• Journal of Advanced Marine Engineering and Technology
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• 제31권1호
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• pp.44-50
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• 2007

Diesel engines have high thermal efficiency, and they have less CO & HC emissions than another engines. while NOx & Soot emissions are very much. compared with exhaust emission standards. However, the limit level is more and more strengthened yearly due to the importance of environmental protection. So, the optimal countermeasures for the reduction of NOx & Soot emissions below limit level are required. Therefore. the author has investigated the effects of emulsified fuel on the characteristics of exhaust emissions. using an four-cycle, four-cylinder and direct injection diesel engine because the using of emulsified fuel among various methods for reducing NOx & Soot emissions is simple in installation low in cost and high in efficiency. The results of investigation according to various operating conditions are as follows : 1) Specific fuel consumption increase maximum 19.8% at low load. but is not affected at full load. 2) In case of emulsion ratio 25%, NOx emission decrease 32% at 75% load. 30% at full load. 3) In case of emulsion ratio 25%, Soot emission decrease 84% at 75% load, 59% at full load.

• International Commerce and Information Review
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• 제8권1호
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• pp.125-141
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• 2006

It is no unnecessary to tell the importance of foreign trade in Korea economics. Nevertheless, government's direct support is impossible owing to WTO's regulation. Accordingly, government have brought focus into trade facilitation as paperless trade. e-Trade document repositary building by government's budget and private sector's cooperation is a part of e-Trade platform and necessary function in connection with relay and certification of e-Trade document. This study examined the estimated operational problems of e-Trade document repositary as compared Licensed Electronic Document Repositary. Firstly, the operator of e-Trade document repositary undertake multiple role and function as Licensed Certification Authorities(e-sign Act), Licensed Electronic Document Repositary(Framework Act on Electronic Transaction) etc. Secondly, sufficient levy that meet operating cost of the e-trade document is the key point of e-Trade document repositary's success, because additional budget invest in that operation is too hard to do. Thirdly, the operator of the e-Trade document repositary have to keep fairness, objectivity and transparency because the operational right is exclusive.

• Transactions of the Korean Society of Automotive Engineers
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• 제11권4호
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• pp.58-67
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• 2003

An automotive engine cooling system is closely related with overall engine performances, such as reduction of fuel consumption, decrease of air pollution, and increase of engine life. Because of complex reaction between each component, the direct experiment, using a vehicle, takes high cost, long time, and slow response to the system change. Therefore, a computer simulation would provide the designer with an inexpensive and effective tool for design, development, and optimization of the engine cooling system over a wide range of operating conditions. In this work, it has been predicted the thermal performance of the engine cooling system in cases of stationary mode, constant speed mode, and city-drive mode by mathematical modelling of each component and numerical analysis. The components are engine, radiator, heater, thermostat, water pump, and cooling fans. Since the engine model is the most important, that is divided into eight sub-sections. The volume mean temperature of eight sub-sections are simultaneously calculated at a time. For detail calculation, the radiator and heater are also divided into many sub-sections like control volumes in finite difference method. Each sub-section is assumed to consist of three parts, coolant, tube with fin, and air. Hence it has been developed the simulation program that can be used in case of design and system configuration changes. The overall performance results obtained by the program were desirable and the time-traced tendencies of the results agreed fairly well with those of actual situations.

• Journal of the Korean Vacuum Society
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• 제4권S2호
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• pp.106-114
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• 1995

Direct implantation of metallic ion species has been employed in surface processing of industrial components and tools with very encouraging improvements in recent years. In spite of high technicla effectiveness, this new surface processing technique has not been extensively accepted by industries mainly because of high cost(capital and operating) compared with other competitive surface processing techniques. High current and large implantation area with eliminating the mass analyzer and the beam-scanning unit make metal vapor vacuum are(MEVVA)source ion implantation versatile, simple and cheap to operate and well suited to commercial surface processing. In this paper, the recent development of MEVVA source ion implantation technique ar Beijing Normal University has been reviewed and the results of production trials of several industrial components and tools implanted by MEVVA source ion implantation have been presented and discussed.

• Journal of the Korean Applied Science and Technology
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• 제31권3호
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• pp.466-471
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• 2014

It is important to develop the smart ventilation system in order to minimize a building energy consumption using ventilation. In this study, We evaluated the efficiency of the smart ventilation system being developed at the nursery. To evaluate the energy savings and carbon dioxide removal efficiency, two kinds of experimental conditions were compared. First, air conditioner and Smart HVAC system were operated. Second, air conditioner was operating and external air was put into the inside by rate of air circulation. It was more effective when working with air conditioning and ventilation system at the same time. If the Smart HVAC system is applied in a multi-use facility, indoor air quality will be comfortable and the social cost will be reduced.

• Journal of Korean Public Health Nursing
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• 제3권2호
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• pp.5-46
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• 1989

The current medical payment Insurance Rates in Korea stipulate charges for medical treatment by the doctor, pharmaceutist, medical technician and maternity nurse. But unfortunately didn't specify those charges for nursing done by the professional nurse. Only basic nursing fee is accounted insufficiently in current medical insurance fee schedule. therefore, Being face with covering entire people by medical insurance by 1991, It seems that the problems pertaining to operating the hospital and medical insurance system would be incessantly expanded in that no mention is made of medical charges rendered by major medical producer service in the current system, For that reason, this study made an attempt to clarify the importance the professional nursing puts of the current medical payment. The purpose of this study was to accounting nursing fee which diveded into the current medical fee schedule. (Method) 1. Data collection; Importance and difficulties in nursing activities was conducted in 'S' National University Hospital. Total nursing activities were selected 72 items which included direct care and indirect care. This study was conducted to evaluating the degree of importance and difficulties according to nursing activities through questionnaire to 204 RN. and so relative difficulties (acuity) were computered because the nursing cost level of each nursing service was differently established by the equivalent coefficient according to degree of relative difficulty and time required. 2. Calculation of cost according to nursing activities; After 47 nursing activities were selected in General surgery nursing units, calculation of nursing cost was as follows Cost of Nursing activity = (relative difficulty X Average hourly wage and benefits of nurse) + material cost of nursing -t- Average nursing administration cost So, Calculated cost by nursing activities was compared to current non-insured and insurance rate. 3. Calculation of nursing cost by K - DRG ; Total of 578 patients who were hospitalized in General Surgery units from January to March 1988 ware classified by K - DRG After estimation of total nursing cost based on the K-DRG, verified the appropriateness of basic nursing fee in medical insurance rate (Results) 1. Analysis of degree of importance and difficulties were 4.16 and 3.67 based on 5 point scale. This score were judged that it is worthy specifying the nursing fee 2. The nursing cost of 47 nursing service items in general surgery patients showed that the average cost of nursing activity was \1374.5 and The lowest cost was \217 of 'oral administration nursing' item, The highest cost was \11,025 of 'saline enematill clear' item 3. The result of comparison between the calculated cost by nursing activities against the current non-insured and insurance rate showed that 13 items(27.7%) involved to payment of insurance rate, 9 items(19.1%) involved to non-insured rate, remainder 25 items (53.2%) were not charged anywhere of total 47 nursing activities 4. When calculated cost by nursing activities was 100. current insurance rate was 62.3, non-insured rate was 176.6. Therefore this showed that most of non-insured rate were higher than calculated nursing cost. The insurance rate, however, were lower than it. Reim-bursement was imputed to non-insured patients. So the current rate system became estrainged from cost system. When Remainder 25 items of nursing activities compared' to \1390 of daily basic nursing fee per patient belonged to payment as a insurance fee schedule, basic nursing fee schedule was 1-2% of calculated cost of nursing activities. Therefore it showed that nursing fee was not counted adequately in it. 5. Nursing cost by K-DRG estimated in chart review based on counting number of nursing activities and length of stay The result showed that average amount of total nursing cost was \183828.1 Comparison of nursing cost calculated by K- DRG and basic nursing fee schedule showed that only 12.3% of nursing cost was charged (Conclusion) From the above research result, It is fact that nursing prime cost should be estimated more accurately and included adequately in current medical payment system. The payment system of nursing activities should be introduced not only nursing activities of drug administration and injection fee belonged to insurance fee schedule but also most nursing activities belonged not to mekical fee schedule. Even if introducing payment system of nursing activities, It should be estimated scientific method of Accounting nursing cost So nurses could offer nursing care of good quality, thereby they could make a great contribution not merely to the convalescence of the patient but to the promotion of the people's health.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 한국소음진동공학회 2009년도 추계학술대회 논문집
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• pp.421-426
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• 2009

This paper presents vibration analysis of maskless exposure module in Printed Circuit Board (PCB) manufacturing system. In order to complete exposure process in PCB, masking type module has been widely used in electronics industries. However, masking process confronts some limitations of application due to higher production cost for masking as well as lower printing resolution. Therefore, maskless exposure module is started to be in the spotlight for flexible production system to meet the needs of fabrication in variable patterns at low cost. Since maskless exposure process adopts direct patterning to PCB, vibration problems become more critical compared to conventional masking type process. Moreover, movements of exposure engine as well as stage generate vibration sources in the system. Thus, it is imperative to analyze the vibration characteristics for the maskless exposure module to improve the quality and accuracy of PCB. In this study, vibration analysis using the Finite Element Analysis is conducted to identify the critical structural parts deteriorating vibration performance. Also, Experimental investigations are conducted by single/dual encoder measurement process under the operating module speed. Measurement points of vibration are selected by three places, which are base of stage, exposure engine and top of stage, to check the effect of vibration from the exposure engine. Comparisons between analysis results and experimental measurement are conducted to confirm the accuracy of analysis results including the developed FE model. Finally, this studies show feasibility of optimal design using the developed FE analysis model.

• Journal of Internet Computing and Services
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• 제13권1호
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• pp.27-36
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• 2012

This study aims to find out the effectiveness of regulation of promotional gifts and exemption of charges by analyzing the judgement criterion of illegality and the corrective action taken by regulatory agencies and suggests effective way of regulation. The results show that recently the differences of price-cut is getting bigger. In addition, Fair Trade Commission has considered discounts as unfair predatory price only if price is below the cost. But in the telecommunication business law enacted by Korea Communications Commission, 'expected profits per subscriber' has been applied as a key criterion. KCC's criterion is based not on the expected profit of individual service provider but on the averaged profit of services providers. It doesn't consider differences of service quality and the cost structure between dominant firm and late comers. Prohibition act of user discrimination result in the increase of subscriber and operating profits of late comers but this is not direct purpose of regulation. It can be desirable in the aspect of fair competition but since it may reduce consumer welfare, the criterion needs to be reconsidered.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• 제19권12호
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• pp.1322-1328
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• 2009

This paper presents vibration analysis of maskless exposure module in printed circuit board(PCB) manufacturing system. In order to complete exposure process in PCB, masking type module has been widely used in electronics industries. However, masking process confronts some limitations of application due to higher production cost for masking as well as lower printing resolution. Therefore, maskless exposure module is started to be in the spotlight for flexible production system to meet the needs of fabrication in variable patterns at low cost. Since maskless exposure process adopts direct patterning to PCB, vibration problems become more critical compared to conventional masking type process. Moreover, movements of exposure engine as well as stage generate vibration sources in the system. Thus, it is imperative to analyze the vibration characteristics for the maskless exposure module to improve the quality and accuracy of PCB. In this study, vibration analysis using the finite element analysis is conducted to identify the critical structural parts deteriorating vibration performance. Also, Experimental investigations are conducted by single/dual encoder measurement process under the operating module speed. Measurement points of vibration are selected by three places, which are base of stage, exposure engine and top of stage, to check the effect of vibration from the exposure engine. Comparisons between analysis results and experimental measurement are conducted to confirm the accuracy of analysis results including the developed FE model. Finally, this studies show feasibility of optimal design using the developed FE analysis model.

• Journal of the Korean Institute of Navigation
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• 제4권2호
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• pp.45-79
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• 1980

The aim of this paper is to analyze the mechanics of price formation in the tramp shipping. For the purpose of this study, the main characteristics of tramp freight rates and the market is examined, and a brief examination of the nature ofthe costs of operation is given which are essential for the understanding of the functioning of shipping firms as well as for the understanding of developments in the tramp freight market. The demand and supply relationships in the market is also analysed in detail. Tramp shipping is an industry that has a market which functions under conditions that are not dissimilar to the theoretical model of perfect competition. However, it does notmean that tramp shipping market is a perfectly competitive market. It is apparent that this realworld competitive system has its imperfections, which means that the market for tramp shipping is near to being a perfectly competitive market on an internaitonal scale and it is freight are therefore subjext to the laws of supply and demand. In theory, the minimum freight rate in the short term is that at which the lowest cost vessels will lay-up in preference to operating, and is equal to the variable costs minus lay-up costs; and this would imply that in all times except those of full employment for ships there is a tendency for newer low-cost, and, probably, faster vessels to be driving the older high-cost vessels in the breaker's yards. In this case, shipowners may be reluctant to lay-up their ships becasue of obligations to crews, or because they would lose credibility with shippers or financiers, or simply because of lost prestige. Mainly, however, the decision is made on strictly economic grounds. When, for example, the total operating costs minus the likely freight earnings are greater than the cost of taking the ship out of service, maintaining it, and recommissioning it, then a ship may be considered for laying-up; shipowners will, in other words, run the ships at freight earnings below operating costs by as much as the cost of laying them up. As described above, the freight rates fixed on the tramp shipping market are subject to the laws of supply and demand. In other words, the basic properties of supply and demand are of significance so far as price or rate fluctuations in the tramp freight market are concerned. In connection with the same of the demand for tramp shipping services, the following points should be brone in mind: (a) That the magnitude of demand for sea transport of dry cargoes in general and for tramp shipping services in particular is increasing in the long run. (b) That owning to external factors, the demand for tramp shipping services is capable of varying sharphy at a given going of time. (c) The demad for the industry's services tends to be price inelastic in the short run. On the other hand the demand for the services offered by the individual shipping firm tends as a rule to be infinitely price elastic. In the meantime, the properties of the supply of the tramp shipping facilities are that it cannot expand or contract in the short run. Also, that in the long run there is a time-lag between entrepreneurs' decision to expand their fleets and the actual time of delivery of the new vessels. Thus, supply is inelastic and not capable of responding to demand and price changes at a given period of time. In conclusion, it can be safely stated that short-run changes in freight rates are a direct result of variations in the magnitude of demand for tramp shipping facilities, whilest the average level of freight rates is brought down to relatively low levels over prolonged periods of time.