• 한국시뮬레이션학회논문지
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• 제10권1호
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• pp.1-12
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• 2001

This article describes the application of discrete event simulation in a process industry (coffee manufacturing) as a daily production-scheduling tool. A large number of end products (around 300), sporadic demand, and limited shelf life of coffee (90 days) make it difficult to generate feasible production schedules manually. To solve this problem, an integrated system was developed incorporating discrete event simulation methodology into scheduling process. The integrated system is comprised of two components: a scheduling program and a simulation model. The scheduling program is used to generate daily schedules for roasting, grinding, and packing coffee. The simulation model uses the generated schedules to simulate the production of coffee and regenerates a modified production schedule. In this paper, each of the components will be described in detail, evaluated in terms of performance factors, and validated with a set of real production data. Although this article focuses on a specific system, we will share our experiences and Intuitions gained and encourage other process industries to develop simulation-based scheduling tools.

• 한국물환경학회지
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• 제21권6호
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• pp.617-623
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• 2005

Forestry and agricultural land uses constitute 85% of Korea and these land uses are typically mixed in many watersheds. Biological Oxygen Demand (BOD) concentration is a primary factor for managing water qualities of the water resources in Korea. BOD loadings from diffuse sources, however, not well monitored yet. This study aims to assess BOD loadings from diffuse sources and their affecting factors to conserve quality of water resources. Event Mean Concentration (EMC) of BOD was calculated based on the monitoring data of forty rainfall events at four agricultural-forestry watersheds. Exceedence cumulative probability of BOD EMCs were plotted to show agricultural activities in a watershed impacts on the magnitude of EMCs. Prediction equation for each rainfall event was proposed to estimate BOD EMCs: $EMC_{BOD}(mg/L)=EXP(0.413+0.0000001157{\times}$(discharged runoff volume in $m^3$)+0.018${\times}$(ratio of agricultural land use to total watershed area).

• 한국정밀공학회지
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• 제32권1호
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• pp.17-24
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• 2015

Smart factory requires 4 Zero factors including Zero Waiting-time, Zero Inventory, Zero Defect, Zero Down-time) that needs IT convergence for production resources of 4M1E(Man, Machine, Material, Method, Energy) in real time and event processing in all type of manufacturing enterprises. This paper will be explaining about core emerging production IT convergence technologies including cyber device security, 4M1E integration, real time event driven architecture, common platform of manufacturing standard applications, smart factory to-be model for small and medium manufacturing enterprises.

• 공학교육연구
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• 제17권3호
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• pp.34-41
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• 2014

In distance education, use of proper software tools can greatly enhance student's attention and learning efficiency. In such software tools, offering diverse multimedia information is one of the most critical factors. However, integration and synchronization of the various media types has been relatively difficult parts of implementation. This paper proposes a prototype system that uses a metafile and event handling mechanism for the uniform treatment of various media types. This event-level integration and synchronization of multimedia makes the implementation relatively simple. With this approach, instructor's behaviors are automatically recorded, and the instructors can freely choose and show any type of multimedia contents while lecturing. Current commercial or non-commercial lecture management systems could incorporate this approach, so that the distance education market could be expanded with richer multimedia contents.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1499-1504
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• 2008

This study shows risk-based evaluation results of casualty accidents for passengers, railway staffs and MOP(Member of public) on the national railway in South Korea. To evaluate risk of these accidents, the hazardous events and the hazardous factors were identified by the review of the accident history and engineering interpretation of the accident behavior. A probability evaluation model for each hazardous event which was based on the accident appearance scenario was developed by using the Fault Tree Analysis (FTA) technique. The probability for each hazardous event was evaluated from the historical data and structured expert judgment. In addition, the severity assessment model utilized by the Event Tree Analysis (ETA) technique was composed of the accident progress scenarios. And the severity for the hazardous events was estimated using fatalities and weighted injuries. The risk assessment model developed can be effectively utilized in defining the risk reduction measures in connection with the option analysis.

• 한국조경학회지
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• 제31권2호
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• pp.28-35
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• 2003

This study was conducted to identify the characteristics of social carrying capacity at mega-events, especially the 2000 Kwangju Biennale in Korea. In particular, this paper has proposed some management policies for mega events taking into account the relations between social carrying capacity, satisfaction and crowding. The research method was to look into the general characteristics and distributive forms of the location, and then to confirm the possibility of sampling the factors involved in satisfaction degree; last, A factor analysis for causal analysis of perceived crowding was performed. The study needed correlation analysis in order to compare expected crowding and perceived crowding, and performed regression to examine the causality of perceived crowding and satisfaction. The research results were as follows: the correlation of expected crowding, perceived crowding, and the total satisfaction was very low or meaningless. The relation between satisfaction and elements for factor analysis such as convenient facilities and value experience showed partial meaningfulness. The factors of convenient facilities, entrance fee, parking lot use, toilet convenience, and exhibit room use had meaningful results; on the other hand, the factors of value experience showed a meaningful result in the guide service of an event place. In conclusion when those holding an event make a basic project, they should consider management measures for convenience of facilities, proper education for guide service, and systematic guidance. Also, as a method for perceived crowding lower than expected crowding, the study has proposed that it is possible to lower expected crowding by providing appropriate information on the number of tourists expected on the weekends and weekdays. Future research should control variables such as personal characteristics, seasons proper for vacation and holidays, and carefully consider their investigation and design. Moreover, it is necessary to study variables involved in expected crowding of more various space-intensive sightseeing places (mesa-events).

• 마케팅과학연구
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• 제15권2호
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• pp.123-140
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• 2005

본 연구는 메가 이벤트 도입에 있어 지역주민들과의 갈등 원인과 거주민의 인구특성과의 관계 그리고 라이프스타일에 따른 주민들의 지각차이를 부정적 지각을 중심으로 도입저해 요인을 탐색하였다. 그 결과 자동차 경주 도입 거부요인으로 도시환경, 생활환경, 교육환경, 지역산업환경, 그리고 관광산업환경으로 나타났다. 이 중 교육환경과 도시환경이 가장 중요한 거부요인으로 밝혀졌다. 인구통계적 특성과 거주지 및 직장위치, 그리고 개인의 라이프스타일에 따라 자동차 경주 도입의 거부에 대한 지각이 다르게 나타났다. 또한 지역주민들이 우려하는 환경요인을 라이프스타일 유형에 따라 분석하여, 자아과다통제형, 자아탄력적통제형, 자아과소통제형에 따라 서로 상이한 지각이 행사됨을 밝혔다.

• 서비스연구
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• 제13권1호
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• pp.1-26
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• 2023

본 연구는 스마트공장 도입의 효과와 관련 요인을 분석하였다. 이를 위해 도입기업과 비도입기업의 표본 데이터를 median-size-industry matching method로 각각 110개, 325개를 수집했다. 도입 전년부터 도입 후 4년도까지 재무제표 데이터(ROA 등)를 활용했는데 event study method에 따른 abnormal operating performance, annual abnormal changes를 구한 뒤 Wilcoxon signed-rank test와 t-test로 분석했다. ROA와 매출증가율은 도입 후 단기적인 효과가 나타났으나 장기적으로 이어지지는 않았다. 또한 도입효과에 인력비중, 연구개발 수준, 이전 재무 성과 세 가지 요인이 조절효과로 영향이 있는지 회귀분석을 한 결과 연구개발 수준과 이전 재무 성과의 조절효과를 확인했다. 도입 효과에 도입시기의 영향과 이와 관련된 요인으로 이전 재무 성과와 기업규모의 조절효과가 있는지 회귀분석을 한 결과 장기에 도입시기가 늦을수록 도입효과가 더 커졌고, 이전 재무 성과와 기업규모의 조절효과를 확인했다.

• Nuclear Engineering and Technology
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• 제49권2호
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• pp.360-372
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• 2017

Many advanced reactor designs rely on passive systems to fulfill safety functions during accident sequences. These systems depend heavily on boundary conditions to induce a motive force, meaning the system can fail to operate as intended because of deviations in boundary conditions, rather than as the result of physical failures. Furthermore, passive systems may operate in intermediate or degraded modes. These factors make passive system operation difficult to characterize within a traditional probabilistic framework that only recognizes discrete operating modes and does not allow for the explicit consideration of time-dependent boundary conditions. Argonne National Laboratory has been examining various methodologies for assessing passive system reliability within a probabilistic risk assessment for a station blackout event at an advanced small modular reactor. This paper provides an overview of a passive system reliability demonstration analysis for an external event. Considering an earthquake with the possibility of site flooding, the analysis focuses on the behavior of the passive Reactor Cavity Cooling System following potential physical damage and system flooding. The assessment approach seeks to combine mechanistic and simulation-based methods to leverage the benefits of the simulation-based approach without the need to substantially deviate from conventional probabilistic risk assessment techniques. Although this study is presented as only an example analysis, the results appear to demonstrate a high level of reliability of the Reactor Cavity Cooling System (and the reactor system in general) for the postulated transient event.

• 한국안전학회지
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• 제24권3호
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• pp.79-87
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• 2009

The objective of this study is to develop accident scenario models for the risk assessment of railway casualty accidents. To develop these scenario models, hazardous events and hazardous factors were identified by gathering various accident reports and information. Then, the accident scenario models were built up. Each accident scenario model consists of an occurrence scenario model and a progress scenario model. The occurrence scenario refers to the occurrence process of the event before the hazardous event. The progress scenario means the progress process of the event after the hazardous event. To manage a large amount of accident/incident data and scenarios, a railway accident analysis information system was developed using railway accident scenario models. To test the feasibility of the developed scenario models, more than 800 domestic railway casualty accidents that occurred in 2004 and 2005 were investigated and quantitative and qualitative analyses were performed using the developed information system.