• Journal of the Korean Society for Precision Engineering
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• v.17 no.12
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• pp.121-128
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• 2000

The scope of this paper is focused to the systems which have the time period and they should be necessarily studied in the sense of stability and design method of controller to stabilize the orignal unstable systems. In general, the time periodic systems or the systems having same motions during certain time interval are easily found in rotating motion device, i.e., satellite or helicopter and widely used in factory automation systems. The characteristics of the selected dynamic systems are analyzed with the new stability concept and stabilization control method based on Lyapunov direct method. The new method from Lyapunov stability criteria which satisfies the energy convergence is studied with linear algebraic method. And the numerical procedures are developed with computational programming method to apply to the practical linear periodic systems. The results from this paper demonstrate the usefulness in analysis of the asymptotic stability and stabilization of the unstable linear periodic system by using the developed simulation procedures.

• Journal of the Korean Society of Tobacco Science
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• v.13 no.1
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• pp.53-60
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• 1991

Seedling rot occurred on burley tobacco at the early growing stage after transplanting was surveyed in the Chonbuk province, the main area for burley tobacco production, during the 3 crop years from 1986. The incidence of disease was about 0.6-0.7% every year and major causal organisms were Pythium spp. More diseased plants were observed in the fields in which tobacco planted with improved mulching system than in that with any other mulching system. The temperature and relative humidity in the planting hole covered with polyethylene film for 11 days after transplanting were recorded by 27-45$^{\circ}C$ and 75~95%, respectively. The punched polyethylene film mulching field showed less diseased plants than that with improved mucking. In improved mulching system the longer period of mulching caused higher incidence of seedling rot(r=0.74**). Soil drench treatment of 200m1 of aqueous Metalaxyl Solution(125ppm) was effective to control the disease.

• Journal of Veterinary Clinics
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• v.16 no.1
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• pp.193-198
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• 1999

Ketoprofen has been used as nonsteroidal anti-inflammatory (NSAI) agent for analgesia in surgical patients and increasing numbers of surgical patients are chronically take some forms of NSAI drugs. The purpose of this study was to investigate the therapeutic effects of ketoprofen on the healing of a closed linear surgical wound and on the contraction of an opened surgical wound in rats. The experimental groups were divided into two groups and ten rats were allocated in each group. In ketoprofen-treated group, the rats were given 2.5 mg/mg/day of ketoprofen by s.c. for ten days. In control group, the rats were given 1ml of benzyl alcohol and distilled water by s.c. for ten days. After time period, all rats were sacrificed, and the breaking strength and the collagen concentrations, at the wound site, were measured. In ketoprofen-treated group, the mean breaking strength and the mean collagen concentration were significantly decreased when compared with those of controls. The ketoprofen-treated group had shown a mean rate of wound contraction less than that of the control, although not statistically significant. These results suggested that ketoprofen impaired wound healing.

• Journal of Chest Surgery
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• v.22 no.4
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• pp.580-588
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• 1989

The potential for enhancing myocardial protection by adding high-energy phosphate to cardioplegic solutions [St. Thomas Hospital solution] was investigated in a rat heart model of cardiopulmonary bypass and ischemic arrest. Creatine phosphate was evaluated as an additive to the St. Thomas Hospital cardioplegic solution. Creatine phosphate 10.0 mmol/L as the optimal concentration which improved recovery of aortic flow and cardiac output after a 30 minute period of normothermic [37oC] ischemic arrest. In comparing mechanical function in both groups the mean postischemic recoveries of aortic flow, cardiac output, stroke volume and stroke work [expressed as a percentage of its preischemic control] were significantly greater in STH-CP group than in CP- free control group. In addition to improving function and decreasing CK release, CP reduced reperfusion arrhythmias significantly decreasing the time between cross-clamp removal and return to regular rhythm from 81.8 * 13.9 [sec] in CP-free group to 35.9 * 6.8 [sec] in CP group [P< 0.05] so, exogenous CP exerts potent protective and antiarrhythmic effects when added to the St. Thomas Hospital cardioplegic solution. However, the mechanism of action remains to be elucidated.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.711-716
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• 2002

The purpose of this study is to develop a strength control model for application of variety internal condition at construction field. The results of this study were shown as follows ; 1) According to results of compressive strength of concrete by using equivalent age, new curve is applicable of construction field because there is similar relation with logistic curve. 2) It is shown that the construction period is shorten by reduction of the formwork removal time, because a predicted compressive strength of using the new curve is high than proposed compressive strength of standard.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.16-18
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• 2003

In a switched reluctance motor drive, it is important to synchronize the stator phase excitation with the rotor position, because the position of rotor is an essential information. In the high-speed region, switching angles are fluctuated back and forth out of the preset value, which is caused by the sampling period of the microprocessor. In this paper, a low cost analog encoder suitable for practical applications is proposed. The validity of the proposed analog encoder with a proper logic controller is verified from the experiments.

• Journal of Nutrition and Health
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• v.4 no.1
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• pp.41-48
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• 1971

The effect of author's recipe of milk-substituting food was studied on 164 children of a primary school. Dividing the subjects into tow groups, A and B respectively, the former being fed with the author's food and the latter served as control, feeding was continued for 6 months daily at lunch hour, with the following results. (1) The effect of the author's milk-substituting food on the body-physique of the children could not be evaluated because of the short period of observation. (2) As observed clinically, various nutritional deficiency symptoms, such as anemia, angular scar glossitis, and hyperkeratosis, were far less frequently occurred in the fed group, while no such significant reduction of occurrence was noted in the control group. It was concluded from the above results that the well-balanced school feeding to the children Is necessary.

• Journal of Nutrition and Health
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• v.28 no.9
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• pp.817-824
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• 1995

This study was performed to evaluate the effect of dietary protein level on Ca efficiency in bone mineral density in growing male rats. Twenty male rate were divided into two groups. The rats in one group were fed on casein 20% diet as control group and the others were fed on casein 40% diet as protein group. All rats were fed on experimental diet and deionized water ad libitum for 9 weeks. The total body, spine and femur bone mineral density and bone mineral content were measured using dual energy-x ray absorptiometry. Urinary calcium, phosphate, pyridinoline and creatinine, serum calcium, phosphate, total protein, albumin, alkaline phosphatase(ALP) and osteocalcin were measured. Urinary Ca excretion, pyridinoline and crosslinks value and serum ALP content seem to be increased in high protein group. It appears that the growing rats in high protein group had a higher bone resprption and bone formation than those in control group. Animal fad a high protein diet had a siginficantly higher Ca efficiency in BMD, BMC of total body, spine and femur. The results of this show that increasing of dietary protein level (40%) is beneficial of improvement of Ca efficiency during growing period.

• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.367-369
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• 2010

본 논문은 열차제어시스템 유지보수업무의 최적화를 위한 정량적 주기산출방법에 관한 것으로, 특히 전장품과 같이 유지보수업무로 주로 교체업무가 선택되는 경우, 운영비용을 최적화하기 위한 교체주기를 정량적으로 산출하기위한 방법을 제시하고, 장치의 고장분포 데이터를 통해, 철도신호장치의 교체주기를 할당한다. 제시한 방법은 유지보수장치의 운영이력을 분석하여, 장치의 고장데이터를 바탕으로 고장분포를 확률적으로 모델링한 뒤, 정확한 LCC데이터가 적용될 때 새롭게 도입되는 장비 및 시스템의 유지보수업무주기를 할당이 가능하고, 이를 통해여 시스템의 운영안전을 보장하면서, 운용비용을 최적화 할 수 있다.

• Journal of Korean Society for Quality Management
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• v.27 no.3
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• pp.170-188
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• 1999

In all activities of companies, manufacturing processes are one of those which have the worst effect on our environment. So manufacturing companies have taken the necessary steps to comply with environmental regulations. But, most of them focused on the environmental standard control equipments, using ‘end-of-pipe techniques’ that can obtain the desired reductions in a short time-period. But these methods are essentially symptomatic treatments and are not enough for sustainable development. 3M's solution is the ‘cleaner techniques’which emphasize prevention rather than corrective control. This paper examines the concept of cleaner techniques and the environmental management system of 3M - how to conduct technological innovation to prevent generation of pollution and waste at the source under the 3P program.