• 한국해양공학회지
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• 제6권1호
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• pp.69-77
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• 1992

The natural frequencies of a beam on elastic foundation are investigated in the present paper. The inhomogeneous elastic foundation can be modelled as a combination of distributed translational spring, rotational spring, intermediate supports and dampers. The natural frequencies and mode shapes of the system are obtained by using the Galerkin's method, and also compared with the results in the literature. Furthermore, the natural frequencies of the beam with elastically mounted masses, which can be used as vibration absorbers, are obtained by an efficient numerical scheme suggested in the present paper.

• 한국생태학회:학술대회논문집
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• 한국생태학회 1999년도 국제 Symposium 및 '99 춘계 공동 학술 발표대회
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• pp.55-62
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• 1999

Four species of Paraphysomonas collected from the fast- ice covered area Syowa Station, East Ongul Island ($69^{\circ}00'S,\;39^{\circ}35'$) ,Antarctica occurred in the seawater throughout the year and occasionally in the sea ice. P.. antarctica is distributed to a water depth of 35m at 51.3 during the period from August 1983 to January 1984 and also down to 600m St. 5 in September 1983 at cell concentrations of 300-350 cells/ml. The Paraphysomonas spp. were dominant during the period from July to November 1983 in the area studied. The mode of the occurrence and vertical distribution of Paraphysomonas apparently coresponds to those of the bacteria and orgarnic debris-like matter in the seawater. The main components of the plankton population in the area studied, under ice-covered conditions, are Paraphysomonas, Choanoflagellates and bacteria. This work clarified that Paraphysomonas is one o f the most important bacterivores in the microbial loop of the Antarctic marine ecosystem.

• Journal of Mechanical Science and Technology
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• 제17권10호
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• pp.1399-1410
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• 2003

In this paper, we develop a joystick manual driving algorithm for an electric vehicle called Cycab. Cycab is developed as a public transportation vehicle, which can be driven either by a manual joystick or an automated driving mode. The vehicle uses six motors for driving four wheels, and front/rear steerings. Cycab utilizes one industrial PC with a real time Linux kernel and four Motorola MPC555 micro controllers, and a CAN network for the communication among the five processors. The developed algorithm consists of two automatic vehicle speed control algorithms for normal and emergency situations that override the driver's joystick command and an open loop torque distribution algorithm for the traction motors. In this study, the algorithm is developed using SynDEx, which is a system level CAD software dedicated to rapid prototyping and optimizing the implementation of real-time embedded applications on distributed architectures. The experimental results verify the usefulness of the two automatic vehicle control algorithms.

• 한국컴퓨터산업학회논문지
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• 제5권9호
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• pp.841-850
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• 2004

본 논문은 분산 시스템하에서 효율적인 분산자원 관리를 위하여, 각 노드는 정확한 의사 결정을 내려야 하는데, 이에 장애가 되는 통신 네트워크상의 지연, 통신 주기, 기타 의사 결정을 위한계산 시간등을 충분히 고려하였다. 또한, 직접 통신 방식을 사용하여 전체 시스템의 성능을 향상시킬 수 있다. 불확실한 부하정보는 시간변화에 따라 부하 정보에 대한 유용성을 변화 시켜 완화하였다.

• 한국잠사곤충학회지
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• 제36권2호
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• pp.115-118
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• 1994

뽕잎분말이 포함되어 있지 않은 MP-O 인공사료에 대한 누에의 섭식성의 유전현상을 구명하기 위하여 품종간의 섭식성의 차이와 그 유전양시겡 관하여 실험하였다. 280개 보존누에품종 및 71개 육종계통에 대해 섭식성을 조사한 결과 품종에 따라 현저한 차이가 있었으며 섭식성의 분포는 비정규분포에 가까웠고 저섭식성 쪽으로 편기되어 있었다. 또한 MP-O 인공사료 고섭식성은 저섭식성에 대해 열성적 형질로 판명되었으며 결과적으로 열성유전자에 의해 지배되고 있음이 명확해졌다.

• 전력전자학회논문지
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• 제23권4호
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• pp.265-272
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• 2018

This paper proposes a new control method for the supercapacitor (SC) to compensate the pulsed load and to enhance the power quality of the DC microgrid. By coordinating the operating frequency, the SC is controlled to handle the surge current, while the low-frequency current component is dealt with by the remaining sources in the system. The operation mode of the SC unit is automatically changed based on the state of charge and DC bus voltage level. Meanwhile, the mismatch in the power demand is covered by the SC unit by regulating the DC bus voltage level. The effectiveness of the proposed method is verified experimentally by the prototype with two distributed generators and one SC unit.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1136_1138
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• 2009

This paper gives a basic Energy performance data of micro gas turbine and Renewable Energy(BIPV and Solar Collector System) installed in Hospital Building. The efficiency of solar collector and BIPV system was 30%, 10% individually, and lower than micro gas turbines. Micro gas turbines are small gas turbines that burn gaseous and liquid fuels to produce a high-energy exhaust gas and to generate the electrical power. Recently the size range for micro gas turbines is form 30 to 500kW and power-only generation or in combined heat and power(CHP) systems. If micro gas turbine was operated only for electric energy, the efficiency was about 30%, but for combined heat and power, the efficiency was about 90%. Finally, installed in large hospital, Micro gas turbine system was operated to CHP mode, was high-efficiency system than Solar collector and BIPV system.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.113-116
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• 2007

The fuel cell which converts directly chemical energy of fuel into electric energy has higher efficiency than the conventional power generation which involves several additional processes. Especially, polymer electrolyte membrane fuel cell (PEMFC) of which the electrolyte is a thin proton conductive polymer membrane is affordable for portable power applications and small-scale distributed power generation including household and small building. It is very important to not only increase the efficiency of FC itself but determine the optimal operation mode. The optimal operational planning of lkW household PEMFC system based on the daily electricity and heat demand patterns was performed. The estimated economic gain was up to 20% by adoption of PEMFC system.

• 한국소음진동공학회논문집
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• 제27권1호
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• pp.107-113
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• 2017

The dynamic characteristics including natural frequencies and excitation frequencies are evaluated for a small 10 kW vertical axis wind turbine. Acceleration responses were measured at 12 distributed locations for impact vibration tests, ambient vibration tests during non-operational and operational conditions, and braking tests during operational condition. The natural frequencies for the lowest 2 bending modes and the first torsional mode were estimated and also the excitation frequencies, i.e. 1P, 2P, 4P, were also estimated according to the rotational speed using the responses under operational conditions (i.e. power generation condition).

• Journal of Chest Surgery
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• 제25권3호
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• pp.283-288
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• 1992

From january 1970 through december 1990, 130 cases of patients with chest penetrating injury were admitted to department of thoracic and cardiovascular surgery in Chosun University Hospital. We analyzed above patients and obtained results were as follows: 1. The ratio of male to female was 7.1:1 in male predominance, and the majority[69.6%] was distributed from 2nd to 3rd decade. 2. The most common cause of chest penetrating injuries was stab wound. 3. 110 cases[84.5%] were arrived to our emergency room within six hours after trauma. 4. The most common injuring mode was hemo, pneumothorax. 5. The frequently injured site of the penetrating chest trauma was left side of the chest [64.65%]. 6. The common associated injuries of penetrating chest injuries were extremities injuries, abdominal injuries, head & facial injuries. 7. The common method of surgical treatment were closed thoracostomy[78 cases], open thoracotomy[20 cases], laparatomy[12 cases]. 8. The overall motality was 3.07%[4/130], and the causes were hypovolemic shock, sepsis and asphyxia.