• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.638-645
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• 2007

Computers are increasingly being introduced into safety and reliability critical systems. The safe and reliable operation of these systems cannot be taken for granted. Malfunctions of these systems can have potentially catastrophic consequences and they have already been involved in serious accidents. Software fault prevention, fault tolerance, fault removal and fault forecasting are the techniques to be used, implemented and verified for embedded software in critical systems as the contributors to safety and reliability of the software. To use them when developing a software product, a relationship must be established between them and the development processes, the methods and techniques to be used to develop software, as well as with the different product architectures. Railroad signaling system software is a safety-critical embedded software with realtime and high reliability requirements. The primary purpose of the safety management is to prevent the loss of lives or physical damages arising from potential hazards in the railroad signaling system. This study provides a systematic approach to analysis of potential hazards for their management during the system life cycle to assure the identification and definition of the most appropriate hazards.

• 대한치과의사협회지
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• 제51권8호
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• pp.442-450
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• 2013

It is well known that the majority of dental injuries occur in children and adolescent. An injury to the teeth can have serious and long-term consequences, leading to their discoloration, malformation, or possible loss. The emotional impact of such an injury can be far reaching. The majority of dental injuries in the primary and permanent dentitions involve the anterior teeth, especially the maxillary central incisors. Concussion, subluxation, and luxation are the commonest injuries in the primary dentition, while uncomplicated crown fractures are commonest in the permanent dentition. If it is decided to preserve a traumatized primary tooth, it should be carefully observed for clinical and radiographic signs of pulpal or periodontal complications. Radiographs are also examined closely to disclose any damage to the permanent successor. The intervals between reexaminations should be individualized depending on the severity of trauma, the expected type of complications and the age of the patient. Most complications are observed within the first year of the trauma. However, the follow-up evaluation of permanent teeth should continue until treatment of all complications is completed, or until a lost or extracted permanent tooth has been adequately replaced. It is important that the dentist and the other members of the dental team are well prepared to meet the many complex and challenging problems in the care of dental emergencies.

• 한국전자파학회논문지
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• 제12권5호
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• pp.713-721
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• 2001

본 논문에서는 이미 설계된 기생 패치 구조와 적층 구조 광대역 마이크로스트립 안테나에 평행 결합 선로 형태의 광대역 임피던스 정합 회로를 결합하여 쉽게 추가적인 대역폭 증가를 이룰 수 있음을 제안하였다. 평행결합 선로 형태의 광대역 임피던스 정합 회로 설계를 위하여 분포 회로 방식의 반복적인 방법을 제시하였고, 설계.제작한 안테나의 측정 결과 기생 패치 구조와 적층 구조에서 각각 약 1.6배 1.5배의 추가적인 임피던스 대역폭 증가를 이룰 수 있었다. 그리고 방사 패턴과 측정된 이득을 보면 평행 결합 선로의 결합으로 인한 방산 패턴에서의 큰 변화는 보이지 않았지만, 이득에서는 평행 결합 선로 부분의 커플링 손실로 인해 최대 이득이 약 1 dB와 0.5 dB 정도 감소하는 것을 확인할 수 있었다.

• Asian Journal of Business Environment
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• 제8권1호
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• pp.7-15
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• 2018

Purpose -This paper is to study the process of the negative effects of Sino-foreign joint ventures, hoping to find out an effective path in which local enterprises can avoid the risks in the utilization of foreign capital, and ultimately achieve independent innovation. Research design, data, and methodology -The outflow of assets, the loss of local brands and the "technology hollowing-out" problem brought by joint ventures is becoming more and more serious. Based on conflict analysis graph model, this paper takes Yuhuan joint venture as an example to identify the conflict problem in Sino-foreign joint ventures. Results -The results of the stability analysis show that establishing joint venture cannot really realize the introduction of technology because the technology is fully controlled by the foreign part. So when introducing foreign capital, local enterprises should participate in R&D and master the initiative. Conclusions - Local enterprises should pay attention to patent containment and technology blockade of multinationals. Domestic enterprises should try to protect state-owned assets and local brands in Sino-foreign joint ventures. Independent innovation is the most effective strategy for the development of enterprises in China.

• 복합신소재구조학회 논문집
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• 제5권4호
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• pp.44-51
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• 2014

As the world energy consumption grows, the interest in marin energy resources is increasing. In excavating such resources, the marine riser which connects the floating structure and sea bed is an essential device. The riser system is often exposed to harsh ocean environment and thus vulnerable to damage. Since the failure of the riser system may cause serious economical loss as well as environmental problem, the structural integrity of the riser is very important. Generally, the riser is an extremely slender structure with a much smaller diameter than a length. Therefore, a structural integrity monitoring methodology for typical buildings and bridges may not be applicable. In this paper, the applicability of a damage identification method for a structure to a marine riser is examined via a numerical example. Also, recent research practices and findings for monitoring the behavior and the structural integrity of the marine riser are examined and summarized.

• 생물정신의학
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• 제5권2호
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• pp.197-209
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• 1998

In mordern society, nutritional and appetite disorders occur in epidemic proportions and are serious health harzards. Obesity and diabetes affect over 30% of American population, while eating disorders, such as anorexia nervosa and bulimia nervosa occur in a growing number of adolescences and young adults. The changes in various sociocultural aspects with the introduction of Westernized culture have had the effect of increasing the risk of same problems in Korea. Disorderd eating patterns are a primary symptom of numerous psychiatric disorders and loss of appetite and cachexia, during illness or in the elderly, preclude proper medical treatment for restoring good health or preserving life. Increased understanding of the systems of the body and brain, related to energy and nutrient balance, may help us to treatment and ultimately prevent these commom disorders. In this review, the author highlights the psychobiological mechanisms or factors which are associated with eating behavior, especially in the view of intake psychobiology. This review would be concentrated on 1) the theoretical concepts and theories of eating behavior ; 2) the psychobiological determinants of food intake ; and 3) the psychobiological control of eating behavior.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.179.1-179.1
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• 2014

Si nanowires have exhibited unique optical characteristics, including nano-antenna effects due to the guided mode resonance, significant optical absorption enhancement in wide wavelength and incident angle range due to resonant optical modes, graded refractive index, and scattering. Since Si poor optical absorption coefficient due to indirect bandgap, all such properties have stimulated proposal of new optoelectronic devices whose performance can surpass that of conventional planar devices. We have carried out finite-difference time-domain simulation studies to design optimal Si nanowire array for solar cell applications. Optical reflectance, transmission, and absorption can be calculated for nanowire arrays with various diameter, length, and period. From the absorption, maximum achievable photocurrent can be estimated. In real devices, serious recombination loss occurring at the surface states is known to limit the photovoltaic performance of the nanowire-based solar cells. In order to address such issue, we will discuss how the geometric parameters of the array can influence the spatial distribution of the optical field (resulting optical generation rate) in the nanowires.

• 전력전자학회논문지
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• 제22권4호
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• pp.345-352
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• 2017

In this paper, a non-dissipative snubber for reducing the switching losses in the step down converter is proposed. The conventional step down converter, e.g., buck converter, suffers from serious switching losses and consequentially heat generation because of its hard switching. Thus, it is unsuitable for high switching frequency operation. Reduction of the reactive components' size, such as an output inductor and capacitor, is difficult. The proposed snubber can slow down the increasing current slopes and switch voltage at turn-on and turn-off transients, thereby significantly reducing the switching loses. Additionally, the slowly increasing current during switch turn-on transition, can effectively solve the output rectifier diode reverse recovery problem. Therefore, the proposed non-dissipative snubber not only leads to the efficiency of converter operation at high switching frequency but also reduces the reactive components size in proportion to the switching frequency. To confirm the validity of the proposed circuit, theoretical analysis and experimental results from a 150 W, 1 MHz prototype are presented.

• 정신신체의학
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• 제19권1호
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• pp.15-19
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• 2011

알코올은 생물학적으로 피부부터 위장, 간장과 같은 장기와 말초 및 중추 신경계의 기능과 구조적 변화를 일으키며 그로 인하여 심리적, 생리적 의존과 함께 다양한 정신 장애를 일으킨다. 그리고 실직, 자살, 가정 내 폭력, 범죄 등의 사회적인 문제와 관련이 깊다. 이런 다양한 이유로 알코올 사용 장애는 타과로부터 흔하게 자문이 의뢰되어 조정되는 대표적인 정신신체 질환이다. 이에, 자문 조정 정신의학에서의 알코올 사용 장애의 유병률, 자문률 등의 현황을 살펴보고 알코올 상용장애 환자를 자문 조정하는 의사로서의 역할과 일반적인 원칙, 그리고 초기 치료 계획을 세울 때 고려해야 할 사항 등에 관하여 살펴보고자 한다.

• The Korean Journal of Pain
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• 제9권1호
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• pp.260-263
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• 1996

High spinal block is a rare complication during epidural block, but it may result in serious events. 56-year-old man with gall stones was scheduled for cholecystectomy under general anesthesia. After operation, lumbar epidural catheterization was done at $T_{8-9}$ interspace for postoperative pain control. At the recovery room, initial bolus drug (0.1% bupivacaine 10 ml containing fentanyl $100{\mu}g$) was administered via epidural catheter and observed carefully. 15 minutes later, hypotension and bradycardia ouccurred. Hartman' solution was administered rapidly and ephedrine 5 mg was injected. 30 minutes after drug administration, loss of consciousness and respiratory arrest developed. Tracheal intubation was done immediately. Cardiovascular and respiratory functions were monitored continuously. The location of intrathecal catheter was confirmed by cerebrospinal fluid (CSF) seen in syringe after aspiration of catheter. The patient recovered gradually and was placed in the ward 4 hours after drug administration, without any problems. He was discharged 1 week later in good health.