• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1001-1006
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• 2004

Railroad disasters are frequently occurred by man-made causes or natural causes. In general, man-made causes are illegal construction practices, deterioration with the lapse of time and railroad crossing accidents, and natural causes are rainfall. snow, wind, earthquake, etc. Of cause, railroad disasters by man-made causes are prevented from keeping the safety principle, constructing multi-level crossing, securing enough men of ability and financial resources and making a thorough check using equipments with high capacity. And railroad disasters by natural causes are also minimized by construction of disaster prevention facilities, introduction and operation of general disaster prevention system and reasonable train passage control. Therefore, to setup the criterion of train passage control for train safety at railroad bridge under heavy rainfall, risky factors, national and oversea criteria under such circumstances are reviewed and a scheme to setup the criterion is suggested.

• 전자공학회논문지B
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• 제33B권10호
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• pp.90-97
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• 1996

This paper presents an efficient parallel implementation and its performance evaluations of a SOFM neural netowrk on the multicomputer. We investigate the parallel performance as the size of a neural network N, the number of the patterns L, and the number of the processors p increase. We propose an analytica performance evaluation model for eac of the parallel implementations and verified the validity of the model through experiments. Analytical result show that the number of processors for a maximum speedup of the network decomposition nd the training-set decomposition increases in proportion to .root.N and .root.L, respectively. The performances of the both decompositions depend on the number of training patterns L and the size of the neural network N and, if L.geq.0.423N, the performance of trhe training-set decomposition is proved to be better than that of the network decomposition.

• 치과방사선
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• 제25권2호
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• pp.561-567
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• 1995

Pleomorphic adenoma is a benign salivary gland tumor with histologic diversity. The majority of these tumor occurs in the parotid gland. The authors experienced the patients, who complained the tumor-like soft tissue mass on the palatal area. After careful analysis of clinical, radiological and histopathological findings, we diagnosed it as pleomorphic adenoma in the palatal area, and obtained characteristic features were as follows: 1. Main clinical symptom was a painless, slow growing, soft tissue mass with normal intact overlying mucosa on the palatal area. 2. In the radiographic examminations, well encapsulated homogeneous soft tissue mass was shown in the lesion site, and cortical thinning on the palate was also observed. 3. In histopathologic examminations, proliferated cellular components in the hyaline stroma were observed as double layered duct-like structure and densely solid sheet appearance.

• Advances in pediatric surgery
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• 제6권1호
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• pp.68-69
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• 2000

A case of primary hyperparathyroidism due to parathyroid adenoma is presented. A 14 year-old male was admitted to the hospital comptaining of voiding difficulty. The intravenous pyelogram demonstrated a stone in the proximal one third of the left ureter and marked hydronephrosis of the left kidney. The Tc-99m sestamibi nuclear scan demonstrated a hot spot below the lower pole of the left lobe of the thyroid. Laboratory study demonstrated hypercalcemia (12.4 mg/dL) and elevated parathyroid hormone (143.67 pg/mL). A parathyroid gland located below the lower pole of the left lobe of the thyroid was excised. A parathyroid adenoma, consisting of mainly chief cells was found on pathologic examination. Postoperatively the patient had transient hypocalcemic symptoms, which resolved with administration of calcium preparation and vitamin D.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2011년도 춘계학술대회
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• pp.362-364
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• 2011

자동조타장치에 의한 조선을 행할 시, 선박의 정침성은 Autopilot의 P와 D값 설정에 따라 많은 영향을 받게 된다. 이 값들은 선종별로 외력에 따라 조정되어야 한다. 이 연구에서는 바람에 의해 가장 많이 영향을 받는 자동차운반선(Pure Car Carrier, PCC)을 대상으로 하여, 풍압력하에서 자동조타시 P와 D치의 적정 설정값을 알아 보았다. 이를 위하여 대상 선박을 저속항행하는 시뮬레이션을 실시하였고, 각 P-D 설정값에 따른 최대 횡이동거리, 횡이동시간 그리고 주어진 침로로 복귀하는데 걸린 시간을 비교하였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2011년도 춘계학술대회
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• pp.147-149
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• 2011

본 연구는 선박사고의 발생과 선박이 지닌 특성(선종/톤수/국적)간에 연관이 있을 것으로 가정하여 관제전문가를 대상으로 하는 설문조사 및 사고통계 분석을 통해 각 특성 별 가중치를 계량화하여 기준점수표를 마련하고자 하였다. 가중치 산정은 분석적 계층화 과정(AHP: Anlaytic Hierachy Process)를 거쳤으며 이를 통해 얻은 기준점수표를 바탕으로 인천항의 1일간 입항선에 적용하여 결과를 준사고이력 보유선박군의 점수와 비교하여 양 집단 간 높은 위험지수 해당선박 존재 비율을 비교하였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2015년도 추계학술대회
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• pp.187-189
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• 2015

해양사고를 야기하는 위기(risk) 또는 해저드(hazard)는 세계 경제 및 물류, 기상환경, 금융, 선종개발, 기술개발 등 다양한 요소에 의해서 수시로 변한다. 변한 위기에 대해서 사전에 대응방안을 수립하지 못한 경우 대규모 해양사고로 연계될 가능성이 크다. 그 이유는 대응방안을 사전에 고려하지 못했거나 준비하지 못한 해양사고는 사전대응책이 마련된 사고와 비교하여 대응하는 방법과 대응속도 등이 다르기 때문이다. 본 연구에서는 현재까지 새로 창출된 다양한 위기를 각종 보고서, 논문 등을 통해서 식별하고 분류하여 현재까지 식별하지 못한 위기를 구분하고, 식별하였더라도 새로운 사고를 유발한 위기를 식별하여 사전에 예방책을 강구하는 것이 목적이다. 연구 대상이 방대하기 때문에 본 연구에서는 일단, 알리안츠 보험회사 자료에서 획득한 위기분석 결과를 토대로 위기를 식별하고, 이에 대한 시나리오를 전개하였다. 이를 통해서 추후 연구방법을 검토하고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.2047-2049
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• 2000

In this study, we describe comparison of insulation characteristics of polyamid papers with heating conditions. The partial discharge behavior until breakdown and breakdown strength for thermal degradation films are observed in $SF_6$ gas chamber. The four layered NOMEX films of thickness of 50${\mu}m$ were used as solid insulation films and the sphere of which diameter is 40mm to sphere electrode system was used and each insulation films were inserted between sphere electrodes. The used gas pressure was 1.0bar and used temperature was each of 250$^{\circ}C$, 270$^{\circ}C$, 300$^{\circ}C$, 320$^{\circ}C$, 350$^{\circ}C$ and the voltage were applied until breakdown films.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1972-1974
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• 2000

In this paper, we made an experiment on fault location of underground cables with travelling wave. The 5C2V coaxial cables of 100, 200m length, connected with discharge gap, are used for simplifying model cable lines of power cable. And 100KHz -2MHz CT and HV probe are installed at one side of the ends. We made travelling pulse in discharge gab and then pulse travelled along the cable to the both ends. Therefore, it is detected in CT and HV probe. Measuring the time difference of the pulse start and arrival, we were able to obtain the distance of pulse travelling. Consequently, our experimental results show the possibility to detect fault location of underground cables with travelling wave.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1903-1905
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• 2000

Power transformers have a tendency of ultra-high voltage capacity as power demand increases day after day KEPCO also will have plan to supply transmission power from 345KV to 765KV in the early of 2000. Therefore, the fault by insulation destruction gives rise to large area of power failure in huge capacity transformers. On-line predictive diagnostics is very important in power transformers because of economic loss and its spreading effect. This study presents the algorithm for transformer oil analysis used KEPCO code, IEC code, gas pattern method and Dornenburg & Roger Ratio method. We also describe the MMI display of expert system programmed by Element Expert Tool(Neuron Data Inc.).