• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권3호
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• pp.205-213
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• 2011

Introduction: The enlargement and deformation of the orbit give rise to a visible enophthalmos. As a consequence, a disturbance of eye motility together with double images is likely to occur. This study examined the degree of enophthalmos according to the extent of orbital wall fracture and volume of herniated orbital tissue in blowout fractures of the medial and inferior orbital wall. Materials and Methods: This study was performed on patients diagnosed with medial and inferior orbital wall fractures at the Department of Oral and maxillofacial surgery, Chonbuk National University Hospital from 2007 to 2009. The patients' age, gender, etiology of fracture and degree of enophthalmos were investigated. The changes in the degree of enophthalomos, diplopia and ocular motility restriction after operation were examined. Results: The degree of enophthalomos increased with increasing extent of orbital wall fracture and volume of herniated orbital tissue. Conclusion: Whether to perform the operation is decided after measuring the extent of the orbital wall fracture and volume of herniated orbital tissue using computed tomography (CT), time for the decision of operation can be shortened. This can cause a decrease in the complications of orbital wall fractures.

• 한국항공운항학회지
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• 제27권2호
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• pp.47-53
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• 2019

The development of the aviation industry and the changes in the military operation mission environment are demanding more long - distance operation (long - time flight), and such a flying environment is a risk factor for fatigue - related accidents. For the aviation related organizations such as ICAO and FAA, fatigue risk management system (FRMS) are applied along with flight time restriction regulations to prevent fatigue related accidents. The most important process in FRMS is fatigue risk management. Fatigue risk management systematically manages fatigue through scientific fatigue risk data collection and fatigue risk assessment. The purpose of this study is to applicate the assessment of scientific fatigue risk management to pilots of airplanes engaged in long flight. We reviewed the current state of risk management and FRMS through previous research. We also developed fatigue risk management indicators and examined the validity of internationally recognized fatigue risk data collection methods and fatigue risk assessment tools. There are 134 mission (flight) data used for development. In order to verify the indicators, the fatigue risk score between the items was assigned through pair-wise comparison. In addition, the verify test results were normalized.

• 한국경영과학회지
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• 제24권4호
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• pp.63-80
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• 1999

In the container transportation of inland depots the empty container is an important issue. The truck dispatching problem in this paper is considered under restriction about empty containers. When a full container arrives in a depot by truck, after unloading operation the full container is changed to an empty container. After loading operation an empty container is changed to a full container. We suggest an integrated approach to the problem of simultaneously managing empty truck and container movements. We suggest an integrated approach to the problem of simultaneously managing empty truck and container movements. We would like to find the truck dispatching method minimizing empty truck movements and empty container movements. In this paper, a mixed integer programming model is developed to obtain the optimal truck dispatching in container transportation and heuristic is developed to give a good solution in much shorter time. The numerical examples are studied and the proposed heuristic is also compared with the result of numerical examples.

• 경영과학
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• 제28권1호
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• pp.107-116
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• 2011

The automated teller machine (ATM) is developed as a system to provide customers with an easy deposit and withdrawal of their money without time restriction and be served for 24 hours. Today, ATM is come up to the level of an unmanned branch. The automatic financing system is developed as an essential one for dealing with the rationalization of management and the globalization of financing in order to improve the efficiency of financial management work and increase the customer service quality. With reducing the operational cost of financial organizations through the efficient maintenance operation of ATM and increasing the service quality through the maximization of its processing efficiency, this study is to draw the scheme to ensure the competitiveness among the finance companies. The importance of ATM is highly recognized as the utilization of ATM is increased and the processing function is extended, but ATM is quite vulnerable to the malfunction occurred during the nighttime after banking hours. The ATM maintenance is done through consignment to the specialized maintenance company. The efficient operation of ATM maintenance work is important to the satisfaction of customer using ATM in the nighttime.

• 한국경제지리학회지
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• 제16권2호
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• pp.198-217
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• 2013

본 연구에서는 원격진료 이용자 행태를 시공간 재구조 관점에서 살펴보았고, 원격진료의 양면적 성격, 즉 확장성과 제약성에 관해 고찰하였다. 연구 결과에 의하면, 원격진료의 도입은 직접적인 온라인 서비스의 수혜자인 환자의 행태 변화에 영향을 끼치나, 이는 원격진료 이전의 일반적 의료 행태와 확연한 차이를 보인 것은 아니다. 이와 더해, 의원급 병원의 의료진 및 원격진료 최종 서비스 제공자인 토가네현립병원의 의료진의 행태에는 거의 영향을 주지 않는 것으로 나타났다. 원격진료의 도입으로 인해 의료기관에로의 접근성 및 효용성의 향상에 도움이 된 것은 사실이나, 여전히 원격진료는 최소한 한번 이상의 직접 진료를 요구하고 있고, 인간의 생명과 직접적으로 연계됨에도 불구하고 불완전한 기술적 특성을 가지고 있으며, 원격진료 이용에 있어서의 의사-환자, 의사 사이의 합의 문제로 인해 시공간적 제약성을 내포하게 된다. 결과적으로, 당초 원격진료가 처음 고안되었을 당시 많은 이용자들에게 주었던 기대감(확장성)과 달리, 오늘날의 원격진료는 시공간을 초월한 개념이라기보다는 기술, 사회, 문화, 경제 등의 다양한 요인으로 인해 제약성을 내포한 형태로 발전하고 있다고 할 수 있다.

• 대한전기학회논문지:시스템및제어부문D
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• 제55권1호
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• pp.24-30
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• 2006

The Controller Area Network (CAN) is being widely used for real-time control application and small-scale distributed computer controller systems. When the stuff bits are generated by bit-stuffing mechanism in the CAN network, it causes jitter including variations in response time and delay In order to eliminate this jitter, stuff bits must be controlled to minimize the response time and to reduce the variation of data transmission time. This paper proposes the method to reduce the stuff bits by restriction of available identifier and bit mask using exclusive OR operation. This da manipulation method are pretty useful to the real-time control strategy with respect to performance. However, the CAN may exhibit unfair behavior under heavy traffic conditions. When there are both high and low priority messages ready for transmission, the proposed precedence priority filtering method allows one low priority message to be exchanged between any two adjacent higher priority messages. In this way, the length of each transmission delays is upper bounded. These procedures are implemented as local controllers for the ISHURO(Inha Semvung Humanoid Robot).

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권11호
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• pp.532-537
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• 2006

Lightning induced faults accounts for more than 66% at the transmission lines of KEPCO. The lightning causes damages to power system equipments including transmission line, the blackout of electricity and the electro-magnetic interference. Because of this reason, we need the real time lightning information for the optimal operation of power system. And, it is required to obtain and accumulate the lightning current parameters for the insulation design. In 2005, KEPRI constructed a lightning detection network, the KLDNet (i.e. Kepco Lightning Detection & Information System) and launched a lightning information service for KEPCO customers. It is intended to provide data service on the operation of transmission lines and collect lightning-related data, which is the most important factor regulating power system design and operation. The new system will replace LPATS, the old detection system, which has been operating since 1995 and is rapidly failing in terms of both detection performance and location accuracy. The purpose of this paper is to explain the work performed and the results of that work in performing a site survey of several locations. The purpose of the site survey is to find locations acceptable for the installation of a lightning location receiver in support of a Lightning detection system(LDS). A restriction was placed on the surveyed locations, as they must belong to the Korea Electric Power Company. This requirement was made to facilitate the communication needs of the LDS network. Total of 15 sites were evaluated as possible LDS sensor sites. Some of the sites were rejected for physical reasons and therefore no electrical testing was performed. Of the 15 sites, total of 10 sites were considered acceptable and 5 sites were rejected for various reason. In this paper, we would like to explain the site survey and detection efficiency for LDS.

• 한국경영과학회지
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• 제23권2호
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• pp.47-65
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• 1998

We consider a multiperiod capacity planning problem for determining a mix of flexible and dedicated capacities under budget restriction. These capacities are controlled by purchasing flexible machines and/or new dedicated machines and disposing old dedicated machines. Acquisition and replacement schedules are determined and operations are assigned to the flexible or dedicated machines for the objective of minimizing the sum of discounted costs of acquisition and operation of flexible machines, new dedicated machines, and old dedicated machines. In this research, the Problem is formulated as a mixed integer linear Program and solved by a Lagrangian relaxation approach. A subgradient optimization method is employed to obtain lower bounds and a multiplier adjustment method is devised to improve the bounds. We develop a linear programming based Lagrangian heuristic algorithm to find a good feasible solution of the original problem. Results of tests on randomly generated test problems show that the algorithm gives relatively good solutions in a reasonable amount of computation time.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.430-434
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• 2001

Virtual manufacturing system is integrated computer model that represents the precise and whole structure of manufacturing system and simulates its physical and logical behavior in operation.[1] A virtual machine is computer model that represents a CNC machine tool and one of core elements of virtual manufacturing system. In this paper, it is emphasized that a virtual machine must be web-based system for serving information to all attendants in a real machine tool without the restriction of time or location, and then in the fault diagnosis, one of important modules of a virtual machine, the methods of both using the controller signal and web-based expert system are proposed.

• 산업경영시스템학회지
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• 제19권39호
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• pp.255-264
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• 1996

This Paper presents a heuristic algorithm for machine-part group formation considering part production information (Production volume, roution sequence, unit operation time, facility size) in cellular manufacturing logistics system. In general, factory space is restricted within limited size when cells are located. A twofold heuristic algorithm is developed for considering factory space restrictions of located cells. The first phase is a aggregation procedure to minimize inter cell movement for satisfactoring space restriction. The second phase is a rearrangement procedure to maximize line balancing efficiency between machines within the cell and non assigned machine during first phase. Numerical example is presented to verify the efficiency of proposed algorithm.