• Aerospace Engineering and Technology
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• v.2 no.2
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• pp.105-114
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• 2003

It is conducted to analyze vibration loads on the 1st stage of KSR-III(KSR : Korea Sounding Rocket) during their ground transportation and various handling process. These loads may be different from the real flight environment. Inadequate assessment of these loads can cause not only local damages on the rocket system but also the critical problem like flight mission failure. Therefore, transportation and handling loads must be considered during design and attenuated to ensure that the rocket structural damage does not occur. This work is concerned with the generation of criteria and prediction of transportation and handling loads for KSR-III. The results show that the shipping container is well designed to satisfy the design requirements. The maximum vibration level recorded during whole transportation and handling for KSR-III is less than 2g, the criteria of KSR-III movement condition.

• Aerospace Engineering and Technology
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• v.7 no.2
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• pp.67-75
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• 2008

The electrostatic charging/discharging mechanism and its effects, and the system design considerations in the space plasma environment are studied in this paper. The electrostatic discharge (ESD) effects are carefully taken into account for a design of the satellite system at the early stage of the development. Generally, the electrical design requirements are specified to protect the satellite system from the ESD effects in the electromagnetic compatibility specifications. Those requirements are included the grounding, the bonding, the shielding, the conductive coating, the electric interfacing and so on. The space charging is caused by the increasing of the voltage difference between the each locations on the satellite surface. If the space charging is continued up to threshold, it may be occurred the system failure. This phenomenon is depended on the mission of system, electrical and mechanical configuration, system operation, and orbit condition. Therefore the related requirements are properly tailored and concentrated into the safety design.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.7
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• pp.709-716
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• 2009

Thermal condition according to the operation attitude of a satellite in orbit would be essential to be known because the orbit attitude is a dominant factor to affect satellite thermal design. In this paper, the change in space thermal environment and the thermal effect in thermal design are studied for a low earth orbit satellite according to the yaw motion. The present satellite retains sun-pointing attitude during daylight due to the fixed type solar arrays. And it also moves along the orbit with constant yaw motion in a longitudinal axis so that a star tracker which is a star sensor for satellite's attitude control always looks into the deep space. This attitude is considered in its better visibility to the stars for a successful mission operation. Also, it is required to access the corresponding thermal effects due to the yaw motion. Therefore, we try to verify these by the thermal analysis for the satellite thermal model with the yaw motion.

• Journal of the Korean Society of Clothing and Textiles
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• v.11 no.3 s.25
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• pp.41-55
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• 1987

The purpose of this study is to investigate the effects of napping of knitted fabric on wear sensation and physiological responses. Experimental garments were four types of warm-ups made of either $100\%$ PET or $65/35\%$ P /C and either napped or unnapped respectively. Two healthy young female adults were chosen as subjects for the experiment. Experimental room conditions were as follows: Temp., $22\pm0.5^{\circ}C$ R.H., $54\pm3\%$ and Air Velocity, 0.25m/ sec or 2. 86m/sec. The subjects exercised on bicycle ergometer and rested alternatively for totally 45-min. The results are summarized as follows. 1) With napped Warm-up, chest, back, mean skin temp. and microclimates, i.e., temp., relative humidity and water vapor pressure inside the clothing, were higher than with unnapped warm-up. And there was no difference in pulse rate between napped and unnapped warm-ups. 2) Wear sensations of thermal, humidity, tactile and comfort were 'more hot' and 'more uncomfortable' in 0.25m/sec air velocity. but in 2.86m/sec condition the tactile sensation was 'better' and 'more comfortable' with napped warm-ups. According to Pearson's Correlation, among various kinds of wear sensations, tactile is most related with comfort. From these results, it can be concluded that napped fabric decreases the rate of heat trans? mission and moisture diffusion through the clothing. Therefore skin and body temp. and temp., R.H., Vapor Pressure inside the clothing are increased.

• Current Industrial and Technological Trends in Aerospace
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• v.7 no.1
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• pp.68-78
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• 2009

In this paper, the electrostatic charging and discharging mechanism, and its effects in space plasma environment are reviewed and the system design control documents, ESD analysis tools and modelling techniques, and the SPIS program in Europe are introduced. A design of the satellite system against the electrostatic discharge (ESD) effects in space plasma environments is carefully taken into account at the early stage of development. In a view of the space system design, it really depended on the mission of system, electrical and mechanical configuration, system operation, and orbit condition. Behavior of the electrons and the ions in those environments may be occurred the sever problem to the satellite operation. So it is carefully understood for implementation of the satellite system. By this reason, the space environments and its effects have been comprehensively studied in U.S.A and Europe.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.27 no.2
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• pp.155-161
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• 2017

When a military vehicle is driven on a cross-country road, the occupants are exposed to vibration at a body resonance. In case that the exposure continues for too long period, the attention ability of the occupant could be affected by the vibration exposure. In the study, it was experimentally tried to find if there is a correlation between degradation of attention and vibration exposure. Two kinds of test among various psychological attention tests were employed, which were selected with considering a situation of carrying out military mission on vehicle. At the result, the searching test for controlled attention showed significant degradation in the accuracy and performance time in case of exposure at the vibration. And the attention degradation appeared to be greater when the vibration exposure increases. The dual task test for divided attention showed the difference between vibration and non-vibration condition, but showed it is insignificant for the attention to degrade by increasing exposure time.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.2
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• pp.69-79
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• 2017

In this study, we developed real-time urban stream discharge forecasting model using short-term rainfall forecasts data simulated by a regional climate model (RCM). The National Centers for Environmental Prediction (NCEP) Climate Forecasting System (CFS) data was used as a boundary condition for the RCM, namely the Global/Regional Integrated Model System(GRIMs)-Regional Model Program (RMP). In addition, we make ensemble (ESB) forecast with different lead time from 1-day to 3-day and its accuracy was validated through temporal correlation coefficient (TCC). The simulated rainfall is compared to observed data, which are automatic weather stations (AWS) data and Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA 3B43; 3 hourly rainfall with $0.25^{\circ}{\times}0.25^{\circ}$ resolution) data over midland of Korea in July 26-29, 2011. Moreover, we evaluated urban rainfall-runoff relationship using Storm Water Management Model (SWMM). Several statistical measures (e.g., percent error of peak, precent error of volume, and time of peak) are used to validate the rainfall-runoff model's performance. The correlation coefficient (CC) and the Nash-Sutcliffe efficiency (NSE) are evaluated. The result shows that the high correlation was lead time (LT) 33-hour, LT 27-hour, and ESB forecasts, and the NSE shows positive values in LT 33-hour, and ESB forecasts. Through this study, it can be expected to utilizing the real-time urban flood alert using short-term weather forecast.

• Journal of Advanced Navigation Technology
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• v.21 no.6
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• pp.529-536
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• 2017

The general ground control system has control and information display functions for the operation of a single unmanned aerial vehicle. Recently, the function of the single ground control system extends to the operation of multiple UAVs. As a result, operators have been exposed to more diverse tasks and are subject to task overload due to various factors during their mission. This study proposes an adaptive ground control system that reflects the operator's condition through the task overload measurement of multiple UAV operators. For this, the ground control software is developed to control multiple UAVs at the same time, and the simulator with six degree-of-freedom aircraft dynamics is constructed for realistic human-machine-interface experiments by the operators.

• Journal of Astronomy and Space Sciences
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• v.18 no.2
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• pp.163-173
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• 2001

In this paper, space radiation environment and single event effect(SEE) have been analyzed for the KOMPSAT-2 operational orbit. As spacecraft external and internal space environment, trapped proton, SEP(solar energetic particle) and GCR(galactic cosmic ray) high energy Protons and heavy ions spectrums are analyzed. Finally, SEU and SEL rate prediction has been performed for the Intel 80386 microprocessor CPU that is planned to be used in the KOMPSAT-2. As the estimation results, under nominal operational condition, it is predicted that trapped proton and high energetic proton induced SBU effect will not occur. But, it is predicted that heavy ion induced SEU can occur several times during KOMPSAT-2 3-year mission operation. KOMPSAT-2 has been implementing system level design to mitigate SEU occurrence using processor CPU error detection function of the on-board flight software.

• Mycobiology
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• v.38 no.4
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• pp.274-281
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• 2010

Cordyceps cardinalis was reported in Japan and the USA in 2004, and its fruiting bodies have recently been cultured in Korea. Herbarium specimens preserved at the Cordyceps Research Institute, Mushtech, Korea were revised and identified as C. cardinalis, based on morphological characters and conidial structures. Most of the C. cardinalis specimens were collected from Mt. Halla in Jeju-do. The effects of various nutritional sources and environmental conditions such as temperature and pH on mycelial growth of C. cardinalis were studied. Oatmeal agar, Martin's peptone dextrose agar, and Schizophyllum (mushroom) genetics complete medium plus yeast extract resulted in the best mycelial growth. Among carbon sources, cereals, and nitrogen sources, maltose, oatmeal, and peptone resulted in the best mycelial growth respectively. Mineral salts helped to increase growth rate but only resulted in thin mycelial density, similar to water agar. A temperature of $25^{\circ}C$ and a pH of 7 resulted in the highest mycelial growth. Based on these results, a Cordyceps cardinalis composite medium (CCM) was formulated with 1% maltose, 2% oatmeal, 1% peptone, and 2% agar. Use of the CCM resulted in slightly better mycelial growth than that of other commonly used agar media. Only organic nitrogen sources imparted a reddish pigmentation to the agar media, but this character diminished after several subcultures. A 7 day culture duration resulted in the best mycelial growth.