접속방법에 따른 접지도체 굵기 제안식

崔洪圭,吳廷錫,宋榮朱 弘益大學校 産業技術硏究所 2004 産業技術 Vol.14 No.-

접지도체의 굵기를 결정하는 국외 규격은 재료의 특성값인 물리적 정수까지 적용하여 광범위하게 적용할 수 있는 반면 수식이 복잡한 문제점이 있고 JIS와 국내규격은 수식은 간단하나 제약조건이 많은 문제점이 있다. 또한, 접지도체의 접속방법에 따라 최대허용온도가 다르게 적용되므로 접지도체 굵기 산정 방식이 복잡하고 적용 방법이 상이하여 시공현장에서 엔지니어들이 적용하는데 많은 어려움이 있다. 따라서, 본 논문에서는 새로운 접지도체 굵기 산정방식을 제시하고 접속방법에 따른 접지도체 굵기 산정 간이식을 제시한다.

충남지역 석불의 암석학적 풍화특성에 관한 연구

최석원,채상정,이효민 공주대학교 문화재보존과학연구소 2003 문화재과학기술 Vol.2 No.1

충청남도내의 중요문화재로 지정된 석불 중 역사적 중요성을 가지고 구조적으로 보아 위험성이 있는 것으로 판단되는 석불 31개를 대상으로 암석학적 특징, 풍화에 의한 암석의 조직 및 광물학적 변화, 풍화에 따른 물성 변화 등, 석불을 이루고 있는 암석의 풍화특성을 파악하였다. 석불을 이루고 있는 암석은 대부분이 중립 내지 조립질의 화강암류이며, 소수 석불만이 편마암으로 이루어져 있다. 시료채취가 가능한 12개 화강암류 석불의 모드분석 결과, 흑운모화강암 8개, 반상화강섬록암 3개, 화강섬록암 1개로 분류되었다. 이것들은 암석자체에 많은 절리, 박리조직과 심한변색을 보이고 있다. 편광현미경하에서의 관찰 결과, 장석류는 견운모화작용이 심하고, 흑운모는 녹니석화작용으로 주변광물을 변색시키며, 석영은 일정한 방향으로 균열이 발생하는 등의 조직변화가 일어나고 있다. 석불을 구성하고 있는 암석은 풍화가 많이 진행되어 카올리나이트화 되었으며. 풍화등급은 MW에서 HW에 속한다. 따라서 대부분의 석불들은 풍화를 많이 받은 상태이고, 각 석불의 풍화특성을 고려하여 과학적이고 비파괴적인 보존방법이 연구되어야 할 것이다. This study was carried out the survey of the petrological weathering characteristics as the petrological texture and the mineralogical alteration and the change of rock physical properties by weathering for 31 Stone-Buddhist images designed as important cultural property in Chungnam province. Most rocks composing Stone-Buddhas are classified into granite which is medium to coarse, but some Stone-Buddhist images comprise in gneiss. As the result of modal composition for 12 Stone-Buddhist images being possible to take samples, they are classified into 8 biotite granite, 3 porphyritic granodiorite and 1 granodiorite, which are showed with many joints, exfoliation and intensive discoloration. Referring to the result of observation under the polarizing microscope, some feldspar are being sericitizated and some biotite are being changed to chlorite Under the observation with SEM, some feldspar are changed into lamella-kaolinite by the weathering. Most rocks composing the stone Buddhist images are being weathered much and kaolinited, and its weathering level is classified into MW to HW referring to the result of these studies. Accordingly it is required studying scientific and undestructive method considering the weathering distinction of Stone-Buddhist images.

상처치유시 Antisense TGF-β1 Oligodeoxynucleotides가 Inducible Nitric Oxide Synthase발현 조절에 미치는 영향

최병민,곽현정,전창덕,임정식,박석돈,정헌택 大韓免疫學會 1996 大韓免疫學會誌 Vol.18 No.4

Wound healing in the skin may be complicated by both microbial invasion and inflammation. Following injury, platelet degranulation releases a number of chemotactic factors including transforming growth factor (TGF-fl) and platelet derived growth factor (PDGF). TGF-19 is a cytokines that modulates many cellular function and gene expression. However, it is not known whether TGF-P could regulate inducible nitric oxide synthase (iNOS) gene expression during wound healing. Here we report that down regulation of TGF-Q gene expression by antisense oligodeoxynucleotides increase iNOS during wound healing. Our reverse transcription- polymerase chain reaction (RT-PCR) result has shown that antisense TGF-fil oligodeoxynucleotides (ODN) targeting the TGF-J11 translation initiation region markedly reduced TGF-(il mRNA levels in wounded skin. Also, marked reduction in TGF-fl1 mRNA after antisense treatment invited that the increment of iNOS mRNA in wounded skin. Therefore, our irnmunohistochemical studies revealed a "pattern of iNOS product in wounded skin treated antisense TGF-fl1 ODN that was similar to the pattern of RNA synthesis detected by RT-PCR. In conclusion, our results indicated that the regulatory actions of TGF fl1 on iNOS. might be involved in the initiation and faciliates the resolution of inflammation following wounding.

한국전통음악공연장의 건축음향특성에 관한 연구Ⅰ : 물리적 음향특성을 중심으로

정대업,최석원 대한건축학회 2005 대한건축학회논문집 Vol.21 No.3

The present study aims at providing practical design data by measuring room acoustic parameters in 10 rooms for traditional Korean Music. The room acoustic parameters considered in this work were RT, EDT, BR, TR, Ts, C50, C80, (1-IACCE3), and LF. The measured room acoustic parameters were analyzed and compared with the optimum ranges for each parameters suggested by previous works. It was found that the acoustics of rooms considered in the present work were generally in accordance with suggested optimum ranges for reverberation and energy related parameters. Also, majority of rooms were designed to have monaural spatial impressions in audience area. The correlation analysis between room acoustic parameters suggested that RT, TR, C50, 1-IACCE3 and LF were orthogonal. However, negative responses from professional musicians and acoustic engineers who have experienced the acoustics of those 10 rooms for traditional Korean Music implies that further extensive researches are strongly necessary in both room acoustic parameters and optimum acoustic design criteria. Further studies will give an emphasis on the subjective listening test using binaural impulse responses obtained in those 10 rooms.

능동 클램프 ZVS 플라이백 컨버터의 역률개선에 관한 연구

최태영,류동균,이우석,안정준,원충연,김수석 성균관대학교 2002 학술회의지원논문목록집 Vol.2002 No.-

본 논문에서는 single-stage, two-stage 두가지 역률보상(PFC)기법을 기존의 능동 클램프 플라이백 컨버터에 적용하여 역률 개선을 하였다. 삽입된 플라이백 컨버터의 능동클램프회로가 주스위치와 보조스위치의 영전압스위칭(ZVS)을 구현하며, 스위칭 손실을 줄임으로써 고효율을 얻을 수 있고, 높은 주파수에서의 스위칭이 가능하다. 하지만 일반적으로 사용되는 다이오드정류기, 평활용커패시터에 의한 낮은 역률의 문제점이 남아있다. 본 논문에서는 300W급 능동 클램프ZVS플라이백 컨버터를 설계하여 single-stage, two-stage방식을 적용, 입력역률개선을 시뮬레이션과 실험에 의해 입증하고자 한다. This paper analyzed PFC of active clamp ZVS flyback converter by adding two method PFC (Power Factor Correction) circuit - two-stage and single-stage. The addition of active clamp circuit also provide a mechanism for achieving ZVS of both the primary and auxiliary switches. ZVS also limits the turn off di/dt of the output rectifier, reducing rectifier switching loss and switching noise, due to diode reverse recovery. As a results, the proposed converters have characteristics of the reduced switching noise and high efficiency in comparison to conventional flyback converter. The simulation and experimental results show that the proposed converters improve the input PF of 300W ZVS flyback converter by adding single-stage, two-stage PFC circuit.

鹽化物 含有梁에 따른 鐵分 腐蝕에 관한 實驗的 硏究

최진석,조철희,신용석,고송균,손순채,김정섭 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(구조계)

As a result of separating river sand and sea sand into the corrosion increased according to the of thinnss or the coating and the Chloride Content and Corrosion of Steel Bar through the experiment, the following conclusions are obtained. 1. There was no corrosion in the case of treating the steel bar with anticorrosive among test specimens cured in the air for 60 days, corrosion was found in the test specimens not treated with anticorrosive and for 60 days of age. 2. The area of corrosion increased according to the thinnss of the coating and the chloride content wher exposed for are more than 60 days. Therefore, it was determined in general that the corrosion progressed more rapidly in water cured specimens than in air cured ones and this was due to the influence of C1_(￣) in the sea sand.

도심지 터널형 방음벽의 환경적 요인 및 외관 디자인에 관한 연구

최정민,윤태호,박창섭,이경희,박진석 국립7개대학공동논문집간행위원회 2005 공업기술연구 Vol.5 No.-

This study is to obtain a basic data for a better environment and visual design improvement for the sound barrier tunnel located along the overpasses which passed through downtown areas. For this purpose, the traffic noise was measured in Daegu. In addition. using the sound analysis software, equivalent sounds were checked and analyzed. Finally, the alternatives of sound barrier tunnel were proposed.

뇌동맥류 파열 환자에서 증후성 뇌혈관연축의 발생 및 회복에 영향을 미치는 인자들

최석민,석종식,권정택,민병국,황성남,김영백,홍현종 대한신경외과학회 1996 Journal of Korean neurosurgical society Vol.25 No.10

To determine the factors affecting development and recovery of symptomatic vasospasm. the author analysed the results of patients with ruptured intracranial aneurysms treated by nimodipine and prophylactic “triple0H” therapy. From January 1991 to December 1995. 199 patients underwent surgery for ruptured intracerebral aneurysms. Combined hypervolemic hemodilution was initiated at the time of admission. Induced hypertension was added immediately after surgery(aneurysmal neck clipping). All patients received nimodipine intravenously or orally until the 14th day of SAH Sixty patients underwent surgery on Day 0 through 2 after attacks of subarachnoid hemorrhage(Goup A) 105 patients on Day 3 through 14(Group B). and 35 patients after Day 14(Group C). Of 199 patients. 76(38%) patients suffered from symtomatic vasospasm. Symptomatic vasospasm occured in 34% of Group A patients. 33% of Group B patients. and 5% of Group C patients. Symtomatic vasospasm occured more frequently in the older age group. the Fisher group 3 and Hunt & Hess grades 3, 4 and 5 groups. Of 76 patients who suffered from symptomatic vasospasm. 47(62%) patients recovered completely. The author analysed the relationship between recovery rate and sex, age. Hunt & Hess agrde and Fisher group among these 76 patients. Recovery rates between these groups were not significantly different. Based on this experience the author believes that Hunt-Hess grade. Fisher group and age are important factors affecting symptomatic vasospasm development.

乳房炎 乳汁에서 分離된 原因菌의 抗菌劑 感受性

崔民淳,金鍾冕,趙正坤,蔡孝錫,姜明大,宋熹鍾 全北大學校 附設 畜産開發硏究所 1987 畜産開發硏究報告 Vol.1 No.-

A total of 189 strains (Streptococcus agalactiae and non-Streptococcus agalactiae 110, Staphylococcus aureus 63, and E. coli 16) isolated from bovine mastitie milk samples by "The Connecticut Mastitis Control Program" in dairy herds were examined for drug susceptibility to 8 drugs and analysed the rate of multiple resistant patterns. 1. All of the isolates were resistant to antimicrobial agents such as penicillin (PC), streptomycin (SM), kanamycin(KM), carbenicillin (CA), lincomycin (LM), gentamicin (GM), and tetracycline (TC), singly or multiply. The isolates were more susceptible to CA (84.1%),PC (78.9%), and SM (78.4%) than the the other drugs such as GM (51.8%), KM (48.7%), TC (19.6%) and LM (19.0%) in order. 2. The multiple resistant isolates (96.3%) were more than those of singly resistant isolates (3.7%) and 58 different drug resistant patterns were observed. Among 7 singly resistant isolates, CP was the commonest. While among 182 multiple resistant isolates, CP-KM-LM-TC-GM, CP-LM-TC, CP-LM-TC-GM, PC-CP-SM-LM-TC-GM, CP-KM-LM-TC, and CP-LM patterns were frequently encounted. 3. The strains of streptococcus spp. were more susceptible to CA (90.1%) and SM (82.9%) than the other drugs such as KM (43.2%), GM (38.7%), LM (13.5%), CP (10.8%) and TC (10.8%). Among them CP-KM-LM-TC-CM pattern was frequently encounted. 4. The strains of Sta. aureus were more susceptible to PC (74.6%),CA (69.8%), SM (65.1%) and GM (63.5%) than the other drugs such as KM (46.0%), CP (22.2%), TC (15.9%) and LM (9.5%). Among them CP-LM-TC pattern was commonly encounted. 5. The strains of E. coli were more susceptible to CA (100%) and KM (75.0%) tnan TC (9.5%). But the other drugs such as PC, SM, GM, CP and LM were not. Among them PC-CP-SM-LM-TC-GM pattern was commonly encounted.

식도를 포함한 전위장관을 침범한 전이성 악성 흑색종 1예

최정영,김준기,신성하,고영춘,조상욱,서강석,강명원,임연근,여향순,김경수 全南大醫大 2001 전남의대학술지 Vol.37 No.1