WorldWideScience

Sample records for empiric uncertain recommendations

  1. TOURISM RECOMMENDATION SYSTEM: EMPIRICAL INVESTIGATION

    OpenAIRE

    Biljana PETREVSKA; Saso KOCESKI

    2012-01-01

    The paper makes an attempt to justify the necessity of implementing recommendation system which will assist tourists in identification of their ideal holiday. The proposed recommendation system based on collaborative filtering notes positive impulses in the case of Macedonia. A software module is developed being capable to generate a personalized list of favorable and tailor-made items. The research outcomes indicate that the designed national tourism web portal can provide satisfactory perfo...

  2. TOURISM RECOMMENDATION SYSTEM: EMPIRICAL INVESTIGATION

    Directory of Open Access Journals (Sweden)

    Biljana PETREVSKA

    2012-12-01

    Full Text Available The paper makes an attempt to justify the necessity of implementing recommendation system which will assist tourists in identification of their ideal holiday. The proposed recommendation system based on collaborative filtering notes positive impulses in the case of Macedonia. A software module is developed being capable to generate a personalized list of favorable and tailor-made items. The research outcomes indicate that the designed national tourism web portal can provide satisfactory performance and may be of high importance to all key-tourism actors in the process of identifying measures necessary for creating competitive tourism product.

  3. Publicly announced access recommendations and consumers’ service time choices with uncertain congestion

    NARCIS (Netherlands)

    Han, Q.; Benedict, G.C.; Dellaert, W.; van Raaij, W.F.; Timmermans, H.J.P.

    2014-01-01

    This article investigates consumers' anticipation of other consumers' service time choices in capacity-constrained services and how this is affected by publicly announced access recommendations. Empirical results from an experiment with simulated congestion experiences show that the impact of

  4. Publicly announced access recommendations and consumers' service time choices with uncertain congestion

    NARCIS (Netherlands)

    Han, Q.; Dellaert, B.G.C.; Raaij, W.F.V.; Timmermans, H.J.P.

    2014-01-01

    This article investigates consumers' anticipation of other consumers' service time choices in capacity-constrained services and how this is affected by publicly announced access recommendations. Empirical results from an experiment with simulated congestion experiences show that the impact of

  5. Steering the Ship through Uncertain Waters: Empirical Analysis and the Future of Evangelical Higher Education

    Science.gov (United States)

    Rine, P. Jesse; Guthrie, David S.

    2016-01-01

    Leaders of evangelical Christian colleges must navigate a challenging environment shaped by public concern about college costs and educational quality, federal inclinations toward increased regulation, and lingering fallout from the Great Recession. Proceeding from the premise that empirical analysis empowers institutional actors to lead well in…

  6. Business Processes Modeling Recommender Systems: User Expectations and Empirical Evidence

    Directory of Open Access Journals (Sweden)

    Michael Fellmann

    2018-04-01

    Full Text Available Recommender systems are in widespread use in many areas, especially electronic commerce solutions. In this contribution, we apply recommender functionalities to business process modeling and investigate their potential for supporting process modeling. To do so, we have implemented two prototypes, demonstrated them at a major fair and collected user feedback. After analysis of the feedback, we have confronted the findings with the results of the experiment. Our results indicate that fairgoers expect increased modeling speed as the key advantage and completeness of models as the most unlikely advantage. This stands in contrast to an initial experiment revealing that modelers, in fact, increase the completeness of their models when adequate knowledge is presented while time consumption is not necessarily reduced. We explain possible causes of this mismatch and finally hypothesize on two “sweet spots” of process modeling recommender systems.

  7. BRCA1 and BRCA2 genetic testing—pitfalls and recommendations for managing variants of uncertain clinical significance

    OpenAIRE

    Eccles, D. M.; Mitchell, G.; Monteiro, A. N. A.; Schmutzler, R.; Couch, F. J.; Spurdle, A. B.; Gómez-García, E. B.

    2015-01-01

    BackgroundIncreasing use of BRCA1/2 testing for tailoring cancer treatment and extension of testing to tumour tissue for somatic mutation is moving BRCA1/2 mutation screening from a primarily prevention arena delivered by specialist genetic services into mainstream oncology practice. A considerable number of gene tests will identify rare variants where clinical significance cannot be inferred from sequence information alone. The proportion of Variants of Uncertain clinical Significance (VUS) ...

  8. Understanding the Organizational Nature of Student Persistence: Empirically-based Recommendations for Practice.

    Science.gov (United States)

    Berger, Joseph B.

    2002-01-01

    Builds on the assumption that colleges and universities are organizations and subsequently that the organizational perspective provides important insights for improving retention on campuses. A review of existing organizational studies of undergraduate persistence serves as the basis for ten empirically-based recommendations for practice that are…

  9. BRCA1 and BRCA2 genetic testing—pitfalls and recommendations for managing variants of uncertain clinical significance

    Science.gov (United States)

    Eccles, D. M.; Mitchell, G.; Monteiro, A. N. A.; Schmutzler, R.; Couch, F. J.; Spurdle, A. B.; Gómez-García, E. B.

    2015-01-01

    Background Increasing use of BRCA1/2 testing for tailoring cancer treatment and extension of testing to tumour tissue for somatic mutation is moving BRCA1/2 mutation screening from a primarily prevention arena delivered by specialist genetic services into mainstream oncology practice. A considerable number of gene tests will identify rare variants where clinical significance cannot be inferred from sequence information alone. The proportion of variants of uncertain clinical significance (VUS) is likely to grow with lower thresholds for testing and laboratory providers with less experience of BRCA. Most VUS will not be associated with a high risk of cancer but a misinterpreted VUS has the potential to lead to mismanagement of both the patient and their relatives. Design Members of the Clinical Working Group of ENIGMA (Evidence-based Network for the Interpretation of Germline Mutant Alleles) global consortium (www.enigmaconsortium.org) observed wide variation in practices in reporting, disclosure and clinical management of patients with a VUS. Examples from current clinical practice are presented and discussed to illustrate potential pitfalls, explore factors contributing to misinterpretation, and propose approaches to improving clarity. Results and conclusion Clinicians, patients and their relatives would all benefit from an improved level of genetic literacy. Genetic laboratories working with clinical geneticists need to agree on a clinically clear and uniform format for reporting BRCA test results to non-geneticists. An international consortium of experts, collecting and integrating all available lines of evidence and classifying variants according to an internationally recognized system, will facilitate reclassification of variants for clinical use. PMID:26153499

  10. BRCA1 and BRCA2 genetic testing-pitfalls and recommendations for managing variants of uncertain clinical significance.

    Science.gov (United States)

    Eccles, D M; Mitchell, G; Monteiro, A N A; Schmutzler, R; Couch, F J; Spurdle, A B; Gómez-García, E B

    2015-10-01

    Increasing use of BRCA1/2 testing for tailoring cancer treatment and extension of testing to tumour tissue for somatic mutation is moving BRCA1/2 mutation screening from a primarily prevention arena delivered by specialist genetic services into mainstream oncology practice. A considerable number of gene tests will identify rare variants where clinical significance cannot be inferred from sequence information alone. The proportion of variants of uncertain clinical significance (VUS) is likely to grow with lower thresholds for testing and laboratory providers with less experience of BRCA. Most VUS will not be associated with a high risk of cancer but a misinterpreted VUS has the potential to lead to mismanagement of both the patient and their relatives. Members of the Clinical Working Group of ENIGMA (Evidence-based Network for the Interpretation of Germline Mutant Alleles) global consortium (www.enigmaconsortium.org) observed wide variation in practices in reporting, disclosure and clinical management of patients with a VUS. Examples from current clinical practice are presented and discussed to illustrate potential pitfalls, explore factors contributing to misinterpretation, and propose approaches to improving clarity. Clinicians, patients and their relatives would all benefit from an improved level of genetic literacy. Genetic laboratories working with clinical geneticists need to agree on a clinically clear and uniform format for reporting BRCA test results to non-geneticists. An international consortium of experts, collecting and integrating all available lines of evidence and classifying variants according to an internationally recognized system, will facilitate reclassification of variants for clinical use. © The Author 2015. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  11. Different recommendations for empiric first-choice antibiotic treatment of uncomplicated urinary tract infections in Europe

    DEFF Research Database (Denmark)

    McQuiston Haslund, Josephine; Rosborg Dinesen, Marianne; Nielsen, Anni Brit Sternhagen

    2013-01-01

    OBJECTIVE: Uncomplicated urinary tract infection (uUTI) is a common reason for antibiotic treatment in primary health care. Due to the increasing prevalence of antibiotic-resistant uropathogens it is crucial to use the most appropriate antibiotics for first-choice empiric treatment of uUTI....... Particularly, it is important to avoid antibiotics associated with a high rate of antimicrobial resistance. This study compares national recommendations from six European countries, investigating recommendations for first-choice antibiotic therapy of uUTI. SETTING: General practice in six European countries...... at least one antibiotic associated with a low (UTI could not be explained by differences in local bacterial aetiology or by different patterns of antimicrobial resistance. Despite resistance rates exceeding 10...

  12. Recommendations

    DEFF Research Database (Denmark)

    Baumeister, Ruth

    2016-01-01

    This article discusses three book publications: C. Kerez: Uncertain Certainty, Tokyo, 2013 H. Hertzberger: Lessons for students in architecture, Rotterdam, 2006, (1991) A. Jorn: Om Formen, Silkeborg, 2014, (1958)......This article discusses three book publications: C. Kerez: Uncertain Certainty, Tokyo, 2013 H. Hertzberger: Lessons for students in architecture, Rotterdam, 2006, (1991) A. Jorn: Om Formen, Silkeborg, 2014, (1958)...

  13. An empirical study of work and family life spheres and emergence of work-life balance initiatives under uncertain economic scenario.

    OpenAIRE

    Naithani, Pranav

    2009-01-01

    In the last six decades, work life and family life spheres of employees have undergone various changes. This paper presents an empirical study of major factors which have influenced employee work-life balance and popular work-life balance tools initiated at organisational level to help an employee balance different life segments such as work, family, personal finances, career and health. Current work-life balance approach, tools and programmes at organisational level primarily address those i...

  14. An empirical study of work and family life spheres and emergence of work-life balance initiatives under uncertain economic scenario

    OpenAIRE

    Naithani, Pranav; Jha, A.N.

    2009-01-01

    In the last six decades, work life and family life spheres of employees have undergone various changes. This paper presents an empirical study of major factors which have influenced employee work-life balance and popular work-life balance tools initiated at organisational level to help an employee balance different life segments such as work, family, personal finances, career and health. Current work-life balance approach, tools and programmes at organisational level primarily address those i...

  15. Empirical Comparison of Graph-based Recommendation Engines for an Apps Ecosystem

    Directory of Open Access Journals (Sweden)

    Luis F. Chiroque

    2015-03-01

    Full Text Available Recommendation engines (RE are becoming highly popular, e.g., in the area of e-commerce. A RE offers new items (products or content to users based on their profile and historical data. The most popular algorithms used in RE are based on collaborative filtering. This technique makes recommendations based on the past behavior of other users and the similarity between users and items. In this paper we have evaluated the performance of several RE based on the properties of the networks formed by users and items. The RE use in a novel way graph theoretic concepts like edges weights or network flow. The evaluation has been conducted in a real environment (ecosystem for recommending apps to smartphone users. The analysis of the results allows concluding that the effectiveness of a RE can be improved if the age of the data, and if a global view of the data is considered. It also shows that graph-based RE are effective, but more experiments are required for a more accurate characterization of their properties.

  16. Development and empirical user-centered evaluation of semantically-based query recommendation for an electronic health record search engine.

    Science.gov (United States)

    Hanauer, David A; Wu, Danny T Y; Yang, Lei; Mei, Qiaozhu; Murkowski-Steffy, Katherine B; Vydiswaran, V G Vinod; Zheng, Kai

    2017-03-01

    The utility of biomedical information retrieval environments can be severely limited when users lack expertise in constructing effective search queries. To address this issue, we developed a computer-based query recommendation algorithm that suggests semantically interchangeable terms based on an initial user-entered query. In this study, we assessed the value of this approach, which has broad applicability in biomedical information retrieval, by demonstrating its application as part of a search engine that facilitates retrieval of information from electronic health records (EHRs). The query recommendation algorithm utilizes MetaMap to identify medical concepts from search queries and indexed EHR documents. Synonym variants from UMLS are used to expand the concepts along with a synonym set curated from historical EHR search logs. The empirical study involved 33 clinicians and staff who evaluated the system through a set of simulated EHR search tasks. User acceptance was assessed using the widely used technology acceptance model. The search engine's performance was rated consistently higher with the query recommendation feature turned on vs. off. The relevance of computer-recommended search terms was also rated high, and in most cases the participants had not thought of these terms on their own. The questions on perceived usefulness and perceived ease of use received overwhelmingly positive responses. A vast majority of the participants wanted the query recommendation feature to be available to assist in their day-to-day EHR search tasks. Challenges persist for users to construct effective search queries when retrieving information from biomedical documents including those from EHRs. This study demonstrates that semantically-based query recommendation is a viable solution to addressing this challenge. Published by Elsevier Inc.

  17. Recommended survey designs for occupancy modelling using motion-activated cameras: insights from empirical wildlife data

    Directory of Open Access Journals (Sweden)

    Graeme Shannon

    2014-08-01

    Full Text Available Motion-activated cameras are a versatile tool that wildlife biologists can use for sampling wild animal populations to estimate species occurrence. Occupancy modelling provides a flexible framework for the analysis of these data; explicitly recognizing that given a species occupies an area the probability of detecting it is often less than one. Despite the number of studies using camera data in an occupancy framework, there is only limited guidance from the scientific literature about survey design trade-offs when using motion-activated cameras. A fuller understanding of these trade-offs will allow researchers to maximise available resources and determine whether the objectives of a monitoring program or research study are achievable. We use an empirical dataset collected from 40 cameras deployed across 160 km2 of the Western Slope of Colorado, USA to explore how survey effort (number of cameras deployed and the length of sampling period affects the accuracy and precision (i.e., error of the occupancy estimate for ten mammal and three virtual species. We do this using a simulation approach where species occupancy and detection parameters were informed by empirical data from motion-activated cameras. A total of 54 survey designs were considered by varying combinations of sites (10–120 cameras and occasions (20–120 survey days. Our findings demonstrate that increasing total sampling effort generally decreases error associated with the occupancy estimate, but changing the number of sites or sampling duration can have very different results, depending on whether a species is spatially common or rare (occupancy = ψ and easy or hard to detect when available (detection probability = p. For rare species with a low probability of detection (i.e., raccoon and spotted skunk the required survey effort includes maximizing the number of sites and the number of survey days, often to a level that may be logistically unrealistic for many studies. For common

  18. Empiric guideline-recommended weight-based vancomycin dosing and mortality in methicillin-resistant Staphylococcus aureus bacteremia: a retrospective cohort study

    Directory of Open Access Journals (Sweden)

    Hall Ronald G

    2012-04-01

    Full Text Available Abstract Background No studies have evaluated the effect of guideline-recommended weight-based dosing on in-hospital mortality of patients with methicillin-resistant Staphylococcus aureus bacteremia. Methods This was a multicenter, retrospective, cohort study of patients with methicillin-resistant Staphylococcus aureus bacteremia receiving at least 48 hours of empiric vancomycin therapy between 01/07/2002 and 30/06/2008. We compared in-hospital mortality for patients treated empirically with weight-based, guideline-recommended vancomycin doses (at least 15 mg/kg/dose to those treated with less than 15 mg/kg/dose. We used a general linear mixed multivariable model analysis with variables identified a priori through a conceptual framework based on the literature. Results A total of 337 patients who were admitted to the three hospitals were included in the cohort. One-third of patients received vancomycin empirically at the guideline-recommended dose. Guideline-recommended dosing was not associated with in-hospital mortality in the univariable (16% vs. 13%, OR 1.26 [95%CI 0.67-2.39] or multivariable (OR 0.71, 95%CI 0.33-1.55 analysis. Independent predictors of in-hospital mortality were ICU admission, Pitt bacteremia score of 4 or greater, age 53 years or greater, and nephrotoxicity. Conclusions Empiric use of weight-based, guideline-recommended empiric vancomycin dosing was not associated with reduced mortality in this multicenter study.

  19. Uncertain differential equations

    CERN Document Server

    Yao, Kai

    2016-01-01

    This book introduces readers to the basic concepts of and latest findings in the area of differential equations with uncertain factors. It covers the analytic method and numerical method for solving uncertain differential equations, as well as their applications in the field of finance. Furthermore, the book provides a number of new potential research directions for uncertain differential equation. It will be of interest to researchers, engineers and students in the fields of mathematics, information science, operations research, industrial engineering, computer science, artificial intelligence, automation, economics, and management science.

  20. Recommendations for the empirical treatment of complicated urinary tract infections using surveillance data on antimicrobial resistance in the Netherlands

    NARCIS (Netherlands)

    Koningstein, Maike; van der Bij, Akke K.; de Kraker, Marlieke E. A.; Monen, Jos C.; Muilwijk, Jan; de Greeff, Sabine C.; Geerlings, Suzanne E.; van Hall, Maurine A. Leverstein-; Vlaspolder, F.; Cohen Stuart, J. W. T.; van Hees, B. C.; Wintermans, R. G. F.; Altorf-van der Kuil, W.; Alblas, J.; van der Bij, A. K.; Frentz, D.; Leenstra, T.; Monen, J. C.; Muilwijk, J.; Notermans, D. W.; de Greeff, S. C.; van Keulen, P. H. J.; Kluytmans, J. A. J. W.; Mattsson, E. E.; Sebens, F. W.; Frenay, H. M. E.; Maraha, B.; Heilmann, F. G. C.; Halaby, T.; Versteeg, D.; Hendrix, R.; Schellekens, J. F. P.; Diederen, B. M. W.; de Brauwer, E. I. G. B.; Stals, F. S.; Bakker, L. J.; Dorigo-Zetsma, J. W.; van Zeijl, J. H.; Bernards, A. T.; de Jongh, B. M.; Vlaminckx, B. J. M.; Horrevorts, A.; Kuipers, S.; Moffie, B.; Brimicombe, R. W.; Jansen, C. L.; Renders, N. H. M.; Hendrickx, B. G. A.; Buiting, A. G. M.; Kaan, J. A.

    2014-01-01

    Complicated urinary tract infections (c-UTIs) are among the most common nosocomial infections and a substantial part of the antimicrobial agents used in hospitals is for the treatment of c-UTIs. Data from surveillance can be used to guide the empirical treatment choices of clinicians when treating

  1. Uncertain data envelopment analysis

    CERN Document Server

    Wen, Meilin

    2014-01-01

    This book is intended to present the milestones in the progression of uncertain Data envelopment analysis (DEA). Chapter 1 gives some basic introduction to uncertain theories, including probability theory, credibility theory, uncertainty theory and chance theory. Chapter 2 presents a comprehensive review and discussion of basic DEA models. The stochastic DEA is introduced in Chapter 3, in which the inputs and outputs are assumed to be random variables. To obtain the probability distribution of a random variable, a lot of samples are needed to apply the statistics inference approach. Chapter 4

  2. Learning from uncertain curves

    DEFF Research Database (Denmark)

    Mallasto, Anton; Feragen, Aasa

    2017-01-01

    We introduce a novel framework for statistical analysis of populations of nondegenerate Gaussian processes (GPs), which are natural representations of uncertain curves. This allows inherent variation or uncertainty in function-valued data to be properly incorporated in the population analysis. Us...

  3. (Approximate) Uncertain Skylines

    DEFF Research Database (Denmark)

    Afshani, Peyman; Agarwal, Pankaj K.; Arge, Lars Allan

    2011-01-01

    Given a set of points with uncertain locations, we consider the problem of computing the probability of each point lying on the skyline, that is, the probability that it is not dominated by any other input point. If each point’s uncertainty is described as a probability distribution over a discre...

  4. (Approximate) Uncertain Skylines

    DEFF Research Database (Denmark)

    Afshani, Peyman; Agarwal, Pankaj K.; Arge, Lars

    2013-01-01

    Given a set of points with uncertain locations, we consider the problem of computing the probability of each point lying on the skyline, that is, the probability that it is not dominated by any other input point. If each point’s uncertainty is described as a probability distribution over a discre...

  5. Ranking Queries on Uncertain Data

    CERN Document Server

    Hua, Ming

    2011-01-01

    Uncertain data is inherent in many important applications, such as environmental surveillance, market analysis, and quantitative economics research. Due to the importance of those applications and rapidly increasing amounts of uncertain data collected and accumulated, analyzing large collections of uncertain data has become an important task. Ranking queries (also known as top-k queries) are often natural and useful in analyzing uncertain data. Ranking Queries on Uncertain Data discusses the motivations/applications, challenging problems, the fundamental principles, and the evaluation algorith

  6. Empirical Validation of Indices for Consideration in the Revision of Recommended Senior School Financial Accounting Textbooks in Southwestern Nigeria

    Science.gov (United States)

    Oyetoro, Oyebode Stephen; Ojo, Oloyede Ezekiel

    2017-01-01

    The study determined a significant difference in teachers' overall evaluations of six recommended Financial Accounting Textbooks in Southwestern Nigeria. It also assessed the specific evaluation parameters that account for the difference. It adopted the survey research design. The multistage sampling technique was used to select a total of 80…

  7. Constructor:synthesizing information about uncertain variables.

    Energy Technology Data Exchange (ETDEWEB)

    Tucker, W. Troy (Applied Biomathematics, Setauket, NY); Ferson, Scott (Applied Biomathematics, Setauket, NY); Hajagos, Janos (Applied Biomathematics, Setauket, NY); Myers, David S. (Applied Biomathematics, Setauket, NY)

    2005-09-01

    Constructor is software for the Microsoft Windows microcomputer environment that facilitates the collation of empirical information and expert judgment for the specification of probability distributions, probability boxes, random sets or Dempster-Shafer structures from data, qualitative shape information, constraints on moments, order statistics, densities, and coverage probabilities about uncertain unidimensional quantities. These quantities may be real-valued, integer-valued or logical values.

  8. Empirical Validation of Indices for Consideration in the Revision of Recommended Senior School Financial Accounting Textbooks in Southwestern Nigeria

    Directory of Open Access Journals (Sweden)

    Oyebode Stephen Oyetoro

    2017-12-01

    Full Text Available The study determined a significant difference in teachers’ overall evaluations of six recommended Financial Accounting Textbooks in Southwestern Nigeria. It also assessed the specific evaluation parameters that account for the difference. It adopted the survey research design. The multistage sampling technique was used to select a total of 80 teachers from 64 schools from the six states in Southwestern Nigeria. Results of data collected which were analysed using the Kruskal-Wallis (H test depicted a significant difference in teachers’ overall evaluations of the textbooks. Also, results revealed that the textbooks differ significantly on the parameters of mechanics, assessment, lesson design and instructional strategy and incorporation of technology into students’ learning. The implications of these findings were discussed and the study concluded that financial accounting textbook writers and ministry of education officials at both national and state levels should give adequate consideration for these parameters in the revision of recommended financial accounting textbooks for improved effectiveness in the realization of curricular objectives in the subject.

  9. A comparison of results of empirical studies of supplementary search techniques and recommendations in review methodology handbooks: a methodological review.

    Science.gov (United States)

    Cooper, Chris; Booth, Andrew; Britten, Nicky; Garside, Ruth

    2017-11-28

    The purpose and contribution of supplementary search methods in systematic reviews is increasingly acknowledged. Numerous studies have demonstrated their potential in identifying studies or study data that would have been missed by bibliographic database searching alone. What is less certain is how supplementary search methods actually work, how they are applied, and the consequent advantages, disadvantages and resource implications of each search method. The aim of this study is to compare current practice in using supplementary search methods with methodological guidance. Four methodological handbooks in informing systematic review practice in the UK were read and audited to establish current methodological guidance. Studies evaluating the use of supplementary search methods were identified by searching five bibliographic databases. Studies were included if they (1) reported practical application of a supplementary search method (descriptive) or (2) examined the utility of a supplementary search method (analytical) or (3) identified/explored factors that impact on the utility of a supplementary method, when applied in practice. Thirty-five studies were included in this review in addition to the four methodological handbooks. Studies were published between 1989 and 2016, and dates of publication of the handbooks ranged from 1994 to 2014. Five supplementary search methods were reviewed: contacting study authors, citation chasing, handsearching, searching trial registers and web searching. There is reasonable consistency between recommended best practice (handbooks) and current practice (methodological studies) as it relates to the application of supplementary search methods. The methodological studies provide useful information on the effectiveness of the supplementary search methods, often seeking to evaluate aspects of the method to improve effectiveness or efficiency. In this way, the studies advance the understanding of the supplementary search methods. Further

  10. The sustainability of new programs and innovations: a review of the empirical literature and recommendations for future research

    Directory of Open Access Journals (Sweden)

    Wiltsey Stirman Shannon

    2012-03-01

    Full Text Available Abstract Background The introduction of evidence-based programs and practices into healthcare settings has been the subject of an increasing amount of research in recent years. While a number of studies have examined initial implementation efforts, less research has been conducted to determine what happens beyond that point. There is increasing recognition that the extent to which new programs are sustained is influenced by many different factors and that more needs to be known about just what these factors are and how they interact. To understand the current state of the research literature on sustainability, our team took stock of what is currently known in this area and identified areas in which further research would be particularly helpful. This paper reviews the methods that have been used, the types of outcomes that have been measured and reported, findings from studies that reported long-term implementation outcomes, and factors that have been identified as potential influences on the sustained use of new practices, programs, or interventions. We conclude with recommendations and considerations for future research. Methods Two coders identified 125 studies on sustainability that met eligibility criteria. An initial coding scheme was developed based on constructs identified in previous literature on implementation. Additional codes were generated deductively. Related constructs among factors were identified by consensus and collapsed under the general categories. Studies that described the extent to which programs or innovations were sustained were also categorized and summarized. Results Although "sustainability" was the term most commonly used in the literature to refer to what happened after initial implementation, not all the studies that were reviewed actually presented working definitions of the term. Most study designs were retrospective and naturalistic. Approximately half of the studies relied on self-reports to assess

  11. The sustainability of new programs and innovations: a review of the empirical literature and recommendations for future research

    Science.gov (United States)

    2012-01-01

    Background The introduction of evidence-based programs and practices into healthcare settings has been the subject of an increasing amount of research in recent years. While a number of studies have examined initial implementation efforts, less research has been conducted to determine what happens beyond that point. There is increasing recognition that the extent to which new programs are sustained is influenced by many different factors and that more needs to be known about just what these factors are and how they interact. To understand the current state of the research literature on sustainability, our team took stock of what is currently known in this area and identified areas in which further research would be particularly helpful. This paper reviews the methods that have been used, the types of outcomes that have been measured and reported, findings from studies that reported long-term implementation outcomes, and factors that have been identified as potential influences on the sustained use of new practices, programs, or interventions. We conclude with recommendations and considerations for future research. Methods Two coders identified 125 studies on sustainability that met eligibility criteria. An initial coding scheme was developed based on constructs identified in previous literature on implementation. Additional codes were generated deductively. Related constructs among factors were identified by consensus and collapsed under the general categories. Studies that described the extent to which programs or innovations were sustained were also categorized and summarized. Results Although "sustainability" was the term most commonly used in the literature to refer to what happened after initial implementation, not all the studies that were reviewed actually presented working definitions of the term. Most study designs were retrospective and naturalistic. Approximately half of the studies relied on self-reports to assess sustainability or elements that

  12. "Right to recommend, wrong to require"- an empirical and philosophical study of the views among physicians and the general public on smoking cessation as a condition for surgery.

    Science.gov (United States)

    Björk, Joar; Juth, Niklas; Lynøe, Niels

    2018-01-08

    In many countries, there are health care initiatives to make smokers give up smoking in the peri-operative setting. There is empirical evidence that this may improve some, but not all, operative outcomes. However, it may be feared that some support for such policies stems from ethically questionable opinions, such as paternalism or anti-smoker sentiments. This study aimed at investigating the support for a policy of smoking cessation prior to surgery among Swedish physicians and members of the general public, as well as the reasons provided for this. A random sample of general practitioners and orthopaedic surgeons (n = 795) as well as members of the general public (n = 485) received a mail questionnaire. It contained a vignette case with a smoking 57-year old male farmer with hip osteoarthritis. The patient had been recommended hip replacement therapy, but told that in order to qualify for surgery he needed to give up smoking four weeks prior to and after surgery. The respondents were asked whether making such qualifying demands is acceptable, and asked to rate their agreement with pre-set arguments for and against this policy. Response rates were 58.2% among physicians and 53.8% among the general public. Of these, 83.9% and 86.6%, respectively, agreed that surgery should be made conditional upon smoking cessation. Reference to the peri-operative risks associated with smoking was the most common argument given. However, there was also strong support for the argument that such a policy is mandated in order to achieve long term health gains. There is strong support for a policy of smoking cessation prior to surgery in Sweden. This support is based on considerations of peri-operative risks as well as the general long term risks of smoking. This study indicates that paternalistic attitudes may inform some of the support for peri-operative smoking cessation policies and that at least some respondents seem to favour a "recommendation strategy" vis-à-vis smoking

  13. Uncertain programming models for portfolio selection with uncertain returns

    Science.gov (United States)

    Zhang, Bo; Peng, Jin; Li, Shengguo

    2015-10-01

    In an indeterminacy economic environment, experts' knowledge about the returns of securities consists of much uncertainty instead of randomness. This paper discusses portfolio selection problem in uncertain environment in which security returns cannot be well reflected by historical data, but can be evaluated by the experts. In the paper, returns of securities are assumed to be given by uncertain variables. According to various decision criteria, the portfolio selection problem in uncertain environment is formulated as expected-variance-chance model and chance-expected-variance model by using the uncertainty programming. Within the framework of uncertainty theory, for the convenience of solving the models, some crisp equivalents are discussed under different conditions. In addition, a hybrid intelligent algorithm is designed in the paper to provide a general method for solving the new models in general cases. At last, two numerical examples are provided to show the performance and applications of the models and algorithm.

  14. Visualization of Uncertain Contour Trees

    DEFF Research Database (Denmark)

    Kraus, Martin

    2010-01-01

    Contour trees can represent the topology of large volume data sets in a relatively compact, discrete data structure. However, the resulting trees often contain many thousands of nodes; thus, many graph drawing techniques fail to produce satisfactory results. Therefore, several visualization methods...... were proposed recently for the visualization of contour trees. Unfortunately, none of these techniques is able to handle uncertain contour trees although any uncertainty of the volume data inevitably results in partially uncertain contour trees. In this work, we visualize uncertain contour trees...... by combining the contour trees of two morphologically filtered versions of a volume data set, which represent the range of uncertainty. These two contour trees are combined and visualized within a single image such that a range of potential contour trees is represented by the resulting visualization. Thus...

  15. Entity resolution for uncertain data

    NARCIS (Netherlands)

    Ayat, N.; Akbarinia, R.; Afsarmanesh, H.; Valduriez, P.

    2012-01-01

    Entity resolution (ER), also known as duplicate detection or record matching, is the problem of identifying the tuples that represent the same real world entity. In this paper, we address the problem of ER for uncertain data, which we call ERUD. We propose two different approaches for the ERUD

  16. Preparing for an Uncertain Forecast

    Science.gov (United States)

    Karolak, Eric

    2011-01-01

    Navigating the world of government relations and public policy can be a little like predicting the weather. One can't always be sure what's in store or how it will affect him/her down the road. But there are common patterns and a few basic steps that can help one best prepare for a change in the forecast. Though the forecast is uncertain, early…

  17. The Uncertain of Scientific Process

    Directory of Open Access Journals (Sweden)

    Jovina dÁvila Bordoni

    2016-10-01

    Full Text Available The study assesses the existence of certainty in the scientific process, it seeks the truth, however, faced with the unknown, causes uncertainties and doubts. We used the bibliographical research, in which it systematized the scientific literature on epistemology and knowledge related to the scientific process and the uncertainties that surround him. The scientific process, though continuously seeks the truth, will not attain perfection, because the researcher deals with the unknown. The science seeks constantly new knowledge and progress with the criticism of the mistakes, seeks the truth, however these are provisional. It is concluded that all scientific knowledge is uncertain.

  18. Energy pricing under uncertain supply

    International Nuclear Information System (INIS)

    Serra, P.J.

    1997-01-01

    This paper introduces a new pricing system - based on the Chilean tariff regulations - to deal with an uncertain energy supply. It consists of a basic rate for each unit actually consumed and a compensation that the utilities pay their customers for each unit of energy that they voluntarily reduce below their normal consumption during an energy shortage. Within the framework of a model that portrays the stylized facts of the Chilean electric system, and assumes risk-neutral agents, this paper shows the equivalency of the new pricing system with both contingent pricing and priority pricing. (Author)

  19. Investment under Uncertain Climate Policy

    DEFF Research Database (Denmark)

    Barradale, Merrill Jones

    2014-01-01

    This paper introduces the concept of payment probability as an important component of carbon risk (the financial risk associated with CO2 emissions under uncertain climate policy). In modeling power plant investment decisions, most existing literature uses the expected carbon price (e.g., the price...... actually be faced in the case of a particular investment. This concept helps explain both the surge of activity in 2005–2006 and the subsequent decline in interest in coal-fired power plant development in the U.S. The data for this case study comes from an extensive online survey of 700 U.S. energy...... design better incentives for investing in low-carbon technologies...

  20. Uncertain deduction and conditional reasoning.

    Science.gov (United States)

    Evans, Jonathan St B T; Thompson, Valerie A; Over, David E

    2015-01-01

    There has been a paradigm shift in the psychology of deductive reasoning. Many researchers no longer think it is appropriate to ask people to assume premises and decide what necessarily follows, with the results evaluated by binary extensional logic. Most every day and scientific inference is made from more or less confidently held beliefs and not assumptions, and the relevant normative standard is Bayesian probability theory. We argue that the study of "uncertain deduction" should directly ask people to assign probabilities to both premises and conclusions, and report an experiment using this method. We assess this reasoning by two Bayesian metrics: probabilistic validity and coherence according to probability theory. On both measures, participants perform above chance in conditional reasoning, but they do much better when statements are grouped as inferences, rather than evaluated in separate tasks.

  1. The empirical basis of substance use disorders diagnosis: research recommendations for the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-V).

    Science.gov (United States)

    Schuckit, Marc A; Saunders, John B

    2006-09-01

    This paper presents the recommendations, developed from a 3-year consultation process, for a program of research to underpin the development of diagnostic concepts and criteria in the Substance Use Disorders section of the Diagnostic and Statistical Manual of Mental Disorders (DSM) and potentially the relevant section of the next revision of the International Classification of Diseases (ICD). A preliminary list of research topics was developed at the DSM-V Launch Conference in 2004. This led to the presentation of articles on these topics at a specific Substance Use Disorders Conference in February 2005, at the end of which a preliminary list of research questions was developed. This was further refined through an iterative process involving conference participants over the following year. Research questions have been placed into four categories: (1) questions that could be addressed immediately through secondary analyses of existing data sets; (2) items likely to require position papers to propose criteria or more focused questions with a view to subsequent analyses of existing data sets; (3) issues that could be proposed for literature reviews, but with a lower probability that these might progress to a data analytic phase; and (4) suggestions or comments that might not require immediate action, but that could be considered by the DSM-V and ICD 11 revision committees as part of their deliberations. A broadly based research agenda for the development of diagnostic concepts and criteria for substance use disorders is presented.

  2. Decision Making Under Uncertain Categorization

    Directory of Open Access Journals (Sweden)

    Stephanie Ying-Fen Chen

    2014-09-01

    Full Text Available Two experiments investigated how category information is used in decision making under uncertainty and whether the framing of category information influences how it is used. Subjects were presented with vignettes in which the categorization of a critical item was ambiguous and were asked to choose among a set of actions with the goal of attaining the desired outcome for the main character in the story. The normative decision making strategy was to base the decision on all possible categories; however, research on a related topic, category-based induction, has found that people often only consider a single category when making predictions when categorization is uncertain. These experiments found that subjects tend to consider multiple categories when making decisions, but do so both when it is and is not appropriate, suggesting that use of multiple categories is not driven by an understanding of what categories are and are not relevant to the decision. Similarly, although a framing manipulation increased the rate of multiple-category use, it did so in situations in which multiple-category use was and was not appropriate.

  3. CONSTRUCTING ACCOUNTING UNCERTAINITY ESTIMATES VARIABLE

    Directory of Open Access Journals (Sweden)

    Nino Serdarevic

    2012-10-01

    Full Text Available This paper presents research results on the BIH firms’ financial reporting quality, utilizing empirical relation between accounting conservatism, generated in created critical accounting policy choices, and management abilities in estimates and prediction power of domicile private sector accounting. Primary research is conducted based on firms’ financial statements, constructing CAPCBIH (Critical Accounting Policy Choices relevant in B&H variable that presents particular internal control system and risk assessment; and that influences financial reporting positions in accordance with specific business environment. I argue that firms’ management possesses no relevant capacity to determine risks and true consumption of economic benefits, leading to creation of hidden reserves in inventories and accounts payable; and latent losses for bad debt and assets revaluations. I draw special attention to recent IFRS convergences to US GAAP, especially in harmonizing with FAS 130 Reporting comprehensive income (in revised IAS 1 and FAS 157 Fair value measurement. CAPCBIH variable, resulted in very poor performance, presents considerable lack of recognizing environment specifics. Furthermore, I underline the importance of revised ISAE and re-enforced role of auditors in assessing relevance of management estimates.

  4. Robust lyapunov controller for uncertain systems

    KAUST Repository

    Laleg-Kirati, Taous-Meriem; Elmetennani, Shahrazed

    2017-01-01

    Various examples of systems and methods are provided for Lyapunov control for uncertain systems. In one example, a system includes a process plant and a robust Lyapunov controller configured to control an input of the process plant. The robust

  5. Forecasts: uncertain, inaccurate and biased?

    DEFF Research Database (Denmark)

    Nicolaisen, Morten Skou; Ambrasaite, Inga; Salling, Kim Bang

    2012-01-01

    Cost Benefit Analysis (CBA) is the dominating methodology for appraisal of transport infrastructure projects across the globe. In order to adequately assess the costs and benefits of such projects two types of forecasts are crucial to the validity of the appraisal. First are the forecasts of cons....... It is recommended that more attention is given to monitoring completed projects so future forecasts can benefit from better data availability through systematic ex-post evaluations, and an example of how to utilize such data in practice is presented.......Cost Benefit Analysis (CBA) is the dominating methodology for appraisal of transport infrastructure projects across the globe. In order to adequately assess the costs and benefits of such projects two types of forecasts are crucial to the validity of the appraisal. First are the forecasts...... of construction costs, which account for the majority of total project costs. Second are the forecasts of travel time savings, which account for the majority of total project benefits. The latter of these is, inter alia, determined by forecasts of travel demand, which we shall use as a proxy for the forecasting...

  6. Inglorious Empire

    DEFF Research Database (Denmark)

    Khair, Tabish

    2017-01-01

    Review of 'Inglorious Empire: What the British did to India' by Shashi Tharoor, London, Hurst Publishers, 2017, 296 pp., £20.00......Review of 'Inglorious Empire: What the British did to India' by Shashi Tharoor, London, Hurst Publishers, 2017, 296 pp., £20.00...

  7. Robust control synthesis for uncertain dynamical systems

    Science.gov (United States)

    Byun, Kuk-Whan; Wie, Bong; Sunkel, John

    1989-01-01

    This paper presents robust control synthesis techniques for uncertain dynamical systems subject to structured parameter perturbation. Both QFT (quantitative feedback theory) and H-infinity control synthesis techniques are investigated. Although most H-infinity-related control techniques are not concerned with the structured parameter perturbation, a new way of incorporating the parameter uncertainty in the robust H-infinity control design is presented. A generic model of uncertain dynamical systems is used to illustrate the design methodologies investigated in this paper. It is shown that, for a certain noncolocated structural control problem, use of both techniques results in nonminimum phase compensation.

  8. Melioration as rational choice: sequential decision making in uncertain environments.

    Science.gov (United States)

    Sims, Chris R; Neth, Hansjörg; Jacobs, Robert A; Gray, Wayne D

    2013-01-01

    Melioration-defined as choosing a lesser, local gain over a greater longer term gain-is a behavioral tendency that people and pigeons share. As such, the empirical occurrence of meliorating behavior has frequently been interpreted as evidence that the mechanisms of human choice violate the norms of economic rationality. In some environments, the relationship between actions and outcomes is known. In this case, the rationality of choice behavior can be evaluated in terms of how successfully it maximizes utility given knowledge of the environmental contingencies. In most complex environments, however, the relationship between actions and future outcomes is uncertain and must be learned from experience. When the difficulty of this learning challenge is taken into account, it is not evident that melioration represents suboptimal choice behavior. In the present article, we examine human performance in a sequential decision-making experiment that is known to induce meliorating behavior. In keeping with previous results using this paradigm, we find that the majority of participants in the experiment fail to adopt the optimal decision strategy and instead demonstrate a significant bias toward melioration. To explore the origins of this behavior, we develop a rational analysis (Anderson, 1990) of the learning problem facing individuals in uncertain decision environments. Our analysis demonstrates that an unbiased learner would adopt melioration as the optimal response strategy for maximizing long-term gain. We suggest that many documented cases of melioration can be reinterpreted not as irrational choice but rather as globally optimal choice under uncertainty.

  9. Uncertain estimation of activity measurement in Nuclear Medicine

    International Nuclear Information System (INIS)

    Lopez Diaz, A.; Palau, S.P.A.; Cardenas, T.A.I.; Garcia, A.I.; Tulio, H.A.

    2007-01-01

    Full text: Accuracy and precision of dose is mandatory in radiopharmaceutical therapy procedures to guarantee the treatment success. The evaluation of uncertain in dose measurement in NM lab becomes a very important step, moreover if the operational parameters change between different equipment. In order to assure the traceability of activity measurements, and the quality assurance of dose administration, the behavior of two dose calibrator Capintec CRC-15R and PTW Curimentor 3, were studied. Accuracy, precision, linearity of activity response and reproducibility, and the activity uncertain determination with a second lab source were determined. Accuracy was evaluate using Tc 99m and I 131 Pstandard source (Secondary Standard Laboratory), for 10R vial (V) and 5 ml syringe (S) geometry, obtaining 1.3% (V-I 131 ), 1.4% (V -Tc 99m ), 0.8% (S -Tc 99m ) for CRC-15R and 2.3% (V-I 131 ), 1.1%(V-Tc 99m ), 1.0% (S-Tc 99m ) for Curimentor 3. Precision and Reproducibility was calculate using Cs 137 source. The reproducibility of CRC-15R and Curimentor 3 was less than 1.1% and 1.2 % respectively, during all evaluation time. The linearity of activity response was evaluate only for Tc 99m , and the results obtained were CRC 15R (672.97mCi 0.07 mCi, 1.3 % like mayor deviation) and Curimentor 3 (670.91mCi 0.08 mCi; 0.6 % like mayor deviation). To calculate the uncertain was use I 131 sources, the influences of calibration factor, linearity to activity, precision, reproducibility, background, half live time took into account. The typical combine uncertain for I 131 activity of was 2.24% for CRC-15R and 2.41% for Curimentor 3. The results were traceable between two equipment, no statistical significant differences were found for all tests. The equipment have a proper performance in the checked parameters, showing compliance with AIEA and National Authorities recommendation. Conclusion: The two equipmentcan be used in NM services with high level of traceability and confidence, with

  10. Uncertain climate policy and the green paradox

    NARCIS (Netherlands)

    Smulders, Sjak A.; Tsur, Y.; Zemel, A.; Moser, E.; Semmler, W.; Tragler, G.; Veliov, V.

    2014-01-01

    Unintended consequences of announcing a climate policy well in advance of its implementation have been studied in a variety of situations. We show that a phenomenon akin to the so-called “Green-Paradox” holds also when the policy implementation date is uncertain. Governments are compelled, by

  11. Quality Measures in Uncertain Data Management

    NARCIS (Netherlands)

    de Keijzer, Ander; van Keulen, Maurice; Prade, H.; Subrahmanian, V.S.

    2007-01-01

    Many applications deal with data that is uncertain. Some examples are applications dealing with sensor information, data integration applications and healthcare applications. Instead of these applications having to deal with the uncertainty, it should be the responsibility of the DBMS to manage all

  12. Management of Uncertain Data - towards unattended integration

    NARCIS (Netherlands)

    de Keijzer, Ander

    2008-01-01

    In recent years, the need to support uncertain data has increased. Sensor applications, for example, are dealing with the inherent uncertainty about the readings of the sensors. Current database management systems are not equipped to deal with this uncertainty, other than as a user defined

  13. Chance constrained uncertain classification via robust optimization

    NARCIS (Netherlands)

    Ben-Tal, A.; Bhadra, S.; Bhattacharayya, C.; Saketha Nat, J.

    2011-01-01

    This paper studies the problem of constructing robust classifiers when the training is plagued with uncertainty. The problem is posed as a Chance-Constrained Program (CCP) which ensures that the uncertain data points are classified correctly with high probability. Unfortunately such a CCP turns out

  14. Robust scheduling in an uncertain environment

    NARCIS (Netherlands)

    Wilson, M.

    2016-01-01

    This thesis presents research on scheduling in an uncertain environment, which forms a part of the rolling stock life cycle logistics applied research and development program funded by Dutch railway industry companies. The focus therefore lies on scheduling of maintenance operations on rolling stock

  15. Enabling time-dependent uncertain eco-weights for road networks

    DEFF Research Database (Denmark)

    Hu, Jilin; Yang, Bin; Jensen, Christian S.

    2017-01-01

    travel costs. Based on the techniques above, different histogram aggregation methods are proposed to accurately estimate time-dependent GHG emissions for routes. Based on a 200-million GPS record data set collected from 150 vehicles in Denmark over two years, a comprehensive empirical study is conducted...... transportation. The foundation of eco-routing is a weighted-graph representation of a road network in which road segments, or edges, are associated with eco-weights that capture the GHG emissions caused by traversing the edges. Due to the dynamics of traffic, the eco-weights are best modeled as being time...... dependent and uncertain. We formalize the problem of assigning a time-dependent, uncertain eco-weight to each edge in a road network based on historical GPS records. In particular, a sequence of histograms is employed to describe the uncertain eco-weight of an edge at different time intervals. Compression...

  16. Fuzzy controller for an uncertain dynamical system

    DEFF Research Database (Denmark)

    Kulczycki, P.; Wisniewski, Rafal

    2002-01-01

    The present paper deals with the time-optimal control for mechanical systems with uncertain load. A fuzzy approach is used in the design of suboptimal feedback controllers, robust with respect to the load. Statistical kernel estimators are used for the specification of crucial parameters. The met......The present paper deals with the time-optimal control for mechanical systems with uncertain load. A fuzzy approach is used in the design of suboptimal feedback controllers, robust with respect to the load. Statistical kernel estimators are used for the specification of crucial parameters....... The methodology proposed in this work may be easily adopted to other modeling uncertainties of mechanical systems, e.g. motion resistance....

  17. Empirical likelihood

    CERN Document Server

    Owen, Art B

    2001-01-01

    Empirical likelihood provides inferences whose validity does not depend on specifying a parametric model for the data. Because it uses a likelihood, the method has certain inherent advantages over resampling methods: it uses the data to determine the shape of the confidence regions, and it makes it easy to combined data from multiple sources. It also facilitates incorporating side information, and it simplifies accounting for censored, truncated, or biased sampling.One of the first books published on the subject, Empirical Likelihood offers an in-depth treatment of this method for constructing confidence regions and testing hypotheses. The author applies empirical likelihood to a range of problems, from those as simple as setting a confidence region for a univariate mean under IID sampling, to problems defined through smooth functions of means, regression models, generalized linear models, estimating equations, or kernel smooths, and to sampling with non-identically distributed data. Abundant figures offer vi...

  18. Restructuring Electricity Markets when Demand is Uncertain

    DEFF Research Database (Denmark)

    Boom, Anette; Buehler, Stefan

    2006-01-01

    We examine the effects of reorganizing electricity markets on capacity investments, retail prices and welfare when demand is uncertain. We study the following market configurations: (i) integrated monopoly, (ii) integrated duopoly with wholesale trade, and (iii) separated duopoly with wholesale...... trade. Assuming that wholesale prices can react to changes in retail prices (but not vice versa), we find that generators install sufficient capacity to serve retail demand in each market configuration, thus avoiding blackouts. Furthermore, aggregate capacity levels and retail prices...

  19. Synchronizing a class of uncertain chaotic systems

    International Nuclear Information System (INIS)

    Chen Maoyin; Zhou Donghua; Shang Yun

    2005-01-01

    This Letter deals with the synchronization of a class of uncertain chaotic systems in the drive-response framework. A robust adaptive observer based response system is designed to synchronize a given chaotic system with unknown parameters and external disturbances. Lyapunov stability ensures the global synchronization between the drive and response systems even if Lipschitz constants on function matrices and bounds on uncertainties are unknown. Numerical simulation of Genesio-Tesi system verifies the effectiveness of this scheme

  20. Uncertain relational reasoning in the parietal cortex.

    Science.gov (United States)

    Ragni, Marco; Franzmeier, Imke; Maier, Simon; Knauff, Markus

    2016-04-01

    The psychology of reasoning is currently transitioning from the study of deductive inferences under certainty to inferences that have degrees of uncertainty in both their premises and conclusions; however, only a few studies have explored the cortical basis of uncertain reasoning. Using transcranial magnetic stimulation (TMS), we show that areas in the right superior parietal lobe (rSPL) are necessary for solving spatial relational reasoning problems under conditions of uncertainty. Twenty-four participants had to decide whether a single presented order of objects agreed with a given set of indeterminate premises that could be interpreted in more than one way. During the presentation of the order, 10-Hz TMS was applied over the rSPL or a sham control site. Right SPL TMS during the inference phase disrupted performance in uncertain relational reasoning. Moreover, we found differences in the error rates between preferred mental models, alternative models, and inconsistent models. Our results suggest that different mechanisms are involved when people reason spatially and evaluate different kinds of uncertain conclusions. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Numerical solution of uncertain neutron diffusion equation for ...

    Indian Academy of Sciences (India)

    The concept of fuzziness is hybridised with ... impreciseness, vagueness, experimental error and different operating conditions affected by the system. ... But the presence of uncertain parameters makes the system uncertain and we get uncer-.

  2. Vessels Route Planning Problem with Uncertain Data

    Directory of Open Access Journals (Sweden)

    Tomasz Neumann

    2016-09-01

    Full Text Available The purpose of this paper is to find a solution for route planning in a transport networks, where the costs of tracks, factor of safety and travel time are ambiguous. This approach is based on the Dempster-Shafer theory and well known Dijkstra's algorithm. In this approach important are the influencing factors of the mentioned coefficients using uncertain possibilities presented by probability intervals. Based on these intervals the quality intervals of each route can be determined. Applied decision rules can be described by the end user.

  3. Empirical Hamiltonians

    International Nuclear Information System (INIS)

    Peggs, S.; Talman, R.

    1987-01-01

    As proton accelerators get larger, and include more magnets, the conventional tracking programs which simulate them run slower. The purpose of this paper is to describe a method, still under development, in which element-by-element tracking around one turn is replaced by a single man, which can be processed far faster. It is assumed for this method that a conventional program exists which can perform faithful tracking in the lattice under study for some hundreds of turns, with all lattice parameters held constant. An empirical map is then generated by comparison with the tracking program. A procedure has been outlined for determining an empirical Hamiltonian, which can represent motion through many nonlinear kicks, by taking data from a conventional tracking program. Though derived by an approximate method this Hamiltonian is analytic in form and can be subjected to further analysis of varying degrees of mathematical rigor. Even though the empirical procedure has only been described in one transverse dimension, there is good reason to hope that it can be extended to include two transverse dimensions, so that it can become a more practical tool in realistic cases

  4. CKD of Uncertain Etiology: A Systematic Review.

    Science.gov (United States)

    Lunyera, Joseph; Mohottige, Dinushika; Von Isenburg, Megan; Jeuland, Marc; Patel, Uptal D; Stanifer, John W

    2016-03-07

    Epidemics of CKD of uncertain etiology (CKDu) are emerging around the world. Highlighting common risk factors for CKD of uncertain etiology across various regions and populations may be important for health policy and public health responses. We searched PubMed, Embase, Scopus and Web of Science databases to identify published studies on CKDu. The search was generated in January of 2015; no language or date limits were used. We used a vote-counting method to evaluate exposures across all studies. We identified 1607 articles, of which 26 met inclusion criteria. Eighteen (69%) were conducted in known CKDu-endemic countries: Sri Lanka (38%), Nicaragua (19%), and El Salvador (12%). The other studies were from India, Japan, Australia, Mexico, Sweden, Tunisia, Tanzania, and the United States. Heavy metals, heat stress, and dietary exposures were reported across all geographic regions. In south Asia, family history, agrochemical use, and heavy metal exposures were reported most frequently, whereas altitude and temperature were reported only in studies from Central America. Across all regions, CKDu was most frequently associated with a family history of CKDu, agricultural occupation, men, middle age, snake bite, and heavy metal exposure. Studies examining etiologies of CKDu have reported many exposures that are heterogeneous and vary by region. To identify etiologies of CKDu, designing consistent and comparative multisite studies across high-risk populations may help elucidate the importance of region-specific versus global risk factors. Copyright © 2016 by the American Society of Nephrology.

  5. Sensitivity in risk analyses with uncertain numbers.

    Energy Technology Data Exchange (ETDEWEB)

    Tucker, W. Troy; Ferson, Scott

    2006-06-01

    Sensitivity analysis is a study of how changes in the inputs to a model influence the results of the model. Many techniques have recently been proposed for use when the model is probabilistic. This report considers the related problem of sensitivity analysis when the model includes uncertain numbers that can involve both aleatory and epistemic uncertainty and the method of calculation is Dempster-Shafer evidence theory or probability bounds analysis. Some traditional methods for sensitivity analysis generalize directly for use with uncertain numbers, but, in some respects, sensitivity analysis for these analyses differs from traditional deterministic or probabilistic sensitivity analyses. A case study of a dike reliability assessment illustrates several methods of sensitivity analysis, including traditional probabilistic assessment, local derivatives, and a ''pinching'' strategy that hypothetically reduces the epistemic uncertainty or aleatory uncertainty, or both, in an input variable to estimate the reduction of uncertainty in the outputs. The prospects for applying the methods to black box models are also considered.

  6. Generalization from uncertain and imprecise data

    Energy Technology Data Exchange (ETDEWEB)

    Bouchon-Meunier, B.; Marsala, C.; Rifqi, M. [Universite P. et M. Curie, Paris (France); Ramdani, M. [Universite P. et M. Curie, Paris (France)]|[Faculte des Sciences et Techniques, Mohammadia (Morocco)

    1996-12-31

    Most of the knowledge available about a given system is imperfect, which means imprecise, uncertain, qualitative, expressed in natural language with words which are generally vague. Some pieces of knowledge are numerical, obtained by means of measurements with more or less precise devices. They can also be incomplete, with unknown values for some elements of the system. Classification of objects, decision-making according to the description of the system, are well known problems which can be approached by various ways. Methods based on a generalization process appear very efficient when a list of already solved cases is available and sufficiently representative of all the possible cases. In this paper, we focus on the case where fuzzy sets are used to represent imperfect knowledge because of the capability of fuzzy sets to help managing imprecise data, possibly submitted to some non probabilistic uncertainty such as a subjective doubt. Fuzzy sets also present the interesting property to establish an interface between numerical and symbolic data and are interesting to use when both types of data are present. We suppose that the objects of the system are described by means of attributes, the value of which can be imprecise, uncertain or undetermined. Our purpose is to find rules enabling us to attach a class to any object of the system. We focus this study on two generalization methods based on the knowledge of a training set of objects associated with their descriptions and their classes.

  7. Stability analysis of fuzzy parametric uncertain systems.

    Science.gov (United States)

    Bhiwani, R J; Patre, B M

    2011-10-01

    In this paper, the determination of stability margin, gain and phase margin aspects of fuzzy parametric uncertain systems are dealt. The stability analysis of uncertain linear systems with coefficients described by fuzzy functions is studied. A complexity reduced technique for determining the stability margin for FPUS is proposed. The method suggested is dependent on the order of the characteristic polynomial. In order to find the stability margin of interval polynomials of order less than 5, it is not always necessary to determine and check all four Kharitonov's polynomials. It has been shown that, for determining stability margin of FPUS of order five, four, and three we require only 3, 2, and 1 Kharitonov's polynomials respectively. Only for sixth and higher order polynomials, a complete set of Kharitonov's polynomials are needed to determine the stability margin. Thus for lower order systems, the calculations are reduced to a large extent. This idea has been extended to determine the stability margin of fuzzy interval polynomials. It is also shown that the gain and phase margin of FPUS can be determined analytically without using graphical techniques. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

  8. Dynamic response of structures with uncertain parameters

    International Nuclear Information System (INIS)

    Cai, Z H; Liu, Y; Yang, Y

    2010-01-01

    In this paper, an interval method for the dynamic response of structures with uncertain parameters is presented. In the presented method, the structural physical and geometric parameters and loads can be considered as interval variables. The structural stiffness matrix, mass matrix and loading vectors are described as the sum of two parts corresponding to the deterministic matrix and the uncertainty of the interval parameters. The interval problem is then transformed into approximate deterministic one. The Laplace transform is used to transform the equations of the dynamic system into linear algebra equations. The Maclaurin series expansion is applied on the modified dynamic equation in order to deal with the linear algebra equations. Numerical examples are studied by the presented interval method for the cases with and without damping. The upper bound and lower bound of the dynamic responses of the examples are compared, and it shows that the presented method is effective.

  9. Robust lyapunov controller for uncertain systems

    KAUST Repository

    Laleg-Kirati, Taous-Meriem

    2017-02-23

    Various examples of systems and methods are provided for Lyapunov control for uncertain systems. In one example, a system includes a process plant and a robust Lyapunov controller configured to control an input of the process plant. The robust Lyapunov controller includes an inner closed loop Lyapunov controller and an outer closed loop error stabilizer. In another example, a method includes monitoring a system output of a process plant; generating an estimated system control input based upon a defined output reference; generating a system control input using the estimated system control input and a compensation term; and adjusting the process plant based upon the system control input to force the system output to track the defined output reference. An inner closed loop Lyapunov controller can generate the estimated system control input and an outer closed loop error stabilizer can generate the system control input.

  10. Towards electricity markets accommodating uncertain offers

    DEFF Research Database (Denmark)

    Papakonstantinou, Athanasios; Pinson, Pierre

    2014-01-01

    formulation of an electricity market, based on the Continuous Ranked Probability Score (CRPS) reduces the impact of poor estimates for both the stochastic producers and the system operator. We introduce a simulation setting which first demonstrates that impact and then proceed to illustrate the main features......The use of renewable energy sources of energy and in particular wind and solar has been on the rise over the last decades with plans to increase it even more. Such developments introduce significant challenges in existing power systems and can result in high electricity prices and costly...... infrastructure investments. In this paper we propose a new electricity market mechanism whereby the uncertain and dynamic nature of wind power and other stochastic sources is embedded in the market mechanism itself, by modelling producers’ bids as probabilistic estimates. An extension on the bilevel programming...

  11. Recommender systems

    OpenAIRE

    Lu L.; Medo M.; Yeung C.H.; Zhang Y.-C.; Zhang Z.-K.; Zhou T.

    2012-01-01

    The ongoing rapid expansion of the Internet greatly increases the necessity of effective recommender systems for filtering the abundant information. Extensive research for recommender systems is conducted by a broad range of communities including social and computer scientists, physicists, and interdisciplinary researchers. Despite substantial theoretical and practical achievements, unification and comparison of different approaches are lacking, which impedes further advances. In this article...

  12. Tsallis’ non-extensive free energy as a subjective value of an uncertain reward

    Science.gov (United States)

    Takahashi, Taiki

    2009-03-01

    Recent studies in neuroeconomics and econophysics revealed the importance of reward expectation in decision under uncertainty. Behavioral neuroeconomic studies have proposed that the unpredictability and the probability of an uncertain reward are distinctly encoded as entropy and a distorted probability weight, respectively, in the separate neural systems. However, previous behavioral economic and decision-theoretic models could not quantify reward-seeking and uncertainty aversion in a theoretically consistent manner. In this paper, we have: (i) proposed that generalized Helmholtz free energy in Tsallis’ non-extensive thermostatistics can be utilized to quantify a perceived value of an uncertain reward, and (ii) empirically examined the explanatory powers of the models. Future study directions in neuroeconomics and econophysics by utilizing the Tsallis’ free energy model are discussed.

  13. Recommender systems

    CERN Document Server

    Kembellec, Gérald; Saleh, Imad

    2014-01-01

    Acclaimed by various content platforms (books, music, movies) and auction sites online, recommendation systems are key elements of digital strategies. If development was originally intended for the performance of information systems, the issues are now massively moved on logical optimization of the customer relationship, with the main objective to maximize potential sales. On the transdisciplinary approach, engines and recommender systems brings together contributions linking information science and communications, marketing, sociology, mathematics and computing. It deals with the understan

  14. Probabilistic logic networks a comprehensive framework for uncertain inference

    CERN Document Server

    Goertzel, Ben; Goertzel, Izabela Freire; Heljakka, Ari

    2008-01-01

    This comprehensive book describes Probabilistic Logic Networks (PLN), a novel conceptual, mathematical and computational approach to uncertain inference. A broad scope of reasoning types are considered.

  15. Empirical Hamiltonians

    International Nuclear Information System (INIS)

    Peggs, S.; Talman, R.

    1986-08-01

    As proton accelerators get larger, and include more magnets, the conventional tracking programs which simulate them run slower. At the same time, in order to more carefully optimize the higher cost of the accelerators, they must return more accurate results, even in the presence of a longer list of realistic effects, such as magnet errors and misalignments. For these reasons conventional tracking programs continue to be computationally bound, despite the continually increasing computing power available. This limitation is especially severe for a class of problems in which some lattice parameter is slowly varying, when a faithful description is only obtained by tracking for an exceedingly large number of turns. Examples are synchrotron oscillations in which the energy varies slowly with a period of, say, hundreds of turns, or magnet ripple or noise on a comparably slow time scale. In these cases one may with to track for hundreds of periods of the slowly varying parameter. The purpose of this paper is to describe a method, still under development, in which element-by-element tracking around one turn is replaced by a single map, which can be processed far faster. Similar programs have already been written in which successive elements are ''concatenated'' with truncation to linear, sextupole, or octupole order, et cetera, using Lie algebraic techniques to preserve symplecticity. The method described here is rather more empirical than this but, in principle, contains information to all orders and is able to handle resonances in a more straightforward fashion

  16. Probabilistic Graph Layout for Uncertain Network Visualization.

    Science.gov (United States)

    Schulz, Christoph; Nocaj, Arlind; Goertler, Jochen; Deussen, Oliver; Brandes, Ulrik; Weiskopf, Daniel

    2017-01-01

    We present a novel uncertain network visualization technique based on node-link diagrams. Nodes expand spatially in our probabilistic graph layout, depending on the underlying probability distributions of edges. The visualization is created by computing a two-dimensional graph embedding that combines samples from the probabilistic graph. A Monte Carlo process is used to decompose a probabilistic graph into its possible instances and to continue with our graph layout technique. Splatting and edge bundling are used to visualize point clouds and network topology. The results provide insights into probability distributions for the entire network-not only for individual nodes and edges. We validate our approach using three data sets that represent a wide range of network types: synthetic data, protein-protein interactions from the STRING database, and travel times extracted from Google Maps. Our approach reveals general limitations of the force-directed layout and allows the user to recognize that some nodes of the graph are at a specific position just by chance.

  17. Fourier phasing with phase-uncertain mask

    International Nuclear Information System (INIS)

    Fannjiang, Albert; Liao, Wenjing

    2013-01-01

    Fourier phasing is the problem of retrieving Fourier phase information from Fourier intensity data. The standard Fourier phase retrieval (without a mask) is known to have many solutions which cause the standard phasing algorithms to stagnate and produce wrong or inaccurate solutions. In this paper Fourier phase retrieval is carried out with the introduction of a randomly fabricated mask in measurement and reconstruction. Highly probable uniqueness of solution, up to a global phase, was previously proved with exact knowledge of the mask. Here the uniqueness result is extended to the case where only rough information about the mask’s phases is assumed. The exponential probability bound for uniqueness is given in terms of the uncertainty-to-diversity ratio of the unknown mask. New phasing algorithms alternating between the object update and the mask update are systematically tested and demonstrated to have the capability of recovering both the object and the mask (within the object support) simultaneously, consistent with the uniqueness result. Phasing with a phase-uncertain mask is shown to be robust with respect to the correlation in the mask as well as the Gaussian and Poisson noises. (paper)

  18. uncertain dynamic systems on time scales

    Directory of Open Access Journals (Sweden)

    V. Lakshmikantham

    1995-01-01

    Full Text Available A basic feedback control problem is that of obtaining some desired stability property from a system which contains uncertainties due to unknown inputs into the system. Despite such imperfect knowledge in the selected mathematical model, we often seek to devise controllers that will steer the system in a certain required fashion. Various classes of controllers whose design is based on the method of Lyapunov are known for both discrete [4], [10], [15], and continuous [3–9], [11] models described by difference and differential equations, respectively. Recently, a theory for what is known as dynamic systems on time scales has been built which incorporates both continuous and discrete times, namely, time as an arbitrary closed sets of reals, and allows us to handle both systems simultaneously [1], [2], [12], [13]. This theory permits one to get some insight into and better understanding of the subtle differences between discrete and continuous systems. We shall, in this paper, utilize the framework of the theory of dynamic systems on time scales to investigate the stability properties of conditionally invariant sets which are then applied to discuss controlled systems with uncertain elements. For the notion of conditionally invariant set and its stability properties, see [14]. Our results offer a new approach to the problem in question.

  19. Investment timing under uncertain renewable energy policy: An empirical study of small hydropower projects

    International Nuclear Information System (INIS)

    Linnerud, Kristin; Andersson, Ane Marte; Fleten, Stein-Erik

    2014-01-01

    Policy uncertainty can be a powerful deterrent to immediate investments. Based on panel data of 214 licenses to construct small run-of-the-river hydropower plants, we examine whether the prospect of a common Swedish–Norwegian market for green certificates (i.e., a renewable portfolio standard scheme) affected the timing of investments. Our results show that traditional utilities and other professional investors in the energy market acted in accordance with a real options investment rule, and the prospect of possible future subsidies delayed their investment decision. On the other hand, our results do not show that farmers and other non-professional investors incorporated timing considerations in their investment decisions. Rather, our results indicate that these investors behaved as if their investment opportunity is now-or-never, investing if the project is profitable according to a net present value investment rule, ignoring the opportunity to create additional value by waiting. The observed difference in behavior between professional and non-professional investors is interesting given the distributed nature of many renewable energy technologies, and can help planners and policymakers better understand the forces shaping the future market for electricity. - Highlights: • We examine whether the prospect of introducing subsidies delayed investments in hydropower. • We find that professional and non-professional investors behaved differently. • Professional investors explored the opportunity to create additional value by waiting. • Farmers behaved as if their investment opportunity was now-or-never. • These observations are interesting given the distributed nature of renewable energy technologies

  20. Investment risks under uncertain climate change policy

    International Nuclear Information System (INIS)

    Blyth, William; Bradley, Richard; Yang, Ming; Bunn, Derek; Clarke, Charlie; Wilson, Tom

    2007-01-01

    This paper describes results from a model of decision-making under uncertainty using a real options methodology, developed by the International Energy Agency (IEA). The model represents investment decisions in power generation from the perspective of a private company. The investments are subject to uncertain future climate policy, which is treated as an external risk factor over which the company has no control. The aims of this paper are to (i) quantify these regulatory risks in order to improve understanding of how policy uncertainty may affect investment behaviour by private companies and (ii) illustrate the effectiveness of the real options approach as a policy analysis tool. The study analysed firms' investment options of coal- and gas-fired power plants and carbon capture and storage (CCS) technologies. Policy uncertainty is represented as an exogenous event that creates uncertainty in the carbon price. Our findings indicate that climate policy uncertainty creates a risk premium for power generation investments. In the case of gas- and coal-fired power generation, the risk premium would lead to an increase in electricity prices of 5-10% in order to stimulate investment. In the case of CCS, the risk premium would increase the carbon price required to stimulate investment by 16-37% compared to a situation of perfect certainty. The option to retrofit CCS acts as a hedge against high future carbon prices, and could accelerate investment in coal plant. This paper concludes that to minimise investment risks in low carbon technologies, policy-makers should aim to provide some long-term regulatory certainty. (author)

  1. Millennial Teachers and Multiculturalism: Considerations for Teaching in Uncertain Times

    Science.gov (United States)

    Hallman, Heidi L.

    2017-01-01

    Purpose: This paper aims to explore the intersection of generational traits of millennial teachers, multiculturalism and teaching in an era of Uncertain Times. Uncertain Times, as a framework for the paper, characterizes changing aspects of the current era in which we live, such as the rise of the internet and interconnectivity, globalization and…

  2. Data Envelopment Analysis with Uncertain Inputs and Outputs

    Directory of Open Access Journals (Sweden)

    Meilin Wen

    2014-01-01

    Full Text Available Data envelopment analysis (DEA, as a useful management and decision tool, has been widely used since it was first invented by Charnes et al. in 1978. On the one hand, the DEA models need accurate inputs and outputs data. On the other hand, in many situations, inputs and outputs are volatile and complex so that they are difficult to measure in an accurate way. The conflict leads to the researches of uncertain DEA models. This paper will consider DEA in uncertain environment, thus producing a new model based on uncertain measure. Due to the complexity of the new uncertain DEA model, an equivalent deterministic model is presented. Finally, a numerical example is presented to illustrate the effectiveness of the uncertain DEA model.

  3. Diversified models for portfolio selection based on uncertain semivariance

    Science.gov (United States)

    Chen, Lin; Peng, Jin; Zhang, Bo; Rosyida, Isnaini

    2017-02-01

    Since the financial markets are complex, sometimes the future security returns are represented mainly based on experts' estimations due to lack of historical data. This paper proposes a semivariance method for diversified portfolio selection, in which the security returns are given subjective to experts' estimations and depicted as uncertain variables. In the paper, three properties of the semivariance of uncertain variables are verified. Based on the concept of semivariance of uncertain variables, two types of mean-semivariance diversified models for uncertain portfolio selection are proposed. Since the models are complex, a hybrid intelligent algorithm which is based on 99-method and genetic algorithm is designed to solve the models. In this hybrid intelligent algorithm, 99-method is applied to compute the expected value and semivariance of uncertain variables, and genetic algorithm is employed to seek the best allocation plan for portfolio selection. At last, several numerical examples are presented to illustrate the modelling idea and the effectiveness of the algorithm.

  4. Wind farm investment risks under uncertain CDM benefit in China

    International Nuclear Information System (INIS)

    Yang, Ming; Nguyen, Francois; T'Serclaes, Philippine de; Buchner, Barbara

    2010-01-01

    China has set an ambitious target to increase its wind power capacity by 35 GW from 2007 to 2020. The country's hunger for clean power provides great opportunities for wind energy investors. However, risks from China's uncertain electricity market regulation and an uncertain energy policy framework, mainly due to uncertain Clean Development Mechanism (CDM) benefits, prevent foreign investors from investing in China's wind energy. The objectives of this paper are to: (1) quantify wind energy investment risk premiums in an uncertain international energy policy context and (2) evaluate the impact of uncertain CDM benefits on the net present values of wind power projects. With four scenarios, this study simulates possible prices of certified emissions reductions (CERs) from wind power projects. Project net present values (NPVs) have been calculated. The project risk premiums are drawn from different and uncertain CER prices. Our key findings show that uncertain CDM benefits will significantly affect the project NPVs. This paper concludes that the Chinese government needs revising its tariff incentives, most likely by introducing fixed feed-in tariffs (FITs), and re-examining its CDM-granting policy and its wind project tax rates, to facilitate wind power development and enable China to achieve its wind energy target. (author)

  5. Evaluation of empirical atmospheric diffusion data

    International Nuclear Information System (INIS)

    Horst, T.W.; Doran, J.C.; Nickola, P.W.

    1979-10-01

    A study has been made of atmospheric diffusion over level, homogeneous terrain of contaminants released from non-buoyant point sources up to 100 m in height. Current theories of diffusion are compared to empirical diffusion data, and specific dispersion estimation techniques are recommended which can be implemented with the on-site meteorological instrumentation required by the Nuclear Regulatory Commission. A comparison of both the recommended diffusion model and the NRC diffusion model with the empirical data demonstrates that the predictions of the recommended model have both smaller scatter and less bias, particularly for groundlevel sources

  6. Evaluation of empirical atmospheric diffusion data

    Energy Technology Data Exchange (ETDEWEB)

    Horst, T.W.; Doran, J.C.; Nickola, P.W.

    1979-10-01

    A study has been made of atmospheric diffusion over level, homogeneous terrain of contaminants released from non-buoyant point sources up to 100 m in height. Current theories of diffusion are compared to empirical diffusion data, and specific dispersion estimation techniques are recommended which can be implemented with the on-site meteorological instrumentation required by the Nuclear Regulatory Commission. A comparison of both the recommended diffusion model and the NRC diffusion model with the empirical data demonstrates that the predictions of the recommended model have both smaller scatter and less bias, particularly for ground-level sources.

  7. Robust Control with Enlaeged Interval of Uncertain Parameters

    Directory of Open Access Journals (Sweden)

    Marek Keresturi

    2002-01-01

    Full Text Available Robust control is advantageous for systems with defined interval of uncertain parameters. This can be substantially enlarged dividing it into a few sub-intervals. Corresponding controllers for each of them may be set after approximate identification of some uncertain plant parameters. The paper deals with application of the pole region assignment method for position control of the crane crab. The same track form is required for uncertain burden mass and approximate value of rope length. Measurement of crab position and speed is supposed, burden deviation angle is observed. Simulation results have verified feasibility of this design procedure.

  8. International recommendations

    International Nuclear Information System (INIS)

    Lindell, Bo

    1986-01-01

    Full text: This short presentation will indicate the general radiation protection background to protective measures against foodstuffs contaminated with radioactive substances. A number of international organizations are involved in various aspects of radiation protection, for example, the International Atomic Energy Agency (IAEA), the United Nations Food and Agriculture Organization (FAO), the United Nations Environment Programme (UNEP), and the World Health Organization (WHO). Two international organizations, however, provide the basic background. These are the International Commission on Radiological Protection (ICRP) and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). UNSCEAR provides the scientific information on radiation levels and effects. It consists of 21 member countries, with truly international coverage. It issues reports to the UN General Assembly, including comprehensive scientific annexes. Its latest comprehensive report was issued in 1982, the next is expected to be published in 1988. That report will include an assessment of the radiological consequences of the Chernobyl accident. The ICRP is a non-governmental organization. It has issued recommendations on radiation protection since 1928. The postulated biological basis for radiation protection recommendations involves two types of biological effects. The so-called non-stochastic effects, mainly due to cell death, appear only when the radiation doses exceed a certain threshold value. These effects, therefore, can only appear after high accidental exposures. After the Chernobyl accident, they only affected about 200 individuals involved in fire extinction and rescue work at the damaged nuclear power plant. Stochastic effects, with some simplification, may be seen as the result of initial changes in the genetic code of some surviving cells. If these cells are germ cells, this may lead to hereditary harm. If they are somatic cells, the result could be cancer

  9. An Artificial Bee Colony Algorithm for Uncertain Portfolio Selection

    OpenAIRE

    Chen, Wei

    2014-01-01

    Portfolio selection is an important issue for researchers and practitioners. In this paper, under the assumption that security returns are given by experts’ evaluations rather than historical data, we discuss the portfolio adjusting problem which takes transaction costs and diversification degree of portfolio into consideration. Uncertain variables are employed to describe the security returns. In the proposed mean-variance-entropy model, the uncertain mean value of the return is ...

  10. Active fault diagnosis in closed-loop uncertain systems

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik

    2006-01-01

    Fault diagnosis of parametric faults in closed-loop uncertain systems by using an auxiliary input vector is considered in this paper, i.e. active fault diagnosis (AFD). The active fault diagnosis is based directly on the socalled fault signature matrix, related to the YJBK (Youla, Jabr, Bongiorno...... and Kucera) parameterization. Conditions are given for exact detection and isolation of parametric faults in closed-loop uncertain systems....

  11. CMAC-based adaptive backstepping synchronization of uncertain chaotic systems

    International Nuclear Information System (INIS)

    Lin, C.-M.; Peng, Y.-F.; Lin, M.-H.

    2009-01-01

    This study proposes an adaptive backstepping control system for synchronizing uncertain chaotic system by using cerebellar model articulation controller (CMAC). CMAC is a nonlinear network with simple computation, good generalization capability and fast learning property. The proposed CMAC-based adaptive backstepping control (CABC) system uses backstepping method and adaptive cerebellar model articulation controller (ACMAC) for synchronizing uncertain chaotic system. Finally, simulation results for the Genesio system are presented to illustrate the effectiveness of the proposed control system.

  12. Neural basis of uncertain cue processing in trait anxiety.

    Science.gov (United States)

    Zhang, Meng; Ma, Chao; Luo, Yanyan; Li, Ji; Li, Qingwei; Liu, Yijun; Ding, Cody; Qiu, Jiang

    2016-02-19

    Individuals with high trait anxiety form a non-clinical group with a predisposition for an anxiety-related bias in emotional and cognitive processing that is considered by some to be a prerequisite for psychiatric disorders. Anxious individuals tend to experience more worry under uncertainty, and processing uncertain information is an important, but often overlooked factor in anxiety. So, we decided to explore the brain correlates of processing uncertain information in individuals with high trait anxiety using the learn-test paradigm. Behaviorally, the percentages on memory test and the likelihood ratios of identifying novel stimuli under uncertainty were similar to the certain fear condition, but different from the certain neutral condition. The brain results showed that the visual cortex, bilateral fusiform gyrus, and right parahippocampal gyrus were active during the processing of uncertain cues. Moreover, we found that trait anxiety was positively correlated with the BOLD signal of the right parahippocampal gyrus during the processing of uncertain cues. No significant results were found in the amygdala during uncertain cue processing. These results suggest that memory retrieval is associated with uncertain cue processing, which is underpinned by over-activation of the right parahippocampal gyrus, in individuals with high trait anxiety.

  13. MAGDM linear-programming models with distinct uncertain preference structures.

    Science.gov (United States)

    Xu, Zeshui S; Chen, Jian

    2008-10-01

    Group decision making with preference information on alternatives is an interesting and important research topic which has been receiving more and more attention in recent years. The purpose of this paper is to investigate multiple-attribute group decision-making (MAGDM) problems with distinct uncertain preference structures. We develop some linear-programming models for dealing with the MAGDM problems, where the information about attribute weights is incomplete, and the decision makers have their preferences on alternatives. The provided preference information can be represented in the following three distinct uncertain preference structures: 1) interval utility values; 2) interval fuzzy preference relations; and 3) interval multiplicative preference relations. We first establish some linear-programming models based on decision matrix and each of the distinct uncertain preference structures and, then, develop some linear-programming models to integrate all three structures of subjective uncertain preference information provided by the decision makers and the objective information depicted in the decision matrix. Furthermore, we propose a simple and straightforward approach in ranking and selecting the given alternatives. It is worth pointing out that the developed models can also be used to deal with the situations where the three distinct uncertain preference structures are reduced to the traditional ones, i.e., utility values, fuzzy preference relations, and multiplicative preference relations. Finally, we use a practical example to illustrate in detail the calculation process of the developed approach.

  14. An artificial bee colony algorithm for uncertain portfolio selection.

    Science.gov (United States)

    Chen, Wei

    2014-01-01

    Portfolio selection is an important issue for researchers and practitioners. In this paper, under the assumption that security returns are given by experts' evaluations rather than historical data, we discuss the portfolio adjusting problem which takes transaction costs and diversification degree of portfolio into consideration. Uncertain variables are employed to describe the security returns. In the proposed mean-variance-entropy model, the uncertain mean value of the return is used to measure investment return, the uncertain variance of the return is used to measure investment risk, and the entropy is used to measure diversification degree of portfolio. In order to solve the proposed model, a modified artificial bee colony (ABC) algorithm is designed. Finally, a numerical example is given to illustrate the modelling idea and the effectiveness of the proposed algorithm.

  15. Uncertain multi-attribute decision making methods and applications

    CERN Document Server

    Xu, Zeshui

    2015-01-01

    This book introduces methods for uncertain multi-attribute decision making including uncertain multi-attribute group decision making and their applications to supply chain management, investment decision making, personnel assessment, redesigning products, maintenance services, military system efficiency evaluation. Multi-attribute decision making, also known as multi-objective decision making with finite alternatives, is an important component of modern decision science. The theory and methods of multi-attribute decision making have been extensively applied in engineering, economics, management and military contexts, such as venture capital project evaluation, facility location, bidding, development ranking of industrial sectors and so on. Over the last few decades, great attention has been paid to research on multi-attribute decision making in uncertain settings, due to the increasing complexity and uncertainty of supposedly objective aspects and the fuzziness of human thought. This book can be used as a ref...

  16. Nonlinear robust hierarchical control for nonlinear uncertain systems

    Directory of Open Access Journals (Sweden)

    Leonessa Alexander

    1999-01-01

    Full Text Available A nonlinear robust control-system design framework predicated on a hierarchical switching controller architecture parameterized over a set of moving nominal system equilibria is developed. Specifically, using equilibria-dependent Lyapunov functions, a hierarchical nonlinear robust control strategy is developed that robustly stabilizes a given nonlinear system over a prescribed range of system uncertainty by robustly stabilizing a collection of nonlinear controlled uncertain subsystems. The robust switching nonlinear controller architecture is designed based on a generalized (lower semicontinuous Lyapunov function obtained by minimizing a potential function over a given switching set induced by the parameterized nominal system equilibria. The proposed framework robustly stabilizes a compact positively invariant set of a given nonlinear uncertain dynamical system with structured parametric uncertainty. Finally, the efficacy of the proposed approach is demonstrated on a jet engine propulsion control problem with uncertain pressure-flow map data.

  17. Polymorphic Uncertain Linear Programming for Generalized Production Planning Problems

    Directory of Open Access Journals (Sweden)

    Xinbo Zhang

    2014-01-01

    Full Text Available A polymorphic uncertain linear programming (PULP model is constructed to formulate a class of generalized production planning problems. In accordance with the practical environment, some factors such as the consumption of raw material, the limitation of resource and the demand of product are incorporated into the model as parameters of interval and fuzzy subsets, respectively. Based on the theory of fuzzy interval program and the modified possibility degree for the order of interval numbers, a deterministic equivalent formulation for this model is derived such that a robust solution for the uncertain optimization problem is obtained. Case study indicates that the constructed model and the proposed solution are useful to search for an optimal production plan for the polymorphic uncertain generalized production planning problems.

  18. Rigid multibody system dynamics with uncertain rigid bodies

    Energy Technology Data Exchange (ETDEWEB)

    Batou, A., E-mail: anas.batou@univ-paris-est.fr; Soize, C., E-mail: christian.soize@univ-paris-est.fr [Universite Paris-Est, Laboratoire Modelisation et Simulation Multi Echelle, MSME UMR 8208 CNRS (France)

    2012-03-15

    This paper is devoted to the construction of a probabilistic model of uncertain rigid bodies for multibody system dynamics. We first construct a stochastic model of an uncertain rigid body by replacing the mass, the center of mass, and the tensor of inertia by random variables. The prior probability distributions of the stochastic model are constructed using the maximum entropy principle under the constraints defined by the available information. The generators of independent realizations corresponding to the prior probability distribution of these random quantities are further developed. Then several uncertain rigid bodies can be linked to each other in order to calculate the random response of a multibody dynamical system. An application is proposed to illustrate the theoretical development.

  19. Passivity analysis and synthesis for uncertain time-delay systems

    Directory of Open Access Journals (Sweden)

    Magdi S. Mahmoud

    2001-01-01

    Full Text Available In this paper, we investigate the robust passivity analysis and synthesis problems for a class of uncertain time-delay systems. This class of systems arises in the modelling effort of studying water quality constituents in fresh stream. For the analysis problem, we derive a sufficient condition for which the uncertain time-delay system is robustly stable and strictly passive for all admissible uncertainties. The condition is given in terms of a linear matrix inequality. Both the delay-independent and delay-dependent cases are considered. For the synthesis problem, we propose an observer-based design method which guarantees that the closed-loop uncertain time-delay system is stable and strictly passive for all admissible uncertainties. Several examples are worked out to illustrate the developed theory.

  20. Robust tracking control of uncertain Duffing-Holmes control systems

    International Nuclear Information System (INIS)

    Sun, Y.-J.

    2009-01-01

    In this paper, the notion of virtual stabilizability for dynamical systems is introduced and the virtual stabilizability of uncertain Duffing-Holmes control systems is investigated. Based on the time-domain approach with differential inequality, a tracking control is proposed such that the states of uncertain Duffing-Holmes control system track the desired trajectories with any pre-specified exponential decay rate and convergence radius. Moreover, we present an algorithm to find such a tracking control. Finally, a numerical example is provided to illustrate the use of the main results.

  1. Uncertain Portfolio Selection with Background Risk and Liquidity Constraint

    Directory of Open Access Journals (Sweden)

    Jia Zhai

    2017-01-01

    Full Text Available This paper discusses an uncertain portfolio selection problem with consideration of background risk and asset liquidity. In addition, the transaction costs are also considered. The security returns, background asset return, and asset liquidity are estimated by experienced experts instead of historical data. Regarding them as uncertain variables, a mean-risk model with background risk, liquidity, and transaction costs is proposed for portfolio selection and the crisp forms of the model are provided when security returns obey different uncertainty distributions. Moreover, for better understanding of the impact of background risk and liquidity on portfolio selection, some important theorems are proved. Finally, numerical experiments are presented to illustrate the modeling idea.

  2. Robust Stabilization of Nonlinear Systems with Uncertain Varying Control Coefficient

    Directory of Open Access Journals (Sweden)

    Zaiyue Yang

    2014-01-01

    Full Text Available This paper investigates the stabilization problem for a class of nonlinear systems, whose control coefficient is uncertain and varies continuously in value and sign. The study emphasizes the development of a robust control that consists of a modified Nussbaum function to tackle the uncertain varying control coefficient. By such a method, the finite-time escape phenomenon has been prevented when the control coefficient is crossing zero and varying its sign. The proposed control guarantees the asymptotic stabilization of the system and boundedness of all closed-loop signals. The control performance is illustrated by a numerical simulation.

  3. Synchronization of uncertain chaotic systems using a single transmission channel

    International Nuclear Information System (INIS)

    Feng Yong; Yu Xinghuo; Sun Lixia

    2008-01-01

    This paper proposes a robust sliding mode observer for synchronization of uncertain chaotic systems with multi-nonlinearities. A new control strategy is proposed for the construction of the robust sliding mode observer, which can avoid the strict conditions in the design process of Walcott-Zak observer. A new method of multi-dimensional signal transmission via single transmission channel is proposed and applied to chaos synchronization of uncertain chaotic systems with multi-nonlinearities. The simulation results are presented to validate the method

  4. Gauging Metallicity of Diffuse Gas under an Uncertain Ionizing Radiation Field

    Science.gov (United States)

    Chen, Hsiao-Wen; Johnson, Sean D.; Zahedy, Fakhri S.; Rauch, Michael; Mulchaey, John S.

    2017-06-01

    Gas metallicity is a key quantity used to determine the physical conditions of gaseous clouds in a wide range of astronomical environments, including interstellar and intergalactic space. In particular, considerable effort in circumgalactic medium (CGM) studies focuses on metallicity measurements because gas metallicity serves as a critical discriminator for whether the observed heavy ions in the CGM originate in chemically enriched outflows or in more chemically pristine gas accreted from the intergalactic medium. However, because the gas is ionized, a necessary first step in determining CGM metallicity is to constrain the ionization state of the gas which, in addition to gas density, depends on the ultraviolet background radiation field (UVB). While it is generally acknowledged that both the intensity and spectral slope of the UVB are uncertain, the impact of an uncertain spectral slope has not been properly addressed in the literature. This Letter shows that adopting a different spectral slope can result in an order of magnitude difference in the inferred CGM metallicity. Specifically, a harder UVB spectrum leads to a higher estimated gas metallicity for a given set of observed ionic column densities. Therefore, such systematic uncertainties must be folded into the error budget for metallicity estimates of ionized gas. An initial study shows that empirical diagnostics are available for discriminating between hard and soft ionizing spectra. Applying these diagnostics helps reduce the systematic uncertainties in CGM metallicity estimates.

  5. Gauging Metallicity of Diffuse Gas under an Uncertain Ionizing Radiation Field

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hsiao-Wen; Zahedy, Fakhri S. [Department of Astronomy and Astrophysics, The University of Chicago, 5640 S Ellis Avenue, Chicago, IL 60637 (United States); Johnson, Sean D. [Department of Astrophysics, Princeton University, Princeton, NJ (United States); Rauch, Michael; Mulchaey, John S., E-mail: hchen@oddjob.uchicago.edu [The Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)

    2017-06-20

    Gas metallicity is a key quantity used to determine the physical conditions of gaseous clouds in a wide range of astronomical environments, including interstellar and intergalactic space. In particular, considerable effort in circumgalactic medium (CGM) studies focuses on metallicity measurements because gas metallicity serves as a critical discriminator for whether the observed heavy ions in the CGM originate in chemically enriched outflows or in more chemically pristine gas accreted from the intergalactic medium. However, because the gas is ionized, a necessary first step in determining CGM metallicity is to constrain the ionization state of the gas which, in addition to gas density, depends on the ultraviolet background radiation field (UVB). While it is generally acknowledged that both the intensity and spectral slope of the UVB are uncertain, the impact of an uncertain spectral slope has not been properly addressed in the literature. This Letter shows that adopting a different spectral slope can result in an order of magnitude difference in the inferred CGM metallicity. Specifically, a harder UVB spectrum leads to a higher estimated gas metallicity for a given set of observed ionic column densities. Therefore, such systematic uncertainties must be folded into the error budget for metallicity estimates of ionized gas. An initial study shows that empirical diagnostics are available for discriminating between hard and soft ionizing spectra. Applying these diagnostics helps reduce the systematic uncertainties in CGM metallicity estimates.

  6. The Exempt Market in Canada: Empirics, Observations and Recommendations

    Directory of Open Access Journals (Sweden)

    Vijay Jog

    2015-03-01

    Full Text Available There is a massive and vital capital market at work in Canada — possibly bigger than rough estimates have so far suggested — and it is one for which several market regulators are preparing new rules. Yet the remarkable thing is how little we know about it. Data about the so-called exempt market are so lacking that were regulators in Ontario and the other provinces contemplating new exempt-market regulations to proceed, they would be creating policies based on anecdotal, incomplete and, potentially, incorrect evidence. Even estimating the size of the Canadian exempt market has been an inexact science, given the incomplete data, but we can estimate that it provides in excess of $100 billion in gross capital flow every year, and that amount continues to grow. While it may be natural to assume that the exempt market is used primarily by small and medium-sized enterprises, it seems it is primarily used by the financial services industry. These institutions appear to rely on the exempt market to raise potentially short-term debt capital relatively free of particularly burdensome information-disclosure requirements. Unfortunately, we are forced to rely here again on deductions based on limited evidence: So incomplete are the data about the exempt market that we lack even complete information on the type of issuers, investors and securities, or the volume and duration of the securities and the level of redemptions. The exempt market exists for important reasons: it is a way out of the regulatory conundrum, wherein the regulator’s mandate to protect investors, through significant requirements for information disclosure, can put too large a burden on certain issuers. That is why it is essential that any new regulations are developed using a thorough understanding of how it operates. Yet the reality is that it is impossible to evaluate how individual investors and small firms are using the exempt market, or their experience in it. This is disconcerting, given that the very logic behind regulating this market is to allow the cost-effective and efficient matchmaking of sophisticated, higher-risk capital to firms unable to access capital through other means. If minimal or no data are available for analysis (as is currently the case, there is no way to tell whether this is in fact happening. This should be rectified before new regulations are imposed. Provincial jurisdictions and major market participants should co-operate to form an “exempt market data repository” to collect structured data, funded through a small fee, based on the size and type of issue. This repository should allow for segmentation by industry, size of issuer, and by whether it is a reporting issuer or not, and it should provide detail on the size of each issue, the types of security, the intended use of the capital, and the liquidity and duration of the security, as well as requiring notification of redemptions. Reporting the costs of intermediation should be mandatory and the accumulated data should indicate the type of investor (segmented by categories such as “accredited” or “eligible” as well as the investment size and type. Of course, none of this should become so costly as to render the exempt market prohibitive to the issuers who rely on it. Nor should it necessarily lead to more onerous regulations. Indeed, another important priority must be a broader debate over the very role of a securities regulator when it comes to regulating capital flows between investors and issuers. But at a very minimum, regulators should be able to make available to investors useful information about how a market operates. Unfortunately, when it comes to the exempt market, that responsibility is the very area where Canadian regulators have so far proved to be remiss.

  7. Quantifying uncertainty in Gulf of Mexico forecasts stemming from uncertain initial conditions

    KAUST Repository

    Iskandarani, Mohamed

    2016-06-09

    Polynomial Chaos (PC) methods are used to quantify the impacts of initial conditions uncertainties on oceanic forecasts of the Gulf of Mexico circulation. Empirical Orthogonal Functions are used as initial conditions perturbations with their modal amplitudes considered as uniformly distributed uncertain random variables. These perturbations impact primarily the Loop Current system and several frontal eddies located in its vicinity. A small ensemble is used to sample the space of the modal amplitudes and to construct a surrogate for the evolution of the model predictions via a nonintrusive Galerkin projection. The analysis of the surrogate yields verification measures for the surrogate\\'s reliability and statistical information for the model output. A variance analysis indicates that the sea surface height predictability in the vicinity of the Loop Current is limited to about 20 days. © 2016. American Geophysical Union. All Rights Reserved.

  8. Invariant set computation for constrained uncertain discrete-time systems

    NARCIS (Netherlands)

    Athanasopoulos, N.; Bitsoris, G.

    2010-01-01

    In this article a novel approach to the determination of polytopic invariant sets for constrained discrete-time linear uncertain systems is presented. First, the problem of stabilizing a prespecified initial condition set in the presence of input and state constraints is addressed. Second, the

  9. Adaptive synchronization of a new hyperchaotic system with uncertain parameters

    International Nuclear Information System (INIS)

    Gao Tiegang; Chen Zengqiang; Yuan Zhuzhi; Yu Dongchuan

    2007-01-01

    This paper discusses control for the master-slave synchronization of a new hyperchaos with five uncertain parameters. An adaptive control law is derived to make the states of two identical hyperchaotic systems asymptotically synchronized based on the Lyapunov stability theory. Finally, a numerical simulation is presented to verify the effectiveness of the proposed synchronization scheme

  10. Distributed Robustness Analysis of Interconnected Uncertain Systems Using Chordal Decomposition

    DEFF Research Database (Denmark)

    Pakazad, Sina Khoshfetrat; Hansson, Anders; Andersen, Martin Skovgaard

    2014-01-01

    Large-scale interconnected uncertain systems commonly have large state and uncertainty dimensions. Aside from the heavy computational cost of performing robust stability analysis in a centralized manner, privacy requirements in the network can also introduce further issues. In this paper, we util...

  11. Synchronization transmission of laser pattern signal within uncertain switched network

    Science.gov (United States)

    Lü, Ling; Li, Chengren; Li, Gang; Sun, Ao; Yan, Zhe; Rong, Tingting; Gao, Yan

    2017-06-01

    We propose a new technology for synchronization transmission of laser pattern signal within uncertain network with controllable topology. In synchronization process, the connection of dynamic network can vary at all time according to different demands. Especially, we construct the Lyapunov function of network through designing a special semi-positive definite function, and the synchronization transmission of laser pattern signal within uncertain network with controllable topology can be realized perfectly, which effectively avoids the complicated calculation for solving the second largest eignvalue of the coupling matrix of the dynamic network in order to obtain the network synchronization condition. At the same time, the uncertain parameters in dynamic equations belonging to network nodes can also be identified accurately via designing the identification laws of uncertain parameters. In addition, there are not any limitations for the synchronization target of network in the new technology, in other words, the target can either be a state variable signal of an arbitrary node within the network or an exterior signal.

  12. Adaptive synchronization of Rossler system with uncertain parameters

    International Nuclear Information System (INIS)

    Park, Ju H.

    2005-01-01

    This article addresses control for the chaos synchronization of Rossler systems with three uncertain parameters. Based on the Lyapunov stability theory, an adaptive control law is derived to make the states of two identical Rossler systems asymptotically synchronized. A numerical simulations is presented to show the effectiveness of the proposed chaos synchronization scheme

  13. Magnetic resonance imaging features of extremity sarcomas of uncertain differentiation

    International Nuclear Information System (INIS)

    Stacy, G.S.; Nair, L.

    2007-01-01

    The purpose of this review is to illustrate the pertinent clinical and imaging features of extremity sarcomas of uncertain differentiation, including synovial sarcoma, epithelioid sarcoma, clear-cell sarcoma, and alveolar soft part sarcoma. These tumours should be considered in the differential diagnosis when a soft-tissue mass is encountered in the extremity of an adolescent or young adult

  14. When, not if: the inescapability of an uncertain climate future.

    Science.gov (United States)

    Ballard, Timothy; Lewandowsky, Stephan

    2015-11-28

    Climate change projections necessarily involve uncertainty. Analysis of the physics and mathematics of the climate system reveals that greater uncertainty about future temperature increases is nearly always associated with greater expected damages from climate change. In contrast to those normative constraints, uncertainty is frequently cited in public discourse as a reason to delay mitigative action. This failure to understand the actual implications of uncertainty may incur notable future costs. It is therefore important to communicate uncertainty in a way that improves people's understanding of climate change risks. We examined whether responses to projections were influenced by whether the projection emphasized uncertainty in the outcome or in its time of arrival. We presented participants with statements and graphs indicating projected increases in temperature, sea levels, ocean acidification and a decrease in arctic sea ice. In the uncertain-outcome condition, statements reported the upper and lower confidence bounds of the projected outcome at a fixed time point. In the uncertain time-of-arrival condition, statements reported the upper and lower confidence bounds of the projected time of arrival for a fixed outcome. Results suggested that people perceived the threat as more serious and were more likely to encourage mitigative action in the time-uncertain condition than in the outcome-uncertain condition. This finding has implications for effectively communicating the climate change risks to policy-makers and the general public. © 2015 The Author(s).

  15. Uncertain input data problems and the worst scenario method

    Czech Academy of Sciences Publication Activity Database

    Hlaváček, Ivan

    2007-01-01

    Roč. 52, č. 3 (2007), s. 187-196 ISSN 0862-7940 R&D Projects: GA ČR GA201/04/1503 Institutional research plan: CEZ:AV0Z10190503 Keywords : uncertain input data * the worst-case approach * fuzzy sets Subject RIV: BA - General Mathematics

  16. Adaptive synchronization of hyperchaotic Chen system with uncertain parameters

    International Nuclear Information System (INIS)

    Park, Ju H.

    2005-01-01

    This article addresses control for the chaos synchronization of hyperchaotic Chen system with five uncertain parameters. Based on the Lyapunov stability theory, an adaptive control law is derived to make the states of two identical hyperchaotic Chen systems asymptotically synchronized. Finally, a numerical simulations is presented to show the effectiveness of the proposed chaos synchronization scheme

  17. Processing Uncertain RFID Data in Traceability Supply Chains

    Directory of Open Access Journals (Sweden)

    Dong Xie

    2014-01-01

    Full Text Available Radio Frequency Identification (RFID is widely used to track and trace objects in traceability supply chains. However, massive uncertain data produced by RFID readers are not effective and efficient to be used in RFID application systems. Following the analysis of key features of RFID objects, this paper proposes a new framework for effectively and efficiently processing uncertain RFID data, and supporting a variety of queries for tracking and tracing RFID objects. We adjust different smoothing windows according to different rates of uncertain data, employ different strategies to process uncertain readings, and distinguish ghost, missing, and incomplete data according to their apparent positions. We propose a comprehensive data model which is suitable for different application scenarios. In addition, a path coding scheme is proposed to significantly compress massive data by aggregating the path sequence, the position, and the time intervals. The scheme is suitable for cyclic or long paths. Moreover, we further propose a processing algorithm for group and independent objects. Experimental evaluations show that our approach is effective and efficient in terms of the compression and traceability queries.

  18. Processing uncertain RFID data in traceability supply chains.

    Science.gov (United States)

    Xie, Dong; Xiao, Jie; Guo, Guangjun; Jiang, Tong

    2014-01-01

    Radio Frequency Identification (RFID) is widely used to track and trace objects in traceability supply chains. However, massive uncertain data produced by RFID readers are not effective and efficient to be used in RFID application systems. Following the analysis of key features of RFID objects, this paper proposes a new framework for effectively and efficiently processing uncertain RFID data, and supporting a variety of queries for tracking and tracing RFID objects. We adjust different smoothing windows according to different rates of uncertain data, employ different strategies to process uncertain readings, and distinguish ghost, missing, and incomplete data according to their apparent positions. We propose a comprehensive data model which is suitable for different application scenarios. In addition, a path coding scheme is proposed to significantly compress massive data by aggregating the path sequence, the position, and the time intervals. The scheme is suitable for cyclic or long paths. Moreover, we further propose a processing algorithm for group and independent objects. Experimental evaluations show that our approach is effective and efficient in terms of the compression and traceability queries.

  19. Fault tolerant control for uncertain systems with parametric faults

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2006-01-01

    A fault tolerant control (FTC) architecture based on active fault diagnosis (AFD) and the YJBK (Youla, Jarb, Bongiorno and Kucera)parameterization is applied in this paper. Based on the FTC architecture, fault tolerant control of uncertain systems with slowly varying parametric faults...... is investigated. Conditions are given for closed-loop stability in case of false alarms or missing fault detection/isolation....

  20. Judgments under competition and uncertainty : empirical evidence from online poker

    OpenAIRE

    Engelbergs, Jörg

    2010-01-01

    Playing poker has many aspects in common with the making of business decisions. Agents act in a strategically rich, dynamic environment, where they are repeatedly facing competition under uncertain prospects. Their main goal is to maximize their resources. However simple this goal is put down, it is difficult to fulfill. As vast and rich research has shown, heuristics and biases affect human decision-making. This work adds to these findings by providing empirical evidence for behavioral patte...

  1. Multiple point statistical simulation using uncertain (soft) conditional data

    Science.gov (United States)

    Hansen, Thomas Mejer; Vu, Le Thanh; Mosegaard, Klaus; Cordua, Knud Skou

    2018-05-01

    Geostatistical simulation methods have been used to quantify spatial variability of reservoir models since the 80s. In the last two decades, state of the art simulation methods have changed from being based on covariance-based 2-point statistics to multiple-point statistics (MPS), that allow simulation of more realistic Earth-structures. In addition, increasing amounts of geo-information (geophysical, geological, etc.) from multiple sources are being collected. This pose the problem of integration of these different sources of information, such that decisions related to reservoir models can be taken on an as informed base as possible. In principle, though difficult in practice, this can be achieved using computationally expensive Monte Carlo methods. Here we investigate the use of sequential simulation based MPS simulation methods conditional to uncertain (soft) data, as a computational efficient alternative. First, it is demonstrated that current implementations of sequential simulation based on MPS (e.g. SNESIM, ENESIM and Direct Sampling) do not account properly for uncertain conditional information, due to a combination of using only co-located information, and a random simulation path. Then, we suggest two approaches that better account for the available uncertain information. The first make use of a preferential simulation path, where more informed model parameters are visited preferentially to less informed ones. The second approach involves using non co-located uncertain information. For different types of available data, these approaches are demonstrated to produce simulation results similar to those obtained by the general Monte Carlo based approach. These methods allow MPS simulation to condition properly to uncertain (soft) data, and hence provides a computationally attractive approach for integration of information about a reservoir model.

  2. Empirical Test Case Specification

    DEFF Research Database (Denmark)

    Kalyanova, Olena; Heiselberg, Per

    This document includes the empirical specification on the IEA task of evaluation building energy simulation computer programs for the Double Skin Facades (DSF) constructions. There are two approaches involved into this procedure, one is the comparative approach and another is the empirical one. I....... In the comparative approach the outcomes of different software tools are compared, while in the empirical approach the modelling results are compared with the results of experimental test cases....

  3. How Uncertain Information on Service Capacity Influences the Intermodal Routing Decision: A Fuzzy Programming Perspective

    Directory of Open Access Journals (Sweden)

    Yan Sun

    2018-01-01

    Full Text Available Capacity uncertainty is a common issue in the transportation planning field. However, few studies discuss the intermodal routing problem with service capacity uncertainty. Based on our previous study on the intermodal routing under deterministic capacity consideration, we systematically explore how service capacity uncertainty influences the intermodal routing decision. First of all, we adopt trapezoidal fuzzy numbers to describe the uncertain information of the service capacity, and further transform the deterministic capacity constraint into a fuzzy chance constraint based on fuzzy credibility measure. We then integrate such fuzzy chance constraint into the mixed-integer linear programming (MILP model proposed in our previous study to develop a fuzzy chance-constrained programming model. To enable the improved model to be effectively programmed in the standard mathematical programming software and solved by exact solution algorithms, a crisp equivalent linear reformulation of the fuzzy chance constraint is generated. Finally, we modify the empirical case presented in our previous study by replacing the deterministic service capacities with trapezoidal fuzzy ones. Using the modified empirical case, we utilize sensitivity analysis and fuzzy simulation to analyze the influence of service capacity uncertainty on the intermodal routing decision, and summarize some interesting insights that are helpful for decision makers.

  4. Energy trading and pricing in microgrids with uncertain energy supply

    DEFF Research Database (Denmark)

    Ma, Kai; Hu, Shubing; Yang, Jie

    2017-01-01

    This paper studies an energy trading and pricing problem for microgrids with uncertain energy supply. The energy provider with the renewable energy (RE) generation (wind power) determines the energy purchase from the electricity markets and the pricing strategy for consumers to maximize its profi....... In particular, the uncertainty of the energy supply from the energy provider is considered. Simulation results show that the energy provider can obtain more profit using the proposed decision-making scheme.......This paper studies an energy trading and pricing problem for microgrids with uncertain energy supply. The energy provider with the renewable energy (RE) generation (wind power) determines the energy purchase from the electricity markets and the pricing strategy for consumers to maximize its profit...

  5. Robust Optimization for Household Load Scheduling with Uncertain Parameters

    Directory of Open Access Journals (Sweden)

    Jidong Wang

    2018-04-01

    Full Text Available Home energy management systems (HEMS face many challenges of uncertainty, which have a great impact on the scheduling of home appliances. To handle the uncertain parameters in the household load scheduling problem, this paper uses a robust optimization method to rebuild the household load scheduling model for home energy management. The model proposed in this paper can provide the complete robust schedules for customers while considering the disturbance of uncertain parameters. The complete robust schedules can not only guarantee the customers’ comfort constraints but also cooperatively schedule the electric devices for cost minimization and load shifting. Moreover, it is available for customers to obtain multiple schedules through setting different robust levels while considering the trade-off between the comfort and economy.

  6. Robust output synchronization of heterogeneous nonlinear agents in uncertain networks.

    Science.gov (United States)

    Yang, Xi; Wan, Fuhua; Tu, Mengchuan; Shen, Guojiang

    2017-11-01

    This paper investigates the global robust output synchronization problem for a class of nonlinear multi-agent systems. In the considered setup, the controlled agents are heterogeneous and with both dynamic and parametric uncertainties, the controllers are incapable of exchanging their internal states with the neighbors, and the communication network among agents is defined by an uncertain simple digraph. The problem is pursued via nonlinear output regulation theory and internal model based design. For each agent, the input-driven filter and the internal model compose the controller, and the decentralized dynamic output feedback control law is derived by using backstepping method and the modified dynamic high-gain technique. The theoretical result is applied to output synchronization problem for uncertain network of Lorenz-type agents. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  7. Uncertain R and D, backstop technology and GHGs stabilization

    International Nuclear Information System (INIS)

    Bosetti, Valentina; Tavoni, Massimo

    2009-01-01

    This paper analyses optimal investments in innovation when dealing with a stringent climate target and with the uncertain effectiveness of R and D. The innovation needed to achieve the deep cut in emissions is modeled by a backstop carbon-free technology whose cost depends on R and D investments. To better represent the process of technological progress, we assume that R and D effectiveness is uncertain. By means of a simple analytical model, we show how accounting for the uncertainty that characterizes technological advancement yields higher investments in innovation and lower policy costs. We then confirm the results via a numerical analysis performed with a stochastic version of WITCH, an energy-economy-climate model. The results stress the importance of a correct specification of the technological change process in economy-climate models. (author)

  8. Synchronization and parameter estimations of an uncertain Rikitake system

    International Nuclear Information System (INIS)

    Aguilar-Ibanez, Carlos; Martinez-Guerra, Rafael; Aguilar-Lopez, Ricardo; Mata-Machuca, Juan L.

    2010-01-01

    In this Letter we address the synchronization and parameter estimation of the uncertain Rikitake system, under the assumption the state is partially known. To this end we use the master/slave scheme in conjunction with the adaptive control technique. Our control approach consists of proposing a slave system which has to follow asymptotically the uncertain Rikitake system, refereed as the master system. The gains of the slave system are adjusted continually according to a convenient adaptation control law, until the measurable output errors converge to zero. The convergence analysis is carried out by using the Barbalat's Lemma. Under this context, uncertainty means that although the system structure is known, only a partial knowledge of the corresponding parameter values is available.

  9. Multiobjective Location Routing Problem considering Uncertain Data after Disasters

    Directory of Open Access Journals (Sweden)

    Keliang Chang

    2017-01-01

    Full Text Available The relief distributions after large disasters play an important role for rescue works. After disasters there is a high degree of uncertainty, such as the demands of disaster points and the damage of paths. The demands of affected points and the velocities between two points on the paths are uncertain in this article, and the robust optimization method is applied to deal with the uncertain parameters. This paper proposes a nonlinear location routing problem with half-time windows and with three objectives. The affected points can be visited more than one time. The goals are the total costs of the transportation, the satisfaction rates of disaster nodes, and the path transport capacities which are denoted by vehicle velocities. Finally, the genetic algorithm is applied to solve a number of numerical examples, and the results show that the genetic algorithm is very stable and effective for this problem.

  10. Valuation of American Call Option Considering Uncertain Volatility

    Czech Academy of Sciences Publication Activity Database

    Hlaváček, Ivan

    2010-01-01

    Roč. 2, č. 2 (2010), s. 211-221 ISSN 2070-0733 R&D Projects: GA AV ČR(CZ) IAA100190803 Institutional research plan: CEZ:AV0Z10190503 Keywords : American options * parabolic variational inequality * uncertain parameter Subject RIV: BA - General Mathematics Impact factor: 0.510, year: 2010 http://www.global-sci.org/aamm/readabs.php?vol=2&no=2&doc=211&year=2010&ppage=221

  11. ON A NUMERICAL ALGORITHM FOR UNCERTAIN SYSTEM ∫ Φ ...

    African Journals Online (AJOL)

    Administrator

    Science World Journal Vol 7 (No 1) 2012 www.scienceworldjournal.org. ISSN 1597-6343. On a Numerical Algorithm for Uncertain System. Newton's Algorithm. Step 1 Calculate. )(),().(k k k. xAxgxF. Step 2. Check if ε. <. )(k xg for a predetermined ,ε if so stop, else. Step3. Set k k. PxA. )( = )(k xg. -. Step4. Set k k k. Px x. +. = +1.

  12. Uncertain CERN cash means UK physicists face grant freeze.

    CERN Document Server

    1996-01-01

    Britain's funding agency Particle Physics and Astronomy Research Council is uncertain about its ability to cover membership costs to the European Laboratory for Particle Physics (CERN). This has resulted in suspension of research grants to university physicists and astronomers. Funding will be available only for genuine hardship, and for major national and international astronomical projects that have already been sanctioned. The new four-year rolling grants to university-based particle physics group is withheld.

  13. Technology Proliferation: Acquisition Strategies and Opportunities for an Uncertain Future

    Science.gov (United States)

    2018-04-20

    COVERED (From - To) 07/31/17 to 04/09/18 Technology Proliferation: Acquisition Strategies and Opportunities for an Uncertain Future Colonel Heather A...efficient and expeditious fielding of technologically superior capabilities. In today’s environment, it is commonplace for private industry to be the...first to develop and deploy technologies that can be adopted for defense systems. The result is that the Department of Defense (DoD) is largely a

  14. Density Estimation in Several Populations With Uncertain Population Membership

    KAUST Repository

    Ma, Yanyuan

    2011-09-01

    We devise methods to estimate probability density functions of several populations using observations with uncertain population membership, meaning from which population an observation comes is unknown. The probability of an observation being sampled from any given population can be calculated. We develop general estimation procedures and bandwidth selection methods for our setting. We establish large-sample properties and study finite-sample performance using simulation studies. We illustrate our methods with data from a nutrition study.

  15. Path Integration Applied to Structural Systems with Uncertain Properties

    DEFF Research Database (Denmark)

    Nielsen, Søren R.K.; Köylüoglu, H. Ugur

    Path integration (cell-to-cell mapping) method is applied to evaluate the joint probability density function (jpdf) of the response of the structural systems, with uncertain properties, subject to white noise excitation. A general methodology to deal with uncertainties is outlined and applied...... to the friction controlled slip of a structure on a foundation where the friction coefficient is modelled as a random variable. Exact results derived using the total probability theorem are compared to the ones obtained via path integration....

  16. Flexible Procurement of Services with Uncertain Durations using Redundancy

    OpenAIRE

    Stein, S; Gerding, E; Rogers, A; Larson, K; Jennings, NR

    2009-01-01

    Emerging service-oriented technologies allow software agents to automatically procure distributed services to complete complex tasks. However, in many application scenarios, service providers demand financial remuneration, execution times are uncertain and consumers have deadlines for their tasks. In this paper, we address these issues by developing a novel approach that dynamically procures multiple, redundant services over time, in order to ensure success by the deadline. Specifically, we f...

  17. Overcoming Learning Aversion in Evaluating and Managing Uncertain Risks.

    Science.gov (United States)

    Cox, Louis Anthony Tony

    2015-10-01

    Decision biases can distort cost-benefit evaluations of uncertain risks, leading to risk management policy decisions with predictably high retrospective regret. We argue that well-documented decision biases encourage learning aversion, or predictably suboptimal learning and premature decision making in the face of high uncertainty about the costs, risks, and benefits of proposed changes. Biases such as narrow framing, overconfidence, confirmation bias, optimism bias, ambiguity aversion, and hyperbolic discounting of the immediate costs and delayed benefits of learning, contribute to deficient individual and group learning, avoidance of information seeking, underestimation of the value of further information, and hence needlessly inaccurate risk-cost-benefit estimates and suboptimal risk management decisions. In practice, such biases can create predictable regret in selection of potential risk-reducing regulations. Low-regret learning strategies based on computational reinforcement learning models can potentially overcome some of these suboptimal decision processes by replacing aversion to uncertain probabilities with actions calculated to balance exploration (deliberate experimentation and uncertainty reduction) and exploitation (taking actions to maximize the sum of expected immediate reward, expected discounted future reward, and value of information). We discuss the proposed framework for understanding and overcoming learning aversion and for implementing low-regret learning strategies using regulation of air pollutants with uncertain health effects as an example. © 2015 Society for Risk Analysis.

  18. Path planning in uncertain flow fields using ensemble method

    KAUST Repository

    Wang, Tong

    2016-08-20

    An ensemble-based approach is developed to conduct optimal path planning in unsteady ocean currents under uncertainty. We focus our attention on two-dimensional steady and unsteady uncertain flows, and adopt a sampling methodology that is well suited to operational forecasts, where an ensemble of deterministic predictions is used to model and quantify uncertainty. In an operational setting, much about dynamics, topography, and forcing of the ocean environment is uncertain. To address this uncertainty, the flow field is parametrized using a finite number of independent canonical random variables with known densities, and the ensemble is generated by sampling these variables. For each of the resulting realizations of the uncertain current field, we predict the path that minimizes the travel time by solving a boundary value problem (BVP), based on the Pontryagin maximum principle. A family of backward-in-time trajectories starting at the end position is used to generate suitable initial values for the BVP solver. This allows us to examine and analyze the performance of the sampling strategy and to develop insight into extensions dealing with general circulation ocean models. In particular, the ensemble method enables us to perform a statistical analysis of travel times and consequently develop a path planning approach that accounts for these statistics. The proposed methodology is tested for a number of scenarios. We first validate our algorithms by reproducing simple canonical solutions, and then demonstrate our approach in more complex flow fields, including idealized, steady and unsteady double-gyre flows.

  19. Representation and management of temporal and uncertain knowledge

    International Nuclear Information System (INIS)

    Chen, Ziqiang

    1993-01-01

    This thesis contributes to the investigation of uncertain temporal knowledge representation and management, especially for process verification and supervisor systems design. The evolution of process behaviour is time dependent and information describing this temporal evolution is uncertain/imprecise. In Artificial Intelligence, time and uncertainty have been, since long-time, considered as two of the most difficult research fields. Furthermore, these two fields, even different, may be present in an interactive way. We now try to deal with this special kind of uncertainty: temporal uncertainty. Integrating time and uncertainty brings out study issues of temporal information representation, events ordering and temporal reasoning under uncertainty. The investigation of these problems has been guided by preserving the intrinsic properties of time. The main contribution of this thesis can be summarised as follows: (1) unified representation of uncertainty and imprecision over temporal information; (2) formal structuring of time under uncertainty; (3) formalising fuzzy temporal reasoning system; (4) modelling temporal evolution of process, providing associated reasoning mechanism to verify the process evolution, modelling fuzzy temporal Petri nets; (5) design and implementation of SURTEL, a programming tool for dealing with uncertain temporal information and knowledge. (author) [fr

  20. Airline Overbooking Problem with Uncertain No-Shows

    Directory of Open Access Journals (Sweden)

    Chunxiao Zhang

    2014-01-01

    Full Text Available This paper considers an airline overbooking problem of a new single-leg flight with discount fare. Due to the absence of historical data of no-shows for a new flight, and various uncertain human behaviors or unexpected events which causes that a few passengers cannot board their aircraft on time, we fail to obtain the probability distribution of no-shows. In this case, the airlines have to invite some domain experts to provide belief degree of no-shows to estimate its distribution. However, human beings often overestimate unlikely events, which makes the variance of belief degree much greater than that of the frequency. If we still regard the belief degree as a subjective probability, the derived results will exceed our expectations. In order to deal with this uncertainty, the number of no-shows of new flight is assumed to be an uncertain variable in this paper. Given the chance constraint of social reputation, an overbooking model with discount fares is developed to maximize the profit rate based on uncertain programming theory. Finally, the analytic expression of the optimal booking limit is obtained through a numerical example, and the results of sensitivity analysis indicate that the optimal booking limit is affected by flight capacity, discount, confidence level, and parameters of the uncertainty distribution significantly.

  1. Empirical Philosophy of Science

    DEFF Research Database (Denmark)

    Mansnerus, Erika; Wagenknecht, Susann

    2015-01-01

    knowledge takes place through the integration of the empirical or historical research into the philosophical studies, as Chang, Nersessian, Thagard and Schickore argue in their work. Building upon their contributions we will develop a blueprint for an Empirical Philosophy of Science that draws upon...... qualitative methods from the social sciences in order to advance our philosophical understanding of science in practice. We will regard the relationship between philosophical conceptualization and empirical data as an iterative dialogue between theory and data, which is guided by a particular ‘feeling with......Empirical insights are proven fruitful for the advancement of Philosophy of Science, but the integration of philosophical concepts and empirical data poses considerable methodological challenges. Debates in Integrated History and Philosophy of Science suggest that the advancement of philosophical...

  2. Minimizing the regrets of long-term urban floodplain management decisions under deeply uncertain climate change

    Science.gov (United States)

    Hecht, J. S.; Kirshen, P. H.; Vogel, R. M.

    2016-12-01

    Making long-term floodplain management decisions under uncertain climate change is a major urban planning challenge of the 21stcentury. To support these efforts, we introduce a screening-level optimization model that identifies adaptation portfolios by minimizing the regrets associated with their flood-control and damage costs under different climate change trajectories that are deeply uncertain, i.e. have probabilities that cannot be specified plausibly. This mixed integer program explicitly considers the coupled damage-reduction impacts of different floodwall designs and property-scale investments (first-floor elevation, wet floodproofing of basements, permanent retreat and insurance), recommends implementation schedules, and assesses impacts to stakeholders residing in three types of homes. An application to a stylized municipality illuminates many nonlinear system dynamics stemming from large fixed capital costs, infrastructure design thresholds, and discharge-depth-damage relationships. If stakeholders tolerate mild damage, floodwalls that fully protect a community from large design events are less cost-effective than portfolios featuring both smaller floodwalls and property-scale measures. Potential losses of property tax revenue from permanent retreat motivate municipal property-tax initiatives for adaptation financing. Yet, insurance incentives for first-floor elevation may discourage locally financed floodwalls, in turn making lower-income residents more vulnerable to severe flooding. A budget constraint analysis underscores the benefits of flexible floodwall designs with low incremental expansion costs while near-optimal solutions demonstrate the scheduling flexibility of many property-scale measures. Finally, an equity analysis shows the importance of evaluating the overpayment and under-design regrets of recommended adaptation portfolios for each stakeholder and contrasts them to single-scenario model results.

  3. First International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions).

    Science.gov (United States)

    Rageth, Christoph J; O'Flynn, Elizabeth Am; Comstock, Christopher; Kurtz, Claudia; Kubik, Rahel; Madjar, Helmut; Lepori, Domenico; Kampmann, Gert; Mundinger, Alexander; Baege, Astrid; Decker, Thomas; Hosch, Stefanie; Tausch, Christoph; Delaloye, Jean-François; Morris, Elisabeth; Varga, Zsuzsanna

    2016-09-01

    The purpose of this study is to obtain a consensus for the therapy of B3 lesions. The first International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions) including atypical ductal hyperplasia (ADH), flat epithelial atypia (FEA), classical lobular neoplasia (LN), papillary lesions (PL), benign phyllodes tumors (PT), and radial scars (RS) took place in January 2016 in Zurich, Switzerland organized by the International Breast Ultrasound School and the Swiss Minimally Invasive Breast Biopsy group-a subgroup of the Swiss Society of Senology. Consensus recommendations for the management and follow-up surveillance of these B3 lesions were developed and areas of research priorities were identified. The consensus recommendation for FEA, LN, PL, and RS diagnosed on core needle biopsy or vacuum-assisted biopsy (VAB) is to therapeutically excise the lesion seen on imaging by VAB and no longer by open surgery, with follow-up surveillance imaging for 5 years. The consensus recommendation for ADH and PT is, with some exceptions, therapeutic first-line open surgical excision. Minimally invasive management of selected B3 lesions with therapeutic VAB is acceptable as an alternative to first-line surgical excision.

  4. Natural history of severe eosinophilia with uncertain aetiology and proposals on a practical approach to its management.

    Science.gov (United States)

    Ang, A L; Wong, R X; Zhuang, Q Y; Linn, Y C

    2012-08-01

    Eosinophilia is commonly encountered during clinical practice. Some can be attributed to well-defined causes while others cannot. Optimal management of hypereosinophilia with unknown aetiology is uncertain as the natural history is not well described. We retrospectively studied patients with hypereosinophilia (>5 × 10(9)/L) and described the characteristics, natural history and treatment of those with eosinophilia of uncertain aetiology. There were 141 patients with hypereosinophilia: 87 with well-defined causes, 54 with uncertain aetiology. The latter was managed as hypereosinophilic syndrome (HES) (n = 5), idiopathic hypereosinophilia (IH) (n = 11), presumptive helminthic infection (n = 11) and reactive eosinophilia (n = 5), while 22 were insufficiently investigated and did not have definite working diagnoses. Their median age and peak eosinophil count were 64 (22 to 94) years and 10.0 (5.2-33.9) × 10(9)/L respectively. Forty-six per cent had symptoms attributable to eosinophilia, with the HES and insufficiently investigated groups having the highest (100%) and lowest (27%) percentages respectively. HES and IH patients were most extensively investigated. All 14 HES or IH patients who received steroids responded. All presumptive helminthic infection patients received mebendazole: nine responded, and two had unassessable responses. For the remaining patients, seven received steroids and all responded; one received mebendazole but defaulted; 19 were not treated: 11 resolved spontaneously. No non-HES patients developed eosinophilia-related organ dysfunction. No mortality was caused by hypereosinophilia. Patients with hypereosinophilia of uncertain aetiology can be empirically managed according to working diagnoses derived from history taking, examination and selective investigations. Most patients have benign short-term outcomes, but longer monitoring is required to assess long-term outcomes from untreated hypereosinophilia. © 2011 The Authors. Internal Medicine

  5. Life Writing After Empire

    DEFF Research Database (Denmark)

    A watershed moment of the twentieth century, the end of empire saw upheavals to global power structures and national identities. However, decolonisation profoundly affected individual subjectivities too. Life Writing After Empire examines how people around the globe have made sense of the post...... in order to understand how individual life writing reflects broader societal changes. From far-flung corners of the former British Empire, people have turned to life writing to manage painful or nostalgic memories, as well as to think about the past and future of the nation anew through the personal...

  6. Theological reflections on empire

    Directory of Open Access Journals (Sweden)

    Allan A. Boesak

    2009-11-01

    Full Text Available Since the meeting of the World Alliance of Reformed Churches in Accra, Ghana (2004, and the adoption of the Accra Declaration, a debate has been raging in the churches about globalisation, socio-economic justice, ecological responsibility, political and cultural domination and globalised war. Central to this debate is the concept of empire and the way the United States is increasingly becoming its embodiment. Is the United States a global empire? This article argues that the United States has indeed become the expression of a modern empire and that this reality has considerable consequences, not just for global economics and politics but for theological refl ection as well.

  7. The role of computed tomography in uncertain obstructive jaundice

    International Nuclear Information System (INIS)

    Saito, Yoshihiro; Yoshino, Toyoaki; Takayanagi, Ryuichi; Negishi, Ken; Tanaka, Teruhiko; Ito, Ichiro.

    1985-01-01

    42 patients with uncertain obstructive jaundice were examined by computed tomography (CT). CT correctly diagnosed obstructive jaundice in 97% of 37 proven cases and the accuracy of CT in determing the level of obstruction was also 97%. But the sensitivity of CT in determing the cause of obstructive jaundice was 62.5%, particularly poor in common bile duct stone (61.5%), inflammation of common bile duct (0%), and common bile duct carcinoma (50%). All cases of diagnosed malignant tumors were inoperable. (author)

  8. Green taxes and uncertain timing of technological change

    International Nuclear Information System (INIS)

    Aronsson, T.

    2001-01-01

    This paper concerns the role of environmental taxation in a model with endogenous technological change, where the latter implies that natural inputs become more productive. The timing of technological change is, in turn, uncertain and the likelihood of discovering the new technology is related to the amount of resources spent on R and D. The analysis is based on a dynamic general equilibrium model. One purpose of the paper is to design a policy so as to internalize the external effects arising from pollution and R and D. Another is to develop cost benefit rules for green tax reforms, when the initial equilibrium is suboptimal

  9. Exponential Synchronization of Uncertain Complex Dynamical Networks with Delay Coupling

    International Nuclear Information System (INIS)

    Wang Lifu; Kong Zhi; Jing Yuanwei

    2010-01-01

    This paper studies the global exponential synchronization of uncertain complex delayed dynamical networks. The network model considered is general dynamical delay networks with unknown network structure and unknown coupling functions but bounded. Novel delay-dependent linear controllers are designed via the Lyapunov stability theory. Especially, it is shown that the controlled networks are globally exponentially synchronized with a given convergence rate. An example of typical dynamical network of this class, having the Lorenz system at each node, has been used to demonstrate and verify the novel design proposed. And, the numerical simulation results show the effectiveness of proposed synchronization approaches. (general)

  10. R&D Collaboration with Uncertain Intellectual Property Rights

    DEFF Research Database (Denmark)

    Czarnitzki, Dirk; Hussinger, Katrin; Schneider, Cédric

    2015-01-01

    uncertain intellectual property rights (IPRs) lead to reduced collaboration between firms and can, hence, hinder knowledge production. This has implications for technology policy as R&D collaborations are exempt from antitrust legislation in order to increase R&D in the economy. We argue that a functional IPR system......Patent pendencies create uncertainty in research and development (R&D) collaboration, which can result in a threat of expropriation of unprotected knowledge, reduced bargaining power and enhanced search costs. We show that—depending of the type of collaboration partner and the size of the company...

  11. R&D Collaboration with Uncertain Intellectual Property Rights

    DEFF Research Database (Denmark)

    Czarnitzki, Dirk; Hussinger, Katrin; Schneider, Cédric

    - uncertain intellectual property rights (IPR) lead to reduced collaboration between firms and may hinder the production of knowledge. This has implications for technology policy as R&D collaborations are exempt from anti-trust legislation in order to increase R&D in the economy. We argue that a functional......Patent pendencies create uncertainty in research and development (R&D) collaboration agreements, resulting in a threat of expropriation of unprotected knowledge by potential partners, reduced bargaining power and enhanced search costs. In this paper, we show that - depending of the type of partner...

  12. When, not if: The inescapability of an uncertain future

    Science.gov (United States)

    Lewandowsky, S.; Ballard, T.

    2014-12-01

    Uncertainty is an inherent feature of most scientific endeavours, and many political decisions must be made in the presence of scientific uncertainty. In the case of climate change, there is evidence that greater scientific uncertainty increases the risk associated with the impact of climate change. Scientific uncertainty thus provides an impetus for cutting emissions rather than delaying action. In contrast to those normative considerations, uncertainty is frequently cited in political and public discourse as a reason to delay mitigation. We examine ways in which this gap between public and scientific understanding of uncertainty can be bridged. In particular, we sought ways to communicate uncertainty in a way that better calibrates people's risk perceptions with the projected impact of climate change. We report two behavioural experiments in which uncertainty about the future was expressed either as outcome uncertainty or temporal uncertainty. The conventional presentation of uncertainty involves uncertainty about an outcome at a given time—for example, the range of possible sea level rise (say 50cm +/- 20cm) by a certain date. An alternative presentation of the same situation presents a certain outcome ("sea levels will rise by 50cm") but places the uncertainty into the time of arrival ("this may occur as early as 2040 or as late as 2080"). We presented participants with a series of statements and graphs indicating projected increases in temperature, sea levels, ocean acidification, and a decrease in artic sea ice. In the uncertain magnitude condition, the statements and graphs reported the upper and lower confidence bounds of the projected magnitude and the mean projected time of arrival. In the uncertain time of arrival condition, they reported the upper and lower confidence bounds of the projected time of arrival and the mean projected magnitude. The results show that when uncertainty was presented as uncertain time of arrival rather than an uncertain

  13. Uncertain Dynamics, Correlation Effects, and Robust Investment Decisions

    DEFF Research Database (Denmark)

    Flor, Christian Riis; Hesel, Søren

    2015-01-01

    We analyze a firm's investment problem when the dynamics of project value and investment cost are uncertain. We provide an explicit solution using a robust method for an ambiguity averse firm taking this into account. Ambiguity aversion regarding a common risk factor impacts differently than...... ambiguity aversion regarding investment cost residual risk. Correlation between project value and investment cost matters; ambiguity aversion regarding common risk can decrease the investment probability only if correlation is positive. Ambiguity aversion regarding residual risk always increases...... the investment probability. When only project value is risky, volatility can monotonically decrease the investment threshold; this does not hold with the multiple prior method....

  14. Empirical Evidence from Kenya

    African Journals Online (AJOL)

    FIRST LADY

    2011-01-18

    Jan 18, 2011 ... Empirical results reveal that consumption of sugar in. Kenya varies ... experiences in trade in different regions of the world. Some studies ... To assess the relationship between domestic sugar retail prices and sugar sales in ...

  15. Expert opinion vs. empirical evidence

    Science.gov (United States)

    Herman, Rod A; Raybould, Alan

    2014-01-01

    Expert opinion is often sought by government regulatory agencies when there is insufficient empirical evidence to judge the safety implications of a course of action. However, it can be reckless to continue following expert opinion when a preponderance of evidence is amassed that conflicts with this opinion. Factual evidence should always trump opinion in prioritizing the information that is used to guide regulatory policy. Evidence-based medicine has seen a dramatic upturn in recent years spurred by examples where evidence indicated that certain treatments recommended by expert opinions increased death rates. We suggest that scientific evidence should also take priority over expert opinion in the regulation of genetically modified crops (GM). Examples of regulatory data requirements that are not justified based on the mass of evidence are described, and it is suggested that expertise in risk assessment should guide evidence-based regulation of GM crops. PMID:24637724

  16. Strict Constraint Feasibility in Analysis and Design of Uncertain Systems

    Science.gov (United States)

    Crespo, Luis G.; Giesy, Daniel P.; Kenny, Sean P.

    2006-01-01

    This paper proposes a methodology for the analysis and design optimization of models subject to parametric uncertainty, where hard inequality constraints are present. Hard constraints are those that must be satisfied for all parameter realizations prescribed by the uncertainty model. Emphasis is given to uncertainty models prescribed by norm-bounded perturbations from a nominal parameter value, i.e., hyper-spheres, and by sets of independently bounded uncertain variables, i.e., hyper-rectangles. These models make it possible to consider sets of parameters having comparable as well as dissimilar levels of uncertainty. Two alternative formulations for hyper-rectangular sets are proposed, one based on a transformation of variables and another based on an infinity norm approach. The suite of tools developed enable us to determine if the satisfaction of hard constraints is feasible by identifying critical combinations of uncertain parameters. Since this practice is performed without sampling or partitioning the parameter space, the resulting assessments of robustness are analytically verifiable. Strategies that enable the comparison of the robustness of competing design alternatives, the approximation of the robust design space, and the systematic search for designs with improved robustness characteristics are also proposed. Since the problem formulation is generic and the solution methods only require standard optimization algorithms for their implementation, the tools developed are applicable to a broad range of problems in several disciplines.

  17. Global sensitivity analysis in stochastic simulators of uncertain reaction networks.

    Science.gov (United States)

    Navarro Jimenez, M; Le Maître, O P; Knio, O M

    2016-12-28

    Stochastic models of chemical systems are often subjected to uncertainties in kinetic parameters in addition to the inherent random nature of their dynamics. Uncertainty quantification in such systems is generally achieved by means of sensitivity analyses in which one characterizes the variability with the uncertain kinetic parameters of the first statistical moments of model predictions. In this work, we propose an original global sensitivity analysis method where the parametric and inherent variability sources are both treated through Sobol's decomposition of the variance into contributions from arbitrary subset of uncertain parameters and stochastic reaction channels. The conceptual development only assumes that the inherent and parametric sources are independent, and considers the Poisson processes in the random-time-change representation of the state dynamics as the fundamental objects governing the inherent stochasticity. A sampling algorithm is proposed to perform the global sensitivity analysis, and to estimate the partial variances and sensitivity indices characterizing the importance of the various sources of variability and their interactions. The birth-death and Schlögl models are used to illustrate both the implementation of the algorithm and the richness of the proposed analysis method. The output of the proposed sensitivity analysis is also contrasted with a local derivative-based sensitivity analysis method classically used for this type of systems.

  18. On the robust optimization to the uncertain vaccination strategy problem

    International Nuclear Information System (INIS)

    Chaerani, D.; Anggriani, N.; Firdaniza

    2014-01-01

    In order to prevent an epidemic of infectious diseases, the vaccination coverage needs to be minimized and also the basic reproduction number needs to be maintained below 1. This means that as we get the vaccination coverage as minimum as possible, thus we need to prevent the epidemic to a small number of people who already get infected. In this paper, we discuss the case of vaccination strategy in term of minimizing vaccination coverage, when the basic reproduction number is assumed as an uncertain parameter that lies between 0 and 1. We refer to the linear optimization model for vaccination strategy that propose by Becker and Starrzak (see [2]). Assuming that there is parameter uncertainty involved, we can see Tanner et al (see [9]) who propose the optimal solution of the problem using stochastic programming. In this paper we discuss an alternative way of optimizing the uncertain vaccination strategy using Robust Optimization (see [3]). In this approach we assume that the parameter uncertainty lies within an ellipsoidal uncertainty set such that we can claim that the obtained result will be achieved in a polynomial time algorithm (as it is guaranteed by the RO methodology). The robust counterpart model is presented

  19. Optimal Order Strategy in Uncertain Demands with Free Shipping Option

    Directory of Open Access Journals (Sweden)

    Qing-Chun Meng

    2014-01-01

    Full Text Available Free shipping with conditions has become one of the most effective marketing tools; more and more companies especially e-business companies prefer to offer free shipping to buyers whenever their orders exceed the minimum quantity specified by them. But in practice, the demands of buyers are uncertain, which are affected by weather, season, and many other factors. Firstly, we model the centralization ordering problem of retailers who face stochastic demands when suppliers offer free shipping, in which limited distributional information such as known mean, support, and some deviation measures of the random data is needed only. Then, based on the linear decision rule mainly for stochastic programming, we analyze the optimal order strategies of retailers and discuss the approximate solution. Further, we present the core allocation between all retailers via dual and cooperative game theory. The existence of core shows that each retailer is pleased to cooperate with others in the centralization problem. Finally, a numerical example is implemented to discuss how uncertain data and parameters affect the optimal solution.

  20. Intelligent diagnosis of jaundice with dynamic uncertain causality graph model*

    Science.gov (United States)

    Hao, Shao-rui; Geng, Shi-chao; Fan, Lin-xiao; Chen, Jia-jia; Zhang, Qin; Li, Lan-juan

    2017-01-01

    Jaundice is a common and complex clinical symptom potentially occurring in hepatology, general surgery, pediatrics, infectious diseases, gynecology, and obstetrics, and it is fairly difficult to distinguish the cause of jaundice in clinical practice, especially for general practitioners in less developed regions. With collaboration between physicians and artificial intelligence engineers, a comprehensive knowledge base relevant to jaundice was created based on demographic information, symptoms, physical signs, laboratory tests, imaging diagnosis, medical histories, and risk factors. Then a diagnostic modeling and reasoning system using the dynamic uncertain causality graph was proposed. A modularized modeling scheme was presented to reduce the complexity of model construction, providing multiple perspectives and arbitrary granularity for disease causality representations. A “chaining” inference algorithm and weighted logic operation mechanism were employed to guarantee the exactness and efficiency of diagnostic reasoning under situations of incomplete and uncertain information. Moreover, the causal interactions among diseases and symptoms intuitively demonstrated the reasoning process in a graphical manner. Verification was performed using 203 randomly pooled clinical cases, and the accuracy was 99.01% and 84.73%, respectively, with or without laboratory tests in the model. The solutions were more explicable and convincing than common methods such as Bayesian Networks, further increasing the objectivity of clinical decision-making. The promising results indicated that our model could be potentially used in intelligent diagnosis and help decrease public health expenditure. PMID:28471111

  1. Adapting environmental management to uncertain but inevitable change.

    Science.gov (United States)

    Nicol, Sam; Fuller, Richard A; Iwamura, Takuya; Chadès, Iadine

    2015-06-07

    Implementation of adaptation actions to protect biodiversity is limited by uncertainty about the future. One reason for this is the fear of making the wrong decisions caused by the myriad future scenarios presented to decision-makers. We propose an adaptive management (AM) method for optimally managing a population under uncertain and changing habitat conditions. Our approach incorporates multiple future scenarios and continually learns the best management strategy from observations, even as conditions change. We demonstrate the performance of our AM approach by applying it to the spatial management of migratory shorebird habitats on the East Asian-Australasian flyway, predicted to be severely impacted by future sea-level rise. By accounting for non-stationary dynamics, our solution protects 25,000 more birds per year than the current best stationary approach. Our approach can be applied to many ecological systems that require efficient adaptation strategies for an uncertain future. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  2. Transitioning nuclear fuel cycles with uncertain fast reactor costs

    Energy Technology Data Exchange (ETDEWEB)

    Phathanapirom, U.B., E-mail: bphathanapirom@utexas.edu; Schneider, E.A.

    2016-06-15

    This paper applies a novel decision making methodology to a case study involving choices leading to the transition from the current once-through light water reactor fuel cycle to one relying on continuous recycle of plutonium and minor actinides in fast reactors in the face of uncertain fast reactor capital costs. Unique to this work is a multi-stage treatment of a range of plausible trajectories for the evolution of fast reactor capital costs over time, characterized by first-of-a-kind penalties as well as time- and unit-based learning. The methodology explicitly incorporates uncertainties in key parameters into the decision-making process by constructing a stochastic model and embedding uncertainties as bifurcations in the decision tree. “Hedging” strategies are found by applying a choice criterion to select courses of action which mitigate “regrets”. These regrets are calculated by evaluating the performance of all possible transition strategies for every feasible outcome of the uncertain parameter. The hedging strategies are those that preserve the most flexibility for adjusting the fuel cycle strategy in response to new information as uncertainties are resolved.

  3. Assimilating uncertain, dynamic and intermittent streamflow observations in hydrological models

    Science.gov (United States)

    Mazzoleni, Maurizio; Alfonso, Leonardo; Chacon-Hurtado, Juan; Solomatine, Dimitri

    2015-09-01

    Catastrophic floods cause significant socio-economical losses. Non-structural measures, such as real-time flood forecasting, can potentially reduce flood risk. To this end, data assimilation methods have been used to improve flood forecasts by integrating static ground observations, and in some cases also remote sensing observations, within water models. Current hydrologic and hydraulic research works consider assimilation of observations coming from traditional, static sensors. At the same time, low-cost, mobile sensors and mobile communication devices are becoming also increasingly available. The main goal and innovation of this study is to demonstrate the usefulness of assimilating uncertain streamflow observations that are dynamic in space and intermittent in time in the context of two different semi-distributed hydrological model structures. The developed method is applied to the Brue basin, where the dynamic observations are imitated by the synthetic observations of discharge. The results of this study show how model structures and sensors locations affect in different ways the assimilation of streamflow observations. In addition, it proves how assimilation of such uncertain observations from dynamic sensors can provide model improvements similar to those of streamflow observations coming from a non-optimal network of static physical sensors. This can be a potential application of recent efforts to build citizen observatories of water, which can make the citizens an active part in information capturing, evaluation and communication, helping simultaneously to improvement of model-based flood forecasting.

  4. Transitioning nuclear fuel cycles with uncertain fast reactor costs

    International Nuclear Information System (INIS)

    Phathanapirom, U.B.; Schneider, E.A.

    2016-01-01

    This paper applies a novel decision making methodology to a case study involving choices leading to the transition from the current once-through light water reactor fuel cycle to one relying on continuous recycle of plutonium and minor actinides in fast reactors in the face of uncertain fast reactor capital costs. Unique to this work is a multi-stage treatment of a range of plausible trajectories for the evolution of fast reactor capital costs over time, characterized by first-of-a-kind penalties as well as time- and unit-based learning. The methodology explicitly incorporates uncertainties in key parameters into the decision-making process by constructing a stochastic model and embedding uncertainties as bifurcations in the decision tree. “Hedging” strategies are found by applying a choice criterion to select courses of action which mitigate “regrets”. These regrets are calculated by evaluating the performance of all possible transition strategies for every feasible outcome of the uncertain parameter. The hedging strategies are those that preserve the most flexibility for adjusting the fuel cycle strategy in response to new information as uncertainties are resolved.

  5. Intelligent diagnosis of jaundice with dynamic uncertain causality graph model.

    Science.gov (United States)

    Hao, Shao-Rui; Geng, Shi-Chao; Fan, Lin-Xiao; Chen, Jia-Jia; Zhang, Qin; Li, Lan-Juan

    2017-05-01

    Jaundice is a common and complex clinical symptom potentially occurring in hepatology, general surgery, pediatrics, infectious diseases, gynecology, and obstetrics, and it is fairly difficult to distinguish the cause of jaundice in clinical practice, especially for general practitioners in less developed regions. With collaboration between physicians and artificial intelligence engineers, a comprehensive knowledge base relevant to jaundice was created based on demographic information, symptoms, physical signs, laboratory tests, imaging diagnosis, medical histories, and risk factors. Then a diagnostic modeling and reasoning system using the dynamic uncertain causality graph was proposed. A modularized modeling scheme was presented to reduce the complexity of model construction, providing multiple perspectives and arbitrary granularity for disease causality representations. A "chaining" inference algorithm and weighted logic operation mechanism were employed to guarantee the exactness and efficiency of diagnostic reasoning under situations of incomplete and uncertain information. Moreover, the causal interactions among diseases and symptoms intuitively demonstrated the reasoning process in a graphical manner. Verification was performed using 203 randomly pooled clinical cases, and the accuracy was 99.01% and 84.73%, respectively, with or without laboratory tests in the model. The solutions were more explicable and convincing than common methods such as Bayesian Networks, further increasing the objectivity of clinical decision-making. The promising results indicated that our model could be potentially used in intelligent diagnosis and help decrease public health expenditure.

  6. On the robust optimization to the uncertain vaccination strategy problem

    Energy Technology Data Exchange (ETDEWEB)

    Chaerani, D., E-mail: d.chaerani@unpad.ac.id; Anggriani, N., E-mail: d.chaerani@unpad.ac.id; Firdaniza, E-mail: d.chaerani@unpad.ac.id [Department of Mathematics, Faculty of Mathematics and Natural Sciences, University of Padjadjaran Indonesia, Jalan Raya Bandung Sumedang KM 21 Jatinangor Sumedang 45363 (Indonesia)

    2014-02-21

    In order to prevent an epidemic of infectious diseases, the vaccination coverage needs to be minimized and also the basic reproduction number needs to be maintained below 1. This means that as we get the vaccination coverage as minimum as possible, thus we need to prevent the epidemic to a small number of people who already get infected. In this paper, we discuss the case of vaccination strategy in term of minimizing vaccination coverage, when the basic reproduction number is assumed as an uncertain parameter that lies between 0 and 1. We refer to the linear optimization model for vaccination strategy that propose by Becker and Starrzak (see [2]). Assuming that there is parameter uncertainty involved, we can see Tanner et al (see [9]) who propose the optimal solution of the problem using stochastic programming. In this paper we discuss an alternative way of optimizing the uncertain vaccination strategy using Robust Optimization (see [3]). In this approach we assume that the parameter uncertainty lies within an ellipsoidal uncertainty set such that we can claim that the obtained result will be achieved in a polynomial time algorithm (as it is guaranteed by the RO methodology). The robust counterpart model is presented.

  7. Global sensitivity analysis in stochastic simulators of uncertain reaction networks

    KAUST Repository

    Navarro, María

    2016-12-26

    Stochastic models of chemical systems are often subjected to uncertainties in kinetic parameters in addition to the inherent random nature of their dynamics. Uncertainty quantification in such systems is generally achieved by means of sensitivity analyses in which one characterizes the variability with the uncertain kinetic parameters of the first statistical moments of model predictions. In this work, we propose an original global sensitivity analysis method where the parametric and inherent variability sources are both treated through Sobol’s decomposition of the variance into contributions from arbitrary subset of uncertain parameters and stochastic reaction channels. The conceptual development only assumes that the inherent and parametric sources are independent, and considers the Poisson processes in the random-time-change representation of the state dynamics as the fundamental objects governing the inherent stochasticity. A sampling algorithm is proposed to perform the global sensitivity analysis, and to estimate the partial variances and sensitivity indices characterizing the importance of the various sources of variability and their interactions. The birth-death and Schlögl models are used to illustrate both the implementation of the algorithm and the richness of the proposed analysis method. The output of the proposed sensitivity analysis is also contrasted with a local derivative-based sensitivity analysis method classically used for this type of systems.

  8. Pricing Strategies in the Remanufacturing Market for the Uncertain Market Size in the Second Period

    Directory of Open Access Journals (Sweden)

    Liurui Deng

    2016-01-01

    Full Text Available Our main endeavor is to investigate the effect of the uncertain market size in the second period on the pricing strategies in the remanufacturing market. Observing the previous research, we find that the market size in the second period is always supposed to be certain. However, there is substantial empirical and experimental evidence that the market size in reality deviates from this assumption. In fact, though the market size in the first period is definitized, it is difficult to confirm the change of the market scale in the second period, since this change is affected by all kinds of elements, such as the awareness of environmental protection, some consumers’ psychological factors, and the related governments’ policies. Hence, we pay attention to the case in which the change rate of the market scale in the second period is random variable. We suppose that this rate satisfies uniform distribution on [0,2]. Underlying this assumption, we further provide an insight into the game-playing relationship between original equipment manufacturers (OEMs and remanufacturers. Moreover, we delicately and subtly incorporate the game theory, stochastic analysis, adversarial risk analysis (ARA, and optimization methods into the pricing strategies in the remanufacturing market. Last but not least, considerable efforts and attempts have been made to subtly test the sensitivity of an optimal solution to the different parameters.

  9. Complementary Variety: When Can Cooperation in Uncertain Environments Outperform Competitive Selection?

    Directory of Open Access Journals (Sweden)

    Martin Hilbert

    2017-01-01

    Full Text Available Evolving biological and socioeconomic populations can sometimes increase their growth rate by cooperatively redistributing resources among their members. In unchanging environments, this simply comes down to reallocating resources to fitter types. In uncertain and fluctuating environments, cooperation cannot always outperform blind competitive selection. When can it? The conditions depend on the particular shape of the fitness landscape. The article derives a single measure that quantifies by how much an intervention in stochastic environments can possibly outperform the blind forces of natural selection. It is a multivariate and multilevel measure that essentially quantifies the amount of complementary variety between different population types and environmental states. The more complementary the fitness of types in different environmental states, the proportionally larger the potential benefit of strategic cooperation over competitive selection. With complementary variety, holding population shares constant will always outperform natural and market selection (including bet-hedging, portfolio management, and stochastic switching. The result can be used both to determine the acceptable cost of learning the details of a fitness landscape and to design multilevel classification systems of population types and environmental states that maximize population growth. Two empirical cases are explored, one from the evolving economy and the other one from migrating birds.

  10. Empirical philosophy of science

    DEFF Research Database (Denmark)

    Wagenknecht, Susann; Nersessian, Nancy J.; Andersen, Hanne

    2015-01-01

    A growing number of philosophers of science make use of qualitative empirical data, a development that may reconfigure the relations between philosophy and sociology of science and that is reminiscent of efforts to integrate history and philosophy of science. Therefore, the first part...... of this introduction to the volume Empirical Philosophy of Science outlines the history of relations between philosophy and sociology of science on the one hand, and philosophy and history of science on the other. The second part of this introduction offers an overview of the papers in the volume, each of which...... is giving its own answer to questions such as: Why does the use of qualitative empirical methods benefit philosophical accounts of science? And how should these methods be used by the philosopher?...

  11. Constructing probability distributions of uncertain variables in models of the performance of the Waste Isolation Pilot Plant: The 1990 performance simulations

    International Nuclear Information System (INIS)

    Tierney, M.S.

    1990-12-01

    A five-step procedure was used in the 1990 performance simulations to construct probability distributions of the uncertain variables appearing in the mathematical models used to simulate the Waste Isolation Pilot Plant's (WIPP's) performance. This procedure provides a consistent approach to the construction of probability distributions in cases where empirical data concerning a variable are sparse or absent and minimizes the amount of spurious information that is often introduced into a distribution by assumptions of nonspecialists. The procedure gives first priority to the professional judgment of subject-matter experts and emphasizes the use of site-specific empirical data for the construction of the probability distributions when such data are available. In the absence of sufficient empirical data, the procedure employs the Maximum Entropy Formalism and the subject-matter experts' subjective estimates of the parameters of the distribution to construct a distribution that can be used in a performance simulation. (author)

  12. Constructing probability distributions of uncertain variables in models of the performance of the Waste Isolation Pilot Plant: The 1990 performance simulations

    Energy Technology Data Exchange (ETDEWEB)

    Tierney, M S

    1990-12-15

    A five-step procedure was used in the 1990 performance simulations to construct probability distributions of the uncertain variables appearing in the mathematical models used to simulate the Waste Isolation Pilot Plant's (WIPP's) performance. This procedure provides a consistent approach to the construction of probability distributions in cases where empirical data concerning a variable are sparse or absent and minimizes the amount of spurious information that is often introduced into a distribution by assumptions of nonspecialists. The procedure gives first priority to the professional judgment of subject-matter experts and emphasizes the use of site-specific empirical data for the construction of the probability distributions when such data are available. In the absence of sufficient empirical data, the procedure employs the Maximum Entropy Formalism and the subject-matter experts' subjective estimates of the parameters of the distribution to construct a distribution that can be used in a performance simulation. (author)

  13. Empire vs. Federation

    DEFF Research Database (Denmark)

    Gravier, Magali

    2011-01-01

    The article discusses the concepts of federation and empire in the context of the European Union (EU). Even if these two concepts are not usually contrasted to one another, the article shows that they refer to related type of polities. Furthermore, they can be used at a time because they shed light...... on different and complementary aspects of the European integration process. The article concludes that the EU is at the crossroads between federation and empire and may remain an ‘imperial federation’ for several decades. This could mean that the EU is on the verge of transforming itself to another type...

  14. Empirical comparison of theories

    International Nuclear Information System (INIS)

    Opp, K.D.; Wippler, R.

    1990-01-01

    The book represents the first, comprehensive attempt to take an empirical approach for comparative assessment of theories in sociology. The aims, problems, and advantages of the empirical approach are discussed in detail, and the three theories selected for the purpose of this work are explained. Their comparative assessment is performed within the framework of several research projects, which among other subjects also investigate the social aspects of the protest against nuclear power plants. The theories analysed in this context are the theory of mental incongruities and that of the benefit, and their efficiency in explaining protest behaviour is compared. (orig./HSCH) [de

  15. Empirical Music Aesthetics

    DEFF Research Database (Denmark)

    Grund, Cynthia M.

    The toolbox for empirically exploring the ways that artistic endeavors convey and activate meaning on the part of performers and audiences continues to expand. Current work employing methods at the intersection of performance studies, philosophy, motion capture and neuroscience to better understand...... musical performance and reception is inspired by traditional approaches within aesthetics, but it also challenges some of the presuppositions inherent in them. As an example of such work I present a research project in empirical music aesthetics begun last year and of which I am a team member....

  16. Melioration as Rational Choice: Sequential Decision Making in Uncertain Environments

    Science.gov (United States)

    Sims, Chris R.; Neth, Hansjorg; Jacobs, Robert A.; Gray, Wayne D.

    2013-01-01

    Melioration--defined as choosing a lesser, local gain over a greater longer term gain--is a behavioral tendency that people and pigeons share. As such, the empirical occurrence of meliorating behavior has frequently been interpreted as evidence that the mechanisms of human choice violate the norms of economic rationality. In some environments, the…

  17. Fuzzy Backstepping Sliding Mode Control for Mismatched Uncertain System

    Directory of Open Access Journals (Sweden)

    H. Q. Hou

    2014-06-01

    Full Text Available Sliding mode controllers have succeeded in many control problems that the conventional control theories have difficulties to deal with; however it is practically impossible to achieve high-speed switching control. Therefore, in this paper an adaptive fuzzy backstepping sliding mode control scheme is derived for mismatched uncertain systems. Firstly fuzzy sliding mode controller is designed using backstepping method based on the Lyapunov function approach, which is capable of handling mismatched problem. Then fuzzy sliding mode controller is designed using T-S fuzzy model method, it can improve the performance of the control systems and their robustness. Finally this method of control is applied to nonlinear system as a case study; simulation results are also provided the performance of the proposed controller.

  18. Design of Distributed Engine Control Systems with Uncertain Delay.

    Directory of Open Access Journals (Sweden)

    Xiaofeng Liu

    Full Text Available Future gas turbine engine control systems will be based on distributed architecture, in which, the sensors and actuators will be connected to the controllers via a communication network. The performance of the distributed engine control (DEC is dependent on the network performance. This study introduces a distributed control system architecture based on a networked cascade control system (NCCS. Typical turboshaft engine-distributed controllers are designed based on the NCCS framework with a H∞ output feedback under network-induced time delays and uncertain disturbances. The sufficient conditions for robust stability are derived via the Lyapunov stability theory and linear matrix inequality approach. Both numerical and hardware-in-loop simulations illustrate the effectiveness of the presented method.

  19. Model Predictive Control of Wind Turbines using Uncertain LIDAR Measurements

    DEFF Research Database (Denmark)

    Mirzaei, Mahmood; Soltani, Mohsen; Poulsen, Niels Kjølstad

    2013-01-01

    , we simplify state prediction for the MPC. Consequently, the control problem of the nonlinear system is simplified into a quadratic programming. We consider uncertainty in the wind propagation time, which is the traveling time of wind from the LIDAR measurement point to the rotor. An algorithm based......The problem of Model predictive control (MPC) of wind turbines using uncertain LIDAR (LIght Detection And Ranging) measurements is considered. A nonlinear dynamical model of the wind turbine is obtained. We linearize the obtained nonlinear model for different operating points, which are determined...... on wind speed estimation and measurements from the LIDAR is devised to find an estimate of the delay and compensate for it before it is used in the controller. Comparisons between the MPC with error compensation, the MPC without error compensation and an MPC with re-linearization at each sample point...

  20. AN UNCERTAIN FEDERALISM: THE STATES AND THE AFFORDABLE CARE ACT.

    Science.gov (United States)

    Plein, L Christopher

    2014-01-01

    This article provides an initial assessment of the Affordable Care Act's recent implementation experience in the states. Drawing on state-level and regional analyses that have been coordinated by the ACA Implementation Network--a cooperative effort involving researchers in 35 states--this article highlights the uncertain policy environment associated with the politics and complexities of the ACA. Understanding the ACA implementation experience requires an appreciation for political context, but must also take into account underlying demographic, market, and state administrative capacity issues in the states. There are indications that the ACA implementation experience is moving from a highly charged partisan nature to a more accommodating posture long associated with intergovernmental relations between the federal and state government in health and human services administration. In short, the key questions going forward will turn on how, not whether, the ACA is implemented.

  1. Modern medicine and the "uncertain body": from corporeality to hyperreality?

    Science.gov (United States)

    Williams, S J

    1997-10-01

    This paper (re)considers the role of medical technology at three interrelated levels: first, the extent to which medical technology renders our bodies increasingly "uncertain" at the turn of the century; second, the analytical purchase which the notion of the (medical) cyborg provides regarding contemporary forms of human embodiment; and finally, at a broader level, the issues this raises in relation to a (late) modernist or postmodernist reading of contemporary medical practice. Key themes here include the plastic body, the bionic body, communal/interchangeable bodies, (genetically) engineered/ chosen bodies, and virtual bodies. The paper concludes with a critical appraisal of these themes and issues, arguing for a late modernist position on medical technology as both a positive and negative rationalising force, and a "life political agenda" in which the "all-too-human" quality of human nature is seen as inviolable.

  2. Chernobyl, the true, the false and the uncertain

    International Nuclear Information System (INIS)

    1996-04-01

    This work makes the part between the true and the false information in France about the Chernobyl accident that have been read in different newspapers during the last years. This document is divide in three parts: what is true, what is false, what is uncertain. In each part are noticed extracts from newspapers face to the synthesis of thoughts about them. It is the fourth edition, the first one was in April 1990, the second one was in 1992 after a report from IAEA on the radiological consequences, the third edition was born in 1994 with the emergence of thyroid cancers especially among children, this fourth edition of 1996 takes into account the sanitary report given by the World Health Organisation experts in 1995. It confirms the progression of thyroid cancers and the absence of any other cancer as well leukemia. (N.C.)

  3. Partnership Selection Involving Mixed Types of Uncertain Preferences

    Directory of Open Access Journals (Sweden)

    Li-Ching Ma

    2013-01-01

    Full Text Available Partnership selection is an important issue in management science. This study proposes a general model based on mixed integer programming and goal-programming analytic hierarchy process (GP-AHP to solve partnership selection problems involving mixed types of uncertain or inconsistent preferences. The proposed approach is designed to deal with crisp, interval, step, fuzzy, or mixed comparison preferences, derive crisp priorities, and improve multiple solution problems. The degree of fulfillment of a decision maker’s preferences is also taken into account. The results show that the proposed approach keeps more solution ratios within the given preferred intervals and yields less deviation. In addition, the proposed approach can treat incomplete preference matrices with flexibility in reducing the number of pairwise comparisons required and can also be conveniently developed into a decision support system.

  4. Probabilistic confidence for decisions based on uncertain reliability estimates

    Science.gov (United States)

    Reid, Stuart G.

    2013-05-01

    Reliability assessments are commonly carried out to provide a rational basis for risk-informed decisions concerning the design or maintenance of engineering systems and structures. However, calculated reliabilities and associated probabilities of failure often have significant uncertainties associated with the possible estimation errors relative to the 'true' failure probabilities. For uncertain probabilities of failure, a measure of 'probabilistic confidence' has been proposed to reflect the concern that uncertainty about the true probability of failure could result in a system or structure that is unsafe and could subsequently fail. The paper describes how the concept of probabilistic confidence can be applied to evaluate and appropriately limit the probabilities of failure attributable to particular uncertainties such as design errors that may critically affect the dependability of risk-acceptance decisions. This approach is illustrated with regard to the dependability of structural design processes based on prototype testing with uncertainties attributable to sampling variability.

  5. Design of Distributed Engine Control Systems with Uncertain Delay.

    Science.gov (United States)

    Liu, Xiaofeng; Li, Yanxi; Sun, Xu

    Future gas turbine engine control systems will be based on distributed architecture, in which, the sensors and actuators will be connected to the controllers via a communication network. The performance of the distributed engine control (DEC) is dependent on the network performance. This study introduces a distributed control system architecture based on a networked cascade control system (NCCS). Typical turboshaft engine-distributed controllers are designed based on the NCCS framework with a H∞ output feedback under network-induced time delays and uncertain disturbances. The sufficient conditions for robust stability are derived via the Lyapunov stability theory and linear matrix inequality approach. Both numerical and hardware-in-loop simulations illustrate the effectiveness of the presented method.

  6. Valuing Interest Rate Swap Contracts in Uncertain Financial Market

    Directory of Open Access Journals (Sweden)

    Chen Xiao

    2016-11-01

    Full Text Available Swap is a financial contract between two counterparties who agree to exchange one cash flow stream for another, according to some predetermined rules. When the cash flows are fixed rate interest and floating rate interest, the swap is called an interest rate swap. This paper investigates two valuation models of the interest rate swap contracts in the uncertain financial market. The new models are based on belief degrees, and require relatively less historical data compared to the traditional probability models. The first valuation model is designed for a mean-reversion term structure, while the second is designed for a term structure with hump effect. Explicit solutions are developed by using the Yao–Chen formula. Moreover, a numerical method is designed to calculate the value of the interest rate swap alternatively. Finally, two examples are given to show their applications and comparisons.

  7. Multilateral Telecoordinated Control of Multiple Robots With Uncertain Kinematics.

    Science.gov (United States)

    Zhai, Di-Hua; Xia, Yuanqing

    2017-06-06

    This paper addresses the telecoordinated control of multiple robots in the simultaneous presence of asymmetric time-varying delays, nonpassive external forces, and uncertain kinematics/dynamics. To achieve the control objective, a neuroadaptive controller with utilizing prescribed performance control and switching control technique is developed, where the basic idea is to employ the concept of motion synchronization in each pair of master-slave robots and among all slave robots. By using the multiple Lyapunov-Krasovskii functionals method, the state-independent input-to-output practical stability of the closed-loop system is established. Compared with the previous approaches, the new design is straightforward and easier to implement and is applicable to a wider area. Simulation results on three pairs of three degrees-of-freedom robots confirm the theoretical findings.

  8. Empirical research through design

    NARCIS (Netherlands)

    Keyson, D.V.; Bruns, M.

    2009-01-01

    This paper describes the empirical research through design method (ERDM), which differs from current approaches to research through design by enforcing the need for the designer, after a series of pilot prototype based studies, to a-priori develop a number of testable interaction design hypothesis

  9. Essays in empirical microeconomics

    NARCIS (Netherlands)

    Péter, A.N.

    2016-01-01

    The empirical studies in this thesis investigate various factors that could affect individuals' labor market, family formation and educational outcomes. Chapter 2 focuses on scheduling as a potential determinant of individuals' productivity. Chapter 3 looks at the role of a family factor on

  10. Worship, Reflection, Empirical Research

    OpenAIRE

    Ding Dong,

    2012-01-01

    In my youth, I was a worshipper of Mao Zedong. From the latter stage of the Mao Era to the early years of Reform and Opening, I began to reflect on Mao and the Communist Revolution he launched. In recent years I’ve devoted myself to empirical historical research on Mao, seeking the truth about Mao and China’s modern history.

  11. Trade and Empire

    DEFF Research Database (Denmark)

    Bang, Peter Fibiger

    2007-01-01

    This articles seeks to establish a new set of organizing concepts for the analysis of the Roman imperial economy from Republic to late antiquity: tributary empire, port-folio capitalism and protection costs. Together these concepts explain better economic developments in the Roman world than the...

  12. Empirically sampling Universal Dependencies

    DEFF Research Database (Denmark)

    Schluter, Natalie; Agic, Zeljko

    2017-01-01

    Universal Dependencies incur a high cost in computation for unbiased system development. We propose a 100% empirically chosen small subset of UD languages for efficient parsing system development. The technique used is based on measurements of model capacity globally. We show that the diversity o...

  13. Semantically Enhanced Recommender Systems

    Science.gov (United States)

    Ruiz-Montiel, Manuela; Aldana-Montes, José F.

    Recommender Systems have become a significant area in the context of web personalization, given the large amount of available data. Ontologies can be widely taken advantage of in recommender systems, since they provide a means of classifying and discovering of new information about the items to recommend, about user profiles and even about their context. We have developed a semantically enhanced recommender system based on this kind of ontologies. In this paper we present a description of the proposed system.

  14. Government Support for Synthetic Pipeline Gas Uncertain and Needs Attention.

    Science.gov (United States)

    1982-05-14

    coal gas. Tear Sheetii RECOMMENDATIONS GAO recommends that the Secretary of Energy - --establish a plan to guide future support of high-Btu coal...recognizes that there are basic dif- ferences expected from large and small scale research projects, GAO believes that the report recognizes these...transportation, including the pipeline system. In its price-setting, or ratemaking function, it represents the interests of gas customers, sometimes

  15. South Caucasus. An Uncertain Path. Analyzing Vulnerabilities in Respecting Human Rights and Some Recommendations for Democratic Construction

    Directory of Open Access Journals (Sweden)

    Cristian Gherasim

    2012-02-01

    Full Text Available Fifteen years after Armenia, Azerbaijan and Georgia Achieved independence, power is still concentrated in the hands of a few. There are strong regional disparities within all three countries, with the capitals having the lion’s share of population, power and resources. Minorities are poorly represented in public life and suffer from lack of educational opportunities and breaches of human rights from those that make up the majority. More often than not, continue weak statehood means that states are incapable of providing basic public services, let alone ensure protection against human rights abuses.

  16. Trust for intelligent recommendation

    CERN Document Server

    Bhuiyan, Touhid

    2013-01-01

    Recommender systems are one of the recent inventions to deal with the ever-growing information overload in relation to the selection of goods and services in a global economy. Collaborative Filtering (CF) is one of the most popular techniques in recommender systems. The CF recommends items to a target user based on the preferences of a set of similar users known as the neighbors, generated from a database made up of the preferences of past users. In the absence of these ratings, trust between the users could be used to choose the neighbor for recommendation making. Better recommendations can b

  17. Pattern-Directed Attention in Uncertain Frequency Detection.

    Science.gov (United States)

    1983-10-14

    performance when compared to a single frequency condition even if the listeners are aware that more than one signal can occur ( Creelman , 1960; Green...be missed. On the-other hand, the multiple band approach, introduced by Green (1958) and modified by Creelman (1960), assumes that listeners base...multiple-band approaches ( Creelman , 1960; Green, 1961; Macmillan & Schwartz, 1975). In general, the two views are difficult to distinguish empirically, and

  18. Redundant correlation effect on personalized recommendation

    Science.gov (United States)

    Qiu, Tian; Han, Teng-Yue; Zhong, Li-Xin; Zhang, Zi-Ke; Chen, Guang

    2014-02-01

    The high-order redundant correlation effect is investigated for a hybrid algorithm of heat conduction and mass diffusion (HHM), through both heat conduction biased (HCB) and mass diffusion biased (MDB) correlation redundancy elimination processes. The HCB and MDB algorithms do not introduce any additional tunable parameters, but keep the simple character of the original HHM. Based on two empirical datasets, the Netflix and MovieLens, the HCB and MDB are found to show better recommendation accuracy for both the overall objects and the cold objects than the HHM algorithm. Our work suggests that properly eliminating the high-order redundant correlations can provide a simple and effective approach to accurate recommendation.

  19. Similarity estimators for irregular and age uncertain time series

    Science.gov (United States)

    Rehfeld, K.; Kurths, J.

    2013-09-01

    Paleoclimate time series are often irregularly sampled and age uncertain, which is an important technical challenge to overcome for successful reconstruction of past climate variability and dynamics. Visual comparison and interpolation-based linear correlation approaches have been used to infer dependencies from such proxy time series. While the first is subjective, not measurable and not suitable for the comparison of many datasets at a time, the latter introduces interpolation bias, and both face difficulties if the underlying dependencies are nonlinear. In this paper we investigate similarity estimators that could be suitable for the quantitative investigation of dependencies in irregular and age uncertain time series. We compare the Gaussian-kernel based cross correlation (gXCF, Rehfeld et al., 2011) and mutual information (gMI, Rehfeld et al., 2013) against their interpolation-based counterparts and the new event synchronization function (ESF). We test the efficiency of the methods in estimating coupling strength and coupling lag numerically, using ensembles of synthetic stalagmites with short, autocorrelated, linear and nonlinearly coupled proxy time series, and in the application to real stalagmite time series. In the linear test case coupling strength increases are identified consistently for all estimators, while in the nonlinear test case the correlation-based approaches fail. The lag at which the time series are coupled is identified correctly as the maximum of the similarity functions in around 60-55% (in the linear case) to 53-42% (for the nonlinear processes) of the cases when the dating of the synthetic stalagmite is perfectly precise. If the age uncertainty increases beyond 5% of the time series length, however, the true coupling lag is not identified more often than the others for which the similarity function was estimated. Age uncertainty contributes up to half of the uncertainty in the similarity estimation process. Time series irregularity

  20. Similarity estimators for irregular and age-uncertain time series

    Science.gov (United States)

    Rehfeld, K.; Kurths, J.

    2014-01-01

    Paleoclimate time series are often irregularly sampled and age uncertain, which is an important technical challenge to overcome for successful reconstruction of past climate variability and dynamics. Visual comparison and interpolation-based linear correlation approaches have been used to infer dependencies from such proxy time series. While the first is subjective, not measurable and not suitable for the comparison of many data sets at a time, the latter introduces interpolation bias, and both face difficulties if the underlying dependencies are nonlinear. In this paper we investigate similarity estimators that could be suitable for the quantitative investigation of dependencies in irregular and age-uncertain time series. We compare the Gaussian-kernel-based cross-correlation (gXCF, Rehfeld et al., 2011) and mutual information (gMI, Rehfeld et al., 2013) against their interpolation-based counterparts and the new event synchronization function (ESF). We test the efficiency of the methods in estimating coupling strength and coupling lag numerically, using ensembles of synthetic stalagmites with short, autocorrelated, linear and nonlinearly coupled proxy time series, and in the application to real stalagmite time series. In the linear test case, coupling strength increases are identified consistently for all estimators, while in the nonlinear test case the correlation-based approaches fail. The lag at which the time series are coupled is identified correctly as the maximum of the similarity functions in around 60-55% (in the linear case) to 53-42% (for the nonlinear processes) of the cases when the dating of the synthetic stalagmite is perfectly precise. If the age uncertainty increases beyond 5% of the time series length, however, the true coupling lag is not identified more often than the others for which the similarity function was estimated. Age uncertainty contributes up to half of the uncertainty in the similarity estimation process. Time series irregularity

  1. Tsunami hazard assessments with consideration of uncertain earthquakes characteristics

    Science.gov (United States)

    Sepulveda, I.; Liu, P. L. F.; Grigoriu, M. D.; Pritchard, M. E.

    2017-12-01

    The uncertainty quantification of tsunami assessments due to uncertain earthquake characteristics faces important challenges. First, the generated earthquake samples must be consistent with the properties observed in past events. Second, it must adopt an uncertainty propagation method to determine tsunami uncertainties with a feasible computational cost. In this study we propose a new methodology, which improves the existing tsunami uncertainty assessment methods. The methodology considers two uncertain earthquake characteristics, the slip distribution and location. First, the methodology considers the generation of consistent earthquake slip samples by means of a Karhunen Loeve (K-L) expansion and a translation process (Grigoriu, 2012), applicable to any non-rectangular rupture area and marginal probability distribution. The K-L expansion was recently applied by Le Veque et al. (2016). We have extended the methodology by analyzing accuracy criteria in terms of the tsunami initial conditions. Furthermore, and unlike this reference, we preserve the original probability properties of the slip distribution, by avoiding post sampling treatments such as earthquake slip scaling. Our approach is analyzed and justified in the framework of the present study. Second, the methodology uses a Stochastic Reduced Order model (SROM) (Grigoriu, 2009) instead of a classic Monte Carlo simulation, which reduces the computational cost of the uncertainty propagation. The methodology is applied on a real case. We study tsunamis generated at the site of the 2014 Chilean earthquake. We generate earthquake samples with expected magnitude Mw 8. We first demonstrate that the stochastic approach of our study generates consistent earthquake samples with respect to the target probability laws. We also show that the results obtained from SROM are more accurate than classic Monte Carlo simulations. We finally validate the methodology by comparing the simulated tsunamis and the tsunami records for

  2. Autobiography After Empire

    DEFF Research Database (Denmark)

    Rasch, Astrid

    of the collective, but insufficient attention has been paid to how individuals respond to such narrative changes. This dissertation examines the relationship between individual and collective memory at the end of empire through analysis of 13 end of empire autobiographies by public intellectuals from Australia......Decolonisation was a major event of the twentieth century, redrawing maps and impacting on identity narratives around the globe. As new nations defined their place in the world, the national and imperial past was retold in new cultural memories. These developments have been studied at the level......, the Anglophone Caribbean and Zimbabwe. I conceive of memory as reconstructive and social, with individual memory striving to make sense of the past in the present in dialogue with surrounding narratives. By examining recurring tropes in the autobiographies, like colonial education, journeys to the imperial...

  3. Gazprom: the new empire

    International Nuclear Information System (INIS)

    Guillemoles, A.; Lazareva, A.

    2008-01-01

    Gazprom is conquering the world. The Russian industrial giant owns the hugest gas reserves and enjoys the privilege of a considerable power. Gazprom edits journals, owns hospitals, airplanes and has even built cities where most of the habitants work for him. With 400000 workers, Gazprom represents 8% of Russia's GDP. This inquiry describes the history and operation of this empire and show how its has become a masterpiece of the government's strategy of russian influence reconquest at the world scale. Is it going to be a winning game? Are the corruption affairs and the expected depletion of resources going to weaken the empire? The authors shade light on the political and diplomatic strategies that are played around the crucial dossier of the energy supply. (J.S.)

  4. Cluster synchronization transmission of different external signals in discrete uncertain network

    Science.gov (United States)

    Li, Chengren; Lü, Ling; Chen, Liansong; Hong, Yixuan; Zhou, Shuang; Yang, Yiming

    2018-07-01

    We research cluster synchronization transmissions of different external signals in discrete uncertain network. Based on the Lyapunov theorem, the network controller and the identification law of uncertain adjustment parameter are designed, and they are efficiently used to achieve the cluster synchronization and the identification of uncertain adjustment parameter. In our technical scheme, the network nodes in each cluster and the transmitted external signal can be different, and they allow the presence of uncertain parameters in the network. Especially, we are free to choose the clustering topologies, the cluster number and the node number in each cluster.

  5. Hypercube algorithms suitable for image understanding in uncertain environments

    International Nuclear Information System (INIS)

    Huntsberger, T.L.; Sengupta, A.

    1988-01-01

    Computer vision in a dynamic environment needs to be fast and able to tolerate incomplete or uncertain intermediate results. An appropriately chose representation coupled with a parallel architecture addresses both concerns. The wide range of numerical and symbolic processing needed for robust computer vision can only be achieved through a blend of SIMD and MIMD processing techniques. The 1024 element hypercube architecture has these capabilities, and was chosen as the test-bed hardware for development of highly parallel computer vision algorithms. This paper presents and analyzes parallel algorithms for color image segmentation and edge detection. These algorithms are part of a recently developed computer vision system which uses multiple valued logic to represent uncertainty in the imaging process and in intermediate results. Algorithms for the extraction of three dimensional properties of objects using dynamic scene analysis techniques within the same framework are examined. Results from experimental studies using a 1024 element hypercube implementation of the algorithm as applied to a series of natural scenes are reported

  6. Augmented nonlinear differentiator design and application to nonlinear uncertain systems.

    Science.gov (United States)

    Shao, Xingling; Liu, Jun; Li, Jie; Cao, Huiliang; Shen, Chong; Zhang, Xiaoming

    2017-03-01

    In this paper, an augmented nonlinear differentiator (AND) based on sigmoid function is developed to calculate the noise-less time derivative under noisy measurement condition. The essential philosophy of proposed AND in achieving high attenuation of noise effect is established by expanding the signal dynamics with extra state variable representing the integrated noisy measurement, then with the integral of measurement as input, the augmented differentiator is formulated to improve the estimation quality. The prominent advantages of the present differentiation technique are: (i) better noise suppression ability can be achieved without appreciable delay; (ii) the improved methodology can be readily extended to construct augmented high-order differentiator to obtain multiple derivatives. In addition, the convergence property and robustness performance against noises are investigated via singular perturbation theory and describing function method, respectively. Also, comparison with several classical differentiators is given to illustrate the superiority of AND in noise suppression. Finally, the robust control problems of nonlinear uncertain systems, including a numerical example and a mass spring system, are addressed to demonstrate the effectiveness of AND in precisely estimating the disturbance and providing the unavailable differential estimate to implement output feedback based controller. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  7. Natural Gas: Investment Strategies In An Uncertain World

    International Nuclear Information System (INIS)

    Soliman, M.; Darwish, M.

    2004-01-01

    Natural Gas investment projects in developing countries (of which Egypt is a typical example) are one of the key industries in the evolving and continually changing energy market. It seems clear that the natural gas industry today is no longer limited by national boundaries, and that countries as well as organizations need to have an adaptive investment strategy and a global perspective if they are to survive and prosper in this . uncertain world. Many strategies will succeed or fail on the basis of their ability to deal with this dynamic environment. Strategy decisions are by their nature complex, and involve many imponderables. The selection of a course of action depends on the availability and interpretation of information, analysis, intuition, emotion, political awareness and many other factors. Different individuals and groups emphasize different aspects and, in the sense that a strategy decision is an advance into tbe unknown, there is no correct course of action; all that can be done is to interpret the current situation, form expectations about the future, and act according to personal views on risk and the likely course of events. It is usually possible to identify courses of action which are unlikely to be successful, and in that sense the strategy process can have real benefits in helping to avoid disastrous courses of action

  8. Dynamics Model Applied to Pricing Options with Uncertain Volatility

    Directory of Open Access Journals (Sweden)

    Lorella Fatone

    2012-01-01

    model is proposed. The data used to test the calibration problem included observations of asset prices over a finite set of (known equispaced discrete time values. Statistical tests were used to estimate the statistical significance of the two parameters of the Black-Scholes model: the volatility and the drift. The effects of these estimates on the option pricing problem were investigated. In particular, the pricing of an option with uncertain volatility in the Black-Scholes framework was revisited, and a statistical significance was associated with the price intervals determined using the Black-Scholes-Barenblatt equations. Numerical experiments involving synthetic and real data were presented. The real data considered were the daily closing values of the S&P500 index and the associated European call and put option prices in the year 2005. The method proposed here for calibrating the Black-Scholes dynamics model could be extended to other science and engineering models that may be expressed in terms of stochastic dynamical systems.

  9. The R Package bgmm : Mixture Modeling with Uncertain Knowledge

    Directory of Open Access Journals (Sweden)

    Przemys law Biecek

    2012-04-01

    Full Text Available Classical supervised learning enjoys the luxury of accessing the true known labels for the observations in a modeled dataset. Real life, however, poses an abundance of problems, where the labels are only partially defined, i.e., are uncertain and given only for a subsetof observations. Such partial labels can occur regardless of the knowledge source. For example, an experimental assessment of labels may have limited capacity and is prone to measurement errors. Also expert knowledge is often restricted to a specialized area and is thus unlikely to provide trustworthy labels for all observations in the dataset. Partially supervised mixture modeling is able to process such sparse and imprecise input. Here, we present an R package calledbgmm, which implements two partially supervised mixture modeling methods: soft-label and belief-based modeling. For completeness, we equipped the package also with the functionality of unsupervised, semi- and fully supervised mixture modeling. On real data we present the usage of bgmm for basic model-fitting in all modeling variants. The package can be applied also to selection of the best-fitting from a set of models with different component numbers or constraints on their structures. This functionality is presented on an artificial dataset, which can be simulated in bgmm from a distribution defined by a given model.

  10. Bayesian inference on genetic merit under uncertain paternity

    Directory of Open Access Journals (Sweden)

    Tempelman Robert J

    2003-09-01

    Full Text Available Abstract A hierarchical animal model was developed for inference on genetic merit of livestock with uncertain paternity. Fully conditional posterior distributions for fixed and genetic effects, variance components, sire assignments and their probabilities are derived to facilitate a Bayesian inference strategy using MCMC methods. We compared this model to a model based on the Henderson average numerator relationship (ANRM in a simulation study with 10 replicated datasets generated for each of two traits. Trait 1 had a medium heritability (h2 for each of direct and maternal genetic effects whereas Trait 2 had a high h2 attributable only to direct effects. The average posterior probabilities inferred on the true sire were between 1 and 10% larger than the corresponding priors (the inverse of the number of candidate sires in a mating pasture for Trait 1 and between 4 and 13% larger than the corresponding priors for Trait 2. The predicted additive and maternal genetic effects were very similar using both models; however, model choice criteria (Pseudo Bayes Factor and Deviance Information Criterion decisively favored the proposed hierarchical model over the ANRM model.

  11. Quantify uncertain emergency search techniques (QUEST) -- Theory and user's guide

    International Nuclear Information System (INIS)

    Johnson, M.M.; Goldsby, M.E.; Plantenga, T.D.; Porter, T.L.; West, T.H.; Wilcox, W.B.; Hensley, W.K.

    1998-01-01

    As recent world events show, criminal and terrorist access to nuclear materials is a growing national concern. The national laboratories are taking the lead in developing technologies to counter these potential threats to the national security. Sandia National laboratories, with support from Pacific Northwest National Laboratory and the Bechtel Nevada, Remote Sensing Laboratory, has developed QUEST (a model to Quantify Uncertain Emergency Search Techniques), to enhance the performance of organizations in the search for lost or stolen nuclear material. In addition, QUEST supports a wide range of other applications, such as environmental monitoring, nuclear facilities inspections, and searcher training. QUEST simulates the search for nuclear materials and calculates detector response for various source types and locations. The probability of detecting a radioactive source during a search is a function of many different variables, including source type, search location and structure geometry (including shielding), search dynamics (path and speed), and detector type and size. Through calculation of dynamic detector response, QUEST makes possible quantitative comparisons of various sensor technologies and search patterns. The QUEST model can be used as a tool to examine the impact of new detector technologies, explore alternative search concepts, and provide interactive search/inspector training

  12. The pan-European environment: glimpses into an uncertain future

    International Nuclear Information System (INIS)

    2007-01-01

    The rapidly changing nature of and increasing inter-linkages between many socio-economic phenomena - population growth and migration, globalisation and trade, personal consumption patterns and use of natural resources . are reflected in many of today's environment policy priorities: minimising and adapting to climate change; loss of biodiversity and ecosystem services; the degradation of such natural resources as land, freshwater and oceans; and the impacts of a wide range of pollutants on our environment and our health. The challenges that environmental policy makers are facing in this century are already very different from those of the last. Given the rapid change in socio.economic trends, both designing and implementing actions are becoming much more complex, and the way in which such policies deliver effective outcomes seems to be becoming increasingly uncertain. Alongside this, the time.lags between policy demands and institutional responses are often lengthening, with the institutional structures charged with designing and implementing agreed actions needing to change in order to keep up with this process. This report aims to contribute to the discussion about plausible future developments relevant to the wider European region and to stimulate medium to long-term thinking in policy-making circles. It does so by sketching some of the key environmental concerns for the pan-European region based on the EEA's Europe's environment - The fourth assessment, and by highlighting some of the many uncertainties the future holds. (au)

  13. Uncertain Environmental Footprint of Current and Future Battery Electric Vehicles.

    Science.gov (United States)

    Cox, Brian; Mutel, Christopher L; Bauer, Christian; Mendoza Beltran, Angelica; van Vuuren, Detlef P

    2018-04-17

    The future environmental impacts of battery electric vehicles (EVs) are very important given their expected dominance in future transport systems. Previous studies have shown these impacts to be highly uncertain, though a detailed treatment of this uncertainty is still lacking. We help to fill this gap by using Monte Carlo and global sensitivity analysis to quantify parametric uncertainty and also consider two additional factors that have not yet been addressed in the field. First, we include changes to driving patterns due to the introduction of autonomous and connected vehicles. Second, we deeply integrate scenario results from the IMAGE integrated assessment model into our life cycle database to include the impacts of changes to the electricity sector on the environmental burdens of producing and recharging future EVs. Future EVs are expected to have 45-78% lower climate change impacts than current EVs. Electricity used for charging is the largest source of variability in results, though vehicle size, lifetime, driving patterns, and battery size also strongly contribute to variability. We also show that it is imperative to consider changes to the electricity sector when calculating upstream impacts of EVs, as without this, results could be overestimated by up to 75%.

  14. Dermal Squamomelanocytic Tumor: Neoplasm of Uncertain Biological Potential

    Directory of Open Access Journals (Sweden)

    Mirsad Dorić

    2008-05-01

    Full Text Available We report a case of exceedingly rare cutaneous neoplasm with histological features of malignancy and uncertain biological potential. The nodular, darkly pigmented facial tumor with central exulceration, size 12x10x7 mm, of the skin 61-year-old man preauricular left was completely exised.Histologically tumor consists of atypical squamous cells, which express signs of moderate to significant pleomorphism, mitotically active, with foci forming of parakeratotic horn cysts (“pearls”. Characteristically tumor also consists of large number of atypical melanocytes with multifocal pattern, inserted between atypical squamous cells, and which contain large amount of dark brown pigment melanin. Immunohistochemically, squamous cells stain positively with keratin (CK116, melanocytes were stained with S -100 protein, HMB 45, and vimentin, but failed to stain with CK 116.To our knowledge this is the sixth reported case in world literature. The follow-up time of four years no evidence of recurrence or metastasis, similar all reported cases, but it is too short period in estimation to guarantee a benign course. However, it appears that this group of neoplasm may have different prognosis from pure squamous carcinoma or malignant melanoma.

  15. Uncertain hybrid model for the response calculation of an alternator

    International Nuclear Information System (INIS)

    Kuczkowiak, Antoine

    2014-01-01

    The complex structural dynamic behavior of alternator must be well understood in order to insure their reliable and safe operation. The numerical model is however difficult to construct mainly due to the presence of a high level of uncertainty. The objective of this work is to provide decision support tools in order to assess the vibratory levels in operation before to restart the alternator. Based on info-gap theory, a first decision support tool is proposed: the objective here is to assess the robustness of the dynamical response to the uncertain modal model. Based on real data, the calibration of an info-gap model of uncertainty is also proposed in order to enhance its fidelity to reality. Then, the extended constitutive relation error is used to expand identified mode shapes which are used to assess the vibratory levels. The robust expansion process is proposed in order to obtain robust expanded mode shapes to parametric uncertainties. In presence of lack-of knowledge, the trade-off between fidelity-to-data and robustness-to-uncertainties which expresses that robustness improves as fidelity deteriorates is emphasized on an industrial structure by using both reduced order model and surrogate model techniques. (author)

  16. Developing a crevice chemistry control target from uncertain data

    International Nuclear Information System (INIS)

    Millett, P.J.

    1996-01-01

    It has been generally accepted that the corrosion of steam generator tubing could be reduced if the local pH in regions where impurities concentrate could be controlled. The practice of molar ratio control is based on this assumption. Direct measurement of the crevice chemistry is not possible at this time. Deterministic models based on bulk water conditions are quite uncertain, due to both the variability of crevices in the steam generator and the level of impurities in the bulk water which are often below or at the level of detection. The current methodology for assessing the crevice chemistry is to monitor the hideout return chemistry when the plant shuts down. This approach also has its shortcomings, but may provide sufficient data to evaluate whether the crevice pH is in a desirable range. In this paper, an approach for establishing a target crevice chemistry based on the plant data which is believed to be the most certain or reliable is presented

  17. The Environmental Kuznets Curve. An empirical analysis for OECD countries

    Energy Technology Data Exchange (ETDEWEB)

    Georgiev, E.

    2008-09-15

    This paper tests the Environmental Kuznets Curve hypothesis for four local (SOx, NOx, CO, VOC) and two global (CO2, GHG) air pollutants. Using a new panel data set of thirty OECD countries, the paper finds that the postulated inverted U-shaped relationship between income and pollution does not hold for all gases. A meaningful Environmental Kuznets Curve exists only for CO, VOC and NOx, where for CO2 the curve is monotonically increasing. For GHG there is indication of an inverted U-shaped relationship between income and pollution, but still most countries are on the increasing path of the curve and hence the future development of the curve is uncertain. For SOx it was found that emissions follow an U-shaped curve. Based on the empirical results, the paper concludes that the Environmental Kuznets Curve does not hold for all gases, it is rather an empirical artefact than a regularity.

  18. The Environmental Kuznets Curve. An empirical analysis for OECD countries

    International Nuclear Information System (INIS)

    Georgiev, E.

    2008-09-01

    This paper tests the Environmental Kuznets Curve hypothesis for four local (SOx, NOx, CO, VOC) and two global (CO2, GHG) air pollutants. Using a new panel data set of thirty OECD countries, the paper finds that the postulated inverted U-shaped relationship between income and pollution does not hold for all gases. A meaningful Environmental Kuznets Curve exists only for CO, VOC and NOx, where for CO2 the curve is monotonically increasing. For GHG there is indication of an inverted U-shaped relationship between income and pollution, but still most countries are on the increasing path of the curve and hence the future development of the curve is uncertain. For SOx it was found that emissions follow an U-shaped curve. Based on the empirical results, the paper concludes that the Environmental Kuznets Curve does not hold for all gases, it is rather an empirical artefact than a regularity.

  19. Enhanced Particle Swarm Optimization-Based Feeder Reconfiguration Considering Uncertain Large Photovoltaic Powers and Demands

    Directory of Open Access Journals (Sweden)

    Ying-Yi Hong

    2014-01-01

    Full Text Available The Kyoto protocol recommended that industrialized countries limit their green gas emissions in 2012 to 5.2% below 1990 levels. Photovoltaic (PV arrays provide clear and sustainable renewable energy to electric power systems. Solar PV arrays can be installed in distribution systems of rural and urban areas, as opposed to wind-turbine generators, which cause noise in surrounding environments. However, a large PV array (several MW may incur several operation problems, for example, low power quality and reverse power. This work presents a novel method to reconfigure the distribution feeders in order to prevent the injection of reverse power into a substation connected to the transmission level. Moreover, a two-stage algorithm is developed, in which the uncertain bus loads and PV powers are clustered by fuzzy-c-means to gain representative scenarios; optimal reconfiguration is then achieved by a novel mean-variance-based particle swarm optimization. The system loss is minimized while the operational constraints, including reverse power and voltage variation, are satisfied due to the optimal feeder reconfiguration. Simulation results obtained from a 70-bus distribution system with 4 large PV arrays validate the proposed method.

  20. Baseload coal investment decisions under uncertain carbon legislation.

    Science.gov (United States)

    Bergerson, Joule A; Lave, Lester B

    2007-05-15

    More than 50% of electricity in the U.S. is generated by coal. The U.S. has large coal resources, the cheapest fuel in most areas. Coal fired power plants are likely to continue to provide much of U.S. electricity. However, the type of power plant that should be built is unclear. Technology can reduce pollutant discharges and capture and sequester the CO2 from coal-fired generation. The U.S. Energy Policy Act of 2005 provides incentives for large scale commercial deployment of Integrated Coal Gasification Combined Cycle (IGCC) systems (e.g., loan guarantees and project tax credits). This analysis examines whether a new coal plant should be Pulverized Coal (PC) or IGCC. Do stricter emissions standards (PM, SO2, NOx, Hg) justify the higher costs of IGCC over PC? How does potential future carbon legislation affect the decision to add carbon capture and storage (CCS) technology? Finally, can the impact of uncertain carbon legislation be minimized? We find that SO2, NOx, PM, and Hg emission standards would have to be far more stringent than twice current standards to justify the increased costs of the IGCC system. A C02 tax less than $29/ton would lead companies to continuing to choose PC, paying the tax for emitted CO2. The earlier a decision-maker believes the carbon tax will be imposed and the higher the tax, the more likely companies will choose IGCC w/CCS. Having government announce the date and level of a carbon tax would promote more sensible decisions, but government would have to use a tax or subsidy to induce companies to choose the technology that is best for society.

  1. Floor response spectra of buildings with uncertain structural properties

    International Nuclear Information System (INIS)

    Chen, P.C.

    1975-01-01

    All Category I equipment, such as reactors, vessels, and major piping systems of nuclear power plants, is required to withstand earthquake loadings in order to minimize risk of seismic damage. The equipment is designed by using response spectra of the floor on which the equipment is mounted. The floor response spectra are constructed usually from the floor response time histories which are obtained through a deterministic dynamic analysis. This analysis assumes that all structural parameters, such as mass, stiffness, and damping have been calculated precisely, and that the earthquakes are known. However, structural parameters are usually difficult to determine precisely if the structures are massive and/or irregular, such as nuclear containments and its internal structures with foundation soil incorporated into the analysis. Faced with these uncertainties, it has been the practice to broaden the floor response spectra peaks by +-10 percent of the peak frequencies on the basis of conservatism. This approach is based on engineering judgement and does not have an analytical basis to provide a sufficient level of confidence in using these spectra for equipment design. To insure reliable design, it is necessary to know structural response variations due to variations in structural properties. This consideration leads to the treatment of structural properties as random variables and the use of probabilistic methods to predict structural response more accurately. New results on floor response spectra of buildings with uncertain structural properties obtained by determining the probabilistic dynamic response from the deterministic dynamic response and its standard deviation are presented. The resulting probabilistic floor response spectra are compared with those obtained deterministically, and are shown to provide a more reliable method for determining seismic forces

  2. An uncertain journey around the tails of multivariate hydrological distributions

    Science.gov (United States)

    Serinaldi, Francesco

    2013-10-01

    Moving from univariate to multivariate frequency analysis, this study extends the Klemeš' critique of the widespread belief that the increasingly refined mathematical structures of probability functions increase the accuracy and credibility of the extrapolated upper tails of the fitted distribution models. In particular, we discuss key aspects of multivariate frequency analysis applied to hydrological data such as the selection of multivariate design events (i.e., appropriate subsets or scenarios of multiplets that exhibit the same joint probability to be used in design applications) and the assessment of the corresponding uncertainty. Since these problems are often overlooked or treated separately, and sometimes confused, we attempt to clarify properties, advantages, shortcomings, and reliability of results of frequency analysis. We suggest a selection method of multivariate design events with prescribed joint probability based on simple Monte Carlo simulations that accounts for the uncertainty affecting the inference results and the multivariate extreme quantiles. It is also shown that the exploration of the p-level probability regions of a joint distribution returns a set of events that is a subset of the p-level scenarios resulting from an appropriate assessment of the sampling uncertainty, thus tending to overlook more extreme and potentially dangerous events with the same (uncertain) joint probability. Moreover, a quantitative assessment of the uncertainty of multivariate quantiles is provided by introducing the concept of joint confidence intervals. From an operational point of view, the simulated event sets describing the distribution of the multivariate p-level quantiles can be used to perform multivariate risk analysis under sampling uncertainty. As an example of the practical implications of this study, we analyze two case studies already presented in the literature.

  3. Epistemology and Empirical Investigation

    DEFF Research Database (Denmark)

    Ahlström, Kristoffer

    2008-01-01

    Recently, Hilary Kornblith has argued that epistemological investigation is substantially empirical. In the present paper, I will ¿rst show that his claim is not contingent upon the further and, admittedly, controversial assumption that all objects of epistemological investigation are natural kinds....... Then, I will argue that, contrary to what Kornblith seems to assume, this methodological contention does not imply that there is no need for attending to our epistemic concepts in epistemology. Understanding the make-up of our concepts and, in particular, the purposes they ¿ll, is necessary...

  4. OARSI Clinical Trials Recommendations

    DEFF Research Database (Denmark)

    McAlindon, T. E.; Driban, J. B.; Henrotin, Y.

    2015-01-01

    The goal of this document is to update the original OARSI recommendations specifically for the design, conduct, and reporting of clinical trials that target symptom or structure modification among individuals with knee osteoarthritis (OA). To develop recommendations for the design, conduct...

  5. Non probabilistic solution of uncertain neutron diffusion equation for imprecisely defined homogeneous bare reactor

    International Nuclear Information System (INIS)

    Chakraverty, S.; Nayak, S.

    2013-01-01

    Highlights: • Uncertain neutron diffusion equation of bare square homogeneous reactor is studied. • Proposed interval arithmetic is extended for fuzzy numbers. • The developed fuzzy arithmetic is used to handle uncertain parameters. • Governing differential equation is modelled by modified fuzzy finite element method. • Fuzzy critical eigenvalues and effective multiplication factors are investigated. - Abstract: The scattering of neutron collision inside a reactor depends upon geometry of the reactor, diffusion coefficient and absorption coefficient etc. In general these parameters are not crisp and hence we get uncertain neutron diffusion equation. In this paper we have investigated the above equation for a bare square homogeneous reactor. Here the uncertain governing differential equation is modelled by a modified fuzzy finite element method. Using modified fuzzy finite element method, obtained eigenvalues and effective multiplication factors are studied. Corresponding results are compared with the classical finite element method in special cases and various uncertain results have been discussed

  6. Empirical microeconomics action functionals

    Science.gov (United States)

    Baaquie, Belal E.; Du, Xin; Tanputraman, Winson

    2015-06-01

    A statistical generalization of microeconomics has been made in Baaquie (2013), where the market price of every traded commodity, at each instant of time, is considered to be an independent random variable. The dynamics of commodity market prices is modeled by an action functional-and the focus of this paper is to empirically determine the action functionals for different commodities. The correlation functions of the model are defined using a Feynman path integral. The model is calibrated using the unequal time correlation of the market commodity prices as well as their cubic and quartic moments using a perturbation expansion. The consistency of the perturbation expansion is verified by a numerical evaluation of the path integral. Nine commodities drawn from the energy, metal and grain sectors are studied and their market behavior is described by the model to an accuracy of over 90% using only six parameters. The paper empirically establishes the existence of the action functional for commodity prices that was postulated to exist in Baaquie (2013).

  7. A Classification-based Review Recommender

    Science.gov (United States)

    O'Mahony, Michael P.; Smyth, Barry

    Many online stores encourage their users to submit product/service reviews in order to guide future purchasing decisions. These reviews are often listed alongside product recommendations but, to date, limited attention has been paid as to how best to present these reviews to the end-user. In this paper, we describe a supervised classification approach that is designed to identify and recommend the most helpful product reviews. Using the TripAdvisor service as a case study, we compare the performance of several classification techniques using a range of features derived from hotel reviews. We then describe how these classifiers can be used as the basis for a practical recommender that automatically suggests the mosthelpful contrasting reviews to end-users. We present an empirical evaluation which shows that our approach achieves a statistically significant improvement over alternative review ranking schemes.

  8. Salmonella typhi time to change empiric treatment

    DEFF Research Database (Denmark)

    Gade, C.; Engberg, J.; Weis, N.

    2008-01-01

    In the present case series report we describe seven recent cases of typhoid fever. All the patients were travellers returning from Pakistan, where typhoid is endemic. Salmonella typhi isolated from the patients by blood culture were reported as intermediary susceptible to fluoroquinolones in six...... out of seven cases. We recommend that empiric treatment of suspected cases of typhoid fever includes a third generation cephalosporin such as ceftriaxon. Furthermore, the present report stresses the importance of typhoid vaccination of travellers to areas where typhoid is endemic Udgivelsesdato: 2008/9/29...

  9. What 'empirical turn in bioethics'?

    Science.gov (United States)

    Hurst, Samia

    2010-10-01

    Uncertainty as to how we should articulate empirical data and normative reasoning seems to underlie most difficulties regarding the 'empirical turn' in bioethics. This article examines three different ways in which we could understand 'empirical turn'. Using real facts in normative reasoning is trivial and would not represent a 'turn'. Becoming an empirical discipline through a shift to the social and neurosciences would be a turn away from normative thinking, which we should not take. Conducting empirical research to inform normative reasoning is the usual meaning given to the term 'empirical turn'. In this sense, however, the turn is incomplete. Bioethics has imported methodological tools from empirical disciplines, but too often it has not imported the standards to which researchers in these disciplines are held. Integrating empirical and normative approaches also represents true added difficulties. Addressing these issues from the standpoint of debates on the fact-value distinction can cloud very real methodological concerns by displacing the debate to a level of abstraction where they need not be apparent. Ideally, empirical research in bioethics should meet standards for empirical and normative validity similar to those used in the source disciplines for these methods, and articulate these aspects clearly and appropriately. More modestly, criteria to ensure that none of these standards are completely left aside would improve the quality of empirical bioethics research and partly clear the air of critiques addressing its theoretical justification, when its rigour in the particularly difficult context of interdisciplinarity is what should be at stake.

  10. Multirelational Social Recommendations via Multigraph Ranking.

    Science.gov (United States)

    Mao, Mingsong; Lu, Jie; Zhang, Guangquan; Zhang, Jinlong

    2017-12-01

    Recommender systems aim to identify relevant items for particular users in large-scale online applications. The historical rating data of users is a valuable input resource for many recommendation models such as collaborative filtering (CF), but these models are known to suffer from the rating sparsity problem when the users or items under consideration have insufficient rating records. With the continued growth of online social networks, the increased user-to-user relationships are reported to be helpful and can alleviate the CF rating sparsity problem. Although researchers have developed a range of social network-based recommender systems, there is no unified model to handle multirelational social networks. To address this challenge, this paper represents different user relationships in a multigraph and develops a multigraph ranking model to identify and recommend the nearest neighbors of particular users in high-order environments. We conduct empirical experiments on two real-world datasets: 1) Epinions and 2) Last.fm, and the comprehensive comparison with other approaches demonstrates that our model improves recommendation performance in terms of both recommendation coverage and accuracy, especially when the rating data are sparse.

  11. Recommendations for reducing ambiguity in written procedures.

    Energy Technology Data Exchange (ETDEWEB)

    Matzen, Laura E.

    2009-11-01

    Previous studies in the nuclear weapons complex have shown that ambiguous work instructions (WIs) and operating procedures (OPs) can lead to human error, which is a major cause for concern. This report outlines some of the sources of ambiguity in written English and describes three recommendations for reducing ambiguity in WIs and OPs. The recommendations are based on commonly used research techniques in the fields of linguistics and cognitive psychology. The first recommendation is to gather empirical data that can be used to improve the recommended word lists that are provided to technical writers. The second recommendation is to have a review in which new WIs and OPs and checked for ambiguities and clarity. The third recommendation is to use self-paced reading time studies to identify any remaining ambiguities before the new WIs and OPs are put into use. If these three steps are followed for new WIs and OPs, the likelihood of human errors related to ambiguity could be greatly reduced.

  12. Recommender Systems for Learning

    CERN Document Server

    Manouselis, Nikos; Verbert, Katrien; Duval, Erik

    2013-01-01

    Technology enhanced learning (TEL) aims to design, develop and test sociotechnical innovations that will support and enhance learning practices of both individuals and organisations. It is therefore an application domain that generally covers technologies that support all forms of teaching and learning activities. Since information retrieval (in terms of searching for relevant learning resources to support teachers or learners) is a pivotal activity in TEL, the deployment of recommender systems has attracted increased interest. This brief attempts to provide an introduction to recommender systems for TEL settings, as well as to highlight their particularities compared to recommender systems for other application domains.

  13. 1990 recommendations of ICRP

    International Nuclear Information System (INIS)

    Clarke, R.H.

    1991-01-01

    The Main Commission of ICRP finalised its new recommendations during its November 1990 meeting. The recommendations will appear in the Annals of the ICRP in 1991 as Publication 60. This paper represents a personal summary of these recommendations. It covers the basic biological risk estimates and the conceptual framework of the system of radiological protection, the definition of radiation detriment and its use both in the definition of radiation quantities and in the establishment of the dose limits adopted by the Main Commissions. (author)

  14. Recommendations for CSF AD biomarkers in the diagnostic evaluation of dementia

    DEFF Research Database (Denmark)

    Simonsen, Anja Hviid; Herukka, Sanna-Kaisa; Andreasen, Niels

    2017-01-01

    . The recommendations were developed by a multidisciplinary working group based on the available evidence and consensus from focused discussions for (i) identification of Alzheimer's disease (AD) as the cause of dementia, (ii) prediction of rate of decline, (iii) cost-effectiveness, and (iv) interpretation of results......This article presents recommendations, based on the Grading of Recommendations, Assessment, Development, and Evaluation method, for the clinical application of cerebrospinal fluid (CSF) amyloid-β1-42, tau, and phosphorylated tau in the diagnostic evaluation of patients with dementia....... The working group found sufficient evidence to support a recommendation to use CSF AD biomarkers as a supplement to clinical evaluation, particularly in uncertain and atypical cases, to identify or exclude AD as the cause of dementia. Because of insufficient evidence, it was uncertain whether CSF AD...

  15. Reproducing an extreme flood with uncertain post-event information

    Directory of Open Access Journals (Sweden)

    D. Fuentes-Andino

    2017-07-01

    Full Text Available Studies for the prevention and mitigation of floods require information on discharge and extent of inundation, commonly unavailable or uncertain, especially during extreme events. This study was initiated by the devastating flood in Tegucigalpa, the capital of Honduras, when Hurricane Mitch struck the city. In this study we hypothesized that it is possible to estimate, in a trustworthy way considering large data uncertainties, this extreme 1998 flood discharge and the extent of the inundations that followed from a combination of models and post-event measured data. Post-event data collected in 2000 and 2001 were used to estimate discharge peaks, times of peak, and high-water marks. These data were used in combination with rain data from two gauges to drive and constrain a combination of well-known modelling tools: TOPMODEL, Muskingum–Cunge–Todini routing, and the LISFLOOD-FP hydraulic model. Simulations were performed within the generalized likelihood uncertainty estimation (GLUE uncertainty-analysis framework. The model combination predicted peak discharge, times of peaks, and more than 90 % of the observed high-water marks within the uncertainty bounds of the evaluation data. This allowed an inundation likelihood map to be produced. Observed high-water marks could not be reproduced at a few locations on the floodplain. Identifications of these locations are useful to improve model set-up, model structure, or post-event data-estimation methods. Rainfall data were of central importance in simulating the times of peak and results would be improved by a better spatial assessment of rainfall, e.g. from radar data or a denser rain-gauge network. Our study demonstrated that it was possible, considering the uncertainty in the post-event data, to reasonably reproduce the extreme Mitch flood in Tegucigalpa in spite of no hydrometric gauging during the event. The method proposed here can be part of a Bayesian framework in which more events

  16. The future context of work in the business environment in South Africa: Some empirical evidence

    OpenAIRE

    PS Nel; AJ Du Plessis; AE Marx

    2014-01-01

    The future is uncertain, but management needs to determine and also be informed about possible change trends. This research, however, reports on empirical results of the views of South African HRM practitioners to identify and prioritise business change trends for 2002 and 2010 in terms of the “hard” or “soft” HRM debate in the literature. All organisations employing HRM practitioners were include and a total of 1640 questionnaires were distributed resulting in 207 useable responses.   ...

  17. Mesothelioma of tunica vaginalis of "uncertain malignant potential" - an evolving concept: case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Yilmaz Asli

    2011-08-01

    Full Text Available Abstract Mesothelioma of tunica vaginalis is a rare neoplasm, typically demonstrating frankly malignant morphology and aggressive behavior. Rare cases of well-differentiated papillary mesotheliomas have also been reported, which, in contrast, demonstrate indolent behavior. There are, however, cases which do not fit into the well-differentiated or diffuse malignant mesothelioma categories and can be considered mesothelioma of tunica vaginalis of "uncertain malignant potential", which is an emerging diagnostic category. A 57-year-old man presented with a neoplasm in a hydrocele sac. The neoplasm was non-invasive, but showed focal complex and solid growth and it was difficult to categorize either as well-differentiated papillary mesotheliomas or malignant mesothelioma. After the initial limited resection, the patient underwent radical orchiectomy with hemiscrotectomy and is alive and without disease progression after 6 years. Documentation of these rare tumors will allow their distinction from true malignant mesotheliomas and will facilitate the development of specific treatment recommendations.

  18. EGG: Empirical Galaxy Generator

    Science.gov (United States)

    Schreiber, C.; Elbaz, D.; Pannella, M.; Merlin, E.; Castellano, M.; Fontana, A.; Bourne, N.; Boutsia, K.; Cullen, F.; Dunlop, J.; Ferguson, H. C.; Michałowski, M. J.; Okumura, K.; Santini, P.; Shu, X. W.; Wang, T.; White, C.

    2018-04-01

    The Empirical Galaxy Generator (EGG) generates fake galaxy catalogs and images with realistic positions, morphologies and fluxes from the far-ultraviolet to the far-infrared. The catalogs are generated by egg-gencat and stored in binary FITS tables (column oriented). Another program, egg-2skymaker, is used to convert the generated catalog into ASCII tables suitable for ingestion by SkyMaker (ascl:1010.066) to produce realistic high resolution images (e.g., Hubble-like), while egg-gennoise and egg-genmap can be used to generate the low resolution images (e.g., Herschel-like). These tools can be used to test source extraction codes, or to evaluate the reliability of any map-based science (stacking, dropout identification, etc.).

  19. Probabilistic approaches to recommendations

    CERN Document Server

    Barbieri, Nicola; Ritacco, Ettore

    2014-01-01

    The importance of accurate recommender systems has been widely recognized by academia and industry, and recommendation is rapidly becoming one of the most successful applications of data mining and machine learning. Understanding and predicting the choices and preferences of users is a challenging task: real-world scenarios involve users behaving in complex situations, where prior beliefs, specific tendencies, and reciprocal influences jointly contribute to determining the preferences of users toward huge amounts of information, services, and products. Probabilistic modeling represents a robus

  20. Synchronization of uncertain time-varying network based on sliding mode control technique

    Science.gov (United States)

    Lü, Ling; Li, Chengren; Bai, Suyuan; Li, Gang; Rong, Tingting; Gao, Yan; Yan, Zhe

    2017-09-01

    We research synchronization of uncertain time-varying network based on sliding mode control technique. The sliding mode control technique is first modified so that it can be applied to network synchronization. Further, by choosing the appropriate sliding surface, the identification law of uncertain parameter, the adaptive law of the time-varying coupling matrix element and the control input of network are designed, it is sure that the uncertain time-varying network can synchronize effectively the synchronization target. At last, we perform some numerical simulations to demonstrate the effectiveness of the proposed results.

  1. A model for the inverse 1-median problem on trees under uncertain costs

    Directory of Open Access Journals (Sweden)

    Kien Trung Nguyen

    2016-01-01

    Full Text Available We consider the problem of justifying vertex weights of a tree under uncertain costs so that a prespecified vertex become optimal and the total cost should be optimal in the uncertainty scenario. We propose a model which delivers the information about the optimal cost which respect to each confidence level \\(\\alpha \\in [0,1]\\. To obtain this goal, we first define an uncertain variable with respect to the minimum cost in each confidence level. If all costs are independently linear distributed, we present the inverse distribution function of this uncertain variable in \\(O(n^{2}\\log n\\ time, where \\(n\\ is the number of vertices in the tree.

  2. Adaptive observer based synchronization of a class of uncertain chaotic systems

    International Nuclear Information System (INIS)

    Bowong, S.; Yamapi, R.

    2005-05-01

    This study addresses the adaptive synchronization of a class of uncertain chaotic systems in the drive-response framework. For a class of uncertain chaotic systems with unknown parameters and external disturbances, a robust adaptive observer based response system is constructed to synchronize the uncertain chaotic system. Lyapunov stability theory and Barbalat lemma ensure the global synchronization between the drive and response systems even if Lipschitz constants on function matrices and bounds on uncertainties are unknown. Numerical simulation of the Genesio-Tesi system verifies the effectiveness of the proposed method. (author)

  3. Robust output feedback H-infinity control and filtering for uncertain linear systems

    CERN Document Server

    Chang, Xiao-Heng

    2014-01-01

    "Robust Output Feedback H-infinity Control and Filtering for Uncertain Linear Systems" discusses new and meaningful findings on robust output feedback H-infinity control and filtering for uncertain linear systems, presenting a number of useful and less conservative design results based on the linear matrix inequality (LMI) technique. Though primarily intended for graduate students in control and filtering, the book can also serve as a valuable reference work for researchers wishing to explore the area of robust H-infinity control and filtering of uncertain systems. Dr. Xiao-Heng Chang is a Professor at the College of Engineering, Bohai University, China.

  4. A Hybrid Recommender System Based on User-Recommender Interaction

    OpenAIRE

    Zhang, Heng-Ru; Min, Fan; He, Xu; Xu, Yuan-Yuan

    2015-01-01

    Recommender systems are used to make recommendations about products, information, or services for users. Most existing recommender systems implicitly assume one particular type of user behavior. However, they seldom consider user-recommender interactive scenarios in real-world environments. In this paper, we propose a hybrid recommender system based on user-recommender interaction and evaluate its performance with recall and diversity metrics. First, we define the user-recommender interaction...

  5. Uncertain Governance and Resilient Subjects in the Risk Society

    Directory of Open Access Journals (Sweden)

    Pat O'Malley

    2013-04-01

    Full Text Available Over the past decade or so, a series of new or revitalised strategies have been promoted to govern the highly uncertain threats that risk appears no longer able to prevent. Most owe their ascendancy to the lessons of 9/11, and the ‘bureaucratising of imagination’ that US sources have proposed as a response, by centring the possible, or even merely imaginable, rather than the statistically probable. Precaution, preparedness and speculative pre-emption have been particularly prominent, although new hybrid statistical and speculative techniques have broadened risk techniques to cope with labile conditions of high uncertainty. But while diverse, each establishes a negative and defensive framework of ‘freedom from’ that has been associated with creating a ’neurotic subject’. In the past decade, programs of resilience, and particularly resiliency training, have been developed with the aim of creating subjects able to thrive and prosper under conditions of extreme uncertainty. They constitute a form of governance promoting a positive ‘freedom to’. Reflecting many of the assumptions and goals of neo-liberal politics, resiliency has already emerged as a principal technology for military and business, and may be the answer to the neo-liberal dream of a society of extreme entrepreneurs. Durante la última década, se han promovido varias estrategias nuevas o renovadas destinadas a gestionar amenazas que el riesgo ya no parece capaz de prevenir. La mayoría deben su predominancia a las lecciones aprendidas tras el 11-S, y la “burocratización de la imaginación” que las fuentes estadounidenses han propuesto como respuesta, predominando lo posible, o incluso simplemente lo imaginable, por encima de lo estadísticamente probable. Han predominado la precaución, preparación y especulación preventivas, aunque las nuevas técnicas estadísticas y especulativas híbridas han ampliado las técnicas de riesgo para hacer frente a las

  6. Characterizing uncertain sea-level rise projections to support investment decisions

    Science.gov (United States)

    Lempert, Robert J.; Wikman-Svahn, Per; Keller, Klaus

    2018-01-01

    Many institutions worldwide are considering how to include uncertainty about future changes in sea-levels and storm surges into their investment decisions regarding large capital infrastructures. Here we examine how to characterize deeply uncertain climate change projections to support such decisions using Robust Decision Making analysis. We address questions regarding how to confront the potential for future changes in low probability but large impact flooding events due to changes in sea-levels and storm surges. Such extreme events can affect investments in infrastructure but have proved difficult to consider in such decisions because of the deep uncertainty surrounding them. This study utilizes Robust Decision Making methods to address two questions applied to investment decisions at the Port of Los Angeles: (1) Under what future conditions would a Port of Los Angeles decision to harden its facilities against extreme flood scenarios at the next upgrade pass a cost-benefit test, and (2) Do sea-level rise projections and other information suggest such conditions are sufficiently likely to justify such an investment? We also compare and contrast the Robust Decision Making methods with a full probabilistic analysis. These two analysis frameworks result in similar investment recommendations for different idealized future sea-level projections, but provide different information to decision makers and envision different types of engagement with stakeholders. In particular, the full probabilistic analysis begins by aggregating the best scientific information into a single set of joint probability distributions, while the Robust Decision Making analysis identifies scenarios where a decision to invest in near-term response to extreme sea-level rise passes a cost-benefit test, and then assembles scientific information of differing levels of confidence to help decision makers judge whether or not these scenarios are sufficiently likely to justify making such investments

  7. Characterizing uncertain sea-level rise projections to support investment decisions.

    Science.gov (United States)

    Sriver, Ryan L; Lempert, Robert J; Wikman-Svahn, Per; Keller, Klaus

    2018-01-01

    Many institutions worldwide are considering how to include uncertainty about future changes in sea-levels and storm surges into their investment decisions regarding large capital infrastructures. Here we examine how to characterize deeply uncertain climate change projections to support such decisions using Robust Decision Making analysis. We address questions regarding how to confront the potential for future changes in low probability but large impact flooding events due to changes in sea-levels and storm surges. Such extreme events can affect investments in infrastructure but have proved difficult to consider in such decisions because of the deep uncertainty surrounding them. This study utilizes Robust Decision Making methods to address two questions applied to investment decisions at the Port of Los Angeles: (1) Under what future conditions would a Port of Los Angeles decision to harden its facilities against extreme flood scenarios at the next upgrade pass a cost-benefit test, and (2) Do sea-level rise projections and other information suggest such conditions are sufficiently likely to justify such an investment? We also compare and contrast the Robust Decision Making methods with a full probabilistic analysis. These two analysis frameworks result in similar investment recommendations for different idealized future sea-level projections, but provide different information to decision makers and envision different types of engagement with stakeholders. In particular, the full probabilistic analysis begins by aggregating the best scientific information into a single set of joint probability distributions, while the Robust Decision Making analysis identifies scenarios where a decision to invest in near-term response to extreme sea-level rise passes a cost-benefit test, and then assembles scientific information of differing levels of confidence to help decision makers judge whether or not these scenarios are sufficiently likely to justify making such investments

  8. Genetic purgatory and the cardiac channelopathies: Exposing the variants of uncertain/unknown significance issue.

    Science.gov (United States)

    Ackerman, Michael J

    2015-11-01

    Merriam-Webster's online dictionary defines purgatory as "an intermediate state after death for expiatory purification" or more specifically as "a place or state of punishment wherein according to Roman Catholic doctrine the souls of those who die in God׳s grace may make satisfaction for past sins and so become fit for heaven." Alternatively, it is defined as "a place or state of temporary suffering or misery." Either way, purgatory is a place where you are stuck, and you don't want to be stuck there. It is in this context that the term genetic purgatory is introduced. Genetic purgatory is a place where the genetic test-ordering physician and patients and their families are stuck when a variant of uncertain/unknown significance (VUS) has been elucidated. It is in this dark place where suffering and misery are occurring because of unenlightened handling of a VUS, which includes using the VUS for predictive genetic testing and making radical treatment recommendations based on the presence or absence of a so-called maybe mutation. Before one can escape from this miserable place, one must first recognize that one is stuck there. Hence, the purpose of this review article is to fully expose the VUS issue as it relates to the cardiac channelopathies and make the cardiologists/geneticists/genetic counselors who order such genetic tests believers in genetic purgatory. Only then can one meaningfully attempt to get out of that place and seek to promote a VUS to disease-causative mutation status or demote it to an utterly innocuous and irrelevant variant. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  9. Characterizing uncertain sea-level rise projections to support investment decisions.

    Directory of Open Access Journals (Sweden)

    Ryan L Sriver

    Full Text Available Many institutions worldwide are considering how to include uncertainty about future changes in sea-levels and storm surges into their investment decisions regarding large capital infrastructures. Here we examine how to characterize deeply uncertain climate change projections to support such decisions using Robust Decision Making analysis. We address questions regarding how to confront the potential for future changes in low probability but large impact flooding events due to changes in sea-levels and storm surges. Such extreme events can affect investments in infrastructure but have proved difficult to consider in such decisions because of the deep uncertainty surrounding them. This study utilizes Robust Decision Making methods to address two questions applied to investment decisions at the Port of Los Angeles: (1 Under what future conditions would a Port of Los Angeles decision to harden its facilities against extreme flood scenarios at the next upgrade pass a cost-benefit test, and (2 Do sea-level rise projections and other information suggest such conditions are sufficiently likely to justify such an investment? We also compare and contrast the Robust Decision Making methods with a full probabilistic analysis. These two analysis frameworks result in similar investment recommendations for different idealized future sea-level projections, but provide different information to decision makers and envision different types of engagement with stakeholders. In particular, the full probabilistic analysis begins by aggregating the best scientific information into a single set of joint probability distributions, while the Robust Decision Making analysis identifies scenarios where a decision to invest in near-term response to extreme sea-level rise passes a cost-benefit test, and then assembles scientific information of differing levels of confidence to help decision makers judge whether or not these scenarios are sufficiently likely to justify making

  10. Birds of the Mongol Empire

    OpenAIRE

    Eugene N. Anderson

    2016-01-01

    The Mongol Empire, the largest contiguous empire the world has ever known, had, among other things, a goodly number of falconers, poultry raisers, birdcatchers, cooks, and other experts on various aspects of birding. We have records of this, largely in the Yinshan Zhengyao, the court nutrition manual of the Mongol empire in China (the Yuan Dynasty). It discusses in some detail 22 bird taxa, from swans to chickens. The Huihui Yaofang, a medical encyclopedia, lists ten taxa used medicinally. Ma...

  11. Growing Wikipedia Across Languages via Recommendation

    Science.gov (United States)

    Wulczyn, Ellery; West, Robert; Zia, Leila; Leskovec, Jure

    2016-01-01

    The different Wikipedia language editions vary dramatically in how comprehensive they are. As a result, most language editions contain only a small fraction of the sum of information that exists across all Wikipedias. In this paper, we present an approach to filling gaps in article coverage across different Wikipedia editions. Our main contribution is an end-to-end system for recommending articles for creation that exist in one language but are missing in another. The system involves identifying missing articles, ranking the missing articles according to their importance, and recommending important missing articles to editors based on their interests. We empirically validate our models in a controlled experiment involving 12,000 French Wikipedia editors. We find that personalizing recommendations increases editor engagement by a factor of two. Moreover, recommending articles increases their chance of being created by a factor of 3.2. Finally, articles created as a result of our recommendations are of comparable quality to organically created articles. Overall, our system leads to more engaged editors and faster growth of Wikipedia with no effect on its quality. PMID:27819073

  12. Empirical techniques in finance

    CERN Document Server

    Bhar, Ramaprasad

    2005-01-01

    This book offers the opportunity to study and experience advanced empi- cal techniques in finance and in general financial economics. It is not only suitable for students with an interest in the field, it is also highly rec- mended for academic researchers as well as the researchers in the industry. The book focuses on the contemporary empirical techniques used in the analysis of financial markets and how these are implemented using actual market data. With an emphasis on Implementation, this book helps foc- ing on strategies for rigorously combing finance theory and modeling technology to extend extant considerations in the literature. The main aim of this book is to equip the readers with an array of tools and techniques that will allow them to explore financial market problems with a fresh perspective. In this sense it is not another volume in eco- metrics. Of course, the traditional econometric methods are still valid and important; the contents of this book will bring in other related modeling topics tha...

  13. Summary (and) recommendations

    International Nuclear Information System (INIS)

    1992-01-01

    This report looks at the Health and Safety record at the Atomic Weapons Establishment at Aldermaston. The last outside report was by Pochin in 1978 which recommended that staffing for health physicists and maintenance staff should be increased and that some buildings where solid and liquid radioactive wastes were processed should be replaced. A new facility to process contaminated heavy equipment was also recommended. This report finds that none of the recommendations have been fully implemented. It also lists accidents, fires and worker contamination. It is concluded that some of the problems are that nuclear weapons production is inherently unsafe and cannot be made safe, that the secrecy surrounding the establishments' safety record is not good for improving it and finally the report calls for production at Aldermaston to be halted. (UK)

  14. Archetypal Game Recommender Systems

    DEFF Research Database (Denmark)

    Sifa, Rafet; Bauckhage, C.; Drachen, Anders

    2014-01-01

    Contemporary users (players, consumers) of digital games have thousands of products to choose from, which makes nding games that t their interests challenging. Towards addressing this challenge, in this paper two dierent formulations of Archetypal Analysis for Top-L recommender tasks using implicit...... feedback are presented: factor- and neighborhood-oriented models. These form the rst application of rec- ommender systems to digital games. Both models are tested on a dataset of 500,000 users of the game distribution platform Steam, covering game ownership and playtime data across more than 3000 games....... Compared to four other recommender models (nearest neighbor, two popularity mod- els, random baseline), the archetype based models provide the highest recall rates showing that Archetypal Analysis can be successfully applied for Top-L recommendation purposes...

  15. OARSI Clinical Trials Recommendations

    DEFF Research Database (Denmark)

    Emery, C. A.; Roos, Ewa M.; Verhagen, E.

    2015-01-01

    The risk of post-traumatic osteoarthritis (PTOA) substantially increases following joint injury. Research efforts should focus on investigating the efficacy of preventative strategies in high quality randomized controlled trials (RCT). The objective of these OARSI RCT recommendations is to inform...... the design, conduct and analytical approaches to RCTs evaluating the preventative effect of joint injury prevention strategies. Recommendations regarding the design, conduct, and reporting of RCTs evaluating injury prevention interventions were established based on the consensus of nine researchers...... internationally with expertise in epidemiology, injury prevention and/or osteoarthritis (OA). Input and resultant consensus was established through teleconference, face to face and email correspondence over a 1 year period. Recommendations for injury prevention RCTs include context specific considerations...

  16. Recommending Multidimensional Queries

    Science.gov (United States)

    Giacometti, Arnaud; Marcel, Patrick; Negre, Elsa

    Interactive analysis of datacube, in which a user navigates a cube by launching a sequence of queries is often tedious since the user may have no idea of what the forthcoming query should be in his current analysis. To better support this process we propose in this paper to apply a Collaborative Work approach that leverages former explorations of the cube to recommend OLAP queries. The system that we have developed adapts Approximate String Matching, a technique popular in Information Retrieval, to match the current analysis with the former explorations and help suggesting a query to the user. Our approach has been implemented with the open source Mondrian OLAP server to recommend MDX queries and we have carried out some preliminary experiments that show its efficiency for generating effective query recommendations.

  17. Guideline recommendations and antimicrobial resistance: the need for a change.

    Science.gov (United States)

    Elias, Christelle; Moja, Lorenzo; Mertz, Dominik; Loeb, Mark; Forte, Gilles; Magrini, Nicola

    2017-07-26

    Antimicrobial resistance has become a global burden for which inappropriate antimicrobial use is an important contributing factor. Any decisions on the selection of antibiotics use should consider their effects on antimicrobial resistance. The objective of this study was to assess the extent to which antibiotic prescribing guidelines have considered resistance patterns when making recommendations for five highly prevalent infectious syndromes. We used Medline searches complemented with extensive use of Web engine to identify guidelines on empirical treatment of community-acquired pneumonia, urinary tract infections, acute otitis media, rhinosinusitis and pharyngitis. We collected data on microbiology and resistance patterns and identified discrete pattern categories. We assessed the extent to which recommendations considered resistance, in addition to efficacy and safety, when recommending antibiotics. We identified 135 guidelines, which reported a total of 251 recommendations. Most (103/135, 79%) were from developed countries. Community-acquired pneumonia was the syndrome mostly represented (51, 39%). In only 16 (6.4%) recommendations, selection of empirical antibiotic was discussed in relation to resistance and specific microbiological data. In a further 69 (27.5%) recommendations, references were made in relation to resistance, but the attempt was inconsistent. Across syndromes, 12 patterns of resistance with implications on recommendations were observed. 50% to 75% of recommendations did not attempt to set recommendation in the context of these patterns. There is consistent evidence that guidelines on empirical antibiotic use did not routinely consider resistance in their recommendations. Decision-makers should analyse and report the extent of local resistance patterns to allow better decision-making. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless

  18. New Insulin Delivery Recommendations.

    Science.gov (United States)

    Frid, Anders H; Kreugel, Gillian; Grassi, Giorgio; Halimi, Serge; Hicks, Debbie; Hirsch, Laurence J; Smith, Mike J; Wellhoener, Regine; Bode, Bruce W; Hirsch, Irl B; Kalra, Sanjay; Ji, Linong; Strauss, Kenneth W

    2016-09-01

    Many primary care professionals manage injection or infusion therapies in patients with diabetes. Few published guidelines have been available to help such professionals and their patients manage these therapies. Herein, we present new, practical, and comprehensive recommendations for diabetes injections and infusions. These recommendations were informed by a large international survey of current practice and were written and vetted by 183 diabetes experts from 54 countries at the Forum for Injection Technique and Therapy: Expert Recommendations (FITTER) workshop held in Rome, Italy, in 2015. Recommendations are organized around the themes of anatomy, physiology, pathology, psychology, and technology. Key among the recommendations are that the shortest needles (currently the 4-mm pen and 6-mm syringe needles) are safe, effective, and less painful and should be the first-line choice in all patient categories; intramuscular injections should be avoided, especially with long-acting insulins, because severe hypoglycemia may result; lipohypertrophy is a frequent complication of therapy that distorts insulin absorption, and, therefore, injections and infusions should not be given into these lesions and correct site rotation will help prevent them; effective long-term therapy with insulin is critically dependent on addressing psychological hurdles upstream, even before insulin has been started; inappropriate disposal of used sharps poses a risk of infection with blood-borne pathogens; and mitigation is possible with proper training, effective disposal strategies, and the use of safety devices. Adherence to these new recommendations should lead to more effective therapies, improved outcomes, and lower costs for patients with diabetes. Copyright © 2016 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  19. An Extended TOPSIS Method for Multiple Attribute Decision Making based on Interval Neutrosophic Uncertain Linguistic Variables

    Directory of Open Access Journals (Sweden)

    Said Broumi

    2015-03-01

    Full Text Available The interval neutrosophic uncertain linguistic variables can easily express the indeterminate and inconsistent information in real world, and TOPSIS is a very effective decision making method more and more extensive applications. In this paper, we will extend the TOPSIS method to deal with the interval neutrosophic uncertain linguistic information, and propose an extended TOPSIS method to solve the multiple attribute decision making problems in which the attribute value takes the form of the interval neutrosophic uncertain linguistic variables and attribute weight is unknown. Firstly, the operational rules and properties for the interval neutrosophic variables are introduced. Then the distance between two interval neutrosophic uncertain linguistic variables is proposed and the attribute weight is calculated by the maximizing deviation method, and the closeness coefficients to the ideal solution for each alternatives. Finally, an illustrative example is given to illustrate the decision making steps and the effectiveness of the proposed method.

  20. 75 FR 54802 - Requirement of a Statement Disclosing Uncertain Tax Positions

    Science.gov (United States)

    2010-09-09

    ... return. Corporations that prepare financial statements are required by generally accepted accounting principles to identify and quantify all uncertain tax positions as described in Financial Accounting..., including International Financial Reporting Standards and country-specific generally accepted accounting...

  1. A Precautionary-Principled Approach Towards Uncertain Risks: Review and Decision-Theoretic Elaboration

    NARCIS (Netherlands)

    Ch. Vlek (Charles)

    2009-01-01

    textabstractPrecautionary judgment, decision, and action are needed in situations involving serious uncertain risk. Examples are mountain climbing, nanotechnology, global warming, and international terrorism. The history of the Precautionary Principle (PP) shows that its proponents and opponents

  2. Information Extraction, Data Integration, and Uncertain Data Management: The State of The Art

    NARCIS (Netherlands)

    Habib, Mena Badieh; van Keulen, Maurice

    2011-01-01

    Information Extraction, data Integration, and uncertain data management are different areas of research that got vast focus in the last two decades. Many researches tackled those areas of research individually. However, information extraction systems should have integrated with data integration

  3. Modelling of risk events with uncertain likelihoods and impacts in large infrastructure projects

    DEFF Research Database (Denmark)

    Schjær-Jacobsen, Hans

    2010-01-01

    to prevent future budget overruns. One of the central ideas is to introduce improved risk management processes and the present paper addresses this particular issue. A relevant cost function in terms of unit prices and quantities is developed and an event impact matrix with uncertain impacts from independent......This paper presents contributions to the mathematical core of risk and uncertainty management in compliance with the principles of New Budgeting laid out in 2008 by the Danish Ministry of Transport to be used in large infrastructure projects. Basically, the new principles are proposed in order...... uncertain risk events is used to calculate the total uncertain risk budget. Cost impacts from the individual risk events on the individual project activities are kept precisely track of in order to comply with the requirements of New Budgeting. Additionally, uncertain likelihoods for the occurrence of risk...

  4. Review of ICRP recommendations

    International Nuclear Information System (INIS)

    Goldfinch, E.P.

    1987-01-01

    Events in both the scientific world and in the public domain have added pressure to review the recommendations of the ICRP on which radiation protection legislation in most countries is founded. A brief editorial pleads for clarity in ICRP recommendations, suggests the use solely of cumulative with age individual occupational dose limits, suggests that collective doses including both occupational and to the public should be kept as low as reasonably achievable, judged on quantitative economic grounds, and suggests the setting of a probability for serious accidents which may be disregarded in planning. (UK)

  5. Structure identification and adaptive synchronization of uncertain general complex dynamical networks

    Energy Technology Data Exchange (ETDEWEB)

    Xu Yuhua, E-mail: yuhuaxu2004@163.co [College of Information Science and Technology, Donghua University, Shanghai 201620 (China) and Department of Maths, Yunyang Teacher' s College, Hubei 442000 (China); Zhou Wuneng, E-mail: wnzhou@163.co [College of Information Science and Technology, Donghua University, Shanghai 201620 (China); Fang Jian' an [College of Information Science and Technology, Donghua University, Shanghai 201620 (China); Lu Hongqian [Shandong Institute of Light Industry, Shandong Jinan 250353 (China)

    2009-12-28

    This Letter proposes an approach to identify the topological structure and unknown parameters for uncertain general complex networks simultaneously. By designing effective adaptive controllers, we achieve synchronization between two complex networks. The unknown network topological structure and system parameters of uncertain general complex dynamical networks are identified simultaneously in the process of synchronization. Several useful criteria for synchronization are given. Finally, an illustrative example is presented to demonstrate the application of the theoretical results.

  6. Structure identification and adaptive synchronization of uncertain general complex dynamical networks

    International Nuclear Information System (INIS)

    Xu Yuhua; Zhou Wuneng; Fang Jian'an; Lu Hongqian

    2009-01-01

    This Letter proposes an approach to identify the topological structure and unknown parameters for uncertain general complex networks simultaneously. By designing effective adaptive controllers, we achieve synchronization between two complex networks. The unknown network topological structure and system parameters of uncertain general complex dynamical networks are identified simultaneously in the process of synchronization. Several useful criteria for synchronization are given. Finally, an illustrative example is presented to demonstrate the application of the theoretical results.

  7. A New Bi-Directional Projection Model Based on Pythagorean Uncertain Linguistic Variable

    OpenAIRE

    Huidong Wang; Shifan He; Xiaohong Pan

    2018-01-01

    To solve the multi-attribute decision making (MADM) problems with Pythagorean uncertain linguistic variable, an extended bi-directional projection method is proposed. First, we utilize the linguistic scale function to convert uncertain linguistic variable and provide a new projection model, subsequently. Then, to depict the bi-directional projection method, the formative vectors of alternatives and ideal alternatives are defined. Furthermore, a comparative analysis with projection model is co...

  8. Chaos synchronization of uncertain Genesio-Tesi chaotic systems with deadzone nonlinearity

    International Nuclear Information System (INIS)

    Sun, Y.-J.

    2009-01-01

    In this Letter, the concept of practical synchronization is introduced and the chaos synchronization of uncertain Genesio-Tesi chaotic systems with deadzone nonlinearity is investigated. Based on the time-domain approach, a tracking control is proposed to realize chaos synchronization for the uncertain Genesio-Tesi chaotic systems with deadzone nonlinearity. Moreover, the guaranteed exponential convergence rate and convergence radius can be pre-specified. Finally, a numerical example is provided to illustrate the feasibility and effectiveness of the obtained result.

  9. Global exponential stability of uncertain fuzzy BAM neural networks with time-varying delays

    International Nuclear Information System (INIS)

    Syed Ali, M.; Balasubramaniam, P.

    2009-01-01

    In this paper, the Takagi-Sugeno (TS) fuzzy model representation is extended to the stability analysis for uncertain Bidirectional Associative Memory (BAM) neural networks with time-varying delays using linear matrix inequality (LMI) theory. A novel LMI-based stability criterion is obtained by LMI optimization algorithms to guarantee the exponential stability of uncertain BAM neural networks with time-varying delays which are represented by TS fuzzy models. Finally, the proposed stability conditions are demonstrated with numerical examples.

  10. Function Projective Synchronization in Discrete-Time Chaotic System with Uncertain Parameters

    International Nuclear Information System (INIS)

    Chen Yong; Li Xin

    2009-01-01

    The function projective synchronization of discrete-time chaotic systems is presented. Based on backstepping design with three controllers, a systematic, concrete and automatic scheme is developed to investigate function projective synchronization (FPS) of discrete-time chaotic systems with uncertain parameters. With the aid of symbolic-numeric computation, we use the proposed scheme to illustrate FPS between two identical 3D Henon-like maps with uncertain parameters. Numeric simulations are used to verify the effectiveness of our scheme. (general)

  11. Final Empirical Test Case Specification

    DEFF Research Database (Denmark)

    Kalyanova, Olena; Heiselberg, Per

    This document includes the empirical specification on the IEA task of evaluation building energy simulation computer programs for the Double Skin Facades (DSF) constructions. There are two approaches involved into this procedure, one is the comparative approach and another is the empirical one....

  12. Adaptive generalized function projective lag synchronization of different chaotic systems with fully uncertain parameters

    International Nuclear Information System (INIS)

    Wu Xiangjun; Lu Hongtao

    2011-01-01

    Highlights: → Adaptive generalized function projective lag synchronization (AGFPLS) is proposed. → Two uncertain chaos systems are lag synchronized up to a scaling function matrix. → The synchronization speed is sensitively influenced by the control gains. → The AGFPLS scheme is robust against noise perturbation. - Abstract: In this paper, a novel projective synchronization scheme called adaptive generalized function projective lag synchronization (AGFPLS) is proposed. In the AGFPLS method, the states of two different chaotic systems with fully uncertain parameters are asymptotically lag synchronized up to a desired scaling function matrix. By means of the Lyapunov stability theory, an adaptive controller with corresponding parameter update rule is designed for achieving AGFPLS between two diverse chaotic systems and estimating the unknown parameters. This technique is employed to realize AGFPLS between uncertain Lue chaotic system and uncertain Liu chaotic system, and between Chen hyperchaotic system and Lorenz hyperchaotic system with fully uncertain parameters, respectively. Furthermore, AGFPLS between two different uncertain chaotic systems can still be achieved effectively with the existence of noise perturbation. The corresponding numerical simulations are performed to demonstrate the validity and robustness of the presented synchronization method.

  13. Remembrances of Empires Past

    Directory of Open Access Journals (Sweden)

    Robert Aldrich

    2010-03-01

    Full Text Available This paper argues that the colonial legacy is ever present in contemporary Europe. For a generation, most Europeans largely tried, publicly, to forget the colonial past, or remembered it only through the rose-coloured lenses of nostalgia; now the pendulum has swung to memory of that past – even perhaps, in the views of some, to a surfeit of memory, where each group agitates for its own version of history, its own recognition in laws and ceremonies, its own commemoration in museums and monuments, the valorization or repatriation of its own art and artefacts. Word such as ‘invasion,’ ‘racism’ and ‘genocide’ are emotional terms that provoke emotional reactions. Whether leaders should apologize for wrongs of the past – and which wrongs – remains a highly sensitive issue. The ‘return of the colonial’ thus has to do with ethics and politics as well as with history, and can link to statements of apology or recognition, legislation about certain views of history, monetary compensation, repatriation of objects, and—perhaps most importantly—redefinition of national identity and policy. The colonial flags may have been lowered, but many barricades seem to have been raised. Private memories—of loss of land, of unacknowledged service, of political, economic, social and cultural disenfranchisement, but also on the other side of defeat, national castigation and self-flagellation—have been increasingly public. Monuments and museums act not only as sites of history but as venues for political agitation and forums for academic debate – differences of opinion that have spread to the streets. Empire has a long after-life.

  14. Privacy enhanced recommender system

    NARCIS (Netherlands)

    Erkin, Zekeriya; Erkin, Zekeriya; Beye, Michael; Veugen, Thijs; Lagendijk, Reginald L.

    2010-01-01

    Recommender systems are widely used in online applications since they enable personalized service to the users. The underlying collaborative filtering techniques work on user’s data which are mostly privacy sensitive and can be misused by the service provider. To protect the privacy of the users, we

  15. Recommendations for Alternative Credit.

    Science.gov (United States)

    Lenderman, Ed; And Others

    Following a review of the mathematics topics taught in accounting, electronics, auto, food and clothing, and metals courses at Linn-Benton Community College, Albany, Oregon, recommendations were made to grant one semester of mathematics credit for completing a two-year sequence of these courses. The other required semester of mathematics should be…

  16. Towards Geosocial Recommender Systems

    NARCIS (Netherlands)

    de Graaff, V.; van Keulen, Maurice; de By, R.A.; de By, Rolf A.

    2012-01-01

    The usage of social networks sites (SNSs), such as Facebook, and geosocial networks (GSNs), such as Foursquare, has increased tremendously over the past years. The willingness of users to share their current locations and experiences facilitate the creation of geographical recommender systems based

  17. Search and Recommendation

    DEFF Research Database (Denmark)

    Bogers, Toine

    2014-01-01

    In just a little over half a century, the field of information retrieval has experienced spectacular growth and success, with IR applications such as search engines becoming a billion-dollar industry in the past decades. Recommender systems have seen an even more meteoric rise to success with wide...

  18. Chapter 10: Management recommendations

    Science.gov (United States)

    Deborah M. Finch; Janie Agyagos; Tracy McCarthey; Robert M. Marshall; Scott H. Stoleson; Mary J. Whitfield

    2000-01-01

    This chapter was developed over a series of meetings using a group-consensus process. Our recommendations are based on published results, on information compiled in the previous chapters, on expert opinion, and on unpublished data of conservation team members. This chapter is available as temporary guidance until the Recovery Plan for the southwestern willow flycatcher...

  19. Privacy in Recommender Systems

    NARCIS (Netherlands)

    Jeckmans, Arjan; Beye, Michael; Erkin, Zekeriya; Erkin, Zekeriya; Hartel, Pieter H.; Lagendijk, Reginald; Tang, Qiang; Ramzan, Naeem; van Zwol, Roelof; Lee, Jong-Seok; Clüver, Kai; Hua, Xian-Sheng

    In many online applications, the range of content that is offered to users is so wide that a need for automated recommender systems arises. Such systems can provide a personalized selection of relevant items to users. In practice, this can help people find entertaining movies, boost sales through

  20. The ICRP 2007 recommendations

    International Nuclear Information System (INIS)

    Streffer, C.

    2007-01-01

    The last comprehensive International Commission on Radiological Protection (ICRP) recommendations have been published in 1991(1). Since that time new data in physics and biology that are relevant for radiological protection have appeared in the scientific literature. Also, the general thinking about safety standards at the workplace as well as for the protection of the public has developed. Thus, a review of the recommendations is needed. However, as the present standards have worked well, these new recommendations should build on the present ones. Only a process of further development should take place allowing for the following key points: - new biological and physical information and trends in the setting of safety standards; - improvement in the presentation of the recommendations; as much stability in the recommendations as is consistent with the new information and environmental aspects will be included. The fundamental principles of radiological protection will remain the same as they have been described in ICRP publication 60(1): Justification: Actions involving new exposures or changes in exposures of individuals have to be justified in advance. A positive net benefit must result. Optimisation: Exposures should be as low as reasonably achievable and should be optimised in relation to with dose constraints. Dose limits: The values will not to be changed from Publication 60. Dose constraints: Development of the concept proposed in Publication 60 will be explained. The ICRP Committees have prepared foundation documents in the fields for which they are responsible and their members have the corresponding expertise. These foundation documents will support the decisions and explain the various statements of the Main Commission in a broader sense. Some of them will be published as Annexes to the recommendations (Annex A: Biological and Epidemiological Information on Health Risks Attributable to Ionising Radiation; Annex B: Quantities used in Radiological

  1. The ICRP 2007 recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Streffer, C. [Chairman of ICRP Committee 2, Institute of Science and Ethics, University Duisburg-Essen, 45117 Essen (Germany)

    2007-07-01

    The last comprehensive International Commission on Radiological Protection (ICRP) recommendations have been published in 1991(1). Since that time new data in physics and biology that are relevant for radiological protection have appeared in the scientific literature. Also, the general thinking about safety standards at the workplace as well as for the protection of the public has developed. Thus, a review of the recommendations is needed. However, as the present standards have worked well, these new recommendations should build on the present ones. Only a process of further development should take place allowing for the following key points: - new biological and physical information and trends in the setting of safety standards; - improvement in the presentation of the recommendations; as much stability in the recommendations as is consistent with the new information and environmental aspects will be included. The fundamental principles of radiological protection will remain the same as they have been described in ICRP publication 60(1): Justification: Actions involving new exposures or changes in exposures of individuals have to be justified in advance. A positive net benefit must result. Optimisation: Exposures should be as low as reasonably achievable and should be optimised in relation to with dose constraints. Dose limits: The values will not to be changed from Publication 60. Dose constraints: Development of the concept proposed in Publication 60 will be explained. The ICRP Committees have prepared foundation documents in the fields for which they are responsible and their members have the corresponding expertise. These foundation documents will support the decisions and explain the various statements of the Main Commission in a broader sense. Some of them will be published as Annexes to the recommendations (Annex A: Biological and Epidemiological Information on Health Risks Attributable to Ionising Radiation; Annex B: Quantities used in Radiological

  2. Empirical Support for Perceptual Conceptualism

    Directory of Open Access Journals (Sweden)

    Nicolás Alejandro Serrano

    2018-03-01

    Full Text Available The main objective of this paper is to show that perceptual conceptualism can be understood as an empirically meaningful position and, furthermore, that there is some degree of empirical support for its main theses. In order to do this, I will start by offering an empirical reading of the conceptualist position, and making three predictions from it. Then, I will consider recent experimental results from cognitive sciences that seem to point towards those predictions. I will conclude that, while the evidence offered by those experiments is far from decisive, it is enough not only to show that conceptualism is an empirically meaningful position but also that there is empirical support for it.

  3. Empire as a Geopolitical Figure

    DEFF Research Database (Denmark)

    Parker, Noel

    2010-01-01

    This article analyses the ingredients of empire as a pattern of order with geopolitical effects. Noting the imperial form's proclivity for expansion from a critical reading of historical sociology, the article argues that the principal manifestation of earlier geopolitics lay not in the nation...... but in empire. That in turn has been driven by a view of the world as disorderly and open to the ordering will of empires (emanating, at the time of geopolitics' inception, from Europe). One implication is that empires are likely to figure in the geopolitical ordering of the globe at all times, in particular...... after all that has happened in the late twentieth century to undermine nationalism and the national state. Empire is indeed a probable, even for some an attractive form of regime for extending order over the disorder produced by globalisation. Geopolitics articulated in imperial expansion is likely...

  4. ICRS Recommendation Document

    DEFF Research Database (Denmark)

    Roos, Ewa M.; Engelhart, Luella; Ranstam, Jonas

    2011-01-01

    and function evaluated for validity and psychometric properties in patients with articular cartilage lesions. Results: The knee-specific instruments, titled the International Knee Documentation Committee Subjective Knee Form and the Knee injury and Osteoarthritis and Outcome Score, both fulfill the basic......Abstract Objective: The purpose of this article is to describe and recommend patient-reported outcome instruments for use in patients with articular cartilage lesions undergoing cartilage repair interventions. Methods: Nonsystematic literature search identifying measures addressing pain...... constructs at all levels according to the International Classification of Functioning. Conclusions: Because there is no obvious superiority of either instrument at this time, both outcome measures are recommended for use in cartilage repair. Rescaling of the Lysholm Scoring Scale has been suggested...

  5. Word-of-mouth is more than recommendations

    DEFF Research Database (Denmark)

    Mattsson, Jan; Söderlund, Magnus

    2011-01-01

    ’s telling of what had happened to him/her, in terms of a story, is an additional part of WOM. We also found that customer satisfaction, generally considered a main determinant of WOM (when it is narrowly defined as recommendations), is a less potent predictor of WOM than the level of incongruence......Word-of-mouth (WOM) is often operationalized as recommendations, which is only one among several aspects of WOM. Therefore, a focus on recommendations is likely to misrepresent what customers say to other customers. Our empirical study found support for this argument: we found that the sender...

  6. Possible world based consistency learning model for clustering and classifying uncertain data.

    Science.gov (United States)

    Liu, Han; Zhang, Xianchao; Zhang, Xiaotong

    2018-06-01

    Possible world has shown to be effective for handling various types of data uncertainty in uncertain data management. However, few uncertain data clustering and classification algorithms are proposed based on possible world. Moreover, existing possible world based algorithms suffer from the following issues: (1) they deal with each possible world independently and ignore the consistency principle across different possible worlds; (2) they require the extra post-processing procedure to obtain the final result, which causes that the effectiveness highly relies on the post-processing method and the efficiency is also not very good. In this paper, we propose a novel possible world based consistency learning model for uncertain data, which can be extended both for clustering and classifying uncertain data. This model utilizes the consistency principle to learn a consensus affinity matrix for uncertain data, which can make full use of the information across different possible worlds and then improve the clustering and classification performance. Meanwhile, this model imposes a new rank constraint on the Laplacian matrix of the consensus affinity matrix, thereby ensuring that the number of connected components in the consensus affinity matrix is exactly equal to the number of classes. This also means that the clustering and classification results can be directly obtained without any post-processing procedure. Furthermore, for the clustering and classification tasks, we respectively derive the efficient optimization methods to solve the proposed model. Experimental results on real benchmark datasets and real world uncertain datasets show that the proposed model outperforms the state-of-the-art uncertain data clustering and classification algorithms in effectiveness and performs competitively in efficiency. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Badali recommends simplified bills

    International Nuclear Information System (INIS)

    Anon

    2003-01-01

    A report on the variety of retail electricity bills across the province, authored by Salvatore Badali of Deloitte Consulting, was recently released by the Ontario Government. The report was commissioned by the Government to examine the underlying reasons for the significant format differences and the wide variation of fixed and variable charges among the approximately 95 local electricity distribution companies across the province. Regarding the appropriateness of the charges the report recommends common definitions for local distribution company (LDC) fixed and variable costs, and consideration of options for reducing LDC charges, mainly by consolidating the sector and sharing such services as customer billing, accounting and out sourcing operations. Seven recommendations deal with bill simplification. These include bills that are clear and easy to read and provide sufficient information for consumers to verify charges; promote energy conservation, e.g. by including historical information; allow comparisons between retail suppliers and distributors; accommodate revenue collection, marketing needs and other billing services. The report also recommends clearly defined and consistently used terminology for standardized line items, suggests ways to provide consumer information in a form useful for making energy conservation decisions, development of an LDC scorecard to enable stake holders to compare their own LDCs with LDCs around the province, creation of a conservation and bill calculation website, consideration of further use of shared services, and solutions to address the removal of line losses from invoices

  8. Badali recommends simplified bills

    Energy Technology Data Exchange (ETDEWEB)

    Anon

    2003-04-01

    A report on the variety of retail electricity bills across the province, authored by Salvatore Badali of Deloitte Consulting, was recently released by the Ontario Government. The report was commissioned by the Government to examine the underlying reasons for the significant format differences and the wide variation of fixed and variable charges among the approximately 95 local electricity distribution companies across the province. Regarding the appropriateness of the charges the report recommends common definitions for local distribution company (LDC) fixed and variable costs, and consideration of options for reducing LDC charges, mainly by consolidating the sector and sharing such services as customer billing, accounting and out sourcing operations. Seven recommendations deal with bill simplification. These include bills that are clear and easy to read and provide sufficient information for consumers to verify charges; promote energy conservation, e.g. by including historical information; allow comparisons between retail suppliers and distributors; accommodate revenue collection, marketing needs and other billing services. The report also recommends clearly defined and consistently used terminology for standardized line items, suggests ways to provide consumer information in a form useful for making energy conservation decisions, development of an LDC scorecard to enable stake holders to compare their own LDCs with LDCs around the province, creation of a conservation and bill calculation website, consideration of further use of shared services, and solutions to address the removal of line losses from invoices.

  9. Human Power Empirically Explored

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, A.J.

    2011-01-18

    Harvesting energy from the users' muscular power to convert this into electricity is a relatively unknown way to power consumer products. It nevertheless offers surprising opportunities for product designers; human-powered products function independently from regular power infrastructure, are convenient and can be environmentally and economically beneficial. This work provides insight into the knowledge required to design human-powered energy systems in consumer products from a scientific perspective. It shows the developments of human-powered products from the first introduction of the BayGen Freeplay radio in 1995 till current products and provides an overview and analysis of 211 human-powered products currently on the market. Although human power is generally perceived as beneficial for the environment, this thesis shows that achieving environmental benefit is only feasible when the environmental impact of additional materials in the energy conversion system is well balanced with the energy demands of the products functionality. User testing with existing products showed a preference for speeds in the range of 70 to 190 rpm for crank lengths from 32 to 95 mm. The muscular input power varied from 5 to 21 W. The analysis of twenty graduation projects from the Faculty of Industrial Design Engineering in the field of human-powered products, offers an interesting set of additional practice based design recommendations. The knowledge based approach of human power is very powerful to support the design of human-powered products. There is substantial potential for improvements in the domains energy conversion, ergonomics and environment. This makes that human power, when applied properly, is environmentally and economically competitive over a wider range of applications than thought previously.

  10. Birds of the Mongol Empire

    Directory of Open Access Journals (Sweden)

    Eugene N. Anderson

    2016-09-01

    Full Text Available The Mongol Empire, the largest contiguous empire the world has ever known, had, among other things, a goodly number of falconers, poultry raisers, birdcatchers, cooks, and other experts on various aspects of birding. We have records of this, largely in the Yinshan Zhengyao, the court nutrition manual of the Mongol empire in China (the Yuan Dynasty. It discusses in some detail 22 bird taxa, from swans to chickens. The Huihui Yaofang, a medical encyclopedia, lists ten taxa used medicinally. Marco Polo also made notes on Mongol bird use. There are a few other records. This allows us to draw conclusions about Mongol ornithology, which apparently was sophisticated and detailed.

  11. A first-order second-moment calculation for seismic hazard assessment with the consideration of uncertain magnitude conversion

    Directory of Open Access Journals (Sweden)

    J. P. Wang

    2013-10-01

    Full Text Available Earthquake size can be described with different magnitudes for different purposes. For example, local magnitude ML is usually adopted to compile an earthquake catalog, and moment magnitude Mw is often prescribed by a ground motion model. Understandably, when inconsistent units are encountered in an earthquake analysis, magnitude conversion needs to be performed beforehand. However, the conversion is not expected at full certainty owing to the model error of empirical relationships. This paper introduces a novel first-order second-moment (FOSM calculation to estimate the annual rate of earthquake motion (or seismic hazard on a probabilistic basis, including the consideration of the uncertain magnitude conversion and three other sources of earthquake uncertainties. In addition to the methodology, this novel FOSM application to engineering seismology is demonstrated in this paper with a case study. With a local ground motion model, magnitude conversion relationship and earthquake catalog, the analysis shows that the best-estimate annual rate of peak ground acceleration (PGA greater than 0.18 g (induced by earthquakes is 0.002 per year at a site in Taipei, given the uncertainties of magnitude conversion, earthquake size, earthquake location, and motion attenuation.

  12. A first-order second-moment calculation for seismic hazard assessment with the consideration of uncertain magnitude conversion

    Science.gov (United States)

    Wang, J. P.; Yun, X.; Wu, Y.-M.

    2013-10-01

    Earthquake size can be described with different magnitudes for different purposes. For example, local magnitude ML is usually adopted to compile an earthquake catalog, and moment magnitude Mw is often prescribed by a ground motion model. Understandably, when inconsistent units are encountered in an earthquake analysis, magnitude conversion needs to be performed beforehand. However, the conversion is not expected at full certainty owing to the model error of empirical relationships. This paper introduces a novel first-order second-moment (FOSM) calculation to estimate the annual rate of earthquake motion (or seismic hazard) on a probabilistic basis, including the consideration of the uncertain magnitude conversion and three other sources of earthquake uncertainties. In addition to the methodology, this novel FOSM application to engineering seismology is demonstrated in this paper with a case study. With a local ground motion model, magnitude conversion relationship and earthquake catalog, the analysis shows that the best-estimate annual rate of peak ground acceleration (PGA) greater than 0.18 g (induced by earthquakes) is 0.002 per year at a site in Taipei, given the uncertainties of magnitude conversion, earthquake size, earthquake location, and motion attenuation.

  13. Uncertain sightings and the extinction of the Ivory-billed Woodpecker.

    Science.gov (United States)

    Solow, Andrew; Smith, Woollcott; Burgman, Mark; Rout, Tracy; Wintle, Brendan; Roberts, David

    2012-02-01

    The extinction of a species can be inferred from a record of its sightings. Existing methods for doing so assume that all sightings in the record are valid. Often, however, there are sightings of uncertain validity. To date, uncertain sightings have been treated in an ad hoc way, either excluding them from the record or including them as if they were certain. We developed a Bayesian method that formally accounts for such uncertain sightings. The method assumes that valid and invalid sightings follow independent Poisson processes and use noninformative prior distributions for the rate of valid sightings and for a measure of the quality of uncertain sightings. We applied the method to a recently published record of sightings of the Ivory-billed Woodpecker (Campephilus principalis). This record covers the period 1897-2010 and contains 39 sightings classified as certain and 29 classified as uncertain. The Bayes factor in favor of extinction was 4.03, which constitutes substantial support for extinction. The posterior distribution of the time of extinction has 3 main modes in 1944, 1952, and 1988. The method can be applied to sighting records of other purportedly extinct species. ©2011 Society for Conservation Biology.

  14. Empirical Legality and Effective Reality

    Directory of Open Access Journals (Sweden)

    Hernán Pringe

    2015-08-01

    Full Text Available The conditions that Kant’s doctrine establishes are examined for the predication of the effective reality of certain empirical objects. It is maintained that a for such a predication, it is necessary to have not only perception but also a certain homogeneity of sensible data, and b the knowledge of the existence of certain empirical objects depends on the application of regulative principles of experience.

  15. Empirical logic and quantum mechanics

    International Nuclear Information System (INIS)

    Foulis, D.J.; Randall, C.H.

    1976-01-01

    This article discusses some of the basic notions of quantum physics within the more general framework of operational statistics and empirical logic (as developed in Foulis and Randall, 1972, and Randall and Foulis, 1973). Empirical logic is a formal mathematical system in which the notion of an operation is primitive and undefined; all other concepts are rigorously defined in terms of such operations (which are presumed to correspond to actual physical procedures). (Auth.)

  16. Empirical Research In Engineering Design

    DEFF Research Database (Denmark)

    Ahmed, Saeema

    2007-01-01

    Increasingly engineering design research involves the use of empirical studies that are conducted within an industrial environment [Ahmed, 2001; Court 1995; Hales 1987]. Research into the use of information by designers or understanding how engineers build up experience are examples of research...... of research issues. This paper describes case studies of empirical research carried out within industry in engineering design focusing upon information, knowledge and experience in engineering design. The paper describes the research methods employed, their suitability for the particular research aims...

  17. Mobile Application Recommender System

    OpenAIRE

    Davidsson, Christoffer

    2010-01-01

    With the amount of mobile applications available increasing rapidly, users have to put a lot of effort into finding applications of interest. The purpose of this thesis is to investigate how to aid users in the process of discovering new mobile applications by providing them with recommendations. A prototype system is then built as a proof-of-concept. The work of the thesis is divided into three phases where the aim of the first phase is to study related work and related systems to identify p...

  18. Clinical Recommendation: Vulvovaginitis.

    Science.gov (United States)

    Zuckerman, Andrea; Romano, Mary

    2016-12-01

    Vulvovaginitis is a commonly encountered condition among prepubertal and adolescent females. The objective of this report is to provide the latest evidence regarding the diagnosis and management of vulvovaginitis in prepubertal and adolescent females. In this systematic review we used the Grading of Recommendations Assessment, Development and Evaluation evidence system. Vulvovaginal complaints are common in the pediatric and adolescent age group. The patient's age in conjunction with history and associated complaints will guide evaluation, diagnosis, and treatment. Treatment should include counseling on hygiene and voiding techniques as well as therapy for any specific pathogens identified. Copyright © 2016.

  19. The new ICRP recommendations

    International Nuclear Information System (INIS)

    Schlesinger, T.

    1977-01-01

    The new ICRP recommendations are based on the concept of risk. The doses received by workers have to be justified and kept as low as practically achievable. The acceptable annual occupational risk is of the order of 10 -4 . This corresponds to an average annual dose equivalent of about 5 mSv(0.5 Rem). The annual dose equivalent limit for whole body irradiation will remain 50 mSv/year (5 Rem/year) provided that the average is about 1/10th of this value. The concept of the critical organ is abandoned and is replaced by the concept of equidetriment. (author)

  20. Personalized professional content recommendation

    Science.gov (United States)

    Xu, Songhua

    2015-10-27

    A personalized content recommendation system includes a client interface configured to automatically monitor a user's information data stream transmitted on the Internet. A hybrid contextual behavioral and collaborative personal interest inference engine resident to a non-transient media generates automatic predictions about the interests of individual users of the system. A database server retains the user's personal interest profile based on a plurality of monitored information. The system also includes a server programmed to filter items in an incoming information stream with the personal interest profile and is further programmed to identify only those items of the incoming information stream that substantially match the personal interest profile.

  1. A Location-Based Business Information Recommendation Algorithm

    Directory of Open Access Journals (Sweden)

    Shudong Liu

    2015-01-01

    Full Text Available Recently, many researches on information (e.g., POI, ADs recommendation based on location have been done in both research and industry. In this paper, we firstly construct a region-based location graph (RLG, in which region node respectively connects with user node and business information node, and then we propose a location-based recommendation algorithm based on RLG, which can combine with user short-ranged mobility formed by daily activity and long-distance mobility formed by social network ties and sequentially can recommend local business information and long-distance business information to users. Moreover, it can combine user-based collaborative filtering with item-based collaborative filtering, and it can alleviate cold start problem which traditional recommender systems often suffer from. Empirical studies from large-scale real-world data from Yelp demonstrate that our method outperforms other methods on the aspect of recommendation accuracy.

  2. Diffusion-based recommendation with trust relations on tripartite graphs

    Science.gov (United States)

    Wang, Ximeng; Liu, Yun; Zhang, Guangquan; Xiong, Fei; Lu, Jie

    2017-08-01

    The diffusion-based recommendation approach is a vital branch in recommender systems, which successfully applies physical dynamics to make recommendations for users on bipartite or tripartite graphs. Trust links indicate users’ social relations and can provide the benefit of reducing data sparsity. However, traditional diffusion-based algorithms only consider rating links when making recommendations. In this paper, the complementarity of users’ implicit and explicit trust is exploited, and a novel resource-allocation strategy is proposed, which integrates these two kinds of trust relations on tripartite graphs. Through empirical studies on three benchmark datasets, our proposed method obtains better performance than most of the benchmark algorithms in terms of accuracy, diversity and novelty. According to the experimental results, our method is an effective and reasonable way to integrate additional features into the diffusion-based recommendation approach.

  3. Recommender Systems in Commercial Use

    OpenAIRE

    Aldrich, Susan E.

    2011-01-01

    Commercial recommender systems are deployed by marketing teams to increase revenue and/or personalize user experience. Marketers evaluate recommender systems not on its algorithms but on how well the vendor‘s expertise and interfaces will support achieving business goals. Driven by a business model that pays based on recommendation success, vendors guide clients through continuous optimization of recommendations. While recommender technology is mature, the solutions and market are still young...

  4. Inferring about the extinction of a species using certain and uncertain sightings.

    Science.gov (United States)

    Kodikara, Saritha; Demirhan, Haydar; Stone, Lewi

    2018-04-07

    The sighting record of threatened species is often used to infer the possibility of extinction. Most of these sightings have uncertain validity. Solow and Beet(2014) developed two models using a Bayesian approach which allowed for uncertainty in the sighting record by formally incorporating both certain and uncertain sightings, but in different ways. Interestingly, the two methods give completely different conclusions concerning the extinction of the Ivory-billed Woodpecker. We further examined these two methods to provide a mathematical explanation, and to explore in more depth, as to why the results differed from one another. It was found that the first model was more sensitive to the last uncertain sighting, while the second was more sensitive to the last certain sighting. The difficulties in choosing the appropriate model are discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. The role of uncertain self-esteem in self-handicapping.

    Science.gov (United States)

    Harris, R N; Snyder, C R

    1986-08-01

    In this article, the hypothesis that some individuals confronted with an intellectual evaluation use a lack of preparation as a "self-handicapping" strategy (Jones & Berglas, 1978) was studied. Sex and both level and certainty of self-esteem were examined in regard to the self-handicapping strategy of lack of effort. Subjects were 54 men and 54 women, certain and uncertain, high and low self-esteem college students, who believed that the experiment was designed to update local norms for a nonverbal test of intellectual ability. After subjects' level of state anxiety was assessed, they were instructed in the benefits of practicing for the evaluation. Subsequently, subjects' state anxiety and preparatory efforts (the primary dependent variables) were measured. Subjects' practice, self-protective attributions, and related affect supported a self-handicapping interpretation for uncertain males but not for uncertain females.

  6. Conclusions and recommendations

    International Nuclear Information System (INIS)

    Carrette, M.

    1997-01-01

    The paper presents conclusions and recommendations at the closing session of the NEA/OECD Workshop held at Fontenay-aux-Roses on 12-14 June 1995. The conclusions refer to issues like: public reaction to foodstuffs containing radioisotope concentrations under the danger standards, possible non-adherence of manufacturers, processors, distributors, et al, to the instructions and guidance from radiation protection specialists, integration of all the food chain factors in the elaboration of the emergency intervention programs, etc. Among the most significant recommendations the following may be mentioned: 1. Differences between different intervention levels and the maximum admissible levels agreed upon by national, regional or international nutrition authorities should be further studied; 2. Problems created by the Chernobyl accident (as for instance, the methods of treatment of food chain products containing unacceptable radioactivity concentrations) are still present and must be solved; 3. Further studies should be done on the socio-cultural aspects of the communication, particularly on the information in rural environment; 4. The preventive measures in agriculture should be implemented as rapidly as possible; 5. In elaborating programmes of agriculture countermeasures, the management of contaminated media, particularly, of forests and their effect on agriculture

  7. Ebola virus: recommendations

    CERN Multimedia

    CERN Medical Service

    2014-01-01

    The CERN Medical Service has been closely following, in particular via the WHO, the development of the Ebola virus outbreak currently affecting some African countries. This infectious disease may be passed on through direct contact with the bodily fluids of a sick person.   Based on the recommendations of the WHO and the two Host States, Switzerland and France, as updated on their respective websites, so far there has been no ban on travel to the countries concerned. However, unless it is absolutely essential, you are advised not to visit any of the countries affected by Ebola (Guinea, Republic of Sierra Leone, Liberia, Nigeria). The two Host States have established an alert system, and a check is carried out on departure from the airports of those countries. It is strongly recommended that you contact the Medical Service if you are travelling to those countries. We remind you to observe the basic rules of hygiene such as frequent hand washing, whatever your destination. The Medical Service is...

  8. Surgery for constipation: systematic review and practice recommendations: Graded practice and future research recommendations.

    Science.gov (United States)

    Knowles, C H; Grossi, U; Horrocks, E J; Pares, D; Vollebregt, P F; Chapman, M; Brown, S; Mercer-Jones, M; Williams, A B; Yiannakou, Y; Hooper, R J; Stevens, N; Mason, J

    2017-09-01

    This manuscript forms the final of seven that address the surgical management of chronic constipation (CC) in adults. The content coalesces results from the five systematic reviews that precede it and of the European Consensus process to derive graded practice recommendations (GPR). Summary of review data, development of GPR and future research recommendations as outlined in detail in the 'introduction and methods' paper. The overall quality of data in the five reviews was poor with 113/156(72.4%) of included studies providing only level IV evidence and only four included level I RCTs. Coalescence of data from the five procedural classes revealed that few firm conclusions could be drawn regarding procedural choice or patient selection: no single procedure dominated in addressing dynamic structural abnormalities of the anorectum and pelvic floor with each having similar overall efficacy. Of one hundred 'prototype' GPRs developed by the clinical guideline group, 85/100 were deemed 'appropriate' based on the independent scoring of a panel of 18 European experts and use of RAND-UCLA consensus methodology. The remaining 15 were all deemed uncertain. Future research recommendations included some potential RCTs but also a strong emphasis on delivery of large multinational high-quality prospective cohort studies. While the evidence base for surgery in CC is poor, the widespread European consensus for GPRs is encouraging. Professional bodies have the opportunity to build on this work by supporting the efforts of their membership to help convert the documented recommendations into clinical guidelines. © 2017 The Authors. Colorectal Disease published by John Wiley & Sons Ltd on behalf of Association of Coloproctology of Great Britain and Ireland.

  9. Mining and representing recommendations in actively evolving recommender systems

    DEFF Research Database (Denmark)

    Assent, Ira

    2010-01-01

    Recommender systems provide an automatic means of filtering out interesting items, usually based on past similarity of user ratings. In previous work, we have suggested a model that allows users to actively build a recommender network. Users express trust, obtain transparency, and grow (anonymous......) recommender connections. In this work, we propose mining such active systems to generate easily understandable representations of the recommender network. Users may review these representations to provide active feedback. This approach further enhances the quality of recommendations, especially as topics...... of interest change over time. Most notably, it extends the amount of control users have over the model that the recommender network builds of their interests....

  10. Altered brain activation and connectivity during anticipation of uncertain threat in trait anxiety.

    Science.gov (United States)

    Geng, Haiyang; Wang, Yi; Gu, Ruolei; Luo, Yue-Jia; Xu, Pengfei; Huang, Yuxia; Li, Xuebing

    2018-06-08

    In the research field of anxiety, previous studies generally focus on emotional responses following threat. A recent model of anxiety proposes that altered anticipation prior to uncertain threat is related with the development of anxiety. Behavioral findings have built the relationship between anxiety and distinct anticipatory processes including attention, estimation of threat, and emotional responses. However, few studies have characterized the brain organization underlying anticipation of uncertain threat and its role in anxiety. In the present study, we used an emotional anticipation paradigm with functional magnetic resonance imaging (fMRI) to examine the aforementioned topics by employing brain activation and general psychophysiological interactions (gPPI) analysis. In the activation analysis, we found that high trait anxious individuals showed significantly increased activation in the thalamus, middle temporal gyrus (MTG), and dorsomedial prefrontal cortex (dmPFC), as well as decreased activation in the precuneus, during anticipation of uncertain threat compared to the certain condition. In the gPPI analysis, the key regions including the amygdala, dmPFC, and precuneus showed altered connections with distributed brain areas including the ventromedial prefrontal cortex (vmPFC), dorsolateral prefrontal cortex (dlPFC), inferior parietal sulcus (IPS), insula, para-hippocampus gyrus (PHA), thalamus, and MTG involved in anticipation of uncertain threat in anxious individuals. Taken together, our findings indicate that during the anticipation of uncertain threat, anxious individuals showed altered activations and functional connectivity in widely distributed brain areas, which may be critical for abnormal perception, estimation, and emotion reactions during the anticipation of uncertain threat. © 2018 Wiley Periodicals, Inc.

  11. Functional brain networks involved in decision-making under certain and uncertain conditions

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, Danielle C.; Moss, Mark B.; Killiany, Ronald J. [Boston University School of Medicine, Department of Anatomy and Neurobiology, Boston, MA (United States); Mian, Asim Z. [Boston University School of Medicine, Department of Radiology, Boston, MA (United States); Budson, Andrew E. [VA Boston Healthcare System, Boston, MA (United States)

    2018-01-15

    The aim of this study was to describe imaging markers of decision-making under uncertain conditions in normal individuals, in order to provide baseline activity to compare to impaired decision-making in pathological states. In this cross-sectional study, 19 healthy subjects ages 18-35 completed a novel decision-making card-matching task using a Phillips T3 Scanner and a 32-channel head coil. Functional data were collected in six functional runs. In one condition of the task, the participant was certain of the rule to apply to match the cards; in the other condition, the participant was uncertain. We performed cluster-based comparison of the two conditions using FSL fMRI Expert Analysis Tool and network-based analysis using MATLAB. The uncertain > certain comparison yielded three clusters - a midline cluster that extended through the midbrain, the thalamus, bilateral prefrontal cortex, the striatum, and bilateral parietal/occipital clusters. The certain > uncertain comparison yielded bilateral clusters in the insula, parietal and temporal lobe, as well as a medial frontal cluster. A larger, more connected functional network was found in the uncertain condition. The involvement of the insula, parietal cortex, temporal cortex, ventromedial prefrontal cortex, and orbitofrontal cortex of the certain condition reinforces the notion that certainty is inherently rewarding. For the uncertain condition, the involvement of the prefrontal cortex, parietal cortex, striatum, thalamus, amygdala, and hippocampal involvement was expected, as these are areas involved in resolving uncertainty and rule updating. The involvement of occipital cortical involvement and midbrain involvement may be attributed to increased visual attention and increased motor control. (orig.)

  12. Functional brain networks involved in decision-making under certain and uncertain conditions

    International Nuclear Information System (INIS)

    Farrar, Danielle C.; Moss, Mark B.; Killiany, Ronald J.; Mian, Asim Z.; Budson, Andrew E.

    2018-01-01

    The aim of this study was to describe imaging markers of decision-making under uncertain conditions in normal individuals, in order to provide baseline activity to compare to impaired decision-making in pathological states. In this cross-sectional study, 19 healthy subjects ages 18-35 completed a novel decision-making card-matching task using a Phillips T3 Scanner and a 32-channel head coil. Functional data were collected in six functional runs. In one condition of the task, the participant was certain of the rule to apply to match the cards; in the other condition, the participant was uncertain. We performed cluster-based comparison of the two conditions using FSL fMRI Expert Analysis Tool and network-based analysis using MATLAB. The uncertain > certain comparison yielded three clusters - a midline cluster that extended through the midbrain, the thalamus, bilateral prefrontal cortex, the striatum, and bilateral parietal/occipital clusters. The certain > uncertain comparison yielded bilateral clusters in the insula, parietal and temporal lobe, as well as a medial frontal cluster. A larger, more connected functional network was found in the uncertain condition. The involvement of the insula, parietal cortex, temporal cortex, ventromedial prefrontal cortex, and orbitofrontal cortex of the certain condition reinforces the notion that certainty is inherently rewarding. For the uncertain condition, the involvement of the prefrontal cortex, parietal cortex, striatum, thalamus, amygdala, and hippocampal involvement was expected, as these are areas involved in resolving uncertainty and rule updating. The involvement of occipital cortical involvement and midbrain involvement may be attributed to increased visual attention and increased motor control. (orig.)

  13. An Uncertain Wage Contract Model with Adverse Selection and Moral Hazard

    Directory of Open Access Journals (Sweden)

    Xiulan Wang

    2014-01-01

    it can be characterized as an uncertain variable. Moreover, the employee's effort is unobservable to the employer, and the employee can select her effort level to maximize her utility. Thus, an uncertain wage contract model with adverse selection and moral hazard is established to maximize the employer's expected profit. And the model analysis mainly focuses on the equivalent form of the proposed wage contract model and the optimal solution to this form. The optimal solution indicates that both the employee's effort level and the wage increase with the employee's ability. Lastly, a numerical example is given to illustrate the effectiveness of the proposed model.

  14. Application of dynamic uncertain causality graph in spacecraft fault diagnosis: Logic cycle

    Science.gov (United States)

    Yao, Quanying; Zhang, Qin; Liu, Peng; Yang, Ping; Zhu, Ma; Wang, Xiaochen

    2017-04-01

    Intelligent diagnosis system are applied to fault diagnosis in spacecraft. Dynamic Uncertain Causality Graph (DUCG) is a new probability graphic model with many advantages. In the knowledge expression of spacecraft fault diagnosis, feedback among variables is frequently encountered, which may cause directed cyclic graphs (DCGs). Probabilistic graphical models (PGMs) such as bayesian network (BN) have been widely applied in uncertain causality representation and probabilistic reasoning, but BN does not allow DCGs. In this paper, DUGG is applied to fault diagnosis in spacecraft: introducing the inference algorithm for the DUCG to deal with feedback. Now, DUCG has been tested in 16 typical faults with 100% diagnosis accuracy.

  15. A New Bi-Directional Projection Model Based on Pythagorean Uncertain Linguistic Variable

    Directory of Open Access Journals (Sweden)

    Huidong Wang

    2018-04-01

    Full Text Available To solve the multi-attribute decision making (MADM problems with Pythagorean uncertain linguistic variable, an extended bi-directional projection method is proposed. First, we utilize the linguistic scale function to convert uncertain linguistic variable and provide a new projection model, subsequently. Then, to depict the bi-directional projection method, the formative vectors of alternatives and ideal alternatives are defined. Furthermore, a comparative analysis with projection model is conducted to show the superiority of bi-directional projection method. Finally, an example of graduate’s job option is given to demonstrate the effectiveness and feasibility of the proposed method.

  16. Licensing Uncertain Patents: Per-Unit Royalty vs Up-Front Fee

    OpenAIRE

    Encaoua , David; Lefouili , Yassine

    2008-01-01

    ED EPS; In this paper we examine the implications of uncertainty over patent validity on patentholders' licensing strategies. Two licensing mechanisms are examined: per-unit royalty and up-front fee.We provide conditions under which uncertain patents are licensed in order to avoid patent litigation. It is shown that while it is possible for the patentholder to reap som e "extra profit" by selling an uncertain patent under the pure per-unit royalty regime, the opportunity to do so does not exi...

  17. Robust Fuzzy Control for Fractional-Order Uncertain Hydroturbine Regulating System with Random Disturbances

    Directory of Open Access Journals (Sweden)

    Fengjiao Wu

    2016-01-01

    Full Text Available The robust fuzzy control for fractional-order hydroturbine regulating system is studied in this paper. First, the more practical fractional-order hydroturbine regulating system with uncertain parameters and random disturbances is presented. Then, on the basis of interval matrix theory and fractional-order stability theorem, a fuzzy control method is proposed for fractional-order hydroturbine regulating system, and the stability condition is expressed as a group of linear matrix inequalities. Furthermore, the proposed method has good robustness which can process external random disturbances and uncertain parameters. Finally, the validity and superiority are proved by the numerical simulations.

  18. On robust control of uncertain chaotic systems: a sliding-mode synthesis via chaotic optimization

    International Nuclear Information System (INIS)

    Lu Zhao; Shieh Leangsan; Chen GuanRong

    2003-01-01

    This paper presents a novel Lyapunov-based control approach which utilizes a Lyapunov function of the nominal plant for robust tracking control of general multi-input uncertain nonlinear systems. The difficulty of constructing a control Lyapunov function is alleviated by means of predefining an optimal sliding mode. The conventional schemes for constructing sliding modes of nonlinear systems stipulate that the system of interest is canonical-transformable or feedback-linearizable. An innovative approach that exploits a chaotic optimizing algorithm is developed thereby obtaining the optimal sliding manifold for the control purpose. Simulations on the uncertain chaotic Chen's system illustrate the effectiveness of the proposed approach

  19. Numerical Solution of Uncertain Beam Equations Using Double Parametric Form of Fuzzy Numbers

    Directory of Open Access Journals (Sweden)

    Smita Tapaswini

    2013-01-01

    Full Text Available Present paper proposes a new technique to solve uncertain beam equation using double parametric form of fuzzy numbers. Uncertainties appearing in the initial conditions are taken in terms of triangular fuzzy number. Using the single parametric form, the fuzzy beam equation is converted first to an interval-based fuzzy differential equation. Next, this differential equation is transformed to crisp form by applying double parametric form of fuzzy number. Finally, the same is solved by homotopy perturbation method (HPM to obtain the uncertain responses subject to unit step and impulse loads. Obtained results are depicted in terms of plots to show the efficiency and powerfulness of the methodology.

  20. Robust stability for uncertain stochastic fuzzy BAM neural networks with time-varying delays

    Science.gov (United States)

    Syed Ali, M.; Balasubramaniam, P.

    2008-07-01

    In this Letter, by utilizing the Lyapunov functional and combining with the linear matrix inequality (LMI) approach, we analyze the global asymptotic stability of uncertain stochastic fuzzy Bidirectional Associative Memory (BAM) neural networks with time-varying delays which are represented by the Takagi-Sugeno (TS) fuzzy models. A new class of uncertain stochastic fuzzy BAM neural networks with time varying delays has been studied and sufficient conditions have been derived to obtain conservative result in stochastic settings. The developed results are more general than those reported in the earlier literatures. In addition, the numerical examples are provided to illustrate the applicability of the result using LMI toolbox in MATLAB.

  1. Robust stability for uncertain stochastic fuzzy BAM neural networks with time-varying delays

    International Nuclear Information System (INIS)

    Syed Ali, M.; Balasubramaniam, P.

    2008-01-01

    In this Letter, by utilizing the Lyapunov functional and combining with the linear matrix inequality (LMI) approach, we analyze the global asymptotic stability of uncertain stochastic fuzzy Bidirectional Associative Memory (BAM) neural networks with time-varying delays which are represented by the Takagi-Sugeno (TS) fuzzy models. A new class of uncertain stochastic fuzzy BAM neural networks with time varying delays has been studied and sufficient conditions have been derived to obtain conservative result in stochastic settings. The developed results are more general than those reported in the earlier literatures. In addition, the numerical examples are provided to illustrate the applicability of the result using LMI toolbox in MATLAB

  2. Symplectic Synchronization of Lorenz-Stenflo System with Uncertain Chaotic Parameters via Adaptive Control

    Directory of Open Access Journals (Sweden)

    Cheng-Hsiung Yang

    2013-01-01

    Full Text Available A new symplectic chaos synchronization of chaotic systems with uncertain chaotic parameters is studied. The traditional chaos synchronizations are special cases of the symplectic chaos synchronization. A sufficient condition is given for the asymptotical stability of the null solution of error dynamics and a parameter difference. The symplectic chaos synchronization with uncertain chaotic parameters may be applied to the design of secure communication systems. Finally, numerical results are studied for symplectic chaos synchronized from two identical Lorenz-Stenflo systems in three different cases.

  3. Conclusions and recommendations

    International Nuclear Information System (INIS)

    1984-01-01

    The FAO/IAEA/GSF/SIDA Co-ordinated Research Programme on Cereal Grain Protein Improvement by Nuclear Techniques was a follow-up to the FAO/IAEA/GSF Co-ordinated Research Programme on the Use of Nuclear Techniques for Seed Protein Improvement. It was initiated in 1969 and ended in 1981. The objectives of the meeting were to review and evaluate the achievements of the current and previous programmes in order to draw conclusions on the possibility of genetic improvement of cereal grain protein using nuclear techniques, to identify unsolved problems and to discuss and propose possible approaches for their solution. Through reviews and discussions, conclusions and recommendations were made by the participants

  4. Recommendations for skin decontamination

    International Nuclear Information System (INIS)

    1989-01-01

    Further to the reecommendations for determining the surface contamination of the skin and estimating the radiation exposure of the skin after contamination (SAAS-Mitt--89-16), measures for skin decontamination are recommended. They are necessary if (1) after simple decontamination by means of water, soap and brush without damaging the skin the surface contamination limits are exceeded and the radiation exposure to be expected for the undamaged healthy skin is estimated as to high, and if (2) a wound is contaminated. To remove skin contaminations, in general universally applicable, non-aggressive decontamination means and methods are sufficient. In special cases, nuclide-specific decontamination is required taking into account the properties of the radioactive substance

  5. Urgent recommendation. Interim report

    International Nuclear Information System (INIS)

    Nakano, Masayuki

    2000-01-01

    The Investigation Committee for Critical Accident at Uranium Processing Plant was founded immediately after the accident to investigate the cause of the accident and to establish measures to prevent the similar accident. On September 30, 1999 around 10:35, the Japan's first criticality accident occurred at JCO Co. Ltd. Uranium processing plant (auxiliary conversion plant) located at Tokai-mura Ibaraki-ken. The criticality continued on and off for approximately 20 hours after the first instantaneous criticality. The accident led the recommendation of tentative evacuation and sheltering indoors for residents living in the neighborhood. The serious exposure to neutrons happened to three workers. The dominant effect is dose due to neutrons and gamma rays from the precipitation tank. When the accident took place, three workers dissolved sequentially about 2.4 kg uranium powder with 18.8 % enrichment in the 10-litter bucket with nitric acid. The procedure of homogenization of uranium nitrate was supposed to be controlled using the shape-limited narrow storage column. Actually, however, the thick and large precipitation tank was used. As a result, about 16.6 kg of uranium was fed into the tank, which presumably caused criticality. The first notification by JCO was delayed and the following communication was not smooth. This led to the delay of correct understanding of the situation and made the initial proper response difficult, then followed by insufficient communication between the nation, prefecture, and local authority. Urgent recommendations were made on the following items; (1) Safety measures to be taken at the accident site, (2) health cares for residents and others, (3) Comprehensive safety securing at nuclear operators such as Establishment of the effective audit system, Safety education for employees and Qualification and licensing system, Safety related documents, etc. (4) Reconstruction of the government's safety regulations such as How safety regulation

  6. Umayyad Relations with Byzantium Empire

    Directory of Open Access Journals (Sweden)

    Mansoor Haidari

    2017-06-01

    Full Text Available This research investigates the political and military relations between Umayyad caliphates with the Byzantine Empire. The aim of this research is to clarify Umayyad caliphate’s relations with the Byzantine Empire. We know that these relations were mostly about war and fight. Because there were always intense conflicts between Muslims and the Byzantine Empire, they had to have an active continuous diplomacy to call truce and settle the disputes. Thus, based on the general policy of the Umayyad caliphs, Christians were severely ignored and segregated within Islamic territories. This segregation of the Christians was highly affected by political relationships. It is worthy of mentioning that Umayyad caliphs brought the governing style of the Sassanid kings and Roman Caesar into the Islamic Caliphate system but they didn’t establish civil institutions and administrative organizations.

  7. Recommendation in evolving online networks

    Science.gov (United States)

    Hu, Xiao; Zeng, An; Shang, Ming-Sheng

    2016-02-01

    Recommender system is an effective tool to find the most relevant information for online users. By analyzing the historical selection records of users, recommender system predicts the most likely future links in the user-item network and accordingly constructs a personalized recommendation list for each user. So far, the recommendation process is mostly investigated in static user-item networks. In this paper, we propose a model which allows us to examine the performance of the state-of-the-art recommendation algorithms in evolving networks. We find that the recommendation accuracy in general decreases with time if the evolution of the online network fully depends on the recommendation. Interestingly, some randomness in users' choice can significantly improve the long-term accuracy of the recommendation algorithm. When a hybrid recommendation algorithm is applied, we find that the optimal parameter gradually shifts towards the diversity-favoring recommendation algorithm, indicating that recommendation diversity is essential to keep a high long-term recommendation accuracy. Finally, we confirm our conclusions by studying the recommendation on networks with the real evolution data.

  8. The property investigation of the numerical code TIGER for the uncertain analysis

    International Nuclear Information System (INIS)

    Ebina, Takanori; Ohi, Takao

    2008-03-01

    In order to obtain the information concerning the safety of the geological disposal under various geological environments, the sensitivity analysis that considers the uncertainty of parameters resulting from the insufficiency of knowledge and information plays an important role. The numerical code TIGER allows the physical and chemical properties within the system to vary with time in the radionuclide migration analysis from vitrified glass to rock and these function is useful for understanding the effect of the property change of each barrier in such sensitivity analysis. Therefore, at this study, some typical processing methods with the engineered barrier system and the host rock were developed at fast, and through the comparison with the calculation time, the step of preprocessing and postprocessing, the most suitable method was considered. After this consideration, the interrelation between the calculation accuracy and the calculation time at the most suitable method was examined for the purpose of using this method to the uncertain analysis. In addition, the STRIDER that was the program to make the input file for the uncertain analysis with setting random parameter and do the preprocessing and the postprocessing, was improved for the uncertain analysis. Through this consideration, the information of the best processing method, the calculation accuracy, and the analysis tool was arranged for an uncertain analysis using TIGER. (author)

  9. On existence of control for a class of uncertain dynamical systems ...

    African Journals Online (AJOL)

    In this paper we prove the existence of control for input bounded uncertain dynamical system, modeled on Euclidean spaces of dimensions n and m. We apply the Conjugate Gradient Method (C.G.M) in generating algorithms to compute control signals for the class of problem under consideration. Keywords: Control ...

  10. Forest Conservation in Costa Rica: when nonuse benefits are uncertain but rising

    NARCIS (Netherlands)

    Bulte, E.H.; Soest, van D.P.; Kooten, van G.C.; Schipper, R.A.

    2002-01-01

    Stochastic dynamic programming is used to investigate optimal holding of primary tropical forest in humid Costa Rica when future nonuse benefits of forest conservation are uncertain and increasing. The quasi-option value of maintaining primary forests is included as a component of investment in

  11. On the C(R) stability of uncertain singularly perturbed systems

    International Nuclear Information System (INIS)

    Sun, Y.-J.

    2009-01-01

    In this paper, a simple criterion for the C(R) stability of uncertain singularly perturbed systems is proposed. Such a criterion can be easily checked by some algebraic inequality. The upper bound of the singular perturbation parameter ε is also given by estimating the unique positive zero of specific function. Finally, a numerical example is provided to illustrate the main result

  12. Decomposition and Projection Methods for Distributed Robustness Analysis of Interconnected Uncertain Systems

    DEFF Research Database (Denmark)

    Pakazad, Sina Khoshfetrat; Hansson, Anders; Andersen, Martin Skovgaard

    2013-01-01

    We consider a class of convex feasibility problems where the constraints that describe the feasible set are loosely coupled. These problems arise in robust stability analysis of large, weakly interconnected uncertain systems. To facilitate distributed implementation of robust stability analysis o...

  13. Optimal core acquisition and remanufacturing policies under uncertain core quality fractions

    NARCIS (Netherlands)

    Teunter, R.H.; Flapper, S.D.P.

    2011-01-01

    Cores acquired by a remanufacturer are typically highly variable in quality. Even if the expected fractions of the various quality levels are known, then the exact fractions when acquiring cores are still uncertain. Our model incorporates this uncertainty in determining optimal acquisition decisions

  14. Intuitionistic uncertain linguistic partitioned Bonferroni means and their application to multiple attribute decision-making

    Science.gov (United States)

    Liu, Zhengmin; Liu, Peide

    2017-04-01

    The Bonferroni mean (BM) was originally introduced by Bonferroni and generalised by many other researchers due to its capacity to capture the interrelationship between input arguments. Nevertheless, in many situations, interrelationships do not always exist between all of the attributes. Attributes can be partitioned into several different categories and members of intra-partition are interrelated while no interrelationship exists between attributes of different partitions. In this paper, as complements to the existing generalisations of BM, we investigate the partitioned Bonferroni mean (PBM) under intuitionistic uncertain linguistic environments and develop two linguistic aggregation operators: intuitionistic uncertain linguistic partitioned Bonferroni mean (IULPBM) and its weighted form (WIULPBM). Then, motivated by the ideal of geometric mean and PBM, we further present the partitioned geometric Bonferroni mean (PGBM) and develop two linguistic geometric aggregation operators: intuitionistic uncertain linguistic partitioned geometric Bonferroni mean (IULPGBM) and its weighted form (WIULPGBM). Some properties and special cases of these proposed operators are also investigated and discussed in detail. Based on these operators, an approach for multiple attribute decision-making problems with intuitionistic uncertain linguistic information is developed. Finally, a practical example is presented to illustrate the developed approach and comparison analyses are conducted with other representative methods to verify the effectiveness and feasibility of the developed approach.

  15. Frequent Symptom Sets Identification from Uncertain Medical Data in Differentially Private Way

    Directory of Open Access Journals (Sweden)

    Zhe Ding

    2017-01-01

    Full Text Available Data mining techniques are applied to identify hidden patterns in large amounts of patient data. These patterns can assist physicians in making more accurate diagnosis. For different physical conditions of patients, the same physiological index corresponds to a different symptom association probability for each patient. Data mining technologies based on certain data cannot be directly applied to these patients’ data. Patient data are sensitive data. An adversary with sufficient background information can make use of the patterns mined from uncertain medical data to obtain the sensitive information of patients. In this paper, a new algorithm is presented to determine the top K most frequent itemsets from uncertain medical data and to protect data privacy. Based on traditional algorithms for mining frequent itemsets from uncertain data, our algorithm applies sparse vector algorithm and the Laplace mechanism to ensure differential privacy for the top K most frequent itemsets for uncertain medical data and the expected supports of these frequent itemsets. We prove that our algorithm can guarantee differential privacy in theory. Moreover, we carry out experiments with four real-world scenario datasets and two synthetic datasets. The experimental results demonstrate the performance of our algorithm.

  16. A design control structure for architectural firms in a highly complex and uncertain situation

    NARCIS (Netherlands)

    Schijlen, J.T.H.A.M.; Otter, den A.F.H.J.; Pels, H.J.

    2011-01-01

    A large architectural firm in a highly complex and uncertain production situation asked to improve its existing ?production control? system for design projects. To that account a research and design project of nine months at the spot was defined. The production control in the organization was based

  17. Using reference trajectories to predicted uncertain systems: exemplified on a power plant

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob; Mataji, B.

    2007-01-01

    This paper presents a method for prediction of uncertain closed loop systems, where the uncertainties are depending on operating points. Such model uncertainties are often present when complicated non-linear systems are predicted. The method uses precomputed mean and variances of the prediction e...

  18. Robust Optimization-Based Generation Self-Scheduling under Uncertain Price

    Directory of Open Access Journals (Sweden)

    Xiao Luo

    2011-01-01

    Full Text Available This paper considers generation self-scheduling in electricity markets under uncertain price. Based on the robust optimization (denoted as RO methodology, a new self-scheduling model, which has a complicated max-min optimization structure, is set up. By using optimal dual theory, the proposed model is reformulated to an ordinary quadratic and quadratic cone programming problems in the cases of box and ellipsoidal uncertainty, respectively. IEEE 30-bus system is used to test the new model. Some comparisons with other methods are done, and the sensitivity with respect to the uncertain set is analyzed. Comparing with the existed uncertain self-scheduling approaches, the new method has twofold characteristics. First, it does not need a prediction of distribution of random variables and just requires an estimated value and the uncertain set of power price. Second, the counterpart of RO corresponding to the self-scheduling is a simple quadratic or quadratic cone programming. This indicates that the reformulated problem can be solved by many ordinary optimization algorithms.

  19. 75 FR 78160 - Requirement of a Statement Disclosing Uncertain Tax Positions

    Science.gov (United States)

    2010-12-15

    ... amendments to the Income Tax Regulations (26 CFR part 1) under section 6012 relating to the returns of income... every person liable for income tax to make the returns required by regulation. Section 6012 requires... corporations to file a schedule disclosing uncertain tax positions related to the tax return as required by the...

  20. Feature-Based versus Category-Based Induction with Uncertain Categories

    Science.gov (United States)

    Griffiths, Oren; Hayes, Brett K.; Newell, Ben R.

    2012-01-01

    Previous research has suggested that when feature inferences have to be made about an instance whose category membership is uncertain, feature-based inductive reasoning is used to the exclusion of category-based induction. These results contrast with the observation that people can and do use category-based induction when category membership is…

  1. Uncertain Climate Forecasts From Multimodel Ensembles: When to Use Them and When to Ignore Them

    OpenAIRE

    Jewson, Stephen; Rowlands, Dan

    2010-01-01

    Uncertainty around multimodel ensemble forecasts of changes in future climate reduces the accuracy of those forecasts. For very uncertain forecasts this effect may mean that the forecasts should not be used. We investigate the use of the well-known Bayesian Information Criterion (BIC) to make the decision as to whether a forecast should be used or ignored.

  2. Robust Hinf control of uncertain switched systems defined on polyhedral sets with Filippov solutions

    DEFF Research Database (Denmark)

    Ahmadi, Mohamadreza; Mojallali, Hamed; Wisniewski, Rafal

    2012-01-01

    This paper considers the control problem of a class of uncertain switched systems defined on polyhedral sets known as piecewise linear systems where, instead of the conventional Carathe ́odory solutions, Filippov solutions are studied. In other words, in contrast to the previous studies, solutions...

  3. A methodology for the synthesis of heat exchanger networks having large numbers of uncertain parameters

    International Nuclear Information System (INIS)

    Novak Pintarič, Zorka; Kravanja, Zdravko

    2015-01-01

    This paper presents a robust computational methodology for the synthesis and design of flexible HEN (Heat Exchanger Networks) having large numbers of uncertain parameters. This methodology combines several heuristic methods which progressively lead to a flexible HEN design at a specific level of confidence. During the first step, a HEN topology is generated under nominal conditions followed by determining those points critical for flexibility. A significantly reduced multi-scenario model for flexible HEN design is formulated at the nominal point with the flexibility constraints at the critical points. The optimal design obtained is tested by stochastic Monte Carlo optimization and the flexibility index through solving one-scenario problems within a loop. This presented methodology is novel regarding the enormous reduction of scenarios in HEN design problems, and computational effort. Despite several simplifications, the capability of designing flexible HENs with large numbers of uncertain parameters, which are typical throughout industry, is not compromised. An illustrative case study is presented for flexible HEN synthesis comprising 42 uncertain parameters. - Highlights: • Methodology for HEN (Heat Exchanger Network) design under uncertainty is presented. • The main benefit is solving HENs having large numbers of uncertain parameters. • Drastically reduced multi-scenario HEN design problem is formulated through several steps. • Flexibility of HEN is guaranteed at a specific level of confidence.

  4. Combining backcasting and exploratory scenarios to develop robust water strategies in face of uncertain futures

    NARCIS (Netherlands)

    Vliet, van M.; Kok, K.

    2015-01-01

    Water management strategies in times of global change need to be developed within a complex and uncertain environment. Scenarios are often used to deal with uncertainty. A novel backcasting methodology has been tested in which a normative objective (e.g. adaptive water management) is backcasted

  5. Adaptive synchronization of uncertain chaotic colpitts oscillators based on parameter identification

    International Nuclear Information System (INIS)

    Fotsin, H.B.; Daafouz, J.

    2005-01-01

    This Letter uses systematic tools from recent papers to design non-linear observers for synchronization of a chaotic colpitts oscillator both in the non adaptive and adaptive cases. It is shown that all parameters of a totally uncertain model of the oscillator can be estimated through adaptive synchronization. A strategy for practical implementation of a secure communication strategy is also discussed

  6. National Recommended Water Quality Criteria

    Data.gov (United States)

    U.S. Environmental Protection Agency — The National Recommended Water Quality Criteria is a compilation of national recommended water quality criteria for the protection of aquatic life and human health...

  7. Recommended Vaccines for Healthcare Workers

    Science.gov (United States)

    ... Vaccination Resources for Healthcare Professionals Recommended Vaccines for Healthcare Workers Recommend on Facebook Tweet Share Compartir On ... for More Information Resources for Those Vaccinating HCWs Healthcare workers (HCWs) are at risk for exposure to ...

  8. Urgent recommendation. Interim report

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Masayuki [International Affairs and Safeguards Division, Atomic Energy Bureau, Science and Technology Agency, Tokyo (Japan)

    2000-12-01

    The Investigation Committee for Critical Accident at Uranium Processing Plant was founded immediately after the accident to investigate the cause of the accident and to establish measures to prevent the similar accident. On September 30, 1999 around 10:35, the Japan's first criticality accident occurred at JCO Co. Ltd. Uranium processing plant (auxiliary conversion plant) located at Tokai-mura Ibaraki-ken. The criticality continued on and off for approximately 20 hours after the first instantaneous criticality. The accident led the recommendation of tentative evacuation and sheltering indoors for residents living in the neighborhood. The serious exposure to neutrons happened to three workers. The dominant effect is dose due to neutrons and gamma rays from the precipitation tank. When the accident took place, three workers dissolved sequentially about 2.4 kg uranium powder with 18.8 % enrichment in the 10-litter bucket with nitric acid. The procedure of homogenization of uranium nitrate was supposed to be controlled using the shape-limited narrow storage column. Actually, however, the thick and large precipitation tank was used. As a result, about 16.6 kg of uranium was fed into the tank, which presumably caused criticality. The first notification by JCO was delayed and the following communication was not smooth. This led to the delay of correct understanding of the situation and made the initial proper response difficult, then followed by insufficient communication between the nation, prefecture, and local authority. Urgent recommendations were made on the following items; (1) Safety measures to be taken at the accident site, (2) health cares for residents and others, (3) Comprehensive safety securing at nuclear operators such as Establishment of the effective audit system, Safety education for employees and Qualification and licensing system, Safety related documents, etc. (4) Reconstruction of the government's safety regulations such as How safety

  9. The conceptual and empirical relationship between gambling, investing, and speculation.

    Science.gov (United States)

    Arthur, Jennifer N; Williams, Robert J; Delfabbro, Paul H

    2016-12-01

    Background and aims To review the conceptual and empirical relationship between gambling, investing, and speculation. Methods An analysis of the attributes differentiating these constructs as well as identification of all articles speaking to their empirical relationship. Results Gambling differs from investment on many different attributes and should be seen as conceptually distinct. On the other hand, speculation is conceptually intermediate between gambling and investment, with a few of its attributes being investment-like, some of its attributes being gambling-like, and several of its attributes being neither clearly gambling or investment-like. Empirically, gamblers, investors, and speculators have similar cognitive, motivational, and personality attributes, with this relationship being particularly strong for gambling and speculation. Population levels of gambling activity also tend to be correlated with population level of financial speculation. At an individual level, speculation has a particularly strong empirical relationship to gambling, as speculators appear to be heavily involved in traditional forms of gambling and problematic speculation is strongly correlated with problematic gambling. Discussion and conclusions Investment is distinct from gambling, but speculation and gambling have conceptual overlap and a strong empirical relationship. It is recommended that financial speculation be routinely included when assessing gambling involvement, and there needs to be greater recognition and study of financial speculation as both a contributor to problem gambling as well as an additional form of behavioral addiction in its own right.

  10. Roussely report: recommendations

    International Nuclear Information System (INIS)

    Anon.

    2010-01-01

    A summary of the Roussely report on how to reinforce and support French nuclear industry, has been made public. This report recommends a series of measures. The main measures are: 1) the quick achievement in the best conditions possible of the Olkiluoto plant, 2) to assure the construction of Flamanville-3 under the best conditions of cost and delay, 3) to benefit totally from the feedback experiences of the construction of Olkiluoto and Flamanville-3 for the construction of Penly-3 and of the English program of EPR, 4) to confirm EDF as a leader for French industrial bids proposing nuclear power plants, 5) to diversify the offer of reactors for international bids, 6) to set a common body of rules for all the employees working in the nuclear sector in France, 7) to support the extension of service life of power reactors up to 60 years if safety is not at stake, 8) to promote French safety regulations at an international scale, and 9) to create a university of nuclear engineering. (A.C.)

  11. Site Recommendation Subsurface Layout

    International Nuclear Information System (INIS)

    C.L. Linden

    2000-01-01

    The purpose of this analysis is to develop a Subsurface Facility layout that is capable of accommodating the statutory capacity of 70,000 metric tons of uranium (MTU), as well as an option to expand the inventory capacity, if authorized, to 97,000 MTU. The layout configuration also requires a degree of flexibility to accommodate potential changes in site conditions or program requirements. The objective of this analysis is to provide a conceptual design of the Subsurface Facility sufficient to support the development of the Subsurface Facility System Description Document (CRWMS M andO 2000e) and the ''Emplacement Drift System Description Document'' (CRWMS M andO 2000i). As well, this analysis provides input to the Site Recommendation Consideration Report. The scope of this analysis includes: (1) Evaluation of the existing facilities and their integration into the Subsurface Facility design. (2) Identification and incorporation of factors influencing Subsurface Facility design, such as geological constraints, thermal loading, constructibility, subsurface ventilation, drainage control, radiological considerations, and the Test and Evaluation Facilities. (3) Development of a layout showing an available area in the primary area sufficient to support both the waste inventories and individual layouts showing the emplacement area required for 70,000 MTU and, if authorized, 97,000 MTU

  12. Novel density-based and hierarchical density-based clustering algorithms for uncertain data.

    Science.gov (United States)

    Zhang, Xianchao; Liu, Han; Zhang, Xiaotong

    2017-09-01

    Uncertain data has posed a great challenge to traditional clustering algorithms. Recently, several algorithms have been proposed for clustering uncertain data, and among them density-based techniques seem promising for handling data uncertainty. However, some issues like losing uncertain information, high time complexity and nonadaptive threshold have not been addressed well in the previous density-based algorithm FDBSCAN and hierarchical density-based algorithm FOPTICS. In this paper, we firstly propose a novel density-based algorithm PDBSCAN, which improves the previous FDBSCAN from the following aspects: (1) it employs a more accurate method to compute the probability that the distance between two uncertain objects is less than or equal to a boundary value, instead of the sampling-based method in FDBSCAN; (2) it introduces new definitions of probability neighborhood, support degree, core object probability, direct reachability probability, thus reducing the complexity and solving the issue of nonadaptive threshold (for core object judgement) in FDBSCAN. Then, we modify the algorithm PDBSCAN to an improved version (PDBSCANi), by using a better cluster assignment strategy to ensure that every object will be assigned to the most appropriate cluster, thus solving the issue of nonadaptive threshold (for direct density reachability judgement) in FDBSCAN. Furthermore, as PDBSCAN and PDBSCANi have difficulties for clustering uncertain data with non-uniform cluster density, we propose a novel hierarchical density-based algorithm POPTICS by extending the definitions of PDBSCAN, adding new definitions of fuzzy core distance and fuzzy reachability distance, and employing a new clustering framework. POPTICS can reveal the cluster structures of the datasets with different local densities in different regions better than PDBSCAN and PDBSCANi, and it addresses the issues in FOPTICS. Experimental results demonstrate the superiority of our proposed algorithms over the existing

  13. Gazprom the new russian empire

    International Nuclear Information System (INIS)

    Cosnard, D.

    2004-01-01

    The author analyzes the economical and political impacts of the great Gazprom group, leader in the russian energy domain, in Russia. Already number one of the world gas industry, this Group is becoming the right-hand of the Kremlin. Thus the author wonders on this empire transparency and limits. (A.L.B.)

  14. Phenomenology and the Empirical Turn

    NARCIS (Netherlands)

    Zwier, Jochem; Blok, Vincent; Lemmens, Pieter

    2016-01-01

    This paper provides a phenomenological analysis of postphenomenological philosophy of technology. While acknowledging that the results of its analyses are to be recognized as original, insightful, and valuable, we will argue that in its execution of the empirical turn, postphenomenology forfeits

  15. Empirical ethics as dialogical practice

    NARCIS (Netherlands)

    Widdershoven, G.A.M.; Abma, T.A.; Molewijk, A.C.

    2009-01-01

    In this article, we present a dialogical approach to empirical ethics, based upon hermeneutic ethics and responsive evaluation. Hermeneutic ethics regards experience as the concrete source of moral wisdom. In order to gain a good understanding of moral issues, concrete detailed experiences and

  16. Teaching "Empire of the Sun."

    Science.gov (United States)

    Riet, Fred H. van

    1990-01-01

    A Dutch teacher presents reading, film viewing, and writing activities for "Empire of the Sun," J. G. Ballard's autobiographical account of life as a boy in Shanghai and in a Japanese internment camp during World War II (the subject of Steven Spielberg's film of the same name). Includes objectives, procedures, and several literature,…

  17. Empirical Specification of Utility Functions.

    Science.gov (United States)

    Mellenbergh, Gideon J.

    Decision theory can be applied to four types of decision situations in education and psychology: (1) selection; (2) placement; (3) classification; and (4) mastery. For the application of the theory, a utility function must be specified. Usually the utility function is chosen on a priori grounds. In this paper methods for the empirical assessment…

  18. Empirical Productivity Indices and Indicators

    NARCIS (Netherlands)

    B.M. Balk (Bert)

    2016-01-01

    textabstractThe empirical measurement of productivity change (or difference) by means of indices and indicators starts with the ex post profit/loss accounts of a production unit. Key concepts are profit, leading to indicators, and profitability, leading to indices. The main task for the productivity

  19. EMPIRICAL RESEARCH AND CONGREGATIONAL ANALYSIS ...

    African Journals Online (AJOL)

    empirical research has made to the process of congregational analysis. 1 Part of this ... contextual congegrational analysis – meeting social and divine desires”) at the IAPT .... methodology of a congregational analysis should be regarded as a process. ... essential to create space for a qualitative and quantitative approach.

  20. Empirical processes: theory and applications

    OpenAIRE

    Venturini Sergio

    2005-01-01

    Proceedings of the 2003 Summer School in Statistics and Probability in Torgnon (Aosta, Italy) held by Prof. Jon A. Wellner and Prof. M. Banerjee. The topic presented was the theory of empirical processes with applications to statistics (m-estimation, bootstrap, semiparametric theory).

  1. Empirical laws, regularity and necessity

    NARCIS (Netherlands)

    Koningsveld, H.

    1973-01-01

    In this book I have tried to develop an analysis of the concept of an empirical law, an analysis that differs in many ways from the alternative analyse's found in contemporary literature dealing with the subject.

    1 am referring especially to two well-known views, viz. the regularity and

  2. Empirical analysis of consumer behavior

    NARCIS (Netherlands)

    Huang, Yufeng

    2015-01-01

    This thesis consists of three essays in quantitative marketing, focusing on structural empirical analysis of consumer behavior. In the first essay, he investigates the role of a consumer's skill of product usage, and its imperfect transferability across brands, in her product choice. It shows that

  3. An improved algorithm for personalized recommendation on MOOCs

    Directory of Open Access Journals (Sweden)

    Yuqin Wang

    2017-09-01

    Full Text Available Purpose – In the past few years, millions of people started to acquire knowledge from the Massive Open Online Courses (MOOCs. MOOCs contain massive video courses produced by instructors, and learners all over the world can get access to these courses via the internet. However, faced with massive courses, learners often waste much time finding courses they like. This paper aims to explore the problem that how to make accurate personalized recommendations for MOOC users. Design/methodology/approach – This paper proposes a multi-attribute weight algorithm based on collaborative filtering (CF to select a recommendation set of courses for target MOOC users. Findings – The recall of the proposed algorithm in this paper is higher than both the traditional CF and a CF-based algorithm – uncertain neighbors’ collaborative filtering recommendation algorithm. The higher the recall is, the more accurate the recommendation result is. Originality/value – This paper reflects the target users’ preferences for the first time by calculating separately the weight of the attributes and the weight of attribute values of the courses.

  4. Justification for recommended uncertainties

    International Nuclear Information System (INIS)

    Pronyaev, V.G.; Badikov, S.A.; Carlson, A.D.

    2007-01-01

    -2 MeV are discussed. The extent to which new measurements and evaluation methodologies will lead to revised results that may differ significantly from the presently recommended data is imponderable. While the present standard values are likely to be closer to the truth than earlier versions, and the given errors are reasonably well justified in the context of contemporary data and evaluation methodology, a healthy open minded attitude remains the most sensible approach, consistent with the fundamental spirit of scientific endeavour and enquiry

  5. Empirically Testing Thematic Analysis (ETTA)

    DEFF Research Database (Denmark)

    Gildberg, Frederik Alkier; Bradley, Stephen K.; Tingleff, Elllen B.

    2015-01-01

    Text analysis is not a question of a right or wrong way to go about it, but a question of different traditions. These tend to not only give answers to how to conduct an analysis, but also to provide the answer as to why it is conducted in the way that it is. The problem however may be that the li...... for themselves. The advantage of utilizing the presented analytic approach is argued to be the integral empirical testing, which should assure systematic development, interpretation and analysis of the source textual material....... between tradition and tool is unclear. The main objective of this article is therefore to present Empirical Testing Thematic Analysis, a step by step approach to thematic text analysis; discussing strengths and weaknesses, so that others might assess its potential as an approach that they might utilize/develop...

  6. Essays in empirical industrial organization

    OpenAIRE

    Aguiar de Luque, Luis

    2013-01-01

    My PhD thesis consists of three chapters in Empirical Industrial Organization. The first two chapters focus on the relationship between firrm performance and specific public policies. In particular, we analyze the cases of cooperative research and development (R&D) in the European Union and the regulation of public transports in France. The third chapter focuses on copyright protection in the digital era and analyzes the relationship between legal and illegal consumption of di...

  7. Empirical research on Waldorf education

    OpenAIRE

    Randoll, Dirk; Peters, Jürgen

    2015-01-01

    Waldorf education began in 1919 with the first Waldorf School in Stuttgart and nowadays is widespread in many countries all over the world. Empirical research, however, has been rare until the early nineties and Waldorf education has not been discussed within educational science so far. This has changed during the last decades. This article reviews the results of surveys during the last 20 years and is mainly focused on German Waldorf Schools, because most investigations have been done in thi...

  8. Empirical distribution function under heteroscedasticity

    Czech Academy of Sciences Publication Activity Database

    Víšek, Jan Ámos

    2011-01-01

    Roč. 45, č. 5 (2011), s. 497-508 ISSN 0233-1888 Grant - others:GA UK(CZ) GA402/09/0557 Institutional research plan: CEZ:AV0Z10750506 Keywords : Robustness * Convergence * Empirical distribution * Heteroscedasticity Subject RIV: BB - Applied Statistics , Operational Research Impact factor: 0.724, year: 2011 http://library.utia.cas.cz/separaty/2011/SI/visek-0365534.pdf

  9. Expert opinion vs. empirical evidence

    OpenAIRE

    Herman, Rod A; Raybould, Alan

    2014-01-01

    Expert opinion is often sought by government regulatory agencies when there is insufficient empirical evidence to judge the safety implications of a course of action. However, it can be reckless to continue following expert opinion when a preponderance of evidence is amassed that conflicts with this opinion. Factual evidence should always trump opinion in prioritizing the information that is used to guide regulatory policy. Evidence-based medicine has seen a dramatic upturn in recent years sp...

  10. Recommendation systems in software engineering

    CERN Document Server

    Robillard, Martin P; Walker, Robert J; Zimmermann, Thomas

    2014-01-01

    With the growth of public and private data stores and the emergence of off-the-shelf data-mining technology, recommendation systems have emerged that specifically address the unique challenges of navigating and interpreting software engineering data.This book collects, structures and formalizes knowledge on recommendation systems in software engineering. It adopts a pragmatic approach with an explicit focus on system design, implementation, and evaluation. The book is divided into three parts: "Part I - Techniques" introduces basics for building recommenders in software engineering, including techniques for collecting and processing software engineering data, but also for presenting recommendations to users as part of their workflow.?"Part II - Evaluation" summarizes methods and experimental designs for evaluating recommendations in software engineering.?"Part III - Applications" describes needs, issues and solution concepts involved in entire recommendation systems for specific software engineering tasks, fo...

  11. A framework for the analysis of vibrations of structures with uncertain attachments

    International Nuclear Information System (INIS)

    Li, Shuo; Mace, Brian R.; Halkyard, Roger; Ferguson, Neil S.

    2016-01-01

    Attachments affect the dynamic response of an assembled structure. When engineers are modelling structures, small attachments will often not be included in the “bare” model, especially in the initial design stages. The location of these attachments might be poorly known, yet they affect the response of the structure. This paper considers how attachments jointed to the structure at uncertain points, can be included in the dynamic model of a structure. Two approaches are proposed. In the time domain, a combination of component mode synthesis, characteristic constraint modes and modal analysis gives a computationally efficient basis for subsequent analysis using, for example, Monte Carlo simulation. The frequency domain approach is based on assembly of frequency response functions of bare structure and attachment. Numerical examples of a beam and a plate with a point mass added at an uncertain location are considered and predictions compared with experiment results. (paper)

  12. Robust Stability and H∞ Control of Uncertain Piecewise Linear Switched Systems with Filippov Solutions

    DEFF Research Database (Denmark)

    Ahmadi, Mohamadreza; Mojallali, Hamed; Wisniewski, Rafal

    2012-01-01

    This paper addresses the robust stability and control problem of uncertain piecewise linear switched systems where, instead of the conventional Carathe ́odory solutions, we allow for Filippov solutions. In other words, in contrast to the previous studies, solutions with infinite switching in fini...... algorithm is proposed to surmount the aforementioned matrix inequality conditions....... time along the facets and on faces of arbitrary dimensions are also taken into account. Firstly, based on earlier results, the stability problem of piecewise linear systems with Filippov solutions is translated into a number of linear matrix inequality feasibility tests. Subsequently, a set of matrix...... inequalities are brought forward, which determines the asymptotic stability of the Filippov solutions of a given uncertain piecewise linear system. Afterwards, bilinear matrix inequality conditions for synthesizing a robust controller with a guaranteed H∞ per- formance are formulated. Finally, a V-K iteration...

  13. Structure Identification of Uncertain Complex Networks Based on Anticipatory Projective Synchronization.

    Directory of Open Access Journals (Sweden)

    Liu Heng

    Full Text Available This paper investigates a method to identify uncertain system parameters and unknown topological structure in general complex networks with or without time delay. A complex network, which has uncertain topology and unknown parameters, is designed as a drive network, and a known response complex network with an input controller is designed to identify the drive network. Under the proposed input controller, the drive network and the response network can achieve anticipatory projective synchronization when the system is steady. Lyapunov theorem and Barbǎlat's lemma guarantee the stability of synchronization manifold between two networks. When the synchronization is achieved, the system parameters and topology in response network can be changed to equal with the parameters and topology in drive network. A numerical example is given to show the effectiveness of the proposed method.

  14. Role of diagnostic laparoscopy in chronic abdominal conditions with uncertain diagnosis

    Directory of Open Access Journals (Sweden)

    Amandeep S Nar

    2014-01-01

    Full Text Available Introduction: Laparoscopy has proved to be an important tool in the minimally invasive exploration of selected patients with chronic abdominal disorders, whose diagnosis remains uncertain, despite exploring the requisite laboratory and imaging investigations like ultrasonography, computed tomography (CT scan, and the like. Materials and Methods: Diagnostic Laparoscopy was conducted on 120 patients, admitted to the Departments of Surgery and Gynecology, Dayanand Medical College and Hospital, Ludhiana, with an uncertain diagnosis after four weeks of onset of symptoms. Conclusion: With laparoscopy providing tissue diagnosis, and helping to achieve the final diagnosis without any significant complication and less operative time, it can be safely concluded that diagnostic laparoscopy is a safe, quick, and effective adjunct to non-surgical diagnostic modalities, for establishing a conclusive diagnosis, but whether it will replace imaging studies as a primary modality for diagnosis needs more evidence.

  15. A Robust Service Selection Method Based on Uncertain QoS

    Directory of Open Access Journals (Sweden)

    Yanping Chen

    2016-01-01

    Full Text Available Nowadays, the number of Web services on the Internet is quickly increasing. Meanwhile, different service providers offer numerous services with the similar functions. Quality of Service (QoS has become an important factor used to select the most appropriate service for users. The most prominent QoS-based service selection models only take the certain attributes into account, which is an ideal assumption. In the real world, there are a large number of uncertain factors. In particular, at the runtime, QoS may become very poor or unacceptable. In order to solve the problem, a global service selection model based on uncertain QoS was proposed, including the corresponding normalization and aggregation functions, and then a robust optimization model adopted to transform the model. Experiment results show that the proposed method can effectively select services with high robustness and optimality.

  16. Parameter Identification and Synchronization of Uncertain Chaotic Systems Based on Sliding Mode Observer

    Directory of Open Access Journals (Sweden)

    Li-lian Huang

    2013-01-01

    Full Text Available The synchronization of nonlinear uncertain chaotic systems is investigated. We propose a sliding mode state observer scheme which combines the sliding mode control with observer theory and apply it into the uncertain chaotic system with unknown parameters and bounded interference. Based on Lyapunov stability theory, the constraints of synchronization and proof are given. This method not only can realize the synchronization of chaotic systems, but also identify the unknown parameters and obtain the correct parameter estimation. Otherwise, the synchronization of chaotic systems with unknown parameters and bounded external disturbances is robust by the design of the sliding surface. Finally, numerical simulations on Liu chaotic system with unknown parameters and disturbances are carried out. Simulation results show that this synchronization and parameter identification has been totally achieved and the effectiveness is verified very well.

  17. Adaptive variable structure control for uncertain chaotic systems containing dead-zone nonlinearity

    International Nuclear Information System (INIS)

    Yan, J.-J.; Shyu, K.-K.; Lin, J.-S.

    2005-01-01

    This paper addresses a practical tracking problem for a class of uncertain chaotic systems with dead-zone nonlinearity in the input function. Based on the Lyapunov stability theorem and Barbalat lemma, an adaptive variable structure controller (AVSC) is proposed to ensure the occurrence of the sliding mode even though the control input contains a dead-zone. Also it is worthy of note that the proposed AVSC involves no information of the upper bound of uncertainty. Thus, the limitation of knowing the bound of uncertainty in advance is certainly released. Furthermore, in the sliding mode, the investigated uncertain chaotic system remains insensitive to the uncertainty, and behaves like a linear system. Finally, a well-known Duffing-Holmes chaotic system is used to demonstrate the feasibility of the proposed AVSC

  18. Disturbance attenuation for uncertain control systems with contributions by Alberto Isidori and Dietrich Flockerzi

    CERN Document Server

    Knobloch, Hans Wilhelm

    2014-01-01

      This book presents a survey on recent attempts to treat classical regulator design problems in case of an uncertain dynamics. It is shown that source of the uncertainty can be twofold: (i) The system is under the influence of an exogenous disturbance about which one has only incomplete - or none - information. (ii) A portion of the dynamical law is unspecified - due to imperfect modeling. Both cases are described by the state space model in a unified way “Disturbance Attenuation for Uncertain Control Systems” presents a variety of approaches to the design problem in the presence of a (partly) unknown disturbance signal. There is a clear philosophy underlying each approach which can be characterized by either one of the following terms: Adaptive Control, Worst Case Design, Dissipation Inequalities.  .

  19. Location Model for Distribution Centers for Fulfilling Electronic Orders of Fresh Foods under Uncertain Demand

    Directory of Open Access Journals (Sweden)

    Hao Zhang

    2017-01-01

    Full Text Available The problem of locating distribution centers for delivering fresh food as a part of electronic commerce is a strategic decision problem for enterprises. This paper establishes a model for locating distribution centers that considers the uncertainty of customer demands for fresh goods in terms of time-sensitiveness and freshness. Based on the methodology of robust optimization in dealing with uncertain problems, this paper optimizes the location model in discrete demand probabilistic scenarios. In this paper, an improved fruit fly optimization algorithm is proposed to solve the distribution center location problem. An example is given to show that the proposed model and algorithm are robust and can effectively handle the complications caused by uncertain demand. The model proposed in this paper proves valuable both theoretically and practically in the selection of locations of distribution centers.

  20. Generalized dislocated lag function projective synchronization of fractional order chaotic systems with fully uncertain parameters

    International Nuclear Information System (INIS)

    Wang, Cong; Zhang, Hong-li; Fan, Wen-hui

    2017-01-01

    In this paper, we propose a new method to improve the safety of secure communication. This method uses the generalized dislocated lag projective synchronization and function projective synchronization to form a new generalized dislocated lag function projective synchronization. Moreover, this paper takes the examples of fractional order Chen system and Lü system with uncertain parameters as illustration. As the parameters of the two systems are uncertain, the nonlinear controller and parameter update algorithms are designed based on the fractional stability theory and adaptive control method. Moreover, this synchronization form and method of control are applied to secure communication via chaotic masking modulation. Many information signals can be recovered and validated. Finally, simulations are used to show the validity and feasibility of the proposed scheme.

  1. Chattering-free fuzzy sliding-mode control strategy for uncertain chaotic systems

    International Nuclear Information System (INIS)

    Yau, H.-T.; Chen, C.-L.

    2006-01-01

    This paper proposes a chattering-free fuzzy sliding-mode control (FSMC) strategy for uncertain chaotic systems. A fuzzy logic control is used to replace the discontinuous sign function of the reaching law in traditional sliding-mode control (SMC), and hence a control input without chattering is obtained in the chaotic systems with uncertainties. Base on the Lyapunov stability theory, we address the design schemes of integration fuzzy sliding-mode control, where the reaching law is proposed by a set of linguistic rules and the control input is chattering free. The Genesio chaotic system is used to test the proposed control strategy and the simulation results show the FSMC not only can control the uncertain chaotic behaviors to a desired state without oscillator very fast, but also the switching function is smooth without chattering. This result implies that this strategy is feasible and effective for chaos control

  2. Robust control of uncertain dynamic systems a linear state space approach

    CERN Document Server

    Yedavalli, Rama K

    2014-01-01

    This textbook aims to provide a clear understanding of the various tools of analysis and design for robust stability and performance of uncertain dynamic systems. In model-based control design and analysis, mathematical models can never completely represent the “real world” system that is being modeled, and thus it is imperative to incorporate and accommodate a level of uncertainty into the models. This book directly addresses these issues from a deterministic uncertainty viewpoint and focuses on the interval parameter characterization of uncertain systems. Various tools of analysis and design are presented in a consolidated manner. This volume fills a current gap in published works by explicitly addressing the subject of control of dynamic systems from linear state space framework, namely using a time-domain, matrix-theory based approach. This book also: Presents and formulates the robustness problem in a linear state space model framework Illustrates various systems level methodologies with examples and...

  3. Uncertain multiobjective redundancy allocation problem of repairable systems based on artificial bee colony algorithm

    Institute of Scientific and Technical Information of China (English)

    Guo Jiansheng; Wang Zutong; Zheng Mingfa; Wang Ying

    2014-01-01

    Based on the uncertainty theory, this paper is devoted to the redundancy allocation problem in repairable parallel-series systems with uncertain factors, where the failure rate, repair rate and other relative coefficients involved are considered as uncertain variables. The availability of the system and the corresponding designing cost are considered as two optimization objectives. A crisp multiobjective optimization formulation is presented on the basis of uncertainty theory to solve this resultant problem. For solving this problem efficiently, a new multiobjective artificial bee colony algorithm is proposed to search the Pareto efficient set, which introduces rank value and crowding distance in the greedy selection strategy, applies fast non-dominated sort procedure in the exploitation search and inserts tournament selection in the onlooker bee phase. It shows that the proposed algorithm outperforms NSGA-II greatly and can solve multiobjective redundancy allocation problem efficiently. Finally, a numerical example is provided to illustrate this approach.

  4. Extreme-Scale Stochastic Particle Tracing for Uncertain Unsteady Flow Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Hanqi; He, Wenbin; Seo, Sangmin; Shen, Han-Wei; Peterka, Tom

    2016-11-13

    We present an efficient and scalable solution to estimate uncertain transport behaviors using stochastic flow maps (SFM,) for visualizing and analyzing uncertain unsteady flows. SFM computation is extremely expensive because it requires many Monte Carlo runs to trace densely seeded particles in the flow. We alleviate the computational cost by decoupling the time dependencies in SFMs so that we can process adjacent time steps independently and then compose them together for longer time periods. Adaptive refinement is also used to reduce the number of runs for each location. We then parallelize over tasks—packets of particles in our design—to achieve high efficiency in MPI/thread hybrid programming. Such a task model also enables CPU/GPU coprocessing. We show the scalability on two supercomputers, Mira (up to 1M Blue Gene/Q cores) and Titan (up to 128K Opteron cores and 8K GPUs), that can trace billions of particles in seconds.

  5. Secure estimation, control and optimization of uncertain cyber-physical systems with applications to power networks

    Science.gov (United States)

    Taha, Ahmad Fayez

    Transportation networks, wearable devices, energy systems, and the book you are reading now are all ubiquitous cyber-physical systems (CPS). These inherently uncertain systems combine physical phenomena with communication, data processing, control and optimization. Many CPSs are controlled and monitored by real-time control systems that use communication networks to transmit and receive data from systems modeled by physical processes. Existing studies have addressed a breadth of challenges related to the design of CPSs. However, there is a lack of studies on uncertain CPSs subject to dynamic unknown inputs and cyber-attacks---an artifact of the insertion of communication networks and the growing complexity of CPSs. The objective of this dissertation is to create secure, computational foundations for uncertain CPSs by establishing a framework to control, estimate and optimize the operation of these systems. With major emphasis on power networks, the dissertation deals with the design of secure computational methods for uncertain CPSs, focusing on three crucial issues---(1) cyber-security and risk-mitigation, (2) network-induced time-delays and perturbations and (3) the encompassed extreme time-scales. The dissertation consists of four parts. In the first part, we investigate dynamic state estimation (DSE) methods and rigorously examine the strengths and weaknesses of the proposed routines under dynamic attack-vectors and unknown inputs. In the second part, and utilizing high-frequency measurements in smart grids and the developed DSE methods in the first part, we present a risk mitigation strategy that minimizes the encountered threat levels, while ensuring the continual observability of the system through available, safe measurements. The developed methods in the first two parts rely on the assumption that the uncertain CPS is not experiencing time-delays, an assumption that might fail under certain conditions. To overcome this challenge, networked unknown input

  6. Parametric optimal control of uncertain systems under an optimistic value criterion

    Science.gov (United States)

    Li, Bo; Zhu, Yuanguo

    2018-01-01

    It is well known that the optimal control of a linear quadratic model is characterized by the solution of a Riccati differential equation. In many cases, the corresponding Riccati differential equation cannot be solved exactly such that the optimal feedback control may be a complex time-oriented function. In this article, a parametric optimal control problem of an uncertain linear quadratic model under an optimistic value criterion is considered for simplifying the expression of optimal control. Based on the equation of optimality for the uncertain optimal control problem, an approximation method is presented to solve it. As an application, a two-spool turbofan engine optimal control problem is given to show the utility of the proposed model and the efficiency of the presented approximation method.

  7. Broadening the study of inductive reasoning: confirmation judgments with uncertain evidence.

    Science.gov (United States)

    Mastropasqua, Tommaso; Crupi, Vincenzo; Tentori, Katya

    2010-10-01

    Although evidence in real life is often uncertain, the psychology of inductive reasoning has, so far, been confined to certain evidence. The present study extends previous research by investigating whether people properly estimate the impact of uncertain evidence on a given hypothesis. Two experiments are reported, in which the uncertainty of evidence is explicitly (by means of numerical values) versus implicitly (by means of ambiguous pictures) manipulated. The results show that people's judgments are highly correlated with those predicted by normatively sound Bayesian measures of impact. This sensitivity to the degree of evidential uncertainty supports the centrality of inductive reasoning in cognition and opens the path to the study of this issue in more naturalistic settings.

  8. Chaos synchronization of uncertain chaotic systems using composite nonlinear feedback based integral sliding mode control.

    Science.gov (United States)

    Mobayen, Saleh

    2018-06-01

    This paper proposes a combination of composite nonlinear feedback and integral sliding mode techniques for fast and accurate chaos synchronization of uncertain chaotic systems with Lipschitz nonlinear functions, time-varying delays and disturbances. The composite nonlinear feedback method allows accurate following of the master chaotic system and the integral sliding mode control provides invariance property which rejects the perturbations and preserves the stability of the closed-loop system. Based on the Lyapunov- Krasovskii stability theory and linear matrix inequalities, a novel sufficient condition is offered for the chaos synchronization of uncertain chaotic systems. This method not only guarantees the robustness against perturbations and time-delays, but also eliminates reaching phase and avoids chattering problem. Simulation results demonstrate that the suggested procedure leads to a great control performance. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  9. Robust digital controllers for uncertain chaotic systems: A digital redesign approach

    Energy Technology Data Exchange (ETDEWEB)

    Ababneh, Mohammad [Department of Controls, FMC Kongsberg Subsea, FMC Energy Systems, Houston, TX 77067 (United States); Barajas-Ramirez, Juan-Gonzalo [CICESE, Depto. De Electronica y Telecomunicaciones, Ensenada, BC, 22860 (Mexico); Chen Guanrong [Centre for Chaos Control and Synchronization, Department of Electronic Engineering, City University of Hong Kong (China); Shieh, Leang S. [Department of Electrical and Computer Engineering, University of Houston, Houston, TX 77204-4005 (United States)

    2007-03-15

    In this paper, a new and systematic method for designing robust digital controllers for uncertain nonlinear systems with structured uncertainties is presented. In the proposed method, a controller is designed in terms of the optimal linear model representation of the nominal system around each operating point of the trajectory, while the uncertainties are decomposed such that the uncertain nonlinear system can be rewritten as a set of local linear models with disturbed inputs. Applying conventional robust control techniques, continuous-time robust controllers are first designed to eliminate the effects of the uncertainties on the underlying system. Then, a robust digital controller is obtained as the result of a digital redesign of the designed continuous-time robust controller using the state-matching technique. The effectiveness of the proposed controller design method is illustrated through some numerical examples on complex nonlinear systems--chaotic systems.

  10. An Integrated Multiechelon Logistics Model with Uncertain Delivery Lead Time and Quality Unreliability

    Directory of Open Access Journals (Sweden)

    Ming-Feng Yang

    2016-01-01

    Full Text Available Nowadays, in order to achieve advantages in supply chain management, how to keep inventory in adequate level and how to enhance customer service level are two critical practices for decision makers. Generally, uncertain lead time and defective products have much to do with inventory and service level. Therefore, this study mainly aims at developing a multiechelon integrated just-in-time inventory model with uncertain lead time and imperfect quality to enhance the benefits of the logistics model. In addition, the Ant Colony Algorithm (ACA is established to determine the optimal solutions. Moreover, based on our proposed model and analysis, the ACA is more efficient than Particle Swarm Optimization (PSO and Lingo in SMEIJI model. An example is provided in this study to illustrate how production run and defective rate have an effect on system costs. Finally, the results of our research could provide some managerial insights which support decision makers in real-world operations.

  11. Mean-Variance portfolio optimization when each asset has individual uncertain exit-time

    Directory of Open Access Journals (Sweden)

    Reza Keykhaei

    2016-12-01

    Full Text Available The standard Markowitz Mean-Variance optimization model is a single-period portfolio selection approach where the exit-time (or the time-horizon is deterministic. ‎In this paper we study the Mean-Variance portfolio selection problem ‎with ‎uncertain ‎exit-time ‎when ‎each ‎has ‎individual uncertain ‎xit-time‎, ‎which generalizes the Markowitz's model‎. ‎‎‎‎‎‎We provide some conditions under which the optimal portfolio of the generalized problem is independent of the exit-times distributions. Also, ‎‎it is shown that under some general circumstances, the sets of optimal portfolios‎ ‎in the generalized model and the standard model are the same‎.

  12. Design of Robust AMB Controllers for Rotors Subjected to Varying and Uncertain Seal Forces

    DEFF Research Database (Denmark)

    Lauridsen, Jonas Skjødt; Santos, Ilmar

    2017-01-01

    This paper demonstrates the design and simulation results of model based controllers for AMB systems, subjectedto uncertain and changing dynamic seal forces. Specifically, a turbocharger with a hole-pattern seal mounted acrossthe balance piston is considered. The dynamic forces of the seal, which...... are dependent on the operational conditions,have a significant effect on the overall system dynamics. Furthermore, these forces are considered uncertain.The nominal and the uncertainty representation of the seal model are established using results from conventionalmodelling approaches, i.e. CFD and Bulkflow......, and experimental results. Three controllers are synthesized: I) AnH∞ controller based on nominal plant representation, II) A µ controller, designed to be robust against uncertaintiesin the dynamic seal model and III) a Linear Parameter Varying (LPV) controller, designed to provide a unifiedperformance over a large...

  13. An Uncertain QFD Approach for the Strategic Management of Logistics Services

    Directory of Open Access Journals (Sweden)

    Shengpeng Yang

    2016-01-01

    Full Text Available Due to customers’ growing concern about logistics performances related to products, logistics service increasingly contributes to the core competence of an enterprise or product, which calls an appropriate tool to develop effective strategic actions to improve logistics performances and gain customer satisfaction. Therefore, an uncertain quality function deployment (QFD approach for selecting the most effective strategic actions in terms of efficiency to meet the customer requirements is developed in this paper, which integrates uncertainty theory into the traditional QFD methodology in order to rationally deal with imprecise information inherently involved in the QFD process. The framework and systematic procedures of the approach are presented in the context of logistics services. Specifically, the calculations for the prioritization of strategic actions are discussed in detail, in which uncertain variables are used to capture the linguistic judgements given by customers and experts. Applications of the proposed approach are presented as well for illustration.

  14. Empirical isotropic chemical shift surfaces

    International Nuclear Information System (INIS)

    Czinki, Eszter; Csaszar, Attila G.

    2007-01-01

    A list of proteins is given for which spatial structures, with a resolution better than 2.5 A, are known from entries in the Protein Data Bank (PDB) and isotropic chemical shift (ICS) values are known from the RefDB database related to the Biological Magnetic Resonance Bank (BMRB) database. The structures chosen provide, with unknown uncertainties, dihedral angles φ and ψ characterizing the backbone structure of the residues. The joint use of experimental ICSs of the same residues within the proteins, again with mostly unknown uncertainties, and ab initio ICS(φ,ψ) surfaces obtained for the model peptides For-(l-Ala) n -NH 2 , with n = 1, 3, and 5, resulted in so-called empirical ICS(φ,ψ) surfaces for all major nuclei of the 20 naturally occurring α-amino acids. Out of the many empirical surfaces determined, it is the 13C α ICS(φ,ψ) surface which seems to be most promising for identifying major secondary structure types, α-helix, β-strand, left-handed helix (α D ), and polyproline-II. Detailed tests suggest that Ala is a good model for many naturally occurring α-amino acids. Two-dimensional empirical 13C α - 1 H α ICS(φ,ψ) correlation plots, obtained so far only from computations on small peptide models, suggest the utility of the experimental information contained therein and thus they should provide useful constraints for structure determinations of proteins

  15. Two concepts of empirical ethics.

    Science.gov (United States)

    Parker, Malcolm

    2009-05-01

    The turn to empirical ethics answers two calls. The first is for a richer account of morality than that afforded by bioethical principlism, which is cast as excessively abstract and thin on the facts. The second is for the facts in question to be those of human experience and not some other, unworldly realm. Empirical ethics therefore promises a richer naturalistic ethics, but in fulfilling the second call it often fails to heed the metaethical requirements related to the first. Empirical ethics risks losing the normative edge which necessarily characterizes the ethical, by failing to account for the nature and the logic of moral norms. I sketch a naturalistic theory, teleological expressivism (TE), which negotiates the naturalistic fallacy by providing a more satisfactory means of taking into account facts and research data with ethical implications. The examples of informed consent and the euthanasia debate are used to illustrate the superiority of this approach, and the problems consequent on including the facts in the wrong kind of way.

  16. Compete, coordinate, and cooperate: How to exploit uncertain environments with social interaction.

    Science.gov (United States)

    Schulze, Christin; Newell, Ben R

    2015-10-01

    Countless decisions, from the trivial to the crucial, are made in complex social contexts while facing uncertain consequences. Yet a large portion of decision making research focuses on either the effects of social interaction or the effects of environmental uncertainty by examining strategic games against others or individual games against nature. Drawing a connection between these approaches, the authors extend a standard individual choice paradigm to include social interaction with 1 other person. In this paradigm, 2 competing decision makers repeatedly select among 2 options, each offering a particular probability of a fixed payoff. When both players choose the same, correct option, the payoff is evenly split; when they choose different options, the player choosing the correct option receives the full payoff. The addition of this social dimension gives players an opportunity to fully exploit an uncertain environment via cooperation: By consistently choosing opposite options, two players can exploit the uncertain environment more effectively than a single player could. We present 2 experiments that manipulate environmental (Experiment 1) and social (Experiment 2) aspects of the paradigm. In Experiment 1, the outcome probabilities were either known or unknown to participants; in Experiment 2, participants' attention was drawn to individual or group gains by introducing either within- or between-group competition. Efficient cooperation did not emerge spontaneously in Experiment 1. Instead, most people probability maximized, mirroring the behavior observed in individual choice. By contrast, between--group competition in Experiment 2 facilitated efficient-but not always equitable--exploitation of uncertain environments. This work links the concepts of individual risky choice and strategic decision making under both environmental and social uncertainty. (c) 2015 APA, all rights reserved).

  17. Chaos control and duration time of a class of uncertain chaotic systems

    International Nuclear Information System (INIS)

    Bowong, Samuel; Moukam Kakmeni, F.M.

    2003-01-01

    This Letter presents a robust control scheme for a class of uncertain chaotic systems in the canonical form, with unknown nonlinearities. To cope with the uncertainties, we combine Lyapunov methodology with observer design. The proposed strategy comprises an exponential linearizing feedback and an uncertainty estimator. The developed control scheme allows chaos suppression. The advantage of this method over the existing results is that the control time is explicitly computed. Simulations studies are conducted to verify the effectiveness of the scheme

  18. Semi-Coercive Variational Inequalities with Uncertain Input Data. Applications to Shaloow Shells

    Czech Academy of Sciences Publication Activity Database

    Hlaváček, Ivan; Lovíšek, J.

    2005-01-01

    Roč. 15, č. 2 (2005), s. 273-299 ISSN 0218-2025 R&D Projects: GA ČR(CZ) GA201/01/1200; GA ČR(CZ) GA201/02/1058 Institutional research plan: CEZ:AV0Z10190503 Keywords : control of variational inequalities * uncertain input data * shallow elastic shells Subject RIV: BA - General Mathematics Impact factor: 1.248, year: 2005

  19. Plastic plate bending problem with friction on the boundary and uncertain input data

    Czech Academy of Sciences Publication Activity Database

    Hlaváček, Ivan

    2010-01-01

    Roč. 31, č. 4 (2010), s. 414-439 ISSN 0163-0563 R&D Projects: GA AV ČR(CZ) IAA100190803 Institutional research plan: CEZ:AV0Z10190503 Keywords : anti- optimization * deformation theory of plasticity * Kačanov method * uncertain input data * worst scenario Subject RIV: BA - General Mathematics Impact factor: 0.687, year: 2010 http://www.tandfonline.com/doi/abs/10.1080/01630563.2010.483311

  20. Enhancing Evolutionary Optimization in Uncertain Environments by Allocating Evaluations via Multi-armed Bandit Algorithms

    OpenAIRE

    Qiu, Xin; Miikkulainen, Risto

    2018-01-01

    Optimization problems with uncertain fitness functions are common in the real world, and present unique challenges for evolutionary optimization approaches. Existing issues include excessively expensive evaluation, lack of solution reliability, and incapability in maintaining high overall fitness during optimization. Using conversion rate optimization as an example, this paper proposes a series of new techniques for addressing these issues. The main innovation is to augment evolutionary algor...

  1. Information Fusion for Hypothesis Generation under Uncertain and Partial Information Access Situation

    Science.gov (United States)

    2008-07-21

    been well investigated in the past. LE CHATELIER -BRAUN’S PRINCIPLE provides a basis for response against perturbations for systems in equilibrium, as...layer from the low level voltage fluctuation. (Fig. 3) Fig 3: Airplane as an example of engineered robust system In principle , robustness of the...as fundamental architectural principle Since the system will be used under hostile and uncertain environments, robustness shall be the major

  2. Risk assessment of salt contamination of groundwater under uncertain aquifer properties

    KAUST Repository

    Litvinenko, Alexander; Keyes, David E.; Logashenko, Dmitry; Tempone, Raul; Wittum, Gabriel

    2017-01-01

    requires a mesh with ~8M grid points and 1500 or more time steps. 200 scenarios are computed concurrently. The total number of cores in parallel computation is 200x32=6400. The main goal of this work is to estimate propagation of uncertainties through the model, to investigate sensitivity of the solution to the input uncertain parameters. Additionally, we demonstrate how the multigrid ug4-based solver can be applied as a black-box in the uncertainty quantification framework.

  3. Adaptive controller design for modified projective synchronization of Genesio-Tesi chaotic system with uncertain parameters

    International Nuclear Information System (INIS)

    Park, Ju H.

    2007-01-01

    The paper addresses control problem for the modified projective synchronization of the Genesio-Tesi chaotic systems with three uncertain parameters. An adaptive control law is derived to make the states of two identical Genesio-Tesi systems asymptotically synchronized up to specific ratios. The stability analysis in the paper is proved using a well-known Lyapunov stability theory. A numerical simulation is presented to show the effectiveness of the proposed chaos synchronization scheme

  4. Optimization Model for Uncertain Statistics Based on an Analytic Hierarchy Process

    Directory of Open Access Journals (Sweden)

    Yongchao Hou

    2014-01-01

    Full Text Available Uncertain statistics is a methodology for collecting and interpreting the expert’s experimental data by uncertainty theory. In order to estimate uncertainty distributions, an optimization model based on analytic hierarchy process (AHP and interpolation method is proposed in this paper. In addition, the principle of least squares method is presented to estimate uncertainty distributions with known functional form. Finally, the effectiveness of this method is illustrated by an example.

  5. GROUP-BUYING ONLINE AUCTION AND OPTIMAL INVENTORY POLICY IN UNCERTAIN MARKET

    Institute of Scientific and Technical Information of China (English)

    Jian CHEN; Yunhui LIU; Xiping SONG

    2004-01-01

    In this paper we consider a group-buying online auction (GBA) model for a monopolistic manufacturer selling novel products in the uncertain market. Firstly, we introduce the bidder's dominant strategy, after which we optimize the GBA price curve and the production volume together.Finally, we compare the GBA with the traditional posted pricing mechanism and find that the GBA is highly probable to be advantageous over the posted pricing mechanism in some appropriate market environments.

  6. Robust Fuzzy Control for Fractional-Order Uncertain Hydroturbine Regulating System with Random Disturbances

    OpenAIRE

    Fengjiao Wu; Guitao Zhang; Zhengzhong Wang

    2016-01-01

    The robust fuzzy control for fractional-order hydroturbine regulating system is studied in this paper. First, the more practical fractional-order hydroturbine regulating system with uncertain parameters and random disturbances is presented. Then, on the basis of interval matrix theory and fractional-order stability theorem, a fuzzy control method is proposed for fractional-order hydroturbine regulating system, and the stability condition is expressed as a group of linear matrix inequalities. ...

  7. Exponential convergence rate estimation for uncertain delayed neural networks of neutral type

    International Nuclear Information System (INIS)

    Lien, C.-H.; Yu, K.-W.; Lin, Y.-F.; Chung, Y.-J.; Chung, L.-Y.

    2009-01-01

    The global exponential stability for a class of uncertain delayed neural networks (DNNs) of neutral type is investigated in this paper. Delay-dependent and delay-independent criteria are proposed to guarantee the robust stability of DNNs via LMI and Razumikhin-like approaches. For a given delay, the maximal allowable exponential convergence rate will be estimated. Some numerical examples are given to illustrate the effectiveness of our results. The simulation results reveal significant improvement over the recent results.

  8. Strong practical stability and stabilization of uncertain discrete linear repetitive processes

    Czech Academy of Sciences Publication Activity Database

    Dabkowski, Pavel; Galkowski, K.; Bachelier, O.; Rogers, E.; Kummert, A.; Lam, J.

    2013-01-01

    Roč. 20, č. 2 (2013), s. 220-233 ISSN 1070-5325 R&D Projects: GA MŠk(CZ) 1M0567 Institutional research plan: CEZ:AV0Z10750506 Institutional support: RVO:67985556 Keywords : strong practical stability * stabilization * uncertain discrete linear repetitive processes * linear matrix inequality Subject RIV: BC - Control Systems Theory Impact factor: 1.424, year: 2013 http://onlinelibrary.wiley.com/doi/10.1002/nla.812/abstract

  9. A Comparison of the Mathematical Modeling Methods in the Inventory Systems under Uncertain Conditions

    OpenAIRE

    A. Mirzazadeh

    2011-01-01

    The inventory models, generally, are derived with considering two methods: (1) minimizing the average annual cost or (2) minimizing the discounted cost. This paper compares the optimal ordering policies determined by these methods under uncertain inflationary situations. The inventory and shortages behavior have been analyzed with using the differential equations. The numerical examples are used to illustrate the theoretical results. A detailed analysis on the models parameters has been perfo...

  10. Recommendation Sets and Choice Queries

    DEFF Research Database (Denmark)

    Viappiani, Paolo Renato; Boutilier, Craig

    2011-01-01

    Utility elicitation is an important component of many applications, such as decision support systems and recommender systems. Such systems query users about their preferences and offer recommendations based on the system's belief about the user's utility function. We analyze the connection between...... the problem of generating optimal recommendation sets and the problem of generating optimal choice queries, considering both Bayesian and regret-based elicitation. Our results show that, somewhat surprisingly, under very general circumstances, the optimal recommendation set coincides with the optimal query....

  11. Energy demand projections based on an uncertain dynamic system modeling approach

    International Nuclear Information System (INIS)

    Dong, S.

    2000-01-01

    Today, China has become the world's second largest pollution source of CO 2 . Owing to coal-based energy consumption, it is estimated that 85--90% of the SO 2 and CO 2 emission of China results from coal use. With high economic growth and increasing environmental concerns, China's energy consumption in the next few decades has become an issue of active concern. Forecasting of energy demand over long periods, however, is getting more complex and uncertain. It is believed that the economic and energy systems are chaotic and nonlinear. Traditional linear system modeling, used mostly in energy demand forecasts, therefore, is not a useful approach. In view of uncertainty and imperfect information about future economic growth and energy development, an uncertain dynamic system model, which has the ability to incorporate and absorb the nature of an uncertain system with imperfect or incomplete information, is developed. Using the model, the forecasting of energy demand in the next 25 years is provided. The model predicts that China's energy demand in 2020 will be about 2,700--3,000 Mtce, coal demand 3,500 Mt, increasing by 128% and 154%, respectively, compared with that of 1995

  12. Multiple Attribute Decision Making Based on Cross-Evaluation with Uncertain Decision Parameters

    Directory of Open Access Journals (Sweden)

    Tao Ding

    2016-01-01

    Full Text Available Multiple attribute decision making (MADM problem is one of the most common and popular research fields in the theory of decision science. A variety of methods have been proposed to deal with such problems. Nevertheless, many of them assumed that attribute weights are determined by different types of additional preference information which will result in subjective decision making. In order to solve such problems, in this paper, we propose a novel MADM approach based on cross-evaluation with uncertain parameters. Specifically, the proposed approach assumes that all attribute weights are uncertain. It can overcome the drawback in prior research that the alternatives’ ranking may be determined by a single attribute with an overestimated weight. In addition, the proposed method can also balance the mean and deviation of each alternative’s cross-evaluation score to guarantee the stability of evaluation. Then, this method is extended to a more generalized situation where the attribute values are also uncertain. Finally, we illustrate the applicability of the proposed method by revisiting two reported studies and by a case study on the selection of community service companies in the city of Hefei in China.

  13. Calibration of uncertain inputs to computer models using experimentally measured quantities and the BMARS emulator

    International Nuclear Information System (INIS)

    Stripling, H.F.; McClarren, R.G.; Kuranz, C.C.; Grosskopf, M.J.; Rutter, E.; Torralva, B.R.

    2011-01-01

    We present a method for calibrating the uncertain inputs to a computer model using available experimental data. The goal of the procedure is to produce posterior distributions of the uncertain inputs such that when samples from the posteriors are used as inputs to future model runs, the model is more likely to replicate (or predict) the experimental response. The calibration is performed by sampling the space of the uncertain inputs, using the computer model (or, more likely, an emulator for the computer model) to assign weights to the samples, and applying the weights to produce the posterior distributions and generate predictions of new experiments within confidence bounds. The method is similar to the Markov chain Monte Carlo (MCMC) calibration methods with independent sampling with the exception that we generate samples beforehand and replace the candidate acceptance routine with a weighting scheme. We apply our method to the calibration of a Hyades 2D model of laser energy deposition in beryllium. We employ a Bayesian Multivariate Adaptive Regression Splines (BMARS) emulator as a surrogate for Hyades 2D. We treat a range of uncertainties in our system, including uncertainties in the experimental inputs, experimental measurement error, and systematic experimental timing errors. The results of the calibration are posterior distributions that both agree with intuition and improve the accuracy and decrease the uncertainty in experimental predictions. (author)

  14. Adaptive control of a quadrotor aerial vehicle with input constraints and uncertain parameters

    Science.gov (United States)

    Tran, Trong-Toan; Ge, Shuzhi Sam; He, Wei

    2018-05-01

    In this paper, we address the problem of adaptive bounded control for the trajectory tracking of a Quadrotor Aerial Vehicle (QAV) while the input saturations and uncertain parameters with the known bounds are simultaneously taken into account. First, to deal with the underactuated property of the QAV model, we decouple and construct the QAV model as a cascaded structure which consists of two fully actuated subsystems. Second, to handle the input constraints and uncertain parameters, we use a combination of the smooth saturation function and smooth projection operator in the control design. Third, to ensure the stability of the overall system of the QAV, we develop the technique for the cascaded system in the presence of both the input constraints and uncertain parameters. Finally, the region of stability of the closed-loop system is constructed explicitly, and our design ensures the asymptotic convergence of the tracking errors to the origin. The simulation results are provided to illustrate the effectiveness of the proposed method.

  15. Formation Learning Control of Multiple Autonomous Underwater Vehicles With Heterogeneous Nonlinear Uncertain Dynamics.

    Science.gov (United States)

    Yuan, Chengzhi; Licht, Stephen; He, Haibo

    2017-09-26

    In this paper, a new concept of formation learning control is introduced to the field of formation control of multiple autonomous underwater vehicles (AUVs), which specifies a joint objective of distributed formation tracking control and learning/identification of nonlinear uncertain AUV dynamics. A novel two-layer distributed formation learning control scheme is proposed, which consists of an upper-layer distributed adaptive observer and a lower-layer decentralized deterministic learning controller. This new formation learning control scheme advances existing techniques in three important ways: 1) the multi-AUV system under consideration has heterogeneous nonlinear uncertain dynamics; 2) the formation learning control protocol can be designed and implemented by each local AUV agent in a fully distributed fashion without using any global information; and 3) in addition to the formation control performance, the distributed control protocol is also capable of accurately identifying the AUVs' heterogeneous nonlinear uncertain dynamics and utilizing experiences to improve formation control performance. Extensive simulations have been conducted to demonstrate the effectiveness of the proposed results.

  16. IP Controller Design for Uncertain Two-Mass Torsional System Using Time-Frequency Analysis

    Directory of Open Access Journals (Sweden)

    Jing Cui

    2018-01-01

    Full Text Available With the development of industrial production, drive systems are demanded for larger inertias of motors and load machines, whereas shafts should be lightweight. In this situation, it will excite mechanical vibrations in load side, which is harmful for industrial production when the motor works. Because of the complexity of the flexible shaft, it is often difficult to calculate stiffness coefficient of the flexible shaft. Furthermore, only the velocity of driving side could be measured, whereas the driving torque, the load torque, and the velocity of load side are immeasurable. Therefore, it is inconvenient to design the controller for the uncertain system. In this paper, a low-order IP controller is designed for an uncertain two-mass torsional system based on polynomial method and time-frequency analysis (TFA. IP controller parameters are calculated by inertias of driving side and load side as well as the resonant frequency based on polynomial method. Therein, the resonant frequency is identified using the time-frequency analysis (TFA of the velocity step response of the driving side under the open-loop system state, which can not only avoid harmful persistent start-stop excitation signal of the traditional method, but also obtain high recognition accuracy under the condition of weak vibration signal submerged in noise. The effectiveness of the designed IP controller is verified by groups of experiments. Experimental results show that good performance for vibration suppression is obtained for uncertain two-mass torsional system in a medium-low shaft stiffness condition.

  17. The Emergency Vehicle Routing Problem with Uncertain Demand under Sustainability Environments

    Directory of Open Access Journals (Sweden)

    Jin Qin

    2017-02-01

    Full Text Available The reasonable utilization of limited resources is critical to realize the sustainable developments. In the initial 72-h crucial rescue period after the disaster, emergency supplies have always been insufficient and the demands in the affected area have always been uncertain. In order to improve timeliness, utilization and sustainability of emergency service, the allocation of the emergency supplies and the emergency vehicle routes should be determined simultaneously. Assuming the uncertain demands follow normal distribution, an optimization model for the emergency vehicle routing, by considering the insufficient supplies and the uncertain demands, is developed. The objective function is applied to minimize the total costs, including the penalty costs induced by more or less supplies than the actual demands at all demand points, as well as the constraints of the time windows and vehicle load capacity taken into account. In more details, a solution method for the model, based on the genetic algorithm, is proposed, which solves the problem in two stages. A numerical example is presented to demonstrate the efficiency and validity of the proposed model and algorithm.

  18. The impact of uncertain threat on affective bias: Individual differences in response to ambiguity.

    Science.gov (United States)

    Neta, Maital; Cantelon, Julie; Haga, Zachary; Mahoney, Caroline R; Taylor, Holly A; Davis, F Caroline

    2017-12-01

    Individuals who operate under highly stressful conditions (e.g., military personnel and first responders) are often faced with the challenge of quickly interpreting ambiguous information in uncertain and threatening environments. When faced with ambiguity, it is likely adaptive to view potentially dangerous stimuli as threatening until contextual information proves otherwise. One laboratory-based paradigm that can be used to simulate uncertain threat is known as threat of shock (TOS), in which participants are told that they might receive mild but unpredictable electric shocks while performing an unrelated task. The uncertainty associated with this potential threat induces a state of emotional arousal that is not overwhelmingly stressful, but has widespread-both adaptive and maladaptive-effects on cognitive and affective function. For example, TOS is thought to enhance aversive processing and abolish positivity bias. Importantly, in certain situations (e.g., when walking home alone at night), this anxiety can promote an adaptive state of heightened vigilance and defense mobilization. In the present study, we used TOS to examine the effects of uncertain threat on valence bias, or the tendency to interpret ambiguous social cues as positive or negative. As predicted, we found that heightened emotional arousal elicited by TOS was associated with an increased tendency to interpret ambiguous cues negatively. Such negative interpretations are likely adaptive in situations in which threat detection is critical for survival and should override an individual's tendency to interpret ambiguity positively in safe contexts. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  19. Optimizing Bus Frequencies under Uncertain Demand: Case Study of the Transit Network in a Developing City

    Directory of Open Access Journals (Sweden)

    Zhengfeng Huang

    2013-01-01

    Full Text Available Various factors can make predicting bus passenger demand uncertain. In this study, a bilevel programming model for optimizing bus frequencies based on uncertain bus passenger demand is formulated. There are two terms constituting the upper-level objective. The first is transit network cost, consisting of the passengers’ expected travel time and operating costs, and the second is transit network robustness performance, indicated by the variance in passenger travel time. The second term reflects the risk aversion of decision maker, and it can make the most uncertain demand be met by the bus operation with the optimal transit frequency. With transit link’s proportional flow eigenvalues (mean and covariance obtained from the lower-level model, the upper-level objective is formulated by the analytical method. In the lower-level model, the above two eigenvalues are calculated by analyzing the propagation of mean transit trips and their variation in the optimal strategy transit assignment process. The genetic algorithm (GA used to solve the model is tested in an example network. Finally, the model is applied to determining optimal bus frequencies in the city of Liupanshui, China. The total cost of the transit system in Liupanshui can be reduced by about 6% via this method.

  20. Simulation optimization based ant colony algorithm for the uncertain quay crane scheduling problem

    Directory of Open Access Journals (Sweden)

    Naoufal Rouky

    2019-01-01

    Full Text Available This work is devoted to the study of the Uncertain Quay Crane Scheduling Problem (QCSP, where the loading /unloading times of containers and travel time of quay cranes are considered uncertain. The problem is solved with a Simulation Optimization approach which takes advantage of the great possibilities offered by the simulation to model the real details of the problem and the capacity of the optimization to find solutions with good quality. An Ant Colony Optimization (ACO meta-heuristic hybridized with a Variable Neighborhood Descent (VND local search is proposed to determine the assignments of tasks to quay cranes and the sequences of executions of tasks on each crane. Simulation is used inside the optimization algorithm to generate scenarios in agreement with the probabilities of the distributions of the uncertain parameters, thus, we carry out stochastic evaluations of the solutions found by each ant. The proposed optimization algorithm is tested first for the deterministic case on several well-known benchmark instances. Then, in the stochastic case, since no other work studied exactly the same problem with the same assumptions, the Simulation Optimization approach is compared with the deterministic version. The experimental results show that the optimization algorithm is competitive as compared to the existing methods and that the solutions found by the Simulation Optimization approach are more robust than those found by the optimization algorithm.

  1. Classification of Recommender Expertise in the Wikipedia Recommender System

    DEFF Research Database (Denmark)

    Jensen, Christian D.; Pilkauskas, Povilas; Lefévre, Thomas

    2011-01-01

    to the quality of articles. The Wikipedia Recommender System (WRS) was developed to help users determine the credibility of articles based on feedback from other Wikipedia users. The WRS implements a collaborative filtering system with trust metrics, i.e., it provides a rating of articles which emphasizes...... an evaluation of four existing knowledge classification schemes with respect to these requirements. This evaluation helped us identify a classification scheme, which we have implemented in the current version of the Wikipedia Recommender System....... feedback from recommenders that the user has agreed with in the past. This exposes the problem that most recommenders are not equally competent in all subject areas. The first WRS prototype did not include an evaluation of the areas of expertise of recommenders, so the trust metric used in the article...

  2. Classification of Recommender Expertise in the Wikipedia Recommender System

    DEFF Research Database (Denmark)

    Jensen, Christian D.; Pilkauskas, Povilas; Lefevre, Thomas

    2011-01-01

    to the quality of articles. The Wikipedia Recommender System (WRS) was developed to help users determine the credibility of articles based on feedback from other Wikipedia users. The WRS implements a collaborative filtering system with trust metrics, i.e., it provides a rating of articles "which emphasizes...... an evaluation of four existing knowledge classification schemes with respect to these requirements. This evaluation helped us identify a classification scheme, which we have implemented in the current version of the Wikipedia Recommender System....... feedback from recommenders that the user has agreed with in the past. This exposes the problem that most recommenders are not equally competent in all subject areas. The first WRS prototype did not include an evaluation of the areas of expertise of recommenders, so the trust metric used in the article...

  3. Empirically evaluating decision-analytic models.

    Science.gov (United States)

    Goldhaber-Fiebert, Jeremy D; Stout, Natasha K; Goldie, Sue J

    2010-08-01

    Model-based cost-effectiveness analyses support decision-making. To augment model credibility, evaluation via comparison to independent, empirical studies is recommended. We developed a structured reporting format for model evaluation and conducted a structured literature review to characterize current model evaluation recommendations and practices. As an illustration, we applied the reporting format to evaluate a microsimulation of human papillomavirus and cervical cancer. The model's outputs and uncertainty ranges were compared with multiple outcomes from a study of long-term progression from high-grade precancer (cervical intraepithelial neoplasia [CIN]) to cancer. Outcomes included 5 to 30-year cumulative cancer risk among women with and without appropriate CIN treatment. Consistency was measured by model ranges overlapping study confidence intervals. The structured reporting format included: matching baseline characteristics and follow-up, reporting model and study uncertainty, and stating metrics of consistency for model and study results. Structured searches yielded 2963 articles with 67 meeting inclusion criteria and found variation in how current model evaluations are reported. Evaluation of the cervical cancer microsimulation, reported using the proposed format, showed a modeled cumulative risk of invasive cancer for inadequately treated women of 39.6% (30.9-49.7) at 30 years, compared with the study: 37.5% (28.4-48.3). For appropriately treated women, modeled risks were 1.0% (0.7-1.3) at 30 years, study: 1.5% (0.4-3.3). To support external and projective validity, cost-effectiveness models should be iteratively evaluated as new studies become available, with reporting standardized to facilitate assessment. Such evaluations are particularly relevant for models used to conduct comparative effectiveness analyses.

  4. Assessing formal teaching of ethics in physiology: an empirical survey, patterns, and recommendations.

    Science.gov (United States)

    Goswami, Nandu; Batzel, Jerry Joseph; Hinghofer-Szalkay, Helmut

    2012-09-01

    Ethics should be an important component of physiological education. In this report, we examined to what extent teaching of ethics is formally being incorporated into the physiology curriculum. We carried out an e-mail survey in which we asked the e-mail recipients whether their institution offered a course or lecture on ethics as part of the physiology teaching process at their institution, using the following query: "We are now doing an online survey in which we would like to know whether you offer a course or a lecture on ethics as part of your physiology teaching curriculum." The response rate was 53.3%: we received 104 responses of a total of 195 sent out. Our responses came from 45 countries. While all of our responders confirmed that there was a need for ethics during medical education and scientific training, the degree of inclusion of formal ethics in the physiology curriculum varied widely. Our survey showed that, in most cases (69%), including at our Medical University of Graz, ethics in physiology is not incorporated into the physiology curriculum. Given this result, we suggest specific topics related to ethics and ethical considerations that could be integrated into the physiology curriculum. We present here a template example of a lecture "Teaching Ethics in Physiology" (structure, content, examples, and references), which was based on guidelines and case reports provided by experts in this area (e.g., Benos DJ. Ethics revisited. Adv Physiol Educ 25: 189-190, 2001). This lecture, which we are presently using in Graz, could be used as a base that could lead to greater awareness of important ethical issues in students at an early point in the educational process.

  5. The Role of Identity in Acculturation among Immigrant People: Theoretical Propositions, Empirical Questions, and Applied Recommendations

    Science.gov (United States)

    Schwartz, Seth J.; Montgomery, Marilyn J.; Briones, Ervin

    2006-01-01

    The present paper advances theoretical propositions regarding the relationship between acculturation and identity. The most central thesis argued is that acculturation represents changes in cultural identity and that personal identity has the potential to "anchor" immigrant people during their transition to a new society. The article emphasizes…

  6. A review of recommendations for sequencing receptive and expressive language instruction.

    Science.gov (United States)

    Petursdottir, Anna Ingeborg; Carr, James E

    2011-01-01

    We review recommendations for sequencing instruction in receptive and expressive language objectives in early and intensive behavioral intervention (EIBI) programs. Several books recommend completing receptive protocols before introducing corresponding expressive protocols. However, this recommendation has little empirical support, and some evidence exists that the reverse sequence may be more efficient. Alternative recommendations include teaching receptive and expressive skills simultaneously (M. L. Sundberg & Partington, 1998) and building learning histories that lead to acquisition of receptive and expressive skills without direct instruction (Greer & Ross, 2008). Empirical support for these recommendations also is limited. Future research should assess the relative efficiency of receptive-before-expressive, expressive-before-receptive, and simultaneous training with children who have diagnoses of autism spectrum disorders. In addition, further evaluation is needed of the potential benefits of multiple-exemplar training and other variables that may influence the efficiency of receptive and expressive instruction.

  7. Empirical Phenomenology: A Qualitative Research Approach (The ...

    African Journals Online (AJOL)

    Empirical Phenomenology: A Qualitative Research Approach (The Cologne Seminars) ... and practical application of empirical phenomenology in social research. ... and considers its implications for qualitative methods such as interviewing ...

  8. Teacher Leadership: Federal Policy Recommendations

    Science.gov (United States)

    Gran, Jackie; Young, Margaret; Broin, Alexandra

    2015-01-01

    This policy brief was developed specifically for federal policymakers, and builds upon the policy recommendations included in "Leading from Every Seat: Empowering Principals to Cultivate Teacher Leadership for School Improvement." The recommendations in this report include the following: (1) Uncover New Leadership Ideas and Seed…

  9. USGEO DMWG Cloud Computing Recommendations

    Science.gov (United States)

    de la Beaujardiere, J.; McInerney, M.; Frame, M. T.; Summers, C.

    2017-12-01

    The US Group on Earth Observations (USGEO) Data Management Working Group (DMWG) has been developing Cloud Computing Recommendations for Earth Observations. This inter-agency report is currently in draft form; DMWG hopes to have released the report as a public Request for Information (RFI) by the time of AGU. The recommendations are geared toward organizations that have already decided to use the Cloud for some of their activities (i.e., the focus is not on "why you should use the Cloud," but rather "If you plan to use the Cloud, consider these suggestions.") The report comprises Introductory Material, including Definitions, Potential Cloud Benefits, and Potential Cloud Disadvantages, followed by Recommendations in several areas: Assessing When to Use the Cloud, Transferring Data to the Cloud, Data and Metadata Contents, Developing Applications in the Cloud, Cost Minimization, Security Considerations, Monitoring and Metrics, Agency Support, and Earth Observations-specific recommendations. This talk will summarize the recommendations and invite comment on the RFI.

  10. Recommendation System for Adaptive Learning.

    Science.gov (United States)

    Chen, Yunxiao; Li, Xiaoou; Liu, Jingchen; Ying, Zhiliang

    2018-01-01

    An adaptive learning system aims at providing instruction tailored to the current status of a learner, differing from the traditional classroom experience. The latest advances in technology make adaptive learning possible, which has the potential to provide students with high-quality learning benefit at a low cost. A key component of an adaptive learning system is a recommendation system, which recommends the next material (video lectures, practices, and so on, on different skills) to the learner, based on the psychometric assessment results and possibly other individual characteristics. An important question then follows: How should recommendations be made? To answer this question, a mathematical framework is proposed that characterizes the recommendation process as a Markov decision problem, for which decisions are made based on the current knowledge of the learner and that of the learning materials. In particular, two plain vanilla systems are introduced, for which the optimal recommendation at each stage can be obtained analytically.

  11. Science and the British Empire.

    Science.gov (United States)

    Harrison, Mark

    2005-03-01

    The last few decades have witnessed a flowering of interest in the history of science in the British Empire. This essay aims to provide an overview of some of the most important work in this area, identifying interpretative shifts and emerging themes. In so doing, it raises some questions about the analytical framework in which colonial science has traditionally been viewed, highlighting interactions with indigenous scientific traditions and the use of network-based models to understand scientific relations within and beyond colonial contexts.

  12. Empirical logic and tensor products

    International Nuclear Information System (INIS)

    Foulis, D.J.; Randall, C.H.

    1981-01-01

    In our work we are developing a formalism called empirical logic to support a generalization of conventional statistics; the resulting generalization is called operational statistics. We are not attempting to develop or advocate any particular physical theory; rather we are formulating a precision 'language' in which such theories can be expressed, compared, evaluated, and related to laboratory experiments. We believe that only in such a language can the connections between real physical procedures (operations) and physical theories be made explicit and perspicuous. (orig./HSI)

  13. Pinning adaptive synchronization of a class of uncertain complex dynamical networks with multi-link against network deterioration

    International Nuclear Information System (INIS)

    Li, Lixiang; Li, Weiwei; Kurths, Jürgen; Luo, Qun; Yang, Yixian; Li, Shudong

    2015-01-01

    For the reason that the uncertain complex dynamic network with multi-link is quite close to various practical networks, there is superiority in the fields of research and application. In this paper, we focus upon pinning adaptive synchronization for uncertain complex dynamic networks with multi-link against network deterioration. The pinning approach can be applied to adapt uncertain coupling factors of deteriorated networks which can compensate effects of uncertainty. Several new synchronization criterions for networks with multi-link are derived, which ensure the synchronized states to be local or global stable with uncertainty and deterioration. Results of simulation are shown to demonstrate the feasibility and usefulness of our method

  14. Avoiding congestion in recommender systems

    International Nuclear Information System (INIS)

    Ren, Xiaolong; Lü, Linyuan; Liu, Runran; Zhang, Jianlin

    2014-01-01

    Recommender systems use the historical activities and personal profiles of users to uncover their preferences and recommend objects. Most of the previous methods are based on objects’ (and/or users’) similarity rather than on their difference. Such approaches are subject to a high risk of increasingly exposing users to a narrowing band of popular objects. As a result, a few objects may be recommended to an enormous number of users, resulting in the problem of recommendation congestion, which is to be avoided, especially when the recommended objects are limited resources. In order to quantitatively measure a recommendation algorithm's ability to avoid congestion, we proposed a new metric inspired by the Gini index, which is used to measure the inequality of the individual wealth distribution in an economy. Besides this, a new recommendation method called directed weighted conduction (DWC) was developed by considering the heat conduction process on a user–object bipartite network with different thermal conductivities. Experimental results obtained for three benchmark data sets showed that the DWC algorithm can effectively avoid system congestion, and greatly improve the novelty and diversity, while retaining relatively high accuracy, in comparison with the state-of-the-art methods. (paper)

  15. Quantifying uncertainty in Gulf of Mexico forecasts stemming from uncertain initial conditions

    KAUST Repository

    Iskandarani, Mohamed; Le Hé naff, Matthieu; Srinivasan, Ashwanth; Knio, Omar

    2016-01-01

    Polynomial Chaos (PC) methods are used to quantify the impacts of initial conditions uncertainties on oceanic forecasts of the Gulf of Mexico circulation. Empirical Orthogonal Functions are used as initial conditions perturbations with their modal

  16. Personalized News Recommendation: A Review and an Experimental Investigation

    Institute of Scientific and Technical Information of China (English)

    Lei Li; Ding-Ding Wang; Shun-Zhi Zhu; Tao Li

    2011-01-01

    Online news articles,as a new format of press releases,have sprung up on the Internet.With its convenience and recency,more and more people prefer to read news online instead of reading the paper-format press releases.However,a gigantic amount of news events might be released at a rate of hundreds,even thousands per hour.A challenging problem is how to efficiently select specific news articles from a large corpus of newly-published press releases to recommend to individual readers,where the selected news items should match the reader's reading preference as much as possible.This issue refers to personalized news recommendation.Recently,personalized news recommendation has become a promising research direction as the Internet provides fast access to real-time information from multiple sources around the world.Existing personalized news recommendation systems strive to adapt their services to individual users by virtue of both user and news content information.A variety of techniques have been proposed to tackle personalized news recommendation,including content-based,collaborative filtering systems and hybrid versions of these two.In this paper,we provide a comprehensive investigation of existing personalized news recommenders.We discuss several essential issues underlying the problem of personalized news recommendation,and explore possible solutions for performance improvement.Further,we provide an empirical study on a collection of news articles obtained from various news websites,and evaluate the effect of different factors for personalized news recommendation.We hope our discussion and exploration would provide insights for researchers who are interested in personalized news recommendation.

  17. A compilation of empirical data and variations in data concerning radiocesium in water, sediments and fish in European lakes after Chernobyl

    International Nuclear Information System (INIS)

    Hakanson, L.

    1999-01-01

    This work concerns the variability of radiocesium within lakes. The focus is on a broad set of data concerning radiocesium after the Chernobyl accident in lake water, sediments and different species of fish. Data are available to the author from three European data bases. Basic questions are: Are there any general patterns to be found concerning the variability of 137 Cs in lakes? Is it possible to give any recommendations concerning CV values (coefficient of variation; CV=SD/MV; SD=standard deviation, MV=mean value) for radiocesium in lake water, sediments and different species of fish? The analysis can be summarised as: 1. The CV values for lake water vary around 0.3 and are rather independent of the time after fallout. 2. One can use a CV of 0.6 as a reference for the typical uncertainty in radiocesium concentration in surficial lake sediments. CV values are generally higher (up to CV=1) for bottom areas dominated by erosion and transport processes (for fine material following Stokes' law) and lower (CV approx. 0.2) for areas dominated by continuous sedimentation and fine deposits (accumulation areas). CV values for radiocesium in sediments are also likely to increase with contamination and the size of the lake. 3. A reference CV of 0.22 would be a reasonable general CV value for lake fish. CV values are typically larger just after fallout (CV approx. 0.3) and decrease with time after fallout (to about 0.15). CV values are likely to increase with trophic level, from about 0.1 for planktivores to about 0.3 for piscivores, but these CV are based on limited data and are quite uncertain. The benefit of general empirical CV values is evident in modelling, e.g., when empirical data are compared to modelled values. The CV values for water, sediments and fish can be used to set empirical uncertainty bands for model predictions to enable meaningful discussions about predictive success. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  18. The new ICRP general recommendations

    International Nuclear Information System (INIS)

    Sasaki, Y.; Lochard, J.; Holm, L.E.; Niwa, O.; Ishigure, N.; Kosako, T.; Kai, M.

    2007-01-01

    The new draft ICRP recommendations was presented by the ICRP chair, Professor Lars-Eric Holm. His presentation was followed by presentations by Japanese members of the various (CRP committees, discussing their views of the draft recommendations based on their own technical experience. After these presentations, questions from the floor raised many of the key issues of the conference: dose constrains, the LNT hypothesis, dose bands, etc. This showed that the conference participants had carefully and completely read the draft, and were very interested in building a final ICRP recommendation that appropriately addresses all their concerns. These issues were also discussed throughout the entire conference. (author)

  19. Empirical reality, empirical causality, and the measurement problem

    International Nuclear Information System (INIS)

    d'Espagnat, B.

    1987-01-01

    Does physics describe anything that can meaningfully be called independent reality, or is it merely operational? Most physicists implicitly favor an intermediate standpoint, which takes quantum physics into account, but which nevertheless strongly holds fast to quite strictly realistic ideas about apparently obvious facts concerning the macro-objects. Part 1 of this article, which is a survey of recent measurement theories, shows that, when made explicit, the standpoint in question cannot be upheld. Part 2 brings forward a proposal for making minimal changes to this standpoint in such a way as to remove such objections. The empirical reality thus constructed is a notion that, to some extent, does ultimately refer to the human means of apprehension and of data processing. It nevertheless cannot be said that it reduces to a mere name just labelling a set of recipes that never fail. It is shown that their usual notion of macroscopic causality must be endowed with similar features

  20. Performance-Driven Robust Identification and Control of Uncertain Dynamical Systems

    Energy Technology Data Exchange (ETDEWEB)

    Basar, Tamer

    2001-10-29

    The grant DEFG02-97ER13939 from the Department of Energy has supported our research program on robust identification and control of uncertain dynamical systems, initially for the three-year period June 15, 1997-June 14, 2000, which was then extended on a no-cost basis for another year until June 14, 2001. This final report provides an overview of our research conducted during this period, along with a complete list of publications supported by the Grant. Within the scope of this project, we have studied fundamental issues that arise in modeling, identification, filtering, control, stabilization, control-based model reduction, decomposition and aggregation, and optimization of uncertain systems. The mathematical framework we have worked in has allowed the system dynamics to be only partially known (with the uncertainties being of both parametric or structural nature), and further the dynamics to be perturbed by unknown dynamic disturbances. Our research over these four years has generated a substantial body of new knowledge, and has led to new major developments in theory, applications, and computational algorithms. These have all been documented in various journal articles and book chapters, and have been presented at leading conferences, as to be described. A brief description of the results we have obtained within the scope of this project can be found in Section 3. To set the stage for the material of that section, we first provide in the next section (Section 2) a brief description of the issues that arise in the control of uncertain systems, and introduce several criteria under which optimality will lead to robustness and stability. Section 4 contains a list of references cited in these two sections. A list of our publications supported by the DOE Grant (covering the period June 15, 1997-June 14, 2001) comprises Section 5 of the report.

  1. A MODIFIED GENETIC ALGORITHM FOR FINDING FUZZY SHORTEST PATHS IN UNCERTAIN NETWORKS

    Directory of Open Access Journals (Sweden)

    A. A. Heidari

    2016-06-01

    Full Text Available In realistic network analysis, there are several uncertainties in the measurements and computation of the arcs and vertices. These uncertainties should also be considered in realizing the shortest path problem (SPP due to the inherent fuzziness in the body of expert's knowledge. In this paper, we investigated the SPP under uncertainty to evaluate our modified genetic strategy. We improved the performance of genetic algorithm (GA to investigate a class of shortest path problems on networks with vague arc weights. The solutions of the uncertain SPP with considering fuzzy path lengths are examined and compared in detail. As a robust metaheuristic, GA algorithm is modified and evaluated to tackle the fuzzy SPP (FSPP with uncertain arcs. For this purpose, first, a dynamic operation is implemented to enrich the exploration/exploitation patterns of the conventional procedure and mitigate the premature convergence of GA technique. Then, the modified GA (MGA strategy is used to resolve the FSPP. The attained results of the proposed strategy are compared to those of GA with regard to the cost, quality of paths and CPU times. Numerical instances are provided to demonstrate the success of the proposed MGA-FSPP strategy in comparison with GA. The simulations affirm that not only the proposed technique can outperform GA, but also the qualities of the paths are effectively improved. The results clarify that the competence of the proposed GA is preferred in view of quality quantities. The results also demonstrate that the proposed method can efficiently be utilized to handle FSPP in uncertain networks.

  2. [Treatment of aerobic vaginitis and clinically uncertain causes of vulvovaginal discomfort].

    Science.gov (United States)

    Cepický, P; Malina, J; Kuzelová, M

    2003-11-01

    The treatment of clinically uncertain conditions of vaginal discomforts with a mixed preparation of nifuratel + nystatin (Macmiror complex) and the relation of uncertain conditions to aerobic vaginitis. A prospective study. Gynecology-Obstetrics Outpatient Department LEVRET Ltd., AescuLab Ltd., Laboratory of Microbiology, Prague. 50 women with vaginal discomfort, causes of which had not been clarified by gynecological examination, determination of pH and the amine test, were examined by vaginal smears using microscopy. The results were evaluated in relation to aerobic vaginitis in a pure form or in combination with other nosological units. The authors also evaluated results of therapy by oral nifuratel (Macmiror tbl) 3 x 200 mg daily and a vaginal combined preparation containing nifuratel 500 mg + nystatin 200 kIU (Macmiror complex 500 glo vag) for the period of 7 days. In 50 women candida was demonstrated 24 times, presence of key cells 11 times, lactobacillus nine times with more than 50 in the field, six women were affected by aerobic vaginitis. In all these cases the pH was 4.8 or higher, leukocytes were significantly represented in all cases (> 15 in the field), as well as gram-negative bacteria and/or cocci (> 30 in the field), indicating a combined picture of mycosis, anaerobic vaginosis or lactobacillosis with aerobic vaginitis. The therapy was successful in all cases, the relapse of complaints during one month occurred in three cases. Aerobic vaginitis in a pure form or with anaerobic vaginosis, mycosis or lactobacillosis is frequently concealed under clinically uncertain pictures of vulvo-vaginal discomfort. The therapy by a combination of nifurated 3 x 200 mg orally together with the combined vaginal preparation nifuratel 500 mg + nystatin 200 kIU for the period of 7 days exerts high effect and a low number of relapses.

  3. Neural correlates of uncertain decision making: ERP evidence from the Iowa Gambling Task

    Directory of Open Access Journals (Sweden)

    Ji-fang eCui

    2013-11-01

    Full Text Available In our daily life, it is very common to make decisions in uncertain situations. The Iowa Gambling Task (IGT has been widely used in laboratory studies because of its good simulation of uncertainty in real life activities. The present study aimed to examine the neural correlates of uncertain decision making with the IGT. Twenty-six university students completed this study. An adapted IGT was administered to them, and the EEG data were recorded. The adapted IGT we used allowed us to analyze the choice evaluation, response selection, and feedback evaluation stages of uncertain decision making within the same paradigm. In the choice evaluation stage, the advantageous decks evoked larger P3 amplitude in the left hemisphere, while the disadvantageous decks evoked larger P3 in the right hemisphere. In the response selection stage, the response of pass (the card was not turned over; the participants neither won nor lost money evoked larger negativity preceding the response compared to that of play (the card was turned over; the participant either won or lost money. In the feedback evaluation stage, feedback-related negativity was only sensitive to the valence (win/loss but not the magnitude (large/small of the outcome, and P3 was sensitive to both the valence and the magnitude of the outcome. These results were consistent with the notion that a positive somatic state was represented in the left hemisphere and a negative somatic state was represented in the right hemisphere. There were also anticipatory ERP effects that guided the participants’ responses and provided evidence for the somatic marker hypothesis with more precise timing.

  4. Update on uncertain etiology of chronic kidney disease in Sri Lanka's north-central dry zone.

    Science.gov (United States)

    Wanigasuriya, Kamani

    2014-04-01

    This manuscript updates a review previously published in a local journal in 2012, about a new form of chronic kidney disease that has emerged over the past two decades in the north-central dry zone of Sri Lanka, where the underlying causes remain undetermined. Disease burden is higher in this area, particularly North Central Province, and affects a rural and disadvantaged population involved in rice-paddy farming. Over the last decade several studies have been carried out to estimate prevalence and identify determinants of this chronic kidney disease of uncertain etiology. Summarize the available evidence on prevalence, clinical profile and risk factors of chronic kidney disease of uncertain etiology in the north-central region of Sri Lanka. PubMed search located 16 manuscripts published in peer-reviewed journals. Three peer-reviewed abstracts of presentations at national scientific conferences were also included in the review. Disease prevalence was 5.1%-16.9% with more severe disease seen in men than in women. Patients with mild to moderate stages of disease were asymptomatic or had nonspecific symptoms; urinary sediments were bland; 24-hour urine protein excretion was urine, and mycotoxins detected in foods were below maximum statutory limits. Calcium-bicarbonate-type water with high levels of fluoride was predominant in endemic regions. Significantly high levels of cadmium in urine of cases compared to controls, as well as the disease's dose-related response to these levels, has drawn attention to this element as a possible contributing factor. Familial clustering of patients is suggestive of a polygenic inheritance pattern comparable to that associated with diseases of multifactorial etiology. Available data suggest that chronic kidney disease of uncertain etiology is an environmentally acquired disease, but to date no definitive causal factor has been identified. Geographic distribution and research findings suggest a multifactorial etiology.

  5. Time-optimal path planning in uncertain flow fields using ensemble method

    KAUST Repository

    Wang, Tong

    2016-01-06

    An ensemble-based approach is developed to conduct time-optimal path planning in unsteady ocean currents under uncertainty. We focus our attention on two-dimensional steady and unsteady uncertain flows, and adopt a sampling methodology that is well suited to operational forecasts, where a set deterministic predictions is used to model and quantify uncertainty in the predictions. In the operational setting, much about dynamics, topography and forcing of the ocean environment is uncertain, and as a result a single path produced by a model simulation has limited utility. To overcome this limitation, we rely on a finitesize ensemble of deterministic forecasts to quantify the impact of variability in the dynamics. The uncertainty of flow field is parametrized using a finite number of independent canonical random variables with known densities, and the ensemble is generated by sampling these variables. For each the resulting realizations of the uncertain current field, we predict the optimal path by solving a boundary value problem (BVP), based on the Pontryagin maximum principle. A family of backward-in-time trajectories starting at the end position is used to generate suitable initial values for the BVP solver. This allows us to examine and analyze the performance of sampling strategy, and develop insight into extensions dealing with regional or general circulation models. In particular, the ensemble method enables us to perform a statistical analysis of travel times, and consequently develop a path planning approach that accounts for these statistics. The proposed methodology is tested for a number of scenarios. We first validate our algorithms by reproducing simple canonical solutions, and then demonstrate our approach in more complex flow fields, including idealized, steady and unsteady double-gyre flows.

  6. RECOMMENDER SYSTEMS IN SOCIAL NETWORKS

    Directory of Open Access Journals (Sweden)

    Cleomar Valois Batista Jr

    2011-12-01

    Full Text Available The continued and diversified growth of social networks has changed the way in which users interact with them. With these changes, what once was limited to social contact is now used for exchanging ideas and opinions, creating the need for new features. Users have so much information at their fingertips that they are unable to process it by themselves; hence, the need to develop new tools. Recommender systems were developed to address this need and many techniques were used for different approaches to the problem. To make relevant recommendations, these systems use large sets of data, not taking the social network of the user into consideration. Developing a recommender system that takes into account the social network of the user is another way of tackling the problem. The purpose of this project is to use the theory of six degrees of separation (Watts 2003 amongst users of a social network to enhance existing recommender systems.

  7. From micronutrient recommendations to policy

    DEFF Research Database (Denmark)

    Timotijevic, Lada; Raats, Monique M.; Barnett, Julie

    2010-01-01

    towards achieving a greater link between micronutrient recommendations and behaviour. This study aims to examine the rationale and processes associated with consumer and stakeholder involvement in setting micronutrient recommendations across Europe. Subjects/Methods: Using the contacts established through......Background/Objectives: To achieve the nutritional goals stipulated by micronutrient recommendations, greater attention must be paid to the behavioural routes to such nutritional outcomes. Coopting stakeholders and consumers into decisions regarding micronutrient recommendations is an important step...... countries and its effect on final decisions. Stakeholders were not involved at the outset of the process ('framing' of the problem) in any of the countries, and there was no evidence of consumer involvement and open public fora. Conclusions: Some of the key explanatory factors for diversity in the degree...

  8. Chapter 6: Conclusions and recommendations

    International Nuclear Information System (INIS)

    1995-01-01

    This chapter provides a brief summary of conclusions with respect to project implementation issues. Furthermore, the chapter contains recommendations on future applications of the modelling system and on water resources management in the project area

  9. "The impact of uncertain threat on affective bias: Individual differences in response to ambiguity": Correction.

    Science.gov (United States)

    2018-04-01

    Reports an error in "The impact of uncertain threat on affective bias: Individual differences in response to ambiguity" by Maital Neta, Julie Cantelon, Zachary Haga, Caroline R. Mahoney, Holly A. Taylor and F. Caroline Davis ( Emotion , 2017[Dec], Vol 17[8], 1137-1143). In this article, the copyright attribution was incorrectly listed under the Creative Commons CC-BY license due to production-related error. The correct copyright should be "In the public domain." The online version of this article has been corrected. (The following abstract of the original article appeared in record 2017-40275-001.) Individuals who operate under highly stressful conditions (e.g., military personnel and first responders) are often faced with the challenge of quickly interpreting ambiguous information in uncertain and threatening environments. When faced with ambiguity, it is likely adaptive to view potentially dangerous stimuli as threatening until contextual information proves otherwise. One laboratory-based paradigm that can be used to simulate uncertain threat is known as threat of shock (TOS), in which participants are told that they might receive mild but unpredictable electric shocks while performing an unrelated task. The uncertainty associated with this potential threat induces a state of emotional arousal that is not overwhelmingly stressful, but has widespread-both adaptive and maladaptive-effects on cognitive and affective function. For example, TOS is thought to enhance aversive processing and abolish positivity bias. Importantly, in certain situations (e.g., when walking home alone at night), this anxiety can promote an adaptive state of heightened vigilance and defense mobilization. In the present study, we used TOS to examine the effects of uncertain threat on valence bias, or the tendency to interpret ambiguous social cues as positive or negative. As predicted, we found that heightened emotional arousal elicited by TOS was associated with an increased tendency to

  10. Parameter-dependent PWQ Lyapunov function stability criteria for uncertain piecewise linear systems

    Directory of Open Access Journals (Sweden)

    Morten Hovd

    2018-01-01

    Full Text Available The calculation of piecewise quadratic (PWQ Lyapunov functions is addressed in view of stability analysis of uncertain piecewise linear dynamics. As main contribution, the linear matrix inequality (LMI approach proposed in (Johansson and Rantzer, 1998 for the stability analysis of PWL and PWA dynamics is extended to account for parametric uncertainty based on a improved relaxation technique. The results are applied for the analysis of a Phase Locked Loop (PLL benchmark and the ability to guarantee a stability region in the parameter space well beyond the state of the art is demonstrated.

  11. Inactivation of DNA mismatch repair by variants of uncertain significance in the PMS2 gene.

    Science.gov (United States)

    Drost, Mark; Koppejan, Hester; de Wind, Niels

    2013-11-01

    Lynch syndrome (LS) is a common cancer predisposition caused by an inactivating mutation in one of four DNA mismatch repair (MMR) genes. Frequently a variant of uncertain significance (VUS), rather than an obviously pathogenic mutation, is identified in one of these genes. The inability to define pathogenicity of such variants precludes targeted healthcare. Here, we have modified a cell-free assay to test VUS in the MMR gene PMS2 for functional activity. We have analyzed nearly all VUS in PMS2 found thus far and describe loss of MMR activity for five, suggesting the applicability of the assay for diagnosis of LS. © 2013 WILEY PERIODICALS, INC.

  12. Sliding mode control for uncertain unified chaotic systems with input nonlinearity

    International Nuclear Information System (INIS)

    Chiang, T.-Y.; Hung, M.-L.; Yan, J.-J.; Yang, Y.-S.; Chang, J.-F.

    2007-01-01

    This paper investigates the stabilization problem for a class of unified chaotic systems subject to uncertainties and input nonlinearity. Using the sliding mode control technique, a robust control law is established which stabilizes the uncertain unified chaotic systems even when the nonlinearity in the actuators is present. A novel adaptive switching surface is introduced to simplify the task of assigning the stability of the closed-loop system in the sliding mode motion. An illustrative example is given to demonstrate the effectiveness of the proposed sliding mode control design

  13. Lesions of uncertain malignant potential in the breast (B3): what do we know?

    International Nuclear Information System (INIS)

    Purushothaman, H.N.; Lekanidi, K.; Shousha, S.; Wilson, R.

    2016-01-01

    Breast lesions classified as of uncertain malignant potential (B3) on biopsy form a diverse group of abnormalities, which pose a diagnostic and management challenge. In this paper, we discuss the imaging and pathology features as well as the management of the most controversial B3 lesions, consisting of papillary lesions, complex sclerosing lesions/radial scars, lobular intraepithelial neoplasia, and atypical epithelial proliferation of ductal type. As there is an association with malignancy at the time of diagnosis, as well as an increase in the risk of subsequent development of cancer, a multidisciplinary discussion is almost always required to tailor treatment.

  14. Towards a Framework for Self-Adaptive Reliable Network Services in Highly-Uncertain Environments

    DEFF Research Database (Denmark)

    Grønbæk, Lars Jesper; Schwefel, Hans-Peter; Ceccarelli, Andrea

    2010-01-01

    In future inhomogeneous, pervasive and highly dynamic networks, end-nodes may often only rely on unreliable and uncertain observations to diagnose hidden network states and decide upon possible remediation actions. Inherent challenges exists to identify good and timely decision strategies to impr...... execution (and monitoring) of remediation actions. We detail the motivations to the ODDR design, then we present its architecture, and finally we describe our current activities towards the realization and assessment of the framework services and the main results currently achieved....

  15. Control uncertain Genesio-Tesi chaotic system: Adaptive sliding mode approach

    International Nuclear Information System (INIS)

    Dadras, Sara; Momeni, Hamid Reza

    2009-01-01

    An adaptive sliding mode control (ASMC) technique is introduced in this paper for a chaotic dynamical system (Genesio-Tesi system). Using the sliding mode control technique, a sliding surface is determined and the control law is established. An adaptive sliding mode control law is derived to make the states of the Genesio-Tesi system asymptotically track and regulate the desired state. The designed control scheme can control the uncertain chaotic behaviors to a desired state without oscillating very fast and guarantee the property of asymptotical stability. An illustrative simulation result is given to demonstrate the effectiveness of the proposed adaptive sliding mode control design.

  16. Adaptive robust PID controller design based on a sliding mode for uncertain chaotic systems

    International Nuclear Information System (INIS)

    Chang Weider; Yan Junjuh

    2005-01-01

    A robust adaptive PID controller design motivated from the sliding mode control is proposed for a class of uncertain chaotic systems in this paper. Three PID control gains, K p , K i , and K d , are adjustable parameters and will be updated online with an adequate adaptation mechanism to minimize a previously designed sliding condition. By introducing a supervisory controller, the stability of the closed-loop PID control system under with the plant uncertainty and external disturbance can be guaranteed. Finally, a well-known Duffing-Holmes chaotic system is used as an illustrative to show the effectiveness of the proposed robust adaptive PID controller

  17. Transient Stability Assessment of Power Systems With Uncertain Renewable Generation: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Villegas Pico, Hugo Nestor [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Aliprantis, Dionysios C. [Purdue University; Lin, Xiaojun [Purdue University

    2017-08-09

    The transient stability of a power system depends heavily on its operational state at the moment of a fault. In systems where the penetration of renewable generation is significant, the dispatch of the conventional fleet of synchronous generators is uncertain at the time of dynamic security analysis. Hence, the assessment of transient stability requires the solution of a system of nonlinear ordinary differential equations with unknown initial conditions and inputs. To this end, we set forth a computational framework that relies on Taylor polynomials, where variables are associated with the level of renewable generation. This paper describes the details of the method and illustrates its application on a nine-bus test system.

  18. Robust H∞ Filtering for Uncertain Neutral Stochastic Systems with Markovian Jumping Parameters and Time Delay

    Directory of Open Access Journals (Sweden)

    Yajun Li

    2015-01-01

    Full Text Available This paper deals with the robust H∞ filter design problem for a class of uncertain neutral stochastic systems with Markovian jumping parameters and time delay. Based on the Lyapunov-Krasovskii theory and generalized Finsler Lemma, a delay-dependent stability condition is proposed to ensure not only that the filter error system is robustly stochastically stable but also that a prescribed H∞ performance level is satisfied for all admissible uncertainties. All obtained results are expressed in terms of linear matrix inequalities which can be easily solved by MATLAB LMI toolbox. Numerical examples are given to show that the results obtained are both less conservative and less complicated in computation.

  19. A guide for functional analysis of BRCA1 variants of uncertain significance

    DEFF Research Database (Denmark)

    Millot, Gaël A; Carvalho, Marcelo A; Caputo, Sandrine M

    2012-01-01

    of these variants, the effect on protein function is unknown making it difficult to infer the consequences on risks of breast and ovarian cancers. Thus, many individuals undergoing genetic testing for BRCA1 mutations receive test results reporting a variant of uncertain clinical significance (VUS), leading...... to issues in risk assessment, counseling, and preventive care. Here, we describe functional assays for BRCA1 to directly or indirectly assess the impact of a variant on protein conformation or function and how these results can be used to complement genetic data to classify a VUS as to its clinical...

  20. Stabilization of constrained uncertain systems by an off-line approach using zonotopes

    Directory of Open Access Journals (Sweden)

    Walid Hamdi

    2018-01-01

    Full Text Available In this paper, stabilization of uncertain systems was established using zonotopic sets. The obtained state feedback control laws are computed by an off-line approach reducing computational burdens. The resolution of a robust model predictive control (MPC allows computing a sequence of state feedback control laws corresponding to a sequence of zonotopic invariant sets. The implemented control laws are then calculated by linear interpolation between the state feedback gains corresponding to the nested pre-computed zonotopic sets. The proposed interpolation with the use of zonotopic sets achieves better control performances.

  1. Functional assays for analysis of variants of uncertain significance in BRCA2

    DEFF Research Database (Denmark)

    Guidugli, Lucia; Carreira, Aura; Caputo, Sandrine M

    2014-01-01

    Missense variants in the BRCA2 gene are routinely detected during clinical screening for pathogenic mutations in patients with a family history of breast and ovarian cancer. These subtle changes frequently remain of unknown clinical significance because of the lack of genetic information that may...... of uncertain significance analyzed, and describe a validation set of (genetically) proven pathogenic and neutral missense variants to serve as a golden standard for the validation of each assay. Guidelines are proposed to enable implementation of laboratory-based methods to assess the impact of the variant...

  2. Robust master-slave synchronization for general uncertain delayed dynamical model based on adaptive control scheme.

    Science.gov (United States)

    Wang, Tianbo; Zhou, Wuneng; Zhao, Shouwei; Yu, Weiqin

    2014-03-01

    In this paper, the robust exponential synchronization problem for a class of uncertain delayed master-slave dynamical system is investigated by using the adaptive control method. Different from some existing master-slave models, the considered master-slave system includes bounded unmodeled dynamics. In order to compensate the effect of unmodeled dynamics and effectively achieve synchronization, a novel adaptive controller with simple updated laws is proposed. Moreover, the results are given in terms of LMIs, which can be easily solved by LMI Toolbox in Matlab. A numerical example is given to illustrate the effectiveness of the method. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  3. Quantification of uncertain outcomes from site characterization: Insights from the ESF-AS

    International Nuclear Information System (INIS)

    Boyle, W.J.; Parrish, D.K.; Beccue, P.C.

    1992-01-01

    As part of the Exploratory Studies Facility Alternatives Study (ESF-AS) the uncertain outcomes from site characterization were quantified using a probabilistic tree known as ''Nature's Tree.'' Nature's Tree distinguished the true characteristics of the Yucca Mountain site from the perceived characteristics deduced from testing. Bayesian probabilistic calculations converted probabilities in Nature's Tree to the probabilistic estimates required for the comparative analysis of Exploratory Studies Facility-repository options. Experts on characterization testing explicitly addressed several site characterization issues that are considered implicitly in many site characterization programs

  4. Deriving the expected utility of a predictive model when the utilities are uncertain.

    Science.gov (United States)

    Cooper, Gregory F; Visweswaran, Shyam

    2005-01-01

    Predictive models are often constructed from clinical databases with the goal of eventually helping make better clinical decisions. Evaluating models using decision theory is therefore natural. When constructing a model using statistical and machine learning methods, however, we are often uncertain about precisely how the model will be used. Thus, decision-independent measures of classification performance, such as the area under an ROC curve, are popular. As a complementary method of evaluation, we investigate techniques for deriving the expected utility of a model under uncertainty about the model's utilities. We demonstrate an example of the application of this approach to the evaluation of two models that diagnose coronary artery disease.

  5. Decentralized H∞ Control for Uncertain Interconnected Systems of Neutral Type via Dynamic Output Feedback

    Directory of Open Access Journals (Sweden)

    Heli Hu

    2014-01-01

    Full Text Available The design of the dynamic output feedback H∞ control for uncertain interconnected systems of neutral type is investigated. In the framework of Lyapunov stability theory, a mathematical technique dealing with the nonlinearity on certain matrix variables is developed to obtain the solvability conditions for the anticipated controller. Based on the corresponding LMIs, the anticipated gains for dynamic output feedback can be achieved by solving some algebraic equations. Also, the norm of the transfer function from the disturbance input to the controlled output is less than the given index. A numerical example and the simulation results are given to show the effectiveness of the proposed method.

  6. Finite-Time H∞ Filtering for Linear Continuous Time-Varying Systems with Uncertain Observations

    Directory of Open Access Journals (Sweden)

    Huihong Zhao

    2012-01-01

    Full Text Available This paper is concerned with the finite-time H∞ filtering problem for linear continuous time-varying systems with uncertain observations and ℒ2-norm bounded noise. The design of finite-time H∞ filter is equivalent to the problem that a certain indefinite quadratic form has a minimum and the filter is such that the minimum is positive. The quadratic form is related to a Krein state-space model according to the Krein space linear estimation theory. By using the projection theory in Krein space, the finite-time H∞ filtering problem is solved. A numerical example is given to illustrate the performance of the H∞ filter.

  7. Novel stability criteria for uncertain delayed Cohen-Grossberg neural networks using discretized Lyapunov functional

    International Nuclear Information System (INIS)

    Souza, Fernando O.; Palhares, Reinaldo M.; Ekel, Petr Ya.

    2009-01-01

    This paper deals with the stability analysis of delayed uncertain Cohen-Grossberg neural networks (CGNN). The proposed methodology consists in obtaining new robust stability criteria formulated as linear matrix inequalities (LMIs) via the Lyapunov-Krasovskii theory. Particularly one stability criterion is derived from the selection of a parameter-dependent Lyapunov-Krasovskii functional, which allied with the Gu's discretization technique and a simple strategy that decouples the system matrices from the functional matrices, assures a less conservative stability condition. Two computer simulations are presented to support the improved theoretical results.

  8. Delay-Dependent Stability Criteria of Uncertain Periodic Switched Recurrent Neural Networks with Time-Varying Delays

    Directory of Open Access Journals (Sweden)

    Xing Yin

    2011-01-01

    uncertain periodic switched recurrent neural networks with time-varying delays. When uncertain discrete-time recurrent neural network is a periodic system, it is expressed as switched neural network for the finite switching state. Based on the switched quadratic Lyapunov functional approach (SQLF and free-weighting matrix approach (FWM, some linear matrix inequality criteria are found to guarantee the delay-dependent asymptotical stability of these systems. Two examples illustrate the exactness of the proposed criteria.

  9. A Novel Adaptive Observer-Based Control Scheme for Synchronization and Suppression of a Class of Uncertain Chaotic Systems

    International Nuclear Information System (INIS)

    Jing, Wang; Zhen-Yu, Tan; Xi-Kui, Ma; Jin-Feng, Gao

    2009-01-01

    A novel adaptive observer-based control scheme is presented for synchronization and suppression of a class of uncertain chaotic system. First, an adaptive observer based on an orthogonal neural network is designed. Subsequently, the sliding mode controllers via the proposed adaptive observer are proposed for synchronization and suppression of the uncertain chaotic systems. Theoretical analysis and numerical simulation show the effectiveness of the proposed scheme. (general)

  10. Empirical Modeling of ICMEs Using ACE/SWICS Ionic Distributions

    Science.gov (United States)

    Rivera, Y.; Landi, E.; Lepri, S. T.; Gilbert, J. A.

    2017-12-01

    Coronal Mass Ejections (CMEs) are some of the largest, most energetic events in the solar system releasing an immense amount of plasma and magnetic field into the Heliosphere. The Earth-bound plasma plays a large role in space weather, causing geomagnetic storms that can damage space and ground based instrumentation. As a CME is released, the plasma experiences heating, expansion and acceleration; however, the physical mechanism supplying the heating as it lifts out of the corona still remains uncertain. From previous work we know the ionic composition of solar ejecta undergoes a gradual transition to a state where ionization and recombination processes become ineffective rendering the ionic composition static along its trajectory. This property makes them a good indicator of thermal conditions in the corona, where the CME plasma likely receives most of its heating. We model this so-called `freeze-in' process in Earth-directed CMEs using an ionization code to empirically determine the electron temperature, density and bulk velocity. `Frozen-in' ions from an ensemble of independently modeled plasmas within the CME are added together to fit the full range of observational ionic abundances collected by ACE/SWICS during ICME events. The models derived using this method are used to estimate the CME energy budget to determine a heating rate used to compare with a variety of heating mechanisms that can sustain the required heating with a compatible timescale.

  11. Estimating economic losses from earthquakes using an empirical approach

    Science.gov (United States)

    Jaiswal, Kishor; Wald, David J.

    2013-01-01

    We extended the U.S. Geological Survey's Prompt Assessment of Global Earthquakes for Response (PAGER) empirical fatality estimation methodology proposed by Jaiswal et al. (2009) to rapidly estimate economic losses after significant earthquakes worldwide. The requisite model inputs are shaking intensity estimates made by the ShakeMap system, the spatial distribution of population available from the LandScan database, modern and historic country or sub-country population and Gross Domestic Product (GDP) data, and economic loss data from Munich Re's historical earthquakes catalog. We developed a strategy to approximately scale GDP-based economic exposure for historical and recent earthquakes in order to estimate economic losses. The process consists of using a country-specific multiplicative factor to accommodate the disparity between economic exposure and the annual per capita GDP, and it has proven successful in hindcast-ing past losses. Although loss, population, shaking estimates, and economic data used in the calibration process are uncertain, approximate ranges of losses can be estimated for the primary purpose of gauging the overall scope of the disaster and coordinating response. The proposed methodology is both indirect and approximate and is thus best suited as a rapid loss estimation model for applications like the PAGER system.

  12. Introduction on health recommender systems.

    Science.gov (United States)

    Sanchez-Bocanegra, C L; Sanchez-Laguna, F; Sevillano, J L

    2015-01-01

    People are looking for appropriate health information which they are concerned about. The Internet is a great resource of this kind of information, but we have to be careful if we don't want to get harmful info. Health recommender systems are becoming a new wave for apt health information as systems suggest the best data according to the patients' needs.The main goals of health recommender systems are to retrieve trusted health information from the Internet, to analyse which is suitable for the user profile and select the best that can be recommended, to adapt their selection methods according to the knowledge domain and to learn from the best recommendations.A brief definition of recommender systems will be given and an explanation of how are they incorporated in the health sector. A description of the main elementary recommender methods as well as their most important problems will also be made. And, to finish, the state of the art will be described.

  13. Hybrid context aware recommender systems

    Science.gov (United States)

    Jain, Rajshree; Tyagi, Jaya; Singh, Sandeep Kumar; Alam, Taj

    2017-10-01

    Recommender systems and context awareness is currently a vital field of research. Most hybrid recommendation systems implement content based and collaborative filtering techniques whereas this work combines context and collaborative filtering. The paper presents a hybrid context aware recommender system for books and movies that gives recommendations based on the user context as well as user or item similarity. It also addresses the issue of dimensionality reduction using weighted pre filtering based on dynamically entered user context and preference of context. This unique step helps to reduce the size of dataset for collaborative filtering. Bias subtracted collaborative filtering is used so as to consider the relative rating of a particular user and not the absolute values. Cosine similarity is used as a metric to determine the similarity between users or items. The unknown ratings are calculated and evaluated using MSE (Mean Squared Error) in test and train datasets. The overall process of recommendation has helped to personalize recommendations and give more accurate results with reduced complexity in collaborative filtering.

  14. Clinical practice recommendations for depression.

    Science.gov (United States)

    Malhi, G S; Adams, D; Porter, R; Wignall, A; Lampe, L; O'Connor, N; Paton, M; Newton, L A; Walter, G; Taylor, A; Berk, M; Mulder, R T

    2009-01-01

    To provide clinically relevant evidence-based recommendations for the management of depression in adults that are informative, easy to assimilate and facilitate clinical decision making. A comprehensive literature review of over 500 articles was undertaken using electronic database search engines (e.g. MEDLINE, PsychINFO and Cochrane reviews). In addition articles, book chapters and other literature known to the authors were reviewed. The findings were then formulated into a set of recommendations that were developed by a multidisciplinary team of clinicians who routinely deal with mood disorders. The recommendations then underwent consultative review by a broader advisory panel that included experts in the field, clinical staff and patient representatives. The clinical practice recommendations for depression (Depression CPR) summarize evidence-based treatments and provide a synopsis of recommendations relating to each phase of the illness. They are designed for clinical use and have therefore been presented succinctly in an innovative and engaging manner that is clear and informative. These up-to-date recommendations provide an evidence-based framework that incorporates clinical wisdom and consideration of individual factors in the management of depression. Further, the novel style and practical approach should promote uptake and implementation.

  15. Uncertain added value of Global Trigger Tool for monitoring of patient safety in cancer care

    DEFF Research Database (Denmark)

    Lipczak, Henriette; Neckelmann, Kirsten; Steding-Jessen, Marianne

    2011-01-01

    Monitoring patient safety is a challenging task. The lack of a golden standard has contributed to the recommendation and introduction of several methods. In 2000 the Danish Lung Cancer Registry (DLCR) was established to monitor the clinical management of lung cancer. In 2008 the Global Trigger Tool...... (GTT) was recommended in Denmark as a tool for the monitoring of patient safety. Ideally, the recommendation of a new tool should be preceded by a critical assessment of its added value....

  16. The Need for Large-Scale, Longitudinal Empirical Studies in Middle Level Education Research

    Science.gov (United States)

    Mertens, Steven B.; Caskey, Micki M.; Flowers, Nancy

    2016-01-01

    This essay describes and discusses the ongoing need for large-scale, longitudinal, empirical research studies focused on middle grades education. After a statement of the problem and concerns, the essay describes and critiques several prior middle grades efforts and research studies. Recommendations for future research efforts to inform policy…

  17. Risk assessment of salt contamination of groundwater under uncertain aquifer properties

    KAUST Repository

    Litvinenko, Alexander

    2017-10-01

    One of the central topics in hydrogeology and environmental science is the investigation of salinity-driven groundwater flow in heterogeneous porous media. Our goals are to model and to predict pollution of water resources. We simulate a density driven groundwater flow with uncertain porosity and permeability. This strongly non-linear model describes the unstable transport of salt water with building ‘fingers’-shaped patterns. The computation requires a very fine unstructured mesh and, therefore, high computational resources. We run the highly-parallel multigrid solver, based on ug4, on supercomputer Shaheen II. A MPI-based parallelization is done in the geometrical as well as in the stochastic spaces. Every scenario is computed on 32 cores and requires a mesh with ~8M grid points and 1500 or more time steps. 200 scenarios are computed concurrently. The total number of cores in parallel computation is 200x32=6400. The main goal of this work is to estimate propagation of uncertainties through the model, to investigate sensitivity of the solution to the input uncertain parameters. Additionally, we demonstrate how the multigrid ug4-based solver can be applied as a black-box in the uncertainty quantification framework.

  18. Data-Driven Optimization of Incentive-based Demand Response System with Uncertain Responses of Customers

    Directory of Open Access Journals (Sweden)

    Jimyung Kang

    2017-10-01

    Full Text Available Demand response is nowadays considered as another type of generator, beyond just a simple peak reduction mechanism. A demand response service provider (DRSP can, through its subcontracts with many energy customers, virtually generate electricity with actual load reduction. However, in this type of virtual generator, the amount of load reduction includes inevitable uncertainty, because it consists of a very large number of independent energy customers. While they may reduce energy today, they might not tomorrow. In this circumstance, a DSRP must choose a proper set of these uncertain customers to achieve the exact preferred amount of load curtailment. In this paper, the customer selection problem for a service provider that consists of uncertain responses of customers is defined and solved. The uncertainty of energy reduction is fully considered in the formulation with data-driven probability distribution modeling and stochastic programming technique. The proposed optimization method that utilizes only the observed load data provides a realistic and applicable solution to a demand response system. The performance of the proposed optimization is verified with real demand response event data in Korea, and the results show increased and stabilized performance from the service provider’s perspective.

  19. Dynamic IQC-Based Control of Uncertain LFT Systems With Time-Varying State Delay.

    Science.gov (United States)

    Yuan, Chengzhi; Wu, Fen

    2016-12-01

    This paper presents a new exact-memory delay control scheme for a class of uncertain systems with time-varying state delay under the integral quadratic constraint (IQC) framework. The uncertain system is described as a linear fractional transformation model including a state-delayed linear time-invariant (LTI) system and time-varying structured uncertainties. The proposed exact-memory delay controller consists of a linear state-feedback control law and an additional term that captures the delay behavior of the plant. We first explore the delay stability and the L 2 -gain performance using dynamic IQCs incorporated with quadratic Lyapunov functions. Then, the design of exact-memory controllers that guarantee desired L 2 -gain performance is examined. The resulting delay control synthesis conditions are formulated in terms of linear matrix inequalities, which are convex on all design variables including the scaling matrices associated with the IQC multipliers. The IQC-based exact-memory control scheme provides a novel approach for delay control designs via convex optimization, and advances existing control methods in two important ways: 1) better controlled performance and 2) simplified design procedure with less computational cost. The effectiveness and advantages of the proposed approach have been demonstrated through numerical studies.

  20. Clinical impact of confocal laser endomicroscopy in the management of gastrointestinal lesions with an uncertain diagnosis.

    Science.gov (United States)

    Robles-Medranda, Carlos; Vargas, Maria; Ospina, Jesenia; Puga-Tejada, Miguel; Valero, Manuel; Soria, Miguel; Bravo, Gladys; Robles-Jara, Carlos; Lukashok, Hannah Pitanga

    2017-08-16

    To evaluate the clinical impact of confocal laser endomicroscopy (CLE) in the diagnosis and management of patients with an uncertain diagnosis. A retrospective chart review was performed. Patients who underwent CLE between November 2013 and October 2015 and exhibited a poor correlation between endoscopic and histological findings were included. Baseline characteristics, indications, previous diagnostic studies, findings at the time of CLE, clinical management and histological results were analyzed. Interventions based on CLE findings were also analyzed. We compared the diagnostic accuracy of CLE and target biopsies of surgical specimens. A total of 144 patients were included. Of these, 51% (74/144) were female. The mean age was 51 years old. In all, 41/144 (28.4%) lesions were neoplastic (13 bile duct, 10 gastric, 8 esophageal, 6 colonic, 1 duodenal, 1 rectal, 1 ampulloma and 1 pancreatic). The sensitivity, specificity, positive predictive value, negative predictive value, and observed agreement when CLE was used to detect N-lesions were 85.37%, 87.38%, 72.92%, 93.75% and 86.81%, respectively. Cohen's Kappa was 69.20%, thus indicating good agreement. Changes in management were observed in 54% of the cases. CLE is a new diagnostic tool that has a significant clinical impact on the diagnosis and treatment of patients with uncertain diagnosis.

  1. Robust DEA under discrete uncertain data: a case study of Iranian electricity distribution companies

    Science.gov (United States)

    Hafezalkotob, Ashkan; Haji-Sami, Elham; Omrani, Hashem

    2015-06-01

    Crisp input and output data are fundamentally indispensable in traditional data envelopment analysis (DEA). However, the real-world problems often deal with imprecise or ambiguous data. In this paper, we propose a novel robust data envelopment model (RDEA) to investigate the efficiencies of decision-making units (DMU) when there are discrete uncertain input and output data. The method is based upon the discrete robust optimization approaches proposed by Mulvey et al. (1995) that utilizes probable scenarios to capture the effect of ambiguous data in the case study. Our primary concern in this research is evaluating electricity distribution companies under uncertainty about input/output data. To illustrate the ability of proposed model, a numerical example of 38 Iranian electricity distribution companies is investigated. There are a large amount ambiguous data about these companies. Some electricity distribution companies may not report clear and real statistics to the government. Thus, it is needed to utilize a prominent approach to deal with this uncertainty. The results reveal that the RDEA model is suitable and reliable for target setting based on decision makers (DM's) preferences when there are uncertain input/output data.

  2. Landscape architectural research in Canada: developing a certain future in uncertain times.

    Directory of Open Access Journals (Sweden)

    Douglas Paterson

    1995-03-01

    Full Text Available LANDSCAPE ARCHITECTURAL RESEARCH in Canada is defined by the uncertain and complex global issues of the times, the significant theoretical and methodological debates facing the world of research in general, and the increased academic pressures for research in a less well-funded and more constricting research environment. It is also affected by the political environment in which its few researchers are outnumbered by the larger disciplines and professions which seem to be getting bigger all the time, and by its own internal struggles between its disciplinary and professional roles. Landscape architectural research efforts in Canada are, as such, both vigorous and hesitant, aggressive yet underfunded, well focused yet somewhat uncertain in their ultimate intention. This paper begins with a brief examination of the present context of our research. It next looks at the basic problems that have and continue to plague design research. With these contextual issues established, the paper then recounts a brief history of the profession and its emerging educational-research base in Canada and gives an overview of current research efforts. It concludes by suggesting several important directions that are needed in Canadian landscape architectural research over' the next 10 years. It is hoped that this personal, historical account of research efforts, problems and opportunities in Canada will allow others in the Asia-Pacific region to recognise the similarities to their own situations.

  3. Data envelopment analysis with uncertain data: An application for Iranian electricity distribution companies

    International Nuclear Information System (INIS)

    Sadjadi, S.J.; Omrani, H.

    2008-01-01

    This paper presents Data Envelopment Analysis (DEA) model with uncertain data for performance assessment of electricity distribution companies. During the past two decades, DEA has been widely used for benchmarking the electricity distribution companies. However, there is no study among many existing DEA approaches where the uncertainty in data is allowed and, at the same time, the distribution of the random data is permitted to be unknown. The proposed method of this paper develops a new DEA method with the consideration of uncertainty on output parameters. The method is based on the adaptation of recently developed robust optimization approaches proposed by Ben-Tal and Nemirovski [2000. Robust solutions of linear programming problems contaminated with uncertain data. Mathematical Programming 88, 411-421] and Bertsimas et al. [2004. Robust linear optimization under general norms. Operations Research Letters 32, 510-516]. The results are compared with an existing parametric Stochastic Frontier Analysis (SFA) using data from 38 electricity distribution companies in Iran to show the effects of the data uncertainties on the performance of DEA outputs. The results indicate that the robust DEA approach can be a relatively more reliable method for efficiency estimating and ranking strategies

  4. Influence of uncertain identification of triggering rainfall on the assessment of landslide early warning thresholds

    Science.gov (United States)

    Peres, David J.; Cancelliere, Antonino; Greco, Roberto; Bogaard, Thom A.

    2018-03-01

    Uncertainty in rainfall datasets and landslide inventories is known to have negative impacts on the assessment of landslide-triggering thresholds. In this paper, we perform a quantitative analysis of the impacts of uncertain knowledge of landslide initiation instants on the assessment of rainfall intensity-duration landslide early warning thresholds. The analysis is based on a synthetic database of rainfall and landslide information, generated by coupling a stochastic rainfall generator and a physically based hydrological and slope stability model, and is therefore error-free in terms of knowledge of triggering instants. This dataset is then perturbed according to hypothetical reporting scenarios that allow simulation of possible errors in landslide-triggering instants as retrieved from historical archives. The impact of these errors is analysed jointly using different criteria to single out rainfall events from a continuous series and two typical temporal aggregations of rainfall (hourly and daily). The analysis shows that the impacts of the above uncertainty sources can be significant, especially when errors exceed 1 day or the actual instants follow the erroneous ones. Errors generally lead to underestimated thresholds, i.e. lower than those that would be obtained from an error-free dataset. Potentially, the amount of the underestimation can be enough to induce an excessive number of false positives, hence limiting possible landslide mitigation benefits. Moreover, the uncertain knowledge of triggering rainfall limits the possibility to set up links between thresholds and physio-geographical factors.

  5. Practical Stabilization of Uncertain Nonholonomic Mobile Robots Based on Visual Servoing Model with Uncalibrated Camera Parameters

    Directory of Open Access Journals (Sweden)

    Hua Chen

    2013-01-01

    Full Text Available The practical stabilization problem is addressed for a class of uncertain nonholonomic mobile robots with uncalibrated visual parameters. Based on the visual servoing kinematic model, a new switching controller is presented in the presence of parametric uncertainties associated with the camera system. In comparison with existing methods, the new design method is directly used to control the original system without any state or input transformation, which is effective to avoid singularity. Under the proposed control law, it is rigorously proved that all the states of closed-loop system can be stabilized to a prescribed arbitrarily small neighborhood of the zero equilibrium point. Furthermore, this switching control technique can be applied to solve the practical stabilization problem of a kind of mobile robots with uncertain parameters (and angle measurement disturbance which appeared in some literatures such as Morin et al. (1998, Hespanha et al. (1999, Jiang (2000, and Hong et al. (2005. Finally, the simulation results show the effectiveness of the proposed controller design approach.

  6. Influence of uncertain identification of triggering rainfall on the assessment of landslide early warning thresholds

    Directory of Open Access Journals (Sweden)

    D. J. Peres

    2018-03-01

    Full Text Available Uncertainty in rainfall datasets and landslide inventories is known to have negative impacts on the assessment of landslide-triggering thresholds. In this paper, we perform a quantitative analysis of the impacts of uncertain knowledge of landslide initiation instants on the assessment of rainfall intensity–duration landslide early warning thresholds. The analysis is based on a synthetic database of rainfall and landslide information, generated by coupling a stochastic rainfall generator and a physically based hydrological and slope stability model, and is therefore error-free in terms of knowledge of triggering instants. This dataset is then perturbed according to hypothetical reporting scenarios that allow simulation of possible errors in landslide-triggering instants as retrieved from historical archives. The impact of these errors is analysed jointly using different criteria to single out rainfall events from a continuous series and two typical temporal aggregations of rainfall (hourly and daily. The analysis shows that the impacts of the above uncertainty sources can be significant, especially when errors exceed 1 day or the actual instants follow the erroneous ones. Errors generally lead to underestimated thresholds, i.e. lower than those that would be obtained from an error-free dataset. Potentially, the amount of the underestimation can be enough to induce an excessive number of false positives, hence limiting possible landslide mitigation benefits. Moreover, the uncertain knowledge of triggering rainfall limits the possibility to set up links between thresholds and physio-geographical factors.

  7. Navigation of autonomous vehicles for oil spill cleaning in dynamic and uncertain environments

    Science.gov (United States)

    Jin, Xin; Ray, Asok

    2014-04-01

    In the context of oil spill cleaning by autonomous vehicles in dynamic and uncertain environments, this paper presents a multi-resolution algorithm that seamlessly integrates the concepts of local navigation and global navigation based on the sensory information; the objective here is to enable adaptive decision making and online replanning of vehicle paths. The proposed algorithm provides a complete coverage of the search area for clean-up of the oil spills and does not suffer from the problem of having local minima, which is commonly encountered in potential-field-based methods. The efficacy of the algorithm is tested on a high-fidelity player/stage simulator for oil spill cleaning in a harbour, where the underlying oil weathering process is modelled as 2D random-walk particle tracking. A preliminary version of this paper was presented by X. Jin and A. Ray as 'Coverage Control of Autonomous Vehicles for Oil Spill Cleaning in Dynamic and Uncertain Environments', Proceedings of the American Control Conference, Washington, DC, June 2013, pp. 2600-2605.

  8. Dynamical Scheduling and Robust Control in Uncertain Environments with Petri Nets for DESs

    Directory of Open Access Journals (Sweden)

    Dimitri Lefebvre

    2017-10-01

    Full Text Available This paper is about the incremental computation of control sequences for discrete event systems in uncertain environments where uncontrollable events may occur. Timed Petri nets are used for this purpose. The aim is to drive the marking of the net from an initial value to a reference one, in minimal or near-minimal time, by avoiding forbidden markings, deadlocks, and dead branches. The approach is similar to model predictive control with a finite set of control actions. At each step only a small area of the reachability graph is explored: this leads to a reasonable computational complexity. The robustness of the resulting trajectory is also evaluated according to a risk probability. A sufficient condition is provided to compute robust trajectories. The proposed results are applicable to a large class of discrete event systems, in particular in the domains of flexible manufacturing. However, they are also applicable to other domains as communication, computer science, transportation, and traffic as long as the considered systems admit Petri Nets (PNs models. They are suitable for dynamical deadlock-free scheduling and reconfiguration problems in uncertain environments.

  9. An Uncertain Programming Model for Land Use Structure Optimization to Promote Effectiveness of Land Use Planning

    Institute of Scientific and Technical Information of China (English)

    LI Xin; MA Xiaodong

    2017-01-01

    Land use structure optimization (LUSO) is an important issue for land use planning.In order for land use planning to have reasonable flexibility,uncertain optimization should be applied for LUSO.In this paper,the researcher first expounded the uncertainties of LUSO.Based on this,an interval programming model was developed,of which interval variables were to hold land use uncertainties.To solve the model,a heuristics based on Genetic Algorithm was designed according to Pareto Optimum principle with a confidence interval under given significance level to represent LUSO result.Proposed method was applied to a real case of Yangzhou,an eastern city in China.The following conclusions were reached.1) Different forms of uncertainties ranged from certainty to indeterminacy lay in the five steps of LUSO,indicating necessary need of comprehensive approach to quantify them.2) With regards to trade-offs of conflicted objectives and preferences to uncertainties,our proposed model displayed good ability of making planning decision process transparent,therefore providing an effective tool for flexible land use planning compiling.3) Under uncertain conditions,land use planning effectiveness can be primarily enhanced by flexible management with reserved space to percept and hold uncertainties in advance.

  10. Adaptive Control for Linear Uncertain Systems with Unmodeled Dynamics Revisited via Optimal Control Modification

    Science.gov (United States)

    Nguyen, Nhan

    2013-01-01

    This paper presents the optimal control modification for linear uncertain plants. The Lyapunov analysis shows that the modification parameter has a limiting value depending on the nature of the uncertainty. The optimal control modification exhibits a linear asymptotic property that enables it to be analyzed in a linear time invariant framework for linear uncertain plants. The linear asymptotic property shows that the closed-loop plants in the limit possess a scaled input-output mapping. Using this property, we can derive an analytical closed-loop transfer function in the limit as the adaptive gain tends to infinity. The paper revisits the Rohrs counterexample problem that illustrates the nature of non-robustness of model-reference adaptive control in the presence of unmodeled dynamics. An analytical approach is developed to compute exactly the modification parameter for the optimal control modification that stabilizes the plant in the Rohrs counterexample. The linear asymptotic property is also used to address output feedback adaptive control for non-minimum phase plants with a relative degree 1.

  11. The Importance of Studying Past Extreme Floods to Prepare for Uncertain Future Extremes

    Science.gov (United States)

    Burges, S. J.

    2016-12-01

    Hoyt and Langbein, 1955 in their book `Floods' wrote: " ..meteorologic and hydrologic conditions will combine to produce superfloods of unprecedented magnitude. We have every reason to believe that in most rivers past floods may not be an accurate measure of ultimate flood potentialities. It is this superflood with which we are always most concerned". I provide several examples to offer some historical perspective on assessing extreme floods. In one example, flooding in the Miami Valley, OH in 1913 claimed 350 lives. The engineering and socio-economic challenges facing the Morgan Engineering Co in how to mitigate against future flood damage and loss of life when limited information was available provide guidance about ways to face an uncertain hydroclimate future, particularly one of a changed climate. A second example forces us to examine mixed flood populations and illustrates the huge uncertainty in assigning flood magnitude and exceedance probability to extreme floods in such cases. There is large uncertainty in flood frequency estimates; knowledge of the total flood hydrograph, not the peak flood flow rate alone, is what is needed for hazard mitigation assessment or design. Some challenges in estimating the complete flood hydrograph in an uncertain future climate, including demands on hydrologic models and their inputs, are addressed.

  12. Feature inference with uncertain categorization: Re-assessing Anderson's rational model.

    Science.gov (United States)

    Konovalova, Elizaveta; Le Mens, Gaël

    2017-09-18

    A key function of categories is to help predictions about unobserved features of objects. At the same time, humans are often in situations where the categories of the objects they perceive are uncertain. In an influential paper, Anderson (Psychological Review, 98(3), 409-429, 1991) proposed a rational model for feature inferences with uncertain categorization. A crucial feature of this model is the conditional independence assumption-it assumes that the within category feature correlation is zero. In prior research, this model has been found to provide a poor fit to participants' inferences. This evidence is restricted to task environments inconsistent with the conditional independence assumption. Currently available evidence thus provides little information about how this model would fit participants' inferences in a setting with conditional independence. In four experiments based on a novel paradigm and one experiment based on an existing paradigm, we assess the performance of Anderson's model under conditional independence. We find that this model predicts participants' inferences better than competing models. One model assumes that inferences are based on just the most likely category. The second model is insensitive to categories but sensitive to overall feature correlation. The performance of Anderson's model is evidence that inferences were influenced not only by the more likely category but also by the other candidate category. Our findings suggest that a version of Anderson's model which relaxes the conditional independence assumption will likely perform well in environments characterized by within-category feature correlation.

  13. Allowances for evolving coastal flood risk under uncertain local sea-level rise

    Science.gov (United States)

    Buchanan, M. K.; Kopp, R. E.; Oppenheimer, M.; Tebaldi, C.

    2015-12-01

    Sea-level rise (SLR) causes estimates of flood risk made under the assumption of stationary mean sea level to be biased low. However, adjustments to flood return levels made assuming fixed increases of sea level are also inaccurate when applied to sea level that is rising over time at an uncertain rate. To accommodate both the temporal dynamics of SLR and their uncertainty, we develop an Average Annual Design Life Level (AADLL) metric and associated SLR allowances [1,2]. The AADLL is the flood level corresponding to a time-integrated annual expected probability of occurrence (AEP) under uncertainty over the lifetime of an asset; AADLL allowances are the adjustment from 2000 levels that maintain current risk. Given non-stationary and uncertain SLR, AADLL flood levels and allowances provide estimates of flood protection heights and offsets for different planning horizons and different levels of confidence in SLR projections in coastal areas. Allowances are a function primarily of local SLR and are nearly independent of AEP. Here we employ probabilistic SLR projections [3] to illustrate the calculation of AADLL flood levels and allowances with a representative set of long-duration tide gauges along U.S. coastlines. [1] Rootzen et al., 2014, Water Resources Research 49: 5964-5972. [2] Hunter, 2013, Ocean Engineering 71: 17-27. [3] Kopp et al., 2014, Earth's Future 2: 383-406.

  14. Robust Economic Control Decision Method of Uncertain System on Urban Domestic Water Supply.

    Science.gov (United States)

    Li, Kebai; Ma, Tianyi; Wei, Guo

    2018-03-31

    As China quickly urbanizes, urban domestic water generally presents the circumstances of both rising tendency and seasonal cycle fluctuation. A robust economic control decision method for dynamic uncertain systems is proposed in this paper. It is developed based on the internal model principle and pole allocation method, and it is applied to an urban domestic water supply system with rising tendency and seasonal cycle fluctuation. To achieve this goal, first a multiplicative model is used to describe the urban domestic water demand. Then, a capital stock and a labor stock are selected as the state vector, and the investment and labor are designed as the control vector. Next, the compensator subsystem is devised in light of the internal model principle. Finally, by using the state feedback control strategy and pole allocation method, the multivariable robust economic control decision method is implemented. The implementation with this model can accomplish the urban domestic water supply control goal, with the robustness for the variation of parameters. The methodology presented in this study may be applied to the water management system in other parts of the world, provided all data used in this study are available. The robust control decision method in this paper is also applicable to deal with tracking control problems as well as stabilization control problems of other general dynamic uncertain systems.

  15. Output Feedback-Based Boundary Control of Uncertain Coupled Semilinear Parabolic PDE Using Neurodynamic Programming.

    Science.gov (United States)

    Talaei, Behzad; Jagannathan, Sarangapani; Singler, John

    2018-04-01

    In this paper, neurodynamic programming-based output feedback boundary control of distributed parameter systems governed by uncertain coupled semilinear parabolic partial differential equations (PDEs) under Neumann or Dirichlet boundary control conditions is introduced. First, Hamilton-Jacobi-Bellman (HJB) equation is formulated in the original PDE domain and the optimal control policy is derived using the value functional as the solution of the HJB equation. Subsequently, a novel observer is developed to estimate the system states given the uncertain nonlinearity in PDE dynamics and measured outputs. Consequently, the suboptimal boundary control policy is obtained by forward-in-time estimation of the value functional using a neural network (NN)-based online approximator and estimated state vector obtained from the NN observer. Novel adaptive tuning laws in continuous time are proposed for learning the value functional online to satisfy the HJB equation along system trajectories while ensuring the closed-loop stability. Local uniformly ultimate boundedness of the closed-loop system is verified by using Lyapunov theory. The performance of the proposed controller is verified via simulation on an unstable coupled diffusion reaction process.

  16. A Robust Adaptive Unscented Kalman Filter for Nonlinear Estimation with Uncertain Noise Covariance.

    Science.gov (United States)

    Zheng, Binqi; Fu, Pengcheng; Li, Baoqing; Yuan, Xiaobing

    2018-03-07

    The Unscented Kalman filter (UKF) may suffer from performance degradation and even divergence while mismatch between the noise distribution assumed as a priori by users and the actual ones in a real nonlinear system. To resolve this problem, this paper proposes a robust adaptive UKF (RAUKF) to improve the accuracy and robustness of state estimation with uncertain noise covariance. More specifically, at each timestep, a standard UKF will be implemented first to obtain the state estimations using the new acquired measurement data. Then an online fault-detection mechanism is adopted to judge if it is necessary to update current noise covariance. If necessary, innovation-based method and residual-based method are used to calculate the estimations of current noise covariance of process and measurement, respectively. By utilizing a weighting factor, the filter will combine the last noise covariance matrices with the estimations as the new noise covariance matrices. Finally, the state estimations will be corrected according to the new noise covariance matrices and previous state estimations. Compared with the standard UKF and other adaptive UKF algorithms, RAUKF converges faster to the actual noise covariance and thus achieves a better performance in terms of robustness, accuracy, and computation for nonlinear estimation with uncertain noise covariance, which is demonstrated by the simulation results.

  17. Adaptive Neural Output Feedback Control for Uncertain Robot Manipulators with Input Saturation

    Directory of Open Access Journals (Sweden)

    Rong Mei

    2017-01-01

    Full Text Available This paper presents an adaptive neural output feedback control scheme for uncertain robot manipulators with input saturation using the radial basis function neural network (RBFNN and disturbance observer. First, the RBFNN is used to approximate the system uncertainty, and the unknown approximation error of the RBFNN and the time-varying unknown external disturbance of robot manipulators are integrated as a compounded disturbance. Then, the state observer and the disturbance observer are proposed to estimate the unmeasured system state and the unknown compounded disturbance based on RBFNN. At the same time, the adaptation technique is employed to tackle the control input saturation problem. Utilizing the estimate outputs of the RBFNN, the state observer, and the disturbance observer, the adaptive neural output feedback control scheme is developed for robot manipulators using the backstepping technique. The convergence of all closed-loop signals is rigorously proved via Lyapunov analysis and the asymptotically convergent tracking error is obtained under the integrated effect of the system uncertainty, the unmeasured system state, the unknown external disturbance, and the input saturation. Finally, numerical simulation results are presented to illustrate the effectiveness of the proposed adaptive neural output feedback control scheme for uncertain robot manipulators.

  18. Recommendations for cerebrospinal fluid Alzheimer's disease biomarkers in the diagnostic evaluation of mild cognitive impairment

    DEFF Research Database (Denmark)

    Herukka, Sanna-Kaisa; Simonsen, Anja Hviid; Andreasen, Niels

    2017-01-01

    ) patient counseling. The working group recommended using CSF AD biomarkers in the diagnostic workup of MCI patients, after prebiomarker counseling, as an add-on to clinical evaluation to predict functional decline or conversion to AD dementia and to guide disease management. Because of insufficient...... evidence, it was uncertain whether CSF AD biomarkers outperform imaging biomarkers. Furthermore, the working group provided recommendations for interpretation of ambiguous CSF biomarker results and for pre- and post-biomarker counseling....... impairment (MCI). The recommendations were developed by a multidisciplinary working group and based on the available evidence and consensus from focused group discussions for 1) prediction of clinical progression to Alzheimer's disease (AD) dementia, 2) cost-effectiveness, 3) interpretation of results, and 4...

  19. Personalized recommendation with corrected similarity

    International Nuclear Information System (INIS)

    Zhu, Xuzhen; Tian, Hui; Cai, Shimin

    2014-01-01

    Personalized recommendation has attracted a surge of interdisciplinary research. Especially, similarity-based methods in applications of real recommendation systems have achieved great success. However, the computations of similarities are overestimated or underestimated, in particular because of the defective strategy of unidirectional similarity estimation. In this paper, we solve this drawback by leveraging mutual correction of forward and backward similarity estimations, and propose a new personalized recommendation index, i.e., corrected similarity based inference (CSI). Through extensive experiments on four benchmark datasets, the results show a greater improvement of CSI in comparison with these mainstream baselines. And a detailed analysis is presented to unveil and understand the origin of such difference between CSI and mainstream indices. (paper)

  20. The new ICRP general recommendations

    International Nuclear Information System (INIS)

    Mason, Ch.; Kosako, T.; Kuniyoshi, H.; Kiryu, Y.; Choi, H.S.; Burns, P.A.; Pan, Z.Q.; Xia, Y.

    2007-01-01

    Regulatory views from Japan, South Korea, Australia, China and Indonesia were explained based on their regional context. Some issues, for example 'optimisation', 'dose constrains', 'natural radioactivity', were addressed from the viewpoint of how each country's current regulation system would adopt these new recommendations. It was noted that there would be a need for some flexibility in applying these new recommendations since different countries have different regulatory criteria and benchmarks as well different decision-making processes. It was also noted that definitions and terminologies should be given serious consideration with regard to non-English speaking countries to assure that the new ICRP recommendations are clearly understood, not misinterpreted, easily translated and finally applied in the field of radiation protection. In addition, some recent radiation protection activities, as well as views on utilisation of nuclear power in several countries were presented. (authors)