• Proceedings of the KIEE Conference
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• summer
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• pp.1040-1042
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• 2004

For past decade, medium voltage circuit breakers have used the spring-driven mechanical system for interrupting of electric power. However, these mechanisms have many disadvantages of high power consumption, mechanical control components and electrical switching ones for the coil current. Recently, the vacuum interrupter operated by permanent magnet actuator gives outlook on improved characteristic, higher reliability and cost price reduction as well as the feature of simple structure and few components. This paper deals with the dynamic characteristics of permanent magnet actuator used in the medium voltage distribution systems. Coupled finite element method is used to analysis the dynamic characteristics of permanent magnetic actuator and we compared with those of conventional ones

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.567-570
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• 2000

Thermal simulation of typical stack-type and newly proposed planar-type micro-gas sensors were studied by FEM method. the thermal analysis for the proposed planar structure including temperature distribution over the sensing layer and power consumption of the heater were carried using finite element method by computer simulation and well compared with those of typical stack-type micro-gas sensor. The thermal properties of the microsensor from thermal simulation were compared with those of an actual device to investigate the acceptability of the computer simulation.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.24-26
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• 2004

For past decade, medium voltage circuit breakers have used the spring-driven mechanical system for interrupting of electric power. However, these mechanisms have many disadvantages of high power consumption, mechanical control components and electrical switching ones for the coil current. Recently, the vacuum interrupter operated by permanent magnet actuator gives outlook on improved characteristic, higher reliability and cost price reduction as well as the feature of simple structure and few components. This paper deals with the dynamic characteristics of permanent magnet actuator used in the medium voltage distribution systems. Coupled finite element method is used to analysis the dynamic characteristics of permanent magnetic actuator and we compared with those of conventional ones.

• Journal of Hydrogen and New Energy
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• v.29 no.6
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• pp.661-667
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• 2018

Electric vehicles are taken a long time to charge and are restricted driving where charging infrastructure was not sufficiently constructed. The vehicle developed to solve these problems is a plug-in hybrid vehicle. It is possible to drive a certain distance by using electric motor and when the battery runs out, it operate the engine. Plug-in hybrid vehicle have a complicated structure and a lot of parts comparing a general vehicle because the electric parts and the internal combustion engine are installed together. Therefore, as the aging (mileage) of the plug-in hybrid vehicle, the influence which change of fuel consumption is expected to be larger than a general vehicle, but an experimental data are lacking. In this paper, we cumulate a mileage of the plug-in hybrid vehicle about 15,000 km and measured the fuel economy when the cumulated distance reached within 160 km, 6,500 km, 15,000 km respectively, by using domestic public test method. For measuring fuel economy of the vehicle, CD mode (driving distance on a single charge) which use only motor and the CS mode which operate motor and combustion engine were measured respectively. As a result, the fuel economy slightly increased at cumulated mileage of 6,500 km compared to the 160 km and the fuel economy of 15,000 km was similar to 160 km.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.4
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• pp.313-320
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• 2008

The dynamic clustering technique has some problems regarding energy consumption. In the cluster configuration aspect the cluster structure must be modified every time the head nodes are re-selected resulting in high energy consumption. Also, there is excessive energy consumption when a cluster head node receives identical data from adjacent cluster sources nodes. This paper proposes a solution to the problems described above from the energy efficiency perspective. The round-robin cluster header(RRCH) technique, which fixes the initially structured cluster and sequentially selects duster head nodes, is suggested for solving the energy consumption problem regarding repetitive cluster construction. Furthermore, the issue of redundant data occurring at the cluster head node is dealt with by broadcasting metadata of the initially received data to prevent reception by a sensor node with identical data. A simulation experiment was performed to verify the validity of the proposed approach. The results of the simulation experiments were compared with the performances of two of the must widely used conventional techniques, the LEACH(Low Energy Adaptive Clustering Hierarchy) and HEED(Hybrid, Energy Efficient Distributed Clustering) algorithms, based on energy consumption, remaining energy for each node and uniform distribution. The evaluation confirmed that in terms of energy consumption, the technique proposed in this paper was 29.3% and 21.2% more efficient than LEACH and HEED, respectively.

• Journal of Distribution Science
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• v.13 no.12
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• pp.73-84
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• 2015

Purpose - Various social issues have arisen since the beginning of the 21st century therefore, enterprises that disregarded social issues have become unsustainable, and social enterprises have appeared to address these issues. A social enterprise is a social mission-focused organization that uses a market-based strategy and has a vulnerable business structure. To be self-sustainable, a social enterprise should make consumers aware of the value that it provides and secure its profitability through consumer consumption. From this perspective, this study investigates the relationship between perceived value (utilitarian and hedonic) and loyalty, and examines how memory and attitudes play mediating roles between perceived value and loyalty. For these purposes, the author developed a structural model consisting of several variables. In this model, perceived value, which was utilitarian and hedonic, was proposed to affect the memory and attitudes toward social enterprise products, thus increasing loyalty. Therefore, memory and attitudes were proposed as core mediating variables between perceived value and loyalty. Research design, data, and methodology - To analyze the proposed model, data were collected from 582 respondents and analyzed using SPSS 21.0 and AMOS 21.0. To test unidimensionality and the nomological validity of the measures of each construct, we employed a scale refinement procedure. The results of the reliability test with Cronbach's α and confirmatory factor analysis warranted the unidimensionality of the measures for each construct. In addition, the nomological validity of the measures was warranted from the results of the correlation analysis. The result of the overall model analysis demonstrated a good fit (χ²=529.881, df=144, χ²/df=3.680, p-value=0.000, GFI=0.905, NFI=0.948, CFI=0.961, RMR=0.036, RMSEA=0.068). Results - The findings are summarized as follows. First, the hedonic and utilitarian value of social enterprise products had positive effects on memory and attitudes. Second, the hedonic value of social enterprise products more strongly affects memory and attitudes than utilitarian value. Third, memory and attitudes had positive effects on loyalty. Lastly, memory had a stronger effect on loyalty than attitudes. Conclusions - The purchase rate of social enterprises' products increases only if the products are included in the "information search" and "alternative evaluation" processes in consumers' purchase decision-making processes. Therefore, a social enterprise must actively promote the fact that it pursues a social value, and shares both the hedonic and utilitarian values of its products. Accordingly, because hedonic value has a more significant impact on a company and attitudes, a social enterprise should develop hedonic values for product consumption, thereby leading consumers who care about value consumption to purchase its products. Moreover, a social enterprise must maintain good memories and attitudes for consumers because memory does not change over time, although attitude does. The limitations of this study and suggestions for future research are as follows. This study viewed "consumer loyalty" as the success factor of social enterprises, thereby considers an "increase in sales" as the success factor. Therefore, in future studies, diverse factors, including social contribution and word-of-mouth intention, should be regarded. In addition, future studies need to thoroughly review and make assurances about the relationship between memory and attitude.

• Korean Chemical Engineering Research
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• v.45 no.1
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• pp.39-45
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• 2007

This paper proposed a shortcut method for the structure design of dividing wall column based on the Fen-ske-Underwood equation by applying it on three conventional simple column configuration. It is shown that the proposed shortcut method can design the column structure including the feed tray, dividing wall section, and side-stream tray in a simple and efficient way in the initial design stage. Simulation study using HYSYS to compare the energy saving performance between the conventional sequential two column system and the dividing wall column designed by the proposed method shows that the proposed dividing wall column system saves from 16% to 65% more over the condepends on the composition of intermediate component while the optimal energy consumption pattern to internal flow distribution on the dividing wall section is characterized by the ESI factor of the feed mixture.

• Journal of Distribution Science
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• v.12 no.2
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• pp.17-25
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• 2014

Purpose - This study used empirical methods to investigate the consciousness structure of vendors in the S marketing area, which is a commercial revitalization district in the country, and examined its effect on their business activities. Based on the results derived through the performance of an actual proof analysis, this study aims to facilitate the promotion of changes in the consciousness structures of traditional market vendors, with a view to allowing them to adapt to the current economic realities in the country. Further, this study aims to provide suggestions that would improve the efficiency of the commercial revitalization program of the government. Research design, data, and methodology - This study examined all the stores in the S marketing area using a questionnaire survey conducted over three weeks beginning on July 4, 2012, and involved the performance of a data analysis on 1,859 samples. The questionnaire consisted of two parts. The first part addressed the market revitalization and the second part addressed the store management strategies. Questionnaire responses were calibrated based on a Likert scale. Statistical analysis was conducted using PASW version 18.0. Results - The results of the analysis of the consciousness structure of merchants in the S marketing area have led to the discovery that they have a medium level of satisfaction with market revitalization. There was a difference in the perceptions of the concept of store management between merchants and customers. Merchants have poor strategies for store management, which do not go much beyond an imitation of the practices of large domestic discount stores. Conclusions - The appearance of big discount stores and the accompanying changes in people's consumption patterns have led to a decline in local market areas. The government has sought new ways to secure autogenic power for local markets. To create regional economies, the government enacted a revised "Law for creating traditional markets and shopping streets" in 2010 and introduced a commercial district revitalization program. This program, which originally supported only the S marketing area, has subsequently expanded into neighboring shopping districts so that the whole of the regional market can be revitalized. However, since the revitalization of the traditional market and the government support required for it were mostly limited to facilities, the result has not proved to be effective. Although there are several reasons why the government investment was characterized by poor efficiency, traditional market vendors' consciousness structure, which did not adapt well to the vagaries of time and its consequent changes, was a major cause. Only when vendors have a true merchant spirit can they have a real service focus that will enable them to clearly understand the distribution organization. This will have the effect of bring about complete customer satisfaction and will ensure the survival and development of traditional markets.

• Current Optics and Photonics
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• v.6 no.2
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• pp.202-211
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• 2022

In the pasteurization of escalator handrails using ultraviolet (UV) sterilizers, a combination of light distribution and escalator speed has priority over other important factors. Furthermore, since part of the escalator handrail has a curved structure, proper design is needed to improve the sterilization rate on the surfaces touched by users. In this paper, two types of sterilizers satisfying these conditions are manufactured with 275-nm UV-C LEDs, after modeling the three-dimensional (3D) structure of an escalator handrail and simulating optical distributions of UV-C irradiation on the handrail's surface according to light-emitting diode (LED) positions and reflector variations in the sterilizers. Pasteurization experiments with the UV-C LED sterilizers are conducted on six types of gram-positive and gram-negative bacteria, with exposure times of 0.2, 5, and 15 s at an actual installation distance of 20 mm. The sterilization rates for the gram-positive bacteria are 10.63% to 27.94% at 0.2 s, 89.44% to 96.30% at 5 s, and 99.64% to 99.88% at 15 s. Those for the gram-negative bacteria are 57.70% to 77.63% at 0.2 s, 98.90% to 99.49% at 5 s, and 99.88% to 99.99% at 15 s. The power consumption of the UV-C LED sterilizer is about 8 W, which can be supplied by a self-generation module instead of an external power supply.

• Journal of the Korea Convergence Society
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• v.12 no.6
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• pp.1-8
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• 2021

The purpose of this study is to study the interaction structure of a smart farm for controlled environment horticulture. As a research method, interaction factors were analyzed by defining the growth stages of humans, plants, and plants, which are the subjects of interaction during the production, distribution, sales and consumption stages of smart farms. Additionally, on-site survey was used to differentiate between one-time, short-term, and long-term, depending on the behavior and operation of the interacting entity and time. As a result, the research came up to a finding that 1) Human and Plant are based on interactions of 'one-time, short-term' 2) Plant and Smart Farm as 'short-term' 3) Smart Farm and Human as 'short-term and long-term'. For this reason, this study is meaningful in deriving the relationship between the subjects and the interaction elements in the production stage of the smart farm and presenting a new interaction structure model by structuring them.