고압 커패시터의 고장 분석을 통한 신뢰도 예측

양석준,김진우,신승우,이희진,신승훈,유동수,장석원 한국비파괴검사학회 2001 한국비파괴검사학회지 Vol.21 No.6

본 논문은 고압 커패시터의 고장분석과 신뢰성 예측 결과를 다루고 있다. 부품의 수명과 고장률을 예측하기 위해서 두 가지 방법으로 고장 모드와 고장 메커니즘을 연구하였다. 에폭시 수지로 성형된 고압 커패시터가 절연내압 시험 하에서 저항이 제로로 되는 고장에 대하여, 근본원인 고장분석 체계를 효과적으로 수립함으로써 고장 메커니즘의 원인을 분석하였다. 특히 세라믹-에폭시 계면에서의 절연파괴 고장 현상이 강조되었으며, 본 연구에서 얻어진 결과의 타당성은 마그네트론에 장착된 고압 커패시터의 열사이클 시험 수행에 의한 가속시험 결과로부터 입증되었다. 시험 결과들은 결함이 있는 로트를 신속히 규명하고 B10수명을 결정하는데 유용하게 사용할 수 있다. 또한, 유전체의 절연파괴에 대해서 부하-강도 간섭모델을 이용하여 고장률을 예측하였다. This paper presents a result of failure analysis and reliability evaluation for high voltage ceramic capacitors. The failure modes and failure mechanisms were studied in two ways in order to estimate component life and failure rate. The causes of failure mechanisms for zero resistance phenomena under withstanding voltage test in high voltage ceramic capacitors molded by epoxy resin were studied y establishing an effective root cause failure analysis. Particular emphasis was placed on breakdown phenomena at the ceramic-epoxy interface. The validity of the results in this study was confirmed by the results of accelerated testing. Thermal cycling test for high voltage ceramic capacitor mounted on a magnetron were implemented. Delamination between ceramic and epoxy, which might cause electrical short in underlying circuitry, can occur during curing or thermal cycle. The results can be conveniently used to quickly identify defective lots, determine B10 life estimation each lot at the level of inspection, and detect major changes in the vendors processes. Also, thd condition for dielectric breakdown was investigated for the estimation of failure rate with load-strength interference model.

한국 정신장애의 역학 조사 연구[I] : 각 정신장애의 유병률

조맹제,함봉진,김장규,박강규,정은기,서동우,김선욱,조성진,이준영,홍진표,최용성,박종익,이동우,이기철,배재남,신정호,정인원,박종한,배안,이충경 大韓神經精神醫學會 2004 신경정신의학 Vol.43 No.4

Objectives : This study aims to estimate the prevalence of the DSM-IV psychiatric disorders in Korean population using the Korean version of Composite International Diagnostic Interview (K-CIDI). Methods : Subjects were selected by taking multi-stage, cluster samples of 7,867 adult household residents, 18 to 64 years of age, in ten catchment areas. Total 78 trained interviewers administered the K-CIDI to the selected respondents, from June 1 to November30,2001. Results : Total 6,275 respondents completed the interview. Some 33.5% of respondents reported at least one lifetime disorder, 20.6% reported at least one-year disorder, and 16.7% reported at least one-month disorder. The most common lifetime disorders were alcohol abuse/dependence (17.24%), nicotine dependence/withdrawal (11.19%), specific phobia (5.16%), and major de-pressive disorder (4.25%). The lifetime prevalence of substance abuse/dependence (0.25%) and schizophrenia (0.16%) was very low. Nicotine and alcohol use disorder showed very high male/female ratio. Mood disorder and anxiety disorder were more prevalent among female than male. Conclusion : The prevalence of psychiatric disorders was high. In comparison with other studies, remarkable differences in distributions of psychiatric disorders across the areas and times were observed.

모션 인식 기반 스마트 미러

김경진,백경동,신진우,박동규 순천향대학교 부설 산업기술연구소 2021 순천향 산업기술연구소논문집 Vol.27 No.1

The Internet of Things, the core of the Fourth Industrial Revolution, is growing by applying various technologies to various fields. Among them, smart home systems that apply IoT technology to home environments are actively being researched, and the home hub market, which is a communication medium for smart homes, is also developing at the same time. However, the security damage from cyber attacks, which are vulnerabilities in IoT technology, is also increasing in proportion to these developments. In this paper, mirror is implemented as an IoT service hub. It can be used in any space where a mirror is installed, and gesture recognition allows control of existing infrared-based devices as well as certain compatible devices. In addition, the system to solve security problems was implemented by applying AES algorithms between all data communications.

GIS를 이용한 소매업종 상권 반경과 중심지 이동분석

신우진,정창무,이상경 한국부동산분석학회 2002 不動産學硏究 Vol.8 No.1

This paper assesses changing patterns of the commercial power of a region and leading sectors of the movement with radial ring-based analyses of 49 categories of retail services in Kangnam-gu, Seoul. The radius of trade market area(R), as the measure of commercial power of a location, is defined as a pre-defined radial distance from the store location. Moving patterns of the regional commercial power is analysed based on the peak of overlapping density of the retail trade area every year. Findings indicate that the centers have been differentiated from each other in the form of an orderly hierarchy of places, with particular retail services developing for lower-ordered places as they reach a threshold, and leading sectors of the movement are usually retail services favored by teenagers.

배 농가의 경영효율성 분석 : 비모수적 접근방법에 의한 사례연구 A case study using non-parametric method

우수곤,유진채,강경하,신용광 한국농촌지도학회 2002 농촌지도와 개발 Vol.9 No.2

The objective of this study was to compare the farm efficiency of members of cooperative firms with that of non-members in Korea. Data were collected from 27 farms members of three cooperatives and 13 non-member farms, based on the managerial achievements of 1999. For the analysis, the data were divided into three different farming types: type I and Ⅱ of member farms and non-member farms. Economic analysis were implemented using DEA(Data Envelopment Analysis). Major findings was as follows. Total average technology efficiency was 0.782, which implies that there still remains 21.8% of improvement possibility. Among the time types, type I showed the highest technology efficiency of 0.9055, while " 11 and non-member farms showed 0.7670 and 0.7171, respectively. This means that these farms have relatively high potential improved. Also, comparing technology efficiency by dividing into pure technology and scale efficiency, all type of the farms exhibit a higher pure technology efficiency compared to scale efficiency. Therefore, to improve current technology efficiency, farms need to focus more on pure technology efficiency improvement. Meanwhile, profit analysis based on farm size indicate that most of the farms demonstrated the increasing-return-to-scale, which means it is necessary to extend the farm size to improve technical efficiency. Type I member farms achieve higher profit and efficiency than other two types and relatively higher producer prices through introducing cooperative sorting, grading and packing. Also, these labor saving technologies increased farm size.

기독교 교역자들이 주장하는 귀신들림에 대한 정신의학적 고찰

신형균,손진욱,우성일 大韓神經精神醫學會 1991 신경정신의학 Vol.30 No.6

Opinions and experiences about demon possession and mental disease were collected from clergymen in the western area of Gyeongsangnamdo by the mail questionnaire and direct interview. The results can be summarized as follows. 1) The majority of respondents thought that demons were fallen angels(92.3%) and existing at that time(96.6%). Many of them(63.2%) thought that the incidence of demon possession was increasing. 2) The majority of respondents(94.9%) had seen individuals possessed by demons and they believed in the existence of demon possession firmly. Those who were possessed by demons were mainly females, in their 20th and 30th, with short academic career, in low SES and with shamanistic beliefs. 3) Many respondents thought that mental diseases were different from demon possession(94.0%) and it was possible to distinguish between them(67.5%). Violent behavior, soliloquy, avoidance of eye contacts with clergyman, bizarre voice, social withdrawal and auditory hallucination were regarded as features of demon possession. 4) As the cause of demon possession, many respondents regarded non-religious factors such as psychological conflict or trauma(59.0%) and personality(10.3%), while smaller number of them regarded religious factors such as own sin or unbelief(35.0%) and divine providence(12.8%). Many respondents(76.2%) had treated individuals possessed by demons with religious healing techniques only, but many respondents(61.5%) also thought that medical treatments must be combined. 5) Many respondents(72.6%) never studied mental diseases and their knowledge about mental diseases were mainly from the Bible. 6) Cases of demon possession collected by mail questionnaire can be diagnosed as follows : 37.5%, schizophrenia, 34.4%, atypical psychosis and schizophreniform disorder, and the remainder, dissociative disorder, mood disorder and delirium tremens. 7) Symptomatic features of demon possession were not different from the symptoms of mental illness, and the cases of demon possession were not essentially different from mental diseases. Through mutual understanding and cooperation, both clergymen and psychiatrists can find better ways of treating the individuals possessed by demons and get deeper insights about human psyche.

하악 매복 지치의 외과적 발거시 Methylprednisolone의 안면 부종 감소 효과에 대한 임상적 연구

신지훈,박진배,한지용,윤혜경,김우형,이희철 인제대학교 백병원 2002 仁濟醫學 Vol.23 No.4

Objective : The third molars, expecially mandibular wisdom teeth, are commonly obliquely impacted, and surgical procedure with odontomy and osteotomy is necessary for their extraction. The surgical extracion of impacted wisdom teeth occasionally in duces variable discomfort. Especially, postoperative swelling, pain and limitation of mouth opening determine the degree of discomfort. For the reduction of these complicaions, drug therapy(antihistamine, enzyme, steroid), cole pack and pressure technique have been studied. It is known that the steroids are the most effective. Methods and Meterial : We selected fifty patients in their twenties, who visited Department of Dentistry, Pusan Paik Hospital from March to August in 1998. All of 50 patients has no other medical problems. Total 50 patients were randomly divided to 30 of experimental group and 20 of control group. The experimental group had orally administration of methyprednisolone 5㎎ every 8 hours 2 times preoperatively and 7 times postoperatively. Five points were marked on the patients' face, and the distances between the points were measured just before operation and 48 hours after operation. Results : Methyprednisolone reduces swelling about 50% after surgical extraction of obliquely impacted mandibular third molars with osteotomy and odontomy. The difference in the amount of tissue edema between experimental and control group was significant(p<0.01). However, there was no significant difference according to the operation time. Conclusion : It seems that the use of methylprednisolone is effective to reduce postoperative swelling following surgical extraction of third molars.

矢狀分割骨切斷術에 依한 顎矯正術의 統計學的 硏究

辛曉根,陳宇政,李俊禮,金晤煥,李炫尙 大韓顎顔面成形再建外科學會 1997 Maxillofacial Plastic Reconstructive Surgery Vol.19 No.2

Recently, combined with social complexity, increment of medical demand and supply and the change of esthetic category, admission and operation of the patients of facial deformity have been changed with annual change. This study was conducted in the concept of helping the overall character of orthognathic surgery in future understood and being an important index in the establishment of better treatment course, through the patient, on whom was operated orthognathic surgery via sagittal split ramal osteotomy in our Dept. of Oral & Maxillofacial Surgery, Chonbuk National University Hospital from 1991. 1. 1 to 1995. 12. 31. The results were obtained as follows. 1. The ratio of male to female was 1 : 1.33 and the ages between 16 and 25 year was 73.6%, and the mean age was 20.4 years. 2. The ratio of setback amount between 6 to 15mm was 84.6% and the advancement amount between 1 to 10mm was 89% and the mean amount of movement was 9.0mm in setback, and 3.6mm in advancement. 3. After removal of maxillomandibular fixation(MMF), the distinction of sex was not statistically significant in ROM. 4. The ROM following methods of fixation was statistically significant in 3rd(P<0.05), 8th, and 12th week(each P<0.01), with faster rehabilitation in rigid fixation which had shorter MMF period. 5. The rehabilitation of ROM following the operation methods was statistically significant in 1st(P<0.05), 2nd, 3rd, 4th, 6th, 8th, and 12th week(each P<0.01) with faster rehabilitation in the case of SSRO than Lefort I / SSRO (Two jaw surgery). 6. The rehabilitation of ROM following directions of mandibular movement did not manifest a statistically significant difference in both setback and advancement.

고주파 가열에 따른 반응고 알루미늄합금의 미세조직 특성

신평우,이정환,이상용,노진호,이영선 國立 昌原大學校 産業技術硏究所 1997 産技硏論文集 Vol.11 No.-

Semi-solid forming is relatively new process for forming alloys in the semi-solid condition into near net produce. It relies on the behaviour of semi-solid slurrys in which the solid exists in the form of non-dendritic, spheroidal particles in a liquid matrix. Powder of the Al-20Si-5Fe-2Ni alloy was manufactured by spray forming and powder metallurgy, one of the rapid cooling method, and its microstructure became fine with several ㎛ size through the extrusion process. Spray forming and powder metallurgy are a rapid solidification process in which capable of producing materials consisted of very fine, uniform particles. Spray forming can be described as incorperating the advantages of powder metallurgy without disadvantages of degassing and consolidation. In this paper, the microstructural evolution of the P/M, S/F Al-20Si-5Fe-2Ni alloys and wrought Al 2024 alloys were investigated various heating conditions by high frequency induction heating system.

VHDL을 이용한 실시간 JPEG 인코더 설계

신인철,어진우,강호준 단국대학교 1997 論文集 Vol.31 No.-

Image compression techniques have been necessary to transfer and save a great amount of image data in an efficient way. Because the compression and decompression of image signal require the real time processing, various hardware implementation methods have been studied. In this paper we propose the algorithm which is parallel form of processing 2 dimensional 8*8 blocks simultaneously, so increase speeds. It outputs compressed bit sequences 8 clocks later for the input data synchronized to clocks. Proposed algorithm is designed using VHDL. Simulation and circuit synthesis has been performed by the Powerview CAD Tool on the SUN Sparc-10 workstation. Results shows that maximum operating frequency is up to 15㎒. The final schematic circuit and comparison of processing speed are shown.