• Journal of the Society of Naval Architects of Korea
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• v.50 no.5
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• pp.334-342
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• 2013

In this paper, we analyze the procedure of the design manager for the enhancement of the hull production design process by use of the simulation method. Normally, design manager assigns design jobs according to various methods and estimates the corresponding results. When the construction drawing which is the output of the detail design where a design is dealt by zones, the design manager identifies blocks and analyzes their work difficulties, and assigns jobs to design engineers who are different in capabilities. These processes including the design engineer who can be modeled with man-hours evaluation model are represented in detail as a simulation model. As the high-level modeling for the discrete-event system, we use Event Graph model. And we implemented the simulation using Simkit which is open simulation engine for the discrete-event system. We made the simulation scenario to be written by a user in the scenario generator which is separated from the simulation model, and made the simulation result to be visualized in the form of Gantt chart in a Web. In the scenario of the irregular issuance for various construction drawings which contain different numbers of blocks, we performed the Monte-Carlo simulation according to various assignment methods to find the assignment result that satisfies the mid-term schedule.

• Journal of the Economic Geographical Society of Korea
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• v.1 no.1
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• pp.137-149
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• 1998

It is likely that the spatial structure of the intraurban accessibility as well as the accessibility value of each of the nodes in the subway network is affected by the addition of new linkages. The changes in the accessibility at individual nodes also affect the accessibility in the surrounding areas at some distances away from the nodes. Graph-theoretic algorithms have been developed as a proper measurement scheme for the nodal accessibility in tracked transport networks such as subway networks. However, the graph-theoretic measurements have limitations to estimate the spatial diffusion effect on the surrounding areas. This study proposes a new model for the spatial diffusion effect estimation of nodal accessibility increment in the subway network toward the surrounding areas. Since the distance decay trend of subway station use reflect the spatial diffusion effect of the accessibility of subway station toward the surrounding area. The model is deduced from the subway station use density function which is formulated by the questionnaire survey data.

• Journal of the Korean School Mathematics Society
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• v.6 no.1
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• pp.163-175
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• 2003

The research was aimed to find a special quality to the mathematical concept development using a graphing calculator in the collaborative learning. I could observe the process in which the students had formed the generalized and abstract mathematical concepts after they were given different concepts. I \ulcorner-Iso observed the characteristics of how they started with a vague syncretic conglomeration and approached to the complicated thoughts and genuine concepts. The advance of the collection type was achieved in the process of teacher's confirming of what the students had observed with a calculator. The language and the instrument were used in order for students to control the partial process. Also, they were given similar types of problems to make them clear when the students confronted 'the crisis of thoughts' at the level of pseudo-concept.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.3
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• pp.263-269
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• 2014

Flight test data visualization functions can improve an understanding of flight test results, test procedures, and the performance of a flight vehicle after flight tests. FlyingView was developed for researchers to analyse flight test data in a 3D virtual environment. It also can display X-Y plots using flight test data. It was developed and applied to flight tests of an air-to-ground weapon system of ADD. This paper describes the capabilities of FlyingView.

• Journal of the Korean Institute of Intelligent Systems
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• v.9 no.4
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• pp.451-456
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• 1999

All the teaching items in a textbook are normally arranged in a prescribed teaching order. However, one can easily find that the textbooks of the same kind, even with the same teaching items, show different arrangements. Without learning preceding teaching items, students may have a difficulty in understanding the teaching items. In this sense, it is very important to decide how to arrange teaching items in terms of teaching sequence. As a solution to this problem, lsamu Matsubara presents a method based on the graph theory. The four types defined in his method are the straight type, the group type, the branch type, and the independent type. Among these, the three types except the straight type lack the objectivity. An objective solution to these three types, based on the fuzzy theory. is propopsed in this paper.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.8 s.179
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• pp.2131-2142
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• 2000

As recent production facilities are usually operated with unmanned material-handling system, the development of an efficient schedule with deadlock avoidance becomes a critical problem. Related researches on deadlock avoidance usually focus on real-time control of manufacturing system using deadlock avoidance policy. But little off-line optimization of deadlock-free schedule has been reported. This paper presents an optimization method for deadlock-free scheduling for Job-Shop system with no buffer. The deadlock-free schedule is acquired by the procedure that generates candidate lists of waiting operations, and applies a deadlock avoidance policy. To verify the proposed approach, simulation resultsare presented for minimizing makespan in three problem types. According to the simulation results the effect of each deadlock avoidance policy is dependent on the type of problem. When the proposed LOEM (Last Operation Exclusion Method) is employed, computing time for optimization as well as makespan is reduced.

• Journal of Educational Research in Mathematics
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• v.9 no.1
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• pp.167-181
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• 1999

The aim of this study is to investigate the influence of graphic calculator in the teaming of function of the underachieved students in the second grade of middle school. Under this purpose of the study, we devised the instruction-plan which incorporates the using of graphic calculator into the traditional paper-and-pencil teaming environments, and executed the function-instruction with the underachieved students according to the devised instruction-plan. During the lesson hours, we observed and analysed the contributions and the carefulness of using graphic calculator in the learning of function of the underachieved students. Furthermore, we carried out the pre-test and the post-test to examine the effects of using graphic calculator in the learning of function of the underachieved students.

• Journal of Korea Society of Digital Industry and Information Management
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• v.17 no.3
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• pp.27-37
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• 2021

Highly informative heuristics in AI planning can help to a more efficient search a solutions. However, in general, to obtain informative heuristics from planning problem specifications requires a lot of computational effort. To address this problem, we propose a Partial Planning Graph(PPG) and Mixed Heuristics for solving planning problems more efficiently. The PPG is an improved graph to be applied to can find a partial heuristic value for each goal condition from the relaxed planning graph which is a means to get heuristics to solve planning problems. Mixed Heuristics using PPG requires size of each graph is relatively small and less computational effort as a partial plan generated for each goal condition compared to the existing planning graph. Mixed Heuristics using PPG can find partial interactions for each goal conditions in an effective way, then consider them in order to estimate the goal state heuristics. Therefore Mixed Heuristics can not only find interactions for each goal conditions more less computational effort, but also have high accuracy of heuristics than the existing max and additive heuristics. In this paper, we present the PPG and the algorithm for computing Mixed Heuristics, and then explain analysis to accuracy and the efficiency of the Mixed Heuristics.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.91-91
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• 2021

최근 기후변화로 인한 국지성 집중호우 증가로 인한 돌발홍수와 강수일수는 감소하고 강수량의 계절적·지역적 편중현상이 심화하여 가뭄의 발생빈도 및 기간이 증가하고 있다. 특히 가뭄에 따른 환경학적 피해로 하천유량의 감소와 더불어 영양물질의 부화로 인해 하천의 수질악화를 야기할 수 있다. 또한 집중호우로 인한 비점오염원 유입이 취약한 유역인 경우 장기적으로 부영양화를 초래하고 지속적인 오염원 축적을 통한 수질오염 특성을 나타낼 수 있다. 따라서 유역별 유량조건에 따른 수질오염원 특성을 파악하고 맞춤형 수질관리를 위한 유역평가방안이 필요한 실정이다. 본 연구에서는 낙동강수계 22개 중권역을 대상으로 요인분석을 실시하여 중권역별 맞춤형 수질관리를 위한 유역진단을 실시하였다. 유역유출모형인 HSPF을 통해 산정된 기준유량을 기준으로 저유량, 고유량 시기를 구분하여 분석하였다. 요인분석 결과값인 각 요인별 수질변동특성을 요인분석 네트워크 그래프를 활용해서 수질변동특성을 분석하고, 유황별 수질환경적 오염원 영향인자들을 파악하였다. 그리고 중권역별 하천 유량조건에 따라 어떠한 오염원에 기인하는지 분류하고 평가하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.160-160
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• 2021

과거 대규모 댐 건설 등 물 개발 중심에서 벗어나 효율적이고, 균형 잡힌 물관리 중심으로 '물관리 패러다임'이 변화되고 있다. 물관리 일부인 수질은 생활하수, 산업폐수, 농·축산 폐수에 의해 하천 및 호소 오염의 심각성이 대두되어, 수질 개선에 관한 연구가 진행되고 있다. 한강 유역은 한강, 남한강, 북한강 등 여러 수계로 구성되어 있으며, 서울을 포함한 주요 도시지역을 포함하고 있다. 한강 유역은 도시 및 농촌지역이 혼재되어 있으며, 도시지역의 경우 수변구역이 주민생활과 밀접한 유역이 많다. 한강대권역관리계획, 지자체별 총량제도를 통하여 관리를 하고 있으나, 각각의 유역별 특성이 다양하여 여러 이슈와 환경적 문제점이 발생하고 있어 유역에 적합한 수질개선 방안이 필요한 실정이다. 국내에서는 수질오염총량제도를 통해 수계의 수질을 관리하고 있지만, 오염물질의 부하량을 기준으로 수립하여 데이터의 다양성을 나타내기에 한계가 있다. 본 연구에서는 하천의 수계를 단위유역 단위가 아닌 중권역 단위로 구분하여 수질 인자의 농도를 활용하여 인자 간의 관계가 하천에 주는 영향을 보고자 한다. 수질 측정망에서 수집된 수질 데이터를 활용하여 여러 기법의 데이터 분석을 통해 한강 유역 수질의 특성과 경향을 시각화 그래프로 나타낸 결과를 토대로 유역특성을 반영한 수질 개선방안을 도출하고자 한다.