• Title/Summary/Keyword: system uncertainty

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Optimal Design of Water Distribution System considering the Uncertainties on the Demands and Roughness Coefficients (수요와 조도계수의 불확실성을 고려한 상수도관망의 최적설계)

  • Jung, Dong-Hwi;Chung, Gun-Hui;Kim, Joong-Hoon
    • Journal of the Korean Society of Hazard Mitigation
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    • v.10 no.1
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    • pp.73-80
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    • 2010
  • The optimal design of water distribution system have started with the least cost design of single objective function using fixed hydraulic variables, eg. fixed water demand and pipe roughness. However, more adequate design is accomplished with considering uncertainties laid on water distribution system such as uncertain future water demands, resulting in successful estimation of real network's behaviors. So, many researchers have suggested a variety of approaches to consider uncertainties in water distribution system using uncertainties quantification methods and the optimal design of multi-objective function is also studied. This paper suggests the new approach of a multi-objective optimization seeking the minimum cost and maximum robustness of the network based on two uncertain variables, nodal demands and pipe roughness uncertainties. Total design procedure consists of two folds: least cost design and final optimal design under uncertainties. The uncertainties of demands and roughness are considered with Latin Hypercube sampling technique with beta probability density functions and multi-objective genetic algorithms (MOGA) is used for the optimization process. The suggested approach is tested in a case study of real network named the New York Tunnels and the applicability of new approach is checked. As the computation time passes, we can check that initial populations, one solution of solutions of multi-objective genetic algorithm, spread to lower right section on the solution space and yield Pareto Optimum solutions building Pareto Front.

New Approach to the Framework for Making the S&T Information Infrastructure in Complex System (복잡계 상황에서의 새로운 과학기술정보인프라구축의 틀 모색)

  • WON, DONG KYU;SUH, JEE HYUN
    • Proceedings of the Korea Contents Association Conference
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    • 2007.11a
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    • pp.188-192
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    • 2007
  • Today, the most pivotal issue in the national research and development, and national scientific and technical policy is to overcome uncertainties in the environment of technology development. The social and economic environment around us is at restricted uncertainty (complex system) where order and disorder coexist. Furthermore, the environment of technology development is more complicated. In order to bring about creativity in practices of technology development, we need a paradigm shift towards a new framework for the construction of the national scientific and technical information infrastructure, which entails a shift to creativity, self-organization and dynamic capability. The paradigm shift will lead the present scientific and technical information infrastructure which centers on information sharing, to move towards one that enables information coherence through self-organization. Thus, it is expected that the new Web 3.0 will provide a client-flexible analysis information system that will make information coherence and feedback possible. Through this system, the policy for the construction of a new scientific and technical infrastructure will evolve, which will bring about co-evolution of individual's knowledge through sharing of self-organizaed knowhow.

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Robust and Non-fragile $H_{\infty}$ Decentralized Fuzzy Model Control Method for Nonlinear Interconnected System with Time Delay (시간지연을 가지는 비선형 상호연결시스템의 견실비약성 $H_{\infty}$ 분산 퍼지모델 제어기법)

  • Kim, Joon-Ki;Yang, Seung-Hyeop;Kwon, Yeong-Sin;Bang, Kyung-Ho;Park, Hong-Bae
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.47 no.6
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    • pp.64-72
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    • 2010
  • In general, due to the interactions among subsystems, it is difficult to design an decentralized controller for nonlinear interconnected systems. In this study, the model of nonlinear interconnected systems is studied via decentralized fuzzy control method with time delay and polytopic uncertainty. First, the nonlinear interconnected system is represented by an equivalent Takagi-Sugeno type fuzzy model. And the represented model can be rewritten as Parameterized Linear Matrix Inequalities(PLMIs), that is, LMIs whose coefficients are functions of a parameter confined to a compact set. We show that the resulting fuzzy controller guarantees the asymptotic stability and disturbance attenuation of the closed-loop system in spite of controller gain variations within a resulted polytopic region by example and simulations.

A Study on Improvement for Service Proliferation Based on Blockchain (블록체인 기반 서비스 확산을 위한 개선 방안 연구)

  • Yoo, Soonduck;Kim, Kiheung
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.1
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    • pp.185-194
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    • 2018
  • This study investigates the limitations of blockchain technology and the ways to improve it by using Delphi technique. Limit factors and improvement measures are classified into technology, service, and legal system. First, from a technical point of view, lack of standardization of the technology, insufficiency of integration, lack of scalability, unclear cancellation or correction policy, excessive cost of transaction verification, insufficient personal information protection and not enough to respond to hacking defense were the limiting factors. In order to improve these, the followings; ensuring standardization, securing integration and scalability, establishing cancellation of each applicable data, establishment of correction policy, efficiency of verification cost, the protection of personal information and countermeasure against hacking are provided. The related technology development and countermeasures must be established to effectively introduce the blockchain technology to the market. Second, in the early stage of blockchain service, it showed lack of utilization of the blockchain, security threat, shortage of skilled workers, and lack of legal liability. As a solution to these problems, it is necessary to suggest various applications, against security threat, training professional manpower, and securing legal responsibility. It should also provide a foundation for providing institutionally stable services. Third, from as legal system point of view, inadequate legal compliance, lack of relevant regulation, and uncertainty in the regulation were the limiting factors. Therefore establishing a legal system, which is the most important area for activating the service, should be accompanied by the provision of legal countermeasures, clearness of regulations and measures to be taken by relevant governmental authorities. This study will contribute as a reference for a research, related to the blockchain.

The national limits and issues of disaster response and management capabilities (국가의 재난대처 및 관리능력의 한계와 문제점)

  • Gong, Bae Wan
    • Convergence Security Journal
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    • v.14 no.3_2
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    • pp.99-109
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    • 2014
  • Disaster is when, where, and how uncertainties, which might occur. Thus, for disaster response and management at the national and local governments have been made. Korea has established the Disaster and Safety Management Basic Act. Disaster Management has been made at the national level which is to prevent disasters and countries in order to protect citizens from harm and dangerous. Korean Disaster management system is well equipped with advanced countries. The Organization of national and local government are well-maintained substantially for the disaster activities and step-by-step manuals activities. Despite that uncertainty, due to the nature of the disaster, while infrequent, causing large-scale tragedy. Minimize the damage of the disaster as a disaster management efforts are needed. Normally a real disaster, a disaster situation, efforts are to be utilized efficiently, the effectiveness of the system will appear. But while the number of large-scale disasters, including the sinking of Sewol this time for the government and local governments see the response process, the system did not work and the manual existed in the cabinet. There was no Prevention and preparation activities, there was no integrated organization for the response management with expertise in the professional staff. Whenever a large disaster raised repeatedly as a problem, but there was a substantial change in formal but no improvement. It will not reduce the damage if the disaster management is not prepared for a revolutionary turning point.

A Study on the Emergence of Environmental Regulation in Complex System Paradigm (복잡계 패러다임에서 환경규제의 출현에 대한 연구)

  • Lee, Han-Woong;Kim, Seong-Hun;Bae, Ha-Na;Seo, Yong-Mo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.10
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    • pp.6905-6916
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    • 2015
  • The primary purpose of this paper is to find out the environmental regulation in our global society with complex system concept. After the industrial revolution, there were working toward solving various problems while there has been an industry advancement. But, there are various issues that a simple international trade or economic technologic levels were not solved. The evolution of technologies through complex systemic thought are not accidental issues. These issues build and provide a predictable technology innovation that system was emergent a new order. With complex systemic thought, the earth that was facing environmental problems was in the phrase edge of chose. These conditions played the trigger role for the solving various problems in environmental regulations but they don't get along well together. There were no causal relationship between structural elements. This paper describes an emergence of new order through these interactions in environmental regulation. These environmental regulations make desperate efforts not only public sectors but also private or/and firms that make an emergence of new order with the critical point reached. Also, we provide the understanding base an environmental regulation with new order for uncertainty.

Statistical Evaluation of Validity of KS Asphalt Penetration Grade System (통계적 분석을 통한 KS 아스팔트 침입도 규격의 문제점 고찰)

  • Kim, Kwang-Woo;Lee, Woo-Hyun;Jung, Jae-Hun;Doh, Young-Soo
    • International Journal of Highway Engineering
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    • v.8 no.4 s.30
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    • pp.125-133
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    • 2006
  • In this study, the Korean Industrial Standard(KS) penetration grade system was examined to evaluate its statistical validity. It was found from this limited study that the system has no gap between each grade, the binder falling out of limit trespasses into other binder grade. Therefore, many products can have similar property level with an adjacent grade even though the mean value is within the specification limit. It was also found out that the equal range setup of each grade, such as 20 for 40-60, 60-80, 80-100, has no statistical foundation. Since KS penetration grade is defined without gap between each grade, the producer must maintain the coefficient of variation below the level by the ASTM system to satisfy the normal quality control limit of products. Due to its lack of a gap between grades, higher percentage of products will be duplicated even if the mean is at the median of the specification limits due to material's quality uncertainty. Especially if the mean moves toward the upper limit, a half or more of the binder grade will be overlapped with the upper binder grade. Therefore, KS penetration specification should be immediately modified by statistically valid methodologies.

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Legal Issues in Clinical Trial on Minor (미성년자 대상 임상시험에 관한 법적 문제점)

  • Song, Young-min
    • The Korean Society of Law and Medicine
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    • v.17 no.2
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    • pp.125-144
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    • 2016
  • All forms of Clinical trial should be fully equipped with protection systems for experimental subjects considering their uncertainty and various risks. Existing laws have some regulations in pharmaceutical affairs act and medical device act. Nonetheless, there is a limit to protect the subjects considering law objective to perform administration of medicine. Furthermore, the clinical trial on minor has no direct regulations in pharmaceutical affairs act, but prescribes certain portion in clinical trial assessment guideline on infants or medicine clinical trial management standard, however there is a limit because that is just recommendation not having legal effectiveness. The legislative solution would be possible for legal problems of clinical trial on minor by examining treatment system on minor in organ transplant act and clinical trial on minor in other foreign laws stronger than usual medical practice in terms of degree of human body invasion. I suppose that the control system of clinical trial being done focusing on the pharmaceutical affairs act, medical device act and other guidelines in existing laws system should be resolved by legislating 'trial subject protection law', in addition, this would be well balanced in organ transplant act on protection system of minor organ donors. Furthermore, the judgement on the consent ability and spontaneity in clinical trial on minor should be judged considering maturity and mentality of minor by clinical trial institutional review board based on legislative solution mentioned above.

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A Study on the Physician's Behavior of Notifiable Communicable Diseases Reporting and its Characteristics Related (법정전염병 신고행태 및 관련특성 연구)

  • 이윤현;맹광호
    • Health Policy and Management
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    • v.9 no.4
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    • pp.41-64
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    • 1999
  • The major concern for this research is to discuss and to offer some solutions to bring the effectiveness of existing notifiable diseases reporting system over the physicians' attitudes of reporting, the actual condition of performance and the reasons of inertia in notifiable diseases reporting through examining the physicians of medical institutions in nationwide such as pediatrics, internal medicine and family medicine. The actual conditions of notifiable communicable diseases(NCD) reporting was surveyed by mail objectifying an internal medicine, pediatrics and family medicine in nationwide on the basis of stratified random sampling method divided into the classification of medical institutions and areas. As a result of survey. the rate of respondents showed 145 persons from physicians, 105 persons from hospitals. 120 persons from general hospitals, and 51 persons from tertiary hospitals. The total number of respondents were 421 and was rated 59.0 %. The analysis of collected survey went through a descriptive analysis primarily to grasp physicians' attitudes on the notifiable communicable diseases reporting, and then upon the dependent variables. Following are major findings obtained form the data analysis. 1. The results of a descriptive analysis on physicians' attitudes towards reporting NCD were as follows: First, the respondents who didn't know that yellow fever is reporting NCD were 11.0% of clinic, 10.5% of hospital. 5.0% of general hospital. 11.8% of tertiary hospital. and in case of hepatitis B, were 26.9% of clinic, 35.2% of hospital. 35.0% of general hospital. 23.5% of tertiary hospital. Second, The rate of physicians' knowledge on penalties of not reporting the NCD by their medical institution were 35.2% of clinic, 45.7% of hospital. 36.7% of general hospital. 62.7% of tertiary hospital. Third, among the no-reporting physicians in whole, the major reason of not reporting NCD were uncertainty of diagnosis(78.9%), no need to report(46.4%), no adequate actions from PHC(29.1%), no knowledge of the cases being notifiable ones in the order of their frequencies(30.4%), meddling from PHC(29.1%), concerning of patient's privacy(26.3%). 2. To analyze the characteristics related to the physicians' behaviors to report NCD, univariate and multiple logistic regression analyses were applied to the variables related to physician, 4 medical facility, PHC, and reporting system. The result were as follows: First, the result of the univariate analysis on physicians' attitude to report NCD and characteristics related to reporting in odds ratio was in the case of hospital. 3.4 times higher positive responses on physicians' attitude to report NCD came up as compared to the clinic. Second, the result of the univariate analysis on physicians' action of reporting NCD and characteristics related to reporting by the classification of medical institutions showed that the odds ratio of hospital was 2.3 times, the odds ratio of general hospital was 2.0 times, the odds ratio of tertiary was 6.8 times significantly higher than clinic. And the medical institution with significantly higher positive attitudes rate by multiple logistic regression analysis was hospital that rated 2.5 times significantly higher than clinic. Also in the PHC related characteristics of reporting, the rate of action in reporting NCD was significantly higher in medical institution that were endowed with the good condition of reporting. In multiple logistic regression analysis, the medical institution that has a good conditions of reporting showed a significantly higher positive rate on the action of reporting than the others.

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Small Business Research and Development Assessment System based on Fuzzy-AHP (Fuzzy-AHP 기반 중소기업 R&D 평가 시스템)

  • Park, Seong-Ho;Oh, Jae-Taek;Lee, Sang-Yong
    • Journal of Digital Convergence
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    • v.18 no.9
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    • pp.323-329
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    • 2020
  • There is a system of mandating the allocation of support to small business in certain percentage or more to facilitate technological innovation at small business. Trying to assess small business R&D projects, which receive a budget of three trillion won or more from the government every year, for their possibilities of success, a group of experts perform a technological evaluation with their technologies and their difficulty levels and review closely the possibilities of their commercialization and success. Used in such a review, the Analytic Hierarchy Process technique cannot make an objective judgment of evaluation criteria for evaluation items and guarantee the professionalism and fairness of small business R&D projects due to the inherent ambiguity and uncertainty of the evaluation criteria. This study proposed an R&D evaluation system based on Fuzzy-AHP for small business to provide objective weight for the evaluation items and assess the possibilities of such projects' success. The evaluation criteria were make objective as they were applied as section values based on triangular fuzzy numbers. Weight was assigned and applied according to the management guidelines of supportive projects for small business' technological development so that it could be reflected on actual assessment. The findings of the study will be helpful for reflecting the scoring weight of these evaluation items again when an expert is appointed for a new project and guaranteeing the professionalism and fairness of small business R&D project based on them.