內燃機關의 排氣騷音이 性能에 미치는 影響

吳栗權,張熙碩,吳炯俊,車京玉 明知大學校 産業技術硏究所 1988 産業技術硏究所論文集 Vol.7 No.-

The theoretical analysis of the exhaust noise of an internal combustion entwine contains various difficult factors. The exhaust system is closely related with these problems, that is, the resistance of tile exhaust system is a factor governing the fuel economy and dynamic performance of an internal combustion engine, while exhaust noise and radiated noise from the system are one of the main factor affecting the quietness of an internal combustion engine and also one of the main sources of external noise of all internal combustion engine. Reducing tile resistance and lowering the exhaust and radiated noise are contracdictory requirements and it has been considered difficult to satisfy these requirements simultaneously. Almost all the studies on the attenuation characteristics of a muffler are an analysis based on the assumption that the time of intake-exhaust valve opening - closing is deadpoint. This paper introduces a practical exhaust system for internal combustion engine newly developed as the result of studies on the reduction of the exhaust system, pulsating noise and draft noise.

工具磨耗에 따른 切削力의 動特性에 대한 硏究

吳錫炯,羅義均 군산대학교 1992 群山水産專門大學 硏究報告 Vol.26 No.1

In recent year, owing to the automization of cutting tools, in-process dectction is more and more important. It is necessary to find how to estimate the tool wear because of problem about precision. Most of studies on in-process detection of tool wear have been carried out by prediction of tool life and measurement of force, heat, vibration, AE(acoustic emission) and image processing in cutting. In this paper, we deal with the relations of tool wear by variations in dynamic cutting force and then derived to correlate the wear with the dynamic component cutting force in the machining SUS304 which is welknown as difficult -to-machine material. The results obtained are as follows 1. At the view point of machinability for tool wear, even in case of same uncutchip cross-sectional area, to makes the slenderness ratio higher is advantageous. 2. The characteristics of RMS in cutting forces is correlated the wear and characterized by the tool life. It is suggested that applying the RMS to in-line process is a effective methods for detecting the tool wear.

工具磨耗에 따른 切削溫度의 變動 特性에 관한 硏究

吳錫炯 군산대학교 1993 群山水産專門大學 硏究報告 Vol.28 No.1

This study is planned with the variation of temperature that is closely associated with the wear when SUS304 is cut. Since SUS304 is a difficult-to-machine material, tool damage is largely affected by cutting conditions, this experiments investigate the relations between the cutting temperature and the characteristics of tool wear which is being in cutting process. In the results, the characteristics of cutting temperature are related to the difficulty of machining characteristics.

육총용류의 면역증진 효과 비교 연구

오정석,함인혜,김형민,최호영 대한본초학회 2005 大韓本草學會誌 Vol.20 No.1

Objectives : This study was to investigate the anti-immobility effect of Cistanche deserticolae Herba (CD) and Cistanche salsae Herba (CS) Methods : Forced swimming test (FST) and changes of blood biochemical parameters related to fatigue, glucose (Glc), blood urea nitrogen (BUN), latic dehydrogenase (LDH) aspartate aminotransferase (AST), alanine aminotransferase (ALT) and total protein (TP) were investigated. Results : CD and CS were orally administered to mice for 7 days. After 7 days, the immobility time was significantly decreased in the CD-treated group and CS-treated group in comparison with the control group. The contents of serum AST were significantly decreased and contents of Glc and LDH were decreased in CD-administration group . However, it had no effect on the elevation of TP level, whereas, the contents of GIc were increased and the contents of ALT, BUN and LDH in the blood serum were decreased in the CS (0.01 g/kg/day)-fed group. Conclusions : These results suggest that Cistanche herba, CD and CS may have immune-enhancing effect.

HPLC-MS/MS를 이용하여 혈장 중 레보티인정의 정량분석

채석,오형근,이상선,김형기,손동렬,염윤기,맹주양,권준택 순천향의학연구소 2008 Journal of Soonchunhyang Medical Science Vol.14 No.2

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항균 활성을 가진 천연약재의 검색

송형석,이지연,오성준,백남인,김해영 경희대학교 생명자원과학연구원 2000 硏究論文集 Vol.21 No.-

We investigated the antimicrobial activity of the hot-water extracts and methanol extracts from medicinal plants. Sixty-two samples were tested by disk diffusion method at concentrations of 5,000ppm and 10,000ppm. Seven species of medicinal plants showed a significant antimicrobial activity against various food-borne microorganisms.

난삭재인 STD11 강의 정면밀링가공시 절삭특성에 관한 연구

김형석,문상돈,오성훈 전북대학교 공학연구원 ( 구 전북대학교 공업기술연구소 ) 2003 工學硏究 Vol.34 No.-

Wear and fracture mode of ceramic tool for hardened Std11 steel was investigated by face milling in this study. The cutting force and acoustic emission(AE) signal were utilized to detect the wear and fracture of ceramic tool. The following conclusions were obtained : (1) The wear and fracture modes of ceramic tool are characterized by the three types : ① wear which has normal wear and notch wear, ② wear caused by scooping on the rake face, ③ large fracture caused by thermal crack in the rake face. (2) The wear behaviour of ceramic tool can be detected by the increase of mean cutting force and the variation of the AE RMS voltage. (3) The catastrophic fracture of ceramic tool can be detected by the cutting force(Fz-component). (4) As the hardness of work material increased, acoustic emission RMS valve and mean cutting force(Fz) increased linearly, but the tool life decrease.

연소에 의한 엔진 진동 특성에 관한 연구

장석영,박경석,오택열,백영남 慶熙大學校 1993 論文集 Vol.22 No.-

Generally, a knock sensor for a high power engine detects cylinder wall vibration and estimates pressure vibration in the combustion chamber. In this study, so combustion pressure detected by pressure tranducer and cylinder wall vibration detected by an accelation sensor are estimated and the difference of those two signals are anlayzed. These two signals are analysed by frequency analysis method and compared with theorical knocking mode in the combustion chamber of the spark ignition engine. Design parameters of the knock sensor are determined by these analysed data.

T1b 병기의 신세포암에서 수술 후 예후를 예측할 수 있는 임상 및 병리학적 인자에 대한 연구

오승용, 김영원, 윤형윤, 서성필, 이상근, 김원태, 윤석중, 이상철, 김원재, 김용준 충북대학교 의과대학 충북대학교 의학연구소 2014 忠北醫大學術誌 Vol.24 No.1

연구목적: T1병기의 국소신세포암(localized clear-cell renal cell carcinoma)은 근치적신적출술이 나 부분신절제술이 표준치료이며 수술 후 타 병기에 비해 양호한 예후를 보인다. 하지만, 많은 수의 환 자에서 추적관찰 중 재발 및 사망이 발생하는데, 이는 T1b 병기에서 더 높게 보고되고 있다. 본 연구 에서는 국소신세포암 중 T1b 병기의 신세포암에서 표준적 치료 후 환자의 예후에 영향을 주는 임상 및 병리학적 인자에 대하여 알아보고자 하였다. 대상 및 방법: 1999년부터 2011년 까지 5개 기관에서 근치적신적출술이나 부분신제술을 시행 받은 3567명의 국소신세포암 환자들 중 병리학적 병기가 T1b로 확진 된 702명을 대상으로 하였다. 이들 환자가 가지는 임상 및 병리학적 특성 [연령, 성별, 고혈압, 당뇨, 비만도, European Cooperative Oncology Group(ECOG) 수행도, 증상유무, 수술방법, 종양크기, 분화도, 조직학적 형태 등]을 이용 하여 환자의 예후 [무재발생존율(relapse-free survival), 암특이생존율(cancer-specific survival) 및 전체생존율(overall survival)]에 영향을 미치는 인자에 대하여 다양한 방법으로 비교분석 하였다. 결과: 추적 관찰 기간은 34.0개월 (중앙값, 0-152개월)이었으며, 이 기간 중 재발, 사망 및 암특이사 망은 각각 72례 (10.3%), 57례 (8.1%) 및 24례 (3.4%)에서 발생하였다. 단변량 및 다변량 Cox 비례위험회귀분석에서 다양한 인자들이 무재발생존율(당뇨 유무, 종양크기 및 Fuhrman등급), 암특이 생존율(나이, 체질량지수, 당뇨 유무, 종양크기) 및 전체생존율(나이, 체질량지수, ECOG 수행도, 종 양크기)에 영향을 줄 수 있는 독립적 예후인자였다. 결론: 본 연구결과 국소신세포암의 예후를 예측할 수 있는 다양한 임상 및 병리학적 인자를 확인 할 수 있었다. 이러한 위험인자를 가지고 있는 환자는 보다 적극적인 추적관찰을 통하여 재발을 조기에 발 견한다면 이들의 생존율 향상에 많은 기여를 할 수 있을 것으로 생각한다.

HT-80鋼 熔接材의 熔接後熱處理時 作用應力이 疲勞龜裂進展擧動에 미치는 影響

羅義均,吳錫炯 군산대학교 1992 群山水産專門大學 硏究報告 Vol.26 No.1

This study was conducted to examine the effects of the applied stress during PWHT on fatigue crack growth behaviours for the weldment of HT -80 steel. Stress during PWHT was applied to the weld HAZ in order to simulate the residual stress at welds. Submerged arc welding was done. Fatigue test was done at the frequency of 30Hz. The obtained data were analyzed between stress intensity factor range and crack growth rate. The fractured surface was observed by SEM and optical microscope. Crack growth rate of as -weld was slower than that of parent because of the singularities at HAZ. Crack growth rate for the specimen subjected to stress of 98Mpa was the fastest among PWHT specimens due to the precipitation of carbides which was formed during PWHT.