• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.549-549
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• 2000

In the previous work, we dealt with a traffic analysis of network-based control system and its architecture using the CAN protocol. It is difficult to determine an optimal network architecture for a specific system. In this paper, we propose the architecture of network-based control system applicable to a specific AGV system with manipulator arms. We define the fixed number of periodic messages to be occurred in this system. In the proposed system architecture, we analyse its traffic for the real-time communication of all messages, determine the optimal sampling period of an analog sensor to be satisfied with the required specification and the number of possible sensors to be added through simulation.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.113-118
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• 2001

Bridge Control and Inspection ensures the safety, utility, and durability of Bridge in use. This Paper compares Control-interval of Germany with that of Korea, which was described in the special law recently revised concerning the Safety Checkup of Facilities, and analyzes Period of Damage Discovery that the Damage report of other countries showed. According to a result of the analysis, damage requiring structure repair and reinforcement more frequently been discovered even in less than a decade after the completion of construction. The paper, therefore, suggested the reregulation on the Korean Control Interval on the basis of the result.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.2
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• pp.117-124
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• 2001

In a SRM drive, the on/off angles of each phase switch should be accurately controlled in order to control to torque and speed in a stable way, The accuracy of the switching angles is dependent upon the resolution of the encoder and the sampling period of the microprocessor. However, as the speed increase, the amount of the switching angle deviation from the preset values is also increased by the sampling period of the microprocessor. Therefore, a low cost encoder suitable for a practical and stable SRM drive is proposed and the control algorithm to provide the switching signals using the simple digital logic circuit is also presented in this paper. It is verified from the experiments that the proposed encoder and logic controller can be a powerful candidate a the practical low cost SRM drive.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.11
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• pp.151-157
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• 2000

The MRAC theory has proved to be one of the most popular algorithms in the field of adaptive control, particularly for practical application to devices such as an hydraulic servosystem of which parameters are unknown or varying during operation. For small sampling period, the discrete time system becomes a nonminimal phase system. The $\delta$-MRAC was introduced to obtain the control performance of nonminimal phase system, because the z-MRAC can not control the plant for small sampling period. In this paper, $\delta$-MRAC is applied to the control of an hydraulic servosystem which is composed of servovalve, hydraulic cylinder and inertia load.

• Korean journal of food and cookery science
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• v.12 no.4
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• pp.562-570
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• 1996

A weight control program has been prescribed to investigate its effects on weight reduction of obese adults. The prescribed weight control program has been followed by 4 overweight adults and fad diets has been followed by 6 ovenveight adults for 3 to 7 months. The prescribed weight control program was basically the low calorie diet (1,500-1,800 kcal per day) and nutrition education was applied to enhance its effects. Fad diets were chosen among the fashionable diets and they were "apple diet" , "yogurt diet" and "Lee Hijae diet" Anthropometric measurements, biochemical parameters, and percent of body fat were measured after the respective period of weight control program. Body weight was significantly (p<0.01) reduced and the rate of obesity was also significantly lowered with the prescribed weight control program while the body weight and rate of obesity were not changed with the fad diets. Weight loss from the prescribed weight control program also led to the change of total cholesterol levels while LDL-cholesterol, HDL-cholesterol, triglyceride were not significantly changed. Nutrition education and counseling of the weight control subjects induced more weight loss and better food behavior. It is suggested that a weight loss program should be based on the low calorie diet with the well-planned nutrition education The fashionable diets were attractive for a short time period in weight reduction but the rapid weight gain was noticed right after the diets ceased.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.7
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• pp.662-668
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• 2015

This paper presents an improved predictive control of an induction machine fed by a matrix converter using N-switching vectors as the control action during a complete sampling period of the controller. The conventional model predictive control scheme based matrix converter uses a single switching vector over the same period which introduces high torque ripple. The proposed switching scheme for a matrix converter based model predictive control of an induction machine drive selects the appropriate switching vectors for control of electromagnetic torque with small variations of the stator flux. The proposed method can reduce the ripple of the electrical variables by selecting the switching state as well as the method used in the space vector modulation techniques. Simulation results are presented to verify the effectiveness of the improved predictive control strategy for induction machine fed by a matrix converter.

• Korean Journal of Adult Nursing
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• v.26 no.4
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• pp.424-433
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• 2014

Purpose: This study was to test the effects of the positional change on low back pain, discomfort, and bleeding complications during the period of bed rest following transarterial chemoembolization (TACE). Methods: The research design for this study was a non-equivalent control group quasi-experimental design. The participants were 23 patients for the experimental group, and 23 patients for the control group. The experimental group received positional change of taking the semi-Fowler's position and the 30-degree lateral position alternatively during the period of bed rest after TACE for 4 hours at one-hour intervals. The control group maintained the supine position continuously during the period of bed rest after TACE. Results: There were statistically significant differences in low back pain and discomfort between the experimental and the control group after intervention. And no significant difference was found in bleeding complication between two groups. Conclusion: The results of the study suggest that the positional change is an effective nursing intervention to reduce low back pain and discomfort without increasing the risk of bleeding after TACE.

• Journal of Environmental Science International
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• v.27 no.10
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• pp.907-923
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• 2018

The aim of this study was to determine the appropriate stockpiling methods for revegetation by comparing the germination status of seed banks before and after preservation for 2 years. Soil temperature in stockpiled topsoil was higher in open treatment and at 1.5 m, whereas soil water content was maintained at lower levels (14.06-19.08%), than those in the control group. The seed banks in stockpiled topsoil had 48 species and 1,559 individuals, among which perennials showed the highest number in terms of life forms, whereas Compositae and Gramineae were dominant in terms of families. Based on seed bank type, persistent seed banks had the highest number of species, while transient seed banks had the highest number of individuals. By stockpiling period, the number of species in the seed bank started to increase after 24 months, while the number of individuals began increasing after 12 months and exceeded that of the control group after 24 months. Regarding the treatment of stockpiling methods, the number of species and individuals in open treatment were closer to those of the control group. When analyzed by height, the number of species and individuals were higher at 0 m, but still lower than those of the control group. A multivariate analysis of variance (MANOVA ) showed that the optimal combination was obtained in open treatment and the number of individuals increased with the lengthening of the stockpiling period.

• Journal of Biosystems Engineering
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• v.15 no.4
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• pp.328-338
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• 1990

The objective of this study was to develop automatic systems of nutrient solution management for optimal nutrient solution environment and labor saving in water culture which enables factory crop production. In this study, an automatic control system and its driving program are developed to prepare, supply, and recover nutrient solution and to keep the optimal solution concentration level using microcomputers. Based on this study, the following conclusions are obtained: 1. The concentration measured by the system using oscillating circuit designed and built in this study, gave good agreements with the actual nutrient solution. 2. In water culture, the period of 12 hours for measuring concentration, pH, and temperature of the nutrient solution was optimum. Addition of control solution due to the decrease of the nutrient solution concentration is required in every 3 to 5 days. 3. It is estimated that the period of the whole solution change is 15 days, however, further research is needed to assure it. In addition, this period must be shortened in the future. 4. Both the hardware and software of the developed optimal nutrient solution control system in the water culture are working very well, however, it is necessary to develop a more economical one-chip micro controller to substitute for the microcomputer.

• Nutritional Sciences
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• v.7 no.1
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• pp.35-40
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• 2004

This study was performed to evaluate the effect of iron supplementation on iron-deficiency-related indices, oxidative stress and antioxidative enzyme activity in female marathoners. Fourteen teenage female marathoners participated in the study. Subjects were divided into two groups: mild anemic and control, depending on their hemoglobin (Hb) level. The mild anemic group had significantly lower RBC count and hematocrit (Hct) and Hb levels compared to the control group. The mild anemic group (〈12.5g Hb/dI, n=7) was given iron supplements (60mg Fe/day) for four weeks during the summer training period. RBC count, Hct and Hb levels showed an increasing tendency through iron supplementation, and significant differences in these variables between the anemic and control groups disappeared in the post-period. There was no difference in plasma malondialdehyde (MDA) between the anemic and control groups. However, catalase (CAT) and glutathione peroxidase (GPx) activity were significantly higher in the anemic group. The significant difference in enzyme activity between the groups disappeared in the post-period. In addition, superoxide dismutase activity significantly decreased after iron supplementation. In conclusion, antioxidative enzyme activity was up-regulated in an anemic condition and mild iron supplementation decreased the antioxidant enzyme activity of female marathoners while improving their anemic condition.