• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.1
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• pp.22-30
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• 2015

In this research, items and contents of SONAR were derived from investigation of OMS/MP of previously-operated submarines and domestic and international references related to weapon system. Such items and contents were established in detail and were categorized into four separate groups after consulting system design experts and specialists in the field of SONAR's operation. Ultimately, based on wartime and peacetime scenario and operation concept of SONAR, RAM values were obtained through various methods using submarine-operating records and maintenance records for the past eleven years.

• Journal of the Korean Society of Hazard Mitigation
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• v.3 no.2 s.9
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• pp.111-118
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• 2003

Korea High-Speed Railway has various safety systems to secure safe and stable transportation and makes assurance doubly sure to minimize casualty and property damage caused by natural disasters. But, there is no regulation that reflects domestic railway line, climate, topographical and geological characteristic in introducing the foreign regulations yet. Therefore, it is necessary for us to modify a regulation which is suitable to domestic high-speed railway. In this study, it is possible to establish more reasonable boundary rainfall by grasping and improving the troubles with existing boundary rainfall that is scheduled to be utilized for high-speed rail-transport operation control under rainfall. Also, it is possible to insure the safety of train by four steps such as 'normal operation', 'warning issue', 'train speed control' and 'train stop' using the established boundary rainfall. It will go far toward minimizing the occurrence of natural disasters.

• Advances in pediatric surgery
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• v.9 no.1
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• pp.1-5
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• 2003

Preauricular sinus and preauricular skin tag are common childhood congenital anomalies. It is important for the pediatric surgeon to be familiar with the embryology and differentiation of head and neck structure to accurately diagnose and treat these lesions. Seventy eight patients with preauricular sinus and twenty-eight with preauricular skin tag treated in the Department of Pediatric Surgery at Hanyang University Hospital from January 1981 to May 2002 were reviewed to determine relative frequency, clinical classification and appropriate treatment. The male to female ratio of preauricular sinus was 1:1.2, and preauricular skin tag was 1:1. The most commonly presenting age of sinus and skin tag was before 5 year (62.8%) and before 1 year (53.6%). Twenty nine of 78 cases of preauricular sinuses were on the left, 25 on the right and 24 bilateral. Signs of infection were seen in 73.0% of patients with preauricular sinus at operation. Only 31.3% of lesions were infected in patients less than one year of age, but 89.5% between 3-5 years and 100% between 5-8 years. Cartilage was present in five patients with preauricular skin tag. Although re-operation due to wound infection was necessary in four cases, no recurrences were found. The preauricular sinus is a common anomaly in childhood, and has had a relatively high recurrence rate. But most of the recurrences were due to incomplete resection because of combined infection. Initial proper diagnosis and early operation are very important. Identification of the exact anatomical location of sinus tract is necessary because total excision of the lesions including those tracts is the only way to prevent recurrence.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.556-558
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• 2004

In this paper, we introduce a new method of detecting faults for a power converter unit in Control Rod Control System. The faults of a power converter unit can exert harmful influence upon the operation of Control Rod Drive Mechanisms and the control of the reactor output. This situation makes the quick and correct detection of failures in a power converter unit very important. We devise a new method of fault detection for the digital power controller and improve the drawbacks of the existing fault detector.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.559-561
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• 2004

In this paper, we design two types of Main Control Unit for Control Rod Control System and Control Element Drive Mechanism Control System, respectively, using a domestic Distributed Control System(DCS) developed to localize the instrumentation and control(I&C) system for nuclear power plant(NPP). There are many parts developed by domestic skills and being operated successfully in NPP, but the development of I&C system as an essential part has been slow in progress. We will show the great possibility of developing peculiar Korean I&C system by applying this domestic DCS to nuclear I&C system and confirming its successful operation.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1704-1709
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• 2004

New reduced chemical kinetic mechanism for prediction of autoignition process of HSDI diesel engine was investigated. For precise prediction of the ignition characteristics of diesel fuel, mechanism coefficients were fitted by the experimental results of ignition delay of diesel spray in a constant volume vessel. Ignition delay of diesel engine on various operation condition was calculated based on the new reduced chemical mechanism. The calculation results agreed well with experimental data.

• Proceedings of the KIEE Conference
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• 2008.09a
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• pp.263-265
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• 2008

분산전원의 배전계통과 연계 시 역 조류, 전압변동, 고조파, 보호협조, 고장전류증가 등의 문제를 일으킬 수 있으므로 배전선로의 안정운전을 위해서는 배전선로의 원활한 보호협조를 통한 적절한 안정운전 방안이 필요하다. 따라서 본 연구에서는 분산형 전원이 연계된 배전계통에서의 리클로저와 변전소 릴레이와의 보호협조 측면에서 악영향을 끼치지 않는 분산형 전원의 연결을 OFFDAS 프로그램에 의하여 검토하여 더 효과적이고 용이한 방법으로 안정 운전할 수 있는 연계방안을 제시하고자 한다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.04c
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• pp.1-5
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• 2008

In this paper, we proposed that when combustible burn with ultraviolet radiation, introduce fire detector with sensor of private-use detectable light energy as ultraviolet in energy of electromagnetic-wave type radiate from flame. This research using ultraviolet flame sensor is pyro-electric ultraviolet sensor based black body radiation theory. To have high sensibility and to gain proper output voltage, it has high responsive performance. This research introduced UV flame detector and proposed method of false alarm reduced to resemble fire. the result proposed the prevention and extinction of fire technique degree, certificated operation of detector.

• International Journal of Precision Engineering and Manufacturing
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• v.3 no.4
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• pp.43-53
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• 2002

Polishing a die that has free-form surfaces is a time-consuming and tedious job, and requires a considerable amount of high-precision skill. In order to reduce the polishing time and cope with the shortage of skilled workers, a user-friendly automatic polishing system was developed. The polishing system is composed of two subsystems, a three-axis machining center and a two-axis polishing robot. The system has five degrees of freedom and is able to keep the polishing tool in a position normal to the die surface during operation. A sliding mode control algorithm with velocity compensation was proposed to reduce tracking errors. Trajectory tracking experiments showed that the tracking error can be reduced prominently by the proposed sliding mode control compared to a PD (proportional derivative) control. To evaluate the polishing performance of the polishing system and to and the optimal polishing conditions, the polishing experiments were conducted.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.290-291
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• 2006

HTS(High Temperature Superconductivity) Power Cable has a different characteristic with conventional distribution line, so installation and operation condition are different. In this paper, internal fault current characteristic s of HTS power cable was analyzed. For this, EMTDC model component of HTS power cable was developed. The developed EMTDC model component is applied to distribution line, then authors analyze internal current characteristics of HTS Power cable when fault occurred.