• Journal of the Korean Society of Clothing and Textiles
• /
• v.18 no.2
• /
• pp.273-282
• /
• 1994

The physiological significances of the upper and lower body on thermoregulation and sensation were studied in this paper. Experiments were carried out on 4 females in a climatic chamber conditioned at 1) $25^{\circ}C\rightarrow35^{\circ}C\rightarrow25^{\circ}C$, 2) $25^{\circ}C\rightarrow15^{\circ}C\rightarrow25^{\circ}C$, both with 50% R.H., covering the upper body (U) or lower body (L) with garments. 1. When the upper or lower body is covered or exposured respectively, the mean skin tempterature of upper body is higher than that of lower body. And upper body is more easily influenced by the environmental temperature than lower body. It means the skin temperatures of the upper body change faster than those of the lower body following the environmental changes. 2. In U and L, the skin temperatures of the upper limbs (thighs, upper arms) are lower than those of the peripherals (hands, feet). 3. Warm sensations and skin temperatures of the upper body showed high correlation and it was the case with cold sensations and skin temperatures of the lower body. 4. In high temperature condition $(25^{\circ}C\rightarrow35^{\circ}C\rightarrow25^{\circ}C)$, mean skill temperature and rectal temperature in L were lower than in U. This lower rectal temperature in L is probably due to the insulation of the lower body with garments that promotes the heat radiation only in the high temperature environment.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2007.04a
• /
• pp.19-23
• /
• 2007

In this paper, the period for the strength correction was determined with each region of south Korea based on the meteorological data of KMA(Korea meteorological administration) by applying KASS-5 regulation. In case of 28 days of strength control age, the period for strength correction with 6MPa was calculated to 50-60 days and, with 3 MPa. to around 80 days. The period for the strength correction was shown to be decreased with the rise of altitude. The period to consider the delay of the strength development due to low temperature including the period of cold weather concrete was nearly 7 months around 1 year. References for determining the strength correction factors with each region of south Korea was provided in this paper.

• Aerospace Engineering and Technology
• /
• v.10 no.1
• /
• pp.136-140
• /
• 2011

In this study, thermal model for backplane of GPS antenna in Low Earth Orbit Satellite is updated and orbit thermal analysis is performed. The analysis is focused on the safehold mode of satellite. During the safehold mode, the solar panel is constantly looking to the Sun, and there is not a mission maneuvering. Therefore, antenna backplane receives the maximum heat influx considering the End-Of-Life condition. To maintain the temperature of antenna within allowable limits, radiating tape is applied and its area is determined. Besides, to verify the lowest temperature of the antenna, cold case with Begin-Of-Life analysis is also performed.

• Journal of ILASS-Korea
• /
• v.22 no.4
• /
• pp.185-189
• /
• 2017

In Korea, sales of passenger cars using diesel and LPG fuels were continuously increased in recent years. From now on 2030, the registrated vehicles will close in about twenty five million in Korea. From these reason, Investigation on the comparison of exhaust emission characteristics of passenger cars using LPG and Diesel fuel in variation of driving mode and ambient conditions were conducted in this study. Exhaust emission characteristics of test vehicles were measured and analyzed by using chassis dynamometer and emission analyzer. Also, test vehicles were selected on the diesel vehicle with 1.7L engine and LPG vehicle with 2.0L engine. In order to study on emission characteristics according to driving cycles, CVS-75, NEDC, US06, SC03, Cold-FTP and HWFET were applied and the test conditions were set up the cases of A/C on and hot start. From these results, it is revealed that the NOx emission of diesel vehicle was higher than that of LPG vehicle and the case of CO emission shows the opposite patterns. In the HC emission, the emission increasing patterns not showed but the NOx emission of diesel vehicle and CO emission of LPG vehicle were showed the variation patterns according to the various driving modes.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2007.04a
• /
• pp.102-105
• /
• 2007

The performance evaluation of the micro thruster utilizing hydrogen peroxide decomposition is described. The catalyst bed was made of porous ceramic material($Isolite^{(R)}$) with large surface to mass ratio. 14%wt platinum was loaded on the catalyst support as a catalyst. Hydrogen peroxide with 85% concentration was used as a monopropellant. The length of the catalyst bed and the feed pressure of the hydrogen peroxide were taken as the parameters for the experiment. All experiments were carried out under cold start condition for 30 seconds. The $c^*$ efficiency was evaluated for each test case using measured pressure data. For the catalyst support length of 30 mm and feed pressure at 5.51 bar, satisfactory $c^*$ efficiency beyond 95% was observed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.19 no.12
• /
• pp.857-864
• /
• 2007

In the current residential building, hot water supply system consumes the second largest energy in order to make the thermal comport condition of residential space. The more residential environment improves the more the demand for hot water and water consumption is increasing gradually. So this study examines the possibility of applying the recirculation for individual hot water supply system compared with the existing method for waiting time for hot water, wasted water and energy consumption. The results are as follows. (1) In case of recirculation system method the waiting time for hot water can be reduced up to $69\sim85%$ in spring and fall period and so dose up to $77\sim85%$ in winter period. (2) The total wasted water has a little change compared with the existing method which can make the total wasted water reduced about $77\sim86%$. (3) The efficiency of hot water supply system can be improved, if the method which blocks the inflow of cold water is applied, when return pump is operated to recirculate hot water in recirculation system.

• Fire Science and Engineering
• /
• v.25 no.6
• /
• pp.178-183
• /
• 2011

In cold season, the elevator systems in super high-rise buildings would make noises at the door-gaps on high floors, and the elevator doors on the 1st floor would suffer from opening/closing trouble due to the pressure differences. Such pressure differences are also the main driving power of smokes through the hoistway in the case of fire. In addition, the pressure differences should be overcome to use the elevator systems as a measure of emergency escape. This paper reviews the way of hoistway pressurization to reduce the adverse influences. Simulations achieved a good result close to the requirements of NFPA 92A and IBC 2012 under the condition that the hoistway should be pressurized after pressure equalizing between floors and hoistway with the openings through the hoistway wall.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.28 no.2
• /
• pp.403-408
• /
• 1999

This study was conducted to investigate chemical properties, quality stability and utilization of approved sardine surimi(ASS) which is developed our laboratory. The product yield of the ASS was about 3 times higher than that of usual sardine surimi(SS). The proper addition concentration of sodium bicarbonate was 0.1% for the neutralization of the ASS. The content of salt soluble protein nitrogen in the ASS was about the half of that in the SS, while the content of water soluble protein nitrogen was 2.4 times higher in ASS. The total amount of free amino acids in the ASS was about 11 times higher than that of the SS. Predominant free amino acids in the ASS were histidine, taurine, glutamic acid and alanine, and those four amino acids occupied 94% of total amount of free amino acids. During cold storage at 21oC for 6 months, the quality of ASS was more stable than that of SS in judging from changes of water soluble and salt soluble protein nitrogen, AV and POV. Quality of fish burger, fish sausage and fried fish paste processed in accordance with commercial processing preparation using the ASS or SS exclusively and mixtures which other white meat fish surimi(alaska pollack, hair tail and sole) were proportionallly added to each of two types of sardine meat were evaluated. In case of fish burger, the product processed from the ASS only were superior.

• Proceedings of the KSME Conference
• /
• 2004.04a
• /
• pp.1237-1242
• /
• 2004

In this study, single-phase heat transfer experiments were conducted with oil cooler with offset strip fin using water. An experimental water loop has been developed to measure the single-phase heat transfer coefficient in a vertical oil cooler. Downflow of hot water in one channel receives heal from the cold water upflow of water in the other channel. Similar to the case of a plate heat exchanger, even at a very low Reynolds number, the flow in the on cooler with offset strip fin remains turbulent. The present data show that the heat transfer coefficient increases with the Reynolds number. Based. On the present data, empirical correlation of the heat transfer coefficient was proposed. Also, performance prediction analysis for oil cooler were executed and compared with experiments. ${\varepsilon}-NTU$ method was used in this prediction program. Independent variables are flow rates and inlet temperature. Compared with experimental data, the accuracy of the program is within the error bounds of ${\pm}5$% in the heat transfer rate.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.23 no.7
• /
• pp.841-855
• /
• 1999

In the present work, the effect of a flow maldistribution on the thermal and conversion response of 8 monolith catalytic converter is Investigated. To achieve this goal, a combined chemical reaction and multi-dimensional fluid dynamic mathematical model has been developed. The present results show that flow uniformity within the monolith brick has 8 great impact on light-off performance of the catalytic converter. In the case of lower flow uniformity, large portions of the monolith remain cold due to locally concentrated high velocities and CO, HC are unconverted during warm-up period, which loads to retardation of light-off. It has been also found that the heat-up pattern of the monolith ill similar to the flow distribution profile, In the early stage of the reaction. It may be concluded that flow maldistribution can cause a significant retardation of the light-off and hence can eventually worsen tho conversion efficiency of automotive catalytic converter.