비공진형 노크센서의 신뢰성 평가실험 연구

심창열,장석형,박경석 경희대학교 산학협력기술연구원 1996 산학협력기술연구논문집 Vol.2 No.-

The main goal of development for an automotive spark ignition engine is to reduce emission, fuel consumption rate and increase engine power. But these cause conflecting technical problems. In an engine, compression ratio should be improved and multivalve system and super charge system should be used to improve engine power. In this case, the mixture in combustion chamber easily causes abnormal combustion: autoignition and knocking produced by improving intake pressure. Therefore electronic control fuel injection system should be used to improve power and the control system which is made for keeping optimum combustion condition by sensing abnormal combustion should be selected. In this study, a main goal is to develop knock sensor for a high power engine. By selecting spark timing as a parameter causing knock, let an engine knock artificially. Knocking occurrence crank angle, knocking pressure and knocking intensity are measured by a statistical method in which 10 data per 1 crank degree for 120 cycle are selected. Generally, knock sensor detects cylinder wall vibration and estimate pressure vibration in a combustion chamber. So combustion pressure detected by pressure transducer and cylinder wall vibration detected by knock sensor, accelerometer are estimated and the difference of those three signals are analyzed. These three signals are analyzed by frequency analysis method(Fast Fourier Transformation) and compared with theoretical knock mode in the combustion chamber. A design parameter of knock sensor is determined by these analysed data.

태권도 수련생들의 사범 자질과 지도에 관한 연구

심병현,김경애 한국안전교육학회 2001 한국안전교육학회지 Vol.4 No.2

To close examine the relationship of Taekwondo instructors 'qualities and trainees' satisfaction, this paper sampled 30 training halls to the population of Taekwondo trainees in Seoul, Kyunggi Province as of 2001, and collected questionnaires from total 400 of partially selected male 12, female 8 from each training hall. As research subjects, it avoided low grade students, and made the 4th, 5th and 6th graders students its subjects. As a survey instrument for examining the relationship of Taekwondo instructors 'qualities and trainees' satisfaction, Yang, Hyun-seok(1999)'s and Lee, Shik(1999)'s adapted and supplemented questionnaire on the satisfaction of the hall setting was used, and its reliability is .62-.84, so its is judged to be reliable. As data analysis, only effective sample was encoded, ANOVA, Scheffe, standard multiple regression were executed using window programs, SPSS/PC+ Version 10.0 and following conclusion was obtained. First, to explore the difference of coach's quality by gender, ANOVA at significance level of p<.05 was indicated as shown at <Table 4>. As a result of verifying the difference of instructor's quality by gender, F value of learning development capability was 7.653, and Sig T=.006, which was statistically significant at p<.05, and F value of instructor's knowledge extent was 7.51, and Sig T=.006, which was statistically significant at p<.05. And facility management was Sig T=0.649, which was not significant. Thus it was clarified that learning development capability and instructor's knowledge level by gender were factors having a significant effect. Second, to explore the difference of coach's quality by school background, ANOVA at significance level of p<.05 was indicated as shown at <Table 5>. As a result of verifying the difference of instructor's quality by school background, F value of learning development capability was 11.832, and Sig T = .000, which was statistically significant at p<.05, and F value of instructor's knowledge extent was 7.51, and Sig T = .006, which was statistically significant at p<.05. And facility management was Sig T =0.726, which was not significant. Thus it was clarified that they are factors having a significant effect on learning development capability and instructor's knowledge level by school background. Third, to explore the difference of instructor's quality by training period, ANOVA at significance level of p<.05 was indicated as shown at <Table 6>. As a result of verifying the difference of instructor's quality by training period, F value of learning development capability was 5.918, and Sig T=.000, which was statistically significant at p<.05, and F value of instructor's knowledge extent was F= 5.918, and Sig T = .000, which was statistically significant at p<.05. And facility management was F=6.582, Sig T=0.000, which was statistically significant. Thus it was clarified that they are factors having a significant effect on learning development capability and instructor's knowledge level by training period. Fourth, to explore satisfaction factors by gender, ANOVA at significance level of p<.05 was indicated as shown at <Table 7>. As a result of verifying the difference of satisfaction factors by gender, F value of satisfaction factors by gender was F= 27.945, and Sig T=.000, which was statistically significant at p<.05, and instruction satisfaction was Sig T=.086, which was statistically insignificant at p<.05, facility satisfaction was Sig T=.130, which was not significant at p<.05. Thus it was clarified that they are factors having a significant effect on learning satisfaction factors by gender. Fifth, to satisfaction factors by school background, ANOVA at significance level of p<.05 was indicated as shown at <Table 8>. As a result of verifying the difference of satisfaction factors by school background, F value of satisfaction factors by gender was 10.126, and Sig T=.000, which was statistically significant at p<.05, and instruction satisfaction was F=39.241, Sig T=0.000, which was statistically insignificant at p<.05, and facility satisfaction was F=3.712, Sig T=.025, which was not significant at p<.05. Thus it was clarified that they are factors having a significant effect on learning satisfaction, instructor's satisfaction and facility satisfaction factors. Sixth, to explore satisfaction factors by training period, ANOVA at significance level of p<.05 was indicated as shown at <Table 9>. As a result of verifying the difference of satisfaction factors by training period, F value of satisfaction factors by training period was 3.666, and Sig T=.006, which was statistically significant at p<.05, and instruction satisfaction was F= 8.982, Sig T=.000, which was statistically insignificant at p<.05, facility satisfaction was F= 6.235, Sig T=.000, which was significant at p<.05. Thus it was clarified that they are factors having a significant effect on learning satisfaction, instructor's satisfaction and facility satisfaction by training period.

브랜드 퍼스낼리티에 관한 실증적 연구

심영환,이경미 한양대학교 산업경영연구소 1999 産業經營硏究 Vol.11 No.-

Ti-Ag 합금의 인공타액 내에서의 전기화학적 특성

심형민,오근택,김경남 大韓齒科器材學會 2003 대한치과재료학회지 Vol.30 No.4

Titanium and its alloys are widely used in biomedical and dental fieds because of their excellent corrosion resistance, biocompatibility, high strength to weight ratio and good fatigue properties. It is well known that titanium is protected from corrosion due to the stability of passive film that controls and determines the corrosion resistance of titanium. The stability of passive film can also determine biocompatibility of titanium and its alloys. The purpose of this study was to evaluate the electrochomical properties of Ti-Ag alloys and the stavility of passive film in artificial saliva. We designed Ti-Ag alloys with silver contents ranging from zero to 5.0 at% in steps of 0.5 at%. The alloys were arc-melted, homogenized, hot-rolled to 2 mm in thickness, and finally solution heat-treated for 1hour and quenched in water. Potentiodynamic and poteniostatic testing were performed and open circuit potential of the Ti-Ag alloys was measured in artificial saliva 37℃. Passive film of the Ti-Ag alloys was analyzed by XPS(x-ray photoelectron spectroscopy). Ti-Ag alloys showed low passive current density and electrochemically stable behavior in the artificial saliva and passive film of the Ti-Ag alloys was composed of TiO_2, Ti_2O_3 and TiO. As Ag content increased, TiO_2 fraction increased and titanium oxide layer of the Ti-Ag alloys formedthicker than that of titanium.It is thought that Ti-Ag alloys can be adopted and used safely with good biocompatibility for dental application.

고등급 이형성을 보인 편평톱니샘종

권경주,정성애,심기남,정정화,강석형,송도경,전승정,김혜인 이화여자대학교 의과학연구소 2012 EMJ (Ewha medical journal) Vol.35 No.1

Until recently, colorectal polyps were classified predominantly as hyperplastic or adenomatous. While adenomatous polyps are well-characterized precursor lesions of adenocarcinomas, hyperplastic polyps have been considered as benign lesion. However, some hyperplastic polyps with serrated morphology of the crypts have been recognized to have distinctive features and these polyps were termed ‘serrated adenomas’. Recent data show that sessile serrated adenomas (SSA) might be the precursors of serrated colonic cancers, underlining the necessity of identifying them. SSA is approximately 3% of all polyps, commonly appears as flat or sessile and yellowish due to mucus production. In the pathogenesis of SSA, progression to high grade dysplasia or early invasive carcinoma may be associated with serrated neoplasia pathway different from adenoma-carcinoma sequence. We report a case with a colon polyp diagnosed as sessile serrated adenoma with high grade dysplasia after endoscopic submucosal dissection.

인체 간 Microsome에서의 우슬 추출물의 Cytochrome P450 약물 대사효소에 대한 억제작용

김경아,이지숙,박히준,김진우,김창주,심인섭,한승무,임사비나 WHO COLLABORATING CENTRE FOR TRADITIONAL MEDICINE 2003 東西醫學硏究所 論文集 Vol.2003 No.-

Objective : Achyranthes bidentata radix (Usul) has been used as anti-arthritic, antiallergic, antidiuretic and so on Recently extracts of Achyranthes bidentata radix have shown anti-inflammatory and cancer preventive effects in vitro and in vivo. Methods : We therefore evaluated the inhibitory potential of ehtanol extracts of Achyranthes bidentata radix on cytochrome P450(CYP) isoforms-catalyzecd reactions, which relate to causes of cancer and inflammation, including CYP1A2, CYP2C9, CYP2C19, CYP2E1, CYP2D6, CYP2C8, and CYP3A4, using human liver microsomal preparations. Results : The extracts showed weak or negligible inhibitory effects on CYP2C9-catalyzed (S)-warfarin 7-hydroxylation, CYP2C19-catalyzed S-mephenytoin 4-hydroxylation, and CYP2D6-catalyzed dextromethorphan O-demethylation with each IC50 over 1750 g/㎖, respectively. However, it showed relatively significant inhibitory effect on CYP1A2-catalyzed phenacetin O-deethylation and CYP2E1-catalyzed chloizoxazone 6-hydroxylation with IC50s of 970.5 g/㎖ and 821.4 g/㎖, respectively. Conclusions : These results suggest that extracts of Achyranthes bidentata radix have inhibitory effects on CYP-catalyzed reactions, expeciallyCYP1A2 and CYP2E1, in human liver microsomes. These effects appear to relate to anti-inflammatory and cancer prevention following decrease of reactive oxygen species formed by CYP, especially CYP1A2 and CYP2E1, by Achyranthes bidentata radix. However, further evaluation is necessary to demonstrate and to confirm its effects in human.

Cunninghamella elegans에 의한 폐 mucormycosis

박경실,서광수,조무자,김춘식,심상인,김선무 대한임상병리사협회 2001 대한임상병리사회지 Vol.21 No.1

Shield Disk 상의 Ag-Cu 공정계 합금 도금기술 개발

윤경도,차동관,심기종,민봉기,최순돈,이상기 嶺南大學校 工業技術硏究所 2003 工業技術硏究所論文集 Vol.31 No.1

The composition and the microstructure of the Ag-Cu alloy electrodeposits electroplated in Succinimide bath were investigated varying the electrolysis conditions such as bath composition, current density and additive agents etc. The cathode overpotential increased with the increase of Succinimide concentration and current density ratio in the bath. The Ag content of the alloy deposits decreased with the increase of current density and pH and temperature in the bath. The optimum condition for 78wt.%Ag-22wt.%Cu code position alloy is an follows : pH10(adjusted by NH_4OH), 0.03M AgNO_3, 0.27M Cu(NO_3)_2 3H_2O, 0.5M Succinimide in bath and 3.5A/dm^2∼5.5A/dm^2 current density.

교육과정 개혁과 학습문화

서경혜,이주연,현성혜,이자연,심수원,김지혜 한국교육과정학회 2007 교육과정연구 Vol.25 No.3

탄성반력의 영향에 따른 직교 이방성 복합판의 고유 진동 해석

정영화,심도식,김경진,이세진 江原大學校 産業技術硏究所 1997 産業技術硏究 Vol.17 No.-

In this paper, the result of application of vibration method to the orthotropic plates with free edges supported on elastic foundation and with a pair of opposite edges under axial forces is presented. Such plates represent the concrete highway slab and hybrid composite pavement of bridges. The reinforced concrete slab can be assumed as a special orthotropic plate, as a close approximation. The highway slab is supported on elastic foundation, with free boundaries. Sometimes, the pair of edges perpendicular to the traffic direction amy be subject to the axial forces. The plate is subject to the concentrated load/loads, in the form of traffic loads, or the test equipments. Finite difference method is used to obtain the deflection influence surfaces needed for vibration analysis. The influence of the modulus of the foundation, the aspect ration of the plate, and the magnitudes of the axial forces and the concentrated attached mass on the plate, under the natural frequency is thoroughly studied.