• Proceedings of the KIEE Conference
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• 1997.07b
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• pp.422-424
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• 1997

In this paper, we characterize the whole class of vector fields that can be linearized by a given nominal state transformation and a feedback linearizing controller. The necessary and sufficient condition for a given uncertain vector field to be so-called "completely linearizable by the nominal coordinate transformation" is given in terms of Lie Bracket of uncertain vector fields and some suitable vector fields of the nominal system.

• The Research Journal of the Costume Culture
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• v.8 no.1
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• pp.30-39
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• 2000

The purpose of this study were to 1) identify types and levels of production environments, 2) classify apparel manufacturers based on production environments and 3) investigate relationship between characteristics of apparel manufacturers and production environment. Apparel manufacturer's characteristics included product line and the number of employees. For this study, the questionnaires were administered to 215 apparel manufacturers in seoul and Kyung-gi region from Feb. to Mar. 1998. Employing a sample of 201, data were analyzed by factor analysis, descriptive statistics, cluster analysis, cluster analysis, discriminant Analysis, and multivariate analysis of variance. The following are the results of this study : 1. The production environment was identified as three types such as complexity of product environment, uncertainty of demand/supply environment and uncertainty of worker environment. 2. Based on three types of the production environment, apparel manufacturers were classified into stable group, uncertain group and complicated group. 3. With respect to product line, men's wear manufacturers were lied the most high complexity of product environment, casual wear and knit wear were lied the most frequently uncertainty of worker environment. With respect to the number employees, apparel manufacturers comprising 50∼99 employees were lied the most high complexity of product environment, while those comprising 100∼299 employees the most high demand/supply environment.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.4
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• pp.559-569
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• 1998

Cellular manufacturing system (CMS) has been recognized as an alternative to improve manufacturing productivity in conventional batch-type manufacturing systems through reducing set-up times, work-in-process inventories and throughput times by means of group technology. Most of the studies on the design of CMS assumed that each part has a unique process plan, and that its demand is known as a deterministic value despite of the probabilistic nature of the real world problems. This study suggests an approach for designing CMS, considering both alternative process plans and uncertain demand. A mathematical model is presented to show how to minimize the expected amortized and operating costs satisfying these two relaxations. Four heuristic algorithms are developed based on tabu search which is well suited for getting an optimal or near-optimal solution. Example problems are carried out to illustrate the heuristic algorithms and each of them is compared with the deterministic counterpart.

• Journal of Chest Surgery
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• v.26 no.2
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• pp.75-79
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• 1993

Myocardial protection against ischemic and reperfusion injuries is still in troublesome eventhough couples of the way of myocardial protection have been applied since 1970's. One of the possibility in myocardial protection is adding Fructose-l,6-diphosphate(FDP) in cardioplegic solution. It is assumed that FDP can promote ATP production under anaerobic condition as well as inhibiting the supressing effect of lactate on phosphofructokinase. We compared the myocardial protecting effects of FDP in crystalloid cardioplegic solution (St. Thomas formula, 10$^{\circ}C$, pH = 7.4) and reperfusate using isolated rat hearts in modified Langendorf apparatus by the parameters of preischemic and post reperfusing heart rate, time to first beat, occurance of arrhythmia, time to stabilization, and the rate of left ventricular pressure developing. Group A (n = 10), containing no FDP in cardioplegic and reperfusing solutions was control. Group B (n = 5), containing FDP in cardioplegic solution, showed statistically significant superiority of postischemic left ventricular pressure development than the control group. Group C (n = 5), containing FDP in reperfusate, showed statistically significant myocardial depressing effect than the controls. Other parameters were unremarkable. The cause is uncertain, but it is assumed that the negative feedback inhibition of FDP in energy metabolism or unknown blocking effect of FDP on certain transmembrane ionic currents is present. In conclusion, 1) FDP in cardioplegic solution has beneficial effect on postischemic left ventricular preservation. 2) FDP is strong acid when is hydrolyzed, so precise acid titration is neccessary. 3) FDP in reperfusate has negative left ventricular preservation, otherwise the mechanism is still uncertain.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.390-394
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• 1994

A elevator group supervisory system is designed to perform efficient operation of multiple elevators, and its basic function is to assign an appropriate elevator to a given hall-cell. In this paper, in order to improve elevator group control performance, we propose a new dispatching system which includes fuzzy multi-attribute decision making(MADM). In most cases, the purpose of group control is to maximize control goals as much as possible. Unfortunately, the decision of optimal elevator to a given hall cell is made with very uncertain information of the system, and some of control goals are related each other. The uncertainty is mainly resulted from car calls generated by serving hall calls. A fuzzy MADM algorithm is proposed to deal with these problems to improve system performance.

• Child Health Nursing Research
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• v.22 no.4
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• pp.336-345
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• 2016

Purpose: This study was conducted to describe health in optimal fitness (HOF) in young children born prematurely and to analyze factors affecting HOF in health status, investment resources, and anthropological values, based on HOF theory. Methods: A case-control study of 76 children with preterm births (PTB) was conducted at 24 to 42 months of corrected age. Their HOF status was evaluated based on height, weight, head circumference, and the Korean-Bayley Scale of Infant Development-II and classified as either HOF-achieved or HOF-uncertain in the domain of growth, development, and all together. Results: For growth, development, and all, 26.3%, 27.6%, and 47.4% of children, respectively, belonged to the HOF-uncertain group. Logistic regression analysis showed that longer length of hospital stay (${\geq}21days$; OR=7.8; 95% CI [1.5, 40.5]), worse scores on the Home Observation for Measurement of the Environment (HOME) (${\geq}38$; OR=0.1; 95% CI [0.0, 0.4]), having a working mother, (OR=5.7; 95% CI [1.2, 27.6]), and an older mother (${\geq}35years$; OR=8.8; 95% CI [2.1, 37.3]) were statistically significant contributors of HOF-uncertain in the domain of all. Conclusion: Findings show that young children born prematurely with prolonged stays in a neonatal intensive care unit and insufficient socioeconomic resources at home are more likely to exhibit delayed growth and development.

• International Journal of Control, Automation, and Systems
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• v.6 no.3
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• pp.306-319
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• 2008

Reaching fault tolerance in technological systems requires to detect malfunctions. This paper presents a diagnostic method that is robust with respect to unknown-but-bounded uncertainties of the dynamical model and the measurements. By using models of the faultless and the faulty behaviours, a state-set observer computes polyhedral sets from which the consistency of the models with the interval measurements is determined. The diagnostic result is proven to be complete, i.e., the set of faults obtained by the diagnostic algorithm includes the actual fault. The algorithm is illustrated by an application example.

• The Journal of Korean Obstetrics and Gynecology
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• v.35 no.3
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• pp.37-55
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• 2022

Objectives: The purpose of this study is to investigate the efficacy and safety of acupuncture on postpartum urinary incontinence. Methods: 'postpartum urinary incontinence', 'postnatal urinary incontinence', 'acupuncture' were searched on 4 online databases (Cochrane Library, Pubmed, CNKI, OASIS). Randomized controlled trials (RCTs) that used acupuncture on postpartum urinary incontinence were included. The methodological quality of each RCT was assessed by using Cochrane risk of bias tool. Results: 12 RCTs were finally selected. The overall risk of bias was evaluated as uncertain. 11 studies showed that combined treatment group was better than control group in effective rate and/or ICIQ-SF total score, but among those 1 study was not statistically significant in ICIQ-SF total score. In the comparison of alone treatment group and control group, 1 study showed favorable effect in ICIQ-SF total score, but 1 study was not significant in effective rate. Conclusions: Treatment that include acupuncture can effect on postpartum urinary incontinence. but considering quality of studies, inconsistent and insufficient evidence, further well-designed studies are needed to confirm the efficacy and safety of this treatment.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.4
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• pp.308-316
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• 2006

Objectives Despite considerable advances in technique, experience and skill, the precise place of surgery in the treatment of facial nerve injury remains uncertain. We designed a facial nerve crush injury model in rats and evaluated the recovery of crushed nerve which is the most common injury type of facial nerve using adenovirus vector mediated in vivo gene transfer of Brain derived neurotrophic factor(BDNF). Materials and methods In 48 Sprague Dawley rats, we made a facial nerve crush injury model to main trunk before the furcation, and injected a $10^{11}$pfu adenoviral BDNF in experimental group(BDNF adenoviral injection group; ad-BDNF) and $3{\mu}l$ saline in control group(Saline injection group; saline). After a period of regeneration from 10 to 40 days, nerve regeneration was evaluated with functioinal test (vibrissae and ocular movement), electrophysiologic study(threshold, peak voltage, conduction velocity) and histomorphometric study of axon density. Results Vibrissae and ocular movement, threshold and conduction velocity improved as time elapse in both group, however axon density was increased significantly only in experimental group. Functional test in 10 days and 20 days showed no difference between experimental group and control group. Vibrissae movement, threshold, conduction velocity and axon density in 30 days revealed that the regeneration in quality of experimental group was significantly superior to that of control group. Conclusion In general, there is tendency for nerve regeneration in experimental group (BDNF-adenovirus injection group) during 40 days, functional recovery was detected successfully after facial nerve crush in 30 days postoperatively.

• Journal of Chest Surgery
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• v.12 no.4
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• pp.442-449
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• 1979

Although anoxic cardiac arrest produces a dry, quiet field, the ability of the myocardium to withstand the anoxic insult is uncertain. The current growth of interest in the use of various cardioplegic solutions ` has resulted in the development of a number of different solutions. In this study, 51 consecutive cases of elective open heart surgery with the aid of extracorporeal circulation were reviewed retrospectively to compare two methods of myocardial preservation. All of these open heart operations had been performed, using hemodilution principle under the moderate hypothermia at the Department of Thoracic and Cardiovascular Surgery, College of Medicine, Kyungpook National University from December, 1975 to July, 1979. In the 31 consecutive cases that form the anoxic arrest group, the operations were done with intermittent aortic cross-clamping and topical cardiac hypothermia. The heart was cooled topically by cold normal saline, which was converted to ice slush before application to the pericardial sac. Twenty of 51 consecutive cases were assigned to the cold cardioplegic method [the cardioplegic group], in which two kinds of cold cardioplegic solutions [Young solution and G IK solution] were infused into the aortic root proximal to the aortic cross clamp for myocardial preservation. Mean total aortic cross clamp times were 43 minutes in the anoxic arrest group and 67 minutes in the cardioplegic group. In the post-operative period, spontaneous regular heart beatings were recovered in 80 percent of the cardioplegic group as opposed to 25.7 percent of the anoxic arrest group. Ventricular fibrillation requiring DC shock was seen in 32.3 percent of the anoxic arrest group and 10 percent of the cardioplegic group. In the cardioplegic group, mean CPK-MB was one positive value on the first post-operative day, and mean LDH 1 was elevated to 51 0 units/ml on the 2nd post-operative day. These results indicate that protecting the myocardium with cold cardioplegia is superior to use of the anoxic cardiac arrest.