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Development of a Robust Design Process Using a Robustness Index (강건성 지수를 이용한 강건설계 기법의 개발)

  • Hwang, Kwang-Hyeon;Park, Gyung-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.8
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    • pp.1426-1435
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    • 2003
  • Design goal is to find the one that has the highest probability of success and the smallest variation. A robustness index has been proposed to satisfy these conditions. The two-step optimization process of the target problem requires a scaling factor. The search process of a scaling factor is replaced with the making of the decoupled design between the mean and the standard deviation. The decoupled design matrix is formed from the sensitivity or the sum of squares. After establishing the design matrix, the robust design process has a new three-step one. The first is ″reduce variability,″ the second is ″make the candidate designs that satisfy constraints and move the mean on the target,″ and the final is ″select the best robust design using the proposed robustness index.″ The robust design process is verified by three examples and the results using the robustness index are compared with those of other indices.

An Expert System for Voltage and Reactive Power Control (전압, 무효전력 제어를 위한 전문가 시스템)

  • Seo, Seung-Woo;Lee, Heung-Jae;Park, Young-Moon
    • Proceedings of the KIEE Conference
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    • 1988.07a
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    • pp.852-854
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    • 1988
  • An expert system is developed to solve the voltage problems occurring in electric transmission power system. It is based on knewledge engineering technique satisfies the performance criteria such as minimizing the number of operation of control device and quantity of reactive power. Also, it uses best-first search technique from the experts. Control devices used in this paper include shunt capaciter/reactor, transformer tap changer, generator output voltage and a generator is used after the availability of other two devices are checked.

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An On-Line Hangul Recognition System Based on the Structural Information and the Best-First Search (구조적 정보를 근거로 최적우선탐색하는 온라인 한글 인식)

  • Kwon, Oh-Sung;Kwon, Young-Bin
    • Annual Conference on Human and Language Technology
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    • 1992.10a
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    • pp.515-523
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    • 1992
  • 일반적으로 한글 인식 과정은 많은 후보들을 생성하며 이 후보들로부터 정확한 인식결과를 얻고 복잡도를 줄이기 위해서는 효과적인 한글 표현과 탐색기법이 요구된다. 이런 목적을 위하여 본 논문에서는 한글에 적합한 구조적 정보들을 4단계 계층적 형태로 표현한다. 그리고 이 정보들을 근거로 후보 문자의 생성과 탐색을 진행하며 전체적으로 최적우선탐색을 이룬다. 인식실험은 다양한 필자들을 대상으로 한글 잦기 상위 422자로 실험한 결과 평균 86% 인식률을 얻을 수 있었다.

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System Requirement Analysis of Multi-Role Helicopter by Implementing Quality Function Deployment (QFD(Quality Function Deployment)를 이용한 다목적 헬리콥터의 시스템 요구도 분석)

  • Kim, Minji;Park, Mi-Young;Lee, Jae-Woo;Byun, Younghan
    • Journal of the Korean Society of Systems Engineering
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    • v.1 no.2
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    • pp.56-62
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    • 2005
  • In this study, we first define user requirements to fulfill the reconnaissance and the search missions, by analyzing the system characteristics and operation environment. By investigating the design technology level, the development and procurement costs, the strong system design concepts and possible alternatives will be proposed. To analyze the system requirements, the Quality Function Deployment of the systems engineering approach will be implemented. The promising design alternatives that satisfy the user requirements are extracted by constructing the Morphological Matrix, then the best design concept will be obtained using the Pugh Concept Selection Matrix and the TOPSIS(Technique of Order Preference by Similarity to Ideal Solution).

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Development of an Expert System for the Fault Diagnosis in power System (전력계통의 고장진단 전문가 시스템에 관한연구)

  • 박영문;이흥재
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.39 no.1
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    • pp.16-21
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    • 1990
  • A Knowledge based expert system is a computer program that emulates the reasoning process of a human expert in a specific problem domain. Expert system has the potential to solve a wide range of problems which require knowledge about the problem rather than a purely analytical approach. This papaer presents the application of knowledge based expert system to power system fault diagnosis. The contents of expert system develpped in this paper is judgement of fault section from a given alarm sets and production of all possible hypothesis for the single fault. Both relay failures and circuit breaker failures are considered simultaneously. Although many types of relay are used in actual system, experts recognize ones as several typical signals corresponding to the fault types. Therefore relays are classified into several types. The expert system is written in an artificial intelligence language "PROLOG" . Best-first search method is used for problem solving. Both forward chaining and backward chaining schemes are used in reasoning process. The application to a part of actual power system proves the availability of the developed expert system.

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New large-update primal interior point algorithms based on kernel functions for LCPs

  • Kim, Min-Kyung;Cho, Gyeong-Mi
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.11 no.4
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    • pp.69-88
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    • 2007
  • In this paper we propose new large-update primal-dual interior point algorithms for $P_{\neq}({\kappa})$ linear complementarity problems(LCPs). New search directions and proximity measures are proposed based on a specific class of kernel functions, ${\psi}(t)={\frac{t^{p+1}-1}{p+1}}+{\frac{t^{-q}-1}{q}}$, q>0, $p{\in}[0,\;1]$, which are the generalized form of the ones in [3] and [12]. It is the first to use this class of kernel functions in the complexity analysis of interior point method(IPM) for $P_*({\kappa})$LCPs. We showed that if a strictly feasible starting point is available, then new large-update primal-dual interior point algorithms for $P_*({\kappa})$ LCPs have the best known complexity $O((1+2{\kappa}){\sqrt{2n}}(log2n)log{\frac{n}{\varepsilon}})$ when p=1 and $q=\frac{1}{2}(log2n)-1$.

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Current Status and the Future of Occupational Safety and Health Legislation in Low- and Middle-Income Countries

  • Ncube, France;Kanda, Artwell
    • Safety and Health at Work
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    • v.9 no.4
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    • pp.365-371
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    • 2018
  • This article addresses three key issues. First, the commonalities, differences, strengths, and limitations of existing occupational safety and health (OSH) legislation of low- and middle-income countries were determined. Second, required revisions were identified and discussed to strengthen the laws in accordance with the best international practice. Finally, proposals for additional OSH laws and interventions were suggested. A literature search of OSH laws of 10 selected low- and middle-income countries was carried out. The laws were subjected to uniform review criteria. Although the agricultural sector employs more than 70% of the population, most of the reviewed countries lack OSH legislation on the sector. Existing OSH laws are gender insensitive, fragmented among various government departments, insufficient, outdated, and nondeterrent to perpetrators and lack incentives for compliance. Conclusively, the legal frameworks require reformation and harmonization for the collective benefit to employees, employers, and regulatory authorities. New OSH legislation for the agricultural sector is required.

A User Profile-based Filtering Method for Information Search in Smart TV Environment (스마트 TV 환경에서 정보 검색을 위한 사용자 프로파일 기반 필터링 방법)

  • Sean, Visal;Oh, Kyeong-Jin;Jo, Geun-Sik
    • Journal of Intelligence and Information Systems
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    • v.18 no.3
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    • pp.97-117
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    • 2012
  • Nowadays, Internet users tend to do a variety of actions at the same time such as web browsing, social networking and multimedia consumption. While watching a video, once a user is interested in any product, the user has to do information searches to get to know more about the product. With a conventional approach, user has to search it separately with search engines like Bing or Google, which might be inconvenient and time-consuming. For this reason, a video annotation platform has been developed in order to provide users more convenient and more interactive ways with video content. In the future of smart TV environment, users can follow annotated information, for example, a link to a vendor to buy the product of interest. It is even better to enable users to search for information by directly discussing with friends. Users can effectively get useful and relevant information about the product from friends who share common interests or might have experienced it before, which is more reliable than the results from search engines. Social networking services provide an appropriate environment for people to share products so that they can show new things to their friends and to share their personal experiences on any specific product. Meanwhile, they can also absorb the most relevant information about the product that they are interested in by either comments or discussion amongst friends. However, within a very huge graph of friends, determining the most appropriate persons to ask for information about a specific product has still a limitation within the existing conventional approach. Once users want to share or discuss a product, they simply share it to all friends as new feeds. This means a newly posted article is blindly spread to all friends without considering their background interests or knowledge. In this way, the number of responses back will be huge. Users cannot easily absorb the relevant and useful responses from friends, since they are from various fields of interest and knowledge. In order to overcome this limitation, we propose a method to filter a user's friends for information search, which leverages semantic video annotation and social networking services. Our method filters and brings out who can give user useful information about a specific product. By examining the existing Facebook information regarding users and their social graph, we construct a user profile of product interest. With user's permission and authentication, user's particular activities are enriched with the domain-specific ontology such as GoodRelations and BestBuy Data sources. Besides, we assume that the object in the video is already annotated using Linked Data. Thus, the detail information of the product that user would like to ask for more information is retrieved via product URI. Our system calculates the similarities among them in order to identify the most suitable friends for seeking information about the mentioned product. The system filters a user's friends according to their score which tells the order of whom can highly likely give the user useful information about a specific product of interest. We have conducted an experiment with a group of respondents in order to verify and evaluate our system. First, the user profile accuracy evaluation is conducted to demonstrate how much our system constructed user profile of product interest represents user's interest correctly. Then, the evaluation on filtering method is made by inspecting the ranked results with human judgment. The results show that our method works effectively and efficiently in filtering. Our system fulfills user needs by supporting user to select appropriate friends for seeking useful information about a specific product that user is curious about. As a result, it helps to influence and convince user in purchase decisions.

Fast PU Decision Method Using Coding Information of Co-Located Sub-CU in Upper Depth for HEVC (상위깊이의 Sub-CU 부호화 정보를 이용한 HEVC의 고속 PU 결정 기법)

  • Jang, Jae-Kyu;Choi, Ho-Youl;Kim, Jae-Gon
    • Journal of Broadcast Engineering
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    • v.20 no.2
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    • pp.340-347
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    • 2015
  • HEVC (High Efficiency Video Coding) achieves high coding efficiency by employing a quadtree-based coding unit (CU) block partitioning structure and various prediction units (PUs), and the determination of the best CU partition structure and the best PU mode based on rate-distortion (R-D) cost. However, the computation complexity of encoding also dramatically increases. In this paper, to reduce such encoding computational complexity, we propose three fast PU mode decision methods based on encoding information of upper depth as follows. In the first method, the search of PU mode of the current CU is early terminated based on the sub-CBF (Coded Block Flag) of upper depth. In the second method, the search of intra prediction modes of PU in the current CU is skipped based on the sub-Intra R-D cost of upper depth. In the last method, the search of intra prediction modes of PU in the lower depth's CUs is skipped based on the sub-CBF of the current depth's CU. Experimental results show that the three proposed methods reduce the computational complexity of HM 14.0 to 31.4%, 2.5%, and 23.4% with BD-rate increase of 1.2%, 0.11%, and 0.9%, respectively. The three methods can be applied in a combined way to be applied to both of inter prediction and intra prediction, which results in the complexity reduction of 34.2% with 1.9% BD-rate increase.

Improving the Quality of Web Spam Filtering by Using Seed Refinement (시드 정제 기술을 이용한 웹 스팸 필터링의 품질 향상)

  • Qureshi, Muhammad Atif;Yun, Tae-Seob;Lee, Jeong-Hoon;Whang, Kyu-Young
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.48 no.6
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    • pp.123-139
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    • 2011
  • Web spam has a significant influence on the ranking quality of web search results because it promotes unimportant web pages. Therefore, web search engines need to filter web spam. web spam filtering is a concept that identifies spam pages - web pages contributing to web spam. TrustRank, Anti-TrustRank, Spam Mass, and Link Farm Spam are well-known web spam filtering algorithms in the research literature. The output of these algorithms depends upon the input seed. Thus, refinement in the input seed may lead to improvement in the quality of web spam filtering. In this paper, we propose seed refinement techniques for the four well-known spam filtering algorithms. Then, we modify algorithms, which we call modified spam filtering algorithms, by applying these techniques to the original ones. In addition, we propose a strategy to achieve better quality for web spam filtering. In this strategy, we consider the possibility that the modified algorithms may support one another if placed in appropriate succession. In the experiments we show the effect of seed refinement. For this goal, we first show that our modified algorithms outperform the respective original algorithms in terms of the quality of web spam filtering. Then, we show that the best succession significantly outperforms the best known original and the best modified algorithms by up to 1.38 times within typical value ranges of parameters in terms of recall while preserving precision.