• The Korean Journal of Pain
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• 제11권1호
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• pp.130-133
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• 1998

We present our failed case of celiac plexus block using the anterior approach under CT guidance in patient with intolerable abdominal pain originating from pancreatic cancer with celiac invasion. In spite of the proper position of needle, the contrast material was not spread due to the tumoral invasion.

• Journal of Chest Surgery
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• 제24권3호
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• pp.261-264
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• 1991

The result of thoracotomy for recurrent and persistent pneumothorax is usually excellent. However the patients undergone thoracotomy suffer from postoperative chest pain and require long postoperative recovery period. Also the operative incision scar gives the patients cosmetic problems. Subpleural blebs are usually causes of pneumothorax. They can be reached through the thoracoscope without thoracotomy and can be ablated by electrical cautery through it. Six patients with recurrent and persistent pneumothorax were managed thoracoscopic-ally. Five patients were successful and one case was failed. The failed case was explored 21 days after thoracoscopy. Follow-up period was from one to eight months. Although the follow-up period was short, thoracoscopic management of recurrent and persistent pneumothorax is thought to be good for preventing thoracotomy.

• 한국신뢰성학회지:신뢰성응용연구
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• 제14권2호
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• pp.122-128
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• 2014

In this paper, we consider the periodic preventive maintenance model for a repairable system following the expiration of extended warranty under replacement-repair warranty. Under the replacement-repair warranty, the failed system is replaced or minimally repaired by the manufacturer at no cost to the user. Also, under extended warranty, the failed system is minimally repaired by the manufacturer at no cost to the user during the original extended warranty period. As a criterion of the optimality, we utilize the expected cost rate per unit time during the life cycle from the user's perspective. And then we determine the optimal preventive maintenance period and the optimal preventive maintenance number by minimizing the expected cost rate per unit time. Finally, the optimal periodic preventive maintenance policy is given for Weibull distribution case.

• Steel and Composite Structures
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• 제4권1호
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• pp.1-8
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• 2004

Tests on steel tubular columns of square, rectangular and circular section filled with normal and lightweight aggregate concrete were conducted to investigate the failure modes of such composite columns. Thirty-six full scale columns filled with lightweight and normal weight aggregate concrete, eighteen specimens for each, were tested under axial loads. Nine hollow steel sections of similar specimens were also tested and results were compared to those of filled sections. The test results were illustrated by a number of load-deflection and axial deformation curves. The results showed that both types of filled columns failed due to overall buckling, while hollow steel columns failed due to bulging at their ends (local buckling). According to the above-mentioned results, and due to low specific gravity and thermal conductivity of the lightweight concrete the further interest should be concentrated in replacing the normal concrete by the lightweight aggregate concrete.

• Journal of the Korean Data and Information Science Society
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• 제14권4호
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• pp.751-758
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• 2003

We consider a life testing experiment in which several two-component shared parallel systems are put on test, and the test is terminated at a predesigned experiment time. The bivariate data obtained from such a system-level life testing can be classified into three cases: 1) the case of failed two components with known failures times, 2) the case of censored two components, and 3) the case of one censored component and the other failed component of which the failure time might be known or unknown. In this thesis, the likelihood estimators for Freund's bivariate exponential life distribution under above censoring scheme are obtained. Results of comparative studies based on Monte Carlo simulation are presented.

• Journal of the Korean Data and Information Science Society
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• 제20권5호
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• pp.941-948
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• 2009

We consider a life testing experiment in which several two component shared parallel system are put on test, and the test is terminated at a specified number of system failures. The bivariate data obtained from such a system level life testing can be classified into three classes: (1) the case of failed two components with known failure times, (2) the case of one censored component and the other failed component of which the failure time might be known or unknown, (3) the case of censored two components. In this thesis, the maximum likelihood estimators of parameters for Block and Basu bivariate exponential distribution under above censoring scheme are obtained. And the results of comparative studies are presented.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국제학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.790-793
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• 1988

It has become clear that through the use of force/torque sensing many previously uneconomical or unsuccessful applications can now be performed successfully. The earlier-anticipated boom of robots dominating factory production has not yet occured. Many robot installations have not met the initial expectations of users or have failed completely, souring the prospects of future robotic applications. Yet the reason many of these earlier applications have failed is very basic, that is that the robot was expected to blindly perform a task perfectly in an imperfect environment. There must be an additional level of feedback so that the robot may adapt to these imperfections, thus ensuring the ultimate success of the application. This additional level of real-world sensing is provided by force/torque sensors and their continued use will ensure the eventual proliferation of factory robots.

• 척추신경추나의학회지
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• 제4권2호
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• pp.163-172
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• 2009

Objectives : The purpose of this study is to evaluate the conservative treatment for FBSS patient. Method : We used Acupuncture, Beevenom, CHUNA manual therapy, Herbal medication, for this patient. And we measured of VNRS and ODI score to evaluate the conservative treatment effects. Result : Patient's LBP & Rt.leg pain VNRS and ODI score were decreased.

• 척추신경추나의학회지
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• 제3권1호
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• pp.9-18
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• 2008

Objective : The purpose of this study is to evaluate the conservative treatment for FBSS patient. Methods : We used Herbal medication, Acupuncture, burning Acupuncture, Physical Therapy for this patient. And we measured of VAS and ODI score to evaluate treatment effects. Results : Patient's sciatica and sensory test has improved. VAS and ODI score were also decreased.

• International Journal of Control, Automation, and Systems
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• 제1권4호
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• pp.444-452
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• 2003

An integration system with multi-measurement sets can be realized via combined application of a centralized and federated Kalman filter. It is difficult for the centralized Kalman filter to remove a failed sensor in comparison with the federated Kalman filter. All varieties of Kalman filters monitor innovation sequence (residual) for detection and isolation of a failed sensor. The innovation sequence, which is selected as an indicator of real time estimation error plays an important role in adaptive mechanism design. In this study, the centralized Kalman filter with adaptive measurement fusion is introduced by means of innovation sequence. The objectives of adaptive measurement fusion are automatic isolation and recovery of some sensor failures as well as inherent monitoring capability. The proposed adaptive filter is applied to the GPS/SDINS integration system with an additional sensor. Simulation studies attest that the proposed adaptive scheme is effective for isolation and recovery of immediate sensor failures.