• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.44
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• pp.263-271
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• 1997

This paper presents a preventive maintenance model for determining the preventive replacement period of a system in which a failure rate is affected by the cumulative damage of fault and inspection. Especially, the failure rate function is considered to be a function of the cumulative damage of the fault and inspection time. Types of replacement considered are preventive replacement and failure replacement. Failure rate and expected cost function between replacement are derived. An optimal policy is obtained that minimizes the average cost per unit time for preventive replacement, failure replacement, inspection and repair.

• Journal of Chest Surgery
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• v.24 no.5
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• pp.505-509
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• 1991

Rupture or laceration of the aorta is a more common result of nonpenetrating traumatic injury than is generally appreciated. If the lesion is promptly diagnosed, a appropriate surgical treatment may be life-saving. Diagnosis may be difficult and at times the rupture may remain clinically silent for variable period.< A 34 - year old male patient had sustained steering wheel injury to his chest during automobile accident 8 weeks prior to admission. The diagnosis of traumatic aneurysm of the aorta was delayed as he was asymptomatic. Surgical repair of false aneurysm of the descending aorta was successfully performed by partial cardiopulmonary bypass through the femoral artery and vein.

• Journal of Chest Surgery
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• v.21 no.6
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• pp.1003-1019
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• 1988

From 1982 to 1987, six patients underwent left ventricular aneurysmectomy with concomitant myocardial revascularization. Simultaneous repair of postinfarction ventricular septal defect was performed in 3 patients and left ventricular thrombectomy in two. There was no hospital mortality and late mortality during 220 months* follow up period-.[Mean 36.7 months, range 13 to 72 months] Their condition was improved in all. They live in physical condition of NYHA class I-II. We believe early surgical intervention can be life-saving, and can be done without undue surgical risk, even in cases of postinfarction VSD and LV aneurysm with failing heart.

• Journal of Korean Society for Quality Management
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• v.31 no.3
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• pp.193-204
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• 2003

In this paper, we consider a periodic preventive maintenance(PM) policy in which each PM reduces the hazard rate but remains the pattern of hazard rate unchanged. And the system undergoes only minimal repairs at failures between PM's. The expected cost rate per unit time is obtained. The optimal number N of PM and the optimal period x, which minimize the expected cost rate per unit time are discussed. Explicit solutions for the optimal periodic PM are given for the Weibull distribution case.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.157.3-157
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• 2001

In this paper, the optimal maintenance scheduling for turbine with considering maintenance replacement rate was proposed in order to reduce the maintenance cost during the whole period of operation, meanwhile keeping current reliability of turbine. The proposed method is only based on a few limited available data with various factors relating to maintenance replacement and repair of turbine. The proposed method will be adopted by Kyushu Electric Power Co., Inc. from April in 2002 to determine the maintenance schedule of thermal power plants.

• Carbon letters
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• v.8 no.4
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• pp.269-273
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• 2007

During a 4-year period (2001-2005) 09 animals were surgically treated because of abdominal wall defects (hernia). Out of 9 animals 8 were bovines and one caprine. In each case the defect was repaired with carbon fibre mesh. All the cases were successfully treated and no complication was observed up to six months postoperatively.

• Journal of Chest Surgery
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• v.24 no.12
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• pp.1161-1167
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• 1991

The study consisted of all patients undergoing surgical repair of isolated secundum type atrial septal defect in patients ages 35 years or older for the period from October 1986 to October 1991. ASD was closed with direct suture in all patients. Response to surgery was excellent. Two patients who had atrial fibrillation was taken low-dose warfarin therapy to prevent stroke. All patients survived operation, and improved by at least one New York Heart Association functional classification. An old age was not a contraindication to surgery.

• Clinics in Shoulder and Elbow
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• v.14 no.2
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• pp.229-235
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• 2011

Purpose: To compare the clinical and radiological result of arthroscopic Mattress Locking suture repair to that of a Simple suture repair with small and medium-sized rotator cuff tears. Materials and Methods: Among 92 patients who were followed up after arthroscopic repair in patients with small and medium-sized rotator cuff tear from April 2007 to October 2010, 27 patients who took Arthroscopic Mattress Locking suture were set as group I and 65 patients who took Simple suture were set as Group II. The average age of patients were 58 years old and average follow-up period was 30 months. For analysis, VAS, ASES and KSS were used to analyze the range of joint movement and pain. And, for the image result, MRI performed after operation were evaluated. Results: The average VAS, KSS, UCLA score and ASES prior to surgery improved in the last follow-up (p<0.001), while was no difference in two groups (p>0.001). In MRI follow-up examination, the 2 cases (7.41%) of group 1 showed increased rupture lesions with improved symptoms. And the 12 cases (18.47%) of group 2 showed increased rupture lesions with improved symptoms. Retears in the group I were significant less than the group II (p<0.001). Conclusion: Comparing patients with small and medium-sized rotator cuff tear who took arthroscopic mattress locking suture repair to those who took simple suture repair after over one year follow up period, the clinical result showed no significant difference between two groups. However, Mattress Locking suture repair showed excellent radiological result compared to simple suture repair when comparing rerupture.

• Korean Journal of Construction Engineering and Management
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• v.14 no.1
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• pp.32-42
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• 2013

The Korean Government introduced a cultural heritage supervision system in January 2010 to control quality and to prevent poor construction. However, cultural heritage related constructions that require supervision, a scope of supervision, supervision cost and placement of supervisors have not been standardized yet. For this reason, standards of supervision for repair works of cultural heritage that reflect the characteristics of small-scale repair works and restoration of cultural heritage are required. Accordingly, this study has suggested standards of supervision works and cost by analyzing the average construction period that is suitable for the characteristics of cultural heritage repair works. In other words, this study has suggested standards of full-time supervision costs by applying the fixed amount-added method (adding direct labor cost, direct expenses, overhead expenses, engineering fee, charges for additional works and VAT) which is the same as the method of calculating supervision costs for public construction projects because a supervisor has to work full time at a construction site to perform supervision if the project is a mid/large-scale cultural heritage repair work. Also, this study has suggested standards of part-time supervision costs for a small-scale cultural heritage repair work and the ways of supervising the construction projects by visiting the project site on important occasions. According to the result of the analysis by applying the forgoing standards of supervision costs for cultural heritage, a full-time supervision cost for cultural heritage repair works is approximately 98% compared to the construction supervision of a public construction project, and a part-time supervision is approximately 158% compared to architectural construction supervision. It is expected that the valuable cultural heritage of Korea will be preserved by controlling quality of cultural heritage repair works through the application of this study result - the standards of supervision costs for cultural heritage repair works - to an actual project.

• Clinics in Shoulder and Elbow
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• v.12 no.2
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• pp.150-158
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• 2009

Purpose: With the better understanding of cuff function, partial repair or "force couple repair" for treating massive irreparable rotator cuff tear has gained some popularity. However, there were few reports on the results of partial repair. The purpose of this study was to report the clinical outcome of massive irreparable rotator cuff tears who received arthroscopic force-couple repair or partial repair. Materials and Methods: From June 2005 to Feb 2008, arthroscopic partial repairs were performed for 16 irreparable rotator cuff tears among the 101 large to massive rotator cuff tears that were operated on. Clinical and radiographic evaluation were done at the final follow-up. Results: There were 7 men and 9 women with a mean age of 66.6 years. The mean follow-up period was 27.3 month (range: 15-46). The pain VAS improved from 4.4 ($\pm2.50$) to 2.1 ($\pm2.26$) and the functional VAS improved from 46.9 ($\pm16.64$) to 70.0 ($\pm22.80$). The ASES score improved from 39.0 ($\pm10.80$) to 80.3 ($\pm16.78$) and the KSS score was 81.9 ($\pm16.74$) at the final follow-up. The acromio-humeral distance was 6.6 cm ($\pm1.74$) preoperatively and 6.2 cm ($\pm1.69$) postoperatively without significant change (p=0.3874). The degenerative changes had no statistically progressed (p=0.2663). Conclusion: Partial repair for massive rotator cuff injury patients showed improvement in the clinical score without progression of arthritic change at a mean of 2.3 years follow-up.