• 산업경영시스템학회지
• /
• 제20권44호
• /
• pp.163-169
• /
• 1997

Due to the increasing of the number of cars and bad road conditions, car accidens are increasing every you in Korea. When a person meets a car accident, it is necessary for him to analyze and determine whether applying insurance or not, because standard discount rate and special increasing rate change with accident types and the amount of accident expenditure. When we consider insurance rate that includes more then ten elements, we need a decision making, In this paper, S insurance company investigated previous car causers in 1988, 1989, 1990 to 1996 with 600,000 real data. We investigate probability density functions and cumulative distribution functions for each year using ARENA software. We can apply the results of this study to various accidents that occur under uncertainty in our life. I hope that this paper contribute to strengthening competitive power of companies and developing new insurance rate systems in future.

• 설비공학논문집
• /
• 제3권5호
• /
• pp.386-394
• /
• 1991

Freezing of saturated porous media contained in a rectangular cavity has been studied experimentally. Water and different diameter glass beads consitituted the liquid and porous media. Solidification front shape, the effects of bead diameter and initial liquid temperature was investigated. When the hot wall temperature was below $4^{\circ}C$, the freezing rate was higher at the top than at the bottom due to the density inversion, but with increasing the hot wall temperature the freezing rate at the top was effected by the liquid temperature and was lower than at the bottom. With increasing the bead diameter, the difference of freezing rate between top and bottom was increased and depends on thermal conductivity. When the liquid temperature was low in the beginning, the freezing rate was high, but with increasing the time almost the same with those of high temperature liquid.

• 태양에너지
• /
• 제9권1호
• /
• pp.43-52
• /
• 1989

Heat transfer rate and heat flux from the condenser with internally triangular fins rotating heat pipe has been numerically studied by finite element method. The results of numerical and P.J. Martos' experimental showed good agreement and it was able to predict to the performance of a rotating heat pipe. By increasing fin half angle or fin height, heat transfer rate from condenser was increased slightly but heat flux was decreased. By increasing condenser radius or r.p.m. of rotating heat pipe, heat transfer rate and heat flux was increased rapidly. Heat transfer rate was rapidly increased with increasing fin numbers in case of few fm numbers but slowly increased at many fin numbers. So the optimum fin numbers were a half of maximum fin numbers which was able to install in the condenser of a rotating heat pipe.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
• /
• pp.269-271
• /
• 2012

To investigate emission characteristics of laminar premixed CH4/air flame, combustion experiments were conducted at three flow rates (5.3L/min, 10.6L/min, 15.5L/min) with changing the combustor pressure(-30Kpa-30Kpa). It was found that with increasing flow rate, NOx emission increased in high pressure condition, while decreased in low pressure condition; and the emission of CO decreased with increasing flow rate. For the influence of pressure, emission of NOx increased with increasing pressure regardless of flow rates, while CO emission decreased on the contrary.

• 한국자동차공학회논문집
• /
• 제4권3호
• /
• pp.156-167
• /
• 1996

The present work is a continuation of our previous study to investigate the effects of parameters such as equivalence ratio, hydrogen supplement rate and initial pressure on combustion characteristics in a disk-shaped constant volume combustion chamber. The main results obtained from the study can be summarized as follows. The flames in near stoichiometric mixture of methane-air are propagated with a spherical shape, but in excess rich or lean mixtures are propagated with a elliptical shape. And, they are changed to an unstable elliptical shape flame with very regular cells by increasing the hydrogen supplement rate. Also, flame is sluggishly propagated at increased initial pressure in combustion chamber. Volume fraction of burned gas and flame radius as the combustion characteristics are increased by increasing the hydrogen supplement rate, especially at the combustion middle period, but then are slowly increased by increasing the initial pressure.

• 한국식생활문화학회지
• /
• 제12권1호
• /
• pp.35-40
• /
• 1997

약과의 튀김 온도와 반죽 횟수가 약과의 품질 특성에 미치는 영향과 혼합 계획(mixture experiment)에 따라 3가지 성된(참기름, 시럽, 소주)의 수준을 변경하여 재료 배합비가 약과의 품질 특성에 미치는 영향을 조사하였다. 튀김 온도와 반죽 횟수에 따른 영향은 색도에서 L(명도)값은 $120^{\circ}C$에서 유의적으로 높았으며, 반죽 횟수가 많을 때 증가하였다. a(적색도)값은 온도가 높을 때 증가하였으나 반죽 횟수의 영향은 별로 없었다. b(황색도)값은 유의차가 없었다. 경도는 온도가 높을수록 유의적으로 커졌으며 반죽 횟수가 많을 때 경도가 약간 커졌다. 지방 흡수율은 온도가 높아짐에 따라 유의적으로 감소하였고, 반죽 횟수가 많을 때 약간 감소하였다. 집청 흡수율은 온도가 낮을수록 유의적으로 증가하였으며, 반죽 횟수에 따른 차이는 없었다. 재료 배합 비율에 따른 영향은 색도는 재료 배합 비율과의 사이에 뚜렷한 관계를 나타내지 않았으며, 경도는 참기름, 소주의 양이 많아지면 단단해지고 시럽이 많아지면 연해졌다. 지방 흡수율은 참기름, 시럽의 함량이 증가할 때 증가하였으며, 집청흡수율은 참기름과 소주의 함량이 감소하고, 시럽의 함량이 증가할 때 증가하였다.

• 한국태양에너지학회 논문집
• /
• 제27권4호
• /
• pp.67-75
• /
• 2007

This study intends to the adequacy inspection of the room temperature variation rate that is available in the building heat performance evaluation index, so we performed the sensitivity analysis about the room temperature variation rate and the energy consumption in the room. For these purpose, we supposed the models which are composed of the various window area, insulation thickness and ventilation rate. Then we analyzed the simulation using the ESP-r and Seoul weather data. In this research, the pattern of the increasing & decreasing rate of annual load according to the change of the various design factors is similar to the pattern of increasing & decreasing rate of not the K-values but the room temperature variation rate. Also we derive the optimum value of the various design factors and the room temperature variation rate in this analysis model. Further study is to be required the development of convenient tool to use in the real design.

• 설비공학논문집
• /
• 제23권11호
• /
• pp.711-717
• /
• 2011

In this study, 5 types of PVS(Passive ventilation system) units are made and experimented its ventilation performance, thermal performance according to open rate and hole diameter of perforated aluminum plane. Results are as follows. 1) The ventilation performance increases approximately 50~70% according by the open rate of PVS increasing. Also, the ventilation performance increases about 2%~12% according by the hole diameter of PVS increasing. 2) In winter temperature/pressure condition(in : $20^{\circ}C$, out : $-2^{\circ}C/{\Delta}P$ : 0.2~5.0Pa) the temperature of inflow air decreases according by the open rate of PVS increasing. Heat gain performance decreases 10.1%, 25.6% when open rate increases 3) In the same condition, Heat gain performance decreases 18.3%, 18.8% according by the hole diameter of PVS increasing.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
• /
• pp.66.1-66.1
• /
• 2010

Microcrystalline silicon at low temperatures has been developed using plasma enhanced chemical vapor deposition (PECVD). It has been found that energetically positive ion and atomic hydrogen collision on to growing surface have important effects on increasing growth rate, and atomic hydrogen density is necessary for the increasing growth rate correspondingly, while keeping ion bombardment is less level. Since the plasma potential is determined by working pressure, the ion energy can be reduced by increasing the deposition pressure of 700-1200 Pa. Also, correlation of the growth rate and crystallinity with deposition parameters such as working pressure, hydrogen flow rate and input power were investigated. Consequently an efficiency of 7.9% was obtained at a high growth rate of 0.92 nm/s at a high RF power 300W using a plasma-enhanced chemical vapor deposition method (27.12MHz).

• 한국초지조사료학회지
• /
• 제12권4호
• /
• pp.211-217
• /
• 1992

This experiment was conducted over a 3-year period (1990-1992) to evaluate the production and quality of orchardgrass (Potomac)-red clover (Kenland) mixture when orchardgrass + red clover mixture was sown at seed rates of 20+0. 18+2, 16+4, 14+6 and 12+8 kg/ha. Total herbage dry matter, crude protein and digestible organic matter production and organic matter intake were markedly affected by increasing rcd clover seed rate, those increased with increasing red clovcr seed rate due to the cnhancernent of red clover percentage of total herbagc in all 3-year. but significant differences occured between the orchardgrass alone and orchardgrass-red clover mixture with a seed rate of 4,6 and 8 kg/ha red clover (P<0.01). But on the other hand increasing red clover seed rate increased red clover percentage in total herbage, the mean red clover percentage of total herbage at the last cutting ranged from 54 to 65% in first year. 58 to 60% in second year, and 62 to 69% in third year, particularly it was observed that red clover was sown at seed rates of 6 and 8 kg/ha for red clover sown dominated strongly as the cutting times were progressed. Considering the maintenance of good botanical composition balance and the enhancement of production and quality of herbage, the optimized seed rate for orchardgrass-red clover mixtures, 16 kg/ha orchardgrass and 4 kg/ha red clover seems to be considered adequate.