• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제38권9호
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• pp.907-913
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• 2010

In this paper, we have described a development of the external instrumentation system of a fighter aircraft for flight test. The external instrumentation system consists of the instrumentation pod and the image pod. The instrumentation pod measures a flight data(attitude, velocity, altitude, etc) of the fighter aircraft by using GPS/AHRS sensor. The image pod takes high-speed images for the separation trajectory of a smart bomb with 2 high-speed cameras and video signal for it with one general camera. We have verified the performance of the external instrumentation system through the ground test, the environment test and the flight test.

• Asian Journal of Atmospheric Environment
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• 제9권1호
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• pp.48-56
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• 2015

The trajectory analysis of boundary layer ozone data at four regional sites in the East Asian outflow regions in Japan was carried out together with boundary layer ozone data observed at Mt. Tai and Mt. Huang in the source region of central eastern China during the monsoon onset in May-June 2003 and 2004. At all sites, the influences of anthropogenic emissions from East Asia have been found. During May and June 2004, the evidences of direct pollution transport from central eastern China to Hedo, an outflow site in Okinawa Island were observed. Ozone mixing ratios associated with air masses from central eastern China averaged 45 ppb while those associated with clean air masses from the Pacific were only 14 ppb, which resulted in averaged 31 ppb increase of ozone mixing ratios during the pollution episodes from central eastern China at Cape Hedo. Using transport time analysis and averaging all ozone episodes transported from central eastern China, the ozone dilution rate of 5.4 ppb per day was roughly estimated during air masses transported from source to outflow regions at Hedo. In the regions nearby Japanese mainland, however ozone increases by long-range transports were more related to both domestic and East Asian sources as a whole.

• Journal of the Korea Institute of Military Science and Technology
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• 제21권4호
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• pp.551-561
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• 2018

Footprint is defined as ground area that is projected from the outer edges of the battle space protected by a defence system. This concept can be effectively used for making decisions on site selection of anti missile systems to defend against enemy's ballistic missiles. In this paper, simulations of ballistic missile trajectories based on various launch conditions are performed first and then the footprint is derived with engagement zone set as a boundary condition. Results of the simulation with various relative positions between the defense system and defended asset are also presented. The proposed method, in which the trajectories are generated based on launch point of the ballistic missile, has an advantage of approximating the defended area close to reality. Two applications are introduced in the present paper to describe how the derivation of defended area could be utilized in deployment decision of defense systems.

• Human Ecology Research
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• 제58권2호
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• pp.163-176
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• 2020

Longitudinal studies have shown mixed findings on the association between body image dissatisfaction and self-esteem among adolescents. This study examined the longitudinal, reciprocal influences between body image dissatisfaction and self-esteem among Korean pre- and early adolescents by using nationally representative longitudinal panel data from the Korean Youth Panel Study (KYPS). Analyses based on 2,230 participants indicated that girls' body image dissatisfaction was significantly higher than boys'. The trajectory of body image dissatisfaction increased sharply during pre- and early adolescence, but stabilized afterwards for both boys and girls. Self-esteem deteriorated rapidly initially, but began to recover as adolescent girls and boys matured. Structural equation modeling showed that reciprocal influences between body image dissatisfaction and self-esteem were detected for boys. Body image dissatisfaction among girls predicted self-esteem during the entire period, while the opposite direction from self-esteem to body image dissatisfaction emerged two years later. The present study found that, during pre- and early adolescence, body image dissatisfaction and self-esteem develop in a circular fashion by forming a vicious cycle. Implications for the development of intervention and prevention programs are discussed in consideration of age and gender.

• Journal of the Korea Institute of Military Science and Technology
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• 제14권3호
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• pp.405-413
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• 2011

Defense Systems Test Center in ADD supports increasingly various missile test requirements such as higher altitude event, multi target operation and low-altitude, high velocity target tracking. In this paper, we have proposed the development of instrumentation radar tracking status simulator based on virtual reality. This simulator can predict the tracking status and risk of failure using several modeling algorithms. It consists of target model, radar model, environment model and several algorithms includes the multipath interference effects. Simulation results show that the predict tracking status and signal are similar to the test results of the live flight test. This simulator predicts and analyze all of the status and critical parameters such as the optimal site location, servo response, optimal flight trajectory, LOS(Line of Sight). This simulator provides the mission plan with a powerful M&S tool to rehearse and analyze instrumentation tracking radar measurement plan for live flight test at DSTC(Defense Systems Test Center).

• Journal of the Korea Institute of Military Science and Technology
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• 제19권2호
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• pp.272-279
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• 2016

Many researches on use of local ground navigation systems can be found to overcome vulnerability of GNSS. Effective use of an altimeter is proposed in GNSS/DME integrated navigation systems. A weighted DOP based on statistics of measurement error is derived for a given vehicle motion trajectory. From the derived DOP, the vertical error is estimated. By comparing the estimated vertical error with error specification of the altimeter, use of the altimeter is determined in the GPS/DME integrated navigation systems. In order to show effectiveness of the proposed method, 50 times Monte-Carlo simulations were performed for a GPS/DME integrated navigation system. The results show that the proposed method gives more accurate navigation outputs when the number of GPS satellites in view varies.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제30권2호
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• pp.66-73
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• 2019

Objectives: This study aimed to investigate the trajectory of change of diverse attention and working memory in Koreans from 4 to 40 years of age. Methods: The data of 912 subjects from 4 to 15 years of age obtained from a previous standardization study of the computerized comprehensive attention test were merged with the newly obtained data of 150 subjects aged 16 to 40 years from this study. We evaluated the various kinds of attention, in which each subtest had five indicators. Working memory, with parameters such as number of correct responses and span, was also measured. Results: Our findings indicated that attention developed as age increased, and it decreased or was maintained after a certain age. Selective and sustained attention developed rapidly in children and adolescents, until mid-teens or 20 s when it ceased development. Divided attention, however, developed up to approximately age 20. In addition, working memory developed until mid-teens or 20 s. Conclusion: We presented the standardized data on diverse kinds of attention and working memory in children, adolescents, and adults in Korea. We could recognize any patterns of change in attention and working memory with increasing age.

• Journal of Information Technology Services
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• 제21권6호
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• pp.39-51
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• 2022

As the 4th Industrial Revolution emerged as a key to improving national competitiveness, OCR technology, one of the major technologies in the 4th industry is in the spotlight. Since characters in various images contain a lot of information, OCR technology for recognizing these characters has evolved into technology used in many industries. In this paper, trends in OCR technology were identified and predicted using thesis data published in 'RISS' and patent data by International patent classification (IPC) under the theme of Optical character recognition (OCR). For patent data 20,000 patents related to OCR technology from 2002 to 2020 were used as data, and 432 papers from 2012 to 2022 were used as data. Through time-series analysis, each patent data and thesis data were investigated since when OCR technology has developed, and various keyword analysis predicted which technology will be used in the future. Finally, the direction of future OCR technology development was presented through network association analysis with patent data and thesis data.

• Journal of the Korea Institute of Military Science and Technology
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• 제26권2호
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• pp.159-170
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• 2023

In the present study, the dynamic behavior characteristics of an amphibious assault vehicle during water entry were analyzed using STAR-CCM+, a commercial computational fluid dynamics(CFD) code. All computations were performed using an overset mesh system and a RANS based flow-solver coupled with dynamic fluid-body interaction(DFBI) solver for simulating three degrees of freedom motion. For numerical validation of the solver, a water entry simulation of inclined circular cylinder was conducted and it was compared between an existing experiment data and CFD results. The pitch angle variation and the trajectory of the circular cylinder during water entry shows good agreement with previous experimental and numerical studies. For the water entry simulations of the amphibious assault vehicle, the analysis of dynamic behaviors of the amphibious assault vehicle with different slope angles, submerged depths and initial velocities were conducted. It is confirmed that the steep slope angle increases the submerged volume of the amphibious assault vehicle, so the buoyancy acting on the vehicle is increased and the moved distance for the re-flotation is decreased. It is also revealed that the submerged volume is increased, bow-up phenomenon occur earlier.

• Journal of Koreanology Reviews
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• 제2권1호
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• pp.17-25
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• 2023

This research aims to provide a comprehensive evaluation of the history of private education in Korea. By delving into the historical aspects of private education, this study aims to uncover key developments, trends, and transformations that have shaped the private education landscape in Korea. By understanding the historical trajectory of private education in Korea, educational practitioners can gain a deeper understanding of the challenges, opportunities, and potential areas for improvement within the private education industry. The literature analysis has shown that there are four significant historical events for developing private education industry in South Korea. First, Japanese colonial period and its Impact on private education in Korea background and context. Second, education reforms in the 1960s and the rise of hagwons in Korea background and context. Third, the role and impact of private education on the Korean education system. Fourth, Education reforms in the 21st Century and the regulation of private education background and context. In sum, this research provides a comprehensive evaluation of the history of private education in Korea, examining four key historical events and their impact on the private education landscape. The findings reveal important insights into private education's development, role, and impact in Korea.