Energy Technology Data Exchange (ETDEWEB)
O`Hara, J.M.
1994-07-01
Advanced control rooms will use advanced human-system interface (HSI) technologies that may have significant implications for plant safety in that they will affect the operator`s overall role in the system, the method of information presentation, and the ways in which operators interact with the system. The U.S. Nuclear Regulatory Commission (NRC) reviews the HSI aspects of control rooms to ensure that they are designed to good human factors engineering principles and that operator performance and reliability are appropriately supported to protect public health and safety. The principal guidance available to the NRC, however, was developed more than ten years ago, well before these technological changes. Accordingly, the human factors guidance needs to be updated to serve as the basis for NRC review of these advanced designs. The purpose of this project was to develop a general approach to advanced HSI review and the human factors guidelines to support NRC safety reviews of advanced systems. This two-volume report provides the results of the project. Volume I describes the development of the Advanced HSI Design Review Guideline (DRG) including (1) its theoretical and technical foundation, (2) a general model for the review of advanced HSIs, (3) guideline development in both hard-copy and computer-based versions, and (4) the tests and evaluations performed to develop and validate the DRG. Volume I also includes a discussion of the gaps in available guidance and a methodology for addressing them. Volume 2 provides the guidelines to be used for advanced HSI review and the procedures for their use.
10 CFR 1023.9 - General guidelines.
2010-01-01
... 10 Energy 4 2010-01-01 2010-01-01 false General guidelines. 1023.9 Section 1023.9 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) CONTRACT APPEALS Overview: Organization, Functions and Authorities § 1023.9 General guidelines. (a) The principles of this Overview shall apply to all Board...
Guidelines for computer security in general practice
Directory of Open Access Journals (Sweden)
Peter Schattner
2007-06-01
Conclusions This paper maps out a process for developing computer security guidelines for general practice. The specific content will vary in different countries according to their levels of adoption of IT, and cultural, technical and other health service factors. Making these guidelines relevant to local contexts should help maximise their uptake.
Adherence to asthma guidelines in general practices.
Roghmann, M C; Sexton, M
1999-06-01
Adherence to asthma practice guidelines is low. Improved compliance could potentially improve care of patients with asthma. The purpose of this study was to determine if patients managed in a general practice with an associated asthma clinic are more likely to use asthma medications according to clinical practice guidelines than patients managed in the general surgery of the practice. A cross-sectional study of adult asthmatics, aged 18-55 years, was conducted in six British general practices. Prescription data on all asthma medication was collected for a 6-month period. Information on asthma clinic attendance, age, sex, employment status, other medical illness, and how patients used their inhaled beta2-agonist was collected through questionnaire. The prescription data for asthma medication and patient use of inhaled beta2-agonist were compared to the British Thoracic Society's (BTS) Guidelines for Management of Asthma in Adults to determine if the patient's asthma medication regimen was appropriate. There was no significant association found between appropriate asthma medication and asthma clinic attendance or other patient characteristics. Adherence to the BTS guidelines was low. Fifty-eight percent of the asthma patients used asthma medication regimens that were not consistent with the BTS guidelines published 1 year earlier. Adherence to the BTS guidelines was low regardless of patient characteristics, including asthma clinic attendance, age, sex, employment status, other medical illness, or individual practice. These findings underscore the need to document the utility of clinical practice guidelines which may improve physician compliance.
Adherence to COPD guidelines in general practice
DEFF Research Database (Denmark)
Ulrik, Charlotte Suppli; Sørensen, Tina Brandt; Højmark, Torben Brunse
2013-01-01
BACKGROUND: The general practitioner (GP) is often the first healthcare contact for patients with chronic obstructive pulmonary disease (COPD). AIMS: To determine whether participating in a standardised educational programme delivered in the GP's own practice is associated with adherence to COPD...... guidelines. METHODS: A nationwide register-based observational before and after study was undertaken with a control group of propensity-matched practices (follow-up period 6 months). COPD was defined as age 40+ years and at least two prescriptions for inhaled medication. The educational programme consisted...... were used to compare the rate of spirometry testing, preventive consultations, and influenza vaccinations provided to COPD patients and the rate of spirometry testing in non-COPD individuals, assumed to reflect diagnostic activity. RESULTS: Data for 102 participating GP practices were analysed...
Clinical guidelines: their implementation in general practice.
M Conroy; Shannon, W
1995-01-01
In recent years the development of clinical guidelines has received increasing attention from medical educators and those involved in standard setting, and has been initiated at both central and local levels. This review article outlines the current state of knowledge with regard to clinical guideline implementation in medical practice. It deals with the main aspects of the current guideline debate, such as, clinical freedom and doctor autonomy, the importance of ownership in guideline implem...
Reporting guidelines for modelling studies
Directory of Open Access Journals (Sweden)
Bennett Carol
2012-11-01
Full Text Available Abstract Background Modelling studies are used widely to help inform decisions about health care and policy and their use is increasing. However, in order for modelling to gain strength as a tool for health policy, it is critical that key model factors are transparent so that users of models can have a clear understanding of the model and its limitations.Reporting guidelines are evidence-based tools that specify minimum criteria for authors to report their research such that readers can both critically appraise and interpret study findings. This study was conducted to determine whether there is an unmet need for population modelling reporting guidelines. Methods We conducted a review of the literature to identify: 1 guidance for reporting population modelling studies; and, 2 evidence on the quality of reporting of population modelling studies. Guidance for reporting was analysed using a thematic approach and the data was summarised as frequencies. Evidence on the quality of reporting was reviewed and summarized descriptively. Results There were no guidelines that specifically addressed the reporting of population modelling studies. We identified a number of reporting guidelines for economic evaluation studies, some of which had sections that were relevant population modelling studies. Amongst seven relevant records, we identified 69 quality criteria that have distinct reporting characteristics. We identified two papers that addressed reporting practices of modelling studies. Overall, with the exception of describing the data used for calibration, there was little consistency in reporting. Conclusions While numerous guidelines exist for developing and evaluating health technology assessment and economic evaluation models, which by extension could be applicable to population modelling studies, there is variation in their comprehensiveness and in the consistency of reporting these methods. Population modelling studies may be an area which would
Heins, M.J.; Jong, J.D. de; Spronk, I.; Ho, V.K.; Brink, M.; Korevaar, J.C.
2016-01-01
Background: Guideline adherence remains a challenge in clinical practice, despite guidelines’ ascribed potential to improve patient outcomes. We studied the level of adherence to recommendations from Dutch national cancer treatment guidelines, and the influence of general and
43 CFR 4.100 - General rules and guidelines.
2010-10-01
... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false General rules and guidelines. 4.100... rules and guidelines. (a) Effective date and applicability—(1) Effective date and general applicability..., in which event the period shall run to the end of the next business day. (e) General...
The wound/burn guidelines - 1: Wounds in general.
Inoue, Yuji; Hasegawa, Minoru; Maekawa, Takeo; Le Pavoux, Andres; Asano, Yoshihide; Abe, Masatoshi; Ishii, Takayuki; Ito, Takaaki; Isei, Taiki; Imafuku, Shinichi; Irisawa, Ryokichi; Ohtsuka, Masaki; Ohtsuka, Mikio; Ogawa, Fumihide; Kadono, Takafumi; Kodera, Masanari; Kawakami, Tamihiro; Kawaguchi, Masakazu; Kukino, Ryuichi; Kono, Takeshi; Sakai, Keisuke; Takahara, Masakazu; Tanioka, Miki; Nakanishi, Takeshi; Nakamura, Yasuhiro; Hashimoto, Akira; Hayashi, Masahiro; Fujimoto, Manabu; Fujiwara, Hiroshi; Matsuo, Koma; Madokoro, Naoki; Yamasaki, Osamu; Yoshino, Yuichiro; Tachibana, Takao; Ihn, Hironobu
2016-04-01
The Japanese Dermatological Association determined to prepare the Wound/Burn Guidelines focusing on treatments, catering to needs for the clinical practice of dermatology. Among these guidelines, "Wounds in General" was intended to explain knowledge necessary "to heal wounds" without specifying particular disorders. © 2016 Japanese Dermatological Association.
Perceived barriers to guideline adherence: A survey among general practitioners
Directory of Open Access Journals (Sweden)
Besters Casper F
2011-09-01
Full Text Available Abstract Background Despite considerable efforts to promote and support guideline use, adherence is often suboptimal. Barriers to adherence vary not only across guidelines but also across recommendations within guidelines. The aim of this study was to assess the perceived barriers to guideline adherence among GPs by focusing on key recommendations within guidelines. Methods We conducted a cross-sectional electronic survey among 703 GPs in the Netherlands. Sixteen key recommendations were derived from four national guidelines. Six statements were included to address the attitudes towards guidelines in general. In addition, GPs were asked to rate their perceived adherence (one statement and the perceived barriers (fourteen statements for each of the key recommendations, based on an existing framework. Results 264 GPs (38% completed the questionnaire. Although 35% of the GPs reported difficulties in changing routines and habits to follow guidelines, 89% believed that following guidelines leads to improved patient care. Perceived adherence varied between 52 and 95% across recommendations (mean: 77%. The most perceived barriers were related to external factors, in particular patient ability and behaviour (mean: 30% and patient preferences (mean: 23%. Lack of applicability of recommendations in general (mean: 22% and more specifically to individual patients (mean: 25% were also frequently perceived as barriers. The scores on perceived barriers differed largely between recommendations [minimum range 14%; maximum range 67%]. Conclusions Dutch GPs have a positive attitude towards the NHG guidelines, report high adherence rates and low levels of perceived barriers. However, the perceived adherence and perceived barriers varied largely across recommendations. The most perceived barriers across recommendations are patient related, suggesting that current guidelines do not always adequately incorporate patient preferences, needs and abilities. It may be
General guidelines for biomedical software development
Silva, Luis Bastiao; Jimenez, Rafael C.; Blomberg, Niklas; Luis Oliveira, José
2017-01-01
Most bioinformatics tools available today were not written by professional software developers, but by people that wanted to solve their own problems, using computational solutions and spending the minimum time and effort possible, since these were just the means to an end. Consequently, a vast number of software applications are currently available, hindering the task of identifying the utility and quality of each. At the same time, this situation has hindered regular adoption of these tools in clinical practice. Typically, they are not sufficiently developed to be used by most clinical researchers and practitioners. To address these issues, it is necessary to re-think how biomedical applications are built and adopt new strategies that ensure quality, efficiency, robustness, correctness and reusability of software components. We also need to engage end-users during the development process to ensure that applications fit their needs. In this review, we present a set of guidelines to support biomedical software development, with an explanation of how they can be implemented and what kind of open-source tools can be used for each specific topic. PMID:28443186
Harrison, R. Van
1994-01-01
General institutional guidelines for gifts from commercial companies are needed, in light of national trends. Commercially supported continuing medical education, those concerning personal gifts to physicians, and conflict of interest and research are areas to be considered. (SK)
Strategy Guideline: Modeling Enclosure Design in Above-Grade Walls
Energy Technology Data Exchange (ETDEWEB)
Lstiburek, J. [Building Science Corporation, Westford, MA (United States); Ueno, K. [Building Science Corporation, Westford, MA (United States); Musunuru, S. [Building Science Corporation, Westford, MA (United States)
2016-02-24
The Strategy Guideline describes how to model and interpret results of models for above grade walls. The Measure Guideline analyzes the failure thresholds and criteria for above grade walls. A library of above-grade walls with historically successful performance was used to calibrate WUFI (Warme Und Feuchte Instationar) software models. The information is generalized for application to a broad population of houses within the limits of existing experience.
Scandinavian clinical practice guidelines on general anaesthesia for emergency situations
DEFF Research Database (Denmark)
Gadegaard Jensen, Anders; Callesen, T; Hagemo, J S;
2010-01-01
Emergency patients need special considerations and the number and severity of complications from general anaesthesia can be higher than during scheduled procedures. Guidelines are therefore needed. The Clinical Practice Committee of the Scandinavian Society of Anaesthesiology and Intensive Care...... Medicine appointed a working group to develop guidelines based on literature searches to assess evidence, and a consensus meeting was held. Consensus opinion was used in the many topics where high-grade evidence was unavailable. The recommendations include the following: anaesthesia for emergency patients...
Rietveld, Remco P; ter Riet, Gerben; Bindels, Patrick JE; Schellevis, François G; van Weert, Henk CPM
2007-01-01
Background In 1996 the guideline 'The Red Eye' was first published by the Dutch College of General Practitioners. The extent to which general practitioners adhere to this guideline is unclear. Recently, data on the management of infectious conjunctivitis by general practitioners became available from the Second Dutch National Survey of General Practice. We measured the age-specific incidence of infectious conjunctivitis, described its management by Dutch general practitioners, and then compared these findings with the recommendations made in the guideline. Methods In 2001, over a 12-month period, data from all patient contacts with 195 general practitioners were taken from electronic medical records. Registration was episode-oriented; all consultations dealing with the same health problem were grouped into disease episodes. Data concerning all episodes of infectious conjunctivitis (ICPC-code F70 and sub codes) were analysed. Results Over one year, 5,213 new and recurrent episodes of infectious conjunctivitis were presented to general practitioners from a population of N = 375,899, resulting in an overall incidence rate of 13.9 per 1000 person-years, varying from more than 80/1000 py in children up to one-year old, to less than 12/1000 py in children over the age of 4. Topical ophthalmic ointments were prescribed in 87% of the episodes, of which 80% was antibiotic treatment. Fusidic acid gel was most frequently prescribed (69%). In most episodes general practitioners did not adhere to the guideline. Conclusion In 2001, the management of infectious conjunctivitis by Dutch general practitioners was not in accordance with the recommendations of the consensus-based guideline published five years previously, despite its wide distribution. In 2006 this guideline was revised. Its successful implementation requires more than distribution alone. Probably the most effective way to achieve this is by following a model for systemic implementation. PMID:17868475
Directory of Open Access Journals (Sweden)
Schellevis François G
2007-09-01
Full Text Available Abstract Background In 1996 the guideline 'The Red Eye' was first published by the Dutch College of General Practitioners. The extent to which general practitioners adhere to this guideline is unclear. Recently, data on the management of infectious conjunctivitis by general practitioners became available from the Second Dutch National Survey of General Practice. We measured the age-specific incidence of infectious conjunctivitis, described its management by Dutch general practitioners, and then compared these findings with the recommendations made in the guideline. Methods In 2001, over a 12-month period, data from all patient contacts with 195 general practitioners were taken from electronic medical records. Registration was episode-oriented; all consultations dealing with the same health problem were grouped into disease episodes. Data concerning all episodes of infectious conjunctivitis (ICPC-code F70 and sub codes were analysed. Results Over one year, 5,213 new and recurrent episodes of infectious conjunctivitis were presented to general practitioners from a population of N = 375,899, resulting in an overall incidence rate of 13.9 per 1000 person-years, varying from more than 80/1000 py in children up to one-year old, to less than 12/1000 py in children over the age of 4. Topical ophthalmic ointments were prescribed in 87% of the episodes, of which 80% was antibiotic treatment. Fusidic acid gel was most frequently prescribed (69%. In most episodes general practitioners did not adhere to the guideline. Conclusion In 2001, the management of infectious conjunctivitis by Dutch general practitioners was not in accordance with the recommendations of the consensus-based guideline published five years previously, despite its wide distribution. In 2006 this guideline was revised. Its successful implementation requires more than distribution alone. Probably the most effective way to achieve this is by following a model for systemic implementation.
Benos, Dale J; Vollmer, Sara H
2010-12-01
Modifying images for scientific publication is now quick and easy due to changes in technology. This has created a need for new image processing guidelines and attitudes, such as those offered to the research community by Doug Cromey (Cromey 2010). We suggest that related changes in technology have simplified the task of detecting misconduct for journal editors as well as researchers, and that this simplification has caused a shift in the responsibility for reporting misconduct. We also argue that the concept of best practices in image processing can serve as a general model for education in best practices in research.
Bosch, W.J.H.M. van den
2003-01-01
The Dutch College of General Practitioners' practice guideline entitled 'Dizziness' concerns a complaint experienced by many people, yet it provides few scientific data to support the recommendations. The standard does, however, provide the general practitioner with some concrete advice: the diagnos
Lieshout, J. van; Wessels, P.; Rijswijk, E. van; Boer, A.M; Wiersma, A.; Goudswaard, A.N.
2007-01-01
--The practice guideline 'Thyroid disorders' developed by the Dutch College of General Practitioners replaces the practice guideline 'Functional thyroid disorders' from 1996. Recommendations for palpable thyroid disorders have been added. --Hypothyroidism can often be treated by the general practiti
[General Strategies for Implementation of Clinical Practice Guidelines].
Valenzuela-Flores, Adriana Abigail; Viniegra-Osorio, Arturo; Torres-Arreola, Laura Laura
2015-01-01
The need to use clinical practice guidelines (CPG) arises from the health conditions and problems that public health institutions in the country face. CPG are informative documents that help improve the quality of care processes and patient safety; having among its objectives, to reduce the variability of medical practice. The Instituto Mexicano del Seguro Social designed a strategic plan for the dissemination, implementation, monitoring and control of CPG to establish an applicable model in the medical units in the three levels of care at the Instituto. This paper summarizes some of the strategies of the plan that were made with the knowledge and experience of clinicians and managers, with which they intend to promote the adoption of the key recommendations of the guidelines, to promote a sense of belonging for health personnel, and to encourage changes in organizational culture.
Generalized Poisson sigma models
Batalin, I; Batalin, Igor; Marnelius, Robert
2001-01-01
A general master action in terms of superfields is given which generates generalized Poisson sigma models by means of a natural ghost number prescription. The simplest representation is the sigma model considered by Cattaneo and Felder. For Dirac brackets considerably more general models are generated.
Bölter, Regine; Freund, Tobias; Ledig, Thomas; Boll, Bernhard; Szecsenyi, Joachim; Roos, Marco
2012-01-01
The planned modification of the Medical Licenses Act in Germany will strengthen the specialty of general practice. Therefore, medical students should get to know the daily routine of general practitioners during their academic studies. At least 10% of students should get the possibility to spend one quarter of the internship, in the last year of their academic studies, in a practice of family medicine. The demonstrated teaching method aims at giving feedback to the student based on video recordings of patient consultations (student-patient) with the help of a checklist. Video-feedback is already successful used in medical teaching in Germany and abroad. This feasibility study aims at assessing the practicability of video-assisted feedback as a teaching method during internship in general practice. First of all, the general practice chooses a guideline as the learning objective. Secondly, a subsequent patient - student - consultation is recorded on video. Afterwards, a video-assisted formative feedback is given by the physician. A checklist with learning objectives (communication, medical examination, a structured case report according to the guideline) is used to structure the feedback content. The feasibility was assessed by a semi structured interview in order to gain insight into barriers and challenges for future implementation. The teaching method was performed in one general practice. Afterwards the teaching physician and the trainee intern were interviewed. The Following four main categories were identified: feasibility, performance, implementation in daily routine, challenges of the teaching concept.The results of the feasibility study show general practicability of this approach. Installing a video camera in one examination room may solve technical problems. The trainee intern mentioned theoretical and practical benefits using the guideline. The teaching physician noted the challenge to reflect on his daily routines in the light of evidence
Transport properties site descriptive model. Guidelines for evaluation and modelling
Energy Technology Data Exchange (ETDEWEB)
Berglund, Sten [WSP Environmental, Stockholm (Sweden); Selroos, Jan-Olof [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)
2004-04-01
This report describes a strategy for the development of Transport Properties Site Descriptive Models within the SKB Site Investigation programme. Similar reports have been produced for the other disciplines in the site descriptive modelling (Geology, Hydrogeology, Hydrogeochemistry, Rock mechanics, Thermal properties, and Surface ecosystems). These reports are intended to guide the site descriptive modelling, but also to provide the authorities with an overview of modelling work that will be performed. The site descriptive modelling of transport properties is presented in this report and in the associated 'Strategy for the use of laboratory methods in the site investigations programme for the transport properties of the rock', which describes laboratory measurements and data evaluations. Specifically, the objectives of the present report are to: Present a description that gives an overview of the strategy for developing Site Descriptive Models, and which sets the transport modelling into this general context. Provide a structure for developing Transport Properties Site Descriptive Models that facilitates efficient modelling and comparisons between different sites. Provide guidelines on specific modelling issues where methodological consistency is judged to be of special importance, or where there is no general consensus on the modelling approach. The objectives of the site descriptive modelling process and the resulting Transport Properties Site Descriptive Models are to: Provide transport parameters for Safety Assessment. Describe the geoscientific basis for the transport model, including the qualitative and quantitative data that are of importance for the assessment of uncertainties and confidence in the transport description, and for the understanding of the processes at the sites. Provide transport parameters for use within other discipline-specific programmes. Contribute to the integrated evaluation of the investigated sites. The site descriptive
General Quality Control (QC) Guidelines for SAM Methods
Learn more about quality control guidelines and recommendations for the analysis of samples using the methods listed in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).
Strategy Guideline. Modeling Enclosure Design in Above-Grade Walls
Energy Technology Data Exchange (ETDEWEB)
Lstiburek, J. [Building Science Corporation, Westford, MA (United States); Ueno, K. [Building Science Corporation, Westford, MA (United States); Musunuru, S. [Building Science Corporation, Westford, MA (United States)
2016-02-01
The Strategy Guideline, written by the U.S. Department of Energy's research team Building Science Corporation, 1) describes how to model and interpret results of models for above-grade walls, and 2) analyzes the failure thresholds and criteria for above-grade walls. A library of above-grade walls with historically successful performance was used to calibrate WUFI (Wärme und Feuchte instationär) software models. The information is generalized for application to a broad population of houses within the limits of existing experience.
Generalized simplicial chiral models
Alimohammadi, M
2000-01-01
Using the auxiliary field representation of the simplicial chiral models on a (d-1)-dimensional simplex, we generalize the simplicial chiral models by replacing the term Tr$(AA^{\\d})$ in the Lagrangian of these models, by an arbitrary class function of $AA^{\\d}; V(AA^{\\d})$. This is the same method that has been used in defining the generalized two-dimensional Yang-Mills theories (gYM_2) from ordinary YM_2. We call these models, the " generalized simplicial chiral models ". With the help of the results of one-link integral over a U(N) matrix, we compute the large-N saddle-point equations for eigenvalue density function $\\ro (z)$ in the weak ($\\b >\\b_c$) and strong ($\\b <\\b_c$) regions. In d=2, where the model somehow relates to gYM_2 theory, we solve the saddle-point equations and find $\\ro (z)$ in two region, and calculate the explicit value of critical point $\\b_c$ for $V(B)=TrB^n (B=AA^{\\d})$. For $V(B)=Tr B^2,Tr B^3$ and Tr$B^4$, we study the critical behaviour of the model at d=2, and by calculating t...
Bosch, W.J.H.M. van den
2002-01-01
The Dutch College of General Practitioners' practice guideline on the menopause will not be any major cause for discussion. The hot issue of giving oestrogens to peri- and postmenopausal women to prevent osteoporosis or cardiovascular disease was already covered in the practice guideline on osteopor
Modeling Guidelines for Code Generation in the Railway Signaling Context
Ferrari, Alessio; Bacherini, Stefano; Fantechi, Alessandro; Zingoni, Niccolo
2009-01-01
recommendations has been performed for the automotive control systems domain in order to enforce code generation [7]. The MAAB guidelines have been found profitable also in the aerospace/avionics sector [1] and they have been adopted by the MathWorks Aerospace Leadership Council (MALC). General Electric Transportation Systems (GETS) is a well known railway signaling systems manufacturer leading in Automatic Train Protection (ATP) systems technology. Inside an effort of adopting formal methods within its own development process, GETS decided to introduce system modeling by means of the MathWorks tools [2], and in 2008 chose to move to code generation. This article reports the experience performed by GETS in developing its own modeling standard through customizing the MAAB rules for the railway signaling domain and shows the result of this experience with a successful product development story.
General Composite Higgs Models
Marzocca, David; Shu, Jing
2012-01-01
We construct a general class of pseudo-Goldstone composite Higgs models, within the minimal $SO(5)/SO(4)$ coset structure, that are not necessarily of moose-type. We characterize the main properties these models should have in order to give rise to a Higgs mass at around 125 GeV. We assume the existence of relatively light and weakly coupled spin 1 and 1/2 resonances. In absence of a symmetry principle, we introduce the Minimal Higgs Potential (MHP) hypothesis: the Higgs potential is assumed to be one-loop dominated by the SM fields and the above resonances, with a contribution that is made calculable by imposing suitable generalizations of the first and second Weinberg sum rules. We show that a 125 GeV Higgs requires light, often sub-TeV, fermion resonances. Their presence can also be important for the model to successfully pass the electroweak precision tests. Interestingly enough, the latter can be passed also by models with a heavy Higgs around 320 GeV. The composite Higgs models of the moose-type conside...
Bosch, W.J.H.M. van den
2003-01-01
The practice guideline 'Anaemia' from the Dutch College of General Practitioners will certainly be a support for the Dutch general practitioner. The inclusion of an algorithm to make a more precise diagnosis is an experiment that needs to be evaluated in the near future. However, many general
Bosch, W.J.H.M. van den
2003-01-01
The practice guideline 'Anaemia' from the Dutch College of General Practitioners will certainly be a support for the Dutch general practitioner. The inclusion of an algorithm to make a more precise diagnosis is an experiment that needs to be evaluated in the near future. However, many general practi
Generalized Nonlinear Yule Models
Lansky, Petr; Polito, Federico; Sacerdote, Laura
2016-10-01
With the aim of considering models related to random graphs growth exhibiting persistent memory, we propose a fractional nonlinear modification of the classical Yule model often studied in the context of macroevolution. Here the model is analyzed and interpreted in the framework of the development of networks such as the World Wide Web. Nonlinearity is introduced by replacing the linear birth process governing the growth of the in-links of each specific webpage with a fractional nonlinear birth process with completely general birth rates. Among the main results we derive the explicit distribution of the number of in-links of a webpage chosen uniformly at random recognizing the contribution to the asymptotics and the finite time correction. The mean value of the latter distribution is also calculated explicitly in the most general case. Furthermore, in order to show the usefulness of our results, we particularize them in the case of specific birth rates giving rise to a saturating behaviour, a property that is often observed in nature. The further specialization to the non-fractional case allows us to extend the Yule model accounting for a nonlinear growth.
Generalized Nonlinear Yule Models
Lansky, Petr; Polito, Federico; Sacerdote, Laura
2016-11-01
With the aim of considering models related to random graphs growth exhibiting persistent memory, we propose a fractional nonlinear modification of the classical Yule model often studied in the context of macroevolution. Here the model is analyzed and interpreted in the framework of the development of networks such as the World Wide Web. Nonlinearity is introduced by replacing the linear birth process governing the growth of the in-links of each specific webpage with a fractional nonlinear birth process with completely general birth rates. Among the main results we derive the explicit distribution of the number of in-links of a webpage chosen uniformly at random recognizing the contribution to the asymptotics and the finite time correction. The mean value of the latter distribution is also calculated explicitly in the most general case. Furthermore, in order to show the usefulness of our results, we particularize them in the case of specific birth rates giving rise to a saturating behaviour, a property that is often observed in nature. The further specialization to the non-fractional case allows us to extend the Yule model accounting for a nonlinear growth.
10 CFR 1047.5 - Exercise of arrest authority-general guidelines.
2010-01-01
... 10 Energy 4 2010-01-01 2010-01-01 false Exercise of arrest authority-general guidelines. 1047.5 Section 1047.5 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) LIMITED ARREST AUTHORITY AND USE OF FORCE BY PROTECTIVE FORCE OFFICERS General Provisions § 1047.5 Exercise of arrest authority—general...
Introduction to general and generalized linear models
Madsen, Henrik
2010-01-01
IntroductionExamples of types of data Motivating examples A first view on the modelsThe Likelihood PrincipleIntroduction Point estimation theory The likelihood function The score function The information matrix Alternative parameterizations of the likelihood The maximum likelihood estimate (MLE) Distribution of the ML estimator Generalized loss-function and deviance Quadratic approximation of the log-likelihood Likelihood ratio tests Successive testing in hypothesis chains Dealing with nuisance parameters General Linear ModelsIntroduction The multivariate normal distribution General linear mod
Jans, M.P.; Schellevis, F.G.; Hensbergen, W. van; Dukkers van Emden, T.; Eijk, J.T.M. van
1998-01-01
Objective: To examine the feasibility of the application of guidelines to the management of asthma and chronic obstructive pulmonary disease (COPD) by assessing compliance with the guidelines and listing the barriers general practitioners (GPs) encountered during implementation. Insight into the fea
Susi, Frank; Mundell, Robert
1980-01-01
Guidelines developed by the Section on Anatomical Sciences of the American Association for Dental Schools are presented. These guidelines were drawn up as an effort to provide a general criterion-referenced standard against which a school can measure its course content in histology. (MLW)
Susi, Frank; Mundell, Robert
1980-01-01
Guidelines developed by the Section on Anatomical Sciences of the American Association for Dental Schools are presented. These guidelines were drawn up as an effort to provide a general criterion-referenced standard against which a school can measure its course content in histology. (MLW)
Major depressive disorder in the general hospital: adaptation of clinical practice guidelines.
Voellinger, Rachel; Berney, Alexandre; Baumann, Pierre; Annoni, Jean Marie; Bryois, Christian; Buclin, Thierry; Büla, Christophe; Camus, Vincent; Christin, Laurent; Cornuz, Jacques; de Goumoëns, Pierre; Lamy, Olivier; Strnad, Jindrich; Burnand, Bernard; Stiefel, Frederic
2003-01-01
Major Depressive Disorder is particularly frequent among physically ill inpatients. Despite the considerable human burden and financial costs, Major Depressive Disorder remains under-detected and under-treated. To improve this situation, clinical practice guidelines for the management of Major Depressive Disorder were developed for patients in the general hospital. They were adapted from existing good quality guidelines. A literature search has been conducted to identify guidelines and systematic reviews about the management of Major Depressive Disorder. The quality of the existing guidelines was evaluated by means of the AGREE instrument (Appraisal of Guidelines for Research and Evaluation). Complementary literature searches were necessary to answer questions such as "depression and physical illness" or "antidepressants and somatic medication". The guidelines were discussed by a multidisciplinary internal panel. The final version was reviewed by an external panel. This paper presents the development process and a summary of these guidelines for the management of Major Depressive Disorder. The adaptation of good quality guidelines to local needs requires much time, effort and skills. Easier ways for the adaptation and use of high quality guidelines at the local level may result from better coordination, organization and updating of guidelines at a national or supranational level.
EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part I. General Aspects (long Version)
DEFF Research Database (Denmark)
Lorentzen, T; Nolsøe, C P; Ewertsen, C;
2015-01-01
This is the first part of the Guidelines on Interventional Ultrasound of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) and covers all general aspects of ultrasound-guided procedures (long version)....
Weel, C. van
2008-01-01
This article reviews the practice guideline from the Dutch College of General Practitioners on smoking cessation. General practitioners (GP) should strive after smoking cessation when patients consult and ask for support to stop smoking. Moreover, the practitioner should also show such initiative wh
Flatland, Bente; Freeman, Kathy P; Friedrichs, Kristen R; Vap, Linda M; Getzy, Karen M; Evans, Ellen W; Harr, Kendal E
2010-09-01
Owing to lack of governmental regulation of veterinary laboratory performance, veterinarians ideally should demonstrate a commitment to self-monitoring and regulation of laboratory performance from within the profession. In response to member concerns about quality management in veterinary laboratories, the American Society for Veterinary Clinical Pathology (ASVCP) formed a Quality Assurance and Laboratory Standards (QAS) committee in 1996. This committee recently published updated and peer-reviewed Quality Assurance Guidelines on the ASVCP website. The Quality Assurance Guidelines are intended for use by veterinary diagnostic laboratories and veterinary research laboratories that are not covered by the US Food and Drug Administration Good Laboratory Practice standards (Code of Federal Regulations Title 21, Chapter 58). The guidelines have been divided into 3 reports on 1) general analytic factors for veterinary laboratory performance and comparisons, 2) hematology and hemostasis, and 3) clinical chemistry, endocrine assessment, and urinalysis. This report documents recommendations for control of general analytical factors within veterinary clinical laboratories and is based on section 2.1 (Analytical Factors Important In Veterinary Clinical Pathology, General) of the newly revised ASVCP QAS Guidelines. These guidelines are not intended to be all-inclusive; rather, they provide minimum guidelines for quality assurance and quality control for veterinary laboratory testing. It is hoped that these guidelines will provide a basis for laboratories to assess their current practices, determine areas for improvement, and guide continuing professional development and education efforts.
Energy Technology Data Exchange (ETDEWEB)
NONE
1995-12-01
These general guidelines are intended to be used as a basis for what requirements are reasonable from a radiation protection point of view and should be part of the contract in connection with the purchase of equipment for x-ray diagnostics. Technical performance requirements are addressed as well as items like documentation, instructions for use and education and training. The guidelines are also useful for the design of quality assurance programs. In the comments in addition to these guidelines legal aspects are noted, including a list of relevant laws, regulations and directives. Standards, both national and international, within the field are referred to with a short description of their content. 40 refs.
10 CFR 1049.5 - Exercise of arrest authority-General guidelines.
2010-01-01
... 10 Energy 4 2010-01-01 2010-01-01 false Exercise of arrest authority-General guidelines. 1049.5 Section 1049.5 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) LIMITED ARREST AUTHORITY AND USE OF FORCE BY PROTECTIVE FORCE OFFICERS OF THE STRATEGIC PETROLEUM RESERVE § 1049.5 Exercise of arrest authority...
[Summary of the 'Stroke' guideline of the Dutch College of General Practitioners' (NHG)
Verburg, A.F.; Tjon, A.T.M.R.; Verstappen, W.H.J.M.; Beusmans, G.H.M.I.; Wiersma, T.; Burgers, J.S.
2014-01-01
The Dutch College of General Practitioners (NHG) guideline 'Stroke' covers the diagnosis, management and long-term care of stroke in general practice. Patients with neurological symptoms suspected to be due to cerebral infarction or haemorrhage should be transferred directly to a stroke unit. The
Digital Imaging and Conservation: Model Guidelines.
Dean, John F.
2003-01-01
Examines the intersection of conservation and digital imaging based on guidelines at the Cornell University (Ithaca, NY) library. Discusses the digitization of artifacts; assessing the condition prior to scanning; scanning considerations, including temperature and humidity, lighting, and security; stable storage of artifacts after scanning; and…
[Summary of the 'Thyroid disorders' guideline of the Dutch College of General Practitioners' (NHG)
Sijbom, M.; Lieshout, J. van; Felix-Schollaart, B.; Burgers, J.S.; Bouma, M.
2013-01-01
- The 'Thyroid disorders' guideline of the Dutch College of General Practitioners (NHG) provides recommendations for the diagnosis and management of hypothyroidism, hyperthyroidism and changes in the size of the thyroid gland, such as goitre and thyroid nodules. - Hypothyroid patients younger than 6
EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part I. General Aspects (Short Version)
DEFF Research Database (Denmark)
Lorentzen, T.; Nolsøe, C P; Ewertsen, C;
2015-01-01
This is the first part of the Guidelines on Interventional Ultrasound of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) and covers all general aspects of ultrasound-guided procedures (short version; the long version is published online)....
[Summary of the Dutch College of General Practitioners' practice guideline on food hypersensitivity
Luning-Koster, M.N.; Lucassen, P.L.B.J.; Boukes, F.S.; Goudswaard, A.
2011-01-01
October 2010 the Dutch College of General Practitioners issued a revised version of their previous practice guideline of 1995 on food hypersensitivity in infants. If patients suspect either themselves or their child of having a food allergy, this is usually not demonstrated in subsequent investigati
Weele, G.M. van der; Olde Rikkert, M.G.M.; Eizenga, W.H.; Assendelft, W.J.J.
2003-01-01
The Dutch College of General Practitioners' practice guideline 'Delirium in elderly people' contains a number of key messages. These are: Consider the diagnosis of delirium in the case of changes in consciousness and attention, incoherent thinking or disorientation, if this picture developed over a
Generalized, Linear, and Mixed Models
McCulloch, Charles E; Neuhaus, John M
2011-01-01
An accessible and self-contained introduction to statistical models-now in a modernized new editionGeneralized, Linear, and Mixed Models, Second Edition provides an up-to-date treatment of the essential techniques for developing and applying a wide variety of statistical models. The book presents thorough and unified coverage of the theory behind generalized, linear, and mixed models and highlights their similarities and differences in various construction, application, and computational aspects.A clear introduction to the basic ideas of fixed effects models, random effects models, and mixed m
Bolter, R.; Freund, T.; Ledig, T.; Boll, B.; Szecsenyi, J.; Roos, M.
2012-01-01
Introduction: The planned modification of the Medical Licenses Act in Germany will strengthen the specialty of general practice. Therefore, medical students should get to know the daily routine of general practitioners during their academic studies. At least 10% of students should get the
Parameterization guidelines and considerations for hydrologic models
R. W. Malone; G. Yagow; C. Baffaut; M.W Gitau; Z. Qi; Devendra Amatya; P.B. Parajuli; J.V. Bonta; T.R. Green
2015-01-01
Â Imparting knowledge of the physical processes of a system to a model and determining a set of parameter values for a hydrologic or water quality model application (i.e., parameterization) are important and difficult tasks. An exponential...
Klomp, M A Rien; Verdaasdonk, Aard L; Striekwold, Manuela P; Teunissen, H Eric; Opstelten, Wim; Goudswaard, A N Lex
2010-01-01
The practice guideline 'Peripheral facial paralysis' of the Dutch College of General Practitioners provides the general practitioner with guidelines for diagnosis and management of patients with a peripheral facial paralysis. In about two-thirds of cases of peripheral facial paralysis no cause can be found. The diagnosis of this so-called idiopathic peripheral facial paralysis is based on the patient's history and physical examination; additional investigations are not indicated. The natural course is usually good: without treatment 65-85% of patients will regain normal function of the facial muscles. Treatment with corticosteroids is recommended for all patients with an idiopathic peripheral facial paralysis, irrespective of the degree of the paralysis. This increases the chance of complete recovery by approximately 10%. Antiviral treatment is not recommended.
van der Heiden, Colin; Methorst, Gerda; Muris, Peter; van der Molen, Henk T
2011-01-01
Generalized anxiety disorder (GAD) is a prevalent and disabling disorder characterised by persistent worrying, anxiety symptoms, and tension. General practitioners and mental healthcare professionals frequently misdiagnose the presenting symptoms. This article addresses the clinical presentation of GAD and provides guidelines for discriminating GAD from other disorders, based on theoretical considerations and clinical experience. Debate relating to the validity of the definition of GAD is discussed, and suggestions are made for improving the criteria for GAD, which may guide future versions of classification systems such as the Diagnostic and Statistical Manual.
Modeling pediatric vaccination guidelines in a data warehouse.
Housman, Daniel; Greim, Julie; Morgan, Stephen J; Nelson, Sarah M; Flanagan, Tara; Martin, Kerry; Eskin, Michael; Einbinder, Jonathan S
2008-11-06
Frequent updates and complexity of vaccination schedules can make it difficult for pediatric practices to ensure adherence to immunization guidelines. To address this problem, Partners HealthCare System (PHS) has created a quality reporting utility to manage pediatric immunizations and to support quality improvement initiatives. The rules-based solution uses reference database tables to model the logic for each vaccine.
Modeling and Simulation. I. Introduction and Guidelines.
1986-06-30
kitten visual cortex. Accession For NTIS GRA&I...of modelling: Plasticity in kitten visual cortex. i k,’t ’ .%, %Z%-% . %i" ’ o’ ’ " "h • .". ". ". " ’"" . " "."’" ".""""-.’ ,’*’"’." . ".’"* " "w...issues of animal care and surgical anesthesia; rather the matter for many seems to be justification for any use of mammals in research 37 . We can
Directory of Open Access Journals (Sweden)
Mazza Danielle
2013-01-01
Full Text Available Abstract Background Despite strong evidence of the benefits of preconception interventions for improving pregnancy outcomes, the delivery and uptake of preconception care and periconceptional folate supplementation remain low. General practitioners play a central role in the delivery of preconception care. Understanding general practitioners’ perceptions of the barriers and enablers to implementing preconception care allows for more appropriate targeting of quality improvement interventions. Consequently, the aim of this study was to examine the barriers and enablers to the delivery and uptake of preconception care guidelines from general practitioners’ perspective using theoretical domains related to behaviour change. Methods We conducted a qualitative study using focus groups consisting of 22 general practitioners who were recruited from three regional general practice support organisations. Questions were based on the theoretical domain framework, which describes 12 domains related to behaviour change. General practitioners’ responses were classified into predefined themes using a deductive process of thematic analysis. Results Beliefs about capabilities, motivations and goals, environmental context and resources, and memory, attention and decision making were the key domains identified in the barrier analysis. Some of the perceived barriers identified by general practitioners were time constraints, the lack of women presenting at the preconception stage, the numerous competing preventive priorities within the general practice setting, issues relating to the cost of and access to preconception care, and the lack of resources for assisting in the delivery of preconception care guidelines. Perceived enablers identified by general practitioners included the availability of preconception care checklists and patient brochures, handouts, and waiting room posters outlining the benefits and availability of preconception care consultations
Thiel, Rainer; Viceconti, Marco; Stroetmann, Karl
2011-01-01
Biocomputational modelling as developed by the European Virtual Physiological Human (VPH) Initiative is the area of ICT most likely to revolutionise in the longer term the practice of medicine. Using the example of osteoporosis management, a socio-economic assessment framework is presented that captures how the transformation of clinical guidelines through VPH models can be evaluated. Applied to the Osteoporotic Virtual Physiological Human Project, a consequent benefit-cost analysis delivers promising results, both methodologically and substantially.
Fleuren, M.; Grol, R.; Haan, M. de; Wijkel, D.; Oudshoorn, C.
1997-01-01
Objective: To determine the feasibility for midwives to adhere to Dutch national guidelines on threatened miscarriage in general practice. Design: Prospective recording of appointments by midwives who agreed to adhere to the guidelines on threatened miscarriage. Interviews with the midwives after th
Conceptual Models and Guidelines for Clinical Assessment of Financial Capacity.
Marson, Daniel
2016-09-01
The ability to manage financial affairs is a life skill of critical importance, and neuropsychologists are increasingly asked to assess financial capacity across a variety of settings. Sound clinical assessment of financial capacity requires knowledge and appreciation of applicable clinical conceptual models and principles. However, the literature has presented relatively little conceptual guidance for clinicians concerning financial capacity and its assessment. This article seeks to address this gap. The article presents six clinical models of financial capacity : (1) the early gerontological IADL model of Lawton, (2) the clinical skills model and (3) related cognitive psychological model developed by Marson and colleagues, (4) a financial decision-making model adapting earlier decisional capacity work of Appelbaum and Grisso, (5) a person-centered model of financial decision-making developed by Lichtenberg and colleagues, and (6) a recent model of financial capacity in the real world developed through the Institute of Medicine. Accompanying presentation of the models is discussion of conceptual and practical perspectives they represent for clinician assessment. Based on the models, the article concludes by presenting a series of conceptually oriented guidelines for clinical assessment of financial capacity. In summary, sound assessment of financial capacity requires knowledge and appreciation of clinical conceptual models and principles. Awareness of such models, principles and guidelines will strengthen and advance clinical assessment of financial capacity.
Ulrik, Charlotte Suppli; Sørensen, Tina Brandt; Højmark, Torben Brunse; Olsen, Kim Rose; Vedsted, Peter
2013-03-01
The general practitioner (GP) is often the first healthcare contact for patients with chronic obstructive pulmonary disease (COPD). To determine whether participating in a standardised educational programme delivered in the GP's own practice is associated with adherence to COPD guidelines. A nationwide register-based observational before and after study was undertaken with a control group of propensity-matched practices (follow-up period 6 months). COPD was defined as age 40+ years and at least two prescriptions for inhaled medication. The educational programme consisted of a 3-hr teaching lesson with a respiratory specialist and five visits by a representative from the sponsoring pharmaceutical company focusing on assessment and management of patients including written algorithms. A one-to-one propensity-matched control group of practices was selected. Register data were used to compare the rate of spirometry testing, preventive consultations, and influenza vaccinations provided to COPD patients and the rate of spirometry testing in non-COPD individuals, assumed to reflect diagnostic activity. Data for 102 participating GP practices were analysed. Participating clinics had a significant increase in preventive consultations and influenza vaccinations (ppractices may improve adherence to COPD guidelines, not least for clinics with a high potential for improvement.
van Spiegel, P I
2008-06-28
The practice guideline 'Smoking cessation' from the Dutch College of General Practitioners has been published. If general practitioners are going to use the standard, this can have a great impact on smoking in the Dutch population. A decrease in smokers among the population will also have an impact on several smoking-related chronic diseases from a preventive point of view. The guideline emphasizes that smoking cessation is not a one-stop shop but that it requires a long-term effort.
Fermions as generalized Ising models
Wetterich, C.
2017-04-01
We establish a general map between Grassmann functionals for fermions and probability or weight distributions for Ising spins. The equivalence between the two formulations is based on identical transfer matrices and expectation values of products of observables. The map preserves locality properties and can be realized for arbitrary dimensions. We present a simple example where a quantum field theory for free massless Dirac fermions in two-dimensional Minkowski space is represented by an asymmetric Ising model on a euclidean square lattice.
CPN Models in General Coordinates
Barnes, K J
2002-01-01
An analysis of CPN models is given in terms of general coordinates or arbitrary interpolating fields.Only closed expressions made from simple functions are involved.Special attention is given to CP2 and CP4. In the first of these the retrieval of stereographic coordinates reveals the hermitian form of the metric. A similar analysis for the latter case allows comparison with the Fubini-Study metric.
nestor Guideline for Preservation Planning – a Process Model
Directory of Open Access Journals (Sweden)
Sabine Schrimpf
2014-02-01
Full Text Available The nestor guideline for preservation planning is the latest in a series of nestor publications. nestor is the German competence network for digital preservation and it offers all interested parties from the private and public domains the possibility to participate in working groups. The guideline for preservation planning is the result of such a working group, which discussed the conceptual and practical issues of implementing the OAIS Functional Entity “Preservation Planning”.The guideline describes a process model and offers some guidance on potential implementations. It integrates and builds on recognized community concepts like Significant Properties, the OAIS Designated Community, the National Archives of Australia’s Performance Model, the PREMIS concept of Intellectual Entities and Representations, and the PLANET’s approach to preservation planning. Furthermore, it introduces the concepts “intended use” (Nutzungsziele, “information type” (Informationstyp and “preservation group” (Erhaltungsgruppe. The purpose of these new categories is that information objects shall be grouped by information type (e.g., audio, video, text… and intended use (e.g., reading for pleasure, search for specific information… to preservation groups for automatic processing. Significant properties can then be derived for whole preservation groups. The file format alone is considered as not completely sufficient for such categorisation. Some exemplary implementation solutions of the new concepts are presented in an annex.The guideline takes into account that resources for preservation planning and preservation actions are limited and has therefore adopted 4 premises: adequacy, financial viability, automation, and authenticity of archived objects. Its pragmatic approach becomes apparent in the definition and explanation of these dimensions. The guideline is written from the point of view of representatives of memory institutions, i
Luning-Koster, Marleen N; Lucassen, Peter L B J; Boukes, Froukje S; Goudswaard, A N Lex
2011-01-01
October 2010 the Dutch College of General Practitioners issued a revised version of their previous practice guideline of 1995 on food hypersensitivity in infants. If patients suspect either themselves or their child of having a food allergy, this is usually not demonstrated in subsequent investigation. Wrongly prescribed elimination diets may have adverse effects. Examination of serum specific IgE levels has no place in the diagnosis of food allergy in general practice. An open elimination challenge is especially suitable in order to exclude a food allergy. A sure diagnosis of food allergy can only be made by a double-blind placebo-controlled food challenge. There are no proven effective measures that can prevent food allergy.
de Wit, Niek J; Berger, Marjolein Y; Vogelenzang, Rogier; Wetzels, Raymond V; van Rijn-van Kortenhof, Nathalie M M; Opstelten, Wim; Goudswaard, A N Lex
2012-01-01
The NHG practice guideline on 'Diverticulitis' provides general practitioners with directions on the diagnosis and treatment of uncomplicated and complicated diverticulitis. Diverticulitis is primarily a clinical diagnosis which can be supported by assessment of CRP. Uncomplicated diverticulitis is strongly suspected if the patient reports the development of persistent sharp, stabbing pain in the lower left abdomen within a couple of days; if there is pressure or rebound tenderness only in the lower left abdomen; and if there are no alarm signals. Alarm signals of complicated diverticulitis are: guarded muscle response, signs of intestinal obstruction, locally palpable resistance, rectal loss of blood, hypotension, and high fever. The policy for uncomplicated diverticulitis is waiting without specific measures, provided that the general practitioner monitors the course actively. There is no indication for antibiotics in patients with uncomplicated diverticulitis. Patients with signs of complicated diverticulitis or with persisting symptoms should be referred.
Branchereau, E; Branger, B; Launay, E; Verstraete, M; Vrignaud, B; Levieux, K; Senand, R; Gras-Le Guen, C
2013-12-01
The Haute autorité de santé released clinical practice guidelines in 2000 to assist in the management of bronchiolitis. These guidelines emphasized supportive care with nasal suctioning and encouraged chest physiotherapy. The aim of this study was to examine the adherence to the french guidelines for the management of bronchiolitis by general practitioners. The study included infants less than 24 months of age with bronchiolitis, consulting a general practitioner in Vendée or in Loire-Atlantique, from November 2011 to April 2012 and whose parents accepted to participate to the study. The primary endpoint was the concordance of therapeutic practice with the french guidelines (administrated treatments, refer to pediatric emergencies). Data were collected through questionaires completed by general practitioners. Of the 1236 questionnaires distributed, 134 were completed and 118 therapeutic practice were analyzed. A total of 52.5% of therapeutic practice were concordant with guidelines and 57.5% in case of first bronchiolitis. 50% of infants with a hospitalization criteria according to the guidelines, have not been, which probably shows the interest of new guidelines, with highlighting of hospitalization criteria. Copyright © 2013 Elsevier Masson SAS. All rights reserved.
Multivariate covariance generalized linear models
DEFF Research Database (Denmark)
Bonat, W. H.; Jørgensen, Bent
2016-01-01
We propose a general framework for non-normal multivariate data analysis called multivariate covariance generalized linear models, designed to handle multivariate response variables, along with a wide range of temporal and spatial correlation structures defined in terms of a covariance link...... function combined with a matrix linear predictor involving known matrices. The method is motivated by three data examples that are not easily handled by existing methods. The first example concerns multivariate count data, the second involves response variables of mixed types, combined with repeated...... are fitted by using an efficient Newton scoring algorithm based on quasi-likelihood and Pearson estimating functions, using only second-moment assumptions. This provides a unified approach to a wide variety of types of response variables and covariance structures, including multivariate extensions...
Maintenance Use of Antidepressants in Dutch General Practice: Non-Guideline Concordant
Piek, Ellen; Kollen, Boudewijn J.; van der Meer, Klaas; Penninx, Brenda W. J. H.; Nolen, Willem A.
2014-01-01
Background There is hardly evidence on maintenance treatment with antidepressants in primary care. Nevertheless, depression guidelines recommend maintenance treatment i.e. treatment to prevent recurrences, in patients with high risk of recurrence, and many patients use maintenance treatment with antidepressants. This study explores the characteristics of patients on maintenance treatment with antidepressants in general practice, and compares these characteristics with guideline recommendations for maintenance treatment. Methods We used data (baseline, two-year and four-year follow-up) of primary care respondents with remitted depressive disorder (≥6 months) from the Netherlands Study of Depression and Anxiety (n = 776). Maintenance treatment was defined as the use of an antidepressant for ≥12 months. Multilevel logistic regression was used to describe the association between sociodemographic, clinical and care characteristics and use of maintenance treatment with antidepressants. Results Older patients, patients with a lower education, those using benzodiazepines or receiving psychological/psychiatric care and patients with a concurrent history of a dysthymic or anxiety disorder more often received maintenance treatment with antidepressants. Limitations Measurements were not made at the start of an episode, but at predetermined points in time. Diagnoses were based on interview (CIDI) data and could therefore in some cases have been different from the GP diagnosis. Conclusions Since patients with chronic or recurrent depression do not use maintenance treatment with antidepressants more often, characteristics of patients on maintenance treatment do not fully correspond with guideline recommendations. However, patients on maintenance treatment appear to be those with more severe disorder and/or more comorbidity. PMID:24858011
Fermions as generalized Ising models
Directory of Open Access Journals (Sweden)
C. Wetterich
2017-04-01
Full Text Available We establish a general map between Grassmann functionals for fermions and probability or weight distributions for Ising spins. The equivalence between the two formulations is based on identical transfer matrices and expectation values of products of observables. The map preserves locality properties and can be realized for arbitrary dimensions. We present a simple example where a quantum field theory for free massless Dirac fermions in two-dimensional Minkowski space is represented by an asymmetric Ising model on a euclidean square lattice.
Prevention of generalized reactions to contrast media: a consensus report and guidelines
Energy Technology Data Exchange (ETDEWEB)
Morcos, S.K. [Dept. of Diagnostic Imaging, Northern General Hospital, Sheffield (United Kingdom); Thomsen, H.S. [Dept. of Diagnostic Radiology, Herlev Hospital, University of Copenhagen (Denmark); Webb, J.A.W. [Diagnostic Radiology Department, St. Bartholomew' s Hospital, London (United Kingdom)
2001-09-01
The aim of this study was to document, using consensus methodology, current practice for prevention of generalized reactions to contrast media, to identify areas where there is disagreement or confusion and to draw up guidelines for reducing the risk of generalized contrast media reactions based on the survey and a review of the literature. A document with 165 questions was mailed to 202 members of the European Society of Urogenital Radiology. The questions covered risk factors and prophylactic measures for generalized contrast media reactions. Sixty-eight members (34%) responded. The majority indicated that a history of moderate and severe reaction(s) to contrast media and asthma are important risk factors. The survey also indicated that patients with risk factors should receive non-ionic contrast media. In patients at high risk of reaction, if the examination is deemed absolutely necessary, a resuscitation team should be available at the time of the procedure. The majority (91%) used corticosteroid prophylaxis given at least 11 h before contrast medium to patients at increased risk of reaction. The frequency of the dosage varied from one to three times. Fifty-five percent also use antihistamine Hl, mainly administered orally and once. Antihistamine H2 and ephedrine are rarely used. All essential drugs are available on the emergency resuscitation trolley. Patients with risk factors are observed up to 30 min by 48% and up to 60 min by 43% of the responders. Prophylactic measures are not taken before extravascular use of contrast media. Prophylactic drugs are given to patients with a history of moderate or severe generalized reaction to contrast media. In patients with asthma, opinion is divided with only half of the responders giving prophylactic drugs. Aspirin, {beta}-blockers, interleukin-2 and non-steroid anti-inflammatory drugs are not considered risk factors and therefore are not stopped before injection of contrast media. The survey showed some variability in
Guidelines for Homology Modeling of Dopamine, Norepinephrine, and Serotonin Transporters.
Haddad, Yazan; Heger, Zbynek; Adam, Vojtech
2016-11-16
The human dopamine, norepinephrine, and serotonin transporters (hDAT, hNET, and hSERT) are carriers of neurotransmitters and targets for many drugs. Pioneering works in the past three years to elucidate experimental models of the Drosophila dDAT and human hSERT structures will rapidly impact the field of neuroscience. Here, we evaluated automated homology-based human models of these transporters, employing systematic physics-based, knowledge-based, and empirical-based check. Modeling guidelines were conveyed with attention to the central binding site (S1), secondary binding site (S2), and the extracellular loops EL2 and EL4. Application of new experimental models (dDAT and hSERT) will improve the accuracy of homology models, previously utilizing prokaryotic leucine transporter (LeuT) structure, and provide better predictions of ligand interactions, which is required for understanding of cellular mechanisms and for development of novel therapeutics.
Mazel, J A
2004-11-06
The Dutch College of General Practitioners' (Dutch acronym: NHG) practice guideline 'Stable angina pectoris' (second revision) provides clear guidelines for the diagnosis and treatment of patients who experience chest pains as a result of angina pectoris, especially if coronary artery disease is the underlying cause of the complaints. The practice guideline clearly indicates for which complaints the general practitioner should suspect angina pectoris and which information from the anamnesis, family history and risk factors can contribute to distinguishing between stable and unstable angina pectoris. However, the physical examination should not be omitted because this can provide important indications for coronary or pulmonary dysfunction. According to the practice guideline, the treatment policy is determined by the estimated risk of significant coronary artery disease. However, additional tests can be useful even in the case of a small risk, as these can reassure patients. The indications and contraindications for medicinal substances are clearly presented.
Olde Hartman, T.C.; Uijen, A.A.
2008-01-01
The revised guideline 'Bacterial skin infections' from the Dutch College ofGeneral Practitioners offers a clear and extensive overview of the most prevalent superficial and deep bacterial infections in general practice. Given the lack of evidence, it is no longer recommended to keep children with im
Bosch, W.J.H.M. van den
2006-01-01
The recently revised version of the practice guideline 'Problematic alcohol consumption' from the Dutch College of General Practitioners offers realistic advice to general practitioners on how to manage problem drinkers. The number of patients with alcohol problems tends to increase among women of m
Izaks, GJ
2003-01-01
Delirium in elderly people is a severe condition that requires vigorous medical attention. Therefore, the Dutch College of General Practitioners has duly chosen to develop a practice guideline 'Delirium in elderly people'. It is likely that many general practitioners are only partly familiar with
Izaks, GJ
2003-01-01
Delirium in elderly people is a severe condition that requires vigorous medical attention. Therefore, the Dutch College of General Practitioners has duly chosen to develop a practice guideline 'Delirium in elderly people'. It is likely that many general practitioners are only partly familiar with de
Bakx, J.C.; Deunk, L.; Gerwen, W.H.E.M. van; Aalst, M. van der; Hoogen, H.J.M. van den; Bosch, W.J.H.M. van den
2003-01-01
OBJECTIVE: To determine whether patients with hypertension in general practice are diagnosed and treated according to the criteria of the Dutch College of General Practitioners guidelines. DESIGN: Retrospective, descriptive. METHOD: Using data from 9 general practices belonging to the general
Generalized model of island biodiversity
Kessler, David A.; Shnerb, Nadav M.
2015-04-01
The dynamics of a local community of competing species with weak immigration from a static regional pool is studied. Implementing the generalized competitive Lotka-Volterra model with demographic noise, a rich dynamics with four qualitatively distinct phases is unfolded. When the overall interspecies competition is weak, the island species recapitulate the mainland species. For higher values of the competition parameter, the system still admits an equilibrium community, but now some of the mainland species are absent on the island. Further increase in competition leads to an intermittent "disordered" phase, where the dynamics is controlled by invadable combinations of species and the turnover rate is governed by the migration. Finally, the strong competition phase is glasslike, dominated by uninvadable states and noise-induced transitions. Our model contains, as a special case, the celebrated neutral island theories of Wilson-MacArthur and Hubbell. Moreover, we show that slight deviations from perfect neutrality may lead to each of the phases, as the Hubbell point appears to be quadracritical.
Generalization performance of regularized neural network models
DEFF Research Database (Denmark)
Larsen, Jan; Hansen, Lars Kai
1994-01-01
Architecture optimization is a fundamental problem of neural network modeling. The optimal architecture is defined as the one which minimizes the generalization error. This paper addresses estimation of the generalization performance of regularized, complete neural network models. Regularization...
van Weel-Baumgarten, E M; van Rijswijk, E
2005-05-28
The recommendations provided by the revised guideline 'Anxiety disorders' are well suited to every-day practice. The multidisciplinary approach reflects the increasing cooperation between primary and secondary care in the management of mental-health problems. The description of the various anxiety disorders and the questions that can be asked to elicit the symptoms will facilitate recognition. The indications for treatment with medication are clear: a limited number of antidepressants should be used. Although it is agreed that patient education is an important part of treatment, the guidelines could have described in more detail how this should be done. Cognitive-behavioural techniques may be used but this requires extra training; its effectiveness when used by general practitioners needs further study. This guideline will add to existing knowledge and improve the skills of general practitioners in dealing with anxiety.
Alachua County Schools, Gainesville, FL.
Presented are guidelines and evaluative data on five instructional models implemented between 1972 and 1975 to educate emotionally disturbed students in Alachua County Schools (Florida). General information includes the philosphy of the program; a definition and list of characteristics of emotionally disturbed students; and an outline of…
Interpretation of NCCN Guidelines: General Therapies on Non-small Cell Lung Cancer (Version 6. 2015
Directory of Open Access Journals (Sweden)
Xin-en HUANG
2015-06-01
Full Text Available Lung cancer is one of the most common malignant tumors in China and ranks the first of cancer-related death. The major etiological agent of lung cancer is an industry-made and promoted addictive product, so lung cancer is considered to be a unique disease in all cancers. Effective policies for public health are required to prevent the smoking initiation so as to reduce the mortality of lung cancer, so Food and Drug Administration (FDA has introduced a series of measures to monitor the tobacco products. As to patients with strong suspicion of lung cancer in stage Ⅰ-Ⅱ, a preoperative biopsy is needed and intra-operative diagnosis is necessary before pneumonectomy, bilobectomy or lobectomy if the preoperative tissue diagnosis is not obtained. However, lung cancer still cannot be easily diagnosed and cured, so the annual improvement and update of new therapeutic protocols and the development of new agents is of great significance. Non-small cell lung cancer (NSCLC accounts for about 80% of all lung cancer, and above 75% NSCLC patients are in middle-advanced stage when diagnosed, so they have lost the optimal therapeutic opportunity and the 5-year survival rate is relatively low. Therefore, this study mainly interpreted the National Comprehensive Cancer Network (NCCN guidelines on the general therapies on NSCLC, hoping to provide references for the treatment of NSCLC patients and prolong their long-term survival.
Communication guidelines as a learning tool: an exploration of user preferences in general practice
Veldhuijzen, W.; Ram, P.M.; Weijden, T.T. van der; Vleuten, C.P.M. van der
2013-01-01
OBJECTIVE: To explore characteristics of written communication guidelines that enhance the success of training aimed at the application of the recommendations in the guidelines. METHODS: Seven mixed focus groups were held consisting of communication skill teachers and communication skill learners an
DEFF Research Database (Denmark)
Ulrik, Charlotte Suppli; Hansen, Ejvind Frausing; Jensen, Michael Skov
2010-01-01
BACKGROUND AND AIM: The general practitioner (GP) is the first contact with the health care system for most patients with COPD in Denmark. We studied, if participating in an educational program could improve adherence to guidelines, not least for diagnosis, staging, and treatment of the disease. ...
Balen, J.A. van; Verduijn, M.M.; Sachs, A.P.; Berger, M.Y.; Lucassen, P.L.B.J.; Wiersma, T.J.; Goudswaard, A.N.
2007-01-01
The practice guideline 'Allergic and non-allergic rhinitis' of the Dutch College ofGeneral Practitioners has been revised based on developments that have occurred in recent years. The most important modifications are: Impermeable covers for beddings are advised only for patients with serious complai
Pinnock, Hilary; Holmes, Steve; Levy, Mark L; McArthur, Ruth; Small, Iain
2010-06-01
A web-based questionnaire, comprising 11 multiple choice questions, tested the knowledge of visitors to the General Practice Airways Group (GPIAG) online summary of the British Asthma guideline. On average, the 413 respondents answered less than half the questions correctly. GP scores were significantly lower than practice nurses. Improving clinicians' knowledge of asthma is a prerequisite for improving management.
Generalized complex geometry, generalized branes and the Hitchin sigma model
Energy Technology Data Exchange (ETDEWEB)
Zucchini, Roberto E-mail: zucchinir@bo.infn.it
2005-03-01
Hitchin's generalized complex geometry has been shown to be relevant in compactifications of superstring theory with fluxes and is expected to lead to a deeper understanding of mirror symmetry. Gualtieri's notion of generalized complex submanifold seems to be a natural candidate for the description of branes in this context. Recently, we introduced a Batalin-Vilkovisky field theoretic realization of generalized complex geometry, the Hitchin sigma model, extending the well known Poisson sigma model. In this paper, exploiting Gualtieri's formalism, we incorporate branes into the model. A detailed study of the boundary conditions obeyed by the world sheet fields is provided. Finally, it is found that, when branes are present, the classical Batalin-Vilkovisky cohomology contains an extra sector that is related non trivially to a novel cohomology associated with the branes as generalized complex submanifolds. (author)
Generalized complex geometry, generalized branes and the Hitchin sigma model
Zucchini, R
2005-01-01
Hitchin's generalized complex geometry has been shown to be relevant in compactifications of superstring theory with fluxes and is expected to lead to a deeper understanding of mirror symmetry. Gualtieri's notion of generalized complex submanifold seems to be a natural candidate for the description of branes in this context. Recently, we introduced a field theoretic realization of generalized complex geometry, the Hitchin sigma model, extending the well known Poisson sigma model. In this paper, exploiting Gualtieri's formalism, we incorporate branes into the model. A detailed study of the boundary conditions obeyed by the world sheet fields is provided. Finally, it is found that, when branes are present, the classical Batalin--Vilkovisky cohomology contains an extra sector that is related non trivially to a novel cohomology associated with the branes as generalized complex submanifolds.
More on generalized Heisenberg ferromagnet models
Oh, P; Oh, Phillial; Park, Q Han
1996-01-01
We generalize the integrable Heisenberg ferromagnet model according to each Hermitian symmetric spaces and address various new aspects of the generalized model. Using the first order formalism of generalized spins which are defined on the coadjoint orbits of arbitrary groups, we construct a Lagrangian of the generalized model from which we obtain the Hamiltonian structure explicitly in the case of CP(N-1) orbit. The gauge equivalence between the generalized Heisenberg ferromagnet and the nonlinear Schr\\"{o}dinger models is given. Using the equivalence, we find infinitely many conserved integrals of both models.
Energy Technology Data Exchange (ETDEWEB)
Neudecker, Denise [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Conlin, Jeremy Lloyd [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gray, Mark Girard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); McCartney, Austin Paul [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Parsons, Donald Kent [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); White, Morgan Curtis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2017-04-12
This memo contains general guidelines on what documentation and tools need to be in place as well as format and data testing requirements such that evaluated nuclear data sets or entire libraries can be adopted by the nuclear data team. Additional requirements beyond this memo might apply for specific nuclear data observables. These guidelines were established based on discussions between J.L. Conlin, M.G. Gray, A.P. McCartney, D. Neudecker, D.K. Parsons and M.C. White.
DEFF Research Database (Denmark)
Brandes, Axel; Overgaard, Mikkel; Plauborg, Liane
2013-01-01
.001) of the patients. Of all patients, 66.3% were treated with oral anticoagulants, 18.7% with antiplatelet drugs only, and 15% received no antithrombotic therapy. Based on the CHADS(2) score, 75.7% of the patients were treated in adherence with the guidelines, 16% were undertreated, and 8.4% overtreated......) score. Applying the CHA(2)DS(2)-VASc score, this proportion was only 53.4%. Antiplatelet drug treatment was in adherence to the guidelines (CHADS(2) and CHA(2)DS(2)-VASc score of 1) in only 31% and 12% of the patients, respectively. ConclusionsAntithrombotic treatment of AF patients is in general well...
Hombach, Michael; Courvalin, Patrice; Böttger, Erik C
2014-07-01
This study critically evaluated the new European Committee for Antimicrobial Susceptibility Testing (EUCAST) antibiotic susceptibility testing guidelines on the basis of a large set of disk diffusion diameters determined for clinical isolates. We report several paradigmatic problems that illustrate key issues in the selection of clinical susceptibility breakpoints, which are of general importance not only for EUCAST but for all guidelines systems, i.e., (i) the need for species-specific determinations of clinical breakpoints/epidemiological cutoffs (ECOFFs), (ii) problems arising from pooling data from various sources, and (iii) the importance of the antibiotic disk content for separating non-wild-type and wild-type populations.
Product model structure for generalized optimal design
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
The framework of the generalized optimization product model with the core of network- and tree-hierarchical structure is advanced to improve the characteristics of the generalized optimal design. Based on the proposed node-repetition technique, a network-hierarchical structure is united with the tree-hierarchical structure to facilitate the modeling of serialization and combination products. The criteria for product decomposition are investigated. Seven tree nodes are defined for the construction of a general product model, and their modeling properties are studied in detail. The developed product modeling system is applied and examined successfully in the modeling practice of the generalized optimal design for a hydraulic excavator.
Multivariate generalized linear mixed models using R
Berridge, Damon Mark
2011-01-01
Multivariate Generalized Linear Mixed Models Using R presents robust and methodologically sound models for analyzing large and complex data sets, enabling readers to answer increasingly complex research questions. The book applies the principles of modeling to longitudinal data from panel and related studies via the Sabre software package in R. A Unified Framework for a Broad Class of Models The authors first discuss members of the family of generalized linear models, gradually adding complexity to the modeling framework by incorporating random effects. After reviewing the generalized linear model notation, they illustrate a range of random effects models, including three-level, multivariate, endpoint, event history, and state dependence models. They estimate the multivariate generalized linear mixed models (MGLMMs) using either standard or adaptive Gaussian quadrature. The authors also compare two-level fixed and random effects linear models. The appendices contain additional information on quadrature, model...
Directory of Open Access Journals (Sweden)
Speriusi-Vlad Alin
2014-07-01
Full Text Available Today, the intellectual property protection is no longer an absolute social and legal that justifies adoption of any measures necessary to protect it. Initially seen as the prerequisite for sustainable development, implementation of new technologies, and encouragement of international trade, the intellectual property, especially prior to ACTA (Anti-Counterfeiting Trade Agreement international trial implementation, and also thereafter, was increasingly identified as a source of violation of fundamental rights and civil liberties, i.e. the right to protection of personal data, the right to privacy, freedom to send and receive information freedom of information, freedom to contract, and freedom to carry out economic activities (freedom of commerce. As far as international trade transactions have often a component of intellectual property that requires to be protected, it is necessary to identify the landmarks, the rules establishing de facto limits in order to protect the intellectual property without risk of infringement of fundamental rights and civil liberties of other persons, in particular users or potential users of goods and services incorporating intellectual property. The best guidelines in this regard may be provided by the CJEU (Court of Justice of the European Union case-law both due to its reasoning underlying the decision of the Parliament to reject ACTA ratification and the fact that the case-law of this Court, especially the most recent one, is highly complex and nuanced, not denying in any way the importance of intellectual property, and identifying certain cases where their primacy persist and whose analysis leads to laying down some general rules in the field.
2010-07-09
..., libraries, institutions of higher education, library and museum professional associations, and museum and... for Guidelines, Applications, and Reporting Forms AGENCY: Institute of Museum and Library Services.... SUMMARY: The Institute of Museum and Library Services announces the following information collection...
Gadipelly, Srinivas; Neshangi, Srisha
2015-06-01
Every general dental practitioner and oral and maxillofacial surgeon needs a thorough knowledge of the diagnosis and management of medical emergencies. Cardiopulmonary arrest is the most urgent of emergencies and diagnosis must be done as soon as possible. This paper discusses the importance of the International Liaison Committee on Resuscitation which forms the guidelines for cardiopulmonary resuscitation (CPR), highlighting the important changes in the guidelines of CPR from the year 2000 to 2010, the basic sequence of performing CPR and also the role of defibrillation and the use of automated external defibrillators. Finally the five part chain of survival which is of utmost importance to dental health care professionals and oral and maxillofacial surgeons. All dental health care personnel and oral & maxillofacial surgeons should recognize the importance of the changes in the guidelines of CPR, be trained and allowed to use a properly maintained defibrillator, to respond to cardiac arrest victims.
Aspects of generalized Calogero model
Meljanac, S; Milekovic, M
2004-01-01
A multispecies model of Calogero type in $D\\geq 1$ dimensions is constructed. The model includes harmonic, two-body and three-body interactions. Using the underlying conformal SU(1,1) algebra, we find the exact eigenenergies corresponding to a class of the exact global collective states. Analysing corresponding Fock space, we detect the universal critical point at which the model exhibits singular behaviour.
Information System Development Model: Theories Analysis and Guidelines
Nayan, Norshita Mat; Badioze Zaman, Halimah
Development of information system project is one of the IT projects which have been developed to offer the best facilities for publics. Process of system development will go through its own life cycle and every process must be refined in order to fulfill aims and objectives. Eventhough information system development is always correlate with failure but a few key factors will help the systems to succeed. There are multiple success factors being discussed by other researches in the information system development but failure figure still at the higher side. The main purpose of this research is to discuss processes involved in the development of information system which positively contribute towards its success. Model of information system development which has been developed (PADM Model) consists of four fundamental processes; planning, requirement analysis, design and maintenance. All processes will be monitored by a main process namely quality as the key performance indicator. Quality plays a vital role in assessing the ability of information system developed in order to fulfill users' expectations. Analysis of theory can be used as a guideline and measurement base towards the system with hope that percentage of failure will reduce subsequently.
Generalized exponential function and discrete growth models
Souto Martinez, Alexandre; Silva González, Rodrigo; Lauri Espíndola, Aquino
2009-07-01
Here we show that a particular one-parameter generalization of the exponential function is suitable to unify most of the popular one-species discrete population dynamic models into a simple formula. A physical interpretation is given to this new introduced parameter in the context of the continuous Richards model, which remains valid for the discrete case. From the discretization of the continuous Richards’ model (generalization of the Gompertz and Verhulst models), one obtains a generalized logistic map and we briefly study its properties. Notice, however that the physical interpretation for the introduced parameter persists valid for the discrete case. Next, we generalize the (scramble competition) θ-Ricker discrete model and analytically calculate the fixed points as well as their stabilities. In contrast to previous generalizations, from the generalized θ-Ricker model one is able to retrieve either scramble or contest models.
Proliferation Risk Characterization Model Prototype Model - User and Programmer Guidelines
Energy Technology Data Exchange (ETDEWEB)
Dukelow, J.S.; Whitford, D.
1998-12-01
A model for the estimation of the risk of diversion of weapons-capable materials was developed. It represents both the threat of diversion and site vulnerability as a product of a small number of variables (two to eight), each of which can take on a small number (two to four) of qualitatively defined (but quantitatively implemented) values. The values of the overall threat and vulnerability variables are then converted to threat and vulnerability categories. The threat and vulnerability categories are used to define the likelihood of diversion, also defined categorically. The evaluator supplies an estimate of the consequences of a diversion, defined categorically, but with the categories based on the IAEA Attractiveness levels. Likelihood and Consequences categories are used to define the Risk, also defined categorically. The threat, vulnerability, and consequences input provided by the evaluator contains a representation of his/her uncertainty in each variable assignment which is propagated all the way through to the calculation of the Risk categories. [Appendix G available on diskette only.
General introduction to simulation models
DEFF Research Database (Denmark)
Hisham Beshara Halasa, Tariq; Boklund, Anette
2012-01-01
Monte Carlo simulation can be defined as a representation of real life systems to gain insight into their functions and to investigate the effects of alternative conditions or actions on the modeled system. Models are a simplification of a system. Most often, it is best to use experiments and field...
Inhomogeneous generalization of some Bianchi models
Carmeli, M.; Charach, Ch.
1980-02-01
Vacuum Bianchi models which can be transformed to the Einstein-Rosen metric are considered. The models are used in order to construct new inhomogeneous universes, which are generalizations of Bianchi cosmologies of types III, V and VIh. Recent generalizations of these Bianchi models, considered by Wainwright et al., are also discussed.
Theoretical Models of Generalized Quasispecies.
Wagner, Nathaniel; Atsmon-Raz, Yoav; Ashkenasy, Gonen
2016-01-01
Theoretical modeling of quasispecies has progressed in several directions. In this chapter, we review the works of Emmanuel Tannenbaum, who, together with Eugene Shakhnovich at Harvard University and later with colleagues and students at Ben-Gurion University in Beersheva, implemented one of the more useful approaches, by progressively setting up various formulations for the quasispecies model and solving them analytically. Our review will focus on these papers that have explored new models, assumed the relevant mathematical approximations, and proceeded to analytically solve for the steady-state solutions and run stochastic simulations . When applicable, these models were related to real-life problems and situations, including changing environments, presence of chemical mutagens, evolution of cancer and tumor cells , mutations in Escherichia coli, stem cells , chromosomal instability (CIN), propagation of antibiotic drug resistance , dynamics of bacteria with plasmids , DNA proofreading mechanisms, and more.
General Pressurization Model in Simscape
Servin, Mario; Garcia, Vicky
2010-01-01
System integration is an essential part of the engineering design process. The Ares I Upper Stage (US) is a complex system which is made up of thousands of components assembled into subsystems including a J2-X engine, liquid hydrogen (LH2) and liquid oxygen (LO2) tanks, avionics, thrust vector control, motors, etc. System integration is the task of connecting together all of the subsystems into one large system. To ensure that all the components will "fit together" as well as safety and, quality, integration analysis is required. Integration analysis verifies that, as an integrated system, the system will behave as designed. Models that represent the actual subsystems are built for more comprehensive analysis. Matlab has been an instrument widely use by engineers to construct mathematical models of systems. Simulink, one of the tools offered by Matlab, provides multi-domain graphical environment to simulate and design time-varying systems. Simulink is a powerful tool to analyze the dynamic behavior of systems over time. Furthermore, Simscape, a tool provided by Simulink, allows users to model physical (such as mechanical, thermal and hydraulic) systems using physical networks. Using Simscape, a model representing an inflow of gas to a pressurized tank was created where the temperature and pressure of the tank are measured over time to show the behavior of the gas. By further incorporation of Simscape into model building, the full potential of this software can be discovered and it hopefully can become a more utilized tool.
Cosmological models in general relativity
Indian Academy of Sciences (India)
B B Paul
2003-12-01
LRS Bianchi type-I space-time ﬁlled with perfect ﬂuid is considered here with deceleration parameter as variable. The metric potentials and are functions of as well as . Assuming '/=(), where prime denotes differentiation with respect to , it was found that =('/) and =(), where =() and is the scale factor which is a function of only. The value of Hubble’s constant 0 was found to be less than half for non-ﬂat model and is equal to 1.3 for a ﬂat model.
Marres, H.A.M.
2008-01-01
In this comment, the practice guideline 'Sore throat' (second revision) is discussed. This guideline, composed by the Dutch College of General Practitioners, offers general practitioners a well-appreciated overview of the common practices regarding diagnostic tests and treatment of pharyngitis and t
Marres, H.A.M.
2008-01-01
In this comment, the practice guideline 'Sore throat' (second revision) is discussed. This guideline, composed by the Dutch College of General Practitioners, offers general practitioners a well-appreciated overview of the common practices regarding diagnostic tests and treatment of pharyngitis and t
LENUS (Irish Health Repository)
Flynn, E
2012-03-01
ABPM is an invaluable clinical tool, as it has been shown to improve blood pressure control in primary care. Many clinical guidelines for hypertension advocate ambulatory blood pressure monitoring. This study aims to quantify the use of clinical guidelines for hypertension and to explore the role of ABPM in Primary Care. A questionnaire survey was sent to GPs working in the West of Ireland. 88% (n=139) of GPs use clinical guidelines that recommend the use of ABPM. 82% (n=130) of GPs find use of clinic blood pressure monitoring insufficient for the diagnosis and monitoring of hypertension. Despite good access to ABPM, GPs report lack of remuneration, 72% (n=116), cost 68% (n=108), and lack of time, 51% (n=83) as the main limiting factors to use of ABPM. GPs recognise the clinical value of ABPM, but this study identifies definite barriers to the use of ABPM in Primary Care.
Choobineh, Alireza; Lahmi, Mohammadali; Shahnavaz, Houshang; Jazani, Reza Khani; Hosseini, Mostafa
2004-01-01
Carpet weaving is a high risk occupation for developing musculoskeletal disorders (MSDs). The objectives of the present study, which was carried out in the Iranian hand-woven carpet industry, were determination of the prevalence of MSD symptoms, identification of major factors associated with MSD symptoms and development of guidelines for workstation design. 1,439 randomly selected weavers participated in this study. A questionnaire was used to collect data on MSD symptoms. The results revealed that the prevalence rates for symptoms in different body regions were high as compared to the general Iranian population (for neck, back and large joints, p loom type, working posture, daily working time and seat type. Based on the results, some general guidelines for designing weaving workstations were developed. A prototype test showed that the new workstation was acceptable for subject tests and that it improved working posture.
DEFF Research Database (Denmark)
Ulrik, Charlotte Suppli; Hansen, Ejvind Frausing; Jensen, Michael Skov;
2010-01-01
BACKGROUND AND AIM: The general practitioner (GP) is the first contact with the health care system for most patients with COPD in Denmark. We studied, if participating in an educational program could improve adherence to guidelines, not least for diagnosis, staging, and treatment of the disease....... DESIGN AND SETTING: Two cross-sectional surveys were performed precisely one year apart before and after an educational program for the participating GPs. A total of 124 GPs completed the study; 1716 and 1342 patients with GP-diagnosed COPD and no concomitant asthma, respectively, were included...... activity, and referral for rehabilitation; use of inhaled corticosteroids in patients with mild COPD (FEV(1) > 80%pred) declined from 76% to 45%. CONCLUSION: Diagnosis and management of COPD in general practice in Denmark is not according to guidelines, but substantial improvements can be achieved...
Guidelines for a graph-theoretic implementation of structural equation modeling
Grace, James B.; Schoolmaster, Donald R.; Guntenspergen, Glenn R.; Little, Amanda M.; Mitchell, Brian R.; Miller, Kathryn M.; Schweiger, E. William
2012-01-01
Structural equation modeling (SEM) is increasingly being chosen by researchers as a framework for gaining scientific insights from the quantitative analyses of data. New ideas and methods emerging from the study of causality, influences from the field of graphical modeling, and advances in statistics are expanding the rigor, capability, and even purpose of SEM. Guidelines for implementing the expanded capabilities of SEM are currently lacking. In this paper we describe new developments in SEM that we believe constitute a third-generation of the methodology. Most characteristic of this new approach is the generalization of the structural equation model as a causal graph. In this generalization, analyses are based on graph theoretic principles rather than analyses of matrices. Also, new devices such as metamodels and causal diagrams, as well as an increased emphasis on queries and probabilistic reasoning, are now included. Estimation under a graph theory framework permits the use of Bayesian or likelihood methods. The guidelines presented start from a declaration of the goals of the analysis. We then discuss how theory frames the modeling process, requirements for causal interpretation, model specification choices, selection of estimation method, model evaluation options, and use of queries, both to summarize retrospective results and for prospective analyses. The illustrative example presented involves monitoring data from wetlands on Mount Desert Island, home of Acadia National Park. Our presentation walks through the decision process involved in developing and evaluating models, as well as drawing inferences from the resulting prediction equations. In addition to evaluating hypotheses about the connections between human activities and biotic responses, we illustrate how the structural equation (SE) model can be queried to understand how interventions might take advantage of an environmental threshold to limit Typha invasions. The guidelines presented provide for
Hermens, R P; Hak, E; Hulscher, M E; Braspenning, J C; Grol, R P
2001-01-01
BACKGROUND: There is still only limited understanding of whether and why interventions to facilitate the implementation of guidelines for improving primary care are successful. It is therefore important to look inside the 'black box' of the intervention, to ascertain which elements work well or less
Wiersma, T.J.; Flikweert, S.; Bosch, W.J.H.M. van den
2004-01-01
The guideline covers the evaluation of patients with one or more painful joints without previous injury and focuses on the distinction between rheumatoid arthritis and other joint complaints. In the case of rheumatoid arthritis, the arthritis is based on aseptic synovitis and is nearly always associ
Immigration and Naturalization Service, Washington, DC. Office of Outreach.
Information concerning the federal regulations governing the basic citizenship skills requirement for immigrant legalization, as amended, is presented. Materials include: (1) a sample memorandum to educational service providers relaying information concerning the requirement; (2) revised requirements and guidelines for courses of study recognized…
2012-07-13
.... The mission of IMLS is to inspire libraries and museums to advance innovation, lifelong learning, and... for Guidelines, Applications, and Reporting Forms AGENCY: Institute of Museum and Library Services.... SUMMARY: The Institute of Museum and Library Services announces the following information collection...
Generalized Kripke models for epistemic logic
Voorbraak, F.
In this paper a generalization of Kripke models is proposed for systemizing the study of the many different epistemic notions that appear in the literature. The generalized Kripke models explicitly represent an agent's epistemic states to which the epistemic notions refer. Two central
Generalized Kripke models for epistemic logic
Voorbraak, F.
2008-01-01
In this paper a generalization of Kripke models is proposed for systemizing the study of the many different epistemic notions that appear in the literature. The generalized Kripke models explicitly represent an agent's epistemic states to which the epistemic notions refer. Two central epistemic noti
General Geographical Economics Model with Congestion
J.G.M. van Marrewijk (Charles)
2005-01-01
textabstractWe derive and discuss a general, but simple geographical economics model with congestion, allowing us to explain the economic viability of small and large locations. The model generalizes some previous work and lends itself to analyzing the impact of public policy in terms of
A UML approach to process modelling of clinical practice guidelines for enactment.
Knape, T; Hederman, L; Wade, V P; Gargan, M; Harris, C; Rahman, Y
2003-01-01
Although clinical practice guidelines (CPGs) have been suggested as a means of encapsulating best practice in evidence-based medical treatment, their usage in clinical environments has been disappointing. Criticisms of guideline representations have been that they are predominantly narrative and are difficult to incorporate into clinical information systems. This paper analyses the use of UML process modelling techniques for guideline representation and proposes the automated generation of executable guidelines using XMI. This hybrid UML-XMI approach provides flexible authoring of guideline decision and control structures whilst integrating appropriate data flow. It also uses an open XMI standard interface to allow the use of authoring tools and process control systems from multiple vendors. The paper first surveys CPG modelling formalisms followed by a brief introduction to process modelling in UMI. Furthermore, the modelling of CPGs in UML is presented leading to a case study of encoding a diabetes mellitus CPG using UML.
Pragmatic guidelines and quality metrics in business process modeling: a case study
Directory of Open Access Journals (Sweden)
Isel Moreno-Montes-de-Oca
2014-04-01
Full Text Available Business process modeling is one of the first steps towards achieving organizational goals. This is why business process modeling quality is an essential aspect for the development and technical support of any company. This work focuses on the quality of business process models at a conceptual l evel (design and evaluation. In the literature there are works that propose practical guidelines for modeling, while others focus on quality metrics that allow the evaluation of the models. In this paper we use practical guidelines during the modeling phase of a business process for postgraduate studies. We applied a set of quality metrics and compare the results with those obtained from a similar model that did not use guidelines. The results provide support for the use of guidelines as a way for business process modeling quality improvement, and the practical utility of quality metrics in their evaluation.
Direct mail improves knowledge of basic life support guidelines in general practice
DEFF Research Database (Denmark)
Secher, Niels; Mikkelsen, Mette Marie; Adelborg, Kasper
2012-01-01
Dette studie viste, at ved at fremsende vejledning i basal genoplivning direkte til alment praktiserende læger var det muligt at øge lægernes viden om dette område samt implementere de nye guidelines på området. Enhver praktiserende læge er til stadighed i kontakt med personer, der potentielt kan...
Choi, Jeeyae; Jansen, Kay; Coenen, Amy
In recent years, Decision Support Systems (DSSs) have been developed and used to achieve "meaningful use". One approach to developing DSSs is to translate clinical guidelines into a computer-interpretable format. However, there is no specific guideline modeling approach to translate nursing guidelines to computer-interpretable guidelines. This results in limited use of DSSs in nursing. Unified modeling language (UML) is a software writing language known to accurately represent the end-users' perspective, due to its expressive characteristics. Furthermore, standard terminology enabled DSSs have been shown to smoothly integrate into existing health information systems. In order to facilitate development of nursing DSSs, the UML was used to represent a guideline for medication management for older adults encode with the International Classification for Nursing Practice (ICNP®). The UML was found to be a useful and sufficient tool to model a nursing guideline for a DSS.
Energy Technology Data Exchange (ETDEWEB)
Halsnaes, K.; Callaway, J.M.; Meyer, H.J.
1999-04-01
The guideline document establishes a general overview of the main components of climate change mitigation assessment. This includes an outline of key economic concepts, scenario structure, common assumptions, modelling tools and country study assumptions. The guidelines are supported by Handbook Reports that contain more detailed specifications of calculation standards, input assumptions and available tools. The major objectives of the project have been provided a methodology, an implementing framework and a reporting system which countries can follow in meeting their future reporting obligations under the FCCC and for GEF enabling activities. The project builds upon the methodology development and application in the UNEP National Abatement Coasting Studies (UNEP, 1994a). The various elements provide countries with a road map for conducting climate change mitigation studies and submitting national reports as required by the FCCC. (au) 121 refs.
A general consumer-resource population model
Lafferty, Kevin D.; DeLeo, Giulio; Briggs, Cheryl J.; Dobson, Andrew P.; Gross, Thilo; Kuris, Armand M.
2015-01-01
Food-web dynamics arise from predator-prey, parasite-host, and herbivore-plant interactions. Models for such interactions include up to three consumer activity states (questing, attacking, consuming) and up to four resource response states (susceptible, exposed, ingested, resistant). Articulating these states into a general model allows for dissecting, comparing, and deriving consumer-resource models. We specify this general model for 11 generic consumer strategies that group mathematically into predators, parasites, and micropredators and then derive conditions for consumer success, including a universal saturating functional response. We further show how to use this framework to create simple models with a common mathematical lineage and transparent assumptions. Underlying assumptions, missing elements, and composite parameters are revealed when classic consumer-resource models are derived from the general model.
Anisotropic Generalized Ghost Pilgrim Dark Energy Model in General Relativity
Santhi, M. Vijaya; Rao, V. U. M.; Aditya, Y.
2017-02-01
A spatially homogeneous and anisotropic locally rotationally symmetric (LRS) Bianchi type- I Universe filled with matter and generalized ghost pilgrim dark energy (GGPDE) has been studied in general theory of relativity. To obtain determinate solution of the field equations we have used scalar expansion proportional to the shear scalar which leads to a relation between the metric potentials. Some well-known cosmological parameters (equation of state (EoS) parameter ( ω Λ), deceleration parameter ( q) and squared speed of sound {vs2}) and planes (ω _{Λ }-dot {ω }_{Λ } and statefinder) are constructed for obtained model. The discussion and significance of these parameters is totally done through pilgrim dark energy parameter ( β) and cosmic time ( t).
Generalization error bounds for stationary autoregressive models
McDonald, Daniel J; Schervish, Mark
2011-01-01
We derive generalization error bounds for stationary univariate autoregressive (AR) models. We show that the stationarity assumption alone lets us treat the estimation of AR models as a regularized kernel regression without the need to further regularize the model arbitrarily. We thereby bound the Rademacher complexity of AR models and apply existing Rademacher complexity results to characterize the predictive risk of AR models. We demonstrate our methods by predicting interest rate movements.
A generalized sinusoidal model and its applications
Institute of Scientific and Technical Information of China (English)
KU Shao-ping; LI Ning
2009-01-01
A physical model of sinusoidal function was established. It is generalized that the force is directly proportional to a power function of the distance in a classical spring-oscillator system. The differential equation of the generalized model was given. Simulations were conducted with different power values. The results show that the solution of the generalized equation is a periodic function. The expressions of the amplitude and the period (frequency) of the generalized equation were derived by the physical method. All the simulation results coincide with the calculation results of the derived expressions. A special function also was deduced and proven to be convergent in the theoretical analysis. The limit value of the special function also was derived. The generalized model can be used in solving a type of differential equation and to generate periodic waveforms.
Mung'ayi, V; Karuga, R
2010-08-01
There are emerging therapies for managing septic critically-ill patients. There is little data from the developing world on their usage. To determine the conformity rate for resuscitation and management bundles for septic patients amongst physicians in a general intensive care unit. Cross sectional observational study. The general intensive care unit, Aga Khan University Hospital,Nairobi. Admitting physicians from all specialties in the general intensive care unit. The physicians had high conformity rates of 92% and 96% for the fluid resuscitation and use of va so pressors respectively for the initial resuscitation bundle. They had moderate conformity rates for blood cultures prior to administering antibiotics (57%) and administration of antibiotics within first hour of recognition of septic shock (54%). There was high conformity rate to the glucose control policy (81%), use of protective lung strategy in acute lung injury/Acute respiratory distress syndrome, venous thromboembolism prophylaxis (100%) and stress ulcer prophylaxis (100%) in the management bundle. Conformity was moderate for use of sedation, analgesia and muscle relaxant policy (69%), continuous renal replacement therapies (54%) and low for steroid policy (35%), administration ofdrotrecogin alfa (0%) and selective digestive decontamination (15%). There is varying conformity to the international sepsis guidelines among physicians caring for patients in our general ICU. Since increased conformity would improve survival and reduce morbidity, there is need for sustained education and guideline based performance improvement.
EOP MIT General Circulation Model (MITgcm)
National Oceanic and Atmospheric Administration, Department of Commerce — This data contains a regional implementation of the Massachusetts Institute of Technology general circulation model (MITgcm) at a 1-km spatial resolution for the...
Generalized Reduced Order Model Generation Project
National Aeronautics and Space Administration — M4 Engineering proposes to develop a generalized reduced order model generation method. This method will allow for creation of reduced order aeroservoelastic state...
Generalized Kahler Geometry from supersymmetric sigma models
Bredthauer, A; Persson, J; Zabzine, M; Bredthauer, Andreas; Lindstrom, Ulf; Persson, Jonas; Zabzine, Maxim
2006-01-01
We give a physical derivation of generalized Kahler geometry. Starting from a supersymmetric nonlinear sigma model, we rederive and explain the results of Gualtieri regarding the equivalence between generalized Kahler geometry and the bi-hermitean geometry of Gates-Hull-Rocek. When cast in the language of supersymmetric sigma models, this relation maps precisely to that between the Lagrangian and the Hamiltonian formalisms. We also discuss topological twist in this context.
Energy Technology Data Exchange (ETDEWEB)
Watson, A.P.; Munro, N.B. (Oak Ridge National Lab., TN (United States)); Sidell, F.R. (Army Medical Research Inst. of Chemical Defense, Aberdeen Proving Ground, MD (United States)); Leffingwell, S.S. (Centers for Disease Control, Atlanta, GA (United States). Center for Environmental Health and Injury Control)
1992-01-01
A number of state and local planners have requested guidance on screening protocols and have expressed interest in sampling body fluids from exposed or potentially exposed individuals as a means of estimating agent dose. These guidelines have been developed to provide a clear statement that could be used by state and local emergency response personnel in the event of a nerve or vesicant agent incident resulting in off-post contamination; maximum protection from harm is the goal. The assumption is that any population group so exposed would be heterogeneous for age, gender, reproductive status, and state of health.
Energy Technology Data Exchange (ETDEWEB)
Watson, A.P.; Munro, N.B. [Oak Ridge National Lab., TN (United States); Sidell, F.R. [Army Medical Research Inst. of Chemical Defense, Aberdeen Proving Ground, MD (United States); Leffingwell, S.S. [Centers for Disease Control, Atlanta, GA (United States). Center for Environmental Health and Injury Control
1992-01-01
A number of state and local planners have requested guidance on screening protocols and have expressed interest in sampling body fluids from exposed or potentially exposed individuals as a means of estimating agent dose. These guidelines have been developed to provide a clear statement that could be used by state and local emergency response personnel in the event of a nerve or vesicant agent incident resulting in off-post contamination; maximum protection from harm is the goal. The assumption is that any population group so exposed would be heterogeneous for age, gender, reproductive status, and state of health.
Manna, D.R.; Bruijnzeels, M.A.; Mokkink, H.G.A.; Berg, M. van den
2003-01-01
OBJECTIVE: To assess whether ethnic differences present in the scientific literature used as the basis for the Dutch College of General Practitioner's (NHG) practice guidelines were reflected in the ethnic-specific information the guidelines contained. DESIGN: Analysis of published information.
Mylanus, E.A.M.
2008-01-01
The first revision of the practice guideline 'Otitis externa' from the Dutch College of General Practitioners describes diagnostic, therapeutic and preventive aspects of care and focuses mainly on the acute form of the disease. In comparison with the previous guideline, some modest but valuable impr
Generalized latent variable modeling multilevel, longitudinal, and structural equation models
Skrondal, Anders
2004-01-01
METHODOLOGY THE OMNI-PRESENCE OF LATENT VARIABLES Introduction 'True' variable measured with error Hypothetical constructs Unobserved heterogeneity Missing values and counterfactuals Latent responses Generating flexible distributions Combining information Summary MODELING DIFFERENT RESPONSE PROCESSES Introduction Generalized linear models Extensions of generalized linear models Latent response formulation Modeling durations or survival Summary and further reading CLASSICAL LATENT VARIABLE MODELS Introduction Multilevel regression models Factor models and item respons
Empirical generalization assessment of neural network models
DEFF Research Database (Denmark)
Larsen, Jan; Hansen, Lars Kai
1995-01-01
competing models. Since all models are trained on the same data, a key issue is to take this dependency into account. The optimal split of the data set of size N into a cross-validation set of size Nγ and a training set of size N(1-γ) is discussed. Asymptotically (large data sees), γopt→1......This paper addresses the assessment of generalization performance of neural network models by use of empirical techniques. We suggest to use the cross-validation scheme combined with a resampling technique to obtain an estimate of the generalization performance distribution of a specific model...
Foundations of linear and generalized linear models
Agresti, Alan
2015-01-01
A valuable overview of the most important ideas and results in statistical analysis Written by a highly-experienced author, Foundations of Linear and Generalized Linear Models is a clear and comprehensive guide to the key concepts and results of linear statistical models. The book presents a broad, in-depth overview of the most commonly used statistical models by discussing the theory underlying the models, R software applications, and examples with crafted models to elucidate key ideas and promote practical model building. The book begins by illustrating the fundamentals of linear models,
All the generalized Georgi-Machacek models
Logan, Heather E
2015-01-01
The Georgi-Machacek model adds two SU(2)_L-triplet scalars to the Standard Model in such a way as to preserve custodial SU(2) symmetry. We study the generalizations of the Georgi-Machacek model to SU(2)_L representations larger than triplets. Perturbative unitarity considerations limit the possibilities to models containing only SU(2)_L quartets, quintets, or sextets. These models are phenomenologically interesting because they allow the couplings of the 125 GeV Higgs boson to WW and ZZ to be larger than their values in the Standard Model. We write down the most general custodial SU(2)-preserving scalar potentials for these models and outline their phenomenology. We find that experimental and theoretical constraints on the fermiophobic custodial-fiveplet states present in each of the models lead to absolute upper bounds on the 125 GeV Higgs boson coupling strength to WW and ZZ.
The HIV Modes of Transmission model: a systematic review of its findings and adherence to guidelines
Directory of Open Access Journals (Sweden)
Zara Shubber
2014-06-01
Full Text Available Introduction: The HIV Modes of Transmission (MOT model estimates the annual fraction of new HIV infections (FNI acquired by different risk groups. It was designed to guide country-specific HIV prevention policies. To determine if the MOT produced context-specific recommendations, we analyzed MOT results by region and epidemic type, and explored the factors (e.g. data used to estimate parameter inputs, adherence to guidelines influencing the differences. Methods: We systematically searched MEDLINE, EMBASE and UNAIDS reports, and contacted UNAIDS country directors for published MOT results from MOT inception (2003 to 25 September 2012. Results: We retrieved four journal articles and 20 UNAIDS reports covering 29 countries. In 13 countries, the largest FNI (range 26 to 63% was acquired by the low-risk group and increased with low-risk population size. The FNI among female sex workers (FSWs remained low (median 1.3%, range 0.04 to 14.4%, with little variability by region and epidemic type despite variability in sexual behaviour. In India and Thailand, where FSWs play an important role in transmission, the FNI among FSWs was 2 and 4%, respectively. In contrast, the FNI among men who have sex with men (MSM varied across regions (range 0.1 to 89% and increased with MSM population size. The FNI among people who inject drugs (PWID, range 0 to 82% was largest in early-phase epidemics with low overall HIV prevalence. Most MOT studies were conducted and reported as per guidelines but data quality remains an issue. Conclusions: Although countries are generally performing the MOT as per guidelines, there is little variation in the FNI (except among MSM and PWID by region and epidemic type. Homogeneity in MOT FNI for FSWs, clients and low-risk groups may limit the utility of MOT for guiding country-specific interventions in heterosexual HIV epidemics.
Biological effects of ultrasound: development of safety guidelines. Part II: general review.
Nyborg, W L
2001-03-01
In the 1920s, the availability of piezoelectric materials and electronic devices made it possible to produce ultrasound (US) in water at high amplitudes, so that it could be detected after propagation through large distances. Laboratory experiments with this new mechanical form of radiation showed that it was capable of producing an astonishing variety of physical, chemical and biologic effects. In this review, the early findings on bioeffects are discussed, especially those from experiments done in the first few decades, as well as the concepts employed in explaining them. Some recent findings are discussed also, noting how the old and the new are related. In the first few decades, bioeffects research was motivated partly by curiosity, and partly by the wish to increase the effectiveness and ensure the safety of therapeutic US. Beginning in the 1970s, the motivation has come also from the need for safety guidelines relevant to diagnostic US. Instrumentation was developed for measuring acoustic pressure in the fields of pulsed and focused US employed, and standards were established for specifying the fields of commercial equipment. Critical levels of US quantities were determined from laboratory experiments, together with biophysical analysis, for bioeffects produced by thermal and nonthermal mechanisms. These are the basis for safety advice and guidelines recommended or being considered by national, international, professional and governmental organizations.
Directory of Open Access Journals (Sweden)
Ghaderi F.
2013-03-01
Full Text Available Statement of Problem: Dental procedures leading to oral tissue injuries may provoke bacterial release to the blood stream causing infective endocarditis (IE in vulnerable patients. The guideline which was proposed by AHA has been updated 9 times having the last update published in 2007. This study was endeavored to uncover the level of knowledge of general dental practitioners in Shiraz, concerning the 2007 AHA guidelines for endocarditis prophylaxis in patients with cardiac problems receiving dental treatments.Materials and Method: This cross- sectional and descriptive analytical study included 150 dentists as participants. All practitioners were given a self –report questionnaire which consisted of three sections. Questions were designed to assess their knowledge of antibiotic prophylaxis in patients with cardiac disease. Results: Almost all participants (93% were aware of antibiotic prophylaxis to be essential for tooth extraction. Most participants did not believe in prophylaxis for noninvasive procedures (such as shedding of primary teeth, impression, intraoral radiography. From all of the respondents, 75% considered Amoxicillin to be the anti-biotic of choice and 57% were acquainted with the correct dose of Amoxicillin for high risk patients.Conclusion: The study identified a potential for under/over prescription of antibiotic prophylaxis under the current guideline. Burden of IE necessitates more accurate knowledge of antibiotic prophylaxis in the undergraduate curriculum and continuing education programs of dentistry.
Simple implementation of general dark energy models
Energy Technology Data Exchange (ETDEWEB)
Bloomfield, Jolyon K. [MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Ave #37241, Cambridge, MA, 02139 (United States); Pearson, Jonathan A., E-mail: jolyon@mit.edu, E-mail: jonathan.pearson@durham.ac.uk [Centre for Particle Theory, Department of Mathematical Sciences, Durham University, South Road, Durham, DH1 3LE (United Kingdom)
2014-03-01
We present a formalism for the numerical implementation of general theories of dark energy, combining the computational simplicity of the equation of state for perturbations approach with the generality of the effective field theory approach. An effective fluid description is employed, based on a general action describing single-scalar field models. The formalism is developed from first principles, and constructed keeping the goal of a simple implementation into CAMB in mind. Benefits of this approach include its straightforward implementation, the generality of the underlying theory, the fact that the evolved variables are physical quantities, and that model-independent phenomenological descriptions may be straightforwardly investigated. We hope this formulation will provide a powerful tool for the comparison of theoretical models of dark energy with observational data.
Micro Data and General Equilibrium Models
DEFF Research Database (Denmark)
Browning, Martin; Hansen, Lars Peter; Heckman, James J.
1999-01-01
Dynamic general equilibrium models are required to evaluate policies applied at the national level. To use these models to make quantitative forecasts requires knowledge of an extensive array of parameter values for the economy at large. This essay describes the parameters required for different ...
Resonance asymptotics in the generalized Winter model
Exner, P; Exner, Pavel; Fraas, Martin
2006-01-01
We consider a modification of the Winter model describing a quantum particle in presence of a spherical barrier given by a fixed generalized point interaction. It is shown that the three classes of such interactions correspond to three different types of asymptotic behaviour of resonances of the model at high energies.
A general model for bidirectional associative memories.
Shi, H; Zhao, Y; Zhuang, X
1998-01-01
This paper proposes a general model for bidirectional associative memories that associate patterns between the X-space and the Y-space. The general model does not require the usual assumption that the interconnection weight from a neuron in the X-space to a neuron in the Y-space is the same as the one from the Y-space to the X-space. We start by defining a supporting function to measure how well a state supports another state in a general bidirectional associative memory (GBAM). We then use the supporting function to formulate the associative recalling process as a dynamic system, explore its stability and asymptotic stability conditions, and develop an algorithm for learning the asymptotic stability conditions using the Rosenblatt perceptron rule. The effectiveness of the proposed model for recognition of noisy patterns and the performance of the model in terms of storage capacity, attraction, and spurious memories are demonstrated by some outstanding experimental results.
Murphy, Kerry; O'Connor, Denise A; Browning, Colette J; French, Simon D; Michie, Susan; Francis, Jill J; Russell, Grant M; Workman, Barbara; Flicker, Leon; Eccles, Martin P; Green, Sally E
2014-03-03
Dementia is a growing problem, causing substantial burden for patients, their families, and society. General practitioners (GPs) play an important role in diagnosing and managing dementia; however, there are gaps between recommended and current practice. The aim of this study was to explore GPs' reported practice in diagnosing and managing dementia and to describe, in theoretical terms, the proposed explanations for practice that was and was not consistent with evidence-based guidelines. Semi-structured interviews were conducted with GPs in Victoria, Australia. The Theoretical Domains Framework (TDF) guided data collection and analysis. Interviews explored the factors hindering and enabling achievement of 13 recommended behaviours. Data were analysed using content and thematic analysis. This paper presents an in-depth description of the factors influencing two behaviours, assessing co-morbid depression using a validated tool, and conducting a formal cognitive assessment using a validated scale. A total of 30 GPs were interviewed. Most GPs reported that they did not assess for co-morbid depression using a validated tool as per recommended guidance. Barriers included the belief that depression can be adequately assessed using general clinical indicators and that validated tools provide little additional information (theoretical domain of 'Beliefs about consequences'); discomfort in using validated tools ('Emotion'), possibly due to limited training and confidence ('Skills'; 'Beliefs about capabilities'); limited awareness of the need for, and forgetting to conduct, a depression assessment ('Knowledge'; 'Memory, attention and decision processes'). Most reported practising in a manner consistent with the recommendation that a formal cognitive assessment using a validated scale be undertaken. Key factors enabling this were having an awareness of the need to conduct a cognitive assessment ('Knowledge'); possessing the necessary skills and confidence ('Skills'; 'Beliefs
The Cosmology of Generalized Modified Gravity Models
Carroll, S M; Duvvuri, V; Easson, D A; Trodden, M; Turner, M S; Carroll, Sean M.; Felice, Antonio De; Duvvuri, Vikram; Easson, Damien A.; Trodden, Mark; Turner, Michael S.
2005-01-01
We consider general curvature-invariant modifications of the Einstein-Hilbert action that become important only in regions of extremely low space-time curvature. We investigate the far future evolution of the universe in such models, examining the possibilities for cosmic acceleration and other ultimate destinies. The models generically possess de Sitter space as an unstable solution and exhibit an interesting set of attractor solutions which, in some cases, provide alternatives to dark energy models.
Cosmology of generalized modified gravity models
Carroll, Sean M.; de Felice, Antonio; Duvvuri, Vikram; Easson, Damien A.; Trodden, Mark; Turner, Michael S.
2005-03-01
We consider general curvature-invariant modifications of the Einstein-Hilbert action that become important only in regions of extremely low space-time curvature. We investigate the far future evolution of the Universe in such models, examining the possibilities for cosmic acceleration and other ultimate destinies. The models generically possess de Sitter space as an unstable solution and exhibit an interesting set of attractor solutions which, in some cases, provide alternatives to dark energy models.
The generic model of General Relativity
Energy Technology Data Exchange (ETDEWEB)
Tsamparlis, Michael, E-mail: mtsampa@phys.uoa.g [Department of Physics, Section Astrophysics Astronomy Mechanics, University of Athens, University of Athens, Zografos 15783, Athens (Greece)
2009-10-01
We develop a generic spacetime model in General Relativity from which all existing model results are produced under specific assumptions, depending on the case. We classify each type of possible assumption, especially the role of observers and that of symmetries, and discuss their role in the development of a model. We apply the results in a step by step approach to the case of a Bianchi I spacetime and a string fluid.
Interacting holographic generalized cosmic Chaplygin gas model
Naji, Jalil
2014-03-01
In this paper we consider a correspondence between the holographic dark energy density and interacting generalized cosmic Chaplygin gas energy density in flat FRW universe. Then, we reconstruct the potential of the scalar field which describe the generalized cosmic Chaplygin cosmology. In the special case we obtain time-dependent energy density and study cosmological parameters. We find stability condition of this model which is depend on cosmic parameter.
General guidelines for biomedical software development [version 2; referees: 2 approved
Directory of Open Access Journals (Sweden)
Luis Bastiao Silva
2017-07-01
Full Text Available Most bioinformatics tools available today were not written by professional software developers, but by people that wanted to solve their own problems, using computational solutions and spending the minimum time and effort possible, since these were just the means to an end. Consequently, a vast number of software applications are currently available, hindering the task of identifying the utility and quality of each. At the same time, this situation has hindered regular adoption of these tools in clinical practice. Typically, they are not sufficiently developed to be used by most clinical researchers and practitioners. To address these issues, it is necessary to re-think how biomedical applications are built and adopt new strategies that ensure quality, efficiency, robustness, correctness and reusability of software components. We also need to engage end-users during the development process to ensure that applications fit their needs. In this review, we present a set of guidelines to support biomedical software development, with an explanation of how they can be implemented and what kind of open-source tools can be used for each specific topic.
Multivariate Generalized Linear Mixed Models Using R
Berridge, Damon M
2011-01-01
To provide researchers with the ability to analyze large and complex data sets using robust models, this book presents a unified framework for a broad class of models that can be applied using a dedicated R package (Sabre). The first five chapters cover the analysis of multilevel models using univariate generalized linear mixed models (GLMMs). The next few chapters extend to multivariate GLMMs and the last chapters address more specialized topics, such as parallel computing for large-scale analyses. Each chapter includes many real-world examples implemented using Sabre as well as exercises and
Modelling anisotropic fluid spheres in general relativity
Boonserm, Petarpa; Visser, Matt
2015-01-01
We argue that an arbitrary general relativistic anisotropic fluid sphere, (spherically symmetric but with transverse pressure not equal to radial pressure), can nevertheless be successfully modelled by suitable linear combinations of quite ordinary classical matter: an isotropic perfect fluid, a classical electromagnetic field, and a classical (minimally coupled) scalar field. While the most general decomposition is not unique, a preferred minimal decomposition can be constructed that is unique. We show how the classical energy conditions for the anisotropic fluid sphere can be related to energy conditions for the isotropic perfect fluid, electromagnetic field, and scalar field components of the model. Furthermore we show how this decomposition relates to the distribution of electric charge density and scalar charge density throughout the model that is used to mimic the anisotropic fluid sphere. Consequently, we can build physically reasonable matter models for almost any spherically symmetric spacetime.
Generalized multicritical one-matrix models
Ambjorn, J; Makeenko, Y
2016-01-01
We show that there exists a simple generalization of Kazakov's multicritical one-matrix model, which interpolates between the various multicritical points of the model. The associated multicritical potential takes the form of a power series with a heavy tail, leading to a cut of the potential and its derivative at the real axis, and reduces to a polynomial at Kazakov's multicritical points. From the combinatorial point of view the generalized model allows polygons of arbitrary large degrees (or vertices of arbitrary large degree, when considering the dual graphs), and it is the weight assigned to these large order polygons which brings about the interpolation between the multicritical points in the one-matrix model.
Generalized multicritical one-matrix models
Ambjørn, J.; Budd, T.; Makeenko, Y.
2016-12-01
We show that there exists a simple generalization of Kazakov's multicritical one-matrix model, which interpolates between the various multicritical points of the model. The associated multicritical potential takes the form of a power series with a heavy tail, leading to a cut of the potential and its derivative at the real axis, and reduces to a polynomial at Kazakov's multicritical points. From the combinatorial point of view the generalized model allows polygons of arbitrary large degrees (or vertices of arbitrary large degree, when considering the dual graphs), and it is the weight assigned to these large order polygons which brings about the interpolation between the multicritical points in the one-matrix model.
On generalized P\\'olya urn models
Chen, May-Ru
2011-01-01
We study an urn model introduced in the paper of Chen and Wei, where at each discrete time step $m$ balls are drawn at random from the urn containing colors white and black. Balls are added to the urn according to the inspected colors, generalizing the well known P\\'olya-Eggenberger urn model, case m=1. We provide exact expressions for the expectation and the variance of the number of white balls after n draws, and determine the structure of higher moments. Moreover, we discuss extensions to more than two colors. Furthermore, we introduce and discuss a new urn model where the sampling of the m balls is carried out in a step-by-step fashion, and also introduce a generalized Friedman's urn model.
Keene, C Dirk; Darvas, Martin; Kraemer, Brian; Liggitt, Denny; Sigurdson, Christina; Ladiges, Warren
2016-01-01
Dozens of transgenic mouse models, generally based on mutations associated with familial Alzheimer's disease (AD), have been developed, in part, for preclinical testing of candidate AD therapies. However, none of these models has successfully predicted the clinical efficacy of drugs for treating AD patients. Therefore, development of more translationally relevant AD mouse models remains a critical unmet need in the field. A concept not previously implemented in AD preclinical drug testing is the use of mouse lines that have been validated for neuropathological features of human AD. Current thinking suggests that amyloid plaque and neurofibrillary tangle deposition is an essential component for accurate modeling of AD. Therefore, the AD translational paradigm would require pathologic Aβ and tau deposition, a disease-relevant distribution of plaques and tangles, and a pattern of disease progression of Aβ and tau isoforms similar to the neuropathological features found in the brains of AD patients. Additional parameters useful to evaluate parallels between AD and animal models would include 1) cerebrospinal fluid (CSF) AD biomarker changes with reduced Aβ and increased phospho-tau/tau; 2) structural and functional neuroimaging patterns including MRI hippocampal atrophy, fluorodeoxyglucose (FDG), and amyloid/tau PET alterations in activity and/or patterns of pathologic peptide deposition and distribution; and 3) cognitive impairment with emphasis on spatial learning and memory to distinguish presymptomatic and symptomatic mice at specific ages. A validated AD mouse model for drug testing would likely show tau-related neurofibrillary degeneration following Aβ deposition and demonstrate changes in pathology, CSF analysis, and neuroimaging that mirror human AD. Development of the ideal model would revolutionize the ability to establish the translational value of AD mouse models and serve as a platform for discussions about national phenotyping guidelines and standards
Directory of Open Access Journals (Sweden)
C. Dirk Keene
2016-06-01
Full Text Available Dozens of transgenic mouse models, generally based on mutations associated with familial Alzheimer's disease (AD, have been developed, in part, for preclinical testing of candidate AD therapies. However, none of these models has successfully predicted the clinical efficacy of drugs for treating AD patients. Therefore, development of more translationally relevant AD mouse models remains a critical unmet need in the field. A concept not previously implemented in AD preclinical drug testing is the use of mouse lines that have been validated for neuropathological features of human AD. Current thinking suggests that amyloid plaque and neurofibrillary tangle deposition is an essential component for accurate modeling of AD. Therefore, the AD translational paradigm would require pathologic Aβ and tau deposition, a disease-relevant distribution of plaques and tangles, and a pattern of disease progression of Aβ and tau isoforms similar to the neuropathological features found in the brains of AD patients. Additional parameters useful to evaluate parallels between AD and animal models would include 1 cerebrospinal fluid (CSF AD biomarker changes with reduced Aβ and increased phospho-tau/tau; 2 structural and functional neuroimaging patterns including MRI hippocampal atrophy, fluorodeoxyglucose (FDG, and amyloid/tau PET alterations in activity and/or patterns of pathologic peptide deposition and distribution; and 3 cognitive impairment with emphasis on spatial learning and memory to distinguish presymptomatic and symptomatic mice at specific ages. A validated AD mouse model for drug testing would likely show tau-related neurofibrillary degeneration following Aβ deposition and demonstrate changes in pathology, CSF analysis, and neuroimaging that mirror human AD. Development of the ideal model would revolutionize the ability to establish the translational value of AD mouse models and serve as a platform for discussions about national phenotyping guidelines
Design guidelines for an umbilical cord blood stem cell therapy quality assessment model
Januszewski, Witold S.; Michałek, Krzysztof; Yagensky, Oleksandr; Wardzińska, Marta
The paper enlists the pivotal guidelines for producing an empirical umbilical cord blood stem cell therapy quality assessment model. The methodology adapted was single equation linear model with domain knowledge derived from MEDAFAR classification. The resulting model is ready for therapeutical application.
Do general practices adhere to organizational guidelines for effective cervical cancer screening?
Hermens, R P; Hak, E; Hulscher, M E; Mulder, J; Braspenning, J C; Grol, R P
1998-01-01
BACKGROUND: Well-organized cervical screening has been shown to be effective in the reduction of both morbidity and mortality from cancer of the uterine cervix. In The Netherlands, the GP plays an important role in the cervical screening. The question is whether the general practices are able to org
General Equilibrium Models: Improving the Microeconomics Classroom
Nicholson, Walter; Westhoff, Frank
2009-01-01
General equilibrium models now play important roles in many fields of economics including tax policy, environmental regulation, international trade, and economic development. The intermediate microeconomics classroom has not kept pace with these trends, however. Microeconomics textbooks primarily focus on the insights that can be drawn from the…
Directory of Open Access Journals (Sweden)
Sebastiano Piccolroaz
2016-04-01
Full Text Available Water temperature plays a primary role in controlling a wide range of physical, geochemical and ecological processes in lakes, with considerable influences on lake water quality and ecosystem functioning. Being able to reliably predict water temperature is therefore a desired goal, which stimulated the development of models of different type and complexity, ranging from simple regression-based models to more sophisticated process-based numerical models. However, both types of models suffer of some limitations: the first are not able to address some fundamental physical processes as e.g., thermal stratification, while the latter generally require a large amount of data in input, which are not always available. In this work, lake surface temperature is simulated by means of air2water, a hybrid physically-based/statistical model, which is able to provide a robust, predictive understanding of LST dynamics knowing air temperature only. This model showed performances that are comparable with those obtained by using process based models (a root mean square error on the order of 1°C, at daily scale, while retaining the simplicity and parsimony of regression-based models, thus making it a good candidate for long-term applications.The aim of the present work is to provide the reader with useful and practical guidelines for proper use of the air2water model and for critical analysis of results. Two case studies have been selected for the analysis: Lake Superior and Lake Erie. These are clear and emblematic examples of a deep and a shallow temperate lake characterized by markedly different thermal responses to external forcing, thus are ideal for making the results of the analysis the most general and comprehensive. Particular attention is paid to assessing the influence of missing data on model performance, and to evaluating when an observed time series is sufficiently informative for proper model calibration or, conversely, data are too scarce thus
van Pinxteren, B; van Vliet, S M; Wiersma, T J; Goudswaard, A N
2006-04-01
The 1999 practice guideline 'Urinary-tract infections' from the Dutch College of General Practitioners has been revised. Not only febrile urinary-tract infections are now regarded as 'complicated', but also all urinary-tract infections in men, pregnant women, children, and patients with kidney or urinary-tract disease, impaired immune response or an indwelling catheter. Under certain conditions, in women recognising the symptoms of an earlier uncomplicated urinary-tract infection, treatment may be instituted without performing supplementary urinalysis. The nitrite dipstick test and dipslide culturing are recommended for the diagnosis of urinary-tract infections; the value of the leukocyte esterase dipstick test is limited. A group-B streptococcal urinary-tract infection during pregnancy is an indication for intravenous antibiotic prophylaxis during the delivery. The recommended duration of treatment with nitrofurantoin is extended from three to five days. Both increased bacterial resistance to trimethoprim and the intention to reduce the use of fluoroquinolones in the treatment of uncomplicated urinary-tract infections were reasons for including phosphomycin in the guideline. In addition to antibiotic prophylaxis, cranberry products may be of value in the prevention of recurrent urinary-tract infections.
Choi, Jeeyae; Choi, Jeungok E
2014-01-01
To provide best recommendations at the point of care, guidelines have been implemented in computer systems. As a prerequisite, guidelines are translated into a computer-interpretable guideline format. Since there are no specific tools to translate nursing guidelines, only a few nursing guidelines are translated and implemented in computer systems. Unified modeling language (UML) is a software writing language and is known to well and accurately represent end-users' perspective, due to the expressive characteristics of the UML. In order to facilitate the development of computer systems for nurses' use, the UML was used to translate a paper-based nursing guideline, and its ease of use and the usefulness were tested through a case study of a genetic counseling guideline. The UML was found to be a useful tool to nurse informaticians and a sufficient tool to model a guideline in a computer program.
Using R In Generalized Linear Models
Directory of Open Access Journals (Sweden)
Mihaela Covrig
2015-09-01
Full Text Available This paper aims to approach the estimation of generalized linear models (GLM on the basis of the glm routine package in R. Particularly, regression models will be analyzed for those cases in which the explained variable follows a Poisson or a Negative Binomial distribution. The paper will briefly present the GLM methodology for count data, while the practical part will revolve around estimating and comparing models in which the response variable shows the number of claims in a portfolio of automobile insurance policies.
General business model patterns for Local Energy Management concepts
Directory of Open Access Journals (Sweden)
Emanuele eFacchinetti
2016-03-01
Full Text Available The transition towards a more sustainable global energy system, significantly relying on renewable energies and decentralized energy systems, requires a deep reorganization of the energy sector. The way how energy services are generated, delivered and traded is expected to be very different in the coming years. Business model innovation is recognized as a key driver for the successful implementation of the energy turnaround. This work contributes to this topic by introducing a heuristic methodology easing the identification of general business model patterns best suited for Local Energy Management concepts such as Energy Hubs. A conceptual framework characterizing the Local Energy Management business model solution space is developed. Three reference business model patterns providing orientation across the defined solution space are identified, analyzed and compared. Through a market review a number of successfully implemented innovative business models have been analyzed and allocated within the defined solution space. The outcomes of this work offer to potential stakeholders a starting point and guidelines for the business model innovation process, as well as insights for policy makers on challenges and opportunities related to Local Energy Management concepts.
String Field Equations from Generalized Sigma Model
Energy Technology Data Exchange (ETDEWEB)
Bardakci, K.; Bernardo, L.M.
1997-01-29
We propose a new approach for deriving the string field equations from a general sigma model on the world-sheet. This approach leads to an equation which combines some of the attractive features of both the renormalization group method and the covariant beta function treatment of the massless excitations. It has the advantage of being covariant under a very general set of both local and non-local transformations in the field space. We apply it to the tachyon, massless and first massive level, and show that the resulting field equations reproduce the correct spectrum of a left-right symmetric closed bosonic string.
Directory of Open Access Journals (Sweden)
Sana Zahabiyoun
2015-10-01
Full Text Available Objectives: Cases of antimicrobial resistance are increasing, partly due to inappropriate prescribing practices by dentists. The purpose of this study was to investigate the prescrib- ing practices and knowledge of dentists with regards to antibiotics. Moreover, this study aimed to determine whether the prescriptions comply with the recommended guidelines and whether clinical audit can alter the prescribing practices of dentists leading to better use of antibiotics in the dental service.Materials and Methods: A clinical audit (before/after non-controlled trial was carried out in two dental clinics in the northeast of England. Retrospective data were collected from 30 antibiotic prescriptions, analysed and compared with the recommended guide- lines. Data collected included age and gender of patients, type of prescribed antibiotics and their dosage, frequency and duration, clinical condition and reason for prescribing. The principles of appropriate prescribing based on guidance by the Faculty of General Dental Practice in the United Kingdom (UK, FGDP, were discussed with the dental clini- cians. Following this, prospective data were collected and similarly managed. Pre and post audit data were then compared. Changes were tested for significance using McNemar's test and P value<0.05 was considered statistically significant.Results: After intervention, data revealed that antibiotic prescribing practices of dentists improved, as there was an increase in the percentage of prescriptions that were in accor- dance with the FGDP (UK guidelines.Conclusion: In view of the limited data collected, this study concludes that there are inap- propriate antibiotic prescribing practices amongst general dental practitioners and that clinical audit can address this situation, leading to a more rational use of antibiotics in dental practice.
Luo, Wei; Phung, Dinh; Tran, Truyen; Gupta, Sunil; Rana, Santu; Karmakar, Chandan; Shilton, Alistair; Yearwood, John; Dimitrova, Nevenka; Ho, Tu Bao; Venkatesh, Svetha; Berk, Michael
2016-12-16
As more and more researchers are turning to big data for new opportunities of biomedical discoveries, machine learning models, as the backbone of big data analysis, are mentioned more often in biomedical journals. However, owing to the inherent complexity of machine learning methods, they are prone to misuse. Because of the flexibility in specifying machine learning models, the results are often insufficiently reported in research articles, hindering reliable assessment of model validity and consistent interpretation of model outputs. To attain a set of guidelines on the use of machine learning predictive models within clinical settings to make sure the models are correctly applied and sufficiently reported so that true discoveries can be distinguished from random coincidence. A multidisciplinary panel of machine learning experts, clinicians, and traditional statisticians were interviewed, using an iterative process in accordance with the Delphi method. The process produced a set of guidelines that consists of (1) a list of reporting items to be included in a research article and (2) a set of practical sequential steps for developing predictive models. A set of guidelines was generated to enable correct application of machine learning models and consistent reporting of model specifications and results in biomedical research. We believe that such guidelines will accelerate the adoption of big data analysis, particularly with machine learning methods, in the biomedical research community.
SCIPUFF - a generalized hazard dispersion model
Energy Technology Data Exchange (ETDEWEB)
Sykes, R.I.; Henn, D.S.; Parker, S.F.; Gabruk, R.S. [Titan Research and Technology, Princeton, NJ (United States)
1996-12-31
One of the more popular techniques for efficiently representing the dispersion process is the Gaussian puff model, which uses a collection of Lagrangian puffs with Gaussian concentration profiles. SCIPUFF (Second-order Closure Integrated Puff) is an advanced Gaussian puff model. SCIPUFF which uses second-order turbulence closure techniques to relate the dispersion rates to measurable turbulent velocity statistics, providing a wide range of applicability. In addition, the closure model provides a prediction of the statistical variance in the concentration field which can be used to estimate the uncertainty in the dispersion prediction resulting from the inherent uncertainty in the wind field. SCIPUFF has been greatly extended from a power plant plume model to describe more general source characteristics, material properties, and longer range dispersion. In addition, a Graphical User Interface has been developed to provide interactive problem definition and output display. This presentation describes the major features of the model, and presents several example calculations.
Customer-centered careflow modeling based on guidelines.
Huang, Biqing; Zhu, Peng; Wu, Cheng
2012-10-01
In contemporary society, customer-centered health care, which stresses customer participation and long-term tailored care, is inevitably becoming a trend. Compared with the hospital or physician-centered healthcare process, the customer-centered healthcare process requires more knowledge and modeling such a process is extremely complex. Thus, building a care process model for a special customer is cost prohibitive. In addition, during the execution of a care process model, the information system should have flexibility to modify the model so that it adapts to changes in the healthcare process. Therefore, supporting the process in a flexible, cost-effective way is a key challenge for information technology. To meet this challenge, first, we analyze various kinds of knowledge used in process modeling, illustrate their characteristics, and detail their roles and effects in careflow modeling. Secondly, we propose a methodology to manage a lifecycle of the healthcare process modeling, with which models could be built gradually with convenience and efficiency. In this lifecycle, different levels of process models are established based on the kinds of knowledge involved, and the diffusion strategy of these process models is designed. Thirdly, architecture and prototype of the system supporting the process modeling and its lifecycle are given. This careflow system also considers the compatibility of legacy systems and authority problems. Finally, an example is provided to demonstrate implementation of the careflow system.
Shearer, Peter; Riviello, James
2011-02-01
Generalized convulsive status epilepticus (GCSE) has a high morbidity and mortality, such that the rapid delivery of anticonvulsant therapy should be initiated within minutes of seizure onset to prevent permanent neuronal damage. GCSE is not a specific disease but is a manifestation of either a primary central nervous system (CNS) insult or a systemic disorder with secondary CNS effects. It is mandatory to look for an underlying cause. First-line therapies for seizures and status epilepticus include the use of a benzodiazepine, followed by an infusion of a phenytoin with a possible role for intravenous valproate or phenobarbital. If these first-line medications fail to terminate the GCSE, treatment includes the continuous infusion of midazolam, pentobarbital, or propofol.
DEFF Research Database (Denmark)
Riis, Allan; Jensen, Cathrine Elgaard; Bro, Flemming
2016-01-01
primary care to secondary care. The primary aim of this project was to reduce secondary care referral within 12 weeks by a multifaceted implementation strategy (MuIS). METHODS: In a cluster randomised design, 189 general practices from the North Denmark Region were invited to participate. Practices were....... In an intention-to-treat analysis, the primary and secondary outcomes pertained to the patient, and a cost-effectiveness analysis was performed from a healthcare sector perspective. Patients and the assessment of outcomes were blinded. Practices and caregivers delivering the interventions were not blinded....... RESULTS: Between January 2013 and July 2014, 60 practices were included, of which 54 practices (28 MuIS, 26 PaIS) included 1101 patients (539 MuIS, 562 PaIS). Follow-up data for the primary outcome were available on 100 % of these patients. Twenty-seven patients (5.0 %) in the MuIS group were referred...
General regression and representation model for classification.
Directory of Open Access Journals (Sweden)
Jianjun Qian
Full Text Available Recently, the regularized coding-based classification methods (e.g. SRC and CRC show a great potential for pattern classification. However, most existing coding methods assume that the representation residuals are uncorrelated. In real-world applications, this assumption does not hold. In this paper, we take account of the correlations of the representation residuals and develop a general regression and representation model (GRR for classification. GRR not only has advantages of CRC, but also takes full use of the prior information (e.g. the correlations between representation residuals and representation coefficients and the specific information (weight matrix of image pixels to enhance the classification performance. GRR uses the generalized Tikhonov regularization and K Nearest Neighbors to learn the prior information from the training data. Meanwhile, the specific information is obtained by using an iterative algorithm to update the feature (or image pixel weights of the test sample. With the proposed model as a platform, we design two classifiers: basic general regression and representation classifier (B-GRR and robust general regression and representation classifier (R-GRR. The experimental results demonstrate the performance advantages of proposed methods over state-of-the-art algorithms.
Generalized Models for Rock Joint Surface Shapes
Directory of Open Access Journals (Sweden)
Shigui Du
2014-01-01
Full Text Available Generalized models of joint surface shapes are the foundation for mechanism studies on the mechanical effects of rock joint surface shapes. Based on extensive field investigations of rock joint surface shapes, generalized models for three level shapes named macroscopic outline, surface undulating shape, and microcosmic roughness were established through statistical analyses of 20,078 rock joint surface profiles. The relative amplitude of profile curves was used as a borderline for the division of different level shapes. The study results show that the macroscopic outline has three basic features such as planar, arc-shaped, and stepped; the surface undulating shape has three basic features such as planar, undulating, and stepped; and the microcosmic roughness has two basic features such as smooth and rough.
Higher Dimensional Generalizations of the SYK Model
Berkooz, Micha; Rozali, Moshe; Simón, Joan
2016-01-01
We discuss a 1+1 dimensional generalization of the Sachdev-Ye-Kitaev model. The model contains $N$ Majorana fermions at each lattice site with a nearest-neighbour hopping term. The SYK random interaction is restricted to low momentum fermions of definite chirality within each lattice site. This gives rise to an ordinary 1+1 field theory above some energy scale and a low energy SYK-like behavior. We exhibit a class of low-pass filters which give rise to a rich variety of hyperscaling behaviour in the IR. We also discuss another set of generalizations which describes probing an SYK system with an external fermion, together with the new scaling behavior they exhibit in the IR.
Generalized Penner models to all genera
Ambjørn, Jan; Kristjansen, C F
1994-01-01
We give a complete description of the genus expansion of the one-cut solution to the generalized Penner model. The solution is presented in a form which allows us in a very straightforward manner to localize critical points and to investigate the scaling behaviour of the model in the vicinity of these points. We carry out an analysis of the critical behaviour to all genera addressing all types of multi-critical points. In certain regions of the coupling constant space the model must be defined via analytical continuation. We show in detail how this works for the Penner model. Using analytical continuation it is possible to reach the fermionic 1-matrix model. We show that the critical points of the fermionic 1-matrix model can be indexed by an integer, $m$, as it was the case for the ordinary hermitian 1-matrix model. Furthermore the $m$'th multi-critical fermionic model has to all genera the same value of $\\gamma_{str}$ as the $m$'th multi-critical hermitian model. However, the coefficients of the topological...
Parallel Computing of Ocean General Circulation Model
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
This paper discusses the parallel computing of the thirdgeneration Ocea n General Circulation Model (OGCM) from the State Key Laboratory of Numerical Mo deling for Atmospheric Science and Geophysical Fluid Dynamics(LASG),Institute of Atmosphere Physics(IAP). Meanwhile, several optimization strategies for paralle l computing of OGCM (POGCM) on Scalable Shared Memory Multiprocessor (S2MP) are presented. Using Message Passing Interface (MPI), we obtain super linear speedup on SGI Origin 2000 for parallel OGCM(POGCM) after optimization.
Modeling the pion Generalized Parton Distribution
Mezrag, C
2015-01-01
We compute the pion Generalized Parton Distribution (GPD) in a valence dressed quarks approach. We model the Mellin moments of the GPD using Ans\\"atze for Green functions inspired by the numerical solutions of the Dyson-Schwinger Equations (DSE) and the Bethe-Salpeter Equation (BSE). Then, the GPD is reconstructed from its Mellin moment using the Double Distribution (DD) formalism. The agreement with available experimental data is very good.
A General Business Model for Marine Reserves
Sala, Enric; Costello, Christopher; Dougherty, Dawn; Heal, Geoffrey; Kelleher, Kieran; Murray, Jason H.; Rosenberg, Andrew A.; Sumaila, Rashid
2013-01-01
Marine reserves are an effective tool for protecting biodiversity locally, with potential economic benefits including enhancement of local fisheries, increased tourism, and maintenance of ecosystem services. However, fishing communities often fear short-term income losses associated with closures, and thus may oppose marine reserves. Here we review empirical data and develop bioeconomic models to show that the value of marine reserves (enhanced adjacent fishing + tourism) may often exceed the pre-reserve value, and that economic benefits can offset the costs in as little as five years. These results suggest the need for a new business model for creating and managing reserves, which could pay for themselves and turn a profit for stakeholder groups. Our model could be expanded to include ecosystem services and other benefits, and it provides a general framework to estimate costs and benefits of reserves and to develop such business models. PMID:23573192
A general business model for marine reserves.
Directory of Open Access Journals (Sweden)
Enric Sala
Full Text Available Marine reserves are an effective tool for protecting biodiversity locally, with potential economic benefits including enhancement of local fisheries, increased tourism, and maintenance of ecosystem services. However, fishing communities often fear short-term income losses associated with closures, and thus may oppose marine reserves. Here we review empirical data and develop bioeconomic models to show that the value of marine reserves (enhanced adjacent fishing + tourism may often exceed the pre-reserve value, and that economic benefits can offset the costs in as little as five years. These results suggest the need for a new business model for creating and managing reserves, which could pay for themselves and turn a profit for stakeholder groups. Our model could be expanded to include ecosystem services and other benefits, and it provides a general framework to estimate costs and benefits of reserves and to develop such business models.
A general business model for marine reserves.
Sala, Enric; Costello, Christopher; Dougherty, Dawn; Heal, Geoffrey; Kelleher, Kieran; Murray, Jason H; Rosenberg, Andrew A; Sumaila, Rashid
2013-01-01
Marine reserves are an effective tool for protecting biodiversity locally, with potential economic benefits including enhancement of local fisheries, increased tourism, and maintenance of ecosystem services. However, fishing communities often fear short-term income losses associated with closures, and thus may oppose marine reserves. Here we review empirical data and develop bioeconomic models to show that the value of marine reserves (enhanced adjacent fishing + tourism) may often exceed the pre-reserve value, and that economic benefits can offset the costs in as little as five years. These results suggest the need for a new business model for creating and managing reserves, which could pay for themselves and turn a profit for stakeholder groups. Our model could be expanded to include ecosystem services and other benefits, and it provides a general framework to estimate costs and benefits of reserves and to develop such business models.
Directory of Open Access Journals (Sweden)
Shaw Lindsey
2006-11-01
Full Text Available Abstract Background Few patients with lower bowel symptoms who consult their general practitioner need a specialist opinion. However data from referred patients suggest that those who are referred would benefit from detailed assessment before referral. Methods A cluster randomised factorial trial. 44 general practices in North Trent, UK. Practices were offered either an electronic interactive referral pro forma, an educational outreach visit by a local colorectal surgeon, both or neither. The main outcome measure was the proportion of cases with severe diverticular disease, cancer or precancerous lesions and inflammatory bowel disease in those referred by each group. A secondary outcome was a referral letter quality score. Semi-structured interviews were conducted to identify key themes relating to the use of the software Results From 150 invitations, 44 practices were recruited with a total list size of 265,707. There were 716 consecutive referrals recorded over a six-month period, for which a diagnosis was available for 514. In the combined software arms 14% (37/261 had significant pathology, compared with 19% (49/253 in the non-software arms, relative risk 0.73 (95% CI: 0.46 to 1.15. In the combined educational outreach arms 15% (38/258 had significant pathology compared with 19% (48/256 in the non-educational arms, relative risk 0.79 (95% CI: 0.50 to 1.24. Pro forma practices documented better assessment of patients at referral. Conclusion There was a lack of evidence that either intervention increased the proportion of patients with organic pathology among those referred. The interactive software did improve the amount of information relayed in referral letters although we were unable to confirm if this made a significant difference to patients or their health care providers. The potential value of either intervention may have been diminished by their limited uptake within the context of a cluster randomised clinical trial. A number of
A proposed general model of information behaviour.
Directory of Open Access Journals (Sweden)
2003-01-01
Full Text Available Presents a critical description of Wilson's (1996 global model of information behaviour and proposes major modification on the basis of research into information behaviour of managers, conducted in Poland. The theoretical analysis and research results suggest that Wilson's model has certain imperfections, both in its conceptual content, and in graphical presentation. The model, for example, cannot be used to describe managers' information behaviour, since managers basically are not the end users of external from organization or computerized information services, and they acquire information mainly through various intermediaries. Therefore, the model cannot be considered as a general model, applicable to every category of information users. The proposed new model encompasses the main concepts of Wilson's model, such as: person-in-context, three categories of intervening variables (individual, social and environmental, activating mechanisms, cyclic character of information behaviours, and the adoption of a multidisciplinary approach to explain them. However, the new model introduces several changes. They include: 1. identification of 'context' with the intervening variables; 2. immersion of the chain of information behaviour in the 'context', to indicate that the context variables influence behaviour at all stages of the process (identification of needs, looking for information, processing and using it; 3. stress is put on the fact that the activating mechanisms also can occur at all stages of the information acquisition process; 4. introduction of two basic strategies of looking for information: personally and/or using various intermediaries.
Links, P.; Horsman, Peter; Kühnel, Karsten; Priddy, M.; Reijnhoudt, Linda; Merenmies, Mark
2013-01-01
The Guidelines follow the conceptual metadata model (deliverable 17.2). They include guidelines for description of collection-holding institutions, document collections, organisations, personalities, events, camps and ghettos. As much as possible the guidelines comply with the descriptive standards
Generalized model of brushless dc generator
Vadher, V. V.; Kettleborough, J. Gordon; Smith, I. R.; Gerges, Wahid R.
1989-07-01
A generalized model is described for a brushless dc machine consisting of a multiphase synchronous machine with a full-wave bridge rectifier connected to its output terminals. The state-variable equations for the machine are suitable for numerical integration on a digital computer, and are assembled in a form which permits investigations to be made on the effects of different numbers of armature phase windings and different winding connections. The model has been used in both steady-state and transient studies on a number of generating units, with the detailed information which is provided being beneficial to design engineers. Comparisons presented between predicted and measured results illustrate the validity of the model and the mathematical techniques adopted, and confirm that accurate information on the performance of a brushless generator may be obtained prior to manufacture.
Gravitational Interactions in a General Multibrane Model
Bloomfield, Jolyon K
2010-01-01
The gravitational interactions of the four-dimensional effective theory describing a general N-brane model in five dimensions without radion stabilization are analyzed. The parameter space is constrained by requiring that there be no ghost modes in the theory, and that the Eddington parameterized post-Newtonian parameter gamma be consistent with observations. We show that we must reside on the brane on which the warp factor is maximized. The resultant theory contains N-1 radion modes in a nonlinear sigma model, with the target space being a subset of hyperbolic space. Imposing observational constraints on the relative strengths of gravitational interactions of dark and visible matter shows that at least 99.8% of the dark matter must live on our brane in this model.
A distributed, collaborative, structuring model for a clinical-guideline digital-library.
Shahar, Yuval; Shalom, Erez; Mayaffit, Alon; Young, Ohad; Galperin, Maya; Martins, Susana; Goldstein, Mary
2003-01-01
The Digital Electronic Guideline Library (DeGeL) is a Web-based framework and a set of distributed tools that facilitate gradual conversion of clinical guidelines from free text, through semi-structured text, to a fully structured, executable representation. Thus, guidelines exist in a hybrid, multiple-format representation The three formats support increasingly sophisticated computational tasks. The tools perform semantic markup, classification, search, and browsing, and support computational modules that we are developing, for run-time application and retrospective quality assessment. We describe the DeGeL architecture and its collaborative-authoring authorization model, which is based on (1) multiple medical-specialty authoring groups, each including a group manager who controls group authorizations, and (2) a hierarchical authorization model based on the different functions involved in the hybrid guideline-specification process. We have implemented the core modules of the DeGeL architecture and demonstrated distributed markup and retrieval using the knowledge roles of two guidelines ontologies (Asbru and GEM). We are currently evaluating several of the DeGeL tools.
A generalized additive regression model for survival times
DEFF Research Database (Denmark)
Scheike, Thomas H.
2001-01-01
Additive Aalen model; counting process; disability model; illness-death model; generalized additive models; multiple time-scales; non-parametric estimation; survival data; varying-coefficient models......Additive Aalen model; counting process; disability model; illness-death model; generalized additive models; multiple time-scales; non-parametric estimation; survival data; varying-coefficient models...
A generalized additive regression model for survival times
DEFF Research Database (Denmark)
Scheike, Thomas H.
2001-01-01
Additive Aalen model; counting process; disability model; illness-death model; generalized additive models; multiple time-scales; non-parametric estimation; survival data; varying-coefficient models......Additive Aalen model; counting process; disability model; illness-death model; generalized additive models; multiple time-scales; non-parametric estimation; survival data; varying-coefficient models...
ASGW Best Practice Guidelines: An Evaluation of the Duluth Model
Pender, Rebecca L.
2012-01-01
Group work is often a preferred method of intervention when treating perpetrators of domestic violence. The Domestic Abuse Intervention Project Duluth Model is one of the most common treatment programs for men who have perpetrated domestic violence (Pence & Paymar, 2003), yet the intervention remains highly debated within the literature. This…
Standards and Guidelines for Numerical Models for Tsunami Hazard Mitigation
Titov, V.; Gonzalez, F.; Kanoglu, U.; Yalciner, A.; Synolakis, C. E.
2006-12-01
An increased number of nations around the workd need to develop tsunami mitigation plans which invariably involve inundation maps for warning guidance and evacuation planning. There is the risk that inundation maps may be produced with older or untested methodology, as there are currently no standards for modeling tools. In the aftermath of the 2004 megatsunami, some models were used to model inundation for Cascadia events with results much larger than sediment records and existing state-of-the-art studies suggest leading to confusion among emergency management. Incorrectly assessing tsunami impact is hazardous, as recent events in 2006 in Tonga, Kythira, Greece and Central Java have suggested (Synolakis and Bernard, 2006). To calculate tsunami currents, forces and runup on coastal structures, and inundation of coastlines one must calculate the evolution of the tsunami wave from the deep ocean to its target site, numerically. No matter what the numerical model, validation (the process of ensuring that the model solves the parent equations of motion accurately) and verification (the process of ensuring that the model used represents geophysical reality appropriately) both are an essential. Validation ensures that the model performs well in a wide range of circumstances and is accomplished through comparison with analytical solutions. Verification ensures that the computational code performs well over a range of geophysical problems. A few analytic solutions have been validated themselves with laboratory data. Even fewer existing numerical models have been both validated with the analytical solutions and verified with both laboratory measurements and field measurements, thus establishing a gold standard for numerical codes for inundation mapping. While there is in principle no absolute certainty that a numerical code that has performed well in all the benchmark tests will also produce correct inundation predictions with any given source motions, validated codes
Modelling debris flows down general channels
Directory of Open Access Journals (Sweden)
S. P. Pudasaini
2005-01-01
Full Text Available This paper is an extension of the single-phase cohesionless dry granular avalanche model over curved and twisted channels proposed by Pudasaini and Hutter (2003. It is a generalisation of the Savage and Hutter (1989, 1991 equations based on simple channel topography to a two-phase fluid-solid mixture of debris material. Important terms emerging from the correct treatment of the kinematic and dynamic boundary condition, and the variable basal topography are systematically taken into account. For vanishing fluid contribution and torsion-free channel topography our new model equations exactly degenerate to the previous Savage-Hutter model equations while such a degeneration was not possible by the Iverson and Denlinger (2001 model, which, in fact, also aimed to extend the Savage and Hutter model. The model equations of this paper have been rigorously derived; they include the effects of the curvature and torsion of the topography, generally for arbitrarily curved and twisted channels of variable channel width. The equations are put into a standard conservative form of partial differential equations. From these one can easily infer the importance and influence of the pore-fluid-pressure distribution in debris flow dynamics. The solid-phase is modelled by applying a Coulomb dry friction law whereas the fluid phase is assumed to be an incompressible Newtonian fluid. Input parameters of the equations are the internal and bed friction angles of the solid particles, the viscosity and volume fraction of the fluid, the total mixture density and the pore pressure distribution of the fluid at the bed. Given the bed topography and initial geometry and the initial velocity profile of the debris mixture, the model equations are able to describe the dynamics of the depth profile and bed parallel depth-averaged velocity distribution from the initial position to the final deposit. A shock capturing, total variation diminishing numerical scheme is implemented to
A generalized model for compact stars
Energy Technology Data Exchange (ETDEWEB)
Aziz, Abdul [Bodai High School (H.S.), Department of Physics, Kolkata, West Bengal (India); Ray, Saibal [Government College of Engineering and Ceramic Technology, Department of Physics, Kolkata, West Bengal (India); Rahaman, Farook [Jadavpur University, Department of Mathematics, Kolkata, West Bengal (India)
2016-05-15
By virtue of the maximum entropy principle, we get an Euler-Lagrange equation which is a highly nonlinear differential equation containing the mass function and its derivatives. Solving the equation by a homotopy perturbation method we derive a generalized expression for the mass which is a polynomial function of the radial distance. Using the mass function we find a partially stable configuration and its characteristics. We show that different physical features of the known compact stars, viz. Her X-1, RX J 1856-37, SAX J (SS1), SAX J (SS2), and PSR J 1614-2230, can be explained by the present model. (orig.)
Testing Parametric versus Semiparametric Modelling in Generalized Linear Models
Härdle, W.K.; Mammen, E.; Müller, M.D.
1996-01-01
We consider a generalized partially linear model E(Y|X,T) = G{X'b + m(T)} where G is a known function, b is an unknown parameter vector, and m is an unknown function.The paper introduces a test statistic which allows to decide between a parametric and a semiparametric model: (i) m is linear, i.e. m(
The General Linear Model as Structural Equation Modeling
Graham, James M.
2008-01-01
Statistical procedures based on the general linear model (GLM) share much in common with one another, both conceptually and practically. The use of structural equation modeling path diagrams as tools for teaching the GLM as a body of connected statistical procedures is presented. A heuristic data set is used to demonstrate a variety of univariate…
Snow hydrology in a general circulation model
Marshall, Susan; Roads, John O.; Glatzmaier, Gary
1994-01-01
A snow hydrology has been implemented in an atmospheric general circulation model (GCM). The snow hydrology consists of parameterizations of snowfall and snow cover fraction, a prognostic calculation of snow temperature, and a model of the snow mass and hydrologic budgets. Previously, only snow albedo had been included by a specified snow line. A 3-year GCM simulation with this now more complete surface hydrology is compared to a previous GCM control run with the specified snow line, as well as with observations. In particular, the authors discuss comparisons of the atmospheric and surface hydrologic budgets and the surface energy budget for U.S. and Canadian areas. The new snow hydrology changes the annual cycle of the surface moisture and energy budgets in the model. There is a noticeable shift in the runoff maximum from winter in the control run to spring in the snow hydrology run. A substantial amount of GCM winter precipitation is now stored in the seasonal snowpack. Snow cover also acts as an important insulating layer between the atmosphere and the ground. Wintertime soil temperatures are much higher in the snow hydrology experiment than in the control experiment. Seasonal snow cover is important for dampening large fluctuations in GCM continental skin temperature during the Northern Hemisphere winter. Snow depths and snow extent show good agreement with observations over North America. The geographic distribution of maximum depths is not as well simulated by the model due, in part, to the coarse resolution of the model. The patterns of runoff are qualitatively and quantitatively similar to observed patterns of streamflow averaged over the continental United States. The seasonal cycles of precipitation and evaporation are also reasonably well simulated by the model, although their magnitudes are larger than is observed. This is due, in part, to a cold bias in this model, which results in a dry model atmosphere and enhances the hydrologic cycle everywhere.
Gaum, Wilma G.; van Rooyen, Hugo G.
1997-01-01
Describes research to develop curriculum guidelines for a distance education course in urban agriculture. The course, designed to train the teacher, is based on an eclectic curriculum design model. The course is aimed at the socioeconomic empowerment of urban farmers and is based on sustainable ecological-agricultural principles, an…
Emergency Medical Science (T-139). Curriculum Models, Guidelines, and Outcome-Competencies.
Lovin, Barbara Keelor
Developed for use by curriculum planners in Emergency Medical Science (EMS) programs throughout the North Carolina Community College System (NCCCS), and by evaluators in their reviews of existing programs, this manual provides a model set of guidelines for the education and training of the Emergency Medical Technician-Paramedic (EMT-P) in…
The epistemological status of general circulation models
Loehle, Craig
2017-05-01
Forecasts of both likely anthropogenic effects on climate and consequent effects on nature and society are based on large, complex software tools called general circulation models (GCMs). Forecasts generated by GCMs have been used extensively in policy decisions related to climate change. However, the relation between underlying physical theories and results produced by GCMs is unclear. In the case of GCMs, many discretizations and approximations are made, and simulating Earth system processes is far from simple and currently leads to some results with unknown energy balance implications. Statistical testing of GCM forecasts for degree of agreement with data would facilitate assessment of fitness for use. If model results need to be put on an anomaly basis due to model bias, then both visual and quantitative measures of model fit depend strongly on the reference period used for normalization, making testing problematic. Epistemology is here applied to problems of statistical inference during testing, the relationship between the underlying physics and the models, the epistemic meaning of ensemble statistics, problems of spatial and temporal scale, the existence or not of an unforced null for climate fluctuations, the meaning of existing uncertainty estimates, and other issues. Rigorous reasoning entails carefully quantifying levels of uncertainty.
General linear matrix model, Minkowski spacetime and the Standard Model
Belyea, Chris
2010-01-01
The Hermitian matrix model with general linear symmetry is argued to decouple into a finite unitary matrix model that contains metastable multidimensional lattice configurations and a fermion determinant. The simplest metastable state is a Hermitian Weyl kinetic operator of either handedness on a 3+1 D lattice with general nonlocal interactions. The Hermiticity produces 16 effective Weyl fermions by species doubling, 8 left- and 8 right-handed. These are identified with a Standard Model generation. Only local non-anomalous gauge fields within the soup of general fluctuations can survive at long distances, and the degrees of freedom for gauge fields of an $SU(8)_L X SU(8)_R$ GUT are present. Standard Model gauge symmetries associate with particular species symmetries, for example change of QCD color associates with permutation of doubling status amongst space directions. Vierbein gravity is probably also generated. While fundamental Higgs fields are not possible, low fermion current masses can arise from chira...
Guidelines for effective radiation transport for cable SGEMP modeling
Energy Technology Data Exchange (ETDEWEB)
Drumm, Clifton Russell [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Fan, Wesley C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Turner, C. David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2014-07-01
This report describes experiences gained in performing radiation transport computations with the SCEPTRE radiation transport code for System Generated ElectroMagnetic Pulse (SGEMP) applications. SCEPTRE is a complex code requiring a fairly sophisticated user to run the code effectively, so this report provides guidance for analysts interested in performing these types of calculations. One challenge in modeling coupled photon/electron transport for SGEMP is to provide a spatial mesh that is sufficiently resolved to accurately model surface charge emission and charge deposition near material interfaces. The method that has been most commonly used to date to compute cable SGEMP typically requires a sub-micron mesh size near material interfaces, which may be difficult for meshing software to provide for complex geometries. We present here an alternative method for computing cable SGEMP that appears to substantially relax this requirement. The report also investigates the effect of refining the energy mesh and increasing the order of the angular approximation to provide some guidance on determining reasonable parameters for the energy/angular approximation needed for x-ray environments. Conclusions for γ-ray environments may be quite different and will be treated in a subsequent report. In the course of the energy-mesh refinement studies, a bug in the cross-section generation software was discovered that may cause underprediction of the result by as much as an order of magnitude for the test problem studied here, when the electron energy group widths are much smaller than those for the photons. Results will be presented and compared using cross sections generated before and after the fix. We also describe adjoint modeling, which provides sensitivity of the total charge drive to the source energy and angle of incidence, which is quite useful for comparing the effect of changing the source environment and for determining most stressing angle of incidence and source
Guidelines for effective radiation transport for cable SGEMP modeling
Energy Technology Data Exchange (ETDEWEB)
Drumm, Clifton Russell [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Fan, Wesley C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Turner, C. David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2014-07-01
This report describes experiences gained in performing radiation transport computations with the SCEPTRE radiation transport code for System Generated ElectroMagnetic Pulse (SGEMP) applications. SCEPTRE is a complex code requiring a fairly sophisticated user to run the code effectively, so this report provides guidance for analysts interested in performing these types of calculations. One challenge in modeling coupled photon/electron transport for SGEMP is to provide a spatial mesh that is sufficiently resolved to accurately model surface charge emission and charge deposition near material interfaces. The method that has been most commonly used to date to compute cable SGEMP typically requires a sub-micron mesh size near material interfaces, which may be difficult for meshing software to provide for complex geometries. We present here an alternative method for computing cable SGEMP that appears to substantially relax this requirement. The report also investigates the effect of refining the energy mesh and increasing the order of the angular approximation to provide some guidance on determining reasonable parameters for the energy/angular approximation needed for x-ray environments. Conclusions for -ray environments may be quite different and will be treated in a subsequent report. In the course of the energy-mesh refinement studies, a bug in the cross-section generation software was discovered that may cause under prediction of the result by as much as an order of magnitude for the test problem studied here, when the electron energy group widths are much smaller than those for the photons. Results will be presented and compared using cross sections generated before and after the fix. We also describe adjoint modeling, which provides sensitivity of the total charge drive to the source energy and angle of incidence, which is quite useful for comparing the effect of changing the source environment and for determining most stressing angle of incidence and
Directory of Open Access Journals (Sweden)
Noe eGarin
2015-07-01
Full Text Available BACKGROUNDAdherence problems, interactions and higher rate of risk activities have been observed in HIV individuals using recreational drugs. Our aim was to describe recreational drug use in both HIV individuals and general population in Europe, and to assess at what extent HIV guidelines address this issue.METHODSData on recreational drug use across Europe were obtained from the European Monitoring Centre for Drugs and Drug Addiction for the general population, and through Pubmed search. for HIV patients. We assessed the incorporation of recreational drug issues in HIV treatment guidelines for the following topics: a recreational drugs; b adherence to antiretrovirals; c interactions; d transmission risk. Guidelines included: World Health Organization; European Aids Clinical Society; U.S. Department of Health and Human Services; International Antiviral Society-USA; and seven European national guidelines.RESULTS29 countries reported recreational drug use in general population. The highest prevalences were observed for Cannabis (i.e. 8-10% in Spain, France and Czech Republic followed by cocaine, amphetamines and ecstasy. The 13 studies selected in the systematic review showed a great variability in recreational drug use on the HIV population. Apart from classical recreational drugs, we found a relevant use of new drugs including sexual experience enhancers. Polydrug consumption was about 50% in some studies. Most guidelines included general information about recreational drugs, showing great variability on the inclusion of the evaluated topics. We found more specific, evidence-based recommendations on interactions, followed by medication adherence and transmission risk.CONCLUSIONSAvailable data on the people living with HIV suggest a higher use of recreational drugs than in the general population, which is already relevant. However, recreational drug issues should be included or addressed more thoroughly in most guidelines.
Garin, Noe; Velasco, Cesar; De Pourcq, Jan T.; Lopez, Belen; Gutierrez, Maria del Mar; Haro, Josep M.; Feliu, Anna; Mangues, Maria A.; Trilla, Antoni
2015-01-01
Background: Adherence problems, interactions and higher rate of risk activities have been observed in HIV individuals using recreational drugs. Our aim was to describe recreational drug use in both HIV individuals and general population in Europe, and to assess at what extent HIV guidelines address this issue. Methods: Data on recreational drug use across Europe were obtained from the European Monitoring Centre for Drugs and Drug Addiction for the general population, and through Pubmed search. for HIV patients. We assessed the incorporation of recreational drug issues in HIV treatment guidelines for the following topics: (a) recreational drugs; (b) adherence to antiretrovirals; (c) interactions; (d) transmission risk. Guidelines included: World Health Organization; European Aids Clinical Society; U.S. Department of Health and Human Services; International Antiviral Society-USA; and seven European national guidelines. Results: 29 countries reported recreational drug use in general population. The highest prevalences were observed for Cannabis (i.e., 8–10% in Spain, France, and Czech Republic) followed by cocaine, amphetamines and ecstasy. The 13 studies selected in the systematic review showed a great variability in recreational drug use on the HIV population. Apart from classical recreational drugs, we found a relevant use of new drugs including sexual experience enhancers. Polydrug consumption was about 50% in some studies. Most guidelines included general information about recreational drugs, showing great variability on the inclusion of the evaluated topics. We found more specific, evidence-based recommendations on interactions, followed by medication adherence and transmission risk. Conclusions: Available data on the people living with HIV suggest a higher use of recreational drugs than in the general population, which is already relevant. However, recreational drug issues should be included or addressed more thoroughly in most guidelines. PMID:26236288
An Informational Model as a Guideline to Design Sustainable Green SLA (GSLA
Directory of Open Access Journals (Sweden)
Iqbal Ahmed
2016-04-01
Full Text Available Recently, Service Level Agreement (SLA and green SLA (GSLA becomes very important for both the service providers/vendors and as well as for the users/customers. There are many ways to inform users/customers about various services with its inherent execution functionalities and even non-functional/Quality of Service (QoS aspects through SLAs. However, these basic SLAs actually do not cover eco-efficient green issues or IT ethics issues for sustainable development. That is why green SLA (GSLA already came into play for achieving sustainability in the industry. Nevertheless, the current practice of GSLA in the industry do not respect the sustainability at all. GSLA defined as a formal agreement incorporating all the traditional commitments respecting some green computing parameters such as carbon footprint, energy consumption etc. Therefore, there are still gaps for achieving sustainability through existing GSLA. To reach the goal of achieving sustainability and getting more customers, many IT (Information Technology and ICT (Information and Communication Technology business are looking for a real GSLA which would meet the ecological, economical and ethical aspects (3Es of sustainability. This research discovers the missing parameters and introduce new parameters under sustainability hoods. In addition, it defines GSLA of sustainability with new green performance indicators and their measurable units. It also discovers the management complexity of proposed new GSLA through designing a general informational model and identifies various new entities and their effects with other entities under three pillars of sustainability. The ICT engineer could use the informational model as a guideline to design a sustainable GSLA for the industry. Therefore, the proposed model could help different service providers/vendors to define their future business strategies for the upcoming sustainable society.
Multipath diffusion: A general numerical model
Lee, J. K. W.; Aldama, A. A.
1992-06-01
The effect of high-diffusivity pathways on bulk diffusion of a solute in a material has been modeled previously for simple geometries such as those in tracer diffusion experiments, but not for the geometries and boundary conditions appropriate for experiments involving bulk exchange. Using a coupled system of equations for simultaneous diffusion of a solute through two families of diffusion pathways with differing diffusivities, a general 1-D finite difference model written in FORTRAN has been developed which can be used to examine the effect of high-diffusivity paths on partial and total concentration profiles within a homogeneous isotropic sphere, infinite cylinder, and infinite slab. The partial differential equations are discretized using the θ-method/central-difference scheme, and an iterative procedure analogous to the Gauss-Seidel method is employed to solve the two systems of coupled equations. Using Fourier convergence analysis, the procedure is shown to be unconditionally convergent. Computer simulations demonstrate that a multipath diffusion mechanism can enhance significantly the bulk diffusivity of a diffusing solute species through a material. The amount of solute escaping from a material is dependent strongly on the exchange coefficients, which govern the transfer of solute from the crystal lattice to the high-diffusivity paths and vice versa. In addition, the exchange coefficients ( ϰ1, and ϰ2) seem to control not only the amount of solute that is lost, but also the shape of the concentration profile. If | K1| < | K2|, concentration profiles generally are non-Fickian in shape, typically having shallow concentration gradients near the center (radius r = 0) and steep gradients towards the outer boundary of the material ( r = R). When | K1| ⩾ | K2| a concentration profile is generated which resembles a Fickian (volume) diffusion profile with an apparent bulk diffusivity between that of the crystal lattice and that of the high-diffusivity pathways
O'Reilly-de Brun, M.; Macfarlane, A.; Brun, T. de; Okonkwo, E.; Bonsenge Bokanga, J.S.; Almeida Silva, M. de; Ogbebor, F.; Mierzejewska, A.; Nnadi, L.; Muijsenbergh, M.E.T.C. van den; Weel-Baumgarten, E.M. van; Weel, C. van
2015-01-01
OBJECTIVE: The aim of this research was to involve migrants and other key stakeholders in a participatory dialogue to develop a guideline for enhancing communication in cross-cultural general practice consultations. In this paper, we focus on findings about the use of formal versus informal
Energy Technology Data Exchange (ETDEWEB)
Halsnaes, K.; Painuly, J.P.; Turkson, J.; Meyer, H.J.; Markandya, A.
1999-09-01
This document is a summary version of the methodological guidelines for climate change mitigation assessment developed as part of the Global Environment Facility (GEF) project Economics of Greenhouse Gas Limitations; Methodological Guidelines. The objectives of this project have been to develop a methodology, an implementing framework and a reporting system which countries can use in the construction of national climate change mitigation policies and in meeting their future reporting obligations under the FCCC. The methodological framework developed in the Methodological Guidelines covers key economic concepts, scenario building, modelling tools and common assumptions. It was used by several country studies included in the project. (au) 13 refs.
A Simple General Model of Evolutionary Dynamics
Thurner, Stefan
Evolution is a process in which some variations that emerge within a population (of, e.g., biological species or industrial goods) get selected, survive, and proliferate, whereas others vanish. Survival probability, proliferation, or production rates are associated with the "fitness" of a particular variation. We argue that the notion of fitness is an a posteriori concept in the sense that one can assign higher fitness to species or goods that survive but one can generally not derive or predict fitness per se. Whereas proliferation rates can be measured, fitness landscapes, that is, the inter-dependence of proliferation rates, cannot. For this reason we think that in a physical theory of evolution such notions should be avoided. Here we review a recent quantitative formulation of evolutionary dynamics that provides a framework for the co-evolution of species and their fitness landscapes (Thurner et al., 2010, Physica A 389, 747; Thurner et al., 2010, New J. Phys. 12, 075029; Klimek et al., 2009, Phys. Rev. E 82, 011901 (2010). The corresponding model leads to a generic evolutionary dynamics characterized by phases of relative stability in terms of diversity, followed by phases of massive restructuring. These dynamical modes can be interpreted as punctuated equilibria in biology, or Schumpeterian business cycles (Schumpeter, 1939, Business Cycles, McGraw-Hill, London) in economics. We show that phase transitions that separate phases of high and low diversity can be approximated surprisingly well by mean-field methods. We demonstrate that the mathematical framework is suited to understand systemic properties of evolutionary systems, such as their proneness to collapse, or their potential for diversification. The framework suggests that evolutionary processes are naturally linked to self-organized criticality and to properties of production matrices, such as their eigenvalue spectra. Even though the model is phrased in general terms it is also practical in the sense
Functional methods in the generalized Dicke model
Energy Technology Data Exchange (ETDEWEB)
Alcalde, M. Aparicio; Lemos, A.L.L. de; Svaiter, N.F. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)]. E-mails: aparicio@cbpf.br; aluis@cbpf.br; nfuxsvai@cbpf.br
2007-07-01
The Dicke model describes an ensemble of N identical two-level atoms (qubits) coupled to a single quantized mode of a bosonic field. The fermion Dicke model should be obtained by changing the atomic pseudo-spin operators by a linear combination of Fermi operators. The generalized fermion Dicke model is defined introducing different coupling constants between the single mode of the bosonic field and the reservoir, g{sub 1} and g{sub 2} for rotating and counter-rotating terms respectively. In the limit N -> {infinity}, the thermodynamic of the fermion Dicke model can be analyzed using the path integral approach with functional method. The system exhibits a second order phase transition from normal to superradiance at some critical temperature with the presence of a condensate. We evaluate the critical transition temperature and present the spectrum of the collective bosonic excitations for the general case (g{sub 1} {ne} 0 and g{sub 2} {ne} 0). There is quantum critical behavior when the coupling constants g{sub 1} and g{sub 2} satisfy g{sub 1} + g{sub 2}=({omega}{sub 0} {omega}){sup 1/2}, where {omega}{sub 0} is the frequency of the mode of the field and {omega} is the energy gap between energy eigenstates of the qubits. Two particular situations are analyzed. First, we present the spectrum of the collective bosonic excitations, in the case g{sub 1} {ne} 0 and g{sub 2} {ne} 0, recovering the well known results. Second, the case g{sub 1} {ne} 0 and g{sub 2} {ne} 0 is studied. In this last case, it is possible to have a super radiant phase when only virtual processes are introduced in the interaction Hamiltonian. Here also appears a quantum phase transition at the critical coupling g{sub 2} ({omega}{sub 0} {omega}){sup 1/2}, and for larger values for the critical coupling, the system enter in this super radiant phase with a Goldstone mode. (author)
Garin, Noe; Velasco Muñoz, César; Pourcq, Jan T. De; Lopez, Belen; Gutiérrez, Maria del Mar; Haro Abad, Josep Maria; Feliu, Anna; Mangues, Maria A.; Trilla García, Antoni
2015-01-01
BACKGROUND: Adherence problems, interactions and higher rate of risk activities have been observed in HIV individuals using recreational drugs. Our aim was to describe recreational drug use in both HIV individuals and general population in Europe, and to assess at what extent HIV guidelines address this issue. METHODS: Data on recreational drug use across Europe were obtained from the European Monitoring Centre for Drugs and Drug Addiction for the general population, and through Pubmed search...
Noe eGarin; Cesar eVelasco; Pourcq, Jan T. De; Belen eLopez; Maria del Mar eGutierrez; Josep Maria Haro; Anna eFeliu; Maria Antonia Mangues; Antoni eTrilla
2015-01-01
BACKGROUNDAdherence problems, interactions and higher rate of risk activities have been observed in HIV individuals using recreational drugs. Our aim was to describe recreational drug use in both HIV individuals and general population in Europe, and to assess at what extent HIV guidelines address this issue.METHODSData on recreational drug use across Europe were obtained from the European Monitoring Centre for Drugs and Drug Addiction for the general population, and through Pubmed search. for...
Garin, Noe; Velasco, Cesar; Pourcq, Jan T. De; Lopez, Belen; Gutierrez, Maria del Mar; Haro, Josep M.; Feliu, Anna; Mangues, Maria A.; Trilla, Antoni
2015-01-01
Background: Adherence problems, interactions and higher rate of risk activities have been observed in HIV individuals using recreational drugs. Our aim was to describe recreational drug use in both HIV individuals and general population in Europe, and to assess at what extent HIV guidelines address this issue. Methods: Data on recreational drug use across Europe were obtained from the European Monitoring Centre for Drugs and Drug Addiction for the general population, and through Pubmed sea...
Directory of Open Access Journals (Sweden)
Hetlevik Irene
2009-10-01
Full Text Available Abstract Background Previous studies indicate that clinical guidelines using combined risk evaluation for cardiovascular diseases (CVD may overestimate risk. The aim of this study was to model and discuss implementation of the current (2007 hypertension guidelines in a general Norwegian population. Methods Implementation of the current European Guidelines for the Management of Arterial Hypertension was modelled on data from a cross-sectional, representative Norwegian population study (The Nord-Trøndelag Health Study 1995-97, comprising 65,028 adults, aged 20-89, of whom 51,066 (79% were eligible for modelling. Results Among individuals with blood pressure ≥120/80 mmHg, 93% (74% of the total, adult population would need regular clinical attention and/or drug treatment, based on their total CVD risk profile. This translates into 296,624 follow-up visits/100,000 adults/year. In the Norwegian healthcare environment, 99 general practitioner (GP positions would be required in the study region for this task alone. The number of GPs currently serving the adult population in the study area is 87 per 100,000 adults. Conclusion The potential workload associated with the European hypertension guidelines could destabilise the healthcare system in Norway, one of the world's most long- and healthy-living nations, by international comparison. Large-scale, preventive medical enterprises can hardly be regarded as scientifically sound and ethically justifiable, unless issues of practical feasibility, sustainability and social determinants of health are considered.
Labs21 Laboratory Modeling Guidelines using ASHRAE 90.1-1999
Energy Technology Data Exchange (ETDEWEB)
Reilly, Susan; Walsh, Michael; Graham, Carl; Maor, Itzhak; Mathew, Paul; Porter, Fred; Sartor, Dale; Van Geet, Otto
2005-10-01
The following is a guideline for energy modeling of laboratory spaces in a building in accordance with the Energy Cost Budget method described in ASHRAE 90.1-1999 Energy Standard for Buildings Except Low-Rise Residential Buildings. For the purposes of this document, a laboratory is defined as any space requiring once through ventilation systems (recirculation of air to other spaces in a building is not allowed). To accomplish this, ventilation systems in laboratories typically provide 100% outside air to the occupied space. The guideline is structured similarly to the ASHRAE 90.1-99 standard. Only those sections being clarified or modified are discussed in the guideline; all other sections should be followed as defined in the standard. Specifically, those sections that are affected include the following: (1) 6.3.3.1 - Fan Power Limitation (modification); (2) 6.3.7.2 - Fume Hoods (modification); (3) 11.3.11 - Schedules (modification); (4) 11.4.3 - HVAC Systems (clarification); (5) 11.4.3 (h) Budget Supply-Air-to-Room Air Temperature Difference (modification); (6) 11.4.3(i) - Fan system efficiency (modification); and (7) Table 11.4.3A - Budget System Descriptions (modification). For energy efficiency measures that are not explicitly addressed by the standard, we recommend application of Section 11.5, Exceptional Calculation Methods. This guideline does not cover the details of such calculation methods.
Thurstonian models for sensory discrimination tests as generalized linear models
DEFF Research Database (Denmark)
Brockhoff, Per B.; Christensen, Rune Haubo Bojesen
2010-01-01
Sensory discrimination tests such as the triangle, duo-trio, 2-AFC and 3-AFC tests produce binary data and the Thurstonian decision rule links the underlying sensory difference 6 to the observed number of correct responses. In this paper it is shown how each of these four situations can be viewed...... as a so-called generalized linear model. The underlying sensory difference 6 becomes directly a parameter of the statistical model and the estimate d' and it's standard error becomes the "usual" output of the statistical analysis. The d' for the monadic A-NOT A method is shown to appear as a standard...... linear contrast in a generalized linear model using the probit link function. All methods developed in the paper are implemented in our free R-package sensR (http://www.cran.r-project.org/package=sensR/). This includes the basic power and sample size calculations for these four discrimination tests...
Jenssen, C; Hocke, M; Fusaroli, P; Gilja, O H; Buscarini, E; Havre, R F; Ignee, A; Saftoiu, A; Vilmann, P; Burmester, E; Nolsøe, C P; Nürnberg, D; D'Onofrio, M; Lorentzen, T; Piscaglia, F; Sidhu, P S; Dietrich, C F
2016-04-01
The fourth part of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Guidelines on Interventional Ultrasound describes general aspects of endoscopic ultrasound-guided diagnostic and therapeutic interventions and assesses the evidence for endoscopic ultrasound-guided sampling. Endoscopic ultrasound combines the most advanced high-resolution ultrasound imaging of lesions within the wall and in the vicinity of the gastrointestinal tract and safe and effective fine needle-based tissue acquisition from these lesions. The guideline addresses the indications, contraindications, techniques, adverse events, training and clinical impact of EUS-guided sampling. Advantages and drawbacks are weighed in comparison with image-guided percutaneous biopsy. Based on the most current evidence, clinical practice recommendations are given for crucial preconditions and steps of EUS-guided sampling as well as for safe performance. Additionally, the guideline deals with the principles and reliability of cytopathological reporting in endoscopic ultrasound-guided sampling (short version; the long version is published online).
Jenssen, C; Hocke, M; Fusaroli, P; Gilja, O H; Buscarini, E; Havre, R F; Ignee, A; Saftoiu, A; Vilmann, P; Burmester, E; Nolsøe, C P; Nürnberg, D; D'Onofrio, M; Lorentzen, T; Piscaglia, F; Sidhu, P S; Dietrich, C F
2016-04-01
The fourth part of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Guidelines on Interventional Ultrasound describes general aspects of endoscopic ultrasound-guided diagnostic and therapeutic interventions and assesses the evidence for endoscopic ultrasound-guided sampling. Endoscopic ultrasound combines the most advanced high-resolution ultrasound imaging of lesions within the wall and in the vicinity of the gastrointestinal tract and safe and effective fine needle based tissue acquisition from these lesions. The guideline addresses the indications, contraindications, techniques, adverse events, training and clinical impact of EUS-guided sampling. Advantages and drawbacks are weighed in comparison with image-guided percutaneous biopsy. Based on the most current evidence, clinical practice recommendations are given for crucial preconditions and steps of EUS-guided sampling as well as for safe performance. Additionally, the guideline deals with the principles and reliability of cytopathological reporting in endoscopic ultrasound-guided sampling (long version).
Mylanus, E A M
2008-05-24
The first revision of the practice guideline 'Otitis externa' from the Dutch College of General Practitioners describes diagnostic, therapeutic and preventive aspects of care and focuses mainly on the acute form of the disease. In comparison with the previous guideline, some modest but valuable improvements have been made with regard to diagnosis and medical treatment. For acute otitis externa, treatment with acid and corticosteroid eardrops is considered the treatment of choice, rather than treatment with acid eardrops only. The guideline clearly discusses indications for referral of patients with otitis externa to an otorhinolaryngologist. Hypersensitivity and more severe pathology should be excluded in persistent cases. For chronic otitis externa, an otorhinolaryngologist can provide surgical treatment with a good chance of success and a low recurrence rate.
Rudy, Ashley C. A.; Lamoureux, Scott F.; Treitz, Paul; van Ewijk, Karin Y.
2016-07-01
To effectively assess and mitigate risk of permafrost disturbance, disturbance-prone areas can be predicted through the application of susceptibility models. In this study we developed regional susceptibility models for permafrost disturbances using a field disturbance inventory to test the transferability of the model to a broader region in the Canadian High Arctic. Resulting maps of susceptibility were then used to explore the effect of terrain variables on the occurrence of disturbances within this region. To account for a large range of landscape characteristics, the model was calibrated using two locations: Sabine Peninsula, Melville Island, NU, and Fosheim Peninsula, Ellesmere Island, NU. Spatial patterns of disturbance were predicted with a generalized linear model (GLM) and generalized additive model (GAM), each calibrated using disturbed and randomized undisturbed locations from both locations and GIS-derived terrain predictor variables including slope, potential incoming solar radiation, wetness index, topographic position index, elevation, and distance to water. Each model was validated for the Sabine and Fosheim Peninsulas using independent data sets while the transferability of the model to an independent site was assessed at Cape Bounty, Melville Island, NU. The regional GLM and GAM validated well for both calibration sites (Sabine and Fosheim) with the area under the receiver operating curves (AUROC) > 0.79. Both models were applied directly to Cape Bounty without calibration and validated equally with AUROC's of 0.76; however, each model predicted disturbed and undisturbed samples differently. Additionally, the sensitivity of the transferred model was assessed using data sets with different sample sizes. Results indicated that models based on larger sample sizes transferred more consistently and captured the variability within the terrain attributes in the respective study areas. Terrain attributes associated with the initiation of disturbances were
Institute of Scientific and Technical Information of China (English)
David Carruthers; Sheng Xiangyu; Christine McHugh
2005-01-01
This paper makes comparisons between Chinese Environmental Impact Assessment (EIA)Guidelines for Air dispersion modelling and the advanced air dispersion model ADMS. Since 2001 the ADMS model has been the first and only foreign model that has been approved by the Appraisal Center for Environment and Engineering (ACEE) to be used in EIA projects in China (http://www. china-eia.com/inden_content/rjrz/rjrz_ADMS/htm). In the paper the following sections provide brief descriptions of the main features of the Chinese Guidelines for Air Dispersion (Section 2) and ADMS (Section 3);Section 4 provides a comparison of the two modelling methods for some simple cases and conclusions and discussion are given in Section 5.
Bayesian Subset Modeling for High-Dimensional Generalized Linear Models
Liang, Faming
2013-06-01
This article presents a new prior setting for high-dimensional generalized linear models, which leads to a Bayesian subset regression (BSR) with the maximum a posteriori model approximately equivalent to the minimum extended Bayesian information criterion model. The consistency of the resulting posterior is established under mild conditions. Further, a variable screening procedure is proposed based on the marginal inclusion probability, which shares the same properties of sure screening and consistency with the existing sure independence screening (SIS) and iterative sure independence screening (ISIS) procedures. However, since the proposed procedure makes use of joint information from all predictors, it generally outperforms SIS and ISIS in real applications. This article also makes extensive comparisons of BSR with the popular penalized likelihood methods, including Lasso, elastic net, SIS, and ISIS. The numerical results indicate that BSR can generally outperform the penalized likelihood methods. The models selected by BSR tend to be sparser and, more importantly, of higher prediction ability. In addition, the performance of the penalized likelihood methods tends to deteriorate as the number of predictors increases, while this is not significant for BSR. Supplementary materials for this article are available online. © 2013 American Statistical Association.
Fung, Nick Lik San; Widya, Ing; Broens, Tom; Larburu, Nekane; Bults, Richard; Shalom, Erez; Jones, Val; Hermens, Hermie
2014-01-01
We present a conceptual framework for modelling clinical guidelines as networks of concurrent processes. This enables the guideline to be partitioned and distributed at run-time across a knowledge-based telemedicine system, which is distributed by definition but whose exact physical configuration ca
Climatology of the HOPE-G global ocean general circulation model - Sea ice general circulation model
Energy Technology Data Exchange (ETDEWEB)
Legutke, S. [Deutsches Klimarechenzentrum (DKRZ), Hamburg (Germany); Maier-Reimer, E. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany)
1999-12-01
The HOPE-G global ocean general circulation model (OGCM) climatology, obtained in a long-term forced integration is described. HOPE-G is a primitive-equation z-level ocean model which contains a dynamic-thermodynamic sea-ice model. It is formulated on a 2.8 grid with increased resolution in low latitudes in order to better resolve equatorial dynamics. The vertical resolution is 20 layers. The purpose of the integration was both to investigate the models ability to reproduce the observed general circulation of the world ocean and to obtain an initial state for coupled atmosphere - ocean - sea-ice climate simulations. The model was driven with daily mean data of a 15-year integration of the atmosphere general circulation model ECHAM4, the atmospheric component in later coupled runs. Thereby, a maximum of the flux variability that is expected to appear in coupled simulations is included already in the ocean spin-up experiment described here. The model was run for more than 2000 years until a quasi-steady state was achieved. It reproduces the major current systems and the main features of the so-called conveyor belt circulation. The observed distribution of water masses is reproduced reasonably well, although with a saline bias in the intermediate water masses and a warm bias in the deep and bottom water of the Atlantic and Indian Oceans. The model underestimates the meridional transport of heat in the Atlantic Ocean. The simulated heat transport in the other basins, though, is in good agreement with observations. (orig.)
Climatology of the HOPE-G global ocean general circulation model - Sea ice general circulation model
Energy Technology Data Exchange (ETDEWEB)
Legutke, S. [Deutsches Klimarechenzentrum (DKRZ), Hamburg (Germany); Maier-Reimer, E. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany)
1999-12-01
The HOPE-G global ocean general circulation model (OGCM) climatology, obtained in a long-term forced integration is described. HOPE-G is a primitive-equation z-level ocean model which contains a dynamic-thermodynamic sea-ice model. It is formulated on a 2.8 grid with increased resolution in low latitudes in order to better resolve equatorial dynamics. The vertical resolution is 20 layers. The purpose of the integration was both to investigate the models ability to reproduce the observed general circulation of the world ocean and to obtain an initial state for coupled atmosphere - ocean - sea-ice climate simulations. The model was driven with daily mean data of a 15-year integration of the atmosphere general circulation model ECHAM4, the atmospheric component in later coupled runs. Thereby, a maximum of the flux variability that is expected to appear in coupled simulations is included already in the ocean spin-up experiment described here. The model was run for more than 2000 years until a quasi-steady state was achieved. It reproduces the major current systems and the main features of the so-called conveyor belt circulation. The observed distribution of water masses is reproduced reasonably well, although with a saline bias in the intermediate water masses and a warm bias in the deep and bottom water of the Atlantic and Indian Oceans. The model underestimates the meridional transport of heat in the Atlantic Ocean. The simulated heat transport in the other basins, though, is in good agreement with observations. (orig.)
Appropriate model selection methods for nonstationary generalized extreme value models
Kim, Hanbeen; Kim, Sooyoung; Shin, Hongjoon; Heo, Jun-Haeng
2017-04-01
Several evidences of hydrologic data series being nonstationary in nature have been found to date. This has resulted in the conduct of many studies in the area of nonstationary frequency analysis. Nonstationary probability distribution models involve parameters that vary over time. Therefore, it is not a straightforward process to apply conventional goodness-of-fit tests to the selection of an appropriate nonstationary probability distribution model. Tests that are generally recommended for such a selection include the Akaike's information criterion (AIC), corrected Akaike's information criterion (AICc), Bayesian information criterion (BIC), and likelihood ratio test (LRT). In this study, the Monte Carlo simulation was performed to compare the performances of these four tests, with regard to nonstationary as well as stationary generalized extreme value (GEV) distributions. Proper model selection ratios and sample sizes were taken into account to evaluate the performances of all the four tests. The BIC demonstrated the best performance with regard to stationary GEV models. In case of nonstationary GEV models, the AIC proved to be better than the other three methods, when relatively small sample sizes were considered. With larger sample sizes, the AIC, BIC, and LRT presented the best performances for GEV models which have nonstationary location and/or scale parameters, respectively. Simulation results were then evaluated by applying all four tests to annual maximum rainfall data of selected sites, as observed by the Korea Meteorological Administration.
Application of Improved Radiation Modeling to General Circulation Models
Energy Technology Data Exchange (ETDEWEB)
Michael J Iacono
2011-04-07
This research has accomplished its primary objectives of developing accurate and efficient radiation codes, validating them with measurements and higher resolution models, and providing these advancements to the global modeling community to enhance the treatment of cloud and radiative processes in weather and climate prediction models. A critical component of this research has been the development of the longwave and shortwave broadband radiative transfer code for general circulation model (GCM) applications, RRTMG, which is based on the single-column reference code, RRTM, also developed at AER. RRTMG is a rigorously tested radiation model that retains a considerable level of accuracy relative to higher resolution models and measurements despite the performance enhancements that have made it possible to apply this radiation code successfully to global dynamical models. This model includes the radiative effects of all significant atmospheric gases, and it treats the absorption and scattering from liquid and ice clouds and aerosols. RRTMG also includes a statistical technique for representing small-scale cloud variability, such as cloud fraction and the vertical overlap of clouds, which has been shown to improve cloud radiative forcing in global models. This development approach has provided a direct link from observations to the enhanced radiative transfer provided by RRTMG for application to GCMs. Recent comparison of existing climate model radiation codes with high resolution models has documented the improved radiative forcing capability provided by RRTMG, especially at the surface, relative to other GCM radiation models. Due to its high accuracy, its connection to observations, and its computational efficiency, RRTMG has been implemented operationally in many national and international dynamical models to provide validated radiative transfer for improving weather forecasts and enhancing the prediction of global climate change.
A Note on the Identifiability of Generalized Linear Mixed Models
DEFF Research Database (Denmark)
Labouriau, Rodrigo
2014-01-01
I present here a simple proof that, under general regularity conditions, the standard parametrization of generalized linear mixed model is identifiable. The proof is based on the assumptions of generalized linear mixed models on the first and second order moments and some general mild regularity ...... conditions, and, therefore, is extensible to quasi-likelihood based generalized linear models. In particular, binomial and Poisson mixed models with dispersion parameter are identifiable when equipped with the standard parametrization......I present here a simple proof that, under general regularity conditions, the standard parametrization of generalized linear mixed model is identifiable. The proof is based on the assumptions of generalized linear mixed models on the first and second order moments and some general mild regularity...
Directory of Open Access Journals (Sweden)
Holder Roger L
2009-07-01
Full Text Available Abstract Background Multiple imputation (MI provides an effective approach to handle missing covariate data within prognostic modelling studies, as it can properly account for the missing data uncertainty. The multiply imputed datasets are each analysed using standard prognostic modelling techniques to obtain the estimates of interest. The estimates from each imputed dataset are then combined into one overall estimate and variance, incorporating both the within and between imputation variability. Rubin's rules for combining these multiply imputed estimates are based on asymptotic theory. The resulting combined estimates may be more accurate if the posterior distribution of the population parameter of interest is better approximated by the normal distribution. However, the normality assumption may not be appropriate for all the parameters of interest when analysing prognostic modelling studies, such as predicted survival probabilities and model performance measures. Methods Guidelines for combining the estimates of interest when analysing prognostic modelling studies are provided. A literature review is performed to identify current practice for combining such estimates in prognostic modelling studies. Results Methods for combining all reported estimates after MI were not well reported in the current literature. Rubin's rules without applying any transformations were the standard approach used, when any method was stated. Conclusion The proposed simple guidelines for combining estimates after MI may lead to a wider and more appropriate use of MI in future prognostic modelling studies.
Brouwers, Melissa C; Makarski, Julie; Kastner, Monika; Hayden, Leigh; Bhattacharyya, Onil
2015-03-15
Practice guideline (PG) implementability refers to PG features that promote their use. While there are tools and resources to promote PG implementability, none are based on an evidence-informed and multidisciplinary perspective. Our objectives were to (i) create a comprehensive and evidence-informed model of PG implementability, (ii) seek support for the model from the international PG community, (iii) map existing implementability tools on to the model, (iv) prioritize areas for further investigation, and (v) describe how the model can be used by PG developers, users, and researchers. A mixed methods approach was used. Using our completed realist review of the literature of seven different disciplines as the foundation, an iterative consensus process was used to create the beta version of the model. This was followed by (i) a survey of international stakeholders (guideline developers and users) to gather feedback and to refine the model, (ii) a content analysis comparing the model to existing PG tools, and (iii) a strategy to prioritize areas of the model for further research by members of the research team. The Guideline Implementability for Decision Excellence Model (GUIDE-M) is comprised of 3 core tactics, 7 domains, 9 subdomains, 44 attributes, and 40 subattributes and elements. Feedback on the beta version was received from 248 stakeholders from 34 countries. The model was rated as logical, relevant, and appropriate. Seven PG tools were selected and compared to the GUIDE-M: very few tools targeted the Contextualization and Deliberations domain. Also, fewer of the tools addressed PG appraisal than PG development and reporting functions. These findings informed the research priorities identified by the team. The GUIDE-M provides an evidence-informed international and multidisciplinary conceptualization of PG implementability. The model can be used by PG developers to help them create more implementable recommendations, by clinicians and other users to help them
PEMAHAMAN DASAR ANALISIS MODEL COMPUTABLE GENERAL EQUILIBRIUM (CGE
Directory of Open Access Journals (Sweden)
Mardiyah Hayati
2013-11-01
Full Text Available Simple paper about basic understanding of computable general equilibrium aimed to give basic understanding about CGE. It consist of history of CGE, assumption of CGE model, excess and lack of CGE model, and creation of simple CGE model for closed economy. CGE model is suitable to be used for seeing impact of new policy implementation. It is because CGE model use general equilibrium in which this theory of general equilibrium explaining about inter-relation among markets in the economy system. CGE model was introduced in 1960s known as Johansen model. Next, it is expanded into various models such as: ORANI Model, General Trade Analysis Project (GTAP Model, and Applied General Equilibrium (AGE Model. In Indonesia, there are CGE ORANI Model, Wayang, Indonesia-E3 and IRCGE. CGE Model is created by assumption of perfect competition. Consumer maximizes utility, producer maximizes profit, and company maximizes zero profit condition.
Guidelines for Using Building Information Modeling for Energy Analysis of Buildings
Directory of Open Access Journals (Sweden)
Thomas Reeves
2015-12-01
Full Text Available Building energy modeling (BEM, a subset of building information modeling (BIM, integrates energy analysis into the design, construction, and operation and maintenance of buildings. As there are various existing BEM tools available, there is a need to evaluate the utility of these tools in various phases of the building lifecycle. The goal of this research was to develop guidelines for evaluation and selection of BEM tools to be used in particular building lifecycle phases. The objectives of this research were to: (1 Evaluate existing BEM tools; (2 Illustrate the application of the three BEM tools; (3 Re-evaluate the three BEM tools; and (4 Develop guidelines for evaluation, selection and application of BEM tools in the design, construction and operation/maintenance phases of buildings. Twelve BEM tools were initially evaluated using four criteria: interoperability, usability, available inputs, and available outputs. Each of the top three BEM tools selected based on this initial evaluation was used in a case study to simulate and evaluate energy usage, daylighting performance, and natural ventilation for two academic buildings (LEED-certified and non-LEED-certified. The results of the case study were used to re-evaluate the three BEM tools using the initial criteria with addition of the two new criteria (speed and accuracy, and to develop guidelines for evaluating and selecting BEM tools to analyze building energy performance. The major contribution of this research is the development of these guidelines that can help potential BEM users to identify the most appropriate BEM tool for application in particular building lifecycle phases.
Multivariate statistical modelling based on generalized linear models
Fahrmeir, Ludwig
1994-01-01
This book is concerned with the use of generalized linear models for univariate and multivariate regression analysis. Its emphasis is to provide a detailed introductory survey of the subject based on the analysis of real data drawn from a variety of subjects including the biological sciences, economics, and the social sciences. Where possible, technical details and proofs are deferred to an appendix in order to provide an accessible account for non-experts. Topics covered include: models for multi-categorical responses, model checking, time series and longitudinal data, random effects models, and state-space models. Throughout, the authors have taken great pains to discuss the underlying theoretical ideas in ways that relate well to the data at hand. As a result, numerous researchers whose work relies on the use of these models will find this an invaluable account to have on their desks. "The basic aim of the authors is to bring together and review a large part of recent advances in statistical modelling of m...
Pasupuleti, Mohan Kumar; Molahally, Subramanya Shetty; Salwaji, Supraja
2016-01-01
Laboratory animal models serve as a facilitator to investigate the etiopathogenesis of periodontal disease, are used to know the efficacy of reconstructive and regenerative procedures, and are also helpful in evaluation of newer therapeutic techniques including laser and implant therapies prior to application in the human beings. The aim of this review is to know the different animal models used in various specialties of dental research and to know the ethical guidelines prior to the usage of experimental models with main emphasis on how to refine, replace, and reduce the number of animal models usage in the laboratory. An online search for experimental animal models used in dental research was performed using MEDLINE/PubMed database. Publications from 2009 to May 2013 in the specialty of periodontics were included in writing this review. A total of 652 references were published in PubMed/MEDLINE databases based on the search terms used. Out of 245 studies, 241 were related to the periodontal research published in English from 2009 to 2013. Relevant papers were chosen according to the inclusion and exclusion criteria. After extensive electronic and hand search on animal models, it has been observed that various animal models were used in dental research. Search on animal models used for dental research purpose revealed that various animals such as rats, mice, guinea pigs, rabbit, beagle dogs, goats, and nonhuman primates were extensively used. However, with the new advancement of ex vivo animal models, it has become easy to investigate disease pathogenesis and to test the efficacy of newer therapeutic modalities with the reduced usage of animal models. This review summarized the large amount of literature on animal models used in periodontal research with main emphasis on ethical guidelines and on reducing the animal model usage in future perspective. PMID:28298815
Directory of Open Access Journals (Sweden)
Mohan Kumar Pasupuleti
2016-01-01
Full Text Available Laboratory animal models serve as a facilitator to investigate the etiopathogenesis of periodontal disease, are used to know the efficacy of reconstructive and regenerative procedures, and are also helpful in evaluation of newer therapeutic techniques including laser and implant therapies prior to application in the human beings. The aim of this review is to know the different animal models used in various specialties of dental research and to know the ethical guidelines prior to the usage of experimental models with main emphasis on how to refine, replace, and reduce the number of animal models usage in the laboratory. An online search for experimental animal models used in dental research was performed using MEDLINE/PubMed database. Publications from 2009 to May 2013 in the specialty of periodontics were included in writing this review. A total of 652 references were published in PubMed/MEDLINE databases based on the search terms used. Out of 245 studies, 241 were related to the periodontal research published in English from 2009 to 2013. Relevant papers were chosen according to the inclusion and exclusion criteria. After extensive electronic and hand search on animal models, it has been observed that various animal models were used in dental research. Search on animal models used for dental research purpose revealed that various animals such as rats, mice, guinea pigs, rabbit, beagle dogs, goats, and nonhuman primates were extensively used. However, with the new advancement of ex vivo animal models, it has become easy to investigate disease pathogenesis and to test the efficacy of newer therapeutic modalities with the reduced usage of animal models. This review summarized the large amount of literature on animal models used in periodontal research with main emphasis on ethical guidelines and on reducing the animal model usage in future perspective.
Modeling local item dependence with the hierarchical generalized linear model.
Jiao, Hong; Wang, Shudong; Kamata, Akihito
2005-01-01
Local item dependence (LID) can emerge when the test items are nested within common stimuli or item groups. This study proposes a three-level hierarchical generalized linear model (HGLM) to model LID when LID is due to such contextual effects. The proposed three-level HGLM was examined by analyzing simulated data sets and was compared with the Rasch-equivalent two-level HGLM that ignores such a nested structure of test items. The results demonstrated that the proposed model could capture LID and estimate its magnitude. Also, the two-level HGLM resulted in larger mean absolute differences between the true and the estimated item difficulties than those from the proposed three-level HGLM. Furthermore, it was demonstrated that the proposed three-level HGLM estimated the ability distribution variance unaffected by the LID magnitude, while the two-level HGLM with no LID consideration increasingly underestimated the ability variance as the LID magnitude increased.
Lagro-Janssen, A.L.M.
2005-01-01
The practice guideline 'Miscarriage' has been reviewed for the second time in fifteen years. It provides the practitioner with distinct diagnostic tools for vaginal bleeding in the first sixteen weeks of pregnancy and a clear management algorithm. The management of miscarriage is based on a joint de
Weel-Baumgarten, E.M. van; Rijswijk, E. van
2005-01-01
The recommendations provided by the revised guideline 'Anxiety disorders' are well suited to every-day practice. The multidisciplinary approach reflects the increasing cooperation between primary and secondary care in the management of mental-health problems. The description of the various anxiety d
A Bayesian modeling approach for generalized semiparametric structural equation models.
Song, Xin-Yuan; Lu, Zhao-Hua; Cai, Jing-Heng; Ip, Edward Hak-Sing
2013-10-01
In behavioral, biomedical, and psychological studies, structural equation models (SEMs) have been widely used for assessing relationships between latent variables. Regression-type structural models based on parametric functions are often used for such purposes. In many applications, however, parametric SEMs are not adequate to capture subtle patterns in the functions over the entire range of the predictor variable. A different but equally important limitation of traditional parametric SEMs is that they are not designed to handle mixed data types-continuous, count, ordered, and unordered categorical. This paper develops a generalized semiparametric SEM that is able to handle mixed data types and to simultaneously model different functional relationships among latent variables. A structural equation of the proposed SEM is formulated using a series of unspecified smooth functions. The Bayesian P-splines approach and Markov chain Monte Carlo methods are developed to estimate the smooth functions and the unknown parameters. Moreover, we examine the relative benefits of semiparametric modeling over parametric modeling using a Bayesian model-comparison statistic, called the complete deviance information criterion (DIC). The performance of the developed methodology is evaluated using a simulation study. To illustrate the method, we used a data set derived from the National Longitudinal Survey of Youth.
Wobbes, Th.
2003-01-01
The new guideline is an adaptation to recent developments in the genetics of breast cancer. Hereditary and familial breast cancer may give rise to many questions in women coping with family members with the disease. Recommendations are given in a clear and succinct way. It is regrettable that breast
Generalization of Random Intercept Multilevel Models
Directory of Open Access Journals (Sweden)
Rehan Ahmad Khan
2013-10-01
Full Text Available The concept of random intercept models in a multilevel model developed by Goldstein (1986 has been extended for k-levels. The random variation in intercepts at individual level is marginally split into components by incorporating higher levels of hierarchy in the single level model. So, one can control the random variation in intercepts by incorporating the higher levels in the model.
Energy Technology Data Exchange (ETDEWEB)
Simmons, C.S.; Cole, C.R.
1985-05-01
This document was written to provide guidance to managers and site operators on how ground-water transport codes should be selected for assessing burial site performance. There is a need for a formal approach to selecting appropriate codes from the multitude of potentially useful ground-water transport codes that are currently available. Code selection is a problem that requires more than merely considering mathematical equation-solving methods. These guidelines are very general and flexible and are also meant for developing systems simulation models to be used to assess the environmental safety of low-level waste burial facilities. Code selection is only a single aspect of the overall objective of developing a systems simulation model for a burial site. The guidance given here is mainly directed toward applications-oriented users, but managers and site operators need to be familiar with this information to direct the development of scientifically credible and defensible transport assessment models. Some specific advice for managers and site operators on how to direct a modeling exercise is based on the following five steps: identify specific questions and study objectives; establish costs and schedules for achieving answers; enlist the aid of professional model applications group; decide on approach with applications group and guide code selection; and facilitate the availability of site-specific data. These five steps for managers/site operators are discussed in detail following an explanation of the nine systems model development steps, which are presented first to clarify what code selection entails.
Smink, Agnes J; Bierma-Zeinstra, Sita M A; Dekker, Joost; Vliet Vlieland, Thea P M; Bijlsma, Johannes W J; Swierstra, Bart A; Kortland, Joke H; Voorn, Theo B; van den Ende, Cornelia H M; Schers, Henk J
2013-03-11
To improve the management of hip or knee osteoarthritis (OA), a multidisciplinary guideline-based stepped-care strategy (SCS) with recommendations regarding the appropriate non-surgical treatment modalities and optimal sequence for care has been developed. Implementation of this SCS in the general practice may be hampered by the negative attitude of general practitioners (GPs) towards the strategy. In order to develop a tailored implementation plan, we assessed the GPs' views regarding specific recommendations in the SCS and their working procedures with regard to OA. A survey was conducted among a random sample of Dutch GPs. Questions included the GP's demographical characteristics and the practice setting as well as how the management of OA was organized and whether the GPs supported the SCS recommendations. In particular, we assessed GP's views regarding the effectiveness of 14 recommended and non-recommended treatment modalities. Furthermore, we calculated their agreement with 7 statements based on the SCS recommendations regarding the sequence for care. With a linear regression model, we identified factors that seemed to influence the GPs' agreement with the SCS recommendations. Four hundred fifty-six GPs (37%) aged 30-65 years, of whom 278 males (61%), responded. Seven of the 11 recommended modalities (i.e. oral Non-Steroidal Anti-Inflammatory Drugs, physical therapy, glucocorticoid intra-articular injections, education, lifestyle advice, acetaminophen, and tramadol) were considered effective by the majority of the GPs (varying between 95-60%). The mean agreement score, based on a 5-point scale, with the recommendations regarding the sequence for care was 2.8 (SD = 0.5). Ten percent of the variance in GPs' agreement could be explained by the GPs' attitudes regarding the effectiveness of the recommended and non-recommended non-surgical treatment modalities and the type of practice. In general, GPs support the recommendations in the SCS. Therefore, we expect
DEFF Research Database (Denmark)
Rong, Li; Nielsen, Peter V.; Bjerg, Bjarne
2016-01-01
scale pig barns was simulated to show the procedures of validating a CFD simulation in livestock buildings. After summarizing the guideline and/or best practice for CFD modeling, the authors addressed the issues related to numerical methods and the governing equations, which were limited to RANS models....... Although it is not necessary to maintain the same format of reporting the CFD modeling as presented in this paper, the authors would suggest including all the information related to the selection of turbulence models, difference schemes, convergence criteria, boundary conditions, geometry simplification......Computational Fluid Dynamics (CFD) is increasingly used to study airflow around and in livestock buildings, to develop technologies to mitigate emissions and to predict the contaminant dispersion from livestock buildings. In this paper, an example of air flow distribution in a room with two full...
Modeling and Design Guidelines for P⁺ Guard Rings in Lightly Doped CMOS Substrates
DEFF Research Database (Denmark)
Shen, Ming; Mikkelsen, Jan H.; Zhang, Ke;
2013-01-01
This paper presents a compact model for ${rm P}^{+}$ guard rings in lightly doped CMOS substrates featuring a P-well layer. Simple expressions for the impedances in the model are derived based on a conformal mapping approach. The model can be used to predict the noise suppression performance...... of ${rm P}^{+}$ guard rings in terms of S-parameters, which is useful for substrate noise mitigation in mixed-signal system-on-chips. Validation of the model has been done by both electromagnetic simulation and experimental results from guard rings implemented using a standard 0.18-$mu{rm m}$ CMOS process....... In addition, design guidelines have been drawn for minimizing the guard ring size while maintaining the noise suppression performance....
Practical guidelines for modelling post-entry spread in invasion ecology
Directory of Open Access Journals (Sweden)
Hazel Parry
2013-09-01
Full Text Available In this article we review a variety of methods to enable understanding and modelling the spread of a pest or pathogen post-entry. Building upon our experience of multidisciplinary research in this area, we propose practical guidelines and a framework for model development, to help with the application of mathematical modelling in the field of invasion ecology for post-entry spread. We evaluate the pros and cons of a range of methods, including references to examples of the methods in practice. We also show how issues of data deficiency and uncertainty can be addressed. The aim is to provide guidance to the reader on the most suitable elements to include in a model of post-entry dispersal in a risk assessment, under differing circumstances. We identify both the strengths and weaknesses of different methods and their application as part of a holistic, multidisciplinary approach to biosecurity research.
Assortativity in generalized preferential attachment models
Krot, Alexander
2016-01-01
In this paper, we analyze assortativity of preferential attachment models. We deal with a wide class of preferential attachment models (PA-class). It was previously shown that the degree distribution in all models of the PA-class follows a power law. Also, the global and the average local clustering coefficients were analyzed. We expand these results by analyzing the assortativity property of the PA-class of models. Namely, we analyze the behavior of $d_{nn}(d)$ which is the average degree of a neighbor of a vertex of degree $d$.
Particle model with generalized Poincaré symmetry
Smith, A.
2017-08-01
Using the techniques of nonlinear coset realization with a generalized Poincaré group, we construct a relativistic particle model, invariant under the generalized symmetries, providing a dynamical realization of the B5 algebra.
Stratospheric General Circulation with Chemistry Model (SGCCM)
Rood, Richard B.; Douglass, Anne R.; Geller, Marvin A.; Kaye, Jack A.; Nielsen, J. Eric; Rosenfield, Joan E.; Stolarski, Richard S.
1990-01-01
In the past two years constituent transport and chemistry experiments have been performed using both simple single constituent models and more complex reservoir species models. Winds for these experiments have been taken from the data assimilation effort, Stratospheric Data Analysis System (STRATAN).
Generalized coupling in the Kuramoto model
DEFF Research Database (Denmark)
Filatrella, G.; Pedersen, Niels Falsig; Wiesenfeld, K.
2007-01-01
We propose a modification of the Kuramoto model to account for the effective change in the coupling constant among the oscillators, as suggested by some experiments on Josephson junction, laser arrays, and mechanical systems, where the active elements are turned on one by one. The resulting model...... with the behavior of Josephson junctions coupled via a cavity....
Directory of Open Access Journals (Sweden)
Ahmed Abdel-Aziz
2013-01-01
Full Text Available Objectives. To assess the standard practice of care of surgeons regarding surgical antibiotic prophylaxis, to identify gaps, and to set recommendations. Methods. A retrospective analysis of data obtained from different surgical units in a single center in Qatar over a 3-month period in 2012. A total of 101 patients who underwent surgery and followed regimes for surgical prophylaxis as per hospital guidelines were included in the study. Results. The overall use of antibiotic was 89%, whereas the current practice did not match the recommended hospital protocols in 53.5% of cases. Prolonged antibiotics use (59.3% was the commonest reason for nonadherence followed by the use of an alternative antibiotic to that recommended in the protocol (31.5% and no prophylaxis was used in 9.2% of cases. The rate of compliance was significantly higher among clean surgery than clean contaminated group (P=0.03. Forty-four percent of clean and 65% of clean-contaminated procedures showed noncompliance with the recommended surgical antimicrobial prophylaxis hospital guidelines. Conclusion. Lack of adherence to hospital protocols is not uncommon. This finding remains a challenge to encourage clinicians to follow hospital guidelines appropriately and to consistently apply the surgical antibiotic prophylaxis. The role of clinical pharmacist may facilitate this process across all surgical disciplines.
Universality in generalized models of inflation
Binétruy, Pierre; Pieroni, Mauro
2016-01-01
We show that the cosmological evolution of a scalar field with non standard kinetic term can be described in terms of a Renormalization Group Equation. In this framework inflation corresponds to the slow evolution in a neighborhood of a fixed point and universality classes for inflationary models can be naturally introduced. Using some examples we show the application of the formalism. The predicted values for the speed of sound $c_s$ and for the amount of non-Gaussianities produced in these models are discussed. In particular, we show that it is possible to introduce models with $c_s^2 \
The Survival Probability in Generalized Poisson Risk Model
Institute of Scientific and Technical Information of China (English)
GONGRi-zhao
2003-01-01
In this paper we generalize the aggregated premium income process from a constant rate process to a poisson process for the classical compound Poinsson risk model,then for the generalized model and the classical compound poisson risk model ,we respectively get its survival probability in finite time period in case of exponential claim amounts.
Description of the General Equilibrium Model of Ecosystem Services (GEMES)
Travis Warziniack; David Finnoff; Jenny Apriesnig
2017-01-01
This paper serves as documentation for the General Equilibrium Model of Ecosystem Services (GEMES). GEMES is a regional computable general equilibrium model that is composed of values derived from natural capital and ecosystem services. It models households, producing sectors, and governments, linked to one another through commodity and factor markets. GEMES was...
Evidence for a General Factor Model of ADHD in Adults
Gibbins, Christopher; Toplak, Maggie E.; Flora, David B.; Weiss, Margaret D.; Tannock, Rosemary
2012-01-01
Objective: To examine factor structures of "Diagnostic and Statistical Manual of Mental Disorders" (4th ed.) symptoms of ADHD in adults. Method: Two sets of models were tested: (a) models with inattention and hyperactivity/impulsivity as separate but correlated latent constructs and (b) hierarchical general factor models with a general factor for…
BEYOND SEM: GENERAL LATENT VARIABLE MODELING
National Research Council Canada - National Science Library
Muthén, Bengt O
2002-01-01
This article gives an overview of statistical analysis with latent variables. Using traditional structural equation modeling as a starting point, it shows how the idea of latent variables captures a wide variety of statistical concepts...
Generalized circuit model for coupled plasmonic systems
Benz, Felix; Tserkezis, Christos; Chikkaraddy, Rohit; Sigle, Daniel O; Pukenas, Laurynas; Evans, Stephen D; Aizpurua, Javier; Baumberg, Jeremy J
2015-01-01
We develop an analytic circuit model for coupled plasmonic dimers separated by small gaps that provides a complete account of the optical resonance wavelength. Using a suitable equivalent circuit, it shows how partially conducting links can be treated and provides quantitative agreement with both experiment and full electromagnetic simulations. The model highlights how in the conducting regime, the kinetic inductance of the linkers set the spectral blue-shifts of the coupled plasmon.
DEFF Research Database (Denmark)
Scarborough, Peter; Kaur, Asha; Cobiac, Linda
2016-01-01
Objectives To model food group consumption and price of diet associated with achieving UK dietary recommendations while deviating as little as possible from the current UK diet, in order to support the redevelopment of the UK food-based dietary guidelines (now called the Eatwell Guide). Design...... Optimisation modelling, minimising an objective function of the difference between population mean modelled and current consumption of 125 food groups, and constraints of nutrient and food-based recommendations. Setting The UK. Population Adults aged 19 years and above from the National Diet and Nutrition...... Survey 2008–2011. Main outcome measures Proportion of diet consisting of major foods groups and price of the optimised diet. Results The optimised diet has an increase in consumption of ‘potatoes, bread, rice, pasta and other starchy carbohydrates’ (+69%) and ‘fruit and vegetables’ (+54%) and reductions...
Invariance Properties for General Diagnostic Classification Models
Bradshaw, Laine P.; Madison, Matthew J.
2016-01-01
In item response theory (IRT), the invariance property states that item parameter estimates are independent of the examinee sample, and examinee ability estimates are independent of the test items. While this property has long been established and understood by the measurement community for IRT models, the same cannot be said for diagnostic…
A General Thermal Equilibrium Discharge Flow Model
Institute of Scientific and Technical Information of China (English)
ZHAO; Min-fu; ZHANG; Dong-xu; LV; Yu-feng
2015-01-01
In isentropic and thermal equilibrium assumptions,a discharge flow model was derived,which unified the rules of normal temperature water discharge,high temperature and high pressure water discharge,two-phase critical flow,saturated steam and superheated steam critical
A generalized network model for polymeric liquids
Jongschaap, R.J.J.; Kamphuis, H.; Doeksen, D.K.
1983-01-01
A kinetic model was developed for relating the molecular structure and the rheological behaviour of polymer-like materials in which bonds are being created and broken. In particular, the stress contribution of molecules that are not a part of the network was taken account of. In two limiting cases
On A General Frame For Macroeconomic Modelling
Directory of Open Access Journals (Sweden)
Emil DINGA
2012-03-01
Full Text Available The purpose of the research project was to identify the methodological bases for the aggregate description of the Romanian national economy, both logically and in terms of the sources of empirical data for modelling. The specific objectives of the project were: a description of the economic markets in correlation with the logic description of the economic behaviours; b determination of the sectoral blocks of the Romanian economy, on the basis of the homogeneity of the economic; activity and behaviour; c association of the sectoral blocks to the national accounts, so as to ensure the sources of empirical data for the calibration and utilisation of the model; d association of the sectoral blocks to the economic markets; e association of the national accounts with the economic markets; f identification of the classes of interactions between the determined sectoral blocks.
Generalized Quadratic Linearization of Machine Models
Parvathy Ayalur Krishnamoorthy; Kamaraj Vijayarajan; Devanathan Rajagopalan
2011-01-01
In the exact linearization of involutive nonlinear system models, the issue of singularity needs to be addressed in practical applications. The approximate linearization technique due to Krener, based on Taylor series expansion, apart from being applicable to noninvolutive systems, allows the singularity issue to be circumvented. But approximate linearization, while removing terms up to certain order, also introduces terms of higher order than those removed into the system. To overcome th...
Multilevel Modeling and Policy Development: Guidelines and Applications to Medical Travel.
Garcia-Garzon, Eduardo; Zhukovsky, Peter; Haller, Elisa; Plakolm, Sara; Fink, David; Petrova, Dafina; Mahalingam, Vaishali; Menezes, Igor G; Ruggeri, Kai
2016-01-01
Medical travel has expanded rapidly in recent years, resulting in new markets and increased access to medical care. Whereas several studies investigated the motives of individuals seeking healthcare abroad, the conventional analytical approach is limited by substantial caveats. Classical techniques as found in the literature cannot provide sufficient insight due to the nested nature of data generated. The application of adequate analytical techniques, specifically multilevel modeling, is scarce to non-existent in the context of medical travel. This study introduces the guidelines for application of multilevel techniques in public health research by presenting an application of multilevel modeling in analyzing the decision-making patterns of potential medical travelers. Benefits and potential limitations are discussed.
Multilevel Modeling and Policy Development: Guidelines and Applications to Medical Travel
Garcia-Garzon, Eduardo; Zhukovsky, Peter; Haller, Elisa; Plakolm, Sara; Fink, David; Petrova, Dafina; Mahalingam, Vaishali; Menezes, Igor G.; Ruggeri, Kai
2016-01-01
Medical travel has expanded rapidly in recent years, resulting in new markets and increased access to medical care. Whereas several studies investigated the motives of individuals seeking healthcare abroad, the conventional analytical approach is limited by substantial caveats. Classical techniques as found in the literature cannot provide sufficient insight due to the nested nature of data generated. The application of adequate analytical techniques, specifically multilevel modeling, is scarce to non-existent in the context of medical travel. This study introduces the guidelines for application of multilevel techniques in public health research by presenting an application of multilevel modeling in analyzing the decision-making patterns of potential medical travelers. Benefits and potential limitations are discussed. PMID:27252672
Generalized Mathematical Model for Hot Rolling Process of Plate
Institute of Scientific and Technical Information of China (English)
Zhenshan CUI; Bingye XU
2003-01-01
A generalized mathematical model is developed to predict the changes of temperature, rolling pressure, strain,strain rate, and austenite grain size for plate hot rolling and cooling processes. The model is established mainly by incorporating analytical an
Hsiao, Ju-Ling; Chen, Rai-Fu
2016-01-16
With the widespread use of information communication technologies, computerized clinical practice guidelines are developed and considered as effective decision supporting tools in assisting the processes of clinical activities. However, the development of computerized clinical practice guidelines in Taiwan is still at the early stage and acceptance level among major users (physicians) of computerized clinical practice guidelines is not satisfactory. This study aims to investigate critical factors influencing physicians' intention to computerized clinical practice guideline use through an integrative model of activity theory and the technology acceptance model. The survey methodology was employed to collect data from physicians of the investigated hospitals that have implemented computerized clinical practice guidelines. A total of 505 questionnaires were sent out, with 238 completed copies returned, indicating a valid response rate of 47.1 %. The collected data was then analyzed by structural equation modeling technique. The results showed that attitudes toward using computerized clinical practice guidelines (γ = 0.451, p critical factors influencing physicians' intention to use computerized clinical practice guidelines, and these factors can explain 68.6 % of the variance in intention to use computerized clinical practice guidelines. This study confirmed that some subject (human) factors, environment (organization) factors, tool (technology) factors mentioned in the activity theory should be carefully considered when introducing computerized clinical practice guidelines. Managers should pay much attention on those identified factors and provide adequate resources and incentives to help the promotion and use of computerized clinical practice guidelines. Through the appropriate use of computerized clinical practice guidelines, the clinical benefits, particularly in improving quality of care and facilitating the clinical processes, will be realized.
A Unified Model of All Generalizations from the Jones Polynomial
Institute of Scientific and Technical Information of China (English)
QIAN Shang-Wu; GU Zhi-Yu
2001-01-01
From the basic properties of skein systems, we build a generalized tangle algebra (GTA). The elements of GTA are four basic tangles. There are three operations, which are connection, splicing and scalar multiplication. From GTA we derive two generalized recursion formulae (GRF) and prove the existence of a generalized skein relation which satisfies GRF. The obtained generalized skein relation epitomizes all generalizations from the Jones polynomial and thus forms a unified model. Two important topological parameters, twisting measure and loop values, appear explicitly in the expressions of the unified model, and this fact greatly simplifies the operations.
Guidelines for a priori grouping of species in hierarchical community models
Pacifici, Krishna; Zipkin, Elise; Collazo, Jaime; Irizarry, Julissa I.; DeWan, Amielle A.
2014-01-01
Recent methodological advances permit the estimation of species richness and occurrences for rare species by linking species-level occurrence models at the community level. The value of such methods is underscored by the ability to examine the influence of landscape heterogeneity on species assemblages at large spatial scales. A salient advantage of community-level approaches is that parameter estimates for data-poor species are more precise as the estimation process borrows from data-rich species. However, this analytical benefit raises a question about the degree to which inferences are dependent on the implicit assumption of relatedness among species. Here, we assess the sensitivity of community/group-level metrics, and individual-level species inferences given various classification schemes for grouping species assemblages using multispecies occurrence models. We explore the implications of these groupings on parameter estimates for avian communities in two ecosystems: tropical forests in Puerto Rico and temperate forests in northeastern United States. We report on the classification performance and extent of variability in occurrence probabilities and species richness estimates that can be observed depending on the classification scheme used. We found estimates of species richness to be most precise and to have the best predictive performance when all of the data were grouped at a single community level. Community/group-level parameters appear to be heavily influenced by the grouping criteria, but were not driven strictly by total number of detections for species. We found different grouping schemes can provide an opportunity to identify unique assemblage responses that would not have been found if all of the species were analyzed together. We suggest three guidelines: (1) classification schemes should be determined based on study objectives; (2) model selection should be used to quantitatively compare different classification approaches; and (3) sensitivity
The General Optimal Market Area Model
1988-06-01
Spatial Competition, American Economic Review 68 (1978) 896. [19] G.M. Carter, J.M. Chaiken, and E. Ignall, Response Areas for Two Emergency Units...25] B.C. Eaton and R.G. Lipsey, The Non-Uniqueness of Equilibrium in the L6schian Location Model, American Economic Review 66 (1976) 77. [26, B.C...4 (1972) 154. [86] S. Valavanis, L6sch on Location, American Economic Review 45 (1955) 637. [87] B. Von Hohenbalken and D.S. West, Manhattan versus
Report to U. S. EPA of the specialists conference on the EPA modeling guideline
Energy Technology Data Exchange (ETDEWEB)
None
1977-01-01
The problem of air pollution control can be approached via two alternative though not mutually exclusive policies: management of emissions and management of air quality. In the former, emphasis is placed on the technology for control of effluents. Air quality management, on the other hand, entails the establishment of air quality goals based upon stated criteria or public policies. Emissions are then limited to the extent necessary to attain and maintain such goals. In the Clean Air Act of 1967, the amendments of 1970, and the most recently proposed amendments of 1976, the U.S. Congress has consistently endorsed a national policy of air quality management. The need within the national air pollution control program for a guidance document on air quality analysis persists. The EPA/Office of Air Quality Planning and Standards (OAQPS) has been given the responsibility for developing the requisite Guideline. The federal EPA and the states had to fulfill the important air quality management responsibilitiesemploying the state-of-the-art in analytical methods, the conferees were challenged to advise EPA on the best available approaches to modeling air quality impacts and to concur with or where possible recommend improvements to the many aspects of the problem addressed in the Guideline.
de Jong, J C
2008-09-27
The main value of the new guideline on influenza and influenza vaccination developed by the Dutch College of General Practitioners is that it provides an update of the old version from 1993. Developments in the fields of vaccination and treatment are adequately described and clearly explained in more detail in numerous notes to the main text. Notable updates include the fact that vaccination will be recommended for people aged more than 60 years rather than 65 years in the coming season, and the introduction ofneuraminidase inhibitors. The complex virological aspects of influenza are well covered.
Modeling electrokinetics in ionic liquids: General
Energy Technology Data Exchange (ETDEWEB)
Wang, Chao [Physical and Computational Science Directorate, Pacific Northwest National Laboratory, Richland WA USA; Bao, Jie [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland WA USA; Pan, Wenxiao [Department of Mechanical Engineering, University of Wisconsin-Madison, Madison WI USA; Sun, Xin [Physical and Computational Science Directorate, Pacific Northwest National Laboratory, Richland WA USA
2017-04-07
Using direct numerical simulations we provide a thorough study on the electrokinetics of ionic liquids. In particular, the modfied Poisson-Nernst-Planck (MPNP) equations are solved to capture the crowding and overscreening effects that are the characteristics of an ionic liquid. For modeling electrokinetic flows in an ionic liquid, the MPNP equations are coupled with the Navier-Stokes equations to study the coupling of ion transport, hydrodynamics, and electrostatic forces. Specifically, we consider the ion transport between two parallel plates, charging dynamics in a 2D straight-walled pore, electro-osmotic ow in a nano-channel, electroconvective instability on a plane ion-selective surface, and electroconvective ow on a curved ion-selective surface. We discuss how the crowding and overscreening effects and their interplay affect the electrokinetic behaviors of ionic liquids in these application problems.
Building a generalized distributed system model
Mukkamala, R.
1992-01-01
The key elements in the second year (1991-92) of our project are: (1) implementation of the distributed system prototype; (2) successful passing of the candidacy examination and a PhD proposal acceptance by the funded student; (3) design of storage efficient schemes for replicated distributed systems; and (4) modeling of gracefully degrading reliable computing systems. In the third year of the project (1992-93), we propose to: (1) complete the testing of the prototype; (2) enhance the functionality of the modules by enabling the experimentation with more complex protocols; (3) use the prototype to verify the theoretically predicted performance of locking protocols, etc.; and (4) work on issues related to real-time distributed systems. This should result in efficient protocols for these systems.
LENUS (Irish Health Repository)
Drummond, Frances J
2009-01-01
BACKGROUND: Increased use of prostate specific antigen (PSA) has been associated with increased prostate cancer incidence. Ireland is estimated to have one of the highest prostate cancer incidences in Europe and has no national guidelines for prostate cancer screening. GPs have a pivotal role in influencing PSA testing, therefore, our aim was to describe GP testing practices and to identify factors influencing these. METHODS: A postal survey, including questions on clinical practice and experience, knowledge and demographics was distributed to all GPs (n = 3,683). The main outcomes were (i) PSA testing asymptomatic men and (ii) "inappropriate" PSA testing, defined as testing asymptomatic men aged < 50 or > 75 years. Factors associated with these outcomes were identified using logistic regression. RESULTS: 1,625 GPs responded (response rate corrected for eligibility = 53%). Most respondents (79%) would PSA test asymptomatic men. Of these, 34% and 51% would test asymptomatic men < 50 and > 75 years, respectively. In multivariate analyses, GPs were more likely to test asymptomatic men if they were >or= 50 years, in practice >or= 10 years, female or less knowledgeable about PSA efficacy. Male GPs who would have a PSA test themselves were > 8-times more likely to PSA test asymptomatic men than GPs who would not have a test. GPs who had an asymptomatic patient diagnosed with prostate cancer following PSA testing, were > 3-times more likely to test asymptomatic men. Practice-related factors positively associated with testing included: running \\'well man\\' clinics, performing occupational health checks and performing other tests routinely with PSA. Factors positively associated with \\'inappropriate\\' testing included; being male and willing to have a PSA test, having worked\\/trained in the UK and supporting annual PSA testing. 91% of respondents supported the development of national PSA testing guidelines. CONCLUSION: Our findings suggest that widespread PSA testing
A generalized model via random walks for information filtering
Energy Technology Data Exchange (ETDEWEB)
Ren, Zhuo-Ming, E-mail: zhuomingren@gmail.com [Department of Physics, University of Fribourg, Chemin du Musée 3, CH-1700, Fribourg (Switzerland); Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, ChongQing, 400714 (China); Kong, Yixiu [Department of Physics, University of Fribourg, Chemin du Musée 3, CH-1700, Fribourg (Switzerland); Shang, Ming-Sheng, E-mail: msshang@cigit.ac.cn [Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, ChongQing, 400714 (China); Zhang, Yi-Cheng [Department of Physics, University of Fribourg, Chemin du Musée 3, CH-1700, Fribourg (Switzerland)
2016-08-06
There could exist a simple general mechanism lurking beneath collaborative filtering and interdisciplinary physics approaches which have been successfully applied to online E-commerce platforms. Motivated by this idea, we propose a generalized model employing the dynamics of the random walk in the bipartite networks. Taking into account the degree information, the proposed generalized model could deduce the collaborative filtering, interdisciplinary physics approaches and even the enormous expansion of them. Furthermore, we analyze the generalized model with single and hybrid of degree information on the process of random walk in bipartite networks, and propose a possible strategy by using the hybrid degree information for different popular objects to toward promising precision of the recommendation. - Highlights: • We propose a generalized recommendation model employing the random walk dynamics. • The proposed model with single and hybrid of degree information is analyzed. • A strategy with the hybrid degree information improves precision of recommendation.
A general and simple method for obtaining R2 from generalized linear mixed‐effects models
National Research Council Canada - National Science Library
Nakagawa, Shinichi; Schielzeth, Holger; O'Hara, Robert B
2013-01-01
The use of both linear and generalized linear mixed‐effects models ( LMM s and GLMM s) has become popular not only in social and medical sciences, but also in biological sciences, especially in the field of ecology and evolution...
Energy Technology Data Exchange (ETDEWEB)
Brannon, R.M.; Wong, M.K.
1996-08-01
A set of model interface guidelines, called MIG, is presented as a means by which any compliant numerical material model can be rapidly installed into any parent code without having to modify the model subroutines. Here, {open_quotes}model{close_quotes} usually means a material model such as one that computes stress as a function of strain, though the term may be extended to any numerical operation. {open_quotes}Parent code{close_quotes} means a hydrocode, finite element code, etc. which uses the model and enforces, say, the fundamental laws of motion and thermodynamics. MIG requires the model developer (who creates the model package) to specify model needs in a standardized but flexible way. MIG includes a dictionary of technical terms that allows developers and parent code architects to share a common vocabulary when specifying field variables. For portability, database management is the responsibility of the parent code. Input/output occurs via structured calling arguments. As much model information as possible (such as the lists of required inputs, as well as lists of precharacterized material data and special needs) is supplied by the model developer in an ASCII text file. Every MIG-compliant model also has three required subroutines to check data, to request extra field variables, and to perform model physics. To date, the MIG scheme has proven flexible in beta installations of a simple yield model, plus a more complicated viscodamage yield model, three electromechanical models, and a complicated anisotropic microcrack constitutive model. The MIG yield model has been successfully installed using identical subroutines in three vectorized parent codes and one parallel C++ code, all predicting comparable results. By maintaining one model for many codes, MIG facilitates code-to-code comparisons and reduces duplication of effort, thereby reducing the cost of installing and sharing models in diverse new codes.
Chatterjee, Robin; Chapman, Tim; Brannan, Mike Gt; Varney, Justin
2017-10-01
Physical activity (PA) brief advice in health care is effective at getting individuals active. It has been suggested that one in four people would be more active if advised by a GP or nurse, but as many as 72% of GPs do not discuss the benefits of physical activity with patients. To assess the knowledge, use, and confidence in national PA and Chief Medical Officer (CMO) health guidelines and tools among GPs in England. Online questionnaire-based survey of self-selecting GPs in England that took place over a 10-day period in March 2016. The questionnaire consisted of six multiple-choice questions and was available on the Doctors.net.uk (DNUK) homepage. Quotas were used to ensure good regional representation. The final analysis included 1013 responses. Only 20% of responders were broadly or very familiar with the national PA guidelines. In all, 70% of GPs were aware of the General Practice Physical Activity Questionnaire (GPPAQ), but 26% were not familiar with any PA assessment tools, and 55% reported that they had not undertaken any training with respect to encouraging PA. The majority of GPs in England (80%) are unfamiliar with the national PA guidelines. Awareness of the recommended tool for assessment, GPPAQ, is higher than use by GPs. This may be because it is used by other clinical staff, for example, as part of the NHS Health Check programme. Although brief advice in isolation by GPs on PA will only be a part of the behaviour change journey, it is an important prompt, especially if repeated as part of routine practice. This study highlights the need for significant improvement in knowledge, skills, and confidence to maximise the potential for PA advice in GP consultations. © British Journal of General Practice 2017.
Intermediate-generalized Chaplygin gas inflationary universe model
Energy Technology Data Exchange (ETDEWEB)
Herrera, Ramon; Olivares, Marco; Videla, Nelson [Pontificia Universidad Catolica de Valparaiso, Instituto de Fisica, Casilla, Valparaiso (Chile)
2013-01-15
An intermediate inflationary universe model in the context of a generalized Chaplygin gas is considered. For the matter we consider two different energy densities; a standard scalar field and a tachyon field, respectively. In general, we discuss the conditions of an inflationary epoch for these models. We also, use recent astronomical observations from Wilkinson Microwave Anisotropy Probe seven year data for constraining the parameters appearing in our models. (orig.)
Generalized Linear Models with Applications in Engineering and the Sciences
Myers, Raymond H; Vining, G Geoffrey; Robinson, Timothy J
2012-01-01
Praise for the First Edition "The obvious enthusiasm of Myers, Montgomery, and Vining and their reliance on their many examples as a major focus of their pedagogy make Generalized Linear Models a joy to read. Every statistician working in any area of applied science should buy it and experience the excitement of these new approaches to familiar activities."-Technometrics Generalized Linear Models: With Applications in Engineering and the Sciences, Second Edition continues to provide a clear introduction to the theoretical foundations and key applications of generalized linear models (GLMs). Ma
Kalman Filter for Generalized 2-D Roesser Models
Institute of Scientific and Technical Information of China (English)
SHENG Mei; ZOU Yun
2007-01-01
The design problem of the state filter for the generalized stochastic 2-D Roesser models, which appears when both the state and measurement are simultaneously subjected to the interference from white noise, is discussed. The wellknown Kalman filter design is extended to the generalized 2-D Roesser models. Based on the method of "scanning line by line", the filtering problem of generalized 2-D Roesser models with mode-energy reconstruction is solved. The formula of the optimal filtering, which minimizes the variance of the estimation error of the state vectors, is derived. The validity of the designed filter is verified by the calculation steps and the examples are introduced.
A General Polygon-based Deformable Model for Object Recognition
DEFF Research Database (Denmark)
Jensen, Rune Fisker; Carstensen, Jens Michael
1999-01-01
We propose a general scheme for object localization and recognition based on a deformable model. The model combines shape and image properties by warping a arbitrary prototype intensity template according to the deformation in shape. The shape deformations are constrained by a probabilistic...... distribution, which combined with a match of the warped intensity template and the image form the final criteria used for localization and recognition of a given object. The chosen representation gives the model an ability to model an almost arbitrary object. Beside the actual model a full general scheme...
O'Reilly-de Brún, Mary; MacFarlane, Anne; de Brún, Tomas; Okonkwo, Ekaterina; Bonsenge Bokanga, Jean Samuel; Manuela De Almeida Silva, Maria; Ogbebor, Florence; Mierzejewska, Aga; Nnadi, Lovina; van den Muijsenbergh, Maria; van Weel-Baumgarten, Evelyn; van Weel, Chris
2015-01-01
Objective The aim of this research was to involve migrants and other key stakeholders in a participatory dialogue to develop a guideline for enhancing communication in cross-cultural general practice consultations. In this paper, we focus on findings about the use of formal versus informal interpreters because dialogues about these issues emerged as central to the identification of recommendations for best practice. Design This qualitative case study involved a Participatory Learning and Action (PLA) research methodology. Participants The sample comprised 80 stakeholders: 51 from migrant communities; 15 general practitioners (GPs) and general practice staff; 7 established migrants as peer researchers; 5 formal, trained interpreters; and 2 service planners from the national health authority. Setting Galway, Ireland. Results There was 100% consensus across stakeholder groups that while informal interpreters have uses for migrants and general practice staff, they are not considered acceptable as best practice. There was also 100% consensus that formal interpreters who are trained and working as per a professional code of practice are acceptable as best practice. Conclusions Policymakers and service planners need to work in partnership with service providers and migrants to progress the implementation of professional, trained interpreters as a routine way of working in general practice. PMID:26391628
Calibrating the ECCO ocean general circulation model using Green's functions
Menemenlis, D.; Fu, L. L.; Lee, T.; Fukumori, I.
2002-01-01
Green's functions provide a simple, yet effective, method to test and calibrate General-Circulation-Model(GCM) parameterizations, to study and quantify model and data errors, to correct model biases and trends, and to blend estimates from different solutions and data products.
A Duality Result for the Generalized Erlang Risk Model
Directory of Open Access Journals (Sweden)
Lanpeng Ji
2014-11-01
Full Text Available In this article, we consider the generalized Erlang risk model and its dual model. By using a conditional measure-preserving correspondence between the two models, we derive an identity for two interesting conditional probabilities. Applications to the discounted joint density of the surplus prior to ruin and the deficit at ruin are also discussed.
General Linear Models: An Integrated Approach to Statistics
Andrew Faulkner; Sylvain Chartier
2008-01-01
Generally, in psychology, the various statistical analyses are taught independently from each other. As a consequence, students struggle to learn new statistical analyses, in contexts that differ from their textbooks. This paper gives a short introduction to the general linear model (GLM), in which it is showed that ANOVA (one-way, factorial, repeated measure and analysis of covariance) is simply a multiple correlation/regression analysis (MCRA). Generalizations to other cases, such as multiv...
Parameter Estimation for a Computable General Equilibrium Model
DEFF Research Database (Denmark)
Arndt, Channing; Robinson, Sherman; Tarp, Finn
2002-01-01
We introduce a maximum entropy approach to parameter estimation for computable general equilibrium (CGE) models. The approach applies information theory to estimating a system of non-linear simultaneous equations. It has a number of advantages. First, it imposes all general equilibrium constraints...
Duals for classical inventory models via generalized geometric programming
Carlton H. Scott; Thomas R. Jefferson; Soheila Jorjani
2004-01-01
Inventory problems generally have a structure that can be exploited for computational purposes. Here, we look at the duals of two seemingly unrelated inventory models that suggest an interesting duality between discrete time optimal control and optimization over an ordered sequence of variables. Concepts from conjugate duality and generalized geometric programming are used to establish the duality.
Ising model on the generalized Bruhat-Tits tree
Zinoviev, Yu. M.
1991-08-01
The partition function and the correlation functions of the Ising model on the generalized Bruhat-Tits tree are calculated. We computed also the averages of these correlation functions when the corresponding vertices are attached to the boundary of the generalized Bruhat-Tits tree.
Parameter Estimation for a Computable General Equilibrium Model
DEFF Research Database (Denmark)
Arndt, Channing; Robinson, Sherman; Tarp, Finn
We introduce a maximum entropy approach to parameter estimation for computable general equilibrium (CGE) models. The approach applies information theory to estimating a system of nonlinear simultaneous equations. It has a number of advantages. First, it imposes all general equilibrium constraints...
Study on Solitary Waves of a General Boussinesq Model
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
In this paper, we employ the bifurcation method of dynamical systems to study the solitary waves and periodic waves of a generalized Boussinesq equations. All possible phase portraits in the parameter plane for the travelling wave systems are obtained. The possible solitary wave solutions, periodic wave solutions and cusp waves for the general Boussinesq type fluid model are also investigated.
Finite Element Modeling of Metasurfaces with Generalized Sheet Transition Conditions
Sandeep, Srikumar; Caloz, Christophe
2016-01-01
A modeling of metasurfaces in the finite element method (FEM) based on generalized sheet transition conditions (GSTCs) is presented. The discontinuities in electromagnetic fields across a metasurface as represented by the GSTC are modeled by assigning nodes to both sides of the metasurface. The FEM-GSTC formulation in both 1D and 2D domains is derived and implemented. The method is extended to handle more general bianistroptic metasurfaces. The formulations are validated by several illustrative examples.
A QCD Model Using Generalized Yang-Mills Theory
Institute of Scientific and Technical Information of China (English)
WANG Dian-Fu; SONG He-Shan; KOU Li-Na
2007-01-01
Generalized Yang-Mills theory has a covariant derivative,which contains both vector and scalar gauge bosons.Based on this theory,we construct a strong interaction model by using the group U(4).By using this U(4)generalized Yang-Mills model,we also obtain a gauge potential solution,which can be used to explain the asymptotic behavior and color confinement.
Dynamical CP violation of the generalized Yang-Mills model
Institute of Scientific and Technical Information of China (English)
WANG Dian-Fu; SUN Xiao-Yu; CHANG Xiao-Jing
2011-01-01
Starting from the generalized Yang-Mills model which contains, besides the vector part Vμ, also a scalar part S and a pseudoscalar part P. It is shown, in terms of the Nambu-Jona-Lasinio (NJL) mechanism,that CP violation can be realized dynamically. The combination of the generalized Yang-MiUs model and the NJL mechanism provides a new way to explain CP violation.
Institute of Scientific and Technical Information of China (English)
Rendao YE; Songgui WANG
2007-01-01
Various random models with balanced data that are relevant for analyzing practical test data are described, along with several hypothesis testing and interval estimation problems concerning variance components. In this paper, we mainly consider these problems in general random effect model with balanced data. Exact tests and confidence intervals for a single variance component corresponding to random effect are developed by using generalized p-values and generalized confidence intervals.The resulting procedures are easy to compute and are applicable to small samples. Exact tests and confidence intervals are also established for comparing the random-effects variance components and the sum of random-effects variance components in two independent general random effect models with balanced data. Furthermore, we investigate the statistical properties of the resulting tests. Finally,some simulation results on the type Ⅰ error probability and power of the proposed test are reported.The simulation results indicate that exact test is extremely satisfactory for controlling type Ⅰ error probability.
Novel model-based dosing guidelines for gentamicin and tobramycin in preterm and term neonates
P.A.J. Välitalo (Pyry A. J.); J.N. van den Anker (John); K. Allegaert (Karel); R.F.W. de Cock (Roosmarijn); M. de Hoog (Matthijs); S.H. Simons (Sinno); J.W. Mouton (Johan); C.A.J. Knibbe (Catherijne)
2015-01-01
textabstractObjectives: In the heterogeneous group of preterm and term neonates, gentamicin and tobramycin are mainly dosed according to empirical guidelines, after which therapeutic drug monitoring and subsequent dose adaptation are applied. In view of the variety of neonatal guidelines available,
DEFF Research Database (Denmark)
Kostoulas, Polychronis; Nielsen, Søren S.; Branscum, Adam J.
2017-01-01
Evaluation of medical tests is usually based on comparing their results to those from a perfect reference (gold standard) procedure. The Standards for Reporting of Diagnostic Accuracy (STARD) initiative (http://www.equator-network.org/reporting-guidelines/stard/) developed reporting guidelines fo...
Inflationary Weak Anisotropic Model with General Dissipation Coefficient
Sharif, M
2015-01-01
This paper explores the dynamics of warm intermediate and logamediate inflationary models during weak dissipative regime with a general form of dissipative coefficient. We analyze these models within the framework of locally rotationally symmetric Bianchi type I universe. In both cases, we evaluate solution of inflaton, effective scalar potential, dissipative coefficient, slow-roll parameters, scalar and tensor power spectra, scalar spectral index and tensor to scalar ratio under slow-roll approximation. We constrain the model parameters using recent data and conclude that anisotropic inflationary universe model with generalized dissipation coefficient remains compatible with WMAP9, Planck and BICEP2 data.
Extending the generalized Chaplygin gas model by using geometrothermodynamics
Aviles, Alejandro; Campuzano, Lorena; Quevedo, Hernando
2012-01-01
We use the formalism of geometrothermodynamics (GTD) to derive fundamental thermodynamic equations that are used to construct general relativistic cosmological models. In particular, we show that the simplest possible fundamental equation, which corresponds in GTD to a system with no internal thermodynamic interaction, describes the different fluids of the standard model of cosmology. In addition, a particular fundamental equation with internal thermodynamic interaction is shown to generate a new cosmological model that correctly describes the dark sector of the Universe and contains as a special case the generalized Chaplygin gas model.
African wave disturbances in a general circulation model
Estoque, M. A.; Jiing, J. G.; Shukla, J.
1983-01-01
Evidence is presented to show that African wave disturbances are reproduced in a general circulation simulation. The model used is the general circulation model developed by the Goddard Laboratory for Atmospheric Sciences of the National Aeronautics and Space Agency. The model was integrated in order to simulate the summer of 1974. A synoptic analysis of the simulated data over Africa for the month of July was done. The results of the analysis show that wave disturbances are generated by the model; the behavior and the structure of the simulated disturbances are similar to those observed over tropical Africa during the northern summer.
Generalized continua as models for classical and advanced materials
Forest, Samuel
2016-01-01
This volume is devoted to an actual topic which is the focus world-wide of various research groups. It contains contributions describing the material behavior on different scales, new existence and uniqueness theorems, the formulation of constitutive equations for advanced materials. The main emphasis of the contributions is directed on the following items - Modelling and simulation of natural and artificial materials with significant microstructure, - Generalized continua as a result of multi-scale models, - Multi-field actions on materials resulting in generalized material models, - Theories including higher gradients, and - Comparison with discrete modelling approaches.
General Friction Model Extended by the Effect of Strain Hardening
DEFF Research Database (Denmark)
Nielsen, Chris V.; Martins, Paulo A.F.; Bay, Niels
2016-01-01
An extension to the general friction model proposed by Wanheim and Bay [1] to include the effect of strain hardening is proposed. The friction model relates the friction stress to the fraction of real contact area by a friction factor under steady state sliding. The original model for the real co...... of friction in metal forming, where the material generally strain hardens. The extension of the model to cover strain hardening materials is validated by comparison to previously published experimental data.......An extension to the general friction model proposed by Wanheim and Bay [1] to include the effect of strain hardening is proposed. The friction model relates the friction stress to the fraction of real contact area by a friction factor under steady state sliding. The original model for the real......-ideally plastic material, and secondly, to extend the solution by the influence of material strain hardening. This corresponds to adding a new variable and, therefore, a new axis to the general friction model. The resulting model is presented in a combined function suitable for e.g. finite element modeling...
Pricing Participating Products under a Generalized Jump-Diffusion Model
Directory of Open Access Journals (Sweden)
Tak Kuen Siu
2008-01-01
Full Text Available We propose a model for valuing participating life insurance products under a generalized jump-diffusion model with a Markov-switching compensator. It also nests a number of important and popular models in finance, including the classes of jump-diffusion models and Markovian regime-switching models. The Esscher transform is employed to determine an equivalent martingale measure. Simulation experiments are conducted to illustrate the practical implementation of the model and to highlight some features that can be obtained from our model.
A Generalized Rough Set Modeling Method for Welding Process
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
Modeling is essential, significant and difficult for the quality and shaping control of arc welding process. A generalized rough set based modeling method was brought forward and a dynamic predictive model for pulsed gas tungsten arc welding (GTAW) was obtained by this modeling method. The results show that this modeling method can well acquire knowledge in welding and satisfy the real life application. In addition, the results of comparison between classic rough set model and back-propagation neural network model respectively are also satisfying.
Easterbrook, Philippa J; Doherty, Meg C; Perriëns, Joseph H; Barcarolo, Jhoney L; Hirnschall, Gottfried O
2014-01-01
Despite the exponential growth in the literature on modelling and simulation studies of impact and cost-effectiveness in different aspects of healthcare, there is no clear consensus on the appropriate role of modelling in the development of recommendations in clinical guidelines. This is compounded both by the lack of a standardised approach to assess the quality of modelling, and lack of clarity on its positioning within the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) method for decision-making in the development of WHO guidelines, that considers both evidence from systematic reviews of randomized clinical trials (RTCs) or observational studies, together with stakeholder values and preferences, resource use, and feasibility issues. In the development of the 2013 WHO Consolidated Guidelines on the use of Antiretroviral drugs for treating and preventing HIV infection, a series of modelling projects were undertaken to inform the recommendations on eligibility criteria for ART initiation, and approaches to monitoring for treatment response. We report our experiences, challenges encountered, and several key considerations to guide the future use of modelling in the development of WHO guidelines. These are: (1) Transparency in the conduct and reporting of model inputs and results; (2) The need for agreed standards for critical appraisal and use of modelling data in healthcare policy making; (3) recognition that modelling of cost-effectiveness is only one component of decision-making in development of WHO recommendations and in priority-setting; (4) The need for closer interaction and an ongoing dialogue between modellers and model end-users or decision-makers; (5) the important role of WHO in convening and facilitating comparative assessment of multiple models; and (6) The need to optimize research and data collection to inform modelling studies.
Adaptation of a general circulation model to ocean dynamics
Turner, R. E.; Rees, T. H.; Woodbury, G. E.
1976-01-01
A primitive-variable general circulation model of the ocean was formulated in which fast external gravity waves are suppressed with rigid-lid surface constraint pressires which also provide a means for simulating the effects of large-scale free-surface topography. The surface pressure method is simpler to apply than the conventional stream function models, and the resulting model can be applied to both global ocean and limited region situations. Strengths and weaknesses of the model are also presented.
Guidelines, evidence, and cultural factors.
Christiaens, T.; Backer, D. de; Burgers, J.S.; Baerheim, A.
2004-01-01
OBJECTIVE: To compare four recent guidelines on uncomplicated cystitis and to examine how cultural factors may have affected recommendations. DESIGN: Descriptive study with a qualitative analysis of authors' reasons for recommendations. MATERIAL: Guidelines for general practitioners published
Model Reduction of Switched Systems Based on Switching Generalized Gramians
DEFF Research Database (Denmark)
Shaker, Hamid Reza; Wisniewski, Rafal
2012-01-01
In this paper, a general method for model order reduction of discrete-time switched linear systems is presented. The proposed technique uses switching generalized gramians. It is shown that several classical reduction methods can be developed into the generalized gramian framework for the model r......-Galerkin projection is constructed instead of the similarity transform approach for reduction. It is proven that the proposed reduction framework preserves the stability of the original switched system. The performance of the method is illustrated by numerical examples....
Generalized multidirectional fuzzy map model of the logistics system networks
Ji, Chun-Rong; Liu, Ming-Yuan; Li, Yan; He, Yue M.
1997-07-01
By conducting [0, 1] treatment to time consuming of logistics system network key links, and regarding the time consumed by manufacture, inspection, storage, assembling, packing and market as a kind of existent extent of the joint and the time consumed by materials handling, transportation and logistics information as the connection strength between joints in a generalized multi-directional fuzzy map, a generalized multi-directional fuzzy map model of logistics system networks is built. The mutual flow among network joints and the special form of generalized fuzzy matrix is analyzed. Finally, an example of model building is given.
General autocatalytic theory and simple model of financial markets
Thuy Anh, Chu; Lan, Nguyen Tri; Viet, Nguyen Ai
2015-06-01
The concept of autocatalytic theory has become a powerful tool in understanding evolutionary processes in complex systems. A generalization of autocatalytic theory was assumed by considering that the initial element now is being some distribution instead of a constant value as in traditional theory. This initial condition leads to that the final element might have some distribution too. A simple physics model for financial markets is proposed, using this general autocatalytic theory. Some general behaviours of evolution process and risk moment of a financial market also are investigated in framework of this simple model.
A generalized statistical model for the size distribution of wealth
Clementi, F.; Gallegati, M.; Kaniadakis, G.
2012-12-01
In a recent paper in this journal (Clementi et al 2009 J. Stat. Mech. P02037), we proposed a new, physically motivated, distribution function for modeling individual incomes, having its roots in the framework of the κ-generalized statistical mechanics. The performance of the κ-generalized distribution was checked against real data on personal income for the United States in 2003. In this paper we extend our previous model so as to be able to account for the distribution of wealth. Probabilistic functions and inequality measures of this generalized model for wealth distribution are obtained in closed form. In order to check the validity of the proposed model, we analyze the US household wealth distributions from 1984 to 2009 and conclude an excellent agreement with the data that is superior to any other model already known in the literature.
Classical tests of general relativity in brane world models
Energy Technology Data Exchange (ETDEWEB)
Boehmer, Christian G [Department of Mathematics and Institute of Origins, University College London, Gower Street, London WC1E 6BT (United Kingdom); De Risi, Giuseppe [Dipartimento di Fisica, Universita degli studi di Bari and Istituto Nazionale di Fisica Nucleare, sez. di Bari, Via G. Amendola 173, 70126 Bari (Italy); Harko, Tiberiu [Department of Physics and Center for Theoretical and Computational Physics, University of Hong Kong, Pok Fu Lam Road (Hong Kong); Lobo, Francisco S N, E-mail: c.boehmer@ucl.ac.u, E-mail: giuseppe.derisi@ba.infn.i, E-mail: harko@hkucc.hku.h, E-mail: flobo@cii.fc.ul.p [Centro de Astronomia e Astrofisica da Universidade de Lisboa, Campo Grande, Ed. C8 1749-016 Lisboa (Portugal)
2010-09-21
The classical tests of general relativity (perihelion precession, deflection of light and the radar echo delay) are considered for several spherically symmetric static vacuum solutions in brane world models. Generally, the spherically symmetric vacuum solutions of the brane gravitational field equations have properties quite distinct as compared to the standard black hole solutions of general relativity. As a first step a general formalism that facilitates the analysis of general relativistic Solar System tests for any given spherically symmetric metric is developed. It is shown that the existing observational Solar System data on the perihelion shift of Mercury, on the light bending around the Sun (obtained using long-baseline radio interferometry), and ranging to Mars using the Viking lander constrain the numerical values of the parameters of the specific models.
Classical tests of general relativity in brane world models
Boehmer, Christian G; Harko, Tiberiu; Lobo, Francisco S N
2009-01-01
The classical tests of general relativity (perihelion precession, deflection of light, and the radar echo delay) are considered for several spherically symmetric static vacuum solutions in brane world models. Generally, the spherically symmetric vacuum solutions of the brane gravitational field equations have properties quite distinct as compared to the standard black hole solutions of general relativity. As a first step a general formalism that facilitates the analysis of general relativistic Solar System tests for any given spherically symmetric metric is developed. It is shown that the existing observational Solar System data on the perihelion shift of Mercury, on the light bending around the Sun (obtained using long-baseline radio interferometry), and ranging to Mars using the Viking lander, constrain the numerical values of the parameters of the specific models. Hence Solar System tests represent very convenient and efficient tools to test the viability of the different black hole solutions in brane worl...
A generalized model via random walks for information filtering
Ren, Zhuo-Ming; Kong, Yixiu; Shang, Ming-Sheng; Zhang, Yi-Cheng
2016-08-01
There could exist a simple general mechanism lurking beneath collaborative filtering and interdisciplinary physics approaches which have been successfully applied to online E-commerce platforms. Motivated by this idea, we propose a generalized model employing the dynamics of the random walk in the bipartite networks. Taking into account the degree information, the proposed generalized model could deduce the collaborative filtering, interdisciplinary physics approaches and even the enormous expansion of them. Furthermore, we analyze the generalized model with single and hybrid of degree information on the process of random walk in bipartite networks, and propose a possible strategy by using the hybrid degree information for different popular objects to toward promising precision of the recommendation.
Nonlocal Generalized Models of Predator-Prey Systems
Kuehn, Christian
2011-01-01
The method of generalized modeling has been applied successfully in many different contexts, particularly in ecology and systems biology. It can be used to analyze the stability and bifurcations of steady-state solutions. Although many dynamical systems in mathematical biology exhibit steady-state behaviour one also wants to understand nonlocal dynamics beyond equilibrium points. In this paper we analyze predator-prey dynamical systems and extend the method of generalized models to periodic solutions. First, we adapt the equilibrium generalized modeling approach and compute the unique Floquet multiplier of the periodic solution which depends upon so-called generalized elasticity and scale functions. We prove that these functions also have to satisfy a flow on parameter (or moduli) space. Then we use Fourier analysis to provide computable conditions for stability and the moduli space flow. The final stability analysis reduces to two discrete convolutions which can be interpreted to understand when the predator...
General expression for linear and nonlinear time series models
Institute of Scientific and Technical Information of China (English)
Ren HUANG; Feiyun XU; Ruwen CHEN
2009-01-01
The typical time series models such as ARMA, AR, and MA are founded on the normality and stationarity of a system and expressed by a linear difference equation; therefore, they are strictly limited to the linear system. However, some nonlinear factors are within the practical system; thus, it is difficult to fit the model for real systems with the above models. This paper proposes a general expression for linear and nonlinear auto-regressive time series models (GNAR). With the gradient optimization method and modified AIC information criteria integrated with the prediction error, the parameter estimation and order determination are achieved. The model simulation and experiments show that the GNAR model can accurately approximate to the dynamic characteristics of the most nonlinear models applied in academics and engineering. The modeling and prediction accuracy of the GNAR model is superior to the classical time series models. The proposed GNAR model is flexible and effective.
A Total Generalized Optimal Velocity Model and Its Numerical Tests
Institute of Scientific and Technical Information of China (English)
ZHU Wen-xing; LIU Yun-cai
2008-01-01
A car-following model named total generalized optimal velocity model (TGOVM) was developed with a consideration of an arbitrary number of preceding vehicles before current one based on analyzing the previous models such as optimal velocity model (OVM), generalized OVM (GOVM) and improved GOVM (IGOVM). This model describes the physical phenomena of traffic flow more exactly and realistically than previous models. Also the performance of this model was checked out by simulating the acceleration and de- celeration process for a small delay time. On a single circular lane, the evolution of the traffic congestion was studied for a different number of headways and relative velocities of the preceding vehicles being taken into account. The simulation results show that TGOVM is reasonable and correct.
Energy Technology Data Exchange (ETDEWEB)
Hsu, Wen-Sheng, E-mail: wshsu@ess.nthu.edu.tw [Nuclear Science and Technology Development Center, Institute of Nuclear Engineering and Science, National Tsing Hua University, Nuclear and New Energy Education and Research Foundation, No. 101, Section 2, Kuang Fu Rd., HsinChu 30013, Taiwan, ROC (China); Chiang, Yu, E-mail: s101013702@m101.nthu.edu.tw [Nuclear Science and Technology Development Center, Institute of Nuclear Engineering and Science, National Tsing Hua University, Nuclear and New Energy Education and Research Foundation, No. 101, Section 2, Kuang Fu Rd., HsinChu 30013, Taiwan, ROC (China); Wang, Jong-Rong, E-mail: jongrongwang@gmail.com [Nuclear Science and Technology Development Center, Institute of Nuclear Engineering and Science, National Tsing Hua University, Nuclear and New Energy Education and Research Foundation, No. 101, Section 2, Kuang Fu Rd., HsinChu 30013, Taiwan, ROC (China); Wang, Ting-Yi, E-mail: minired1119@gmail.com [Nuclear Science and Technology Development Center, Institute of Nuclear Engineering and Science, National Tsing Hua University, Nuclear and New Energy Education and Research Foundation, No. 101, Section 2, Kuang Fu Rd., HsinChu 30013, Taiwan, ROC (China); Wang, Te-Chuan, E-mail: tcwang@iner.gov.tw [Institute of Nuclear Energy Research Atomic Energy Council, R.O.C., 1000, Wenhua Road Jiaan Village, Longtan Township, Taoyuan County 32546, Taiwan (China); Teng, Jyh-Tong, E-mail: jyhtong@cycu.edu.tw [Department of Mechanical Engineering, Chung Yuan Christian University, 200, Chung Pei Rd, Chung Li 32023, Taiwan, ROC (China); Chen, Shao-Wen, E-mail: chensw@mx.nthu.edu.tw [Nuclear Science and Technology Development Center, Institute of Nuclear Engineering and Science, National Tsing Hua University, Nuclear and New Energy Education and Research Foundation, No. 101, Section 2, Kuang Fu Rd., HsinChu 30013, Taiwan, ROC (China); and others
2017-01-15
Highlights: • The establishment of a MELCOR/SNAP model of Chinshan (BWR/4). • MELCOR/SNAP model was used to estimate the effectiveness of URG for Chinshan. • The MELCOR results were compared to MAAP, TRACE and PCTRAN. • URG is a new method to prevent a Fukushima-like accident. • The low raw water (150 GPM) can make the cladding temperature below 1088.7 K. - Abstract: After Fukushima Daiichi disaster, the safety analysis of severe accidents became one of the safety concerns in Taiwan. The Emergency Operating Procedure (EOP) cannot cope with a multiple system failure situation under a severe accident since it is a “Symptom-basis” procedure. To deal with that, Taiwan Power Company built up a new strategy for Fukushima-like accident called Ultimate Response Guideline (URG). It is a simple strategy with three main conditions: loss of regular motor driven injection system, loss of all AC power and tsunami/earthquake warning. If two of three happen, the operating procedure will change from EOP to URG and start the main works by following the strategy. There are three main works in URG: controlled-depressurization, line up low pressure injection water and prepare containment venting. In this study, MELCOR2.1 was used to calculate the cases of URG and checked the goal of the strategy that prevents the accident or not. There were three steps in this research. First, a model of Chinshan nuclear power plant (NPP) was built. Second, one was the case with URG and the other was not by using the above MELCOR model. The results were compared to MAAP5.0, TRACE and PCTRAN. Finally, some sensitivity studies of depressurization and water injection rate were done.
Nonstructural seismic restraint guidelines
Energy Technology Data Exchange (ETDEWEB)
Butler, D.M.; Czapinski, R.H.; Firneno, M.J.; Feemster, H.C.; Fornaciari, N.R.; Hillaire, R.G.; Kinzel, R.L.; Kirk, D.; McMahon, T.T.
1993-08-01
The Nonstructural Seismic Restraint Guidelines provide general information about how to secure or restrain items (such as material, equipment, furniture, and tools) in order to prevent injury and property, environmental, or programmatic damage during or following an earthquake. All SNL sites may experience earthquakes of magnitude 6.0 or higher on the Richter scale. Therefore, these guidelines are written for all SNL sites.
A generalized trigonometric series function model for determining ionospheric delay
Institute of Scientific and Technical Information of China (English)
YUAN Yunbin; OU Jikun
2004-01-01
A generalized trigonometric series function (GTSF) model, with an adjustable number of parameters, is proposed and analyzed to study ionosphere by using GPS, especially to provide ionospheric delay correction for single frequency GPS users. The preliminary results show that, in comparison with the trigonometric series function (TSF) model and the polynomial (POLY) model, the GTSF model can more precisely describe the ionospheric variation and more efficiently provide the ionospheric correction when GPS data are used to investigate or extract the earth's ionospheric total electron content. It is also shown that the GTSF model can further improve the precision and accuracy of modeling local ionospheric delays.
A generalized hard-sphere model for Monte Carlo simulation
Hassan, H. A.; Hash, David B.
1993-01-01
A new molecular model, called the generalized hard-sphere, or GHS model, is introduced. This model contains, as a special case, the variable hard-sphere model of Bird (1981) and is capable of reproducing all of the analytic viscosity coefficients available in the literature that are derived for a variety of interaction potentials incorporating attraction and repulsion. In addition, a new procedure for determining interaction potentials in a gas mixture is outlined. Expressions needed for implementing the new model in the direct simulation Monte Carlo methods are derived. This development makes it possible to employ interaction models that have the same level of complexity as used in Navier-Stokes calculations.
A generalized item response tree model for psychological assessments.
Jeon, Minjeong; De Boeck, Paul
2016-09-01
A new item response theory (IRT) model with a tree structure has been introduced for modeling item response processes with a tree structure. In this paper, we present a generalized item response tree model with a flexible parametric form, dimensionality, and choice of covariates. The utilities of the model are demonstrated with two applications in psychological assessments for investigating Likert scale item responses and for modeling omitted item responses. The proposed model is estimated with the freely available R package flirt (Jeon et al., 2014b).
A random effects generalized linear model for reliability compositive evaluation
Institute of Scientific and Technical Information of China (English)
无
2009-01-01
This paper first proposes a random effects generalized linear model to evaluate the storage life of one kind of high reliable and small sample-sized products by combining multi-sources information of products coming from the same population but stored at different environments. The relevant algorithms are also provided. Simulation results manifest the soundness and effectiveness of the proposed model.
Bianchi type IX string cosmological model in general relativity
Indian Academy of Sciences (India)
Raj Bali; Shuchi Dave
2001-04-01
We have investigated Bianchi type IX string cosmological models in general relativity. To get a determinate solution, we have assumed a condition ρ= i.e. rest energy density for a cloud of strings is equal to the string tension density. The various physical and geometrical aspects of the models are also discussed.
A general model for matroids and the greedy algorithm
Faigle, U.; Fujishige, Saturo
2009-01-01
We present a general model for set systems to be independence families with respect to set families which determine classes of proper weight functions on a ground set. Within this model, matroids arise from a natural subclass and can be characterized by the optimality of the greedy algorithm. This
General Separations Area (GSA) Groundwater Flow Model Update: Hydrostratigraphic Data
Energy Technology Data Exchange (ETDEWEB)
Bagwell, L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Bennett, P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Flach, G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2017-02-21
This document describes the assembly, selection, and interpretation of hydrostratigraphic data for input to an updated groundwater flow model for the General Separations Area (GSA; Figure 1) at the Department of Energy’s (DOE) Savannah River Site (SRS). This report is one of several discrete but interrelated tasks that support development of an updated groundwater model (Bagwell and Flach, 2016).
Applying the General Linear Model to Repeated Measures Problems.
Pohlmann, John T.; McShane, Michael G.
The purpose of this paper is to demonstrate the use of the general linear model (GLM) in problems with repeated measures on a dependent variable. Such problems include pretest-posttest designs, multitrial designs, and groups by trials designs. For each of these designs, a GLM analysis is demonstrated wherein full models are formed and restrictions…
A random effects generalized linear model for reliability compositive evaluation
Institute of Scientific and Technical Information of China (English)
ZHAO Hui; YU Dan
2009-01-01
This paper first proposes a random effects generalized linear model to evaluate the storage life of one kind of high reliable and small sample-sized products by combining multi-sources information of products coming from the same population but stored at different environments.The relevant algorithms are also provided.Simulation results manifest the soundness and effectiveness of the proposed model.
A generalized dynamic conditional correlation model for many asset returns
C.M. Hafner (Christian); Ph.H.B.F. Franses (Philip Hans)
2003-01-01
textabstractIn this paper we put forward a generalization of the Dynamic Conditional Correlation (DCC) Model of Engle (2002). Our model allows for asset-specific correlation sensitivities, which is useful in particular if one aims to summarize a large number of asset returns. The resultant GDCC
A generalized dynamic conditional correlation model for many asset returns
C.M. Hafner (Christian); Ph.H.B.F. Franses (Philip Hans)
2003-01-01
textabstractIn this paper we put forward a generalization of the Dynamic Conditional Correlation (DCC) Model of Engle (2002). Our model allows for asset-specific correlation sensitivities, which is useful in particular if one aims to summarize a large number of asset returns. The resultant GDCC mode
A general model for membrane-based separation processes
DEFF Research Database (Denmark)
Soni, Vipasha; Abildskov, Jens; Jonsson, Gunnar Eigil;
2009-01-01
behaviour will play an important role. In this paper, modelling of membrane-based processes for separation of gas and liquid mixtures are considered. Two general models, one for membrane-based liquid separation processes (with phase change) and another for membrane-based gas separation are presented...
Bayesian Analysis for Binomial Models with Generalized Beta Prior Distributions.
Chen, James J.; Novick, Melvin, R.
1984-01-01
The Libby-Novick class of three-parameter generalized beta distributions is shown to provide a rich class of prior distributions for the binomial model that removes some restrictions of the standard beta class. A numerical example indicates the desirability of using these wider classes of densities for binomial models. (Author/BW)
An applied general equilibrium model for Dutch agribusiness policy analysis.
Peerlings, J.H.M.
1993-01-01
The purpose of this thesis was to develop a basic static applied general equilibrium (AGE) model to analyse the effects of agricultural policy changes on Dutch agribusiness. In particular the effects on inter-industry transactions, factor demand, income, and trade are of interest.The model is fairly
Residuals analysis of the generalized linear models for longitudinal data.
Chang, Y C
2000-05-30
The generalized estimation equation (GEE) method, one of the generalized linear models for longitudinal data, has been used widely in medical research. However, the related sensitivity analysis problem has not been explored intensively. One of the possible reasons for this was due to the correlated structure within the same subject. We showed that the conventional residuals plots for model diagnosis in longitudinal data could mislead a researcher into trusting the fitted model. A non-parametric method, named the Wald-Wolfowitz run test, was proposed to check the residuals plots both quantitatively and graphically. The rationale proposedin this paper is well illustrated with two real clinical studies in Taiwan.
Interaction Strength and a Generalized Bak-Sneppen Evolution Model
Institute of Scientific and Technical Information of China (English)
李炜; 蔡勖
2002-01-01
The Bak-Sneppen evolution model is generalized in terms of a new concept and quantity: interaction strength.Based on a quantitative definition, the interaction strength describes the strength of the interaction between thenearest-neighbour individuals in the model Self-organized criticality is observed for the generalized model withten different values of interaction strength. The gap equation governing the self-organization is derived. It is alsofound that the self-organized threshold depends on the value of the interaction strength.
A general technique to train language models on language models
Nederhof, MJ
2005-01-01
We show that under certain conditions, a language model can be trained oil the basis of a second language model. The main instance of the technique trains a finite automaton on the basis of a probabilistic context-free grammar, such that the Kullback-Leibler distance between grammar and trained auto
León Ruiz, M; Rodríguez Sarasa, M L; Sanjuán Rodríguez, L; Pérez Nieves, M T; Ibáñez Estéllez, F; Arce Arce, S; García-Albea Ristol, E; Benito-León, J
2017-02-27
Very little has been written on seizure management in palliative care (PC). Given this situation, and considering the forthcoming setting up of the Palliative Care Unit at our neurorehabilitation centre, the Clínica San Vicente, we decided to establish a series of guidelines on the use of antiepileptic drugs (AEDs) for handling seizures in PC. We conducted a literature search in PubMed to identify articles, recent manuals, and clinical practice guidelines on seizure management in PC published by the most relevant scientific societies. Clinical practice guidelines are essential to identify patients eligible for PC, manage seizures adequately, and avoid unnecessary distress to these patients and their families. Given the profile of these patients, we recommend choosing AEDs with a low interaction potential and which can be administered by the parenteral route, preferably intravenously. Diazepam and midazolam appear to be the most suitable AEDs during the acute phase whereas levetiracetam, valproic acid, and lacosamide are recommended for refractory cases and long-term treatment. These guidelines provide general recommendations that must be adapted to each particular clinical case. Nevertheless, we will require further well-designed randomised controlled clinical trials including large samples of patients eligible for PC to draft a consensus document recommending adequate, rational, and effective use of AEDs, based on a high level of evidence, in this highly complex area of medical care. Copyright © 2017 The Authors. Publicado por Elsevier España, S.L.U. All rights reserved.
QCD Sum Rules and Models for Generalized Parton Distributions
Energy Technology Data Exchange (ETDEWEB)
Anatoly Radyushkin
2004-10-01
I use QCD sum rule ideas to construct models for generalized parton distributions. To this end, the perturbative parts of QCD sum rules for the pion and nucleon electromagnetic form factors are interpreted in terms of GPDs and two models are discussed. One of them takes the double Borel transform at adjusted value of the Borel parameter as a model for nonforward parton densities, and another is based on the local duality relation. Possible ways of improving these Ansaetze are briefly discussed.
Directory of Open Access Journals (Sweden)
Bölter, Regine
2012-11-01
Full Text Available [english] Introduction: The planned modification of the Medical Licenses Act in Germany will strengthen the specialty of general practice. Therefore, medical students should get to know the daily routine of general practitioners during their academic studies. At least 10% of students should get the possibility to spend one quarter of the internship, in the last year of their academic studies, in a practice of family medicine. The demonstrated teaching method aims at giving feedback to the student based on video recordings of patient consultations (student-patient with the help of a checklist. Video-feedback is already successful used in medical teaching in Germany and abroad. This feasibility study aims at assessing the practicability of video-assisted feedback as a teaching method during internship in general practice. Teaching method: First of all, the general practice chooses a guideline as the learning objective. Secondly, a subsequent patient – student – consultation is recorded on video. Afterwards, a video-assisted formative feedback is given by the physician. A checklist with learning objectives (communication, medical examination, a structured case report according to the guideline is used to structure the feedback content. Feasibility: The feasibility was assessed by a semi structured interview in order to gain insight into barriers and challenges for future implementation. The teaching method was performed in one general practice. Afterwards the teaching physician and the trainee intern were interviewed. The following four main categories were identified: feasibility, performance, implementation in daily routine, challenges of the teaching concept.The results of the feasibility study show general practicability of this approach. Installing a video camera in one examination room may solve technical problems. The trainee intern mentioned theoretical and practical benefits using the guideline. The teaching physician noted the
Jacques, David A; Guss, J Mitchell; Svergun, Dmitri I; Trewhella, Jill
2012-06-01
Small-angle scattering is becoming a mainstream technique for structural molecular biology. As such, it is important to establish guidelines for publication that will ensure that there is adequate reporting of the data and its treatment so that reviewers and readers can independently assess the quality of the data and the basis for any interpretations presented. This article presents a set of preliminary guidelines that emerged after consultation with the IUCr Commission on Small-Angle Scattering and other experts in the field and discusses the rationale for their application. At the 2011 Congress of the IUCr in Madrid, the Commission on Journals agreed to adopt these preliminary guidelines for the presentation of biomolecular structures from small-angle scattering data in IUCr publications. Here, these guidelines are outlined and the reasons for standardizing the way in which small-angle scattering data are presented.
10 CFR 960.4 - Postclosure guidelines.
2010-01-01
... 10 Energy 4 2010-01-01 2010-01-01 false Postclosure guidelines. 960.4 Section 960.4 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Postclosure Guidelines § 960.4 Postclosure guidelines. The guidelines in this subpart specify...
10 CFR 960.5 - Preclosure guidelines.
2010-01-01
... 10 Energy 4 2010-01-01 2010-01-01 false Preclosure guidelines. 960.5 Section 960.5 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Preclosure Guidelines § 960.5 Preclosure guidelines. The guidelines in this subpart specify...
10 CFR 960.3 - Implementation guidelines.
2010-01-01
... 10 Energy 4 2010-01-01 2010-01-01 false Implementation guidelines. 960.3 Section 960.3 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Implementation Guidelines § 960.3 Implementation guidelines. The guidelines of this...
General Linear Models: An Integrated Approach to Statistics
Directory of Open Access Journals (Sweden)
Andrew Faulkner
2008-09-01
Full Text Available Generally, in psychology, the various statistical analyses are taught independently from each other. As a consequence, students struggle to learn new statistical analyses, in contexts that differ from their textbooks. This paper gives a short introduction to the general linear model (GLM, in which it is showed that ANOVA (one-way, factorial, repeated measure and analysis of covariance is simply a multiple correlation/regression analysis (MCRA. Generalizations to other cases, such as multivariate and nonlinear analysis, are also discussed. It can easily be shown that every popular linear analysis can be derived from understanding MCRA.
Blind source separation based on generalized gaussian model
Institute of Scientific and Technical Information of China (English)
YANG Bin; KONG Wei; ZHOU Yue
2007-01-01
Since in most blind source separation (BSS) algorithms the estimations of probability density function (pdf) of sources are fixed or can only switch between one sup-Gaussian and other sub-Gaussian model,they may not be efficient to separate sources with different distributions. So to solve the problem of pdf mismatch and the separation of hybrid mixture in BSS, the generalized Gaussian model (GGM) is introduced to model the pdf of the sources since it can provide a general structure of univariate distributions. Its great advantage is that only one parameter needs to be determined in modeling the pdf of different sources, so it is less complex than Gaussian mixture model. By using maximum likelihood (ML) approach, the convergence of the proposed algorithm is improved. The computer simulations show that it is more efficient and valid than conventional methods with fixed pdf estimation.
Modeling the brain morphology distribution in the general aging population
Huizinga, W.; Poot, D. H. J.; Roshchupkin, G.; Bron, E. E.; Ikram, M. A.; Vernooij, M. W.; Rueckert, D.; Niessen, W. J.; Klein, S.
2016-03-01
Both normal aging and neurodegenerative diseases such as Alzheimer's disease cause morphological changes of the brain. To better distinguish between normal and abnormal cases, it is necessary to model changes in brain morphology owing to normal aging. To this end, we developed a method for analyzing and visualizing these changes for the entire brain morphology distribution in the general aging population. The method is applied to 1000 subjects from a large population imaging study in the elderly, from which 900 were used to train the model and 100 were used for testing. The results of the 100 test subjects show that the model generalizes to subjects outside the model population. Smooth percentile curves showing the brain morphology changes as a function of age and spatiotemporal atlases derived from the model population are publicly available via an interactive web application at agingbrain.bigr.nl.
A general diagnostic model applied to language testing data.
von Davier, Matthias
2008-11-01
Probabilistic models with one or more latent variables are designed to report on a corresponding number of skills or cognitive attributes. Multidimensional skill profiles offer additional information beyond what a single test score can provide, if the reported skills can be identified and distinguished reliably. Many recent approaches to skill profile models are limited to dichotomous data and have made use of computationally intensive estimation methods such as Markov chain Monte Carlo, since standard maximum likelihood (ML) estimation techniques were deemed infeasible. This paper presents a general diagnostic model (GDM) that can be estimated with standard ML techniques and applies to polytomous response variables as well as to skills with two or more proficiency levels. The paper uses one member of a larger class of diagnostic models, a compensatory diagnostic model for dichotomous and partial credit data. Many well-known models, such as univariate and multivariate versions of the Rasch model and the two-parameter logistic item response theory model, the generalized partial credit model, as well as a variety of skill profile models, are special cases of this GDM. In addition to an introduction to this model, the paper presents a parameter recovery study using simulated data and an application to real data from the field test for TOEFL Internet-based testing.
Directory of Open Access Journals (Sweden)
Yunisrina Qismullah Yusuf
2015-10-01
Full Text Available Guidelines for Article Submission SiELE journal accepts articles on research and development in the field of teaching and learning of English, linguistics, educational development, policy and cultural studies in education.To be considered for publication, the article should be presented in the following system:First page: include a title page with the full title of the paper (must not exceed 16 words, the author(s’ name(s, affiliation(s, phone number(s and e-mail address of the corresponding author. A brief bio-data of the author(s (maximum of 100 words is provided in this page.Second page and subsequent page: Submissions should be between 4000-6000 (including abstract, table(s, figure(s and references in A4 size paper with margins as the following: top 3 cm, bottom 3 cm, right 2.5 cm and left 4 cm. The font is Times New Roman, size 12 and single spaced. The article should generally consist of the following sections: introduction, review of literature, method, findings, discussion and conclusion.Headings and subheadings should be presented as follows (provide a space between the headings and sub-headings. 1 INTRODUCTION1.1 Subheading of the Content 1.1.1 Subheading of the Content For Tables, the title size is 12 and the content size is 10. Please number the tables subsequently throughout your article and the title is written above the table.For Figures, the title size is 12 and the content size (if any is 10. Please number the figures subsequently throughout your article and the title is written below the figure.The reference list should be arranged alphabetically following the guidelines of the Publication Manual of the American Psychological Association (5th ed.. See the following examples: Book: Ellis, R. (2003. Task-based language learning and teaching. Oxford: Oxford University Press.Internet source: Andrewes, S. (2003. Group work v. whole-class activities. Retrieved October 1, 2012 from http://www
Directory of Open Access Journals (Sweden)
Yunisrina Qismullah Yusuf
2014-03-01
Full Text Available Guidelines for Article Submission SiELE journal accepts articles on research and development in the field of teaching and learning of English, linguistics, educational development, policy and cultural studies in education.To be considered for publication, the article should be presented in the following system:First page: include a title page with the full title of the paper (must not exceed 16 words, the author(s’ name(s, affiliation(s, phone number(s and e-mail address of the corresponding author. A brief bio-data of the author(s (maximum of 100 words is provided in this page.Second page and subsequent page: Submissions should be between 4000-6000 (including abstract, table(s, figure(s and references in A4 size paper with margins as the following: top 3 cm, bottom 3 cm, right 2.5 cm and left 4 cm. The font is Times New Roman, size 12 and single spaced. The article should generally consist of the following sections: introduction, review of literature, method, findings, discussion and conclusion.Headings and subheadings should be presented as follows (provide a space between the headings and sub-headings. 1 INTRODUCTION1.1 Subheading of the content 1.1.1 Subheading of the content For Tables, the title size is 12 and the content size is 10. Please number the tables subsequently throughout your article and the title is written above the table.For Figures, the title size is 12 and the content size (if any is 10. Please number the figures subsequently throughout your article and the title is written below the figure.The reference list should be arranged alphabetically following the guidelines of the Publication Manual of the American Psychological Association (5th ed.. See the following examples: Book: Ellis, R. (2003. Task-based language learning and teaching. Oxford: Oxford University Press.Internet source: Andrewes, S. (2003. Group work v. whole-class activities. Retrieved October 1, 2012 from http://www
Directory of Open Access Journals (Sweden)
Yunisrina Qismullah Yusuf
2014-09-01
Full Text Available Guidelines for Article Submission SiELE journal accepts articles on research and development in the field of teaching and learning of English, linguistics, educational development, policy and cultural studies in education.To be considered for publication, the article should be presented in the following system:First page: include a title page with the full title of the paper (must not exceed 16 words, the author(s’ name(s, affiliation(s, phone number(s and e-mail address of the corresponding author. A brief bio-data of the author(s (maximum of 100 words is provided in this page.Second page and subsequent page: Submissions should be between 4000-6000 (including abstract, table(s, figure(s and references in A4 size paper with margins as the following: top 3 cm, bottom 3 cm, right 2.5 cm and left 4 cm. The font is Times New Roman, size 12 and single spaced. The article should generally consist of the following sections: introduction, review of literature, method, findings, discussion and conclusion.Headings and subheadings should be presented as follows (provide a space between the headings and sub-headings. 1 INTRODUCTION1.1 Subheading of the content 1.1.1 Subheading of the content For Tables, the title size is 12 and the content size is 10. Please number the tables subsequently throughout your article and the title is written above the table.For Figures, the title size is 12 and the content size (if any is 10. Please number the figures subsequently throughout your article and the title is written below the figure.The reference list should be arranged alphabetically following the guidelines of the Publication Manual of the American Psychological Association (5th ed.. See the following examples: Book: Ellis, R. (2003. Task-based language learning and teaching. Oxford: Oxford University Press.Internet source: Andrewes, S. (2003. Group work v. whole-class activities. Retrieved October 1, 2012 from http://www
Directory of Open Access Journals (Sweden)
Yunisrina Qismullah Yusuf
2016-03-01
Full Text Available Guidelines for Article Submission SiELE journal accepts articles on research and development in the field of teaching and learning of English, linguistics, educational development, policy and cultural studies in education. To be considered for publication, the article should be presented in the following system: First page: include a title page with the full title of the paper (must not exceed 16 words, the author(s’ name(s, affiliation(s, phone number(s and e-mail address of the corresponding author. A brief bio-data of the author(s (maximum of 100 words is provided in this page. Second p age and subsequent page: Submissions should be between 4000-6000 (including abstract, table(s, figure(s and references in A4 size paper with margins as the following: top 3 cm, bottom 3 cm, right 2.5 cm and left 4 cm. The font is Times New Roman, size 12 and single spaced. The article should generally consist of the following sections: introduction, review of literature, method, findings, discussion and conclusion. Headings and subheadings should be presented as follows (provide a space between the headings and sub-headings. 1 INTRODUCTION 1.1 Subheading of the Content 1.1.1 Subheading of the Content For Tables, the title size is 12 and the content size is 10. Please number the tables subsequently throughout your article and the title is written above the table. For Figures, the title size is 12 and the content size (if any is 10. Please number the figures subsequently throughout your article and the title is written below the figure. The reference list should be arranged alphabetically following the guidelines of the Publication Manual of the American Psychological Association (5th ed.. See the following examples: Book: Ellis, R. (2003. Task-based language learning and teaching. Oxford: Oxford University Press. Internet source: Andrewes, S. (2003. Group work v. whole-class activities. Retrieved October 1, 2012 from http://www.teachingenglish.org
Directory of Open Access Journals (Sweden)
Yunisrina Qismullah Yusuf
2015-03-01
Full Text Available Guidelines for Article Submission SiELE journal accepts articles on research and development in the field of teaching and learning of English, linguistics, educational development, policy and cultural studies in education. To be considered for publication, the article should be presented in the following system: First page: include a title page with the full title of the paper (must not exceed 16 words, the author(s’ name(s, affiliation(s, phone number(s and e-mail address of the corresponding author. A brief bio-data of the author(s (maximum of 100 words is provided in this page. Second page and subsequent page: Submissions should be between 4000-6000 (including abstract, table(s, figure(s and references in A4 size paper with margins as the following: top 3 cm, bottom 3 cm, right 2.5 cm and left 4 cm. The font is Times New Roman, size 12 and single spaced. The article should generally consist of the following sections: introduction, review of literature, method, findings, discussion and conclusion. Headings and subheadings should be presented as follows (provide a space between the headings and sub-headings. 1 INTRODUCTION 1.1 Subheading of the content 1.1.1 Subheading of the content For Tables, the title size is 12 and the content size is 10. Please number the tables subsequently throughout your article and the title is written above the table. For Figures, the title size is 12 and the content size (if any is 10. Please number the figures subsequently throughout your article and the title is written below the figure. The reference list should be arranged alphabetically following the guidelines of the Publication Manual of the American Psychological Association (5th ed.. See the following examples: Back Matter| 79 80 | STUDIES IN ENGLISH LANGUAGE AND EDUCATION, Volume 1, Number 1, March 2014 Book: Ellis, R. (2003. Task-based language learning and teaching. Oxford: Oxford University Press. Internet source: Andrewes, S. (2003. Group work v
Modelling dynamic programming problems by generalized d-graphs
Kátai, Zoltán
2010-01-01
In this paper we introduce the concept of generalized d-graph (admitting cycles) as special dependency-graphs for modelling dynamic programming (DP) problems. We describe the d-graph versions of three famous single-source shortest algorithms (The algorithm based on the topological order of the vertices, Dijkstra algorithm and Bellman-Ford algorithm), which can be viewed as general DP strategies in the case of three different class of optimization problems. The new modelling method also makes possible to classify DP problems and the corresponding DP strategies in term of graph theory.
GEMFsim: A Stochastic Simulator for the Generalized Epidemic Modeling Framework
Sahneh, Faryad Darabi; Shakeri, Heman; Fan, Futing; Scoglio, Caterina
2016-01-01
The recently proposed generalized epidemic modeling framework (GEMF) \\cite{sahneh2013generalized} lays the groundwork for systematically constructing a broad spectrum of stochastic spreading processes over complex networks. This article builds an algorithm for exact, continuous-time numerical simulation of GEMF-based processes. Moreover the implementation of this algorithm, GEMFsim, is available in popular scientific programming platforms such as MATLAB, R, Python, and C; GEMFsim facilitates simulating stochastic spreading models that fit in GEMF framework. Using these simulations one can examine the accuracy of mean-field-type approximations that are commonly used for analytical study of spreading processes on complex networks.
Dynamic generalized linear models for monitoring endemic diseases
DEFF Research Database (Denmark)
Lopes Antunes, Ana Carolina; Jensen, Dan Børge; Halasa, T.
The objective was to use a Dynamic Generalized Linear Model (DGLM) based on abinomial distribution with a linear trend, for monitoring the PRRS (Porcine Reproductive and Respiratory Syndrome sero-prevalence in Danish swine herds. The DGLM was described and its performance for monitoring control...... in sero-prevalence. Based on this, it was possible to detect variations in the growth model component. This study is a proof-of-concept, demonstrating the use of DGLMs for monitoring endemic diseases. In addition, the principles stated might be useful in general research on monitoring and surveillance...
Directory of Open Access Journals (Sweden)
Tam H Ho
Full Text Available OBJECTIVE: To assess the impact of individualised, reconciled evidence-based recommendations (IRERs and multidisciplinary care in patients with chronic heart failure (CHF on clinical guideline compliance for CHF and common comorbid conditions. DESIGN AND SETTING: A retrospective hospital clinical audit conducted between 1st July 2006 and February 2011. PARTICIPANTS: A total of 255 patients with a diagnosis of CHF who attended the Multidisciplinary Ambulatory Consulting Services (MACS clinics, at the Royal Adelaide Hospital, were included. MAIN OUTCOME MEASURES: Compliance with Australian clinical guideline recommendations for CHF, atrial fibrillation, diabetes mellitus and ischaemic heart disease. RESULTS: Study participants had a median of eight medical conditions (IQR 6-10 and were on an average of 10 (±4 unique medications. Compliance with clinical guideline recommendations for pharmacological therapy for CHF, comorbid atrial fibrillation, diabetes or ischaemic heart disease was high, ranging from 86% for lipid lowering therapy to 98% anti-platelet agents. For all conditions, compliance with lifestyle recommendations was lower than pharmacological therapy, ranging from no podiatry reviews for CHF patients with comorbid diabetes to 75% for heart failure education. Concordance with many guideline recommendations was significantly associated if the patient had IRERs determined, a greater number of recommendations, more clinic visits or if patients participated in a heart failure program. CONCLUSIONS: Despite the high number of comorbid conditions and resulting complexity of the management, high compliance to clinical guideline recommendations was associated with IRER determination in older patients with CHF. Importantly these recommendations need to be communicated to the patient's general practitioner, regularly monitored and adjusted at clinic visits.
Directory of Open Access Journals (Sweden)
IRNANDA AIKO FIFI DJUUNA
2010-07-01
Full Text Available Djuuna IAF, Abbott LK, Van Niel K (2010 Predicting infectivity of Arbuscular Mycorrhizal fungi from soil variables using Generalized Additive Models and Generalized Linear Models. Biodiversitas 11: 145-150. The objective of this study was to predict the infectivity of arbuscular mycorrhizal fungi (AM fungi, from field soil based on soil properties and land use history using generalized additive models (GAMs and generalized linear models (GLMs. A total of 291 soil samples from a farm in Western Australia near Wickepin were collected and used in this study. Nine soil properties, including elevation, pH, EC, total C, total N, P, K, microbial biomass carbon, and soil texture, and land use history of the farm were used as independent variables, while the percentage of root length colonized (%RLC was used as the dependent variable. GAMs parameterized for the percent of root length colonized suggested skewed quadratic responses to soil pH and microbial biomass carbon; cubic responses to elevation and soil K; and linear responses to soil P, EC and total C. The strength of the relationship between percent root length colonized by AM fungi and environmental variables showed that only elevation, total C and microbial biomass carbon had strong relationships. In general, GAMs and GLMs models confirmed the strong relationship between infectivity of AM fungi (assessed in a glasshouse bioassay for soil collected in summer prior to the first rain of the season and soil properties.
Coexistence of Interacting Opinions in a Generalized Sznajd Model
Timpanaro, André M
2011-01-01
The Sznajd model is a sociophysics model that mimics the propagation of opinions in a closed society, where the interactions favour groups of agreeing people. It is based in the Ising and Potts ferromagnetic models and although the original model used only linear chains, it has since been adapted to general networks. This model has a very rich transient, that has been used to model several aspects of elections, but its stationary states are always consensus states. In order to model more complex behaviours we have, in a recent work, introduced the idea of biases and prejudices to the Sznajd model, by generalizing the bounded confidence rule that is common to many continuous opinion models. In that work we have found that the mean-field version of this model (corresponding to a complete network) allows for stationary states where non-interacting opinions survive, but never for the coexistence of interacting opinions. In the present work, we provide networks that allow for the coexistence of interacting opinion...
Scarborough, Peter; Cobiac, Linda; Owens, Paul; Parlesak, Alexandr; Sweeney, Kate; Rayner, Mike
2016-01-01
Objectives To model food group consumption and price of diet associated with achieving UK dietary recommendations while deviating as little as possible from the current UK diet, in order to support the redevelopment of the UK food-based dietary guidelines (now called the Eatwell Guide). Design Optimisation modelling, minimising an objective function of the difference between population mean modelled and current consumption of 125 food groups, and constraints of nutrient and food-based recommendations. Setting The UK. Population Adults aged 19 years and above from the National Diet and Nutrition Survey 2008–2011. Main outcome measures Proportion of diet consisting of major foods groups and price of the optimised diet. Results The optimised diet has an increase in consumption of ‘potatoes, bread, rice, pasta and other starchy carbohydrates’ (+69%) and ‘fruit and vegetables’ (+54%) and reductions in consumption of ‘beans, pulses, fish, eggs, meat and other proteins’ (−24%), ‘dairy and alternatives’ (−21%) and ‘foods high in fat and sugar’ (−53%). Results within food groups show considerable variety (eg, +90% for beans and pulses, −78% for red meat). The modelled diet would cost £5.99 (£5.93 to £6.05) per adult per day, very similar to the cost of the current diet: £6.02 (£5.96 to £6.08). The optimised diet would result in increased consumption of n-3 fatty acids and most micronutrients (including iron and folate), but decreased consumption of zinc and small decreases in consumption of calcium and riboflavin. Conclusions To achieve the UK dietary recommendations would require large changes in the average diet of UK adults, including in food groups where current average consumption is well within the recommended range (eg, processed meat) or where there are no current recommendations (eg, dairy). These large changes in the diet will not lead to significant changes in the price of the diet. PMID:28003292
Generalized memory associativity in a network model for the neuroses
Wedemann, Roseli S.; Donangelo, Raul; de Carvalho, Luís A. V.
2009-03-01
We review concepts introduced in earlier work, where a neural network mechanism describes some mental processes in neurotic pathology and psychoanalytic working-through, as associative memory functioning, according to the findings of Freud. We developed a complex network model, where modules corresponding to sensorial and symbolic memories interact, representing unconscious and conscious mental processes. The model illustrates Freud's idea that consciousness is related to symbolic and linguistic memory activity in the brain. We have introduced a generalization of the Boltzmann machine to model memory associativity. Model behavior is illustrated with simulations and some of its properties are analyzed with methods from statistical mechanics.
Vortices in generalized Abelian Chern-Simons-Higgs model
Casana, Rodolfo
2015-01-01
We study a generalization of abelian Chern-Simons-Higgs model by introducing nonstandard kinetic terms. We will obtain a generic form of Bogomolnyi equations by minimizing the energy functional of the model. This generic form of Bogomolnyi equations produce an infinity number of soliton solutions. As a particular limit of these generic Bogomolnyi equations, we obtain the Bogomolnyi equations of the abelian Maxwell-Higgs model and the abelian Chern-Simons Higgs model. Finally, novel soliton solutions emerge from these generic Bogomolnyi equations. We analyze these solutions from theoretical and numerical point of view.
Observational constraints on the generalized $\\alpha$ attractor model
Shahalam, M; Myrzakul, Shynaray; Wang, Anzhong
2016-01-01
We study the generalized $\\alpha$ attractor model in context of late time cosmic acceleration; the model interpolates between freezing and thawing dark energy models. In the slow roll regime, the originally potential is modified whereas the modification ceases in the asymptotic regime and the effective potential behaves as quadratic. In our setting, field rolls slowly around the present epoch and mimics dark matter in future. We put observational constraints on the model parameters for which we use an integrated data base (SN+Hubble+BAO+CMB) for carrying out the data analysis.
Generalized memory associativity in a network model for the neuroses.
Wedemann, Roseli S; Donangelo, Raul; de Carvalho, Luís A V
2009-03-01
We review concepts introduced in earlier work, where a neural network mechanism describes some mental processes in neurotic pathology and psychoanalytic working-through, as associative memory functioning, according to the findings of Freud. We developed a complex network model, where modules corresponding to sensorial and symbolic memories interact, representing unconscious and conscious mental processes. The model illustrates Freud's idea that consciousness is related to symbolic and linguistic memory activity in the brain. We have introduced a generalization of the Boltzmann machine to model memory associativity. Model behavior is illustrated with simulations and some of its properties are analyzed with methods from statistical mechanics.
Generalized F test and generalized deviance test in two-way ANOVA models for randomized trials.
Shen, Juan; He, Xuming
2014-01-01
We consider the problem of detecting treatment effects in a randomized trial in the presence of an additional covariate. By reexpressing a two-way analysis of variance (ANOVA) model in a logistic regression framework, we derive generalized F tests and generalized deviance tests, which provide better power in detecting common location-scale changes of treatment outcomes than the classical F test. The null distributions of the test statistics are independent of the nuisance parameters in the models, so the critical values can be easily determined by Monte Carlo methods. We use simulation studies to demonstrate how the proposed tests perform compared with the classical F test. We also use data from a clinical study to illustrate possible savings in sample sizes.
Practical likelihood analysis for spatial generalized linear mixed models
DEFF Research Database (Denmark)
Bonat, W. H.; Ribeiro, Paulo Justiniano
2016-01-01
We investigate an algorithm for maximum likelihood estimation of spatial generalized linear mixed models based on the Laplace approximation. We compare our algorithm with a set of alternative approaches for two datasets from the literature. The Rhizoctonia root rot and the Rongelap are, respectiv......We investigate an algorithm for maximum likelihood estimation of spatial generalized linear mixed models based on the Laplace approximation. We compare our algorithm with a set of alternative approaches for two datasets from the literature. The Rhizoctonia root rot and the Rongelap are...... of Laplace approximation include the computation of the maximized log-likelihood value, which can be used for model selection and tests, and the possibility to obtain realistic confidence intervals for model parameters based on profile likelihoods. The Laplace approximation also avoids the tuning...
Automation of electroweak NLO corrections in general models
Energy Technology Data Exchange (ETDEWEB)
Lang, Jean-Nicolas [Universitaet Wuerzburg (Germany)
2016-07-01
I discuss the automation of generation of scattering amplitudes in general quantum field theories at next-to-leading order in perturbation theory. The work is based on Recola, a highly efficient one-loop amplitude generator for the Standard Model, which I have extended so that it can deal with general quantum field theories. Internally, Recola computes off-shell currents and for new models new rules for off-shell currents emerge which are derived from the Feynman rules. My work relies on the UFO format which can be obtained by a suited model builder, e.g. FeynRules. I have developed tools to derive the necessary counterterm structures and to perform the renormalization within Recola in an automated way. I describe the procedure using the example of the two-Higgs-doublet model.
Improved Generalized Force Model considering the Comfortable Driving Behavior
Directory of Open Access Journals (Sweden)
De-Jie Xu
2015-01-01
Full Text Available This paper presents an improved generalized force model (IGFM that considers the driver’s comfortable driving behavior. Through theoretical analysis, we propose the calculation methods of comfortable driving distance and velocity. Then the stability condition of the model is obtained by the linear stability analysis. The problems of the unrealistic acceleration of the leading car existing in the previous models were solved. Furthermore, the simulation results show that IGFM can predict correct delay time of car motion and kinematic wave speed at jam density, and it can exactly describe the driver’s behavior under an urgent case, where no collision occurs. The dynamic properties of IGFM also indicate that stability has improved compared to the generalized force model.
SELECTION MOMENTS AND GENERALIZED METHOD OF MOMENTS FOR HETEROSKEDASTIC MODELS
Directory of Open Access Journals (Sweden)
Constantin ANGHELACHE
2016-06-01
Full Text Available In this paper, the authors describe the selection methods for moments and the application of the generalized moments method for the heteroskedastic models. The utility of GMM estimators is found in the study of the financial market models. The selection criteria for moments are applied for the efficient estimation of GMM for univariate time series with martingale difference errors, similar to those studied so far by Kuersteiner.
General Model for Infrastructure Multi-channel Wireless LANs
Fayez Gebali; Abdelsalam Amer
2010-01-01
In this paper we develop an integrated model for request mechanism and data transmission in multi-channel wireless local area networks. We calculated the performance parameters for single and multi-channel wireless networks when the channel is noisy. The proposed model is general it can be applied to different wireless networks such as IEEE802.11x, IEEE802.16, CDMA operated networks and Hiperlan\\2.
Development of the Model of the Generalized Quintom Dark Energy
Institute of Scientific and Technical Information of China (English)
WANG Wei; GUI Yuan-Xing; SHAO Ying
2006-01-01
@@ We consider a generalized quintom (GQ) dark energy modelfor changing the equal weight of the negative-kinetic scalar field (phantom) and the normal scalar field (quintessence) in quintom dark energy. Though the phantomdominated scaling solution is a stable late-time attractor, the early evolution of GQ is different from that of the quintom model and the adjustability of the dark energy state equation in the model is improved.
The direction of migration: a dynamic general equilibrium model.
Lee, K S
1984-11-01
A two-sector dynamic general equilibrium model is developed "to investigate the direction of migration in response to differing demographic and consumption demand behavior, as well as variations in production conditions." The model, which involves a rural sector and an urban sector, incorporates "returns to scale and the natural rate of sectoral population growth as important determinants of the direction of migration, in addition to price and income elasticities, and the sectoral technical change rate with which...previous studies dealt."
Bianchi type-V string cosmological models in general relativity
Indian Academy of Sciences (India)
Anil Kumar Yadav; Vineet Kumar Yadav; Lallan Yadav
2011-04-01
Bianchi type-V string cosmological models in general relativity are investigated. To get the exact solution of Einstein’s ﬁeld equations, we have taken some scale transformations used by Camci et al [Astrophys. Space Sci. 275, 391 (2001)]. It is shown that Einstein’s ﬁeld equations are solvable for any arbitrary cosmic scale function. Solutions for particular forms of cosmic scale functions are also obtained. Some physical and geometrical aspects of the models are discussed.
Estimation linear model using block generalized inverse of a matrix
Jasińska, Elżbieta; Preweda, Edward
2013-01-01
The work shows the principle of generalized linear model, point estimation, which can be used as a basis for determining the status of movements and deformations of engineering objects. The structural model can be put on any boundary conditions, for example, to ensure the continuity of the deformations. Estimation by the method of least squares was carried out taking into account the terms and conditions of the Gauss- Markov for quadratic forms stored using Lagrange function. The original sol...
Directory of Open Access Journals (Sweden)
Qinghua Xie
2017-01-01
Full Text Available Recently, a general polarimetric model-based decomposition framework was proposed by Chen et al., which addresses several well-known limitations in previous decomposition methods and implements a simultaneous full-parameter inversion by using complete polarimetric information. However, it only employs four typical models to characterize the volume scattering component, which limits the parameter inversion performance. To overcome this issue, this paper presents two general polarimetric model-based decomposition methods by incorporating the generalized volume scattering model (GVSM or simplified adaptive volume scattering model, (SAVSM proposed by Antropov et al. and Huang et al., respectively, into the general decomposition framework proposed by Chen et al. By doing so, the final volume coherency matrix structure is selected from a wide range of volume scattering models within a continuous interval according to the data itself without adding unknowns. Moreover, the new approaches rely on one nonlinear optimization stage instead of four as in the previous method proposed by Chen et al. In addition, the parameter inversion procedure adopts the modified algorithm proposed by Xie et al. which leads to higher accuracy and more physically reliable output parameters. A number of Monte Carlo simulations of polarimetric synthetic aperture radar (PolSAR data are carried out and show that the proposed method with GVSM yields an overall improvement in the final accuracy of estimated parameters and outperforms both the version using SAVSM and the original approach. In addition, C-band Radarsat-2 and L-band AIRSAR fully polarimetric images over the San Francisco region are also used for testing purposes. A detailed comparison and analysis of decomposition results over different land-cover types are conducted. According to this study, the use of general decomposition models leads to a more accurate quantitative retrieval of target parameters. However, there
Computerized Classification Testing under the Generalized Graded Unfolding Model
Wang, Wen-Chung; Liu, Chen-Wei
2011-01-01
The generalized graded unfolding model (GGUM) has been recently developed to describe item responses to Likert items (agree-disagree) in attitude measurement. In this study, the authors (a) developed two item selection methods in computerized classification testing under the GGUM, the current estimate/ability confidence interval method and the cut…
Suggesting a General ESP Model for Adult Learners
Al-Jumaily, Samir
2011-01-01
The study suggests a general model that could guarantee the cooperation between teachers and their students to overcome the difficulties encountered in ESP learning. It tries to join together different perspectives in the research of adult education, specifically in the teaching of English for Specific Purposes. It also provides some sort of trust…
Anisotropic cosmological models and generalized scalar tensor theory
Indian Academy of Sciences (India)
Subenoy Chakraborty; Batul Chandra Santra; Nabajit Chakravarty
2003-10-01
In this paper generalized scalar tensor theory has been considered in the background of anisotropic cosmological models, namely, axially symmetric Bianchi-I, Bianchi-III and Kortowski–Sachs space-time. For bulk viscous ﬂuid, both exponential and power-law solutions have been studied and some assumptions among the physical parameters and solutions have been discussed.
A general circulation model (GCM) parameterization of Pinatubo aerosols
Energy Technology Data Exchange (ETDEWEB)
Lacis, A.A.; Carlson, B.E.; Mishchenko, M.I. [NASA Goddard Institute for Space Studies, New York, NY (United States)
1996-04-01
The June 1991 volcanic eruption of Mt. Pinatubo is the largest and best documented global climate forcing experiment in recorded history. The time development and geographical dispersion of the aerosol has been closely monitored and sampled. Based on preliminary estimates of the Pinatubo aerosol loading, general circulation model predictions of the impact on global climate have been made.
RF Circuit linearity optimization using a general weak nonlinearity model
Cheng, W.; Oude Alink, M.S.; Annema, Anne J.; Croon, Jeroen A.; Nauta, Bram
2012-01-01
This paper focuses on optimizing the linearity in known RF circuits, by exploring the circuit design space that is usually available in today’s deep submicron CMOS technologies. Instead of using brute force numerical optimizers we apply a generalized weak nonlinearity model that only involves AC
An applied general equilibrium model for Dutch agribusiness policy analysis
Peerlings, J.
1993-01-01
The purpose of this thesis was to develop a basic static applied general equilibrium (AGE) model to analyse the effects of agricultural policy changes on Dutch agribusiness. In particular the effects on inter-industry transactions, factor demand, income, and trade are of interest.
[General systems theory, analog models and essential arterial hypertension].
Indovina, I; Bonelli, M
1991-02-15
The application of the General System Theory to the fields of biology and particularly of medicine is fraught with many difficulties deriving from the mathematical complexities of application. The authors suggest that these difficulties can be overcome by applying analogical models, thus opening new prospects for the resolution of the manifold problems involved in connection with the study of arterial hypertension.
An applied general equilibrium model for Dutch agribusiness policy analysis
Peerlings, J.
1993-01-01
The purpose of this thesis was to develop a basic static applied general equilibrium (AGE) model to analyse the effects of agricultural policy changes on Dutch agribusiness. In particular the effects on inter-industry transactions, factor demand, income, and trade are of
Sharing Rule Identification for General Collective Consumption Models
Cherchye, L.J.H.; de Rock, B.; Lewbel, A.; Vermeulen, F.M.P.
2012-01-01
Abstract: We propose a method to identify bounds (i.e. set identification) on the sharing rule for a general collective household consumption model. Unlike the effects of distribution factors, it is well known that the level of the sharing rule cannot be uniquely identified without strong assumption
Suggesting a General ESP Model for Adult Learners
Al-Jumaily, Samir
2011-01-01
The study suggests a general model that could guarantee the cooperation between teachers and their students to overcome the difficulties encountered in ESP learning. It tries to join together different perspectives in the research of adult education, specifically in the teaching of English for Specific Purposes. It also provides some sort of trust…
Lip, Gregory Y H; Laroche, Cécile; Popescu, Mircea Iaochim; Rasmussen, Lars Hvilsted; Vitali-Serdoz, Laura; Dan, Gheorghe-Andrei; Kalarus, Zbigniew; Crijns, Harry J G M; Oliveira, Mario Martins; Tavazzi, Luigi; Maggioni, Aldo P; Boriani, Giuseppe
2015-12-01
Guideline-adherent therapy for stroke prevention in atrial fibrillation has been associated with better outcomes, in terms of thromboembolism (TE) and bleeding. In this report from the EuroObservational Research Programme-Atrial Fibrillation (EORP-AF) Pilot General Registry, we describe the associated baseline features of 'high risk' AF patients in relation to guideline-adherent antithrombotic treatment, i.e. whether they were adherent, over-treated, or under-treated based on the 2012 European Society of Cardiology (ESC) guidelines. Secondly, we assessed the predictors of guideline-adherent antithrombotic treatment. Thirdly, we evaluated outcomes for all-cause mortality, TE, bleeding, and the composite endpoint of 'any TE, cardiovascular death or bleeding' in relation to whether they were ESC guideline-adherent treatment. From the EORP-AF cohort, the follow-up dataset of 2634 subjects was used to assess the impact of guideline adherence or non-adherence. Of these, 1602 (60.6%) were guideline adherent, whilst 458 (17.3%) were under-treated, and 574 (21.7%) were over-treated. Non-guideline-adherent treatment can be related to region of Europe as well as associated clinical features, but not age, AF type, symptoms, or echocardiography indices. Over-treatment per se was associated with symptoms, using the EHRA score, as well as other comorbidities. Guideline-adherent antithrombotic management based on the ESC guidelines is associated with significantly better outcomes. Specifically, the endpoint of 'all cause death and any TE' is increased by >60% by undertreatment [hazard ratio (HR) 1.679 (95% confidence interval (CI) 1.202-2.347)] or over-treatment [HR 1.622 (95% CI 1.173-2.23)]. For the composite endpoint of 'cardiovascular death, any TE or bleeding', over-treatment increased risk by >70% [HR 1.722 (95% CI 1.200-2.470)]. Even in this cohort with high overall rates of oral anticoagulation use, ESC guideline-adherent antithrombotic management is associated with
Isbell, James M; Deppen, Stephen; Putnam, Joe B; Nesbitt, Jonathan C; Lambright, Eric S; Dawes, Aaron; Massion, Pierre P; Speroff, Theodore; Jones, David R; Grogan, Eric L
2011-01-01
Patients undergoing resections for suspicious pulmonary lesions have a 9% to 55% benign rate. Validated prediction models exist to estimate the probability of malignancy in a general population and current practice guidelines recommend their use. We evaluated these models in a surgical population to determine the accuracy of existing models to predict benign or malignant disease. We conducted a retrospective review of our thoracic surgery quality improvement database (2005 to 2008) to identify patients who underwent resection of a pulmonary lesion. Patients were stratified into subgroups based on age, smoking status, and fluorodeoxyglucose positron emission tomography (PET) results. The probability of malignancy was calculated for each patient using the Mayo and solitary pulmonary nodules prediction models. Receiver operating characteristic and calibration curves were used to measure model performance. A total of 189 patients met selection criteria; 73% were malignant. Patients with preoperative PET scans were divided into four subgroups based on age, smoking history, and nodule PET avidity. Older smokers with PET-avid lesions had a 90% malignancy rate. Patients with PET-nonavid lesions, PET-avid lesions with age less than 50 years, or never smokers of any age had a 62% malignancy rate. The area under the receiver operating characteristic curve for the Mayo and solitary pulmonary nodules models was 0.79 and 0.80, respectively; however, the models were poorly calibrated (p<0.001). Despite improvements in diagnostic and imaging techniques, current general population models do not accurately predict lung cancer among patients referred for surgical evaluation. Prediction models with greater accuracy are needed to identify patients with benign disease to reduce nontherapeutic resections. Copyright © 2011 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.
Estimation of Phylogeny Using a General Markov Model
Directory of Open Access Journals (Sweden)
John Robinson
2005-01-01
Full Text Available The non-homogeneous model of nucleotide substitution proposed by Barry and Hartigan (Stat Sci, 2: 191-210 is the most general model of DNA evolution assuming an independent and identical process at each site. We present a computational solution for this model, and use it to analyse two data sets, each violating one or more of the assumptions of stationarity, homogeneity, and reversibility. The log likelihood values returned by programs based on the F84 model (J Mol Evol, 29: 170-179, the general time reversible model (J Mol Evol, 20: 86-93, and Barry and Hartigan’s model are compared to determine the validity of the assumptions made by the first two models. In addition, we present a method for assessing whether sequences have evolved under reversible conditions and discover that this is not so for the two data sets. Finally, we determine the most likely tree under the three models of DNA evolution and compare these with the one favoured by the tests for symmetry.
A Graphical User Interface to Generalized Linear Models in MATLAB
Directory of Open Access Journals (Sweden)
Peter Dunn
1999-07-01
Full Text Available Generalized linear models unite a wide variety of statistical models in a common theoretical framework. This paper discusses GLMLAB-software that enables such models to be fitted in the popular mathematical package MATLAB. It provides a graphical user interface to the powerful MATLAB computational engine to produce a program that is easy to use but with many features, including offsets, prior weights and user-defined distributions and link functions. MATLAB's graphical capacities are also utilized in providing a number of simple residual diagnostic plots.
A Generalized Preferential Attachment Model for Complex Systems
Yamasaki, K; Fu, D; Buldyrev, S V; Pammolli, F; Riccaboni, M; Stanley, H E; Yamasaki, Kazuko; Matia, Kaushik; Fu, Dongfeng; Buldyrev, Sergey V.; Pammolli, Fabio; Riccaboni, Massimo
2005-01-01
Complex systems can be characterized by classes of equivalency of their elements defined according to system specific rules. We propose a generalized preferential attachment model to describe the class size distribution. The model postulates preferential growth of the existing classes and the steady influx of new classes. We investigate how the distribution depends on the initial conditions and changes from a pure exponential form for zero influx of new classes to a power law with an exponential cutoff form when the influx of new classes is substantial. We apply the model to study the growth dynamics of pharmaceutical industry.
Concurrent approaches to Generalized Parton Distribution modeling: the pion's case
Chouika, N.; Mezrag, C.; Moutarde, H.; Rodríguez-Quintero, J.
2017-03-01
The concept of Generalized Parton Distributions promises an understanding of the generation of the charge, spin, and energy-momentum structure of hadrons by quarks and gluons. Forthcoming measurements with unprecedented accuracy at Jefferson Lab and at CERN will challenge our quantitative description of the three-dimensional structure of hadrons. To fully exploit these future measurements, new tools and models are currently being developed. We explain the difficulties of Generalized Parton Distribution modeling, and present some recent progresses. In particular we describe the symmetry-preserving Dyson-Schwinger and Bethe-Salpeter framework. We also discuss various equivalent parameterizations and sketch how to combine them to obtain models satisfying a priori all required theoretical constraints. At last we explain why these developments naturally fit in a versatile software framework, named PARTONS, dedicated to the theory and phenomenology of GPDs.
Holographic entanglement entropy in general holographic superconductor models
Peng, Yan
2014-01-01
We study the entanglement entropy of general holographic dual models both in AdS soliton and AdS black hole backgrounds with full backreaction. We find that the entanglement entropy is a good probe to explore the properties of the holographic superconductors and provides richer physics in the phase transition. We obtain the effects of the scalar mass, model parameter and backreaction on the entropy, and argue that the jump of the entanglement entropy may be a quite general feature for the first order phase transition. In strong contrast to the insulator/superconductor system, we note that the backreaction coupled with the scalar mass can not be used to trigger the first order phase transition if the model parameter is below its bottom bound in the metal/superconductor system.
Garcia, Diego; Moro, Claudia Maria C; Cintho, Lilian Mie M
2015-01-01
The lack of a unique, standardized format for representing data and knowledge is one of the existing difficulties to integrating decision support into Electronic Health Records (EHRs). Propose an archetype-based model to allow the integration of Clinical Practice Guidelines (CPG) and EHRs; design and implement this proposed model. A generic model was designed for the integration of CPG into EHRs, and an archetype-based EHR for Chronic Kidney Disease Prevention based on rules from CPGs, was made as a proof of concept of this novel integration.
Guidelines for Use of the Approximate Beta-Poisson Dose-Response Model.
Xie, Gang; Roiko, Anne; Stratton, Helen; Lemckert, Charles; Dunn, Peter K; Mengersen, Kerrie
2016-10-05
For dose-response analysis in quantitative microbial risk assessment (QMRA), the exact beta-Poisson model is a two-parameter mechanistic dose-response model with parameters α>0 and β>0, which involves the Kummer confluent hypergeometric function. Evaluation of a hypergeometric function is a computational challenge. Denoting PI(d) as the probability of infection at a given mean dose d, the widely used dose-response model PI(d)=1-(1+dβ)-α is an approximate formula for the exact beta-Poisson model. Notwithstanding the required conditions α1, issues related to the validity and approximation accuracy of this approximate formula have remained largely ignored in practice, partly because these conditions are too general to provide clear guidance. Consequently, this study proposes a probability measure Pr(0 (22α̂)0.50 for 0.020.99) . This validity measure and rule of thumb were validated by application to all the completed beta-Poisson models (related to 85 data sets) from the QMRA community portal (QMRA Wiki). The results showed that the higher the probability Pr(0 dose-response curve.
El Ghalbzouri, A; Siamari, R; Willemze, R; Ponec, M
2008-08-01
In the ECVAM validation studies two common skin protocols have been developed, the skin corrosion and skin irritation protocol. Both protocols include next to general and functional conditions that the skin model must meet, also the correct prediction of the activity of certain reference chemicals. For the skin corrosion protocol, the OECD TG 431 defined 12 reference chemicals that should be correctly predicted by the epidermal skin model. For skin irritation 20 test substances should meet the defined criteria. In this study we aimed to subject our Leiden human epidermal (LHE) model to both common protocols according to the ECVAM guidelines. The LHE model generated in this study has been fully characterized and shows very high similarities with the native skin. After minor technical changes in both protocols, corrosion classifications were obtained in concordance with those reported for the validated human skin models EpiSkin and EpiDerm. The results obtained with the common skin irritation protocol were very similar to that of earlier studies with the SkinEthic, EpiSkin and EpiDerm models. This means that the protocols and prediction models developed during the validation studies with a specific skin model can be used with other similar skin models. This study demonstrates that reconstructed human skin equivalents have been proven to be efficient and reliable alternatives to animal testing.
THE ROC CURVE MODEL FROM GENERALIZED-EXPONENTIAL DISTRIBUTION
Directory of Open Access Journals (Sweden)
Ehtesham Hussain
2011-04-01
Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 In biomedical studies often yield continuously positively skewed (non- normal distributed data. In this regard Generalized-Exponential Distribution is suggested for analyzing such data. In this paper the parametric equation of the Receiving Operating Characteristic (ROC curve model is established under the assumptions of bi-distributional population based on pair of Generalized-Exponential Distributions. Also its maximum likelihood estimator MLE, sampling distribution , equivalence test statistic and exact confidence interval are derived.
Extended Generalized-K (EGK): A New Simple and General Model for Composite Fading Channels
Yilmaz, Ferkan
2010-01-01
In this paper, we introduce a generalized composite fading distribution (termed extended generalized-K (EGK)) to model the envelope and the power of the received signal in millimeter wave (60 GHz or above) and free-space optical channels. We obtain the first and the second-order statistics of the received signal envelope characterized by the EGK composite fading distribution. In particular, expressions for probability density function, cumulative distribution function, level crossing rate and average fade duration, and fractional moments are derived. In addition performance measures such as amount of fading, average bit error probability, outage probability, average capacity, and outage capacity are offered in closed-form. Selected numerical and computer simulation examples validate the accuracy of the presented mathematical analysis.
A generalized exponential time series regression model for electricity prices
DEFF Research Database (Denmark)
Haldrup, Niels; Knapik, Oskar; Proietti, Tomasso
We consider the issue of modeling and forecasting daily electricity spot prices on the Nord Pool Elspot power market. We propose a method that can handle seasonal and non-seasonal persistence by modelling the price series as a generalized exponential process. As the presence of spikes can distort...... the estimation of the dynamic structure of the series we consider an iterative estimation strategy which, conditional on a set of parameter estimates, clears the spikes using a data cleaning algorithm, and reestimates the parameters using the cleaned data so as to robustify the estimates. Conditional...... on the estimated model, the best linear predictor is constructed. Our modeling approach provides good fit within sample and outperforms competing benchmark predictors in terms of forecasting accuracy. We also find that building separate models for each hour of the day and averaging the forecasts is a better...
Hairy black holes in the general Skyrme model
Adam, C; Shnir, Ya; Wereszczynski, A
2016-01-01
We study the existence of hairy black holes in the generalized Einstein-Skyrme model. It is proven that in the BPS model limit there are no hairy black hole solutions, although the model admits gravitating (and flat space) solitons. Furthermore, we find strong evidence that a necessary condition for the existence of black holes with Skyrmionic hair is the inclusion of the Skyrme term $\\mathcal{L}_4$. As an example, we show that there are no hairy black holes in the $\\mathcal{L}_2+\\mathcal{L}_6+\\mathcal{L}_0$ model and present a new kind of black hole solutions with compact Skyrmion hair in the $\\mathcal{L}_4+\\mathcal{L}_6+\\mathcal{L}_0$ model.
A Generalized Gamma Mixture Model for Ultrasonic Tissue Characterization
Directory of Open Access Journals (Sweden)
Gonzalo Vegas-Sanchez-Ferrero
2012-01-01
Full Text Available Several statistical models have been proposed in the literature to describe the behavior of speckles. Among them, the Nakagami distribution has proven to very accurately characterize the speckle behavior in tissues. However, it fails when describing the heavier tails caused by the impulsive response of a speckle. The Generalized Gamma (GG distribution (which also generalizes the Nakagami distribution was proposed to overcome these limitations. Despite the advantages of the distribution in terms of goodness of fitting, its main drawback is the lack of a closed-form maximum likelihood (ML estimates. Thus, the calculation of its parameters becomes difficult and not attractive. In this work, we propose (1 a simple but robust methodology to estimate the ML parameters of GG distributions and (2 a Generalized Gama Mixture Model (GGMM. These mixture models are of great value in ultrasound imaging when the received signal is characterized by a different nature of tissues. We show that a better speckle characterization is achieved when using GG and GGMM rather than other state-of-the-art distributions and mixture models. Results showed the better performance of the GG distribution in characterizing the speckle of blood and myocardial tissue in ultrasonic images.
The Chaotic General Economic Equilibrium Model and Monopoly
Directory of Open Access Journals (Sweden)
Vesna D. Jablanovic
2012-09-01
Full Text Available The basic aim of this study is to construct a relatively simple chaotic general economic equilibrium growth model that is capable of generating stable equilibrium, cycles, or chaos. An important example of general economic equilibrium is provided by monopolies. A key hypothesis of this study is based on the idea that the coefficient π = b mRS/m (α-1 (1+1/e mRT plays a crucial role in explaining local stability of the general equilibrium output, where, b: The coefficient of the quadratic marginal-cost function, m: The coefficient of the inverse demand function, mRS: The marginal rate of substitution, mRT: Marginal rate of transformation, α: The coefficient of the monopoly price growth, e: The coefficient of the price elasticity of demand.
Pinning control of a generalized complex dynamical network model
Institute of Scientific and Technical Information of China (English)
Huizhong YANG; Li SHENG
2009-01-01
This paper investigates the local and global synchronization of a generalized complex dynamical network model with constant and delayed coupling.Without assuming symmetry of the couplings,we proved that a single controller can pin the generalized complex network to a homogenous solution.Some previous synchronization results are generalized.In this paper,we first discuss how to pin an array of delayed neural networks to the synchronous solution by adding only one controller.Next,by using the Lyapunov functional method,some sufficient conditions are derived for the local and global synchronization of the coupled systems.The obtained results are expressed in terms of LMIs,which can be efficiently checked by the Matlab LMI toolbox.Finally,an example is given to illustrate the theoretical results.
Boeder, Niklas; Holzer, Matthias; Schelling, Jörg
2012-01-01
Graded exams are prerequisites for the admission to the medical state examination. Accordingly the exams must be of good quality in order to allow benchmarking with the faculty and between different universities. Criteria for good quality need to be considered - namely objectivity, validity and reliability. The guidelines for the processing of exams published by the GMA are supposed to help maintaining those criteria. In 2008 the Department of General Medicine at the University of Munich fulfils only 14 of 18 items. A review process, appropriate training of the staff and the introduction of the IMSm software were the main changes that helped to improve the 'GMA-score' to 30 fulfilled items. We see the introduction of the IMSm system as our biggest challenge ahead. IMSm helps to streamline the necessary workflow and improves their quality (e.g. by the detection of cueing, item analysis). Overall, we evaluate the steps to improve the exam process as very positive. We plan to engage co-workers outside the department to assist in the various review processes in the future. Furthermore we think it might be of value to get into contact with other departments and faculties to benefit from each other's question pools.
Invariants and flavour in the general Two Higgs Doublet Model
Energy Technology Data Exchange (ETDEWEB)
Botella, F.J., E-mail: fbotella@uv.es [Departament de Física Teòrica and IFIC, Universitat de València-CSIC, E-46100, Burjassot (Spain); Branco, G.C., E-mail: gustavo.branco@cern.ch [Departamento de Física and Centro de Física Teórica de Partículas (CFTP), Instituto Superior Técnico, Av. Rovisco Pais, P-1049-001 Lisboa (Portugal); Rebelo, M.N., E-mail: margarida.rebelo@cern.ch [Universidade Técnica de Lisboa, Centro de Física Teórica de Partículas (CFTP), Instituto Superior Técnico, Av. Rovisco Pais, P-1049-001 Lisboa (Portugal)
2013-05-13
The flavour structure of the general Two Higgs Doublet Model (2HDM) is analysed and a detailed study of the parameter space is presented, showing that flavour mixing in the 2HDM can be parametrized by various unitary matrices which arise from the misalignment in flavour space between pairs of various Hermitian flavour matrices which can be constructed within the model. This is entirely analogous to the generation of the CKM matrix in the Standard Model (SM). We construct weak basis invariants which can give insight into the physical implications of any flavour model, written in an arbitrary weak basis (WB) in the context of 2HDM. We apply this technique to two special cases, models with MFV and models with NNI structures. In both cases non-trivial CP-odd WB invariants arise in a mass power order much smaller than what one encounters in the SM, which can have important implications for baryogenesis in the framework of the general 2HDM.
Attractive Hubbard model with disorder and the generalized Anderson theorem
Energy Technology Data Exchange (ETDEWEB)
Kuchinskii, E. Z., E-mail: kuchinsk@iep.uran.ru; Kuleeva, N. A., E-mail: strigina@iep.uran.ru; Sadovskii, M. V., E-mail: sadovski@iep.uran.ru [Russian Academy of Sciences, Institute for Electrophysics, Ural Branch (Russian Federation)
2015-06-15
Using the generalized DMFT+Σ approach, we study the influence of disorder on single-particle properties of the normal phase and the superconducting transition temperature in the attractive Hubbard model. A wide range of attractive potentials U is studied, from the weak coupling region, where both the instability of the normal phase and superconductivity are well described by the BCS model, to the strong-coupling region, where the superconducting transition is due to Bose-Einstein condensation (BEC) of compact Cooper pairs, formed at temperatures much higher than the superconducting transition temperature. We study two typical models of the conduction band with semi-elliptic and flat densities of states, respectively appropriate for three-dimensional and two-dimensional systems. For the semi-elliptic density of states, the disorder influence on all single-particle properties (e.g., density of states) is universal for an arbitrary strength of electronic correlations and disorder and is due to only the general disorder widening of the conduction band. In the case of a flat density of states, universality is absent in the general case, but still the disorder influence is mainly due to band widening, and the universal behavior is restored for large enough disorder. Using the combination of DMFT+Σ and Nozieres-Schmitt-Rink approximations, we study the disorder influence on the superconducting transition temperature T{sub c} for a range of characteristic values of U and disorder, including the BCS-BEC crossover region and the limit of strong-coupling. Disorder can either suppress T{sub c} (in the weak-coupling region) or significantly increase T{sub c} (in the strong-coupling region). However, in all cases, the generalized Anderson theorem is valid and all changes of the superconducting critical temperature are essentially due to only the general disorder widening of the conduction band.
Directory of Open Access Journals (Sweden)
Azeem S Sheikh
2012-09-01
Full Text Available Background: Chest pain is a very common symptom leading to a significant number of patients visiting the primary care trusts, emergency departments and a huge number of emergency hospital admissions.Objective: The objective of our audit was to investigate whether patients with recent onset of chest pain referred to the Rapid Access Chest Pain Clinic were being investigated in accordance with the recommendations by the National Institute for Health and Clinical Excellence (NICE, in a busy District General Hospital setting.Design: Retrospective collection of dataSetting: Southend University Hospital NHS Foundation TrustPatients: We collected data over a period of three months for all the patients who underwent invasive coronary angiogram after being referred via Rapid Access Chest Pain Clinic (RACPC or General Cardiology Clinic presenting with recent onset of chest pain. A total of 157 patients were enrolled in the study. The patients were then categorised into four groups based upon their description of symptoms, age and risk factors, as defined by NICE.Results: We found that 86% (135/157 patients had estimated likelihood of CAD >60% and 51% of these had unnecessary non-invasive investigations contrary to what NICE recommends. This shows that adhering to the NICE guidelines would have saved a substantial amount of hospital resources and time of the healthcare team and the patients.Conclusions: The development of strategies for cost-conscious quality care must begin with the history, risk factors for coronary artery disease and patients’ investigations should be based on their risk stratification.
Optimal reinsurance/investment problems for general insurance models
Liu, Yuping; 10.1214/08-AAP582
2009-01-01
In this paper the utility optimization problem for a general insurance model is studied. The reserve process of the insurance company is described by a stochastic differential equation driven by a Brownian motion and a Poisson random measure, representing the randomness from the financial market and the insurance claims, respectively. The random safety loading and stochastic interest rates are allowed in the model so that the reserve process is non-Markovian in general. The insurance company can manage the reserves through both portfolios of the investment and a reinsurance policy to optimize a certain utility function, defined in a generic way. The main feature of the problem lies in the intrinsic constraint on the part of reinsurance policy, which is only proportional to the claim-size instead of the current level of reserve, and hence it is quite different from the optimal investment/consumption problem with constraints in finance. Necessary and sufficient conditions for both well posedness and solvability...
A Non-Gaussian Spatial Generalized Linear Latent Variable Model
Irincheeva, Irina
2012-08-03
We consider a spatial generalized linear latent variable model with and without normality distributional assumption on the latent variables. When the latent variables are assumed to be multivariate normal, we apply a Laplace approximation. To relax the assumption of marginal normality in favor of a mixture of normals, we construct a multivariate density with Gaussian spatial dependence and given multivariate margins. We use the pairwise likelihood to estimate the corresponding spatial generalized linear latent variable model. The properties of the resulting estimators are explored by simulations. In the analysis of an air pollution data set the proposed methodology uncovers weather conditions to be a more important source of variability than air pollution in explaining all the causes of non-accidental mortality excluding accidents. © 2012 International Biometric Society.
On virtual states and generalized completeness relation in Friedrichs Model
Xiao, Zhiguang
2016-01-01
We study the well-known Friedrichs model, in which a discrete state is coupled to a continuum state. By examining the pole behaviors of the Friedrichs model in a specific form factor thoroughly, we find that, in general, when the bare discrete state is below the threshold of the continuum state, there should also be a virtual-state pole accompanying the bound-state pole originating from the bare discrete state as the coupling is turned on. There are also other second-sheet poles originating from the singularities of the form factor. We give a general argument for the existence of these two kinds of states. As the coupling is increased to a certain value, the second-sheet poles may merge and become higher-order poles. We then discuss the completeness relations incorporating bound states, virtual states, and resonant states corresponding to higher-order poles.
Aeolian Sediment Transport Integration in General Stratigraphic Forward Modeling
Directory of Open Access Journals (Sweden)
T. Salles
2011-01-01
Full Text Available A large number of numerical models have been developed to simulate the physical processes involved in saltation, and, recently to investigate the interaction between soil vegetation cover and aeolian transport. These models are generally constrained to saltation of monodisperse particles while natural saltation occurs over mixed soils. We present a three-dimensional numerical model of steady-state saltation that can simulate aeolian erosion, transport and deposition for unvegetated mixed soils. Our model simulates the motion of saltating particles using a cellular automata algorithm. A simple set of rules is used and takes into account an erosion formula, a transport model, a wind exposition function, and an avalanching process. The model is coupled to the stratigraphic forward model Sedsim that accounts for a larger number of geological processes. The numerical model predicts a wide range of typical dune shapes, which have qualitative correspondence to real systems. The model reproduces the internal structure and composition of the resulting aeolian deposits. It shows the complex formation of dune systems with cross-bedding strata development, bounding surfaces overlaid by fine sediment and inverse grading deposits. We aim to use it to simulate the complex interactions between different sediment transport processes and their resulting geological morphologies.
Treatment of cloud radiative effects in general circulation models
Energy Technology Data Exchange (ETDEWEB)
Wang, W.C.; Dudek, M.P.; Liang, X.Z.; Ding, M. [State Univ. of New York, Albany, NY (United States)] [and others
1996-04-01
We participate in the Atmospheric Radiation Measurement (ARM) program with two objectives: (1) to improve the general circulation model (GCM) cloud/radiation treatment with a focus on cloud verticle overlapping and layer cloud optical properties, and (2) to study the effects of cloud/radiation-climate interaction on GCM climate simulations. This report summarizes the project progress since the Fourth ARM Science Team meeting February 28-March 4, 1994, in Charleston, South Carolina.
Unitary transformation method for solving generalized Jaynes-Cummings models
Indian Academy of Sciences (India)
Sudha Singh
2006-03-01
Two fully quantized generalized Jaynes-Cummings models for the interaction of a two-level atom with radiation field are treated, one involving intensity dependent coupling and the other involving multiphoton interaction between the field and the atom. The unitary transformation method presented here not only solves the time dependent problem but also allows a determination of the eigensolutions of the interacting Hamiltonian at the same time.
Conditional likelihood inference in generalized linear mixed models.
Sartori, Nicola; Severini , T.A
2002-01-01
Consider a generalized linear model with a canonical link function, containing both fixed and random effects. In this paper, we consider inference about the fixed effects based on a conditional likelihood function. It is shown that this conditional likelihood function is valid for any distribution of the random effects and, hence, the resulting inferences about the fixed effects are insensitive to misspecification of the random effects distribution. Inferences based on the conditional likelih...
Credibility analysis of risk classes by generalized linear model
Erdemir, Ovgucan Karadag; Sucu, Meral
2016-06-01
In this paper generalized linear model (GLM) and credibility theory which are frequently used in nonlife insurance pricing are combined for reliability analysis. Using full credibility standard, GLM is associated with limited fluctuation credibility approach. Comparison criteria such as asymptotic variance and credibility probability are used to analyze the credibility of risk classes. An application is performed by using one-year claim frequency data of a Turkish insurance company and results of credible risk classes are interpreted.
Generalized Bogoliubov Polariton Model: An Application to Stock Exchange Market
Thuy Anh, Chu; Anh, Truong Thi Ngoc; Lan, Nguyen Tri; Viet, Nguyen Ai
2016-06-01
A generalized Bogoliubov method for investigation non-simple and complex systems was developed. We take two branch polariton Hamiltonian model in second quantization representation and replace the energies of quasi-particles by two distribution functions of research objects. Application to stock exchange market was taken as an example, where the changing the form of return distribution functions from Boltzmann-like to Gaussian-like was studied.
Scalar products in generalized models with SU(3)-symmetry
Wheeler, M.
2012-01-01
We consider a generalized model with SU(3)-invariant R-matrix, and review the nested Bethe Ansatz for constructing eigenvectors of the transfer matrix. A sum formula for the scalar product between generic Bethe vectors, originally obtained by Reshetikhin [11], is discussed. This formula depends on a certain partition function Z(\\{\\lambda\\},\\{\\mu\\}|\\{w\\},\\{v\\}), which we evaluate explicitly. In the limit when the variables \\{\\mu\\} or \\{v\\} approach infinity, this object reduces to the domain w...
A General Theoretical Model of Enthalpy-EntropyCompensation
Institute of Scientific and Technical Information of China (English)
LIU，Lei; GUO, Qing-Xiang
2001-01-01
Enthalpy-entropy compensation remains a mystery in chemistry and biophysics.recent study suggested that the solventreorganization might constitute the physical orihin of the compensation, which was unforumstely not wisely applicable because compensation was also observeserved in solid phade reactions.In this study,a general theoretical model based upon strictmathematical deduction was presented,which indicated thatthe redistribution of the distinguishable subspecies might bethe physical origin of the enthalpy-intropy compensations in solvation and surface adsorption weue discussed.
Electromagnetic axial anomaly in a generalized linear sigma model
Fariborz, Amir H.; Jora, Renata
2017-06-01
We construct the electromagnetic anomaly effective term for a generalized linear sigma model with two chiral nonets, one with a quark-antiquark structure, the other one with a four-quark content. We compute in the leading order of this framework the decays into two photons of six pseudoscalars: π0(137 ), π0(1300 ), η (547 ), η (958 ), η (1295 ) and η (1760 ). Our results agree well with the available experimental data.
Energy Technology Data Exchange (ETDEWEB)
Simmons, C.S.; Cole, C.R.
1985-05-01
This document was written for the National Low-Level Waste Management Program to provide guidance for managers and site operators who need to select ground-water transport codes for assessing shallow-land burial site performance. The guidance given in this report also serves the needs of applications-oriented users who work under the direction of a manager or site operator. The guidelines are published in two volumes designed to support the needs of users having different technical backgrounds. An executive summary, published separately, gives managers and site operators an overview of the main guideline report. This volume includes specific recommendations for decision-making managers and site operators on how to use these guidelines. The more detailed discussions about the code selection approach are provided. 242 refs., 6 figs.
Structural dynamic analysis with generalized damping models analysis
Adhikari , Sondipon
2013-01-01
Since Lord Rayleigh introduced the idea of viscous damping in his classic work ""The Theory of Sound"" in 1877, it has become standard practice to use this approach in dynamics, covering a wide range of applications from aerospace to civil engineering. However, in the majority of practical cases this approach is adopted more for mathematical convenience than for modeling the physics of vibration damping. Over the past decade, extensive research has been undertaken on more general ""non-viscous"" damping models and vibration of non-viscously damped systems. This book, along with a related book
Generalized model for Memristor-based Wien family oscillators
Talukdar, Abdul Hafiz Ibne
2012-07-23
In this paper, we report the unconventional characteristics of Memristor in Wien oscillators. Generalized mathematical models are developed to analyze four members of the Wien family using Memristors. Sustained oscillation is reported for all types though oscillating resistance and time dependent poles are present. We have also proposed an analytical model to estimate the desired amplitude of oscillation before the oscillation starts. These Memristor-based oscillation results, presented for the first time, are in good agreement with simulation results. © 2011 Elsevier Ltd.
Regularization Paths for Generalized Linear Models via Coordinate Descent
Directory of Open Access Journals (Sweden)
Jerome Friedman
2010-02-01
Full Text Available We develop fast algorithms for estimation of generalized linear models with convex penalties. The models include linear regression, two-class logistic regression, and multi- nomial regression problems while the penalties include ℓ1 (the lasso, ℓ2 (ridge regression and mixtures of the two (the elastic net. The algorithms use cyclical coordinate descent, computed along a regularization path. The methods can handle large problems and can also deal efficiently with sparse features. In comparative timings we find that the new algorithms are considerably faster than competing methods.
Principle Generalized Net Model of a Human Stress Reaction
Directory of Open Access Journals (Sweden)
Anthony Shannon
2008-04-01
Full Text Available The present study was aimed at investigating the mechanism of a human stress reaction by means of Generalized Nets (GNs. A principle GN-model of the main structures, organs and systems of the human body taking part in the acute and chronic reaction of the organism to a stress stimulus is generated. A possible application of the GN-model of the human stress reaction for testing the effect of known or newly synthesized pharmacological products as well as of food supplements is discussed.
Automorphisms and Generalized Involution Models of Finite Complex Reflection Groups
Marberg, Eric
2010-01-01
We prove that a finite complex reflection group has a generalized involution model, as defined by Bump and Ginzburg, if and only if each of its irreducible factors is either $G(r,p,n)$ with $\\gcd(p,n)=1$; $G(r,p,2)$ with $r/p$ odd; or $G_{23}$, the Coxeter group of type $H_3$. We additionally provide explicit formulas for all automorphisms of $G(r,p,n)$, and construct new Gelfand models for the groups $G(r,p,n)$ with $\\gcd(p,n)=1$.
Tropical disturbances in relation to general circulation modeling
Estoque, M. A.
1982-01-01
The initial results of an evaluation of the performance of the Goddard Laboratory of Atmospheric Simulation general circulation model depicting the tropical atmosphere during the summer are presented. Because the results show the existence of tropical wave disturbances throughout the tropics, the characteristics of synoptic disturbances over Africa were studied and a synoptic case study of a selected disturbance in this area was conducted. It is shown that the model is able to reproduce wave type synoptic disturbances in the tropics. The findings show that, in one of the summers simulated, the disturbances are predominantly closed vortices; in another summer, the predominant disturbances are open waves.
Anisotropic Mesoscale Eddy Transport in Ocean General Circulation Models
Reckinger, S. J.; Fox-Kemper, B.; Bachman, S.; Bryan, F.; Dennis, J.; Danabasoglu, G.
2014-12-01
Modern climate models are limited to coarse-resolution representations of large-scale ocean circulation that rely on parameterizations for mesoscale eddies. The effects of eddies are typically introduced by relating subgrid eddy fluxes to the resolved gradients of buoyancy or other tracers, where the proportionality is, in general, governed by an eddy transport tensor. The symmetric part of the tensor, which represents the diffusive effects of mesoscale eddies, is universally treated isotropically in general circulation models. Thus, only a single parameter, namely the eddy diffusivity, is used at each spatial and temporal location to impart the influence of mesoscale eddies on the resolved flow. However, the diffusive processes that the parameterization approximates, such as shear dispersion, potential vorticity barriers, oceanic turbulence, and instabilities, typically have strongly anisotropic characteristics. Generalizing the eddy diffusivity tensor for anisotropy extends the number of parameters to three: a major diffusivity, a minor diffusivity, and the principal axis of alignment. The Community Earth System Model (CESM) with the anisotropic eddy parameterization is used to test various choices for the newly introduced parameters, which are motivated by observations and the eddy transport tensor diagnosed from high resolution simulations. Simply setting the ratio of major to minor diffusivities to a value of five globally, while aligning the major axis along the flow direction, improves biogeochemical tracer ventilation and reduces global temperature and salinity biases. These effects can be improved even further by parameterizing the anisotropic transport mechanisms in the ocean.
Border Collision Bifurcations in a Generalized Model of Population Dynamics
Directory of Open Access Journals (Sweden)
Lilia M. Ladino
2016-01-01
Full Text Available We analyze the dynamics of a generalized discrete time population model of a two-stage species with recruitment and capture. This generalization, which is inspired by other approaches and real data that one can find in literature, consists in considering no restriction for the value of the two key parameters appearing in the model, that is, the natural death rate and the mortality rate due to fishing activity. In the more general case the feasibility of the system has been preserved by posing opportune formulas for the piecewise map defining the model. The resulting two-dimensional nonlinear map is not smooth, though continuous, as its definition changes as any border is crossed in the phase plane. Hence, techniques from the mathematical theory of piecewise smooth dynamical systems must be applied to show that, due to the existence of borders, abrupt changes in the dynamic behavior of population sizes and multistability emerge. The main novelty of the present contribution with respect to the previous ones is that, while using real data, richer dynamics are produced, such as fluctuations and multistability. Such new evidences are of great interest in biology since new strategies to preserve the survival of the species can be suggested.
Generalized linear models with coarsened covariates: a practical Bayesian approach.
Johnson, Timothy R; Wiest, Michelle M
2014-06-01
Coarsened covariates are a common and sometimes unavoidable phenomenon encountered in statistical modeling. Covariates are coarsened when their values or categories have been grouped. This may be done to protect privacy or to simplify data collection or analysis when researchers are not aware of their drawbacks. Analyses with coarsened covariates based on ad hoc methods can compromise the validity of inferences. One valid method for accounting for a coarsened covariate is to use a marginal likelihood derived by summing or integrating over the unknown realizations of the covariate. However, algorithms for estimation based on this approach can be tedious to program and can be computationally expensive. These are significant obstacles to their use in practice. To overcome these limitations, we show that when expressed as a Bayesian probability model, a generalized linear model with a coarsened covariate can be posed as a tractable missing data problem where the missing data are due to censoring. We also show that this model is amenable to widely available general-purpose software for simulation-based inference for Bayesian probability models, providing researchers a very practical approach for dealing with coarsened covariates.
Item Response Theory Using Hierarchical Generalized Linear Models
Directory of Open Access Journals (Sweden)
Hamdollah Ravand
2015-03-01
Full Text Available Multilevel models (MLMs are flexible in that they can be employed to obtain item and person parameters, test for differential item functioning (DIF and capture both local item and person dependence. Papers on the MLM analysis of item response data have focused mostly on theoretical issues where applications have been add-ons to simulation studies with a methodological focus. Although the methodological direction was necessary as a first step to show how MLMs can be utilized and extended to model item response data, the emphasis needs to be shifted towards providing evidence on how applications of MLMs in educational testing can provide the benefits that have been promised. The present study uses foreign language reading comprehension data to illustrate application of hierarchical generalized models to estimate person and item parameters, differential item functioning (DIF, and local person dependence in a three-level model.
The linear model and hypothesis a general unifying theory
Seber, George
2015-01-01
This book provides a concise and integrated overview of hypothesis testing in four important subject areas, namely linear and nonlinear models, multivariate analysis, and large sample theory. The approach used is a geometrical one based on the concept of projections and their associated idempotent matrices, thus largely avoiding the need to involve matrix ranks. It is shown that all the hypotheses encountered are either linear or asymptotically linear, and that all the underlying models used are either exactly or asymptotically linear normal models. This equivalence can be used, for example, to extend the concept of orthogonality in the analysis of variance to other models, and to show that the asymptotic equivalence of the likelihood ratio, Wald, and Score (Lagrange Multiplier) hypothesis tests generally applies.
Predicting the Probability of Lightning Occurrence with Generalized Additive Models
Fabsic, Peter; Mayr, Georg; Simon, Thorsten; Zeileis, Achim
2017-04-01
This study investigates the predictability of lightning in complex terrain. The main objective is to estimate the probability of lightning occurrence in the Alpine region during summertime afternoons (12-18 UTC) at a spatial resolution of 64 × 64 km2. Lightning observations are obtained from the ALDIS lightning detection network. The probability of lightning occurrence is estimated using generalized additive models (GAM). GAMs provide a flexible modelling framework to estimate the relationship between covariates and the observations. The covariates, besides spatial and temporal effects, include numerous meteorological fields from the ECMWF ensemble system. The optimal model is chosen based on a forward selection procedure with out-of-sample mean squared error as a performance criterion. Our investigation shows that convective precipitation and mid-layer stability are the most influential meteorological predictors. Both exhibit intuitive, non-linear trends: higher values of convective precipitation indicate higher probability of lightning, and large values of the mid-layer stability measure imply low lightning potential. The performance of the model was evaluated against a climatology model containing both spatial and temporal effects. Taking the climatology model as a reference forecast, our model attains a Brier Skill Score of approximately 46%. The model's performance can be further enhanced by incorporating the information about lightning activity from the previous time step, which yields a Brier Skill Score of 48%. These scores show that the method is able to extract valuable information from the ensemble to produce reliable spatial forecasts of the lightning potential in the Alps.
A general mixture model for sediment laden flows
Liang, Lixin; Yu, Xiping; Bombardelli, Fabián
2017-09-01
A mixture model for general description of sediment-laden flows is developed based on an Eulerian-Eulerian two-phase flow theory, with the aim at gaining computational speed in the prediction, but preserving the accuracy of the complete two-fluid model. The basic equations of the model include the mass and momentum conservation equations for the sediment-water mixture, and the mass conservation equation for sediment. However, a newly-obtained expression for the slip velocity between phases allows for the computation of the sediment motion, without the need of solving the momentum equation for sediment. The turbulent motion is represented for both the fluid and the particulate phases. A modified k-ε model is used to describe the fluid turbulence while an algebraic model is adopted for turbulent motion of particles. A two-dimensional finite difference method based on the SMAC scheme was used to numerically solve the mathematical model. The model is validated through simulations of fluid and suspended sediment motion in steady open-channel flows, both in equilibrium and non-equilibrium states, as well as in oscillatory flows. The computed sediment concentrations, horizontal velocity and turbulent kinetic energy of the mixture are all shown to be in good agreement with available experimental data, and importantly, this is done at a fraction of the computational efforts required by the complete two-fluid model.
Generalized effective medium resistivity model for low resistivity reservoir
Institute of Scientific and Technical Information of China (English)
2008-01-01
With the advancement in oil exploration,producible oil and gas are being found in low resistivity reservoirs,which may otherwise be erroneously thought as water zones from their resistivity.However,the evaluation of low resistivity reservoirs remains difficult from log interpretation.Since low resistivity in hydrocarbon bearing sands can be caused by dispersed clay,laminated shale,conductive matrix grains,microscopic capillary pores and high saline water,a new resistivity model is required for more accurate hydrocarbon saturation prediction for low resistivity formations.Herein,a generalized effective medium resistivity model has been proposed for low resistivity reservoirs,based on experimental measurements on artificial low resistivity shaly sand samples,symmetrical anisotropic effective medium theory for resistivity interpretations,and geneses and conductance mechanisms of low resistivity reservoirs.By analyzing effects of some factors on the proposed model,we show theoretically the model can describe conductance mechanisms of low resistivity reservoirs with five geneses.Also,shale distribution largely affects water saturation predicted by the model.Resistivity index decreases as fraction and conductivity of laminated shale,or fraction of dispersed clay,or conductivity of rock matrix grains increases.Resistivity index decreases as matrix percolation exponent,or percolation rate of capillary bound water increases,and as percolation exponent of capillary bound water,or matrix percolation rate,or free water percolation rate decreases.Rock sample data from low resistivity reservoirs with different geneses and interpretation results for log data show that the proposed model can be applied in low resistivity reservoirs containing high salinity water,dispersed clay,microscopic capillary pores,laminated shale and conductive matrix grains,and thus is considered as a generalized resistivity model for low resistivity reservoir evaluation.
Generalized effective medium resistivity model for low resistivity reservoir
Institute of Scientific and Technical Information of China (English)
SONG YanJie; TANG XiaoMin
2008-01-01
With the advancement in oil exploration, producible oil and gas are being found in low resistivity reservoirs, which may otherwise be erroneously thought as water zones from their resistivity. However,the evaluation of low resistivity reservoirs remains difficult from log interpretation. Since low resistivity in hydrocarbon bearing sands can be caused by dispersed clay, laminated shale, conductive matrix grains, microscopic capillary pores and high saline water, a new resistivity model is required for more accurate hydrocarbon saturation prediction for low resistivity formations. Herein, a generalized effective medium resistivity model has been proposed for low resistivity reservoirs, based on experimental measurements on artificial low resistivity shaly sand samples, symmetrical anisotropic effective medium theory for resistivity interpretations, and geneses and conductance mechanisms of low resistivity reservoirs. By analyzing effects of some factors on the proposed model, we show theoretically the model can describe conductance mechanisms of low resistivity reservoirs with five geneses. Also,shale distribution largely affects water saturation predicted by the model. Resistivity index decreases as fraction and conductivity of laminated shale, or fraction of dispersed clay, or conductivity of rock matrix grains increases. Resistivity index decreases as matrix percolation exponent, or percolation rate of capillary bound water increases, and as percolation exponent of capillary bound water, or matrix percolation rate, or free water percolation rate decreases. Rock sample data from low resistivity reservoirs with different geneses and interpretation results for log data show that the proposed model can be applied in low resistivity reservoirs containing high salinity water, dispersed clay, microscopic capillary pores, laminated shale and conductive matrix grains, and thus is considered as a generalized resistivity model for low resistivity reservoir evaluation.
Bayesian generalized linear mixed modeling of Tuberculosis using informative priors.
Ojo, Oluwatobi Blessing; Lougue, Siaka; Woldegerima, Woldegebriel Assefa
2017-01-01
TB is rated as one of the world's deadliest diseases and South Africa ranks 9th out of the 22 countries with hardest hit of TB. Although many pieces of research have been carried out on this subject, this paper steps further by inculcating past knowledge into the model, using Bayesian approach with informative prior. Bayesian statistics approach is getting popular in data analyses. But, most applications of Bayesian inference technique are limited to situations of non-informative prior, where there is no solid external information about the distribution of the parameter of interest. The main aim of this study is to profile people living with TB in South Africa. In this paper, identical regression models are fitted for classical and Bayesian approach both with non-informative and informative prior, using South Africa General Household Survey (GHS) data for the year 2014. For the Bayesian model with informative prior, South Africa General Household Survey dataset for the year 2011 to 2013 are used to set up priors for the model 2014.
Fermion Masses and Mixing in General Warped Extra Dimensional Models
Frank, Mariana; Pourtolami, Nima; Toharia, Manuel
2015-01-01
We analyze fermion masses and mixing in a general warped extra dimensional model, where all the Standard Model (SM) fields, including the Higgs, are allowed to propagate in the bulk. In this context, a slightly broken flavor symmetry imposed universally on all fermion fields, without distinction, can generate the full flavor structure of the SM, including quarks, charged leptons and neutrinos. For quarks and charged leptons, the exponential sensitivity of their wave-functions to small flavor breaking effects yield naturally hierarchical masses and mixing as it is usual in warped models with fermions in the bulk. In the neutrino sector, the exponential wave-function factors can be flavor-blind and thus insensitive to the small flavor symmetry breaking effects, directly linking their masses and mixing angles to the flavor symmetric structure of the 5D neutrino Yukawa couplings. The Higgs must be localized in the bulk and the model is naturally more successful in generalized warped scenarios where the metric bac...
Fermion masses and mixing in general warped extra dimensional models
Frank, Mariana; Hamzaoui, Cherif; Pourtolami, Nima; Toharia, Manuel
2015-06-01
We analyze fermion masses and mixing in a general warped extra dimensional model, where all the Standard Model (SM) fields, including the Higgs, are allowed to propagate in the bulk. In this context, a slightly broken flavor symmetry imposed universally on all fermion fields, without distinction, can generate the full flavor structure of the SM, including quarks, charged leptons and neutrinos. For quarks and charged leptons, the exponential sensitivity of their wave functions to small flavor breaking effects yield hierarchical masses and mixing as it is usual in warped models with fermions in the bulk. In the neutrino sector, the exponential wave-function factors can be flavor blind and thus insensitive to the small flavor symmetry breaking effects, directly linking their masses and mixing angles to the flavor symmetric structure of the five-dimensional neutrino Yukawa couplings. The Higgs must be localized in the bulk and the model is more successful in generalized warped scenarios where the metric background solution is different than five-dimensional anti-de Sitter (AdS5 ). We study these features in two simple frameworks, flavor complimentarity and flavor democracy, which provide specific predictions and correlations between quarks and leptons, testable as more precise data in the neutrino sector becomes available.
Generalized Manning Condensation Model Captures the RNA Ion Atmosphere
Hayes, Ryan L.; Noel, Jeffrey K.; Mandic, Ana; Whitford, Paul C.; Sanbonmatsu, Karissa Y.; Mohanty, Udayan; Onuchic, José N.
2016-01-01
RNA is highly sensitive to the ionic environment, and typically requires Mg2+ to form compact structures. There is a need for models capable of describing the ion atmosphere surrounding RNA with quantitative accuracy. We present a model of RNA electrostatics and apply it within coarse-grained molecular dynamics simulation. The model treats Mg2+ ions explicitly to account for ion-ion correlations neglected by mean field theories. Since mean-field theories capture KCl well, it is treated implicitly by a generalized Manning counterion condensation model. The model extends Manning condensation to deal with arbitrary RNA conformations, non-limiting KCl concentrations, and the ion inaccessible volume of RNA. The model is tested against experimental measurements of the excess Mg2+ associated with the RNA, Γ2+, because Γ2+ is directly related to the Mg2+-RNA interaction free energy. The excellent agreement with experiment demonstrates the model captures the ionic dependence of the RNA free energy landscape. PMID:26197147
Generalized Semi-Analytical Models of Supernova Light Curves
Chatzopoulos, Emmanouil; Vinko, Jozsef
2011-01-01
We present generalized supernova (SN) light curve (LC) models for a variety of power inputs. We provide an expression for the power input that is produced by self-similar forward and reverse shocks in SN ejecta - circumstellar matter (CSM) interaction. We find that this ejecta-CSM interaction luminosity is in agreement with results from multi-dimensional radiation hydrodynamics simulations in the optically-thin case. We develop a model for the case of an optically-thick CSM by invoking an approximation for the effects of radiative diffusion. In the context of this model, we provide predictions for the time of forward shock break-out from the optically-thick part of the CSM envelope. We also introduce a hybrid LC model that incorporates ejecta-CSM interaction plus Ni-56 and Co-56 radioactive decay input. We fit this hybrid model to the LC of the Super-Luminous Supernova (SLSN) 2006gy. We find that this model provides a better fit to the LC of this event than previously presented models. We also address the rel...
A new approach for modeling generalization gradients: A case for Hierarchical Models
Directory of Open Access Journals (Sweden)
Koen eVanbrabant
2015-05-01
Full Text Available A case is made for the use of hierarchical models in the analysis of generalization gradients. Hierarchical models overcome several restrictions that are imposed by repeated measures analysis-of-variance (rANOVA, the default statistical method in current generalization research. More specifically, hierarchical models allow to include continuous independent variables and overcomes problematic assumptions such as sphericity. We focus on how generalization research can benefit from this added flexibility. In a simulation study we demonstrate the dominance of hierarchical models over rANOVA. In addition, we show the lack of efficiency of the Mauchly's sphericity test in sample sizes typical for generalization research, and confirm how violations of sphericity increase the probability of type I errors. A worked example of a hierarchical model is provided, with a specific emphasis on the interpretation of parameters relevant for generalization research.
A new approach for modeling generalization gradients: a case for hierarchical models.
Vanbrabant, Koen; Boddez, Yannick; Verduyn, Philippe; Mestdagh, Merijn; Hermans, Dirk; Raes, Filip
2015-01-01
A case is made for the use of hierarchical models in the analysis of generalization gradients. Hierarchical models overcome several restrictions that are imposed by repeated measures analysis-of-variance (rANOVA), the default statistical method in current generalization research. More specifically, hierarchical models allow to include continuous independent variables and overcomes problematic assumptions such as sphericity. We focus on how generalization research can benefit from this added flexibility. In a simulation study we demonstrate the dominance of hierarchical models over rANOVA. In addition, we show the lack of efficiency of the Mauchly's sphericity test in sample sizes typical for generalization research, and confirm how violations of sphericity increase the probability of type I errors. A worked example of a hierarchical model is provided, with a specific emphasis on the interpretation of parameters relevant for generalization research.
Toward a general evaluation model for soil respiration (GEMSR)
Institute of Scientific and Technical Information of China (English)
2008-01-01
Soil respiration is an important component of terrestrial carbon budget. Its accurate evaluation is es- sential to the study of terrestrial carbon source/sink. Studies on soil respiration at present mostly focus on the temporal variations and the controlling factors of soil respiration, but its spatial variations and controlling factors draw less attention. Moreover, the evaluation models for soil respiration at present include only the effects of water and heat factors, while the biological and soil factors controlling soil respiration and their interactions with water and heat factors have not been considered yet. These models are not able to accurately evaluate soil respiration in different vegetation/terrestrial ecosystems at different temporal and spatial scales. Thus, a general evaluation model for soil respiration (GEMSR) including the interacting meteorological (water and heat factors), soil nutrient and biological factors is suggested in this paper, and the basic procedure developing GEMSR and the research tasks of soil respiration in the future are also discussed.
Synchronization criteria based on a general complex dynamical network model
Institute of Scientific and Technical Information of China (English)
ZHANG Jian-lin; WANG Chang-jian; XU Cong-fu
2008-01-01
Many complex dynamical networks display synchronization phenomena. We introduce a general complex dynamical network model. The model is equivalent to a simple vector model of adopting the Kronecker product. Some synchronization criteria, including time-variant networks and time-varying networks, are deduced based on Lyapunov's stability theory, and they are proven on the condition of obtaining a certain synchronous solution of an isolated cell. In particular, the inner-coupling matrix directly determines the synchronization of the time-invariant network; while for a time-varying periodic dynamical network, the asymptotic stability of a synchronous solution is determined by a constant matrix which is related to the fundamental solution matrices of the linearization system. Finally, illustrative examples are given to validate the results.
A generalized and parameterized interference model for cognitive radio networks
Mahmood, Nurul Huda
2011-06-01
For meaningful co-existence of cognitive radios with primary system, it is imperative that the cognitive radio system is aware of how much interference it generates at the primary receivers. This can be done through statistical modeling of the interference as perceived at the primary receivers. In this work, we propose a generalized model for the interference generated by a cognitive radio network, in the presence of small and large scale fading, at a primary receiver located at the origin. We then demonstrate how this model can be used to estimate the impact of cognitive radio transmission on the primary receiver in terms of different outage probabilities. Finally, our analytical findings are validated through some selected computer-based simulations. © 2011 IEEE.
Generalized self-dual Maxwell-Chern-Simons-Higgs model
Bazeia, D; da Hora, E; Menezes, R
2012-01-01
We present a consistent BPS framework for a generalized Maxwell-Chern-Simons-Higgs model. The overall model, including its self-dual potential, depends on three different functions, h(|{\\phi}|,N), w(|{\\phi}|) and G(|{\\phi}|), which are functions of the scalar fields only. The BPS energy is proportional to the magnetic flux when w(|{\\phi}|) and G(|{\\phi}|) are related to each other by a differential constraint. We present an explicit non-standard model and its topologically non-trivial static configurations, which are described by the usual radially symmetric profile. Finally, we note that the non-standard results behave in a similar way as their standard counterparts, as expected, reinforcing the consistence of the overall construction.
Generalized self-dual Maxwell-Chern-Simons-Higgs model
Bazeia, D.; Casana, R.; da Hora, E.; Menezes, R.
2012-06-01
We present a consistent Bogomol’nyi-Prasad-Sommerfield (BPS) framework for a generalized Maxwell-Chern-Simons-Higgs model. The overall model, including its self-dual potential, depends on three different functions, h(|ϕ|,N), w(|ϕ|), and G(|ϕ|), which are functions of the scalar fields only. The BPS energy is proportional to the magnetic flux when w(|ϕ|) and G(|ϕ|) are related to each other by a differential constraint. We present an explicit nonstandard model and its topologically nontrivial static configurations, which are described by the usual radially symmetric profile. Finally, we note that the nonstandard results behave in a similar way as their standard counterparts, as expected, reinforcing the consistence of the overall construction.
A General Approach to the Modelling of Trophic Chains
Dilão, R; Dilao, Rui; Domingos, Tiago
1999-01-01
Based on the law of mass action (and its microscopic foundation) and mass conservation, we present here a method to derive consistent dynamic models for the time evolution of systems with an arbitrary number of species. Equations are derived through a mechanistic description, ensuring that all parameters have ecological meaning. After discussing the biological mechanisms associated to the logistic and Lotka-Volterra equations, we show how to derive general models for trophic chains, including the effects of internal states at fast time scales. We show that conformity with the mass action law leads to different functional forms for the Lotka-Volterra and trophic chain models. We use mass conservation to recover the concept of carrying capacity for an arbitrary food chain.
Asymptotics of the QMLE for General ARCH(q) Models
DEFF Research Database (Denmark)
Kristensen, Dennis; Rahbek, Anders Christian
2009-01-01
Asymptotics of the QMLE for Non-Linear ARCH Models Dennis Kristensen, Columbia University Anders Rahbek, University of Copenhagen Abstract Asymptotic properties of the quasi-maximum likelihood estimator (QMLE) for non-linear ARCH(q) models -- including for example Asymmetric Power ARCH and log......-ARCH -- are derived. Strong consistency is established under the assumptions that the ARCH process is geometrically ergodic, the conditional variance function has a finite log-moment, and finite second moment of the rescaled error. Asymptotic normality of the estimator is established under the additional assumption...... that certain ratios involving the conditional variance function are suitably bounded, and that the rescaled errors have little more than fourth moment. We verify our general conditions, including identification, for a wide range of leading specific ARCH models....
Thermal power system analysis using a generalized network flow model
Energy Technology Data Exchange (ETDEWEB)
Kumar, John Arun [Former Senior Design Engineer, Power System Analysis and Control Group, Bharat Heavy Electricals Limited, New Delhi (India); Chebiyam, Radhakrishna [Former Director, Academic Staff College, JNT University, Hyderabad-72 (India)
2012-07-01
This paper analyzes an Integrated Thermal Power System using a Multiperiod Generalized Network Flow Model. The thermal system analysis is carried out by taking into account the complex dynamics involved in utilizing multiple energy carriers (coal, diesel and natural gas). The model comprises energy source nodes, energy transformation nodes, energy storage nodes, energy demand nodes and their interconnections. The solution to the integrated energy system problem involves the evaluation of energy flows that meet the electricity demand at minimum total cost, while satisfying system constraints. This is illustrated through the India case study using a minimum time-step of one hour. MATLAB based software was developed for carrying out this study. TOMLAB/CPLEX software was utilized for obtaining the optimal solution. The model and the methodology utilized for conducting the study would be of interest to those involved in integrated energy system planning for a country or a region.
Dimensional Reduction for the General Markov Model on Phylogenetic Trees.
Sumner, Jeremy G
2017-03-01
We present a method of dimensional reduction for the general Markov model of sequence evolution on a phylogenetic tree. We show that taking certain linear combinations of the associated random variables (site pattern counts) reduces the dimensionality of the model from exponential in the number of extant taxa, to quadratic in the number of taxa, while retaining the ability to statistically identify phylogenetic divergence events. A key feature is the identification of an invariant subspace which depends only bilinearly on the model parameters, in contrast to the usual multi-linear dependence in the full space. We discuss potential applications including the computation of split (edge) weights on phylogenetic trees from observed sequence data.
General Study of Perturbations in Bouncing and Cyclic Models
Mayes, Riley; Biswas, Tirthabir; Lattyak, Colleen
2015-04-01
Perturbations are important in both understanding and evaluating the importance of bounces and turnarounds in models that predict a cyclic evolution of our Universe. Moreover, tracking these perturbations through the entirety of the cycle is important as it provides an outlet for a qualitative comparison with Cosmic Microwave Background (CMB) observations. However, tracking these perturbations through each cycle proves difficult as the physics to describe bounces and turnarounds is not well established. Therefore, we first studied general anaytical and numerical techniques in order to understand the evolution of fluctuations in simple cosmological models where physics is better understood. In our research, we first developed analytical techniques from background solutions to establish a solid foundation for describing super-Hubble fluctuations in our early Universe. These analytical solutions were developed for both bounces and turnarounds allowing us to numerically verify and then further investigate the consequences of these solutions in models such as bounce inflation and cyclic inflation.
Toward a general evaluation model for soil respiration (GEMSR)
Institute of Scientific and Technical Information of China (English)
ZHOU GuangSheng; JIA BingRui; HAN GuangXuan; ZHOU Li
2008-01-01
Soil respiration is an important component of terrestrial carbon budget. Its accurate evaluation is essential to the study of terrestrial carbon source/sink. Studies on soil respiration at present mostly focus on the temporal variations and the controlling factors of soil respiration, but its spatial variations and controlling factors draw less attention. Moreover, the evaluation models for soil respiration at present include only the effects of water and heat factors, while the biological and soil factors controlling soil respiration and their interactions with water and heat factors have not been considered yet. These models are not able to accurately evaluate soil respiration in different vegetation/terrestrial ecosystems at different temporal and spatial scales. Thus, a general evaluation model for soil respiration (GEMSR)including the interacting meteorological (water and heat factors), soil nutrient and biological factors is suggested in this paper, and the basic procedure developing GEMSR and the research tasks of soil respiration in the future are also discussed.
Analysis of Robust Quasi-deviances for Generalized Linear Models
Directory of Open Access Journals (Sweden)
Eva Cantoni
2004-04-01
Full Text Available Generalized linear models (McCullagh and Nelder 1989 are a popular technique for modeling a large variety of continuous and discrete data. They assume that the response variables Yi , for i = 1, . . . , n, come from a distribution belonging to the exponential family, such that E[Yi ] = ?i and V[Yi ] = V (?i , and that ?i = g(?i = xiT?, where ? ? IR p is the vector of parameters, xi ? IR p, and g(. is the link function. The non-robustness of the maximum likelihood and the maximum quasi-likelihood estimators has been studied extensively in the literature. For model selection, the classical analysis-of-deviance approach shares the same bad robustness properties. To cope with this, Cantoni and Ronchetti (2001 propose a robust approach based on robust quasi-deviance functions for estimation and variable selection. We refer to that paper for a deeper discussion and the review of the literature.
A General Mechanistic Model of Solid Oxide Fuel Cells
Institute of Scientific and Technical Information of China (English)
SHI Yixiang; CAI Ningsheng
2006-01-01
A comprehensive model considering all forms of polarization was developed. The model considers the intricate interdependency among the electrode microstructure, the transport phenomena, and the electrochemical processes. The active three-phase boundary surface was expressed as a function of electrode microstructure parameters (porosity, coordination number, contact angle, etc.). The exchange current densities used in the simulation were obtained by fitting a general formulation to the polarization curves proposed as a function of cell temperature and oxygen partial pressure. A validation study shows good agreement with published experimental data. Distributions of overpotentials, gas component partial pressures, and electronic/ionic current densities have been calculated. The effects of a porous electrode structure and of various operation conditions on cell performance were also predicted. The mechanistic model proposed can be used to interpret experimental observations and optimize cell performance by incorporating reliable experimental data.
Extensive investigation of the generalized dark matter model
Kopp, Michael; Skordis, Constantinos; Thomas, Dan B.
2016-08-01
The cold dark matter (CDM) model, wherein the dark matter is treated as a pressureless perfect fluid, provides a good fit to galactic and cosmological data. With the advent of precision cosmology, it should be asked whether this simplest model needs to be extended, and whether doing so could improve our understanding of the properties of dark matter. One established parametrization for generalizing the CDM fluid is the generalized dark matter (GDM) model, in which dark matter is an imperfect fluid with pressure and shear viscosity that fulfill certain postulated closure equations. We investigate these closure equations and the three new parametric functions they contain: the background equation of state w , the speed of sound cs2 and the viscosity cvis2. Taking these functions to be constant parameters, we analyze an exact solution of the perturbed Einstein equations in a flat GDM-dominated universe and discuss the main effects of the three parameters on the cosmic microwave background (CMB). Our analysis suggests that the CMB alone is not able to distinguish between the GDM sound speed and viscosity parameters, but that other observables, such as the matter power spectrum, are required to break this degeneracy. In order to elucidate further the meaning of the GDM closure equations, we also consider other descriptions of imperfect fluids that have a nonperturbative definition and relate these to the GDM model. In particular, we consider scalar fields, an effective field theory (EFT) of fluids, an EFT of large-scale structure, nonequilibrium thermodynamics and tightly coupled fluids. These descriptions could be used to extend the GDM model into the nonlinear regime of structure formation, which is necessary if the wealth of data available on those scales is to be employed in constraining the model. We also derive the initial conditions for adiabatic and isocurvature perturbations in the presence of GDM and standard cosmological fluids and provide the result in a
A Global Ocean Biogeochemistry General Circulation Model and its Simulations
Institute of Scientific and Technical Information of China (English)
XU Yongfu; LI Yangchun; CHU Min
2013-01-01
An ocean biogeochemistry model was developed and incorporated into a global ocean general circulation model (LICOM) to form an ocean biogeochemistry general circulation model (OBGCM).The model was used to study the natural carbon cycle and the uptake and storage of anthropogenic CO2 in the ocean.A global export production of 12.5 Pg C yr-1 was obtained.The model estimated that in the pre-industrial era the global equatorial region within ±15° of the equator released 0.97 Pg C yr-1 to the atmosphere,which was balanced by the gain of CO2 in other regions.The post-industrial air-sea CO2 flux indicated the oceanic uptake of CO2 emitted by human activities.An increase of 20-50 μmol kg-1 for surface dissolved inorganic carbon (DIC) concentrations in the 1990s relative to pre-industrial times was obtained in the simulation,which was consistent with data-based estimates.The model generated a total anthropogenic carbon inventory of 105 Pg C as of 1994,which was within the range of estimates by other researchers.Various transports of both natural and anthropogenic DIC as well as labile dissolved organic carbon (LDOC)were estimated from the simulation.It was realized that the Southern Ocean and the high-latitude region of the North Pacific are important export regions where accumulative air-sea CO2 fluxes are larger than the DIC inventory,whereas the subtropical regions are acceptance regions.The interhemispheric transport of total natural carbon (DIC+LDOC) was found to be northward (0.11 Pg C yr-1),which was just balanced by the gain of carbon from the atmosphere in the Southern Hemisphere.
[Guidelines for clinical practice].
Vleugels, A M
1997-01-01
Clinical practice guidelines are systematically developed statements that are intended to support medical decision making in well-defined clinical situations. Essentially, their object is to reduce the variability in medical practice, to improve quality, and to make appropriated control of the financial resources possible. Internationally, ever more organisations, associations, and institutions are concerned with the development of guidelines in many different areas of care. Making implicit knowledge explicit is one of the associated advantages of guidelines: they have a potential utility in training, in process evaluation, and in the reevaluation of outcome studies. In liability issues, their existence has a double effect: they can be used to justify medical behaviour, and they constitute a generally accepted reference point. A derivative problem is the legal liability of the compilers of the guidelines. The principle of the guideline approach can be challenged academically: science cannot give a definition of optimal care with absolute certainty. What is called objectivity often rests on methodologically disputable analyses; also the opinion of opinion leaders is not always a guarantee for scientific soundness. Moreover, patients are not all identical: biological variability, situational factors, patient expectations, and other elements play a role in this differentiation. Clinicians are often hesitant with respect to clinical guidelines: they are afraid of cookbook medicine and curtailment of their professional autonomy. Patients fear reduction of individualization of care and the use of guidelines as a rationing instrument. The effects of the introduction of clinical practice guidelines on medical practice, on the results and on the cost of care vary but are generally considered to be favourable. The choice of appropriate strategies in development, dissemination, and implementation turns out to be of critical importance. The article ends with concrete
Generalized Stefan models accounting for a discontinuous temperature field
Danescu, A.
We construct a class of generalized Stefan models able to account for a discontinuous temperature field across a nonmaterial interface. The resulting theory introduces a constitutive scalar interfacial field, denoted by /lineθ and called the equivalent temperature of the interface. A classical procedure, based on the interfacial dissipation inequality, relates the interfacial energy release to the interfacial mass flux and restricts the equivalent temperature of the interface. We show that previously proposed theories are obtained as particular cases when /lineθ = ⪉θ > or /lineθ = ⪉(1)/(θ )>-1 or, more generally, when /lineθ = ⪉θ r ⪉ 1/θ1-r-1 for 0<= r<= 1. We study in a particular constitutive framework the solidification of an under-cooled liquid and we are able to give a sufficient condition for the existence of travelling wave solutions.
Mathematical model and general laws of wet compression
Institute of Scientific and Technical Information of China (English)
王永青; 刘铭; 廉乐明; 何健勇; 严家騄
2002-01-01
Wet compression is an effective way to enhance the performance of gas turbines and it has attracted a good deal of attention in recent years. The one-sidedness and inaccuracy of previous studies,which took concentration gradient as mass transfer potential are discussed. The mass transfer process is analyzed from the viewpoint of non-equilibrium thermodynamics,by taking generalized thermodynamic driving force as mass transfer potential,and the corresponding mass-transfer coefficient is obtained using the heat and mass transfer equilibrium occurring between moist air and water droplets at wet-bulb temperature for the sake of avoiding complex tests and providing more accurate formulas. A mathematical model of wet compression is therefore established,and the general laws of wet compression are investigated. The results show that the performance of atomizer is critical for wet compression and wet compression is more suitable for compressors with higher pressure ratio and longer compression time.
Generalized fish life-cycle poplulation model and computer program
Energy Technology Data Exchange (ETDEWEB)
DeAngelis, D. L.; Van Winkle, W.; Christensen, S. W.; Blum, S. R.; Kirk, B. L.; Rust, B. W.; Ross, C.
1978-03-01
A generalized fish life-cycle population model and computer program have been prepared to evaluate the long-term effect of changes in mortality in age class 0. The general question concerns what happens to a fishery when density-independent sources of mortality are introduced that act on age class 0, particularly entrainment and impingement at power plants. This paper discusses the model formulation and computer program, including sample results. The population model consists of a system of difference equations involving age-dependent fecundity and survival. The fecundity for each age class is assumed to be a function of both the fraction of females sexually mature and the weight of females as they enter each age class. Natural mortality for age classes 1 and older is assumed to be independent of population size. Fishing mortality is assumed to vary with the number and weight of fish available to the fishery. Age class 0 is divided into six life stages. The probability of survival for age class 0 is estimated considering both density-independent mortality (natural and power plant) and density-dependent mortality for each life stage. Two types of density-dependent mortality are included. These are cannibalism of each life stage by older age classes and intra-life-stage competition.
Generalized Magnetic Field Effects in Burgers' Nanofluid Model
Rashidi, M. M.; Yang, Z.; Awais, Muhammad; Nawaz, Maria; Hayat, Tasawar
2017-01-01
Analysis has been conducted to present the generalized magnetic field effects on the flow of a Burgers' nanofluid over an inclined wall. Mathematical modelling for hydro-magnetics reveals that the term “σB02u/ρ” is for the Newtonian model whereas the generalized magnetic field term (as mentioned in Eq 4) is for the Burgers’ model which is incorporated in the current analysis to get the real insight of the problem for hydro-magnetics. Brownian motion and thermophoresis phenomenon are presented to analyze the nanofluidics for the non-Newtonian fluid. Mathematical analysis is completed in the presence of non-uniform heat generation/absorption. The constructed set of partial differential system is converted into coupled nonlinear ordinary differential system by employing the suitable transformations. Homotopy approach is employed to construct the analytical solutions which are shown graphically for sundr5y parameters including Deborah numbers, magnetic field, thermophoresis, Brownian motion and non-uniform heat generation/absorption. A comparative study is also presented showing the comparison of present results with an already published data. PMID:28045965
A message passing approach for general epidemic models
Karrer, Brian
2010-01-01
In most models of the spread of disease over contact networks it is assumed that the probabilities of disease transmission and recovery from disease are constant in time. In real life, however, this is far from true. In many diseases, for instance, recovery occurs at about the same time after infection for all individuals, rather than at a constant rate. In this paper, we study a generalized version of the SIR (susceptible-infected-recovered) model of epidemic disease that allows for arbitrary nonuniform distributions of transmission and recovery times. Standard differential equation approaches cannot be used for this generalized model, but we show that the problem can be reformulated as a time-dependent message passing calculation on the appropriate contact network. The calculation is exact on trees (i.e., loopless networks) or locally tree-like networks (such as random graphs) in the large system size limit. On non-tree-like networks we show that the calculation gives a rigorous bound on the size of disease...
2010-01-01
... 7 Agriculture 6 2010-01-01 2010-01-01 false Guidelines. 622.5 Section 622.5 Agriculture... AGRICULTURE WATER RESOURCES WATERSHED PROJECTS General § 622.5 Guidelines. Guidelines for carrying out... Environmental Principles and Guidelines for Water and Related Land Resources Implementation Studies issued...
Uppal, Elaine
2016-01-01
This article is part of the Advancing practice series which is aimed at exploring practice issues in more depth, considering topics that are frequently encountered and facilitating the development of new insights. Elaine Uppal focuses on the importance of all midwives developing guideline writing skills to ensure that local, national and international midwifery/maternity guidelines are up to date, relevant and reflect midwifery knowledge alongside 'gold' standard evidence. The article aims to consider the development, use and critical appraisal of clinical guidelines. It will define and explain guidelines; discuss their development and dissemination; and consider issues relating to their use in practice. Techniques to critique and develop guidelines using the AGREE tool will be outlined in the form of practice challenges to be undertaken by the individual or in a group.
[Guidelines for the management of dyslipidemia].
Díaz Rodríguez, Ángel
2014-09-01
The AHA/ACC 2013 guideline on the treatment of blood cholesterol to reduce atherosclerotic cardiovascular disease (ASCVD) in adults contains major differences with the previous ESC/EAS 2011 guidelines and the remaining international guidelines, which has generated major controversies. The AHA/ACC document has developed a new model for estimating cardiovascular risk for primary prevention which is not comparable with the SCORE recommended in the European guidelines. This guideline does not establish a fixed target for low-density lipoprotein cholesterol (LDLc). Instead, it identifies 4 major statin benefit groups at risk for the development ASCVD, who should receive low-, moderate-, and high-intensity statin therapy to reduce LCLc. In contrast, the European guidelines maintain LDLc as the main treatment target and non-high-density lipoprotein cholesterol as a secondary treatment target. The document recommends calculating cardiovascular risk for the overall treatment of patients with dyslipidemia according to 4 risk levels (low, moderate, high, and very high), establishes LDLc treatment targets, and recommends a statin-based therapeutic strategy and other, lipid-lowering strategies, aimed at achieving these targets. The American guidelines cannot be extrapolated to the European population. Target-based treatment, as recommended in the EAS/ESC guidelines, is the best strategy for Europe. In Spain, the Primary Care Guidelines of the Spanish Society of Family and Community Medicine (semFYC) and the Spanish Society of Primary Care Physicians (SEMERGEN) are based on the European recommendations. Finally, the Spanish Society of Arteriosclerosis (SEA), SEMERGEN, semFYC and the Spanish Society of General Medicine (SEMG) are reaching a consensus on the approach and management of patients with atherogenic dyslipidemia in primary care.
A seasonal model of the Mediterranean Sea general circulation
Roussenov, Vassil; Stanev, Emil; Artale, Vincenzo; Pinardi, Nadia
1995-07-01
This paper describes the seasonal characteristics of the Mediterranean Sea general circulation as simulated by a primitive equation general circulation model. The forcing is composed of climatological monthly mean atmospheric parameters, which are used to compute the heat and momentum budgets at the air-sea interface of the model. This allows heat fluxes to be determined by a realistic air-sea interaction physics. The Strait of Gibraltar is open, and the model resolution is ? in the horizontal and 19 levels in the vertical. The results show the large seasonal cycle of the circulation and its transient characteristics. The heat budget at the surface is characterized by lateral boundary intensifications occurring in downwelling and up welling areas of the basin. The general circulation is composed of subbasin gyres, and cyclonic motion dominates the northern and anticyclonic motion the southern part of the basin. The Atlantic stream which enters from Gibraltar and assumes the form of different boundary current subsystems is a coherent structure at the surface. At depth it appears as current segments and jets around a vigorous gyre system. The seasonal variability is manifested not only by a change in amplitude and location of the gyres but also by the appearance of seasonally recurrent gyres in different parts of the basin. Distinct westward propagation of these gyres occurs, together with amplitude changes. For the first time a Mersa-Matruh Gyre is successfully simulated due to the introduction of our heat fluxes at the air-sea interface. The seasonal thermocline is formed each summer, and a deep winter mixed layer is produced in the region of Levantine intermediate water formation. Deep water renewal does not occur, probably due to the climatological forcing used.
A GENERALIZATION OF TRADITIONAL KANO MODEL FOR CUSTOMER REQUIREMENTS ANALYSIS
Directory of Open Access Journals (Sweden)
Renáta Turisová
2015-07-01
Full Text Available Purpose: The theory of attractiveness determines the relationship between the technically achieved and customer perceived quality of product attributes. The most frequently used approach in the theory of attractiveness is the implementation of Kano‘s model. There exist a lot of generalizations of that model which take into consideration various aspects and approaches focused on understanding the customer preferences and identification of his priorities for a selling product. The aim of this article is to outline another possible generalization of Kano‘s model.Methodology/Approach: The traditional Kano’s model captures the nonlinear relationship between reached attributes of quality and customer requirements. The individual attributes of quality are divided into three main categories: must-be, one-dimensional, attractive quality and into two side categories: indifferent and reverse quality. The well selling product has to contain the must-be attribute. It should contain as many one-dimensional attributes as possible. If there are also supplementary attractive attributes, it means that attractiveness of the entire product, from the viewpoint of the customer, nonlinearly sharply rises what has a direct positive impact on a decision of potential customer when purchasing the product. In this article, we show that inclusion of individual quality attributes of a product to the mentioned categories depends, among other things, also on costs on life cycle of the product, respectively on a price of the product on the market.Findings: In practice, we are often encountering the inclusion of products into different price categories: lower, middle and upper class. For a certain type of products the category is either directly declared by a producer (especially in automotive industry, or is determined by a customer by means of assessment of available market prices. To each of those groups of a products different customer expectations can be assigned
A General Random Walk Model of Molecular Motor
Institute of Scientific and Technical Information of China (English)
WANG Xian-Ju; AI Bao-Quan; LIU Guo-Tao; LIU Liang-Gang
2003-01-01
A general random walk model framework is presented which can be used to statistically describe the internaldynamics and external mechanical movement of molecular motors along filament track. The motion of molecular motorin a periodic potential and a constant force is considered. We show that the molecular motor's movement becomesslower with the potential barrier increasing, but if the forceis increased, the molecular motor's movement becomesfaster. The relation between the effective rate constant and the potential barrier's height, and that between the effectiverate constant and the value of the force are discussed. Our results are consistent with the experiments and relevanttheoretical consideration, and can be used to explain some physiological phenomena.
Estimation and variable selection for generalized additive partial linear models
Wang, Li
2011-08-01
We study generalized additive partial linear models, proposing the use of polynomial spline smoothing for estimation of nonparametric functions, and deriving quasi-likelihood based estimators for the linear parameters. We establish asymptotic normality for the estimators of the parametric components. The procedure avoids solving large systems of equations as in kernel-based procedures and thus results in gains in computational simplicity. We further develop a class of variable selection procedures for the linear parameters by employing a nonconcave penalized quasi-likelihood, which is shown to have an asymptotic oracle property. Monte Carlo simulations and an empirical example are presented for illustration. © Institute of Mathematical Statistics, 2011.
Consolidation of data base for Army generalized missile model
Klenke, D. J.; Hemsch, M. J.
1980-01-01
Data from plume interaction tests, nose mounted canard configuration tests, and high angle of attack tests on the Army Generalized Missile model are consolidated in a computer program which makes them readily accessible for plotting, listing, and evaluation. The program is written in FORTRAN and will run on an ordinary minicomputer. It has the capability of retrieving any coefficient from the existing DATAMAN tapes and displaying it in tabular or plotted form. Comparisons of data taken in several wind tunnels and of data with the predictions of Program MISSILE2 are also presented.
Adaptive quasi-likelihood estimate in generalized linear models
Institute of Scientific and Technical Information of China (English)
CHEN Xia; CHEN Xiru
2005-01-01
This paper gives a thorough theoretical treatment on the adaptive quasilikelihood estimate of the parameters in the generalized linear models. The unknown covariance matrix of the response variable is estimated by the sample. It is shown that the adaptive estimator defined in this paper is asymptotically most efficient in the sense that it is asymptotic normal, and the covariance matrix of the limit distribution coincides with the one for the quasi-likelihood estimator for the case that the covariance matrix of the response variable is completely known.
An Optimal Capacity Planning Model for General Cargo Seaport
Directory of Open Access Journals (Sweden)
Čedomir Dundović
2012-10-01
Full Text Available In this paper the application of the queuing the01y in optimalcapacity planning for general cargo seaport is presented.The seaport as a queuing syslem is defined and tlws, on the basisof the arrival and serviced number of ships in an obsen•edtime unit, the appropriate operating indicators of a port systemare calculated. Using the model of total port costs, the munberof berths and cranes on the berth can be determined wherebythe optimal port system functioning is achieved.
Gauge Potts model with generalized action: A Monte Carlo analysis
Energy Technology Data Exchange (ETDEWEB)
Fanchiotti, H.; Canal, C.A.G.; Sciutto, S.J.
1985-08-15
Results of a Monte Carlo calculation on the q-state gauge Potts model in d dimensions with a generalized action involving planar 1 x 1, plaquette, and 2 x 1, fenetre, loop interactions are reported. For d = 3 and q = 2, first- and second-order phase transitions are detected. The phase diagram for q = 3 presents only first-order phase transitions. For d = 2, a comparison with analytical results is made. Here also, the behavior of the numerical simulation in the vicinity of a second-order transition is analyzed.
A generalized methodology to characterize composite materials for pyrolysis models
McKinnon, Mark B.
The predictive capabilities of computational fire models have improved in recent years such that models have become an integral part of many research efforts. Models improve the understanding of the fire risk of materials and may decrease the number of expensive experiments required to assess the fire hazard of a specific material or designed space. A critical component of a predictive fire model is the pyrolysis sub-model that provides a mathematical representation of the rate of gaseous fuel production from condensed phase fuels given a heat flux incident to the material surface. The modern, comprehensive pyrolysis sub-models that are common today require the definition of many model parameters to accurately represent the physical description of materials that are ubiquitous in the built environment. Coupled with the increase in the number of parameters required to accurately represent the pyrolysis of materials is the increasing prevalence in the built environment of engineered composite materials that have never been measured or modeled. The motivation behind this project is to develop a systematic, generalized methodology to determine the requisite parameters to generate pyrolysis models with predictive capabilities for layered composite materials that are common in industrial and commercial applications. This methodology has been applied to four common composites in this work that exhibit a range of material structures and component materials. The methodology utilizes a multi-scale experimental approach in which each test is designed to isolate and determine a specific subset of the parameters required to define a material in the model. Data collected in simultaneous thermogravimetry and differential scanning calorimetry experiments were analyzed to determine the reaction kinetics, thermodynamic properties, and energetics of decomposition for each component of the composite. Data collected in microscale combustion calorimetry experiments were analyzed to
Directory of Open Access Journals (Sweden)
Perria Carla
2004-06-01
Full Text Available Abstract Background Despite broad agreement on the necessity to improve quality of diabetic care through implementation of clinical guidelines, in Italy many people with diabetes still lack adequate care in general practice. In addition there is little evidence to support the choice of implementation strategies, especially in the Lazio region (central Italy, where comparative studies among general practitioners (GPs are uncommon. The primary objective of the study is to assess the effectiveness of different strategies for the implementation of an evidence-based guideline for the management of non-complicated type 2 diabetes mellitus (DM among GPs of the Lazio region. Methods/Design Three-arm cluster-randomised trial (C-RCT. 252 GPs were randomised either to arm 1 (comprising a training module and administration of the guideline, or to arm 2 (administration of guideline without training, or to arm 3 (control arm, continuing current practice. Arm 1 participants attended a two-day course with CME credits. Data collection will be performed using current information systems. Patients' health data was also collected to describe diabetic populations cared for by GP participants. Process outcomes will be measured at the patient level and at the cluster level one year after the intervention. We will assess GPs' adherence to guideline recommendations for diabetes management relative to: 1 pharmacological management of diabetes; 2 pharmacological management of cardiovascular risk factors (hypertension and dislypidaemia; 3 measurement of glycosilated haemoglobin as the principal indicator of glycaemic control; 4 micro- and macrovascular complications assessment tests. Outcomes will be expressed as proportions of patients cared for by GPs who will have prescriptions of drugs, requests for tests and for outpatient appointment visits. To estimate the efficiency of resource use associated with the intervention a cost-effectiveness analysis will be carried out
Estimating parameters for generalized mass action models with connectivity information
Directory of Open Access Journals (Sweden)
Voit Eberhard O
2009-05-01
Full Text Available Abstract Background Determining the parameters of a mathematical model from quantitative measurements is the main bottleneck of modelling biological systems. Parameter values can be estimated from steady-state data or from dynamic data. The nature of suitable data for these two types of estimation is rather different. For instance, estimations of parameter values in pathway models, such as kinetic orders, rate constants, flux control coefficients or elasticities, from steady-state data are generally based on experiments that measure how a biochemical system responds to small perturbations around the steady state. In contrast, parameter estimation from dynamic data requires time series measurements for all dependent variables. Almost no literature has so far discussed the combined use of both steady-state and transient data for estimating parameter values of biochemical systems. Results In this study we introduce a constrained optimization method for estimating parameter values of biochemical pathway models using steady-state information and transient measurements. The constraints are derived from the flux connectivity relationships of the system at the steady state. Two case studies demonstrate the estimation results with and without flux connectivity constraints. The unconstrained optimal estimates from dynamic data may fit the experiments well, but they do not necessarily maintain the connectivity relationships. As a consequence, individual fluxes may be misrepresented, which may cause problems in later extrapolations. By contrast, the constrained estimation accounting for flux connectivity information reduces this misrepresentation and thereby yields improved model parameters. Conclusion The method combines transient metabolic profiles and steady-state information and leads to the formulation of an inverse parameter estimation task as a constrained optimization problem. Parameter estimation and model selection are simultaneously carried out
Generalization Technique for 2D+SCALE Dhe Data Model
Karim, Hairi; Rahman, Alias Abdul; Boguslawski, Pawel
2016-10-01
Different users or applications need different scale model especially in computer application such as game visualization and GIS modelling. Some issues has been raised on fulfilling GIS requirement of retaining the details while minimizing the redundancy of the scale datasets. Previous researchers suggested and attempted to add another dimension such as scale or/and time into a 3D model, but the implementation of scale dimension faces some problems due to the limitations and availability of data structures and data models. Nowadays, various data structures and data models have been proposed to support variety of applications and dimensionality but lack research works has been conducted in terms of supporting scale dimension. Generally, the Dual Half Edge (DHE) data structure was designed to work with any perfect 3D spatial object such as buildings. In this paper, we attempt to expand the capability of the DHE data structure toward integration with scale dimension. The description of the concept and implementation of generating 3D-scale (2D spatial + scale dimension) for the DHE data structure forms the major discussion of this paper. We strongly believed some advantages such as local modification and topological element (navigation, query and semantic information) in scale dimension could be used for the future 3D-scale applications.
Computable general equilibrium model fiscal year 2013 capability development report
Energy Technology Data Exchange (ETDEWEB)
Edwards, Brian Keith [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rivera, Michael Kelly [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Boero, Riccardo [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2016-05-17
This report documents progress made on continued developments of the National Infrastructure Simulation and Analysis Center (NISAC) Computable General Equilibrium Model (NCGEM), developed in fiscal year 2012. In fiscal year 2013, NISAC the treatment of the labor market and tests performed with the model to examine the properties of the solutions computed by the model. To examine these, developers conducted a series of 20 simulations for 20 U.S. States. Each of these simulations compared an economic baseline simulation with an alternative simulation that assumed a 20-percent reduction in overall factor productivity in the manufacturing industries of each State. Differences in the simulation results between the baseline and alternative simulations capture the economic impact of the reduction in factor productivity. While not every State is affected in precisely the same way, the reduction in manufacturing industry productivity negatively affects the manufacturing industries in each State to an extent proportional to the reduction in overall factor productivity. Moreover, overall economic activity decreases when manufacturing sector productivity is reduced. Developers ran two additional simulations: (1) a version of the model for the State of Michigan, with manufacturing divided into two sub-industries (automobile and other vehicle manufacturing as one sub-industry and the rest of manufacturing as the other subindustry); and (2) a version of the model for the United States, divided into 30 industries. NISAC conducted these simulations to illustrate the flexibility of industry definitions in NCGEM and to examine the simulation properties of in more detail.
General review on in vitro hepatocyte models and their applications.
Guguen-Guillouzo, Christiane; Guillouzo, Andre
2010-01-01
In vitro hepatocyte models represent very useful systems in both fundamental research and various application areas. Primary hepatocytes appear as the closest model for the liver in vivo. However, they are phenotypically unstable, have a limited life span and in addition, exhibit large interdonor variability when of human origin. Hepatoma cell lines appear as an alternative but only the HepaRG cell line exhibits various functions, including major cytochrome P450 activities, at levels close to those found in primary hepatocytes. In vitro hepatocyte models have brought a substantial contribution to the understanding of the biochemistry, physiology, and cell biology of the normal and diseased liver and in various application domains such as xenobiotic metabolism and toxicity, virology, parasitology, and more generally cell therapies. In the future, new well-differentiated hepatocyte cell lines derived from tumors or from either embryonic or adult stem cells might be expected and although hepatocytes will continue to be used in various fields, these in vitro liver models should allow marked advances, especially in cell-based therapies and predictive and mechanistic hepatotoxicity of new drugs and other chemicals. All models will benefit from new developments in throughput screening based on cell chips coupled with high-content imaging and in toxicogenomics technologies.
Manchikanti, Laxmaiah; Falco, Frank J E; Singh, Vijay; Benyamin, Ramsin M; Racz, Gabor B; Helm, Standiford; Caraway, David L; Calodney, Aaron K; Snook, Lee T; Smith, Howard S; Gupta, Sanjeeva; Ward, Stephen P; Grider, Jay S; Hirsch, Joshua A
2013-04-01
In 2011, the Institute of Medicine (IOM) re-engineered its definition of clinical guidelines as follows: "clinical practice guidelines are statements that include recommendations intended to optimize patient care that are informed by a systematic review of evidence and an assessment of the benefit and harms of alternative care options." This new definition departs from a 2-decade old definition from a 1990 IOM report that defined guidelines as "systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances." The revised definition clearly distinguishes between the term "clinical practice guideline" and other forms of clinical guidance derived from widely disparate development processes, such as consensus statements, expert advice, and appropriate use criteria. The IOM committee acknowledged that for many clinical domains, high quality evidence was lacking or even nonexistent. Even though the guidelines are important decision-making tools, along with expert clinical judgment and patient preference, their value and impact remains variable due to numerous factors. Some of the many factors that impede the development of clinical practice guidelines include bias due to a variety of conflicts of interest, inappropriate and poor methodological quality, poor writing and ambiguous presentation, projecting a view that these are not applicable to individual patients or too restrictive with elimination of clinician autonomy, and overzealous and inappropriate recommendations, either positive, negative, or non-committal. Consequently, a knowledgeable, multidisciplinary panel of experts must develop guidelines based on a systematic review of the existing evidence, as recently recommended by the IOM. Chronic pain is a complex and multifactorial phenomenon associated with significant economic, social, and health outcomes. Interventional pain management is an emerging specialty facing a
Modeling of Testability Requirement Based on Generalized Stochastic Petri Nets
Institute of Scientific and Technical Information of China (English)
SU Yong-ding; QIU Jing; LIU Guan-jun; QIAN Yan-ling
2009-01-01
Testability design is an effective way to realize the fault detection and isolation. Its important step is to determine testability figures of merits (TFOM). Firstly, some influence factors for TFOMs are analyzed, such as the processes of system operation, maintenance and support, fault detection and isolation and so on. Secondly, a testability requirement analysis model is built based on generalized stochastic Petri net (GSPN). Then, the system's reachable states are analyzed based on the model, a Markov chain isomorphic with Petri net is constructed, a state transition matrix is created and the system's steady state probability is obtained. The relationship between the steady state availability and testability parameters can be revealed and reasoned. Finally, an example shows that the proposed method can determine TFOM, such as fault detection rate and fault isolation rate, effectively and reasonably.
A Chemical Containment Model for the General Purpose Work Station
Flippen, Alexis A.; Schmidt, Gregory K.
1994-01-01
Contamination control is a critical safety requirement imposed on experiments flying on board the Spacelab. The General Purpose Work Station, a Spacelab support facility used for life sciences space flight experiments, is designed to remove volatile compounds from its internal airpath and thereby minimize contamination of the Spacelab. This is accomplished through the use of a large, multi-stage filter known as the Trace Contaminant Control System. Many experiments planned for the Spacelab require the use of toxic, volatile fixatives in order to preserve specimens prior to postflight analysis. The NASA-Ames Research Center SLS-2 payload, in particular, necessitated the use of several toxic, volatile compounds in order to accomplish the many inflight experiment objectives of this mission. A model was developed based on earlier theories and calculations which provides conservative predictions of the resultant concentrations of these compounds given various spill scenarios. This paper describes the development and application of this model.
On the thermodynamic properties of the generalized Gaussian core model
Directory of Open Access Journals (Sweden)
B.M.Mladek
2005-01-01
Full Text Available We present results of a systematic investigation of the properties of the generalized Gaussian core model of index n. The potential of this system interpolates via the index n between the potential of the Gaussian core model and the penetrable sphere system, thereby varying the steepness of the repulsion. We have used both conventional and self-consistent liquid state theories to calculate the structural and thermodynamic properties of the system; reference data are provided by computer simulations. The results indicate that the concept of self-consistency becomes indispensable to guarantee excellent agreement with simulation data; in particular, structural consistency (in our approach taken into account via the zero separation theorem is obviously a very important requirement. Simulation results for the dimensionless equation of state, β P / ρ, indicate that for an index-value of 4, a clustering transition, possibly into a structurally ordered phase might set in as the system is compressed.
Explicit estimating equations for semiparametric generalized linear latent variable models
Ma, Yanyuan
2010-07-05
We study generalized linear latent variable models without requiring a distributional assumption of the latent variables. Using a geometric approach, we derive consistent semiparametric estimators. We demonstrate that these models have a property which is similar to that of a sufficient complete statistic, which enables us to simplify the estimating procedure and explicitly to formulate the semiparametric estimating equations. We further show that the explicit estimators have the usual root n consistency and asymptotic normality. We explain the computational implementation of our method and illustrate the numerical performance of the estimators in finite sample situations via extensive simulation studies. The advantage of our estimators over the existing likelihood approach is also shown via numerical comparison. We employ the method to analyse a real data example from economics. © 2010 Royal Statistical Society.
Confidence Intervals of Variance Functions in Generalized Linear Model
Institute of Scientific and Technical Information of China (English)
Yong Zhou; Dao-ji Li
2006-01-01
In this paper we introduce an appealing nonparametric method for estimating variance and conditional variance functions in generalized linear models (GLMs), when designs are fixed points and random variables respectively. Bias-corrected confidence bands are proposed for the (conditional) variance by local linear smoothers. Nonparametric techniques are developed in deriving the bias-corrected confidence intervals of the (conditional) variance. The asymptotic distribution of the proposed estimator is established and show that the bias-corrected confidence bands asymptotically have the correct coverage properties. A small simulation is performed when unknown regression parameter is estimated by nonparametric quasi-likelihood. The results are also applicable to nonparametric autoregressive times series model with heteroscedastic conditional variance.
Entanglement in a generalized Jaynes-Cummings model
Institute of Scientific and Technical Information of China (English)
Zhang Guo-Feng; Liu Jia
2007-01-01
We investigate the pairwise entanglement and global entanglement in a generalized Jaynes-Cummings model,which can be used to realize Greenberger-Horne-Zeilinger (GHZ) entangled state (Zheng S B 2001 Phys. Rev. Lett. 87230404). Our results show that the W-type entangled states cannot be generated based on the model. The dependences of entanglement on Rabi frequency λ and dipole-dipole coupling strength Ω are given. It is found that there exists the quantum phase transition when λ = Ω. For typical experimental data, the critical temperature for pairwise entanglement is on the order of 10-6 K. Based on these results, two strategies that overcome decoherence are proposed.
Relaxation of polymers modeled by generalized Husimi cacti
Galiceanu, M.
2010-07-01
We focus on the generalized Husimi cacti, which are dual structures to the dendrimers but, distinct from the latter, contain loops. We determine their complete spectra by making use of the normal mode analysis. These spectra have been used in computing some physical quantities, such as the averaged monomer displacement and the mechanical relaxation moduli with its two components: the storage and the loss modulus. We also study the dynamics of Husimi cacti in solutions, introducing the hydrodynamic interactions in a preaveraged Oseen fashion, the so-called Zimm model. We observe that the relaxation quantities mentioned above do not scale, in the presence or in the absence of the hydrodynamic interactions. Our results show that all the relaxation forms depend on the number of monomers in the networks in the absence of the hydrodynamic interactions (Rouse model), while by taking into account the hydrodynamic interactions the results do not vary too much.
Relaxation of polymers modeled by generalized Husimi cacti
Energy Technology Data Exchange (ETDEWEB)
Galiceanu, M, E-mail: mircea@fisica.ufpr.b [Departamento de Fisica, Universidade Federal do Parana, 81531-990 Curitiba (Brazil)
2010-07-30
We focus on the generalized Husimi cacti, which are dual structures to the dendrimers but, distinct from the latter, contain loops. We determine their complete spectra by making use of the normal mode analysis. These spectra have been used in computing some physical quantities, such as the averaged monomer displacement and the mechanical relaxation moduli with its two components: the storage and the loss modulus. We also study the dynamics of Husimi cacti in solutions, introducing the hydrodynamic interactions in a preaveraged Oseen fashion, the so-called Zimm model. We observe that the relaxation quantities mentioned above do not scale, in the presence or in the absence of the hydrodynamic interactions. Our results show that all the relaxation forms depend on the number of monomers in the networks in the absence of the hydrodynamic interactions (Rouse model), while by taking into account the hydrodynamic interactions the results do not vary too much.
Convex Relaxations for a Generalized Chan-Vese Model
Bae, Egil
2013-01-01
We revisit the Chan-Vese model of image segmentation with a focus on the encoding with several integer-valued labeling functions. We relate several representations with varying amount of complexity and demonstrate the connection to recent relaxations for product sets and to dual maxflow-based formulations. For some special cases, it can be shown that it is possible to guarantee binary minimizers. While this is not true in general, we show how to derive a convex approximation of the combinatorial problem for more than 4 phases. We also provide a method to avoid overcounting of boundaries in the original Chan-Vese model without departing from the efficient product-set representation. Finally, we derive an algorithm to solve the associated discretized problem, and demonstrate that it allows to obtain good approximations for the segmentation problem with various number of regions. © 2013 Springer-Verlag.
String networks in generalized May-Leonard models
Avelino, P P; Menezes, J; de Oliveira, B F
2013-01-01
Generalized May-Leonard models have proven to be a powerful tool in the study of the dynamics complex biological and ecological systems. In this letter we give specific examples of models leading to the formation of string networks. We show that, in order to promote coexistence, the species may arrange themselves around regions with a high number density of empty sites generated by predator-prey interactions between competing species. These configurations extend into the third dimension giving rise to string networks. We investigate the corresponding dynamics using both stochastic and mean field theory simulations, showing that the coarsening of these string networks follows a scaling law which is analogous to that found in other physical systems in condensed matter and cosmology.
Generalized Skyrme model with the loosely bound potential
Gudnason, Sven Bjarke; Ma, Nana
2016-01-01
We study a generalization of the loosely bound Skyrme model which consists of the Skyrme model with a sixth-order derivative term and the second-order loosely bound potential. We use the rational map approximation for the 4-Skyrmion and calculate the binding energy and estimate the systematic error in using the latter approximation. In the parameter space that we can explore within the rational map approximation, we find classical binding energies as low as 1.8% and once taking into account the contribution from spin-isospin quantization we obtain binding energies as low as 5.3%. We also calculate the contribution from the sixth-order derivative term to the electric charge density and axial coupling.
A stellar model with diffusion in general relativity
Alho, Artur
2016-01-01
We consider a spherically symmetric stellar model in general relativity whose interior consists of a pressureless fluid undergoing microscopic velocity diffusion in a cosmological scalar field. We show that the diffusion dynamics compel the interior to be spatially homogeneous, by which one can infer immediately that within our model, and in contrast to the diffusion-free case, no naked singularities can form in the gravitational collapse. We then study the problem of matching an exterior Bondi type metric to the surface of the star and find that the exterior can be chosen to be a modified Vaidya metric with variable cosmological constant. Finally, we study in detail the causal structure of an explicit, self-similar solution.
Optimisation of a parallel ocean general circulation model
Directory of Open Access Journals (Sweden)
M. I. Beare
Full Text Available This paper presents the development of a general-purpose parallel ocean circulation model, for use on a wide range of computer platforms, from traditional scalar machines to workstation clusters and massively parallel processors. Parallelism is provided, as a modular option, via high-level message-passing routines, thus hiding the technical intricacies from the user. An initial implementation highlights that the parallel efficiency of the model is adversely affected by a number of factors, for which optimisations are discussed and implemented. The resulting ocean code is portable and, in particular, allows science to be achieved on local workstations that could otherwise only be undertaken on state-of-the-art supercomputers.