• Title/Summary/Keyword: Subjective Uncertainty

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Reliability and Safety Analysis of Structure System of Retaining Walls (옹벽구조시스템의 신뢰성 및 안전도 해석)

  • Jung, Chul-Won;Yun, Boung-Jo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.2 no.3
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    • pp.223-234
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    • 1998
  • In this study, an attempt is made to apply the concept of fuzzy-bayesian theory to the integrity assessment of structure system, and uncertainty states are represented in terms of fuzzy sets which define several linguistic variables such as "very good", "good", "average", "poor", "very poor", etc. Especially, the concept of fuzzy conditional probability aids to derive a new reliability analysis which includes the subjective assessment of engineers without introducing any additional correction factors. The fuzzy concept are also used as reliability indexes for the condition assessment based on the proposed models, the proposed fuzzy theory-based approach with the results of PEM and AFOSM are applied to retaining wall.

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Fuzzy Classification Rule Learning by Decision Tree Induction

  • Lee, Keon-Myung;Kim, Hak-Joon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.3 no.1
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    • pp.44-51
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    • 2003
  • Knowledge acquisition is a bottleneck in knowledge-based system implementation. Decision tree induction is a useful machine learning approach for extracting classification knowledge from a set of training examples. Many real-world data contain fuzziness due to observation error, uncertainty, subjective judgement, and so on. To cope with this problem of real-world data, there have been some works on fuzzy classification rule learning. This paper makes a survey for the kinds of fuzzy classification rules. In addition, it presents a fuzzy classification rule learning method based on decision tree induction, and shows some experiment results for the method.

Development of Integrity Assessment Model for Reinforced Concrete Highway Bridges Using Fuzzy Concept (Fuzzy 개념을 이용한 RC도로교의 건전성평가 모델 개발)

  • Na, Ki-Hyun;Park, Ju-Won;Lee, Cheung-Bin;Jung, Chul-Won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.2 no.2
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    • pp.151-161
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    • 1998
  • In this study, an attempt is made to apply the concept of fuzzy-bayesian theory to the integrity assessment of RC highway bridge, and uncertainty states are represented in terms of fuzzy sets which define several linguistic variables such as "very good", "good", "average", "poor", "very poor", etc. Especially, the concept of fuzzy conditional probability aids to derive a new reliability analysis which includes the subjective assessment of engineers without introducing any additional correction factors. The fuzzy concept are also used as reliability indexes for the condition assessment based on the proposed models, the proposed fuzzy theory-based approach with the results of visual inspection and extensive field load tests are applied to the integrity assessment of a new RC highway bridge, namely, Jichok bridge.

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A STUDY ON RISK WEIGHT USING FUZZY IN REAL ESTATE DEVELOPMENT PROJECTS

  • Sung Cho;Kyung-ha Lee ;Yong Cho ;Joon-Hong Paek
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.1176-1182
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    • 2009
  • Due to recession in real estate market, interest of risk analysis is increasing. Feasibility study in the first stage takes a great role in a project. There are not objectified tools which are able to cope with uncertainty of project, and feasibility study based on selected method of determinism does not include liquidity of weight risk. Also, shortage of consideration for subjective and atypical external factors causes inappropriate results. Therefore, this study proposes feasibility study model focused on risk factor influences in construction cost and sales cost. Considering effective level of cost based on objective risk factors and probable weight of risk by this model, real workers are able to bring correct and scientific decisions better than former method based on selective analysis of real estate development.

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The Effect of Career Planning on Subjective Career Success of Organization Employees: Mediating Effects of Person-Organization Fit and Person-Job Fit (직장인의 경력계획이 주관적 경력성공에 미치는 영향: 개인-조직적합성과 개인-직무적합성의 매개효과)

  • Kim, Dongyoun;Jin, Sungmi
    • Journal of vocational education research
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    • v.37 no.1
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    • pp.31-53
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    • 2018
  • Uncertainty of career environment driven by globalization and shift of employment context drives heavy competition of labor market and anxiety of employment for individuals. New career paradigm based on this environmental change puts emphasis on subjective career success from individual's viewpoint as important career outcome and individual's proactive career development efforts. In addition to this, importance of person-environment fit and person-job fit is growing in relationship between career planning and career success. Based on this perspective, this study aims to identify whether person-environment fit and person-job fit mediate the relationship between career development and subjective career success. Data analysis of questionnaire from 220 employees showed that both fits mediate the relationship. This result implies that individual's proactive career planning is critical to career success and this strengthens one's satisfaction to organization and job. To organization, strategies need to be developed to design career development of employees' based on their career needs and organizational intervention such as job-rotation system.

A Study on the Degree of Self-care Activities of Stroke Patients, the Family Burden, and the Educational Needs of Primary Caregivers (뇌졸중 환자의 자가간호 수행과 가족 부담감 및 교육적 요구에 관한 연구)

  • Cho, Bok-Hee;Kim, Mi-Hyang;Seo, Nam-Sook;So, Hyang-Sook
    • The Korean Journal of Rehabilitation Nursing
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    • v.2 no.2
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    • pp.243-256
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    • 1999
  • The purpose of this study was to identify the degree of self-care activities of stroke patients, the family burden, and the educational needs of primary caregivers. A descriptive survey research was conducted in 97 stroke patients and their respective primary caregivers. Data were collected by the interviews using a structured questionnare from July 26th to August 5th, 1999. NIH stroke status was $12.15{\pm}8.40$, the degree of self-care activities of stroke patients was $26.85{\pm}9.39$. The score of objective burden of primary caregivers was $31.24{\pm}4.81$ and subjective burden was $24.30{\pm}6.99$. The score of the educational needs was $89.78{\pm}9.99$. We present several imformations about clients from these scores as follows: The patients were convalescent and their depentant level of self- care was middle range; The objective burden was higher than the subjective burden; And the educational needs of family caregivers were very high. The Elain Mattis Educational Wants of Family Caregivers of Disabled Adults Questionnaire was used to assess the educational needs of primary caregivers of stroke patients. The results of this research are offered to help nurses understand the feelings of uncertainty about the new and unexpected role that family caregivers face and to help nurses meet the needs of families preparing to care stroke survivors at home.

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Optimization of Contaminated Land Investigation based on Different Fitness-for-Purpose Criteria (조사목적별 기준에 부합하는 오염부지 조사방법의 최적화 방안에 관한 연구)

  • Jong-Chun Lee;Michael H. Ramsey
    • Economic and Environmental Geology
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    • v.36 no.3
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    • pp.191-200
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    • 2003
  • Investigations on the contaminated lands due to heavy metals from mining activities or hydrocarbons from oil spillage for example, should be planned based on specific fitness-for-purpose criteria(FFP criteria). A FFP criterion is site specific or varies with situation, based on which not only the data quality but also the decision quality can be determined. The limiting factors on the qualities can be, for example, the total budget for the investigation, regulatory guidance or expert's subjective fitness-for-purpose criterion. This paper deals with planning of investigation methods that can satisfy each suggested FFP criterion based on economic factors and the data quality. To this aim, a probabilistic loss function was applied to derive the cost effective investigation method that balances the measurement uncertainty, which estimates the degree of the data quality, with the decision quality. In addition, investigation planning methods when the objectives of investigations do not lie in the classification of the land but simply in producing the estimation of the mean concentration of the contaminant at the site(e.g. for the use in risk assessment), were also suggested. Furthermore, the efficient allocation of resources between sampling and analysis was also devised. These methods were applied to the two contaminated sites in the UK to test the validity of each method.

The Social Workers' Subjective Perception Type on the School Violence of Adolescents : Application of Q-Methodology (청소년의 학교폭력에 대한 학교사회복지사의 주관적 인식유형 : Q방법론의 활용)

  • Jung, Hyun-Tae;Yeum, Dong-Moon;Lim, Chae-Young
    • The Journal of the Korea Contents Association
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    • v.16 no.11
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    • pp.384-398
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    • 2016
  • The purpose of this study is to explore how school social workers recognize on the school violence of adolescents by using Q methodology. To this study, selected 31 of Q samples related school violence of adolescent by applying Q methodology and 33 of socials workers completed classification table, and three types were derived. The first type is named 'a type of improvement parents' concern with nonprofessional perception' because it has a significant part in bringing up children by parents to prevent school violence of adolescent and also has a negative perception, which is difficult to approach professional intervention. The second type is named 'a type of uncertainty of responsibility with passive perception' because there is an ambiguousness between responsibility and criteria through connection of official on the school violence. The third type is named 'a type of absence of responsibility with professional perception' because it is perceived absence of job roles to prevent school violence. This type showed school social workers, as a professionals of school violence of adolescents, wanted to intervene school violence but realistic intervention was difficult. From this study, it is considered subjective perception of school social workers on the school violence of adolescents will be affected on the change of adolescents in the future, and it is a significant way to use them as a basic data to prevent or remove school violence of adolescents in the school through conception and typology of them.

A Theoretical Study on Trust Building in Economic Space (경제공간에서 신뢰형성에 관한 이론적 고찰)

  • Sung, Sin-Je;Lee, Hee-Yul
    • Journal of the Korean Geographical Society
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    • v.42 no.4
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    • pp.560-581
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    • 2007
  • The purpose of this paper is to present a conceptual framework and a stage of development of trust building and to study the factors affecting on the trust building in economics space. Conceptual framework on trust building in economics space is combined of in the three approaches. The macro(structural and institutional) approach includes normative and regulative factors(laws, norms), and positionality in social and economic systems(beliefs, political ideologies, institutions). The meso(intersubjective) approach contains the personal fronts(expressive factors, social cues, significant symbols) and settings(physical space, intermediary such as technologies & knowledges). The micro(subjective) approach comprises the willingness(internalization of value) and calculation(risk and uncertainties analysis) of economic actors. According to sustainable cooperation among economic actors, trust building to the macro(structural and institutional) level, the meso(intersubjective) level, and the micro(subjective) level develop by stages. The factors such as long-term and repeated interaction, information sharing and reciprocity, interdependence and asset specificity, uncertainty, proximity, and culture & norm of corporate and formal institution are determinants on the trust building across economic actors in economic space.

Reliability Evaluation of a Microgrid Considering Its Operating Condition

  • Xu, Xufeng;Mitra, Joydeep;Wang, Tingting;Mu, Longhua
    • Journal of Electrical Engineering and Technology
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    • v.11 no.1
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    • pp.47-54
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    • 2016
  • Microgrids offer several reliability benefits, such as the improvement of load-point reliability and the opportunity for reliability-differentiated services. The primary goal of this work is to investigate the impacts of operating condition on the reliability index for microgrid system. It relies on a component failure rate model which quantifies the relationship between component failure rate and state variables. Some parameters involved are characterized by subjective uncertainty. Thus, fuzzy numbers are introduced to represent such parameters, and an optimization model based on Fuzzy Chance Constrained Programming (FCCP) is established for reliability index calculation. In addition, we present a hybrid algorithm which combines scenario enumeration and fuzzy simulation as a solution tool. The simulations in a microgrid test system show that reliability indices without considering operating condition can often prove to be optimistic. We also investigate two groups of situations, which include the different penetration levels of microsource and different confidence levels. The results support the necessity of considering operating condition for achieving accurate reliability evaluation.