• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.205-215
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• 2008

As static traffic assignment has reached its limitation with ITS policy applications and due to the increase of interest in studies of ITS policies since the late 1980's, dynamic traffic assignment has been considered a tool to overcome such limitations. This study used the Dynameq program, which simulates route choice behavior by macroscopic modeling and dynamic network loading and traffic flow by microscopic modeling in consideration of the feasibility of the analysis of practical traffic policy. The essence of this study is to evaluate the feasibility for analysis in practical transportation policy of using the dynamic traffic assignment technique. The study involves the verification of the values estimated from the dynamic traffic assignment with South Korea's expressway network and dynamic O/D data by comparing results with observed link traffic volumes. This study used dynamic O/D data between each toll booth, which can be accurately obtained from the highway Toll Collection System. Then, as an example of its application, exclusive bus-lane policies were analyzed with the dynamic traffic assignment model while considering hourly variations.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.1
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• pp.12-17
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• 2007

This study was conducted to evaluate the characteristics of nonpoint source pollutants discharge from a small rural watershed. A typical rural area in Gongju City, Korea, was selected as the research site. Water quality and quantity in streams and rainfall samples were analyzed periodically from May to October 2005. Pollutant loads were estimated from a nonpoint source pollution model (AvSWAT, Arcview Soil and Water Assessment Tool). During the rainy season, from June 26 to 30 September 2005 and the dry season, before 26 June and after 30 September 2005, biological oxygen demands and chemical oxygen demands accounted for 91.3% and 93.7% of annual load, respectively, while total-N and total-P were 97.1% and 91.1% of annual load, respectively. The observed stream flow was $66.5m^3sec^{-1}$, while simulation stream flow was $66.2m^3sec^{-1}$. That can be assumed that simulation can be used to estimate the stream flow without practical measurement. However, the runoff trend following the occurrence of a storm event was not recorded properly.

• The Journal of the Korea Contents Association
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• v.21 no.10
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• pp.90-102
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• 2021

Technology evaluation is to assess the ability of technology commercialization entities to generate profits by using the subject technology, and domestic technology evaluation agencies have established and implemented their own evaluation systems. In particular, the recently developed technology evaluation model in the fields of marine and fishery does not sufficiently reflect the poor environment for technology development compared to other industries, so it does not pass the level of T4 rating, which is considered appropriate for investment. This is recognized as a challenge that occurs when the common evaluation indicators and evaluation scales used in other industries, and when the scoring system for T1 to T10 grading is similarly or identically utilized. Therefore, through this study, we intend to secure the appropriateness and reliability of the results of the comprehensive rating calculation by developing technology evaluation models and indicators that well explain the nine marine and fisheries industry classification systems. Based on KED and technology evaluation case data, AHP-based index weighting and Monte Carlo simulation-based rating system are applied and the results of case studies are verified. Through the proposed model, we aim to enhance the usability of R&D and commercialization support programs based on fast, convenient and objective evaluation results by applying to upcoming technology evaluation cases.

• Journal of Navigation and Port Research
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• v.47 no.6
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• pp.305-314
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• 2023

In this study, a mathematical model of a 9.77 G/T small fishing vessel was established based on captive model tests. The powering and manoeuvring performances of the vessel in the harbor and coastal sea were focused on, so captive model tests were conducted up to the full-scale speed of 8 knots. Propeller open water, resistance, and self-propulsion tests of a 1/3.5-scaled model ship were performed in a towing tank, and the full-scale powering performance was predicted. Hydrodynamic coefficients in the mathematical model were obtained by rudder open water, horizontal planar motion mechanism tests of the same model ship. In particular, in static drift and pure yaw tests which were conducted at a speed of 2 to 8 knots, the linear hydrodynamic coefficients varied with the ship speed. The effect of the ship speed on the linear coefficients was considered in the mathematical model, and manoeuvring motions, such as turning circles and zig-zags, were simulated with various approach speeds and analyzed.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.411-416
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• 2003

다목적 대형 댐의 건설로 수몰된 과거의 삶의 공간을 20년이 지나서 다시 복원한다는 것은 그곳에 살던 실향민 등에게는 참으로 반가운 소식이다. 본 연구에서는 1980년대 초에 완공된 충주댐으로 인하여 물 속에 잠긴 청풍 지구를 수몰이전의 입체 지형 공간적으로 원형복원하기 위한 원격탐사 기법을 적용한 것이다. 비교적 해상도가 좋은 인공위성 사진자료와 원격탐지된 디지털 영상자료를 수집하고, 수몰직전에 제작된 지형도를 이용하여 위성영상자료의 통합 적용하여 수몰이전의 지형공간정보를 현재시간으로 영상 복원하는 실험을 한 것이다. 이를 위하여 지형도에서 추출한 등고선과 현재의 등고선과의 접목을 통하여 청풍 주변지역을 중심으로 당시의 수치표고모형을 생성하였다. 또한 이를 입체적으로 보여주기 위한 투시조감도를 각 방향에서 생성함으로서 수몰이전의 아름다운 모습을 3차원적으로 영상복원 하였다. 좀더 가깝게 수몰마을을 보기 위한 최근접 시뮬레이션 동영상을 제작하여 과거 기억 속의 고향을 찾아볼 수 있도록 한 것이다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.44
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• pp.153-161
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• 1997

This paper has proposed the modelling by simulation in order to evaluate the performance of process through discrete event simulation using SIMAN language in flexible manufacturing systems. The production system is assumed to be a job shop type of system under the batch production of discrete products. In this paper, the input data is the workstation(process) time, the number of workstation(process), a probability distribution, the number of simulation runs. Also, transient period is considered. In the case study, this paper deals with three products in real flexible manufacturing systems. Finally, a number of simulation runs were executed under different experimental conditions to obtain preliminary statistics on the following performance measures: operating rate of facility and average system operating rate, transient period, central processing unit, average system throughput, and average waiting time in queues.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1241-1245
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• 2011

High RAM performance and efficient operation plan and maintenance equipment and policies are needed for improving the system availability performance such as punctuality and schedule adherence while reducing life cycle cost. Because railway systems are repairable, complex and have multi-echelon maintenance support structure, it is much complicated to set RAM performance targets and operation and maintenance plan. It is not easy to solve these problem by mathematical method and simulation can be consider for them. This article suggests the conceptual simulation model for analysing availability of railway system which has complex system structure and operation/maintenance environment.

• Journal of Biosystems Engineering
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• v.13 no.4
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• pp.30-37
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• 1988

A mathematical model was developed and programmed for computer simulation of a prototype hot water boiler system with rice hull furnace to predict the temperature distributions in the rice hull furnace and water tank, mass flow rate of hot water and thermal efficiency of the system under various operation and design conditions. The effects of feed rate of rice hull, thickness of the furnace wall, the type of heat exchanger, diameter of the water circulation pipe, etc, on the performance of the system can be evaluated with this model. The validity and simulation results of this model will be published in the next paper.

• KDI Journal of Economic Policy
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• v.11 no.3
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• pp.131-146
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• 1989

본고(本稿)에서는 가계(家計)의 저축행태(貯蓄行態)가 일생적기(一生適期)(life cycle)에 걸쳐 연령(年齡)-자산관계(資産關係)(age-wealth profile)를 통해 어떻게 나타나는가를 이론적으로 그리고 미시적(微視的) 시뮬레이션의 결과로 살펴보았다. 본고(本稿)에서는 기존의 Ando-Modigliani의 모형(模型)에 성인상당수(成人相當數)라는 개념(槪念)을 도입(導入), 무자녀가구(無子女家口)와 유자녀가구(有子女家口) 사이에 자산저축경로(資産著畜經路)의 차이가 존재함을 밝혔다. 즉, 유자녀가구(有子女家口)의 경우, 자녀의 교육비를 지원함으로써-좀 더 정확히 표현하면 또다른 형태의 세대간교부(世代間交付)(intergenerational transfer)라고 할 수 있는 자녀의 인적자산형성(人的資産形成)에 투자함으로써-소비(消費)가 이 시기에 급상승하게 되고 따라서 자산저축(資産著畜)이 무자녀가구(無子女家口)의 경우보다 완만해질 수 있음을 밝혔다.

• Electrical & Electronic Materials
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• v.4 no.1
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• pp.31-37
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• 1991

습도센서용 기판으로 사용하기 위한 MgFe$_{2}$O$_{4}$ 세라믹스의 성능개선을 위하여 Li$_{2}$CO$_{3}$와 V$_{2}$O$_{5}$를 첨가한 MgFe$_{2}$O$_{4}$-LiMgVO$_{4}$ 세라믹스를 만들고, 기공율, 기공분포, 센서특성, 응답속도 등을 조사하여 다음의 결과를 얻었다. 기공율은 MgFe$_{2}$O$_{4}$ 세라믹스가 29[%]에서 34[%]인데 비하여 본 연구결과는 34.5[%]에서 39[%]로 증가하였으며 센서특성은 $10^{7}$ [.OMEGA.] 단위의 변화에서 $10^{7}$ [.OMEGA.]에서 $10^{6}$[.OMEGA.] 단위로 변화함을 알수 있었고 응답속도는 10초정도 빨라졌음을 알수 있었다. 또한 기공분포를 이용하여 모형 센서를 제안하여 시뮬레이션을 하고 실제 특성과 이론적인 특성을 비교하였다.