• Advances in pediatric surgery
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• v.14 no.2
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• pp.125-133
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• 2008

To evaluate the long-term prognosis of biliary atresia after Kasai operation, a total of 14 patients (of the 41 patients operated upon from 1982 to 1997), who had been followed up for more than 10 years, were included in this retrospective study. Eleven out of 14 patients survived with their native livers, and their data analyzed for age at operation, clearing time of jaundice, histological outcome, postoperative complications, effectiveness after the application of an intussusception anti-reflex valve, and quality of life. Average age at surgery was 62.8 days. Serum bilirubin was normalized within three months in all patients. Six among the eleven long-term survivors had ascending cholangitis as one of the postoperative complications. The application of an intussusception anti-reflux valve did not show any statistical significance in long-term survival. Most of long-term survivors appeared to enjoy good quality of life. Kasai operation might not be the definitive treatment for biliary atresia; however, Kasai operation made it possible to achieve long-term survival for patients with biliary atresia when the patients were detected and treated as early as possible.

• Journal of Energy Engineering
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• v.8 no.4
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• pp.519-524
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• 1999

this paper proposes the operation algorithm of 1MW class Battery Energy Storage System(BESS) installed at the extra-high voltage customer. The objective of the proposed algorithm is to reduce electric charges during the operation of the BESS interconnected to power system. This paper simulates the electric charges in 1998 considering Season and Time of Use Rate and Power Factor in the assumption that electricity demand in 1998 is the same amount of that in 1997 and shows the saving of about 40 million won in the total electric charges. The results comparing the real electric charges of June. July and August in 1997 with that in 1998 show that the implementation of the proposed algorithm could significantly reduce electric charges during the operation the BESS.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3418-3426
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• 2009

The purpose of this study was to investigate the feasibility of field operation protocol for cardiopulmonary resuscitation(CPR) in person with non-traumatic arrest. This study was performed from May 1 through June 27, 2008, and subjects were 150 students who are attending the department of Emergency Medical Service in J and K universities which located in Jeollabuk-do and Jeollanam-do areas. Practical conformance was verified using by nonequivalent control group pretest-posttest design. This study divided into two groups; experimental group that employed field operation protocol and control group that applied conventional CPR protocol, and comparative analyzed statistically the necessary time of the items of each protocol. The results indicated that each performance time of 18 items was reduced over 3 seconds except 5 items(assessment of consciousness, airway control, two times of artificial respiration, check of circulation, and five cycles of CPR). And time of 6 items(intubation, peripheral intravenous line, reassessment of consciousness, pupil reaction, carotid artery pulse, and vital sign) was minimized more than 60 seconds, and total performing time was shortened 110.85 seconds. The results suggested that total performing time in pre and post test where the protocol was applied for two groups showed a statistically significant decrease(t=-6.580, p=.000). Consequently, field operation protocol for cardiopulmonary resuscitation(CPR) in person with non-traumatic arrest will be a available manual which support prompt and accurate decision making, and improve emergency medical service.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1024-1027
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• 1996

The cyclic production lines have the first machines starved and the last machine blocked due to the lack or the excess of empty pallets in the feedback buffer. A workpiece in the cyclic production lines is transported on a pallet, and the total sum of pallets in the system does not changed during the system operation time. Therefore, the production rate of the cyclic production lines are dependent on the total number of pallets in the system. In this paper, we suggest the performance analysis method for the cyclic production lines with inspection machines and the optimal total number of pallets in the system that maximizes the production rate of the system. Finally, we validate the suggested methods by simulations.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.6
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• pp.33-39
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• 1998

This paper is related to economic design of tool-resetting period in NC machining. In NC lathe machining, the mean and variance of components dimension fluctuate in slow time and we should reset tool program to compensate the variation from the fluctuation. In this paper. we propose the procedure determining the optimal resetting period based on the total expected operating cost which consists of resetting cost and the quality cost related to dimension variation. As a case study, using experimental data about dimension changes of a lathe machining, we obtain the regression equations of mean and variance of the dimension fluctuation, total expected operating cost, and optimal resetting period.

• Information Systems Review
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• v.7 no.2
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• pp.229-255
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• 2005

The Korea Development Bank promoted a total outsourcing for IT operation in 1999 for the first time in the banking industry. The Korea Development Bank became the center of public attention because the most banks were unwilling to take an outsourcing with external sources for the reason of financial operation accidents, securities, and threats of strikes. After the introduction of the total IT outsourcing, the Korea Development Bank has continuously diagnosed the problems of the IT outsourcing and adopted various proper complements for the enhancement of the IT outsourcing. As the result of the enhancement, the IT outsourcing of the Korea Development Bank marched into the joint liability operation period after going through the outsourcing operation period and the co-operation period. The joint liability operation which is the most leading outsourcing system which is adopted by the Korea Development Bank for the first time in the banking industry. Through the joint liability operation, the Korea Development Bank could accept the most up-to-date IT, concentrate internal manpower on the core capability, and secure flexibility of manpower. Also, the bank changed the relationship between the bank and the external sources from the one-sided relationship between a producers and a consumer to the joint liability relationship on which both sides are responsible for the operation, and could integrate the internal capacity with the professional know-how of the external IT outsourcing company. In this paper, we testified the soundness and validity for the worries of banks about the total IT outsourcing with external sources. And, we arranged the advantages and outcomes of the total IT outsourcing with external sources compared to the IT outsourcing with internal sources. Moreover, we expect that we can improve the closed financial IT outsourcing industry structure and raise the world competitive power of domestic IT outsourcing companies by correcting wrong ideas on the IT outsourcing with external sources.

• Journal of Korean Society of Forest Science
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• v.80 no.2
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• pp.220-231
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• 1991

The main purpose of this research is to standardize the logging operation with special reference to the net working time for thinning. This study was carried out to obtain the standard working method and working technique for Korean logging operation through the comparison of the present Korean working method and the German standard working method 1. The net working time devided into work elements showed little difference between those two working methods. 2. From the correlation analysis, net working time was significantly correlated with breast height diameter, the dependant variable, with the highest correlation coefficient in each species. 3. Total working time increases by 11 to 13 seconds to every 1 centimeter increase in breast height diameter from i to 16 centimeter. 4. The result of this study concluded that the German working method is recommended for improving the labour problems in the forest operation due to high wages and lack of manpower gradually increasing from now in Korea. In addition to the application of this standard working method, the technical training for the method should be done to the workers for improving the productivity.

• Journal of Chest Surgery
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• v.14 no.1
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• pp.1-8
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• 1981

Alterations in serum enzymes were studied in twenty-five patients who underwent open heart surgery in N.M.C. during the period from June 1979, to Feb. 1980. There were fifteen congenital and ten acquired heart diseases. In all patients, Rygg-Kyvsgaard five head roller pump and Polystan bubble oxygenator were used and serial determination of total level of Creatine phosphokinase [CPK], Lactic dehydrogenase [LDH], Glutamic oxaloacetic transaminase [SGOT] were made preoperatively, operation day [just after aortic clamp release, 2 hrs later, 4 hrs later, 6 hrs later], and postoperative days up to 5th day. Immediate postoperative clinical courses were also evaluated. Twenty-five patients were divided into two groups: Group A[13] was cardiopulmonary bypass time more than 95 minutes and aortic clamp time more than 45 minutes. Group B[12] was cardiopulmonary bypass time less than 95 minutes and aortic clamp time less than 45 minutes. The peak levels of SGOT, LDH in Group A were more significantly elevated than Group B [P<0.05]. But peak levels of CPK were not significant between two groups. In the view of clinical evaluation, poor clinical courses were more frequent in Group A [54%] than Group B[8%].

• Journal of Korean Society for Quality Management
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• v.18 no.2
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• pp.33-42
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• 1990

This paper proposes the maintenance model of multi-component system when the failure characteristics and types of components are considered. In this model, it is assumed that a system is composed of a critical component, a major component and a minor component. Also, failure types is classified into major failure and minor failure. If major failure occurs to critical component before system age replacement time, the system is renewed. If major failure does not occur until its age replacement time, preventive maintenance is performed at age replacement time T. Minimal repairs are carried out after each minor failure. Major component is minimal-repaired if any failure is discovered during operation. Minor component should be replaced as soon as any failure is found. This paper determines the optimal replacement time of the system which minimizes total maintenance cost. Numerical example illustrates these results.

• Journal of Korean Institute of Industrial Engineers
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• v.15 no.1
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• pp.51-63
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• 1989

This paper considers software release problems based on Goel-Okumoto and S-shaped reliability growth models. Test of the software system is terminated after a preassigned time T, and it is released to the operational phase. It is assumed that correction cost of an error is increasing with test or operation time. Optimum software release time is obtained using total expected cost on the software life time as a criterion for optimization. In addition, optimal software release policies under the constraint of a software reliability requirement are discussed.