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        검색결과 243

        61.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A steady-state controllable M/G/1 queueing model operating under the {T:Min(T,N)} policy is considered where the {T:Min(T,N)} policy is defined as the next busy period will be initiated either after T time units elapsed from the end of the previous busy period if at least one customer arrives at the system during that time period, or after T time units elapsed without a customer’ arrival, the time instant when Nth customer arrives at the system or T time units elapsed with at least one customer arrives at the system whichever comes first. After deriving the necessary system characteristics including the expected number of customers in the system, the expected length of busy period and so on, the total expected cost function per unit time for the system operation is constructed to determine the optimal operating policy. To do so, the cost elements associated with such system characteristics including the customers’ waiting cost in the system and the server’s removal and activating cost are defined. Then, procedures to determine the optimal values of the decision variables included in the operating policy are provided based on minimizing the total expected cost function per unit time to operate the queueing system under considerations.
        4,000원
        62.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, a System Dynamics(SD) computer simulation model has been developed to assess the effects of developing and providing an alternate water source. A water service index was also developed to estimate the level of overall customer satisfaction on water supply service. Data from the Busan water supply service and the Korea Development Institute regarding the Nak Dong river bank storage development were utilized during the modeling processes. Some important indicators of the system under study were analyzed by the simulations of development of the alternate water source for Busan. The developed SD model and the water service index can be further utilized as a tool that can assess the extent and timing of an additional service improvement project.
        4,000원
        63.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The occupational health and safety accidents were continuously increased during handling, usage and manufacturing the chemical materials according to increase of small and medium sized enterprises in domestic industries. These accidents mainly resulted from insufficient occupational health and safety management and deteriorative facilities and focused on corresponding operation to minimize the damage of accidents after occurrence. But, it was required that we grasped the occurrence causes of occupational health and safety risk in handling, usage and manufacturing the chemical materials and develop the adequate corresponding operation and system according to the possible occurrence of occupational health and safety risk. This study deals with the development of risk assessment model to derive the risk and important risk of occupational health and safety and then help to construct the self-controlled occupational health and safety system for small and medium sized enterprises handling the chemical materials.
        4,000원
        64.
        2014.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: This paper evaluates, using LS/DYNA-3D software, the vehicle impact performance of flexible barriers made of steel WBeam supported by four different types of post configurations. These types include circular post, H-shape post, C-shape post, and square post. METHODS : The post-soil interaction has been investigated according to different impact angles. For this purpose, energy absorption, maximum displacements of post and rail, and occupant risk index of THIV have been compared each other. The three dimensional soil material model, instead of the conventional spring model based on Winkler and p-y curve, has been used to increase the correctness of computational model. RESULTS: It is noted the crash energy absorption has been increased with respect to the increase of impact angle. CONCLUSIONS : In particular, a post with open section(H-shape, C-shape) shows the greater crash energy absorption capability as compared with a post with closed section under the same level of impact conditions.
        4,000원
        65.
        2014.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        2013년 여름철 집중관측기간(장마기간: 2013년 6월 20일-7월 7일, 집중호우기간: 2013년 7월 8일-30일) 동안 이동식 기상관측시스템의 레윈존데 관측 자료를 전 지구 통합예측시스템 3차원 자료동화에 이용하여 그 효과를 살펴보았다. 효과 분석을 위한 2가지 모의실험 중 규준실험은 기존 기상청 관측 자료만 사용한 것이고 관측시스템실험은 기상청 관측 자료에 이동식 기상관측시스템의 레윈존데 자료를 추가한 것이다. 장마기간 동안 두 실험의 500 hPa 지위고도, 850 hPa 기온, 300 hPa 풍속의 관측 및 분석검증 비교 결과 큰 차이를 보이지 않았는데, 이는 고정관측소의 레윈존데 자료(0000 UTC 및 1200 UTC)만을 기준으로 검증이 이루어졌기 때문이다. 하지만, 종관기상관측시스템의 시간별 누적 강수량 자료를 이용한 강수검증에 있어서 관측시스템실험의 평균 공정임계지수가 규준실험에 비해 2% 수준으로 개선된 결과를 보였다. 특히 강수검증에서 긍정적인 효과가 나타난 사례만 비교한 경우, 관측시스템실험의 평균 공정임계지수가 규준실험에 비해 41%까지 개선된 결과를 보여 이동식 기상관측시스템 레윈존데 관측 자료가 수치모델의 예측정확도 향상에 유용함을 알 수 있었다.
        4,000원
        67.
        2014.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        우리 해군은 함정 제품모델(Naval Ship Product Model, NSPM)을 중심으로 하는 협업 제품개발 환경 구축을 통해 설계 데이터의 재사용성과 M&S의 활용도를 높이고 있다. 그 결과 설계결과의 신뢰성이 높아지고 있으며, 이를 활용한 운영, 건조 시뮬레이션을 통해 소요군의 요구사항이 면밀히 반영되도록 하는 연구도 진행 중에 있다. 이에 따라 설계 데이터의 DB 구축 및 그 품질에 대한 중요성이 부각되고 있으나, 그와 관련된 연구는 초기상태에 머물러 있는 실정이다. 본 연구에서는 저자들의 선행연구 결과인 함정 제품모델의 품질검증 방법론에 기초하여 함정 제품모델을 구성하고 있는 형상요소의 구체적인 품질검증 방안과 이를 자동화하기 위한 연구를 수행하였다. 함정 제품모델 데이터 중 상대적으로 중요하며, 검증과정에 많은 시간이 소요되고 있는 선각모델을 사례연구 대상으로 정의하였으며, 자동차산업에서 사용되고 있는 제품데이터품질(Product Data Quality, PDQ)을 형상검증 기준으로 활용하였다. 최종적으로 선각모델의 형상 품질검증을 위한 기준과 알고리즘을 제안하였으며 이에 기반 한 초기 시스템을 개발하였다.
        4,000원
        68.
        2014.02 구독 인증기관·개인회원 무료
        It is intended to develop an experimental apparatus which can visualize flow patterns in condensate water reuse system with various cross sections. PVC particles on fluid surface help to obtain clear flow images. The flow region that were found in the experiments are steady, unsteady and significantly-mixed flows.
        69.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Currently, Game Rating Board is regulating online web board games for the purpose of eradicating the speculation of the games through prohibition on direct charge system of the game and now is trying to even ban the indirect charge method. However not only the direct charge system but also the indirect charge system is a legal business model under the Promotion Act on Game Industry. There are 3 reasons: First, the web board game is essentially different from gambling. In order for the activity in question to be considered as gambling, it should meet all of the three requirements which are consideration, chance and prize. However, the game doesn't give prizes so that excludes it from gambling. Second, the deliberation about the prohibition on direct charge system of the game deviates from the limits of delegated legislation. Since the web board games do not fall under the purview of the concept of gambling, the deliberation is a subordinate to the Promotion Act on Game Industry, the deliberation itself may be in violation of the delegation range if the web board games are judged as operating illegally. Lastly, the prohibitions on the business model of the web board games transcend the constitutional limits of the regulations of games involving gambling and in the long run fringe constitutional rights. The essential cause of the problem surrounding online games is attributed to exchanging real money into game money outside the system of the game, not in the online web board game itself. Hence, impetuous regulation on indirect charge system of the web board games will substantially shrink the national online game industry, making other competitors from other nations enjoy the benefits.
        5,100원
        70.
        2013.05 구독 인증기관·개인회원 무료
        As the competition is globalized, companies are building the Factory automation system for increment of management effectiveness and growth of productivity as one of strategies for sustainable growth. But most of companies undergoes various trials and errors due to carrying forward without elaborate preparation of factory automation. To reduce these trials and errors, there must be a project team consist of clears project basic and experts. otherwise to consult a expert is a way to reduce trials and errors. In this study, I tried to verify what factors affect to effective building distribution automation system which is a branch of factory automation system and studied consulting model for building Material Handling Automation System utilizing Stage Gate Process which is product development process. This paper summarizes master's thesis.
        73.
        2013.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근 몇 년간 에너지 위기에 대한 우려가 급격히 증가하고 있으며, 방대한 에너지소비에 따른 환경오염도 큰 문제로 대두되고 있다. 사회적으로 에너지 위기가 고조되고 있는 가운데 새로운 에너지나 신재생에너지에 대한 관심이 증가하고 있다. 본 연구는 이러한 문제를 해결하기 위한 하나의 해결책으로 양어장 등에서 사용되는 폭기장치를 구동하기 위한 에너지를 자연으로부터 얻을 수 있는 가능성을 타진해 본 연구이다. 연구의 목적은 풍력에너지를 이용한 폭기장치의 개발에 있으며, 다양한 풍속 및 수풍면적에 대한 풍력폭기장치의 가능성을 살펴보고 있다. 또한, 최대의 효율을 얻을 수 있는 풍력펌프의 각도에 대한 토출구의 높이를 유도하여 유사한 장치의 설계에 있어 도움을 줄 수 있는 데이터를 제공하고 있다.
        4,000원
        74.
        2012.12 구독 인증기관 무료, 개인회원 유료
        Songji lagoon, one of the major lagoons located along the East coast, is considered to be worth preserving because of its good water quality. To consider ways to manage the water quality of Songji lagoon, this study was conducted by employing the analysis technique for system analysis of the water quality model. This study used WASP model which is a model with hydraulic part and water quality part combined. The model for Songji lagoon used the same value as the coefficients of water quality reaction used for Hwajinpo model. And it was revised and verified with the water quality measured in Songji lagoon. The spatial concentration of water quality of Songji lagoon and Hwajin po exhibited different distribution respectively, yet showing a similar characteristic in physical and water side structure. The major water quality items used in system analysis are BOD, limiting nutrients (N, P). The principal conditions reflected the system analysis are an increase or decrease of Allochthonous pollution load and removal of sediment. The study results show that the water quality of Songji lagoon is considerably changed more in sediment than Allochthonous pollution load. Especially, the management of Nonpoint pollution due to a temporary rainfall is more important among allochthonous pollution load.
        4,000원
        75.
        2012.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: This paper evaluates, using LS/DYNA-3D software, the vehicle impact performance of flexible barriers made of steel WBeam supported by four different types of post configurations. These types include circular post, H-shape post, C-shape post, and square post. METHODS : The post-soil interaction has been investigated according to different impact angles. For this purpose, energy absorption, maximum displacements of post and rail, and occupant risk index of THIV have been compared each other. The three dimensional soil material model, instead of the conventional spring model based on Winkler and p-y curve, has been used to increase the correctness of computational model. RESULTS: It is noted the crash energy absorption has been increased with respect to the increase of impact angle. CONCLUSIONS : In particular, a post with open section(H-shape, C-shape) shows the greater crash energy absorption capability as compared with a post with closed section under the same level of impact conditions.
        4,000원
        76.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        풍동시험에서 지지 장치는 모델을 고정하고 원하는 받음각을 구현하기 위해 사용되지만, 지지 장치가 모델에 작용하는 유동에 간섭효과를 발생시키게 되므로 이에 대한 평가와 보정이 수행되어야 한다. 본 연구에서는 스포츠급 경항공기 1/5 축소 모델의 전기체와 동체 형상에 적용된 배면스팅-반달형 지지장치의 유동간섭 효과를 더미 스팅 방법을 이용하여 공력의 변화를 측정하여 정량적으로 분석하였다. 풍동실험 결과, 하방 스팅의 유동간섭은 전기체 형상의 경우 양력계수에는 2.8%, 항력계수에는 3.4%의 영향을 끼치는 것으로 확인되었다.
        4,000원
        77.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The important elements and conditions to improve corporate competitiveness are customer development, new product development, sales increase, net profit increase, and other factors. Even if those competitiveness elements are well prepared, obstacles may exist. In this paper, we examined the risk, the deadliest obstacle that can affect corporate. We selected the risk factors that exist in functional categories in the system connected complicatedly and variously by organizational value chain of corporate, and examined the conceptual model of Enterprise Risk Management System based on the precedent studies.
        4,000원
        78.
        2012.04 구독 인증기관 무료, 개인회원 유료
        A fundamental concepts of business environment changes and the importance of stakeholder's value creation is changing in the business. This study ISO9004: 2009 quality management system of Category 5: Strategy and Policy, Category 10: improvement, innovation and learning (Note) SBK target was to develop a model that is the company's sustained success. Three concepts of the new revision of ISO9004 "in response to environmental changes," "learning", "innovation" (Note) SBK applied to the project settings and talent establish long-term vision was to establish the process as the organization's learning content was TDR for the creation of exceptional and innovative programs were introduced. As a result, (Note) SBK three years of continuous business performance indicator has grown dramatically to more than 50% continued success is going to create business models. But 100 years to accomplish the vision, ISO9004 model needs to extends the entire category as a management system to achieve the optimization needed.
        5,100원
        79.
        2012.03 구독 인증기관 무료, 개인회원 유료
        Recent projects for transferring Public Office buildings and estimation of appropriate construction expense are highly important for both government and construction firms. Moreover, estimation and management of construction expense can be regarded as extremely important duties for effective execution of a national budget as nation’s finance is invested in the Public office building projects progressed by the government. To progress one project for Public office building, not only the organization demanding the project but also an investment screening organization, a budget-managing organization, a feasibility assessment institution and many other related organizations participate in the project and a lot of decisions arisen from the project operation are made on the basis of construction expenses calculated for relevant stages. And estimation of rational construction expense is also critical for designers in order to create design within the fixed budget simultaneously with securing the quality and efficiency of structures to the maximum. Therefore this research suggested an improvement process to analyze problems in current construction expense management process and to administer the construction expenses effectively.
        4,000원
        80.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        기초자료의 획득 체계 및 가공 체계의 부재와 복잡한 사용자 입력 체계로 인해서 유출유 확산 예측 모델의 활용에 제약이 따른다. 이러한 상황에서 유류오염사고에 신속하게 대응하기 위한 과학적 방제 전략 수립은 어렵다. 본 연구에서는 현재 실정을 고려하여 유출유 확산 예측 모델 구동을 위한 최선의 상시 활용 체계를 수립하였다. 모든 기초자료를 직접 구축하고 관리하는 것이 불가능하기 때문에 외부 기관의 실시간 동적 자료를 연계하고 최소한의 데이터베이스만을 직접 구축하여 실시간 유출유 확산 예측의 상시 활용이 가능함을 확인하였다. 또한 사용자와 모델간 인터페이스부분에서 발생하는 오류를 최소화하는 사용자 입력 인터페이스와 모델 연산 결과를 시공간 측면에서 다차원적으로 분석할 수 있는 결과 표출 인터페이스를 제안하였다. 본 연구 결과로 구축된 유출유 확산 예측 모델의 상시 운용 체계는 외부 자료에 의존하기 때문에 모델 결과의 불확실성이 존재하지만, 유류오염사고 발생시 신속하게 모델을 구동하여 유출유 확산 예측을 수행할 수 있다는 측면에서 실제 방제 현장에서 의미있게 활용될 수 있다.
        4,000원
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