WorldWideScience

Sample records for modeling approach employed

  1. Modeling energy fluxes in heterogeneous landscapes employing a mosaic approach

    Science.gov (United States)

    Klein, Christian; Thieme, Christoph; Priesack, Eckart

    2015-04-01

    Recent studies show that uncertainties in regional and global climate and weather simulations are partly due to inadequate descriptions of the energy flux exchanges between the land surface and the atmosphere. One major shortcoming is the limitation of the grid-cell resolution, which is recommended to be about at least 3x3 km² in most models due to limitations in the model physics. To represent each individual grid cell most models select one dominant soil type and one dominant land use type. This resolution, however, is often too coarse in regions where the spatial diversity of soil and land use types are high, e.g. in Central Europe. An elegant method to avoid the shortcoming of grid cell resolution is the so called mosaic approach. This approach is part of the recently developed ecosystem model framework Expert-N 5.0. The aim of this study was to analyze the impact of the characteristics of two managed fields, planted with winter wheat and potato, on the near surface soil moistures and on the near surface energy flux exchanges of the soil-plant-atmosphere interface. The simulated energy fluxes were compared with eddy flux tower measurements between the respective fields at the research farm Scheyern, North-West of Munich, Germany. To perform these simulations, we coupled the ecosystem model Expert-N 5.0 to an analytical footprint model. The coupled model system has the ability to calculate the mixing ratio of the surface energy fluxes at a given point within one grid cell (in this case at the flux tower between the two fields). This approach accounts for the differences of the two soil types, of land use managements, and of canopy properties due to footprint size dynamics. Our preliminary simulation results show that a mosaic approach can improve modeling and analyzing energy fluxes when the land surface is heterogeneous. In this case our applied method is a promising approach to extend weather and climate models on the regional and on the global scale.

  2. Markowitz portfolio optimization model employing fuzzy measure

    Science.gov (United States)

    Ramli, Suhailywati; Jaaman, Saiful Hafizah

    2017-04-01

    Markowitz in 1952 introduced the mean-variance methodology for the portfolio selection problems. His pioneering research has shaped the portfolio risk-return model and become one of the most important research fields in modern finance. This paper extends the classical Markowitz's mean-variance portfolio selection model applying the fuzzy measure to determine the risk and return. In this paper, we apply the original mean-variance model as a benchmark, fuzzy mean-variance model with fuzzy return and the model with return are modeled by specific types of fuzzy number for comparison. The model with fuzzy approach gives better performance as compared to the mean-variance approach. The numerical examples are included to illustrate these models by employing Malaysian share market data.

  3. Employment Effects of Renewable Energy Expansion on a Regional Level—First Results of a Model-Based Approach for Germany

    Directory of Open Access Journals (Sweden)

    Ulrike Lehr

    2012-02-01

    Full Text Available National studies have shown that both gross and net effects of the expansion of energy from renewable sources on employment are positive for Germany. These modeling approaches also revealed that this holds true for both present and future perspectives under certain assumptions on the development of exports, fossil fuel prices and national politics. Yet how are employment effects distributed within Germany? What components contribute to growth impacts on a regional level? To answer these questions (new methods of regionalization were explored and developed for the example “wind energy onshore” for Germany’s federal states. The main goal was to develop a methodology which is applicable to all renewable energy technologies in future research. For the quantification and projection, it was necessary to distinguish between jobs generated by domestic investments and exports on the one hand, and jobs for operation and maintenance of existing plants on the other hand. Further, direct and indirect employment is analyzed. The results show, that gross employment is particularly high in the northwestern regions of Germany. However, especially the indirect effects are spread out over the whole country. Regions in the south not only profit from the delivery of specific components, but also from other industry and service inputs.

  4. An Elderly Employment Model For The Thai Automotive Industry

    Directory of Open Access Journals (Sweden)

    Pornrat Sadangharn

    2017-10-01

    Full Text Available This research aims at studying an elderly employment model for the Thai automotive industry. Mixed methods with a sequential exploratory strategy were utilized. Grounded theory was employed by using in-depth interviews to investigate the characteristics of elderly employment in the Thai automotive industry. For this stage of the research, theoretical and purposive sampling was used to select 32 key informants from four groups of stakeholders: (1 elderly workers, (2 employers or human resource managers, (3 government officers, and (4 academics. The findings were then validated using a quantitative approach with structural equation modelling (SEM. A total of 308 elderly workers and human resource managers were surveyed regarding their opinion about elderly employment. Based on the survey, the elderly employment model in the Thai automotive industry, which is comprised of the approach to elderly employment, elderly employment preparation, and key success factors for elderly employment, was revealed to be a good fit. 

  5. Employer Practices in Improving Employment Outcomes for People with Disabilities: A Transdisciplinary and Employer-Inclusive Research Approach

    Science.gov (United States)

    Barrington, Linda; Bruyère, M.; Waelder, Margaret

    2014-01-01

    Objective: Share new knowledge about workplace practices related to employer success in hiring, retaining, and promoting people with disabilities, and promote use of findings to employers and service providers. Design: A transdisciplinary and multifaceted data gathering approach. Results: Provides an overview of the research approach taken and the…

  6. An Ecosystem Approach to Employment and Autism Spectrum Disorder

    Science.gov (United States)

    Nicholas, David B.; Mitchell, Wendy; Dudley, Carolyn; Clarke, Margaret; Zulla, Rosslynn

    2018-01-01

    Relatively little is yet known about employment readiness and elements that promote access to, and the retention of, employment for adults with autism spectrum disorder (ASD). This paper posits elements within the ecosystem of employment and ASD. The ecosystem approach locates employment among persons with ASD as inextricably linked with broader…

  7. Analysis of the Romanian employment rate. A panel data approach

    Directory of Open Access Journals (Sweden)

    Larisa APARASCHIVEI

    2012-07-01

    Full Text Available This paper examines the evolution of the employment rate in Romania. I employ a panel data approach, considering the 42 counties, in order to explore the relationship between labour productivity, average earnings, investments and employment. The results reveal a positive impact of the average wage and gross investments and a negative impact of the labour productivity on employment rate.

  8. An employer brand predictive model for talent attraction and retention

    Directory of Open Access Journals (Sweden)

    Annelize Botha

    2011-11-01

    Full Text Available Orientation: In an ever shrinking global talent pool organisations use employer brand to attract and retain talent, however, in the absence of theoretical pointers, many organisations are losing out on a powerful business tool by not developing or maintaining their employer brand correctly. Research purpose: This study explores the current state of knowledge about employer brand and identifies the various employer brand building blocks which are conceptually integrated in a predictive model. Motivation for the study: The need for scientific progress though the accurate representation of a set of employer brand phenomena and propositions, which can be empirically tested, motivated this study. Research design, approach and method: This study was nonempirical in approach and searched for linkages between theoretical concepts by making use of relevant contextual data. Theoretical propositions which explain the identified linkages were developed for purpose of further empirical research. Main findings: Key findings suggested that employer brand is influenced by target group needs, a differentiated Employer Value Proposition (EVP, the people strategy, brand consistency, communication of the employer brand and measurement of Human Resources (HR employer branding efforts. Practical/managerial implications: The predictive model provides corporate leaders and their human resource functionaries a theoretical pointer relative to employer brand which could guide more effective talent attraction and retention decisions. Contribution/value add: This study adds to the small base of research available on employer brand and contributes to both scientific progress as well as an improved practical understanding of factors which influence employer brand.

  9. A new approach in measuring graduate employability skills

    Science.gov (United States)

    Zakaria, Mohd Hafiz; Yatim, Bidin; Ismail, Suzilah

    2014-06-01

    Globalization makes graduate recruitment for an organization becomes more complex because employers believe that a holistic workforce is the key success of an organization. Currently, although graduates are said to possess specific skills but they still lack of employability skills, and this lead to increment of training cost either by government or even employers. Therefore, graduate level of employability skills should be evaluated before entering work market. In this study, a valid and reliable instrument embedding a new approach of measuring employability skills was developed using Situational Judgment Test (SJT). The instrument comprises of twelve (12) items measuring communication skill, professional ethics and morality, entrepreneurial skill, critical thinking in problem solving and personal quality. Instrument's validity was achieved through expert opinion and the reliability (in terms of stability) was based on the Chi-Square for homogeneity test. Generally, the instrument is beneficial to graduates, employers, government agencies, university, and workforce recruitment agencies when evaluating the level of employability skills.

  10. On-line detection of apnea/hypopnea events using SpO2 signal: a rule-based approach employing binary classifier models.

    Science.gov (United States)

    Koley, Bijoy Laxmi; Dey, Debangshu

    2014-01-01

    This paper presents an online method for automatic detection of apnea/hypopnea events, with the help of oxygen saturation (SpO2) signal, measured at fingertip by Bluetooth nocturnal pulse oximeter. Event detection is performed by identifying abnormal data segments from the recorded SpO2 signal, employing a binary classifier model based on a support vector machine (SVM). Thereafter the abnormal segment is further analyzed to detect different states within the segment, i.e., steady, desaturation, and resaturation, with the help of another SVM-based binary ensemble classifier model. Finally, a heuristically obtained rule-based system is used to identify the apnea/hypopnea events from the time-sequenced decisions of these classifier models. In the developmental phase, a set of 34 time domain-based features was extracted from the segmented SpO2 signal using an overlapped windowing technique. Later, an optimal set of features was selected on the basis of recursive feature elimination technique. A total of 34 subjects were included in the study. The results show average event detection accuracies of 96.7% and 93.8% for the offline and the online tests, respectively. The proposed system provides direct estimation of the apnea/hypopnea index with the help of a relatively inexpensive and widely available pulse oximeter. Moreover, the system can be monitored and accessed by physicians through LAN/WAN/Internet and can be extended to deploy in Bluetooth-enabled mobile phones.

  11. Employer Branding and Corporate Social Responsibility – a postmodern approach

    Directory of Open Access Journals (Sweden)

    Mihaela-Alexandra TUDOR-IONESCU

    2009-01-01

    Full Text Available In the present article we designed an exploratory analysis from a postmodern perspective on employer branding and corporate social responsibility in order to overcome the disciplinary dogmatic approach that is found in the organizational and management studies. Our approach is based on investigating theoretical background for the two concepts that have a relatively recent history and it emphasizes their role of legitimation micro-structures with an organizational -corporate nature, arguing for the thesis that they represent founding micronarratives, with different histories, but similar aims.

  12. Productivity and Regional Employment in Spain: A Dynamic Approach

    Directory of Open Access Journals (Sweden)

    F. Javier Escribá Pérez

    2013-01-01

    Full Text Available This paper analyses the impact of sectorial and territorial factors on the dynamics of employment in regional industries in Spain over the period 1980-2006. A dynamic panel data model is estimated using panel data techniques (System-GMM, which provide an alternative methodology for addressing the problem of variable endogeneity. The results confirm the robustness of the contemporary effects: diversification, market size and dynamics in the sector affect employment in the short term. However, effects in the long term are more uncertain.

  13. Analytical model and behavioral simulation approach for a ΣΔ fractional-N synthesizer employing a sample-hold element

    DEFF Research Database (Denmark)

    Cassia, Marco; Shah, Peter Jivan; Bruun, Erik

    2003-01-01

    A previously unknown intrinsic nonlinearity of standard SigmaDelta fractional-N synthesizers is identified. A general analytical model for SigmaDelta fractional-N phased-locked loops (PLLs) that includes the effect of the nonlinearity is derived and an improvement to the synthesizer topology is d...

  14. Sustainable employability - definition, conceptualization, and implications : A perspective based on the capability approach

    NARCIS (Netherlands)

    van der Klink, Jac J. L.; Bultmann, Ute; Burdorf, Alex; Schaufeli, Wilmar B.; Zijlstra, Fred R. H.; Abma, Femke I.; Brouwer, Sandra; van der Wilt, Gert Jan

    Objectives The aim of this paper is to propose anew model of sustainable employability based on the capability approach, encompassing the complexity of contemporary work, and placing particular emphasis on work-related values. Methods Having evaluated existing conceptual models of work, health, and

  15. Sustainable employability - definition, conceptualization, and implications : A perspective based on the capability approach

    NARCIS (Netherlands)

    van der Klink, J.J.L.; Bültmann, U.; Burdorf, A.; Schaufeli, W.B.; Zijlstra, F.R.H.; Abma, F.I.; Brouwer, S.; van der Wilt, G.J.

    2016-01-01

    Objectives The aim of this paper is to propose a new model of sustainable employability based on the capability approach, encompassing the complexity of contemporary work, and placing particular emphasis on work-related values. Methods Having evaluated existing conceptual models of work, health, and

  16. Employment for adults with autism spectrum disorders: A retrospective review of a customized employment approach.

    Science.gov (United States)

    Wehman, Paul; Brooke, Valerie; Brooke, Alissa Molinelli; Ham, Whitney; Schall, Carol; McDonough, Jennifer; Lau, Stephanie; Seward, Hannah; Avellone, Lauren

    2016-01-01

    Over the past few decades, there has been an increase in prevalence of children with autism spectrum disorders (ASD), and those children are now becoming young adults in need of competitive integrated employment (CIE). Customized employment (CE) is one pathway to employment that has been successful for other individuals with developmental disabilities (DD), though research has been very limited on the effectiveness with individuals with ASD. This paper provides a retrospective review of 64 individuals with ASD who came to our program from 2009 to 2014 for supported employment services as referred by the state vocational rehabilitation services agency. Employment specialists engaged in situational assessment, discovery, job development, customized job descriptions, on-site training and support, positive behavioral supports, and job retention techniques. The employment specialists were responsible for tracking their actual time spent working directly with or for the jobseeker with autism spectrum disorders (ASD). All vocational rehabilitation clients with ASD served during this time successfully secured CIE, and maintained their employment with ongoing supports, with intensity of support time decreasing over time. The majority (63/64, 98.4%) of individuals successfully secured CIE through the use of supported employment, in 72 unique employment positions. Of the majority of the individuals who secured employment, 77% (50) individuals indicated that they had never worked before and additional 18% (12) reported having short intermittent histories of employment. Despite this lack of employment experience, in all cases the jobseeker directed the job search and ultimately the job selection. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Future employability, a new approach to cost-effectiveness analysis of antipsychotic therapy.

    Science.gov (United States)

    Ganguly, Rahul; Miller, L Stephen; Martin, Bradley C

    2003-09-01

    Schizophrenia patients pose a substantial burden in terms of indirect costs, much of which is attributable to loss of employment. We present a new approach to assess the cost-effectiveness (CE) of risperidone vs. haloperidol using employability as an outcome measure. A decision analytic CE model was developed to compare the two treatments over a 1-year period including all direct medical costs and the number of employable persons as a measure of effectiveness. A measure of executive functioning, the Wisconsin Card Sorting Test Category score (WCST-Cat score), was used as an intermediate endpoint from which employability was modeled. A Monte Carlo procedure, using WCST-Cat score sampling distributions from clinical trials, simulated the WCST-Cat score distribution for a cohort of 10,000 patients. A clinically stable patient, with a Positive and Negative Syndrome Scale (PANSS) score increase of at least 20% and a WCST-Cat score of > or =3.5 was assumed to be employable. Sensitivity analysis was performed for key values. The base case per-patient cost of risperidone and haloperidol was 6,422 US dollars and 4,989 US dollars, respectively, and the number of employable persons was 3,258 (32.58%) and 2,517 (25.17%), respectively, which translates to an incremental CE ratio of 19,609 US dollars per employable person for risperidone. Risperidone remained cost increasing and had higher number of employable persons over all the ranges used in the sensitivity analysis. The incremental CE ratio ranged from a high of 1,000,000 US dollars to a low of 3,000 US dollars per employable persons when the rates of clinical stability for risperidone and haloperidol therapy were varied. Gains from earning rates for employed persons with schizophrenia, savings in informal caregiver costs and other human benefits could justify an incremental cost of 19,609 US dollars for each additional employable person prescribed risperidone.

  18. Sustainable employability--definition, conceptualization, and implications: A perspective based on the capability approach.

    Science.gov (United States)

    van der Klink, Jac J L; Bültmann, Ute; Burdorf, Alex; Schaufeli, Wilmar B; Zijlstra, Fred R H; Abma, Femke I; Brouwer, Sandra; van der Wilt, Gert Jan

    2016-01-01

    The aim of this paper is to propose a new model of sustainable employability based on the capability approach, encompassing the complexity of contemporary work, and placing particular emphasis on work-related values. Having evaluated existing conceptual models of work, health, and employability, we concluded that prevailing models lack an emphasis on important work-related values. Amartya Sen's capability approach (CA) provides a framework that incorporates a focus on values and reflects the complexity of sustainable employability. We developed a model of sustainable employability based on the CA. This model can be used as starting point for developing an assessment tool to investigate sustainable employability. A fundamental premise of the CA is that work should create value for the organization as well as for the worker. This approach challenges researchers, policy-makers, and practitioners to investigate what people find important and valuable--what they would like to achieve in a given (work) context--and moreover to ascertain whether people are able and enabled to do so. According to this approach, it is not only the individual who is responsible for achieving this; the work context is also important. Rather than merely describing relationships between variables, as existing descriptive models often do, the CA depicts a valuable goal: a set of capabilities that constitute valuable work. Moreover, the CA fits well with recent conceptions of health and modern insights into work, in which the individual works towards his or her own goals that s/he has to achieve within the broader goals of the organization.

  19. Minimum Wages and Teen Employment: A Spatial Panel Approach

    OpenAIRE

    Charlene Kalenkoski; Donald Lacombe

    2011-01-01

    The authors employ spatial econometrics techniques and Annual Averages data from the U.S. Bureau of Labor Statistics for 1990-2004 to examine how changes in the minimum wage affect teen employment. Spatial econometrics techniques account for the fact that employment is correlated across states. Such correlation may exist if a change in the minimum wage in a state affects employment not only in its own state but also in other, neighboring states. The authors show that state minimum wages negat...

  20. ANALYSIS MODEL FOR RETURN ON CAPITAL EMPLOYED

    Directory of Open Access Journals (Sweden)

    BURJA CAMELIA

    2013-02-01

    Full Text Available At the microeconomic level, the appreciation of the capitals’ profitability is a very complex action which is ofinterest for stakeholders. This study has as main purpose to extend the traditional analysis model for the capitals’profitability, based on the ratio “Return on capital employed”. In line with it the objectives of this work aim theidentification of factors that exert an influence on the capital’s profitability utilized by a company and the measurementof their contribution in the manifestation of the phenomenon. The proposed analysis model is validated on the use caseof a representative company from the agricultural sector. The results obtained reveal that in a company there are somefactors which can act positively on the capitals’ profitability: capital turnover, sales efficiency, increase the share ofsales in the total revenues, improvement of the expenses’ efficiency. The findings are useful both for the decisionmakingfactors in substantiating the economic strategies and for the capital owners who are interested in efficiency oftheir investments.

  1. An integrative model for measuring graduates’ employability skills—A study in China

    Directory of Open Access Journals (Sweden)

    Wenping Su

    2015-12-01

    Full Text Available Employability is a key issue in graduates’ job-hunting, but little research has been done on that of the graduates in Chinese universities. These universities have been experiencing a decline in their graduate employment since the past decade. This paper attempts to tackle this issue. It reviews the relevant research on employability and develops a research-based theoretical framework to evaluate and analyze the graduates’ employability in China. It adopts multiple approaches to establish the skills that will enhance university students’ employability. Investigating around 100 employers and 200 undergraduates from the universities in Beijing, the paper explores the characteristics of and factors influencing the graduates’ employability. Subsequently, it proposes a qualitative model to measure graduates’ employability. Based on the findings, it discusses the theoretical and practical implications and provides advice for Chinese graduates to improve their employability.

  2. Employer branding: A new approach for the hospitality industry ...

    African Journals Online (AJOL)

    The Western hospitality industry experiences a shortage of skilled professionals due to a poor image and competition from othersectors. Employer branding, which is used as a human resources strategy to differentiate brands, has the potential to deal withsome of the problems. An employer brand is closely connected to a ...

  3. Employability among people with uncontrolled seizures: An interpretative phenomenological approach.

    Science.gov (United States)

    Wo, Monica Chen Mun; Lim, Kheng Seang; Choo, Wan Yuen; Tan, Chong Tin

    2015-04-01

    This study aimed to explore positive and negative factors affecting the employability in patients with uncontrolled seizures. Semistructured interviews with 21 patients with uncontrolled seizures were analyzed using interpretative phenomenological analysis. Eleven (52.4%) of the participants interviewed were employed; 7 were holding full-time position with more than 4years of working experience. The mean age was 34.6years, 71.4% were female, 38% were married, 71.4% had at least 11years of education, 38% had a driving license, 19% received government monetary aid, 66.7% had seizure onset before reaching 17years of age, 66.7% experienced monthly seizures, and 76% were on polytherapy. A total of 6 main themes were found to be affecting the employability among people with uncontrolled seizures: (a) ability to work; (b) intention to work; (c) support and stigma at workplace; (d) family support, overdependence, and protection; (e) life event; and (f) government and welfare support. Subthemes under the main theme ability to work included education, cognitive and physical functions, ability to continue working after seizures, ability to travel to work, self-perceived ability to work, and ability to cope with stress. Many shared the same idea that employment is important, but their intention to work varied. The employed group tended to work for a future goal and self-satisfaction, and the unemployed group tended to have no or lack intention to work. Positive factors were noted in the following themes: ability to work; intention to work; support and stigma at workplace; and family support, overdependence, and protection. There were internal and external factors affecting the employability among people with uncontrolled seizures both positively and negatively. Positive internal factors such as ability and intention to work require further exploration. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Employing a Qualitative Description Approach in Health Care Research

    OpenAIRE

    Bradshaw, Carmel; Atkinson, Sandra; Doody, Owen

    2017-01-01

    A qualitative description design is particularly relevant where information is required directly from those experiencing the phenomenon under investigation and where time and resources are limited. Nurses and midwives often have clinical questions suitable to a qualitative approach but little time to develop an exhaustive comprehension of qualitative methodological approaches. Qualitative description research is sometimes considered a less sophisticated approach for epistemological reasons. A...

  5. How can the EMMA approach to learning analytics improve employability?

    NARCIS (Netherlands)

    Brouns, Francis; Tammets, Kairit; Padrón-Nápoles, Carmen L.

    2014-01-01

    In our current society there is a strong need for citizens to work on their employability and to develop key competences. Developing those competences should starts during formal education, but maintained throughout working life. MOOCs can accommodate several of the needs of the lifelong learners.

  6. Employing a Qualitative Description Approach in Health Care Research.

    Science.gov (United States)

    Bradshaw, Carmel; Atkinson, Sandra; Doody, Owen

    2017-01-01

    A qualitative description design is particularly relevant where information is required directly from those experiencing the phenomenon under investigation and where time and resources are limited. Nurses and midwives often have clinical questions suitable to a qualitative approach but little time to develop an exhaustive comprehension of qualitative methodological approaches. Qualitative description research is sometimes considered a less sophisticated approach for epistemological reasons. Another challenge when considering qualitative description design is differentiating qualitative description from other qualitative approaches. This article provides a systematic and robust journey through the philosophical, ontological, and epistemological perspectives, which evidences the purpose of qualitative description research. Methods and rigor issues underpinning qualitative description research are also appraised to provide the researcher with a systematic approach to conduct research utilizing this approach. The key attributes and value of qualitative description research in the health care professions will be highlighted with the aim of extending its usage.

  7. Tracing employment in business functions. A sectoral and occupational approach

    OpenAIRE

    Geurts, Karen; Ramioul, Monique

    2007-01-01

    Economic globalisation and the increased pressure on firms to outsource or relocate activities, are often perceived as primarily resulting in job losses. This perspective takes no account of the positive employment effects entailed by these developments, both in terms of new companies and of job creation in existing companies. Recently, different attempts have been made to estimate the impact of economic globalisation on job losses and job gains. The methods applied to this end differ widely,...

  8. Employability and Related Context Prediction Framework for University Graduands: A Machine Learning Approach

    Directory of Open Access Journals (Sweden)

    Manushi P. Wijayapala

    2016-12-01

    Full Text Available In Sri Lanka (SL, graduands’ employability remains a national issue due to the increasing number of graduates produced by higher education institutions each year. Thus, predicting the employability of university graduands can mitigate this issue since graduands can identify what qualifications or skills they need to strengthen up in order to find a job of their desired field with a good salary, before they complete the degree. The main objective of the study is to discover the plausibility of applying machine learning approach efficiently and effectively towards predicting the employability and related context of university graduands in Sri Lanka by proposing an architectural framework which consists of four modules; employment status prediction, job salary prediction, job field prediction and job relevance prediction of graduands while also comparing performance of classification algorithms under each prediction module. Series of machine learning algorithms such as C4.5, Naïve Bayes and AODE have been experimented on the Graduand Employment Census - 2014 data. A pre-processing step is proposed to overcome challenges embedded in graduand employability data and a feature selection process is proposed in order to reduce computational complexity. Additionally, parameter tuning is also done to get the most optimized parameters. More importantly, this study utilizes several types of Sampling (Oversampling, Undersampling and Ensemble (Bagging, Boosting, RF techniques as well as a newly proposed hybrid approach to overcome the limitations caused by the class imbalance phenomena. For the validation purposes, a wide range of evaluation measures was used to analyze the effectiveness of applying classification algorithms and class imbalance mitigation techniques on the dataset. The experimented results indicated that RandomForest has recorded the highest classification performance for 3 modules, achieving the selected best predictive models under hybrid

  9. Employment, Production and Consumption model: Patterns of phase transitions

    Science.gov (United States)

    Lavička, H.; Lin, L.; Novotný, J.

    2010-04-01

    We have simulated the model of Employment, Production and Consumption (EPC) using Monte Carlo. The EPC model is an agent based model that mimics very basic rules of industrial economy. From the perspective of physics, the nature of the interactions in the EPC model represents multi-agent interactions where the relations among agents follow the key laws for circulation of capital and money. Monte Carlo simulations of the stochastic model reveal phase transition in the model economy. The two phases are the phase with full unemployment and the phase with nearly full employment. The economy switches between these two states suddenly as a reaction to a slight variation in the exogenous parameter, thus the system exhibits strong non-linear behavior as a response to the change of the exogenous parameters.

  10. Determination of Constructs and Dimensions of Employability Skills Based Work Performance Prediction: A Triangular Approach

    OpenAIRE

    Rahmat, Normala; Buntat, Yahya; Ayub, Abdul Rahman

    2015-01-01

    The level of the employability skills of the graduates as determined by job role and mapped to the employability skills, which correspond to the requirement of employers, will have significant impact on the graduates’ job performance. The main objective of this study was to identify the constructs and dimensions of employability skills, which can predict the work performance of electronic polytechnic graduate in electrical and electronics industry. A triangular qualitative approach was used i...

  11. Economic and industrial development. EID - EMPLOY. Final report. Task 1. Review of approaches for employment impact assessment of renewable energy deployment

    Energy Technology Data Exchange (ETDEWEB)

    Breitschopf, Barbara [Fraunhofer-Institut fuer System- und Innovationsforschung (ISI), Karlsruhe (Germany); Nathani, Carsten; Resch, Gustav

    2011-11-15

    The objective of this study is to provide an overview of existing impact assessment studies that analyse employment impacts of renewable energy (RE) deployment and to show which methodological approaches are best suitable to assess employment effect in the field of RE- electricity. A first review shows a large variety of impact assessment studies in the field of energy deployment applying a rather broad array of methodological approaches. Bounding the studies to RE-electricity considerably reduces the number of studies, but not necessarily the number of approaches. Due to different approaches the questions answered by the impact assessment studies cover a wide range that captures e.g. limited impacts in the RE industry as well as overarching employment impacts in the overall economy. First, based on the research focus of the studies and their impacts (Figure 0-1), we classify the assessed studies on employment impacts into two groups: gross employment studies and net employment studies. They aim to answer different policy questions and capture different effects: - Gross employment studies focus on the economic relevance of the RE industry in terms of employment, thus on the number of jobs provided in the RE industry and the structural analysis of employment in the RE industry. Furthermore employment in supplying industries are also included as indirect or induced impacts. The aim is to provide transparency on employment in an industry that is in the public interest but not adequately represented in official statistics, and, furthermore, enabling monitoring of this industry in the course of RE promotion. Gross studies take into account positive effects of RE deployment. - Net employment impact studies aim to assess the overall economic impact of promoting RE deployment, thus the change of the number of jobs in the total economy. For this, they take into account negative and positive effects of RE deployment on employment in all economic sectors and hence provide a

  12. Motion Model Employment using interacting Motion Model Algorithm

    DEFF Research Database (Denmark)

    Hussain, Dil Muhammad Akbar

    2006-01-01

    model being correct is computed through a likelihood function for each model.  The study presented a simple technique to introduce additional models into the system using deterministic acceleration which basically defines the dynamics of the system.  Therefore, based on this value more motion models can...

  13. HEDR modeling approach

    International Nuclear Information System (INIS)

    Shipler, D.B.; Napier, B.A.

    1992-07-01

    This report details the conceptual approaches to be used in calculating radiation doses to individuals throughout the various periods of operations at the Hanford Site. The report considers the major environmental transport pathways--atmospheric, surface water, and ground water--and projects and appropriate modeling technique for each. The modeling sequence chosen for each pathway depends on the available data on doses, the degree of confidence justified by such existing data, and the level of sophistication deemed appropriate for the particular pathway and time period being considered

  14. Modeling prosody: Different approaches

    Science.gov (United States)

    Carmichael, Lesley M.

    2002-11-01

    Prosody pervades all aspects of a speech signal, both in terms of raw acoustic outcomes and linguistically meaningful units, from the phoneme to the discourse unit. It is carried in the suprasegmental features of fundamental frequency, loudness, and duration. Several models have been developed to account for the way prosody organizes speech, and they vary widely in terms of their theoretical assumptions, organizational primitives, actual procedures of application to speech, and intended use (e.g., to generate speech from text vs. to model the prosodic phonology of a language). In many cases, these models overtly contradict one another with regard to their fundamental premises or their identification of the perceptible objects of linguistic prosody. These competing models are directly compared. Each model is applied to the same speech samples. This parallel analysis allows for a critical inspection of each model and its efficacy in assessing the suprasegmental behavior of the speech. The analyses illustrate how different approaches are better equipped to account for different aspects of prosody. Viewing the models and their successes from an objective perspective allows for creative possibilities in terms of combining strengths from models which might otherwise be considered fundamentally incompatible.

  15. Employment impacts of energy conservation schemes in the residential sector. Calculation of direct and indirect employment effects using a dedicated input/output simulation approach

    International Nuclear Information System (INIS)

    Jeeninga, H.; Weber, C.; Maeenpaeae, I.; Rivero Garcia, F.; Wiltshire, V.; Wade, J.

    1999-10-01

    The relationship between investments in energy efficiency and employment is investigated. The employment effects of several energy conservation schemes implemented in the residential sector are determined by means of a dedicated input/output simulation approach. The employment effects of energy conservation schemes were determined for France, Germany, the Netherlands, Spain and the United Kingdom. Within the time frame of the project, it was not feasible to perform a comparable analysis for Greece, Ireland and Austria. For Finland, the employment effects of energy auditing schemes were investigated by means of a macro economic simulation model. The main driving force behind the positive employment effect of investment in energy efficiency in the residential sector is the fact that the energy sector has a rather low labour intensity. The resulting shift of expenditures from the energy sector to other sectors with higher labour intensity leads to increased employment. The main mechanisms that determine the net shift in employment resulting from investments in energy conservation are: 1. The employment effect related to the initial investment in energy efficiency; 2. The energy saving effect. Due to lower energy bill, a shift in expenditure pattern will occur from the labour extensive energy sector towards sectors with higher labour intensity, thus inducing a net positive effect on employment; 3. The effects of money transfers between sectors. For example, when the investment is subsidised by the government, money is transferred from the governmental sector to the residential sector; 4. Changes in the total government budget as a result of changes in total tax revenue and expenditures on unemployment benefits. Different financing methods for the investment in energy efficiency are analysed. The initial investment can be financed from the general household consumption budget, by means of a loan, using a subsidy or using private savings. The following input parameters

  16. Voices from the Field: Developing Employability Skills for Archaeological Students Using a Project Based Learning Approach

    Science.gov (United States)

    Wood, Gaynor

    2016-01-01

    Graduate employment statistics are receiving considerable attention in UK universities. This paper looks at how a wide range of employability attributes can be developed with students, through the innovative use of the Project Based Learning (PjBL) approach. The case study discussed here involves a group of archaeology students from the University…

  17. Material Modelling - Composite Approach

    DEFF Research Database (Denmark)

    Nielsen, Lauge Fuglsang

    1997-01-01

    This report is part of a research project on "Control of Early Age Cracking" - which, in turn, is part of the major research programme, "High Performance Concrete - The Contractor's Technology (HETEK)", coordinated by the Danish Road Directorate, Copenhagen, Denmark, 1997.A composite-rheological ......This report is part of a research project on "Control of Early Age Cracking" - which, in turn, is part of the major research programme, "High Performance Concrete - The Contractor's Technology (HETEK)", coordinated by the Danish Road Directorate, Copenhagen, Denmark, 1997.A composite......-rheological model of concrete is presented by which consistent predictions of creep, relaxation, and internal stresses can be made from known concrete composition, age at loading, and climatic conditions. No other existing "creep prediction method" offers these possibilities in one approach.The model...... in this report is that cement paste and concrete behave practically as linear-viscoelastic materials from an age of approximately 10 hours. This is a significant age extension relative to earlier studies in the literature where linear-viscoelastic behavior is only demonstrated from ages of a few days. Thus...

  18. The Employers' Perspective on Barriers and Facilitators to Employment of People with Intellectual Disability: A Differential Mixed-Method Approach

    Science.gov (United States)

    Kocman, Andreas; Fischer, Linda; Weber, Germain

    2018-01-01

    Background: Obtaining employment is among the most important ambitions of people with intellectual disability. Progress towards comprehensive inclusive employment is hampered by numerous barriers. Limited research is available on these barriers and strategies to overcome them. Method: A mixed method approach in a sample of 30 HR-managers was used…

  19. Investigating Preservice Teachers' Beliefs toward Cultural Diversity Employing an Inquiry through Literature Approach

    Science.gov (United States)

    Rangseechatchawan, Dusadee

    2012-01-01

    This study investigated preservice teachers' beliefs toward cultural diversity by employing an inquiry through literature approach. The purpose of this study was to examine the impact of an inquiry through literature instructional format, such as book clubs, and whole class and individual inquiry, on preservice teachers' beliefs regarding cultural…

  20. Leveraging Work-Integrated Learning through On-Campus Employment: A University-Wide Approach

    Science.gov (United States)

    Mitchell, Gaon; Kay, Judie

    2013-01-01

    At Victoria University, Melbourne, Australia, the majority of students engage in paid employment alongside their studies; and, every student has the opportunity to engage with work-integrated learning as a key component of their academic course. This paper explores an innovative structured approach the university has initiated to align these two…

  1. Employee well-being, intention to leave and perceived employability: A psychological contract approach

    Directory of Open Access Journals (Sweden)

    Leoni van der Vaart

    2015-03-01

    Full Text Available Employability emerged as a “new psychological contract” that may have beneficial effects on both individual and organisational outcomes. The study set out to investigate the relationship between perceived employability and employee well-being on the one hand and perceived employability and employees’ intention to leave on the other. The role of the state of the psychological contract, in terms of retaining employable employees while improving their well-being, was also investigated. Cross-sectional data were obtained from employees representing various organisations (N = 246. Contrary to expectations, structural equation modelling (SEM indicated no significant relationship between perceived employability and well-being. Perceived employability was a significant predictor of employees’ intention to leave the organisation. Results also indicated that the state of the psychological contract does not moderate the relationship between perceived employability and employee well-being and their intention to leave, respectively. The study stresses the importance of fulfilling promises made to employees ensuring that promises are fair and continuing to fulfil promises. The importance of interventions on individual-level, to enhance well-being in the workplace, is also emphasised.

  2. Approach to cost-benefit analysis between supported employment and special employment centers through comparative simulation with 24 workers

    Directory of Open Access Journals (Sweden)

    Francisco de Borja Jordán de Urríes Vega

    2014-06-01

    Full Text Available This work presents a cost-benefit analysis comparing supported employment (SE with special employment center (EEC, from an individual, corporate and society perspective. A simulation was carried out with a sample of 24 workers in regular employment by SE and hypothetical data were obtained for the same workers as if they were in a similar job in EEC. The results show that SE workers, working the same amount of hours, have higher hourly earnings than in EEC (9.22 € compared to 4.59 €. The SE also generates less social burden from the company (22.21 % than EEC (85.54 %. The Supported Employment’s payoff for society is much higher (315.03% than that of the EEC (83.14%. Therefore, the conclusions of the study are directed towards the consideration that supported employment is more beneficial in terms of cost benefit for the individual, business and society when compared to the special employment centers.

  3. Comparison of two novel approaches to model fibre reinforced concrete

    NARCIS (Netherlands)

    Radtke, F.K.F.; Simone, A.; Sluys, L.J.

    2009-01-01

    We present two approaches to model fibre reinforced concrete. In both approaches, discrete fibre distributions and the behaviour of the fibre-matrix interface are explicitly considered. One approach employs the reaction forces from fibre to matrix while the other is based on the partition of unity

  4. Employment among Working-Age Adults with Multiple Sclerosis: A Data-Mining Approach to Identifying Employment Interventions

    Science.gov (United States)

    Bishop, Malachy; Chan, Fong; Rumrill, Phillip D., Jr.; Frain, Michael P.; Tansey, Timothy N.; Chiu, Chung-Yi; Strauser, David; Umeasiegbu, Veronica I.

    2015-01-01

    Purpose: To examine demographic, functional, and clinical multiple sclerosis (MS) variables affecting employment status in a national sample of adults with MS in the United States. Method: The sample included 4,142 working-age (20-65 years) Americans with MS (79.1% female) who participated in a national survey. The mean age of participants was…

  5. Demand planning approaches employed by clothing industry stakeholders in Gauteng, South Africa

    OpenAIRE

    Ntombizodwa J. Matsoma; Intaher M. Ambe

    2017-01-01

    Background: The decline in the productivity of the South African clothing industry was attributed to changing trends in the number of clothing production organisations, which together with a decline in manufacturing output and a fluctuation in employment had all contributed to complexities in demand planning. Purpose: This article investigates demand planning approaches in the clothing industry in Gauteng. Method: A descriptive study was conducted based on a structured questionnaire. ...

  6. Transient modeling/analysis of hyperbolic heat conduction problems employing mixed implicit-explicit alpha method

    Science.gov (United States)

    Tamma, Kumar K.; D'Costa, Joseph F.

    1991-01-01

    This paper describes the evaluation of mixed implicit-explicit finite element formulations for hyperbolic heat conduction problems involving non-Fourier effects. In particular, mixed implicit-explicit formulations employing the alpha method proposed by Hughes et al. (1987, 1990) are described for the numerical simulation of hyperbolic heat conduction models, which involves time-dependent relaxation effects. Existing analytical approaches for modeling/analysis of such models involve complex mathematical formulations for obtaining closed-form solutions, while in certain numerical formulations the difficulties include severe oscillatory solution behavior (which often disguises the true response) in the vicinity of the thermal disturbances, which propagate with finite velocities. In view of these factors, the alpha method is evaluated to assess the control of the amount of numerical dissipation for predicting the transient propagating thermal disturbances. Numerical test models are presented, and pertinent conclusions are drawn for the mixed-time integration simulation of hyperbolic heat conduction models involving non-Fourier effects.

  7. Full employment and competition in the Aspen economic model: implications for modeling acts of terrorism.

    Energy Technology Data Exchange (ETDEWEB)

    Sprigg, James A.; Ehlen, Mark Andrew

    2004-11-01

    Acts of terrorism could have a range of broad impacts on an economy, including changes in consumer (or demand) confidence and the ability of productive sectors to respond to changes. As a first step toward a model of terrorism-based impacts, we develop here a model of production and employment that characterizes dynamics in ways useful toward understanding how terrorism-based shocks could propagate through the economy; subsequent models will introduce the role of savings and investment into the economy. We use Aspen, a powerful economic modeling tool developed at Sandia, to demonstrate for validation purposes that a single-firm economy converges to the known monopoly equilibrium price, output, and employment levels, while multiple-firm economies converge toward the competitive equilibria typified by lower prices and higher output and employment. However, we find that competition also leads to churn by consumers seeking lower prices, making it difficult for firms to optimize with respect to wages, prices, and employment levels. Thus, competitive firms generate market ''noise'' in the steady state as they search for prices and employment levels that will maximize profits. In the context of this model, not only could terrorism depress overall consumer confidence and economic activity but terrorist acts could also cause normal short-run dynamics to be misinterpreted by consumers as a faltering economy.

  8. Employer-driven consumerism: integrating health into the business model.

    Science.gov (United States)

    Thompson, Michael; Checkley, Joseph

    2006-01-01

    Consumer-driven health care is a misnomer. Notwithstanding the enormous role the individual consumer has to play in reshaping the U.S. health care delivery system, this article will focus on the employer as the key driver of change and innovation in the consumerism revolution. American Standard provides a case study of how one major employer has evaluated health care in the context of its business and aggressively integrated consumerism and health into the core of its business. Other companies will appropriately execute consumerism strategies in a fashion consistent with their own needs, culture, resources and populations. However, the principles supporting those strategies will be very much consistent.

  9. Governance Models of Training for Employment: A European Perspective

    Science.gov (United States)

    Greinert, Wolf-Dietrich

    2010-01-01

    Internationally, the question of how to qualify the workforce seems to be of increasing importance for competitive economies. How can politics govern the quantity and quality of employment structures and optimise both? In this article a theoretical framework is outlined that has been developed for the analysis of institutional constructs serving…

  10. Student Employment as a Model for Experiential Learning

    Science.gov (United States)

    Fede, Jacquelyn H.; Gorman, Kathleen S.; Cimini, Maria E.

    2018-01-01

    Background: Evidence suggests experiential learning promotes the development of a range of transferrable skills including communication, responsibility, and social skills. However, many students are unable to participate in internships or other common forms of experiential education because they need to work for pay. University employment has been…

  11. An integrative model for measuring graduates’ employability skills—A study in China

    OpenAIRE

    Wenping Su; Miao Zhang

    2015-01-01

    Employability is a key issue in graduates’ job-hunting, but little research has been done on that of the graduates in Chinese universities. These universities have been experiencing a decline in their graduate employment since the past decade. This paper attempts to tackle this issue. It reviews the relevant research on employability and develops a research-based theoretical framework to evaluate and analyze the graduates’ employability in China. It adopts multiple approaches to establish the...

  12. Demand planning approaches employed by clothing industry stakeholders in Gauteng, South Africa

    Directory of Open Access Journals (Sweden)

    Ntombizodwa J. Matsoma

    2017-10-01

    Full Text Available Background: The decline in the productivity of the South African clothing industry was attributed to changing trends in the number of clothing production organisations, which together with a decline in manufacturing output and a fluctuation in employment had all contributed to complexities in demand planning. Purpose: This article investigates demand planning approaches in the clothing industry in Gauteng. Method: A descriptive study was conducted based on a structured questionnaire. Findings: The results revealed that both hierarchical and optimal approaches should be considered in clothing manufacturing. Managerial implications: In order to improve demand planning practices in the clothing industry, managers are recommended to apply hierarchical and optimal demand planning approaches, which might bring about improvements to demand planning in the Gauteng clothing industry. Conclusion: It is recommended that clothing manufacturers consider the types of product offering before making decisions about adopting the hierarchical or optimal demand planning approaches. When planning for basic clothes, manufacturers should consider a hierarchical demand planning approach, whereas the optimal demand planning approach is recommended for fashion clothes.

  13. Economic and Industrial Development: EID - EMPLOY. Final Report, task 1. Review of approaches for employment impact assessment of renewable energy deployment

    Energy Technology Data Exchange (ETDEWEB)

    Breitschopf, Barbara; Nathani, Carsten; Resch, Gustav

    2011-11-15

    The importance of renewable energy in energy systems is increasing at an impressive rate, and the expectation is that this tendency will continue in the longer term. As a consequence, there is a strong need for reliable insight into the employment benefits from renewable energy. The current knowledge on the economic impacts of large-scale deployment of renewable energy technologies is more or less derived on an ad hoc basis and consists of a variety of different methodologies with different objectives. This is why the International Energy Agency's Implementing Agreement on Renewable Energy Technology Deployment (IEA-RETD) would like to facilitate a more structural approach, which will contribute to reliable and consistent insights of employment effects from deployment of renewable energy technologies. The objectives of the EMPLOY-EID project are to: Provide guidelines based on a thorough review of best practices, which are able to contribute to a consistent, reliable framework in which to measure employment effects from renewable energy deployment and which can be replicated from one country to another; Identify data sources and/or inputs required in application of such guidelines; Provide better understanding of key parameters and mechanisms that determine contribution of renewable energy employment; Assess availability of sources for employment benefit data for all RETD member countries as well as other interesting countries; Provide concrete gross employment benefit data to countries where data is available through application of the guidelines and best practices; and, Document the economic effects of renewable energy deployment through a publishable brochure of the main project results, presentations, the guidelines and background report. This project will help achieve the IEA-RETD's objective to ''empowering policy makers and energy market actors through the provision of information, tools and resources'' by underlining the

  14. A secure approach for encrypting and compressing biometric information employing orthogonal code and steganography

    Science.gov (United States)

    Islam, Muhammad F.; Islam, Mohammed N.

    2012-04-01

    The objective of this paper is to develop a novel approach for encryption and compression of biometric information utilizing orthogonal coding and steganography techniques. Multiple biometric signatures are encrypted individually using orthogonal codes and then multiplexed together to form a single image, which is then embedded in a cover image using the proposed steganography technique. The proposed technique employs three least significant bits for this purpose and a secret key is developed to choose one from among these bits to be replaced by the corresponding bit of the biometric image. The proposed technique offers secure transmission of multiple biometric signatures in an identification document which will be protected from unauthorized steganalysis attempt.

  15. Manufacturing Employment and Wage Differentials After Structural Adjustment Reforms in Colombia: An Efficiency Wages Approach

    Directory of Open Access Journals (Sweden)

    Rodrigo Taborda

    2011-06-01

    Full Text Available In the framework of the structural reforms in Colombia one of the most important policy proposals was reducing rigidities in the labor market. A perspective to assess the results of such reforms is the analysis of the relationship between firm employment and wage differentials in manufacturing before and after the reforms. If the labor reforms reached the intended objective of making more flexible the labor market, the employment levels must change faster, along with the behavior of wages and other labor costs, given some characteristics of firms and the economy. This paper addresses this topic proposing a model of wage differential and employment growth and testing its propositions before and after the structural reforms and controlling for industry and firm characteristics. A first finding is the confirmation of the positive relationship proposed between intra-industry wage differential and employment. In the inter-industry wage differential estimation, we find heterogeneous responses depending on the industry and a reduction in the autonomous labor turnover.

  16. Can self-efficacy ameliorate interrole conflict among employed family caregivers? A moderated mediation approach.

    Science.gov (United States)

    Morimoto, Hiroshi; Furuta, Nobuo; Kono, Mitsue; Kabeya, Mayumi

    2017-06-01

    This study examined the moderation effect of different dimensions of self-efficacy on the way in which various types of interrole conflict mediate between caregiving demands and the mental health of employed family caregivers. Using a moderated mediation approach, we examined the moderation effect of self-efficacy on interrole conflict's mediation between caregiving demands and mental health (psychological strain and quality of life) in a sample of Japanese employed family caregivers who regularly provide care at home (263 males aged 53.14 ± 8.28 years and 116 females aged 47.92 ± 9.77 years). Increased self-efficacy in managing dementia and in self-care were correlated with lower caregiving demands and better mental health among family caregivers. Self-efficacy in managing dementia was also positively correlated with increased interrole conflict. Increased caregiving demands were related to higher psychological strain in those with higher (+1SD), but not lower (-SD) self-efficacy in managing dementia. Self-efficacy does not play a protective role in managing the effect of caregiving demands on interrole conflict. It also does not appear to protect against any indirect effects of caregiving demands on the mental health of employed family caregivers.

  17. Effects of Employing Ridge Regression in Structural Equation Models.

    Science.gov (United States)

    McQuitty, Shaun

    1997-01-01

    LISREL 8 invokes a ridge option when maximum likelihood or generalized least squares are used to estimate a structural equation model with a nonpositive definite covariance or correlation matrix. Implications of the ridge option for model fit, parameter estimates, and standard errors are explored through two examples. (SLD)

  18. A Set Theoretical Approach to Maturity Models

    DEFF Research Database (Denmark)

    Lasrado, Lester; Vatrapu, Ravi; Andersen, Kim Normann

    2016-01-01

    of it application on a social media maturity data-set. Specifically, we employ Necessary Condition Analysis (NCA) to identify maturity stage boundaries as necessary conditions and Qualitative Comparative Analysis (QCA) to arrive at multiple configurations that can be equally effective in progressing to higher......Maturity Model research in IS has been criticized for the lack of theoretical grounding, methodological rigor, empirical validations, and ignorance of multiple and non-linear paths to maturity. To address these criticisms, this paper proposes a novel set-theoretical approach to maturity models...... characterized by equifinality, multiple conjunctural causation, and case diversity. We prescribe methodological guidelines consisting of a six-step procedure to systematically apply set theoretic methods to conceptualize, develop, and empirically derive maturity models and provide a demonstration...

  19. Absorbed dose in fibrotic microenvironment models employing Monte Carlo simulation

    International Nuclear Information System (INIS)

    Zambrano Ramírez, O.D.; Rojas Calderón, E.L.; Azorín Vega, E.P.; Ferro Flores, G.; Martínez Caballero, E.

    2015-01-01

    The presence or absence of fibrosis and yet more, the multimeric and multivalent nature of the radiopharmaceutical have recently been reported to have an effect on the radiation absorbed dose in tumor microenvironment models. Fibroblast and myofibroblast cells produce the extracellular matrix by the secretion of proteins which provide structural and biochemical support to cells. The reactive and reparative mechanisms triggered during the inflammatory process causes the production and deposition of extracellular matrix proteins, the abnormal excessive growth of the connective tissue leads to fibrosis. In this work, microenvironment (either not fibrotic or fibrotic) models composed of seven spheres representing cancer cells of 10 μm in diameter each with a 5 μm diameter inner sphere (cell nucleus) were created in two distinct radiation transport codes (PENELOPE and MCNP). The purpose of creating these models was to determine the radiation absorbed dose in the nucleus of cancer cells, based on previously reported radiopharmaceutical retain (by HeLa cells) percentages of the 177 Lu-Tyr 3 -octreotate (monomeric) and 177 Lu-Tyr 3 -octreotate-AuNP (multimeric) radiopharmaceuticals. A comparison in the results between the PENELOPE and MCNP was done. We found a good agreement in the results of the codes. The percent difference between the increase percentages of the absorbed dose in the not fibrotic model with respect to the fibrotic model of the codes PENELOPE and MCNP was found to be under 1% for both radiopharmaceuticals. (authors)

  20. Employment, Production and Consumption model: Patterns of phase transitions

    Czech Academy of Sciences Publication Activity Database

    Lavička, H.; Lin, L.; Novotný, Jan

    2010-01-01

    Roč. 389, č. 8 (2010), s. 1708-1720 ISSN 0378-4371 Institutional research plan: CEZ:AV0Z10480505 Keywords : EPC * Agent based model * Phase transition Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.521, year: 2010

  1. A Simple Forecasting Model Linking Macroeconomic Policy to Industrial Employment Demand.

    Science.gov (United States)

    Malley, James R.; Hady, Thomas F.

    A study detailed further a model linking monetary and fiscal policy to industrial employment in metropolitan and nonmetropolitan areas of four United States regions. The model was used to simulate the impacts on area and regional employment of three events in the economy: changing real gross national product (GNP) via monetary policy, holding the…

  2. An Evaluation of High School Curricula Employing Using the Element-Based Curriculum Development Model

    Science.gov (United States)

    Aslan, Dolgun; Günay, Rafet

    2016-01-01

    This study was conducted with the aim of evaluating the curricula that constitute the basis of education provision at high schools in Turkey from the perspective of the teachers involved. A descriptive survey model, a quantitative research method was employed in this study. An item-based curriculum evaluation model was employed as part of the…

  3. A multiscale approach for modeling atherosclerosis progression.

    Science.gov (United States)

    Exarchos, Konstantinos P; Carpegianni, Clara; Rigas, Georgios; Exarchos, Themis P; Vozzi, Federico; Sakellarios, Antonis; Marraccini, Paolo; Naka, Katerina; Michalis, Lambros; Parodi, Oberdan; Fotiadis, Dimitrios I

    2015-03-01

    Progression of atherosclerotic process constitutes a serious and quite common condition due to accumulation of fatty materials in the arterial wall, consequently posing serious cardiovascular complications. In this paper, we assemble and analyze a multitude of heterogeneous data in order to model the progression of atherosclerosis (ATS) in coronary vessels. The patient's medical record, biochemical analytes, monocyte information, adhesion molecules, and therapy-related data comprise the input for the subsequent analysis. As indicator of coronary lesion progression, two consecutive coronary computed tomography angiographies have been evaluated in the same patient. To this end, a set of 39 patients is studied using a twofold approach, namely, baseline analysis and temporal analysis. The former approach employs baseline information in order to predict the future state of the patient (in terms of progression of ATS). The latter is based on an approach encompassing dynamic Bayesian networks whereby snapshots of the patient's status over the follow-up are analyzed in order to model the evolvement of ATS, taking into account the temporal dimension of the disease. The quantitative assessment of our work has resulted in 93.3% accuracy for the case of baseline analysis, and 83% overall accuracy for the temporal analysis, in terms of modeling and predicting the evolvement of ATS. It should be noted that the application of the SMOTE algorithm for handling class imbalance and the subsequent evaluation procedure might have introduced an overestimation of the performance metrics, due to the employment of synthesized instances. The most prominent features found to play a substantial role in the progression of the disease are: diabetes, cholesterol and cholesterol/HDL. Among novel markers, the CD11b marker of leukocyte integrin complex is associated with coronary plaque progression.

  4. Re-engineering pre-employment check-up systems: a model for improving health services.

    Science.gov (United States)

    Rateb, Said Abdel Hakim; El Nouman, Azza Abdel Razek; Rateb, Moshira Abdel Hakim; Asar, Mohamed Naguib; El Amin, Ayman Mohammed; Gad, Saad abdel Aziz; Mohamed, Mohamed Salah Eldin

    2011-01-01

    The purpose of this paper is to develop a model for improving health services provided by the pre-employment medical fitness check-up system affiliated to Egypt's Health Insurance Organization (HIO). Operations research, notably system re-engineering, is used in six randomly selected centers and findings before and after re-engineering are compared. The re-engineering model follows a systems approach, focusing on three areas: structure, process and outcome. The model is based on six main components: electronic booking, standardized check-up processes, protected medical documents, advanced archiving through an electronic content management (ECM) system, infrastructure development, and capacity building. The model originates mainly from customer needs and expectations. The centers' monthly customer flow increased significantly after re-engineering. The mean time spent per customer cycle improved after re-engineering--18.3 +/- 5.5 minutes as compared to 48.8 +/- 14.5 minutes before. Appointment delay was also significantly decreased from an average 18 to 6.2 days. Both beneficiaries and service providers were significantly more satisfied with the services after re-engineering. The model proves that re-engineering program costs are exceeded by increased revenue. Re-engineering in this study involved multiple structure and process elements. The literature review did not reveal similar re-engineering healthcare packages. Therefore, each element was compared separately. This model is highly recommended for improving service effectiveness and efficiency. This research is the first in Egypt to apply the re-engineering approach to public health systems. Developing user-friendly models for service improvement is an added value.

  5. Developments in convective heat transfer models featuring seamless and selected detail surfaces, employing electroless plating

    Science.gov (United States)

    Stalmach, C. J., Jr.

    1975-01-01

    Several model/instrument concepts employing electroless metallic skin were considered for improvement of surface condition, accuracy, and cost of contoured-geometry convective heat transfer models. A plated semi-infinite slab approach was chosen for development and evaluation in a hypersonic wind tunnel. The plated slab model consists of an epoxy casting containing fine constantan wires accurately placed at specified surface locations. An electroless alloy was deposited on the plastic surface that provides a hard, uniformly thick, seamless skin. The chosen alloy forms a high-output thermocouple junction with each exposed constantan wire, providing means of determining heat transfer during tunnel testing of the model. A selective electroless plating procedure was used to deposit scaled heatshield tiles on the lower surface of a 0.0175-scale shuttle orbiter model. Twenty-five percent of the tiles were randomly selected and plated to a height of 0.001-inch. The purpose was to assess the heating effects of surface roughness simulating misalignment of tiles that may occur during manufacture of the spacecraft.

  6. Analysis and interpretation of geophysical surveys in archaeological sites employing different integrated approach.

    Science.gov (United States)

    Piro, Salvatore; Papale, Enrico; Kucukdemirci, Melda; Zamuner, Daniela

    2017-04-01

    Non-destructive ground surface geophysical prospecting methods are frequently used for the investigation of archaeological sites, where a detailed physical and geometrical reconstructions of hidden volumes is required prior to any excavation work. All methods measure the variations of single physical parameters, therefore if these are used singularly, they could not permit a complete location and characterization of anomalous bodies. The probability of a successful result rapidly increases if a multhimethodological approach is adopted, according to the logic of objective complementarity of information and of global convergence toward a high quality multiparametric imaging of the buried structures. The representation of the static configuration of the bodies in the subsoil and of the space-time evolution of the interaction processes between targets and hosting materials have to be actually considered fundamental elements of primary knowledge in archaeological prospecting. The main effort in geophysical prospecting for archaeology is therefore the integration of different, absolutely non-invasive techniques, especially if managed in view of a ultra-high resolution three-dimensional (3D) tomographic representation mode. Following the above outlined approach, we have integrated geophysical methods which measure the variations of potential field (gradiometric methods) with active methods which measure the variations of physical properties due to the body's geometry and volume (GPR and ERT). In this work, the results obtained during the surveys of three archaeological sites, employing Ground Penetrating Radar (GPR), Electrical Resistivity Tomography (ERT) and Fluxgate Differential Magnetic (FDM) to obtain precise and detailed maps of subsurface bodies, are presented and discussed. The first site, situated in a suburban area between Itri and Fondi, in the Aurunci Natural Regional Park (Central Italy), is characterized by the presence of remains of past human activity

  7. A Bourdieusian Approach to Understanding Employability: Becoming a "Fish in Water"

    Science.gov (United States)

    Clark, Martyn; Zukas, Miriam

    2013-01-01

    It is assumed in the current policy environment that higher education should lead to graduate employability, although understandings of employability are generally limited. In this paper, we discuss issues relating to graduate employability with reference to a case study of an information technology (IT) student progressing to a graduate role in…

  8. Using the Student Lifecycle Approach to Enhance Employability: An Example from Criminology and Criminal Justice

    Science.gov (United States)

    Bates, Lyndel; Hayes, Hennessey

    2017-01-01

    Universities are increasingly focusing on the employability of students after they graduate from their studies. While practicums is one way of enhancing students' employability, the School of Criminology and Criminal Justice embeds employability throughout its degree programs using a range of strategies. These methods are based on the student…

  9. HEDR modeling approach: Revision 1

    International Nuclear Information System (INIS)

    Shipler, D.B.; Napier, B.A.

    1994-05-01

    This report is a revision of the previous Hanford Environmental Dose Reconstruction (HEDR) Project modeling approach report. This revised report describes the methods used in performing scoping studies and estimating final radiation doses to real and representative individuals who lived in the vicinity of the Hanford Site. The scoping studies and dose estimates pertain to various environmental pathways during various periods of time. The original report discussed the concepts under consideration in 1991. The methods for estimating dose have been refined as understanding of existing data, the scope of pathways, and the magnitudes of dose estimates were evaluated through scoping studies

  10. HEDR modeling approach: Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Shipler, D.B.; Napier, B.A.

    1994-05-01

    This report is a revision of the previous Hanford Environmental Dose Reconstruction (HEDR) Project modeling approach report. This revised report describes the methods used in performing scoping studies and estimating final radiation doses to real and representative individuals who lived in the vicinity of the Hanford Site. The scoping studies and dose estimates pertain to various environmental pathways during various periods of time. The original report discussed the concepts under consideration in 1991. The methods for estimating dose have been refined as understanding of existing data, the scope of pathways, and the magnitudes of dose estimates were evaluated through scoping studies.

  11. Mathematical and computer modeling of electro-optic systems using a generic modeling approach

    OpenAIRE

    Smith, M.I.; Murray-Smith, D.J.; Hickman, D.

    2007-01-01

    The conventional approach to modelling electro-optic sensor systems is to develop separate models for individual systems or classes of system, depending on the detector technology employed in the sensor and the application. However, this ignores commonality in design and in components of these systems. A generic approach is presented for modelling a variety of sensor systems operating in the infrared waveband that also allows systems to be modelled with different levels of detail and at diffe...

  12. Developing a Sustainable Practical Model of Graduate Employability for Higher Education

    Directory of Open Access Journals (Sweden)

    Ahmed Umar Rufai

    2015-01-01

    Full Text Available The purpose of this paper is to evolve a sustainable practical model of employability skills that is sure to capture relevant learning aspects of a particular occupational discipline to be used as framework for Undergraduate students to develop their employability potentials. The study was conducted in three Universities and Polytechnics each with three multi-national companies. Data were collected using semi-structured interviews. Using purposeful sampling 18 academic staff and 3 professionals representing company employers were selected as the study participants. The study evolved a model that is work-based, explicit in its outcome, fully articulated and realistic in terms of employability skill experiences. The proposed model can be used to establish a common higher education programme or curricula that is work-based and skill experience oriented, that can encourage students in higher education to think about work place learning more explicitly and reflectively, that will in turn help them to develop a broad range of knowledge, skills, attitudes, and values, each of which ultimately contribute in some manner to graduate employability.  The paper is considered a contribution to the evolution and growth of knowledge on the linkage between higher education and workplace, through which the ‘skill gap’ occurring between the demand of employment and the level of educational preparation of graduates can be bridged. Keywords: Employability, Higher Education, Graduates, Model/Framework,   academic staff, Employers/Professionals

  13. Testing a Model of Undergraduate Competence in Employability Skills and Its Implications for Stakeholders

    Science.gov (United States)

    Jackson, Denise

    2014-01-01

    Despite the development of employability skills being firmly entrenched in higher education's strategic agenda worldwide; recent graduates' standards in certain skills are not meeting industry expectations. This paper presents and tests a model of undergraduate competence in employability skills. It highlights those factors which impact on…

  14. Developing a Sustainable Practical Model of Graduate Employability for Higher Education

    Science.gov (United States)

    Rufai, Ahmed Umar; Bakar, Ab Rahim Bin; Rashi, Abdullah Bin Mat

    2015-01-01

    The purpose of this paper is to evolve a sustainable practical model of employability skills that is sure to capture relevant learning aspects of a particular occupational discipline to be used as framework for Undergraduate students to develop their employability potentials. The study was conducted in three Universities and Polytechnics each with…

  15. A Conceptual Model for Employer Training to Manage Employee Counter-Productive Behaviors

    Science.gov (United States)

    Rock, Naomi Spickard

    2011-01-01

    The purpose of this study was to develop a model for employer training to manage employees who possess counter-productive behaviors. With the increasing encouragement for employers to hire without discriminating, the number of individuals with disabilities in the workforce will rise. There is limited training in universities and businesses to…

  16. Determination of income, production, and employment under pollution control: an input-output approach

    Energy Technology Data Exchange (ETDEWEB)

    Rhee, J.J.; Miranowski, J.A.

    1984-02-01

    It can be shown that a variation of the multiplier approach solves the Leontief pollution model in a more directly interpretable and computationally efficient manner than the conventional method of directly using the augmented Leontief inverse matrix. The solution of each endogenous variable of the model can be expressed in terms of the non-augmented Leontief inverse, exogenous variables, and two important multipliers, ''the pollution control multiplier'' and ''a modified Keynesian multiplier,'' modified by pollution control. The so-called induced effect and the effect of pollution control on a given economy can be separated from the model. 6 references, 5 footnotes, 1 table.

  17. Modeling Approaches in Planetary Seismology

    Science.gov (United States)

    Weber, Renee; Knapmeyer, Martin; Panning, Mark; Schmerr, Nick

    2014-01-01

    Of the many geophysical means that can be used to probe a planet's interior, seismology remains the most direct. Given that the seismic data gathered on the Moon over 40 years ago revolutionized our understanding of the Moon and are still being used today to produce new insight into the state of the lunar interior, it is no wonder that many future missions, both real and conceptual, plan to take seismometers to other planets. To best facilitate the return of high-quality data from these instruments, as well as to further our understanding of the dynamic processes that modify a planet's interior, various modeling approaches are used to quantify parameters such as the amount and distribution of seismicity, tidal deformation, and seismic structure on and of the terrestrial planets. In addition, recent advances in wavefield modeling have permitted a renewed look at seismic energy transmission and the effects of attenuation and scattering, as well as the presence and effect of a core, on recorded seismograms. In this chapter, we will review these approaches.

  18. Method of Moments of Coupled-Cluster Equations: Externally Corrected Approaches Employing Configuration Interaction Wave Functions

    Directory of Open Access Journals (Sweden)

    Ian S.O. Pimienta

    2002-05-01

    Full Text Available Abstract: A new approach to the many-electron correlation problem, termed the method of moments of coupled-cluster equations (MMCC, is further developed and tested. The main idea of the MMCC theory is that of the noniterative energy corrections which, when added to the energies obtained in the standard coupled-cluster calculations, recover the exact (full configuration interaction energy. The MMCC approximations require that a guess is provided for the electronic wave function of interest. The idea of using simple estimates of the wave function, provided by the inexpensive configuration interaction (CI methods employing small sets of active orbitals to define higher–than–double excitations, is tested in this work. The CI-corrected MMCC methods are used to study the single bond breaking in HF and the simultaneous breaking of both O–H bonds in H2O.

  19. 'Intelligent' approach to radioimmunoassay sample counting employing a microprocessor controlled sample counter

    International Nuclear Information System (INIS)

    Ekins, R.P.; Sufi, S.; Malan, P.G.

    1977-01-01

    The enormous impact on medical science in the last two decades of microanalytical techniques employing radioisotopic labels has, in turn, generated a large demand for automatic radioisotopic sample counters. Such instruments frequently comprise the most important item of capital equipment required in the use of radioimmunoassay and related techniques and often form a principle bottleneck in the flow of samples through a busy laboratory. It is therefore particularly imperitive that such instruments should be used 'intelligently' and in an optimal fashion to avoid both the very large capital expenditure involved in the unnecessary proliferation of instruments and the time delays arising from their sub-optimal use. The majority of the current generation of radioactive sample counters nevertheless rely on primitive control mechanisms based on a simplistic statistical theory of radioactive sample counting which preclude their efficient and rational use. The fundamental principle upon which this approach is based is that it is useless to continue counting a radioactive sample for a time longer than that required to yield a significant increase in precision of the measurement. Thus, since substantial experimental errors occur during sample preparation, these errors should be assessed and must be releted to the counting errors for that sample. It is the objective of this presentation to demonstrate that the combination of a realistic statistical assessment of radioactive sample measurement, together with the more sophisticated control mechanisms that modern microprocessor technology make possible, may often enable savings in counter usage of the order of 5-10 fold to be made. (orig.) [de

  20. An 'intelligent' approach to radioimmunoassay sample counting employing a microprocessor-controlled sample counter

    International Nuclear Information System (INIS)

    Ekins, R.P.; Sufi, S.; Malan, P.G.

    1978-01-01

    The enormous impact on medical science in the last two decades of microanalytical techniques employing radioisotopic labels has, in turn, generated a large demand for automatic radioisotopic sample counters. Such instruments frequently comprise the most important item of capital equipment required in the use of radioimmunoassay and related techniques and often form a principle bottleneck in the flow of samples through a busy laboratory. It is therefore imperative that such instruments should be used 'intelligently' and in an optimal fashion to avoid both the very large capital expenditure involved in the unnecessary proliferation of instruments and the time delays arising from their sub-optimal use. Most of the current generation of radioactive sample counters nevertheless rely on primitive control mechanisms based on a simplistic statistical theory of radioactive sample counting which preclude their efficient and rational use. The fundamental principle upon which this approach is based is that it is useless to continue counting a radioactive sample for a time longer than that required to yield a significant increase in precision of the measurement. Thus, since substantial experimental errors occur during sample preparation, these errors should be assessed and must be related to the counting errors for that sample. The objective of the paper is to demonstrate that the combination of a realistic statistical assessment of radioactive sample measurement, together with the more sophisticated control mechanisms that modern microprocessor technology make possible, may often enable savings in counter usage of the order of 5- to 10-fold to be made. (author)

  1. MERGING DIGITAL SURFACE MODELS IMPLEMENTING BAYESIAN APPROACHES

    Directory of Open Access Journals (Sweden)

    H. Sadeq

    2016-06-01

    Full Text Available In this research different DSMs from different sources have been merged. The merging is based on a probabilistic model using a Bayesian Approach. The implemented data have been sourced from very high resolution satellite imagery sensors (e.g. WorldView-1 and Pleiades. It is deemed preferable to use a Bayesian Approach when the data obtained from the sensors are limited and it is difficult to obtain many measurements or it would be very costly, thus the problem of the lack of data can be solved by introducing a priori estimations of data. To infer the prior data, it is assumed that the roofs of the buildings are specified as smooth, and for that purpose local entropy has been implemented. In addition to the a priori estimations, GNSS RTK measurements have been collected in the field which are used as check points to assess the quality of the DSMs and to validate the merging result. The model has been applied in the West-End of Glasgow containing different kinds of buildings, such as flat roofed and hipped roofed buildings. Both quantitative and qualitative methods have been employed to validate the merged DSM. The validation results have shown that the model was successfully able to improve the quality of the DSMs and improving some characteristics such as the roof surfaces, which consequently led to better representations. In addition to that, the developed model has been compared with the well established Maximum Likelihood model and showed similar quantitative statistical results and better qualitative results. Although the proposed model has been applied on DSMs that were derived from satellite imagery, it can be applied to any other sourced DSMs.

  2. The Impact of Trade Openness on Employment and Real Wage in Iranian Food and Beverage Industries (A Dynamic Panel Data Approach

    Directory of Open Access Journals (Sweden)

    Ali Dehghani

    2014-03-01

    Full Text Available The main purpose of this paper is to investigate the impact of trade openness on the Employment and the real Wage for the Iranian Food and Beverage Industries over the year 2007. For this purpose in this study, the ratio of export to Production Value has been considered as a proxy for trade openness and the main model has been estimated using a Dynamic Panel Data (DPD approach. The main findings of this study indicate that the trade openness has positive and significant effect on the employment and the real wage in the Iranian Food and Beverage Industries. Moreover, output value and real wage have positive and significant effect on the employment. Hence, the main recommendation of this paper to policy makers is to expand the food and beverage exports for improvement of employment and real wage in the Iranian Food and Beverage Industries.

  3. STEM employment in the new economy: A labor market segmentation approach

    Science.gov (United States)

    Torres-Olave, Blanca M.

    The present study examined the extent to which the U.S. STEM labor market is stratified in terms of quality of employment. Through a series of cluster analyses and Chi-square tests on data drawn from the 2008 Survey of Income Program Participation (SIPP), the study found evidence of segmentation in the highly-skilled STEM and non-STEM samples, which included workers with a subbaccalaureate diploma or above. The cluster analyses show a pattern consistent with Labor Market Segmentation theory: Higher wages are associated with other primary employment characteristics, including health insurance and pension benefits, as well as full-time employment. In turn, lower wages showed a tendency to cluster with secondary employment characteristics, such as part-time employment, multiple employment, and restricted access to health insurance and pension benefits. The findings also suggest that women have a higher likelihood of being employed in STEM jobs with secondary characteristics. The findings reveal a far more variegated employment landscape than is usually presented in national reports of the STEM workforce. There is evidence that, while STEM employment may be more resilient than non-STEM employment to labor restructuring trends in the new economy, the former is far from immune to secondary labor characteristics. There is a need for ongoing dialogue between STEM education (at all levels), employers, policymakers, and other stakeholders to truly understand not only the barriers to equity in employment relations, but also the mechanisms that create and maintain segmentation and how they may impact women, underrepresented minorities, and the foreign-born.

  4. Approach to Employability Skills in Technical Education & its impact on satisfaction of selecting an Institute

    OpenAIRE

    Mahajan, Prashant; Golahit, Suresh

    2017-01-01

    International audience; ABSRACT Ample of the current motivation to teach and assess employability skills will decide India's ability to compete in the world economy. For a win-win situation, there must not be any differences in Institute's perception and students' experience in accessing employability skills for future prospective. What this paper aims to demonstrate is that, although as academics/service providers, we can use a general term " Employability skills " , we need to describe what...

  5. Branding approach and valuation models

    Directory of Open Access Journals (Sweden)

    Mamula Tatjana

    2006-01-01

    Full Text Available Much of the skill of marketing and branding nowadays is concerned with building equity for products whose characteristics, pricing, distribution and availability are really quite close to each other. Brands allow the consumer to shop with confidence. The real power of successful brands is that they meet the expectations of those that buy them or, to put it another way, they represent a promise kept. As such they are a contract between a seller and a buyer: if the seller keeps to its side of the bargain, the buyer will be satisfied; if not, the buyer will in future look elsewhere. Understanding consumer perceptions and associations is an important first step to understanding brand preferences and choices. In this paper, we discuss different models to measure value of brand according to couple of well known approaches according to request by companies. We rely upon several empirical examples.

  6. Waveguide damage detection by the matching pursuit approach employing the dispersion-based chirp functions.

    Science.gov (United States)

    Hong, Jin-Chul; Sun, Kyung Ho; Kim, Yoon Young

    2006-03-01

    If the wave mode used in guided wave non-destructive inspection is dispersive, reflected pulses from damaged parts may be significantly distorted due to wave dispersion. The main concern, in this case, is how to detect the reflected pulses in noisy signals, and to extract meaningful damage information from the detected pulses. However, current signal processing techniques used for guided wave inspection do not account for pulse dispersion, so the extracted information is often not so accurate. The objective of this study is to develop an efficient technique to deal with dispersed pulses for guided-wave nondestructive evaluation. Our idea is to model dispersed pulses by chirp functions of special form that can simulate up to quadratically varying group delay. To determine the parameters of the chirp functions approximating dispersed, reflected pulses, an adaptive matching pursuit algorithm is employed. Once the characterizing parameters are found, the damage location and extent can be estimated. The proposed method is tested with experimentally measured signals of longitudinal waves in a circular cylinder.

  7. Bridging the Gap: Creating a New Approach for Assuring 21st Century Employability Skills

    Science.gov (United States)

    Wolff, Ralph; Booth, Melanie

    2017-01-01

    Which higher education paths will truly prepare students for the future is a big question with serious implications for students and families who invest their time and money, as well as for employers and communities that seek capable career candidates. It also leads to a bigger question: "Should graduates' employability be central to the…

  8. HIV/AIDS and Employment Research: A Need for an Integrative Approach

    Science.gov (United States)

    Conyers, Liza Marie

    2008-01-01

    This article provides a reflection on the three articles that compose the Major Contribution on HIV/AIDS and employment research. It highlights the merits of the contribution in the broader context of HIV/AIDS employment research and recommends future directions for this area of inquiry, including theory integration, an investigation of HIV health…

  9. Modeling of critical experiments employing Raschig rings in uranyl nitrate solution

    International Nuclear Information System (INIS)

    Tanner, J.E.

    1989-01-01

    Four critical experiments employing borated glass rings in concentrated uranyl nitrate solution yielded k eff higher by 0. 04 when modeled with a flux-weighted, homogenized cross section set than when modeled with discrete rings. k eff varied by 0.014 for a 10% boron uncertainty and by up to 0.04 for a 10% packing fraction uncertainty

  10. The Best and the Next-Best: The Two-Tiered Approach to Recruitment by Japanese Employers.

    Science.gov (United States)

    Kublin, Michael; And Others

    1993-01-01

    Describes Japan's two-tiered approach to recruitment in which graduates from top Japanese universities are automatic hires, while those from second-place schools must do job searches to find employment. Notes that, in Japan, university personnel play very large role in recruiting and that Japanese companies are concerned with goodness of fit…

  11. A Bayesian approach to model uncertainty

    International Nuclear Information System (INIS)

    Buslik, A.

    1994-01-01

    A Bayesian approach to model uncertainty is taken. For the case of a finite number of alternative models, the model uncertainty is equivalent to parameter uncertainty. A derivation based on Savage's partition problem is given

  12. Feature Compensation Employing Multiple Environmental Models for Robust In-Vehicle Speech Recognition

    Science.gov (United States)

    Kim, Wooil; Hansen, John H. L.

    An effective feature compensation method is developed for reliable speech recognition in real-life in-vehicle environments. The CU-Move corpus, used for evaluation, contains a range of speech and noise signals collected for a number of speakers under actual driving conditions. PCGMM-based feature compensation, considered in this paper, utilizes parallel model combination to generate noise-corrupted speech model by combining clean speech and the noise model. In order to address unknown time-varying background noise, an interpolation method of multiple environmental models is employed. To alleviate computational expenses due to multiple models, an Environment Transition Model is employed, which is motivated from Noise Language Model used in Environmental Sniffing. An environment dependent scheme of mixture sharing technique is proposed and shown to be more effective in reducing the computational complexity. A smaller environmental model set is determined by the environment transition model for mixture sharing. The proposed scheme is evaluated on the connected single digits portion of the CU-Move database using the Aurora2 evaluation toolkit. Experimental results indicate that our feature compensation method is effective for improving speech recognition in real-life in-vehicle conditions. A reduction of 73.10% of the computational requirements was obtained by employing the environment dependent mixture sharing scheme with only a slight change in recognition performance. This demonstrates that the proposed method is effective in maintaining the distinctive characteristics among the different environmental models, even when selecting a large number of Gaussian components for mixture sharing.

  13. Employing the intelligence cycle process model within the Homeland Security Enterprise

    OpenAIRE

    Stokes, Roger L.

    2013-01-01

    CHDS State/Local The purpose of this thesis was to examine the employment and adherence of the intelligence cycle process model within the National Network of Fusion Centers and the greater Homeland Security Enterprise by exploring the customary intelligence cycle process model established by the United States Intelligence Community (USIC). This thesis revealed there are various intelligence cycle process models used by the USIC and taught to the National Network. Given the numerous differ...

  14. A Social Constructivist Approach to Introducing Skills for Employment to Foundation Degree Students

    Science.gov (United States)

    Rutt, L.; Gray, C.; Turner, R.; Swain, J.; Hulme, S.; Pomeroy, R.

    2013-01-01

    Expectations for higher education providers to produce graduates ready for the workplace have shaped provision, with the introduction of the Foundation Degree, and expectations of an employability component within higher education programmes. This paper reports on an intervention for three groups of foundation degree students, which introduces…

  15. Summative Co-Assessment: A Deep Learning Approach To Enhancing Employability Skills and Attributes

    Science.gov (United States)

    Deeley, Susan J.

    2014-01-01

    Service-learning is a pedagogy that combines academic study with service to the community. Voluntary work placements are integral to service-learning and offer students an ideal opportunity to develop their employability skills and attributes. In a service-learning course, it was considered good practice to raise students' awareness of the…

  16. Reduction of Severe Problem Behavior in Community Employment Using an Hypothesis-Driven Multicomponent Intervention Approach.

    Science.gov (United States)

    Kemp, Duane C.; Carr, Edward G.

    1995-01-01

    This study evaluated a strategy for reducing severe problem behavior in an employment situation for three adults with mental retardation and autism. The strategy involved intervention based on hypotheses about the problem behavior's maintaining variables, multiple component intervention, and evaluation using a measure of latency to problem…

  17. The Employment of spatial autoregressive models in predicting demand for natural gas

    International Nuclear Information System (INIS)

    Castro, Jorge Henrique de; Silva, Alexandre Pinto Alves da

    2010-01-01

    Develop the natural gas network is critical success factor for the distribution company. It is a decision that employs the demand given location 'x' and a future time 't' so that the net allows the best conditions for the return of the capital. In this segment, typical network industry, the spatial infra-structure vision associated to the market allows better evaluation of the business because to mitigate costs and risks. In fact, economic models little developed in order to assess the question of the location, due to its little employment by economists. The objective of this article is to analyze the application of spatial perspective in natural gas demand forecasting and to identify the models that can be employed observing issues of dependency and spatial heterogeneity; as well as the capacity of mapping of variables associated with the problem. (author)

  18. Soldiers’ employment attitude and employability: An exploratory study

    Directory of Open Access Journals (Sweden)

    Peng Gao

    2015-04-01

    Full Text Available Purpose: Nowadays it is very difficult for Chinese retired soldiers to find proper jobs, and the primary reason is the significant gap between job requirements and soldiers owned job skills. Therefore, it is very important to improve the soldiers’ job skills and enhance their understanding of employment.Design/methodology/approach: This paper expands the study scope from the soldiers’ job skills to the employability, initiatively introduces the employment attitude which has obvious impact on the employment of soldiers, and analyses the influence that employment attitude can play on employability. At last, this paper develops statistical method to find the relationship between soldiers’ employment attitude and employability.Findings: The empirical analysis shows that soldiers’ employment attitude has the positive linkage with employability, which makes the employment attitude a measurable variable for the employability rather than an absolute standard.Research limitations/implications: According to the research purpose, more variables should be considered in the model, consequently, there are only three indicators to describe solders’ employment attitude and four indicators to describe solders’ employability.Originality/value: This paper takes research on soldiers’ employability in a new perspective. The soldiers’ employment attitude is served as the entry point, showing the influence that soldiers’ employment attitude has on employability.

  19. Learning Action Models: Qualitative Approach

    NARCIS (Netherlands)

    Bolander, T.; Gierasimczuk, N.; van der Hoek, W.; Holliday, W.H.; Wang, W.-F.

    2015-01-01

    In dynamic epistemic logic, actions are described using action models. In this paper we introduce a framework for studying learnability of action models from observations. We present first results concerning propositional action models. First we check two basic learnability criteria: finite

  20. Determinants of Employer-Provided Further Training: A Multi-Level Approach

    OpenAIRE

    Bellmann, Lutz; Hohendanner, Christian; Hujer, Reinhard

    2010-01-01

    We analyse the influence of regional determinants on the decision of employers to provide within-firm further training. We estimate the effects of the regional population density, the unemployment rate and the regional concentration of an industry against the background of several determinants of further training at the establishment level. To account for the clustered and longitudinal structure of our data - with annual observations of firms and firms nested within regions - we apply multi-l...

  1. STEM Employment in the New Economy: A Labor Market Segmentation Approach

    Science.gov (United States)

    Torres-Olave, Blanca M.

    2013-01-01

    The present study examined the extent to which the U.S. STEM labor market is stratified in terms of quality of employment. Through a series of cluster analyses and Chi-square tests on data drawn from the 2008 Survey of Income Program Participation (SIPP), the study found evidence of segmentation in the highly-skilled STEM and non-STEM samples,…

  2. Toward an Integrated Competence-based System Supporting Lifelong Learning and Employability: Concepts, Model, and Challenges

    NARCIS (Netherlands)

    Miao, Yongwu; Van der Klink, Marcel; Boon, Jo; Sloep, Peter; Koper, Rob

    2009-01-01

    Miao, Y., Van der Klink, M., Boon, J., Sloep, P. B., & Koper, R. (2009). Toward an Integrated Competence-based System Supporting Lifelong Learning and Employability: Concepts, Model, and Challenges. In M. Spaniol, Q. Li, R. Klamma & R. W. H. Lau (Eds.), Proceedings of the 8th International

  3. Toward an Integrated Competence-based System Supporting Lifelong Learning and Employability: Concepts, Model, and Challenges

    NARCIS (Netherlands)

    Miao, Yongwu; Van der Klink, Marcel; Boon, Jo; Sloep, Peter; Koper, Rob

    2009-01-01

    Miao, Y., Van der Klink, M., Boon, J., Sloep, P. B., & Koper, R. (2009). Toward an Integrated Competence-based System Supporting Lifelong Learning and Employability: Concepts, Model, and Challenges. Presentation at the 8th International Conference Advances in Web Based Learning - ICWL 2009. August,

  4. Using the Social Enterprise Intervention (SEI) and Individual Placement and Support (IPS) models to improve employment and clinical outcomes of homeless youth with mental illness.

    Science.gov (United States)

    Ferguson, Kristin M

    2013-09-01

    Prior research reveals high unemployment rates among homeless youth. The literature offers many examples of using evidence-informed and evidence-based supported employment models with vulnerable populations to assist them in obtaining and maintaining employment and concurrently addressing mental health challenges. However, there are few examples to date of these models with homeless youth with mental illness. The purpose of this article was thus to describe a methodology for establishing a university-agency research partnership to design, implement, evaluate, and replicate evidence-informed and evidence-based interventions with homeless youth with mental illness to enhance their employment, mental health, and functional outcomes. Data from two studies are used to illustrate the relationship between vocational skill-building/employment and mental health among homeless youth. The article concludes with a discussion of the implications of conducting community-based participatory employment and clinical intervention research. The author highlights the opportunities and tensions associated with this approach.

  5. Using the Social Enterprise Intervention (SEI) and Individual Placement and Support (IPS) models to improve employment and clinical outcomes of homeless youth with mental illness1

    Science.gov (United States)

    Ferguson, Kristin M.

    2013-01-01

    Prior research reveals high unemployment rates among homeless youth. The literature offers many examples of using evidence-informed and evidence-based supported employment models with vulnerable populations to assist them in obtaining and maintaining employment and concurrently addressing mental health challenges. However, there are few examples to date of these models with homeless youth with mental illness. The purpose of this article was thus to describe a methodology for establishing a university-agency research partnership to design, implement, evaluate, and replicate evidence-informed and evidence-based interventions with homeless youth with mental illness to enhance their employment, mental health, and functional outcomes. Data from two studies are used to illustrate the relationship between vocational skill-building/employment and mental health among homeless youth. The article concludes with a discussion of the implications of conducting community-based participatory employment and clinical intervention research. The author highlights the opportunities and tensions associated with this approach. PMID:24294127

  6. VIA Employability

    DEFF Research Database (Denmark)

    Andersen, Henrik Mariendal

    2017-01-01

    The fact that students develop employability during their education is a key point for educational institutions and the focus on this issue has never been greater. This project looks into personal experience from VIA-graduates of "developing their employability" during the education and how it......’s realized at the entrance to the labor market and in the future career. The purpose is to find opportunities to improve employability-developing activities and to adapt it to specific needs from the students. Based on a number of qualitative interviews and personality tests of the graduates, an increased...... personal approach is proposed in the agenda of employability. And ensure a wide range of offers, that appeal to multiple and differentiated personal and professional approaches to employability....

  7. modeling, observation and control, a multi-model approach

    OpenAIRE

    Elkhalil, Mansoura

    2011-01-01

    This thesis is devoted to the control of systems which dynamics can be suitably described by a multimodel approach from an investigation study of a model reference adaptative control performance enhancement. Four multimodel control approaches have been proposed. The first approach is based on an output reference model control design. A successful experimental validation involving a chemical reactor has been carried out. The second approach is based on a suitable partial state model reference ...

  8. Global energy modeling - A biophysical approach

    Energy Technology Data Exchange (ETDEWEB)

    Dale, Michael

    2010-09-15

    This paper contrasts the standard economic approach to energy modelling with energy models using a biophysical approach. Neither of these approaches includes changing energy-returns-on-investment (EROI) due to declining resource quality or the capital intensive nature of renewable energy sources. Both of these factors will become increasingly important in the future. An extension to the biophysical approach is outlined which encompasses a dynamic EROI function that explicitly incorporates technological learning. The model is used to explore several scenarios of long-term future energy supply especially concerning the global transition to renewable energy sources in the quest for a sustainable energy system.

  9. Estimating the short run effects of South Africa's Employment Tax Incentive on youth employment probabilities using a difference-in-differences approach

    OpenAIRE

    Vimal Ranchhod; Arden Finn

    2014-01-01

    What effect did the introduction of the Employment Tax Incentive (ETI) have on youth employment probabilities in South Africa in the short run? The ETI came into effect on the 1st of January 2014. Its purpose is to stimulate youth employment levels and ease the challenges that many youth experience in finding their first jobs. Under the ETI, firms that employ youth are eligible to claim a deduction from their taxes due, for the portion of their wage bill that is paid to certain groups of yout...

  10. Learning Actions Models: Qualitative Approach

    DEFF Research Database (Denmark)

    Bolander, Thomas; Gierasimczuk, Nina

    2015-01-01

    —they are identifiable in the limit.We then move on to a particular learning method, which proceeds via restriction of a space of events within a learning-specific action model. This way of learning closely resembles the well-known update method from dynamic epistemic logic. We introduce several different learning...... identifiability (conclusively inferring the appropriate action model in finite time) and identifiability in the limit (inconclusive convergence to the right action model). We show that deterministic actions are finitely identifiable, while non-deterministic actions require more learning power...... methods suited for finite identifiability of particular types of deterministic actions....

  11. Labour market for youth in Romania – a demographic and qualitative approach of their employability

    Directory of Open Access Journals (Sweden)

    Silvia Pisică

    2015-09-01

    Full Text Available The paper analyzes the implications of demographic developments on the labour market in terms of potential labour from structural and professional perspectives. The aspects of the youth demographic and educational potential for labour market, of the national policies potential for new job creation and of the opportunities of alternative free movement of workers are presented. The paper emphasizes positive and negative labour market pressures as derived from the demographic structure (including ethnicity, skills and competences, and educational attainment. The influences factors on qualitative youth employability in Romania are also highlighted. Some empirical analyses of the working age population in terms of demographic factors, as well as its demographic forecast are presented. Statistical software used for this analysis is the R Project, along with specific packages forecasting analysis. Final part of the paper is focused on some specific recommendations for policy instruments and measures to support youth employability on the national labor market based on the changed typology of the youth supply on labour market.

  12. A Comprehensive Approach in Recruitment and Employment Policies for Faculty Members: A Critical Review

    Directory of Open Access Journals (Sweden)

    Soleiman Ahmady

    2016-12-01

    Full Text Available Experts in the field of human resource management have always emphasized on human work force as the most important strategic factor and the organization's most valuable asset and believe that effective management of human resources is the key to organizational success. Recruitment and selection are one of the aspects of human resource management that are of great importance and adopting appropriate policies in this area could provide the appropriate use of human resources. In universities and higher education institutions, faculty members are one of the major capitals and development and application of appropriate policies play a major role in their success. This study is based on critical review where relevant search terms were used to collect the studies using extensive and structured search of the databases. One hundred fifty titles were retrieved. Then, with purposive sampling, texts screening was conducted in three stages: A primary screening or title screening on the grounds that are associated with managing recruiting faculty members, B secondary screening performed based on study summary and introduction texts, and C tertiary screening: the texts were briefly studied and the texts were prioritized based on conceptual richness and related to contextual studies and irrelevant articles were excluded. Complete and in-depth study of the richest papers began. Forty-five articles and text were examined. The results suggest that in most universities management of recruiting faculty members is decentralized and based on the department. Findings show that policies such as reducing the use of tenure track, the long-term contracts, limiting the tenure to faculty of science, limiting tenure to higher levels of associate professor and design the diverse career paths and different forms of employment are of the policies that can be considered by university managers. The findings also suggest that universities can use flexible policies, such as

  13. A Unified Approach to Modeling and Programming

    DEFF Research Database (Denmark)

    Madsen, Ole Lehrmann; Møller-Pedersen, Birger

    2010-01-01

    of this paper is to go back to the future and get inspiration from SIMULA and propose a unied approach. In addition to reintroducing the contributions of SIMULA and the Scandinavian approach to object-oriented programming, we do this by discussing a number of issues in modeling and programming and argue3 why we......SIMULA was a language for modeling and programming and provided a unied approach to modeling and programming in contrast to methodologies based on structured analysis and design. The current development seems to be going in the direction of separation of modeling and programming. The goal...

  14. Tuning University Undergraduates for High Mobility and Employability under the Content and Language Integrated Learning Approach

    Science.gov (United States)

    Yang, Wenhsien

    2017-01-01

    Globalisation affects both language use and the economics of higher education. Considering how to design new instructional approaches to prepare graduates with competence in using language and professional knowledge interactively and interculturally has thus become a major concern of higher education institutes. Content and language integrated…

  15. Is HRM a New Approach in the Employment Scene in Developing ...

    African Journals Online (AJOL)

    It compares and contrasts HRM, welfare, traditional Personnel Management and Industrial relations approaches. It pulls the threads together to draw a balance sheet of the discussion by portraying that HRM is an evolutionary rather than revolutionary process. African Journal of Finance and Management Vol.8(1) 1999: 14- ...

  16. A systematic risk management approach employed on the CloudSat project

    Science.gov (United States)

    Basilio, R. R.; Plourde, K. S.; Lam, T.

    2000-01-01

    The CloudSat Project has developed a simplified approach for fault tree analysis and probabilistic risk assessment. A system-level fault tree has been constructed to identify credible fault scenarios and failure modes leading up to a potential failure to meet the nominal mission success criteria.

  17. A partnership-based model for embedding employability in urban planning education

    Directory of Open Access Journals (Sweden)

    Neale Blair

    2016-01-01

    Full Text Available This paper proposes a partnership-based model for embedding employability in urban planning education. The model is based on the author’s experiences of implementing an international project which supported the development of employability skills in urban and regional planning education in Malawi. Since independence, urban planners have typically trained outside the country, attending university in the UK and other Commonwealth countries. More recently, the paradigm has shifted towards in-country education delivered by academic staff cognisant with the opportunities and challenges of development in Malawi. There remains, though, a gap between graduate knowledge of the subject and the skills necessary to pursue a professional career in the sector. Although there is no consensus yet on the meaning of employability in the literature, lessons from the project indicate that academic–public–private collaboration helps incorporate in curriculum skills that employers anticipate. Applicability of these principles is however context dependent, particularly in the emerging economy context where institutional capacity may be less developed compared to elsewhere.

  18. An ecological approach to understanding barriers to employment for youth with disabilities compared to their typically developing peers: views of youth, employers, and job counselors.

    Science.gov (United States)

    Lindsay, Sally; McDougall, Carolyn; Menna-Dack, Dolly; Sanford, Robyn; Adams, Tracey

    2015-01-01

    The purpose of this study is to explore the extent to which youth with physical disabilities encounter different barriers to finding employment compared to their typically developing peers. This study draws on 50 qualitative in-depth interviews with a purposive sample of 31 youth (16 typically developing and 15 with a disability), and youth employers and job counselors knowledgeable about employment readiness among adolescents (n = 19). We utilize Bronfrebrenner's ecological framework to reveal the complex web of factors shaping youth's labor market outcomes. Only half of youth with a disability were working or looking for work compared to their peers. The findings show this was a result of different expectations of, and attitudes toward, youth with disabilities. For many youth with a disability, their peers, family and social networks often acted as a barrier to getting a job. Many youth also lacked independence and life skills that are needed to get a job (i.e. self-care and navigating public transportation) compared to their peers. Job counselors focused on linking youth to employers and mediating parental concerns. Employers appeared to have weaker links to youth with disabilities. System level barriers included lack of funding and policies to enhance disability awareness among employers. Youth with physical disabilities encounter some similar barriers to finding employment compared to their typically developing peers but in a stronger way. Barriers to employment exist at several levels including individual, sociostructural and environmental. The results highlight that although there are several barriers to employment for young people at the microsystem level, they are linked with larger social and environmental barriers. Clinicians working with youth should promote the development of skills that can lead to improved self-confidence and communication skills for youth. Encourage the development of extracurricular activities and social networking to build these

  19. Szekeres models: a covariant approach

    Science.gov (United States)

    Apostolopoulos, Pantelis S.

    2017-05-01

    We exploit the 1  +  1  +  2 formalism to covariantly describe the inhomogeneous and anisotropic Szekeres models. It is shown that an average scale length can be defined covariantly which satisfies a 2d equation of motion driven from the effective gravitational mass (EGM) contained in the dust cloud. The contributions to the EGM are encoded to the energy density of the dust fluid and the free gravitational field E ab . We show that the quasi-symmetric property of the Szekeres models is justified through the existence of 3 independent intrinsic Killing vector fields (IKVFs). In addition the notions of the apparent and absolute apparent horizons are briefly discussed and we give an alternative gauge-invariant form to define them in terms of the kinematical variables of the spacelike congruences. We argue that the proposed program can be used in order to express Sachs’ optical equations in a covariant form and analyze the confrontation of a spatially inhomogeneous irrotational overdense fluid model with the observational data.

  20. Environmental Radiation Effects on Mammals A Dynamical Modeling Approach

    CERN Document Server

    Smirnova, Olga A

    2010-01-01

    This text is devoted to the theoretical studies of radiation effects on mammals. It uses the framework of developed deterministic mathematical models to investigate the effects of both acute and chronic irradiation in a wide range of doses and dose rates on vital body systems including hematopoiesis, small intestine and humoral immunity, as well as on the development of autoimmune diseases. Thus, these models can contribute to the development of the system and quantitative approaches in radiation biology and ecology. This text is also of practical use. Its modeling studies of the dynamics of granulocytopoiesis and thrombocytopoiesis in humans testify to the efficiency of employment of the developed models in the investigation and prediction of radiation effects on these hematopoietic lines. These models, as well as the properly identified models of other vital body systems, could provide a better understanding of the radiation risks to health. The modeling predictions will enable the implementation of more ef...

  1. [Medical inventions: developments and approaches in employer-employee [correction of worker-employee] relations].

    Science.gov (United States)

    Teff, Zvi

    2012-11-01

    The past twenty years have witnessed a huge increase in research activity on the government health system in Israel. Consequently, a number of questions of enhanced importance arise: to whom the resultant IP (intellectual property) belongs?--to the researcher or the employer? and what compensation should the researcher receive for his inventive efforts? The government found many cases where the IP was registered in the name of the inventor/researcher, thus denying the government ownership of the IP. In 2009, the government sued Omryx over ownership of such an IP. Following these developments, the government issued new rules for management of IP in the government health system. They came into effect in November 2010. In many respects, the new rules are more stringent than the Israeli Patent Law in respect of the inventor. However, the stipulation of awards to the inventor in the new rules is generous. In order for the new rules to be enforceable, the following guidelines are recommended: The new rules should be more aligned with the Patent Law and with the meaning given to the Law by the judicial system, and There is need for the assent and awareness of health system workers to the conditions set out in the new rules, preferably in the form of new work contracts that clearly and concurrently delineate the worker's duties, particularly those pertaining to IP.

  2. Training therapists to perform Pre-Employment Functional Assessments: A telerehabilitation approach.

    Science.gov (United States)

    Cotton, Zoë; Russell, Trevor; Johnston, Venerina; Legge, Jennifer

    2017-01-01

    Pre-Employment Functional Assessments (PEFA) are increasingly used in an attempt to obtain objective information on a potential employee's functional capabilities. In rural and remote communities, there is typically reduced access to qualified therapists to perform these assessments, in part attributable to the time and costs associated with travelling to training courses. One potential method of providing the relevant training to conduct PEFAs is through the use of technologies such as videoconferencing or internet-based modules. The purpose of this project is to investigate the effectiveness of training therapists and therapy students in performing JobFit System PEFAs via technology when compared with a face-to-face control group. Fifty-three participants, consisting of 28 professional physiotherapists and occupational therapists, and 25 final year University of Queensland (UQ) physiotherapy and occupational therapy students, underwent JobFit Systems International PEFA training via one of four intervention groups: face-to-face, realtime videoconferencing, group-based online module and individual online module. Of the 53 participants, 49 achieved the minimum competency level of 75% in post-training competency assessments. No significant difference was found in training levels between intervention groups. The results of this study suggest that technology, such as real-time videoconference and online learning modules, can be used to train both therapists and students in how to perform JobFit System PEFAs.

  3. Multiple Model Approaches to Modelling and Control,

    DEFF Research Database (Denmark)

    appeal in building systems which operate robustly over a wide range of operating conditions by decomposing them into a number of simplerlinear modelling or control problems, even for nonlinear modelling or control problems. This appeal has been a factor in the development of increasinglypopular `local...... to problems in the process industries, biomedical applications and autonomoussystems. The successful application of the ideas to demanding problems is already encouraging, but creative development of the basic framework isneeded to better allow the integration of human knowledge with automated learning....... The underlying question is `How should we partition the system - what is `local'?'. This book presents alternative ways of bringing submodels together,which lead to varying levels of performance and insight. Some are further developed for autonomous learning of parameters from data, while others havefocused...

  4. Modeling software behavior a craftsman's approach

    CERN Document Server

    Jorgensen, Paul C

    2009-01-01

    A common problem with most texts on requirements specifications is that they emphasize structural models to the near exclusion of behavioral models-focusing on what the software is, rather than what it does. If they do cover behavioral models, the coverage is brief and usually focused on a single model. Modeling Software Behavior: A Craftsman's Approach provides detailed treatment of various models of software behavior that support early analysis, comprehension, and model-based testing. Based on the popular and continually evolving course on requirements specification models taught by the auth

  5. System Behavior Models: A Survey of Approaches

    Science.gov (United States)

    2016-06-01

    the Petri model allowed a quick assessment of all potential states but was more cumbersome to build than the MP model. A comparison of approaches...identical state space results. The combined state space graph of the Petri model allowed a quick assessment of all potential states but was more...59 INITIAL DISTRIBUTION LIST ...................................................................................65 ix LIST

  6. Plasma Arc Cutting Dimensional Accuracy Optimization employing the Parameter Design approach

    Directory of Open Access Journals (Sweden)

    Kechagias John

    2017-01-01

    Full Text Available Plasma Arc Cutting (PAC is a thermal manufacturing process used for metal plates cutting. This work experimentally investigates the influence of process parameters onto the dimensional accuracy performance of the plasma arc cutting process. The cutting parameters studied were cutting speed (mm/min, torch standoff distance (mm, and arc voltage (volts. Linear dimensions of a rectangular workpiece were measured after PAC cutting following the full factorial design experimental approach. For each one of the three process parameters, three parameter levels were used. Analysis of means (ANOM and analysis of variances (ANOVA were performed in order for the effect of each parameter on the leaner dimensional accuracy to be assessed.

  7. Current approaches to gene regulatory network modelling

    Directory of Open Access Journals (Sweden)

    Brazma Alvis

    2007-09-01

    Full Text Available Abstract Many different approaches have been developed to model and simulate gene regulatory networks. We proposed the following categories for gene regulatory network models: network parts lists, network topology models, network control logic models, and dynamic models. Here we will describe some examples for each of these categories. We will study the topology of gene regulatory networks in yeast in more detail, comparing a direct network derived from transcription factor binding data and an indirect network derived from genome-wide expression data in mutants. Regarding the network dynamics we briefly describe discrete and continuous approaches to network modelling, then describe a hybrid model called Finite State Linear Model and demonstrate that some simple network dynamics can be simulated in this model.

  8. The psychological contract: is the UK National Health Service a model employer?

    Science.gov (United States)

    Fielden, Sandra; Whiting, Fiona

    2007-05-01

    The UK National Health Service (NHS) is facing recruitment challenges that mean it will need to become an 'employer of choice' if it is to continue to attract high-quality employees. This paper reports the findings from a study focusing on allied health professional staff (n = 67), aimed at establishing the expectations of the NHS inherent in their current psychological contract and to consider whether the government's drive to make the NHS a model employer meets those expectations. The findings show that the most important aspects of the psychological contract were relational and based on the investment made in the employment relationship by both parties. The employment relationship was one of high involvement but also one where transactional contract items, such as pay, were still of some importance. Although the degree of employee satisfaction with the relational content of the psychological contract was relatively positive, there was, nevertheless, a mismatch between levels of importance placed on such aspects of the contract and levels of satisfaction, with employees increasingly placing greater emphasis on those items the NHS is having the greatest difficulty providing. Despite this apparent disparity between employee expectation and the fulfilment of those expectations, the overall health of the psychological contract was still high.

  9. Hispanic Youth Employment Guidebook: Local Government Approaches Using Public-Private Partnerships.

    Science.gov (United States)

    Nieto, Margaret; Kubo, Christine, Ed.

    This guidebook was developed as an aid to communities seeking to create partnerships between public and private sector sources to reduce the youth unemployment among Hispanics. The International City Management Association (ICMA), as part of a project sponsored by the Department of Health and Human Services, identifies six model ventures using the…

  10. A model-data based systems approach to process intensification

    DEFF Research Database (Denmark)

    Gani, Rafiqul

    . Their developments, however, are largely due to experiment based trial and error approaches and while they do not require validation, they can be time consuming and resource intensive. Also, one may ask, can a truly new intensified unit operation be obtained in this way? An alternative two-stage approach is to apply...... for focused validation of only the promising candidates in the second-stage. This approach, however, would be limited to intensification based on “known” unit operations, unless the PI process synthesis/design is considered at a lower level of aggregation, namely the phenomena level. That is, the model......-based synthesis method must employ models at lower levels of aggregation and through combination rules for phenomena, generate (synthesize) new intensified unit operations. An efficient solution procedure for the synthesis problem is needed to tackle the potentially large number of options that would be obtained...

  11. Mechanochemical approaches to employ silicon as a lithium-ion battery anode

    Directory of Open Access Journals (Sweden)

    Norihiro Shimoi

    2015-05-01

    Full Text Available Silicon is essential as an active material in lithium-ion batteries because it provides both high-charge and optimal cycle characteristics. The authors attempted to realize a composite by a simple mechanochemical grinding approach of individual silicon (Si particles and copper monoxide (CuO particles to serve as an active material in the anode and optimize the charge-discharge characteristics of a lithium-ion battery. The composite with Si and CuO allowed for a homogenous dispersion with nano-scale Si grains, nano-scale copper-silicon alloy grains and silicon monoxide oxidized the oxide from CuO. The authors successfully achieved the synthesis of an active composite unites the structural features of an active material based on silicon composite as an anode in Li-ion battery with high capacity and cyclic reversible charge properties of 3256 mAh g−1 after 200 cycles.

  12. Distributed simulation a model driven engineering approach

    CERN Document Server

    Topçu, Okan; Oğuztüzün, Halit; Yilmaz, Levent

    2016-01-01

    Backed by substantive case studies, the novel approach to software engineering for distributed simulation outlined in this text demonstrates the potent synergies between model-driven techniques, simulation, intelligent agents, and computer systems development.

  13. Predictive models to determine imagery strategies employed by children to judge hand laterality.

    Science.gov (United States)

    Spruijt, Steffie; Jongsma, Marijtje L A; van der Kamp, John; Steenbergen, Bert

    2015-01-01

    A commonly used paradigm to study motor imagery is the hand laterality judgment task. The present study aimed to determine which strategies young children employ to successfully perform this task. Children of 5 to 8 years old (N = 92) judged laterality of back and palm view hand pictures in different rotation angles. Response accuracy and response duration were registered. Response durations of the trials with a correct judgment were fitted to a-priori defined predictive sinusoid models, representing different strategies to successfully perform the hand laterality judgment task. The first model predicted systematic changes in response duration as a function of rotation angle of the displayed hand. The second model predicted that response durations are affected by biomechanical constraints of hand rotation. If observed data could be best described by the first model, this would argue for a mental imagery strategy that does not involve motor processes to solve the task. The second model reflects a motor imagery strategy to solve the task. In line with previous research, we showed an age-related increase in response accuracy and decrease in response duration in children. Observed data for both back and palm view showed that motor imagery strategies were used to perform hand laterality judgments, but that not all the children use these strategies (appropriately) at all times. A direct comparison of response duration patterns across age sheds new light on age-related differences in the strategies employed to solve the task. Importantly, the employment of the motor imagery strategy for successful task performance did not change with age.

  14. Modeling electricity spot and futures price dependence: A multifrequency approach

    Science.gov (United States)

    Malo, Pekka

    2009-11-01

    Electricity prices are known to exhibit multifractal properties. We accommodate this finding by investigating multifractal models for electricity prices. In this paper we propose a flexible Copula-MSM (Markov Switching Multifractal) approach for modeling spot and weekly futures price dynamics. By using a conditional copula function, the framework allows us to separately model the dependence structure, while enabling use of multifractal stochastic volatility models to characterize fluctuations in marginal returns. An empirical experiment is carried out using data from Nord Pool. A study of volatility forecasting performance for electricity spot prices reveals that multifractal techniques are a competitive alternative to GARCH models. We also demonstrate how the Copula-MSM model can be employed for finding optimal portfolios, which minimizes the Conditional Value-at-Risk.

  15. Multiphysics modeling using COMSOL a first principles approach

    CERN Document Server

    Pryor, Roger W

    2011-01-01

    Multiphysics Modeling Using COMSOL rapidly introduces the senior level undergraduate, graduate or professional scientist or engineer to the art and science of computerized modeling for physical systems and devices. It offers a step-by-step modeling methodology through examples that are linked to the Fundamental Laws of Physics through a First Principles Analysis approach. The text explores a breadth of multiphysics models in coordinate systems that range from 1D to 3D and introduces the readers to the numerical analysis modeling techniques employed in the COMSOL Multiphysics software. After readers have built and run the examples, they will have a much firmer understanding of the concepts, skills, and benefits acquired from the use of computerized modeling techniques to solve their current technological problems and to explore new areas of application for their particular technological areas of interest.

  16. Validation of Modeling Flow Approaching Navigation Locks

    Science.gov (United States)

    2013-08-01

    USACE, Pittsburgh District ( LRP ) requested that the US Army Engineer Research and Development Center, Coastal and ERDC/CHL TR-13-9 2 Hydraulics...approaching the lock and dam. The second set of experiments considered a design, referred to as Plan B lock approach, which contained the weir field in...conditions and model parameters A discharge of 1.35 cfs was set as the inflow boundary condition at the upstream end of the model. The outflow boundary was

  17. Employing Measures of Heterogeneity and an Object-Based Approach to Extrapolate Tree Species Distribution Data

    Directory of Open Access Journals (Sweden)

    Trevor G. Jones

    2014-07-01

    Full Text Available Information derived from high spatial resolution remotely sensed data is critical for the effective management of forested ecosystems. However, high spatial resolution data-sets are typically costly to acquire and process and usually provide limited geographic coverage. In contrast, moderate spatial resolution remotely sensed data, while not able to provide the spectral or spatial detail required for certain types of products and applications, offer inexpensive, comprehensive landscape-level coverage. This study assessed using an object-based approach to extrapolate detailed tree species heterogeneity beyond the extent of hyperspectral/LiDAR flightlines to the broader area covered by a Landsat scene. Using image segments, regression trees established ecologically decipherable relationships between tree species heterogeneity and the spectral properties of Landsat segments. The spectral properties of Landsat bands 4 (i.e., NIR: 0.76–0.90 µm, 5 (i.e., SWIR: 1.55–1.75 µm and 7 (SWIR: 2.08–2.35 µm were consistently selected as predictor variables, explaining approximately 50% of variance in richness and diversity. Results have important ramifications for ongoing management initiatives in the study area and are applicable to wide range of applications.

  18. Hybrid approaches to physiologic modeling and prediction

    Science.gov (United States)

    Olengü, Nicholas O.; Reifman, Jaques

    2005-05-01

    This paper explores how the accuracy of a first-principles physiological model can be enhanced by integrating data-driven, "black-box" models with the original model to form a "hybrid" model system. Both linear (autoregressive) and nonlinear (neural network) data-driven techniques are separately combined with a first-principles model to predict human body core temperature. Rectal core temperature data from nine volunteers, subject to four 30/10-minute cycles of moderate exercise/rest regimen in both CONTROL and HUMID environmental conditions, are used to develop and test the approach. The results show significant improvements in prediction accuracy, with average improvements of up to 30% for prediction horizons of 20 minutes. The models developed from one subject's data are also used in the prediction of another subject's core temperature. Initial results for this approach for a 20-minute horizon show no significant improvement over the first-principles model by itself.

  19. Selection of robust variables for transfer of classification models employing the successive projections algorithm.

    Science.gov (United States)

    Milanez, Karla Danielle Tavares Melo; Araújo Nóbrega, Thiago César; Silva Nascimento, Danielle; Galvão, Roberto Kawakami Harrop; Pontes, Márcio José Coelho

    2017-09-01

    Multivariate models have been widely used in analytical problems involving quantitative and qualitative analyzes. However, there are cases in which a model is not applicable to spectra of samples obtained under new experimental conditions or in an instrument not involved in the modeling step. A solution to this problem is the transfer of multivariate models, usually performed using standardization of the spectral responses or enhancement of the robustness of the model. This present paper proposes two new criteria for selection of robust variables for classification transfer employing the successive projections algorithm (SPA). These variables are then used to build models based on linear discriminant analysis (LDA) with low sensitivity with respect to the differences between the responses of the instruments involved. For this purpose, transfer samples are included in the calculation of the cost for each subset of variables under consideration. The proposed methods are evaluated for two case studies involving identification of adulteration of extra virgin olive oil (EVOO) and hydrated ethyl alcohol fuel (HEAF) using UV-Vis and NIR spectroscopy, respectively. In both cases, similar or better classification transfer results (obtained for a test set measured on the secondary instrument) employing the two criteria were obtained in comparison with direct standardization (DS) and piecewise direct standardization (PDS). For the UV-Vis data, both proposed criteria achieved the correct classification rate (CCR) of 85%, while the best CCR obtained for the standardization methods was 81% for DS. For the NIR data, 92.5% of CCR was obtained by both criteria as well as DS. The results demonstrated the possibility of using either of the criteria proposed for building robust models as an alternative to the standardization of spectral responses for transfer of classification. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Modeling gene expression measurement error: a quasi-likelihood approach

    Directory of Open Access Journals (Sweden)

    Strimmer Korbinian

    2003-03-01

    Full Text Available Abstract Background Using suitable error models for gene expression measurements is essential in the statistical analysis of microarray data. However, the true probabilistic model underlying gene expression intensity readings is generally not known. Instead, in currently used approaches some simple parametric model is assumed (usually a transformed normal distribution or the empirical distribution is estimated. However, both these strategies may not be optimal for gene expression data, as the non-parametric approach ignores known structural information whereas the fully parametric models run the risk of misspecification. A further related problem is the choice of a suitable scale for the model (e.g. observed vs. log-scale. Results Here a simple semi-parametric model for gene expression measurement error is presented. In this approach inference is based an approximate likelihood function (the extended quasi-likelihood. Only partial knowledge about the unknown true distribution is required to construct this function. In case of gene expression this information is available in the form of the postulated (e.g. quadratic variance structure of the data. As the quasi-likelihood behaves (almost like a proper likelihood, it allows for the estimation of calibration and variance parameters, and it is also straightforward to obtain corresponding approximate confidence intervals. Unlike most other frameworks, it also allows analysis on any preferred scale, i.e. both on the original linear scale as well as on a transformed scale. It can also be employed in regression approaches to model systematic (e.g. array or dye effects. Conclusions The quasi-likelihood framework provides a simple and versatile approach to analyze gene expression data that does not make any strong distributional assumptions about the underlying error model. For several simulated as well as real data sets it provides a better fit to the data than competing models. In an example it also

  1. ECONOMETRIC MODELING OF GDP BY EMPLOYMENT AND THE VALUE OF TANGIBLE FIXED ASSESTS

    Directory of Open Access Journals (Sweden)

    Cristina BURGHELEA

    2015-04-01

    Full Text Available The economic potential of a country is consistently a primary goal of existence and sustainable development, to ensure the livelihood of all residents, increase living standards. To achieve this major goal rigorous study must be complex to formulate a diagnosis and real economic status and rationale, on the basis of economic and legislative policy decisions, decisions addressing both immediate time horizons as well as longer periods of time. In this context, we analyzed dynamics of GDP according to the dynamics of employment and dynamics of tangible fixed assets of the economy by applying a rigorous econometric modeling methodology.

  2. Risk Modelling for Passages in Approach Channel

    Directory of Open Access Journals (Sweden)

    Leszek Smolarek

    2013-01-01

    Full Text Available Methods of multivariate statistics, stochastic processes, and simulation methods are used to identify and assess the risk measures. This paper presents the use of generalized linear models and Markov models to study risks to ships along the approach channel. These models combined with simulation testing are used to determine the time required for continuous monitoring of endangered objects or period at which the level of risk should be verified.

  3. Project Career: An individualized postsecondary approach to promoting independence, functioning, and employment success among students with traumatic brain injuries.

    Science.gov (United States)

    Minton, Deborah; Elias, Eileen; Rumrill, Phillip; Hendricks, Deborah J; Jacobs, Karen; Leopold, Anne; Nardone, Amanda; Sampson, Elaine; Scherer, Marcia; Gee Cormier, Aundrea; Taylor, Aiyana; DeLatte, Caitlin

    2017-09-14

    Project Career is a five-year interdisciplinary demonstration project funded by NIDILRR. It provides technology-driven supports, merging Cognitive Support Technology (CST) evidence-based practices and rehabilitation counseling, to improve postsecondary and employment outcomes for veteran and civilian undergraduate students with traumatic brain injury (TBI). Provide a technology-driven individualized support program to improve career and employment outcomes for students with TBI. Project staff provide assessments of students' needs relative to assistive technology, academic achievement, and career preparation; provide CST training to 150 students; match students with mentors; provide vocational case management; deliver job development and placement assistance; and maintain an electronic portal regarding accommodation and career resources. Participating students receive cognitive support technology training, academic enrichment, and career preparatory assistance from trained professionals at three implementation sites. Staff address cognitive challenges using the 'Matching Person with Technology' assessment to accommodate CST use (iPad and selected applications (apps)). JBS International (JBS) provides the project's evaluation. To date, 117 students participate with 63% report improved life quality and 75% report improved academic performance. Project Career provides a national model based on best practices for enabling postsecondary students with TBI to attain academic, employment, and career goals.

  4. Employing Model-Based Reasoning in Interdisciplinary Research Teams: Evidence-Based Practices for Integrating Knowledge Across Systems

    Science.gov (United States)

    Pennington, D. D.; Vincent, S.

    2017-12-01

    The NSF-funded project "Employing Model-Based Reasoning in Socio-Environmental Synthesis (EMBeRS)" has developed a generic model for exchanging knowledge across disciplines that is based on findings from the cognitive, learning, social, and organizational sciences addressing teamwork in complex problem solving situations. Two ten-day summer workshops for PhD students from large, NSF-funded interdisciplinary projects working on a variety of water issues were conducted in 2016 and 2017, testing the model by collecting a variety of data, including surveys, interviews, audio/video recordings, material artifacts and documents, and photographs. This presentation will introduce the EMBeRS model, the design of workshop activities based on the model, and results from surveys and interviews with the participating students. Findings suggest that this approach is very effective for developing a shared, integrated research vision across disciplines, compared with activities typically provided by most large research projects, and that students believe the skills developed in the EMBeRS workshops are unique and highly desireable.

  5. Off-the-job training for VATS employing anatomically correct lung models.

    Science.gov (United States)

    Obuchi, Toshiro; Imakiire, Takayuki; Miyahara, Sou; Nakashima, Hiroyasu; Hamanaka, Wakako; Yanagisawa, Jun; Hamatake, Daisuke; Shiraishi, Takeshi; Moriyama, Shigeharu; Iwasaki, Akinori

    2012-02-01

    We evaluated our simulated major lung resection employing anatomically correct lung models as "off-the-job training" for video-assisted thoracic surgery trainees. A total of 76 surgeons voluntarily participated in our study. They performed video-assisted thoracic surgical lobectomy employing anatomically correct lung models, which are made of sponges so that vessels and bronchi can be cut using usual surgical techniques with typical forceps. After the simulation surgery, participants answered questionnaires on a visual analogue scale, in terms of their level of interest and the reality of our training method as off-the-job training for trainees. We considered that the closer a score was to 10, the more useful our method would be for training new surgeons. Regarding the appeal or level of interest in this simulation surgery, the mean score was 8.3 of 10, and regarding reality, it was 7.0. The participants could feel some of the real sensations of the surgery and seemed to be satisfied to perform the simulation lobectomy. Our training method is considered to be suitable as an appropriate type of surgical off-the-job training.

  6. Towards new approaches in phenological modelling

    Science.gov (United States)

    Chmielewski, Frank-M.; Götz, Klaus-P.; Rawel, Harshard M.; Homann, Thomas

    2014-05-01

    Modelling of phenological stages is based on temperature sums for many decades, describing both the chilling and the forcing requirement of woody plants until the beginning of leafing or flowering. Parts of this approach go back to Reaumur (1735), who originally proposed the concept of growing degree-days. Now, there is a growing body of opinion that asks for new methods in phenological modelling and more in-depth studies on dormancy release of woody plants. This requirement is easily understandable if we consider the wide application of phenological models, which can even affect the results of climate models. To this day, in phenological models still a number of parameters need to be optimised on observations, although some basic physiological knowledge of the chilling and forcing requirement of plants is already considered in these approaches (semi-mechanistic models). Limiting, for a fundamental improvement of these models, is the lack of knowledge about the course of dormancy in woody plants, which cannot be directly observed and which is also insufficiently described in the literature. Modern metabolomic methods provide a solution for this problem and allow both, the validation of currently used phenological models as well as the development of mechanistic approaches. In order to develop this kind of models, changes of metabolites (concentration, temporal course) must be set in relation to the variability of environmental (steering) parameters (weather, day length, etc.). This necessarily requires multi-year (3-5 yr.) and high-resolution (weekly probes between autumn and spring) data. The feasibility of this approach has already been tested in a 3-year pilot-study on sweet cherries. Our suggested methodology is not only limited to the flowering of fruit trees, it can be also applied to tree species of the natural vegetation, where even greater deficits in phenological modelling exist.

  7. A Review of Models for Dose Assessment Employed by SKB in the Renewed Safety Assessment for SFR 1

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, George [Imperial College of Science Technology and Medicine (United Kingdom)

    2002-09-01

    This document provides a critical review, on behalf of SSI, of the models employed by the Swedish Nuclear Fuel and Waste Management Co (SKB) for dose assessment in the renewed safety assessment for the final repository for radioactive operational waste (SFR 1) in Forsmark, Sweden. The main objective of the review is to examine the models used by SKB for radiological dose assessment in a series of evolving biotopes in the vicinity of the Forsmark repository within a time frame beginning in 3000 AD and extending beyond 7500 AD. Five biosphere models (for coasts, lakes, agriculture, mires and wells) are described in Report TR-01-04. The principal consideration of the review is to determine whether these models are fit for the purpose of dose evaluation over the time frames involved and in the evolving sequence of biotopes specified. As well as providing general observations and comments on the modelling approach taken, six specific questions are addressed, as follows. Are the assumptions underlying the models justifiable? Are all reasonably foreseeable environmental processes considered? Has parameter uncertainty been sufficiently and reasonably addressed? Have sufficient models been used to address all reasonably foreseeable biotopes? Are the transitions between biotopes modelled adequately (specifically, are initial conditions for developing biotopes adequately specified by calculations for subsiding biotopes)? Have all critical radionuclides been identified? It is concluded that, in general, the assumptions underlying most of the models are justifiable. The exceptions are a) the rather simplistic approach taken in the Coastal Model and b) the lack of consideration of wild foods and age-dependence when calculating exposures of humans to radionuclides via dietary pathways. Most foreseeable processes appear to have been accounted for within the constraints of the models used, although it is recommended that attention be paid to future climate states when considering

  8. Toward an Integrated Competence-Based System Supporting Lifelong Learning and Employability: Concepts, Model, and Challenges

    Science.gov (United States)

    Miao, Yongwu; van der Klink, Marcel; Boon, Jo; Sloep, Peter; Koper, Rob

    Efficient and effective lifelong learning requires that people can make informed decisions about their continuous personal development in the different stages of their life. In this paper we state that lifelong learners need to be characterized as decision-makers. In order to improve the quality of their decisions, we propose the development of an integrated lifelong learning and employment support system, which traces learners’ competence development and provides a decision support environment. An abstract conceptual model has been developed and the main design ideas have been documented using Z notation. Moreover, we analyzed the main technical challenges for the realization of the target system: competence information fusion, decision analysis models, spatial indexing structures and browsing structures and visualization of competence-related information objects.

  9. The role of political affiliation in employment decisions: A model and research agenda.

    Science.gov (United States)

    Roth, Philip L; Goldberg, Caren B; Thatcher, Jason B

    2017-09-01

    Organizational researchers have studied how individuals identify with groups and organizations and how this affiliation influences behavior for decades (e.g., Tajfel, 1982). Interestingly, investigation into political affiliation and political affiliation similarity in the organizational sciences is extremely rare. This is striking, given the deep political divides that exist between groups of individuals described in the political science literature. We draw from theories based on similarity, organizational identification, and person-environment fit, as well as theoretical notions related to individuating information, to develop a model, the political affiliation model (PAM), which describes the implications of political affiliation and political similarity for employment decisions. We set forth a number of propositions based on PAM, to spur future research in the organizational sciences for a timely topic which has received little attention. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  10. The Anglo-Saxon model of employment in the current economic context. The case of United Kingdom

    OpenAIRE

    Mirela Ionela ACELEANU

    2012-01-01

    The Anglo-Saxon model of employment has certain features that derive from the specificity of the political and economic system of Great Britain. The labour market policies in the United Kingdom were different depending on the historical and political period; however, the Anglo-Saxon model is characterized mainly by high flexibility but low security. This paper presents the main features of the Anglo-Saxon model of employment, compared to the Nordic and the Mediterranean m...

  11. SLS Navigation Model-Based Design Approach

    Science.gov (United States)

    Oliver, T. Emerson; Anzalone, Evan; Geohagan, Kevin; Bernard, Bill; Park, Thomas

    2018-01-01

    The SLS Program chose to implement a Model-based Design and Model-based Requirements approach for managing component design information and system requirements. This approach differs from previous large-scale design efforts at Marshall Space Flight Center where design documentation alone conveyed information required for vehicle design and analysis and where extensive requirements sets were used to scope and constrain the design. The SLS Navigation Team has been responsible for the Program-controlled Design Math Models (DMMs) which describe and represent the performance of the Inertial Navigation System (INS) and the Rate Gyro Assemblies (RGAs) used by Guidance, Navigation, and Controls (GN&C). The SLS Navigation Team is also responsible for the navigation algorithms. The navigation algorithms are delivered for implementation on the flight hardware as a DMM. For the SLS Block 1-B design, the additional GPS Receiver hardware is managed as a DMM at the vehicle design level. This paper provides a discussion of the processes and methods used to engineer, design, and coordinate engineering trades and performance assessments using SLS practices as applied to the GN&C system, with a particular focus on the Navigation components. These include composing system requirements, requirements verification, model development, model verification and validation, and modeling and analysis approaches. The Model-based Design and Requirements approach does not reduce the effort associated with the design process versus previous processes used at Marshall Space Flight Center. Instead, the approach takes advantage of overlap between the requirements development and management process, and the design and analysis process by efficiently combining the control (i.e. the requirement) and the design mechanisms. The design mechanism is the representation of the component behavior and performance in design and analysis tools. The focus in the early design process shifts from the development and

  12. Hybrid Approach for Biliary Interventions Employing MRI-Guided Bile Duct Puncture with Near-Real-Time Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wybranski, Christian, E-mail: Christian.Wybranski@uk-koeln.de [University Hospital of Cologne, Department of Diagnostic and Interventional Radiology (Germany); Pech, Maciej [Otto-von-Guericke University Medical School, Department of Radiology and Nuclear Medicine (Germany); Lux, Anke [Otto-von-Guericke University Medical School, Institute of Biometry and Medical Informatics (Germany); Ricke, Jens; Fischbach, Frank; Fischbach, Katharina [Otto-von-Guericke University Medical School, Department of Radiology and Nuclear Medicine (Germany)

    2017-06-15

    ObjectiveTo assess the feasibility of a hybrid approach employing MRI-guided bile duct (BD) puncture for subsequent fluoroscopy-guided biliary interventions in patients with non-dilated (≤3 mm) or dilated BD (≥3 mm) but unfavorable conditions for ultrasonography (US)-guided BD puncture.MethodsA total of 23 hybrid interventions were performed in 21 patients. Visualization of BD and puncture needles (PN) in the interventional MR images was rated on a 5-point Likert scale by two radiologists. Technical success, planning time, BD puncture time and positioning adjustments of the PN as well as technical success of the biliary intervention and complication rate were recorded.ResultsVisualization even of third-order non-dilated BD and PN was rated excellent by both radiologists with good to excellent interrater agreement. MRI-guided BD puncture was successful in all cases. Planning and BD puncture times were 1:36 ± 2.13 (0:16–11:07) min. and 3:58 ± 2:35 (1:11–9:32) min. Positioning adjustments of the PN was necessary in two patients. Repeated capsular puncture was not necessary in any case. All biliary interventions were completed successfully without major complications.ConclusionA hybrid approach which employs MRI-guided BD puncture for subsequent fluoroscopy-guided biliary intervention is feasible in clinical routine and yields high technical success in patients with non-dilated BD and/or unfavorable conditions for US-guided puncture. Excellent visualization of BD and PN in near-real-time interventional MRI allows successful cannulation of the BD.

  13. Getting unemployed job seekers back to work: the development of a process model of employment counseling behavior

    NARCIS (Netherlands)

    Noordzij, G.; van Hooft, E.A.J.; van Mierlo, H.; van Dam, A.; Born, M.Ph.

    2013-01-01

    The aim of this study was to propose a tentative model of employment counseling based on 31 critical incident interviews with supervisors, employment counselors, and unemployed job seekers. The incidents (N= 599) mentioned in the interviews were inductively used to develop a category framework

  14. Increasing Employability by Implementing a Work-Integrated Learning Partnership Model in South Africa--A Student Perspective

    Science.gov (United States)

    Taylor, Susanne; Govender, Cookie M.

    2017-01-01

    In South Africa, 70 per cent of the population is under 35 years old. South Africa has a vision to increase youth employment by focusing on education, training and skills development that will promote employment opportunities. A work-integrated learning (WIL) partnership model was developed to provide students with work experience and to increase…

  15. Predictive models for the assessment of occupational exposure to chemicals: A new challenge for employers

    Directory of Open Access Journals (Sweden)

    Jan Piotr Gromiec

    2013-10-01

    Full Text Available Employers are obliged to carry out and document the risk associated with the use of chemical substances. The best but the most expensive method is to measure workplace concentrations of chemicals. At present no "measureless" method for risk assessment is available in Poland, but predictive models for such assessments have been developed in some countries. The purpose of this work is to review and evaluate the applicability of selected predictive methods for assessing occupational inhalation exposure and related risk to check the compliance with Occupational Exposure Limits (OELs, as well as the compliance with REACH obligations. Based on the literature data HSE COSHH Essentials, EASE, ECETOC TRA, Stoffenmanager, and EMKG-Expo-Tool were evaluated. The data on validation of predictive models were also examined. It seems that predictive models may be used as a useful method for Tier 1 assessment of occupational exposure by inhalation. Since the levels of exposure are frequently overestimated, they should be considered as "rational worst cases" for selection of proper control measures. Bearing in mind that the number of available exposure scenarios and PROC categories is limited, further validation by field surveys is highly recommended. Predictive models may serve as a good tool for preliminary risk assessment and selection of the most appropriate risk control measures in Polish small and medium size enterprises (SMEs providing that they are available in the Polish language. This also requires an extensive training of their future users. Med Pr 2013;64(5:699–716

  16. A Conceptual Modeling Approach for OLAP Personalization

    Science.gov (United States)

    Garrigós, Irene; Pardillo, Jesús; Mazón, Jose-Norberto; Trujillo, Juan

    Data warehouses rely on multidimensional models in order to provide decision makers with appropriate structures to intuitively analyze data with OLAP technologies. However, data warehouses may be potentially large and multidimensional structures become increasingly complex to be understood at a glance. Even if a departmental data warehouse (also known as data mart) is used, these structures would be also too complex. As a consequence, acquiring the required information is more costly than expected and decision makers using OLAP tools may get frustrated. In this context, current approaches for data warehouse design are focused on deriving a unique OLAP schema for all analysts from their previously stated information requirements, which is not enough to lighten the complexity of the decision making process. To overcome this drawback, we argue for personalizing multidimensional models for OLAP technologies according to the continuously changing user characteristics, context, requirements and behaviour. In this paper, we present a novel approach to personalizing OLAP systems at the conceptual level based on the underlying multidimensional model of the data warehouse, a user model and a set of personalization rules. The great advantage of our approach is that a personalized OLAP schema is provided for each decision maker contributing to better satisfy their specific analysis needs. Finally, we show the applicability of our approach through a sample scenario based on our CASE tool for data warehouse development.

  17. Power system stability enhancement employing controllers based on a versatile modeling

    Science.gov (United States)

    Chung, Chi Yung

    Rapid advances in power electronics have made it both practicable and economic to design powerful thyristor-controlled devices, such as Flexible AC Transmission Systems (FACTS), for stability enhancements. The discrepancies of existing modeling approaches have limited the feasibility of handling these devices or designing its damping controller. In this thesis, a versatile and generalized approach to model standard power system components is proposed. The more systematic and realistic representation, accompanied by the development of powerful eigenvalue-analysis techniques, facilitates the study of small signal stability (monotonic and oscillatory) of the power systems. In monotonic stability study, the effect of exciter and governor is critically reviewed based on the exploitation of eigenvalues, modal and sensitivity analyses over a wide range of operating conditions. In oscillatory stability study, a common FACTS device, the static var compensator (SVC), is used to improve system damping. This study reveals the inadequacy of many conventional methodologies in SVC design since they have ignored (or cannot handle) some important factors such as SVC mode instability and robustness of the power system. Two approaches, combined sensitivities and Hinfinity algorithms, are introduced to solve these limitations. Finally, an extended Hinfinity algorithm, which is applied to PSS design and successfully solves certain limitations of the existing H infinity based PSS design, is also presented. Although these studies are developed on selected controller devices or typical systems for convenience of discussion, extension to more complex systems can be dealt with in a similar way because of the versatility of the proposed modeling methodology.

  18. Neural network approaches for noisy language modeling.

    Science.gov (United States)

    Li, Jun; Ouazzane, Karim; Kazemian, Hassan B; Afzal, Muhammad Sajid

    2013-11-01

    Text entry from people is not only grammatical and distinct, but also noisy. For example, a user's typing stream contains all the information about the user's interaction with computer using a QWERTY keyboard, which may include the user's typing mistakes as well as specific vocabulary, typing habit, and typing performance. In particular, these features are obvious in disabled users' typing streams. This paper proposes a new concept called noisy language modeling by further developing information theory and applies neural networks to one of its specific application-typing stream. This paper experimentally uses a neural network approach to analyze the disabled users' typing streams both in general and specific ways to identify their typing behaviors and subsequently, to make typing predictions and typing corrections. In this paper, a focused time-delay neural network (FTDNN) language model, a time gap model, a prediction model based on time gap, and a probabilistic neural network model (PNN) are developed. A 38% first hitting rate (HR) and a 53% first three HR in symbol prediction are obtained based on the analysis of a user's typing history through the FTDNN language modeling, while the modeling results using the time gap prediction model and the PNN model demonstrate that the correction rates lie predominantly in between 65% and 90% with the current testing samples, and 70% of all test scores above basic correction rates, respectively. The modeling process demonstrates that a neural network is a suitable and robust language modeling tool to analyze the noisy language stream. The research also paves the way for practical application development in areas such as informational analysis, text prediction, and error correction by providing a theoretical basis of neural network approaches for noisy language modeling.

  19. Heat transfer modeling an inductive approach

    CERN Document Server

    Sidebotham, George

    2015-01-01

    This innovative text emphasizes a "less-is-more" approach to modeling complicated systems such as heat transfer by treating them first as "1-node lumped models" that yield simple closed-form solutions. The author develops numerical techniques for students to obtain more detail, but also trains them to use the techniques only when simpler approaches fail. Covering all essential methods offered in traditional texts, but with a different order, Professor Sidebotham stresses inductive thinking and problem solving as well as a constructive understanding of modern, computer-based practice. Readers learn to develop their own code in the context of the material, rather than just how to use packaged software, offering a deeper, intrinsic grasp behind models of heat transfer. Developed from over twenty-five years of lecture notes to teach students of mechanical and chemical engineering at The Cooper Union for the Advancement of Science and Art, the book is ideal for students and practitioners across engineering discipl...

  20. Fuzzy clustering: critical analysis of the contextual mechanisms employed by three neural network models

    Science.gov (United States)

    Baraldi, Andrea; Parmiggiani, Flavio

    1996-06-01

    According to the following definition, taken from the literature, a fuzzy clustering mechanism allows the same input pattern to belong to multiple categories to different degrees. Many clustering neural network (NN) models claim to feature fuzzy properties, but several of them (like the Fuzzy ART model) do not satisfy this definition. Vice versa, we believe that Kohonen's Self-Organizing Map, SOM, satisfies the definition provided above, even though this NN model is well-known to (robustly) perform topologically ordered mapping rather than fuzzy clustering. This may sound as a paradox if we consider that several fuzzy NN models (such as the Fuzzy Learning Vector Quantization, FLVQ, which was first called Fuzzy Kohonen Clustering Network, FKCN) were originally developed to enhance Kohonen's models (such as SOM and the vector quantization model, VQ). The fuzziness of SOM indicates that a network of processing elements (PEs) can verify the fuzzy clustering definition when it exploits local rules which are biologically plausible (such as the Kohonen bubble strategy). This is equivalent to state that the exploitation of the fuzzy set theory in the development of complex systems (e.g., clustering NNs) may provide new mathematical tools (e.g., the definition of membership function) to simulate the behavior of those cooperative/competitive mechanisms already identified by neurophysiological studies. When a biologically plausible cooperative/competitive strategy is pursued effectively, neighboring PEs become mutually coupled to gain sensitivity to contextual effects. PEs which are mutually coupled are affected by vertical (inter-layer) as well as horizontal (intra-layer) connections. To summarize, we suggest to relate the study of fuzzy clustering mechanisms to the multi-disciplinary science of complex systems, with special regard to the investigation of the cooperative/competitive local rules employed by complex systems to gain sensitivity to contextual effects in

  1. Employing Organizational Modeling and Simulation to Reduce F/A-18E/F F414 Engine Maintenance Time

    National Research Council Canada - National Science Library

    Hagan, Joel J; Slack, William G

    2006-01-01

    ...) at Naval Air Station (NAS) Lemoore, California. To achieve this goal, organizational modeling was employed to evaluate how changes to the organizational structure of the Lemoore AIMD affected engine throughput time...

  2. A multiscale modeling approach for biomolecular systems

    Energy Technology Data Exchange (ETDEWEB)

    Bowling, Alan, E-mail: bowling@uta.edu; Haghshenas-Jaryani, Mahdi, E-mail: mahdi.haghshenasjaryani@mavs.uta.edu [The University of Texas at Arlington, Department of Mechanical and Aerospace Engineering (United States)

    2015-04-15

    This paper presents a new multiscale molecular dynamic model for investigating the effects of external interactions, such as contact and impact, during stepping and docking of motor proteins and other biomolecular systems. The model retains the mass properties ensuring that the result satisfies Newton’s second law. This idea is presented using a simple particle model to facilitate discussion of the rigid body model; however, the particle model does provide insights into particle dynamics at the nanoscale. The resulting three-dimensional model predicts a significant decrease in the effect of the random forces associated with Brownian motion. This conclusion runs contrary to the widely accepted notion that the motor protein’s movements are primarily the result of thermal effects. This work focuses on the mechanical aspects of protein locomotion; the effect ATP hydrolysis is estimated as internal forces acting on the mechanical model. In addition, the proposed model can be numerically integrated in a reasonable amount of time. Herein, the differences between the motion predicted by the old and new modeling approaches are compared using a simplified model of myosin V.

  3. Quasirelativistic quark model in quasipotential approach

    CERN Document Server

    Matveev, V A; Savrin, V I; Sissakian, A N

    2002-01-01

    The relativistic particles interaction is described within the frames of quasipotential approach. The presentation is based on the so called covariant simultaneous formulation of the quantum field theory, where by the theory is considered on the spatial-like three-dimensional hypersurface in the Minkowski space. Special attention is paid to the methods of plotting various quasipotentials as well as to the applications of the quasipotential approach to describing the characteristics of the relativistic particles interaction in the quark models, namely: the hadrons elastic scattering amplitudes, the mass spectra and widths mesons decays, the cross sections of the deep inelastic leptons scattering on the hadrons

  4. A new approach for developing adjoint models

    Science.gov (United States)

    Farrell, P. E.; Funke, S. W.

    2011-12-01

    Many data assimilation algorithms rely on the availability of gradients of misfit functionals, which can be efficiently computed with adjoint models. However, the development of an adjoint model for a complex geophysical code is generally very difficult. Algorithmic differentiation (AD, also called automatic differentiation) offers one strategy for simplifying this task: it takes the abstraction that a model is a sequence of primitive instructions, each of which may be differentiated in turn. While extremely successful, this low-level abstraction runs into time-consuming difficulties when applied to the whole codebase of a model, such as differentiating through linear solves, model I/O, calls to external libraries, language features that are unsupported by the AD tool, and the use of multiple programming languages. While these difficulties can be overcome, it requires a large amount of technical expertise and an intimate familiarity with both the AD tool and the model. An alternative to applying the AD tool to the whole codebase is to assemble the discrete adjoint equations and use these to compute the necessary gradients. With this approach, the AD tool must be applied to the nonlinear assembly operators, which are typically small, self-contained units of the codebase. The disadvantage of this approach is that the assembly of the discrete adjoint equations is still very difficult to perform correctly, especially for complex multiphysics models that perform temporal integration; as it stands, this approach is as difficult and time-consuming as applying AD to the whole model. In this work, we have developed a library which greatly simplifies and automates the alternate approach of assembling the discrete adjoint equations. We propose a complementary, higher-level abstraction to that of AD: that a model is a sequence of linear solves. The developer annotates model source code with library calls that build a 'tape' of the operators involved and their dependencies, and

  5. An equilibrium approach to modelling social interaction

    Science.gov (United States)

    Gallo, Ignacio

    2009-07-01

    The aim of this work is to put forward a statistical mechanics theory of social interaction, generalizing econometric discrete choice models. After showing the formal equivalence linking econometric multinomial logit models to equilibrium statical mechanics, a multi-population generalization of the Curie-Weiss model for ferromagnets is considered as a starting point in developing a model capable of describing sudden shifts in aggregate human behaviour. Existence of the thermodynamic limit for the model is shown by an asymptotic sub-additivity method and factorization of correlation functions is proved almost everywhere. The exact solution of the model is provided in the thermodynamical limit by finding converging upper and lower bounds for the system's pressure, and the solution is used to prove an analytic result regarding the number of possible equilibrium states of a two-population system. The work stresses the importance of linking regimes predicted by the model to real phenomena, and to this end it proposes two possible procedures to estimate the model's parameters starting from micro-level data. These are applied to three case studies based on census type data: though these studies are found to be ultimately inconclusive on an empirical level, considerations are drawn that encourage further refinements of the chosen modelling approach.

  6. Full experimental modelling of a liver tissue mimicking phantom for medical ultrasound studies employing different hydrogels.

    Science.gov (United States)

    Casciaro, Sergio; Conversano, Francesco; Musio, Stefano; Casciaro, Ernesto; Demitri, Christian; Sannino, Alessandro

    2009-04-01

    Tissue mimicking phantoms have been widely reported to be an important tool for development, optimisation and performance testing of ultrasound-based diagnostic techniques. In particular, modern applications of tissue mimicking phantoms often include characterisation of the nonlinear behaviour of experimental ultrasound contrast agents. In such cases, the tissue-mimicking materials should be chosen not only based on the values of their density, speed of sound and attenuation coefficient, but also considering their effect on the appearance of "native harmonics" due to nonlinear distortion of ultrasound signal during propagation. In a previous paper it was demonstrated that a cellulose-based hydrogel is suitable to simulate nonlinear acoustical behaviour of liver tissue for thicknesses up to 8 cm. In this paper we present the experimental characterisation of the nonlinear acoustical behaviour of a different polyethylene glycol diacrylate (PEGDA)-based hydrogel, in order to assess whether and how it can improve the performances and overcome some limitations of the cellulose-based hydrogel as liver tissue-mimicking material. Samples of pig liver tissue, cellulose-based hydrogel and PEGDA-based hydrogel were insonified in a through-transmission set-up, employing 2.25-MHz pulses with different mechanical index (MI) values. Second harmonic and first harmonic amplitudes were extracted from the spectra of received signals and their difference was then used to compare sample behaviours. Obtained results show how a new more accurate and combined experimental model of linear and nonlinear acoustical behaviour of liver tissue is feasible. In fact, a further confirmation of the cellulose-based hydrogel effectiveness to precisely simulate the liver tissue for penetration depths up to 8 cm was provided, and it was also shown that the employment of the PEGDA-based hydrogel can extend the range of useful tissue-mimicking material thicknesses up to 11 cm, moreover allowing a

  7. Evolutionary modeling-based approach for model errors correction

    Directory of Open Access Journals (Sweden)

    S. Q. Wan

    2012-08-01

    Full Text Available The inverse problem of using the information of historical data to estimate model errors is one of the science frontier research topics. In this study, we investigate such a problem using the classic Lorenz (1963 equation as a prediction model and the Lorenz equation with a periodic evolutionary function as an accurate representation of reality to generate "observational data."

    On the basis of the intelligent features of evolutionary modeling (EM, including self-organization, self-adaptive and self-learning, the dynamic information contained in the historical data can be identified and extracted by computer automatically. Thereby, a new approach is proposed to estimate model errors based on EM in the present paper. Numerical tests demonstrate the ability of the new approach to correct model structural errors. In fact, it can actualize the combination of the statistics and dynamics to certain extent.

  8. Ecotoxicological modelling of cosmetics for aquatic organisms: A QSTR approach.

    Science.gov (United States)

    Khan, K; Roy, K

    2017-07-01

    In this study, externally validated quantitative structure-toxicity relationship (QSTR) models were developed for toxicity of cosmetic ingredients on three different ecotoxicologically relevant organisms, namely Pseudokirchneriella subcapitata, Daphnia magna and Pimephales promelas following the OECD guidelines. The final models were developed by partial least squares (PLS) regression technique, which is more robust than multiple linear regression. The obtained model for P. subcapitata shows that molecular size and complexity have significant impacts on the toxicity of cosmetics. In case of P. promelas and D. magna, we found that the largest contribution to the toxicity was shown by hydrophobicity and van der Waals surface area, respectively. All models were validated using both internal and test compounds employing multiple strategies. For each QSTR model, applicability domain studies were also performed using the "Distance to Model in X-space" method. A comparison was made with the ECOSAR predictions in order to prove the good predictive performances of our developed models. Finally, individual models were applied to predict toxicity for an external set of 596 personal care products having no experimental data for at least one of the endpoints, and the compounds were ranked based on a decreasing order of toxicity using a scaling approach.

  9. MODELS OF TECHNOLOGY ADOPTION: AN INTEGRATIVE APPROACH

    Directory of Open Access Journals (Sweden)

    Andrei OGREZEANU

    2015-06-01

    Full Text Available The interdisciplinary study of information technology adoption has developed rapidly over the last 30 years. Various theoretical models have been developed and applied such as: the Technology Acceptance Model (TAM, Innovation Diffusion Theory (IDT, Theory of Planned Behavior (TPB, etc. The result of these many years of research is thousands of contributions to the field, which, however, remain highly fragmented. This paper develops a theoretical model of technology adoption by integrating major theories in the field: primarily IDT, TAM, and TPB. To do so while avoiding mess, an approach that goes back to basics in independent variable type’s development is proposed; emphasizing: 1 the logic of classification, and 2 psychological mechanisms behind variable types. Once developed these types are then populated with variables originating in empirical research. Conclusions are developed on which types are underpopulated and present potential for future research. I end with a set of methodological recommendations for future application of the model.

  10. Interfacial Fluid Mechanics A Mathematical Modeling Approach

    CERN Document Server

    Ajaev, Vladimir S

    2012-01-01

    Interfacial Fluid Mechanics: A Mathematical Modeling Approach provides an introduction to mathematical models of viscous flow used in rapidly developing fields of microfluidics and microscale heat transfer. The basic physical effects are first introduced in the context of simple configurations and their relative importance in typical microscale applications is discussed. Then,several configurations of importance to microfluidics, most notably thin films/droplets on substrates and confined bubbles, are discussed in detail.  Topics from current research on electrokinetic phenomena, liquid flow near structured solid surfaces, evaporation/condensation, and surfactant phenomena are discussed in the later chapters. This book also:  Discusses mathematical models in the context of actual applications such as electrowetting Includes unique material on fluid flow near structured surfaces and phase change phenomena Shows readers how to solve modeling problems related to microscale multiphase flows Interfacial Fluid Me...

  11. Continuum modeling an approach through practical examples

    CERN Document Server

    Muntean, Adrian

    2015-01-01

    This book develops continuum modeling skills and approaches the topic from three sides: (1) derivation of global integral laws together with the associated local differential equations, (2) design of constitutive laws and (3) modeling boundary processes. The focus of this presentation lies on many practical examples covering aspects such as coupled flow, diffusion and reaction in porous media or microwave heating of a pizza, as well as traffic issues in bacterial colonies and energy harvesting from geothermal wells. The target audience comprises primarily graduate students in pure and applied mathematics as well as working practitioners in engineering who are faced by nonstandard rheological topics like those typically arising in the food industry.

  12. The Anglo-Saxon model of employment in the current economic context. The case of United Kingdom

    Directory of Open Access Journals (Sweden)

    Mirela Ionela ACELEANU

    2012-11-01

    Full Text Available The Anglo-Saxon model of employment has certain features that derive from the specificity of the political and economic system of Great Britain. The labour market policies in the United Kingdom were different depending on the historical and political period; however, the Anglo-Saxon model is characterized mainly by high flexibility but low security. This paper presents the main features of the Anglo-Saxon model of employment, compared to the Nordic and the Mediterranean model and shows Britain's economic situation before and after the crisis.

  13. Fusion modeling approach for novel plasma sources

    International Nuclear Information System (INIS)

    Melazzi, D; Manente, M; Pavarin, D; Cardinali, A

    2012-01-01

    The physics involved in the coupling, propagation and absorption of RF helicon waves (electronic whistler) in low temperature Helicon plasma sources is investigated by solving the 3D Maxwell-Vlasov model equations using a WKB asymptotic expansion. The reduced set of equations is formally Hamiltonian and allows for the reconstruction of the wave front of the propagating wave, monitoring along the calculation that the WKB expansion remains satisfied. This method can be fruitfully employed in a new investigation of the power deposition mechanisms involved in common Helicon low temperature plasma sources when a general confinement magnetic field configuration is allowed, unveiling new physical insight in the wave propagation and absorption phenomena and stimulating further research for the design of innovative and more efficient low temperature plasma sources. A brief overview of this methodology and its capabilities has been presented in this paper.

  14. Datamining approaches for modeling tumor control probability.

    Science.gov (United States)

    Naqa, Issam El; Deasy, Joseph O; Mu, Yi; Huang, Ellen; Hope, Andrew J; Lindsay, Patricia E; Apte, Aditya; Alaly, James; Bradley, Jeffrey D

    2010-11-01

    Tumor control probability (TCP) to radiotherapy is determined by complex interactions between tumor biology, tumor microenvironment, radiation dosimetry, and patient-related variables. The complexity of these heterogeneous variable interactions constitutes a challenge for building predictive models for routine clinical practice. We describe a datamining framework that can unravel the higher order relationships among dosimetric dose-volume prognostic variables, interrogate various radiobiological processes, and generalize to unseen data before when applied prospectively. Several datamining approaches are discussed that include dose-volume metrics, equivalent uniform dose, mechanistic Poisson model, and model building methods using statistical regression and machine learning techniques. Institutional datasets of non-small cell lung cancer (NSCLC) patients are used to demonstrate these methods. The performance of the different methods was evaluated using bivariate Spearman rank correlations (rs). Over-fitting was controlled via resampling methods. Using a dataset of 56 patients with primary NCSLC tumors and 23 candidate variables, we estimated GTV volume and V75 to be the best model parameters for predicting TCP using statistical resampling and a logistic model. Using these variables, the support vector machine (SVM) kernel method provided superior performance for TCP prediction with an rs=0.68 on leave-one-out testing compared to logistic regression (rs=0.4), Poisson-based TCP (rs=0.33), and cell kill equivalent uniform dose model (rs=0.17). The prediction of treatment response can be improved by utilizing datamining approaches, which are able to unravel important non-linear complex interactions among model variables and have the capacity to predict on unseen data for prospective clinical applications.

  15. ISM Approach to Model Offshore Outsourcing Risks

    Directory of Open Access Journals (Sweden)

    Sunand Kumar

    2014-07-01

    Full Text Available In an effort to achieve a competitive advantage via cost reductions and improved market responsiveness, organizations are increasingly employing offshore outsourcing as a major component of their supply chain strategies. But as evident from literature number of risks such as Political risk, Risk due to cultural differences, Compliance and regulatory risk, Opportunistic risk and Organization structural risk, which adversely affect the performance of offshore outsourcing in a supply chain network. This also leads to dissatisfaction among different stake holders. The main objective of this paper is to identify and understand the mutual interaction among various risks which affect the performance of offshore outsourcing.  To this effect, authors have identified various risks through extant review of literature.  From this information, an integrated model using interpretive structural modelling (ISM for risks affecting offshore outsourcing is developed and the structural relationships between these risks are modeled.  Further, MICMAC analysis is done to analyze the driving power and dependency of risks which shall be helpful to managers to identify and classify important criterions and to reveal the direct and indirect effects of each criterion on offshore outsourcing. Results show that political risk and risk due to cultural differences are act as strong drivers.

  16. Enthalpy-based equation of state for highly porous materials employing modified soft sphere fluid model

    Science.gov (United States)

    Nayak, Bishnupriya; Menon, S. V. G.

    2018-01-01

    Enthalpy-based equation of state based on a modified soft sphere model for the fluid phase, which includes vaporization and ionization effects, is formulated for highly porous materials. Earlier developments and applications of enthalpy-based approach had not accounted for the fact that shocked states of materials with high porosity (e.g., porosity more than two for Cu) are in the expanded fluid region. We supplement the well known soft sphere model with a generalized Lennard-Jones formula for the zero temperature isotherm, with parameters determined from cohesive energy, specific volume and bulk modulus of the solid at normal condition. Specific heats at constant pressure, ionic and electronic enthalpy parameters and thermal excitation effects are calculated using the modified approach and used in the enthalpy-based equation of state. We also incorporate energy loss from the shock due to expansion of shocked material in calculating porous Hugoniot. Results obtained for Cu, even up to initial porosities ten, show good agreement with experimental data.

  17. Experimental validation of convection-diffusion discretisation scheme employed for computational modelling of biological mass transport

    Directory of Open Access Journals (Sweden)

    Ku David N

    2010-07-01

    Full Text Available Abstract Background The finite volume solver Fluent (Lebanon, NH, USA is a computational fluid dynamics software employed to analyse biological mass-transport in the vasculature. A principal consideration for computational modelling of blood-side mass-transport is convection-diffusion discretisation scheme selection. Due to numerous discretisation schemes available when developing a mass-transport numerical model, the results obtained should either be validated against benchmark theoretical solutions or experimentally obtained results. Methods An idealised aneurysm model was selected for the experimental and computational mass-transport analysis of species concentration due to its well-defined recirculation region within the aneurysmal sac, allowing species concentration to vary slowly with time. The experimental results were obtained from fluid samples extracted from a glass aneurysm model, using the direct spectrophometric concentration measurement technique. The computational analysis was conducted using the four convection-diffusion discretisation schemes available to the Fluent user, including the First-Order Upwind, the Power Law, the Second-Order Upwind and the Quadratic Upstream Interpolation for Convective Kinetics (QUICK schemes. The fluid has a diffusivity of 3.125 × 10-10 m2/s in water, resulting in a Peclet number of 2,560,000, indicating strongly convection-dominated flow. Results The discretisation scheme applied to the solution of the convection-diffusion equation, for blood-side mass-transport within the vasculature, has a significant influence on the resultant species concentration field. The First-Order Upwind and the Power Law schemes produce similar results. The Second-Order Upwind and QUICK schemes also correlate well but differ considerably from the concentration contour plots of the First-Order Upwind and Power Law schemes. The computational results were then compared to the experimental findings. An average error of 140

  18. Experimental validation of convection-diffusion discretisation scheme employed for computational modelling of biological mass transport.

    Science.gov (United States)

    Carroll, Gráinne T; Devereux, Paul D; Ku, David N; McGloughlin, Timothy M; Walsh, Michael T

    2010-07-19

    The finite volume solver Fluent (Lebanon, NH, USA) is a computational fluid dynamics software employed to analyse biological mass-transport in the vasculature. A principal consideration for computational modelling of blood-side mass-transport is convection-diffusion discretisation scheme selection. Due to numerous discretisation schemes available when developing a mass-transport numerical model, the results obtained should either be validated against benchmark theoretical solutions or experimentally obtained results. An idealised aneurysm model was selected for the experimental and computational mass-transport analysis of species concentration due to its well-defined recirculation region within the aneurysmal sac, allowing species concentration to vary slowly with time. The experimental results were obtained from fluid samples extracted from a glass aneurysm model, using the direct spectrophometric concentration measurement technique. The computational analysis was conducted using the four convection-diffusion discretisation schemes available to the Fluent user, including the First-Order Upwind, the Power Law, the Second-Order Upwind and the Quadratic Upstream Interpolation for Convective Kinetics (QUICK) schemes. The fluid has a diffusivity of 3.125 x 10-10 m2/s in water, resulting in a Peclet number of 2,560,000, indicating strongly convection-dominated flow. The discretisation scheme applied to the solution of the convection-diffusion equation, for blood-side mass-transport within the vasculature, has a significant influence on the resultant species concentration field. The First-Order Upwind and the Power Law schemes produce similar results. The Second-Order Upwind and QUICK schemes also correlate well but differ considerably from the concentration contour plots of the First-Order Upwind and Power Law schemes. The computational results were then compared to the experimental findings. An average error of 140% and 116% was demonstrated between the experimental

  19. Crime Modeling using Spatial Regression Approach

    Science.gov (United States)

    Saleh Ahmar, Ansari; Adiatma; Kasim Aidid, M.

    2018-01-01

    Act of criminality in Indonesia increased both variety and quantity every year. As murder, rape, assault, vandalism, theft, fraud, fencing, and other cases that make people feel unsafe. Risk of society exposed to crime is the number of reported cases in the police institution. The higher of the number of reporter to the police institution then the number of crime in the region is increasing. In this research, modeling criminality in South Sulawesi, Indonesia with the dependent variable used is the society exposed to the risk of crime. Modelling done by area approach is the using Spatial Autoregressive (SAR) and Spatial Error Model (SEM) methods. The independent variable used is the population density, the number of poor population, GDP per capita, unemployment and the human development index (HDI). Based on the analysis using spatial regression can be shown that there are no dependencies spatial both lag or errors in South Sulawesi.

  20. Importance, Approaches and Organizational Framework of Employer and Behavioral Branding within Companies: Results of an Exploratory Empirical Study

    OpenAIRE

    Regine Kalka; Dorothee Lux

    2011-01-01

    The company’s success depends much on the employees contribute. But finding the right employees and tie them to the company over a long period is not easy. The competition on the job market becomes harder and harder. Also the conceptions concerning the ideal employer are becoming much more defined. In theory employer branding takes part. It is a concept of building an employer brand to find the best employee out of the fitting ones and to tie those best employees to the company. Employer bran...

  1. A multi-model ensemble approach to seabed mapping

    Science.gov (United States)

    Diesing, Markus; Stephens, David

    2015-06-01

    Seabed habitat mapping based on swath acoustic data and ground-truth samples is an emergent and active marine science discipline. Significant progress could be achieved by transferring techniques and approaches that have been successfully developed and employed in such fields as terrestrial land cover mapping. One such promising approach is the multiple classifier system, which aims at improving classification performance by combining the outputs of several classifiers. Here we present results of a multi-model ensemble applied to multibeam acoustic data covering more than 5000 km2 of seabed in the North Sea with the aim to derive accurate spatial predictions of seabed substrate. A suite of six machine learning classifiers (k-Nearest Neighbour, Support Vector Machine, Classification Tree, Random Forest, Neural Network and Naïve Bayes) was trained with ground-truth sample data classified into seabed substrate classes and their prediction accuracy was assessed with an independent set of samples. The three and five best performing models were combined to classifier ensembles. Both ensembles led to increased prediction accuracy as compared to the best performing single classifier. The improvements were however not statistically significant at the 5% level. Although the three-model ensemble did not perform significantly better than its individual component models, we noticed that the five-model ensemble did perform significantly better than three of the five component models. A classifier ensemble might therefore be an effective strategy to improve classification performance. Another advantage is the fact that the agreement in predicted substrate class between the individual models of the ensemble could be used as a measure of confidence. We propose a simple and spatially explicit measure of confidence that is based on model agreement and prediction accuracy.

  2. Social Informatics: Natural Tools for Students' Information Training in The Conditions of Embodied and Mental Approaches Being Employed

    Directory of Open Access Journals (Sweden)

    Daria Barkhatova

    2017-09-01

    Full Text Available The relevance of the problem under study is due to the society's requirements for the quality information training of a personality which is oriented to forming the solid fundamental knowledge as well as to developing the cognitive capacities that are needed for solving mental tasks. With regard to this, the paper is aimed at finding out the opportunities of applying the natural tools in information training of students from the standpoints of embodied and mental approaches. The main idea of these is integrated studying of an object, beginning with learning it in an "embodied" way and finishing with abstract models formed in the human memory. The leading approach to the research is the integrated one taking into account the psychological and pedagogical, didactic and methodological constituents. It allows identifying the psychological and pedagogical conditions of application of natural tools as well as the possible ways of their use. The authors describe models of natural tools of computer science training in individual sections of the school course as the main results. The materials of the paper are of practical value in methods of teaching computer science to students at various stages of education.

  3. Building Professionalism and Employability Skills: Embedding Employer Engagement within First-Year Computing Modules

    Science.gov (United States)

    Hanna, Philip; Allen, Angela; Kane, Russell; Anderson, Neil; McGowan, Aidan; Collins, Matthew; Hutchison, Malcolm

    2015-01-01

    This paper outlines a means of improving the employability skills of first-year university students through a closely integrated model of employer engagement within computer science modules. The outlined approach illustrates how employability skills, including communication, teamwork and time management skills, can be contextualised in a manner…

  4. Analysis of thermoluminescence kinetics of Mg2SiO4:Tb compounds employing an interactive model

    International Nuclear Information System (INIS)

    Marcazzo, J.; Prokic, M.; Santiago, M.; Molina, P.; Caselli, E.

    2009-01-01

    The kinetics involved in the thermoluminescence (TL) of Mg 2 SiO 4 :Tb compounds has been investigated by unfolding glow curves employing both the General Order model and a model that takes into account interactions among traps. The dependence of the glow curve shape on dose is only correctly described if interaction among traps is included in the analysis.

  5. The Menu Approach to supported employment for individuals with severe and persistent mental illness: Outcomes in an Oregon community based program.

    Science.gov (United States)

    Roush, Sean

    2009-01-01

    The purpose of this study was to determine the vocational outcomes at the Abacus Program, a Menu Approach supported employment program designed to assist individuals with serious mental illness (SMI) achieve competitive employment. A summative evaluation method was used to determine the vocational outcomes between the years 2000-2006 at the Abacus Program. Data was gathered from existing Abacus Program records and the Statistical Package for the Social Sciences (SPSS) 15.0 was used to calculate outcomes. The Abacus Program served 264 clients during the study period. Within those clients, there were 140 cases of vocational services that met study criteria which resulted in 83 successful instances of employment (59%). Initial data from a single site indicate that the Menu Approach to supported employment produces successful employment outcomes comparable to other published studies. Further research is warranted in order to confirm the initial results of this study in other settings. Randomized controlled trials should be conducted in order to compare the outcomes of the Menu Approach to other methods of providing supported employment services to individuals with SMI.

  6. A Modeling Approach for Marine Observatory

    Directory of Open Access Journals (Sweden)

    Charbel Geryes Aoun

    2015-02-01

    Full Text Available Infrastructure of Marine Observatory (MO is an UnderWater Sensor Networks (UW-SN to perform collaborative monitoring tasks over a given area. This observation should take into consideration the environmental constraints since it may require specific tools, materials and devices (cables, servers, etc.. The logical and physical components that are used in these observatories provide data exchanged between the various devices of the environment (Smart Sensor, Data Fusion. These components provide new functionalities or services due to the long period running of the network. In this paper, we present our approach in extending the modeling languages to include new domain- specific concepts and constraints. Thus, we propose a meta-model that is used to generate a new design tool (ArchiMO. We illustrate our proposal with an example from the MO domain on object localization with several acoustics sensors. Additionally, we generate the corresponding simulation code for a standard network simulator using our self-developed domain-specific model compiler. Our approach helps to reduce the complexity and time of the design activity of a Marine Observatory. It provides a way to share the different viewpoints of the designers in the MO domain and obtain simulation results to estimate the network capabilities.

  7. Implicit moral evaluations: A multinomial modeling approach.

    Science.gov (United States)

    Cameron, C Daryl; Payne, B Keith; Sinnott-Armstrong, Walter; Scheffer, Julian A; Inzlicht, Michael

    2017-01-01

    Implicit moral evaluations-i.e., immediate, unintentional assessments of the wrongness of actions or persons-play a central role in supporting moral behavior in everyday life. Yet little research has employed methods that rigorously measure individual differences in implicit moral evaluations. In five experiments, we develop a new sequential priming measure-the Moral Categorization Task-and a multinomial model that decomposes judgment on this task into multiple component processes. These include implicit moral evaluations of moral transgression primes (Unintentional Judgment), accurate moral judgments about target actions (Intentional Judgment), and a directional tendency to judge actions as morally wrong (Response Bias). Speeded response deadlines reduced Intentional Judgment but not Unintentional Judgment (Experiment 1). Unintentional Judgment was stronger toward moral transgression primes than non-moral negative primes (Experiments 2-4). Intentional Judgment was associated with increased error-related negativity, a neurophysiological indicator of behavioral control (Experiment 4). Finally, people who voted for an anti-gay marriage amendment had stronger Unintentional Judgment toward gay marriage primes (Experiment 5). Across Experiments 1-4, implicit moral evaluations converged with moral personality: Unintentional Judgment about wrong primes, but not negative primes, was negatively associated with psychopathic tendencies and positively associated with moral identity and guilt proneness. Theoretical and practical applications of formal modeling for moral psychology are discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. A nationwide modelling approach to decommissioning - 16182

    International Nuclear Information System (INIS)

    Kelly, Bernard; Lowe, Andy; Mort, Paul

    2009-01-01

    In this paper we describe a proposed UK national approach to modelling decommissioning. For the first time, we shall have an insight into optimizing the safety and efficiency of a national decommissioning strategy. To do this we use the General Case Integrated Waste Algorithm (GIA), a universal model of decommissioning nuclear plant, power plant, waste arisings and the associated knowledge capture. The model scales from individual items of plant through cells, groups of cells, buildings, whole sites and then on up to a national scale. We describe the national vision for GIA which can be broken down into three levels: 1) the capture of the chronological order of activities that an experienced decommissioner would use to decommission any nuclear facility anywhere in the world - this is Level 1 of GIA; 2) the construction of an Operational Research (OR) model based on Level 1 to allow rapid what if scenarios to be tested quickly (Level 2); 3) the construction of a state of the art knowledge capture capability that allows future generations to learn from our current decommissioning experience (Level 3). We show the progress to date in developing GIA in levels 1 and 2. As part of level 1, GIA has assisted in the development of an IMechE professional decommissioning qualification. Furthermore, we describe GIA as the basis of a UK-Owned database of decommissioning norms for such things as costs, productivity, durations etc. From level 2, we report on a pilot study that has successfully tested the basic principles for the OR numerical simulation of the algorithm. We then highlight the advantages of applying the OR modelling approach nationally. In essence, a series of 'what if...' scenarios can be tested that will improve the safety and efficiency of decommissioning. (authors)

  9. Modeling in transport phenomena a conceptual approach

    CERN Document Server

    Tosun, Ismail

    2007-01-01

    Modeling in Transport Phenomena, Second Edition presents and clearly explains with example problems the basic concepts and their applications to fluid flow, heat transfer, mass transfer, chemical reaction engineering and thermodynamics. A balanced approach is presented between analysis and synthesis, students will understand how to use the solution in engineering analysis. Systematic derivations of the equations and the physical significance of each term are given in detail, for students to easily understand and follow up the material. There is a strong incentive in science and engineering to

  10. Model approach brings multi-level success.

    Science.gov (United States)

    Howell, Mark

    2012-08-01

    n an article that first appeared in US magazine, Medical Construction & Design, Mark Howell, senior vice-president of Skanska USA Building, based in Seattle, describes the design and construction of a new nine-storey, 350,000 ft2 extension to the Good Samaritan Hospital in Puyallup, Washington state. He explains how the use of an Integrated Project Delivery (IPD) approach by the key players, and extensive use of building information modelling (BIM), combined to deliver a healthcare facility that he believes should meet the needs of patients, families, and the clinical care team, 'well into the future'.

  11. PROCRU: A model for analyzing crew procedures in approach to landing

    Science.gov (United States)

    Baron, S.; Muralidharan, R.; Lancraft, R.; Zacharias, G.

    1980-01-01

    A model for analyzing crew procedures in approach to landing is developed. The model employs the information processing structure used in the optimal control model and in recent models for monitoring and failure detection. Mechanisms are added to this basic structure to model crew decision making in this multi task environment. Decisions are based on probability assessments and potential mission impact (or gain). Sub models for procedural activities are included. The model distinguishes among external visual, instrument visual, and auditory sources of information. The external visual scene perception models incorporate limitations in obtaining information. The auditory information channel contains a buffer to allow for storage in memory until that information can be processed.

  12. Pedagogic process modeling: Humanistic-integrative approach

    Directory of Open Access Journals (Sweden)

    Boritko Nikolaj M.

    2007-01-01

    Full Text Available The paper deals with some current problems of modeling the dynamics of the subject-features development of the individual. The term "process" is considered in the context of the humanistic-integrative approach, in which the principles of self education are regarded as criteria for efficient pedagogic activity. Four basic characteristics of the pedagogic process are pointed out: intentionality reflects logicality and regularity of the development of the process; discreteness (stageability in dicates qualitative stages through which the pedagogic phenomenon passes; nonlinearity explains the crisis character of pedagogic processes and reveals inner factors of self-development; situationality requires a selection of pedagogic conditions in accordance with the inner factors, which would enable steering the pedagogic process. Offered are two steps for singling out a particular stage and the algorithm for developing an integrative model for it. The suggested conclusions might be of use for further theoretic research, analyses of educational practices and for realistic predicting of pedagogical phenomena. .

  13. Learning at the workplace and sustainable employability: a multi-source model moderated by age

    NARCIS (Netherlands)

    van der Heijden, Beatrice; Gorgievski, Marjan J.; de Lange, Annet H.

    2015-01-01

    This study, among 330 pairs of employees and their supervisors, tested whether self- versus supervisor ratings of five employability dimensions (occupational expertise, corporate sense, personal flexibility, anticipation and optimization, and balance) are associated with different learning

  14. Student employment

    DEFF Research Database (Denmark)

    Jacob, Marita; Gerth, Maria; Weiss, Felix

    2018-01-01

    In this article, we examine social origin differences in employment patterns across different stages of higher education and compare these differences between vocational and academic fields of study. Using data from a large-scale German student survey, we study the development of inequality, acco...... decrease as students progress through higher education. While we find evidence for this hypothesis, we also show in multivariate models that the reduction of inequality in the student labour market is explained by prior differences between social origin groups.......In this article, we examine social origin differences in employment patterns across different stages of higher education and compare these differences between vocational and academic fields of study. Using data from a large-scale German student survey, we study the development of inequality...

  15. Diversity detection in non-Gaussian noise employing the generalized approach to signal processing in noise with fading diversity channels

    Science.gov (United States)

    Tuzlukov, Vyacheslav

    2011-06-01

    In this paper, we consider the problem of M-ary signal detection based on the generalized approach to signal processing (GASP) in noise over a single-input multiple-output (SIMO) channel affected by frequency-dispersive Rayleigh distributed fading and corrupted by additive non-Gaussian noise modeled as spherically invariant random process. We derive both the optimum generalized detector (GD) structure based on GASP and a suboptimal reduced-complexity GD applying the low energy coherence approach jointly with the GASP in noise. Both GD structures are independent of the actual noise statistics. We also carry out a performance analysis of both GDs and compare with the conventional receivers. The performance analysis is carried out with reference to the case that the channel is affected by a frequency-selective fading and for a binary frequency-shift keying (BFSK) signaling format. The results obtained through both a Chernoff-bounding technique and Monte Carlo simulations reveal that the adoption of diversity also represents a suitable means to restore performance in the presence of dispersive fading and impulsive non-Gaussian noise. It is also shown that the suboptimal GD incurs a limited loss with respect to the optimum GD and this loss is less in comparison with the conventional receiver.

  16. Virtuous organization: A structural equation modeling approach

    Directory of Open Access Journals (Sweden)

    Majid Zamahani

    2013-02-01

    Full Text Available For years, the idea of virtue was unfavorable among researchers and virtues were traditionally considered as culture-specific, relativistic and they were supposed to be associated with social conservatism, religious or moral dogmatism, and scientific irrelevance. Virtue and virtuousness have been recently considered seriously among organizational researchers. The proposed study of this paper examines the relationships between leadership, organizational culture, human resource, structure and processes, care for community and virtuous organization. Structural equation modeling is employed to investigate the effects of each variable on other components. The data used in this study consists of questionnaire responses from employees in Payam e Noor University in Yazd province. A total of 250 questionnaires were sent out and a total of 211 valid responses were received. Our results have revealed that all the five variables have positive and significant impacts on virtuous organization. Among the five variables, organizational culture has the most direct impact (0.80 and human resource has the most total impact (0.844 on virtuous organization.

  17. Employee well-being, turnover intention and perceived employability : a psychological contract approach / L. van der Vaart.

    OpenAIRE

    Van der Vaart, Leoni

    2012-01-01

    The contemporary working environment is characterised by constant change and increased cognitive and emotional demands on employees. At the same time, long-term employment is no longer guaranteed and often employees are not loyal to one organisation throughout their careers. These changes alter and threaten the viability of the employment relationship. Employees still provide a competitive edge for organisations and their expectations should be managed in such a way that the current organisat...

  18. Overview of the FEP analysis approach to model development

    International Nuclear Information System (INIS)

    Bailey, L.

    1998-01-01

    This report heads a suite of documents describing the Nirex model development programme. The programme is designed to provide a clear audit trail from the identification of significant features, events and processes (FEPs) to the models and modelling processes employed within a detailed safety assessment. A five stage approach has been adopted, which provides a systematic framework for addressing uncertainty and for the documentation of all modelling decisions and assumptions. The five stages are as follows: Stage 1: EP Analysis - compilation and structuring of a FEP database; Stage 2: Scenario and Conceptual Model Development; Stage 3: Mathematical Model Development; Stage 4: Software Development; Stage 5: confidence Building. This report describes the development and structuring of a FEP database as a Master Directed Diagram (MDD) and explains how this may be used to identify different modelling scenarios, based upon the identification of scenario -defining FEPs. The methodology describes how the possible evolution of a repository system can be addressed in terms of a base scenario, a broad and reasonable representation of the 'natural' evolution of the system, and a number of variant scenarios, representing the effects of probabilistic events and processes. The MDD has been used to identify conceptual models to represent the base scenario and the interactions between these conceptual models have been systematically reviewed using a matrix diagram technique. This has led to the identification of modelling requirements for the base scenario, against which existing assessment software capabilities have been reviewed. A mechanism for combining probabilistic scenario-defining FEPs to construct multi-FEP variant scenarios has been proposed and trialled using the concept of a 'timeline', a defined sequence of events, from which consequences can be assessed. An iterative approach, based on conservative modelling principles, has been proposed for the evaluation of

  19. A new approach to modeling aviation accidents

    Science.gov (United States)

    Rao, Arjun Harsha

    views aviation accidents as a set of hazardous states of a system (pilot and aircraft), and triggers that cause the system to move between hazardous states. I used the NTSB's accident coding manual (that contains nearly 4000 different codes) to develop a "dictionary" of hazardous states, triggers, and information codes. Then, I created the "grammar", or a set of rules, that: (1) orders the hazardous states in each accident; and, (2) links the hazardous states using the appropriate triggers. This approach: (1) provides a more correct count of the causes for accidents in the NTSB database; and, (2) checks for gaps or omissions in NTSB accident data, and fills in some of these gaps using logic-based rules. These rules also help identify and count causes for accidents that were not discernable from previous analyses of historical accident data. I apply the model to 6200 helicopter accidents that occurred in the US between 1982 and 2015. First, I identify the states and triggers that are most likely to be associated with fatal and non-fatal accidents. The results suggest that non-fatal accidents, which account for approximately 84% of the accidents, provide valuable opportunities to learn about the causes for accidents. Next, I investigate the causes of inflight loss of control using both a conventional approach and using the state-based approach. The conventional analysis provides little insight into the causal mechanism for LOC. For instance, the top cause of LOC is "aircraft control/directional control not maintained", which does not provide any insight. In contrast, the state-based analysis showed that pilots' tendency to clip objects frequently triggered LOC (16.7% of LOC accidents)--this finding was not directly discernable from conventional analyses. Finally, I investigate the causes for improper autorotations using both a conventional approach and the state-based approach. The conventional approach uses modifiers (e.g., "improper", "misjudged") associated with "24520

  20. Towards intelligent diagnostic system employing integration of mathematical and engineering model

    Science.gov (United States)

    Isa, Nor Ashidi Mat

    2015-05-01

    The development of medical diagnostic system has been one of the main research fields during years. The goal of the medical diagnostic system is to place a nosological system that could ease the diagnostic evaluation normally performed by scientists and doctors. Efficient diagnostic evaluation is essentials and requires broad knowledge in order to improve conventional diagnostic system. Several approaches on developing the medical diagnostic system have been designed and tested since the earliest 60s. Attempts on improving their performance have been made which utilizes the fields of artificial intelligence, statistical analyses, mathematical model and engineering theories. With the availability of the microcomputer and software development as well as the promising aforementioned fields, medical diagnostic prototypes could be developed. In general, the medical diagnostic system consists of several stages, namely the 1) data acquisition, 2) feature extraction, 3) feature selection, and 4) classifications stages. Data acquisition stage plays an important role in converting the inputs measured from the real world physical conditions to the digital numeric values that can be manipulated by the computer system. One of the common medical inputs could be medical microscopic images, radiographic images, magnetic resonance image (MRI) as well as medical signals such as electrocardiogram (ECG) and electroencephalogram (EEG). Normally, the scientist or doctors have to deal with myriad of data and redundant to be processed. In order to reduce the complexity of the diagnosis process, only the significant features of the raw data such as peak value of the ECG signal or size of lesion in the mammogram images will be extracted and considered in the subsequent stages. Mathematical models and statistical analyses will be performed to select the most significant features to be classified. The statistical analyses such as principal component analysis and discriminant analysis as well

  1. Towards intelligent diagnostic system employing integration of mathematical and engineering model

    International Nuclear Information System (INIS)

    Isa, Nor Ashidi Mat

    2015-01-01

    The development of medical diagnostic system has been one of the main research fields during years. The goal of the medical diagnostic system is to place a nosological system that could ease the diagnostic evaluation normally performed by scientists and doctors. Efficient diagnostic evaluation is essentials and requires broad knowledge in order to improve conventional diagnostic system. Several approaches on developing the medical diagnostic system have been designed and tested since the earliest 60s. Attempts on improving their performance have been made which utilizes the fields of artificial intelligence, statistical analyses, mathematical model and engineering theories. With the availability of the microcomputer and software development as well as the promising aforementioned fields, medical diagnostic prototypes could be developed. In general, the medical diagnostic system consists of several stages, namely the 1) data acquisition, 2) feature extraction, 3) feature selection, and 4) classifications stages. Data acquisition stage plays an important role in converting the inputs measured from the real world physical conditions to the digital numeric values that can be manipulated by the computer system. One of the common medical inputs could be medical microscopic images, radiographic images, magnetic resonance image (MRI) as well as medical signals such as electrocardiogram (ECG) and electroencephalogram (EEG). Normally, the scientist or doctors have to deal with myriad of data and redundant to be processed. In order to reduce the complexity of the diagnosis process, only the significant features of the raw data such as peak value of the ECG signal or size of lesion in the mammogram images will be extracted and considered in the subsequent stages. Mathematical models and statistical analyses will be performed to select the most significant features to be classified. The statistical analyses such as principal component analysis and discriminant analysis as well

  2. Towards intelligent diagnostic system employing integration of mathematical and engineering model

    Energy Technology Data Exchange (ETDEWEB)

    Isa, Nor Ashidi Mat [Imaging and Intelligent System Research Team (ISRT), School of Electrical and Electronic Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)

    2015-05-15

    The development of medical diagnostic system has been one of the main research fields during years. The goal of the medical diagnostic system is to place a nosological system that could ease the diagnostic evaluation normally performed by scientists and doctors. Efficient diagnostic evaluation is essentials and requires broad knowledge in order to improve conventional diagnostic system. Several approaches on developing the medical diagnostic system have been designed and tested since the earliest 60s. Attempts on improving their performance have been made which utilizes the fields of artificial intelligence, statistical analyses, mathematical model and engineering theories. With the availability of the microcomputer and software development as well as the promising aforementioned fields, medical diagnostic prototypes could be developed. In general, the medical diagnostic system consists of several stages, namely the 1) data acquisition, 2) feature extraction, 3) feature selection, and 4) classifications stages. Data acquisition stage plays an important role in converting the inputs measured from the real world physical conditions to the digital numeric values that can be manipulated by the computer system. One of the common medical inputs could be medical microscopic images, radiographic images, magnetic resonance image (MRI) as well as medical signals such as electrocardiogram (ECG) and electroencephalogram (EEG). Normally, the scientist or doctors have to deal with myriad of data and redundant to be processed. In order to reduce the complexity of the diagnosis process, only the significant features of the raw data such as peak value of the ECG signal or size of lesion in the mammogram images will be extracted and considered in the subsequent stages. Mathematical models and statistical analyses will be performed to select the most significant features to be classified. The statistical analyses such as principal component analysis and discriminant analysis as well

  3. Approaches and models of intercultural education

    Directory of Open Access Journals (Sweden)

    Iván Manuel Sánchez Fontalvo

    2013-10-01

    Full Text Available Needed to be aware of the need to build an intercultural society, awareness must be assumed in all social spheres, where stands the role play education. A role of transcendental, since it must promote educational spaces to form people with virtues and powers that allow them to live together / as in multicultural contexts and social diversities (sometimes uneven in an increasingly globalized and interconnected world, and foster the development of feelings of civic belonging shared before the neighborhood, city, region and country, allowing them concern and critical judgement to marginalization, poverty, misery and inequitable distribution of wealth, causes of structural violence, but at the same time, wanting to work for the welfare and transformation of these scenarios. Since these budgets, it is important to know the approaches and models of intercultural education that have been developed so far, analysing their impact on the contexts educational where apply.   

  4. Employing general fit-bases for construction of potential energy surfaces with an adaptive density-guided approach

    Science.gov (United States)

    Klinting, Emil Lund; Thomsen, Bo; Godtliebsen, Ian Heide; Christiansen, Ove

    2018-02-01

    We present an approach to treat sets of general fit-basis functions in a single uniform framework, where the functional form is supplied on input, i.e., the use of different functions does not require new code to be written. The fit-basis functions can be used to carry out linear fits to the grid of single points, which are generated with an adaptive density-guided approach (ADGA). A non-linear conjugate gradient method is used to optimize non-linear parameters if such are present in the fit-basis functions. This means that a set of fit-basis functions with the same inherent shape as the potential cuts can be requested and no other choices with regards to the fit-basis functions need to be taken. The general fit-basis framework is explored in relation to anharmonic potentials for model systems, diatomic molecules, water, and imidazole. The behaviour and performance of Morse and double-well fit-basis functions are compared to that of polynomial fit-basis functions for unsymmetrical single-minimum and symmetrical double-well potentials. Furthermore, calculations for water and imidazole were carried out using both normal coordinates and hybrid optimized and localized coordinates (HOLCs). Our results suggest that choosing a suitable set of fit-basis functions can improve the stability of the fitting routine and the overall efficiency of potential construction by lowering the number of single point calculations required for the ADGA. It is possible to reduce the number of terms in the potential by choosing the Morse and double-well fit-basis functions. These effects are substantial for normal coordinates but become even more pronounced if HOLCs are used.

  5. Personalization of models with many model parameters: an efficient sensitivity analysis approach.

    Science.gov (United States)

    Donders, W P; Huberts, W; van de Vosse, F N; Delhaas, T

    2015-10-01

    Uncertainty quantification and global sensitivity analysis are indispensable for patient-specific applications of models that enhance diagnosis or aid decision-making. Variance-based sensitivity analysis methods, which apportion each fraction of the output uncertainty (variance) to the effects of individual input parameters or their interactions, are considered the gold standard. The variance portions are called the Sobol sensitivity indices and can be estimated by a Monte Carlo (MC) approach (e.g., Saltelli's method [1]) or by employing a metamodel (e.g., the (generalized) polynomial chaos expansion (gPCE) [2, 3]). All these methods require a large number of model evaluations when estimating the Sobol sensitivity indices for models with many parameters [4]. To reduce the computational cost, we introduce a two-step approach. In the first step, a subset of important parameters is identified for each output of interest using the screening method of Morris [5]. In the second step, a quantitative variance-based sensitivity analysis is performed using gPCE. Efficient sampling strategies are introduced to minimize the number of model runs required to obtain the sensitivity indices for models considering multiple outputs. The approach is tested using a model that was developed for predicting post-operative flows after creation of a vascular access for renal failure patients. We compare the sensitivity indices obtained with the novel two-step approach with those obtained from a reference analysis that applies Saltelli's MC method. The two-step approach was found to yield accurate estimates of the sensitivity indices at two orders of magnitude lower computational cost. Copyright © 2015 John Wiley & Sons, Ltd.

  6. Effectiveness of Facebook Based Learning to Enhance Creativity among Islamic Studies Students by Employing Isman Instructional Design Model

    Science.gov (United States)

    Alias, Norlidah; Siraj, Saedah; Daud, Mohd Khairul Azman Md; Hussin, Zaharah

    2013-01-01

    The study examines the effectiveness of Facebook based learning to enhance creativity among Islamic Studies students in the secondary educational setting in Malaysia. It describes the design process by employing the Isman Instructional Design Model. A quantitative study was carried out using experimental method and background survey. The…

  7. Do Labour Market Programmes Necessarily Crowd out Regular Employment? A Matching Model Analysis

    NARCIS (Netherlands)

    Miller, J.G.

    1996-01-01

    It is often claimed that the usage of labour market programmes will necessarily crowd out regular employment (see, for example, Holmlund & Lindén (1993)). As a result, it could be argued that, despite their probable negative impact on unemployment, the overall benefits of using labour market

  8. Predictive models to determine imagery strategies employed by children to judge hand laterality

    NARCIS (Netherlands)

    Spruijt, S.; Jongsma, M.L.A.; Kamp, J. van der; Steenbergen, B.

    2015-01-01

    A commonly used paradigm to study motor imagery is the hand laterality judgment task. The present study aimed to determine which strategies young children employ to successfully perform this task. Children of 5 to 8 years old (N = 92) judged laterality of back and palm view hand pictures in

  9. Predictive models to determine imagery strategies employed by children to judge hand laterality.

    NARCIS (Netherlands)

    Spruijt, S.; Jongsma, M.L.; Kamp, J. van der; Steenbergen, B.

    2015-01-01

    A commonly used paradigm to study motor imagery is the hand laterality judgment task. The present study aimed to determine which strategies young children employ to successfully perform this task. Children of 5 to 8 years old (N = 92) judged laterality of back and palm view hand pictures in

  10. Modelling Diverse Soil Attributes with Visible to Longwave Infrared Spectroscopy Using PLSR Employed by an Automatic Modelling Engine

    Directory of Open Access Journals (Sweden)

    Veronika Kopačková

    2017-02-01

    Full Text Available The study tested a data mining engine (PARACUDA® to predict various soil attributes (BC, CEC, BS, pH, Corg, Pb, Hg, As, Zn and Cu using reflectance data acquired for both optical and thermal infrared regions. The engine was designed to utilize large data in parallel and automatic processing to build and process hundreds of diverse models in a unified manner while avoiding bias and deviations caused by the operator(s. The system is able to systematically assess the effect of diverse preprocessing techniques; additionally, it analyses other parameters, such as different spectral resolutions and spectral coverages that affect soil properties. Accordingly, the system was used to extract models across both optical and thermal infrared spectral regions, which holds significant chromophores. In total, 2880 models were evaluated where each model was generated with a different preprocessing scheme of the input spectral data. The models were assessed using statistical parameters such as coefficient of determination (R2, square error of prediction (SEP, relative percentage difference (RPD and by physical explanation (spectral assignments. It was found that the smoothing procedure is the most beneficial preprocessing stage, especially when combined with spectral derivation (1st or 2nd derivatives. Automatically and without the need of an operator, the data mining engine enabled the best prediction models to be found from all the combinations tested. Furthermore, the data mining approach used in this study and its processing scheme proved to be efficient tools for getting a better understanding of the geochemical properties of the samples studied (e.g., mineral associations.

  11. Systems Approaches to Modeling Chronic Mucosal Inflammation

    Science.gov (United States)

    Gao, Boning; Choudhary, Sanjeev; Wood, Thomas G.; Carmical, Joseph R.; Boldogh, Istvan; Mitra, Sankar; Minna, John D.; Brasier, Allan R.

    2013-01-01

    The respiratory mucosa is a major coordinator of the inflammatory response in chronic airway diseases, including asthma and chronic obstructive pulmonary disease (COPD). Signals produced by the chronic inflammatory process induce epithelial mesenchymal transition (EMT) that dramatically alters the epithelial cell phenotype. The effects of EMT on epigenetic reprogramming and the activation of transcriptional networks are known, its effects on the innate inflammatory response are underexplored. We used a multiplex gene expression profiling platform to investigate the perturbations of the innate pathways induced by TGFβ in a primary airway epithelial cell model of EMT. EMT had dramatic effects on the induction of the innate pathway and the coupling interval of the canonical and noncanonical NF-κB pathways. Simulation experiments demonstrate that rapid, coordinated cap-independent translation of TRAF-1 and NF-κB2 is required to reduce the noncanonical pathway coupling interval. Experiments using amantadine confirmed the prediction that TRAF-1 and NF-κB2/p100 production is mediated by an IRES-dependent mechanism. These data indicate that the epigenetic changes produced by EMT induce dynamic state changes of the innate signaling pathway. Further applications of systems approaches will provide understanding of this complex phenotype through deterministic modeling and multidimensional (genomic and proteomic) profiling. PMID:24228254

  12. ECOMOD - An ecological approach to radioecological modelling

    International Nuclear Information System (INIS)

    Sazykina, Tatiana G.

    2000-01-01

    A unified methodology is proposed to simulate the dynamic processes of radionuclide migration in aquatic food chains in parallel with their stable analogue elements. The distinguishing feature of the unified radioecological/ecological approach is the description of radionuclide migration along with dynamic equations for the ecosystem. The ability of the methodology to predict the results of radioecological experiments is demonstrated by an example of radionuclide (iron group) accumulation by a laboratory culture of the algae Platymonas viridis. Based on the unified methodology, the 'ECOMOD' radioecological model was developed to simulate dynamic radioecological processes in aquatic ecosystems. It comprises three basic modules, which are operated as a set of inter-related programs. The 'ECOSYSTEM' module solves non-linear ecological equations, describing the biomass dynamics of essential ecosystem components. The 'RADIONUCLIDE DISTRIBUTION' module calculates the radionuclide distribution in abiotic and biotic components of the aquatic ecosystem. The 'DOSE ASSESSMENT' module calculates doses to aquatic biota and doses to man from aquatic food chains. The application of the ECOMOD model to reconstruct the radionuclide distribution in the Chernobyl Cooling Pond ecosystem in the early period after the accident shows good agreement with observations

  13. Hierarchical Multi-Scale Approach To Validation and Uncertainty Quantification of Hyper-Spectral Image Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Engel, David W.; Reichardt, Thomas A.; Kulp, Thomas J.; Graff, David; Thompson, Sandra E.

    2016-09-17

    Validating predictive models and quantifying uncertainties inherent in the modeling process is a critical component of the HARD Solids Venture program [1]. Our current research focuses on validating physics-based models predicting the optical properties of solid materials for arbitrary surface morphologies and characterizing the uncertainties in these models. We employ a systematic and hierarchical approach by designing physical experiments and comparing the experimental results with the outputs of computational predictive models. We illustrate this approach through an example comparing a micro-scale forward model to an idealized solid-material system and then propagating the results through a system model to the sensor level. Our efforts should enhance detection reliability of the hyper-spectral imaging technique and the confidence in model utilization and model outputs by users and stakeholders.

  14. A chain reaction approach to modelling gene pathways.

    Science.gov (United States)

    Cheng, Gary C; Chen, Dung-Tsa; Chen, James J; Soong, Seng-Jaw; Lamartiniere, Coral; Barnes, Stephen

    2012-08-01

    nutrient-containing diets regulate gene expression in the estrogen synthesis pathway during puberty; (II) global tests to assess an overall association of this particular pathway with time factor by utilizing generalized linear models to analyze microarray data; and (III) a chain reaction model to simulate the pathway. This is a novel application because we are able to translate the gene pathway into the chemical reactions in which each reaction channel describes gene-gene relationship in the pathway. In the chain reaction model, the implicit scheme is employed to efficiently solve the differential equations. Data analysis results show the proposed model is capable of predicting gene expression changes and demonstrating the effect of nutrient-containing diets on gene expression changes in the pathway. One of the objectives of this study is to explore and develop a numerical approach for simulating the gene expression change so that it can be applied and calibrated when the data of more time slices are available, and thus can be used to interpolate the expression change at a desired time point without conducting expensive experiments for a large amount of time points. Hence, we are not claiming this is either essential or the most efficient way for simulating this problem, rather a mathematical/numerical approach that can model the expression change of a large set of genes of a complex pathway. In addition, we understand the limitation of this experiment and realize that it is still far from being a complete model of predicting nutrient-gene interactions. The reason is that in the present model, the reaction rates were estimated based on available data at two time points; hence, the gene expression change is dependent upon the reaction rates and a linear function of the gene expressions. More data sets containing gene expression at various time slices are needed in order to improve the present model so that a non-linear variation of gene expression changes at different time

  15. Risk communication: a mental models approach

    National Research Council Canada - National Science Library

    Morgan, M. Granger (Millett Granger)

    2002-01-01

    ... information about risks. The procedure uses approaches from risk and decision analysis to identify the most relevant information; it also uses approaches from psychology and communication theory to ensure that its message is understood. This book is written in nontechnical terms, designed to make the approach feasible for anyone willing to try it. It is illustrat...

  16. A fourth order spline collocation approach for a business cycle model

    Science.gov (United States)

    Sayfy, A.; Khoury, S.; Ibdah, H.

    2013-10-01

    A collocation approach, based on a fourth order cubic B-splines is presented for the numerical solution of a Kaleckian business cycle model formulated by a nonlinear delay differential equation. The equation is approximated and the nonlinearity is handled by employing an iterative scheme arising from Newton's method. It is shown that the model exhibits a conditionally dynamical stable cycle. The fourth-order rate of convergence of the scheme is verified numerically for different special cases.

  17. A comparative analysis of reactor lower head debris cooling models employed in the existing severe accident analysis codes

    International Nuclear Information System (INIS)

    Ahn, K.I.; Kim, D.H.; Kim, S.B.; Kim, H.D.

    1998-08-01

    MELCOR and MAAP4 are the representative severe accident analysis codes which have been developed for the integral analysis of the phenomenological reactor lower head corium cooling behavior. Main objectives of the present study is to identify merits and disadvantages of each relevant model through the comparative analysis of the lower plenum corium cooling models employed in these two codes. The final results will be utilized for the development of LILAC phenomenological models and for the continuous improvement of the existing MELCOR reactor lower head models, which are currently being performed at the KAERI. For these purposes, first, nine reference models are selected featuring the lower head corium behavior based on the existing experimental evidences and related models. Then main features of the selected models have been critically analyzed, and finally merits and disadvantages of each corresponding model have been summarized in the view point of realistic corium behavior and reasonable modeling. Being on these evidences, summarized and presented the potential improvements for developing more advanced models. The present study has been focused on the qualitative comparison of each model and so more detailed quantitative analysis is strongly required to obtain the final conclusions for their merits and disadvantages. In addition, in order to compensate the limitations of the current model, required further studies relating closely the detailed mechanistic models with the molten material movement and heat transfer based on phase-change in the porous medium, to the existing simple models. (author). 36 refs

  18. A systems biology-based approach to deciphering the etiology of steatosis employing patient-derived dermal fibroblasts and iPS cells

    Directory of Open Access Journals (Sweden)

    Justyna eJozefczuk

    2012-09-01

    Full Text Available Nonalcoholic fatty liver disease (NAFLD comprises a broad spectrum of disease states ranging from simple steatosis to nonalcoholic steatohepatitis (NASH. As a result of increases in the prevalences of obesity, insulin resistance, and hyperlipidemia, the number of people with hepatic steatosis continues to increase. Differences in susceptibility to steatohepatitis and its progression to cirrhosis have been attributed to a complex interplay of genetic and external factors all addressing the intracellular network. Increase in sugar or refined carbohydrate consumption results in an increase of insulin and insulin resistance that can lead to the accumulation of fat in the liver. Here we demonstrate how a multidisciplinary approach encompassing cellular reprogramming, transcriptomics, proteomics, metabolomics, modeling, network reconstruction and data management can be employed to unveil the mechanisms underlying the progression of steatosis. Proteomics revealed reduced AKT/mTOR signaling in fibroblasts derived from steatosis patients and further establishes that the insulin-resistant phenotype is present not only in insulin-metabolizing central organs, e.g. the liver, but is also manifested in skin fibroblasts. Transcriptome data enabled the generation of a regulatory network based on the transcription factor SREBF1, linked to a metabolic network of glycerolipid and fatty acid biosynthesis including the downstream transcriptional targets of SREBF1 which include LIPIN1 (LPIN and low density lipoprotein receptor (LDLR. Glutathione metabolism was among the pathways enriched in steatosis patients in comparison to healthy controls. By using a model of the glutathione pathway we predict a significant increase in the flux through glutathione synthesis as both gamma-glutamylcysteine synthetase and glutathione synthetase have an increased flux. We anticipate that a larger sample of patients and matching controls will confirm our preliminary findings presented

  19. Employment opportunities for the disabled

    NARCIS (Netherlands)

    Delsen, L.W.M.

    1996-01-01

    Policy makers in the OECD Member States have developed quite different programmes and institutional arrangements to create and promote employment opportunities for the disabled. These policy approaches include legal interventions, employment support services, financial support of open employment and

  20. Modeling regional population-employment dynamics across different sectors of the economy

    NARCIS (Netherlands)

    Graaff, T. de; Oort, F.G. van; Florax, R.

    An important subset of the literature on agglomeration externalities hypothesizes that intrasectoral and intersectoral relations are endogenously determined in models of local and regional economic growth. Remarkably, structural adjustment models describing the spatio-temporal dynamics of

  1. A new multi-objective approach to finite element model updating

    Science.gov (United States)

    Jin, Seung-Seop; Cho, Soojin; Jung, Hyung-Jo; Lee, Jong-Jae; Yun, Chung-Bang

    2014-05-01

    The single objective function (SOF) has been employed for the optimization process in the conventional finite element (FE) model updating. The SOF balances the residual of multiple properties (e.g., modal properties) using weighting factors, but the weighting factors are hard to determine before the run of model updating. Therefore, the trial-and-error strategy is taken to find the most preferred model among alternative updated models resulted from varying weighting factors. In this study, a new approach to the FE model updating using the multi-objective function (MOF) is proposed to get the most preferred model in a single run of updating without trial-and-error. For the optimization using the MOF, non-dominated sorting genetic algorithm-II (NSGA-II) is employed to find the Pareto optimal front. The bend angle related to the trade-off relationship of objective functions is used to select the most preferred model among the solutions on the Pareto optimal front. To validate the proposed approach, a highway bridge is selected as a test-bed and the modal properties of the bridge are obtained from the ambient vibration test. The initial FE model of the bridge is built using SAP2000. The model is updated using the identified modal properties by the SOF approach with varying the weighting factors and the proposed MOF approach. The most preferred model is selected using the bend angle of the Pareto optimal front, and compared with the results from the SOF approach using varying the weighting factors. The comparison shows that the proposed MOF approach is superior to the SOF approach using varying the weighting factors in getting smaller objective function values, estimating better updated parameters, and taking less computational time.

  2. A Nonparametric Operational Risk Modeling Approach Based on Cornish-Fisher Expansion

    Directory of Open Access Journals (Sweden)

    Xiaoqian Zhu

    2014-01-01

    Full Text Available It is generally accepted that the choice of severity distribution in loss distribution approach has a significant effect on the operational risk capital estimation. However, the usually used parametric approaches with predefined distribution assumption might be not able to fit the severity distribution accurately. The objective of this paper is to propose a nonparametric operational risk modeling approach based on Cornish-Fisher expansion. In this approach, the samples of severity are generated by Cornish-Fisher expansion and then used in the Monte Carlo simulation to sketch the annual operational loss distribution. In the experiment, the proposed approach is employed to calculate the operational risk capital charge for the overall Chinese banking. The experiment dataset is the most comprehensive operational risk dataset in China as far as we know. The results show that the proposed approach is able to use the information of high order moments and might be more effective and stable than the usually used parametric approach.

  3. Assessment of training effects on employability within the institutional Spanish training model

    Directory of Open Access Journals (Sweden)

    Ramírez-del-Río, Antonio

    2011-12-01

    Full Text Available The association between quantity of training and employability was analysed through a non experimental research with two non equivalent groups. The operationalization of training quantity is considered to provide an indicator of training effort. Thus, training effort (number of courses was analysed as the independent variable and employability as dependent variable (occupation indicators, activity enhancement and job performance. The results show that training is related to activity enhancement, specially when workers belong to a small/medium enterprise (SME and/or to technical or qualified positions. A positive association between training and performance also appeared in the case of SMEs. Se analiza la asociación entre cantidad de formación y empleabilidad mediante una investigación no experimental con dos grupos no equivalentes. Se considera que la operativización de la cantidad de formación proporciona un indicador próximo al esfuerzo formativo realizado. Así, se estudió la variable independiente esfuerzo formativo (número de cursos y la dependiente, empleabilidad (indicadores de ocupación, enriquecimiento de actividad y desempeño. Los resultados muestran que la formación está asociada al enriquecimiento de la actividad, sobre todo si los trabajadores pertenecen a una PYME y/o a puestos técnicos o cualificados. También hay una asociación positiva entre formación y desempeño en PYMES.

  4. Bayesian Model Averaging Employing Fixed and Flexible Priors: The BMS Package for R

    Directory of Open Access Journals (Sweden)

    Stefan Zeugner

    2015-11-01

    Full Text Available This article describes the BMS (Bayesian model sampling package for R that implements Bayesian model averaging for linear regression models. The package excels in allowing for a variety of prior structures, among them the "binomial-beta" prior on the model space and the so-called "hyper-g" specifications for Zellner's g prior. Furthermore, the BMS package allows the user to specify her own model priors and offers a possibility of subjective inference by setting "prior inclusion probabilities" according to the researcher's beliefs. Furthermore, graphical analysis of results is provided by numerous built-in plot functions of posterior densities, predictive densities and graphical illustrations to compare results under different prior settings. Finally, the package provides full enumeration of the model space for small scale problems as well as two efficient MCMC (Markov chain Monte Carlo samplers that sort through the model space when the number of potential covariates is large.

  5. A structural econometric model of family valuation and choice of employer-sponsored health insurance in the United States.

    Science.gov (United States)

    Vanness, David J

    2003-09-01

    This paper estimates a fully structural unitary household model of employment and health insurance decisions for dual wage-earner families with children in the United States, using data from the 1987 National Medical Expenditure Survey. Families choose hours of work and the breakdown of compensation between cash wages and health insurance benefits for each wage earner in order to maximize expected utility under uncertain need for medical care. Heterogeneous demand for the employer-sponsored health insurance is thus generated directly from variations in health status and earning potential. The paper concludes by discussing the benefits of using structural models for simulating welfare effects of insurance reform relative to the costly assumptions that must be imposed for identification. Copyright 2003 John Wiley & Sons, Ltd.

  6. Identify Strategies to Expand Employment in Rural Areas Using the SWOT Model (Case Study: Badr District, Ravansar Township

    Directory of Open Access Journals (Sweden)

    Davood Jamini

    2015-01-01

    Full Text Available The aim of the present study, Is the nature and procedure respectively of the applied research and descriptive, Provide solutions to expand employment in the village of Badr District. The main research instrument was researcher made questionnaire and to achieve this goal, researchers have used opinions 23 expert relating to rural affairs Ravansar Township. Is used to analyze the data from the Excel software and the SWOT Model. The results showed there are in the study area 23 strength of (with a final score of 1.800 and 25 opportunities (with a final score of 1.933 for employment development. While face village of Bedar District with 35 point of weakness (with a final score of 11.946 and 16 threat (with a final score of 1.993 to develop employment. In total the results showed, According to the Preponderance weaknesses and threats on the strengths and opportunities in the study area, there is Defensive strategy (WT, priority employment development strategies in village of Badr District. Therefore, is necessary for provide solutions development employment In rural areas in the study area, Weaken the Internal weaknesses (such as lack of initial capital available to villagers With The final weight 0.136, There Fixer and intermediaries With The final weight 0.105 and External threats (such as limited capital in the hands of villagers With final weight 0.272 and Rising production costs with the final weight 0.262, Which have the greatest weight. Finally, According to research findings, was developed to promote employment in the village of Badr district, Practical and effective solutions, which have been the main focus on the Limiting the identified weaknesses and threats.

  7. Employment and familiar agriculture agribusiness in the Brazilian economy: an interregional Leontief-Miyazawa model approach

    OpenAIRE

    Guilhoto, Joaquim José Martins; Camargo, Fernanda Sartori de

    2008-01-01

    The agricultural sector has great importance in the socio-economic development. Its development throughout history has enabled the emergence of other activities and therefore new jobs. Furthermore, the importance of the agribusiness can be evidence for its share of about 30% in the total Brazilian GDP and its importance in generating jobs. To study this sector in more detail, the agricultural sector was broken down into two sectors: Familiar and Non-Familiar Agriculture Agribusiness. The goal...

  8. Water uptake in crop growth models for land use systems analysis. I. A review of approaches and their pedigrees

    NARCIS (Netherlands)

    Berg, van den M.; Driessen, P.M.

    2002-01-01

    Descriptions of crop water uptake/transpiration are of widely varying complexity and employ considerably different approaches. This paper examines simple approaches that could be used in crop growth simulation models for application in land use systems analysis. Many apparently conceptual

  9. Sea-floor classification using multibeam echo-sounding angular backscatter data: A real-time approach employing hybrid neural network architecture

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, B.; Kodagali, V.N.; Baracho, J.

    OF OCEANIC ENGINEERING, VOL. 28, NO. 1, JANUARY 2003 121 Technical Communications__________________________________________________ Sea-Floor Classification Using Multibeam Echo-Sounding Angular Backscatter Data: A Real-Time Approach Employing Hybrid Neural... vector quantization (LVQ), multibeam echo sounder, sea-floor classification, self-organizing feature map (SOFM). I. INTRODUCTION U SE OF multibeam echo-sounding systems for sea-floor bathymetry and backscatter studies are well known for understanding...

  10. mMWeb--an online platform for employing multiple ecological niche modeling algorithms.

    Science.gov (United States)

    Qiao, Huijie; Lin, Congtian; Ji, Liqiang; Jiang, Zhigang

    2012-01-01

    Predicting the ecological niche and potential habitat distribution of a given organism is one of the central domains of ecological and biogeographical research. A wide variety of modeling techniques have been developed for this purpose. In order to implement these models, the users must prepare a specific runtime environment for each model, learn how to use multiple model platforms, and prepare data in a different format each time. Additionally, often model results are difficult to interpret, and a standardized method for comparing model results across platforms does not exist. We developed a free and open source online platform, the multi-models web-based (mMWeb) platform, to address each of these problems, providing a novel environment in which the user can implement and compare multiple ecological niche model (ENM) algorithms. mMWeb combines 18 existing ENMs and their corresponding algorithms and provides a uniform procedure for modeling the potential habitat niche of a species via a common web browser. mMWeb uses Java Native Interface (JNI), Java R Interface to combine the different ENMs and executes multiple tasks in parallel on a super computer. The cross-platform, user-friendly interface of mMWeb simplifies the process of building ENMs, providing an accessible and efficient environment from which to explore and compare different model algorithms.

  11. mMWeb--an online platform for employing multiple ecological niche modeling algorithms.

    Directory of Open Access Journals (Sweden)

    Huijie Qiao

    Full Text Available BACKGROUND: Predicting the ecological niche and potential habitat distribution of a given organism is one of the central domains of ecological and biogeographical research. A wide variety of modeling techniques have been developed for this purpose. In order to implement these models, the users must prepare a specific runtime environment for each model, learn how to use multiple model platforms, and prepare data in a different format each time. Additionally, often model results are difficult to interpret, and a standardized method for comparing model results across platforms does not exist. We developed a free and open source online platform, the multi-models web-based (mMWeb platform, to address each of these problems, providing a novel environment in which the user can implement and compare multiple ecological niche model (ENM algorithms. METHODOLOGY: mMWeb combines 18 existing ENMs and their corresponding algorithms and provides a uniform procedure for modeling the potential habitat niche of a species via a common web browser. mMWeb uses Java Native Interface (JNI, Java R Interface to combine the different ENMs and executes multiple tasks in parallel on a super computer. The cross-platform, user-friendly interface of mMWeb simplifies the process of building ENMs, providing an accessible and efficient environment from which to explore and compare different model algorithms.

  12. MULTIREGION: a simulation-forecasting model of BEA economic area population and employment. [Bureau of Economic Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, R.J.; Westley, G.W.; Herzog, H.W. Jr.; Kerley, C.R.; Bjornstad, D.J.; Vogt, D.P.; Bray, L.G.; Grady, S.T.; Nakosteen, R.A.

    1977-10-01

    This report documents the development of MULTIREGION, a computer model of regional and interregional socio-economic development. The MULTIREGION model interprets the economy of each BEA economic area as a labor market, measures all activity in terms of people as members of the population (labor supply) or as employees (labor demand), and simultaneously simulates or forecasts the demands and supplies of labor in all BEA economic areas at five-year intervals. In general the outputs of MULTIREGION are intended to resemble those of the Water Resource Council's OBERS projections and to be put to similar planning and analysis purposes. This report has been written at two levels to serve the needs of multiple audiences. The body of the report serves as a fairly nontechnical overview of the entire MULTIREGION project; a series of technical appendixes provide detailed descriptions of the background empirical studies of births, deaths, migration, labor force participation, natural resource employment, manufacturing employment location, and local service employment used to construct the model.

  13. A Discrete Monetary Economic Growth Model with the MIU Approach

    Directory of Open Access Journals (Sweden)

    Wei-Bin Zhang

    2008-01-01

    Full Text Available This paper proposes an alternative approach to economic growth with money. The production side is the same as the Solow model, the Ramsey model, and the Tobin model. But we deal with behavior of consumers differently from the traditional approaches. The model is influenced by the money-in-the-utility (MIU approach in monetary economics. It provides a mechanism of endogenous saving which the Solow model lacks and avoids the assumption of adding up utility over a period of time upon which the Ramsey approach is based.

  14. Mathematical Modelling Approach in Mathematics Education

    Science.gov (United States)

    Arseven, Ayla

    2015-01-01

    The topic of models and modeling has come to be important for science and mathematics education in recent years. The topic of "Modeling" topic is especially important for examinations such as PISA which is conducted at an international level and measures a student's success in mathematics. Mathematical modeling can be defined as using…

  15. A new approach to modeling of selected human respiratory system diseases, directed to computer simulations.

    Science.gov (United States)

    Redlarski, Grzegorz; Jaworski, Jacek

    2013-10-01

    This paper presents a new versatile approach to model severe human respiratory diseases via computer simulation. The proposed approach enables one to predict the time histories of various diseases via information accessible in medical publications. This knowledge is useful to bioengineers involved in the design and construction of medical devices that are employed for monitoring of respiratory condition. The approach provides the data that are crucial for testing diagnostic systems. This can be achieved without the necessity of probing the physiological details of the respiratory system as well as without identification of parameters that are based on measurement data. © 2013 Elsevier Ltd. All rights reserved.

  16. A Multivariate Approach to Functional Neuro Modeling

    DEFF Research Database (Denmark)

    Mørch, Niels J.S.

    1998-01-01

    by the application of linear and more flexible, nonlinear microscopic regression models to a real-world dataset. The dependency of model performance, as quantified by generalization error, on model flexibility and training set size is demonstrated, leading to the important realization that no uniformly optimal model......, provides the basis for a generalization theoretical framework relating model performance to model complexity and dataset size. Briefly summarized the major topics discussed in the thesis include: - An introduction of the representation of functional datasets by pairs of neuronal activity patterns...... exists. - Model visualization and interpretation techniques. The simplicity of this task for linear models contrasts the difficulties involved when dealing with nonlinear models. Finally, a visualization technique for nonlinear models is proposed. A single observation emerges from the thesis...

  17. Simulation of Electric Faults in Doubly-Fed Induction Generators Employing Advanced Mathematical Modelling

    DEFF Research Database (Denmark)

    Martens, Sebastian; Mijatovic, Nenad; Holbøll, Joachim

    2015-01-01

    Efficient fault detection in generators often require prior knowledge of fault behavior, which can be obtained from theoretical analysis, often carried out by using discrete models of a given generator. Mathematical models are commonly represented in the DQ0 reference frame, which is convenient...... in many areas of electrical machine analysis. However, for fault investigations, the phase-coordinate representation has been found more suitable. This paper presents a mathematical model in phase coordinates of the DFIG with two parallel windings per rotor phase. The model has been implemented in Matlab...... and its properties in context of fault simulations and investigations has been investigated. Some of the most common faults have been simulated, namely broken rotor bars or windings, dynamic eccentricities and stator phase winding short circuits. These fault conditions propagate to the stator current...

  18. Employing Predictive Spatial Models to Inform Conservation Planning for Seabirds in the Labrador Sea

    Directory of Open Access Journals (Sweden)

    David A. Fifield

    2017-05-01

    Full Text Available Seabirds are vulnerable to incidental harm from human activities in the ocean, and knowledge of their seasonal distribution is required to assess risk and effectively inform marine conservation planning. Significant hydrocarbon discoveries and exploration licenses in the Labrador Sea underscore the need for quantitative information on seabird seasonal distribution and abundance, as this region is known to provide important habitat for seabirds year-round. We explore the utility of density surface modeling (DSM to improve seabird information available for regional conservation and management decision making. We, (1 develop seasonal density surface models for seabirds in the Labrador Sea using data from vessel-based surveys (2006–2014; 13,783 linear km of surveys, (2 present measures of uncertainty in model predictions, (3 discuss how density surface models can inform conservation and management decision making, and 4 explore challenges and potential pitfalls associated with using these modeling procedures. Models predicted large areas of high seabird density in fall over continental shelf waters (max. ~80 birds·km−2 driven largely by the southward migration of murres (Uria spp. and dovekies (Alle alle from Arctic breeding colonies. The continental shelf break was also highlighted as an important habitat feature, with predictions of high seabird densities particularly during summer (max. ~70 birds·km−2. Notable concentrations of seabirds overlapped with several significant hydrocarbon discoveries on the continental shelf and large areas in the vicinity of the southern shelf break, which are in the early stages of exploration. Some, but not all, areas of high seabird density were within current Ecologically and Biologically Significant Area (EBSA boundaries. Building predictive spatial models required knowledge of Distance Sampling and GAMs, and significant investments of time and computational power—resource needs that are becoming more

  19. Uncertainty in biology a computational modeling approach

    CERN Document Server

    Gomez-Cabrero, David

    2016-01-01

    Computational modeling of biomedical processes is gaining more and more weight in the current research into the etiology of biomedical problems and potential treatment strategies.  Computational modeling allows to reduce, refine and replace animal experimentation as well as to translate findings obtained in these experiments to the human background. However these biomedical problems are inherently complex with a myriad of influencing factors, which strongly complicates the model building and validation process.  This book wants to address four main issues related to the building and validation of computational models of biomedical processes: Modeling establishment under uncertainty Model selection and parameter fitting Sensitivity analysis and model adaptation Model predictions under uncertainty In each of the abovementioned areas, the book discusses a number of key-techniques by means of a general theoretical description followed by one or more practical examples.  This book is intended for graduate stude...

  20. Relaxed memory models: an operational approach

    OpenAIRE

    Boudol , Gérard; Petri , Gustavo

    2009-01-01

    International audience; Memory models define an interface between programs written in some language and their implementation, determining which behaviour the memory (and thus a program) is allowed to have in a given model. A minimal guarantee memory models should provide to the programmer is that well-synchronized, that is, data-race free code has a standard semantics. Traditionally, memory models are defined axiomatically, setting constraints on the order in which memory operations are allow...

  1. Numerical modelling approach for mine backfill

    Indian Academy of Sciences (India)

    ... of mine backfill material needs special attention as the numerical model must behave realistically and in accordance with the site conditions. This paper discusses a numerical modelling strategy for modelling mine backfill material. Themodelling strategy is studied using a case study mine from Canadian mining industry.

  2. Gleaning: Sheltered Employment for Retarded Adults in Rural Areas

    Science.gov (United States)

    Jacobs, J. Walter

    1978-01-01

    The Gleaner's Project, a model for providing extended sheltered employment for severely retarded adults in rural areas, is suggested; and the advantages, both economic and humanitarian, of the proposed model over more traditional approaches are discussed. (Author/SBH)

  3. BER analysis of DS-UWB system employing a laplace distribution model

    KAUST Repository

    Mehbodniya, Abolfazl

    2011-01-01

    This letter takes a new approach to extract a closed-form expression for the bit error rate (BER) of direct-sequence ultra wideband (DS-UWB) system. In the analysis, the main signal is impaired by multi-user interference (MUI) and an external source of interference originated by simultanously transmitting multiband orthogonal frequency division multiplexing (MB-OFDM) systems which are located in the vicinity of the DS-UWB receiver. All the transmission channels are affected by Nakagami-m fading. A Laplacian distribution is considered for MUI to comply more with real statistical behaviors of this kind of interference. © IEICE 2011.

  4. EMPLOYMENT OF A «SIDE POPULATION» APPROACH TO STEM CELL ISOLATION IN NORMAL AND TUMOR TISSUES

    Directory of Open Access Journals (Sweden)

    O. R. Tsinkalovsky

    2008-01-01

    Full Text Available Abstract. A combination of fluorescent staining with Hoechst 33342 dye, and flow cytometry of murine bone marrow cells may be used for separation of a side population (SP, which is highly enriched for hematopoietic stem cells capable of long-term hematopoietic reconstitution in lethally irradiated recipients. Recently, this approach was also applied to analysis of SP cells in several types of non-hematopoietic tissues, and malignant tumours. In spite of yet poor definition of phenotype and functional potency of SP cells from various tissues, the method of SP isolation may be a useful tool for analysis and pre-enrichment of stem cell-like cells of different origin. Present review article presents a brief description of Hoechst 33342-staining approach, and of recent reports concerning SP studies in various normal and malignant tissues. (Med. Immunol., vol. 10, N 4-5, pp 319-326.

  5. Perspectives of employability skills

    OpenAIRE

    ANNE LOUISE NEWTON

    2017-01-01

    The study investigated the different perspectives held by young people, employers and policy makers around Employability Skills and it examined how young people learnt these skills. This study draws young peoples’ perspectives into the research around Employability Skills and highlights the way in which social and cultural capital mediate their development. The research points to a model to re-vision employability skills which recognises the many ways in which they are learnt, over time a...

  6. A developmental approach to learning causal models for cyber security

    Science.gov (United States)

    Mugan, Jonathan

    2013-05-01

    To keep pace with our adversaries, we must expand the scope of machine learning and reasoning to address the breadth of possible attacks. One approach is to employ an algorithm to learn a set of causal models that describes the entire cyber network and each host end node. Such a learning algorithm would run continuously on the system and monitor activity in real time. With a set of causal models, the algorithm could anticipate novel attacks, take actions to thwart them, and predict the second-order effects flood of information, and the algorithm would have to determine which streams of that flood were relevant in which situations. This paper will present the results of efforts toward the application of a developmental learning algorithm to the problem of cyber security. The algorithm is modeled on the principles of human developmental learning and is designed to allow an agent to learn about the computer system in which it resides through active exploration. Children are flexible learners who acquire knowledge by actively exploring their environment and making predictions about what they will find,1, 2 and our algorithm is inspired by the work of the developmental psychologist Jean Piaget.3 Piaget described how children construct knowledge in stages and learn new concepts on top of those they already know. Developmental learning allows our algorithm to focus on subsets of the environment that are most helpful for learning given its current knowledge. In experiments, the algorithm was able to learn the conditions for file exfiltration and use that knowledge to protect sensitive files.

  7. Theoretical modelling of experimental diagnostic procedures employed during pre-dose dosimetry of quartz

    International Nuclear Information System (INIS)

    Pagonis, V.; Chen, R.; Kitis, G.

    2006-01-01

    The pre-dose technique in thermoluminescence (TL) is used for dating archaeological ceramics and for accident dosimetry. During routine applications of this technique, the sensitisation of the quartz samples is measured as a function of the annealing temperature, yielding the so-called thermal activation characteristic (TAC). The measurement of multiple TACs and the study of the effect of UV-radiation on the TL sensitivity of quartz are important analytical and diagnostic tools. In this paper, it is shown that a modified Zimmerman model for quartz can successfully model the experimental steps undertaken during a measurement of multiple TACs. (authors)

  8. Modelling Approach to Assess Future Agricultural Water Demand

    Science.gov (United States)

    Spano, D.; Mancosu, N.; Orang, M.; Sarreshteh, S.; Snyder, R. L.

    2013-12-01

    The combination of long-term climate changes (e.g., warmer average temperatures) and extremes events (e.g., droughts) can have decisive impacts on water demand, with further implications on the ecosystems. In countries already affected by water scarcity, water management problems are becoming increasingly serious. The sustainable management of available water resources at the global, regional, and site-specific level is necessary. In agriculture, the first step is to compute how much water is needed by crops in regards to climate conditions. Modelling approach can be a way to compute crop water requirement (CWR). In this study, the improved version of the SIMETAW model was used. The model is a user friendly soil water balance model, developed by the University of California, Davis, the California Department of Water Resource, and the University of Sassari. The SIMETAW# model assesses CWR and generates hypothetical irrigation scheduling for a wide range of irrigated crops experiencing full, deficit, or no irrigation. The model computes the evapotranspiration of the applied water (ETaw), which is the sum of the net amount of irrigation water needed to match losses due to the crop evapotranspiration (ETc). ETaw is determined by first computing reference evapotranspiration (ETo) using the daily standardized Reference Evapotranspiration equation. ETaw is computed as ETaw = CETc - CEr, where CETc and CE are the cumulative total crop ET and effective rainfall values, respectively. Crop evapotranspiration is estimated as ETc = ETo x Kc, where Kc is the corrected midseason tabular crop coefficient, adjusted for climate conditions. The net irrigation amounts are determined from a daily soil water balance, using an integrated approach that considers soil and crop management information, and the daily ETc estimates. Using input information on irrigation system distribution uniformity and runoff, when appropriate, the model estimates the applied water to the low quarter of the

  9. Employer branding

    OpenAIRE

    Mičková, Kateřina

    2008-01-01

    The demand for qualified employees is higher then the offering, both in Czech republic and internationally. Demand for specific skills, in addition to a greater demand for workforce generally, is making employee recruitment and retention much more difficult and expensive. Employer Branding claims to be an answer to this new challenge. This international concept focuses on developing an "employer brand" - mental image of a company as an employer. To achieve this, it is necessary to demonstrate...

  10. University-Community Partnership Models: Employing Organizational Management Theories of Paradox and Strategic Contradiction

    Science.gov (United States)

    Bowers, Amanda M.

    2017-01-01

    University-Community (U-C) partnerships have the potential to respond to society's most pressing needs through engaged scholarship. Despite this promise, partnerships face paradoxical tensions and inherent contradictions that are often not fully addressed in U-C partnership models or frameworks, or in practice. This article seeks to explore the…

  11. Fuzzy Investment Portfolio Selection Models Based on Interval Analysis Approach

    Directory of Open Access Journals (Sweden)

    Haifeng Guo

    2012-01-01

    Full Text Available This paper employs fuzzy set theory to solve the unintuitive problem of the Markowitz mean-variance (MV portfolio model and extend it to a fuzzy investment portfolio selection model. Our model establishes intervals for expected returns and risk preference, which can take into account investors' different investment appetite and thus can find the optimal resolution for each interval. In the empirical part, we test this model in Chinese stocks investment and find that this model can fulfill different kinds of investors’ objectives. Finally, investment risk can be decreased when we add investment limit to each stock in the portfolio, which indicates our model is useful in practice.

  12. X-slave boson approach to the periodic Anderson model

    International Nuclear Information System (INIS)

    Franco, R.; Figueira, M.S.; Foglio, M.E.

    2001-01-01

    The periodic anderson model (PAM) in the limit U=∞, can be studied by employing the Hubbard X operators to project out the unwanted states. In a previous work, we have studied the cumulant expansion of this Hamiltonian employing the hybridization as a perturbation, but probability conservation of the local states (completeness) is not usually satisfied when partial expansions like the 'chain approximation (CHA)' are employed. To consider this problem, we use a technique similar to the one employed by Coleman to treat the same problem with slave-bosons in the mean-field approximation. Assuming a particular renormalization for hybridization, we obtain a description that avoids an unwanted phase transition that appears in the mean-field slave-boson method at intermediate temperatures

  13. Models Portability: Some Considerations about Transdisciplinary Approaches

    Science.gov (United States)

    Giuliani, Alessandro

    Some critical issues about the relative portability of models and solutions across disciplinary barriers are discussed. The risks linked to the use of models and theories coming from different disciplines are evidentiated with a particular emphasis on biology. A metaphorical use of conceptual tools coming from other fields is suggested, together with the unescapable need to judge about the relative merits of a model on the basis of the amount of facts relative to the particular domain of application it explains. Some examples of metaphorical modeling coming from biochemistry and psychobiology are briefly discussed in order to clarify the above positions.

  14. Nonlinear Modeling of the PEMFC Based On NNARX Approach

    OpenAIRE

    Shan-Jen Cheng; Te-Jen Chang; Kuang-Hsiung Tan; Shou-Ling Kuo

    2015-01-01

    Polymer Electrolyte Membrane Fuel Cell (PEMFC) is such a time-vary nonlinear dynamic system. The traditional linear modeling approach is hard to estimate structure correctly of PEMFC system. From this reason, this paper presents a nonlinear modeling of the PEMFC using Neural Network Auto-regressive model with eXogenous inputs (NNARX) approach. The multilayer perception (MLP) network is applied to evaluate the structure of the NNARX model of PEMFC. The validity and accurac...

  15. Control method and system for hydraulic machines employing a dynamic joint motion model

    Science.gov (United States)

    Danko, George [Reno, NV

    2011-11-22

    A control method and system for controlling a hydraulically actuated mechanical arm to perform a task, the mechanical arm optionally being a hydraulically actuated excavator arm. The method can include determining a dynamic model of the motion of the hydraulic arm for each hydraulic arm link by relating the input signal vector for each respective link to the output signal vector for the same link. Also the method can include determining an error signal for each link as the weighted sum of the differences between a measured position and a reference position and between the time derivatives of the measured position and the time derivatives of the reference position for each respective link. The weights used in the determination of the error signal can be determined from the constant coefficients of the dynamic model. The error signal can be applied in a closed negative feedback control loop to diminish or eliminate the error signal for each respective link.

  16. Model-based document categorization employing semantic pattern analysis and local structure clustering

    Science.gov (United States)

    Fume, Kosei; Ishitani, Yasuto

    2008-01-01

    We propose a document categorization method based on a document model that can be defined externally for each task and that categorizes Web content or business documents into a target category in accordance with the similarity of the model. The main feature of the proposed method consists of two aspects of semantics extraction from an input document. The semantics of terms are extracted by the semantic pattern analysis and implicit meanings of document substructure are specified by a bottom-up text clustering technique focusing on the similarity of text line attributes. We have constructed a system based on the proposed method for trial purposes. The experimental results show that the system achieves more than 80% classification accuracy in categorizing Web content and business documents into 15 or 70 categories.

  17. A fuzzy-logic-based approach to qualitative safety modelling for marine systems

    International Nuclear Information System (INIS)

    Sii, H.S.; Ruxton, Tom; Wang Jin

    2001-01-01

    Safety assessment based on conventional tools (e.g. probability risk assessment (PRA)) may not be well suited for dealing with systems having a high level of uncertainty, particularly in the feasibility and concept design stages of a maritime or offshore system. By contrast, a safety model using fuzzy logic approach employing fuzzy IF-THEN rules can model the qualitative aspects of human knowledge and reasoning processes without employing precise quantitative analyses. A fuzzy-logic-based approach may be more appropriately used to carry out risk analysis in the initial design stages. This provides a tool for working directly with the linguistic terms commonly used in carrying out safety assessment. This research focuses on the development and representation of linguistic variables to model risk levels subjectively. These variables are then quantified using fuzzy sets. In this paper, the development of a safety model using fuzzy logic approach for modelling various design variables for maritime and offshore safety based decision making in the concept design stage is presented. An example is used to illustrate the proposed approach

  18. A visual approach for modeling spatiotemporal relations

    NARCIS (Netherlands)

    R.L. Guimarães (Rodrigo); C.S.S. Neto; L.F.G. Soares

    2008-01-01

    htmlabstractTextual programming languages have proven to be difficult to learn and to use effectively for many people. For this sake, visual tools can be useful to abstract the complexity of such textual languages, minimizing the specification efforts. In this paper we present a visual approach for

  19. DIVERSE APPROACHES TO MODELLING THE ASSIMILATIVE ...

    African Journals Online (AJOL)

    This study evaluated the assimilative capacity of Ikpoba River using different approaches namely: homogeneous differential equation, ANOVA/Duncan Multiple rage test, first and second order differential equations, correlation analysis, Eigen values and eigenvectors, multiple linear regression, bootstrapping and far-field ...

  20. Modeling Approaches for Describing Microbial Population Heterogeneity

    DEFF Research Database (Denmark)

    Lencastre Fernandes, Rita

    in a computational (CFD) fluid dynamic model. The anaerobic Growth of a budding yeast population in a continuously run microbioreactor was used as example. The proposed integrated model describes the fluid flow, the local cell size and cell cycle position distributions, as well as the local concentrations of glucose...

  1. A simplified approach to feedwater train modeling

    International Nuclear Information System (INIS)

    Ollat, X.; Smoak, R.A.

    1990-01-01

    This paper presents a method to simplify feedwater train models for power plants. A simple set of algebraic equations, based on mass and energy balances, is developed to replace complex representations of the components under certain assumptions. The method was tested and used to model the low pressure heaters of the Sequoyah Nuclear Plant in a larger simulation

  2. Integrated approaches for implementing building information modelling (BIM) in engineering education

    OpenAIRE

    Hjelseth, Eilif

    2015-01-01

    The construction industry faces high demand for candidates with relevant Building Information Modelling (BIM) competency, yet higher education continues to struggle in providing such competencies. This conceptual paper explores the use of an integrated approach to implement BIM into the curriculum for undergraduates and graduates in engineering. The curriculum under study employed the Technological Pedagogical Content Knowledge (TPACK) pedagogical framework for integrating three BIM related s...

  3. Who will have Sustainable Employment After a Back Injury? The Development of a Clinical Prediction Model in a Cohort of Injured Workers

    DEFF Research Database (Denmark)

    Shearer, Heather M.; Côté, Pierre; Boyle, Eleanor

    2017-01-01

    intensity, mental health-related quality of life, claim litigation and employer type (c-index = 0.77). At 6 months, sustainable employment was predicted by physical and mental health-related quality of life, claim litigation and employer type (c-index = 0.77). Adding health-related and work......-related variables to models improved predictive accuracy by 8.5 and 10 % at 1 and 6 months respectively. Conclusion We developed clinically-relevant models to predict sustainable employment in injured workers who made a workers’ compensation claim for LBP. Inquiring about back pain intensity, physical and mental......Purpose Our objective was to develop a clinical prediction model to identify workers with sustainable employment following an episode of work-related low back pain (LBP). Methods We used data from a cohort study of injured workers with incident LBP claims in the USA to predict employment patterns 1...

  4. Industry Employment

    Science.gov (United States)

    Occupational Outlook Quarterly, 2012

    2012-01-01

    This article illustrates projected employment change by industry and industry sector over 2010-20 decade. Workers are grouped into an industry according to the type of good produced or service provided by the establishment for which they work. Industry employment projections are shown in terms of numeric change (growth or decline in the total…

  5. D Recording for 2d Delivering - the Employment of 3d Models for Studies and Analyses -

    Science.gov (United States)

    Rizzi, A.; Baratti, G.; Jiménez, B.; Girardi, S.; Remondino, F.

    2011-09-01

    In the last years, thanks to the advances of surveying sensors and techniques, many heritage sites could be accurately replicated in digital form with very detailed and impressive results. The actual limits are mainly related to hardware capabilities, computation time and low performance of personal computer. Often, the produced models are not visible on a normal computer and the only solution to easily visualized them is offline using rendered videos. This kind of 3D representations is useful for digital conservation, divulgation purposes or virtual tourism where people can visit places otherwise closed for preservation or security reasons. But many more potentialities and possible applications are available using a 3D model. The problem is the ability to handle 3D data as without adequate knowledge this information is reduced to standard 2D data. This article presents some surveying and 3D modeling experiences within the APSAT project ("Ambiente e Paesaggi dei Siti d'Altura Trentini", i.e. Environment and Landscapes of Upland Sites in Trentino). APSAT is a multidisciplinary project funded by the Autonomous Province of Trento (Italy) with the aim documenting, surveying, studying, analysing and preserving mountainous and hill-top heritage sites located in the region. The project focuses on theoretical, methodological and technological aspects of the archaeological investigation of mountain landscape, considered as the product of sequences of settlements, parcelling-outs, communication networks, resources, and symbolic places. The mountain environment preserves better than others the traces of hunting and gathering, breeding, agricultural, metallurgical, symbolic activities characterised by different lengths and environmental impacts, from Prehistory to the Modern Period. Therefore the correct surveying and documentation of this heritage sites and material is very important. Within the project, the 3DOM unit of FBK is delivering all the surveying and 3D material to

  6. Crustal Models Assessment in Western Part of Romania Employing Active Seismic and Seismologic Methods

    Science.gov (United States)

    Bala, Andrei; Toma-Danila, Dragos; Tataru, Dragos; Grecu, Bogdan

    2017-12-01

    In the years 1999 - 2000 two regional seismic refraction lines were performed within a close cooperation with German partners from University of Karlsruhe. One of these lines is Vrancea 2001, with 420 km in length, almost half of them recorded in Transylvanian Basin. The structure of the crust along the seismic line revealed a very complicated crustal structure beginning with Eastern Carpathians and continuing in the Transylvanian Basin until Medias. As a result of the development of the National Seismic Network in the last ten years, more than 100 permanent broadband stations are now continuously operating in Romania. Complementary to this national dataset, maintained and developed in the National Institute for Earth Physics, new data emerged from the temporary seismologic networks established during the joint projects with European partners in the last decades. The data gathered so far is valuable both for seismology purposes and crustal structure studies, especially for the western part of the country, where this kind of data were sparse until now. Between 2009 and 2011, a new reference model for the Earth’s crust and mantle of the European Plate was defined through the NERIES project from existing data and models. The database gathered from different kind of measurements in Transylvanian Basin and eastern Pannonian Basin were included in this NERIES model and an improved and upgraded model of the Earth crust emerged for western part of Romania. Although the dataset has its origins in several periods over the last 50 years, the results are homogeneous and they improve and strengthen our image about the depth of the principal boundaries in the crust. In the last chapter two maps regarding these boundaries are constructed, one for mid-crustal boundary and one for Moho. They were build considering all the punctual information available from different sources in active seismic and seismology which are introduced in the general maps from the NERIES project for

  7. The workshop on ecosystems modelling approaches for South ...

    African Journals Online (AJOL)

    roles played by models in the OMP approach, and raises questions about the costs of the data collection. (in particular) needed to apply a multispecies modelling approach in South African fisheries management. It then summarizes the deliberations of workshops held by the Scientific Committees of two international ma-.

  8. A combined structural dynamics approach identifies a putative switch in factor VIIa employed by tissue factor to initiate blood coagulation

    DEFF Research Database (Denmark)

    Olsen, Ole H; Rand, Kasper D; Østergaard, Henrik

    2007-01-01

    ) simulations and hydrogen/deuterium exchange (HX) mass spectrometry on free and TF-bound FVIIa. The differences in conformational dynamics from MD simulations are shown to be confined to regions of FVIIa observed to undergo structural stabilization as judged by HX experiments, especially implicating activation......Coagulation factor VIIa (FVIIa) requires tissue factor (TF) to attain full catalytic competency and to initiate blood coagulation. In this study, the mechanism by which TF allosterically activates FVIIa is investigated by a structural dynamics approach that combines molecular dynamics (MD...... stability of activation loop 3. Altogether, our findings strongly support an allosteric activation mechanism initiated by the stabilization of the Leu305{163}/Phe374{225} pair, which, in turn, stabilizes activation loop 3 and the S(1) and S(3) substrate pockets, the activation pocket, and N...

  9. A simple approach to modeling ductile failure.

    Energy Technology Data Exchange (ETDEWEB)

    Wellman, Gerald William

    2012-06-01

    Sandia National Laboratories has the need to predict the behavior of structures after the occurrence of an initial failure. In some cases determining the extent of failure, beyond initiation, is required, while in a few cases the initial failure is a design feature used to tailor the subsequent load paths. In either case, the ability to numerically simulate the initiation and propagation of failures is a highly desired capability. This document describes one approach to the simulation of failure initiation and propagation.

  10. Advanced language modeling approaches, case study: Expert search

    NARCIS (Netherlands)

    Hiemstra, Djoerd

    2008-01-01

    This tutorial gives a clear and detailed overview of advanced language modeling approaches and tools, including the use of document priors, translation models, relevance models, parsimonious models and expectation maximization training. Expert search will be used as a case study to explain the

  11. Chemotaxis: A Multi-Scale Modeling Approach

    Science.gov (United States)

    Bhowmik, Arpan

    We are attempting to build a working simulation of population level self-organization in dictyostelium discoideum cells by combining existing models for chemo-attractant production and detection, along with phenomenological motility models. Our goal is to create a computationally-viable model-framework within which a population of cells can self-generate chemo-attractant waves and self-organize based on the directional cues of those waves. The work is a direct continuation of our previous work published in Physical Biology titled ``Excitable waves and direction-sensing in Dictyostelium Discoideum: steps towards a chemotaxis model''. This is a work in progress, no official draft/paper exists yet.

  12. An Integrated Approach to Modeling Evacuation Behavior

    Science.gov (United States)

    2011-02-01

    A spate of recent hurricanes and other natural disasters have drawn a lot of attention to the evacuation decision of individuals. Here we focus on evacuation models that incorporate two economic phenomena that seem to be increasingly important in exp...

  13. Infectious disease modeling a hybrid system approach

    CERN Document Server

    Liu, Xinzhi

    2017-01-01

    This volume presents infectious diseases modeled mathematically, taking seasonality and changes in population behavior into account, using a switched and hybrid systems framework. The scope of coverage includes background on mathematical epidemiology, including classical formulations and results; a motivation for seasonal effects and changes in population behavior, an investigation into term-time forced epidemic models with switching parameters, and a detailed account of several different control strategies. The main goal is to study these models theoretically and to establish conditions under which eradication or persistence of the disease is guaranteed. In doing so, the long-term behavior of the models is determined through mathematical techniques from switched systems theory. Numerical simulations are also given to augment and illustrate the theoretical results and to help study the efficacy of the control schemes.

  14. Challenges and opportunities for integrating lake ecosystem modelling approaches

    Science.gov (United States)

    Mooij, Wolf M.; Trolle, Dennis; Jeppesen, Erik; Arhonditsis, George; Belolipetsky, Pavel V.; Chitamwebwa, Deonatus B.R.; Degermendzhy, Andrey G.; DeAngelis, Donald L.; Domis, Lisette N. De Senerpont; Downing, Andrea S.; Elliott, J. Alex; Ruberto, Carlos Ruberto; Gaedke, Ursula; Genova, Svetlana N.; Gulati, Ramesh D.; Hakanson, Lars; Hamilton, David P.; Hipsey, Matthew R.; Hoen, Jochem 't; Hulsmann, Stephan; Los, F. Hans; Makler-Pick, Vardit; Petzoldt, Thomas; Prokopkin, Igor G.; Rinke, Karsten; Schep, Sebastiaan A.; Tominaga, Koji; Van Dam, Anne A.; Van Nes, Egbert H.; Wells, Scott A.; Janse, Jan H.

    2010-01-01

    A large number and wide variety of lake ecosystem models have been developed and published during the past four decades. We identify two challenges for making further progress in this field. One such challenge is to avoid developing more models largely following the concept of others ('reinventing the wheel'). The other challenge is to avoid focusing on only one type of model, while ignoring new and diverse approaches that have become available ('having tunnel vision'). In this paper, we aim at improving the awareness of existing models and knowledge of concurrent approaches in lake ecosystem modelling, without covering all possible model tools and avenues. First, we present a broad variety of modelling approaches. To illustrate these approaches, we give brief descriptions of rather arbitrarily selected sets of specific models. We deal with static models (steady state and regression models), complex dynamic models (CAEDYM, CE-QUAL-W2, Delft 3D-ECO, LakeMab, LakeWeb, MyLake, PCLake, PROTECH, SALMO), structurally dynamic models and minimal dynamic models. We also discuss a group of approaches that could all be classified as individual based: super-individual models (Piscator, Charisma), physiologically structured models, stage-structured models and trait-based models. We briefly mention genetic algorithms, neural networks, Kalman filters and fuzzy logic. Thereafter, we zoom in, as an in-depth example, on the multi-decadal development and application of the lake ecosystem model PCLake and related models (PCLake Metamodel, Lake Shira Model, IPH-TRIM3D-PCLake). In the discussion, we argue that while the historical development of each approach and model is understandable given its 'leading principle', there are many opportunities for combining approaches. We take the point of view that a single 'right' approach does not exist and should not be strived for. Instead, multiple modelling approaches, applied concurrently to a given problem, can help develop an integrative

  15. "Dispersion modeling approaches for near road | Science ...

    Science.gov (United States)

    Roadway design and roadside barriers can have significant effects on the dispersion of traffic-generated pollutants, especially in the near-road environment. Dispersion models that can accurately simulate these effects are needed to fully assess these impacts for a variety of applications. For example, such models can be useful for evaluating the mitigation potential of roadside barriers in reducing near-road exposures and their associated adverse health effects. Two databases, a tracer field study and a wind tunnel study, provide measurements used in the development and/or validation of algorithms to simulate dispersion in the presence of noise barriers. The tracer field study was performed in Idaho Falls, ID, USA with a 6-m noise barrier and a finite line source in a variety of atmospheric conditions. The second study was performed in the meteorological wind tunnel at the US EPA and simulated line sources at different distances from a model noise barrier to capture the effect on emissions from individual lanes of traffic. In both cases, velocity and concentration measurements characterized the effect of the barrier on dispersion.This paper presents comparisons with the two datasets of the barrier algorithms implemented in two different dispersion models: US EPA’s R-LINE (a research dispersion modelling tool under development by the US EPA’s Office of Research and Development) and CERC’s ADMS model (ADMS-Urban). In R-LINE the physical features reveal

  16. Workplace accommodations for employees with disabilities: A multilevel model of employer decision-making.

    Science.gov (United States)

    Telwatte, Apsara; Anglim, Jeromy; Wynton, Sarah K A; Moulding, Richard

    2017-02-01

    Existing research suggests that the decision to grant or deny workplace accommodations for people with disabilities is influenced by a range of legal and nonlegal factors. However, less is known about how these factors operate at the within-person level. Thus, we proposed and tested a multilevel model of the accommodation decision-making process, which we applied to better understand why people with psychological disabilities often experience greater challenges in obtaining accommodations. A sample of 159 Australian adults, composed mostly of managers and HR professionals, read 12 vignettes involving requests for accommodations from existing employees. The requests differed in whether they were for psychological or physical disabilities. For each vignette, participants rated their empathy with the employee, the legitimacy of the employee's disability, the necessity for productivity, the perceived cost, and the reasonableness, and indicated whether they would grant the accommodation. Multilevel modeling indicated that greater empathy, legitimacy, and necessity, and lower perceived cost predicted perceptions of greater reasonableness and greater granting. Accommodation requests from employees with psychological disabilities were seen as less reasonable and were less likely to be granted; much of this effect seemed to be driven by perceptions that such accommodations were less necessary for productivity. Ratings on accommodations were influenced both by general between-person tendencies and within-person appraisals of particular scenarios. The study points to a need for organizations to more clearly establish guidelines for how decision-makers should fairly evaluate accommodation requests for employees with psychological disabilities and disability more broadly. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  17. A Model-Based Systems Engineering Methodology for Employing Architecture In System Analysis: Developing Simulation Models Using Systems Modeling Language Products to Link Architecture and Analysis

    Science.gov (United States)

    2016-06-01

    Filling Designs for Complex System Simulations.” Ph.D. Dissertation, Naval Postgraduate School. MacCalman, Alex, Hyangshim Kwak, Mary McDonald, and...Michael, Peter Bryant, Mike Wilkinson, Paul King, Ady James, and Stuart Arnold. 2012. “Interpreting ‘Systems Architecting.’” Systems Engineering 15(4...Hyangshim Kwak, Mary McDonald, and Stephen Upton. 2015. “Capturing experimental design insights in support of the model-based systems engineering approach

  18. Employment of Lithuanian Statistical Data Into Tax-Benefit Micro-Simulation Models

    Directory of Open Access Journals (Sweden)

    Viginta Ivaškaitė-Tamošiūnė

    2012-07-01

    Full Text Available In this study, we aim to assess the “best fit” of the existing Lithuanian micro-datasets for constructing a national micro-simulation model. Specifically, we compare and evaluate the potential of two (state level representative micro-data surveys in terms of their potential to simulate Lithuanian (direct taxes, social contributions and social benefits. Both selected datasets contain rich information on the socio-economic and demographical conditions of the country: the Household Budget Survey (HBS for the years 2004 and 2005 and the European Community Statistics on Income and Living Conditions (EU-SILC in Lithuania for the year 2005. The selected databases offer the most comprehensive range of income and other socio-demographic attributes, needed for simulation of tax and contributions’ payers/amounts and benefits’ recipients/amounts. The evaluation of the dataset capacity to simulate these measures is done by a comparative statistical analysis. Among the comparative categories are definitions (of households, incomes, survey collection modes, level of aggregation of various variables, demographic and incomes variables and corresponding numbers (amounts.The comparative analysis of the HBS and EU-SILC datasets shows, that despite embedded differences and shortages regarding simulation capacities of both surveys, these datasets contain valuable and sufficient information for the purpose of simulation of Lithuanian tax-benefit policies.In general a conclusion could be drawn, that HBS offers higher possibilities of simulating the Lithuanian tax-benefit system. This dataset contains more detailed national income categories (i.e. recipients of maternity/paternity insurance, diverse pensions, etc.— information on which is not available in the EU-SILC. The latter dataset does not contain national policy system specific components, but offer information on income aggregates, such all old-age pensions, social exclusion benefits, etc. Additionally

  19. Toward real-time diffuse optical tomography: accelerating light propagation modeling employing parallel computing on GPU and CPU

    Science.gov (United States)

    Doulgerakis, Matthaios; Eggebrecht, Adam; Wojtkiewicz, Stanislaw; Culver, Joseph; Dehghani, Hamid

    2017-12-01

    Parameter recovery in diffuse optical tomography is a computationally expensive algorithm, especially when used for large and complex volumes, as in the case of human brain functional imaging. The modeling of light propagation, also known as the forward problem, is the computational bottleneck of the recovery algorithm, whereby the lack of a real-time solution is impeding practical and clinical applications. The objective of this work is the acceleration of the forward model, within a diffusion approximation-based finite-element modeling framework, employing parallelization to expedite the calculation of light propagation in realistic adult head models. The proposed methodology is applicable for modeling both continuous wave and frequency-domain systems with the results demonstrating a 10-fold speed increase when GPU architectures are available, while maintaining high accuracy. It is shown that, for a very high-resolution finite-element model of the adult human head with ˜600,000 nodes, consisting of heterogeneous layers, light propagation can be calculated at ˜0.25 s/excitation source.

  20. A consortium approach to glass furnace modeling.

    Energy Technology Data Exchange (ETDEWEB)

    Chang, S.-L.; Golchert, B.; Petrick, M.

    1999-04-20

    Using computational fluid dynamics to model a glass furnace is a difficult task for any one glass company, laboratory, or university to accomplish. The task of building a computational model of the furnace requires knowledge and experience in modeling two dissimilar regimes (the combustion space and the liquid glass bath), along with the skill necessary to couple these two regimes. Also, a detailed set of experimental data is needed in order to evaluate the output of the code to ensure that the code is providing proper results. Since all these diverse skills are not present in any one research institution, a consortium was formed between Argonne National Laboratory, Purdue University, Mississippi State University, and five glass companies in order to marshal these skills into one three-year program. The objective of this program is to develop a fully coupled, validated simulation of a glass melting furnace that may be used by industry to optimize the performance of existing furnaces.

  1. Fractal approach to computer-analytical modelling of tree crown

    International Nuclear Information System (INIS)

    Berezovskaya, F.S.; Karev, G.P.; Kisliuk, O.F.; Khlebopros, R.G.; Tcelniker, Yu.L.

    1993-09-01

    In this paper we discuss three approaches to the modeling of a tree crown development. These approaches are experimental (i.e. regressive), theoretical (i.e. analytical) and simulation (i.e. computer) modeling. The common assumption of these is that a tree can be regarded as one of the fractal objects which is the collection of semi-similar objects and combines the properties of two- and three-dimensional bodies. We show that a fractal measure of crown can be used as the link between the mathematical models of crown growth and light propagation through canopy. The computer approach gives the possibility to visualize a crown development and to calibrate the model on experimental data. In the paper different stages of the above-mentioned approaches are described. The experimental data for spruce, the description of computer system for modeling and the variant of computer model are presented. (author). 9 refs, 4 figs

  2. Employment of Lithuanian Statistical Data Into Tax-Benefit Micro-Simulation Models

    Directory of Open Access Journals (Sweden)

    Viginta Ivaškaitė-Tamošiūnė

    2013-01-01

    Full Text Available In this study, we aim to assess the “best fit” of the existing Lithuanian micro-datasets for constructing a national micro-simulation model. Specifically, we compare and evaluate the potential of two (state level representative micro-data surveys in terms of their potential to simulate Lithuanian (direct taxes, social contributions and social benefits. Both selected datasets contain rich information on the socio-economic and demographical conditions of the country: the Household Budget Survey (HBS for the years 2004 and 2005 and the European Community Statistics on Income and Living Conditions (EU-SILC in Lithuania for the year 2005. The selected databases offer the most comprehensive range of income and other socio-demographic attributes, needed for simulation of tax and contributions’ payers/amounts and benefits’ recipients/amounts. The evaluation of the dataset capacity to simulate these measures is done by a comparative statistical analysis. Among the comparative categories are definitions (of households, incomes, survey collection modes, level of aggregation of various variables, demographic and incomes variables and corresponding numbers (amounts. The comparative analysis of the HBS and EU-SILC datasets shows, that despite embedded differences and shortages regarding simulation capacities of both surveys, these datasets contain valuable and sufficient information for the purpose of simulation of Lithuanian tax-benefit policies. In general a conclusion could be drawn, that HBS offers higher possibilities of simulating the Lithuanian tax-benefit system. This dataset contains more detailed national income categories (i.e. recipients of maternity/paternity insurance, diverse pensions, etc.— information on which is not available in the EU-SILC. The latter dataset does not contain national policy system specific components, but offer information on income aggregates, such all old-age pensions, social exclusion benefits, etc

  3. Lipoprotein transport in the metabolic syndrome: pathophysiological and interventional studies employing stable isotopy and modelling methods.

    Science.gov (United States)

    Chan, Dick C; Barrett, P Hugh R; Watts, Gerald F

    2004-09-01

    The accompanying review in this issue of Clinical Science [Chan, Barrett and Watts (2004) Clin. Sci. 107, 221-232] presented an overview of lipoprotein physiology and the methodologies for stable isotope kinetic studies. The present review focuses on our understanding of the dysregulation and therapeutic regulation of lipoprotein transport in the metabolic syndrome based on the application of stable isotope and modelling methods. Dysregulation of lipoprotein metabolism in metabolic syndrome may be due to a combination of overproduction of VLDL [very-LDL (low-density lipoprotein)]-apo (apolipoprotein) B-100, decreased catabolism of apoB-containing particles and increased catabolism of HDL (high-density lipoprotein)-apoA-I particles. These abnormalities may be consequent on a global metabolic effect of insulin resistance, partly mediated by depressed plasma adiponectin levels, that collectively increases the flux of fatty acids from adipose tissue to the liver, the accumulation of fat in the liver and skeletal muscle, the hepatic secretion of VLDL-triacylglycerols and the remodelling of both LDL (low-density lipoprotein) and HDL particles in the circulation. These lipoprotein defects are also related to perturbations in both lipolytic enzymes and lipid transfer proteins. Our knowledge of the pathophysiology of lipoprotein metabolism in the metabolic syndrome is well complemented by extensive cell biological data. Nutritional modifications may favourably alter lipoprotein transport in the metabolic syndrome by collectively decreasing the hepatic secretion of VLDL-apoB and the catabolism of HDL-apoA-I, as well as by potentially increasing the clearance of LDL-apoB. Several pharmacological treatments, such as statins, fibrates or fish oils, can also correct the dyslipidaemia by diverse kinetic mechanisms of action, including decreased secretion and increased catabolism of apoB, as well as increased secretion and decreased catabolism of apoA-I. The complementary

  4. Phytoplankton as Particles - A New Approach to Modeling Algal Blooms

    Science.gov (United States)

    2013-07-01

    ER D C/ EL T R -1 3 -1 3 Civil Works Basic Research Program Phytoplankton as Particles – A New Approach to Modeling Algal Blooms E nv... Phytoplankton as Particles – A New Approach to Modeling Algal Blooms Carl F. Cerco and Mark R. Noel Environmental Laboratory U.S. Army Engineer Research... phytoplankton blooms can be modeled by treating phytoplankton as discrete particles capable of self- induced transport via buoyancy regulation or other

  5. Contribution of a companion modelling approach

    African Journals Online (AJOL)

    2009-09-16

    Sep 16, 2009 ... This paper describes the role of participatory modelling and simulation as a way to provide a meaningful framework to enable actors to understand the interdependencies in peri-urban catchment management. A role-playing game, connecting the quantitative and qualitative dynamics of the resources with ...

  6. Numerical modelling approach for mine backfill

    Indian Academy of Sciences (India)

    Muhammad Zaka Emad

    2017-07-24

    Jul 24, 2017 ... Abstract. Numerical modelling is broadly used for assessing complex scenarios in underground mines, including mining sequence and blast-induced vibrations from production blasting. Sublevel stoping mining methods with delayed backfill are extensively used to exploit steeply dipping ore bodies by ...

  7. Energy and development : A modelling approach

    NARCIS (Netherlands)

    van Ruijven, B.J.|info:eu-repo/dai/nl/304834521

    2008-01-01

    Rapid economic growth of developing countries like India and China implies that these countries become important actors in the global energy system. Examples of this impact are the present day oil shortages and rapidly increasing emissions of greenhouse gases. Global energy models are used explore

  8. Numerical modelling approach for mine backfill

    Indian Academy of Sciences (India)

    Muhammad Zaka Emad

    2017-07-24

    Jul 24, 2017 ... pulse is applied as a stress history on the CRF stope. Blast wave data obtained from the on-site monitoring are very complex. It requires processing before interpreting and using it for numerical models. Generally, mining compa- nies hire geophysics experts for interpretation of such data. The blast wave ...

  9. A new approach to model mixed hydrates

    Czech Academy of Sciences Publication Activity Database

    Hielscher, S.; Vinš, Václav; Jäger, A.; Hrubý, Jan; Breitkopf, C.; Span, R.

    2018-01-01

    Roč. 459, March (2018), s. 170-185 ISSN 0378-3812 R&D Projects: GA ČR(CZ) GA17-08218S Institutional support: RVO:61388998 Keywords : gas hydrate * mixture * modeling Subject RIV: BJ - Thermodynamics Impact factor: 2.473, year: 2016 https://www. science direct.com/ science /article/pii/S0378381217304983

  10. Energy and Development. A Modelling Approach

    International Nuclear Information System (INIS)

    Van Ruijven, B.J.

    2008-01-01

    Rapid economic growth of developing countries like India and China implies that these countries become important actors in the global energy system. Examples of this impact are the present day oil shortages and rapidly increasing emissions of greenhouse gases. Global energy models are used to explore possible future developments of the global energy system and identify policies to prevent potential problems. Such estimations of future energy use in developing countries are very uncertain. Crucial factors in the future energy use of these regions are electrification, urbanisation and income distribution, issues that are generally not included in present day global energy models. Model simulations in this thesis show that current insight in developments in low-income regions lead to a wide range of expected energy use in 2030 of the residential and transport sectors. This is mainly caused by many different model calibration options that result from the limited data availability for model development and calibration. We developed a method to identify the impact of model calibration uncertainty on future projections. We developed a new model for residential energy use in India, in collaboration with the Indian Institute of Science. Experiments with this model show that the impact of electrification and income distribution is less univocal than often assumed. The use of fuelwood, with related health risks, can decrease rapidly if the income of poor groups increases. However, there is a trade off in terms of CO2 emissions because these groups gain access to electricity and the ownership of appliances increases. Another issue is the potential role of new technologies in developing countries: will they use the opportunities of leapfrogging? We explored the potential role of hydrogen, an energy carrier that might play a central role in a sustainable energy system. We found that hydrogen only plays a role before 2050 under very optimistic assumptions. Regional energy

  11. Energy and Development. A Modelling Approach

    Energy Technology Data Exchange (ETDEWEB)

    Van Ruijven, B.J.

    2008-12-17

    Rapid economic growth of developing countries like India and China implies that these countries become important actors in the global energy system. Examples of this impact are the present day oil shortages and rapidly increasing emissions of greenhouse gases. Global energy models are used to explore possible future developments of the global energy system and identify policies to prevent potential problems. Such estimations of future energy use in developing countries are very uncertain. Crucial factors in the future energy use of these regions are electrification, urbanisation and income distribution, issues that are generally not included in present day global energy models. Model simulations in this thesis show that current insight in developments in low-income regions lead to a wide range of expected energy use in 2030 of the residential and transport sectors. This is mainly caused by many different model calibration options that result from the limited data availability for model development and calibration. We developed a method to identify the impact of model calibration uncertainty on future projections. We developed a new model for residential energy use in India, in collaboration with the Indian Institute of Science. Experiments with this model show that the impact of electrification and income distribution is less univocal than often assumed. The use of fuelwood, with related health risks, can decrease rapidly if the income of poor groups increases. However, there is a trade off in terms of CO2 emissions because these groups gain access to electricity and the ownership of appliances increases. Another issue is the potential role of new technologies in developing countries: will they use the opportunities of leapfrogging? We explored the potential role of hydrogen, an energy carrier that might play a central role in a sustainable energy system. We found that hydrogen only plays a role before 2050 under very optimistic assumptions. Regional energy

  12. Predicting the breakdown strength and lifetime of nanocomposites using a multi-scale modeling approach

    Science.gov (United States)

    Huang, Yanhui; Zhao, He; Wang, Yixing; Ratcliff, Tyree; Breneman, Curt; Brinson, L. Catherine; Chen, Wei; Schadler, Linda S.

    2017-08-01

    It has been found that doping dielectric polymers with a small amount of nanofiller or molecular additive can stabilize the material under a high field and lead to increased breakdown strength and lifetime. Choosing appropriate fillers is critical to optimizing the material performance, but current research largely relies on experimental trial and error. The employment of computer simulations for nanodielectric design is rarely reported. In this work, we propose a multi-scale modeling approach that employs ab initio, Monte Carlo, and continuum scales to predict the breakdown strength and lifetime of polymer nanocomposites based on the charge trapping effect of the nanofillers. The charge transfer, charge energy relaxation, and space charge effects are modeled in respective hierarchical scales by distinctive simulation techniques, and these models are connected together for high fidelity and robustness. The preliminary results show good agreement with the experimental data, suggesting its promise for use in the computer aided material design of high performance dielectrics.

  13. Dynamic Metabolic Model Building Based on the Ensemble Modeling Approach

    Energy Technology Data Exchange (ETDEWEB)

    Liao, James C. [Univ. of California, Los Angeles, CA (United States)

    2016-10-01

    Ensemble modeling of kinetic systems addresses the challenges of kinetic model construction, with respect to parameter value selection, and still allows for the rich insights possible from kinetic models. This project aimed to show that constructing, implementing, and analyzing such models is a useful tool for the metabolic engineering toolkit, and that they can result in actionable insights from models. Key concepts are developed and deliverable publications and results are presented.

  14. A cost-effective approach to produce 15N-labelled amino acids employing Chlamydomonas reinhardtii CC503.

    Science.gov (United States)

    Nicolás Carcelén, Jesús; Marchante-Gayón, Juan Manuel; González, Pablo Rodríguez; Valledor, Luis; Cañal, María Jesús; Alonso, José Ignacio García

    2017-08-18

    The use of enriched stable isotopes is of outstanding importance in chemical metrology as it allows the application of isotope dilution mass spectrometry (IDMS). Primary methods based on IDMS ensure the quality of the analytical measurements and traceability of the results to the international system of units. However, the synthesis of isotopically labelled molecules from enriched stable isotopes is an expensive and a difficult task. Either chemical and biochemical methods to produce labelled molecules have been proposed, but so far, few cost-effective methods have been described. The aim of this study was to use the microalgae Chlamydomonas reinhardtii to produce, at laboratory scale, 15 N-labelled amino acids with a high isotopic enrichment. To do that, a culture media containing 15 NH 4 Cl was used. No kinetic isotope effect (KIE) was observed. The labelled proteins biosynthesized by the microorganism were extracted from the biomass and the 15 N-labelled amino acids were obtained after a protein hydrolysis with HCl. The use of the wall deficient strain CC503 cw92 mt+ is fit for purpose, as it only assimilates ammonia as nitrogen source, avoiding isotope contamination with nitrogen from the atmosphere or the reagents used in the culture medium, and enhancing the protein extraction efficiency compared to cell-walled wild type Chlamydomonas. The isotopic enrichment of the labelled amino acids was calculated from their isotopic composition measured by gas chromatography mass spectrometry (GC-MS). The average isotopic enrichment for the 16 amino acids characterized was 99.56 ± 0.05% and the concentration of the amino acids in the hydrolysate ranged from 18 to 90 µg/mL. Previously reported biochemical methods to produce isotopically labelled proteins have been applied in the fields of proteomics and fluxomics. For these approaches, low amounts of products are required and the isotopic enrichment of the molecules has never been properly determined. So far, only 13

  15. Integration models: multicultural and liberal approaches confronted

    Science.gov (United States)

    Janicki, Wojciech

    2012-01-01

    European societies have been shaped by their Christian past, upsurge of international migration, democratic rule and liberal tradition rooted in religious tolerance. Boosting globalization processes impose new challenges on European societies, striving to protect their diversity. This struggle is especially clearly visible in case of minorities trying to resist melting into mainstream culture. European countries' legal systems and cultural policies respond to these efforts in many ways. Respecting identity politics-driven group rights seems to be the most common approach, resulting in creation of a multicultural society. However, the outcome of respecting group rights may be remarkably contradictory to both individual rights growing out from liberal tradition, and to reinforced concept of integration of immigrants into host societies. The hereby paper discusses identity politics upturn in the context of both individual rights and integration of European societies.

  16. Modelling thermal plume impacts - Kalpakkam approach

    International Nuclear Information System (INIS)

    Rao, T.S.; Anup Kumar, B.; Narasimhan, S.V.

    2002-01-01

    A good understanding of temperature patterns in the receiving waters is essential to know the heat dissipation from thermal plumes originating from coastal power plants. The seasonal temperature profiles of the Kalpakkam coast near Madras Atomic Power Station (MAPS) thermal out fall site are determined and analysed. It is observed that the seasonal current reversal in the near shore zone is one of the major mechanisms for the transport of effluents away from the point of mixing. To further refine our understanding of the mixing and dilution processes, it is necessary to numerically simulate the coastal ocean processes by parameterising the key factors concerned. In this paper, we outline the experimental approach to achieve this objective. (author)

  17. A novel multi-model probability battery state of charge estimation approach for electric vehicles using H-infinity algorithm

    International Nuclear Information System (INIS)

    Lin, Cheng; Mu, Hao; Xiong, Rui; Shen, Weixiang

    2016-01-01

    Highlights: • A novel multi-model probability battery SOC fusion estimation approach was proposed. • The linear matrix inequality-based H∞ technique is employed to estimate the SOC. • The Bayes theorem has been employed to realize the optimal weight for the fusion. • The robustness of the proposed approach is verified by different batteries. • The results show that the proposed method can promote global estimation accuracy. - Abstract: Due to the strong nonlinearity and complex time-variant property of batteries, the existing state of charge (SOC) estimation approaches based on a single equivalent circuit model (ECM) cannot provide the accurate SOC for the entire discharging period. This paper aims to present a novel SOC estimation approach based on a multiple ECMs fusion method for improving the practical application performance. In the proposed approach, three battery ECMs, namely the Thevenin model, the double polarization model and the 3rd order RC model, are selected to describe the dynamic voltage of lithium-ion batteries and the genetic algorithm is then used to determine the model parameters. The linear matrix inequality-based H-infinity technique is employed to estimate the SOC from the three models and the Bayes theorem-based probability method is employed to determine the optimal weights for synthesizing the SOCs estimated from the three models. Two types of lithium-ion batteries are used to verify the feasibility and robustness of the proposed approach. The results indicate that the proposed approach can improve the accuracy and reliability of the SOC estimation against uncertain battery materials and inaccurate initial states.

  18. Modelling approach for photochemical pollution studies

    International Nuclear Information System (INIS)

    Silibello, C.; Catenacci, G.; Calori, G.; Crapanzano, G.; Pirovano, G.

    1996-01-01

    The comprehension of the relationships between primary pollutants emissions and secondary pollutants concentration and deposition is necessary to design policies and strategies for the maintenance of a healthy environment. The use of mathematical models is a powerful tool to assess the effect of the emissions and of physical and chemical transformations of pollutants on air quality. A photochemical model, Calgrid, developed by CARB (California Air Resources Board), has been used to test the effect of different meteorological and air quality, scenarios on the ozone concentration levels. This way we can evaluate the influence of these conditions to determine the most important chemical species and reactions in atmosphere. The ozone levels are strongly related to the reactive hydrocarbons concentrations and to the solar radiation flux

  19. Development of RBMK-1500 Relap5 model by employing main circulation pump trip events at Ignalina NPP date base

    International Nuclear Information System (INIS)

    Kaliatka, A.; Krivoshein, G.; Uspuras, E.

    2001-01-01

    The Ignalina Nuclear Power Plant is a twin-unit with two RBMK-1500, graphite moderated, boiling water, multichannel reactors. The state of the art code RELAP5 was originally designed for Pressurized Water Reactors. Because of unique RBMK design, the application of this code to RBMK-1500 encountered several problems. The paper deals with the development of proper Ignalina NPP RELAP5 model and investigation of MCPs trip events. A successful best estimate RELAP5 model of the Ignalina NPP has been developed. This model includes the reactor main circulation circuit, reactor control systems and plant safety systems required for transient analysis. There were few events when one MCP was inadvertently tripped at the Ignalina NPP. On May 14, 1996 one MCP at Ignalina Unit 2 was inadvertently tripped. The similar event took place on January 23, 1998. During this event, the MCP check valve failed to close, causing a re-circulation loop to develop by means of a reversed flow through the tripped pump. On July 31, 2000 three MCPs at Ignalina Unit 2 were tripped one after another, due to inadvertent activation of fire protection system. Calculations performed with Ignalina NPP RELAP5 model agree favorably with the plant data. The developed RELAP5 model is proper and may be employed for the plant analysis. (author)

  20. Colour texture segmentation using modelling approach

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Mikeš, Stanislav

    2005-01-01

    Roč. 3687, č. - (2005), s. 484-491 ISSN 0302-9743. [International Conference on Advances in Pattern Recognition /3./. Bath, 22.08.2005-25.08.2005] R&D Projects: GA MŠk 1M0572; GA AV ČR 1ET400750407; GA AV ČR IAA2075302 Institutional research plan: CEZ:AV0Z10750506 Keywords : colour texture segmentation * image models * segmentation benchmark Subject RIV: BD - Theory of Information

  1. Tumour resistance to cisplatin: a modelling approach

    International Nuclear Information System (INIS)

    Marcu, L; Bezak, E; Olver, I; Doorn, T van

    2005-01-01

    Although chemotherapy has revolutionized the treatment of haematological tumours, in many common solid tumours the success has been limited. Some of the reasons for the limitations are: the timing of drug delivery, resistance to the drug, repopulation between cycles of chemotherapy and the lack of complete understanding of the pharmacokinetics and pharmacodynamics of a specific agent. Cisplatin is among the most effective cytotoxic agents used in head and neck cancer treatments. When modelling cisplatin as a single agent, the properties of cisplatin only have to be taken into account, reducing the number of assumptions that are considered in the generalized chemotherapy models. The aim of the present paper is to model the biological effect of cisplatin and to simulate the consequence of cisplatin resistance on tumour control. The 'treated' tumour is a squamous cell carcinoma of the head and neck, previously grown by computer-based Monte Carlo techniques. The model maintained the biological constitution of a tumour through the generation of stem cells, proliferating cells and non-proliferating cells. Cell kinetic parameters (mean cell cycle time, cell loss factor, thymidine labelling index) were also consistent with the literature. A sensitivity study on the contribution of various mechanisms leading to drug resistance is undertaken. To quantify the extent of drug resistance, the cisplatin resistance factor (CRF) is defined as the ratio between the number of surviving cells of the resistant population and the number of surviving cells of the sensitive population, determined after the same treatment time. It is shown that there is a supra-linear dependence of CRF on the percentage of cisplatin-DNA adducts formed, and a sigmoid-like dependence between CRF and the percentage of cells killed in resistant tumours. Drug resistance is shown to be a cumulative process which eventually can overcome tumour regression leading to treatment failure

  2. A scalable approach to modeling groundwater flow on massively parallel computers

    International Nuclear Information System (INIS)

    Ashby, S.F.; Falgout, R.D.; Tompson, A.F.B.

    1995-12-01

    We describe a fully scalable approach to the simulation of groundwater flow on a hierarchy of computing platforms, ranging from workstations to massively parallel computers. Specifically, we advocate the use of scalable conceptual models in which the subsurface model is defined independently of the computational grid on which the simulation takes place. We also describe a scalable multigrid algorithm for computing the groundwater flow velocities. We axe thus able to leverage both the engineer's time spent developing the conceptual model and the computing resources used in the numerical simulation. We have successfully employed this approach at the LLNL site, where we have run simulations ranging in size from just a few thousand spatial zones (on workstations) to more than eight million spatial zones (on the CRAY T3D)-all using the same conceptual model

  3. Agribusiness model approach to territorial food development

    Directory of Open Access Journals (Sweden)

    Murcia Hector Horacio

    2011-04-01

    Full Text Available

    Several research efforts have coordinated the academic program of Agricultural Business Management from the University De La Salle (Bogota D.C., to the design and implementation of a sustainable agribusiness model applied to food development, with territorial projection. Rural development is considered as a process that aims to improve the current capacity and potential of the inhabitant of the sector, which refers not only to production levels and productivity of agricultural items. It takes into account the guidelines of the Organization of the United Nations “Millennium Development Goals” and considered the concept of sustainable food and agriculture development, including food security and nutrition in an integrated interdisciplinary context, with holistic and systemic dimension. Analysis is specified by a model with an emphasis on sustainable agribusiness production chains related to agricultural food items in a specific region. This model was correlated with farm (technical objectives, family (social purposes and community (collective orientations projects. Within this dimension are considered food development concepts and methodologies of Participatory Action Research (PAR. Finally, it addresses the need to link the results to low-income communities, within the concepts of the “new rurality”.

  4. Smeared crack modelling approach for corrosion-induced concrete damage

    DEFF Research Database (Denmark)

    Thybo, Anna Emilie Anusha; Michel, Alexander; Stang, Henrik

    2017-01-01

    In this paper a smeared crack modelling approach is used to simulate corrosion-induced damage in reinforced concrete. The presented modelling approach utilizes a thermal analogy to mimic the expansive nature of solid corrosion products, while taking into account the penetration of corrosion...... products into the surrounding concrete, non-uniform precipitation of corrosion products, and creep. To demonstrate the applicability of the presented modelling approach, numerical predictions in terms of corrosion-induced deformations as well as formation and propagation of micro- and macrocracks were...

  5. Applied Regression Modeling A Business Approach

    CERN Document Server

    Pardoe, Iain

    2012-01-01

    An applied and concise treatment of statistical regression techniques for business students and professionals who have little or no background in calculusRegression analysis is an invaluable statistical methodology in business settings and is vital to model the relationship between a response variable and one or more predictor variables, as well as the prediction of a response value given values of the predictors. In view of the inherent uncertainty of business processes, such as the volatility of consumer spending and the presence of market uncertainty, business professionals use regression a

  6. Jackiw-Pi model: A superfield approach

    Science.gov (United States)

    Gupta, Saurabh

    2014-12-01

    We derive the off-shell nilpotent and absolutely anticommuting Becchi-Rouet-Stora-Tyutin (BRST) as well as anti-BRST transformations s ( a) b corresponding to the Yang-Mills gauge transformations of 3D Jackiw-Pi model by exploiting the "augmented" super-field formalism. We also show that the Curci-Ferrari restriction, which is a hallmark of any non-Abelian 1-form gauge theories, emerges naturally within this formalism and plays an instrumental role in providing the proof of absolute anticommutativity of s ( a) b .

  7. A modular approach to numerical human body modeling

    NARCIS (Netherlands)

    Forbes, P.A.; Griotto, G.; Rooij, L. van

    2007-01-01

    The choice of a human body model for a simulated automotive impact scenario must take into account both accurate model response and computational efficiency as key factors. This study presents a "modular numerical human body modeling" approach which allows the creation of a customized human body

  8. Mathematical Modeling in Mathematics Education: Basic Concepts and Approaches

    Science.gov (United States)

    Erbas, Ayhan Kürsat; Kertil, Mahmut; Çetinkaya, Bülent; Çakiroglu, Erdinç; Alacaci, Cengiz; Bas, Sinem

    2014-01-01

    Mathematical modeling and its role in mathematics education have been receiving increasing attention in Turkey, as in many other countries. The growing body of literature on this topic reveals a variety of approaches to mathematical modeling and related concepts, along with differing perspectives on the use of mathematical modeling in teaching and…

  9. Keyring models: An approach to steerability

    Science.gov (United States)

    Miller, Carl A.; Colbeck, Roger; Shi, Yaoyun

    2018-02-01

    If a measurement is made on one half of a bipartite system, then, conditioned on the outcome, the other half has a new reduced state. If these reduced states defy classical explanation—that is, if shared randomness cannot produce these reduced states for all possible measurements—the bipartite state is said to be steerable. Determining which states are steerable is a challenging problem even for low dimensions. In the case of two-qubit systems, a criterion is known for T-states (that is, those with maximally mixed marginals) under projective measurements. In the current work, we introduce the concept of keyring models—a special class of local hidden state models. When the measurements made correspond to real projectors, these allow us to study steerability beyond T-states. Using keyring models, we completely solve the steering problem for real projective measurements when the state arises from mixing a pure two-qubit state with uniform noise. We also give a partial solution in the case when the uniform noise is replaced by independent depolarizing channels.

  10. Employer Branding

    DEFF Research Database (Denmark)

    Frimann, Søren; Mønsted, Bolette Rye

    2012-01-01

    Employer branding er både for den private og den offentlige sektor blevet en måde, de kan imødekomme ændrede arbejdsmarkedsvilkår og organisatoriske udfordringer i en postmoderne og globaliseret verden. Den aktuelle finanskrise har skabt nye udfordringer for organisationer i deres bestræbelser på...... at tiltrække- og fastholde attraktive medarbejdere. Men hvilken betydning har det, når Grundfos siger ”Mennesket er i fokus”, og hvad siger ”mangfoldighed” om Københavns Kommune som arbejdsplads i relation til employer branding? Er der egentlig sammenhæng mellem tankerne bag employer branding og de eksternt...... kommunikerede employer brandprodukter. Eller bliver det unikke ved arbejdspladserne ersattet af buzzwords uden substans og inddragelse af ansatte og interessenter? Artiklen har til formål at vurdere disse spørgsmål på baggrund af analyser af to cases med employer branding....

  11. Functional RG approach to the Potts model

    Science.gov (United States)

    Ben Alì Zinati, Riccardo; Codello, Alessandro

    2018-01-01

    The critical behavior of the (n+1) -states Potts model in d-dimensions is studied with functional renormalization group techniques. We devise a general method to derive β-functions for continuous values of d and n and we write the flow equation for the effective potential (LPA’) when instead n is fixed. We calculate several critical exponents, which are found to be in good agreement with Monte Carlo simulations and ɛ-expansion results available in the literature. In particular, we focus on Percolation (n\\to0) and Spanning Forest (n\\to-1) which are the only non-trivial universality classes in d  =  4,5 and where our methods converge faster.

  12. Genetic Algorithm Approaches to Prebiobiotic Chemistry Modeling

    Science.gov (United States)

    Lohn, Jason; Colombano, Silvano

    1997-01-01

    We model an artificial chemistry comprised of interacting polymers by specifying two initial conditions: a distribution of polymers and a fixed set of reversible catalytic reactions. A genetic algorithm is used to find a set of reactions that exhibit a desired dynamical behavior. Such a technique is useful because it allows an investigator to determine whether a specific pattern of dynamics can be produced, and if it can, the reaction network found can be then analyzed. We present our results in the context of studying simplified chemical dynamics in theorized protocells - hypothesized precursors of the first living organisms. Our results show that given a small sample of plausible protocell reaction dynamics, catalytic reaction sets can be found. We present cases where this is not possible and also analyze the evolved reaction sets.

  13. Carbonate rock depositional models: A microfacies approach

    Energy Technology Data Exchange (ETDEWEB)

    Carozzi, A.V.

    1988-01-01

    Carbonate rocks contain more than 50% by weight carbonate minerals such as calcite, dolomite, and siderite. Understanding how these rocks form can lead to more efficient methods of petroleum exploration. Micofacies analysis techniques can be used as a method of predicting models of sedimentation for carbonate rocks. Micofacies in carbonate rocks can be seen clearly only in thin sections under a microscope. This section analysis of carbonate rocks is a tool that can be used to understand depositional environments, diagenetic evolution of carbonate rocks, and the formation of porosity and permeability in carbonate rocks. The use of micofacies analysis techniques is applied to understanding the origin and formation of carbonate ramps, carbonate platforms, and carbonate slopes and basins. This book will be of interest to students and professionals concerned with the disciplines of sedimentary petrology, sedimentology, petroleum geology, and palentology.

  14. Wind Turbine Control: Robust Model Based Approach

    DEFF Research Database (Denmark)

    Mirzaei, Mahmood

    . This is because, on the one hand, control methods can decrease the cost of energy by keeping the turbine close to its maximum efficiency. On the other hand, they can reduce structural fatigue and therefore increase the lifetime of the wind turbine. The power produced by a wind turbine is proportional...... to the square of its rotor radius, therefore it seems reasonable to increase the size of the wind turbine in order to capture more power. However as the size increases, the mass of the blades increases by cube of the rotor size. This means in order to keep structural feasibility and mass of the whole structure...... reasonable, the ratio of mass to size should be reduced. This trend results in more flexible structures. Control of the flexible structure of a wind turbine in a wind field with stochastic nature is very challenging. In this thesis we are examining a number of robust model based methods for wind turbine...

  15. Risk prediction model: Statistical and artificial neural network approach

    Science.gov (United States)

    Paiman, Nuur Azreen; Hariri, Azian; Masood, Ibrahim

    2017-04-01

    Prediction models are increasingly gaining popularity and had been used in numerous areas of studies to complement and fulfilled clinical reasoning and decision making nowadays. The adoption of such models assist physician's decision making, individual's behavior, and consequently improve individual outcomes and the cost-effectiveness of care. The objective of this paper is to reviewed articles related to risk prediction model in order to understand the suitable approach, development and the validation process of risk prediction model. A qualitative review of the aims, methods and significant main outcomes of the nineteen published articles that developed risk prediction models from numerous fields were done. This paper also reviewed on how researchers develop and validate the risk prediction models based on statistical and artificial neural network approach. From the review done, some methodological recommendation in developing and validating the prediction model were highlighted. According to studies that had been done, artificial neural network approached in developing the prediction model were more accurate compared to statistical approach. However currently, only limited published literature discussed on which approach is more accurate for risk prediction model development.

  16. A dual model approach to ground water recovery trench design

    International Nuclear Information System (INIS)

    Clodfelter, C.L.; Crouch, M.S.

    1992-01-01

    The design of trenches for contaminated ground water recovery must consider several variables. This paper presents a dual-model approach for effectively recovering contaminated ground water migrating toward a trench by advection. The approach involves an analytical model to determine the vertical influence of the trench and a numerical flow model to determine the capture zone within the trench and the surrounding aquifer. The analytical model is utilized by varying trench dimensions and head values to design a trench which meets the remediation criteria. The numerical flow model is utilized to select the type of backfill and location of sumps within the trench. The dual-model approach can be used to design a recovery trench which effectively captures advective migration of contaminants in the vertical and horizontal planes

  17. A hybrid modelling approach to simulating foot-and-mouth disease outbreaks in Australian livestock

    Directory of Open Access Journals (Sweden)

    Richard A Bradhurst

    2015-03-01

    Full Text Available Foot-and-mouth disease (FMD is a highly contagious and economically important viral disease of cloven-hoofed animals. Australia's freedom from FMD underpins a valuable trade in live animals and animal products. An outbreak of FMD would result in the loss of export markets and cause severe disruption to domestic markets. The prevention of, and contingency planning for, FMD are of key importance to government, industry, producers and the community. The spread and control of FMD is complex and dynamic due to a highly contagious multi-host pathogen operating in a heterogeneous environment across multiple jurisdictions. Epidemiological modelling is increasingly being recognized as a valuable tool for investigating the spread of disease under different conditions and the effectiveness of control strategies. Models of infectious disease can be broadly classified as: population-based models that are formulated from the top-down and employ population-level relationships to describe individual-level behaviour, individual-based models that are formulated from the bottom-up and aggregate individual-level behaviour to reveal population-level relationships, or hybrid models which combine the two approaches into a single model.The Australian Animal Disease Spread (AADIS hybrid model employs a deterministic equation-based model (EBM to model within-herd spread of FMD, and a stochastic, spatially-explicit agent-based model (ABM to model between-herd spread and control. The EBM provides concise and computationally efficient predictions of herd prevalence and clinical signs over time. The ABM captures the complex, stochastic and heterogeneous environment in which an FMD epidemic operates. The AADIS event-driven hybrid EBM/ABM architecture is a flexible, efficient and extensible framework for modelling the spread and control of disease in livestock on a national scale. We present an overview of the AADIS hybrid approach and a description of the model

  18. Simple queueing approach to segregation dynamics in Schelling model

    OpenAIRE

    Sobkowicz, Pawel

    2007-01-01

    A simple queueing approach for segregation of agents in modified one dimensional Schelling segregation model is presented. The goal is to arrive at simple formula for the number of unhappy agents remaining after the segregation.

  19. MGF approach to the capacity analysis of Generalized Two-Ray fading models

    KAUST Repository

    Rao, Milind

    2015-09-11

    We propose a class of Generalized Two-Ray (GTR) fading channels that consists of two line of sight (LOS) components with random phase and a diffuse component. Observing that the GTR fading model can be expressed in terms of the underlying Rician distribution, we derive a closed-form expression for the moment generating function (MGF) of the signal-to-noise ratio (SNR) of this model. We then employ this approach to compute the ergodic capacity with receiver side information. The impact of the underlying phase difference between the LOS components on the average SNR of the signal received is also illustrated. © 2015 IEEE.

  20. A systemic approach for modeling soil functions

    Science.gov (United States)

    Vogel, Hans-Jörg; Bartke, Stephan; Daedlow, Katrin; Helming, Katharina; Kögel-Knabner, Ingrid; Lang, Birgit; Rabot, Eva; Russell, David; Stößel, Bastian; Weller, Ulrich; Wiesmeier, Martin; Wollschläger, Ute

    2018-03-01

    The central importance of soil for the functioning of terrestrial systems is increasingly recognized. Critically relevant for water quality, climate control, nutrient cycling and biodiversity, soil provides more functions than just the basis for agricultural production. Nowadays, soil is increasingly under pressure as a limited resource for the production of food, energy and raw materials. This has led to an increasing demand for concepts assessing soil functions so that they can be adequately considered in decision-making aimed at sustainable soil management. The various soil science disciplines have progressively developed highly sophisticated methods to explore the multitude of physical, chemical and biological processes in soil. It is not obvious, however, how the steadily improving insight into soil processes may contribute to the evaluation of soil functions. Here, we present to a new systemic modeling framework that allows for a consistent coupling between reductionist yet observable indicators for soil functions with detailed process understanding. It is based on the mechanistic relationships between soil functional attributes, each explained by a network of interacting processes as derived from scientific evidence. The non-linear character of these interactions produces stability and resilience of soil with respect to functional characteristics. We anticipate that this new conceptional framework will integrate the various soil science disciplines and help identify important future research questions at the interface between disciplines. It allows the overwhelming complexity of soil systems to be adequately coped with and paves the way for steadily improving our capability to assess soil functions based on scientific understanding.

  1. An approach to adjustment of relativistic mean field model parameters

    Directory of Open Access Journals (Sweden)

    Bayram Tuncay

    2017-01-01

    Full Text Available The Relativistic Mean Field (RMF model with a small number of adjusted parameters is powerful tool for correct predictions of various ground-state nuclear properties of nuclei. Its success for describing nuclear properties of nuclei is directly related with adjustment of its parameters by using experimental data. In the present study, the Artificial Neural Network (ANN method which mimics brain functionality has been employed for improvement of the RMF model parameters. In particular, the understanding capability of the ANN method for relations between the RMF model parameters and their predictions for binding energies (BEs of 58Ni and 208Pb have been found in agreement with the literature values.

  2. A Constructive Neural-Network Approach to Modeling Psychological Development

    Science.gov (United States)

    Shultz, Thomas R.

    2012-01-01

    This article reviews a particular computational modeling approach to the study of psychological development--that of constructive neural networks. This approach is applied to a variety of developmental domains and issues, including Piagetian tasks, shift learning, language acquisition, number comparison, habituation of visual attention, concept…

  3. Towards Translating Graph Transformation Approaches by Model Transformations

    NARCIS (Netherlands)

    Hermann, F.; Kastenberg, H.; Modica, T.; Karsai, G.; Taentzer, G.

    2006-01-01

    Recently, many researchers are working on semantics preserving model transformation. In the field of graph transformation one can think of translating graph grammars written in one approach to a behaviourally equivalent graph grammar in another approach. In this paper we translate graph grammars

  4. An Almost Integration-free Approach to Ordered Response Models

    NARCIS (Netherlands)

    van Praag, B.M.S.; Ferrer-i-Carbonell, A.

    2006-01-01

    'In this paper we propose an alternative approach to the estimation of ordered response models. We show that the Probit-method may be replaced by a simple OLS-approach, called P(robit)OLS, without any loss of efficiency. This method can be generalized to the analysis of panel data. For large-scale

  5. Optimizing technology investments: a broad mission model approach

    Science.gov (United States)

    Shishko, R.

    2003-01-01

    A long-standing problem in NASA is how to allocate scarce technology development resources across advanced technologies in order to best support a large set of future potential missions. Within NASA, two orthogonal paradigms have received attention in recent years: the real-options approach and the broad mission model approach. This paper focuses on the latter.

  6. A generalized quarter car modelling approach with frame flexibility ...

    Indian Academy of Sciences (India)

    ... mass distribution and damping. Here we propose a generalized quarter-car modelling approach, incorporating both the frame as well as other-wheel ground contacts. Our approach is linear, uses Laplace transforms, involves vertical motions of key points of interest and has intermediate complexity with improved realism.

  7. Fitting additive hazards models for case-cohort studies: a multiple imputation approach.

    Science.gov (United States)

    Jung, Jinhyouk; Harel, Ofer; Kang, Sangwook

    2016-07-30

    In this paper, we consider fitting semiparametric additive hazards models for case-cohort studies using a multiple imputation approach. In a case-cohort study, main exposure variables are measured only on some selected subjects, but other covariates are often available for the whole cohort. We consider this as a special case of a missing covariate by design. We propose to employ a popular incomplete data method, multiple imputation, for estimation of the regression parameters in additive hazards models. For imputation models, an imputation modeling procedure based on a rejection sampling is developed. A simple imputation modeling that can naturally be applied to a general missing-at-random situation is also considered and compared with the rejection sampling method via extensive simulation studies. In addition, a misspecification aspect in imputation modeling is investigated. The proposed procedures are illustrated using a cancer data example. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  8. Numerical approaches to expansion process modeling

    Directory of Open Access Journals (Sweden)

    G. V. Alekseev

    2017-01-01

    Full Text Available Forage production is currently undergoing a period of intensive renovation and introduction of the most advanced technologies and equipment. More and more often such methods as barley toasting, grain extrusion, steaming and grain flattening, boiling bed explosion, infrared ray treatment of cereals and legumes, followed by flattening, and one-time or two-time granulation of the purified whole grain without humidification in matrix presses By grinding the granules. These methods require special apparatuses, machines, auxiliary equipment, created on the basis of different methods of compiled mathematical models. When roasting, simulating the heat fields arising in the working chamber, provide such conditions, the decomposition of a portion of the starch to monosaccharides, which makes the grain sweetish, but due to protein denaturation the digestibility of the protein and the availability of amino acids decrease somewhat. Grain is roasted mainly for young animals in order to teach them to eat food at an early age, stimulate the secretory activity of digestion, better development of the masticatory muscles. In addition, the high temperature is detrimental to bacterial contamination and various types of fungi, which largely avoids possible diseases of the gastrointestinal tract. This method has found wide application directly on the farms. Apply when used in feeding animals and legumes: peas, soy, lupine and lentils. These feeds are preliminarily ground, and then cooked or steamed for 1 hour for 30–40 minutes. In the feed mill. Such processing of feeds allows inactivating the anti-nutrients in them, which reduce the effectiveness of their use. After processing, legumes are used as protein supplements in an amount of 25–30% of the total nutritional value of the diet. But it is recommended to cook and steal a grain of good quality. A poor-quality grain that has been stored for a long time and damaged by pathogenic micro flora is subject to

  9. Graphical approach to model reduction for nonlinear biochemical networks.

    Science.gov (United States)

    Holland, David O; Krainak, Nicholas C; Saucerman, Jeffrey J

    2011-01-01

    Model reduction is a central challenge to the development and analysis of multiscale physiology models. Advances in model reduction are needed not only for computational feasibility but also for obtaining conceptual insights from complex systems. Here, we introduce an intuitive graphical approach to model reduction based on phase plane analysis. Timescale separation is identified by the degree of hysteresis observed in phase-loops, which guides a "concentration-clamp" procedure for estimating explicit algebraic relationships between species equilibrating on fast timescales. The primary advantages of this approach over Jacobian-based timescale decomposition are that: 1) it incorporates nonlinear system dynamics, and 2) it can be easily visualized, even directly from experimental data. We tested this graphical model reduction approach using a 25-variable model of cardiac β(1)-adrenergic signaling, obtaining 6- and 4-variable reduced models that retain good predictive capabilities even in response to new perturbations. These 6 signaling species appear to be optimal "kinetic biomarkers" of the overall β(1)-adrenergic pathway. The 6-variable reduced model is well suited for integration into multiscale models of heart function, and more generally, this graphical model reduction approach is readily applicable to a variety of other complex biological systems.

  10. Graphical approach to model reduction for nonlinear biochemical networks.

    Directory of Open Access Journals (Sweden)

    David O Holland

    Full Text Available Model reduction is a central challenge to the development and analysis of multiscale physiology models. Advances in model reduction are needed not only for computational feasibility but also for obtaining conceptual insights from complex systems. Here, we introduce an intuitive graphical approach to model reduction based on phase plane analysis. Timescale separation is identified by the degree of hysteresis observed in phase-loops, which guides a "concentration-clamp" procedure for estimating explicit algebraic relationships between species equilibrating on fast timescales. The primary advantages of this approach over Jacobian-based timescale decomposition are that: 1 it incorporates nonlinear system dynamics, and 2 it can be easily visualized, even directly from experimental data. We tested this graphical model reduction approach using a 25-variable model of cardiac β(1-adrenergic signaling, obtaining 6- and 4-variable reduced models that retain good predictive capabilities even in response to new perturbations. These 6 signaling species appear to be optimal "kinetic biomarkers" of the overall β(1-adrenergic pathway. The 6-variable reduced model is well suited for integration into multiscale models of heart function, and more generally, this graphical model reduction approach is readily applicable to a variety of other complex biological systems.

  11. Data Analysis A Model Comparison Approach, Second Edition

    CERN Document Server

    Judd, Charles M; Ryan, Carey S

    2008-01-01

    This completely rewritten classic text features many new examples, insights and topics including mediational, categorical, and multilevel models. Substantially reorganized, this edition provides a briefer, more streamlined examination of data analysis. Noted for its model-comparison approach and unified framework based on the general linear model, the book provides readers with a greater understanding of a variety of statistical procedures. This consistent framework, including consistent vocabulary and notation, is used throughout to develop fewer but more powerful model building techniques. T

  12. A Model Management Approach for Co-Simulation Model Evaluation

    NARCIS (Netherlands)

    Zhang, X.C.; Broenink, Johannes F.; Filipe, Joaquim; Kacprzyk, Janusz; Pina, Nuno

    2011-01-01

    Simulating formal models is a common means for validating the correctness of the system design and reduce the time-to-market. In most of the embedded control system design, multiple engineering disciplines and various domain-specific models are often involved, such as mechanical, control, software

  13. Maine's Employability Skills Program

    Science.gov (United States)

    McMahon, John M.; Wolffe, Karen E.; Wolfe, Judy; Brooker, Carrie

    2013-01-01

    This Practice Report describes the development and implementation of the "Maine Employability Skills Program," a model employment program developed by the Maine Division for the Blind and Visually Impaired (DBVI). The program was designed to support the efforts of the chronically unemployed or underemployed. These consumers were either…

  14. Who will have Sustainable Employment After a Back Injury? The Development of a Clinical Prediction Model in a Cohort of Injured Workers.

    Science.gov (United States)

    Shearer, Heather M; Côté, Pierre; Boyle, Eleanor; Hayden, Jill A; Frank, John; Johnson, William G

    2017-09-01

    Purpose Our objective was to develop a clinical prediction model to identify workers with sustainable employment following an episode of work-related low back pain (LBP). Methods We used data from a cohort study of injured workers with incident LBP claims in the USA to predict employment patterns 1 and 6 months following a workers' compensation claim. We developed three sequential models to determine the contribution of three domains of variables: (1) basic demographic/clinical variables; (2) health-related variables; and (3) work-related factors. Multivariable logistic regression was used to develop the predictive models. We constructed receiver operator curves and used the c-index to measure predictive accuracy. Results Seventy-nine percent and 77 % of workers had sustainable employment at 1 and 6 months, respectively. Sustainable employment at 1 month was predicted by initial back pain intensity, mental health-related quality of life, claim litigation and employer type (c-index = 0.77). At 6 months, sustainable employment was predicted by physical and mental health-related quality of life, claim litigation and employer type (c-index = 0.77). Adding health-related and work-related variables to models improved predictive accuracy by 8.5 and 10 % at 1 and 6 months respectively. Conclusion We developed clinically-relevant models to predict sustainable employment in injured workers who made a workers' compensation claim for LBP. Inquiring about back pain intensity, physical and mental health-related quality of life, claim litigation and employer type may be beneficial in developing programs of care. Our models need to be validated in other populations.

  15. A novel approach to modeling and diagnosing the cardiovascular system

    Energy Technology Data Exchange (ETDEWEB)

    Keller, P.E.; Kangas, L.J.; Hashem, S.; Kouzes, R.T. [Pacific Northwest Lab., Richland, WA (United States); Allen, P.A. [Life Link, Richland, WA (United States)

    1995-07-01

    A novel approach to modeling and diagnosing the cardiovascular system is introduced. A model exhibits a subset of the dynamics of the cardiovascular behavior of an individual by using a recurrent artificial neural network. Potentially, a model will be incorporated into a cardiovascular diagnostic system. This approach is unique in that each cardiovascular model is developed from physiological measurements of an individual. Any differences between the modeled variables and the variables of an individual at a given time are used for diagnosis. This approach also exploits sensor fusion to optimize the utilization of biomedical sensors. The advantage of sensor fusion has been demonstrated in applications including control and diagnostics of mechanical and chemical processes.

  16. A model-driven approach to information security compliance

    Science.gov (United States)

    Correia, Anacleto; Gonçalves, António; Teodoro, M. Filomena

    2017-06-01

    The availability, integrity and confidentiality of information are fundamental to the long-term survival of any organization. Information security is a complex issue that must be holistically approached, combining assets that support corporate systems, in an extended network of business partners, vendors, customers and other stakeholders. This paper addresses the conception and implementation of information security systems, conform the ISO/IEC 27000 set of standards, using the model-driven approach. The process begins with the conception of a domain level model (computation independent model) based on information security vocabulary present in the ISO/IEC 27001 standard. Based on this model, after embedding in the model mandatory rules for attaining ISO/IEC 27001 conformance, a platform independent model is derived. Finally, a platform specific model serves the base for testing the compliance of information security systems with the ISO/IEC 27000 set of standards.

  17. Reusable Component Model Development Approach for Parallel and Distributed Simulation

    Science.gov (United States)

    Zhu, Feng; Yao, Yiping; Chen, Huilong; Yao, Feng

    2014-01-01

    Model reuse is a key issue to be resolved in parallel and distributed simulation at present. However, component models built by different domain experts usually have diversiform interfaces, couple tightly, and bind with simulation platforms closely. As a result, they are difficult to be reused across different simulation platforms and applications. To address the problem, this paper first proposed a reusable component model framework. Based on this framework, then our reusable model development approach is elaborated, which contains two phases: (1) domain experts create simulation computational modules observing three principles to achieve their independence; (2) model developer encapsulates these simulation computational modules with six standard service interfaces to improve their reusability. The case study of a radar model indicates that the model developed using our approach has good reusability and it is easy to be used in different simulation platforms and applications. PMID:24729751

  18. Mathematical models for therapeutic approaches to control HIV disease transmission

    CERN Document Server

    Roy, Priti Kumar

    2015-01-01

    The book discusses different therapeutic approaches based on different mathematical models to control the HIV/AIDS disease transmission. It uses clinical data, collected from different cited sources, to formulate the deterministic as well as stochastic mathematical models of HIV/AIDS. It provides complementary approaches, from deterministic and stochastic points of view, to optimal control strategy with perfect drug adherence and also tries to seek viewpoints of the same issue from different angles with various mathematical models to computer simulations. The book presents essential methods and techniques for students who are interested in designing epidemiological models on HIV/AIDS. It also guides research scientists, working in the periphery of mathematical modeling, and helps them to explore a hypothetical method by examining its consequences in the form of a mathematical modelling and making some scientific predictions. The model equations, mathematical analysis and several numerical simulations that are...

  19. Systematic narrative review of decision frameworks to select the appropriate modelling approaches for health economic evaluations.

    Science.gov (United States)

    Tsoi, B; O'Reilly, D; Jegathisawaran, J; Tarride, J-E; Blackhouse, G; Goeree, R

    2015-06-17

    In constructing or appraising a health economic model, an early consideration is whether the modelling approach selected is appropriate for the given decision problem. Frameworks and taxonomies that distinguish between modelling approaches can help make this decision more systematic and this study aims to identify and compare the decision frameworks proposed to date on this topic area. A systematic review was conducted to identify frameworks from peer-reviewed and grey literature sources. The following databases were searched: OVID Medline and EMBASE; Wiley's Cochrane Library and Health Economic Evaluation Database; PubMed; and ProQuest. Eight decision frameworks were identified, each focused on a different set of modelling approaches and employing a different collection of selection criterion. The selection criteria can be categorized as either: (i) structural features (i.e. technical elements that are factual in nature) or (ii) practical considerations (i.e. context-dependent attributes). The most commonly mentioned structural features were population resolution (i.e. aggregate vs. individual) and interactivity (i.e. static vs. dynamic). Furthermore, understanding the needs of the end-users and stakeholders was frequently incorporated as a criterion within these frameworks. There is presently no universally-accepted framework for selecting an economic modelling approach. Rather, each highlights different criteria that may be of importance when determining whether a modelling approach is appropriate. Further discussion is thus necessary as the modelling approach selected will impact the validity of the underlying economic model and have downstream implications on its efficiency, transparency and relevance to decision-makers.

  20. Selection of hydrologic modeling approaches for climate change assessment: A comparison of model scale and structures

    Science.gov (United States)

    Surfleet, Christopher G.; Tullos, Desirèe; Chang, Heejun; Jung, Il-Won

    2012-09-01

    SummaryA wide variety of approaches to hydrologic (rainfall-runoff) modeling of river basins confounds our ability to select, develop, and interpret models, particularly in the evaluation of prediction uncertainty associated with climate change assessment. To inform the model selection process, we characterized and compared three structurally-distinct approaches and spatial scales of parameterization to modeling catchment hydrology: a large-scale approach (using the VIC model; 671,000 km2 area), a basin-scale approach (using the PRMS model; 29,700 km2 area), and a site-specific approach (the GSFLOW model; 4700 km2 area) forced by the same future climate estimates. For each approach, we present measures of fit to historic observations and predictions of future response, as well as estimates of model parameter uncertainty, when available. While the site-specific approach generally had the best fit to historic measurements, the performance of the model approaches varied. The site-specific approach generated the best fit at unregulated sites, the large scale approach performed best just downstream of flood control projects, and model performance varied at the farthest downstream sites where streamflow regulation is mitigated to some extent by unregulated tributaries and water diversions. These results illustrate how selection of a modeling approach and interpretation of climate change projections require (a) appropriate parameterization of the models for climate and hydrologic processes governing runoff generation in the area under study, (b) understanding and justifying the assumptions and limitations of the model, and (c) estimates of uncertainty associated with the modeling approach.

  1. Interoperable transactions in business models: A structured approach

    NARCIS (Netherlands)

    Weigand, H.; Verharen, E.; Dignum, F.P.M.

    1996-01-01

    Recent database research has given much attention to the specification of "flexible" transactions that can be used in interoperable systems. Starting from a quite different angle, Business Process Modelling has approached the area of communication modelling as well (the Language/Action

  2. A Model-Driven Approach to e-Course Management

    Science.gov (United States)

    Savic, Goran; Segedinac, Milan; Milenkovic, Dušica; Hrin, Tamara; Segedinac, Mirjana

    2018-01-01

    This paper presents research on using a model-driven approach to the development and management of electronic courses. We propose a course management system which stores a course model represented as distinct machine-readable components containing domain knowledge of different course aspects. Based on this formally defined platform-independent…

  3. Modeling Alaska boreal forests with a controlled trend surface approach

    Science.gov (United States)

    Mo Zhou; Jingjing Liang

    2012-01-01

    An approach of Controlled Trend Surface was proposed to simultaneously take into consideration large-scale spatial trends and nonspatial effects. A geospatial model of the Alaska boreal forest was developed from 446 permanent sample plots, which addressed large-scale spatial trends in recruitment, diameter growth, and mortality. The model was tested on two sets of...

  4. Sensitivity analysis approaches applied to systems biology models.

    Science.gov (United States)

    Zi, Z

    2011-11-01

    With the rising application of systems biology, sensitivity analysis methods have been widely applied to study the biological systems, including metabolic networks, signalling pathways and genetic circuits. Sensitivity analysis can provide valuable insights about how robust the biological responses are with respect to the changes of biological parameters and which model inputs are the key factors that affect the model outputs. In addition, sensitivity analysis is valuable for guiding experimental analysis, model reduction and parameter estimation. Local and global sensitivity analysis approaches are the two types of sensitivity analysis that are commonly applied in systems biology. Local sensitivity analysis is a classic method that studies the impact of small perturbations on the model outputs. On the other hand, global sensitivity analysis approaches have been applied to understand how the model outputs are affected by large variations of the model input parameters. In this review, the author introduces the basic concepts of sensitivity analysis approaches applied to systems biology models. Moreover, the author discusses the advantages and disadvantages of different sensitivity analysis methods, how to choose a proper sensitivity analysis approach, the available sensitivity analysis tools for systems biology models and the caveats in the interpretation of sensitivity analysis results.

  5. Towards modeling future energy infrastructures - the ELECTRA system engineering approach

    DEFF Research Database (Denmark)

    Uslar, Mathias; Heussen, Kai

    2016-01-01

    of the IEC 62559 use case template as well as needed changes to cope particularly with the aspects of controller conflicts and Greenfield technology modeling. From the original envisioned use of the standards, we show a possible transfer on how to properly deal with a Greenfield approach when modeling....

  6. Child human model development: a hybrid validation approach

    NARCIS (Netherlands)

    Forbes, P.A.; Rooij, L. van; Rodarius, C.; Crandall, J.

    2008-01-01

    The current study presents a development and validation approach of a child human body model that will help understand child impact injuries and improve the biofidelity of child anthropometric test devices. Due to the lack of fundamental child biomechanical data needed to fully develop such models a

  7. Refining the Committee Approach and Uncertainty Prediction in Hydrological Modelling

    NARCIS (Netherlands)

    Kayastha, N.

    2014-01-01

    Due to the complexity of hydrological systems a single model may be unable to capture the full range of a catchment response and accurately predict the streamflows. The multi modelling approach opens up possibilities for handling such difficulties and allows improve the predictive capability of

  8. Refining the committee approach and uncertainty prediction in hydrological modelling

    NARCIS (Netherlands)

    Kayastha, N.

    2014-01-01

    Due to the complexity of hydrological systems a single model may be unable to capture the full range of a catchment response and accurately predict the streamflows. The multi modelling approach opens up possibilities for handling such difficulties and allows improve the predictive capability of

  9. Product Trial Processing (PTP): a model approach from ...

    African Journals Online (AJOL)

    Product Trial Processing (PTP): a model approach from theconsumer's perspective. ... Global Journal of Social Sciences ... Among the constructs used in the model of consumer's processing of product trail includes; experiential and non- experiential attributes, perceived validity of product trial, consumer perceived expertise, ...

  10. A MIXTURE LIKELIHOOD APPROACH FOR GENERALIZED LINEAR-MODELS

    NARCIS (Netherlands)

    WEDEL, M; DESARBO, WS

    1995-01-01

    A mixture model approach is developed that simultaneously estimates the posterior membership probabilities of observations to a number of unobservable groups or latent classes, and the parameters of a generalized linear model which relates the observations, distributed according to some member of

  11. Illegal employment

    Directory of Open Access Journals (Sweden)

    Jana Mervartová

    2013-01-01

    Full Text Available Since 2007 Labour Code contains the definition of dependent work, which can be carried out only in labour-law relations. The Amendment to Labour Code from 2012 makes the definition more precise, when it stipulates essential elements of dependent work and designates the others as conditions, under which dependent work should be carried out. The Amendment to Employment Act changes the definition of illegal work. Illegal work is a performance of dependent work by natural person except for labour-law relation, or if natural person – foreigner carries out work in conflict with issued permission to employment or without this permission. Since 2012 sanctions for illegal work were increased. Labour inspection is entitled to impose sanctions, in case of foreigners it is Customs Office. For control purposes employer is obliged to have copies of documents at the workplace proving the existence of labour-law relation. Goal of controls and high fines is to limit illegal employment of citizens of Czech Republic and foreigners as well. Illegal work has unfavourable economic impact on state budget. It comes to extensive tax evasions and also to evasions within health insurance and social security. If a concluded commercial-law relation meets the attributes of dependent work, then it stands for a concealed legal relationship. Tax Office can subsequently assess an income tax to businessman. Labour-law relationship enjoys a higher legal protection than commercial-law relationship; nonetheless it is not suitable to limit liberty of contract in cases when it is not unambiguously a dependent activity.

  12. Meta-analysis a structural equation modeling approach

    CERN Document Server

    Cheung, Mike W-L

    2015-01-01

    Presents a novel approach to conducting meta-analysis using structural equation modeling. Structural equation modeling (SEM) and meta-analysis are two powerful statistical methods in the educational, social, behavioral, and medical sciences. They are often treated as two unrelated topics in the literature. This book presents a unified framework on analyzing meta-analytic data within the SEM framework, and illustrates how to conduct meta-analysis using the metaSEM package in the R statistical environment. Meta-Analysis: A Structural Equation Modeling Approach begins by introducing the impo

  13. A study of multidimensional modeling approaches for data warehouse

    Science.gov (United States)

    Yusof, Sharmila Mat; Sidi, Fatimah; Ibrahim, Hamidah; Affendey, Lilly Suriani

    2016-08-01

    Data warehouse system is used to support the process of organizational decision making. Hence, the system must extract and integrate information from heterogeneous data sources in order to uncover relevant knowledge suitable for decision making process. However, the development of data warehouse is a difficult and complex process especially in its conceptual design (multidimensional modeling). Thus, there have been various approaches proposed to overcome the difficulty. This study surveys and compares the approaches of multidimensional modeling and highlights the issues, trend and solution proposed to date. The contribution is on the state of the art of the multidimensional modeling design.

  14. Numerical linked-cluster approach to quantum lattice models.

    Science.gov (United States)

    Rigol, Marcos; Bryant, Tyler; Singh, Rajiv R P

    2006-11-03

    We present a novel algorithm that allows one to obtain temperature dependent properties of quantum lattice models in the thermodynamic limit from exact diagonalization of small clusters. Our numerical linked-cluster approach provides a systematic framework to assess finite-size effects and is valid for any quantum lattice model. Unlike high temperature expansions, which have a finite radius of convergence in inverse temperature, these calculations are accurate at all temperatures provided the range of correlations is finite. We illustrate the power of our approach studying spin models on kagomé, triangular, and square lattices.

  15. Metamodelling Approach and Software Tools for Physical Modelling and Simulation

    Directory of Open Access Journals (Sweden)

    Vitaliy Mezhuyev

    2015-02-01

    Full Text Available In computer science, metamodelling approach becomes more and more popular for the purpose of software systems development. In this paper, we discuss applicability of the metamodelling approach for development of software tools for physical modelling and simulation.To define a metamodel for physical modelling the analysis of physical models will be done. The result of such the analyses will show the invariant physical structures, we propose to use as the basic abstractions of the physical metamodel. It is a system of geometrical objects, allowing to build a spatial structure of physical models and to set a distribution of physical properties. For such geometry of distributed physical properties, the different mathematical methods can be applied. To prove the proposed metamodelling approach, we consider the developed prototypes of software tools.

  16. Learning the Task Management Space of an Aircraft Approach Model

    Science.gov (United States)

    Krall, Joseph; Menzies, Tim; Davies, Misty

    2014-01-01

    Validating models of airspace operations is a particular challenge. These models are often aimed at finding and exploring safety violations, and aim to be accurate representations of real-world behavior. However, the rules governing the behavior are quite complex: nonlinear physics, operational modes, human behavior, and stochastic environmental concerns all determine the responses of the system. In this paper, we present a study on aircraft runway approaches as modeled in Georgia Tech's Work Models that Compute (WMC) simulation. We use a new learner, Genetic-Active Learning for Search-Based Software Engineering (GALE) to discover the Pareto frontiers defined by cognitive structures. These cognitive structures organize the prioritization and assignment of tasks of each pilot during approaches. We discuss the benefits of our approach, and also discuss future work necessary to enable uncertainty quantification.

  17. An integrated modeling approach to age invariant face recognition

    Science.gov (United States)

    Alvi, Fahad Bashir; Pears, Russel

    2015-03-01

    This Research study proposes a novel method for face recognition based on Anthropometric features that make use of an integrated approach comprising of a global and personalized models. The system is aimed to at situations where lighting, illumination, and pose variations cause problems in face recognition. A Personalized model covers the individual aging patterns while a Global model captures general aging patterns in the database. We introduced a de-aging factor that de-ages each individual in the database test and training sets. We used the k nearest neighbor approach for building a personalized model and global model. Regression analysis was applied to build the models. During the test phase, we resort to voting on different features. We used FG-Net database for checking the results of our technique and achieved 65 percent Rank 1 identification rate.

  18. Modeling Approaches and Systems Related to Structured Modeling.

    Science.gov (United States)

    1987-02-01

    Lasdon 򒾂> and Maturana 򒾃> for surveys of several modern systems. A -6- N NN- %0 CAMPS (Lucas and Mitra 򒾁>) -- Computer Assisted Mathe- %l...583-589. MATURANA , S. 򒾃>. "Comparative Analysis of Mathematical Modeling Systems," informal note, Graduate School of Manage- ment, UCLA, February

  19. Soil moisture simulations using two different modelling approaches

    Czech Academy of Sciences Publication Activity Database

    Šípek, Václav; Tesař, Miroslav

    2013-01-01

    Roč. 64, 3-4 (2013), s. 99-103 ISSN 0006-5471 R&D Projects: GA AV ČR IAA300600901; GA ČR GA205/08/1174 Institutional research plan: CEZ:AV0Z20600510 Keywords : soil moisture modelling * SWIM model * box modelling approach Subject RIV: DA - Hydrology ; Limnology http://www.boku.ac.at/diebodenkultur/volltexte/sondernummern/band-64/heft-3-4/sipek.pdf

  20. Addressing the midwifery workforce crisis: evaluating an employment model for undergraduate midwifery students at a tertiary maternity hospital in Melbourne, Australia.

    Science.gov (United States)

    McLachlan, Helen L; Forster, Della A; Ford, Rachael L; Farrell, Tanya

    2011-12-01

    In Victoria, maternity services are under significant strain due to increased numbers of women giving birth and critical workforce shortages. Hospitals have experienced challenges in adequately staffing maternity units, particularly on postnatal wards. In 2008, a tertiary maternity hospital in Melbourne introduced a model where undergraduate midwifery students were employed as Division 2 nurses (SMW_Div2) (enrolled nurses), to work in the postnatal area only. This study explored the pilot employment model from the perspective of the SMW_Div2 and hospital midwives. A web-based survey was administered to hospital midwives and the SMW_Div2s in the employment model in January 2010. The survey explored the views of midwives and SMW_Div2s regarding the perceived impact of the model on workforce readiness, recruitment and retention, and clinical competence and confidence. Forty-seven of 158 midwives (30%) and five of nine SMW_Div2s employed in the model responded to the survey. Both groups considered the model to have benefits for the organisation, including increased: student workforce readiness; clinical confidence and competence; and organisational loyalty. Both groups also considered that the model would facilitate: workforce recruitment; a teaching and learning culture within the organisation; and enhanced partnerships between students, hospitals and universities. Caution was expressed regarding workload and the need for ongoing support for SMW_Div2s working in the model. SMW_Div2s and midwives were positive about the introduction of the paid employment model at the Women's. The findings are consistent with evaluations of similar programs in the nursing setting. The employment model has potential short and long term individual and organisational advantages, which is important in the context of increasing births and workforce shortages. Progression of such models will be contingent on the collaboration and cooperation of the various stakeholders involved in maternity

  1. A generic approach to haptic modeling of textile artifacts

    Science.gov (United States)

    Shidanshidi, H.; Naghdy, F.; Naghdy, G.; Wood Conroy, D.

    2009-08-01

    Haptic Modeling of textile has attracted significant interest over the last decade. In spite of extensive research, no generic system has been proposed. The previous work mainly assumes that textile has a 2D planar structure. They also require time-consuming measurement of textile properties in construction of the mechanical model. A novel approach for haptic modeling of textile is proposed to overcome the existing shortcomings. The method is generic, assumes a 3D structure for the textile, and deploys computational intelligence to estimate the mechanical properties of textile. The approach is designed primarily for display of textile artifacts in museums. The haptic model is constructed by superimposing the mechanical model of textile over its geometrical model. Digital image processing is applied to the still image of textile to identify its pattern and structure through a fuzzy rule-base algorithm. The 3D geometric model of the artifact is automatically generated in VRML based on the identified pattern and structure obtained from the textile image. Selected mechanical properties of the textile are estimated by an artificial neural network; deploying the textile geometric characteristics and yarn properties as inputs. The estimated mechanical properties are then deployed in the construction of the textile mechanical model. The proposed system is introduced and the developed algorithms are described. The validation of method indicates the feasibility of the approach and its superiority to other haptic modeling algorithms.

  2. The Effect of Environmental Regulation on Employment in Resource-Based Areas of China—An Empirical Research Based on the Mediating Effect Model

    Science.gov (United States)

    Cao, Wenbin; Wang, Hui; Ying, Huihui

    2017-01-01

    While environmental pollution is becoming more and more serious, many countries are adopting policies to control pollution. At the same time, the environmental regulation will inevitably affect economic and social development, especially employment growth. The environmental regulation will not only affect the scale of employment directly, but it will also have indirect effects by stimulating upgrades in the industrial structure and in technological innovation. This paper examines the impact of environmental regulation on employment, using a mediating model based on the data from five typical resource-based provinces in China from 2000 to 2015. The estimation is performed based on the system GMM (Generalized Method of Moments) estimator. The results show that the implementation of environmental regulation in resource-based areas has both a direct effect and a mediating effect on employment. These findings provide policy implications for these resource-based areas to promote the coordinating development between the environment and employment. PMID:29257068

  3. The Effect of Environmental Regulation on Employment in Resource-Based Areas of China-An Empirical Research Based on the Mediating Effect Model.

    Science.gov (United States)

    Cao, Wenbin; Wang, Hui; Ying, Huihui

    2017-12-19

    While environmental pollution is becoming more and more serious, many countries are adopting policies to control pollution. At the same time, the environmental regulation will inevitably affect economic and social development, especially employment growth. The environmental regulation will not only affect the scale of employment directly, but it will also have indirect effects by stimulating upgrades in the industrial structure and in technological innovation. This paper examines the impact of environmental regulation on employment, using a mediating model based on the data from five typical resource-based provinces in China from 2000 to 2015. The estimation is performed based on the system GMM (Generalized Method of Moments) estimator. The results show that the implementation of environmental regulation in resource-based areas has both a direct effect and a mediating effect on employment. These findings provide policy implications for these resource-based areas to promote the coordinating development between the environment and employment.

  4. Time-History Seismic Analysis of Masonry Buildings: A Comparison between Two Non-Linear Modelling Approaches

    Directory of Open Access Journals (Sweden)

    Michele Betti

    2015-05-01

    Full Text Available The paper presents a comparison between two numerical modelling approaches employed to investigate the seismic behavior of unreinforced masonry buildings with flexible diaphragms. The comparison is performed analyzing a two-story prototype tested on a shaking table at the CNR-ENEA research center of Casaccia (Italy. The first numerical model was built by using the finite element (FE technique, while the second one was built by a simplified macro-element (ME approach. Both models were employed to perform non-linear dynamic analyses, integrating the equations of motion by step-by-step procedures. The shaking table tests were simulated to analyze the behavior of the prototype from the initial elastic state until the development of extensive damage. The main results of the analyses are discussed and critically compared in terms of engineering parameters, such as accelerations, displacements and base shears. The effectiveness of both models within the investigated typology of buildings is then evaluated in depth.

  5. Employment relations, flexibility and risk

    DEFF Research Database (Denmark)

    Jensen, Carsten Strøby

    Employment relations literature often distinguishes between social democratic/corporatist models of employment relations and liberal models of employment relations as they are seen as opposite or at least different ways of organizing labor markets. They are often characterized as having very...... different risk profiles in terms of relationships between employees, employers, and the state. Low levels of labor market regulation very often characterize the liberal models of employment relations as we know them from, for instance, the USA and the UK. This means that employment conditions are very often...

  6. Wave Resource Characterization Using an Unstructured Grid Modeling Approach

    Directory of Open Access Journals (Sweden)

    Wei-Cheng Wu

    2018-03-01

    Full Text Available This paper presents a modeling study conducted on the central Oregon coast for wave resource characterization, using the unstructured grid Simulating WAve Nearshore (SWAN model coupled with a nested grid WAVEWATCH III® (WWIII model. The flexibility of models with various spatial resolutions and the effects of open boundary conditions simulated by a nested grid WWIII model with different physics packages were evaluated. The model results demonstrate the advantage of the unstructured grid-modeling approach for flexible model resolution and good model skills in simulating the six wave resource parameters recommended by the International Electrotechnical Commission in comparison to the observed data in Year 2009 at National Data Buoy Center Buoy 46050. Notably, spectral analysis indicates that the ST4 physics package improves upon the ST2 physics package’s ability to predict wave power density for large waves, which is important for wave resource assessment, load calculation of devices, and risk management. In addition, bivariate distributions show that the simulated sea state of maximum occurrence with the ST4 physics package matched the observed data better than with the ST2 physics package. This study demonstrated that the unstructured grid wave modeling approach, driven by regional nested grid WWIII outputs along with the ST4 physics package, can efficiently provide accurate wave hindcasts to support wave resource characterization. Our study also suggests that wind effects need to be considered if the dimension of the model domain is greater than approximately 100 km, or O (102 km.

  7. Intelligent Transportation and Evacuation Planning A Modeling-Based Approach

    CERN Document Server

    Naser, Arab

    2012-01-01

    Intelligent Transportation and Evacuation Planning: A Modeling-Based Approach provides a new paradigm for evacuation planning strategies and techniques. Recently, evacuation planning and modeling have increasingly attracted interest among researchers as well as government officials. This interest stems from the recent catastrophic hurricanes and weather-related events that occurred in the southeastern United States (Hurricane Katrina and Rita). The evacuation methods that were in place before and during the hurricanes did not work well and resulted in thousands of deaths. This book offers insights into the methods and techniques that allow for implementing mathematical-based, simulation-based, and integrated optimization and simulation-based engineering approaches for evacuation planning. This book also: Comprehensively discusses the application of mathematical models for evacuation and intelligent transportation modeling Covers advanced methodologies in evacuation modeling and planning Discusses principles a...

  8. A review of function modeling: Approaches and applications

    OpenAIRE

    Erden, M.S.; Komoto, H.; Van Beek, T.J.; D'Amelio, V.; Echavarria, E.; Tomiyama, T.

    2008-01-01

    This work is aimed at establishing a common frame and understanding of function modeling (FM) for our ongoing research activities. A comparative review of the literature is performed to grasp the various FM approaches with their commonalities and differences. The relations of FM with the research fields of artificial intelligence, design theory, and maintenance are discussed. In this discussion the goals are to highlight the features of various classical approaches in relation to FM, to delin...

  9. A model-data based systems approach to process intensification

    DEFF Research Database (Denmark)

    Gani, Rafiqul

    . Their developments, however, are largely due to experiment based trial and error approaches and while they do not require validation, they can be time consuming and resource intensive. Also, one may ask, can a truly new intensified unit operation be obtained in this way? An alternative two-stage approach is to apply...... a model-based synthesis method to systematically generate and evaluate alternatives in the first stage and an experiment-model based validation in the second stage. In this way, the search for alternatives is done very quickly, reliably and systematically over a wide range, while resources are preserved...... for focused validation of only the promising candidates in the second-stage. This approach, however, would be limited to intensification based on “known” unit operations, unless the PI process synthesis/design is considered at a lower level of aggregation, namely the phenomena level. That is, the model-based...

  10. METHODOLOGICAL APPROACHES FOR MODELING THE RURAL SETTLEMENT DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Gorbenkova Elena Vladimirovna

    2017-10-01

    Full Text Available Subject: the paper describes the research results on validation of a rural settlement developmental model. The basic methods and approaches for solving the problem of assessment of the urban and rural settlement development efficiency are considered. Research objectives: determination of methodological approaches to modeling and creating a model for the development of rural settlements. Materials and methods: domestic and foreign experience in modeling the territorial development of urban and rural settlements and settlement structures was generalized. The motivation for using the Pentagon-model for solving similar problems was demonstrated. Based on a systematic analysis of existing development models of urban and rural settlements as well as the authors-developed method for assessing the level of agro-towns development, the systems/factors that are necessary for a rural settlement sustainable development are identified. Results: we created the rural development model which consists of five major systems that include critical factors essential for achieving a sustainable development of a settlement system: ecological system, economic system, administrative system, anthropogenic (physical system and social system (supra-structure. The methodological approaches for creating an evaluation model of rural settlements development were revealed; the basic motivating factors that provide interrelations of systems were determined; the critical factors for each subsystem were identified and substantiated. Such an approach was justified by the composition of tasks for territorial planning of the local and state administration levels. The feasibility of applying the basic Pentagon-model, which was successfully used for solving the analogous problems of sustainable development, was shown. Conclusions: the resulting model can be used for identifying and substantiating the critical factors for rural sustainable development and also become the basis of

  11. An algebraic approach to modeling in software engineering

    International Nuclear Information System (INIS)

    Loegel, C.J.; Ravishankar, C.V.

    1993-09-01

    Our work couples the formalism of universal algebras with the engineering techniques of mathematical modeling to develop a new approach to the software engineering process. Our purpose in using this combination is twofold. First, abstract data types and their specification using universal algebras can be considered a common point between the practical requirements of software engineering and the formal specification of software systems. Second, mathematical modeling principles provide us with a means for effectively analyzing real-world systems. We first use modeling techniques to analyze a system and then represent the analysis using universal algebras. The rest of the software engineering process exploits properties of universal algebras that preserve the structure of our original model. This paper describes our software engineering process and our experience using it on both research and commercial systems. We need a new approach because current software engineering practices often deliver software that is difficult to develop and maintain. Formal software engineering approaches use universal algebras to describe ''computer science'' objects like abstract data types, but in practice software errors are often caused because ''real-world'' objects are improperly modeled. There is a large semantic gap between the customer's objects and abstract data types. In contrast, mathematical modeling uses engineering techniques to construct valid models for real-world systems, but these models are often implemented in an ad hoc manner. A combination of the best features of both approaches would enable software engineering to formally specify and develop software systems that better model real systems. Software engineering, like mathematical modeling, should concern itself first and foremost with understanding a real system and its behavior under given circumstances, and then with expressing this knowledge in an executable form

  12. A Latent Markov Model with Covariates to Study Unobserved Heterogeneity among Fertility Patterns of Couples Employing Natural Family Planning Methods

    Directory of Open Access Journals (Sweden)

    Fulvia Pennoni

    2017-08-01

    Full Text Available PurposeWe use the historical data from the European Study of Daily Fecundability and we develop an algorithm to determine the fertile window in a woman’s cycle according to the rules of the C.A.Me.N. symptothermal method proposed by the Centro Ambrosiano Metodi Naturali. Our aim is to identify variables acting on the probability of conception by considering the fertile window and factors that cannot be explained by employing the observed covariates of individuals and couples.MethodsWe adopt the latent Markov model with covariates tailored for data collected at times when a latent process detects the dependence across fertile periods of each woman’s cycle. We consider measurement errors, transitions between conception and non-conception, and the prediction of conception rate over the fertile windows.ConclusionWe find that the conception pattern is mainly related to sexual intercourse behavior during the fertile window and to previous pregnancies. For the cohort under study, we predict a steep decline in the average conception rate across fertile windows.

  13. Impact of simulating borderline personality disorder on the MMPI-2: a costs-benefits model employing base rates.

    Science.gov (United States)

    Sivec, H J; Hilsenroth, M J; Lynn, S J

    1995-04-01

    This investigation extends current work on the impact of role-specific response sets on dissimulated Minnesota Multiphasic Personality Inventory-2 (MMPI-2; Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) profiles. Specifically, one group of subjects was given specific symptom information and instructed to simulate borderline personality disorder on the MMPI-2. This dissimulation performance was compared to a clinical comparison group of clients diagnosed with borderline personality disorder, a group of subjects instructed to simulate major depression, and a group of subjects who responded honestly to the MMPI-2. In both simulating conditions, subjects produced significantly higher elevations on a majority of clinical and validity scales than the clinical comparison group. A rigorous evaluation of the F scale was conducted to provide a range of predictive values for different F scale cutting scores for detecting malingering. Sensitivity, specificity, and positive and negative predictive power were computed for this range of F scale values. A similar analysis was conducted for the Borderline Personality Disorder Scale (BPDsc) of Morey, Waugh, and Blashfield (1985). These results are integrated with extant research. A costs-benefits model is proposed for employing F scale cutting scores in clinical situations with different base rates of malingering.

  14. Systematic comparison of barriers for heavy-ion fusion calculated on the basis of the double-folding model by employing two versions of nucleon–nucleon interaction

    Energy Technology Data Exchange (ETDEWEB)

    Gontchar, I. I. [Omsk State Transport University (Russian Federation); Chushnyakova, M. V., E-mail: maria.chushnyakova@gmail.com [Omsk State Technical University (Russian Federation)

    2016-07-15

    A systematic calculation of barriers for heavy-ion fusion was performed on the basis of the double-folding model by employing two versions of an effective nucleon–nucleon interaction: M3Y interaction and Migdal interaction. The results of calculations by the Hartree–Fockmethod with the SKX coefficients were taken for nuclear densities. The calculations reveal that the fusion barrier is higher in the case of employing theMigdal interaction than in the case of employing the Ðœ3Y interaction. In view of this, the use of the Migdal interaction in describing heavy-ion fusion is questionable.

  15. Joint Modeling of Multiple Crimes: A Bayesian Spatial Approach

    Directory of Open Access Journals (Sweden)

    Hongqiang Liu

    2017-01-01

    Full Text Available A multivariate Bayesian spatial modeling approach was used to jointly model the counts of two types of crime, i.e., burglary and non-motor vehicle theft, and explore the geographic pattern of crime risks and relevant risk factors. In contrast to the univariate model, which assumes independence across outcomes, the multivariate approach takes into account potential correlations between crimes. Six independent variables are included in the model as potential risk factors. In order to fully present this method, both the multivariate model and its univariate counterpart are examined. We fitted the two models to the data and assessed them using the deviance information criterion. A comparison of the results from the two models indicates that the multivariate model was superior to the univariate model. Our results show that population density and bar density are clearly associated with both burglary and non-motor vehicle theft risks and indicate a close relationship between these two types of crime. The posterior means and 2.5% percentile of type-specific crime risks estimated by the multivariate model were mapped to uncover the geographic patterns. The implications, limitations and future work of the study are discussed in the concluding section.

  16. Injury prevention risk communication: A mental models approach

    DEFF Research Database (Denmark)

    Austin, Laurel Cecelia; Fischhoff, Baruch

    2012-01-01

    Individuals' decisions and behaviour can play a critical role in determining both the probability and severity of injury. Behavioural decision research studies peoples' decision-making processes in terms comparable to scientific models of optimal choices, providing a basis for focusing...... interventions on the most critical opportunities to reduce risks. That research often seeks to identify the ‘mental models’ that underlie individuals' interpretations of their circumstances and the outcomes of possible actions. In the context of injury prevention, a mental models approach would ask why people...... and uses examples to discuss how the approach can be used to develop scientifically validated context-sensitive injury risk communications....

  17. Assessing risk factors for dental caries: a statistical modeling approach.

    Science.gov (United States)

    Trottini, Mario; Bossù, Maurizio; Corridore, Denise; Ierardo, Gaetano; Luzzi, Valeria; Saccucci, Matteo; Polimeni, Antonella

    2015-01-01

    The problem of identifying potential determinants and predictors of dental caries is of key importance in caries research and it has received considerable attention in the scientific literature. From the methodological side, a broad range of statistical models is currently available to analyze dental caries indices (DMFT, dmfs, etc.). These models have been applied in several studies to investigate the impact of different risk factors on the cumulative severity of dental caries experience. However, in most of the cases (i) these studies focus on a very specific subset of risk factors; and (ii) in the statistical modeling only few candidate models are considered and model selection is at best only marginally addressed. As a result, our understanding of the robustness of the statistical inferences with respect to the choice of the model is very limited; the richness of the set of statistical models available for analysis in only marginally exploited; and inferences could be biased due the omission of potentially important confounding variables in the model's specification. In this paper we argue that these limitations can be overcome considering a general class of candidate models and carefully exploring the model space using standard model selection criteria and measures of global fit and predictive performance of the candidate models. Strengths and limitations of the proposed approach are illustrated with a real data set. In our illustration the model space contains more than 2.6 million models, which require inferences to be adjusted for 'optimism'.

  18. A modeling approach to hospital location for effective marketing.

    Science.gov (United States)

    Cokelez, S; Peacock, E

    1993-01-01

    This paper develops a mixed integer linear programming model for locating health care facilities. The parameters of the objective function of this model are based on factor rating analysis and grid method. Subjective and objective factors representative of the real life situations are incorporated into the model in a unique way permitting a trade-off analysis of certain factors pertinent to the location of hospitals. This results in a unified approach and a single model whose credibility is further enhanced by inclusion of geographical and demographical factors.

  19. Deep Appearance Models: A Deep Boltzmann Machine Approach for Face Modeling

    OpenAIRE

    Duong, Chi Nhan; Luu, Khoa; Quach, Kha Gia; Bui, Tien D.

    2016-01-01

    The "interpretation through synthesis" approach to analyze face images, particularly Active Appearance Models (AAMs) method, has become one of the most successful face modeling approaches over the last two decades. AAM models have ability to represent face images through synthesis using a controllable parameterized Principal Component Analysis (PCA) model. However, the accuracy and robustness of the synthesized faces of AAM are highly depended on the training sets and inherently on the genera...

  20. Prediction of hybrid performance in maize with a ridge regression model employed to DNA markers and mRNA transcription profiles.

    Science.gov (United States)

    Zenke-Philippi, Carola; Thiemann, Alexander; Seifert, Felix; Schrag, Tobias; Melchinger, Albrecht E; Scholten, Stefan; Frisch, Matthias

    2016-03-29

    Ridge regression models can be used for predicting heterosis and hybrid performance. Their application to mRNA transcription profiles has not yet been investigated. Our objective was to compare the prediction accuracy of models employing mRNA transcription profiles with that of models employing genome-wide markers using a data set of 98 maize hybrids from a breeding program. We predicted hybrid performance and mid-parent heterosis for grain yield and grain dry matter content and employed cross validation to assess the prediction accuracy. Prediction with a ridge regression model using random effects for mRNA transcription profiles resulted in similar prediction accuracies than employing the model to DNA markers. For hybrids, of which none of the parental inbred lines was part of the training set, the ridge regression model did not reach the prediction accuracy that was obtained with a model using transcriptome-based distances. We conclude that mRNA transcription profiles are a promising alternative to DNA markers for hybrid prediction, but further studies with larger data sets are required to investigate the superiority of alternative prediction models.

  1. Earthquake response analysis of RC bridges using simplified modeling approaches

    Science.gov (United States)

    Lee, Do Hyung; Kim, Dookie; Park, Taehyo

    2009-07-01

    In this paper, simplified modeling approaches describing the hysteretic behavior of reinforced concrete bridge piers are proposed. For this purpose, flexure-axial and shear-axial interaction models are developed and implemented into a nonlinear finite element analysis program. Comparative verifications for reinforced concrete columns prove that the analytical predictions obtained with the new formulations show good correlation with experimental results under various levels of axial forces and section types. In addition, analytical correlation studies for the inelastic earthquake response of reinforced concrete bridge structures are also carried out using the simplified modeling approaches. Relatively good agreement is observed in the results between the current modeling approach and the elaborated fiber models. It is thus encouraging that the present developments and approaches are capable of identifying the contribution of deformation mechanisms correctly. Subsequently, the present developments can be used as a simple yet effective tool for the deformation capacity evaluation of reinforced concrete columns in general and reinforced concrete bridge piers in particular.

  2. The Application of Solution-Focused Work in Employment Counseling

    Science.gov (United States)

    Bezanson, Birdie J.

    2004-01-01

    The author explores the applicability of a solution-focused therapy (SFT) model as a comprehensive approach to employment counseling. SFT focuses the client on developing a vision of a preferred future and assumes that the client has the talents and resources that can be accessed in the employment counseling process. The solution-focused counselor…

  3. Bianchi VI0 and III models: self-similar approach

    International Nuclear Information System (INIS)

    Belinchon, Jose Antonio

    2009-01-01

    We study several cosmological models with Bianchi VI 0 and III symmetries under the self-similar approach. We find new solutions for the 'classical' perfect fluid model as well as for the vacuum model although they are really restrictive for the equation of state. We also study a perfect fluid model with time-varying constants, G and Λ. As in other studied models we find that the behaviour of G and Λ are related. If G behaves as a growing time function then Λ is a positive decreasing time function but if G is decreasing then Λ 0 is negative. We end by studying a massive cosmic string model, putting special emphasis in calculating the numerical values of the equations of state. We show that there is no SS solution for a string model with time-varying constants.

  4. Modeling and control approach to a distinctive quadrotor helicopter.

    Science.gov (United States)

    Wu, Jun; Peng, Hui; Chen, Qing; Peng, Xiaoyan

    2014-01-01

    The referenced quadrotor helicopter in this paper has a unique configuration. It is more complex than commonly used quadrotors because of its inaccurate parameters, unideal symmetrical structure and unknown nonlinear dynamics. A novel method was presented to handle its modeling and control problems in this paper, which adopts a MIMO RBF neural nets-based state-dependent ARX (RBF-ARX) model to represent its nonlinear dynamics, and then a MIMO RBF-ARX model-based global LQR controller is proposed to stabilize the quadrotor's attitude. By comparing with a physical model-based LQR controller and an ARX model-set-based gain scheduling LQR controller, superiority of the MIMO RBF-ARX model-based control approach was confirmed. This successful application verified the validity of the MIMO RBF-ARX modeling method to the quadrotor helicopter with complex nonlinearity. © 2013 Published by ISA. All rights reserved.

  5. Software sensors based on the grey-box modelling approach

    DEFF Research Database (Denmark)

    Carstensen, J.; Harremoës, P.; Strube, Rune

    1996-01-01

    In recent years the grey-box modelling approach has been applied to wastewater transportation and treatment Grey-box models are characterized by the combination of deterministic and stochastic terms to form a model where all the parameters are statistically identifiable from the on......-line measurements. With respect to the development of software sensors, the grey-box models possess two important features. Firstly, the on-line measurements can be filtered according to the grey-box model in order to remove noise deriving from the measuring equipment and controlling devices. Secondly, the grey......-box models may contain terms which can be estimated on-line by use of the models and measurements. In this paper, it is demonstrated that many storage basins in sewer systems can be used as an on-line flow measurement provided that the basin is monitored on-line with a level transmitter and that a grey...

  6. Modelling dynamic ecosystems : venturing beyond boundaries with the Ecopath approach

    OpenAIRE

    Coll, Marta; Akoglu, E.; Arreguin-Sanchez, F.; Fulton, E. A.; Gascuel, D.; Heymans, J. J.; Libralato, S.; Mackinson, S.; Palomera, I.; Piroddi, C.; Shannon, L. J.; Steenbeek, J.; Villasante, S.; Christensen, V.

    2015-01-01

    Thirty years of progress using the Ecopath with Ecosim (EwE) approach in different fields such as ecosystem impacts of fishing and climate change, emergent ecosystem dynamics, ecosystem-based management, and marine conservation and spatial planning were showcased November 2014 at the conference "Ecopath 30 years-modelling dynamic ecosystems: beyond boundaries with EwE". Exciting new developments include temporal-spatial and end-to-end modelling, as well as novel applications to environmental ...

  7. Regularization of quantum gravity in the matrix model approach

    International Nuclear Information System (INIS)

    Ueda, Haruhiko

    1991-02-01

    We study divergence problem of the partition function in the matrix model approach for two-dimensional quantum gravity. We propose a new model V(φ) = 1/2Trφ 2 + g 4 /NTrφ 4 + g'/N 4 Tr(φ 4 ) 2 and show that in the sphere case it has no divergence problem and the critical exponent is of pure gravity. (author)

  8. Gray-box modelling approach for description of storage tunnel

    DEFF Research Database (Denmark)

    Harremoës, Poul; Carstensen, Jacob

    1999-01-01

    The dynamics of a storage tunnel is examined using a model based on on-line measured data and a combination of simple deterministic and black-box stochastic elements. This approach, called gray-box modeling, is a new promising methodology for giving an on-line state description of sewer systems. ...... in a SCADA system because the most important information on the specific system is provided on-line...

  9. Development of a Conservative Model Validation Approach for Reliable Analysis

    Science.gov (United States)

    2015-01-01

    conservativeness level , the conservative probability of failure obtained from Section 4 must be maintained. The mathematical formulation of conservative model... CIE 2015 August 2-5, 2015, Boston, Massachusetts, USA [DRAFT] DETC2015-46982 DEVELOPMENT OF A CONSERVATIVE MODEL VALIDATION APPROACH FOR RELIABLE...PDF and a probability of failure are selected from these predicted output PDFs at a user-specified conservativeness level for validation. For

  10. Novel approach for dam break flow modeling using computational intelligence

    Science.gov (United States)

    Seyedashraf, Omid; Mehrabi, Mohammad; Akhtari, Ali Akbar

    2018-04-01

    A new methodology based on the computational intelligence (CI) system is proposed and tested for modeling the classic 1D dam-break flow problem. The reason to seek for a new solution lies in the shortcomings of the existing analytical and numerical models. This includes the difficulty of using the exact solutions and the unwanted fluctuations, which arise in the numerical results. In this research, the application of the radial-basis-function (RBF) and multi-layer-perceptron (MLP) systems is detailed for the solution of twenty-nine dam-break scenarios. The models are developed using seven variables, i.e. the length of the channel, the depths of the up-and downstream sections, time, and distance as the inputs. Moreover, the depths and velocities of each computational node in the flow domain are considered as the model outputs. The models are validated against the analytical, and Lax-Wendroff and MacCormack FDM schemes. The findings indicate that the employed CI models are able to replicate the overall shape of the shock- and rarefaction-waves. Furthermore, the MLP system outperforms RBF and the tested numerical schemes. A new monolithic equation is proposed based on the best fitting model, which can be used as an efficient alternative to the existing piecewise analytic equations.

  11. Estimating, Testing, and Comparing Specific Effects in Structural Equation Models: The Phantom Model Approach

    Science.gov (United States)

    Macho, Siegfried; Ledermann, Thomas

    2011-01-01

    The phantom model approach for estimating, testing, and comparing specific effects within structural equation models (SEMs) is presented. The rationale underlying this novel method consists in representing the specific effect to be assessed as a total effect within a separate latent variable model, the phantom model that is added to the main…

  12. Comparative flood damage model assessment: towards a European approach

    Science.gov (United States)

    Jongman, B.; Kreibich, H.; Apel, H.; Barredo, J. I.; Bates, P. D.; Feyen, L.; Gericke, A.; Neal, J.; Aerts, J. C. J. H.; Ward, P. J.

    2012-12-01

    There is a wide variety of flood damage models in use internationally, differing substantially in their approaches and economic estimates. Since these models are being used more and more as a basis for investment and planning decisions on an increasingly large scale, there is a need to reduce the uncertainties involved and develop a harmonised European approach, in particular with respect to the EU Flood Risks Directive. In this paper we present a qualitative and quantitative assessment of seven flood damage models, using two case studies of past flood events in Germany and the United Kingdom. The qualitative analysis shows that modelling approaches vary strongly, and that current methodologies for estimating infrastructural damage are not as well developed as methodologies for the estimation of damage to buildings. The quantitative results show that the model outcomes are very sensitive to uncertainty in both vulnerability (i.e. depth-damage functions) and exposure (i.e. asset values), whereby the first has a larger effect than the latter. We conclude that care needs to be taken when using aggregated land use data for flood risk assessment, and that it is essential to adjust asset values to the regional economic situation and property characteristics. We call for the development of a flexible but consistent European framework that applies best practice from existing models while providing room for including necessary regional adjustments.

  13. A Final Approach Trajectory Model for Current Operations

    Science.gov (United States)

    Gong, Chester; Sadovsky, Alexander

    2010-01-01

    Predicting accurate trajectories with limited intent information is a challenge faced by air traffic management decision support tools in operation today. One such tool is the FAA's Terminal Proximity Alert system which is intended to assist controllers in maintaining safe separation of arrival aircraft during final approach. In an effort to improve the performance of such tools, two final approach trajectory models are proposed; one based on polynomial interpolation, the other on the Fourier transform. These models were tested against actual traffic data and used to study effects of the key final approach trajectory modeling parameters of wind, aircraft type, and weight class, on trajectory prediction accuracy. Using only the limited intent data available to today's ATM system, both the polynomial interpolation and Fourier transform models showed improved trajectory prediction accuracy over a baseline dead reckoning model. Analysis of actual arrival traffic showed that this improved trajectory prediction accuracy leads to improved inter-arrival separation prediction accuracy for longer look ahead times. The difference in mean inter-arrival separation prediction error between the Fourier transform and dead reckoning models was 0.2 nmi for a look ahead time of 120 sec, a 33 percent improvement, with a corresponding 32 percent improvement in standard deviation.

  14. The Generalised Ecosystem Modelling Approach in Radiological Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Klos, Richard

    2008-03-15

    An independent modelling capability is required by SSI in order to evaluate dose assessments carried out in Sweden by, amongst others, SKB. The main focus is the evaluation of the long-term radiological safety of radioactive waste repositories for both spent fuel and low-level radioactive waste. To meet the requirement for an independent modelling tool for use in biosphere dose assessments, SSI through its modelling team CLIMB commissioned the development of a new model in 2004, a project to produce an integrated model of radionuclides in the landscape. The generalised ecosystem modelling approach (GEMA) is the result. GEMA is a modular system of compartments representing the surface environment. It can be configured, through water and solid material fluxes, to represent local details in the range of ecosystem types found in the past, present and future Swedish landscapes. The approach is generic but fine tuning can be carried out using local details of the surface drainage system. The modular nature of the modelling approach means that GEMA modules can be linked to represent large scale surface drainage features over an extended domain in the landscape. System change can also be managed in GEMA, allowing a flexible and comprehensive model of the evolving landscape to be constructed. Environmental concentrations of radionuclides can be calculated and the GEMA dose pathway model provides a means of evaluating the radiological impact of radionuclide release to the surface environment. This document sets out the philosophy and details of GEMA and illustrates the functioning of the model with a range of examples featuring the recent CLIMB review of SKB's SR-Can assessment

  15. Modeling of phase equilibria with CPA using the homomorph approach

    DEFF Research Database (Denmark)

    Breil, Martin Peter; Tsivintzelis, Ioannis; Kontogeorgis, Georgios

    2011-01-01

    For association models, like CPA and SAFT, a classical approach is often used for estimating pure-compound and mixture parameters. According to this approach, the pure-compound parameters are estimated from vapor pressure and liquid density data. Then, the binary interaction parameters, kij......, are estimated from binary systems; one binary interaction parameter per system. No additional mixing rules are needed for cross-associating systems, but combining rules are required, e.g. the Elliott rule or the so-called CR-1 rule. There is a very large class of mixtures, e.g. water or glycols with aromatic...... interaction parameters are often used for solvating systems; one for the physical part (kij) and one for the association part (βcross). This limits the predictive capabilities and possibilities of generalization of the model. In this work we present an approach to reduce the number of adjustable parameters...

  16. A Two Step Face Alignment Approach Using Statistical Models

    Directory of Open Access Journals (Sweden)

    Ying Cui

    2012-10-01

    Full Text Available Although face alignment using the Active Appearance Model (AAM is relatively stable, it is known to be sensitive to initial values and not robust under inconstant circumstances. In order to strengthen the ability of AAM performance for face alignment, a two step approach for face alignment combining AAM and Active Shape Model (ASM is proposed. In the first step, AAM is used to locate the inner landmarks of the face. In the second step, the extended ASM is used to locate the outer landmarks of the face under the constraint of the estimated inner landmarks by AAM. The two kinds of landmarks are then combined together to form the whole facial landmarks. The proposed approach is compared with the basic AAM and the progressive AAM methods. Experimental results show that the proposed approach gives a much more effective performance.

  17. A review of function modeling : Approaches and applications

    NARCIS (Netherlands)

    Erden, M.S.; Komoto, H.; Van Beek, T.J.; D'Amelio, V.; Echavarria, E.; Tomiyama, T.

    2008-01-01

    This work is aimed at establishing a common frame and understanding of function modeling (FM) for our ongoing research activities. A comparative review of the literature is performed to grasp the various FM approaches with their commonalities and differences. The relations of FM with the research

  18. The Bipolar Approach: A Model for Interdisciplinary Art History Courses.

    Science.gov (United States)

    Calabrese, John A.

    1993-01-01

    Describes a college level art history course based on the opposing concepts of Classicism and Romanticism. Contends that all creative work, such as film or architecture, can be categorized according to this bipolar model. Includes suggestions for objects to study and recommends this approach for art education at all education levels. (CFR)

  19. Model-independent approach for dark matter phenomenology ...

    Indian Academy of Sciences (India)

    We have studied the phenomenology of dark matter at the ILC and cosmic positron experiments based on model-independent approach. We have found a strong correlation between dark matter signatures at the ILC and those in the indirect detection experiments of dark matter. Once the dark matter is discovered in the ...

  20. A Behavioral Decision Making Modeling Approach Towards Hedging Services

    NARCIS (Netherlands)

    Pennings, J.M.E.; Candel, M.J.J.M.; Egelkraut, T.M.

    2003-01-01

    This paper takes a behavioral approach toward the market for hedging services. A behavioral decision-making model is developed that provides insight into how and why owner-managers decide the way they do regarding hedging services. Insight into those choice processes reveals information needed by

  1. Comparing State SAT Scores Using a Mixture Modeling Approach

    Science.gov (United States)

    Kim, YoungKoung Rachel

    2009-01-01

    Presented at the national conference for AERA (American Educational Research Association) in April 2009. The large variability of SAT taker population across states makes state-by-state comparisons of the SAT scores challenging. Using a mixture modeling approach, therefore, the current study presents a method of identifying subpopulations in terms…

  2. Export of microplastics from land to sea. A modelling approach

    NARCIS (Netherlands)

    Siegfried, Max; Koelmans, A.A.; Besseling, E.; Kroeze, C.

    2017-01-01

    Quantifying the transport of plastic debris from river to sea is crucial for assessing the risks of plastic debris to human health and the environment. We present a global modelling approach to analyse the composition and quantity of point-source microplastic fluxes from European rivers to the sea.

  3. A novel Monte Carlo approach to hybrid local volatility models

    NARCIS (Netherlands)

    A.W. van der Stoep (Anton); L.A. Grzelak (Lech Aleksander); C.W. Oosterlee (Cornelis)

    2017-01-01

    textabstractWe present in a Monte Carlo simulation framework, a novel approach for the evaluation of hybrid local volatility [Risk, 1994, 7, 18–20], [Int. J. Theor. Appl. Finance, 1998, 1, 61–110] models. In particular, we consider the stochastic local volatility model—see e.g. Lipton et al. [Quant.

  4. Hidden Markov model-based approach for generation of Pitman ...

    Indian Academy of Sciences (India)

    Speech is one of the most basic means of human communication. ... human beings is carried out with the aid of communication and has facilitated the development ... Hidden Markov model-based approach for generation of PSL symbols. 279. Table 1. PSL basic strokes and English consonants. English consonant.

  5. A novel Monte Carlo approach to hybrid local volatility models

    NARCIS (Netherlands)

    van der Stoep, A.W.; Grzelak, L.A.; Oosterlee, C.W.

    2017-01-01

    We present in a Monte Carlo simulation framework, a novel approach for the evaluation of hybrid local volatility [Risk, 1994, 7, 18–20], [Int. J. Theor. Appl. Finance, 1998, 1, 61–110] models. In particular, we consider the stochastic local volatility model—see e.g. Lipton et al. [Quant. Finance,

  6. Model-independent approach for dark matter phenomenology

    Indian Academy of Sciences (India)

    We have studied the phenomenology of dark matter at the ILC and cosmic positron experiments based on model-independent approach. We have found a strong correlation between dark matter signatures at the ILC and those in the indirect detection experiments of dark matter. Once the dark matter is discovered in the ...

  7. Model-independent approach for dark matter phenomenology ...

    Indian Academy of Sciences (India)

    Abstract. We have studied the phenomenology of dark matter at the ILC and cosmic positron experiments based on model-independent approach. We have found a strong correlation between dark matter signatures at the ILC and those in the indirect detec- tion experiments of dark matter. Once the dark matter is discovered ...

  8. Using artificial neural network approach for modelling rainfall–runoff ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 122; Issue 2. Using artificial neural network approach for modelling ... Nevertheless, water level and flow records are essential in hydrological analysis for designing related water works of flood management. Due to the complexity of the hydrological process, ...

  9. An Approach to Quality Estimation in Model-Based Development

    DEFF Research Database (Denmark)

    Holmegaard, Jens Peter; Koch, Peter; Ravn, Anders Peter

    2004-01-01

    We present an approach to estimation of parameters for design space exploration in Model-Based Development, where synthesis of a system is done in two stages. Component qualities like space, execution time or power consumption are defined in a repository by platform dependent values. Connectors...

  10. Hidden Markov model-based approach for generation of Pitman ...

    Indian Academy of Sciences (India)

    In this paper, an approach for feature extraction using Mel frequency cep- stral coefficients (MFCC) and classification using hidden Markov models (HMM) for generating strokes comprising consonants and vowels (CV) in the process of production of Pitman shorthand language from spoken English is proposed. The.

  11. Pruning Chinese trees : an experimental and modelling approach

    NARCIS (Netherlands)

    Zeng, Bo

    2001-01-01

    Pruning of trees, in which some branches are removed from the lower crown of a tree, has been extensively used in China in silvicultural management for many purposes. With an experimental and modelling approach, the effects of pruning on tree growth and on the harvest of plant material were studied.

  12. Non-frontal Model Based Approach to Forensic Face Recognition

    NARCIS (Netherlands)

    Dutta, A.; Veldhuis, Raymond N.J.; Spreeuwers, Lieuwe Jan

    2012-01-01

    In this paper, we propose a non-frontal model based approach which ensures that a face recognition system always gets to compare images having similar view (or pose). This requires a virtual suspect reference set that consists of non-frontal suspect images having pose similar to the surveillance

  13. Genome-scale modeling of human metabolism - a systems biology approach.

    Science.gov (United States)

    Mardinoglu, Adil; Gatto, Francesco; Nielsen, Jens

    2013-09-01

    Altered metabolism is linked to the appearance of various human diseases and a better understanding of disease-associated metabolic changes may lead to the identification of novel prognostic biomarkers and the development of new therapies. Genome-scale metabolic models (GEMs) have been employed for studying human metabolism in a systematic manner, as well as for understanding complex human diseases. In the past decade, such metabolic models - one of the fundamental aspects of systems biology - have started contributing to the understanding of the mechanistic relationship between genotype and phenotype. In this review, we focus on the construction of the Human Metabolic Reaction database, the generation of healthy cell type- and cancer-specific GEMs using different procedures, and the potential applications of these developments in the study of human metabolism and in the identification of metabolic changes associated with various disorders. We further examine how in silico genome-scale reconstructions can be employed to simulate metabolic flux distributions and how high-throughput omics data can be analyzed in a context-dependent fashion. Insights yielded from this mechanistic modeling approach can be used for identifying new therapeutic agents and drug targets as well as for the discovery of novel biomarkers. Finally, recent advancements in genome-scale modeling and the future challenge of developing a model of whole-body metabolism are presented. The emergent contribution of GEMs to personalized and translational medicine is also discussed. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Reconciliation with oneself and with others: From approach to model

    Directory of Open Access Journals (Sweden)

    Nikolić-Ristanović Vesna

    2010-01-01

    Full Text Available The paper intends to present the approach to dealing with war and its consequences which was developed within Victimology Society of Serbia over the last five years, in the framework of Association Joint Action for Truth and Reconciliation (ZAIP. First, the short review of the Association and the process through which ZAIP approach to dealing with a past was developed is presented. Then, the detailed description of the approach itself, with identification of its most important specificities, is presented. In the conclusion, next steps, aimed at development of the model of reconciliation which will have the basis in ZAIP approach and which will be appropriate to social context of Serbia and its surrounding, are suggested.

  15. EXTENDE MODEL OF COMPETITIVITY THROUG APPLICATION OF NEW APPROACH DIRECTIVES

    Directory of Open Access Journals (Sweden)

    Slavko Arsovski

    2009-03-01

    Full Text Available The basic subject of this work is the model of new approach impact on quality and safety products, and competency of our companies. This work represents real hypothesis on the basis of expert's experiences, in regard to that the infrastructure with using new approach directives wasn't examined until now, it isn't known which product or industry of Serbia is related to directives of the new approach and CE mark, and it is not known which are effects of the use of the CE mark. This work should indicate existing quality reserves and product's safety, the level of possible competency improvement and increasing the profit by discharging new approach directive requires.

  16. Accounting for model error in Bayesian solutions to hydrogeophysical inverse problems using a local basis approach

    Science.gov (United States)

    Irving, J.; Koepke, C.; Elsheikh, A. H.

    2017-12-01

    Bayesian solutions to geophysical and hydrological inverse problems are dependent upon a forward process model linking subsurface parameters to measured data, which is typically assumed to be known perfectly in the inversion procedure. However, in order to make the stochastic solution of the inverse problem computationally tractable using, for example, Markov-chain-Monte-Carlo (MCMC) methods, fast approximations of the forward model are commonly employed. This introduces model error into the problem, which has the potential to significantly bias posterior statistics and hamper data integration efforts if not properly accounted for. Here, we present a new methodology for addressing the issue of model error in Bayesian solutions to hydrogeophysical inverse problems that is geared towards the common case where these errors cannot be effectively characterized globally through some parametric statistical distribution or locally based on interpolation between a small number of computed realizations. Rather than focusing on the construction of a global or local error model, we instead work towards identification of the model-error component of the residual through a projection-based approach. In this regard, pairs of approximate and detailed model runs are stored in a dictionary that grows at a specified rate during the MCMC inversion procedure. At each iteration, a local model-error basis is constructed for the current test set of model parameters using the K-nearest neighbour entries in the dictionary, which is then used to separate the model error from the other error sources before computing the likelihood of the proposed set of model parameters. We demonstrate the performance of our technique on the inversion of synthetic crosshole ground-penetrating radar traveltime data for three different subsurface parameterizations of varying complexity. The synthetic data are generated using the eikonal equation, whereas a straight-ray forward model is assumed in the inversion

  17. Accurate phenotyping: Reconciling approaches through Bayesian model averaging.

    Directory of Open Access Journals (Sweden)

    Carla Chia-Ming Chen

    Full Text Available Genetic research into complex diseases is frequently hindered by a lack of clear biomarkers for phenotype ascertainment. Phenotypes for such diseases are often identified on the basis of clinically defined criteria; however such criteria may not be suitable for understanding the genetic composition of the diseases. Various statistical approaches have been proposed for phenotype definition; however our previous studies have shown that differences in phenotypes estimated using different approaches have substantial impact on subsequent analyses. Instead of obtaining results based upon a single model, we propose a new method, using Bayesian model averaging to overcome problems associated with phenotype definition. Although Bayesian model averaging has been used in other fields of research, this is the first study that uses Bayesian model averaging to reconcile phenotypes obtained using multiple models. We illustrate the new method by applying it to simulated genetic and phenotypic data for Kofendred personality disorder-an imaginary disease with several sub-types. Two separate statistical methods were used to identify clusters of individuals with distinct phenotypes: latent class analysis and grade of membership. Bayesian model averaging was then used to combine the two clusterings for the purpose of subsequent linkage analyses. We found that causative genetic loci for the disease produced higher LOD scores using model averaging than under either individual model separately. We attribute this improvement to consolidation of the cores of phenotype clusters identified using each individual method.

  18. Integrated approaches to modeling the organic and inorganic atmospheric aerosol components

    Science.gov (United States)

    Koo, Bonyoung; Ansari, Asif S.; Pandis, Spyros N.

    A series of modeling approaches for the description of the dynamic behavior of secondary organic aerosol (SOA) components and their interactions with inorganics is presented. The models employ a lumped species approach based on available smog chamber studies and the UNIquac Functional-group Activity Coefficient (UNIFAC) method to estimate SOA water absorption. The additional water due to SOA species can change the partitioning behavior of the semi-volatile inorganics. Primary organic particles significantly influence the SOA partitioning between gas and aerosol phases. The SOA size distribution predicted by a bulk equilibrium approach is biased toward smaller sizes compared with that of a fully dynamic model. An improved weighting scheme for the bulk equilibrium approach is proposed in this work and is shown to minimize this discrepancy. SOA is predicted to increase the total aerosol water in Southern California by 2-13% depending on conditions. However, the effect of SOA water absorption on aerosol nitrate is insignificant for all the cases studied in Southern California.

  19. Evaluation of Workflow Management Systems - A Meta Model Approach

    Directory of Open Access Journals (Sweden)

    Michael Rosemann

    1998-11-01

    Full Text Available The automated enactment of processes through the use of workflow management systems enables the outsourcing of the control flow from application systems. By now a large number of systems, that follow different workflow paradigms, are available. This leads to the problem of selecting the appropriate workflow management system for a given situation. In this paper we outline the benefits of a meta model approach for the evaluation and comparison of different workflow management systems. After a general introduction on the topic of meta modeling the meta models of the workflow management systems WorkParty (Siemens Nixdorf and FlowMark (IBM are compared as an example. These product specific meta models can be generalized to meta reference models, which helps to specify a workflow methodology. Exemplary, an organisational reference meta model is presented, which helps users in specifying their requirements for a workflow management system.

  20. Setting conservation management thresholds using a novel participatory modeling approach.

    Science.gov (United States)

    Addison, P F E; de Bie, K; Rumpff, L

    2015-10-01

    We devised a participatory modeling approach for setting management thresholds that show when management intervention is required to address undesirable ecosystem changes. This approach was designed to be used when management thresholds: must be set for environmental indicators in the face of multiple competing objectives; need to incorporate scientific understanding and value judgments; and will be set by participants with limited modeling experience. We applied our approach to a case study where management thresholds were set for a mat-forming brown alga, Hormosira banksii, in a protected area management context. Participants, including management staff and scientists, were involved in a workshop to test the approach, and set management thresholds to address the threat of trampling by visitors to an intertidal rocky reef. The approach involved trading off the environmental objective, to maintain the condition of intertidal reef communities, with social and economic objectives to ensure management intervention was cost-effective. Ecological scenarios, developed using scenario planning, were a key feature that provided the foundation for where to set management thresholds. The scenarios developed represented declines in percent cover of H. banksii that may occur under increased threatening processes. Participants defined 4 discrete management alternatives to address the threat of trampling and estimated the effect of these alternatives on the objectives under each ecological scenario. A weighted additive model was used to aggregate participants' consequence estimates. Model outputs (decision scores) clearly expressed uncertainty, which can be considered by decision makers and used to inform where to set management thresholds. This approach encourages a proactive form of conservation, where management thresholds and associated actions are defined a priori for ecological indicators, rather than reacting to unexpected ecosystem changes in the future. © 2015 The

  1. A simplified GIS approach to modeling global leaf water isoscapes.

    Directory of Open Access Journals (Sweden)

    Jason B West

    Full Text Available The stable hydrogen (delta(2H and oxygen (delta(18O isotope ratios of organic and inorganic materials record biological and physical processes through the effects of substrate isotopic composition and fractionations that occur as reactions proceed. At large scales, these processes can exhibit spatial predictability because of the effects of coherent climatic patterns over the Earth's surface. Attempts to model spatial variation in the stable isotope ratios of water have been made for decades. Leaf water has a particular importance for some applications, including plant organic materials that record spatial and temporal climate variability and that may be a source of food for migrating animals. It is also an important source of the variability in the isotopic composition of atmospheric gases. Although efforts to model global-scale leaf water isotope ratio spatial variation have been made (especially of delta(18O, significant uncertainty remains in models and their execution across spatial domains. We introduce here a Geographic Information System (GIS approach to the generation of global, spatially-explicit isotope landscapes (= isoscapes of "climate normal" leaf water isotope ratios. We evaluate the approach and the resulting products by comparison with simulation model outputs and point measurements, where obtainable, over the Earth's surface. The isoscapes were generated using biophysical models of isotope fractionation and spatially continuous precipitation isotope and climate layers as input model drivers. Leaf water delta(18O isoscapes produced here generally agreed with latitudinal averages from GCM/biophysical model products, as well as mean values from point measurements. These results show global-scale spatial coherence in leaf water isotope ratios, similar to that observed for precipitation and validate the GIS approach to modeling leaf water isotopes. These results demonstrate that relatively simple models of leaf water enrichment

  2. Accumulating approach to the life-cycle pension model: practical advantages

    Directory of Open Access Journals (Sweden)

    Yaniv Azoulay

    2016-12-01

    Full Text Available In the present study, we make an effort to enhance the practical advantages of the life-cycle pension model. We observe that previous studies are based on a “switching”approach, that is, on the assumption that when a pension fund member reaches a certain age, his accumulated savings are fully switched to another fund with a lower risk profile; we suggest an “accumulating” approach, according to which, at the same age, the member’s previously accumulated wealth continues to be invested in the same fund, while his new regular pension contributions start being directed to another (less risky fund. We consider a hypothetical (average Israeli employee, analyze two age-dependent life-cycle investment distributions of his pension savings, and perform a comparison between the two approaches to the life-cycle model by employing an estimation-based and a simulation-based technique. The results demonstrate that the “accumulating” approach provides: (i higher estimated annualized real returns and real accumulated savings; (ii significantly higher simulated mean and median values of real accumulated savings. Moreover, we document that, though the “accumulating” approach increases the standard deviation of total savings, it does not lead to critically low pension wealth levels even for relatively unfavorable sequences of financial assets’ returns. Therefore, we conclude that the “accumulating” approach to the life-cycle model has a potential significantly to increase pension fund members’ total accumulated wealth relatively to the common “switching” approach, without significantly increasing the members’ risk.

  3. Integrated approach to model decomposed flow hydrograph using artificial neural network and conceptual techniques

    Science.gov (United States)

    Jain, Ashu; Srinivasulu, Sanaga

    2006-02-01

    This paper presents the findings of a study aimed at decomposing a flow hydrograph into different segments based on physical concepts in a catchment, and modelling different segments using different technique viz. conceptual and artificial neural networks (ANNs). An integrated modelling framework is proposed capable of modelling infiltration, base flow, evapotranspiration, soil moisture accounting, and certain segments of the decomposed flow hydrograph using conceptual techniques and the complex, non-linear, and dynamic rainfall-runoff process using ANN technique. Specifically, five different multi-layer perceptron (MLP) and two self-organizing map (SOM) models have been developed. The rainfall and streamflow data derived from the Kentucky River catchment were employed to test the proposed methodology and develop all the models. The performance of all the models was evaluated using seven different standard statistical measures. The results obtained in this study indicate that (a) the rainfall-runoff relationship in a large catchment consists of at least three or four different mappings corresponding to different dynamics of the underlying physical processes, (b) an integrated approach that models the different segments of the decomposed flow hydrograph using different techniques is better than a single ANN in modelling the complex, dynamic, non-linear, and fragmented rainfall runoff process, (c) a simple model based on the concept of flow recession is better than an ANN to model the falling limb of a flow hydrograph, and (d) decomposing a flow hydrograph into the different segments corresponding to the different dynamics based on the physical concepts is better than using the soft decomposition employed using SOM.

  4. A method to employ the spatial organization of catchments into semi-distributed rainfall-runoff models

    Science.gov (United States)

    Oppel, Henning; Schumann, Andreas

    2017-08-01

    A distributed or semi-distributed deterministic hydrological model should consider the hydrologically most relevant catchment characteristics. These are heterogeneously distributed within a watershed but often interrelated and subject to a certain spatial organization which results in archetypes of combined characteristics. In order to reproduce the natural rainfall-runoff response the reduction of variance of catchment properties as well as the incorporation of the spatial organization of the catchment are desirable. In this study the width-function approach is utilized as a basic characteristic to analyse the succession of catchment characteristics. By applying this technique we were able to assess the context of catchment properties like soil or topology along the streamflow length and the network geomorphology, giving indications of the spatial organization of a catchment. Moreover, this information and this technique have been implemented in an algorithm for automated sub-basin ascertainment, which included the definition of zones within the newly defined sub-basins. The objective was to provide sub-basins that were less heterogeneous than common separation schemes. The algorithm was applied to two parameters characterizing the topology and soil of four mid-European watersheds. Resulting partitions indicated a wide range of applicability for the method and the algorithm. Additionally, the intersection of derived zones for different catchment characteristics could give insights into sub-basin similarities. Finally, a HBV96 case study demonstrated the potential benefits of modelling with the new subdivision technique.

  5. A method to employ the spatial organization of catchments into semi-distributed rainfall–runoff models

    Directory of Open Access Journals (Sweden)

    H. Oppel

    2017-08-01

    Full Text Available A distributed or semi-distributed deterministic hydrological model should consider the hydrologically most relevant catchment characteristics. These are heterogeneously distributed within a watershed but often interrelated and subject to a certain spatial organization which results in archetypes of combined characteristics. In order to reproduce the natural rainfall–runoff response the reduction of variance of catchment properties as well as the incorporation of the spatial organization of the catchment are desirable. In this study the width-function approach is utilized as a basic characteristic to analyse the succession of catchment characteristics. By applying this technique we were able to assess the context of catchment properties like soil or topology along the streamflow length and the network geomorphology, giving indications of the spatial organization of a catchment. Moreover, this information and this technique have been implemented in an algorithm for automated sub-basin ascertainment, which included the definition of zones within the newly defined sub-basins. The objective was to provide sub-basins that were less heterogeneous than common separation schemes. The algorithm was applied to two parameters characterizing the topology and soil of four mid-European watersheds. Resulting partitions indicated a wide range of applicability for the method and the algorithm. Additionally, the intersection of derived zones for different catchment characteristics could give insights into sub-basin similarities. Finally, a HBV96 case study demonstrated the potential benefits of modelling with the new subdivision technique.

  6. Possibility of object recognition using Altera's model based design approach

    International Nuclear Information System (INIS)

    Tickle, A J; Harvey, P K; Smith, J S; Wu, F

    2009-01-01

    Object recognition is an image processing task of finding a given object in a selected image or video sequence. Object recognition can be divided into two areas: one of these is decision-theoretic and deals with patterns described by quantitative descriptors, for example such as length, area, shape and texture. With this Graphical User Interface Circuitry (GUIC) methodology employed here being relatively new for object recognition systems, the aim of this work is to identify if the developed circuitry can detect certain shapes or strings within the target image. A much smaller reference image feeds the preset data for identification, tests are conducted for both binary and greyscale and the additional mathematical morphology to highlight the area within the target image with the object(s) are located is also presented. This then provides proof that basic recognition methods are valid and would allow the progression to developing decision-theoretical and learning based approaches using GUICs for use in multidisciplinary tasks.

  7. A Genetic Algorithm Approach for Modeling a Grounding Electrode

    Science.gov (United States)

    Mishra, Arbind Kumar; Nagaoka, Naoto; Ametani, Akihiro

    This paper has proposed a genetic algorithm based approach to determine a grounding electrode model circuit composed of resistances, inductances and capacitances. The proposed methodology determines the model circuit parameters based on a general ladder circuit directly from a measured result. Transient voltages of some electrodes were measured when applying a step like current. An EMTP simulation of a transient voltage on the grounding electrode has been carried out by adopting the proposed model circuits. The accuracy of the proposed method has been confirmed to be high in comparison with the measured transient voltage.

  8. Comparative animal models for the study of lymphohematopoietic tumors: strengths and limitations of present approaches.

    Science.gov (United States)

    O'Connor, Owen A; Toner, Lorraine E; Vrhovac, Radovan; Budak-Alpdogan, Tulin; Smith, Emily A; Bergman, Philip

    2005-07-01

    The lymphomas probably represent the most complex and heterogenous set of malignancies known to cancer medicine. Underneath the single term lymphoma exist some of the fastest growing cancers known to science (i.e Burkitt's and lymphoblastic lymphoma), as well as some of the slowest growing (i.e. small lymphocytic lymphoma [SLL] and follicular lymphoma). It is this very biology that can dictate the selection of drugs and treatment approaches for managing these patients, strategies that can range from very aggressive combination chemotherapy administered in an intensive care unit (for example, patients with Burkitt's lymphoma), to watch and wait approaches that may go on for years in patients with SLL. This impressive spectrum of biology emerges from a relatively restricted number of molecular defects. The importance of these different molecular defects is of course greatly influenced by the intrinsic biology that defines the lymphocyte at its different stages of differentiation and maturation. It is precisely this molecular understanding that is beginning to form the basis for a new approach to thinking about lymphoma, and novel approaches to its management. Unfortunately, while our understanding of human lymphoma has blossomed, our ability to generate appropriate animal models reflective of this biology has not. Most preclinical models of these diseases still rely upon sub-cutaneous xenograft models of only the most aggressive lymphomas like Burkitt's lymphoma. While these models clearly serve an important role in understanding biology, and perhaps more importantly, in identifying promising new drugs for these diseases, they fall short in truly representing the broader, more heterogenous biology found in patients. Clearly, depending upon the questions being posed, or the types of drugs being studied, the best model to employ may vary from situation to situation. In this article, we will review the numerous complexities associated with various animal models of

  9. Data-driven approach to dynamic visual attention modelling

    Science.gov (United States)

    Culibrk, Dubravko; Sladojevic, Srdjan; Riche, Nicolas; Mancas, Matei; Crnojevic, Vladimir

    2012-06-01

    Visual attention deployment mechanisms allow the Human Visual System to cope with an overwhelming amount of visual data by dedicating most of the processing power to objects of interest. The ability to automatically detect areas of the visual scene that will be attended to by humans is of interest for a large number of applications, from video coding, video quality assessment to scene understanding. Due to this fact, visual saliency (bottom-up attention) models have generated significant scientific interest in recent years. Most recent work in this area deals with dynamic models of attention that deal with moving stimuli (videos) instead of traditionally used still images. Visual saliency models are usually evaluated against ground-truth eye-tracking data collected from human subjects. However, there are precious few recently published approaches that try to learn saliency from eyetracking data and, to the best of our knowledge, no approaches that try to do so when dynamic saliency is concerned. The paper attempts to fill this gap and describes an approach to data-driven dynamic saliency model learning. A framework is proposed that enables the use of eye-tracking data to train an arbitrary machine learning algorithm, using arbitrary features derived from the scene. We evaluate the methodology using features from a state-of-the art dynamic saliency model and show how simple machine learning algorithms can be trained to distinguish between visually salient and non-salient parts of the scene.

  10. Polynomial Chaos Expansion Approach to Interest Rate Models

    Directory of Open Access Journals (Sweden)

    Luca Di Persio

    2015-01-01

    Full Text Available The Polynomial Chaos Expansion (PCE technique allows us to recover a finite second-order random variable exploiting suitable linear combinations of orthogonal polynomials which are functions of a given stochastic quantity ξ, hence acting as a kind of random basis. The PCE methodology has been developed as a mathematically rigorous Uncertainty Quantification (UQ method which aims at providing reliable numerical estimates for some uncertain physical quantities defining the dynamic of certain engineering models and their related simulations. In the present paper, we use the PCE approach in order to analyze some equity and interest rate models. In particular, we take into consideration those models which are based on, for example, the Geometric Brownian Motion, the Vasicek model, and the CIR model. We present theoretical as well as related concrete numerical approximation results considering, without loss of generality, the one-dimensional case. We also provide both an efficiency study and an accuracy study of our approach by comparing its outputs with the ones obtained adopting the Monte Carlo approach, both in its standard and its enhanced version.

  11. Common modelling approaches for training simulators for nuclear power plants

    International Nuclear Information System (INIS)

    1990-02-01

    Training simulators for nuclear power plant operating staff have gained increasing importance over the last twenty years. One of the recommendations of the 1983 IAEA Specialists' Meeting on Nuclear Power Plant Training Simulators in Helsinki was to organize a Co-ordinated Research Programme (CRP) on some aspects of training simulators. The goal statement was: ''To establish and maintain a common approach to modelling for nuclear training simulators based on defined training requirements''. Before adapting this goal statement, the participants considered many alternatives for defining the common aspects of training simulator models, such as the programming language used, the nature of the simulator computer system, the size of the simulation computers, the scope of simulation. The participants agreed that it was the training requirements that defined the need for a simulator, the scope of models and hence the type of computer complex that was required, the criteria for fidelity and verification, and was therefore the most appropriate basis for the commonality of modelling approaches. It should be noted that the Co-ordinated Research Programme was restricted, for a variety of reasons, to consider only a few aspects of training simulators. This report reflects these limitations, and covers only the topics considered within the scope of the programme. The information in this document is intended as an aid for operating organizations to identify possible modelling approaches for training simulators for nuclear power plants. 33 refs

  12. Estimating a DIF decomposition model using a random-weights linear logistic test model approach.

    Science.gov (United States)

    Paek, Insu; Fukuhara, Hirotaka

    2015-09-01

    A differential item functioning (DIF) decomposition model separates a testlet item DIF into two sources: item-specific differential functioning and testlet-specific differential functioning. This article provides an alternative model-building framework and estimation approach for a DIF decomposition model that was proposed by Beretvas and Walker (2012). Although their model is formulated under multilevel modeling with the restricted pseudolikelihood estimation method, our approach illustrates DIF decomposition modeling that is directly built upon the random-weights linear logistic test model framework with the marginal maximum likelihood estimation method. In addition to demonstrating our approach's performance, we provide detailed information on how to implement this new DIF decomposition model using an item response theory software program; using DIF decomposition may be challenging for practitioners, yet practical information on how to implement it has previously been unavailable in the measurement literature.

  13. Modeling and analysis of a decentralized electricity market: An integrated simulation/optimization approach

    International Nuclear Information System (INIS)

    Sarıca, Kemal; Kumbaroğlu, Gürkan; Or, Ilhan

    2012-01-01

    In this study, a model is developed to investigate the implications of an hourly day-ahead competitive power market on generator profits, electricity prices, availability and supply security. An integrated simulation/optimization approach is employed integrating a multi-agent simulation model with two alternative optimization models. The simulation model represents interactions between power generator, system operator, power user and power transmitter agents while the network flow optimization model oversees and optimizes the electricity flows, dispatches generators based on two alternative approaches used in the modeling of the underlying transmission network: a linear minimum cost network flow model and a non-linear alternating current optimal power flow model. Supply, demand, transmission, capacity and other technological constraints are thereby enforced. The transmission network, on which the scenario analyses are carried out, includes 30 bus, 41 lines, 9 generators, and 21 power users. The scenarios examined in the analysis cover various settings of transmission line capacities/fees, and hourly learning algorithms. Results provide insight into key behavioral and structural aspects of a decentralized electricity market under network constraints and reveal the importance of using an AC network instead of a simplified linear network flow approach. -- Highlights: ► An agent-based simulation model with an AC transmission environment with a day-ahead market. ► Physical network parameters have dramatic effects over price levels and stability. ► Due to AC nature of transmission network, adaptive agents have more local market power than minimal cost network flow. ► Behavior of the generators has significant effect over market price formation, as pointed out by bidding strategies. ► Transmission line capacity and fee policies are found to be very effective in price formation in the market.

  14. Plenary lecture: innovative modeling approaches applicable to risk assessments.

    Science.gov (United States)

    Oscar, T P

    2011-06-01

    Proper identification of safe and unsafe food at the processing plant is important for maximizing the public health benefit of food by ensuring both its consumption and safety. Risk assessment is a holistic approach to food safety that consists of four steps: 1) hazard identification; 2) exposure assessment; 3) hazard characterization; and 4) risk characterization. Risk assessments are modeled by mapping the risk pathway as a series of unit operations and associated pathogen events and then using probability distributions and a random sampling method to simulate the rare, random, variable and uncertain nature of pathogen events in the risk pathway. To model pathogen events, a rare event modeling approach is used that links a discrete distribution for incidence of the pathogen event with a continuous distribution for extent of the pathogen event. When applied to risk assessment, rare event modeling leads to the conclusion that the most highly contaminated food at the processing plant does not necessarily pose the highest risk to public health because of differences in post-processing risk factors among distribution channels and consumer populations. Predictive microbiology models for individual pathogen events can be integrated with risk assessment models using the rare event modeling method. Published by Elsevier Ltd.

  15. A global sensitivity analysis approach for morphogenesis models

    KAUST Repository

    Boas, Sonja E. M.

    2015-11-21

    Background Morphogenesis is a developmental process in which cells organize into shapes and patterns. Complex, non-linear and multi-factorial models with images as output are commonly used to study morphogenesis. It is difficult to understand the relation between the uncertainty in the input and the output of such ‘black-box’ models, giving rise to the need for sensitivity analysis tools. In this paper, we introduce a workflow for a global sensitivity analysis approach to study the impact of single parameters and the interactions between them on the output of morphogenesis models. Results To demonstrate the workflow, we used a published, well-studied model of vascular morphogenesis. The parameters of this cellular Potts model (CPM) represent cell properties and behaviors that drive the mechanisms of angiogenic sprouting. The global sensitivity analysis correctly identified the dominant parameters in the model, consistent with previous studies. Additionally, the analysis provided information on the relative impact of single parameters and of interactions between them. This is very relevant because interactions of parameters impede the experimental verification of the predicted effect of single parameters. The parameter interactions, although of low impact, provided also new insights in the mechanisms of in silico sprouting. Finally, the analysis indicated that the model could be reduced by one parameter. Conclusions We propose global sensitivity analysis as an alternative approach to study the mechanisms of morphogenesis. Comparison of the ranking of the impact of the model parameters to knowledge derived from experimental data and from manipulation experiments can help to falsify models and to find the operand mechanisms in morphogenesis. The workflow is applicable to all ‘black-box’ models, including high-throughput in vitro models in which output measures are affected by a set of experimental perturbations.

  16. A global sensitivity analysis approach for morphogenesis models.

    Science.gov (United States)

    Boas, Sonja E M; Navarro Jimenez, Maria I; Merks, Roeland M H; Blom, Joke G

    2015-11-21

    Morphogenesis is a developmental process in which cells organize into shapes and patterns. Complex, non-linear and multi-factorial models with images as output are commonly used to study morphogenesis. It is difficult to understand the relation between the uncertainty in the input and the output of such 'black-box' models, giving rise to the need for sensitivity analysis tools. In this paper, we introduce a workflow for a global sensitivity analysis approach to study the impact of single parameters and the interactions between them on the output of morphogenesis models. To demonstrate the workflow, we used a published, well-studied model of vascular morphogenesis. The parameters of this cellular Potts model (CPM) represent cell properties and behaviors that drive the mechanisms of angiogenic sprouting. The global sensitivity analysis correctly identified the dominant parameters in the model, consistent with previous studies. Additionally, the analysis provided information on the relative impact of single parameters and of interactions between them. This is very relevant because interactions of parameters impede the experimental verification of the predicted effect of single parameters. The parameter interactions, although of low impact, provided also new insights in the mechanisms of in silico sprouting. Finally, the analysis indicated that the model could be reduced by one parameter. We propose global sensitivity analysis as an alternative approach to study the mechanisms of morphogenesis. Comparison of the ranking of the impact of the model parameters to knowledge derived from experimental data and from manipulation experiments can help to falsify models and to find the operand mechanisms in morphogenesis. The workflow is applicable to all 'black-box' models, including high-throughput in vitro models in which output measures are affected by a set of experimental perturbations.

  17. A Hybrid Latent Class Analysis Modeling Approach to Analyze Urban Expressway Crash Risk.

    Science.gov (United States)

    Yu, Rongjie; Wang, Xuesong; Abdel-Aty, Mohamed

    2017-04-01

    Crash risk analysis is rising as a hot research topic as it could reveal the relationships between traffic flow characteristics and crash occurrence risk, which is beneficial to understand crash mechanisms which would further refine the design of Active Traffic Management System (ATMS). However, the majority of the current crash risk analysis studies have ignored the impact of geometric characteristics on crash risk estimation while recent studies proved that crash occurrence risk was affected by the various alignment features. In this study, a hybrid Latent Class Analysis (LCA) modeling approach was proposed to account for the heterogeneous effects of geometric characteristics. Crashes were first segmented into homogenous subgroups, where the optimal number of latent classes was identified based on bootstrap likelihood ratio tests. Then, separate crash risk analysis models were developed using Bayesian random parameter logistic regression technique; data from Shanghai urban expressway system were employed to conduct the empirical study. Different crash risk contributing factors were unveiled by the hybrid LCA approach and better model goodness-of-fit was obtained while comparing to an overall total crash model. Finally, benefits of the proposed hybrid LCA approach were discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. A fuzzy approach for modelling radionuclide in lake system

    International Nuclear Information System (INIS)

    Desai, H.K.; Christian, R.A.; Banerjee, J.; Patra, A.K.

    2013-01-01

    Radioactive liquid waste is generated during operation and maintenance of Pressurised Heavy Water Reactors (PHWRs). Generally low level liquid waste is diluted and then discharged into the near by water-body through blowdown water discharge line as per the standard waste management practice. The effluents from nuclear installations are treated adequately and then released in a controlled manner under strict compliance of discharge criteria. An attempt was made to predict the concentration of 3 H released from Kakrapar Atomic Power Station at Ratania Regulator, about 2.5 km away from the discharge point, where human exposure is expected. Scarcity of data and complex geometry of the lake prompted the use of Heuristic approach. Under this condition, Fuzzy rule based approach was adopted to develop a model, which could predict 3 H concentration at Ratania Regulator. Three hundred data were generated for developing the fuzzy rules, in which input parameters were water flow from lake and 3 H concentration at discharge point. The Output was 3 H concentration at Ratania Regulator. These data points were generated by multiple regression analysis of the original data. Again by using same methodology hundred data were generated for the validation of the model, which were compared against the predicted output generated by using Fuzzy Rule based approach. Root Mean Square Error of the model came out to be 1.95, which showed good agreement by Fuzzy model of natural ecosystem. -- Highlights: • Uncommon approach (Fuzzy Rule Base) of modelling radionuclide dispersion in Lake. • Predicts 3 H released from Kakrapar Atomic Power Station at a point of human exposure. • RMSE of fuzzy model is 1.95, which means, it has well imitated natural ecosystem

  19. A Simplified Micromechanical Modeling Approach to Predict the Tensile Flow Curve Behavior of Dual-Phase Steels

    Science.gov (United States)

    Nanda, Tarun; Kumar, B. Ravi; Singh, Vishal

    2017-11-01

    Micromechanical modeling is used to predict material's tensile flow curve behavior based on microstructural characteristics. This research develops a simplified micromechanical modeling approach for predicting flow curve behavior of dual-phase steels. The existing literature reports on two broad approaches for determining tensile flow curve of these steels. The modeling approach developed in this work attempts to overcome specific limitations of the existing two approaches. This approach combines dislocation-based strain-hardening method with rule of mixtures. In the first step of modeling, `dislocation-based strain-hardening method' was employed to predict tensile behavior of individual phases of ferrite and martensite. In the second step, the individual flow curves were combined using `rule of mixtures,' to obtain the composite dual-phase flow behavior. To check accuracy of proposed model, four distinct dual-phase microstructures comprising of different ferrite grain size, martensite fraction, and carbon content in martensite were processed by annealing experiments. The true stress-strain curves for various microstructures were predicted with the newly developed micromechanical model. The results of micromechanical model matched closely with those of actual tensile tests. Thus, this micromechanical modeling approach can be used to predict and optimize the tensile flow behavior of dual-phase steels.

  20. A COGNITIVE APPROACH TO CORPORATE GOVERNANCE: A VISUALIZATION TEST OF MENTAL MODELS WITH THE COGNITIVE MAPPING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Garoui NASSREDDINE

    2012-01-01

    Full Text Available The idea of this paper is to determine the mental models of actors in the fi rm with respect to the cognitive approach of corporate governance. The paper takes a corporate governance perspective, discusses mental models and uses the cognitive map to view the diagrams showing the ways of thinking and the conceptualization of the cognitive approach. In addition, it employs a cognitive mapping technique. Returning to the systematic exploration of grids for each actor, it concludes that there is a balance of concepts expressing their cognitive orientation.

  1. A New Approach of Modeling an Ultra-Super-Critical Power Plant for Performance Improvement

    Directory of Open Access Journals (Sweden)

    Guolian Hou

    2016-04-01

    Full Text Available A suitable model of coordinated control system (CCS with high accuracy and simple structure is essential for the design of advanced controllers which can improve the efficiency of the ultra-super-critical (USC power plant. Therefore, with the demand of plant performance improvement, an improved T-S fuzzy model identification approach is proposed in this paper. Firstly, the improved entropy cluster algorithm is applied to identify the premise parameters which can automatically determine the cluster numbers and initial cluster centers by introducing the concept of a decision-making constant and threshold. Then, the learning algorithm is used to modify the initial cluster center and a new structure of concluding part is discussed, the incremental data around the cluster center is used to identify the local linear model through a weighted recursive least-square algorithm. Finally, the proposed approach is employed to model the CCS of a 1000 MW USC one-through boiler power plant by using on-site measured data. Simulation results show that the T-S fuzzy model built in this paper is accurate enough to reflect the dynamic performance of CCS and can be treated as a foundation model for the overall optimizing control of the USC power plant.

  2. Approaches for Reduced Order Modeling of Electrically Actuated von Karman Microplates

    KAUST Repository

    Saghir, Shahid

    2016-07-25

    This article presents and compares different approaches to develop reduced order models for the nonlinear von Karman rectangular microplates actuated by nonlinear electrostatic forces. The reduced-order models aim to investigate the static and dynamic behavior of the plate under small and large actuation forces. A fully clamped microplate is considered. Different types of basis functions are used in conjunction with the Galerkin method to discretize the governing equations. First we investigate the convergence with the number of modes retained in the model. Then for validation purpose, a comparison of the static results is made with the results calculated by a nonlinear finite element model. The linear eigenvalue problem for the plate under the electrostatic force is solved for a wide range of voltages up to pull-in. Results among the various reduced-order modes are compared and are also validated by comparing to results of the finite-element model. Further, the reduced order models are employed to capture the forced dynamic response of the microplate under small and large vibration amplitudes. Comparison of the different approaches are made for this case. Keywords: electrically actuated microplates, static analysis, dynamics of microplates, diaphragm vibration, large amplitude vibrations, nonlinear dynamics

  3. Modeling Soft Tissue Damage and Failure Using a Combined Particle/Continuum Approach

    Science.gov (United States)

    Rausch, M. K.; Karniadakis, G. E.; Humphrey, J. D.

    2016-01-01

    Biological soft tissues experience damage and failure as a result of injury, disease, or simply age; examples include torn ligaments and arterial dissections. Given the complexity of tissue geometry and material behavior, computational models are often essential for studying both damage and failure. Yet, because of the need to account for discontinuous phenomena such as crazing, tearing, and rupturing, continuum methods are limited. Therefore, we model soft tissue damage and failure using a particle/continuum approach. Specifically, we combine continuum damage theory with Smoothed Particle Hydrodynamics (SPH). Because SPH is a meshless particle method, and particle connectivity is determined solely through a neighbor list, discontinuities can be readily modeled by modifying this list. We show, for the first time, that an anisotropic hyperelastic constitutive model commonly employed for modeling soft tissue can be conveniently implemented within a SPH framework and that SPH results show excellent agreement with analytical solutions for uniaxial and biaxial extension as well as finite element solutions for clamped uniaxial extension in 2D and 3D. We further develop a simple algorithm that automatically detects damaged particles and disconnects the spatial domain along rupture lines in 2D and rupture surfaces in 3D. We demonstrate the utility of this approach by simulating damage and failure under clamped uniaxial extension and in a peeling experiment of virtual soft tissue samples. In conclusion, SPH in combination with continuum damage theory may provide an accurate and efficient framework for modeling damage and failure in soft tissues. PMID:27538848

  4. Value-based benefit design: using a predictive modeling approach to improve compliance.

    Science.gov (United States)

    Mahoney, John J

    2008-07-01

    Increased medication compliance rates have been demonstrated to result in improved clinical outcomes and reduced overall medical expenditures. As such, managed care stakeholders should take the total value approach to benefit design and consider total medical costs beyond the cost of pharmacotherapy alone. To describe the value-based benefit design employed by Pitney Bowes (specifically, the predictive modeling approach), to improve medication compliance, and to report the results of this intervention. Despite significant skepticism surrounding value-based benefit design, there is growing evidence that these plans can be used in conjunction with careful pharmacy management. In fact, value-based design provides a different lever on pharmacy management and allows for the appropriate drug to be channeled to the appropriate person. Studies demonstrating the adverse impact of high coinsurance levels further augment the argument for value-based benefit design. Value-based benefit design was employed at Pitney Bowes, a $6.1-billion global provider of integrated mailstream solutions, with noticeable success. Patients were either placed in a disease management program or in a secondary program promoting preventive care. The company selectively cut copays to achieve that end, and this total value approach translated into significant savings. To develop a successful value-based benefit design, stakeholders cannot simply cut costs or cut copays. Action must be taken as part of a concerted program, coupled with disease management or similar interventions. "Value based" means that positive outcomes are the ultimate goal, and barriers to those positive outcomes must be addressed.

  5. Bayesian approach to errors-in-variables in regression models

    Science.gov (United States)

    Rozliman, Nur Aainaa; Ibrahim, Adriana Irawati Nur; Yunus, Rossita Mohammad

    2017-05-01

    In many applications and experiments, data sets are often contaminated with error or mismeasured covariates. When at least one of the covariates in a model is measured with error, Errors-in-Variables (EIV) model can be used. Measurement error, when not corrected, would cause misleading statistical inferences and analysis. Therefore, our goal is to examine the relationship of the outcome variable and the unobserved exposure variable given the observed mismeasured surrogate by applying the Bayesian formulation to the EIV model. We shall extend the flexible parametric method proposed by Hossain and Gustafson (2009) to another nonlinear regression model which is the Poisson regression model. We shall then illustrate the application of this approach via a simulation study using Markov chain Monte Carlo sampling methods.

  6. Understanding Resilient Urban Futures: A Systemic Modelling Approach

    Directory of Open Access Journals (Sweden)

    Ralph Chapman

    2013-07-01

    Full Text Available The resilience of cities in response to natural disasters and long-term climate change has emerged as a focus of academic and policy attention. In particular, how to understand the interconnectedness of urban and natural systems is a key issue. This paper introduces an urban model that can be used to evaluate city resilience outcomes under different policy scenarios. The model is the Wellington Integrated Land Use-Transport-Environment Model (WILUTE. It considers the city (i.e., Wellington as a complex system characterized by interactions between a variety of internal urban processes (social, economic and physical and the natural environment. It is focused on exploring the dynamic relations between human activities (the geographic distribution of housing and employment, infrastructure layout, traffic flows and energy consumption, environmental effects (carbon emissions, influences on local natural and ecological systems and potential natural disasters (e.g., inundation due to sea level rise and storm events faced under different policy scenarios. The model gives insights that are potentially useful for policy to enhance the city’s resilience, by modelling outcomes, such as the potential for reduction in transportation energy use, and changes in the vulnerability of the city’s housing stock and transport system to sea level rise.

  7. A screening-level modeling approach to estimate nitrogen ...

    Science.gov (United States)

    This paper presents a screening-level modeling approach that can be used to rapidly estimate nutrient loading and assess numerical nutrient standard exceedance risk of surface waters leading to potential classification as impaired for designated use. It can also be used to explore best management practice (BMP) implementation to reduce loading. The modeling framework uses a hybrid statistical and process based approach to estimate source of pollutants, their transport and decay in the terrestrial and aquatic parts of watersheds. The framework is developed in the ArcGIS environment and is based on the total maximum daily load (TMDL) balance model. Nitrogen (N) is currently addressed in the framework, referred to as WQM-TMDL-N. Loading for each catchment includes non-point sources (NPS) and point sources (PS). NPS loading is estimated using export coefficient or event mean concentration methods depending on the temporal scales, i.e., annual or daily. Loading from atmospheric deposition is also included. The probability of a nutrient load to exceed a target load is evaluated using probabilistic risk assessment, by including the uncertainty associated with export coefficients of various land uses. The computed risk data can be visualized as spatial maps which show the load exceedance probability for all stream segments. In an application of this modeling approach to the Tippecanoe River watershed in Indiana, USA, total nitrogen (TN) loading and risk of standard exce

  8. A fuzzy approach for modelling radionuclide in lake system.

    Science.gov (United States)

    Desai, H K; Christian, R A; Banerjee, J; Patra, A K

    2013-10-01

    Radioactive liquid waste is generated during operation and maintenance of Pressurised Heavy Water Reactors (PHWRs). Generally low level liquid waste is diluted and then discharged into the near by water-body through blowdown water discharge line as per the standard waste management practice. The effluents from nuclear installations are treated adequately and then released in a controlled manner under strict compliance of discharge criteria. An attempt was made to predict the concentration of (3)H released from Kakrapar Atomic Power Station at Ratania Regulator, about 2.5 km away from the discharge point, where human exposure is expected. Scarcity of data and complex geometry of the lake prompted the use of Heuristic approach. Under this condition, Fuzzy rule based approach was adopted to develop a model, which could predict (3)H concentration at Ratania Regulator. Three hundred data were generated for developing the fuzzy rules, in which input parameters were water flow from lake and (3)H concentration at discharge point. The Output was (3)H concentration at Ratania Regulator. These data points were generated by multiple regression analysis of the original data. Again by using same methodology hundred data were generated for the validation of the model, which were compared against the predicted output generated by using Fuzzy Rule based approach. Root Mean Square Error of the model came out to be 1.95, which showed good agreement by Fuzzy model of natural ecosystem. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. BUSINESS MODEL ROADMAPPING: A PRACTICAL APPROACH TO COME FROM AN EXISTING TO A DESIRED BUSINESS MODEL

    OpenAIRE

    MARK DE REUVER; HARRY BOUWMAN; TIMBER HAAKER

    2013-01-01

    Literature on business models deals extensively with how to design new business models, but hardly with how to make the transition from an existing to a newly designed business model. The transition to a new business model raises several practical and strategic issues, such as how to replace an existing value proposition with a new one, when to acquire new resources and capabilities, and when to start new partnerships. In this paper, we coin the term business model roadmapping as an approach ...

  10. Anthropomorphic Coding of Speech and Audio: A Model Inversion Approach

    Directory of Open Access Journals (Sweden)

    W. Bastiaan Kleijn

    2005-06-01

    Full Text Available Auditory modeling is a well-established methodology that provides insight into human perception and that facilitates the extraction of signal features that are most relevant to the listener. The aim of this paper is to provide a tutorial on perceptual speech and audio coding using an invertible auditory model. In this approach, the audio signal is converted into an auditory representation using an invertible auditory model. The auditory representation is quantized and coded. Upon decoding, it is then transformed back into the acoustic domain. This transformation converts a complex distortion criterion into a simple one, thus facilitating quantization with low complexity. We briefly review past work on auditory models and describe in more detail the components of our invertible model and its inversion procedure, that is, the method to reconstruct the signal from the output of the auditory model. We summarize attempts to use the auditory representation for low-bit-rate coding. Our approach also allows the exploitation of the inherent redundancy of the human auditory system for the purpose of multiple description (joint source-channel coding.

  11. A modal approach to modeling spatially distributed vibration energy dissipation.

    Energy Technology Data Exchange (ETDEWEB)

    Segalman, Daniel Joseph

    2010-08-01

    The nonlinear behavior of mechanical joints is a confounding element in modeling the dynamic response of structures. Though there has been some progress in recent years in modeling individual joints, modeling the full structure with myriad frictional interfaces has remained an obstinate challenge. A strategy is suggested for structural dynamics modeling that can account for the combined effect of interface friction distributed spatially about the structure. This approach accommodates the following observations: (1) At small to modest amplitudes, the nonlinearity of jointed structures is manifest primarily in the energy dissipation - visible as vibration damping; (2) Correspondingly, measured vibration modes do not change significantly with amplitude; and (3) Significant coupling among the modes does not appear to result at modest amplitudes. The mathematical approach presented here postulates the preservation of linear modes and invests all the nonlinearity in the evolution of the modal coordinates. The constitutive form selected is one that works well in modeling spatially discrete joints. When compared against a mathematical truth model, the distributed dissipation approximation performs well.

  12. The Employment of spatial autoregressive models in predicting demand for natural gas; O Emprego de modelos auto-regressivos espaciais na previsao de demanda para gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Jorge Henrique de [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil); Silva, Alexandre Pinto Alves da [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Eletrica

    2010-07-01

    Develop the natural gas network is critical success factor for the distribution company. It is a decision that employs the demand given location 'x' and a future time 't' so that the net allows the best conditions for the return of the capital. In this segment, typical network industry, the spatial infra-structure vision associated to the market allows better evaluation of the business because to mitigate costs and risks. In fact, economic models little developed in order to assess the question of the location, due to its little employment by economists. The objective of this article is to analyze the application of spatial perspective in natural gas demand forecasting and to identify the models that can be employed observing issues of dependency and spatial heterogeneity; as well as the capacity of mapping of variables associated with the problem. (author)

  13. Governing EU employment policy

    DEFF Research Database (Denmark)

    Sørensen, Eva; Triantafillou, Peter; Damgaard, Bodil

    2015-01-01

    In the European Union (EU), employment policy is a prerogative of the member states. Therefore the EU's ability to govern in this area depends on its capability to involve national governments and relevant stakeholders in a collaborative effort to formulate and implement shared policy objectives....... Drawing an analytical distinction between cooperation, coordination and collaboration, the article analyses the formulation and implementation of EU employment policies. It concludes that while the formulation of policy objectives and the discussion of national policy approaches do involve elements...... of collaboration, the implementation phase mainly consists in the less demanding forms of cooperation and coordination....

  14. [Illegal migrants and sanctions against employers in the United States: the anti-model of state laws].

    Science.gov (United States)

    Ardittis, S

    1984-06-01

    This study attempts to demonstrate the various reasons why sanctions against employers of illegal migrants have never been effectively enforced in the 11 US states and 1 city that have passed such legislation, and to assess the factors involved in the ineffectiveness of state laws: the lack of resources and experience for enforcement, and the exclusively local authority of the laws. Some of the state laws refer only to the legal residence of the migrants while others pertain to the lack of work permits. In all jurisdictions only 5 cases have been brought as a result of the laws. The ostensible reasons for the failure of the laws include uncertainties about proof of the employer's knowledge of the immigrants' legal status and uncertainties related to the primacy of federal legislation covering migrants and the lack of specific provisions covering employment within such legislation. The deeper reasons for the failure of such laws result from absolute opposition to them by civil rights activists and minority groups, especially hispanics, on the 1 hand, and on the other by the economic groups most directly affected, which are primarily the traditional employers of illegal workers. It must be asked whether the major problem resulting from non-application of the laws is the lack of results obtained by the states or the absence of experience that could guide impending federal legislation by indicating the results of sanctions against employers on the rate of irregular migration or whether a substantial reduction in the number of illegal workers in the secondary sector of the economy results in a greater employment of lower level native workers.

  15. A Novel Approach to Implement Takagi-Sugeno Fuzzy Models.

    Science.gov (United States)

    Chang, Chia-Wen; Tao, Chin-Wang

    2017-09-01

    This paper proposes new algorithms based on the fuzzy c-regressing model algorithm for Takagi-Sugeno (T-S) fuzzy modeling of the complex nonlinear systems. A fuzzy c-regression state model (FCRSM) algorithm is a T-S fuzzy model in which the functional antecedent and the state-space-model-type consequent are considered with the available input-output data. The antecedent and consequent forms of the proposed FCRSM consists mainly of two advantages: one is that the FCRSM has low computation load due to only one input variable is considered in the antecedent part; another is that the unknown system can be modeled to not only the polynomial form but also the state-space form. Moreover, the FCRSM can be extended to FCRSM-ND and FCRSM-Free algorithms. An algorithm FCRSM-ND is presented to find the T-S fuzzy state-space model of the nonlinear system when the input-output data cannot be precollected and an assumed effective controller is available. In the practical applications, the mathematical model of controller may be hard to be obtained. In this case, an online tuning algorithm, FCRSM-FREE, is designed such that the parameters of a T-S fuzzy controller and the T-S fuzzy state model of an unknown system can be online tuned simultaneously. Four numerical simulations are given to demonstrate the effectiveness of the proposed approach.

  16. A Hybrid Acoustic and Pronunciation Model Adaptation Approach for Non-native Speech Recognition

    Science.gov (United States)

    Oh, Yoo Rhee; Kim, Hong Kook

    In this paper, we propose a hybrid model adaptation approach in which pronunciation and acoustic models are adapted by incorporating the pronunciation and acoustic variabilities of non-native speech in order to improve the performance of non-native automatic speech recognition (ASR). Specifically, the proposed hybrid model adaptation can be performed at either the state-tying or triphone-modeling level, depending at which acoustic model adaptation is performed. In both methods, we first analyze the pronunciation variant rules of non-native speakers and then classify each rule as either a pronunciation variant or an acoustic variant. The state-tying level hybrid method then adapts pronunciation models and acoustic models by accommodating the pronunciation variants in the pronunciation dictionary and by clustering the states of triphone acoustic models using the acoustic variants, respectively. On the other hand, the triphone-modeling level hybrid method initially adapts pronunciation models in the same way as in the state-tying level hybrid method; however, for the acoustic model adaptation, the triphone acoustic models are then re-estimated based on the adapted pronunciation models and the states of the re-estimated triphone acoustic models are clustered using the acoustic variants. From the Korean-spoken English speech recognition experiments, it is shown that ASR systems employing the state-tying and triphone-modeling level adaptation methods can relatively reduce the average word error rates (WERs) by 17.1% and 22.1% for non-native speech, respectively, when compared to a baseline ASR system.

  17. Systematic approach to verification and validation: High explosive burn models

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Laboratory; Scovel, Christina A. [Los Alamos National Laboratory

    2012-04-16

    Most material models used in numerical simulations are based on heuristics and empirically calibrated to experimental data. For a specific model, key questions are determining its domain of applicability and assessing its relative merits compared to other models. Answering these questions should be a part of model verification and validation (V and V). Here, we focus on V and V of high explosive models. Typically, model developers implemented their model in their own hydro code and use different sets of experiments to calibrate model parameters. Rarely can one find in the literature simulation results for different models of the same experiment. Consequently, it is difficult to assess objectively the relative merits of different models. This situation results in part from the fact that experimental data is scattered through the literature (articles in journals and conference proceedings) and that the printed literature does not allow the reader to obtain data from a figure in electronic form needed to make detailed comparisons among experiments and simulations. In addition, it is very time consuming to set up and run simulations to compare different models over sufficiently many experiments to cover the range of phenomena of interest. The first difficulty could be overcome if the research community were to support an online web based database. The second difficulty can be greatly reduced by automating procedures to set up and run simulations of similar types of experiments. Moreover, automated testing would be greatly facilitated if the data files obtained from a database were in a standard format that contained key experimental parameters as meta-data in a header to the data file. To illustrate our approach to V and V, we have developed a high explosive database (HED) at LANL. It now contains a large number of shock initiation experiments. Utilizing the header information in a data file from HED, we have written scripts to generate an input file for a hydro code

  18. A Composite Modelling Approach to Decision Support by the Use of the CBA-DK Model

    DEFF Research Database (Denmark)

    Barfod, Michael Bruhn; Salling, Kim Bang; Leleur, Steen

    2007-01-01

    This paper presents a decision support system for assessment of transport infrastructure projects. The composite modelling approach, COSIMA, combines a cost-benefit analysis by use of the CBA-DK model with multi-criteria analysis applying the AHP and SMARTER techniques. The modelling uncertaintie...

  19. Employing conformational analysis in the molecular modeling of agrochemicals: insights on QSAR parameters of 2,4-D

    Directory of Open Access Journals (Sweden)

    Matheus Puggina de Freitas

    2013-12-01

    Full Text Available A common practice to compute ligand conformations of compounds with various degrees of freedom to be used in molecular modeling (QSAR and docking studies is to perform a conformational distribution based on repeated random sampling, such as Monte-Carlo methods. Further calculations are often required. This short review describes some methods used for conformational analysis and the implications of using selected conformations in QSAR. A case study is developed for 2,4-dichlorophenoxyacetic acid (2,4-D, a widely used herbicide which binds to TIR1 ubiquitin ligase enzyme. The use of such an approach and semi-empirical calculations did not achieve all possible minima for 2,4-D. In addition, the conformations and respective energies obtained by the semi-empirical AM1 method do not match the calculated trends obtained by a high level DFT method. Similar findings were obtained for the carboxylate anion, which is the bioactive form. Finally, the crystal bioactive structure of 2,4-D was not found as a minimum when using Monte-Carlo/AM1 and is similarly populated with another conformer in implicit water solution according to optimization at the B3LYP/aug-cc-pVDZ level. Therefore, quantitative structure-activity relationship (QSAR methods based on three dimensional chemical structures are not fundamental to provide predictive models for 2,4-D congeners as TIR1 ubiquitin ligase ligands, since they do not necessarily reflect the bioactive conformation of this molecule. This probably extends to other systems.

  20. MODELING OF HIGH SPEED FRICTION STIR SPOT WELDING USING A LAGRANGIAN FINITE ELEMENT APPROACH

    Energy Technology Data Exchange (ETDEWEB)

    Miles, Michael; Karki, U.; Woodward, C.; Hovanski, Yuri

    2013-09-03

    Friction stir spot welding (FSSW) has been shown to be capable of joining steels of very high strength, while also being very flexible in terms of controlling the heat of welding and the resulting microstructure of the joint. This makes FSSW a potential alternative to resistance spot welding (RSW) if tool life is sufficiently high, and if machine spindle loads are sufficiently low so that the process can be implemented on an industrial robot. Robots for spot welding can typically sustain vertical loads of about 8kN, but FSSW at tool speeds of less than 3000 rpm cause loads that are too high, in the range of 11-14 kN. Therefore, in the current work tool speeds of 3000 rpm and higher were employed, in order to generate heat more quickly and to reduce welding loads to acceptable levels. The FSSW process was modeled using a finite element approach with the Forge® software package. An updated Lagrangian scheme with explicit time integration was employed to model the flow of the sheet material, subjected to boundary conditions of a rotating tool and a fixed backing plate [3]. The modeling approach can be described as two-dimensional, axisymmetric, but with an aspect of three dimensions in terms of thermal boundary conditions. Material flow was calculated from a velocity field which was two dimensional, but heat generated by friction was computed using a virtual rotational velocity component from the tool surface. An isotropic, viscoplastic Norton-Hoff law was used to model the evolution of material flow stress as a function of strain, strain rate, and temperature. The model predicted welding temperatures and the movement of the joint interface with reasonable accuracy for the welding of a dual phase 980 steel.

  1. The place of quantitative energy models in a prospective approach

    International Nuclear Information System (INIS)

    Taverdet-Popiolek, N.

    2009-01-01

    Futurology above all depends on having the right mind set. Gaston Berger summarizes the prospective approach in 5 five main thrusts: prepare for the distant future, be open-minded (have a systems and multidisciplinary approach), carry out in-depth analyzes (draw out actors which are really determinant or the future, as well as established shed trends), take risks (imagine risky but flexible projects) and finally think about humanity, futurology being a technique at the service of man to help him build a desirable future. On the other hand, forecasting is based on quantified models so as to deduce 'conclusions' about the future. In the field of energy, models are used to draw up scenarios which allow, for instance, measuring medium or long term effects of energy policies on greenhouse gas emissions or global welfare. Scenarios are shaped by the model's inputs (parameters, sets of assumptions) and outputs. Resorting to a model or projecting by scenario is useful in a prospective approach as it ensures coherence for most of the variables that have been identified through systems analysis and that the mind on its own has difficulty to grasp. Interpretation of each scenario must be carried out in the light o the underlying framework of assumptions (the backdrop), developed during the prospective stage. When the horizon is far away (very long-term), the worlds imagined by the futurologist contain breaks (technological, behavioural and organizational) which are hard to integrate into the models. It is here that the main limit for the use of models in futurology is located. (author)

  2. Approach for ontological modeling of database schema for the generation of semantic knowledge on the web

    Science.gov (United States)

    Rozeva, Anna

    2015-11-01

    Currently there is large quantity of content on web pages that is generated from relational databases. Conceptual domain models provide for the integration of heterogeneous content on semantic level. The use of ontology as conceptual model of a relational data sources makes them available to web agents and services and provides for the employment of ontological techniques for data access, navigation and reasoning. The achievement of interoperability between relational databases and ontologies enriches the web with semantic knowledge. The establishment of semantic database conceptual model based on ontology facilitates the development of data integration systems that use ontology as unified global view. Approach for generation of ontologically based conceptual model is presented. The ontology representing the database schema is obtained by matching schema elements to ontology concepts. Algorithm of the matching process is designed. Infrastructure for the inclusion of mediation between database and ontology for bridging legacy data with formal semantic meaning is presented. Implementation of the knowledge modeling approach on sample database is performed.

  3. Innovation Networks New Approaches in Modelling and Analyzing

    CERN Document Server

    Pyka, Andreas

    2009-01-01

    The science of graphs and networks has become by now a well-established tool for modelling and analyzing a variety of systems with a large number of interacting components. Starting from the physical sciences, applications have spread rapidly to the natural and social sciences, as well as to economics, and are now further extended, in this volume, to the concept of innovations, viewed broadly. In an abstract, systems-theoretical approach, innovation can be understood as a critical event which destabilizes the current state of the system, and results in a new process of self-organization leading to a new stable state. The contributions to this anthology address different aspects of the relationship between innovation and networks. The various chapters incorporate approaches in evolutionary economics, agent-based modeling, social network analysis and econophysics and explore the epistemic tension between insights into economics and society-related processes, and the insights into new forms of complex dynamics.

  4. Research on teacher education programs: logic model approach.

    Science.gov (United States)

    Newton, Xiaoxia A; Poon, Rebecca C; Nunes, Nicole L; Stone, Elisa M

    2013-02-01

    Teacher education programs in the United States face increasing pressure to demonstrate their effectiveness through pupils' learning gains in classrooms where program graduates teach. The link between teacher candidates' learning in teacher education programs and pupils' learning in K-12 classrooms implicit in the policy discourse suggests a one-to-one correspondence. However, the logical steps leading from what teacher candidates have learned in their programs to what they are doing in classrooms that may contribute to their pupils' learning are anything but straightforward. In this paper, we argue that the logic model approach from scholarship on evaluation can enhance research on teacher education by making explicit the logical links between program processes and intended outcomes. We demonstrate the usefulness of the logic model approach through our own work on designing a longitudinal study that focuses on examining the process and impact of an undergraduate mathematics and science teacher education program. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Understanding complex urban systems multidisciplinary approaches to modeling

    CERN Document Server

    Gurr, Jens; Schmidt, J

    2014-01-01

    Understanding Complex Urban Systems takes as its point of departure the insight that the challenges of global urbanization and the complexity of urban systems cannot be understood – let alone ‘managed’ – by sectoral and disciplinary approaches alone. But while there has recently been significant progress in broadening and refining the methodologies for the quantitative modeling of complex urban systems, in deepening the theoretical understanding of cities as complex systems, or in illuminating the implications for urban planning, there is still a lack of well-founded conceptual thinking on the methodological foundations and the strategies of modeling urban complexity across the disciplines. Bringing together experts from the fields of urban and spatial planning, ecology, urban geography, real estate analysis, organizational cybernetics, stochastic optimization, and literary studies, as well as specialists in various systems approaches and in transdisciplinary methodologies of urban analysis, the volum...

  6. DISCRETE LATTICE ELEMENT APPROACH FOR ROCK FAILURE MODELING

    Directory of Open Access Journals (Sweden)

    Mijo Nikolić

    2017-01-01

    Full Text Available This paper presents the ‘discrete lattice model’, or, simply, the ‘lattice model’, developed for rock failure modeling. The main difficulties in numerical modeling, namely, those related to complex crack initiations and multiple crack propagations, their coalescence under the influence of natural disorder, and heterogeneities, are overcome using the approach presented in this paper. The lattice model is constructed as an assembly of Timoshenko beams, representing the cohesive links between the grains of the material, which are described by Voronoi polygons. The kinematics of the Timoshenko beams are enhanced by the embedded strong discontinuities in their axial and transversal directions so as to provide failure modes I, II, and III. The model presented is suitable for meso-scale rock simulations. The representative numerical simulations, in both 2D and 3D settings, are provided in order to illustrate the model’s capabilities.

  7. Computer Modeling of Violent Intent: A Content Analysis Approach

    Energy Technology Data Exchange (ETDEWEB)

    Sanfilippo, Antonio P.; Mcgrath, Liam R.; Bell, Eric B.

    2014-01-03

    We present a computational approach to modeling the intent of a communication source representing a group or an individual to engage in violent behavior. Our aim is to identify and rank aspects of radical rhetoric that are endogenously related to violent intent to predict the potential for violence as encoded in written or spoken language. We use correlations between contentious rhetoric and the propensity for violent behavior found in documents from radical terrorist and non-terrorist groups and individuals to train and evaluate models of violent intent. We then apply these models to unseen instances of linguistic behavior to detect signs of contention that have a positive correlation with violent intent factors. Of particular interest is the application of violent intent models to social media, such as Twitter, that have proved to serve as effective channels in furthering sociopolitical change.

  8. A fuzzy approach to the Weighted Overlap Dominance model

    DEFF Research Database (Denmark)

    Franco de los Rios, Camilo Andres; Hougaard, Jens Leth; Nielsen, Kurt

    2013-01-01

    Decision support models are required to handle the various aspects of multi-criteria decision problems in order to help the individual understand its possible solutions. In this sense, such models have to be capable of aggregating and exploiting different types of measurements and evaluations...... in an interactive way, where input data can take the form of uniquely-graded or interval-valued information. Here we explore the Weighted Overlap Dominance (WOD) model from a fuzzy perspective and its outranking approach to decision support and multidimensional interval analysis. Firstly, imprecision measures...... are introduced for characterizing the type of uncertainty being expressed by intervals, examining at the same time how the WOD model handles both non-interval as well as interval data, and secondly, relevance degrees are proposed for obtaining a ranking over the alternatives. Hence, a complete methodology...

  9. A reservoir simulation approach for modeling of naturally fractured reservoirs

    Directory of Open Access Journals (Sweden)

    H. Mohammadi

    2012-12-01

    Full Text Available In this investigation, the Warren and Root model proposed for the simulation of naturally fractured reservoir was improved. A reservoir simulation approach was used to develop a 2D model of a synthetic oil reservoir. Main rock properties of each gridblock were defined for two different types of gridblocks called matrix and fracture gridblocks. These two gridblocks were different in porosity and permeability values which were higher for fracture gridblocks compared to the matrix gridblocks. This model was solved using the implicit finite difference method. Results showed an improvement in the Warren and Root model especially in region 2 of the semilog plot of pressure drop versus time, which indicated a linear transition zone with no inflection point as predicted by other investigators. Effects of fracture spacing, fracture permeability, fracture porosity, matrix permeability and matrix porosity on the behavior of a typical naturally fractured reservoir were also presented.

  10. Fibroblast motility on substrates with different rigidities: modeling approach

    Science.gov (United States)

    Gracheva, Maria; Dokukina, Irina

    2009-03-01

    We develop a discrete model for cell locomotion on substrates with different rigidities and simulate experiments described in Lo, Wang, Dembo, Wang (2000) ``Cell movement is guided by the rigidity of the substrate'', Biophys. J. 79: 144-152. In these experiments fibroblasts were planted on a substrate with a step rigidity and showed preference for locomotion over stiffer side of the substrate when approaches the boundary between the soft and the stiff sides of the substrate. The model reproduces experimentally observed behavior of fibroblasts. In particular, we are able to show with our model how cell characteristics (such as cell length, shape, area and speed) change during cell crawling through the ``soft-stiff'' substrate boundary. Also, our model suggests the temporary increase of both cell speed and area in that very moment when cell leaves soft side of substrate.

  11. Modeling fabrication of nuclear components: An integrative approach

    Energy Technology Data Exchange (ETDEWEB)

    Hench, K.W.

    1996-08-01

    Reduction of the nuclear weapons stockpile and the general downsizing of the nuclear weapons complex has presented challenges for Los Alamos. One is to design an optimized fabrication facility to manufacture nuclear weapon primary components in an environment of intense regulation and shrinking budgets. This dissertation presents an integrative two-stage approach to modeling the casting operation for fabrication of nuclear weapon primary components. The first stage optimizes personnel radiation exposure for the casting operation layout by modeling the operation as a facility layout problem formulated as a quadratic assignment problem. The solution procedure uses an evolutionary heuristic technique. The best solutions to the layout problem are used as input to the second stage - a simulation model that assesses the impact of competing layouts on operational performance. The focus of the simulation model is to determine the layout that minimizes personnel radiation exposures and nuclear material movement, and maximizes the utilization of capacity for finished units.

  12. THE SIGNAL APPROACH TO MODELLING THE BALANCE OF PAYMENT CRISIS

    Directory of Open Access Journals (Sweden)

    O. Chernyak

    2016-12-01

    Full Text Available The paper considers and presents synthesis of theoretical models of balance of payment crisis and investigates the most effective ways to model the crisis in Ukraine. For mathematical formalization of balance of payment crisis, comparative analysis of the effectiveness of different calculation methods of Exchange Market Pressure Index was performed. A set of indicators that signal the growing likelihood of balance of payments crisis was defined using signal approach. With the help of minimization function thresholds indicators were selected, the crossing of which signalize increase in the probability of balance of payment crisis.

  13. Risk Modeling Approaches in Terms of Volatility Banking Transactions

    Directory of Open Access Journals (Sweden)

    Angelica Cucşa (Stratulat

    2016-01-01

    Full Text Available The inseparability of risk and banking activity is one demonstrated ever since banking systems, the importance of the topic being presend in current life and future equally in the development of banking sector. Banking sector development is done in the context of the constraints of nature and number of existing risks and those that may arise, and serves as limiting the risk of banking activity. We intend to develop approaches to analyse risk through mathematical models by also developing a model for the Romanian capital market 10 active trading picks that will test investor reaction in controlled and uncontrolled conditions of risk aggregated with harmonised factors.

  14. Modeling software with finite state machines a practical approach

    CERN Document Server

    Wagner, Ferdinand; Wagner, Thomas; Wolstenholme, Peter

    2006-01-01

    Modeling Software with Finite State Machines: A Practical Approach explains how to apply finite state machines to software development. It provides a critical analysis of using finite state machines as a foundation for executable specifications to reduce software development effort and improve quality. This book discusses the design of a state machine and of a system of state machines. It also presents a detailed analysis of development issues relating to behavior modeling with design examples and design rules for using finite state machines. This volume describes a coherent and well-tested fr

  15. Surrogate based approaches to parameter inference in ocean models

    KAUST Repository

    Knio, Omar

    2016-01-06

    This talk discusses the inference of physical parameters using model surrogates. Attention is focused on the use of sampling schemes to build suitable representations of the dependence of the model response on uncertain input data. Non-intrusive spectral projections and regularized regressions are used for this purpose. A Bayesian inference formalism is then applied to update the uncertain inputs based on available measurements or observations. To perform the update, we consider two alternative approaches, based on the application of Markov Chain Monte Carlo methods or of adjoint-based optimization techniques. We outline the implementation of these techniques to infer dependence of wind drag, bottom drag, and internal mixing coefficients.

  16. Understanding Gulf War Illness: An Integrative Modeling Approach

    Science.gov (United States)

    2017-10-01

    high-order diffusion imaging in a rat model of Gulf War Illness. §These authors contributed equally to the work. Brain Behavior and Immunity. pii...astrocyte specific transcriptome responses to neurotoxicity. §These authors contributed equally to the work. Submitted for Internal CDC-NIOSH...Antagonist: Evaluation of Beneficial Effects for Gulf War Illness 4) GW160116 (Nathanson) Genomics approach to find gender specific mechanisms of GWI

  17. An Approach for Modeling and Formalizing SOA Design Patterns

    OpenAIRE

    Tounsi , Imen; Hadj Kacem , Mohamed; Hadj Kacem , Ahmed; Drira , Khalil

    2013-01-01

    11 pages; International audience; Although design patterns has become increasingly popular, most of them are presented in an informal way, which can give rise to ambiguity and may lead to their incorrect usage. Patterns proposed by the SOA design pattern community are described with informal visual notations. Modeling SOA design patterns with a standard formal notation contributes to avoid misunderstanding by software architects and helps endowing design methods with refinement approaches for...

  18. An approach for quantifying small effects in regression models.

    Science.gov (United States)

    Bedrick, Edward J; Hund, Lauren

    2018-04-01

    We develop a novel approach for quantifying small effects in regression models. Our method is based on variation in the mean function, in contrast to methods that focus on regression coefficients. Our idea applies in diverse settings such as testing for a negligible trend and quantifying differences in regression functions across strata. Straightforward Bayesian methods are proposed for inference. Four examples are used to illustrate the ideas.

  19. A Conditional Approach to Panel Data Models with Common Shocks

    Directory of Open Access Journals (Sweden)

    Giovanni Forchini

    2016-01-01

    Full Text Available This paper studies the effects of common shocks on the OLS estimators of the slopes’ parameters in linear panel data models. The shocks are assumed to affect both the errors and some of the explanatory variables. In contrast to existing approaches, which rely on using results on martingale difference sequences, our method relies on conditional strong laws of large numbers and conditional central limit theorems for conditionally-heterogeneous random variables.

  20. Modeling Electronic Circular Dichroism within the Polarizable Embedding Approach

    DEFF Research Database (Denmark)

    Nørby, Morten S; Olsen, Jógvan Magnus Haugaard; Steinmann, Casper

    2017-01-01

    We present a systematic investigation of the key components needed to model single chromophore electronic circular dichroism (ECD) within the polarizable embedding (PE) approach. By relying on accurate forms of the embedding potential, where especially the inclusion of local field effects...... are in focus, we show that qualitative agreement between rotatory strength parameters calculated by full quantum mechanical calculations and the more efficient embedding calculations can be obtained. An important aspect in the computation of reliable absorption parameters is the need for conformational...

  1. Social Network Analyses and Nutritional Behavior: An Integrated Modeling Approach

    Directory of Open Access Journals (Sweden)

    Alistair McNair Senior

    2016-01-01

    Full Text Available Animals have evolved complex foraging strategies to obtain a nutritionally balanced diet and associated fitness benefits. Recent advances in nutrition research, combining state-space models of nutritional geometry with agent-based models of systems biology, show how nutrient targeted foraging behavior can also influence animal social interactions, ultimately affecting collective dynamics and group structures. Here we demonstrate how social network analyses can be integrated into such a modeling framework and provide a tangible and practical analytical tool to compare experimental results with theory. We illustrate our approach by examining the case of nutritionally mediated dominance hierarchies. First we show how nutritionally explicit agent-based models that simulate the emergence of dominance hierarchies can be used to generate social networks. Importantly the structural properties of our simulated networks bear similarities to dominance networks of real animals (where conflicts are not always directly related to nutrition. Finally, we demonstrate how metrics from social network analyses can be used to predict the fitness of agents in these simulated competitive environments. Our results highlight the potential importance of nutritional mechanisms in shaping dominance interactions in a wide range of social and ecological contexts. Nutrition likely influences social interaction in many species, and yet a theoretical framework for exploring these effects is currently lacking. Combining social network analyses with computational models from nutritional ecology may bridge this divide, representing a pragmatic approach for generating theoretical predictions for nutritional experiments.

  2. Modeling Defibrillation of the Heart: Approaches and Insights

    Science.gov (United States)

    Trayanova, Natalia; Constantino, Jason; Ashihara, Takashi; Plank, Gernot

    2012-01-01

    Cardiac defibrillation, as accomplished nowadays by automatic, implantable devices (ICDs), constitutes the most important means of combating sudden cardiac death. While ICD therapy has proved to be efficient and reliable, defibrillation is a traumatic experience. Thus, research on defibrillation mechanisms, particularly aimed at lowering defibrillation voltage, remains an important topic. Advancing our understanding towards a full appreciation of the mechanisms by which a shock interacts with the heart is the most promising approach to achieve this goal. The aim of this paper is to assess the current state-of-the-art in ventricular defibrillation modeling, focusing on both numerical modeling approaches and major insights that have been obtained using defibrillation models, primarily those of realistic ventricular geometry. The paper showcases the contributions that modeling and simulation have made to our understanding of the defibrillation process. The review thus provides an example of biophysically based computational modeling of the heart (i.e., cardiac defibrillation) that has advanced the understanding of cardiac electrophysiological interaction at the organ level and has the potential to contribute to the betterment of the clinical practice of defibrillation. PMID:22273793

  3. Genetic programming based models in plant tissue culture: An addendum to traditional statistical approach.

    Science.gov (United States)

    Mridula, Meenu R; Nair, Ashalatha S; Kumar, K Satheesh

    2018-02-01

    In this paper, we compared the efficacy of observation based modeling approach using a genetic algorithm with the regular statistical analysis as an alternative methodology in plant research. Preliminary experimental data on in vitro rooting was taken for this study with an aim to understand the effect of charcoal and naphthalene acetic acid (NAA) on successful rooting and also to optimize the two variables for maximum result. Observation-based modelling, as well as traditional approach, could identify NAA as a critical factor in rooting of the plantlets under the experimental conditions employed. Symbolic regression analysis using the software deployed here optimised the treatments studied and was successful in identifying the complex non-linear interaction among the variables, with minimalistic preliminary data. The presence of charcoal in the culture medium has a significant impact on root generation by reducing basal callus mass formation. Such an approach is advantageous for establishing in vitro culture protocols as these models will have significant potential for saving time and expenditure in plant tissue culture laboratories, and it further reduces the need for specialised background.

  4. An Appraisal Model Based on a Synthetic Feature Selection Approach for Students’ Academic Achievement

    Directory of Open Access Journals (Sweden)

    Ching-Hsue Cheng

    2017-11-01

    Full Text Available Obtaining necessary information (and even extracting hidden messages from existing big data, and then transforming them into knowledge, is an important skill. Data mining technology has received increased attention in various fields in recent years because it can be used to find historical patterns and employ machine learning to aid in decision-making. When we find unexpected rules or patterns from the data, they are likely to be of high value. This paper proposes a synthetic feature selection approach (SFSA, which is combined with a support vector machine (SVM to extract patterns and find the key features that influence students’ academic achievement. For verifying the proposed model, two databases, namely, “Student Profile” and “Tutorship Record”, were collected from an elementary school in Taiwan, and were concatenated into an integrated dataset based on students’ names as a research dataset. The results indicate the following: (1 the accuracy of the proposed feature selection approach is better than that of the Minimum-Redundancy-Maximum-Relevance (mRMR approach; (2 the proposed model is better than the listing methods when the six least influential features have been deleted; and (3 the proposed model can enhance the accuracy and facilitate the interpretation of the pattern from a hybrid-type dataset of students’ academic achievement.

  5. A hybrid particle–field molecular dynamics approach: a route toward efficient coarse-grained models for biomembranes

    International Nuclear Information System (INIS)

    Milano, Giuseppe; De Nicola, Antonio; Kawakatsu, Toshihiro

    2013-01-01

    This paper gives an overview of the coarse-grained models of phospholipids recently developed by the authors in the frame of a hybrid particle–field molecular dynamics technique. This technique employs a special class of coarse-grained models that are gaining popularity because they allow simulations of large scale systems and, at the same time, they provide sufficiently detailed chemistry for the mapping scheme adopted. The comparison of the computational costs of our approach with standard molecular dynamics simulations is a function of the system size and the number of processors employed in the parallel calculations. Due to the low amount of data exchange, the larger the number of processors, the better are the performances of the hybrid particle–field models. This feature makes these models very promising ones in the exploration of several problems in biophysics. (paper)

  6. Preparing At-Risk Youth for a Changing World: Revisiting a Person-in-Context Model for Transition to Employment

    Science.gov (United States)

    DeLuca, Christopher; Godden, Lorraine; Hutchinson, Nancy L.; Versnel, Joan

    2015-01-01

    Background: The current global cohort of youth has been called "a generation at-risk", marked by a dramatic rise in youth who are not in employment, education or training programmes. In 2010, youth were three times as likely as adults to be unemployed, with youth unemployment worsening in 2012 and 2013. Accordingly, there is an urgent…

  7. Combining Quality Work-Integrated Learning and Career Development Learning through the Use of the SOAR Model to Enhance Employability

    Science.gov (United States)

    Reddan, Gregory; Rauchle, Maja

    2017-01-01

    This paper presents students' perceptions of the benefits to employability of a suite of courses that incorporate both work-integrated learning (WIL) and career development learning (CDL). Field Project A and Field Project B are elective courses in the Bachelor of Exercise Science at Griffith University. These courses engage students in active and…

  8. Consensus approach for modeling HTS assays using in silico descriptors

    Directory of Open Access Journals (Sweden)

    Ahmed eAbdelaziz Sayed

    2016-02-01

    Full Text Available The need for filling information gaps while reducing toxicity testing in animals is becoming more predominant in risk assessment. Recent legislations are accepting in silico approaches for predicting toxicological outcomes. This article describes the results of Quantitative Structure Activity Relationship (QSAR modeling efforts within Tox21 Data Challenge 2014, which calculated the best balanced accuracy across all molecular pathway endpoints as well as the highest scores for ATAD5 and mitochondrial membrane potential disruption. Automated QSPR workflow systems, OCHEM (http://ochem.eu, the analytics platform, KNIME and the statistics software, CRAN R, were used to conduct the analysis and develop consensus models using ten different descriptor sets. A detailed analysis of QSAR models for all 12 molecular pathways and the effect of underlying models’ accuracy on the quality of the consensus model are provided. The resulting consensus models yielded a balanced accuracy as high as 88.1%±0.6 for mitochondrial membrane disruptors. Such high balanced accuracy and use of the applicability domain show a promising potential for in silico modeling to complement design HTS screening experiments. The summary statistics of all models are publicly available online at https://github.com/amaziz/Tox21-Challenge-Publication while the developed consensus models can be accessed at http://ochem.eu/article/98009.

  9. Policy harmonized approach for the EU agricultural sector modelling

    Directory of Open Access Journals (Sweden)

    G. SALPUTRA

    2008-12-01

    Full Text Available Policy harmonized (PH approach allows for the quantitative assessment of the impact of various elements of EU CAP direct support schemes, where the production effects of direct payments are accounted through reaction prices formed by producer price and policy price add-ons. Using the AGMEMOD model the impacts of two possible EU agricultural policy scenarios upon beef production have been analysed – full decoupling with a switch from historical to regional Single Payment scheme or alternatively with re-distribution of country direct payment envelopes via introduction of EU-wide flat area payment. The PH approach, by systematizing and harmonizing the management and use of policy data, ensures that projected differential policy impacts arising from changes in common EU policies reflect the likely actual differential impact as opposed to differences in how “common” policies are implemented within analytical models. In the second section of the paper the AGMEMOD model’s structure is explained. The policy harmonized evaluation method is presented in the third section. Results from an application of the PH approach are presented and discussed in the paper’s penultimate section, while section 5 concludes.;

  10. Metabolic network modeling approaches for investigating the "hungry cancer".

    Science.gov (United States)

    Sharma, Ashwini Kumar; König, Rainer

    2013-08-01

    Metabolism is the functional phenotype of a cell, at a given condition, resulting from an intricate interplay of various regulatory processes. The study of these dynamic metabolic processes and their capabilities help to identify the fundamental properties of living systems. Metabolic deregulation is an emerging hallmark of cancer cells. This deregulation results in rewiring of the metabolic circuitry conferring an exploitative metabolic advantage for the tumor cells which leads to a distinct benefit in survival and lays the basis for unbound progression. Metabolism can be considered as a thermodynamic open-system in which source substrates of high value are being processed through a well established interconnected biochemical conversion system, strictly obeying physiochemical principles, generating useful intermediates and finally resulting in the release of byproducts. Based on this basic principle of an input-output balance, various models have been developed to interrogate metabolism elucidating its underlying functional properties. However, only a few modeling approaches have proved computationally feasible in elucidating the metabolic nature of cancer at a systems level. Besides this, statistical approaches have been set up to identify biochemical pathways being more relevant for specific types of tumor cells. In this review, we are briefly introducing the basic statistical approaches followed by the major modeling concepts. We have put an emphasis on the methods and their applications that have been used to a greater extent in understanding the metabolic remodeling of cancer. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Implementing public employment policy

    DEFF Research Database (Denmark)

    Larsen, Flemming; Bredgaard, Thomas

    . But there is an interesting question to investigate here: whether and if so how, NPM-inspired reforms are related to changes in employment policy towards a work-first approach? Are changes in public management systems created as deliberate policy changes, or do they bring about more indirect and unintended policy changes......Like most other areas within welfare policy, the employment and social policy areas are undergoing far-reaching changes in many countries. Partly in the shape of new forms of governance inspired by New Public Management (NPM), partly through new policies oriented towards activation and stronger...... disciplining of the unemployed (work first) (cf.Bredgaard & Larsen, 2005; Sol & Westerweld, 2005). It is, however, remarkable that in the research field there seems to be a division of labour so that changes in public administration and changes in the substance of employment policies are dealt with separately...

  12. A switching control law approach for cancer immunotherapy of an evolutionary tumor growth model.

    Science.gov (United States)

    Doban, Alina I; Lazar, Mircea

    2017-02-01

    We propose a new approach for tumor immunotherapy which is based on a switching control strategy defined on domains of attraction of equilibria of interest. For this, we consider a recently derived model which captures the effects of the tumor cells on the immune system and viceversa, through predator-prey competition terms. Additionally, it incorporates the immune system's mechanism for producing hunting immune cells, which makes the model suitable for immunotherapy strategies analysis and design. For computing domains of attraction for the tumor nonlinear dynamics, and thus, for deriving immunotherapeutic strategies we employ rational Lyapunov functions. Finally, we apply the switching control strategy to destabilize an invasive tumor equilibrium and steer the system trajectories to tumor dormancy. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Relativistic three-body quark model of light baryons based on hypercentral approach

    Science.gov (United States)

    Aslanzadeh, M.; Rajabi, A. A.

    2015-05-01

    In this paper, we have treated the light baryons as a relativistic three-body bound system. Inspired by lattice QCD calculations, we treated baryons as a spin-independent three-quark system within a relativistic three-quark model based on the three-particle Klein-Gordon equation. We presented the analytical solution of three-body Klein-Gordon equation with employing the constituent quark model based on a hypercentral approach through which two- and three-body forces are taken into account. Herewith the average energy values of the up, down and strange quarks containing multiplets are reproduced. To describe the hyperfine structure of the baryon, the splittings within the SU(6)-multiplets are produced by the generalized Gürsey Radicati mass formula. The considered SU(6)-invariant potential is popular "Coulomb-plus-linear" potential and the strange and non-strange baryons spectra are in general well reproduced.

  14. A Novel Numerical Approach for a Nonlinear Fractional Dynamical Model of Interpersonal and Romantic Relationships

    Directory of Open Access Journals (Sweden)

    Jagdev Singh

    2017-07-01

    Full Text Available In this paper, we propose a new numerical algorithm, namely q-homotopy analysis Sumudu transform method (q-HASTM, to obtain the approximate solution for the nonlinear fractional dynamical model of interpersonal and romantic relationships. The suggested algorithm examines the dynamics of love affairs between couples. The q-HASTM is a creative combination of Sumudu transform technique, q-homotopy analysis method and homotopy polynomials that makes the calculation very easy. To compare the results obtained by using q-HASTM, we solve the same nonlinear problem by Adomian’s decomposition method (ADM. The convergence of the q-HASTM series solution for the model is adapted and controlled by auxiliary parameter ℏ and asymptotic parameter n. The numerical results are demonstrated graphically and in tabular form. The result obtained by employing the proposed scheme reveals that the approach is very accurate, effective, flexible, simple to apply and computationally very nice.

  15. Multiscale modeling of alloy solidification using a database approach

    Science.gov (United States)

    Tan, Lijian; Zabaras, Nicholas

    2007-11-01

    A two-scale model based on a database approach is presented to investigate alloy solidification. Appropriate assumptions are introduced to describe the behavior of macroscopic temperature, macroscopic concentration, liquid volume fraction and microstructure features. These assumptions lead to a macroscale model with two unknown functions: liquid volume fraction and microstructure features. These functions are computed using information from microscale solutions of selected problems. This work addresses the selection of sample problems relevant to the interested problem and the utilization of data from the microscale solution of the selected sample problems. A computationally efficient model, which is different from the microscale and macroscale models, is utilized to find relevant sample problems. In this work, the computationally efficient model is a sharp interface solidification model of a pure material. Similarities between the sample problems and the problem of interest are explored by assuming that the liquid volume fraction and microstructure features are functions of solution features extracted from the solution of the computationally efficient model. The solution features of the computationally efficient model are selected as the interface velocity and thermal gradient in the liquid at the time the sharp solid-liquid interface passes through. An analytical solution of the computationally efficient model is utilized to select sample problems relevant to solution features obtained at any location of the domain of the problem of interest. The microscale solution of selected sample problems is then utilized to evaluate the two unknown functions (liquid volume fraction and microstructure features) in the macroscale model. The temperature solution of the macroscale model is further used to improve the estimation of the liquid volume fraction and microstructure features. Interpolation is utilized in the feature space to greatly reduce the number of required

  16. Object-Oriented Approach to Modeling Units of Pneumatic Systems

    Directory of Open Access Journals (Sweden)

    Yu. V. Kyurdzhiev

    2014-01-01

    Full Text Available The article shows the relevance of the approaches to the object-oriented programming when modeling the pneumatic units (PU.Based on the analysis of the calculation schemes of aggregates pneumatic systems two basic objects, namely a cavity flow and a material point were highlighted.Basic interactions of objects are defined. Cavity-cavity interaction: ex-change of matter and energy with the flows of mass. Cavity-point interaction: force interaction, exchange of energy in the form of operation. Point-point in-teraction: force interaction, elastic interaction, inelastic interaction, and inter-vals of displacement.The authors have developed mathematical models of basic objects and interactions. Models and interaction of elements are implemented in the object-oriented programming.Mathematical models of elements of PU design scheme are implemented in derived from the base class. These classes implement the models of flow cavity, piston, diaphragm, short channel, diaphragm to be open by a given law, spring, bellows, elastic collision, inelastic collision, friction, PU stages with a limited movement, etc.A numerical integration of differential equations for the mathematical models of PU design scheme elements is based on the Runge-Kutta method of the fourth order. On request each class performs a tact of integration i.e. calcu-lation of the coefficient method.The paper presents an integration algorithm of the system of differential equations. All objects of the PU design scheme are placed in a unidirectional class list. Iterator loop cycle initiates the integration tact of all the objects in the list. One in four iteration makes a transition to the next step of integration. Calculation process stops when any object shows a shutdowns flag.The proposed approach was tested in the calculation of a number of PU designs. With regard to traditional approaches to modeling, the authors-proposed method features in easy enhancement, code reuse, high reliability

  17. Modeling drug- and chemical- induced hepatotoxicity with systems biology approaches

    Directory of Open Access Journals (Sweden)

    Sudin eBhattacharya

    2012-12-01

    Full Text Available We provide an overview of computational systems biology approaches as applied to the study of chemical- and drug-induced toxicity. The concept of ‘toxicity pathways’ is described in the context of the 2007 US National Academies of Science report, Toxicity testing in the 21st Century: A Vision and A Strategy. Pathway mapping and modeling based on network biology concepts are a key component of the vision laid out in this report for a more biologically-based analysis of dose-response behavior and the safety of chemicals and drugs. We focus on toxicity of the liver (hepatotoxicity – a complex phenotypic response with contributions from a number of different cell types and biological processes. We describe three case studies of complementary multi-scale computational modeling approaches to understand perturbation of toxicity pathways in the human liver as a result of exposure to environmental contaminants and specific drugs. One approach involves development of a spatial, multicellular virtual tissue model of the liver lobule that combines molecular circuits in individual hepatocytes with cell-cell interactions and blood-mediated transport of toxicants through hepatic sinusoids, to enable quantitative, mechanistic prediction of hepatic dose-response for activation of the AhR toxicity pathway. Simultaneously, methods are being developing to extract quantitative maps of intracellular signaling and transcriptional regulatory networks perturbed by environmental contaminants, using a combination of gene expression and genome-wide protein-DNA interaction data. A predictive physiological model (DILIsymTM to understand drug-induced liver injury (DILI, the most common adverse event leading to termination of clinical development programs and regulatory actions on drugs, is also described. The model initially focuses on reactive metabolite-induced DILI in response to administration of acetaminophen, and spans multiple biological scales.

  18. Inverse modelling in estimating soil hydraulic functions: a Genetic Algorithm approach

    Science.gov (United States)

    Ines, A. V. M.; Droogers, P.

    The practical application of simulation models in the field is sometimes hindered by the difficulty of deriving the soil hydraulic properties of the study area. The procedure so-called inverse modelling has been investigated in many studies to address the problem where most of the studies were limited to hypothetical soil profile and soil core samples in the laboratory. Often, the numerical approach called forward-backward simulation is employed to generate synthetic data then added with random errors to mimic the real-world condition. Inverse modelling is used to backtrack the expected values of the parameters. This study explored the potential of a Genetic Algorithm (GA) to estimate inversely the soil hydraulic functions in the unsaturated zone. Lysimeter data from a wheat experiment in India were used in the analysis. Two cases were considered: (1) a numerical case where the forward-backward approach was employed and (2) the experimental case where the real data from the lysimeter experiment were used. Concurrently, the use of soil water, evapotranspiration (ET) and the combination of both were investigated as criteria in the inverse modelling. Results showed that using soil water as a criterion provides more accurate parameter estimates than using ET. However, from a practical point of view, ET is more attractive as it can be obtained with reasonable accuracy on a regional scale from remote sensing observations. The experimental study proved that the forward-backward approach does not take into account the effects of model errors. The formulation of the problem is found to be critical for a successful parameter estimation. The sensitivity of parameters to the objective function and their zone of influence in the soil column are major determinants in the solution. Generally, their effects sometimes lead to non-uniqueness in the solution but to some extent are partly handled by GA. Overall, it was concluded that the GA approach is promising to the inverse problem

  19. Inverse modelling in estimating soil hydraulic functions: a Genetic Algorithm approach

    Directory of Open Access Journals (Sweden)

    A. V. M. Ines

    2002-01-01

    Full Text Available The practical application of simulation models in the field is sometimes hindered by the difficulty of deriving the soil hydraulic properties of the study area. The procedure so-called inverse modelling has been investigated in many studies to address the problem where most of the studies were limited to hypothetical soil profile and soil core samples in the laboratory. Often, the numerical approach called forward-backward simulation is employed to generate synthetic data then added with random errors to mimic the real-world condition. Inverse modelling is used to backtrack the expected values of the parameters. This study explored the potential of a Genetic Algorithm (GA to estimate inversely the soil hydraulic functions in the unsaturated zone. Lysimeter data from a wheat experiment in India were used in the analysis. Two cases were considered: (1 a numerical case where the forward-backward approach was employed and (2 the experimental case where the real data from the lysimeter experiment were used. Concurrently, the use of soil water, evapotranspiration (ET and the combination of both were investigated as criteria in the inverse modelling. Results showed that using soil water as a criterion provides more accurate parameter estimates than using ET. However, from a practical point of view, ET is more attractive as it can be obtained with reasonable accuracy on a regional scale from remote sensing observations. The experimental study proved that the forward-backward approach does not take into account the effects of model errors. The formulation of the problem is found to be critical for a successful parameter estimation. The sensitivity of parameters to the objective function and their zone of influence in the soil column are major determinants in the solution. Generally, their effects sometimes lead to non-uniqueness in the solution but to some extent are partly handled by GA. Overall, it was concluded that the GA approach is promising to the

  20. Quantitative versus qualitative modeling: a complementary approach in ecosystem study.

    Science.gov (United States)

    Bondavalli, C; Favilla, S; Bodini, A

    2009-02-01

    Natural disturbance or human perturbation act upon ecosystems by changing some dynamical parameters of one or more species. Foreseeing these modifications is necessary before embarking on an intervention: predictions may help to assess management options and define hypothesis for interventions. Models become valuable tools for studying and making predictions only when they capture types of interactions and their magnitude. Quantitative models are more precise and specific about a system, but require a large effort in model construction. Because of this very often ecological systems remain only partially specified and one possible approach to their description and analysis comes from qualitative modelling. Qualitative models yield predictions as directions of change in species abundance but in complex systems these predictions are often ambiguous, being the result of opposite actions exerted on the same species by way of multiple pathways of interactions. Again, to avoid such ambiguities one needs to know the intensity of all links in the system. One way to make link magnitude explicit in a way that can be used in qualitative analysis is described in this paper and takes advantage of another type of ecosystem representation: ecological flow networks. These flow diagrams contain the structure, the relative position and the connections between the components of a system, and the quantity of matter flowing along every connection. In this paper it is shown how these ecological flow networks can be used to produce a quantitative model similar to the qualitative counterpart. Analyzed through the apparatus of loop analysis this quantitative model yields predictions that are by no means ambiguous, solving in an elegant way the basic problem of qualitative analysis. The approach adopted in this work is still preliminary and we must be careful in its application.