음향방출을 이용한 저어널 베어링의 조기파손감지(Ⅱ) : Part Ⅱ : Intervention of Foreign Particles in Lubrication 윤활유 이물질 혼입의 영향 및 감시

권오양,윤동진,김경웅,정민화 韓國非破壞檢査學會 1994 한국비파괴검사학회지 Vol.14 No.2

일반적으로 회전기기의 저어널 베어링 부분은 윤활유 공급의 부족이나 윤활층에 이물질이 혼입되면 시스템의 고장이나 가동중단 등의 원인이 되기도 한다. 따라서 베어링 손상에 기인하는 사고와 관련된 안전운전 문제와 유지비용의 절감을 위해 여러가지 파괴 및 비파괴시험법들이 사용되어 왔다. 본 연구에서는 저어널 베어링에서 가장 발생하기 쉬운 윤활층에의 이물질이 혼입에 의해 야기되는 베어링 파손의 조기검출을 위해 음향방출 기술을 적용하였으며, 전보의 연구에 이어 좀더 정량적이고 체계적인 실험을 수행하였다. 실험실용으로 직접 제작한 모의베어링 시스템을 이용하여 여러 형태의 인위적인 이물질 흔입 상태를 만들어 실험하였으며 베어링 손상 및 결함 형태의 해석을 위해 AE rms level, 파형분석, AE 변수 등의 여러 파라메터를 사용하여 분석 고찰하였다. 그 결과 AE rms level의 변화가 이물질 흔입의 영향에 민감함을 보여주었으며 AE변수등 다른 정보들로부터 손상 원일별로 신호형태를 확인할 수 있었다. Journal bearings in the rotating machineries are vulnerable to the contamination or the insufficient supply of lubricating oil, which is likely to be the cause of unexpected shutdown or malfunction of these systems. Various destructive and nondestructive testing methods had been used for the reduction of maintenance cost and the operational safety problems due to the accidents related to bearing damages. In this experimental approach, acoustic emission monitoring in employed to the detection of incipient failure caused by intervention of foreign particles most probable in the journal bearing systems. Experimental schedules for the intervention of foreign particles was composed to be more quantitative and systematic than last study in consideration of minimum oil film thickness and particle size . The experiment was conducted under such designed conditions as inserting alumina particles to the lubrication layer in the simulated journal bearing system. Several parameters such as AE rms level, waveform, AE energy distribution and other AE event parameter are used for analysis and characterization of damage source. The results showed that the history of damage was well correlated with the changes of AE rms level and the types of damage source signal can be verified using other informations such an waveform, distribution of AE parameter etc.

한의진단명과 진단요건의 표준화 연구 II (표준화 실례) : 2차년도 연구결과 중간 보고

양기상,최선미,최승훈,안규석,박경모,박종현,김성우,신승호,정우열,전병훈,고현,김정범,신상우,김성훈,김동희,권영규,엄현섭,장혜옥 한국한의학연구원 1996 한국한의학연구원논문집 Vol.2 No.1

The diagnostic requirements were suggested and explained regarding the systems of differentiation of symptoms and signs in the second year study of standardization and unification of the terms and conditions used for diagnosis in oriental medicine. The systems were as follows; - differential diagnosis according to condition of body fluid, differentiation of syndromes according to the state of qi and blood, differential diagnosis according to relative excessiveness or deficiency of yin and yang(氣血陰陽津液辨證) - differentiation of diseases according to pathological changes of the viscera and their interrelation - analyzing and differentiating of febrile diseases in accordance with the theory of the six channels(傷寒辨證) The individual diagnosis pattern was arranged by the diagnostic requirements in the following order : another name(異名), notion of diagnosis pattern, index of differentiation of symptoms and signs(辨證指標), the main point of diagnosis, analysis of diagnosis pattern(證候分析), discrimination of diagnosis pattern(證候鑑別), a way of curing a diseases(治法), prescription(處方), herb in common use(常用藥物), diseases appearing the diagnosis pattern(常見疾病), documents(文獻調査). This study was carried out on the basis of the Chinese documents and references.

Alkylhalide가 Mouse의 LDH isozyme 분포에 미치는 영향 : Cellulose Acetate Electrophoresis Method

권미경,김영옥,박은주,이동화,이명미,이문희,이양자 曉星女子大學校 藥學大學 學生會 1988 曉星藥誌 Vol.4 No.-

The effect of Carbontetrachloride administration on Lactatedehydrogenase isozyme patterns were analyzed by cellulose acetate electrophoresis for the brain, heart, kidney, lung, liver and mouse muscle. Each other tissue was found to have a characteristic distribution of these isozymes. At normal condition, aerobic tissue such as brain, heart, kidney, and lung were found to have all five isozymes from LDH_1 to LDH_5, while anaerobic tissues such as liver and muscle were found to have superiorly LDH_5 The toxicity of Carbontetrachloride administration was most prominence in the liver, and lung toxicity was occured also.

A Study on E-commerce Recommender Systems Based on LSI and Fuzzy Model

권영직,양춘우,권동훈 대구대학교 정보통신연구소 2009 情報通信硏究 Vol.6 No.1

This paper combines two analytical techniques to create a model that not only narrows product choices but also producesa prioritized product list of recommendations tailored to a specific customer. Specifically, the paper proposes to create a recommender system based on applications of Latent Semantic Indexing (LSI) and Fuzzy Synthetic Judgment (FSJ). The application ofthese two analytic models will serve a two-fold purpose. Latent Semantic Indexing will enable the model to account for incomplete rating information in the collaborative rating matrix so that the completed rating matrix can then be decomposed using the Singular Value Decomposition (SVD) method. Fuzzy Synthetic Judgment will then provide a prioritized list to the customer of recommended selections. In order to provide a clearer understanding of the proposed recommender process, the authors will demonstrate the requisite calculations through an application. In addition to clarifying the process, the example will serve to help validate the proposed model.

Ladle 내에서 기포에 따른 액상 영역의 유동학적 특성에 관한 가시적 연구

오율권,서동표,양호동 조선대학교 에너지.자원신기술연구소 2004 에너지·자원신기술연구소 논문지 Vol.26 No.2

In the present study, the gas injection system based on air-water model was designed to investigate the fluid-dynamics characteristics of liquid zone into a ladle. PIV system and camera techniques were applied to analysis flow patterns at the liquid zone. Gas flow rate is one of most important factors which could feature a flow pattern in a gas injection system. At low gas flow rate, upward bubble flow induced by buoyancy force is predominant and does not make an impact on mixing due to a weak circulation flow. However, with increasing gas flow rate, the kinetic energy of bubble increases and a strong circulation flow develops in the liquid. Such a flow in the liquid develops vortex and improve the mixing process. Due to the centrifugal force, circulation flow was well developed near both wall sides and upper region respectively.

수치해석을 이용한 음향장내의 압력장 해석에 관한 연구

오율권,양호동,서동표 조선대학교 에너지.자원신기술연구소 2004 에너지·자원신기술연구소 논문지 Vol.26 No.2

Applying ultrasonic waves in a medium enhance the heat transfer, judging from the facts that applying ultrasonic waves to the liquid medium gives rise to areas of high and low local pressure. Therefore, in the present study, a coupled finite element-boundary element method(FE-BEM) was used to calculate the acoustic pressure in a medium. For the numerical analysis, we performed the process of finite element modeling. This modeling data was converted to the boundary element data by SVS(Structure Vibtation Simulator). SVS programmed was composed of FORTRAN language and based on a coupled FE-BEM. The results of numerical analysis reveal that acoustic pressure is increased by 60% at the ultrasonic intensity of 340W and the higher acoustic pressure distribution near two ultrasonic transducers.

FEM을 이용한 자동차 타이어용 알류미늄 합금 금형의 열변형 특성에 관한 연구

오율권,서동표,양호동,박근욱,김용범 朝鮮大學校 機械技術硏究所 2006 機械技術硏究 Vol.9 No.1

대부분의 타이어 제조를 위한 금형생산 공정은 실험적인 결과에 바탕을 두어 거의 경험치에 의존하고 있다. 이러한 방법은 금형제품을 생산하는데 있어 비효율적이고 비경제적인 측면이 많다. 따라서, 정밀도를 향상시키고 품질이 좋은 타이어를 제조하기 위해 금형의 제조공정은 재평가가 이루어져야 한다. 본 연구에서는 자동차 타이어용 알루미늄 합금 금형의열변형 및 특성을 조사하기 위해 유한요소법을 이용하여 수치해석적으로 연구를 수행하고자 하였다. 알루미늄 합금의 금형의 열변형 및 특성에 관해 조사하기 위해, 알루미늄 합금 금형 내부에서 발생되는 온도분포, 수축량, 응력 그리고 변형량을 수치해석적으로 계산하는연구를 수행하였다. 뿐만 아니라, 정밀도를 향상시키고 좋은 품질의 금형을 얻기 위해, 알루미늄 합금과 연강의 수치해석 결과를 비교하였다. 결국, 수치해석을 통해 얻은 결과들은향후 효과적이고 최상의 금형 제품을 제작하는데 도움을 줄 수 있으리라 본다. Most the mold product process is based on a experimental results and is almost dependent on experiments for tire manufacturing. This method produced the mold product is not only the ineffectiveness but also the bad economy. So, the product process of metal mold should be revaluated to produce the improved precision and good quality of tires. In this study, numerical analysis applied a finite element method (FEM) was used to predict the thermal strain characteristics of Aluminum (AI) alloy mold for automobile tire. To investigate the thermal strain and characteristics of Al alloy mold, it was performed that the temperature distribution. the contraction rates, the stress and the strain occurred on the inside of Al alloy mold was calculated by numerical works. Moreover, numerical analysis results of Al alloy mold were compared with those of mild steel mold in order to obtain the improved precision and good quality of mold. So, the numerical results of this study will be presented to help to make the effective and the best mold products.

카드뮴이 인간 단핵구 세포주(THP-1)에서 cytokine 유전자 발현에 미치는 영향

신동훈,박관규,강미정,서석권,정인성,양선희 大韓産業醫學會 1997 대한직업환경의학회지 Vol.9 No.2

Cadmium, a potent toxic metal, posses a serious environmental threat but the mechanism of its toxicity remains unclear. Also, cadmium is a known immunotoxic agent in animal studies and induces pathophysiological effects by modulating components of immune system. Cytokines are being increasingly recognized as essential mediators of normal and pathologic immune response. Cells of mononuclear phagocytic system are strategically located at portals of entry in humans and therefore may be particularly at risk for cadmium exposure through contaminated air, food, and drinking water. In the present study, we investigated the effect of cadmium cytotoxicity for the monocyte and expression of cytokine gene in the control and cadmium treated human monocytic cell lines using RT-PCR method. The results showed that cadmium inhibited cell proliferation at 0.1mM cadimium treated cells for 24 hours. The TNF-α mRNA was expressed in both control and cadmium treated cells but not IL-6 and IL-1β. The mRNA levels of TNF-αwere examined during 24 hours culture period, at different time points. The expression of TNF-αmRNA increased in both 0.01mM and 0.1mM cadmium treated cells, but did not show dose-response relationship. According to cadimium treated duration, expression of TNF-αmRNA was more decreased in 24 hours than 6 hours. The decreased levels of mRNA of TNF-α suggest that cadmium suppresses its production at the transcription level.

만성부비동염 환자에서 부비동 단순 X-선 사진과 전산화 단층(CT) 사진 소견의 비교

선동일,윤선호,신민호,서병도,양일권 釜算慶南耳鼻咽喉科學會 1993 임상이비인후과 Vol.4 No.1

成人의 身體組成 評價를 위한 生體電氣低抗法의 妥當性 檢討

李東洙,金基學,梁金山,權善鈺 慶北大學校 師範大學 體育學硏究會 1992 體育學會誌 Vol.20 No.-

This study is concerned with a comparison of the UW and the BI methods as they are applied to the evaluation of body composition. The validity of the BI method is studied in detail, and the SFT method is also examined in detail in comparison with the other methods. Altogether 49 healthy adults(13 males and 36 females)were estimated, and the following results have been obtained: 1. A comparison of the % body fat measured by the three methods is schematically summarized below: ◁표 삽입▷(원문을 참조하세요) 2. There was a higher correlation between the UW and the BI methods than between the UW and the SFT methods in the estimate of the body composition. 3. The measurements of the %body fat, the height and weight, and the fat thickness by means of the UW method did not reveal significant correlation with respect to the physical constitution of the males, but there was a significant correlation(0.5754) with respect to the weight of the females. 4. In the estimated of the % body fat, the BI method showed a smaller standard and relative deviation than the SFT method both for the male and the female subjects, and the highest degree of accuracy was obtained in the BI method applied to the male subjects.