• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.259-262
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• 2012

The most of military systems that developed today are composed with many sub-systems for mission execution. The test of military systems for delivery test of mass product such that part test, PCB test, component test, integration test. This paper discusses improving productivity test method that functional test of PCB has a various function. Improving productivity is minimize testing item by man and minimize kind of tester, so that decrease product cost by production time for test. PCB tester be developed many kind of test method that systems were developed by many different engineers. This paper study testing check point for testing that how to minimize of kind of tester, how to automatic test for all of function that have inputs and outputs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.64-70
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• 2018

The development of weapon systems (or components) is hindered by the number of tests due to the limited development period and cost, which reduces the scale of accumulated data related to failures. Nevertheless, because a large amount of failure data and maintenance details during the operational period are managed by computerized data, the cause of failure of weapon systems (or components) can be analyzed using the data. On the other hand, analyzing the failure and maintenance details of various weapon systems is difficult because of the variation among groups and companies, and details of the cause of failure are described as unstructured text data. Fortunately, the recent developments of big data processing technology, machine learning algorithm, and improved HW computation ability have supported major research into various methods for processing the above unstructured data. In this paper, unstructured data related to the failure / maintenance of defense weapon systems (or components) is presented by applying doc2vec, a machine learning technique, to analyze the failure cases.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.10
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• pp.105-111
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• 2003

A measurement of spacecraft alignment is an important process of spacecraft assembly, integration and test. Because, it is necessary that a operator of a ground station controls the precise positions of on-orbit spacecraft by using the alignment data of attitude orbit control sensors(AOCS) on spacecraft. And, an accuracy of spacecraft alignment requirement is about $0.1^{\circ}{\sim}0.7^{\circ}$. A spacecraft alignment is measured by autocollimation of theodolite. This paper describes the measurement principle and method of spacecraft alignment. The result shows that all the AOCS on the spacecraft are aligned within the tolerance required through the alignment measurement.

• The Journal of the Convergence on Culture Technology
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• v.5 no.4
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• pp.387-394
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• 2019

In this study, in order to evaluate the damage and deterioration of the track components of sleeper floating track (STEDEF), the field samples(specimens) were taken from the serviced line over 20 years old, and the track components were visually inspected, and investigated by laboratory tests and finite element analysis. As a result of visual inspection, the damage of the rail pad and fastener was slight, but the rubber boot was worn and torn at the edges of bottom. The resilience pads were clearly examined for thickness reduction and fatigue hardening layer. As a result of spring stiffness test of rail pad and resilience pad, the deterioration of rail pad was insignificant, but the deterioration of resilience pad exceeded design standard value. Therefore resilience pad was directly affected by train passing tonnage. As a result of comparing the deterioration state of the field sample and the numerical analysis result, the stress and displacement concentration position of the finite element model and the damage position of the field sample were coincident.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.3
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• pp.219-224
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• 2017

A study on dissimilar friction-welded joints was performed for cam shaft applications using solid bar samples, 20mm in diameter, of forging steel(SF45) and carbon steel(SM45C). The main parameters of friction welding such as tensile tests, Vickers hardness surveys of the bond of area, the heat affected zone (HAZ), and the observation of microstructure were investigated to ensure a good quality of friction welding through visual observations. The specimens were tested as-welded and post weld heat treatment(PWHT). This paper deals with optimizing the welding conditions and analyzing various rotary bending fatigue test(RBFT) properties about heat-treated base metal(BM), as-welded and PWHT. Consequently, two materials for friction welding are strongly mixed with a well-combined structure of micro-particles without any molten material, particle growth, or any defect. Moreover, the fatigue limit of BM(SF45) and PWHT for the RBFT were observed as 180MPa and 250MPa, respectively. It was confirmed that the PWHT causes approximately 40％ improvement in the fatigue limit when compared to the BM(SF45).

• Journal of the Korea Convergence Society
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• v.9 no.7
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• pp.241-249
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• 2018

The military purpose vehicles are developed by using the platform of civil vehicles according to the commercial vehicle expansion plan and military supplied product commercialization policy. But the information related to the military purpose vehicle which adopts the same platform with the civil vehicle is forced to be exposed because its information is revealed by containing into the maintenance manual and electric circuit diagram. Especially, the information disclosure should be blocked by reviewing the application of technology protection because the military vehicle becomes combating purposed mixed equipment when the missile and radar are mounted. The mixed equipment means the one configured with more than 2 types of equipment, and it is categorized into the main and sub equipment. This study was performed to derive the problems in Korean system for vehicle part test evaluation on the mixed equipment and the defense industry technology protection system, and to derive the methods for improving through interviews with the specialists. The conflicts between the civil laws and army regulation were reduced by adding a clause that the engine reflected with the newest emission gas standard should be mounted based on the time of force integration, and the commercialized military supplies were designated as element technology of defense industry technology in consideration of its roles and functions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.13-18
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• 2016

Humidifiers are used to control indoor humidity. Element-type humidifiers have the advantages of simple structure and low energy consumption, and Japanese products have been widely used for the humidifying elements. In this study, a new humidifying element made of cellulose and PET was developed, and the performance was compared with that of a Japanese element. The mass transfer rates and pressure drops were measured for an element installed at the entrance of a suction-type wind tunnel. The humidification efficiency of the new element was 2 to 4% greater and the pressure drop was 23 to 32% smaller compared to the Japanese element. The mass transfer effectiveness ($j_m/f$) of the new element is also 5 to 28% higher. However, the water absorption capacity was smaller than that of the Japanese element, meaning further development is needed.

• Aerospace Engineering and Technology
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• v.8 no.2
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• pp.1-7
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• 2009

The Geostationary Ocean Color Imager (GOCI) is under development to provide a monitoring of ocean-color around the Korean Peninsula from geostationary platforms. It is planned to be loaded on Communication, Ocean, and Meteorological Satellite (COMS) of Korea. In this study, the radiometric model of GOCI, which is constructed based on the functional model of sub-system, is introduced. Non-linearity for each channel is analyzed in terms of linear gain and nonlinear gain by using the radiometric model. The non-linearity characteristic is validated by using test data which have been achieved during ground test at payload level. The non-linearity $G^3$/b shows identical characteristic for all channels.

• Applied Biological Chemistry
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• v.22 no.1
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• pp.33-38
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• 1979

The Anthocyanins in the Korean native Brassica juncea, which were favorably used directly for food or as condiments, were investigated. Two kinds of anthocyanin were separated from Korean native Brassica juncea by T.L chromatography and then Robinson test, spectrophotometry, T.L. chromatography, partial hydrolysis were tested for the structural elucidation of these two anthocyanins. It was known that two pigments were peonidin-3-glucoside and peonidin-3-galactoside.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2670-2675
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• 2010

Wall of hanok is related to exterior, inner environment, and the period and cost of construction. This study analyzes traditional wall execution method and suggests improved one. The characters of the improved execution method are use of ready made goods, application of dry and prefabricated method and improvement of airtightness and insulation capacity etc. The result of this study needs production of pilot productions and tests of capacity. But this new method will be useful to save the period and cost of hanok construction.