• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.2 no.1
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• pp.125-134
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• 1991

In an attempt to study sex differences in child behavior disorders, 834 clinic-refered children(582 boys and 252 girls) between the ages of 6 to 11 were assessed using CBCL parental form and the data were factor analysed to form empirically derived syndromes for each sex. The analyses yielded eight behavior disorder syndromes for boys and ten, for girls. Six syndromes(aggressive, hyperactive, delinquent, social withdrawal, emotional lability, physical complaints) were found in both sexes while obsessive, depressive and psychotic syndromes were organized differently in boys and girls. There were also considerable differences in item composition of the six syndromes common to box sexes, suggesting that clinical features of common behavior disorders such as aggression and hyperactiveity might be different for boys and girls despite their apparent similarity. The results were discussed in terms of culturally shared attitudes and beliefs concerning sex differences in behaviors.

• Journal of Advanced Navigation Technology
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• v.18 no.4
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• pp.334-340
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• 2014

Recently, in an effort to decrease aviation accident worldwide, there has not been any significant decline of the aviation accident rate. Therefore, in the international society, it is more focused on removing risk factors based on data collected and analyzed, in order to improve the aviation safety. This paper introduces on the characteristic of ECCAIRS 5 which become the standard for the worldwide aviation safety reporting and data exchange system. Also, using domestic aviation accident data collected during last 10 years(from 2003 to 2012), we analyze the distribution of the aviation accidents/incidents, annual and monthly aviation accident rate, flight phase, and occurrence category according aircraft type(Fixed/Rotary wing). The analyzation regarding the tendency of aviation accident/serious incident will give the direction to approach the quantitative safety management.

• Journal of Advanced Navigation Technology
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• v.16 no.1
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• pp.1-7
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• 2012

In this research, a single-axis attitude control test bed is developed, and simulation and tests experiments are performed, as a preliminary research of a quad-rotor aerial vehicle development. A single-axis test bed with seesaw configuration is manufactured using two motors and propellers, and the aerodynamic parameters are derived by thrust tests. The response of the system is estimated with Matlab/Simulink, and experiments are performed with attitude control computer and an attitude sensor onboard the test bed. Comparing the results of simulated and tested data, factors of steady-state errors during experiments are found, and performances of used attitude control algorithm and the control computer were verified. In these process, essential preliminary data for attitude control of a quad-rotor unmanned aerial vehicle were acquired.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.5
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• pp.110-116
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• 2003

With the growth of aircraft performance and needs for light aircraft, the problems associated with hail impacts on aircraft during flights and grounding become and important issue. These hail encounters can cause severe damages to aircraft and result in major concerns in safety and cost. Since nearly all external components of the commercial and military aircraft-in particular, the nose section and the leading edge of the wing and tail-are subject to damages, much effort has been put into understanding of this problem. However, most of the previous studies have focused on the composite components and few results have been reported for the metallic components. In this paper, we study the ice impacts on the aluminum component with the finite element analysis method utilizing commercial non-linear dynamics solver LS-DYNA. The results are compared with the experimental data and a simple measure of the ice impact effects is proposed.

• Korean Journal of Remote Sensing
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• v.32 no.6
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• pp.657-672
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• 2016

Coastal erosion happens frequently in many different types. To control coastal erosion zone effectively and establish response plans, we need to accumulate data indicating topography changes through monitoring the erosion situation continuously. UAV photogrammetric systems, which can fly autonomously at a low altitude, are recommended as an economical and precision means to monitor the coastal zones. In this study, we aim to verify the accuracy of the generated orthoimages and DEM as a result of processing the UAV data of a coastal zone by comparing them with various reference data. We established a verification routine and examined the possibilities of applying the UAV photogrammetric systems to monitoring coastal erosion by checking the analyzed accuracy by the routine. As a result of verifying the generated the geospatial information from acquired data under various configurations, the horizontal and vertical accuracy (RMSE) were about 2.7 cm and 4.8 cm respectively, which satisfied 5 cm, the accuracy required for coastal erosion monitoring.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.8
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• pp.99-104
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• 2005

The major role of a spacecraft structure is to keep and support the spacecraft safely in all the launch environment, on-orbit condition and during ground-transportation and handling. In a satellite development, a structural and thermal model (STM) is developed for two goals ; demonstration of a structural and a thermal stability. In the structure point of view, STM is used to verify the static/dynamic characteristics of structure in the initial stage of development. In this paper, the structure design/analysis of high resolution LEO earth observation satellite STM is described. Also, a low level sine vibration test is performed and compared to the results of finite element analysis.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.1
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• pp.34-38
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• 2012

호산구는 염증 반응에 의해 활성화되며, 주로 기생충 감염이나 알러지 질환 등에 대한 면역 작용을 담당한다고 알려져 있다. 호산구 증가증은 약물 반응, 알러지, 국소적인 기생충 감염 등에 의한 경우가 많지만, 자가면역성 질환이나 종양에 의한 경우도 있다. 최근 연구를 통해 위염의 대표적인 원인균 중 하나인 유문나선균 역시 위점막에서 나타나는 조직 호산구 증가증의 원인이 될 수 있다고 밝혀지고 있으나, 유문나선균에 의한 호산구 증가증 발생 기전이나 빈도는 아직까지 확립되지 않고 있다. 위점막 내 호산구 침윤과 동반되는 위염은 복통, 오심, 구토, 설사, 장폐색 등을 일으킬 뿐만 아니라, 아토피성 피부염, 천식, 위식도 역류, 염증성 장질환 등의 발생과 관련이 있다고 보고되고 있다. 위염 및 다양한 관련 질환에 의한 증상은 공중 근무자들의 임무 수행 능력을 저하시켜 항공기 사고를 발생시킬 수 있는 가능성을 가지고 있다는 점에서 항공의학적으로 매우 중요하며, 실제로 호산구성 위염이나 유문나선균 감염의 치료 여부가 공중 근무자에게 일시적 또는 영구적 비행임무정지를 부과할 수 있는 기준이 되기도 한다. 본 연구에서는 대한민국 공군 장병 환자를 대상으로 내시경을 통해 얻은 위점막 조직 내 호산구수를 측정하고, 이를 위점막 표면의 유문나선균 존재 유무와 관련지어 보았다. 111명 중 20명의 환자에서 한 고배율 시야 당 30개 이상의 호산구가 관찰되었고, 63명의 환자의 위점막 표면에서 유문나선균을 확인하였다. 또한 위점막 내 호산구의 밀도와 유문나선균의 존재 간의 관계는 통계학적으로 유의하였다. 본 연구의 결과는 대한민국 공군 장병을 대상으로 하여 조직 호산구 증가증과 유문나선균의 빈도 및 상호 관계를 최초로 분석했다는 점에서 의의가 있으며, 추후 유문나선균이 어떤 기전으로 위점막 조직 내 호산구의 증가에 관여하는지에 대한 연구를 진행하기 위한 기초 자료로서 활용될 수 있을 것이다.

• Journal of Digital Convergence
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• v.14 no.2
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• pp.197-208
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• 2016

In this paper, data mining regression analysis and decision tree analysis techniques were used to analyze factors affecting the life satisfaction of middle school students. For this purpose, we analyzed Korean Children and Youth Panel Survey(KCYPS) data. As results, the common influencing factors to the life satisfaction were derived from regression analysis. Those factors are self-esteem, depression, total grade satisfaction, regional community awareness, career identity, annual delinquency damage experience, siblings' factors, trust, behavioral control, and concentration. Based on the result described by decision tree analysis, the factors that indicate a significant impact on the life satisfaction of middle school students were self-esteem, depression, career identity and attention factor.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.1
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• pp.81-87
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• 2015

We present an implementation result of a computer GUI-based simulator using MATLAB to verify the performance of interferometric radar altimeter(IRA) which is possible to measure the slant range altitude and the cross-track angle to the nearest point for terrain aided navigation(TAN). After a brief description of the principle of TAN and IRA, we present that the grids are divided for the modeling of the reflected signal in digital elevation map(DEM) and so the radar cross section(RCS) of each grid is calculated and the signal-noise ratio(SNR) of the reflected signal in the radar beam width. And the signal processing procedures of the IRA and the structure of the IRA simulator are shown.

• Nuclear Engineering and Technology
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• v.23 no.2
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• pp.183-199
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• 1991

Transient response of temperature distributions in a Pressurized Water Reactor (PWR) pressurizer vessel wall for the Inadvertent Auxiliary Spray transient has been analyzed with conservatism accounted for the resulting thermal stresses in the regions of the vessel wall which are wetted by the spray water droplets. In order to determine the forced convective heat transfer coefficient at the inner boundary surface of vessel wall where the droplets impinge on and flow down, the transient temperatures of spray droplets when they reach the inner surface of the vessel wall after travelling from the spray nozzle through the pressurizer interior space occupied with the saturated steam-noncondensable hydrogen gas mixture have been predicted. The transient temperature distributions in the vessel wall have been obtained by using the finite element method, and the typical results have been provided. It has been shown that the results of thermal analysis are consistent with representation of the input transient and have plausible physical meaning.