• Title/Summary/Keyword: Performance Issues

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Design of a Modbile Agent-based Workflow System (이동에이전트 기반 워크플로우 시스템의 설계)

  • Seo, Young-Ho;Yoo, Jeong-Joon;Lee, Dong-Ik
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.8
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    • pp.2370-2387
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    • 2000
  • This paper proposes a new design strategy that can overcome limitations of two existing approaches, focusing on performance and scalability issues among various architectural issues which must be considered in designing workflow systems. In the proposed approach, we suggest to introduce 'delegation model' which corresponds to the high-level strategy utilizing the fundamental characteristics of mobile agents, after establishing a mobile agent-based workflow system architecture focused on performance and scalability. We point out three major issues that should be considered in this approach and propose a 3-tier mobile agent-based workflow system architecture that effectively reflects these considerations. Also, we show that the new approach can provide better performance and scalability than existing ones - approaches based on the client-server paradigm and other approaches based on mobile agent paradigm represented by DartFlow system - by evaluating performance of the proposed architecture through the GSPN simulation.

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Human Reliability Analysis of Soft Control Operations in Nuclear Power Plants: Issues and Perspectives

  • Lee, Seung Jun;Jung, Wondea
    • Journal of the Ergonomics Society of Korea
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    • v.32 no.1
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    • pp.87-96
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    • 2013
  • Objective: The aim of this study is to describe several issues which should be considered in the human reliability analysis of soft control operations in nuclear power plants. Background: The operational environment of advanced main control rooms is totally different from that of conventional control rooms. The soft control is one of the major distinguishable features of the advanced main control rooms. The soft control operations should be analyzed to estimate the effects on human reliability. Method: The literatures, about task analysis, simulation data analysis, and a human reliability analysis method for the soft control, were reviewed. From the review, important issues for the human reliability analysis of the soft control were raised. Results: The results of task and simulation data analysis showed that the soft control characteristics could have large effect on human reliability and they should be considered in the human reliability analysis of the soft control operations. Conclusion: The soft control may affect human error and performance of operators. The issues described in this paper should be considered in the human reliability method for the advanced main control rooms. Application: The results of the soft control operation analysis might help to design more efficient interface and education/training program for preventing human errors. The described issues might help to develop a human reliability analysis method for soft control operations.

Why Do Government Policies Fail in Boosting Independent Retailers?

  • Young-Sang CHO
    • The Journal of Industrial Distribution & Business
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    • v.15 no.1
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    • pp.19-29
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    • 2024
  • Purpose: It is necessary to look at the reasons why the Korean government has failed in boosting mom and pops, even though many aid programs for independent retailers have been introduced. Furthermore, this research will provide policy makers and practitioners with new insight to improve the performance of government policies. Research design: the researcher has had an interview with the 26 practitioners to gather the right information. Furthermore, interview results have been categorized into the government-related issues, support programs and shop owner-related issues, from a practitioner's perspectives. Results: The researcher found that the confusion of governmental support organization, the lack of retail marketing experts, frequent job rotation, the lack of cooperation between bureaucrats and associations, concerned about the governmental-related issues, are failure reasons. In terms of support program issues, the research found the following reasons: no blueprint, the lack of retail experts, relevance to budget scale, and the complexity of budget implementation. Associated with shop owner-related issues, the author found that the causes of failure are closely related to aging shopkeepers, the absence of a successor and increasing dependence on a government. Conclusions: The author proposes that a government has to rebuild existing support programs for small shop owners.

Observation Likelihood Function Design and Slippage Error Compensation Scheme for Indoor Mobile Robots (실내용 이동로봇을 위한 위치추정 관측모델 설계 및 미끄러짐 오차 보상 기법 개발)

  • Moon, Chang-Bae;Kim, Kyoung-Rok;Song, Jae-Bok;Chung, Woo-Jin
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.11
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    • pp.1092-1098
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    • 2007
  • A mobile robot localization problem can be classified into following three sub-problems as an observation likelihood model, a motion model and a filtering technique. So far, we have developed the range sensor based, integrated localization scheme, which can be used in human-coexisting real environment such as a science museum and office buildings. From those experiences, we found out that there are several significant issues to be solved. In this paper, we focus on three key issues, and then illustrate our solutions to the presented problems. Three issues are listed as follows: (1) Investigation of design requirements of a desirable observation likelihood model, and performance analysis of our design (2) Performance evaluation of the localization result by computing the matching error (3) The semi-global localization scheme to deal with localization failure due to abrupt wheel slippage In this paper, we show the significance of each concept, developed solutions and the experimental results. Experiments were carried out in a typical modern building environment, and the results clearly show that the proposed solutions are useful to develop practical and integrated localization schemes.

RDP: A storage-tier-aware Robust Data Placement strategy for Hadoop in a Cloud-based Heterogeneous Environment

  • Muhammad Faseeh Qureshi, Nawab;Shin, Dong Ryeol
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.9
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    • pp.4063-4086
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    • 2016
  • Cloud computing is a robust technology, which facilitate to resolve many parallel distributed computing issues in the modern Big Data environment. Hadoop is an ecosystem, which process large data-sets in distributed computing environment. The HDFS is a filesystem of Hadoop, which process data blocks to the cluster nodes. The data block placement has become a bottleneck to overall performance in a Hadoop cluster. The current placement policy assumes that, all Datanodes have equal computing capacity to process data blocks. This computing capacity includes availability of same storage media and same processing performances of a node. As a result, Hadoop cluster performance gets effected with unbalanced workloads, inefficient storage-tier, network traffic congestion and HDFS integrity issues. This paper proposes a storage-tier-aware Robust Data Placement (RDP) scheme, which systematically resolves unbalanced workloads, reduces network congestion to an optimal state, utilizes storage-tier in a useful manner and minimizes the HDFS integrity issues. The experimental results show that the proposed approach reduced unbalanced workload issue to 72%. Moreover, the presented approach resolve storage-tier compatibility problem to 81% by predicting storage for block jobs and improved overall data block placement by 78% through pre-calculated computing capacity allocations and execution of map files over respective Namenode and Datanodes.

Performance Improvement of a Movie Recommendation System based on Personal Propensity and Secure Collaborative Filtering

  • Jeong, Woon-Hae;Kim, Se-Jun;Park, Doo-Soon;Kwak, Jin
    • Journal of Information Processing Systems
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    • v.9 no.1
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    • pp.157-172
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    • 2013
  • There are many recommendation systems available to provide users with personalized services. Among them, the most frequently used in electronic commerce is 'collaborative filtering', which is a technique that provides a process of filtering customer information for the preparation of profiles and making recommendations of products that are expected to be preferred by other users, based on such information profiles. Collaborative filtering systems, however, have in their nature both technical issues such as sparsity, scalability, and transparency, as well as security issues in the collection of the information that becomes the basis for preparation of the profiles. In this paper, we suggest a movie recommendation system, based on the selection of optimal personal propensity variables and the utilization of a secure collaborating filtering system, in order to provide a solution to such sparsity and scalability issues. At the same time, we adopt 'push attack' principles to deal with the security vulnerability of collaborative filtering systems. Furthermore, we assess the system's applicability by using the open database MovieLens, and present a personal propensity framework for improvement in the performance of recommender systems. We successfully come up with a movie recommendation system through the selection of optimal personalization factors and the embodiment of a safe collaborative filtering system.

Safety Assessment Scenarios for Cyclist AEB (자전거 대상 자동비상제동장치의 성능평가 시나리오 개발)

  • Kim, Taewoo;Yi, Kyongsu;Lee, EunDok
    • Journal of Auto-vehicle Safety Association
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    • v.9 no.2
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    • pp.13-19
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    • 2017
  • This paper presents safety assessment scenarios for cyclist autonomous emergency braking(AEB) system. To assess the safety performance of AEB in real traffic situation with limited number of scenarios, scenario should reflect the characteristics of real traffic collision cases. For this, statistic data of real traffic car-to-cyclist collision in Korea are analyzed. Many types of accidents are listed and categorized based on the movement of vehicle and cycle just before the collision. Then, the characteristics, main issues and limitations of each scenarios are discussed. Not only the test scenario itself but also the cost and time for the test are very important issues for the test scenarios to actually repeat the test for various systems. Also, the performance of AEB can be effected by the algorithm of AEB and the technical limitation of the sensors and hardwares. Therefore, required number of tests, possibility of dummy destruction and other technical issues are discussed for each scenarios. Based on these information, typical scenarios are selected. Also, using this information, vehicle speed range, cyclist speed and collision point are established. Proposed scenarios are verified and modified based on the vehicle test results. vehicle test was evaluated 5 times for each scenarios. Based on this results, final test scenarios are modified and proposed.

Analysis of Types and Forms of "At-Risk Youth" Portrayed in Dance Works: Focusing on Matthew Bourne's <Romeo + Juliet>

  • So-jung, Chang
    • International Journal of Advanced Culture Technology
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    • v.12 no.3
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    • pp.303-308
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    • 2024
  • There is no standardized concept of "at-risk youth," but from an overall perspective, they are youth exposed to various crises. "At-risk youth" are categorized into personal, familial, educational, and social crisis areas, encompassing factors such as family background, educational difficulties, and mental health issues. There is a dance piece that addresses these "at-risk youth. Matthew Bourne created a dance piece that addresses "at-risk youth" in <Romeo + Juliet>. Currently, Matthew Bourne is a popular choreographer from England who reflects certain social phenomena and does not differentiate between classic art and public art. In 2019, Matthew Bourne collaborated with young creators to reinterpret <Romeo + Juliet> as a narrative centered around youth. In this dance work, youth is both the subject and the expression of the story. In <Romeo + Juliet>, "at-risk youth" are depicted in various forms. The work explores mental health issues including homosexuality, trauma, and depression among teenagers, as well as societal issues such as violence and weapons. The stage depicted how teenagers perceive themselves and how they navigate the challenges faced by "at-risk youth". We would like to interpret the work in relation to the types of "at-risk youth" and the expression methods of the performance. Of course, there may be differences when examining performance cases in other countries compared to youth in Korean society. However, It has meaning in itself to analyze Matthew Bourne's <Romeo + Juliet> in various ways in relation to "at-risk youth" and to examine social phenomena from a broader perspective through this.

Development of Component Framework for Supply-Chain Management

  • Wang, Gi-Nam;Choi, Jung-Won
    • Proceedings of the CALSEC Conference
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    • 1999.07b
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    • pp.431-445
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    • 1999
  • This paper introduces a development of component based framework of supply-chain management. The existing legacy system, which is not designed for object-oriented paradigm, is re-modeled using unified modeling language. Components are extracted from the legacy application, and frameworks are also designed in order to increase productivities of software development. Design issues concerning component and framework development are discussed with real situation. Performance and development productivity issue are also discussed with discussing component size and scope. A real case is presented in connection with the discussed issues.

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