to obtain the best performance possible. Contrasting opinion on the performance of EPI by clinicians, radiation therapists, medical physicists and engineers often exists, even when the same system and even the same image are being evaluated. Differing opinion occurs because of differences in task end points and task assessment methods of two broad groups of individuals, the human-observer group and the technical-measurement group. Each group uses different task criteria and methodology for assessing performance. The human-observer group is primarily interested in system performance that assures a high level clinical-task performance while the technical-measurement group is concerned with system performance that assures a high level of imaging-task performance. The technical-measurement group tends to be closely associated with imaging system technology, testing, adjustment and optimisation tasks which are couched in terms imaging-task criteria. The human-observer group is usually attempting to optimise performance using clinical-task criteria. The challenge is to provide a balanced evaluation using complementary imaging-task performance and clinical-task performance assessments. Comparison of the systems is on the basis of imaging-task performance i.e. technical-measurement through physical performance assessments such as spatial resolution and noise level, and clinical-task performance i.e. human-observer measurements through the application of psychophysical

  1. The relationship between motor recovery and gait velocity during dual tasks in patients with chronic stroke.

    Science.gov (United States)

    Lee, Kyoung Bo; Kim, Jang Hwan; Lee, Kang Sung

    2015-04-01

    [Purpose] The aims of this study were to identify the relationship between motor recovery and gait velocity during dual tasks in patients with chronic stroke and determine automatic gait ability following stroke. [Subjects and Methods] Thirty-three outpatients and twelve healthy subjects participated in a cross-sectional assessment. Community ambulation was assessed using a self-administered questionnaire. Outcome measures included the Motricity index, Berg Balance Scale, and gait speed under three conditions (self-paced ambulation for 10 m, ambulation while performing dual cognitive tasks, and ambulation while performing dual manual tasks). Gait automaticity was calculated. [Results] No significant differences were observed for muscle strength or balance between the limited community ambulation and the community ambulation groups. However, a significant difference in gait velocity was observed between the groups under the three conditions. In particular, a significant difference was detected only in the limited community ambulation group depending on the level of motor function recovery during cognitive and manual dual task ambulation. Additionally, we revealed that the community ambulation group had a lower level of gait automaticity compared with that in the normal group. [Conclusion] Our results show the influence of motor recovery on the change in gait velocity depending on the task if a patient is limitedly ambulatory. We revealed that community ambulators did not have a sufficient level of gait automaticity. PMID:25995582

  2. Cohesiveness and Performance on an Additive Task: Evidence for Multidimensionality.

    Science.gov (United States)

    Zaccaro, Stephen J.; Lowe, Charles A.

    1988-01-01

    Presents a study designed to contrast the effects of task-based and interpersonal cohesiveness on group performance of students. Concludes that high task cohesion helped group performance, while interpersonal attraction had no apparent effect. Finding that increased interpersonal cohesion improved task commitment, the authors suggest that…

  3. The Relationship between Task Cohesion and Competitive State Anxiety.

    Science.gov (United States)

    Eys, Mark A.; Hardy, James; Carron, Albert V.; Beauchamp, Mark R.

    2003-01-01

    Examined the association between athlete perceptions of task cohesiveness (Individual Attractions to the Group-Task and Group Integration-Task) and the degree to which they viewed their perceptions of the presence of pre-competition anxiety symptoms as facilitative or debilitative. Survey data indicated that the more positive their perceptions of…

  4. Project Tasks in Robotics

    DEFF Research Database (Denmark)

    Sørensen, Torben; Hansen, Poul Erik

    1998-01-01

    Description of the compulsary project tasks to be carried out as a part of DTU course 72238 Robotics......Description of the compulsary project tasks to be carried out as a part of DTU course 72238 Robotics...

  5. Novice supervisors' tasks and training

    DEFF Research Database (Denmark)

    Nielsen, Jan; Jacobsen, Claus Haugaard; Mathiesen, Birgit Bork

    2012-01-01

    The debut as a clinical supervisor is still rather unknown. The aim of this study is to explore what kind of tasks novice supervisors undertake and how they are prepared for these. During 2009–2010, 350 Danish clinical psychologists have responded to the Development of Psychotherapists Common Core...... Questionnaire covering a wide range of items on professional development, experience, and practice. In this paper we focus on background data (experience, training and practice), specifically the tasks and training of the respondents as novice supervisors. The results show, that a majority of novice supervisors...... were confronted with complicated jobs, e.g., group, internal and interdisciplinary supervision, but were not prepared, i.e. trained, prior to these tasks. These findings imply that more training is needed for novice supervisors. Preferably, this training should be introduced before, or at least...

  6. Launching Complex Tasks

    Science.gov (United States)

    Jackson, Kara J.; Shahan, Emily C.; Gibbons, Lynsey K.; Cobb, Paul A.

    2012-01-01

    Mathematics lessons can take a variety of formats. In this article, the authors discuss lessons organized around complex mathematical tasks. These lessons usually unfold in three phases. First, the task is introduced to students. Second, students work on solving the task. Third, the teacher "orchestrates" a concluding whole-class discussion in…

  7. Analysis of Spectral Features of EEG during four different Cognitive Tasks

    Directory of Open Access Journals (Sweden)

    S.BAGYARAJ

    2014-05-01

    Full Text Available Cognition is a group of information processing activities that involves the visual attention, visual awareness, problem solving and decision making. Finding the cognitive task related regional cerebral activations are of great interest among researchers in cognitive neuroscience. In this study four different types of cognitive tasks, namely tracking pendulum movement and counting, red flash counting, sequential subtraction, spot the difference is performed by 32 subjects and the EEG signals are acquired by using 24 channels RMS EEG-32 Super Spec machine. The analyses of the EEG signal are done by using well known spectral methods. The band powers are calculated in the frequency domain by using the Welch method. The task- relaxes relative band power values and the ratios of theta band power/ beta band power are the two variables used to find the regional cerebral activations during the four different cognitive tasks. The statistical paired t test is used to evaluate the significant difference between the particular tasks related cerebral activations and relaxation. The statistical significance level is set at p< 0.05. During the tracking pendulum movement and counting task, the cerebral activations are found to be bilateral prefrontal, frontal, right central and temporal regions. Red flash counting task has activations in bilateral prefrontal, frontal, right central, right parietal and right occipital lobes. Bilateral prefrontal regions are activated during the sequence subtraction task. The spot the difference task has activations in the left and right prefrontal cortex. The unique and common activations regions for the selected four different cognitive tasks are found to be left and right prefrontal cortex. The pre frontal lobe electrodes namely Fp1 & Fp2 can be used as the recording electrodes for detailed cognitive task analysis were cerebral activations are observed when compared with the other cerebral regions.

  8. Self-timing in Memory and Visual Search Tasks

    OpenAIRE

    Han, H J; Viau-Quesnel, C.; Xi, Z; Schweickert, R.; Fortin, C.

    2010-01-01

    We investigated the ability of people to time themselves as they perform cognitive tasks. One group did a memory search task, another did a visual search task. After each response, participants estimated the duration of their own reaction time. In both tasks, correlations between reaction times and temporal judgments were significant, showing that people can provide precise quantitative estimates of mental processes when they perform memory and visual search tasks. Increasing l...

  9. Users Report of HIP-TEDDI. A two dimensional, four group code for the calculation of the neutron fluence in experiment positions and operating data of the materials testing reactor HFR at Petten

    International Nuclear Information System (INIS)

    HIP-TEDDI is a computer code package for the calculation of nuclear quantities in experiments or experiment positions and data relevant for the operation of the materials testing reactor HFR at Petten. It is based upon the calculation of the neutron flux densities in four broad energy groups, in X, Y geometry, averaged over the fuel height. From these flux densities and from-pre-calculated fine group spectra in several core regions, various nuclear quantities are derived such as fast flux densities (E > 0.1 MeV and E > 1.0 MeV), equivalent fission neutron flux density, 2200 m/s flux density, damaging flux densities, damage-to-activation ratio (DAR), equivalent DIDO nickel flux density and the nuclear heating rate. After each burn-up step the corresponding fluences, displacements per atom (DPA) and burn-up averaged DAR are determined. For the operation of the reactor a number of important data are calculated such as over reactivity, control rod insertion depth, shut-down time margin and thermal safety data e.g. allowable maximum inlet temperature of primary water. Calculations are performed at start-up with initial concentration of fission products, at start-up with equilibrium concentration of rapidly saturing fission products and after each burn-up step for the actual concentration of fission products. For all these situations the control rod setting is taken into account. Information about the history of the fuel elements is produced for subsequent HIP-TEDDI runs and for fuel transport and administration programmes. The HIP-TEDDI package consists of a number of computer programmes written in FORTRAN IV. The data transmission between these programmes takes place by means of files which are temporarily stored at backbround memory. The programme operates on the CDC 6600 computer at Petten. A complete calculation for one cycle of 26 days, with 15 copies for the experimentators and the operation staff, needs a field length of 60 K (decimal) words, a central processor

  10. Error Sonification of a Complex Motor Task

    Directory of Open Access Journals (Sweden)

    Riener Robert

    2011-12-01

    Full Text Available Visual information is mainly used to master complex motor tasks. Thus, additional information providing augmented feedback should be displayed in other modalities than vision, e.g. hearing. The present work evaluated the potential of error sonification to enhance learning of a rowing-type motor task. In contrast to a control group receiving self-controlled terminal feedback, the experimental group could not significantly reduce spatial errors. Thus, motor learning was not enhanced by error sonification, although during the training the participant could benefit from it. It seems that the motor task was too slow, resulting in immediate corrections of the movement rather than in an internal representation of the general characteristics of the motor task. Therefore, further studies should elaborate the impact of error sonification when general characteristics of the motor tasks are already known.

  11. Task Specialization, Immigration, and Wages

    OpenAIRE

    Peri, Giovanni; Sparber, Chad

    2008-01-01

    Many workers with low levels of educational attainment immigrated to the United States in recent decades. Large inflows of less-educated immigrants would reduce wages paid to comparably-educated native-born workers if the two groups are perfectly substitutable in production. In a simple model exploiting comparative advantage, however, we show that if less-educated foreign and native-born workers specialize in performing different tasks, immigration will cause natives to reallocate their...

  12. New and extended parameterization of the thermodynamic model AIOMFAC: calculation of activity coefficients for organic-inorganic mixtures containing carboxyl, hydroxyl, carbonyl, ether, ester, alkenyl, alkyl, and aromatic functional groups

    Directory of Open Access Journals (Sweden)

    A. Zuend

    2011-09-01

    Full Text Available We present a new and considerably extended parameterization of the thermodynamic activity coefficient model AIOMFAC (Aerosol Inorganic-Organic Mixtures Functional groups Activity Coefficients at room temperature. AIOMFAC combines a Pitzer-like electrolyte solution model with a UNIFAC-based group-contribution approach and explicitly accounts for interactions between organic functional groups and inorganic ions. Such interactions constitute the salt-effect, may cause liquid-liquid phase separation, and affect the gas-particle partitioning of aerosols. The previous AIOMFAC version was parameterized for alkyl and hydroxyl functional groups of alcohols and polyols. With the goal to describe a wide variety of organic compounds found in atmospheric aerosols, we extend here the parameterization of AIOMFAC to include the functional groups carboxyl, hydroxyl, ketone, aldehyde, ether, ester, alkenyl, alkyl, aromatic carbon-alcohol, and aromatic hydrocarbon. Thermodynamic equilibrium data of organic-inorganic systems from the literature are critically assessed and complemented with new measurements to establish a comprehensive database. The database is used to determine simultaneously the AIOMFAC parameters describing interactions of organic functional groups with the ions H+, Li+, Na+, K+, NH4+, Mg2+, Ca2+, Cl, Br, NO3, HSO4, and SO42−. Detailed descriptions of different types of thermodynamic data, such as vapor-liquid, solid-liquid, and liquid-liquid equilibria, and their use for the model parameterization are provided. Issues regarding deficiencies of the database, types and uncertainties of experimental data, and limitations of the model, are discussed. The challenging parameter optimization problem is solved with a novel combination of powerful global minimization

  13. New and extended parameterization of the thermodynamic model AIOMFAC: calculation of activity coefficients for organic-inorganic mixtures containing carboxyl, hydroxyl, carbonyl, ether, ester, alkenyl, alkyl, and aromatic functional groups

    Directory of Open Access Journals (Sweden)

    A. Zuend

    2011-05-01

    Full Text Available We present a new and considerably extended parameterization of the thermodynamic activity coefficient model AIOMFAC (Aerosol Inorganic-Organic Mixtures Functional groups Activity Coefficients at room temperature. AIOMFAC combines a Pitzer-like electrolyte solution model with a UNIFAC-based group-contribution approach and explicitly accounts for interactions between organic functional groups and inorganic ions. Such interactions constitute the salt-effect, may cause liquid-liquid phase separation, and affect the gas-particle partitioning of aerosols. The previous AIOMFAC version was parameterized for alkyl and hydroxyl functional groups of alcohols and polyols. With the goal to describe a wide variety of organic compounds found in atmospheric aerosols, we extend here the parameterization of AIOMFAC to include the functional groups carboxyl, hydroxyl, ketone, aldehyde, ether, ester, alkenyl, alkyl, aromatic carbon-alcohol, and aromatic hydrocarbon. Thermodynamic equilibrium data of organic-inorganic systems from the literature are critically assessed and complemented with new measurements to establish a comprehensive database. The database is used to determine simultaneously the AIOMFAC parameters describing interactions of organic functional groups with the ions H+, Li+, Na+, K+, NH4+, Mg2+, Ca2+, Cl, Br, NO3, HSO4, and SO42−. Detailed descriptions of different types of thermodynamic data, such as vapor-liquid, solid-liquid, and liquid-liquid equilibria, and their use for the model parameterization are provided. Issues regarding deficiencies of the database, types and uncertainties of experimental data, and limitations of the model, are discussed. The challenging parameter optimization problem is solved with a novel combination of powerful global minimization

  14. Activation on occipital lobe in children with abacus mental calculation training: an fMRI study

    International Nuclear Information System (INIS)

    Objective: By exploring the activation on occipital lobe in children with and without abacus mental calculation training when they engaged in different calculation tasks with functional magnetic resonance imaging (fMRI), to identify the possible mechanism of occipital lobe in abacus mental calculation. Methods: fMRI was performed in children trained with and without (sixteen in each group) abacus mental calculation when they engaged in addition, subtraction. multiplication, division, and number-object control judging tasks. The data processing and statistical analysis were performed on SPM 2.0 (statistical parametric mapping 2.0) and the related-brain functional areas were identified. The activation on occipital lobe was observed carefully. The difference in activated areas of occipital lobe was statistically significant between two groups engaged in different tasks of calculations (P<0.01). Result: Bilateral occipital lobe, especially in the cuneus and lingual gyrus, were activated in children trained with abacus mental calculation. The main activated area was lingual gyrus in children without abacus mental calculation. Conclusion: The occipital lobe participates visuospatial processing in the abacus mental calculations. The neuromechanism maybe account for the specific activation in occipital lobe. (authors)

  15. Transport Task Force Leadership, Task 4

    International Nuclear Information System (INIS)

    The Transport Task Force (TTF) was initiated as a broad-based US magnetic fusion community activity during the fall of 1988 to focus attention on and encourage development of an increased understanding of anomalous transport in tokamaks. The overall TTF goal is to make progress on Characterizing, Understanding and Identifying how to Reduce plasma transport in tokamaks -- to CUIR transport

  16. A Brief Analysis of Communication Tasks in Task- based Teaehing

    Institute of Scientific and Technical Information of China (English)

    Xu Xiaoying

    2011-01-01

    Task -Based Language Teaching (TBLT) aims at proving opportunities for the learners to experiment with and explore both spoken and written language through learning activities. This passage further exam if the following four communicative tasks jigsaw tasks, role - play tasks, problem solving tasks, and information gap tasks can assist classroom learning.

  17. Dynamical Models of Task Organization in Social Insect Colonies.

    Science.gov (United States)

    Kang, Yun; Theraulaz, Guy

    2016-05-01

    The organizations of insect societies, such as division of labor, task allocation, collective regulation, mass action responses, have been considered as main reasons for the ecological success. In this article, we propose and study a general modeling framework that includes the following three features: (a) the average internal response threshold for each task (the internal factor); (b) social network communications that could lead to task switching (the environmental factor); and (c) dynamical changes of task demands (the external factor). Since workers in many social insect species exhibit age polyethism, we also extend our model to incorporate age polyethism in which worker task preferences change with age. We apply our general modeling framework to the cases of two task groups: the inside colony task versus the outside colony task. Our analytical study of the models provides important insights and predictions on the effects of colony size, social communication, and age-related task preferences on task allocation and division of labor in the adaptive dynamical environment. Our study implies that the smaller size colony invests its resource for the colony growth and allocates more workers in the risky tasks such as foraging while the larger colony shifts more workers to perform the safer tasks inside the colony. Social interactions among different task groups play an important role in shaping task allocation depending on the relative cost and demands of the tasks. PMID:27125656

  18. Guessing versus Choosing an Upcoming Task.

    Science.gov (United States)

    Kleinsorge, Thomas; Scheil, Juliane

    2016-01-01

    We compared the effects of guessing vs. choosing an upcoming task. In a task-switching paradigm with four tasks, two groups of participants were asked to either guess or choose which task will be presented next under otherwise identical conditions. The upcoming task corresponded to participants' guesses or choices in 75 % of the trials. However, only participants in the Choosing condition were correctly informed about this, whereas participants in the Guessing condition were told that tasks were determined at random. In the Guessing condition, we replicated previous findings of a pronounced reduction of switch costs in case of incorrect guesses. This switch cost reduction was considerably less pronounced with denied choices in the Choosing condition. We suggest that in the Choosing condition, the signaling of prediction errors associated with denied choices is attenuated because a certain proportion of denied choices is consistent with the overall representation of the situation as conveyed by task instructions. In the Guessing condition, in contrast, the mismatch of guessed and actual task is resolved solely on the level of individual trials by strengthening the representation of the actual task. PMID:27047423

  19. Estimating the operator's performance time of emergency procedural tasks based on a task complexity measure

    International Nuclear Information System (INIS)

    It is important to understand the amount of time required to execute an emergency procedural task in a high-stress situation for managing human performance under emergencies in a nuclear power plant. However, the time to execute an emergency procedural task is highly dependent upon expert judgment due to the lack of actual data. This paper proposes an analytical method to estimate the operator's performance time (OPT) of a procedural task, which is based on a measure of the task complexity (TACOM). The proposed method for estimating an OPT is an equation that uses the TACOM as a variable, and the OPT of a procedural task can be calculated if its relevant TACOM score is available. The validity of the proposed equation is demonstrated by comparing the estimated OPTs with the observed OPTs for emergency procedural tasks in a steam generator tube rupture scenario.

  20. Scheduling PVM Tasks

    Institute of Scientific and Technical Information of China (English)

    鞠九滨; 王勇; 等

    1997-01-01

    This paper describes a PVM task scheduler designed and implemented by the authors.The scheduler supports selecting idle workstations,scheduling pool tasks and dynamically produced subtasks.It can improve resource utilization,reduce job response time and simplify programming.

  1. Task Description Language

    Science.gov (United States)

    Simmons, Reid; Apfelbaum, David

    2005-01-01

    Task Description Language (TDL) is an extension of the C++ programming language that enables programmers to quickly and easily write complex, concurrent computer programs for controlling real-time autonomous systems, including robots and spacecraft. TDL is based on earlier work (circa 1984 through 1989) on the Task Control Architecture (TCA). TDL provides syntactic support for hierarchical task-level control functions, including task decomposition, synchronization, execution monitoring, and exception handling. A Java-language-based compiler transforms TDL programs into pure C++ code that includes calls to a platform-independent task-control-management (TCM) library. TDL has been used to control and coordinate multiple heterogeneous robots in projects sponsored by NASA and the Defense Advanced Research Projects Agency (DARPA). It has also been used in Brazil to control an autonomous airship and in Canada to control a robotic manipulator.

  2. Microscopic group constants determination

    International Nuclear Information System (INIS)

    The method of microscopic group constants determination for nuclear reactor calculations is described in this paper. The principle of this method is group averaging of microscopic cross sections with respect to the standard spectrum. The group cross sections obtained are used for the calculation of fast critical assembly Jezebel. (author)

  3. MEMS Calculator

    Science.gov (United States)

    SRD 166 MEMS Calculator (Web, free access)   This MEMS Calculator determines the following thin film properties from data taken with an optical interferometer or comparable instrument: a) residual strain from fixed-fixed beams, b) strain gradient from cantilevers, c) step heights or thicknesses from step-height test structures, and d) in-plane lengths or deflections. Then, residual stress and stress gradient calculations can be made after an optical vibrometer or comparable instrument is used to obtain Young's modulus from resonating cantilevers or fixed-fixed beams. In addition, wafer bond strength is determined from micro-chevron test structures using a material test machine.

  4. TSORT - an automated tool for allocating tasks to training strategies

    International Nuclear Information System (INIS)

    An automated tool (TSORT) that can aid training system developers in determining which training strategy should be applied to a particular task and in grouping similar tasks into training categories has been developed. This paper describes the rationale for TSORT's development and addresses its structure, including training categories, task description dimensions, and categorization metrics. It also provides some information on TSORT's application

  5. Learning one task by interleaving practice with another task

    OpenAIRE

    Szpiro, Sarit; Wright, Beverly A.; Carrasco, Marisa

    2014-01-01

    Perceptual learning is a sustainable improvement in performance on a perceptual task following training. A hallmark of perceptual learning is task specificity – after participants have trained on and learned a particular task, learning rarely transfers to another task, even with identical stimuli. Accordingly, it is assumed that performing a task throughout training is a requirement for learning to occur on that specific task. Thus, interleaving training trials of a target task, with those of...

  6. Spatial dependency between task positive and task negative networks

    OpenAIRE

    Leech, Robert; Scott, Gregory; Carhart-Harris, Robin; Turkheimer, Federico; Taylor-Robinson, Simon D; Sharp, David J.

    2013-01-01

    Functional neuroimaging reveals both increases (task-positive) and decreases (task-negative) in neural activation with many tasks. Many studies show a temporal relationship between task positive and task negative networks that is important for efficient cognitive functioning. Here we provide evidence for a spatial relationship between task positive and negative networks. There are strong spatial similarities between many reported task negative brain networks, termed the default mode network, ...

  7. Task-specific dystonia: pathophysiology and management.

    Science.gov (United States)

    Sadnicka, Anna; Kassavetis, Panagiotis; Pareés, Isabel; Meppelink, Anne Marthe; Butler, Katherine; Edwards, Mark

    2016-09-01

    Task-specific dystonia is a form of isolated focal dystonia with the peculiarity of being displayed only during performance of a specific skilled motor task. This distinctive feature makes task-specific dystonia a particularly mysterious and fascinating neurological condition. In this review, we cover phenomenology and its increasingly broad-spectrum risk factors for the disease, critically review pathophysiological theories and evaluate current therapeutic options. We conclude by highlighting the unique features of task-specific dystonia within the wider concept of dystonia. We emphasise the central contribution of environmental risk factors, and propose a model by which these triggers may impact on the motor control of skilled movement. By viewing task-specific dystonia through this new lens which considers the disorder a modifiable disorder of motor control, we are optimistic that research will yield novel therapeutic avenues for this highly motivated group of patients. PMID:26818730

  8. Reconsideration of the simulated work task situation

    DEFF Research Database (Denmark)

    Borlund, Pia; Schneider, Jesper Wiborg

    2010-01-01

    ’ of the simulated work task situations, which is emphasised through the need for tailoring of the simulated work task situations towards the group of study participant to ensure the depicted situations are realistic and interesting from the participants’ point of view. Likewise it seems that the......The present paper reports on the initial study and the preliminary findings of how the concept of simulated work task situation is reported used in the research literature. The overall objective of the study is in a systematic manner to learn how and for what types of evaluations the concept is...... applied. In particular we are interested to learn whether the recommendations for how to apply simulated work task situations are followed. The preliminary findings indicate a need for clarifications of the recommendations of how to use simulated work task situations. Particularly with respect to ‘realism...

  9. Is Distributed Cognition Group Level Cognition?

    Directory of Open Access Journals (Sweden)

    Ludwig Kirk

    2015-09-01

    Full Text Available This paper shows that recent arguments from group problem solving and task performance to emergent group level cognition that rest on the social parity and related principles are invalid or question begging. The paper shows that standard attributions of problem solving or task performance to groups require only multiple agents of the outcome, not a group agent over and above its members, whether or not any individual member of the group could have accomplished the task independently.

  10. Fuel oil quality task force

    Energy Technology Data Exchange (ETDEWEB)

    Laisy, J.; Turk, V. [R.W. Beckett Corp., Elyria, OH (United States)

    1997-09-01

    In April, 1996, the R.W. Beckett Corporation became aware of a series of apparently unrelated symptoms that made the leadership of the company concerned that there could be a fuel oil quality problem. A task force of company employees and industry consultants was convened to address the topic of current No. 2 heating oil quality and its effect on burner performance. The task force studied changes in fuel oil specifications and trends in properties that have occurred over the past few years. Experiments were performed at Beckett and Brookhaven National Laboratory to understand the effect of changes in some fuel oil properties. Studies by other groups were reviewed, and field installations were inspected to gain information about the performance of fuel oil that is currently being used in the U.S. and Canada. There was a special concern about the use of red dye in heating oils and the impact of sulfur levels due to the October, 1993 requirement of low sulfur (<0.05%) for on-highway diesel fuel. The results of the task force`s efforts were published in July, 1996. The primary conclusion of the task force was that there is not a crisis or widespread general problem with fuel oil quality. Localized problems that were seen may have been related to refinery practices and/or non-traditional fuel sources. System cleanliness is very important and the cause of many oil burner system problems. Finally, heating oil quality should get ongoing careful attention by Beckett engineering personnel and heating oil industry groups.

  11. Hypervigilance or avoidance of trigger related cues in migraineurs? - A case-control study using the emotional stroop task

    Directory of Open Access Journals (Sweden)

    Puschmann Anne-Katrin

    2011-11-01

    Full Text Available Abstract Background "Negative affect" is one of the major migraine triggers. The aim of the study was to assess attentional biases for negative affective stimuli that might be related to migraine triggers in migraine patients with either few or frequent migraine and healthy controls. Methods Thirty-three subjects with frequent migraine (FM or with less frequent episodic migraine, and 20 healthy controls conducted two emotional Stroop tasks in the interictal period. In task 1, general affective words and in task 2, pictures of affective faces (angry, neutral, happy were used. For each task we calculated two emotional Stroop indices. Groups were compared using one-way ANOVAs. Results The expected attentional bias in migraine patients was not found. However, in task 2 the controls showed a significant attentional bias to negative faces, whereas the FM group showed indices near zero. Thus, the FM group responded faster to negative than to positive stimuli. The difference between the groups was statistically significant. Conclusions The findings in the FM group may reflect a learned avoidance mechanism away from affective migraine triggers.

  12. Supporting complex search tasks

    DEFF Research Database (Denmark)

    Gäde, Maria; Hall, Mark; Huurdeman, Hugo;

    2015-01-01

    fragmented at best. The workshop addressed the many open research questions: What are the obvious use cases and applications of complex search? What are essential features of work tasks and search tasks to take into account? And how do these evolve over time? With a multitude of information, varying from...... introductory to specialized, and from authoritative to speculative or opinionated, when to show what sources of information? How does the information seeking process evolve and what are relevant differences between different stages? With complex task and search process management, blending searching, browsing...

  13. Is Task-Irrelevant Learning Really Task-Irrelevant?

    OpenAIRE

    Seitz, Aaron R.; Watanabe, Takeo

    2008-01-01

    In the present study we address the question of whether the learning of task-irrelevant stimuli found in the paradigm of task-irrelevant learning (TIPL) [1]–[9] is truly task irrelevant. To test the hypothesis that associations that are beneficial to task-performance may develop between the task-relevant and task-irrelevant stimuli, or the task-responses and the task-irrelevant stimuli, we designed a new procedure in which correlations between the presentation of task-irrelevant motion stimul...

  14. Set Shifting Training with Categorization Tasks

    OpenAIRE

    Anna Soveri; Otto Waris; Matti Laine

    2013-01-01

    The very few cognitive training studies targeting an important executive function, set shifting, have reported performance improvements that also generalized to untrained tasks. The present randomized controlled trial extends set shifting training research by comparing previously used cued training with uncued training. A computerized adaptation of the Wisconsin Card Sorting Test was utilized as the training task in a pretest-posttest experimental design involving three groups of university s...

  15. Computerized management of plant intervention tasks

    International Nuclear Information System (INIS)

    The concept of 'computerized management' of plant intervention tasks was developed by TRACTEBEL in 1983 for the Belgian power plants of ELECTRABEL. The main objective of the 'Computerized Management of Plant Intervention Tasks' is to help the staff of a nuclear or a conventional power plant in planning, organizing, and carrying out any (preventive or corrective) maintenance task. It consists of a group of interconnected functional modules acting on a unique and homogeneous data base. A short description of 3 modules is given, i.e., the 'User' Module, the 'Equipment' Module and the 'Periodic Procedure' Module. (Z.S.)

  16. A Comparative Study of Task-based vs. Task- supported Teaching Approaches in an EFL Context

    Directory of Open Access Journals (Sweden)

    Mahdieh Shafipoor

    2015-09-01

    Full Text Available In spite of the numerous merits of task-based language instruction as claimed by its supporters in the last few decades, task-supported teaching approach as an alternative was introduced. Since then, there have been controversial debates over the superiority of each of these two approaches. Thus, in the current research project, the purpose was to consider these two teaching approaches in the scope of English language teaching, with the purpose of exploring the most efficient one in an Iranian EFL context. To this end, 120 sophomore students, majoring in English language translation course at Islamic Azad University, Shar-e-Qods branch were selected among 4 intact reading comprehension II classes. Next, they were divided into two experimental groups. The first experimental group received task-based instruction and for the second experimental group, task-trusted teaching approach was applied. The results of the data analyses turned out that task-trusted teaching approach was superior to task-based teaching in teaching reading to EFL learners.Keywords: task-bsed language teaching (TBLT, task-supported language teaching (TSLT, reading comprehension 

  17. Dual-task interference with equal task emphasis: graded capacity sharing or central postponement?

    Science.gov (United States)

    Ruthruff, Eric; Pashler, Harold E.; Hazeltine, Eliot

    2003-01-01

    Most studies using the psychological refractory period (PRP) design suggest that dual-task performance is limited by a central bottleneck. Because subjects are usually told to emphasize Task 1, however, the bottleneck might reflect a strategic choice rather than a structural limitation. To evaluate the possibility that central operations can proceed in parallel, albeit with capacity limitations, we conducted two dual-task experiments with equal task emphasis. In both experiments, subjects tended to either group responses together or respond to one task well before the other. In addition, stimulus-response compatibility effects were roughly constant across stimulus onset asynchronies (SOAs). At the short SOA, compatibility effects also carried over onto response times for the other task. This pattern of results is difficult to reconcile with the possibility that subjects share capacity roughly equally between simultaneous central operations. However, this pattern is consistent with the existence of a structural central bottleneck.

  18. Data analysis tasks: BATSE

    Science.gov (United States)

    Paciesas, William S.

    1993-01-01

    Miscellaneous tasks related to the operation of, and analysis of data from, the Burst and Transient Experiment (BATSE) on the Compton Gamma Ray Observatory (CGRO) were performed. The results are summarized and relevant references are included.

  19. IRIS core criticality calculations

    International Nuclear Information System (INIS)

    Three-dimensional Monte Carlo computer code KENO-VI of CSAS26 sequence of SCALE-4.4 code system was applied for pin-by-pin calculations of the effective multiplication factor for the first cycle IRIS reactor core. The effective multiplication factors obtained by the above mentioned Monte Carlo calculations using 27-group ENDF/B-IV library and 238-group ENDF/B-V library have been compared with the effective multiplication factors achieved by HELIOS/NESTLE, CASMO/SIMULATE, and modified CORD-2 nodal calculations. The results of Monte Carlo calculations are found to be in good agreement with the results obtained by the nodal codes. The discrepancies in effective multiplication factor are typically within 1%. (author)

  20. Reliability Calculations

    DEFF Research Database (Denmark)

    Petersen, Kurt Erling

    1986-01-01

    probabilistic approaches have been introduced in some cases for the calculation of the reliability of structures or components. A new computer program has been developed based upon numerical integration in several variables. In systems reliability Monte Carlo simulation programs are used especially in analysis...... of very complex systems. In order to increase the applicability of the programs variance reduction techniques can be applied to speed up the calculation process. Variance reduction techniques have been studied and procedures for implementation of importance sampling are suggested....

  1. The fMRI study on the front-parietal activation in abacus mental calculation trained children

    International Nuclear Information System (INIS)

    Objective: To investigate the difference in front-parietal activation between the trained and untrained children engaged in addition and multiplication with functional magnetic resonance imaging (fMRI), and to explore the role of abacus mental calculation in brain development. Methods: Twenty-four children trained with abacus mental calculation and twelve untrained children performed mental calculation tasks including addition, multiplication and number-object control judging tasks. Blood oxygenation level dependence (BOLD) fMRI was performed when they were calculating. All data were analyzed by SPM2 (statistical parametric mapping 2) to generate the brain activation map. Results: The performance of the trained group had better correctness and shorter reaction time than that of the untrained group. The front-parietal activation between two groups had obvious difference. The activation involved less prefrontal cortex in the trained group than in the untrained group (P<0.05). The parietal activation in the trained group was mainly in the posterior superior parietal lobe/ precuneus, whereas the activation areas focused on the inferior parietal lobule in the untrained group. Conclusion: Abacus mental calculation involves multiple functional areas. and these areas may work together as a whole in processing arithmetic problems. Abacus mental calculation not only enhances the information processing in some brain areas and improves the utilization efficiency of neural resources, but also plays an important role in developing brain. (authors)

  2. Group Problem Solving

    CERN Document Server

    Laughlin, Patrick R

    2011-01-01

    Experimental research by social and cognitive psychologists has established that cooperative groups solve a wide range of problems better than individuals. Cooperative problem solving groups of scientific researchers, auditors, financial analysts, air crash investigators, and forensic art experts are increasingly important in our complex and interdependent society. This comprehensive textbook--the first of its kind in decades--presents important theories and experimental research about group problem solving. The book focuses on tasks that have demonstrably correct solutions within mathematical

  3. Cortical subnetwork dynamics during human language tasks.

    Science.gov (United States)

    Collard, Maxwell J; Fifer, Matthew S; Benz, Heather L; McMullen, David P; Wang, Yujing; Milsap, Griffin W; Korzeniewska, Anna; Crone, Nathan E

    2016-07-15

    Language tasks require the coordinated activation of multiple subnetworks-groups of related cortical interactions involved in specific components of task processing. Although electrocorticography (ECoG) has sufficient temporal and spatial resolution to capture the dynamics of event-related interactions between cortical sites, it is difficult to decompose these complex spatiotemporal patterns into functionally discrete subnetworks without explicit knowledge of each subnetwork's timing. We hypothesized that subnetworks corresponding to distinct components of task-related processing could be identified as groups of interactions with co-varying strengths. In this study, five subjects implanted with ECoG grids over language areas performed word repetition and picture naming. We estimated the interaction strength between each pair of electrodes during each task using a time-varying dynamic Bayesian network (tvDBN) model constructed from the power of high gamma (70-110Hz) activity, a surrogate for population firing rates. We then reduced the dimensionality of this model using principal component analysis (PCA) to identify groups of interactions with co-varying strengths, which we term functional network components (FNCs). This data-driven technique estimates both the weight of each interaction's contribution to a particular subnetwork, and the temporal profile of each subnetwork's activation during the task. We found FNCs with temporal and anatomical features consistent with articulatory preparation in both tasks, and with auditory and visual processing in the word repetition and picture naming tasks, respectively. These FNCs were highly consistent between subjects with similar electrode placement, and were robust enough to be characterized in single trials. Furthermore, the interaction patterns uncovered by FNC analysis correlated well with recent literature suggesting important functional-anatomical distinctions between processing external and self-produced speech. Our

  4. Orientation Preferences of Backbone Secondary Amide Functional Groups in Peptide Nucleic Acid Complexes: Quantum Chemical Calculations Reveal an Intrinsic Preference of Cationic D-Amino Acid-Based Chiral PNA Analogues for the P-form

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Jeremy C [ORNL; Topham, Christopher [University of Heidelberg

    2007-01-01

    Geometric descriptions of nonideal interresidue hydrogen bonding and backbone-base water bridging in the minor groove are established in terms of polyamide backbone carbonyl group orientation from analyses of residue junction conformers in experimentally determined peptide nucleic acid (PNA) complexes. Two types of interresidue hydrogen bonding are identified in PNA conformers in heteroduplexes with nucleic acids that adopt A-like base pair stacking. Quantum chemical calculations on the binding of a water molecule to an O2 base atom in glycine-based PNA thymine dimers indicate that junctions modeled with P-form backbone conformations are lower in energy than a dimer comprising the predominant conformation observed in A-like helices. It is further shown in model systems that PNA analogs based on D-lysine are better able to preorganize in a conformation exclusive to P-form helices than is glycine-based PNA. An intrinsic preference for this conformation is also exhibited by positively charged chiral PNA dimers carrying 3-amino-D-alanine or 4-aza-D-leucine residue units that provide for additional rigidity by side-chain hydrogen bonding to the backbone carbonyl oxygen. Structural modifications stabilizing P-form helices may obviate the need for large heterocycles to target DNA pyrimidine bases via PNADNA-PNA triplex formation. Quantum chemical modeling methods are used to propose candidate PNA Hoogsteen strand designs.

  5. Orientation preferences of backbone secondary amide functional groups in peptide nucleic acid complexes: quantum chemical calculations reveal an intrinsic preference of cationic D-amino acid-based chiral PNA analogues for the P-form.

    Science.gov (United States)

    Topham, Christopher M; Smith, Jeremy C

    2007-02-01

    Geometric descriptions of nonideal interresidue hydrogen bonding and backbone-base water bridging in the minor groove are established in terms of polyamide backbone carbonyl group orientation from analyses of residue junction conformers in experimentally determined peptide nucleic acid (PNA) complexes. Two types of interresidue hydrogen bonding are identified in PNA conformers in heteroduplexes with nucleic acids that adopt A-like basepair stacking. Quantum chemical calculations on the binding of a water molecule to an O2 base atom in glycine-based PNA thymine dimers indicate that junctions modeled with P-form backbone conformations are lower in energy than a dimer comprising the predominant conformation observed in A-like helices. It is further shown in model systems that PNA analogs based on D-lysine are better able to preorganize in a conformation exclusive to P-form helices than is glycine-based PNA. An intrinsic preference for this conformation is also exhibited by positively charged chiral PNA dimers carrying 3-amino-D-alanine or 4-aza-D-leucine residue units that provide for additional rigidity by side-chain hydrogen bonding to the backbone carbonyl oxygen. Structural modifications stabilizing P-form helices may obviate the need for large heterocycles to target DNA pyrimidine bases via PNA.DNA-PNA triplex formation. Quantum chemical modeling methods are used to propose candidate PNA Hoogsteen strand designs. PMID:17071666

  6. Evidence of a short-range incommensurate d-wave charge order from a fermionic two-loop renormalization group calculation of a 2D model with hot spots

    International Nuclear Information System (INIS)

    The two-loop renormalization group (RG) calculation is considerably extended here for the two-dimensional (2D) fermionic effective field theory model, which includes only the so-called “hot spots” that are connected by the spin-density-wave (SDW) ordering wavevector on a Fermi surface generated by the 2D t−t′ Hubbard model at low hole doping. We compute the Callan–Symanzik RG equation up to two loops describing the flow of the single-particle Green’s function, the corresponding spectral function, the Fermi velocity, and some of the most important order-parameter susceptibilities in the model at lower energies. As a result, we establish that–in addition to clearly dominant SDW correlations–an approximate (pseudospin) symmetry relating a short-range incommensurated-wave charge order to the d-wave superconducting order indeed emerges at lower energy scales, which is in agreement with recent works available in the literature addressing the 2D spin-fermion model. We derive implications of this possible electronic phase in the ongoing attempt to describe the phenomenology of the pseudogap regime in underdoped cuprates

  7. SPEI Calculator

    OpenAIRE

    Beguería, Santiago; Vicente Serrano, Sergio M.

    2009-01-01

    [EN] *Objectives: The program calculates time series of the Standardised Precipitation-Evapotransporation Index (SPEI). *Technical Characteristics: The program is executed from the Windows console. From an input data file containing monthly time series of precipitation and mean temperature, plus the geographic coordinates of the observatory, the program computes the SPEI accumulated at the time interval specified by the user, and generates a new data file with the SPEI time serie...

  8. Burnout calculation

    International Nuclear Information System (INIS)

    Reviewed is the effect of heat flux of different system parameters on critical density in order to give an initial view on the value of several parameters. A thorough analysis of different equations is carried out to calculate burnout is steam-water flows in uniformly heated tubes, annular, and rectangular channels and rod bundles. Effect of heat flux density distribution and flux twisting on burnout and storage determination according to burnout are commended

  9. Rostering and Task Scheduling

    DEFF Research Database (Denmark)

    Dohn, Anders Høeg

    rostering process is non-trivial and especially when service is required around the clock, rostering may involve considerable effort from a designated planner. Therefore, in order to minimize costs and overstaffing, to maximize the utilization of available staff, and to ensure a high level of satisfaction...... among the employees, sophisticated scheduling methods are required. When approaching the day of operation, the detail level of the planning becomes finer. With a given allocation of shifts to employees, the focus is turned to tasks scheduling within those shifts. The objective is to assign as much work...... as possible to the available staff, while respecting various requirements and rules and while including possible transportation time between tasks. This thesis presents a number of industrial applications in rostering and task scheduling. The applications exist within various contexts in health care...

  10. Algebra task & drill sheets

    CERN Document Server

    Reed, Nat

    2011-01-01

    For grades 3-5, our State Standards-based combined resource meets the algebraic concepts addressed by the NCTM standards and encourages the students to review the concepts in unique ways. The task sheets introduce the mathematical concepts to the students around a central problem taken from real-life experiences, while the drill sheets provide warm-up and timed practice questions for the students to strengthen their procedural proficiency skills. Included are opportunities for problem-solving, patterning, algebraic graphing, equations and determining averages. The combined task & drill sheets

  11. Algebra task & drill sheets

    CERN Document Server

    Reed, Nat

    2011-01-01

    For grades 6-8, our State Standards-based combined resource meets the algebraic concepts addressed by the NCTM standards and encourages the students to review the concepts in unique ways. The task sheets introduce the mathematical concepts to the students around a central problem taken from real-life experiences, while the drill sheets provide warm-up and timed practice questions for the students to strengthen their procedural proficiency skills. Included are opportunities for problem-solving, patterning, algebraic graphing, equations and determining averages. The combined task & drill sheets

  12. Performing Task Integration

    DEFF Research Database (Denmark)

    Elkjaer, Bente; Nickelsen, Niels Christian Mossfeldt

    In the paper, we deal with how to organize work for cross-professional knowledge sharing. We do so inspired by relational coordination theory, which is affiliated with positive organizational scholarship. Relational coordination theory is constituted by a combination of relationships marked by...... shared goals and knowledge as well as mutual respect and frequent, timely, accurate and problem-solving ways of communication with the purpose of dealing with the tasks at hand in an integrated way. We introduce and discuss relational coordination theory through a case-study within public healthcare...... away with differences regarding task definitions and working conditions as well as professional knowledge hierarchies and responsibilities for parts and wholes....

  13. Energy Efficient Task Light

    DEFF Research Database (Denmark)

    Logadottir, Asta; Ardkapan, Siamak Rahimi; Johnsen, Kjeld;

    2014-01-01

    only standard components in the prototype, the optimal light distribution for the purpose of meeting the requirements could not be obtained . The light distribution was approximated to the requirements by using combinations of different beam shaping lenses. A final product would benefit from custom...... made lenses, capable of providing the desired light distribution. The user test shows that when working with general lighti ng of 100 lx in the room the developed task lig ht with its wide light distribution provides flexibility in choosing a reading task area on the desk and provides more visibility...

  14. Assessing L2 Task Performance: Understanding Effects of Task Design

    Science.gov (United States)

    Tavakoli, Parvaneh

    2009-01-01

    The overarching aim of the research reported here was to investigate the effects of task structure and storyline complexity of oral narrative tasks on second language task performance. Participants were 60 Iranian language learners of English who performed six narrative tasks of varying degree of structure and storyline complexity in an assessment…

  15. Set shifting training with categorization tasks.

    Directory of Open Access Journals (Sweden)

    Anna Soveri

    Full Text Available The very few cognitive training studies targeting an important executive function, set shifting, have reported performance improvements that also generalized to untrained tasks. The present randomized controlled trial extends set shifting training research by comparing previously used cued training with uncued training. A computerized adaptation of the Wisconsin Card Sorting Test was utilized as the training task in a pretest-posttest experimental design involving three groups of university students. One group received uncued training (n = 14, another received cued training (n = 14 and the control group (n = 14 only participated in pre- and posttests. The uncued training group showed posttraining performance increases on their training task, but neither training group showed statistically significant transfer effects. Nevertheless, comparison of effect sizes for transfer effects indicated that our results did not differ significantly from the previous studies. Our results suggest that the cognitive effects of computerized set shifting training are mostly task-specific, and would preclude any robust generalization effects with this training.

  16. Calculator calculus

    CERN Document Server

    McCarty, George

    1982-01-01

    How THIS BOOK DIFFERS This book is about the calculus. What distinguishes it, however, from other books is that it uses the pocket calculator to illustrate the theory. A computation that requires hours of labor when done by hand with tables is quite inappropriate as an example or exercise in a beginning calculus course. But that same computation can become a delicate illustration of the theory when the student does it in seconds on his calculator. t Furthermore, the student's own personal involvement and easy accomplishment give hi~ reassurance and en­ couragement. The machine is like a microscope, and its magnification is a hundred millionfold. We shall be interested in limits, and no stage of numerical approximation proves anything about the limit. However, the derivative of fex) = 67.SgX, for instance, acquires real meaning when a student first appreciates its values as numbers, as limits of 10 100 1000 t A quick example is 1.1 , 1.01 , 1.001 , •••• Another example is t = 0.1, 0.01, in the functio...

  17. Reliability calculations

    International Nuclear Information System (INIS)

    Risk and reliability analysis is increasingly being used in evaluations of plant safety and plant reliability. The analysis can be performed either during the design process or during the operation time, with the purpose to improve the safety or the reliability. Due to plant complexity and safety and availability requirements, sophisticated tools, which are flexible and efficient, are needed. Such tools have been developed in the last 20 years and they have to be continuously refined to meet the growing requirements. Two different areas of application were analysed. In structural reliability probabilistic approaches have been introduced in some cases for the calculation of the reliability of structures or components. A new computer program has been developed based upon numerical integration in several variables. In systems reliability Monte Carlo simulation programs are used especially in analysis of very complex systems. In order to increase the applicability of the programs variance reduction techniques can be applied to speed up the calculation process. Variance reduction techniques have been studied and procedures for implementation of importance sampling are suggested. (author)

  18. A Daunting Task Still

    Institute of Scientific and Technical Information of China (English)

    ZHANG ZHIPING

    2010-01-01

    @@ Despite steady economic growth for three decades, China is still a developing country facing daunting poverty alleviation tasks. According to the poverty line of 1,196 yuan ($176) per capita net income in a year set in March 2009, the country still has a poverty population of more than 40 million, mainly living in rural areas.

  19. Creating Positive Task Constraints

    Science.gov (United States)

    Mally, Kristi K.

    2006-01-01

    Constraints are characteristics of the individual, the task, or the environment that mold and shape movement choices and performances. Constraints can be positive--encouraging proficient movements or negative--discouraging movement or promoting ineffective movements. Physical educators must analyze, evaluate, and determine the effect various…

  20. Task 1 quarternary tectonics

    Energy Technology Data Exchange (ETDEWEB)

    Bell, J.W.

    1994-12-31

    Activities on the task of quarternary tectonics for the Yucca Mountain Site investigations are described. Technical topics include: A preliminary reveiw of Bare Mountain Trench; A preliminary detailed lineament map of the Southwestern part of the proposed repository; A discussion on the 1994 Double Spring Flat, Nevada earthquake; and evidence for temporal clustering.

  1. Highly task-related diversity vs. less task-related diversity among university staff

    DEFF Research Database (Denmark)

    Lauring, Jakob; Selmer, Jan

    2013-01-01

    from 489 university staff members showed that age diversity and cultural diversity, representing highly task-related diversity, were positively associated with most of the variables depicting group cohesiveness. On the other hand, gender diversity, illustrating less task-related diversity, seemed to...... have a mostly negative influence on the variables portraying group cohesiveness. Implications of these findings are discussed in detail.......As only very few large-scale studies have investigated multi-cultural university staff and as none of these studies have dealt with diversity and group processes, this survey was directed toward staffs in 16 science departments from three large universities in Denmark. Results based on the response...

  2. Microprocessor multi-task monitor

    International Nuclear Information System (INIS)

    This paper describes a multi-task monitor program for microprocessors. Although written for the Intel 8085, it incorporates features that would be beneficial for implementation in other microprocessors used in controlling and monitoring experiments and accelerators. The monitor places permanent programs (tasks) arbitrarily located throughout ROM in a priority ordered queue. The programmer is provided with the flexibility to add new tasks or modified versions of existing tasks, without having to comply with previously defined task boundaries or having to reprogram all of ROM. Scheduling of tasks is triggered by timers, outside stimuli (interrupts), or inter-task communications. Context switching time is of the order of tenths of a milllisecond

  3. Microprocessor multi-task monitor

    Energy Technology Data Exchange (ETDEWEB)

    Ludemann, C.A.

    1983-01-01

    This paper describes a multi-task monitor program for microprocessors. Although written for the Intel 8085, it incorporates features that would be beneficial for implementation in other microprocessors used in controlling and monitoring experiments and accelerators. The monitor places permanent programs (tasks) arbitrarily located throughout ROM in a priority ordered queue. The programmer is provided with the flexibility to add new tasks or modified versions of existing tasks, without having to comply with previously defined task boundaries or having to reprogram all of ROM. Scheduling of tasks is triggered by timers, outside stimuli (interrupts), or inter-task communications. Context switching time is of the order of tenths of a milllisecond.

  4. Group evaporation

    Science.gov (United States)

    Shen, Hayley H.

    1991-01-01

    Liquid fuel combustion process is greatly affected by the rate of droplet evaporation. The heat and mass exchanges between gas and liquid couple the dynamics of both phases in all aspects: mass, momentum, and energy. Correct prediction of the evaporation rate is therefore a key issue in engineering design of liquid combustion devices. Current analytical tools for characterizing the behavior of these devices are based on results from a single isolated droplet. Numerous experimental studies have challenged the applicability of these results in a dense spray. To account for the droplets' interaction in a dense spray, a number of theories have been developed in the past decade. Herein, two tasks are examined. One was to study how to implement the existing theoretical results, and the other was to explore the possibility of experimental verifications. The current theoretical results of group evaporation are given for a monodispersed cluster subject to adiabatic conditions. The time evolution of the fluid mechanic and thermodynamic behavior in this cluster is derived. The results given are not in the form of a subscale model for CFD codes.

  5. Record of the fourth meeting of sub-group A, Vienna, 18-19 September 1978

    International Nuclear Information System (INIS)

    The items discussed include the Co-Chairman's report on June 1978 Technical Co-ordinating Committee; Working Group 4 final report (format); task 1: requirements for reprocessing. (Incl. discussions of NEA documents), task 2: national reprocessing plans, task 3: base case reprocessing plant, task 4: resource utilization, task 5: identification of criteria: (Identification of economic criteria, identification of environmental criteria), task 6: evaluation of reprocessing, task 7: proliferation resistance, task 8: alternative reprocessing schemes and tasks 13-16: alternative institutional arrangements

  6. Event Related Potentials (ERPs) in Elementary Cognitive Tasks Reflect Task Difficulty and Task Threshold.

    Science.gov (United States)

    Caryl, P. G.; Harper, Alison

    1996-01-01

    Effects on the event-related potential (ERP) waveform of differences in stimuli (task difficulty) and threshold were studied with 35 undergraduates performing a visual inspection time task and 30 performing a pitch discrimination task. In both tasks, ERP differences related to threshold were temporally localized differences in waveform shape. (SLD)

  7. Organizing Core Tasks

    DEFF Research Database (Denmark)

    Boll, Karen

    has remained much the same within the last 10 years. However, how the core task has been organized has changed considerable under the influence of various “organizing devices”. The paper focusses on how organizing devices such as risk assessment, output-focus, effect orientation, and treatment...... projects influence the organization of core tasks within the tax administration. The paper shows that the organizational transformations based on the use of these devices have had consequences both for the overall collection of revenue and for the employees’ feeling of “making a difference”. All in all......, the paper is an investigation into how various (mundane) organizing devices interact with, influence, and shape particular organizational practices which are assumed to perform the well-functioning welfare state....

  8. Social Loafing in a Co-operative Classroom Task.

    Science.gov (United States)

    North, Adrian C.; Linley, P. Alex; Hargreaves, David J.

    2000-01-01

    Investigates whether social loafing (the tendency for individuals to reduce their input when performing as part of a group) existed in a collaborative educational task employing groups of three and eight participants. Indicates that individuals working in smaller groups were more productive than those working in larger groups. (CMK)

  9. Task analysis and support for problem solving tasks

    International Nuclear Information System (INIS)

    This paper is concerned with Task Analysis as the basis for ergonomic design to reduce human error rates, rather than for predicting human error rates. Task Analysis techniques usually provide a set of categories for describing sub tasks, and a framework describing the relations between sub-tasks. Both the task type categories and their organisation have implications for optimum interface and training design. In this paper, the framework needed for considering the most complex tasks faced by operators in process industries is discussed such as fault management in unexpected situations, and what is likely to minimise human error in these circumstances. (author)

  10. Futures Trading: Task Analysis

    Czech Academy of Sciences Publication Activity Database

    Zeman, Jan

    Praha: UTIA AV ČR, v.v.i, - DAR, 2009 - (Janžura; Ivánek). s. 38-38 [5th International Workshop on Data – Algorithms – Decision Making. 29.11.2009-01.12.2009, Plzeň] Institutional research plan: CEZ:AV0Z10750506 Keywords : decision making * futures trading * optimization Subject RIV: IN - Informatics, Computer Science http://library.utia.cas.cz/separaty/2009/AS/zeman-futures trading task analysis .pdf

  11. Features or tasks?

    DEFF Research Database (Denmark)

    Heilesen, Simon

    In this paper for the Workshop on Human-computer interaction and e-learning, NordiCHI 2002, the author argues that in developing innovative E-learning systems, especially if constructivist pedagogy is to be applied, it will be useful to model the user interface on the often complex tasks that the...... user has to perform rather than just focusing on technical features (and adapting system use to them)....

  12. Effects of noise and task loading on a communication task loading on a communication task

    Science.gov (United States)

    Orrell, Dean H., II

    Previous research had shown the effect of noise on a single communication task. This research has been criticized as not being representative of a real world situation since subjects allocated all of their attention to only one task. In the present study, the effect of adding a loading task to a standard noise-communication paradigm was investigated. Subjects performed both a communication task (Modified Rhyme Test; House et al. 1965) and a short term memory task (Sternberg, 1969) in simulated levels of aircraft noise (95, 105 and 115 dB overall sound pressure level (OASPL)). Task loading was varied with Sternberg's task by requiring subjects to memorize one, four, or six alphanumeric characters. Simulated aircraft noise was varied between levels of 95, 105 and 115 dB OASPL using a pink noise source. Results show that the addition of Sternberg's task and little effect on the intelligibility of the communication task while response time for the communication task increased.

  13. Gap Task Force

    CERN Multimedia

    Lissuaer, D

    One of the more congested areas in the ATLAS detector is the GAP region (the area between the Barrel Calorimeter and the End Cap calorimeter) where Inner Detector services, LAr Services and some Tile services all must co-habitat in a very limited area. It has been clear for some time that the space in the GAP region is not sufficient to accommodate all that is needed. In the last few month additional problems of routing all the services to Z=0 have been encountered due to the very limited space between the Tile Calorimeter and the first layer of Muon chambers. The Technical Management Board (TMB) and the Executive Board (EB) decided in the middle of March to establish a Task Force to look at this problem and come up with a solution within well-specified guidelines. The task force consisted of experts from the ID, Muon, Liquid Argon and Tile systems in addition to experts from the Technical Coordination team and the Physics coordinator. The task force held many meetings and in general there were some very l...

  14. Urban task force

    Directory of Open Access Journals (Sweden)

    Grubović Ljiljana V.

    2002-01-01

    Full Text Available The Urban Task Force Report has brought to our attention, that English towns and cities today require a new renaissance. The comprehensive planning has retarded urban living (Urban Renaissance, Sharing the Vision 01.99, 1999. Forty percent of inner-urban housing stock is subsidized 'social' housing. A review of the demographic and development trends have lead to the UK Government’s new urban policy that prioritizes the regeneration of towns and cities by building on recycled urban land and protecting the countryside. As result, Urban Task Force (UTF was founded the with the following aims To identify causes of urban decline in England; To recommend practical solutions how to bring people back into cities; To establish a new vision for urban regeneration based on the principles of design excellence, social well being and environmental responsibility within a viable economic and legislative framework (Urban Task Force, 1999:1. This paper represents the analysis of the economic and political effects of the program and its viability.

  15. The task force process

    International Nuclear Information System (INIS)

    This paper focuses on the unique aspects of the Fernald Citizens Task Force process that have contributed to a largely successful public participation effort at Fernald. The Fernald Citizens Task Force passed quickly by many procedural issues. Instead, the Task Force concentrated on (a) educating itself about the site, its problems, and possible solutions, and (b) choosing a directed way to approach its mandate: To make recommendations on several open-quotes big pictureclose quotes issues, including future use of the site, cleanup levels, waste disposition, and cleanup priorities. This paper presents the approach used at Fernald for establishing and running a focused site-specific advisory board, the key issues that have been faced, and how these issues were resolved. The success of Fernald in establishing a strong and functioning site-specific advisory board serves as a useful model for other DOE facilities, although the Fernald model is just one of many approaches that can be taken. However, the approach presented here has worked extremely well for Fernald

  16. The Variety of Group Learning

    Institute of Scientific and Technical Information of China (English)

    HaoYanyan; YuZhihao

    2004-01-01

    With the rapid enrollment expansion in the recent years,the author feels it urgent to reform the traditional group work,and therefore to form a new and more effective pattern of group learning. The new of group word is based on the principles of cooperation and that of the task with the more flexible marking system.

  17. Task-specific effects of reward on task switching.

    Science.gov (United States)

    Umemoto, Akina; Holroyd, Clay B

    2015-07-01

    Although cognitive control and reinforcement learning have been researched extensively over the last few decades, only recently have studies investigated their interrelationship. An important unanswered question concerns how the control system decides what task to execute and how vigorously to carry out the task once selected. Based on a recent theory of control formulated according to principles of hierarchical reinforcement learning, we asked whether rewards can affect top-down control over task performance at the level of task representation. Participants were rewarded for correctly performing only one of two tasks in a standard task-switching experiment. Reaction times and error rates were lower for the reinforced task compared to the non-reinforced task. Moreover, the switch cost in error rates for the non-reinforced task was significantly larger compared to the reinforced task, especially for trials in which the imperative stimulus afforded different responses for the two tasks, resulting in a "non-paradoxical" asymmetric switch cost. These findings suggest that reinforcement at the task level resulted in greater application of top-down control rather than in stronger stimulus-response pathways for the rewarded task. PMID:24984832

  18. Effects of Gait and Cognitive Task Difficulty on Cognitive-Motor Interference in Aging

    Directory of Open Access Journals (Sweden)

    Prudence Plummer-D'Amato

    2012-01-01

    Full Text Available Although gait-related dual-task interference in aging is well established, the effect of gait and cognitive task difficulty on dual-task interference is poorly understood. The purpose of this study was to examine the effect of gait and cognitive task difficulty on cognitive-motor interference in aging. Fifteen older adults (72.1 years, SD 5.2 and 20 young adults (21.7 years, SD 1.6 performed three walking tasks of varying difficulty (self-selected speed, fast speed, and fast speed with obstacle crossing under single- and dual-task conditions. The cognitive tasks were the auditory Stroop task and the clock task. There was a significant Group × Gait Task × Cognitive Task interaction for the dual-task effect on gait speed. After adjusting for education, there were no significant effects of gait or cognitive task difficulty on the dual-task effects on cognitive task performance. The results of this study provide evidence that gait task difficulty influences dual-task effects on gait speed, especially in older adults. Moreover, the effects of gait task difficulty on dual-task interference appear to be influenced by the difficulty of the cognitive task. Education is an important factor influencing cognitive-motor interference effects on cognition, but not gait.

  19. Image enhancement of digital periapical radiographs according to diagnostic tasks

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin Woo; Han, Won Jeong; Kim, Eun Kyung [Dept. of Oral and Maxillofacial Radiology, Dankook University College of Dentistry, Cheonan (Korea, Republic of)

    2014-03-15

    his study was performed to investigate the effect of image enhancement of periapical radiographs according to the diagnostic task. Eighty digital intraoral radiographs were obtained from patients and classified into four groups according to the diagnostic tasks of dental caries, periodontal diseases, periapical lesions, and endodontic files. All images were enhanced differently by using five processing techniques. Three radiologists blindly compared the subjective image quality of the original images and the processed images using a 5-point scale. There were significant differences between the image quality of the processed images and that of the original images (P<0.01) in all the diagnostic task groups. Processing techniques showed significantly different efficacy according to the diagnostic task (P<0.01). Image enhancement affects the image quality differently depending on the diagnostic task. And the use of optimal parameters is important for each diagnostic task.

  20. Image enhancement of digital periapical radiographs according to diagnostic tasks

    International Nuclear Information System (INIS)

    his study was performed to investigate the effect of image enhancement of periapical radiographs according to the diagnostic task. Eighty digital intraoral radiographs were obtained from patients and classified into four groups according to the diagnostic tasks of dental caries, periodontal diseases, periapical lesions, and endodontic files. All images were enhanced differently by using five processing techniques. Three radiologists blindly compared the subjective image quality of the original images and the processed images using a 5-point scale. There were significant differences between the image quality of the processed images and that of the original images (P<0.01) in all the diagnostic task groups. Processing techniques showed significantly different efficacy according to the diagnostic task (P<0.01). Image enhancement affects the image quality differently depending on the diagnostic task. And the use of optimal parameters is important for each diagnostic task.

  1. Intraindividual variability across cognitive tasks as a potential marker for prodromal Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Andrea Maria Kälin

    2014-07-01

    Full Text Available Recent studies have shown that increased cognitive intraindividual variability (IIV across accuracy scores from tests representing different cognitive domains (across-domain IIV might indicate prodromal Alzheimer’s disease (AD. Although IIV has been proposed to index cognitive control processes, IIV across accuracy scores from cognitive control tasks (within-domain IIV has not been examined in healthy controls subjects (HCS, mild cognitive impairment (MCI and AD patients in a single comparative study. This study examines the discriminative properties of within-domain IIV, and across-domain IIV in 149 HCS, 31 MCI and 26 AD. Three tasks representing different cognitive domains were identified to calculate across-domain IIV. Three other tasks representing cognitive control were identified to calculate within-domain IIV. The intraindividual standard deviation (ISD was calculated across accuracy scores. To compare IIV between groups, ANCOVAs with the covariates age, gender, education, and mean performance were computed. IIV scores in general were higher in AD vs. HCS (p< 0.01. Only across-domain IIV was higher in AD vs. MCI (p=0.001, and only within-domain IIV was higher in MCI vs. HCS (p=0.05. Within-domain IIV may constitute a cognitive marker for the detection of prodromal AD at the MCI stage, whereas across-domain IIV may detect beginning AD at the MCI stage.

  2. Intraindividual variability across cognitive tasks as a potential marker for prodromal Alzheimer’s disease

    Science.gov (United States)

    Kälin, Andrea M.; Pflüger, Marlon; Gietl, Anton F.; Riese, Florian; Jäncke, Lutz; Nitsch, Roger M.; Hock, Christoph

    2014-01-01

    Recent studies have shown that increased cognitive intraindividual variability (IIV) across accuracy scores from tests representing different cognitive domains (across-domain IIV) might indicate prodromal Alzheimer’s disease (AD). Although IIV has been proposed to index cognitive control processes, IIV across accuracy scores from cognitive control tasks (within-domain IIV) has not been examined in healthy controls subjects (HCS), mild cognitive impairment (MCI), and AD patients in a single comparative study. This study examines the discriminative properties of within-domain IIV, and across-domain IIV in 149 HCS, 31 MCI, and 26 AD. Three tasks representing different cognitive domains were identified to calculate across-domain IIV. Three other tasks representing cognitive control were identified to calculate within-domain IIV. The intraindividual standard deviation was calculated across accuracy scores. To compare IIV between groups, ANCOVAs with the covariates age, gender, education, and mean performance were computed. IIV scores in general were higher in AD vs. HCS (p < 0.01). Only across-domain IIV was higher in AD vs. MCI (p = 0.001), and only within-domain IIV was higher in MCI vs. HCS (p = 0.05). Within-domain IIV may constitute a cognitive marker for the detection of prodromal AD at the MCI stage, whereas across-domain IIV may detect beginning AD at the MCI stage. PMID:25071556

  3. Influence of mental abacus calculation practice on mental arithmetic in children: a fMRI study

    International Nuclear Information System (INIS)

    Objective: To investigate the influence of mental abacus calculation practice on mental arithmetic in children with functional magnetic resonance imaging (fMRI). Methods: Twelve children who had practiced mental abacus calculation for 3 years and 12 untrained children (The two groups were matched in terms of age, handedness and education) underwent fMRI during mental calculation tasks. The related behavior data were recorded at the same time. All data were analyzed with statistical parametric mapping 2. Results: The calculation accuracy was significantly higher [(95.00±7.16)% vs.(74.26±16.07)%. t=-4.084, P<0.01]; and the reaction time was significantly shorter [(597.91±124.05) ms vs. (770.07± 148.54) ms, t=3.082, P<0.01] in trained group than untrained group. The extent and magnitude of the activated areas were significantly increased in the untrained group compared with the trained group. The activated areas mainly localized in the frontal and parietal lobes in untrained group, while the brain activated areas were few and mainly localized in occipital and parietal lobes in the trained group. Conclusion: Mental abacus calculation can enhance the information processing m some brain areas, and improve the utilization efficiency of neural resources. (authors)

  4. The Impact of Task Complexity and Strategic Planning Time on EFL Learners’ Accuracy and Fluency in Written Task Production

    Directory of Open Access Journals (Sweden)

    Asghar Salimi

    2012-11-01

    Full Text Available The past twenty years has witnessed a remarkable increase in the number of studies investigating different aspects and features of tasks in the second and foreign language class and their effects on learners’ oral and written task performance. Building up on a review of the studies conducted in the field of task-based language teaching a gap was revealed in the literature on the joint effects of task complexity and types of pre-task planning on L2 learners’ performance. The present study investigates the effects of strategic pre-task planning time and task complexity on a group of L2 learners’ written performance in terms of accuracy and fluency. The means of accuracy and fluency of 50 intermediate English language learners, both male and female, chosen randomly from Iran National Language Institute, Miandoab Branch were compared using T-test as the statistical means of analysis. The findings revealed a positive influence of pre-task strategic planning time in both simple and complex tasks, suggesting significant implications for syllabus and task designers, language teachers, and SLA researchers.Keywords: Task-based language teaching, Planning time, Strategic planning, Task complexity, Accuracy, Fluency

  5. 以“任务”为导向的英语分组合作学习效用研究--以建设类高职英语教学为例%Research on the Effectiveness of English Group Coopera-tive Learning Oriented by "Tasks":A Case Study on Higher Vocational Architecture English Teaching

    Institute of Scientific and Technical Information of China (English)

    胡澎; 贺华锋; 熊丽

    2014-01-01

    The group cooperative learning oriented by "tasks" is widely used by the classroom teaching in many developed coun-tries, as it plays a significant role in improving students' academic performance, activating class atmosphere, and improving learn-ers' group cooperative quality. This paper explores the effective-ness of group cooperative learning in high vocational architecture English teaching, proposes its importance in English classroom teaching, and analyzes the effective strategies for its implementa-tion.%以“任务”为导向的分组合作学习在许多发达国家英语课堂教学中被广泛地使用,它对提高学生成绩、活跃课堂气氛、提升学习者团队合作品质等方面有显著成效。本文探讨了该分组合作学习方式在建设类高职英语教学中的效用,提出其在英语课堂教学中的重要作用,并分析其实施的有效策略。

  6. Overview of the ImageCLEFphoto 2008 photographic retrieval task

    OpenAIRE

    Arni, T.; Clough, P.; Sanderson, M.; Grubinger, M.

    2008-01-01

    ImageCLEFphoto 2008 is an ad-hoc photo retrieval task and part of the ImageCLEF evaluation campaign. This task provides both the resources and the framework necessary to perform comparative laboratory-style evaluation of visual information retrieval systems. In 2008, the evaluation task concentrated on promoting diversity within the top 20 results from a multilingual image collection. This new challenge attracted a record number of submissions: a total of 24 participating group...

  7. Tasks Scheduling using Ant Colony Optimization

    Directory of Open Access Journals (Sweden)

    A. P. Shanthi

    2012-01-01

    Full Text Available Problem statement: Efficient scheduling of the tasks to heterogeneous processors for any application is critical in order to achieve high performance. Finding a feasible schedule for a given task set to a set of heterogeneous processors without exceeding the capacity of the processors, in general, is NP-Hard. Even if there are many conventional approaches available, people have been looking at unconventional approaches for solving this problem. This study uses a paradigm using Ant Colony Optimisation (ACO for arriving at a schedule. Approach: An attempt is made to arrive at a feasible schedule of a task set on heterogeneous processors ensuring load balancing across the processors. The heterogeneity of the processors is modelled by assuming different utilisation times for the same task on different processors. ACO, a bio-inspired computing paradigm, is used for generating the schedule. Results: For a given instance of the problem, ten runs are conducted based on an ACO algorithm and the average wait time of all tasks is computed. Also the average utilisation of each processor is calculated. For the same instance, the two parameters: average wait time of tasks and utilisation of processors are computed using the First Come First Served (FCFS. The results are tabulated and compared and it is found that ACO performs better than the FCFS with respect to the wait time. Although the processor utilisation is more for some processors using FCFS algorithm, it is found that the load is better balanced among the processors in ACO. There is a marginal increase in the time for arriving at a schedule in ACO compared to FCFS algorithm. Conclusion: This approach to the tasks assignment problem using ACO performs better with respect to the two parameters used compared to the FCFS algorithm but the time taken to come up with the schedule using ACO is slightly more than that of FCFS.

  8. Cognitive task load analysis : Allocating tasks and designing support

    OpenAIRE

    Neerincx, M.A.

    2003-01-01

    We present a method for Cognitive Task Analysis that guides the early stages of software development, aiming at an optimal cognitive load for operators of process control systems. The method is based on a practical theory of cognitive task load and support. In addition to the classical measure percentage time occupied, this theory distinguishes two load factors that affect cognitive task performance and mental effort: the level of information processing and the number of task-set switches. Re...

  9. 运用规范行为区分任务测查攻击/受欺儿童的情感预期能力%A Study on Affective Anticipation of Children with Different Aggression/ Victim Groups by Using Normative Behavior Identifying Tasks

    Institute of Scientific and Technical Information of China (English)

    李亚真; 桑标

    2012-01-01

    儿童社会信息加工的情绪一认知整合模型指出.对各种反应的情绪后果预期会影响儿童对反应的提取、决策及对情绪活动的评价。本研究运用规范行为区分任务(原称为社会情境任务)测查不同攻击/受欺类型儿童的情感预期能力,结果发现:不同类型儿童在3个规范一违反行为判断子任务上得分及总分上均不存在显著性差异,但在对规范行为和对违反行为判断的差异上,未卷入儿童在各个情境中所判定的差异都更大:未卷入儿童在三个任务情境上的规范行为觉知能力都优于其他类型儿童,其规范行为觉知能力具有跨情境的一致性:三个任务情境都具有检测力.但不同任务情境具有不同的检测力或区分力。%According to Integrated Model of Emotion Processes and Cognition in Social Information Pro- cessing(IEC-SIP), emotional outcome expectations of responses would influence response generation,evalua- tion, and decision. Study aims to find out the features of affective anticipation of children with different aggression/victim groups by using story tests, which originally called social situtations task, to explore children's ability to differentiate normative behavior from violation behavior. The results see that there isn't significant difference in each of normative-violation identifying tasks among different aggression/victim groups, so as to the total score, but difference between normative and violation behavior judged by non- involved children is significant and greater than any other kinds of children; non-involved children's ability to apperceive normative behavior is the best and has cross-situational consistency; all of the three social situtations tasks can test, but each has different degree of effectiveness.

  10. Marine Strategy Framework Directive - Task Group 6 Seafloor integrity

    OpenAIRE

    Rice, Jake; Arvanitidis, Christos; Borja, Angel; Frid, Chris; HIDDINK Jan; Krause, Jochen; Lorance, Pascal; RAGNARSSON Stefán Áki; Sköld, Mattias; Trabucco, Benedetta

    2010-01-01

    The Marine Strategy Framework Directive (2008/56/EC) (MSFD) requires that the European Commission (by 15 July 2010) should lay down criteria and methodological standards to allow consistency in approach in evaluating the extent to which Good Environmental Status (GES) is being achieved. ICES and JRC were contracted to provide scientific support for the Commission in meeting this obligation. A total of 10 reports have been prepared relating to the descriptors of GES listed in Annex I of the...

  11. Report of the heavy-ion fusion task group

    International Nuclear Information System (INIS)

    An assessment of heavy-ion fusion has been completed. Energetic heavy ions, for example 10-GeV uranium, provided by an rf linac or an induction linac, are used as alternatives to laser light to drive inertial confinement fusion pellets. The assessment has covered accelerator technology, transport of heavy-ion beams, target interaction physics, civilian power issues, and military applications. It is concluded that particle accelerators promise to be efficient pellet drivers, but that there are formidable technical problems to be solved. It is recommended that a moderate level research program on heavy-ion fusion be pursued and that LASL should continue to work on critical issues in accelerator development, beam transport, reactor systems studies, and target physics over the next few years

  12. Unique Signal mathematical analysis task group FY03 status report.

    Energy Technology Data Exchange (ETDEWEB)

    Baty, Roy Stuart (Los Alamos National Laboratory, Los Alamos, NM); Johnston, Anna Marie; Hart, Elizabeth (Utah State University, Logan, UT); White, Allan (NASA, Langley Research Center, Hampton, VA); Cooper, James Arlin

    2003-12-01

    The Unique Signal is a key constituent of Enhanced Nuclear Detonation Safety (ENDS). Although the Unique Signal approach is well prescribed and mathematically assured, there are numerous unsolved mathematical problems that could help assess the risk of deviations from the ideal approach. Some of the mathematics-based results shown in this report are: 1. The risk that two patterns with poor characteristics (easily generated by inadvertent processes) could be combined through exclusive-or mixing to generate an actual Unique Signal pattern has been investigated and found to be minimal (not significant when compared to the incompatibility metric of actual Unique Signal patterns used in nuclear weapons). 2. The risk of generating actual Unique Signal patterns with linear feedback shift registers is minimal, but the patterns in use are not as invulnerable to inadvertent generation by dependent processes as previously thought. 3. New methods of testing pair-wise incompatibility threats have resulted in no significant problems found for the set of Unique Signal patterns currently used. Any new patterns introduced would have to be carefully assessed for compatibility with existing patterns, since some new patterns under consideration were found to be deficient when associated with other patterns in use. 4. Markov models were shown to correspond to some of the engineered properties of Unique Signal sequences. This gives new support for the original design objectives. 5. Potential dependence among events (caused by a variety of communication protocols) has been studied. New evidence has been derived of the risk associated with combined communication of multiple events, and of the improvement in abnormal-environment safety that can be achieved through separate-event communication.

  13. Operator's Performance Time of Emergency Procedural Tasks in SGTR Scenario

    International Nuclear Information System (INIS)

    It is important to understand operator's performance time of an emergency procedural task for managing human performance in a nuclear power plant. However, the time to execute an emergency procedural task situation is highly dependent upon expert judgment due to the lack of actual data. This paper proposes an analytical method to estimate the operator's performance time (OPT) of a procedural emergency task, which is based on a measure of the task complexity (TACOM). The proposed method for estimating an OPT is an equation that uses the TACOM as a variable, and the OPT of a procedural task can be calculated if its relevant TACOM score is available. The validity of the proposed equation is demonstrated by comparing estimated OPTs with observed OPTs for emergency tasks in a steam generator tube rupture scenario

  14. Quarternary tectonics, Task 1

    Energy Technology Data Exchange (ETDEWEB)

    Bell, J.W.

    1993-09-30

    Activities conducted for the evaluation of the geology and seismotectonics stability of Yucca Mountain as a potential site for the underground disposal of high-level radioactive wastes continued. Tasks concerned with quaternary tectonics include: scheduling of photography of Little Skull Mountain area; the collection and dating of rock varnish samples from the 1932 Cedar Mountain earthquake area for carbon 14 AMS and cation-ratio analysis; collection of samples for thermoluminescence dating from the 1932 Cedar Mountain earthquake area; mapping of the northern area of Crater Flat; and surveying of the May 17, 1993 Eureka the Valley earthquake area.

  15. Adaptive group coordination and role differentiation.

    Science.gov (United States)

    Roberts, Michael E; Goldstone, Robert L

    2011-01-01

    Many real world situations (potluck dinners, academic departments, sports teams, corporate divisions, committees, seminar classes, etc.) involve actors adjusting their contributions in order to achieve a mutually satisfactory group goal, a win-win result. However, the majority of human group research has involved situations where groups perform poorly because task constraints promote either individual maximization behavior or diffusion of responsibility, and even successful tasks generally involve the propagation of one correct solution through a group. Here we introduce a group task that requires complementary actions among participants in order to reach a shared goal. Without communication, group members submit numbers in an attempt to collectively sum to a randomly selected target number. After receiving group feedback, members adjust their submitted numbers until the target number is reached. For all groups, performance improves with task experience, and group reactivity decreases over rounds. Our empirical results provide evidence for adaptive coordination in human groups, and as the coordination costs increase with group size, large groups adapt through spontaneous role differentiation and self-consistency among members. We suggest several agent-based models with different rules for agent reactions, and we show that the empirical results are best fit by a flexible, adaptive agent strategy in which agents decrease their reactions when the group feedback changes. The task offers a simple experimental platform for studying the general problem of group coordination while maximizing group returns, and we distinguish the task from several games in behavioral game theory. PMID:21811595

  16. Adaptive group coordination and role differentiation.

    Directory of Open Access Journals (Sweden)

    Michael E Roberts

    Full Text Available Many real world situations (potluck dinners, academic departments, sports teams, corporate divisions, committees, seminar classes, etc. involve actors adjusting their contributions in order to achieve a mutually satisfactory group goal, a win-win result. However, the majority of human group research has involved situations where groups perform poorly because task constraints promote either individual maximization behavior or diffusion of responsibility, and even successful tasks generally involve the propagation of one correct solution through a group. Here we introduce a group task that requires complementary actions among participants in order to reach a shared goal. Without communication, group members submit numbers in an attempt to collectively sum to a randomly selected target number. After receiving group feedback, members adjust their submitted numbers until the target number is reached. For all groups, performance improves with task experience, and group reactivity decreases over rounds. Our empirical results provide evidence for adaptive coordination in human groups, and as the coordination costs increase with group size, large groups adapt through spontaneous role differentiation and self-consistency among members. We suggest several agent-based models with different rules for agent reactions, and we show that the empirical results are best fit by a flexible, adaptive agent strategy in which agents decrease their reactions when the group feedback changes. The task offers a simple experimental platform for studying the general problem of group coordination while maximizing group returns, and we distinguish the task from several games in behavioral game theory.

  17. A Task that Elicits Reasoning: A Dual Analysis

    Science.gov (United States)

    Yankelewitz, Dina; Mueller, Mary; Maher, Carolyn A.

    2010-01-01

    This paper reports on the forms of reasoning elicited as fourth grade students in a suburban district and sixth grade students in an urban district worked on similar tasks involving reasoning with the use of Cuisenaire rods. Analysis of the two data sets shows similarities in the reasoning used by both groups of students on specific tasks, and the…

  18. Affordances and synchronization in collective creative construction tasks

    DEFF Research Database (Denmark)

    Tylén, Kristian; Fusaroli, Riccardo

    heart rate measurements and employ recurrence analysis techniques to quantify the mutual adaptability of heart rates among the participants in the different tasks. We show that during individual tasks individual heart rates synchronize both within and between groups (but not with controls) plausibly due...

  19. Social Pressures and Task Performance

    OpenAIRE

    Shearer, Greg

    2013-01-01

    Previous research has demonstrated the impact of the actions of others on task performance – citing that both social acceptance and ostracism can increase task performance (Lustenberger & Jagacinski, 2010; Jamieson et. al., 2010). In this study, the relationship between social inclusion/ostracism and performance on a verbal comprehension task is investigated in an attempt to discover which is more potent in influencing task performance. Two forms of social conditioning are used; face-to-face ...

  20. Skill Components of Task Analysis

    Science.gov (United States)

    Adams, Anne E.; Rogers, Wendy A.; Fisk, Arthur D.

    2013-01-01

    Some task analysis methods break down a task into a hierarchy of subgoals. Although an important tool of many fields of study, learning to create such a hierarchy (redescription) is not trivial. To further the understanding of what makes task analysis a skill, the present research examined novices' problems with learning Hierarchical Task…

  1. Reverse-Engineering Communication Tasks

    Science.gov (United States)

    Lamber, Craig

    2004-01-01

    This article introduces an approach to planning sequences of communication tasks that require learners to become personally involved in their learning. By drawing on their own ideas and experiences, as a product of earlier tasks in a given sequence, learners generate the content and resource material on which subsequent tasks operate. The article…

  2. Neutron shielding calculation for VVER NPP

    International Nuclear Information System (INIS)

    There are two methods for neutron transport (shielding) calculation used in Energoproject, Prague, the method of discrete ordinates (code TORT-DORT) and the Monte Carlo method (codes MCNP and module within the code SCALE). The task concerning neutron dose rates calculation near casks with VVER spent fuel are presented as an example. Measured neutron dose rates of real loaded C-30 casks for VVER spent fuel assemblies are compared with calculated values in the frame of the international benchmark calculation task. A part of the task realized by the Atomic Energy Research (AER) organization concerning neutron shielding is calculated. The cask C-30 is used in Slovak Jaslovske Bohunice NPP for transport of spent fuel assemblies to the storage facility. The benchmark task has been calculated by the two-dimensional code DORT originated from Oak Ridge National Laboratory. The code solves transport problems using the method of discrete ordinates (SN - method). Calculated neutron dose rates in azimuth and vertical directions show good agreement with the experiment within the range of the measurement errors. In comparison with the other codes the results of DORT are approximately 20% lower. There have been analysed differences between one- and two- dimensional approach and influence of the flux-to-dose rate conversion factors set

  3. Musical Training, Bilingualism, and Executive Function: A Closer Look at Task Switching and Dual-Task Performance

    Science.gov (United States)

    Moradzadeh, Linda; Blumenthal, Galit; Wiseheart, Melody

    2015-01-01

    This study investigated whether musical training and bilingualism are associated with enhancements in specific components of executive function, namely, task switching and dual-task performance. Participants (n = 153) belonging to one of four groups (monolingual musician, bilingual musician, bilingual non-musician, or monolingual non-musician)…

  4. Brain network adaptability across task states.

    Directory of Open Access Journals (Sweden)

    Elizabeth N Davison

    2015-01-01

    Full Text Available Activity in the human brain moves between diverse functional states to meet the demands of our dynamic environment, but fundamental principles guiding these transitions remain poorly understood. Here, we capitalize on recent advances in network science to analyze patterns of functional interactions between brain regions. We use dynamic network representations to probe the landscape of brain reconfigurations that accompany task performance both within and between four cognitive states: a task-free resting state, an attention-demanding state, and two memory-demanding states. Using the formalism of hypergraphs, we identify the presence of groups of functional interactions that fluctuate coherently in strength over time both within (task-specific and across (task-general brain states. In contrast to prior emphases on the complexity of many dyadic (region-to-region relationships, these results demonstrate that brain adaptability can be described by common processes that drive the dynamic integration of cognitive systems. Moreover, our results establish the hypergraph as an effective measure for understanding functional brain dynamics, which may also prove useful in examining cross-task, cross-age, and cross-cohort functional change.

  5. Job and task analysis for technical staff

    International Nuclear Information System (INIS)

    In September of 1989 Cooper Nuclear Station began a project to upgrade the Technical Staff Training Program. This project's roots began by performing job and Task Analysis for Technical Staff. While the industry has long been committed to Job and Task Analysis to target performance based instruction for single job positions, this approach was unique in that it was not originally considered appropriate for a group as diverse as Tech Staff. Much to his satisfaction the Job and Task Analysis Project was much less complicated for Technical Staff than the author had imagined. The benefits of performing the Job and Task Analysis for Technical Staff have become increasingly obvious as he pursues lesson plan development and course revisions. The outline for this presentation will be as follows: philosophy adopted; preparation of the job survey document; performing the job analysis; performing task analysis for technical staff and associated pitfalls; clustering objectives for training and comparison to existing program; benefits now and in the future; final phase (comparison to INPO guides and meeting the needs of non-degreed engineering professionals); and conclusion. By focusing on performance based needs for engineers rather than traditional academics for training the author is confident the future Technical Staff Program will meet the challenges ahead and will exceed requirements for accreditation

  6. Analysis of operators' diagnosis tasks based on cognitive process

    International Nuclear Information System (INIS)

    Diagnosis tasks in nuclear power plants characterized as high-dynamic uncertainties are complex reasoning tasks. Diagnosis errors are the main causes for the error of commission. Firstly, based on mental model theory and perception/action cycle theory, a cognitive model for analyzing operators' diagnosis tasks is proposed. Then, the model is used to investigate a trip event which occurred at crystal river nuclear power plant. The application demonstrates typical cognitive bias and mistakes which operators may make when performing diagnosis tasks. They mainly include the strong confirmation tendency, difficulty to produce complete hypothesis sets, group mindset, non-systematic errors in hypothesis testing, and etc. (authors)

  7. Cognitive Task Complexity and L2 Narrative Writing Performance

    OpenAIRE

    Ali Akbar Khomeijani Farahani; Seyed Reza Meraji

    2011-01-01

    The present study was an attempt to chart the effects of two task design features, namely pre-task planning time and immediacy on written narrative performance. This is of pronounced importance since the synergistic effects of these two task features have gone largely unheeded in task-based research except for a smattering of studies (e.g., Gilabert, 2007). Accordingly, 123 participants were assigned to one of the 4 groups in the study, i.e., No planning & Here-and-Now, No planning & ...

  8. Are women better than men at multi-tasking?

    OpenAIRE

    Stoet, Gijsbert; O’Connor, Daryl B.; Conner, Mark; Laws, Keith R.

    2013-01-01

    Background: There seems to be a common belief that women are better in multi-tasking than men, but there is practically no scientific research on this topic. Here, we tested whether women have better multi-tasking skills than men. Methods: In Experiment 1, we compared performance of 120 women and 120 men in a computer-based task-switching paradigm. In Experiment 2, we compared a different group of 47 women and 47 men on "paper-and-pencil" multi-tasking tests. Results: In Expe...

  9. Task Analysis Technologies at KSC

    Science.gov (United States)

    Carstens, Deborah S.

    2003-01-01

    Project objective: (1) Form an integrated team of NASA. USA, Boeing, and Dynacs researches. (2) Create a user friendly software prototype that assists an analyst in performing a human factors process failure modes and effects analysis (HF-PFMEA). (3)Perform four task analyses on center: cargo late access task analysis (NASA/Boeing team); payload test and verification system task analysis (NASA/Boeing team); slammer cover installation operations task analysis (NASA/USA team); ATDC LOX pump acceptance test procedure task analysis (NASA/Dynacs team).

  10. The Effect of Different Types of Walking on Dual-Task Performance and Task Prioritization among Community-Dwelling Older Adults

    Directory of Open Access Journals (Sweden)

    Maayan Agmon

    2014-01-01

    Full Text Available Background. The ability to safely conduct different types of walking concurrently with a cognitive task (i.e., dual task is crucial for daily life. The contribution of different walking types to dual-task performance has not yet been determined, nor is there agreement on the strategies that older adults use to divide their attention between two tasks (task prioritization. Objectives. To compare the effect of walking in three different directions (forward, backward, and sideways on dual-task performance and to explore the strategies of older adults to allocate their attention in response to different motor task demands. Design. A cross-sectional study. Subjects. Thirty-two (22 female community-dwelling older adults (aged 72.7±5.7 years. Methods. Subjects randomly conducted single and dual task: walking to three directions separately, cognitive tasks separately, and combination of the two. Results. Walking forward was the least demanding task, during single (FW < BW, SW (P<.001 and dual tasks (FW < BW < SW (P<.001. The calculation of DTC revealed the same pattern (P<.001. DTC of the cognitive tasks was not significantly different among the three walking types. Conclusions. The decline mainly in the motor performance during dual task indicates that participants prioritized the cognitive task. These findings challenge the “posture first” paradigm for task prioritization.

  11. Selection of maintenance tasks

    International Nuclear Information System (INIS)

    Two methodologies for maintenance task selection, Reliability Centre Maintenance (RCM) and Degradation Mode Analysis (DMA), are compared with regard to application in the nuclear industry and potential for application at CANDU nuclear power plants. RCM is the favoured one of the two methodologies. It is more thorough than DMA, is well supported within the US nuclear industry, and - with experience in application - is gaining cost effectiveness. There is interest in the use of RCM in other nations, including France and Japan, and it is already being implemented at Bruce A NGS and Bruce B NGS in Canada. DMA lags behind RCM in development and currently there is little experience to support claims of major benefits at reduced cost. Significant advantages over RCM need to be demonstrated if DMA is to gain acceptance in the nuclear industry. (author). 41 refs., 7 tabs., 8 figs

  12. AMU NEXRAD Exploitation Task

    Science.gov (United States)

    Lambert, Winifred C.; Wheeler, Mark M.

    1997-01-01

    This report documents the results of the Applied Meteorology Unit's NEXRAD Exploitation Task. The objectives of this task are to determine what radar signatures are present prior to and at the time of convection initiation, and to determine radar signatures which will help distinguish whether the ensuing convection will become severe. Radar data from the WSR-88D radar located at NWS Melbourne (WSR-88D/KMLB) were collected between June and September 1995, and 16 convective case studies were analyzed for which the radar was operating during the entire period of interest. All WSR-88D/KMLB products were scrutinized for their utility in detecting convection initiation and severe storm signatures. Through process of elimination, it was found that the 0.5 deg reflectivity product with the lowest reflectivity values displayed is the best product to monitor for convection initiation signatures. Seven meteorological features associated with the initiation of deep convection were identified: the Merritt Island and Indian River convergence zones, interlake convergence, horizontal convective rolls, the sea breeze, storm outflow boundaries, and fires. Their reflectivity values ranged from -5 to 20 dBZ. Of the three severe weather phenomena (winds greater than or equal to 50 kts, tornado, 3/4 inch hail), high wind events due to microbursts were most common in the data set. It was found that the values and trends of composite reflectivity, vertically integrated liquid, and core aspect ratio were key indicators of the potential of a cell to produce a microburst. The data were not analyzed for the other two severe weather phenomena because they rarely occurred during the data collection period. This report also includes suggestions for new WSR-88D products, summaries of ongoing research aimed at creating new products, and explicit recommended procedures for detecting convection initiation and severe storm signatures in the radar data using the currently available technology.

  13. A flexible algorithm for calculating pair interactions on SIMD architectures

    CERN Document Server

    Páll, Szilárd

    2013-01-01

    Calculating interactions or correlations between pairs of particles is typically the most time-consuming task in particle simulation or correlation analysis. Straightforward implementations using a double loop over particle pairs have traditionally worked well, especially since compilers usually do a good job of unrolling the inner loop. In order to reach high performance on modern CPU and accelerator architectures, single-instruction multiple-data (SIMD) parallelization has become essential. Avoiding memory bottlenecks is also increasingly important and requires reducing the ratio of memory to arithmetic operations. Moreover, when pairs only interact within a certain cut-off distance, good SIMD utilization can only be achieved by reordering input and output data, which quickly becomes a limiting factor. Here we present an algorithm for SIMD parallelization based on grouping a fixed number of particles, e.g. 2, 4, or 8, into spatial clusters. Calculating all interactions between particles in a pair of such cl...

  14. Task conflicts and exclusive professionalism in nursing in South Korea.

    Science.gov (United States)

    Jung, Minsoo

    2014-01-01

    Task conflicts among medical professions are essential problems to be solved in health care organizations. This study examined job conflicts between practical nurses (PNs) and registered nurses (RNs) in their duties and tasks with representative panelists from South Korea. This qualitative study used the Dacum Task Analysis process. Subject-matter experts in practical nursing were recruited utilizing stratified sampling: Ten experts developed job descriptions of PNs, and 20 validated the descriptions. The on-site tasks and duties of the PNs were measured by means of Dacum, and the results were reviewed by RNs using 3 focus-group interviews. The job description of PNs consisted of 10 duties and 117 tasks, overlapping with some tasks of RNs. Core tasks performed by PNs, such as invasive activities, led to task conflicts between the 2 groups, as these activities were regarded as the inherent duty of nursing professions. Thus, the RNs did not concede the expanded job scope of the PNs in terms of exclusive professionalism. To reduce task conflict, there is a need for the balanced development of nursing professionalism. PMID:24463592

  15. Predicting Satisfaction with Group Work Assignments

    Science.gov (United States)

    Burdett, Jane; Hastie, Brianne

    2009-01-01

    Universities are increasingly using group based assessment tasks; however, as with work-place teams, such tasks often elicit mixed feelings from participants. This study investigated factors that may predict student satisfaction with group work at university. Final-year business students completed a questionnaire addressing experiences of group…

  16. Cardiovascular reactivity and adaptation to recurrent psychological stress: effects of prior task exposure.

    Science.gov (United States)

    Kelsey, R M; Blascovich, J; Tomaka, J; Leitten, C L; Schneider, T R; Wiens, S

    1999-11-01

    The effects of prior task exposure on cardiovascular reactivity to stress were examined in two experiments by randomly assigning participants to repeated exposure groups that performed mental arithmetic pretest and test tasks versus delayed exposure groups that performed only the test task after prolonged rest. Impedance cardiographic and blood pressure measures were recorded continuously from 60 undergraduate men in Experiment 1 and 112 undergraduate men and women in Experiment 2. Task repetition attenuated cardiovascular reactivity and improved task performance in repeated exposure groups (p < .001), suggesting an integrated process of behavioral adaptation. During the test task, delayed exposure groups showed greater cardiac reactivity (p < .01), but not vascular reactivity, than repeated exposure groups. Thus, cardiac reactivity varied as a specific function of prior task exposure, whereas vascular reactivity varied as a general function of time. PMID:10554594

  17. Masticatory muscle activity during deliberately performed oral tasks

    International Nuclear Information System (INIS)

    The aim of this study was to investigate masticatory muscle activity during deliberately performed functional and non-functional oral tasks. Electromyographic (EMG) surface activity was recorded unilaterally from the masseter, anterior temporalis and suprahyoid muscles in 11 subjects (5 men, 6 women; age = 34.6 ± 10.8 years), who were accurately instructed to perform 30 different oral tasks under computer guidance using task markers. Data were analyzed by descriptive statistics, repeated measurements analysis of variance (ANOVA) and hierarchical cluster analysis. The maximum EMG amplitude of the masseter and anterior temporalis muscles was more often found during hard chewing tasks than during maximum clenching tasks. The relative contribution of masseter and anterior temporalis changed across the tasks examined (F ≥ 5.2; p ≤ 0.001). The masseter muscle was significantly (p ≤ 0.05) more active than the anterior temporalis muscle during tasks involving incisal biting, jaw protrusion, laterotrusion and jaw cupping, the difference being statistically significant (p ≤ 0.05). The anterior temporalis muscle was significantly (p ≤ 0.01) more active than the masseter muscle during tasks performed in intercuspal position, during tooth grinding, and during hard chewing on the working side. Based upon the relative contribution of the masseter, anterior temporalis, and suprahyoid muscles, the investigated oral tasks could be grouped into six separate clusters. The findings provided further insight into muscle- and task-specific EMG patterns during functional and non-functional oral behaviors

  18. Group cubization

    OpenAIRE

    Osajda, Damian

    2016-01-01

    We present a procedure of group cubization: It results in a group whose some features resemble the ones of a given group, and which acts without fixed points on a CAT(0) cubical complex. As a main application we establish lack of Kazhdan's property (T) for Burnside groups. Other applications include new constructions of non-exact groups.

  19. Development of one group constant library for the computer code ORIGEN-2 using JENDL-3.2

    International Nuclear Information System (INIS)

    Standard one group constant libraries for the ORIGEN-2 code are prepared using JENDL-3.2 for calculating the amount of nuclides generated in spent fuel of BWR, PWR and FBR, and the adaptability of the libraries is examined for the safety evaluation of the nuclear fuel cycle. This task is performed as a part of the activities of the nuclide generation evaluation working group of Japanese Nuclear Data Committee. (author)

  20. Challenges Facing Group Work Online

    Science.gov (United States)

    Chang, Bo; Kang, Haijun

    2016-01-01

    Online group work can be complicated because of its asynchronous characteristics and lack of physical presence, and its requirements for skills in handling technology, human relationships, and content-related tasks. This study focuses on the administrative, logistical and relationship-related challenges in online group work. Challenges in areas…

  1. Defining and Classifying Interest Groups

    DEFF Research Database (Denmark)

    Baroni, Laura; Carroll, Brendan; Chalmers, Adam; Marquez, Luz Maria Muñoz; Rasmussen, Anne

    2014-01-01

    The interest group concept is defined in many different ways in the existing literature and a range of different classification schemes are employed. This complicates comparisons between different studies and their findings. One of the important tasks faced by interest group scholars engaged in l...

  2. Integrated system for production of neutronics and photonics calculational constants. Volume XVI. Tabular and graphical presentation of 175 neutron group constants derived from the LLL evaluated neutron data library (ENDL)

    International Nuclear Information System (INIS)

    As of February 3, 1975, 175 neutron group constants had been derived from the Evaluated Nuclear Data Library (ENDL) at LLL. In this volume, tables and graphs of the constants are presented along with the conventions used in their preparation. (U.S.)

  3. LWR decay heat calculations using a GRS improved ENDF/B-6 based ORIGEN data library

    International Nuclear Information System (INIS)

    The known ORNL ORIGEN code is widely spread over the world for inventory, activity and decay heat tasks and is used stand-alone or implemented in activation, shielding or burn-up systems. More than 1000 isotopes with more than six coupled neutron capture and radioactive decay channels are handled simultaneously by the code. The characteristics of the calculated inventories, e.g., masses, activities, neutron and photon source terms or the decay heat during short or long decay time steps are achieved by summing over all isotopes, characterized in the ORIGEN libraries. An extended nuclear GRS-ORIGENX data library is now developed for practical appliance. The library was checked for activation tasks of structure material isotopes and for actinide and fission product burn-up calculations compared with experiments and standard methods. The paper is directed to the LWR decay heat calculation features of the new library and shows the differences of dynamical and time integrated results of Endf/B-6 based and older Endf/B-5 based libraries for decay heat tasks compared to fission burst experiments, ANS curves and some other published data. A multi-group time exponential evaluation is given for the fission burst power of 235U, 238U, 239Pu and 241Pu, to be used in quick LWR reactor accident decay heat calculation tools. (authors)

  4. Zero Temperature Hope Calculations

    International Nuclear Information System (INIS)

    The primary purpose of the HOPE code is to calculate opacities over a wide temperature and density range. It can also produce equation of state (EOS) data. Since the experimental data at the high temperature region are scarce, comparisons of predictions with the ample zero temperature data provide a valuable physics check of the code. In this report we show a selected few examples across the periodic table. Below we give a brief general information about the physics of the HOPE code. The HOPE code is an ''average atom'' (AA) Dirac-Slater self-consistent code. The AA label in the case of finite temperature means that the one-electron levels are populated according to the Fermi statistics, at zero temperature it means that the ''aufbau'' principle works, i.e. no a priory electronic configuration is set, although it can be done. As such, it is a one-particle model (any Hartree-Fock model is a one particle model). The code is an ''ion-sphere'' model, meaning that the atom under investigation is neutral within the ion-sphere radius. Furthermore, the boundary conditions for the bound states are also set at the ion-sphere radius, which distinguishes the code from the INFERNO, OPAL and STA codes. Once the self-consistent AA state is obtained, the code proceeds to generate many-electron configurations and proceeds to calculate photoabsorption in the ''detailed configuration accounting'' (DCA) scheme. However, this last feature is meaningless at zero temperature. There is one important feature in the HOPE code which should be noted; any self-consistent model is self-consistent in the space of the occupied orbitals. The unoccupied orbitals, where electrons are lifted via photoexcitation, are unphysical. The rigorous way to deal with that problem is to carry out complete self-consistent calculations both in the initial and final states connecting photoexcitations, an enormous computational task. The Amaldi correction is an attempt to address this problem by distorting the

  5. A Study on Affective Decision -making of Children with Different Aggression/Victim Groups by Gambling Task,%运用赌博任务测查不同攻击/受欺类别儿童的情感决策过程

    Institute of Scientific and Technical Information of China (English)

    李亚真; 桑标

    2012-01-01

    攻击行为认知研究存在的一个重要问题是忽视情感对儿童认知加工的影响。考虑了情绪-认知整合过程的儿童行为决策更能全面而真实地反映社会信息加工情境下的攻击/受欺行为卷入过程。情感决策的赌博任务范式被认为能诱发类似于个人真实生活决策的表现,本研究运用计算机程序编制的标准赌博任务,以过程的视角考察了不同攻击/受欺儿童的情感决策特点。结果发现,不同类型儿童的有利-不利选择净分数、对有利-不利选择及奖惩频数的决策偏向存在显著差异。研究结果反映未卷入儿童在赌博任务上的整体表现优于其他类型儿童,攻击-受欺儿童仅次于未卷入儿童;直接攻击、攻击-受欺、未卷入儿童呈现惩罚定向的决策风格,但这三类儿童也表现出截然不同的趋势。%Aggressive behavior has been a hot topic in the field of developmental psychology. One of the important problems in the study of aggressive behavior is that researchers neglect the influence of emotion on children's cognitive procession. In addition, there were few studies that probed the characteristics of decision-making of the children involved in the aggression/victim situation. If researchers took the integrated process of emotion and cognition into consideration when exploring children's decision-making, the results would reflect more truly and comprehensively the involved process of aggression/victim in social information processing. The gambling task paradigm of affective decision-making is believed to induce performance similar to the individual decision-making behavior in real life. A self-designed computer program of standard gambling task, in which 80 test items were divided into four blocks, was used to compare the decision-making achievement of the children belonging to different aggression/victim groups in different periods from the process perspective to reveal the

  6. Calculational methods, codes and results of calculational and experimental investigations of control rod worth in power fast reactors

    International Nuclear Information System (INIS)

    The paper aims to present the main physical principles for selection of design characteristics of the fast reactor control rods (CR) system. The brief analysis of problems of CR physical calculations is given. Four components are described for the correction to the control rod worth calculated by the routine method based on the few - group three - dimensional diffusion code (TRIGEX) in hexagonal geometry. Principle considerations are given for the choice of the original task discretization methods implemented in this code to minimize the total error. Brief information is given about methods and codes used for the evaluation of error components of control rod worths calculated in a standard way. The results of experimental and calculational investigations of control rod physical characteristics are presented. These results were obtained at BFS critical assemblies simulating LMFBR cores. The investigations have been carried out for different types of core configurations. The experimental and calculated values are given on the distortion of power distribution due to the control rod insertion in the core. (author). 51 refs, 9 figs, 5 tabs

  7. Establishment of IAEA knowledge of integrity of the geological repository boundaries and disposed spent fuel assemblies in the context of the Finnish geological repository. Experts' Group meeting Report on Task JNT/C 1204 of the Member States' Support Programme to IAEA Safeguards

    International Nuclear Information System (INIS)

    The Geological Repository Safeguards Experts Group (Member State Support Programme tasks JNT/C1204 and C1226), agreed that annual meetings should be held to address interface issues between IAEA safeguards and radioactive waste management and to explore the use of safety and operational information to make International Atomic Energy Agency (IAEA) safeguards more effective and efficient for geological repository facilities. It has also been recognised that the safeguards measures for geological repositories are to be developed site-specifically. To address these issues to the planned Olkiluoto repository in Finland a meeting of experts in safety, geological repository operations,and safeguards from 6 States, European Commission, and IAEA was held in Olkiluoto and Rauma, Finland, during September 29 - October 4, 2003. The pre-operational phase of the Olkiluoto repository should be efficiently used by the parties involved in safeguards. The applicability and reliability of the potential new techniques and the efficient practices must be developed and proven before their implementation as safeguards measures to be applied at the subsequent stages of the repository development. The visit to the location of the proposed Olkiluoto repository and neighbouring areas and subsequent presentations enabled the working groups to discuss the various issues with reference to actual site conditions. The working groups were thus able to identify potential measurement and monitoring techniques and research and development requirements for consideration by the Finnish authorities, in addition to making recommendations to the IAEA on planned activities for carrying out before and during the early investigation phase of the proposed Olkiluoto repository. It was understood that all parties shall take good care of the implementation of the planned activities to ensure that proven means, approaches and the required verified information is at hand at the time the projected facility will

  8. Analysis of Brain Cognitive State for Arithmetic Task and Motor Task Using Electroencephalography Signal

    Directory of Open Access Journals (Sweden)

    R Kalpana

    2013-08-01

    Full Text Available To localize the brain dynamics for cognitive processes from EEG signature has been a challenging taskfrom last two decades. In this paper we explore the spatial-temporal correlations of brain electricalneuronal activity for cognitive task such as Arithmetic and Motor Task using 3D cortical distributionmethod. Ten healthy right handed volunteers participated in the experiment. EEG signal was acquiredduring resting state with eyes open and eyes closed; performing motor task and arithmetic calculations.The signal was then computed for three dimensional cortical distributions on realistic head model withMNI152 template using standardized low resolution brain electromagnetic tomography (sLORETA. Thiswas followed by an appropriate standardization of the current density, producing images of electricneuronal activity without localization bias. Neuronal generators responsible for cognitive state such asArithmetic Task and Motor Task were localized. The result was correlated with the previous neuroimaging(fMRI study investigation. Hence our result directed that the neuronal activity from EEG signal can bedemonstrated in cortical level with good spatial resolution. 3D cortical distribution method, thus, may beused to obtain both spatial and temporal information from EEG signal and may prove to be a significanttechnique to investigate the cognitive functions in mental health and brain dysfunctions. Also, it may behelpful for brain/human computer interfacing.

  9. Correlates of academic procrastination: discomfort, task aversiveness, and task capability.

    Science.gov (United States)

    Milgram, N; Marshevsky, S; Sadeh, C

    1995-03-01

    The relationships among five aspects of academic procrastination--behavioral delay, personal upset about the delay, task aversiveness, task capability, and the desire to reduce behavioral delay--were investigated in 10th-grade Israeli students (N = 195). Upset about delay was weakly related to delay itself, and--unlike delay--was strongly related to perceived capability to perform academic tasks and to the desire to change delaying behavior. Students delayed more on academic tasks labeled unpleasant than pleasant, were neutral in between, and were correspondingly more upset about the former than the latter. They more frequently acknowledged reasons for academic procrastination that were less threatening to their self-image (e.g., problems in time management) than reasons that were more threatening (e.g., lack of ability). Interest in reducing delay is related more to self-perceived ability to handle tasks than to time spent procrastinating or reasons given for procrastinating. PMID:7760291

  10. Group conflict and faculty engagement

    DEFF Research Database (Denmark)

    Selmer, Jan; Jonasson, Charlotte; Lauring, Jakob

    2013-01-01

    In educational settings, substantial scholarly interest has focused on student engagement as an antecedent for educational development and positive school outcomes. Very limited research, however, has focused on the engagement of academic staff members. This may be a crucial oversight because...... assessed the effect of group trust, group relational conflict and group task conflict on indicators of behavioural, cognitive and emotional engagement. Our findings show a strong positive association between group trust and all academic staff engagement variables as well as a strong negative association...... between group relational conflict and all staff engagement variables. Task conflict was negatively associated with indicators of staff cognitive engagement. However, surprisingly, group trust did not have any moderating effect. Implications for educational organisation managers and policy makers are...

  11. Parietal contributions to visual working memory depend on task difficulty

    Directory of Open Access Journals (Sweden)

    MarianBerryhill

    2012-09-01

    Full Text Available The nature of parietal contributions to working memory (WM remain poorly understood but of considerable interest. We previously reported that posterior parietal damage selectively impaired WM probed by recognition (Berryhill & Olson, 2008a. Recent studies provided support using a neuromodulatory technique, transcranial direct current stimulation (tDCS applied to the right parietal cortex (P4. These studies confirmed parietal involvement in WM because parietal tDCS altered WM performance: anodal current tDCS improved performance in a change detection task, and cathodal current tDCS impaired performance on a sequential presentation task. In Experiment 1, we applied cathodal and anodal tDCS to the right parietal cortex and tested participants on both previously used WM tasks. When the WM task was difficult, parietal stimulation (anodal or cathodal improved WM performance selectively in participants with high WM capacity. In the low WM capacity group, parietal stimulation (anodal or cathodal impaired WM performance. These nearly equal and opposite effects were only observed when the WM task was challenging, as in the change detection task. Experiment 2 probed the interplay of WM task difficulty and WM capacity in a parametric manner by varying set size in the WM change detection task. Here, the effect of parietal stimulation (anodal or cathodal on the high WM capacity group followed a linear function as WM task difficulty increased with set size. These findings provide evidence that parietal involvement in WM performance depends on both WM capacity and WM task demands. We discuss these findings in terms of alternative WM strategies employed by low and high WM capacity individuals. We speculate that low WM capacity individuals do not recruit the posterior parietal lobe for WM tasks as efficiently as high WM capacity individuals. Consequently, tDCS provides greater benefit to individuals with high WM capacity.

  12. Irregular head movement patterns in whiplash patients during a trajectory task.

    Science.gov (United States)

    Woodhouse, Astrid; Stavdahl, Øyvind; Vasseljen, Ottar

    2010-03-01

    Patients with whiplash associated disorders (WAD) have shown less accuracy in trajectory head motion compared to asymptomatic controls, which comply with clinical observations. The aim of this study was to investigate whether a trajectory head movement task can differ between WAD patients, chronic non-traumatic neck pain (CNP) patients and asymptomatic controls. Study groups included subjects with WAD (n = 35) with persistent neck pain after a car accident, CNP (n = 45), and asymptomatic controls (n = 48). Head motion was recorded from an unsupported standing position using a 3D Fastrak device. A laser pointer was attached to the head and by moving the head the subjects were asked to trace a figure of eight displayed on the wall at three different paces (slow, moderate and fast). The motion signal was decomposed into 1 Hz frequency bands and angular velocity (deg/s) within each frequency band was calculated. Significantly higher angular RMS velocity was found in the WAD group compared to the two other groups for the slow paced test (3-4 and 4-5 Hz frequency bands) and the moderate paced test (3-4 Hz frequency band) indicating irregular and uncoordinated movements. Angular RMS velocity was associated with pain and dizziness, but only with severe symptom levels. In conclusion, irregular head movements during a complex task were found in the WAD group, indicating altered central sensorimotor processing. The irregularities were found within frequency levels observable to clinicians. PMID:19820919

  13. Evaluating Energy Sector Investments: Calculating Volatility

    Directory of Open Access Journals (Sweden)

    Edson de Oliveira Pamplona

    2013-01-01

    Full Text Available A major task in assessing risks of investment projects is defining the approach to calculating the project’s volatility. Looking at assorted estimation techniques, this paper calculates their volatilities. The techniques originate from authors in the area and involve project-specific variables of uncertainty. These techniques are applied to a case of electricity distribution through real options. Results are then compared. The difference between the calculated volatilities was low, leaving, in the case of the project evaluated here, the decision unchanged. The paper’s contribution consists of providing a detailed presentation of calculating volatility by the methods cited and by comparing the results obtained by its application.

  14. University Students' Emotion During Online Search Task: A Multiple Achievement Goal Perspective.

    Science.gov (United States)

    Zhou, Mingming

    2016-07-01

    Endorsing a multiple goal perspective, students' academic emotions were examined with different goal profiles while solving learning tasks online. One hundred and seven Chinese undergraduates were classified based on the 2 × 2 achievement goal framework into three groups: Mastery-approach-focused, Approach-oriented, and Avoidance-oriented group. Participants' emotional states were assessed immediately prior to the task and following the task. Prior to the task, the Avoidance-oriented group reported significantly higher levels of deactivated negative emotion (i.e., bored and confused) than the Approach-oriented group. The Mastery-approach-focused group reported significantly higher levels of activated positive emotions (i.e., excited and eager) than the Avoidance-oriented group after the task. Within each group, all three groups followed a similar emotion change pattern prior versus after the search task in deactivated positive emotion, with a significant increase. In addition, the Mastery-approach-focused group also reported a significantly higher level of happiness after completing the task, whereas the other two groups did not report much change. The Avoidance-oriented group also reported a significant drop in the feeling of excitement, eagerness, anxiety, and nervousness; whereas, the Approach-oriented group reported a significantly higher level of confusion after the task was finished. Implications of the findings are further discussed. PMID:26914815

  15. Postural Adaptations to a Suprapostural Memory Task among Children with and without Developmental Coordination Disorder

    Science.gov (United States)

    Chen, Fu-Chen; Tsai, Chia-Liang; Stoffregen, Thomas A.; Chang, Chihu-Hui; Wade, Michael G.

    2012-01-01

    Aim: The present study investigated the effects of varying the cognitive demands of a memory task (a suprapostural task) while recording postural motion on two groups of children, one diagnosed with developmental coordination disorder (DCD) and an age-matched group of typically developing children. Method: Two groups, each comprising 38 child…

  16. Task-based working memory guidance of visual attention.

    Science.gov (United States)

    Chen, Zhe; Tsou, Brian H

    2011-05-01

    Previous research has established that holding a stimulus in working memory (WM) facilitates the deployment of visual attention to that stimulus relative to other stimuli. The present study examined whether maintaining a specific task in WM would also bias the allocation of attention to the stimuli associated with that task. Participants performed a speeded letter search task while simultaneously keeping in WM one of two task cues shown at the beginning of each trial. The results showed that task-based WM guidance of attention was modulated by response latencies. Whereas the participants with fast reaction times showed little influence of WM contents, the participants with slow reaction times took longer to respond when the letter target appeared in a distractor stimulus consistent with the task cue held in mind. A subsequent Stroop experiment found a larger Stroop interference effect from the participants in the slow group compared with those in the fast group, suggesting that the differential WM effect between the two groups may be associated with an individual's ability to inhibit task-irrelevant information. Taken together, these results expanded the realm of previous research and provided further evidence for a close link between attention and WM. PMID:21264740

  17. Effect of repeated restraint stress on memory in different tasks

    Directory of Open Access Journals (Sweden)

    Gamaro G.D.

    1999-01-01

    Full Text Available The present study investigated the effect of repeated stress applied to female rats on memory evaluated by three behavioral tasks: two-way shuttle avoidance, inhibitory avoidance and habituation to an open field. Repeated stress had different effects on rat behavior when different tasks were considered. In the two-way active avoidance test the stressed animals presented memory of the task, but their memory scores were impaired when compared to all other groups. In the habituation to the open field, only the control group showed a significant difference in the number of rearings between training and testing sessions, which is interpreted as an adequate memory of the task. In the handled and chronically stressed animals, on the other hand, no memory was observed, suggesting that even a very mild repeated stress would be enough to alter habituation to this task. The performance in the inhibitory avoidance task presented no significant differences between groups. The findings suggest that repeated restraint stress might induce cognitive impairments that are dependent on the task and on stress intensity.

  18. Group Milieu in systemic and psychodynamic group therapy

    DEFF Research Database (Denmark)

    Lau, Marianne Engelbrecht

    subscales: Cohesion (p< 0.05), Leader support (p=0.001), Expressiveness (p< 0.001), Task Orientation (p=0.01) and Order and Organization (p< 0.001). Conclusions: Substantial differences in the group milieu were seen. The systemic group turned out to be evaluated as the most structured therapy and also to be...... randomized study of systemic versus psychodynamic group therapy, that the short-term outcome for patients who received systemic group psychotherapy was significantly better than the outcome for patients who received psychodynamic group psychotherapy. The current study assessed the group milieu in both groups....... Methods: This randomized prospective study included 106 women: 52 assigned to psychodynamic group psychotherapy and 54 assigned to systemic group psychotherapy. The Group Environment Scale (GES) was filled in the mid phase of therapy and analysed in three dimensions and 10 subscales. Results: The systemic...

  19. Evolution of Self-Organized Task Specialization in Robot Swarms.

    Directory of Open Access Journals (Sweden)

    Eliseo Ferrante

    2015-08-01

    Full Text Available Division of labor is ubiquitous in biological systems, as evidenced by various forms of complex task specialization observed in both animal societies and multicellular organisms. Although clearly adaptive, the way in which division of labor first evolved remains enigmatic, as it requires the simultaneous co-occurrence of several complex traits to achieve the required degree of coordination. Recently, evolutionary swarm robotics has emerged as an excellent test bed to study the evolution of coordinated group-level behavior. Here we use this framework for the first time to study the evolutionary origin of behavioral task specialization among groups of identical robots. The scenario we study involves an advanced form of division of labor, common in insect societies and known as "task partitioning", whereby two sets of tasks have to be carried out in sequence by different individuals. Our results show that task partitioning is favored whenever the environment has features that, when exploited, reduce switching costs and increase the net efficiency of the group, and that an optimal mix of task specialists is achieved most readily when the behavioral repertoires aimed at carrying out the different subtasks are available as pre-adapted building blocks. Nevertheless, we also show for the first time that self-organized task specialization could be evolved entirely from scratch, starting only from basic, low-level behavioral primitives, using a nature-inspired evolutionary method known as Grammatical Evolution. Remarkably, division of labor was achieved merely by selecting on overall group performance, and without providing any prior information on how the global object retrieval task was best divided into smaller subtasks. We discuss the potential of our method for engineering adaptively behaving robot swarms and interpret our results in relation to the likely path that nature took to evolve complex sociality and task specialization.

  20. Task Models in the Digital Ocean

    Science.gov (United States)

    DiCerbo, Kristen E.

    2014-01-01

    The Task Model is a description of each task in a workflow. It defines attributes associated with that task. The creation of task models becomes increasingly important as the assessment tasks become more complex. Explicitly delineating the impact of task variables on the ability to collect evidence and make inferences demands thoughtfulness from…

  1. Task Switching: A PDP Model

    Science.gov (United States)

    Gilbert, Sam J.; Shallice, Tim

    2002-01-01

    When subjects switch between a pair of stimulus-response tasks, reaction time is slower on trial N if a different task was performed on trial N--1. We present a parallel distributed processing (PDP) model that simulates this effect when subjects switch between word reading and color naming in response to Stroop stimuli. Reaction time on "switch…

  2. Cosmetology Series. Duty Task List.

    Science.gov (United States)

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains the occupational duty/task lists for three occupations in the cosmetology series. Each occupation is divided into a number of duties. A separate page for each duty in the occupation lists the tasks in that duty along with its code number and columns to indicate whether that particular duty has been taught and to provide…

  3. Group X

    Energy Technology Data Exchange (ETDEWEB)

    Fields, Susannah

    2007-08-16

    This project is currently under contract for research through the Department of Homeland Security until 2011. The group I was responsible for studying has to remain confidential so as not to affect the current project. All dates, reference links and authors, and other distinguishing characteristics of the original group have been removed from this report. All references to the name of this group or the individual splinter groups has been changed to 'Group X'. I have been collecting texts from a variety of sources intended for the use of recruiting and radicalizing members for Group X splinter groups for the purpose of researching the motivation and intent of leaders of those groups and their influence over the likelihood of group radicalization. This work included visiting many Group X websites to find information on splinter group leaders and finding their statements to new and old members. This proved difficult because the splinter groups of Group X are united in beliefs, but differ in public opinion. They are eager to tear each other down, prove their superiority, and yet remain anonymous. After a few weeks of intense searching, a list of eight recruiting texts and eight radicalizing texts from a variety of Group X leaders were compiled.

  4. TRANSLATION: A MULTIDIMENSIONAL TASK

    Directory of Open Access Journals (Sweden)

    Rana Raddawi

    2005-01-01

    Full Text Available The aim of this paper is to shed light on the pedagogical function of translation, and how it can contribute to teaching or fostering language acquisition using either traditional tools of language teaching such as textbooks, and handouts, or by technological means. In this paper the role of L1 (the learner's first language is emphasized as an assistant to second language teaching (L2. The facts presented in this article are the results of my experience working on translation shared with a group of students enrolled in the Intensive English Program before they were admitted in their major.

  5. The classical task

    DEFF Research Database (Denmark)

    Gillis, Steven; Souman, Agnita; Dhollander, Sim; Molemans, Inge; Kjærbæk, Laila; Rehfeldt, Katja; Basbøll, Hans; Lambertsen, Claus; Laaha, Sabine; Bertl, Johannes; Dressler, Wolfgang U.; Lavie, Naama; Levie, Ronit; Ravid, Dorit

    articulated: Prediction 1: a global analysis of the plural forms provided by the subjects is expected to show an increase of the correct responses as children grow older. Prediction 2: As to suffix selection, we expect that the plural of nouns selecting a fully predictable suffix will be more readily mastered...... than the plural of nouns with a partially predictable suffix, and plurals that are exceptional as to their suffix selection will be most difficult, and, hence mastered later. Prediction 3: As to stem change, we expect that plurals with no stem change involved will be ‘easier' in each age group, and...

  6. Group Flow and Group Genius

    Science.gov (United States)

    Sawyer, Keith

    2015-01-01

    Keith Sawyer views the spontaneous collaboration of group creativity and improvisation actions as "group flow," which organizations can use to function at optimum levels. Sawyer establishes ideal conditions for group flow: group goals, close listening, complete concentration, being in control, blending egos, equal participation, knowing…

  7. HENRY'S LAW CALCULATOR

    Science.gov (United States)

    On-Site was developed to provide modelers and model reviewers with prepackaged tools ("calculators") for performing site assessment calculations. The philosophy behind OnSite is that the convenience of the prepackaged calculators helps provide consistency for simple calculations,...

  8. A TASK-ORIENTED DISASTER INFORMATION CORRELATION METHOD

    Directory of Open Access Journals (Sweden)

    Q. Linyao

    2015-07-01

    Full Text Available With the rapid development of sensor networks and Earth observation technology, a large quantity of disaster-related data is available, such as remotely sensed data, historic data, case data, simulated data, and disaster products. However, the efficiency of current data management and service systems has become increasingly difficult due to the task variety and heterogeneous data. For emergency task-oriented applications, the data searches primarily rely on artificial experience based on simple metadata indices, the high time consumption and low accuracy of which cannot satisfy the speed and veracity requirements for disaster products. In this paper, a task-oriented correlation method is proposed for efficient disaster data management and intelligent service with the objectives of 1 putting forward disaster task ontology and data ontology to unify the different semantics of multi-source information, 2 identifying the semantic mapping from emergency tasks to multiple data sources on the basis of uniform description in 1, and 3 linking task-related data automatically and calculating the correlation between each data set and a certain task. The method goes beyond traditional static management of disaster data and establishes a basis for intelligent retrieval and active dissemination of disaster information. The case study presented in this paper illustrates the use of the method on an example flood emergency relief task.

  9. a Task-Oriented Disaster Information Correlation Method

    Science.gov (United States)

    Linyao, Q.; Zhiqiang, D.; Qing, Z.

    2015-07-01

    With the rapid development of sensor networks and Earth observation technology, a large quantity of disaster-related data is available, such as remotely sensed data, historic data, case data, simulated data, and disaster products. However, the efficiency of current data management and service systems has become increasingly difficult due to the task variety and heterogeneous data. For emergency task-oriented applications, the data searches primarily rely on artificial experience based on simple metadata indices, the high time consumption and low accuracy of which cannot satisfy the speed and veracity requirements for disaster products. In this paper, a task-oriented correlation method is proposed for efficient disaster data management and intelligent service with the objectives of 1) putting forward disaster task ontology and data ontology to unify the different semantics of multi-source information, 2) identifying the semantic mapping from emergency tasks to multiple data sources on the basis of uniform description in 1), and 3) linking task-related data automatically and calculating the correlation between each data set and a certain task. The method goes beyond traditional static management of disaster data and establishes a basis for intelligent retrieval and active dissemination of disaster information. The case study presented in this paper illustrates the use of the method on an example flood emergency relief task.

  10. a Task-Driven Disaster Data Link Approach

    Science.gov (United States)

    Qiu, L. Y.; Zhu, Q.; Gu, J. Y.; Du, Z. Q.

    2015-08-01

    With the rapid development of sensor networks and Earth observation technology, a large quantity of disaster-related data is available, such as remotely sensed data, historic data, cases data, simulation data, disaster products and so on. However, the efficiency of current data management and service systems has become increasingly serious due to the task variety and heterogeneous data. For emergency task-oriented applications, data searching mainly relies on artificial experience based on simple metadata index, whose high time-consuming and low accuracy cannot satisfy the requirements of disaster products on velocity and veracity. In this paper, a task-oriented linking method is proposed for efficient disaster data management and intelligent service, with the objectives of 1) putting forward ontologies of disaster task and data to unify the different semantics of multi-source information, 2) identifying the semantic mapping from emergency tasks to multiple sources on the basis of uniform description in 1), 3) linking task-related data automatically and calculating the degree of correlation between each data and a target task. The method breaks through traditional static management of disaster data and establishes a base for intelligent retrieval and active push of disaster information. The case study presented in this paper illustrates the use of the method with a flood emergency relief task.

  11. The Impact of Task-based Approach in Enhancing Non-English Major Students’ Speaking Fluency

    Directory of Open Access Journals (Sweden)

    Hooshang Khoshsima

    2015-05-01

    Full Text Available This paper sought to scrutinize the effects of tasks-based instruction on non-English major students’ speaking fluency. To this aim 40 students were selected who were divided into two homogeneous groups by administering  a pretest to determine their current proficiency level in speaking skill. Both control and experimental groups received the same kinds of language material. Only experimental group received material through tasks-based instruction. Findings of post test revealed significant differences between control and experimental groups in term of their speaking fluency.Keywords: Tasks, Tasks –based language teaching, speaking skill

  12. Measuring group cohesion in document collections

    OpenAIRE

    Renoust B.; Melancon G.; Viaud M.-L.

    2013-01-01

    Exploring document collections remains a focus of research. This task can be tackled using various techniques, typically ranking documents according to a relevance index or grouping documents based on various clustering algorithms. The task complexity produces results of varying quality that inevitably carry noise. Users must be careful when interpreting document relevance or groupings. We address this problem by computing cohesion measures for a group of documents confirming/infirming whether ...

  13. KENO, Multigroup P1 Scattering Monte-Carlo Transport Calculation for Criticality, Keff, Flux in 3-D. KENO-5, SCALE-1 Module with Pn Scattering, Super-grouping, Diffusion Albedo Reflection

    International Nuclear Information System (INIS)

    1 - Description of problem or function: KENO is a multigroup, Monte Carlo criticality code containing a special geometry package which allows easy description of systems composed of cylinders, spheres, and cuboids (rectangular parallelepipeds) arranged in any order with only one restriction. They cannot be rotated or translated. Each geometrical region must be described as completely enclosing all regions interior to it. For systems not describable using this special geometry package, the program can use the generalized geometry package (GEOM) developed for the O5R Monte Carlo code. It allows any system that can be described by a collection of planes and/or quadratic surfaces, arbitrarily oriented and intersecting in arbitrary fashion. The entire problem can be mocked up in generalized geometry, or one generalized geometry unit or box type can be used alone or in combination with standard KENO units or box types. Rectangular arrays of fissile units are allowed with or without external reflector regions. Output from KENO consists of keff for the system plus an estimate of its standard deviation and the leakage, absorption, and fissions for each energy group plus the totals for all groups. Flux as a function of energy group and region and fission densities as a function of region are optional output. KENO-4: Added features include a neutron balance edit, PICTURE routines to check the input geometry, and a random number sequencing subroutine written in FORTRAN-4. 2 - Method of solution: The scattering treatment used in KENO assumes that the differential neutron scattering cross section can be represented by a P1 Legendre polynomial. Absorption of neutrons in KENO is not allowed. Instead, at each collision point of a neutron tracking history the weight of the neutron is reduced by the absorption probability. When the neutron weight has been reduced below a specified point for the region in which the collision occurs, Russian roulette is played to determine if the

  14. Measurement of action planning in children, adolescents, and adults: A comparison between 3 tasks

    NARCIS (Netherlands)

    Jongbloed-Pereboom, M.; Spruijt, S.; Nijhuis-Van der Sanden, M.W.G.; Steenbergen, B.

    2016-01-01

    Purpose: To compare age-related action planning performance on 3 different tasks, focusing on differences in task complexity. Methods: A total of 119 participants were divided across 6 age groups (4-5, 6-7, 8-9, 10-12,14-16, and 20-22 years). Participants performed 3 action planning tasks: the overt

  15. Quality of the Tasks in the New Turkish Elementary Mathematics Textbooks: The Case of Proportional Reasoning

    Science.gov (United States)

    Bayazit, Ibrahim

    2013-01-01

    This study examines new Turkish elementary school mathematics textbooks to provide perspectives on the quality of the tasks related to the proportion concept and the ways they are presented. Tasks were analysed for several dimensions with a particular focus on their level of cognitive demands (LCD). Tasks were distinguished in two groups in terms…

  16. 75 FR 27857 - Aviation Rulemaking Advisory Committee; Transport Airplane and Engine Issue Area-New Task

    Science.gov (United States)

    2010-05-18

    ... Issue Area--New Task AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of new task... ARAC tasking notice published in the Federal Register on April 2, 2010 (75 FR 16902). The following is... Airworthiness Issues for Transport Airplanes'' (70 FR 40166, July 12, 2005). The ARAC working group...

  17. Theory of Mind in Williams Syndrome Assessed Using a Nonverbal Task

    Science.gov (United States)

    Porter, Melanie A.; Coltheart, Max; Langdon, Robyn

    2008-01-01

    This study examined Theory of Mind in Williams syndrome (WS) and in normal chronological age-matched and mental age-matched control groups, using a picture sequencing task. This task assesses understanding of pretence, intention and false belief, while controlling for social-script knowledge and physical cause-and-effect reasoning. The task was…

  18. Novice supervisors' tasks and training - a descriptive study

    DEFF Research Database (Denmark)

    Nielsen, Jan; Jacobsen, Claus H.; Mathiesen, Birgit Bork

    . The aim of this study was to explore what kind of tasks novice supervisors undertake and how they are prepared for these. During 2009--2010, 350 Danish clinical psychologists have responded to the Development of Psychotherapists Common Core Questionnaire covering a wide range of items on professional...... development, experience, and practice. In this presentation we focus on the tasks and training of the respondents as novice supervisors. The results show, that a majority of novice supervisors were confronted with complicated jobs, e.g., group, internal and interdisciplinary supervision, but were not prepared......, i.e. trained, prior to these tasks. These findings imply that more training is needed for novice supervisors. Preferably, this training should be introduced before, or at least parallel to, the first supervisor tasks, preparing the novice supervisors for the often complicated tasks they are meeting....

  19. The modality effect of ego depletion: Auditory task modality reduces ego depletion.

    Science.gov (United States)

    Li, Qiong; Wang, Zhenhong

    2016-08-01

    An initial act of self-control that impairs subsequent acts of self-control is called ego depletion. The ego depletion phenomenon has been observed consistently. The modality effect refers to the effect of the presentation modality on the processing of stimuli. The modality effect was also robustly found in a large body of research. However, no study to date has examined the modality effects of ego depletion. This issue was addressed in the current study. In Experiment 1, after all participants completed a handgrip task, one group's participants completed a visual attention regulation task and the other group's participants completed an auditory attention regulation task, and then all participants again completed a handgrip task. The ego depletion phenomenon was observed in both the visual and the auditory attention regulation task. Moreover, participants who completed the visual task performed worse on the handgrip task than participants who completed the auditory task, which indicated that there was high ego depletion in the visual task condition. In Experiment 2, participants completed an initial task that either did or did not deplete self-control resources, and then they completed a second visual or auditory attention control task. The results indicated that depleted participants performed better on the auditory attention control task than the visual attention control task. These findings suggest that altering task modality may reduce ego depletion. PMID:27241617

  20. Group negotiation : more people more problems? : examining dyadic and group negotiation

    OpenAIRE

    Traavik, Laura E. Mercer

    1997-01-01

    An experimental study of the differences and similarities between dyadic and group negotiation was conducted, comparing the processes and outcomes of dyads and groups on similar negotiation tasks. The group negotiation of interest in this study is one in which 4 parties, with non- identical preferences attempt to reach a joint decision. The increase in the number of parties (dyads to groups of 4) was conceptualised as an increase in objective task complexity. The subjects...