• Korean Management Science Review
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• v.17 no.2
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• pp.115-124
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• 2000

Activity-Based Costing(ABC) is an accounting cost system which allocates the overhead cost to each cost object more accurately. ABC system achieves improved accuracy in estimating the cost of cost object by using multiple cost drivers to trace the cost of activities to the cost objects associated with the resources consumed by those activities. The selection and the aggregation of these cost driver candidates can pose difficult problems. This paper deals with these problems in mathematical programming approach. The first model is formulated as an integer programming model in cost driver selection and the second model is formulated as multi-objective goal programming model in reduction of cost drivers already selected.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.1
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• pp.42-48
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• 2016

Light-emitting diode (LED) drivers are recently replacing fluorescent lamps; these drivers can operate adaptively with various ballasts without modifying and removing such ballasts. To satisfy these trends, a LED driver that is compatible with both electronic and magnetic ballasts is proposed in this study. Unlike conventional LED drivers, the proposed driver has a ballast recognition circuit and a mode selection circuit to operate ballasts at optimal conditions. Therefore, it features low voltage stress, high efficiency, and good compatibility with both electronic and magnetic ballasts. Moreover, it can be compatible with a wide selection of ballasts from various manufacturers. To confirm the validity of the proposed LED driver, results of the theoretical analysis and experimental verification performed on a 15 W-rated prototype are presented.

• Journal of Korean Institute of Industrial Engineers
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• v.30 no.1
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• pp.50-57
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• 2004

The aim of this study is to collect driver's psychophysiological signal under various road condition and to select and quantify psychophysiological variables for diagnosis of road-driver compatibility. A 4x4 vehicle with measuring devices was developed to collect driver's psychophysiological signal and collected driver's psychophysiological signal under various road conditions. The collected data were analyzed by the temporal pattern of signal overtime. Thirteen bio-signals with consistent pattern were selected and quantified in terms of slope and amplitude of the signal. These quantified values could be used as a part of tool to diagnose the road-driver compatibility.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.4
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• pp.302-305
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• 2021

Selection of the optimal inductance for power factor improvement of a buck AC/DC light-emitting diode (LED) driver with wide input voltage range is described in this study. The power factor change based on the slope compensation is obtained for various normalized output current (NOC) values using discrete-time domain analysis. The possibility of implementing constant slope compensation is described using power factor curves for various NOC values. NOC = 0.5 is chosen for the value of inductance with consideration for the simple implementation and reduction of inductor size. Experimental results of the inductance corresponding to NOC = 0.5 are presented.

• Design & Manufacturing
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• v.12 no.1
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• pp.36-40
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• 2018

The car requires an inside mirror installed between the driver's seat and the passenger's seat to ensure the driver's rear and side view of the driver. Inside mirrors must always be attached to the vehicle to ensure the driver's visibility. Inside mirrors attached to the windshield of a vehicle are always exposed to direct sunlight and should be semi-permanently usable in hot and humid summer weather in Korea. Therefore, the mirror mount, which is the junction of the inside mirror, is particularly important in corrosion resistance and wear resistance suitable for humidity. Mirror mounts are currently difficult to manufacture due to their reliance on powder molding technology in advanced countries such as Japan and Germany. This paper focuses on the fabrication of high corrosion resistant stainless mirror mounts by vacuum sintering technique and focuses on the selection of materials suitable for the production of mirror mounts through experiments of 300 series stainless steel and 400 series stainless steel manufactured by vacuum sintering.

• Journal of the Korean Institute of Gas
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• v.20 no.1
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• pp.7-12
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• 2016

Natural gas liquefaction process is essential to transport natural gas for long distances. Lots of compressors in this process are needed and the energy for these compressors can be supplied by drivers. Total driver cost can be changed by selecting various drivers. This study focused on the minimization of the driver cost to provide the energy to the compressors. Moreover, scenarios, extracting velocity is changed during whole operating period, are set with considering gas well capacity. The mathematical model was established by considering trade off relationship between the capital cost and the operating cost of the turbines. The model also considers the life time of the driver equipments. As the result, the driver cost of the optimized case was reduced by 6.4% than the base case.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.6 s.360
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• pp.69-76
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• 2007

A new circuit design for Bus-Invert Coding is presented in this paper. The new scheme sends the coding information through the bus-lines instead of the invert-line which has been used conventionally for many types of Bus-Invert algorithms. By employing a newly developed bus-driver called Flip-Driver and a selection circuit, it not only removes the invert-line but suppresses the additional bus-transitions in sending coding information. It is verified by simulations that the efficiency of various Bus-Invert algorithms is increased about 40% to 100% by employing the new design.

• Journal of Korean Elementary Science Education
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• v.25 no.3
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• pp.231-243
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• 2006

The purpose of this study was to investigate misconceptions regarding the structure of flowers and the function of the course based on the 'Flower' section of 5th grade elementary school science courses. It also sought to investigate how misconceptions are changed before and after the application of a Driver learning model, and finally analysing any differences in the correction of misconceptions. A questionnaire was created for 199 5th grade elementary school pupils. The major results before and after using an applied Driver learning mode teaching plan are as follows: In the response for questions, 13.6% and 14.5% of misconceptions were corrected for male and female pupils, respectively. For rural and urban pupils, 14.8% and 11.2% of misconceptions were corrected, respectively. In the comparison of male and female pupils according to the reasons for selection of responses before and after using an applied Driver learning model teaching plan, 27.8% of male and 30.0% of female pupils scientific conceptions showed improvement. For rural and urban schools, 26.6% and 32.2% of scientific conceptions were improved, respectively. Data from this study may help teachers to reconsider their own conceptions regarding the study of the flower as it is presently conducted in elementary school.

• Journal of the Ergonomics Society of Korea
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• v.25 no.4
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• pp.137-144
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• 2006

The goal of this study is to find out correlation between Driver's Unsafe acts(errors and violations) and Personality types. The experiment was performed on 180 subjects, men and women between 20's and 60's having experience in driving for 6 months at least. Personality types of the subjects were classified by MBTI(Myers-Briggs Type Indicator) GS type and Driver's unsafe acts were measured by KDBQ(Korean Driver Behavior Questionnaire) based on Reason's DBQ(Driver Behavior Questionnaire). The result of experiment showed several facts about the relation. The first is that the drivers of P (Perceiving) type commit more violations and slips than drivers of J(Judging) type. The second is that in the comparison among attitude indexes(EP, EJ, IP, IJ) the drivers of EP(Extroversions - Perceiving) commit more violations than other type drivers. Finally, only men of P(Perceiving) type commits more violations than men of J(Judging). Based on these facts, it is possible to use Personality types as a device to prevent unsafe acts in various fields for driver selection and accident prevention training classified by Personality types etc.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.3
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• pp.39-46
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• 1994

CMOS LCD driving circuits using poly-Si TFT have been designed and basic blocks including test patterns have been fabricated. Column driver drives the pixels by block because polu-Si TFT can not operate at the speed of video signal. Row driver has mode selection circuit which can select a mode between interlacing mode and non-interlacing mode. Experimental results show shift register can operate at 1MHz colck frequency with 4pF load.