• Communications for Statistical Applications and Methods
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• v.15 no.3
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• pp.387-402
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• 2008

In this thesis we propose a two-stage periodic inspection model for maintaining the reliability of a system in long-term storage. There are two types of tests available; a fallible test and an error-free test. The system is overhauled at detection of failure or when the storage reliability after inspection becomes less than or equal to the prespecified value. The expected cost per unit time until overhaul is derived and a procedure for minimizing the expected cost is suggested. The two-stage periodic inspection model is compared with the one-stage periodic inspection model for various parameters of the cost function when the failure time follows exponential and Weibull distributions. The proposed model is then applied to an existing missile system for comparison with the current inspection policy.

• Journal of Oral Medicine and Pain
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• v.22 no.1
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• pp.31-44
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• 1997

저자들은 악관절내장증의 증상과 징후의 객관적 평가법을 개발하기 위하여 서울대학교치과 병원 구강진단과 악안면동통진료실을 내원한 환자중 좌우 양 관절중 한 관절 이상의 관절에 악관절내장이 있는 남자 8명(평균연령 19.9$\pm$2.9세), 여자 34명(평균연령:32.8$\pm$11.8세) 총 42명(84개 관절)에 대하여 VAS 및 압통역치 측정, 악관절조영술, 골신티그래피 검사 및 악관절 활액의 분석을 시행하였다. 악관절 동통의 심도는 VAS로 측정을 하였으며 PPT는 electronic algometer로 평가를 하였다. 악관절조영사진을 얻기 직전 활액을 채취하였으며 그 성분중 Hyaluronic acid, 총단백질, IgG, IgM과 albumin을 분석하여 그 상관관계를 분석한 결과 다음과 같은 결론을 얻었다. 1. 악관절 내장증으로 내원한 환자 42명, 총 84개 관절중, 무통성이고 관절잡음이 없는 경우가 7개 관절, 무통성이고 단순관절음만 존재하는 경우가 18개 관절, 동통 및 단순관절음이 존재하는 경우가 18개 관절, 간헐적인 폐구 과두걸림이 있는 경우가 11개 관절, 급성 폐구성 과두걸림의 경우가 11개 관절, 만성 폐구성 과두걸림의 경우가 3개 관절, 퇴행성 관절질환이 존재하는 경우가 16개 관절이었다. 2. 연구대상중 18명의 환자, 총 36개 관절에 대한 골 신티그래피 검사 결과, 활동성으로 나타난 경우가 33개 관절이었고 이중 23개 관절이 동통성이었으며, 활동 상태 관절의 VAS 항목과 압통역치 항목 및 여러 검사 항목들은 비활동 상태 관절의 항목과 유의한 차이를 나타내지 않았다. 3. 악관절내장의 진행정도에 따른 악관절부위의 동통의 측정에 있어서는 압통역치의 측정보다는 VAS에 의한 방법이 더 유용하며 특히, 후방부의 촉진시에 유의한 정보를 얻을 수 있었다. 4. 악관절 내장즈으이 진행 단계에 따라, VAS항목과 압통역치 항목을 비교해 본 결고, 주기적인 과두걸림(II) 단계에서 가장 높은 VAS 수치와 가장 낮은 압통역치를 나타내었으며 상방 촉진시 VAS 항목에서 주기적인 과두걸림(II) 단계와 증상 및 징후가 없는(0) 단계 사이와 후방 촉진시 VAS 항목에서 주기적인 과두걸림(II) 단계 및 퇴행성 관절 질환(V) 단계와 증상 및 징후가 없는(0) 단계 사이에서만 유의성을 나타내었다. 5. 활액내 총단백질량, albumin 량, IgG 및 IgM 농도는 악과？ㄹ 내장증의 진행에 따라 유의성을 나타내지는 않았으나 퇴행성 관절 질환(V) 단계에서 증가되는 양상을 나타내었다. 6. 활액내 hyaluronic acid의 농도는 악관절 내장증의 진행에 따라 유의성을 나타내지는 않았으나 만성 폐구성 과두걸림(IV) 단계에서 감소되는 양상을 나타내었다.

• Journal of the military operations research society of Korea
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• v.32 no.2
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• pp.92-113
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• 2006

The main purpose of this study is to determine the optimal periodic inspection for Anti-Ship-Missile(Harpoon Block 1) fielding on Korea Navy Ship. In order to perform this study, the data from the Korea Navy (Harpoon maintenance & storage reliability) were collected from 1984 to 2004. Storage failure rate & MTBF for Harpoon block 1 were analysed by using mathematical model & reliability analysis software(Relex) and finally determined optimal periodic inspection. The suggested methodology will be used to determine and reevaluate the periodic inspection of Anti-Ship-Missiles for the Korea Navy.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2761-2763
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• 2002

원자력발전소에서는 건설완료 단계에서 기기, 배관 및 각종 지지구조물에 대하여 PSI(Pre-Service Inspection)를 실시하여 시공된 설비의 건전성을 점검하고, 운영중에는 주기적으로 시간의 경과에 따른 취약화 정도를 비과괴검사로 감시 및 평가하는 ISI (In-Service Inspection)를 실시하여 안전성 관련 설비의 건전성을 점검하고 있다. 이 과정에서 방대한 양의 검사데이터가 생산되며 원전 가동년수가 증가함에 따라 검사자원을 체계적으로 관리하고 자동화 할 수 있는 시스템 개발이 필요하게 되었다. 본 논문에서는 PSI/ISI 검사결과 정보관리를 비롯하여 검사 기초자료 관리 및 검사계획 수립, 파괴역학 분식 기능 등을 포함한 Web 기반의 Application 개발 사례를 소개한다. 또한 가상현실 기법을 적용하여 기존의 2차원적 DB 운영을 3차원 가상공간에서 운영할 수 있는 'Touch & Tell' 기법을 개발하고 그 구현방법을 제시한다.

• The KIPS Transactions:PartD
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• v.10D no.4
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• pp.727-734
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• 2003

Recently various quality assurance activities have been applied in software industry for the purpose of software qualify improvement, and the ultimate target of those activities are focused on removing defects from its developed applications. We declared "ZERO DEFECT 21" movement on March 1999 whose purpose is to deliver defect-free applications to the customer. In this paper we would like to introduce the followings $\circled1$ Approaching Methods, $\circled2$ Achievements of "ZERO DEFECT 21". After accomplishing first you of "ZERO DEFECT 21" movement which consist of Audits and Software inspections, we could get the following improvement . $\circled1$ due to conducting the "Audits," we could prevent 22 cases of customer claims, enhance 11.7% of design quality and improve 23.3% of deliverable reusability : $\circled2$ also, due to conducting the "Periodic Sampling inspection and Final inspection," we could enhance 123% of defect rate compared with early stage of development and 247% of defect rate compared with previous yew. Based on the survey results, we could conclude that "ZERO DEFECT 21 " movement provides confidence to project team members and reliability to our customers.ce to project team members and reliability to our customers.

• Korean Journal of Remote Sensing
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• v.36 no.5_1
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• pp.707-723
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• 2020

In this study, a decision tree type of quality control (QC) method was developed to improve the temporal-spatial representation and accuracy of the visibility data being operated by the Korea Meteorological Administration (KMA). The quality of the developed QC method was evaluated through the application to the 3 years (2016.03-2019.02) of 290 stations visibility data. For qualitative and quantitative verification of the developed QC method, visibility and naked-eye data provided by the KMA and QC method of the Norwegian Meteorological Institute (NMI) were used. Firstly, if the sum of missing and abnormal data exceeds 10% of the total data, the corresponding point was removed. In the 2nd step, a temporal continuity test was performed under the assumption that the visibility changes continuously in time. In this process, the threshold was dynamically set considering the different temporal variability depending on the visibility. In the 3rd step, the spatial continuity test was performed under the assumption of spatial continuity for visibility. Finally, the 10-minute visibility data was calculated using weighted average method, considering that the accuracy of the visibility meter was inversely proportional to the visibility. As results, about 10% of the data were removed in the first step due to the large temporal-spatial variability of visibility. In addition, because the spatial variability was significant, especially around the fog area, the 3rd step was not applied. Through the quantitative verification results, it suggested that the QC method developed in this study can be used as a QC tool for visibility data.

• Journal of Veterinary Clinics
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• v.27 no.6
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• pp.729-734
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• 2010

An 11-year old, intact female Poodle (weighing 2.3 kg) was referred with signs of consistent coughing, dyspnea, poor exercise tolerance, and anorexia. Diagnostic imaging and laboratory studies revealed idiopathic hemorrhagic pericardial effusion complicated with ISACHC Ib stage of chronic mitral valvular degeneration. Percutaneous transcatheter pericardiotomy (PTP) was performed at the right precordium using alligator forceps with fluoroscopic guidance. Immediately after PTP, electrocardiogram and echocardiogram showed dramatic improvement of cardiac performance. Patient was released with the prescription of furosemide (1 mg/kg, bid, PO), enalapril (0.5 mg/kg, bid, PO), cephradine (20 mg/kg, bid, PO) for mild mitral regurgitation and post-management of infection. Diagnostic studies performed at 2 weeks after PTP revealed no further accumulation of pericardial effusion and improvement of clinical signs. The dog is currently medicated with enalapril and monitored regularly.

• Sleep Medicine and Psychophysiology
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• v.24 no.1
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• pp.24-31
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• 2017

Objectives: Periodic limb movement disorder (PLMD) has been debated with regard to its clinical significance and diagnostic criteria. The current diagnostic criterion for PLMD in adults has been changed from periodic limb movement index (PLMI) > 5/hour to PLMI > 15/hour by the International Classification of Sleep Disorders (ICSD). In this study, we aimed to investigate the changes in polysomnographic sleep variables according to PLMI and to determine the relevance of the diagnostic criterion for PLMD. Methods: Out of 4195 subjects who underwent standard polysomnography, we selected 666 subjects (370 males and 296 females, aged $47.1{\pm}14.8$) who were older than 17 years and were not diagnosed with primary insomnia, sleep apnea, narcolepsy, or REM sleep behavior disorder. Subjects were divided into three groups according to PLMI severity: group 1 ($PLMI{\leq}5$), group 2 (5 < $PLMI{\leq}15$), and group 3 (PLMI > 15). Demographic and polysomnographic sleep variables and Epworth sleepiness scale (ESS) were compared among the three groups. Results: There were significant differences among the three groups in age and gender. Sleep efficiency (SE) and stage 3 sleep percentage in group 1 were significantly higher than those in groups 2 and 3. The wake after sleep onset (WASO) score in group 1 was significantly lower than those in groups 2 and 3. However, there were no significant differences in SE, stage 3 sleep percentage, or WASO between groups 2 and 3. Sleep latency (SL) in group 1 was significantly lower than that in group 3, but there was no difference in SL between group 2 and group 3. ESS score in group 1 was significantly higher than that in group 3, but there was no difference between group 2 and group 3. Partial correlation analysis adjusted by age showed that PLMI was significantly related to SE and WASO. Conclusion: This study suggests that PLMI influences polysomnographic sleep variables. In addition, we found the individuals who did not have PLMD but had PLMI > 5 were not different in polysomnographic sleep variables from the individuals who had PLMD according to the current criterion. These results raise questions about the relevance of the current diagnostic criterion of PLMD.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.9
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• pp.2209-2215
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• 2014

This paper presents, a deinterlacing method by improving the Direction-Oriented Interpolation (DOI) technique. The technique is considered to be a very strong tool for intrafield-based deinterlacing. However, DOI has some problems such as long processing time, wrong edge detection in periodic pattern. To remedy this problem, we replace the full search in DOI by a two-step search to reduce processing time and introduces two additional processes to improve image quality. In the proposed method, the spatial direction vectors (SDVs) misread data are reconsidered to prevent them utilizing in the next interpolation step, resulting in an accurate deinterlacing method. We conduct experiments with ISO experimental images to compare the proposed method with the existing methods including line evarage (LA), edge-based line averaging (ELA), DOI, selective deinterlacing algorithm (SDA). Experimental results show the proposed method gives better performance in objective and subjective quality than existing deinterlacing methods.

• Pediatric Infection and Vaccine
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• v.7 no.2
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• pp.218-224
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• 2000

Purpose : In Korea, vivax malaria has been reemerged since 1993 after being abscent for more than 10 years. There are several possibilities of casuality of recent epidemic, although it is still unclear. The epidemiologic studies including case analysis and entomological reseach have been undertaken for a successful control measure. But, unfortunately those studies have been rarely dealt with cases of children. Therefore, this study was designed to figure out the characteristics of epidemiolgic and clinical features in children with indigenous vivax malaria. Methods : The study 21 cases below 15 years of age, who were diagnosed as vivax malaria and resided in kyounggi-do province area during 1998. 9~1999. 8. We retrospectively analyzed epidemiologic data concernig with occurrence of vivax, and clinical manifestations, abnormal laboratory findings and outcomes including therapeutic responses. Results : All cases were inhabitants of the endemic areas for vivax malaria in northwestern part of Kyonggi-do or western Kangwon-do, and Paju-gun was the most prevalent. Indigenous malaria cases of this study were more prevalent in children above 10 years old age, and in male. Seasonally, vivax malaria in children occurred throughout the year except January, March and November, and the incidence was the highest in July. Clinical manifestations revealed that 48 hour cyclic fever pattern was the major fever pattern, and other symptoms such as headache, vomiting, poor appetites, chilling, abdominal pain and diarrhea were concomitantly developed. And splenomegaly revealed the main abnormal findings on physical examination, and anemia was the most frequent abnormal finding in laboratory examinations. Young trophozoite was frequently observed on peripheral blood smears. The therapeutic responses of chlorquine were very good in all cases, and no recurrence developed in follow up cases. Conclusion : Geographical and seasonal occurrence distributions of indigenous vivax malaria cases in children were very similar to those of adults as followings; Inhabitants of the endemic region, more prevalent in male, and more common during the summer season. Clinically, 48 hour cyclic fever pattern, splenomegaly and anemia were most frequent and important manifestations in children cases, and clinical courses were not serious. On blood smears, young trophozoite was most dominantly examined in children. Generally, the therapeutic outcomes were excellent, and recurrences were not observed.