• Transactions of the Korean hydrogen and new energy society
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• v.9 no.1
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• pp.1-7
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• 1998

Most of today's energy supply is obtained from fossil fuels. Despite of high energy density, higher store efficiency and long mileage, fossil fuels cause environmental pollution and their reserves are limited. In this study pure hydrogen gas and oxygen gas are burned without the emission of pollution. A gas turbine is used to obtain power. Water is injected into a combustor, which prevents overheating and recovers cooling heat. Excessively supplied water is recirculated. With variation of mass flow rate and equivalence ratio, the affection of water injection rate and the temperature of injected water on efficiency and power are experimented. Injected water gets cooling heat, is expanded from liquid to vapor and raises the thermal efficiency. It is enable to determine the rate of water injection, which makes the maximum power. The increase of temperature of water injection raises the efficiency of the system.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1324-1327
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• 2009

Social infrastructure is the basis of public welfare and should be recognized and managed as important assets. Bridge is one of the most important infrastructures to be managed systematically because the impact of the failure is critical. It is essential to monitor the performance of bridges in order to manage them as an asset. But current analytical methods such as predictive modeling and structural analysis are very complicated and difficult to use in practice. To apply these methods, structural and material condition data collection should be performed in each element of bridge. But it is difficult to collect these detailed data in large numbers and various kinds of bridges. Therefore, it is necessary to collect data of major measurement items and predict the life of bridges roughly with advanced information technologies. When certain measurement items reach predefined limits in the monitoring bridges, precise performance measurement will be done by detailed site measurement. This paper describes the selection of major measurement items that can represent the tendency of bridge life and introduces automated bridge data collection test-bed using wireless sensor network technology. The following will be major parts of this paper: 1) Examining the features of conventional bridge management system and data collection method 2) Mileage concept as a bridge life indicator and measuring method of the indicator 3) Test-bed of automated and real-time based bridge life indicator monitoring system using wireless sensor network

• Journal of IKEEE
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• v.20 no.2
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• pp.200-204
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• 2016

In this paper, we have estimated the performance of an overflow valve for EURO type CRDI(common rail direct injection) engine. In order to implement the overflow valve with friendly circumstance, it is necessity for considering spring load. Especially, the performance evaluation of diesel car with accuracy control will be considered a mileage improvement and circumstance regulation. In order to evaluate the performance of overflow valve, The leak test system checks the pressure, switching time and operating time under 3.0 bar below 100 cc, 3.3 bar among 150 cc and 200 cc, finally 4.0 bar upper 250 cc.

• Journal of Digital Contents Society
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• v.16 no.2
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• pp.317-324
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• 2015

In this paper, we analyze the optimum moving speed of taxi for maximum revenue. In the analysis, we vary taxi speed from 5km/h through 80km/h to see how revenue of a taxi varies applying the practical gas mileage of LPG taxi and taxi fare system in Korea. From the results of the analysis, we see that the probability that a taxi meets passengers goes high as taxi speed gets fast, however the fuel cost also goes up. We also obtain the optimum speed for the maximum revenue according to passenger distribution while varing moving speed.

• Journal of the Korean Society for Railway
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• v.16 no.2
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• pp.93-98
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• 2013

Railway system is today the most efficient way for transportation in many cases in several forms of application. Yet, wear phenomenon, profile evolution, fatigue, fracture, derailment are the major worries (financial and safety) in this system which force significant direct and indirect maintenance costs. To improve the cyclic maintenance procedures and the safety issues, it can be very satisfactory to be informed of the state of wheel/rail interaction with mileage. In present paper, an investigation of the behavior of the shear stresses by logged distance is approached, by implementing the field measurement procedure, in order to determine the real conduct of the most important cause of defects in wheel/rail contact, shear stress. The results coming from a simulation procedure indicate that the amounts of shear stresses are still in high-magnitudes when the wheel and rail are completely worn; even though in simulation based on the laboratory measurements of profile evolutions, the stresses become significantly reduced by logged distance.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.2 s.257
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• pp.188-194
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• 2007

New diesel engines equipped with common-rail injection systems and advanced engine management control allow drastic decreases in the production of particulate matters and nitrogen oxides with a significant advantage in terms of the fuel consumption and $CO_2$ emissions. Nevertheless, the contribution of exhaust gas after treatment in the ultra low emission vehicles conception has become unavoidable today. Recently the passive type DPF(Diesel Particulate Filter Trap) system for diesel passenger vehicle has been manufactured into mass production from a French automotive maker since the year of 2000. This passive DPF system fully relies on the catalytic effects from additives blended into the diesel fuel and additives injected into the DPF system. In this study, the effects of PM regeneration in the commercial diesel passenger vehicle with the passive type DPF system were investigated in chassis dynamometer CVS(constant volume sampler)-75 mode. As shown in this experimental results, the DPF regeneration was observed at temperature as low as $350^{\circ}C$. And the engine-controlled the DPF regeneration founded to be one of the most promising regeneration technologies. Moreover, the durability of this DPF system was evaluated with a season weather in terms of the differential pressure and exhaust gas temperature traces from a road test during the total mileage of 80,000km.

• Korea Journal of Hospital Management
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• v.6 no.1
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• pp.18-40
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• 2001

This study purports to investigate the readiness of the university hospital employees in the knowledge-based management. Data were collected from 550 employees including administrative, nursing, and technical staff of 9 university hospitals located in Seoul and Kyunggi Province through the self-administered questionnaires. The response rate was 79% and 425 questionnaires were used as final data and analyzed using 2 test, t-test, and ANOVA. The main findings of the study are as follows. 1) It seems that most employees of the study hospitals have basic knowledge on the concept of knowledge-based management. This finding implies that the implementation of the knowledge-based management in Korean university hospitals will not likely to face strong resistance from their employees. 2) The results show that Korean hospital employees are still not so accustomed to using e-mail as the main communication tool. This finding suggests that it is necessary to use various communication tools which include electronic data interchange, teleconference, and cyber chatting for facilitating the knowledge-based management in Korean university hospitals. 3) It is desirable to appoint a chief knowledge officer(CKO) for operating knowledge-based management system effectively. 4) A reward system for employees who show a distinguished performance in the creation and sharing of new knowledge should be established. Knowledge mileage system, selection of the best knowledge employee and team will be a good example of the effective reward system. 5) The participation and support from the chief executive officers (CEO) of the hospitals is an important factor for successful knowledge-based management. Furthermore, to make physicians actively participate in the knowledge-based management is another important factor for obtaining valuable outputs from the system. 6) It is found that the knowledge and skills of the hospitals employees on the information technology (IT) are not sufficient for making knowledge-based management more popular. This implies that it is very important to select IT-oriented employees and educate them continuously on the knowledge-based management.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.1 s.149
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• pp.1-11
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• 2006

The purpose of this study was to analyze the current CRM situation in Korean apparel industry. Specifically, research purposes were 1) to examine the concepts and benefits of CRM, 2) to examine CRM strategies, 3) to analyze CRM system(i.e., customer relationship management service, customer segmentation criteria, DB management system), and 4) to analyze the potential problems and CRM adoption plan. The subjects for this research were thirty CRM managers in Korean apparel firms classified by the company type(woman's wear, man's wear, casual wear, children's wear, retailer) interviewed from December 2003 to March 1004. The results of this study were as follows: First, the concept of CRM represented the prime customer relationship, continuous consideration, and customer management system. The benefits of CRM reflected re-sales, improvement of profit share, and acquisition of customer's data base. Second, concerning the CRM strategies, most companies focused on persistent customer management through mileage program, membership cards and also implemented product strategies such as demand forecasting, customization based on customer data analysis. We also found that industry preferred to use pricing strategies, for example, segmentation of customer through discrepancies of price in which customers are provided by discount and gift voucher services. Regarding distribution strategy, channel diversification, localized service, and convenient delivery system were used. As promotion strategies, they chose celebrating customers' personal events and promoting cultural events and issuing coupons. Third, regarding CRM system, information service was the most frequently adopted, important and highly beneficial category. Also POS/web-POS, homepage were main sources of information. RFM is the mostly commonly used customer segmentation criteria. Fourth, potential problems in CRM adoption were lack of CRM knowledge and performance measurement of CRM. Future CRM adoption plan included CRM education and development of CRM performance measures.

• IE interfaces
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• v.13 no.3
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• pp.471-478
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• 2000

One of the most important problems encountered by parcel transportation firms or LTL (Less-than-truckload) firms is the planning of daily linehaul operations. The transportation firm's goal is to determine the most efficient way to move all freight from its originating terminal to its destination terminal after each shipment is picked up from the shipping dock. The purpose of this study is to design a transportation system and develop an efficient scheduling algorithm for linehaul operations carrying small amount of shipment. This paper presents three approaches for efficient linehaul operations. The first approach examines drivers using the roundtrips which start from a terminal, visit several terminals, and return to the starting terminal. The second approach uses a freight assembly center where drivers take freight for a number of destination terminals which they then swap for freight for their starting terminal. The third approach is similar to the second approach in that it uses a transshipment point like a freight assembly terminal for shipment, but it has several transshipment points since each shipment may have a different transshipment point. In this study, we developed a mathematical formulation and algorithm for each approach. The experimental results using data of a LTL firm show that the third approach is more efficient than the other two. Mileage and overnight stays of the third approach are reduced by 10% and 30%, respectively.

• Fashion & Textile Research Journal
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• v.16 no.4
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• pp.596-603
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• 2014

The purpose of this study was to find affecting consumer's usage motivation on purchase satisfaction and repurchase intension when purchasing fashion products in social commerce. The data were collected via a self-administered questionnaire from 239 male and female who living in Busan with experience in social commerce purchasing fashion products. Using SPSS 20.0 and AMOS 20.0 package, Cronbach's ${\alpha}$, a confirmotory factor analysis and a structural equation modeling analysis were performed. The results are as follows. Hedonic, economical efficiency and interaction without information provide subjective norms significantly influenced the purchase satisfaction. And aforementioned subjective norms significantly influenced repurchase intension, too. The purchase satisfaction positively influenced the repurchase intension. Therefore, social commerce sellers of fashion products ought to offer variety price benift and promotion to raise the purchase satisfaction and repurchase intension. To offer variety price benift, they should respond sensitively to the price set by comparing prices with other sellers. And promotion to raise the purchase satisfaction and repurchase intension need to consider such variety of missions, discount coupons or event and mileage. In addition, they should develop customer service system for interaction with customer and connect to the repurchase increases the purchass satisfaction through faster customer response to the product information or sales, service.