• Journal of Advanced Marine Engineering and Technology
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• 제30권1호
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• pp.42-49
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• 2006

In this research. the diesel cycle was thermodynamically interpreted to evaluate the possibility of high efficiency by converting diesel engines to the high expansion diesel cycle, and general cycle features were analyzed after comparing these two cycles. Based on these analyses. an experimental single cylinder a long stroke with high expansion-diesel engine. of which S/B ratio was more than 3, was manufactured. After evaluating the base engine through basic experiments, a diesel engine was converted into the high expansion diesel engine by establish VCR device and VVT system Accordingly, the high expansion diesel cycle can be implemented when the quantity of intake air is compensated by supercharge and the effective compression ratio is maintained at its initial level through the reduction of the clearance volume. In this case, heat efficiency increased by $5.0\%$ at the same expansion-compression ratio when the apparent compression ratio was 20 and the fuel cut off ratio was 2. As explained above, when the atkinson cycle was used for diesel cycle, heat efficiency was improved. In order to realize high expansion through retarding the intake value closing time, the engine needs to be equipped with variable valve timing equipment, variable compression ratio equipment and supercharged pressure equipment. Then a high expansion diesel cycle engine is realized.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.281-286
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• 2001

Tilting pad journal bearings have been widely used in a high speed rotating machinery, such as steam turbines and gas turbines, owing to their inherent stability characteristics. However, some peculiar fatigue failure in the babbitt metal due to spragging has been continuously occurred at the leading edge of the upper pads. The spragging is defined as the pad vibration initiated on the upper unloaded pads in a tilting pad journal bearing. This paper describes both several kinds of bearing failure related with spragging and the theoretical investigation on the prevention of the spragging phenomenon using the variation of preload. Results show that positive preload(m>0.5) assures all pads remain statically loaded under all operating conditions. For the change of design parameter to prevent spragging, thermo-hydrodynamic lubrication and rotor dynamic analysis were performed to verify temperature limitation on bearing and vibration problems on rotor bearing system.

• Journal of Pharmaceutical Investigation
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• 제22권2호
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• pp.77-96
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• 1992

In recent years intranasal administration of drugs has received great attention as a convenient and efficent method of drug delivery because of its potential to improve the systemic effect of substances with a poor oral bioavailability. In addition to offering advantages such as rapid absorption, fast onset of action and avoiding the first -pass effect, it provides for delivery of drugs from very lipophilic drugs such as steroids to polar and hydrophilic drugs such as peptides and proteins. However, little is still known about the nature of various barriers existing in the nasal mucosae as well as mechanism by which these molecules are absorbed. This review article therefore intends to discuss nasal physiology, experimental methods and evaluation of absorption from the nasal cavity, factors influencing nasal absorption, mechanism of nasal absorption, approaches to improve the residence time and to obtain the sustained-release effect of intranasally administered drugs, promoters and mechanism for the enhancement of nasal absorption, Several examples for intranasal delivery of various systemically effective drugs will be reviewed and illustrated. Drug metabolism in the nasal mucosae and problems associated with intranasal administration of drugs will be also discussed.

• 한국콘텐츠학회논문지
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• 제8권7호
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• pp.146-152
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• 2008

현대사회에는 수많은 영상미디어의 홍수 속에서 영상미디어는 급속도로 발전하고 있다. 송신자와 수신자 사이의 효과적인 커뮤니케이션 수단으로 영상표현 기법의 한 분야인 모션그래픽이 대두되고 있는 실정이다. 모션그래픽은 수신자에게 정보를 보다 쉽고 정확하게 전달하기 위해 시각정보의 명확성을 부여하고 이미지의 전달과 정보전달의 효과를 높이기 위하여 커뮤니케이션 과정의 효과를 증대한다. 본 연구에서 논자는 사례를 통하여 최근 관심이 커지고 있는 모션그래픽의 한 분야인 타이틀 디자인이라는 짧지만 함축적인 정보의 전달로 강력한 시각전달로 모션그래픽의 표현방법상의 연구와 구조를 분석하여 실무제작에 있어 보다 낳은 방향으로 커뮤니케이션의 편리성과 효율성을 향상시키기 위한 모션그래픽의 제작방법을 조명해보고자 한다.

• 한국의류학회지
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• 제19권1호
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• pp.142-148
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• 1995

In this study, FVM (Finite Volume Method) which is one of the 2-dimensional numerical approach has been conducted to anticipate the temperature distribution between skin and clothes by the change of air temperature and fabric characteristics including fabric thickness. Several experimental works have been done to understand the thermal insulation effect (If fabrics on a human body by measuring the averaged temperature in the air layer between skin and clothes or by measuring the thermal resistance of fabrics. However, the formal method is inconvenient to measure the temperature distribution in the air layer to evaluate the insulation rate of the clothes on the skin because the real size of the clearance between skin and the clothes is too small to place the temperature sensor, and in the Tatter method the relationship between human body and the fabrics are ignored. However, the numerical method will be very effective and economical way to evaluate the insulation efficiency of clothes when the computational result is in the reliable range. As the result of this study, the temperature change in the sir layer between skin and clothes was linear to the fabric thickness and this result coincides with many previous experimental results. Moreover, it is possible to predict the optimum fabric thickness for the best thermal insulation in the air layer between skin and clothes.

• 한국경영과학회지
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• 제30권3호
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• pp.17-39
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• 2005

The coordination of a three-level supply chain consisting of a supplier, a retailer, and a discount outlet (DCO) is studied here. We assume that the product is sold in two consecutive periods a Normal Sales Period (NSP) and a subsequent Clearance Salvage Period (CSP). A benchmark case is studied Initially in which the supply chain is coordinated by a s1n91e agent. Thus, the supplier the retailer, and the discount outlet design a common system that allows centralized decision making about stocking quantities, markdown time schedules, and policies on disposing of leftovers to deliver the greatest possible expected supply chain profit. Next, we consider a decentralized supply chain. Here, decisions are made without coordination. The objective is to maximize an individual party's expected profits. The focus of the study is on the following questions: what factors make the coordination an effective approach for the supply chain? How do we coordinate the supply chain so as to maximize the supply chain Joint expected profit? These and other related study issues are explored in this paper.

• 무역상무연구
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• 제43권
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• pp.397-422
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• 2009

Electronic trade reduces additional costs generated from the issuing and management of paper documents, and overcomes the physical limitations of commercial transactions as well as the geographical and time limitations resulting from trading with foreign countries. These characteristics of electronic trade guarantees better and more effective global marketing for companies. In addition, by expanding relative superiority of large corporations to medium-small sized companies, many medium-small companies have shown great interest in electronic trade to promote its exporting businesses, and implementing changes to facilitate electronic trade into their business system. Therefore, it is expected that the electronic trade will be more widely distributed and utilized by businesses of all sizes in the future. The adaptation and implementation of the electronic trade system can only have prosperous effects when there is a high efficiency in the utilization and service process of the concerned company. Under this premise, this research first examined electronic trade, characteristics of the company and information utilization as the key elements to determine the effectiveness of the utility aspect. Then it examines confirmation of product demand, registration of revenues, and authorization as the key elements to determine the level of service process.

• Journal of Pharmaceutical Investigation
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• 제38권3호
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• pp.151-155
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• 2008

Circadian variations of acebutolol and its main metabolite, diacetolol pharmacokinetics were studied after a single oral administration of acebutolol (10 mg/kg) to eight rabbits at 10 : 00 AM (in the morning) and 10 : 00 PM (at night). The plasma concentration profiles of acebutolol were significantly different (P<0.05) between 10 : 00 AM and 22 : 00 PM, suggesting circadian variations of pharmacokinetic behaviors. A significant circadian rhythm of pharmacokinetic parameters was noted in rabbits, showing higher total body clearance (CL/F), and lower the area under the plasma concentration-time curves (AUC) of acebutolol than that at night. The half-life ($t_{1/2}$) of acebutolol and diacetolol were also significantly shorter in the morning than at night (P<0.05). Metabolite-parent AUC ratio at night significantly decreased compared to in the morning, implying that night time could inhibit acebutolol metabolism than in the morning. From this study there was an administration-time difference of acebutolol pharmacokinetics in the rabbits. The optimized dosing regimen of acebutolol can be decided by considering circadian rhythm so that the effective therapies are established for patients.

• 통상정보연구
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• 제11권1호
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• pp.3-25
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• 2009

These days international trade has been converting to e-Trade formation. At this point, Korea has been striving for the trade facilitation; reducing logistics cost and improving foreign competitiveness by computerization operations of the maritime transportation that logistics and customs clearance are involved. However, due to the substantial characteristic of logistics service, the necessity of flexible and various logistics service development using internet has been strongly suggested. In particular, the logistics service which could share documents related to international physical movement between shippers and logistics organization. In this regard, this study carried out interview to explore the problems of physical distribution service and to suggest development direction of e-logistics service. The reason why this survey carried out is that most of users want more effective e-logistic service that could diminish successively real expense decrease. After analysis of survey results, this paper presents the basic development direction and emphasis development subjects. Therefore, the basic direction is presented from four viewpoints; customer-oriented approach, service-oriented approach, total approach and step-by-step implementation. Furthermore six development subjects; web-based standard module development for small and medium forwarders, development of standard logistics ERP system, collaboration model between KTNET and KLNET, system improvement for real users, on-demand system building for SMEs and connection with legacy system have been required.

• Childhood Kidney Diseases
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• 제6권2호
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• pp.251-258
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• 2002

저자들은 다장기 부전과 패혈증에 의한 ?상태의 급성 신부전 환아 세 명에서 펌프를 이용한 CVVH를 이용하여 효과적으로 한외여과액을 유지할 수 있었던 경험을 문헌 고찰과 함께 보고하는 바이다.