사출성형된 섬유강화 플라스틱 복합재의 뒤틀림에 관한 연구

윤성운 朝鮮大學校 機械技術硏究所 2000 機械技術硏究 Vol.3 No.2

The injection molded part shrinks in the process of solidification by the amount of the coefficient of linear thermal expansion multiplied by the temperature difference between the room temperature and the temperature at which the solid structure is formed in the mold. And it is called warpage for this type of deformation that shrinkage are not uniform throughout the injection molded part. To predict warpage phenomena in the articles, the results obtained theoretically from the change of mold temperature, fiber content of composites have been compared with experimental results.

超硬合金의 放電과 超音波複合 加工에 관한 硏究

尹聖雲 조선대학교 동력자원연구소 1991 動力資源硏究所誌 Vol.13 No.1

The combination of two machining processes may result in the increase of productivity. This is an approach worthy to be tried, especially for the machining of so-called difficult to machine materials. In this study, ultrasonic machining(USM)is combined with electric discharge machining(EDM)for the machining of cemented carbide. It is confirmed through the experiments that this new machining process is effective in attaining a high material removal rate.

龜裂材의 疲勞龜裂成長擧動에 관한 硏究

尹聖雲,崔秉起 조선대학교 동력자원연구소 1988 動力資源硏究所誌 Vol.10 No.1

To evaluate the possibility of crack growth under the influence of cyclic stress, it is useful in aluminium alloy to employ the concept of threshold stress intensity factor range (ΔK_th) below which fatigue crack will not occur. Then the determination of the resistance of a material to fatigue crack growth relies on crack growth rate per cycle (da/dN) and amplitude of the stress intensity factor ΔK. The main conclusions are as follows. 1. Because the relation of da/dN-ΔK was described in a parallel straight line to the -axis of da/dN, region Ⅰ and Ⅱ are clearly distinguished with ΔK_th, and while the cyclic stress is continued, Nf is increased and crack is initiated, and the fracture arise from the increase of ΔK with the increase of da/dN. 2. It is reasonable to assume that ΔK is conveyed with the apparent crack arrest when it makes ΔK decrease to ΔK_th as the fracture toughness of material. 3. Test results coincide with the low critical equation of ΔK, and the value ofV_o is 0.5~2×10^-6㎜/cycle.

타이어 설계인자를 고려한 자동차의 조종 및 안정 특성에 관한 연구

윤성운,홍석주,최규남 朝鮮大學校 機械技術硏究所 2004 機械技術硏究 Vol.7 No.2

As the technique of automobile industry is being advanced, the advancement of performance for vehicle is being required. In order to achieve this purpose, the study on the handling and stability which are produced by moving vehicle is carried out actively. Ability to predict vehicle performance using computer simulation is essential to reducing the development time for tire companies as well as car makers. From the previous research. we showed that handling simulation tool developed for J-turn and lane change maneuvers on ADAMS could be used in predicting the performance difference among tires with different specifications in vehicle mild handling behaviors. Through this study, some meaningful correlations were achieved. Also barriers to direct application of the simulation technique to tire development process and several technical problems that should be resolved were iden tified. In this results, ability to predict vehicle performance using computer simulation is essential to reducing the development time for tire companies as well as car makers.

퍼머제의 중금속 농도에 관한 연구

윤복연,문덕환,박명희,황용식,함성애,손병철,김대환,이창희,김휘동,이채언 인제대학교 백병원 2002 仁濟醫學 Vol.23 No.5

Objective : This study was conducted to prepare the fundamental data on heavy metal concentration in hair permanents agents and to prevent the health impairment due to heavy metal. Methods and Material : The author determined of 5 heavy metals(Pb, Cr, Mn, Ni, and Cu) concentration hair permanent agents in the market with flameless atomic absorption spectrophotometer. Results : The results were as follows: 1. The geometic mean concentrations of total subjects were 0.04㎍/g for Pb, 0.09㎍/g for Cr, 0.06㎍/g for Mn, 0.03㎍/g for Ni, and 0.04㎍/g for Cu. 2. The most highest mean concentrations of heavy metals in hair permanent agents by using type were Cr for wave agent and straight cream agent, Cu for setting iron agent, Cr and Cu for coating perm agent. 3. Metal most hlghest mean concentrations of heavy in hair permanent agents by type of color was green for Cu. 4. The mean concentration of Cu among 5 heavy metals in hair permanent agents by marker was most highest. 5. There was most statistically significant difference on mean concentration in hair permanent agents between domestic and foreign products. 6. The exposure amount of heavy metal concentration by one time using the permanent agent were 4.O㎍ for Pb, 9.O㎍ for Cr, 6.0㎍ for Mn, 3.O㎍ for Ni and 4.0㎍ for Cu. Conclusion : As above results author suggest to prepare the preventive program of health impairment due to heavy metal by long term chronic exposure to who were using the hair permanent agents hair designer and customers.

섬유강화 플라스틱 복합재료의 사출성형에 있어서 기계적 물성치에 미치는 성형조건의 영향

윤성운 조선대학교 동력자원연구소 1997 動力資源硏究所誌 Vol.19 No.1

Injection molding is the most widely used process for the industrial forming of plastic articles. In this paper, the effects of fiber length, fiber content and molding conditions on the mechanical material properties, which have strength, strain, modulus are studied experimentally.

당뇨병환자에서 게이트심장혈액풀신티그라피를 이용한 심기능 평가

윤상임,송치운,이진홍,안미애,성기양,송민호,이강욱,신영태,김영건,노흥규 충남대학교 의과대학 지역사회의학연구소 1993 충남의대잡지 Vol.20 No.2

Major cardiovascular complications of diabetes are coronary atherosclerosis, diabetic dilated cardiomyopathy, autonomic neuropathy and those are major causes of morbidity and mortality in diabetic patients. Gated blood pool heart scan is noninvasive and useful method for evaluation of functional status of heart in diabetics. We evaluated 52 patients with diabetes and divided 3 groups. Group 1 were 11 patients without proteinuria or with proteinuria less than 550mng during 24 hours. Group 2 were 9 patients with proteinuria more than 550mg during 24 hours and group 3 were 32 patients with endstage renal diasese due to diabetes. We performed 99mTc-HSA cardiac gated blood pool scan and used left ventricular ejection fraction(LVEF), peak ejection rate(PEF) to indices of LV systolic function and peak filling rate(PER) to index of LV diastolic function. The results were follows : 1) LVEF, PER were significantly lower in diabetics with ESRD than diabetics without ESRD, but there were no significant difference between normal controls and diabetics without ESRD 2) PFR was significantly lower in diabetics than normal controls, but there were no significant differences in diabetics with or without nephropathy. 3) There were negative correlation between PER, PFR and duration of diabetes. On the basis of results, PFR is a LV functional index of GBPS which can disclose early change of LV dysfunction in patients with diabetes.

대학교 대형강의실의 조명조건별 조명환경평가

최윤정,이상운,조현주 충북대학교 교육 ·생활연구소 생활과학연구센터 2003 생활과학연구논총 Vol.7 No.1

The purposes of this study are to evaluate the lighting environment of a university assembly hall and to make clear the problems of conditions of lighting operation. The field measurement on the illumination level and the questionnaire survey on subject response of the lighting environment with students were carried out at an assembly hall in C university, Cheongju. These survey were taken on 4th and 9th of December, 2002. The illumination levels of the assembly hall in the condition A (157∼403 lux) were lower than standard (400lux). The illumination levels of the condition B (16∼372 lux) and condition C (0∼1 lux) were poor. The illumination levels of the condition D (231∼510 lux) were somewhat lower than standard. It was found that the present condition of the lighting environment of the university assembly hall is inappropriate illumination level and uniformity for lecture.

다수의 냉동시스템에 의한 저온 저장고의 에너지 성능평가

김성만,윤종호,박영하,이의준,강동언,현명택 제주대학교 산업기술연구소 2000 尖端技術硏究所論文集 Vol.11 No.1

The cool storage system(CSS) is a specific building that is required only cooling load without heating during the whole year. CSS uses a electric energy which is very expensive and is required much amount of energy due to temperature differences between interior and ambient temperatures. The purpose of this study is to assess the energy performance of the multi-unit cooler operating control system. For the prediction of its performance, two types of test cell are installed at Korea Institute of Energy Research (KIER). First cell is equiped with one large unit cooler, and second cell consists of two small unit coolers. According to the results of experiments using these cells, the multi-unit cooler operating control system is found to be effective in energy saving and beneficial for storage due to much less deviation of temperature.

다수의 냉동시스템에 의한 저온 저장고의 에너지 성능평가

강동언,김성만,운종호,이의준,박영하,현명택 濟州大學校 産業技術硏究所 2000 산업기술연구소논문집 Vol.11 No.1

The cool storage system(CSS) is a specific building that is required only cooling load without heating during the whole year. CSS uses a electric energy which is very expensive and is required much amount of energy due to temperature differences between interior and ambient temperatures. The purpose of this study is to assess the energy performance of the multi-unit cooler operating control system. For the prediction of its performance, two types of test (KIER). First cell is equiped with one .are installed a t Korea Institute of Energy Research large unit cooler. and second cell consists of two small unit coolers. According to the results of experiments using these cells. the multi-unit cooler operating control system is found to be effective in energy saving and beneficial for storage due to much less deviation of temperature.