• 전기학회논문지
• /
• 제62권6호
• /
• pp.881-885
• /
• 2013

In this paper, we present a deterioration judgment model of urban rail power equipment using driving history, the frequency and number of failures. In addition, we have developed a deterioration judgment program based on the derived failure rate. A deterioration judgment model of power equipments on metro system was designed to establish how much environmental factors, such as thermal cycling, humidity, overvoltage and partial discharge. The deterioration rate of the transformers followed the Arrhenius log life versus reciprocal Kelvin temperature (hotspot temperature) relation. The deterioration judgment program is linked to the online condition monitoring system of urban railway system. The deterioration judgment program is based on the user interface it is possible to apply immediately to the urban rail power equipment.

• 유체기계공업학회:학술대회논문집
• /
• 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
• /
• pp.391-396
• /
• 2003

A cross-flow fan relatively produces higher dynamic pressure at low speed because a working fluid passes through an impeller blade twice and blades have a forward curved shape. The performance of a cross-flow fan is influenced 25% by the impeller, 60% by the rearguider and the stabilizer, and 15% by the heat exchanger. At the low flow rate, there exist a rapid pressure head reduction, a noise increase and an unsteady flow against a stabilizer and a rearguider. The purpose of this study is to investigate the reciprocal relation among each parameter Experiments are conducted to study the effects of a rearguider and a diameter ratio of impeller on the performance analysis of a cross-flow fan. Comparing with the rearguider of radial type, the Archimedes type shows excellent results for various diameter ratios.

• 경영과정보연구
• /
• 제31권3호
• /
• pp.141-160
• /
• 2012

본 연구는 공급사슬의 네트워크 내재성의 관점에서 관계적 내재성을 중심으로 공급사슬과 성과와의 관계를 살펴보고자 한다. 이를 위해 관계적 내재성을 상호작용, 연계강도, 신뢰 그리고 상호의존성으로 제시하고 이들이 공급사슬의 기업관계 성과에 미치는 영향을 알아보았다. 이후 기업관계성과가 재무적 성과에 어떠한 영향을 미치는가를 살펴봄으로써 공급사슬 하에서 관계적 내재성과 성과와의 관계를 밝히는 것을 목적으로 한다. 가설검증결과 공급사슬의 관계적 내재성은 전반적으로 공급사슬의 성과에 영향을 미치는 것으로 나타났다. 공급사슬의 관계적 내재성 가운데에서도 특히 상호의존성과 신뢰, 그리고 연계강도가 높을수록 기업관계성과에 긍정적인 영향을 미치는 것으로 나타났는데, 이는 네트워크의 관계적 내재성이 높을수록 네트워크 내 구성원들 간의 관계성과가 높아진다는 기존의 연구와 일치함을 알아볼 수 있었다. 또한 공급사슬의 기업관계성과가 높으면 높을수록 공급사슬의 재무적 성과에 긍정적인 영향을 미치는 것으로 나타나 네트워크의 관계적 성과차원의 개선이 실제로 기업의 재무적 성과차원에도 크게 기여하는 것으로 나타났다.

• 한국응급구조학회지
• /
• 제6권1호
• /
• pp.169-184
• /
• 2002

The purpose of this study was to find out the 119 rescue and first aid's satisfaction level for their occupations, understand the influential factors of the satisfaction level and also analyze the level of each working districts. Therefore to provide basic information of policy decisions to increase the satisfaction level. Date were collected from 400 national the 119 rescue and first aids by questionnaire and using the tools, which has developed by Slavitt, from August 2 to September 30, 2002. The data were analyzed by percentage, mean t-test and ANOVA. Divided 39 items into 7 provinces to find out the satisfaction level of each province, follow as the influential factors of the satisfaction level. 1. The most of the 119 rescue and first aids were satisfying about their occupations as they got 3.02 marks out of 5, which is the full mark. 2. As the results after analyzed the relation ship between the satisfaction level and the general characteristics of analyzed the relation ship between the satisfaction level and the general characteristics of the 119 rescue and first aids, there were not statistically significant differences of sex distinction, age, scholarship, not married and has or have married, grade and qualification. There were statistically significant differences follow as working period, applying motive, moving, seeking a job, working place, an adviser, work overtime and compensation follow as work overtime. 3. It appeared that all the 119 rescue and first aids were satisfying enough about duty itself but were dissatisfying about working condition. As the results; job itself got 4.00, reciprocal action got 3.74, business demand got 3.28, autonomy got 3.06, organization demand got 2.96, pay got 2.43 and working condition got 1.72, each out of 5 full marks. As you see the results, most of the 119 rescue and first aids are satisfying about a job itself but they are dissatisfying about their working condition. Therefore we should formulate a plan that can increase the satisfaction level by improving duty system for 24 working hours per week.

• 대한기계학회논문집A
• /
• 제40권7호
• /
• pp.647-652
• /
• 2016

유도초음파를 활용한 비파괴검사기법은 장거리 배관 검사에 많이 활용된다. 장시간 사용에 따라 배관에는 표면 부식과 같은 형태의 결함이 주로 발생한다. 표면 부식형 결함의 경우 장거리 유도 초음파 검사 기법을 활용한 신호 해석에 어려움이 있다. 상반 정리는 복잡한 수학적 표현을 간단히 나타내주는 기법으로 잘 알려져 있다. 상반 정리는 평판, 반무한체의 산란 문제를 해결하는데 이미 적용된 바가 있지만 원통형 구조물에서는 적용된 사례가 없다. 이 논문에서는 배관 진단을 위해 상용 장비에서 많이 사용되는 비틀림파의 산란 신호를 상반 정리를 적용하여 해석하였다. 산란 신호는 상반 정리를 활용하여 산란 체의 형태와 위치에 따라 단순한 닫힘 해로 표현하였다. 타원형 결함과 사각 결함의 폭과 깊이 변화에 따라 주파수 별로 발생되는 산란 신호가 계산되었으며, 주파수 증가에 따른 주기적인 결과를 나타내는 것을 확인하였다. 산란 신호 해석을 위한 닫힘 해는 결함의 크기를 정량적으로 해석하는데 중요한 역할을 할 것으로 기대된다.

• 인터넷정보학회논문지
• /
• 제12권5호
• /
• pp.73-85
• /
• 2011

문헌에 존재하는 핵심개체 간의 관계를 자동으로 추출할 때 다양한 형태의 문서 분석 결과를 활용할 수 있다. 본 논문에서 는 기존에 개발되어 비교적 높은 성능을 보여준 합성곱 구문 트리 커널의 구절 구조 유사성 정보와 두 개체 사이의 유의미한 연관관계를 표현해주는 술어-논항 구조 패턴의 유사성 정보를 동시에 활용하는 혼합 커널을 제안한다. 구문적 구조를 이용하는 기존의 합성곱 구문 트리 커널에 술어와 논항 간의 의미적 구조를 활용하는 술어-논항 구조 패턴 유사도 커널을 결합하여 상호보완적인 혼합 커널을 구성하였고, 다양한 테스트컬렉션 기반의 실험을 통하여 개발된 커널의 성능을 측정하였다. 실험결과 구절 구조 정보를 이용하는 합성곱 구문 트리 커널만을 단독으로 사용했을 때보다 술어-논항 구조의 패턴 정보를 결합한 혼합 커널을 사용했을 때에 더 좋은 성능을 보이는 것을 확인할 수 있었다. 또한 기존의 시스템보다 우수한 성능을 보이는 것도 함께 확인할 수 있었다.

• 한국전산구조공학회논문집
• /
• 제22권6호
• /
• pp.627-637
• /
• 2009

복합재료는 재료적, 역학적으로 뛰어난 특성을 가진 재료로서 엔지니어링분야의 많은 부분에 적용되고 있다. 특히 무게 대비 강성비가 높은 특성을 가지고 있으며 다양한 형상에 대한 성형성도 뛰어나다. 그러나 재료의 특성상 두 가지 재료를 조합하여 제작하는 복잡한 과정은 재료상수에 높은 임의성을 야기할 가능성이 있다. 본 연구에서는 재료상수 중 포아송비의 공간적 임의성을 고려한 추계론적 유한요소해석 정식화를 제시한다. 직교이방성 복합적층구조의 두 재료축에 대한 상호관계를 적용하여 두 재료축방향의 포아송비를 하나의 대표값으로 나타내었고, 이를 합력-변형률관계에 적용하였다. 이를 통하여 합력-변형률관계를 포아송비의 변동항의 수학적 표현인 추계장함수의 차수에 따라 분해된 형태로 유도하였고, 이를 정식화에 적용하여 응답분산계수를 제시하였다. 제시한 응답분산계수는 몬테카를로 해석의 결과와 비교하였다.

• 생물정신의학
• /
• 제15권3호
• /
• pp.175-185
• /
• 2008

Accumulating evidence has suggested the existence of reciprocal communication between immune, endocrine, and neurotransmitter system. Cytokine hypothesis of depression implies that increased pro-inflammatory cytokine such as -1, IL-6, IL-12, TNF-${\alpha}$, and IFN-${\gamma}$ in major depression, acting neuromodulators, play a key role in the mediation of behavioral, neuroendocrine, and neurochemical disturbances in depression. Concerning the relation between cytokines and serotonin metabolism, pro-inflammatory cytokines have profound effects on the metabolism of brain serotonin through the enzyme indoleamine-2,3-dioxygenase(IDO) that metabolizes tryptophan, the precursor of 5-HT to neurodegenerative quinolinate and neuroprotective kynurenate. The neurodegeneration process is reinforced by the neurotoxic effect of the hypercortisolemia during depression. From this perspective, it is possible that efficacy of antidepressants in the treatment of depression may, at least in part, rely on downregulation of pro-inflammatory cytokine synthesis. So, the use of cytokine synthesis inhibitors or cytokine antagonists may be a new treatment approach in depression. However, at present the question whether cytokines play a causal role in the onset of depression or are mere epiphenomena sustaining depressive symptoms remains to be elucidated. Nevertheless, cytokine hypothesis has created new perspectives in the study of psychological and pathophysiological mechanism that are associated with major depression, as well as the prospect for developing a new generation antidepressants.

• Clinical and Experimental Reproductive Medicine
• /
• 제18권2호
• /
• pp.223-231
• /
• 1991

During the years 1984 to 1989, in order to determine of chromosome abnormalities are associated with recurrent spontaneous abortions, cytogenetic studies were performed 384 couples. Abnormal karyotypes were found in 51(13.3%) couples. There was no apparent relation with the number of abortions. The abnormalities were as follows: 17(4.4%) balanced translocation; 15(3.9%) mosaicisms; 17(4.4%) pericentric inversion; 2(0.5%) addition or isochromosome. Chromosome abnormalities were observed in 34(67%) of the wives and 17(33%) of the husbands. In addition, we detected polymorphic variants of chromosomes in 89(23.2%) subjects. Reciprocal translocations(13/17) were more common than the robertsonian type(4/17). All of the mosaicisms were associated with the sex chromosomes in 10 females and 5 males subjects. Pericentric inversions were most common in chromosome 9. Compared to previously studied general populations, significantly higher frequencies of translocations, mosaicisms and inversions were found in couples with repetitive spontaneous abortion. This suggests that couples should have chromosome studies after two or more abortions.

• 무역상무연구
• /
• 제53권
• /
• pp.265-288
• /
• 2012

Trade in service, which deals with intangible product, is distinguished from trade of goods for tangible product. The current multilateral service trade is based on GATS which includes MFN, securing the predictability as well as transparency of related service rules, specific commitment basis market access national treatment. Recently the WTO service disputes are increasing according to the frequent filing complaints against the regulation of service trade in China. The rules of GATS are not as strict as those of GATT. The commitment schedules, which were materialized between members, gets binding effect through the obligatory provisions of GATS. The GATS is inseparable relation with the Appendix of finance, of telecommunication, and of air transport, with the schedules of commitment of member states, and with the reference paper to the 4th protocol. GATS article XIV which is the general exception of GATS has a similar structure of GATT article XX. Based on the possibility of filing to the WTO, there is a need to examine whether the whole rules, regulation, and policy international trade in service of Korea perfectly macthed with the GATS. Korea with poor resources should take up the more positive attitude for the opening of international service market. According to the reciprocal aspects of concession, if Korea doesn't open a service market, the other WTO member country wouldn't allow Korea to access the their market as well as national treatment.