• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2012년도 춘계학술대회
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• pp.386-387
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• 2012

마리나는 쾌적하고 안전한 환경조성이 매우 중요하기 때문에 마리나 시설이 위치한 해역의 특성을 고려한 환경관리 및 설계가 필요하다. 특히 해역환경은 시간적-공간적인 변화가 크기 때문에 체계적인 조사가 선행되어져야 하며, 표준화된 하나의 설계 및 관리기준을 따르기 보다는 실질적으로 달성가능하고 최소 요구수준을 만족하는 정도에서 관리수준이 결정되어져야 한다. 본 논문은 마리나 환경관리를 위한 기본 단계와 각각의 단계에서 필요로 하는 기술제시를 목적으로 한다.

• 한국자동차공학회논문집
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• 제10권4호
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• pp.77-84
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• 2002

For the purpose of obtaining a fundamental data which is needed to develope the port injection type charged LPLi engine system, we manufactured intake port injection system of liquid charging LPG and modified heavy duty single cylinder LPLi engine from heavy duty diesel engine. Engine output and emission characteristics were analyzed under variable air/fuel ratio and charging pressure. Since LPG is consisted of propane and butane, we investigated combustion characteristics using this two kinds of fuel. From the result of charging engine performance test, engine torque increase about 30% ∼ 40% with 0.3bar charging pressure. In low speed condition, as charging pressure increase, combustion stability improve ill lean bum condition, but, in high speed condition, combustion stability make worse in lean bum condition. We know that engine output decreased rapidly from the condition of air excess ratio 1.3. In addition, we measured emission characteristics under the lean bum and charging condition. From this experiment, we found that CO emission is out of the question in the range from stiochiometric to lean burn and charging condition, but charging pressure has influence on HC emission.

• 한국자동차공학회논문집
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• 제17권4호
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• pp.55-62
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• 2009

As an experiment investigation, the effects of ethanol blended gasoline fuel with different injection method on nano-sized particle emission characteristics were examined in a 0.5L spark-ignited single-cylinder engine with a compression ratio of 10. Because this engine nano-particles are currently attracting interest due to its adverse health effects and their impact on the environments. So a pure gasoline and an ethanol blended gasoline fuels, namely E85 fuel, used for this study. And, as a particle measuring instrument, a fast-response particle spectrometer (DMS 500) with heated sample line was used for continuous measurement of the particle size and number distribution in the size range of 5 to 1000nm (aerodynamic diameter). As this research results, we found that the effect of ethanol blending gasoline caused drastic decrease of nano-particle emissions when port fuel injection was used for making better air-fuel mixture than direct fuel injection. Also injection timing, specially direct fuel injection, could be a dominant factor in controlling the exhaust particle emissions.

• 한국항해항만학회지
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• 제33권4호
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• pp.255-261
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• 2009

Prediction of the stability for ships is very complex in reality. In this paper, risk based approach is applied to predict the probability of capsize for a certified ship, which is effected by the forces of sea especially the wave loading Safety assessment and risk analysis process are also applied for the probabilistic prediction of stability for ships. The probability of shipsencountering different waves at sea is calculated by the existed statistics data and risk based models. Finally, ship capsizing probability is calculated according to single degree of freedom(SDF) rolling differential equation and basin erosion theory of nonlinear dynamics. Calculation results show that the survival probabilities of ship excited by the forces of the seas, especially in the beam seas status, can be predicted by the risk based method.

• 한국통신학회논문지
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• 제19권6호
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• pp.1046-1055
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• 1994

본 논문에서는 영상 신호처리에 적합한 고속 1 line VRAM을 ASIC화 설계하기 위하여 엑세스 시간특성 및 집적도가 우수한 3-TR dual-port 다이나믹 셀을 채용하여 메모리 코어를 설계하였다. 고속 파이프라인 동작을 위하여 서브어레이 1로부터 첫 행을 분리하였고, TM기 비트 라인에 데이터 래치 구조를 채용하여 한 번지의 동시 입.출력이 가능하도록 설계하였다. 주변 회로로 번지 선택기, 1/2V 전압 발생기를 각각 설계하여 개선된 동작특성을 확인한 후 1.5[ m] CMOS 설계규칙을 이용하여 ASIC화 설계하였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1996년도 The Korean Institute of Navigation 1996년도 춘계학술발표회 논문집
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• pp.59-76
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• 1996

Vessels in the world merchant fleet generally operate in either liner or bulk trade. The supply and the demand trend of general cargo ship are both on the ebb however those trend of tankers and containers are ins light ascension. Oil tankers are so far the largest single vessel type in the world fleet and the tanker market is often cited as a texbook example of perfect competition. Some shipping statistics in recent years show that there has been a radical fluctuation in spot charter rate under easy charter's market. This implies that the proper scheduling of tankers under spot market fluctuation has the great potential of improving the owner's profit and economic performance of shipping. This paper aims at developing the TS-DSS(Decision Support System for Tanker Scheduling) in the context of the importance of scheduling decisions. TS-DSS is defined as a DSS based on the optimization models for tanker scheduling. The system has been developed through the life cycle of systems analysis design and implementation to be user-friendly system. The performance of the system has been tested and examined by using the data edited under several tanker scheduling has been tested and examined by using the data edited under several tanker scheduling scenarios and thereby the effectiveness of TS-DSS is validated satisfactorily. The authors conclude the paper with the comments of the need of appropriate support environment such as data-based DSS and network system for successful implementatio of the TS-DSS.

• Journal of Yeungnam Medical Science
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• 제21권1호
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• pp.108-113
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• 2004

A 23 years old single nulligravida woman underwent laparoscopic removal of a huge cystic adnexal mass that occupied her entire abdomen, giving the appearance of a full term pregnancy. After anesthesia, a vertical infra-umbilical incision, 1 cm long, was made and a telescope was introduced through the port to determine the status of the intra-abdomen and the surface contour of the mass. A needle tipped with a laparoscopic suction apparatus was inserted into the cyst through the infra-umbilical port, directly under the mass. Subsequently, 3,200 ml of cystic fluid was aspirated without spillage. A huge cyst, reaching to the level of the xyphoid process was effectively excised through the operative laparoscopy after prelaparoscopic drainage. Operation time was 140 minutes and hospital stay was 2 days. There were no complications during hospital stay and after discharge. It seems the size of the cyst is not a criteria for the contraindication of laparoscopic surgery.

• 한국항해항만학회지
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• 제28권5호
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• pp.443-448
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• 2004

해양수산부에서는 어업분야의 선진화를 위하여 어로활동의 현황파악 및 문제점을 실시간으로 분석하는 어업성보화의 발전방향을 설정하여 해양자원 관리 및 활용성 제고를 통한 종합적이고 체계적인 정보화 기반을 조성하고 있다. 어업통신의 정보화는 전산화되는 자료가 원격지 여부에 관계없이 자료를 필요로 하는 사용자에게 공유될 수 있는 환경을 구축하는 것으로 전산화-정보통신망-이용자서비스 까지를 종합적으로 고려되어야 한다. 따라서, 본 연구에서는 어선용 VMs(Vessel Monitoring System)를 구현하기 위한 최적의 방안으로 기존의 SSB(Single Side Band) 통신시스템을 이용하여 운용비 부담이 없는 HF(High Frequency)대 SSB 통신에 의한 어선의 어업통신망의 구성 및 무선통신망 프로토콜에 대하여 제안하였다.

• International Journal of Automotive Technology
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• 제3권1호
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• pp.41-46
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• 2002

Effect of secondary air injection (SAI) on hydrocarbon reduction has been investigated in a single cylinder Sl engine operating at cold-steady/cold-start conditions. The hydrocarbon emission and exhaust gas temperature with and without catalytic converter were compared with continuous and synchronized SAIs, which injected secondary air intermittently into exhaust port. Effects of SAI location, SAI pressure, SAI timing, and location of catalytic converter have been investigated and the results are compared for both SAls with base condition. At cold-steady condition, the rate of HC reduction increased as the location of SAI was closer to the exhaust valve for both synchronized and continuous SAls. The emission of HC decreased with increasing exhaust-A/F when it was rich, and was relatively insensitive when it was lean. The timing of SAI in synchronized SAI had significant effect on HC reduction and exhaust gas temperature and the synchronized SAI was found to be more effective in HC reduction and exhaust gas temperature compared to the continuous SAI . At cold-start condition, when the catalytic converter was located 20 cm downstream from the exhaust port exit, the catalytic converter warm-up period for both SAls decreased by about 50%, and the accumulated hydrocarbon emission during the first 120 s decreased about by 56% and 22% with the synchronized and continuous SAIs, respectively, compared to that of the base condition.

• 한국해양환경ㆍ에너지학회지
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• 제12권3호
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• pp.124-132
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• 2009

하수의 해양방류시스템의 형식과 방류위치 결정을 위해 해수유동모의, 근해역 희석률 모의 그리고 원해역 확산모의가 수행되었다. 방류 후보지점 주변의 조위와 조류는 관측조위 및 조류를 잘 재현하는 2차원 유한요소모형에 의해 수행되었으며, 계산된 조위 및 조류 모의결과에 기초하여 방류 후보지점이 결정되었다. 방류시스템으로는 단일확산관과 다공확산관이 고려되었다. 단일확산관과 다공확산관을 통한 하수 방류의 근역 확산이 CORMIX모형에 의해 검토되었으며, 원역 확산이 2차원 Random-walk 확산모형에 의해 실시되었다. 모의결과로부터 수심, 조류, 방류위치, 방류속도, 확산관 길이 등이 확산범위와 희석률에 미치는 영향이 다각도로 검토되었다.