• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.24-26
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• 1995

The Development of A.C. Induction Motor for Railway Rolling Stock. The traction motor is designed as 4-pole induction motor with self ventilation. The winding insulation is throughout of materials of class C. The rotor is designed as a squrrel rotor with copper bar and casting. The rotor speed is detected by means of a pulse generator. The newer tection motor have no casting(frame). Punched-in holes make up the air duct and transfer the heat losses in complete. Maximim motor rpm is higher due to rotor construction. New is the entry of water-cooled traction motors in urban, However the water cooling design in - unfortunately - not applicable in traction motor.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 1991년도 수공학논총 제33권
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• pp.221-230
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• 1991

Various Models of the moisture content-capillary pressure hysteresie based on the approach of domain concept in porous media are compared with each other, Model III-1(Mualem, 1984) is superio to others as expected. A new model based on Model III-1 is proposed of which asuumption is the linearization of P$$($\theta$) accounting for the pore blockage effect against air-entry. The feature of this model is that only one branch of boundary curve is needed to calibrate it, which is the advantage to Model III-1. The prediction of boundary drying curve from boundary wetting curve using this model is better than that using Model I-1, II-1 compared with the experimental data. This model is to simulate scanning curves, while Model I-1, II-1 is not.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.79-79
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• 2023

국제사회는 신기후체제 출범(COP21, '15)을 통해 선진국뿐만 아니라 개도국에도 2020년부터 탄소감축 의무를 부과하고 있다. 이에 우리나라와 경제적으로 밀접한 동남아시아 국가에서는 신재생에너지 분야에 대한 관심이 매우 높다. 예로써 말레이시아에서는 신재생에너지 비중을 2025년 31%, 2035년에는 40%까지 제고시키다는 계획이며, 인도네시아는 2070년 완전한 탄소중립 달성을 목표로 태양광 및 바이오에너지 비중을 확대하고 있다. 특히 수상태양광은 댐 수면을 활용함에 따라 입지의 영향이 적고 최적부지 확보가 용이하다는 이유에서 기존 지상 태양광의 문제점을 해소하는 대안으로 부상하고 있다. 이에 본 연구에서는 지리적·기술적 여건의 관점에서 향후 시장 성장성이 클 것으로 판단되는 동남아시아 주요 협력국가를 대상으로 전력 동향 및 향후 발전 전망 등을 분석함으로써 수상태양광 분야의 전략적 타겟시장을 선정, 제시하고자 한다.

• 한국환경과학회지
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• 제14권8호
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• pp.739-748
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• 2005

The purpose of this study is to analyze seasonal changes in structure and landscape of Gongji stream corridor in Chuncheon, and to suggest some guidelines to contribute to creating a desirable close-to- nature stream. The study seasonally surveyed floodplain and revetment conditions, channel micro-topography, streamflow level and velocity, and vegetational cover. Flooding, water level, and vegetation were major factors of affecting seasonal changes in streambed structure and stream landscape. Small sand bars and islands were considerably disturbed by flooding and water level change. However, large islands and sand bars in the upper and middle section of the study stream remained or reappeared even after flooding. Flooding also tended to repeat channel sedimentation at the same spot. Controlling water volume of the Euiam Lake, which is adjacent to the study stream, caused higher water level downstream in the dry seasons. The majority of vegetation in sand bars and islands was washed away by the floods. Vehicle passing, crop cultivation, and ball game were other elements which disturbed vegetation in the floodplain. Creating a close-to-nature stream should reflect micro-topographical changes of channel by flooding, prevent improper vehicle entry and human use, and remove concrete material in the revetment and floodplain.

• 한국항해항만학회지
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• 제34권1호
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• pp.71-75
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• 2010

아이스슬러리의 생성을 위하여 냉각평판에 작동수를 분사하는 실험을 수행하여 그에 대한 영향에 대하여 영향을 평가하였다. 실험에 사용된 에틸렌글리콜 수용액은 10~20wt%의 수용액을 사용하였다. 실험장치는 슬러리아이스 저장탱크, 브라인 탱크, 브라인 순환장치, 유량계 및 온도기록계로 구성되어 있다. 실험조건은 평균유속 1.0~2.0m/s, 냉각온도 $-17{\sim}-10^{\circ}C$의 조건 하에 실험을 수행하였다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.75-75
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• 2023

글로벌 물시장 동향을 살펴보면 ① 첨단 기술기반의 글로벌, ② 운영관리 시장의 확대, ③ 물기업의 토털 솔류션화(제조+건설+엔지니어링+운영관리), ④ 기후변화 대비 신규시장 형성 등 글로벌 물산업의 트렌드가 전환되고 있다. 특히 4차산업 혁명 기술과 코비드19의 영향으로 이러한 변화는 물산업 선도국가 및 선도기업의 정책·전략에 있어 지역별 특성과 분야별 물시장의 특성을 반영한 전략목표 재설정 및 재수립이 요구되고 있다. 한편 국내 물시장은 2020년 기준 상·하수도 보급률, 각각 98.7%, 94.5% 수준을 달성했음에도 불구하고. 해외시장 진출에 있어서는 미미한 수준에 머물고 있다. 따라서 국내 물산업의 지속적 발전을 위해서는 포화된 국내 시장을 벗어난 신시장 발굴이 필요한 상황이며, 국가별 상황에 대한 실태조사와 목표 시장별 분석을 통해 국가별, 분야별 맞춤 진출전략을 수립해야 한다. 본 연구에서는 국내 물기업의 유럽지역(프랑스/스페인) 진출 활성화를 위해 각 국가별 상황에 부합하는 목표 시장별 차별적 전략 도출을 위해 국가별 물시장 동향 및 전망, 진출목표 분야를 분석함으로써 국내 물기업의 프랑스/스페인 물시장 진입전략 방안을 제시하고자 한다.

• Geomechanics and Engineering
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• 재33권6호
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• pp.625-633
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• 2023

The volume changes associated with moisture or suction variation in expansive soils are of geotechnical and geoenvironmental design concern. These changes can impact the performance of infrastructure projects and lightweight structures. Assessment of unsaturated function for these materials leads to better interpretation and understanding, as well as providing accurate and economic design. In this study, expansive soils from different regions of Saudi Arabia were studied for their basic properties including gradation, plasticity and shrinkage, swelling, and consolidation characteristics. The unsaturated soil functions of saturated water content, air-entry values, and residual states were determined by conducting the tests for the entire soil water characteristic curves (SWCC) using different techniques. An attempt has been made to provide a prediction model for unsaturated properties based on the basic properties of these soils. Once the profile of SWCC has been predicted the time and cost for many tests can be saved. These predictions can be utilized in practice for the application of unsaturated soil mechanics on geotechnical and geoenvironmental projects.

• 동의신경정신과학회지
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• 제10권2호
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• pp.115-126
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• 1999

This study was conducted to find out the effects of Woohwangchungsimwon on learning and memory in the NOS inhibitor treated rats. The Morris water maze was used in evaluating them. The result of the study was summarized as follows. 1. In the learning test, three groups have showed a gradual improvement of learning ability by repeating the trials in Morris water maze. WHCS group have showed statistical improvement than control group at 4,5,6 trial(p<0.05, p<0.01, p<0.01). 2. In the memory test, the first latency of WHCH group was statistically shortened than that of control group(p<0.05). 3. In the memory test, there was no statistical difference in the entry number between WHCH group and control. 4. In the memory test, there was no statistical difference in the memory score between WHCH group and control. The result of this experimental study presents that Woohwangchungsimwon has the improving effect on impaired learning and memory in NOS inhibitor treated rats, and implies that Woohwangchungsimwon may be one of the useful prescription for the treatment of vascular dementia after cerebral ischemia.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회 2차
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• pp.53-60
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• 2010

The natural soils are classified in saturated soils and unsaturated soils according to level of ground water but the research for only saturated soils has been conducted by this time. However, there are many proble.ms which are not solved by using the concept and principle of saturated soils on the natural soils. In fact, it is known that unsaturated soils represent the behavior characteristic unlike completely saturated soils because of the adhesion under the influence of negative pore water pressure, the high angle of friction and the low water permeability by the air entry. So it needs to conduct the various researches on insufficient unsaturated soils. In this paper, unsaturated triaxial compressive tests are conducted in order to do research on shear strength characteristic on sands and silty sands of Nakdong river. As a result of the tests, the cohesion is increased in non-linear type according to the change of the matric suction, but the angle of internal friction is not changed much.

• 설비공학논문집
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• 제16권2호
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• pp.142-149
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• 2004

Recently, the government introduced the thermal storage system for reducing the electric power load. Especially, the ice slurry type has gained lots of interest due to its good heat transfer and flowing characteristics. This study was peformed to understand the effects of transporting ice slurry through elbows of various angle. Propylene glycol water solution was used and about 2 mm ice particles were circulated. The experiments were carried out under various conditions, such as concentration and velocity of water solution ranging between 0∼20 wt％, 1.5∼2.5 m/s, respectively. And elbows with 4 different angles of 30$^{\circ}$, 45$^{\circ}$, 90$^{\circ}$, 180$^{\circ}$. The differential pressure and IPF (ice packing factor) between the pipe entry and exit were measured. The tendency of pressure loss and outlet IPF in elbow is that the pressure loss was reduced as concentration and flow velocity of water solution is increased, and low value appeared at 10 wt％ and 2.5 m/s. The variation of outlet IPF was compared with the inlet IPF in the range of $\pm$20％.