• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.9
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• pp.1837-1845
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• 2015

The longitudinal velocity is necessary for accurate vehicular positioning in urban environment. The pitch angle, which is a road slope, should be calculated to acquire the longitudinal velocity. However, it is impossible to consider very accurate pitch, when using a sensor and an algorithm. That's why process noise and positioning stimation error of IMU should be adjusted to the driving environment and fuse GPS, OBD data with ACF which consist of AKF, CF in this paper. Then, final pitch angle which is appropriate for driving environment is estimated by IMMKF in order to optimize the system model according to road slope models.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.4
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• pp.553-562
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• 2010

This survey investigates the conditions of summer working uniforms for contracted foodservice workers. The data were obtained from 67 workers through in-depth interviews (July 2005~October 2005). The results of study are as follows: The working environment changed to menu and cooking method (air temperature $28\sim37^{\circ}C$, humidity 72~86 %RH, radiant temperature $27\sim37^{\circ}C$, air velocity 0.14~0.37m/sec). They answered that the working environment has high temperatures, humidity, excessive noise, and liability to slide. The typical accidents were burns, cuts, slide, and ligament injuries in the workplace. Work duties consisted of cooking, serving food, washing, and cleaning up leftover food. All the employees carried out multi tasks. The primary working postures and motions were standing, crouching, and lifting. The female workers usually wore underwear (panty and brassiere), upper and lower work wear, aprons, waterproof-aprons, cotton-gloves, rubber-gloves, socks, and rubber-boots. The satisfaction of the uniform was relatively low for trousers and waterproof-aprons. The answer about the fit was generally "comfortable." They answered "back," "chest," and "head" were wet with perspiration during work. The uncomfortable parts were the crotch and neck. Questions concerning their satisfaction with the material of uniforms indicated a high rate of dissatisfaction, particularly for ventilation and absorbency. In case of the colors of the working uniform, workers preferred white color for the upper part, and black color for the lower part.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.825-839
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• 2010

The global and domestic market for offshore wind farm is expected to grow fast, and the design and installation of substructure and foundation is getting more important. As for the offshore wind farms located in the shallow(depth < 20m) water, the construction and installation of the substructure and foundation makes up about 1/4 ~1/3 of the offshore wind farm construction cost, and the portion is expected to increase because the turbine capacity is increasing from 2 ~ 3MW to 5MW or larger and the water depth of wind farms is also increasing over 30m. As a foundation for offshore wind turbine, the suction caisson foundation is being considered to be a highly competitive alternative to the conventional monopile or gravity based structure, because it has features suitable for the offshore construction such as quick installation, no heavy equipment for penetration and no hammering noise for driving. In order to study the installation behaviour of the suction caisson, laboratory tests were performed with sand. The pore water pressure and displacement were measured to analyze the suction pressure during penetration, the penetration speed and the amount of heaving.

• Journal of radiological science and technology
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• v.41 no.2
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• pp.123-128
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• 2018

Recently, the use of contrast agents has been increasing as a broader range of tests and dynamic tests have become common due to the development of equipment and imaging techniques such as Multi-Detector CT. However, the side effects of using contrast agents have been reduced by the development of non-ionic contrast agents, but they are still occurring often. The purpose of this study was to propose a method to minimize the side effect of contrast agent by using the amount of contrast agent injected to the brain angiography test to suppress excessive use of contrast agent and analyze the amount of contrast agent. Patients who were prescribed Brain Angiography due to cerebrovascular disease, According to the results of the comparison of the results obtained by dividing into 4 groups of 10ml each according to the amount of contrast medium injected with contrast agent according to the BMI of the patient, BA and SNR were not different between groups, and even if the amount of contrast injection was reduced, there was no problem in the evaluation of CT angiography through 3D reconstruction. This result shows that even if the contrast medium is injected into the blood vessels of the patient first and then the contrast medium is used as the physiological saline solution, the contrast medium is reduced by 40% it can be expected to minimize.

• Journal of Satellite, Information and Communications
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• v.1 no.2
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• pp.56-62
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• 2006

This paper describes the MMIC product qualification of the Ka band satellite transponder for the COMS(Communication, Ocean and Meteorological Satellite). Ka-band active equipment for the COMS communications transponder are being developed by using 12 kinds of MMICs which include low noise amplifiers, medium power amplifiers, frequency mixers, frequency multipliers, RF switch, and HEMT attenuator MMIC, Those MMICs had been fabricated at the MMIC production foundry of northrop Grumman Space Technology (Velocium) which is qualified for space application, and experienced in various space programs during past decades. For the MMIC product qualification, Visual inspection and SEM inspection had been performed, and burn-in test for 240 hours and accelerated life-test for 1000 hours had been done on test fixtures of individual MMIC products at $125^{\circ}C$. Additionally, infrared temperature scanning and finite element simulation were performed to analyze and confirm the channel temperature of semiconductor devices on several representatives of those MMIC products that os one of the most important factors in performance degradation and life reduction.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.2
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• pp.266-271
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• 2014

The Electromagnetic Interference(EMI) generating from corona discharge of transformer area can interference the digital Instrument and Control(I&C) systems located nearby transformers. When the potential gradient of the electric field around the conductor is high enough to form a conductive region but not high enough to cause electrical breakdown to nearby objects, the EMI of corona discharge emits with the conducted and radiated noise and it interferences the signals of the I&C systems. Since digital I&C systems have an efficiency and competitive price, the analog I&C systems have been upgraded and displaced with the digital I&C systems but which have less EMI Immunity. There was no assessment to I&C systems by EMI generating corona discharge nearby transformers. When the safety-related I&C systems are installed in plants, the verification of equipment EMI should be done not in site-specific test but in test facilities. There are the need to do the site-specific EMI evaluation of corona discharge nearby transformers. This paper assesses the margin between plant emission limits and the highest composite plant emission of corona. When the non safety-related I&C systems are placed in transformer area, it suggests the appropriate radiated susceptibility level to EMI of corona discharge.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.500-506
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• 2011

The deep mixing method, which is generally considered as a method for improving soft ground, is assessed in terms of its applicability for urban construction. Using small equipment tailored to perform deep mixing in congested urban areas, deep mixing was performed to reinforce the foundation ground of a retaining wall in a redevelopment site in Seoul. Strengths characteristics, construction vibrations and displacements induced to an adjacent old masonry wall were evaluated by laboratory tests and field monitoring. The results indicate that the strength of ground was improved appropriately whilst the vibrations and displacements induced by deep mixing were slight enough to satisfy the general requirements for construction works in urban environments. Therefore, it is concluded that deep mixing method can be a practical option for foundation methods in urban construction works where minimizing noise and vibrations is an important concern.

• Journal of Astronomy and Space Sciences
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• v.23 no.2
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• pp.153-160
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• 2006

A Protomodel Space Infrared Cryogenic System (PSICS) cooled by a stirling cry-ocooler has been designed. The PSICS has an IR sensor inside the cold box which is cooled by a stirling cryocooler with refrigeration capacity of 500mW at 80K in a vacuum vessel. It is important to minimize the heat load so that the background thermal noise can be reduced. In order to design the cryogenic system with low heat load and to reduce the remained heat load, we have performed numerical analyses. In this paper, we present the design factors and the results obtained by the thermal analysis of the PSICS.

• Journal of environmental and Sanitary engineering
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• v.1 no.1 s.1
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• pp.81-96
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• 1986

510 random samples were studied during the months of may through November 1985 at the various industries and conclustions were made as follows; 1. $43.94\%$ of the plants studied operated their plants with semiautomatic control system, and better efficiency were observed at the plants where automatic control systems emplorid and also large industries showed more tendency adopting the automatic plant control system. 2. Overall efficiency of the treatment plants were seen much higher at the first and secand discharge class categories then the lower discharge classes, $80.79\%$ of the plants were see their daily plant operation being controlled by the operator himself. 3. The main causes of the plant stopage and in efficient discharge control were found to be malfunctioning of the plants machineries and equipment or inadequate decision made by the management to save chemicals or electricity. 4. The study showed $60\%$ of the industry treated their wastwater wholly and the rest discharged only with dilution without receiving any further treatment, and this tendency pronounced at the 4th and 5th class discharge category industries. 5. $66.17\%$ of the industry had their storage capacity to accommodate the waste discharge during plants outage while $92.67\%$ of the air pollution discharge industries had no means for the plant outage. 6. $56.77\%$ of the studied industry maintained 24 hour operation of their discharge control systems whill $18.67\%$ of air pollution discharge industries and $10.53\%$ of the waste water discharge industries showed no control effort during the night.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.8
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• pp.1765-1772
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• 2012

Success rate of transplantation of body organs improved due to development of medical equipment and diagnostic technology. In particular, a liver transplant due to liver dysfunction has increased. With the development of image processing and analysis to obtain the volume for liver transplantation have increased the accuracy and efficiency. In this thesis, we try to reconstruct the regions of the liver within three dimensional images using the mevislab tool, which is effective in quick comparison and analysis of various algorithms, and in expedient development of prototypes. Liver is divided by applying threshold values and region growing method to the original image, and by removing noise and unnecessary entities through morphology and region filling, and setting of areas of interest. It is deemed that high temporal efficiency, and presentation of diverse range of comparison and analysis module application methods through usage of MeVisLab would make contribution towards expanding of baseline of medical image processing researches.