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.

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.

느릅나무 뿌리껍질 성분의 유방염균에 대한 항균효과

신성진,윤민호,권순경,최우영 충남대학교 농업과학연구소 1999 농업과학연구 Vol.26 No.1

젖소 유방염 병원균에 대한 느릅나무 뿌리껍질(楡白皮)의 항균활성을 검토하기 위하여 용매분획별로 시험한 결과 일반적으로 chloroform 분획이 가장 효과적이었고 butanol 및 물분획의 활성은 낮았다. 유방염균을 Fleish extract broth에서 액체 배양할 경우에 chloroform 분획을 첨가하면 생육이 억제되었으며 특히 Staphylococcus aureus 및 Streptococcus sp. No. 12는 초기생육이 현저하게 저해되는 경향을 나타내었다. Hoechst 제약의 표준방법에 의한 MIC 시험에서도 유사한 결과를 얻었다. 또한 건조한 느릅나무의 뿌리껍질 100g을 물로 추출하여 겉보기 점도 77.5 cP, 최대흡수 파장 440㎚의 황갈색 수용성 점질물 4.500㎖를 회수할수 있었다. 이를 정제 건조한 무게는 32~35g이었으며, 탄수화물 함량이 61.0±1.0%, 단백질 8.0±0.2%로서 다당이 주성분이었다. 이상의 실험결과를 통해 유백피의 용매 추출분획물은 항균활성을 나타내는 성분으로, 그리고 수용성 점질물은 흡수성과 점성이 높은 다당류로서 염증 부위에 수렴작용을 나타내는 성분으로 결론지을 수 있었다. The methanolic extracts from the elm (Ulmus davidiana var japonica) root barks which have been known as an oriental medicine Eubackpie for the treatment of edema, ulcer and inflammation were examined for their bacteriocidal effects on mastitis pathogens of milk cows. The growth of the pathogenic bacteria such as Staphylococcus aureus and Streptococcus sp. No. 12 was markedly inhibited by the chloroform fraction among the extracts, and these antibacterial activities were also supported by MIC test. Water-soluble mucilage was obtained from the root barks with a yield of 36.8∼40.2% bf dry weight basis. This substance appeared to be a kind of polysaccharide with 61.0±1.0% carbohydrate content, and to have hygroscopic and astringent properties due to its high viscosity and water absorption.

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.

Cone Beam CT를 이용한 하악 제 1대구치 맹출 양상에 관한 연구

신정근,김재곤,백병주,양연미,정진우 大韓小兒齒科學會 2009 大韓小兒齒科學會誌 Vol.36 No.3

건강한 정상 교합 어린이 83명(남자 42명, 여자 41명)을 대상으로 보호자 동의하에 cone beam CT 영상을 촬영하여, 하악 제1대구치의 맹출 양상을 연구하였다. 대상을 발육 정도에 따라 Nolla stage(4-10단계)로 구분한 후 삼차원 기준 평면인 전두면(frontal), 시상면(Sagittal), 수평면(horizontal)에서 각각 하악 제1대구치의 맹출 양상을 관찰하였다. 1. 전두면과 수평면에서, 하악 제1대구치간 폭경은 감소하였는데, stage 5에서 stage 8까지 가장 크게 감소했다가 약간 증가하였다. 2. 시상면과 전두면에서, 하악 제1대구치 맹출량은 교합평면을 기준으로 stage 5에서 stage 7까지 가장 많은 맹출 이동을 보였다. 3. 수평면과 시상면에서, 하악 제1대구치는 제2유구치 원심면으로부터 stage 4에서 stage 6까지 원심으로 이동하였고 이후 큰 변화가 없었다. 4. 시상면에서, 교합 평면과 하악 제1대구치의 근원심 치축이 이루는 각은 stage 4에서 stage 8까지 증가하였다. 5. 전두면에서, 교합 평면과 하악 제1대구치의 협설측 치축이 이루는 각은 지속적으로 증가하였다. 6. 수평면에서, 정중 시상면과 하악 제1대구치의 치축이 이루는 각은 stage 5부터 stage 8까지 증가하다 stage 8이후에는 다시 약간 감소하였다. The purpose of this study was to investigate the eruption pattern of the mandibular first molar in sagittal. frontal and horizontal views using the cone beam CT scanning. CT images were obtained from healthy 83 children(42 boys. 41 girls) between 3 to 10 years of age with a normal dentition according to Nolla stage. 1. In the frontal and horizontal view. the intermolar width decreased continuously with stage and slightly increased at the last stage. 2. In the sagittal and frontal view. eruption distances from occlusal plane were observed the largest change between stage 5 and 7. 3. In the horizontal and sagittal view. mandibular first molar from distal surface of primary second molar moved distally between stage 4 and 6. 4. In the sagittal view, angle from occlusal plane to mesio-distal axis increased between stage 4 and 8. 5. In the frontal view, angle from occlusal plane to bucco-lingual axis increased continuously during all stage. 6. In the horizontal view, angle from midsagittal plane to long axis increased between stage 5 and 8.

구강악안면 외상환자의 조직손상의 양상 및 정도에 관한 임상적 연구

신효근,소병수,안태섭,진우성,윤철희 大韓顎顔面成形再建外科學會 1995 Maxillofacial Plastic Reconstructive Surgery Vol.17 No.3

This is a clinical and retropective study on th patients with oral and maxillofacial trauma. This study was based on a series of 917 patients were treated as in-patients, at Chon-buk National University Hospital, during the period of Jan., 1989 through Dec., 1993. The results obtained were as follows : 1. The ratio of men to women were 3.59 : 1 in oral and maxillofacial injuries, 3.92 : 1 in facial bone fractures, and 3.18 : 1 in soft tissue injuries. 2. The oral and maxillofacial injuries occurred most frequently in the third decade(32.2%), and fourth, second, fifth decade in orders. 3. The major etiologic factors were traffic accident(57.4%) and fall-down(17.1%), interpersonal accident(16.6%), and industrial accident were next in order of frequency. 4. The incidence of facial bone fracture was 72.1%, soft tissue injury 58.8%, and dental injury 40.5%. 5. The most common site of fracture were mandible(62.9%) and maxilla(19.9%), zygoma and zygomatic arch(18.7%), and nasal bone(4.7%) were next in order of frequency. 6. The most common type of soft tissue injury was laceration(51.0%). The lesion of soft tissue injuries were mostly 1 or 2 lesions and deep.

달맞이꽃(Oenothera odorata Jacquin) 뿌리에서 추출한 항균성분의 특성

신성진,권순경,이권행,성낙도,최우영 충남대학교 농업과학연구소 1994 농업과학연구 Vol.21 No.1

An antibacterial component was isolated from the roots of evening primrose (Oenothera odorata Jacquin). The component was purified by repeated preparative TLC of the chloroform-extract with solvent system of toluene(7): ethyl acetate(4) : formic acid(O.8). NMR spectrum indicated that it is a steroid compound containing radical(-C=C-C=0) and aromatic structures. Its antibacterial activity against strains of the genus Streptococcus was relatively high, the MIC value was 50 according to the Hoechst Manual-345, as compared with the other genera such as Staphylococcus and Escherichia.

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.

음성 인식 헬스케어 시스템

신진우,조우승,조성빈,김재훈,정지은,사예지,백경동,박동규 순천향대학교 부설 산업기술연구소 2021 순천향 산업기술연구소논문집 Vol.27 No.2

As modern people's interest in health grows, wearable healthcare-related technologies that can collect biometric information and receive health-related services regardless of time and place are developing. This paper proposes the healthcare system based on voice recognition function. Unlike conventional wearable healthcare systems, the proposed system provides real-time telemedicine and diagnosis and the direct connection with doctors is possible through it. And almost all functions of the application in it are operated with voice commands to lower user access barriers. Because it deals with personal information including medical information, encryption algorithms have been applied between all data movements. Finally, the healthcare system proposed in this paper is expected to increase convenience in health care and reduce the medical gap.