• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권5호
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• pp.507-513
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• 2000

Objective : The purpose of this study is to evaluate the vitality of the teeth in and adjacent to the mandibular fracture line according to variable conditions of fracture and to establish the protocol of treatment of fracture line teeth. Materials and Methods : The vitality of 97 teeth in fracture line and 104 teeth adjacent to fracture line of 52 patients were invested preoperatively. Of these, 66 teeth in fracture line and 72 teeth adjacent to fracture line were monitored at least 6 months after operation. An electric pulp tester was used to measure pulpal response. The relationships between the vitality of teeth in variable time(preoperation, immediate post-operation; within 1 week after operation, and 6 months after operation) and variable conditions of fracture(horizontal, vertical gap of fracture line, the number of fracture line)were evaluated statistically. Result : The vitality of fracture line teeth in the 6 months after operation statistically differed by the vertical gap of fracture line and the number of fracture line. The vitality of fracture line adjacent teeth in the immediate post-operation only statistically differed by the vertical gap of fracture line. There were statistically differences between preoperative EPT value and vitality of fracture line teeth on 6 months after operation. There were 5 cases of complications including periapical and periodontal abscess. Of these, only one tooth was extracted and the others were well treated with endodontic treatment and subgingival curettage. Conclusion : It is recommended to retain teeth and to monitor the vitality of teeth in and adjacent to fracture line, unless there is an absolute indication for extraction.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.693-698
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• 2001

This paper establishes a coding method system including the liberation and size distribution of recycling materials in the shredder operation. Every particle in the shredded product becomes a code number using the liberation model and size distribution equation transforming of weight percentage into particles number percentage. One set of database can be obtained after all particles have been coded. This database is suitable for the size reduction operation in the process simulation of waste recycling. Coupling with the developed air classification, sizing and separating operations, the whole process simulation will be completely established for diversified application. A typical simulation for the rolling cutting shredder product of waste TV had been demonstrated under this coding system. The breakage size distribution of Gaudin and Schumann equation were selected for the shredding operation simulation. The Gaudin's liberation model was suitable fur the liberation simulation. Both of these equations were transformed weight percentage into particles distribution for the necessary of particle coding method. A better recycling operation for this shredded solid waste can be concluded from the comparison of simulation results with their sorted grade, recovery or economic of materials in different processes.

• 대한전기학회논문지:전력기술부문A
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• 제51권6호
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• pp.290-295
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• 2002

The present assignment in installing the number of switches for distribution line was made on the basis of a normal feeder capacity 7,000kVA in KEPCO(Korea Electric Power Corporation), Korea. But the normal capacity is revised to 10000kVA in 1998. Even increasing limit of the operating capacity of the distribution lines enables us to give some benefit for the operation flexibility and investment cost of the distribution system. It is disadvantageous in the viewpoint of supply reliability. In distribution systems, switches are equipped to improve the reliability of distribution systems by minimizing the outage section due to fault and maintenance. Utility generally improves the reliability by minimizing the length of outage section, which is caused by fault and maintenance, through switch equipment on distribution system. In order to cope with the changes such as operation capacity, it is necessary to study whether the present criteria is reasonable or not, also to confirm whether the present criteria of installing switches in line is improved or not. In this study, we proposes the number of switch per feeder on the basis of present operation capacity in distribution system.

• 산업경영시스템학회지
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• 제47권2호
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• pp.190-197
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• 2024

By the recent fast growth of e-commerce markets, it has been stimulated to study order picking systems to improve their efficiency in distribution centers. Many companies and researchers have been developed various types of order picking systems and pursued the corresponding optimal operation policies. However, the performances of the systems with the optimal policies often depend on the structures of the centers and the operation environments. Based on a simulation model that mimics a unique zone picking system operated by a real company in the Republic of Korea, this study compares several operation policies and finds the most appropriate order selection rule and worker assignment policy for the system. Under all scenarios considered in this study, simulation results show that it is recommendable to assign more efficient workers to the zones with heavier workload. It also shows that selecting the order with the maximum number of non-repeatedly visited zones from the order list provides the most consistent and stable performances with respect to flow time, makespan, and utilization of the system even under the scenario with the breakdown zones. On the other hand, selecting the order with the minimum ratio of penalty to the number of zones performs the worst in all scenarios considered.

• 한국안전학회지
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• 제29권3호
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• pp.129-135
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• 2014

The number of abnormal operation procedures (AOPs) for mitigating a plant abnormal status amounts to about one hundreds for the most of 1000MWe optimized power plant (OPR1000) and it is expected that the number of AOPs would be increased to cope with an abnormal status occurred newly. However, it is not well organized for operators to select a proper AOP from alarms occurred in main control room (MCR) during a plant abnormal status. It may be a burden to operators since the selection of AOP to respond an abnormal status is authorized by operators. When multiple alarms occur in MCR, it would take more time to respond them than a single alarm. To reduce the efforts, various MCR operation support systems have been developed. The purpose of this study was to develop a multi-alarm pattern card to select an appropriate AOP effectively when multiple alarms occurs in a single upper layout (UL) of MCR. It can be applied for an operation support tool as well as an education tool.

• 한국환경과학회지
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• 제11권1호
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• pp.63-68
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• 2002

In this study, we examined statistical analysis between sewage plant operations parameters and effluent quality We got six components from principle component analysis of the operation parameters and secondary effluent quality. 91.8% of the total variance was explained by the six components. The components were identified in the following order : 1) organic matter removal by aeration basin microbe, 2) settleability on secondary clarifier load, 3) removal of nutrients, 4) microbial number increasement and species diversity, 5) microbial activity in aeration basin, 6) oxidation in aeration basin.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 춘계학술대회 논문집
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• pp.451-456
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• 2004

본 연구에서는 장치장 운영규칙의 현실성을 높이기 위해서 트랜스퍼 크레인의 작업운영체계를 분석하고 작업우선순위의 적용을 위한 운영규칙의 적용방법을 설명하였다. 또한 장치장에서 주행로의 특성에 따른 대기 및 주행로 점거형태를 분석하여 블록에 진입하여 대기할 수 있는 최대 대기차량수를 도출할 수 있는 산정식을 정리하고 공간의 제약상태를 분석하였다. 또한 공간의 제약사항 극복하기 위해서 공간자원을 정의할 수 있는 다작업원칙을 제시하고 그 원칙을 위한 해법과 순서도를 묘사하였다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2002년도 추계학술대회 및 정기총회
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• pp.41-45
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• 2002

From the paper which it sees a strong random number generator it uses a fuzzy set from 16 method of the statistical test which is a cryptograph random number test it verifies. 16 statistical test of NIST extends in crptograph and engineering whole it is a scale which is important distinguishes the distinction incapable characterstic of the random numbers which are used. To try introduce a fuzzy set the possibility of having a more strong randomness in order to be, it strengthens the function of the random number generator.

• 해양환경안전학회지
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• 제25권3호
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• pp.251-258
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• 2019

This study was conducted to propose an effective port operation method in terms of the design capacity of waiting anchorage by comparing the ratio and the number of waiting anchorage according to the port operation method of Busan New Port. For this, the Arena simulation program compared the rates of waiting vessels according to the application of the multi-user terminal, liner terminal and hybrid liner terminal operation methods. As a result, analysis suggested the necessary anchorage space can be reduced to about 18 % when using the multi-user terminal operation method and about 15.6 % when using the hybrid liner terminal operation method, as compared with the liner terminal operation method. Specifically, it was effective to apply the multi-user terminal operation method in terms of the anchorage capacity to be designated to Busan New Port. This study can apply to the designation of the new anchorage in the Busan New Port by reflecting the contents of the design of the anchorage in accordance with the port operation method.

• 대한교통학회지
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• 제23권2호
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• pp.131-142
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• 2005

버스 운행 정시성은 운행계획에 따라 정시에 운행하는 정도를 나타낸다. 이용자의 대기시간은 버스 운행의 정시성에 직접적으로 영향을 받기 때문에 정시성지표는 이용자 관점에서 버스 운행의 신뢰성을 평가하는 지료로 가장 널리 사용되는 평가척도 중 하나이다. 그러나 실제 버스 운행은 도로여건, 교통상황, 승객수요 등 여러 가지 상황에 의해 사전에 작성된 운행 계획을 준수하지 못하게 된다. 따라서 여러 가지 상황에 따라 버스 운행의 정시성을 평가할 수 있는 정시성 지표를 개발하여 제시한다. 또한 서울시에서 운행하는 여러 버스 노선의 운행 자료를 분석하여 정시성 지표를 산출하였으며 이를 통해 여러 가지 운행 여건에 따른 정시성지표의 변화 특성을 분석하였다.