• Journal of Korean Society for Quality Management
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• v.31 no.3
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• pp.136-159
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• 2003

The purpose of this paper is to propose the effective guidance of Quality Circle(QC) activities. Since 1975, variety of organizations in Korea have widely implemented QC activities for their management systems. The industries have enthusiastically used QC activities and were influenced from them. However, the academics were less interested in this subject, as a result, there were no systematic guidances for QC activities. Thus, in this paper, the effective guidance for QC activities were suggested which were based on the survey from QC proceedings presented in the companies, in the local areas and the national wide contests. As a result, the first main issue is to pick repeated mistakes up during the process period such as unmatched the causes and effects relations in characteristics diagrams, improper selection of important control items in Pareto diagram and so on. Secondly, how to overcome statistics and use them for QC activities. Thirdly, to remind team members about Quality Control 7 tools. Finally, Minitab(Release-13) software has been found that it is not matched with using Korean Standards(KS).

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.1185-1187
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• 1992

In this paper, PWM control is applied to the microprcessor-based adjustable speed dc motor drives. The motor drive system is composed of phase locked loop. Main drive circuit of the system is consisted of H-type bridge with switching transistors. PWM drive circuit is linearized by adding flywheeling diodes. And also. We study the optimum PWM data and period time so that it hase a nearly liner relationship between current and torque.

• Journal of Food Hygiene and Safety
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• v.7 no.2
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• pp.107.1-112
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• 1992

Free-, soluble- and insoluble phenolic acids were extracted from defatted Galla Rhois. The extracts were then dissolved in equal amounts of an soybean oil, and POV (peroxide value) of the resulting substrates, portion of the soybean oil (control) and 0.02% BHT were measured by AOM (active oxygen method) test at 97.8$^{\circ}C$ for 40 hours through Rancimat method. Induction period of control, BHT, free phenolic acids, soluble phenolic acids and insoluble phenolic acids by the Rancimat method were 4.8, 10.5, 23.9 and 30.5hr. The phenolic acids separated and tentati-vely identified by gas chromatography were catechol, gallic acid, vanillin, protocatechuic acid, syri-ngic acid, ferulic acid.

• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.2058-2064
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• 2014

In transformer fault diagnosis, dissolved gas analysis (DGA) is been widely employed for a long period and numerous methods have been innovated to interpret its results. Still in some cases it fails to identify the corresponding faults. Due to the limitation of training data and non-linearity, the estimation of key-gas ratio in the transformer oil becomes more complicated. This paper presents Intuitionistic Fuzzy expert System (IFS) to diagnose several faults in a transformer. This revised approach is well suitable to diagnosis the transformer faults and the corresponding action to be taken. The proposed method is applied to an independent data of different power transformers and various case studies of historic trends of transformer units. It has been proved to be a very advantageous tool for transformer diagnosis and upkeep planning. This method has been successfully used to identify the type of fault developing within a transformer even if there is conflict in the results of AI technique applied to DGA data.

• Journal of Korean Institute of Industrial Engineers
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• v.33 no.4
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• pp.419-423
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• 2007

In this paper, we consider the M/G/1 queueing system with randomized control of T-policy. Whenever the busy period ends, the server is turned off and takes multiple vacations whose interval is fixed time T with probability p or stays on and waits for arriving customers with probability 1-p. We introduce the cost function and determine the optimal combination of (p, T) to minimize the average cost per unit time.

• Magazine of the Korean Society of Agricultural Engineers
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• v.12 no.2
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• pp.1960-1964
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• 1970

Underdrainage has been studied by using PVC suction pipes in the low and wet Paddy field: Fist, three test plot and three control plots were set and drainage methods and Soil tempratures in the test plots have been examined. The experiment was conducted making use of the 'NONG-RIM No, 4'(Wheat) 'DOWON' (rice barley), a recommended variety. Test period was from September, to December, 1969. The experimental methodsand results obtained through this experimontation are as follows: 1) Ground water level in the test plot goes down by 34 cm. 2) In sprouting, control plot is earlier than test plot by three days. 3) The rate of sprouting is equal.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2004.03a
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• pp.216-219
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• 2004

• Journal of Nutrition and Health
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• v.30 no.2
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• pp.177-186
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• 1997

To evaluate the effectiveness of nutritional supplements for cancer patients, the study was performed in 30 cncer patients, receiving chemotherapy. Patients were randomly divided into two groups -15 patients for the nutritionally supplemented group and 15 patients for the control group. Patients of the supplemented group were nutritionally supported with a commercial product for 9 weeks. Nutritional status of the patients was detrmined by dietary intake data, anthropometric measurements and hematological analysis at the beginning and after 3, 6 and 9 weeks of supplemental priod. Mean daily intake levels of energy, protein, calcium, phosphorus, thiamin, riboflavin, niacin and asorbic acid for the supplemented group were significantly higher than those of control group. Significant increase in mid-arm circumference, triceps skinfold thickness and arm fat area were observed in supplemented group during the study period. However, the changes of body weight, body mass index and arm muscle area were not significantly increased. Serum transferrin level improved slightly by nutritioal support, but serum albumin levle did not change significantly. There data show that nutritional status of cancer patients receiving chemotherapy can be improved by utritional supplementation for 9 weeks.

• Proceedings of the KAIS Fall Conference
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• 2010.11b
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• pp.785-787
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• 2010

It is well known that most power steering systems obtain the power by a hydraulic mechanism. Therefore, it consumes more energy because the oil power should be sustained all the times. Recently, to solve this problem the Electric Power System(EPS) or Motor Driven Power System(MDPS) has widely equipped in passenger vehicles. In this research the concurrent simulation technique for an EPS system with MATLAB/SIMULINK and a full vehicle model has been developed. The dynamic responses of vehicle chassis and steering system are evaluated. Then, a full vehicle model interacted with EPS control is concurrently simulated with an impulsive steering wheel torque input to analyze the stability of 'free control' or hands free motion for SUV. This integrated method allows engineers to reduce the prototype testing cost and to shorten the developing period.

• Journal of Satellite, Information and Communications
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• v.10 no.2
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• pp.115-120
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• 2015

Until now, AOCS SW has used FPU which is one of CPU resources for satellite attitude control. And most of the SW Throughput was consumed to calculate Matrix Multiply. As SW throughput margin is decreasing seriously with shorter control period and more computational burden at next satellite programs, a dedicated HW matrix multiplier is absolutely required. This paper represents results of HW implementation & performance measurement and mentions several techniques for performance improvement, further works.