• Journal of Welding and Joining
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• 제34권5호
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• pp.19-25
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• 2016

Global warming is hot issue to keep the earth everlastingly. Despite the increase of the world population and the energy demand, the world oil supply and the oil price are hold the steady state. If we are not decrease the world population and the energy consumption, unforeseeable energy crisis will come in the immediate future. AMT acronym of Advanced Materials for Transportation is a non-profitable IEA-affiliated organization to mitigate the oil consumption and the environment contamination for the transportation. In recent, Annex X Multi-materials Joining was added to enhance the car body weight reduction cause the high fuel efficiency and the low emission of exhaust gas. Multi-materials are the advanced materials application technology to optimize the weight, the performance and the cost with the combination of different materials such as Al-alloy, Mg- alloy, AHSS and CFRP. In this study, the trends of AMT strategy and Al-alloy based multi-materials joining technology were review. Also several technologies for Al-alloy dissimilar joining were investigated.

• 동아시아경상학회지
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• 제3권4호
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• pp.5-8
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• 2015

In addition to the increased used for smart phones daily, various characteristics and problems for social commerce have been drawn attention recently, and also, have been analyzed by various impact factors which were given to the purchasing behaviors of consumers through social commerce. The study investigated consumers' use of social commerce based on SNS by using articles of Fair Trade Commission, Korea Consumer Agency and so on. As a result, cost reduction characteristics of social commerce, the impulse buy, and to understand in Review effect, latest mobile shopping growth of increases explosively, market by market conditions to move from offline to online, the social commerce it was found to have a significant impact on the time of the purchase of the consumer. In addition, the study has discussed the results of the significance and limitation. With those things, they can be a suggestion for future research. More than half of the consumers were satisfied with social commerce. The consumers made use of social commerce 1 or 2 times a month and when they were watching banner advertising. In detail, food and beverage tickets such as restaurants, café and bars occupied 35%, and they showed the highest. 'We-make-price', 'Ticket Monster' and 'Coupang' were used to investigate as representative social commerce companies.

• 한국병원경영학회지
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• 제13권4호
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• pp.101-118
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• 2008

Japanese national health expenditure was 8.0% of GDP in 2004, and it was lower than average of OECD countries. But it has increased rapidly in recent years. Japan has relatively many acute care beds and high-price medical equipments, and the average length of stay is long. Japanese government is trying healthcare reform to contain healthcare expenditure, increase the efficiency of management and improve the quality of healthcare. As healthcare policies for hospitals such as DPC (Diagnosis Procedure Combination) for acute care beds, reduction of long-term care beds, and functional differentiation and liaison among healthcare institutions are implemented, the number of hospitals in financial difficulties is increasing. The serious situation urges hospitals to adapt to changes and search new directions of management. They need to establish and implement appropriate positioning strategy, and increase management efficiencies. Korean healthcare system has similarities with Japanese in many aspects. The recent reform and changes in Japanese healthcare system and hospitals give suggestions to Korean hospitals as to how they can prepare for environmental changes and improve management.

• 가족자원경영과 정책
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• 제9권1호
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• pp.1-15
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• 2005

This study was designrd to determination factors of purchase expansion for environment-friendly agricultural products on consumers. The 310 subjects formatted questionnaires were analyzed to frequency, percentage, descriptives, T-test and logistic regression by SPSS WIN 10.0. The results were as follows : First, it is proved that degree of cognition, standard of information acquisition, basis of valuation were significant variables, Second, it is revealed that the producer and the direct deal, the consumer organization's co-op and the food floor of large-sized discount hoarded goods for purchase places of environment-friendly agricultural products were significant variables. Third, it is proved that reduction in a price the improvement matter for purchase expansion of environment-friendly agricultural products was determination factors. Forth, it is proved that age and income for purchase expansion of environment-friendly agricultural products was determination factors. Accordingly, we should find the positive factors of purchase and consumption that it will become an important subject for environment-friendly agricultural products on consumers.

• 한국생산제조학회지
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• 제21권5호
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• pp.778-783
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• 2012

Due to the increase of oil price, the needs of the reduction of the fuel cost is rising. Therefore, necessity of hybrid vehicle that runs with engine and the electric motor is on the rise. In order to improve the performance of hybrid vehicle, many researches is carried out. Hybrid vehicles have been developed with the various layout such as serial type, parallel type, power split type, and multi-mode type. The multi-mode hybrid vehicles are designed to show the efficient driving characteristics at low speed and high speed. But the multi-mode system have the problem such as frequent clutch engagement. Frequent clutch engagement causes the shock of vehicles, and the shock inhibits the ride comfort. In this study, automation mechanism of clutch operation is proposed to mitigate the shock at engaging clutch. For this purpose, the dynamic characteristics of motor control is numerically analyzed by using Matlab/Simulink.

• 상하수도학회지
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• 제26권4호
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• pp.513-520
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• 2012

The use of food waste disposers (FWDs) can be an emerging option to manage organic food wastes in municipal sewage system. The cost-benefit analysis (CBA) of introducing domestic FDWs is conducted to access the allowable disposer market price and the economic impact on food waste management from conventional solid waste management system. If the convenience value of 10,000 won/month is taken into consideration based on survey results, the introduction of FDWs can lead to net economic benefits, allowing the capital cost of disposer up to 1,000,000 won/unit. Without the consideration of convenience value, the introduction of FWDs becomes profitable if the capital cost of disposer is less than 50,000 won/unit. In case that the value of convenience is more than 7,000 won/month, the reduction of food waste management cost is not valid for the introduction of FWDs to be non-profitable. However, if environmental externalities are considered, the proposed system could become breakeven with the cost of food waste management decreases by 54 % (60,000 won per ton).

• 한국가스학회지
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• 제15권4호
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• pp.33-38
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• 2011

The introduction of alternative fuels is beneficial to overcome the fuel shortage and reduce engine exhaust emissions. LPG and CNG are relatively clean fuel and considered as most promising alternative automotive fuels worldwide because of its emission reduction potential and lower fuel price compared to gasoline. Now a day’s adaptation of dual fuel approach is the growing as common trend. The two fuels can be successfully implemented with existing gasoline engine with little modification. The present study was done to analyze the performance and emissions analysis of a multi cylinder spark ignition engine fuelled with the benefits of CNG and LPG aseffective alternate automotive fuels by simply using them in an unmodified petrol engine. The test results indicate, the energy content of CNG and LPG is the most limiting factor in acceptance for fuel economy and performance reasons. Thermal efficiency was high for CNG lowest for gasoline and LPG between the two. BSFC, CO and HC were low and NOx was high for CNG and low for gasoline, LPG lies between the two.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.354-357
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• 2008

Drag reduction is one of main concerns for commercial aircraft companies than ever because fuel price has been tripled in ten years. In this research, Natural Laminar Flow airfoil is designed and tested to reduce drag at cruise condition, $c_l$=0.3, Re=3.4${\times}$10$^6$ and M=0.6. NLF airfoil is characterized by delayed transition from laminar to turbulent flow, which comes from maintaining favorable pressure gradient to downstream. Transition is predicted by solving Boundary Layer equations in viscous boundary layer and by solving Euler Equation outside the boundary layer. Once boundary layer thickness and momentum thickness are obtained, $e^N$-method is used for transition point prediction. As results, KARI's NLF airfoil is designed and shows better characteristics than NLF-0115. The characteristics are tested and verified at low Reynolds numbers, but at high Reynolds numbers, laminar flow characteristics are not obtainable because of fully turbulent flow over airfoil surfaces. Precious experiences, however, relating NLF airfoil design, subsonic and transonic tests are acquired.

• 한국CDE학회지
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• 제4권3호
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• pp.26-31
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• 1998

Recent trend of popularity of CAE(Computer Aided Engineering) tools and its availability, partly contributed by significant price reduction of H/W and SW, makes us believe CAE has already established terra firma as de jure tools, enablint the design improvement in the manufacturing am. However, if your jobs are required to be working closely with engineers located in the front line of manufacturing site, CAE is observed far from popularity, still being regarded as exclusive tools for engineers holding advanced degrees. Conventional methodologies depending on knowledge that was accumulated thorough trial and errors, depending primarily on engineering tables and formulas or proprietary know-how, are preferred as the de factor standard under the roof of contemporary development shops. Samsung camera, having stared its business since early 、80, has accumulated enough technological strength to compete in the world market. As today's consumers demand more sophisticated featured-lighter weight, built-in multi zoom and miniature size fitting in the palm-from camera manufacturer, so should Samsung camera respond to ever-delicate consumer's needs with great flexibility. Consequently conventional designers, without sophisticated analytical tools, with encounter solving the critical design factors that have never been treated as seriousness-marginal safety factors induced by reduced size of parts. In the study, CAE results of boss and gears were demonstrated as examples, which confirms the facts that the simple analysis done by front line designers, can bring distinguishable effects on the potential improvements of design and on the consequential influences on the future design process-simulation before actual tooling and productions.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.376-380
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• 2009

Peer-to-Peer content delivery technology recently begins to be used not only for file sharing applications such as eDonkey but also for every kind of content services. KBS, a broadcasting company in Korea, is aggressively driving to apply Peer-to-Peer technology to KBS's commercial internet video service but we found that there are two big huddles. First, end users may refuse to share their own resources for KBS's cost reduction using Peer-to-Peer content delivery technology. Second, it may cause that the number of free-riders increases and the efficiency of the overall system would fall. From commercial service provider's perspective, we have to avoid that end users have unfavorable impressions on the service and the usefulness of Peer-to-Peer technology decreases. In order to overcome these problems, we studied how to offer incentive to end users and how much incentive would be reasonable, and then applied the result to real service for verification.