• Proceedings of the ESK Conference
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• 1996.04a
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• pp.291-300
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• 1996

This study is to determine the biomechanical characteristics of Korean. Male 58 and Female 54 were participated for the measurement which was performed by immersion method and reaction board method. Body parts were head with neck, trunk, upper arm, forearm, hand, thigh, leg, and foot. Their volumes were measures by immersion method. Their weight were determined by using Dempster(1995), Drills and Contini(1969) density data. Each center of body part weight were determined by specific posture on the reaction board. The postures were asked to the subject forearm- lifted posture, total let- lifted posture, foot-lifted posture. According to each posture, the center of each part were calculated.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.9
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• pp.827-832
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• 2012

In this paper, we will design the speed measurement board of LEO Satellite's reaction wheel which has two speed measuring methods as M-Method type and T-Method type. therefore we can use the advantage of two methods. and we will verify the availability of design on the on-board computer at the real LEO Satellite(KOMPSAT-3). In the reaction wheels satellite that can change the satellite's attitude is one of the leading drivers by the rotational inertia of the motor will perform attitude control. Reaction methods for detecting wheel rotation speed generated during a certain period T internal reaction wheel tacho pulse counting M-Method to detect wheel speed and wheel tacho pulses are generated by measuring the time between the detection rate can be divided into T-Method. M-method is simple to implement and benefit measurement time is constant, but slow fall in the velocity measurement accuracy is a disadvantage. In contrast, the time between tacho pulses to measure the T-Method to measure the precise speed at low speed and to measure the time delay is small, has the advantage. However, this method also in the actual implementation and the complexity of the operation at different speeds depending on the speed of operation has the disadvantage.

• Nuclear Engineering and Technology
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• v.51 no.3
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• pp.746-754
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• 2019

Vitrification of radioactive liquid waste (RLW) provides a feasible solution for isolating radionuclides from the biosphere for an extended period. In vitrification, base glass and radioactive waste are added simultaneously into the melter. Determination of heat and mass transfer rates is necessary for rational design and sizing of melter. For obtaining an assured product quality, knowledge of reaction kinetics associated with the thermal decomposition of waste constituents is essential. In this study Thermogravimetry (TG) - Differential Thermogravimetry (DTG) of eight kinds of nitrates and two oxides, which are major components of RLW, is investigated in the temperature range of 298-1273 K in the presence of base glasses of five component (5C) and seven component (7C). Studies on thermal behavior of constituents in RLW were carried out at heating rates ranging from 10 to $40\;K\;min^{-1}$ using TG - DTG. Thermal behavior and related kinetic parameters of waste constituents, in the presence of 5C and 7C base glass compositions were also investigated. The activation energy, pre-exponential factor and order of the reaction for the thermal decomposition of 24% waste oxide loaded glasses were estimated using Kissinger method.

• Journal of Sasang Constitutional Medicine
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• v.10 no.1
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• pp.143-160
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• 1998

PURPOSE This studied the biomechanical body segment parameters of Korean adults with reference to Sasang Constitutional Medicine(SCM). We anlyzed the characteristics of Sasang constitution through Body Measurement, Immersion Method, and Reaction Board Method. SUBJECT Subjects were 72 persons. There were made 49 and Female 23. Mean age was . And There were Taeumin 30, Soyangin 17, and Soeumin 25. METHOD The items of Body Measurement were 51. Limbs were measured right side. Volume was gained with Immersion Method and Weight was calculated with the density equation for limbs from Drills and Contini. Center of Mass was gained with Reaction Board Method. RESULT 1. In Body Measurement there were the significant differences with each constitution of man's circumference. 2. In Volume there were the significant differences between Taeumin and Soeumin in mand. And the volume rate of head and neck, hand, and foot was the lowest in Taeumin, but the highest in Soeumin. 3. In center of mass Soyangin was higher than others.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.7
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• pp.529-536
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• 2020

Reaction Control System of the third stage of the Korean Space Launch Vehicle II conducts roll control and 3 axis control throughout third stage engine start, satellite separation, and collision and contamination avoidance maneuver. Reaction control system consumes its propellant in each thruster operation. Hence, loading of proper amount of the propellant is important for mission success. It is needed to have a rough estimation method of propellant consumption during the flight. In this paper, we developed a energy equation using pressure and temperature data which are acquired in the on-board reaction control system. We constructed a test system which is similar with the on-board reaction control system to verify the energy equation. Test results using deionized water were compared with estimated propellant consumption. We also conducted an error analysis of the energy equation. We also presented the propellant consumption result of a system level operation test.

• ETRI Journal
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• v.33 no.1
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• pp.121-124
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• 2011

Digital harmonics, which may reduce the radio frequency sensitivity of a system, can be coupled with an antenna in a mobile handset. This letter presents a decoupling method for increasing the isolation between digital harmonics on a flexible printed circuit board (FPCB) and an antenna in terms of the ground mode current and the concept of reaction. We model the signal and ground lines in an FPCB as a loop circuit exciting a ground mode current and demonstrate a simple but efficient decoupling method for reducing the excited ground mode current.

• The Journal of Korean Physical Therapy
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• v.5 no.1
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• pp.61-69
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• 1993

It was performed to encourage for Physical Therapist to apply the theory of center of the human body and segments in clinical situations. This study was investigated literarily on center of the human body and segments. Methods which search for the center-2 types, that is, method using reaction broad and segmental method-was suggested. The center location difference of gravity in human body depends on individual character. Generally, the center location is in kent of 2nd sacrum, that is, at $55\%$ of height from foot. The center of each segment is on 'link'. In the first place we must how the weight of segment we can search for the center easily. Mean segment coater location of extremities is at $42.33\%$ from each proximal end, and mean center of head and trunk lies at $45\%$.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.3
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• pp.237-242
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• 2014

Recently much research are has been done into the compositions of lead-free solders. As a result, there has been a rapid increase in the number of new compositions. In the past, the properties of these new compositions were determined and verified through drop-impact tests. However, these drop tests were expensive and it took a long time to obtain a result. The main goal of this study was to establish an analytical method capable of predicting the impact life-time of a new solder composition for board-level flip chips though the application of drop simulations using LS-DYNA. Based on the reaction load obtain with LS-DYNA, the drop-impact fracture cycles were predicted. The study was performed using a Sn-3.0Ag-0.5Cu solder (305 composition). To verify the reliability of the proposed analytical method, the results of the drop-impact tests and life-time analysis were compared, and were found to be in good agreement. Thus, the new analytical method was shown to be very useful and effective.

• Korean Journal of Agricultural Science
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• v.36 no.1
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• pp.11-18
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• 2009

The purpose of this study is to examine a proper amount of addition and a proper point for addition of titanium dioxide for the manufacture of E0 type of urea-formaldehyde resin (UF). The reduction of free formaldehyde from UF resin treated particle board was also investigated. $TiO_2$ content was 0.5%, 1% and 3% on the dry basis of UF resin. UV light was used to initiate reaction. The results of this study are as follows: 1. During UF resin manufacturing process, the second adding step of urea was proper point for $TiO_2$ addition. 2. 1 % addition of $TiO_2$ gave good values for the Eo type urea-formaldehyde resin. 3. There was no significant difference between physical properties of particle board, but the higher the adding content of titanium dioxide resulted in the lower the mechanical properties.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.8
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• pp.126-132
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• 2002

Jitter induced from several payloads on-board satellites degrade the performance of pointing accuracy and attenuate the resolving power of highly-precise camera image such as KOMPSAT II. In this paper, we introduce a micro-vibration measurement technique, analysis of dynamic characteristics, and modeling method for a reaction wheel assembly which is one of the major sources of jitter in satellites and an effective vibration reduction techniques are considered. Based on these techniques, vibration measurement and passive control were performed with an micro-vibration generator which was designed to have similar dynamic performances with an actual reaction wheel assembly above 50Hz.