• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.3
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• pp.204-212
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• 2020

For general target tracking works by receiving a set of measurements from sensor. However, if the SNR(Signal to Noise Ratio) is low due to small RCS(Radar Cross Section), caused by remote small targets, the target's information can be lost during signal processing. TBD(Track Before Detect) is an algorithm that performs target tracking without threshold for detection. That is, all sensor data is sent to the tracking system, which prevents the loss of the target's information by thresholding the signal intensity. On the other hand, using all sensor data inevitably leads to computational problems that can severely limit the application. In this paper, we propose an iterative Joint Integrated Probabilistic Data Association as a practical target tracking technique suitable for a low SNR multi-target environment with real time operation capability, and verify its performance through simulation studies.

• Journal of Environmental Science International
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• v.24 no.9
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• pp.1131-1138
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• 2015

Radon exhalation rates have been determined for samples of concrete, gypsum board, marble, and tile among building materials that are used in domestic construction environment. Radon emanation was measured using the closed chamber method based on CR-39 nuclear track detectors. The radon concentrations in apartments of 100 households in Seoul, Busan and Gyeonggi Provinces were measured to verify the prediction model of indoor radon concentration. The results obtained by the four samples showed the largest radon exhalation rate of $0.34314Bq/m^2{\cdot}h$ for sample concrete. The radon concentration contribution to indoor radon in the house due to exhalation from the concrete was $31.006{\pm}7.529Bq/m^3$. The difference between the prediction concentration and actual measured concentration was believed to be due to the uncertainty resulting from the model implementation.

• Journal of The Korean Association For Science Education
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• v.39 no.3
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• pp.321-335
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• 2019

This study aims to explore the influencing factors and the process of enhancing science self-efficacy (SSE) and to lay the foundation in understanding science self-efficacy of students. The ten categories related to the science self-efficacy were derived through the coding of the interview data based on the grounded theory and paradigm analysis to develop a process model of science self-efficacy improvement. Through the process analysis, four cyclical phases were found in the process of enhancing SSE: 'Entering into learning science' phase, 'enhancing SSE' phase, 'adjustment' phase, and 'result' phase. More specifically, the phase of 'entering into learning science' is where students choose science track and stimulated to construct SSE. The phase of 'enhancing SSE' is where students taking a science track actively learn science and perform science activities. In the phase of 'adjustment', students come to have successful performance about learning science and performing science activities by using diverse strategies. Finally, 'result' phase indicates different appearances of students depending on SSE levels. The phases were non-linear and periodically repeat depending on situation. The core category in the selective coding was indicated to be 'enhancing science self-efficacy.' Students' SSE form by learning science and performing science activities. These finding may help better understand the behavior of students who are taking a science track by facilitating effective science learning through the increase of their SSE levels.

• Journal of The Korean Association For Science Education
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• v.39 no.5
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• pp.613-624
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• 2019

The purpose of this study is to explore high school students' perception of the relationship among science, history, and history of science which is one of the career elective subjects in the 2015 revised science curriculum. This study compares students' perception before and after experiencing history of science course. To do this, data in the format of Venn diagram that students draw to represent their perception on relationship between the history of science, science, and history were collected. The collected data were inductively categorized. As a result of analyzing the Venn Diagram data, there are five different kinds of categories: 'History of science as an intersection of science and history,' 'History of science as an independent domain,' 'History of science as part of history,' 'History of science as part of science,' and 'History of science encompassing both science and history.' And there were 27 different sub-categories within the 5 categories. In addition, before taking the course on history of science, many students tended to regard science history as the intersection of science and history. However, after the course, students' perception changed and differed according to their affiliated academic track. For the humanities, history of science is perceived as part of history, and for the students in science track it is perceived as a part of science. Based on these findings, we suggest that history of science teaching-learning should be conducted that help high school students to experience a new perspective that is different from the curriculum in affiliated academic track.

• Journal of Radiation Protection and Research
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• v.38 no.1
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• pp.44-51
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• 2013

ICRP recommended that cosmic ray exposure to the pilot and cabin crew would be considered as an occupational exposure due to their relatively high exposure. Since 2012 with the Act No. 10908 (Natural radiation management), the guideline of cosmic ray exposure to the pilot was established in Korea. The applicability of the solid-state nuclear track detector for personal dose assessment of pilot and cabin crew was evaluated. Dose linearity and angle dependence of dosimeters to the neutron were evaluated by $^{252}Cf$ neutron emitting source. The track density has a good agreement with the dose ($r^2$=0.99) and highly dependent on the degree of an angular of the dosimeter to the neutron source. In addition, the dosimeters (SSNTD) were exposed to cosmic ray in an aircraft during its cruising for more than two months in collaboration with Airline Pilots Association of Korea. Although the correlation between the track density from aircraft cruising altitude and expected neutron dose is low, however RSNS dosimeter could be used for personal neutron dosimeter. For application of RSNS as a personal dosimeter for pilot and cabin crew, additional studies are required.

• Journal of Preventive Medicine and Public Health
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• v.54 no.6
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• pp.451-460
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• 2021

Objectives: This study aimed to determine the associations between parental depression and early childhood development among children aged 36 months to 59 months in Indonesia. Methods: From Indonesia's Basic Health Survey (RISKESDAS) 2018, this study included 6433 children aged 36 months to 59 months and their parents. Maternal and paternal depression was examined using the Mini International Neuropsychiatric Interview survey instrument, which was previously translated into Indonesian. The study also used the Early Child Development Index to measure child development and its 4 domains (cognitive, physical, socio-emotional, and learning). Multivariate logistic regression analysis was performed to determine the association between parental depression and early childhood development. Results: Overall, 10.3% of children aged 36 months to 59 months were off-track for development. After adjusting for biological, parental, and social characteristics, children born to parents with depression were found to be 4.72 times more likely to be off-track for development (95% confidence interval, 1.83 to 12.15). Conclusions: Children of depressed parents were more likely to be off-track for development. The findings highlight the need for early diagnosis and timely intervention for parental depression to promote early childhood development.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.3
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• pp.249-256
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• 2015

Quantitative Mokpo-Jeju undersea tunnel is currently on the basis plan for reviewing validation. As for the cross section shape for express boat of 105 km line, sing track two tube is being reviewed as the Euro tunnel equipped with service tunnel. Also, 10 carriage trains have been planned to operate 76 times for one way a day. So, in this study, quantitative risk assessment method is settled, which is intended to review the optimal space between evacuation connection hall of tunnel by quantitative risk analysis method. In addition to this, optimal evacuation connection hall space is calculated by the types of cross section, which are Type 3 (double track single tube), Type 1 (sing track two tube), and Type 2 (separating double track on tube with partition). As a result, cross section of Type 2 is most efficient for securing evacuation safety, and the evacuation connection space is required for 350 m in Type 1, 400 m in Type 2, and 1,500 m in Type3 to satisfy current domestic social risk assessment standard.

• Journal of Radiation Protection and Research
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• v.28 no.1
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• pp.43-50
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• 2003

This study describes a practical method for interpretation of bioassay results of inhaled uranium to assess the committed effective doses both for chronic and acute intake situations. Organs in the body were represented by a series of mathematical compartments for analysis of the behavior of uranium in the body according to the gastrointestinal track model, respiratory track model and biokinetic model recommended by the ICRP. An analytical solutions of the system of balance equations among the compartments were obtained using the Birchall's algorithm, and the urinary excretion function and the lung retention function of uranium were obtained. An initial or total intakes by intake modes were calculated by applying excretion and retention functions to the urinary uranium concentration and the lung burden measured with a lung counter. The dose coefficients given in ICRP 78 are used to estimate the committed effective doses from the calculated intakes.

• Journal of Digital Convergence
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• v.19 no.11
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• pp.555-564
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• 2021

This study aims to examine the relationship between the expertise of track and field coaches, the team atmosphere, and athletic satisfaction in elite sports. To achieve this research purpose, data were collected using questionnaires from 221 student athletes from junior high to university students registered with the Korea Association of Athletics Federation in 2021 and collected using Google online questionnaires in consideration of the pandemic situation. For data processing, frequency analysis, exploratory factor analysis, reliability analysis, correlation analysis, and multiple regression analysis were performed using the statistical program SPSS 22.0, and the following conclusions were drawn. First, it was found that the expertise of the athletics coaches had a positive (+) effect on the team atmosphere. Second, among the sub-factors of athletics coach expertise, only athlete management was found to have a negative (-) effect on daily life satisfaction, a sub-factor of athletic satisfaction. Third, it was found that among the sub-factors of the team atmosphere, only role characteristics and leader characteristics had a positive (+) effect on social approval satisfaction, a sub-factor of athletic satisfaction.

• Journal of Korean Association for Spatial Structures
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• v.4 no.3 s.13
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• pp.49-56
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• 2004

This paper predicted the shear deformation, such as strain of shear reinforcement and shear track width, of reinforced concrete (RC) members using Transformation Angle Truss Model (TATM) in order to apply to the shea, analysis of RC buildings. To check the validity of TATM for the shear deformation of RC beams, four RC beams with different shear span-to-depth ratios were cast, instrumented and tested. Observed results were compared with theoretical results by MCFT(Response-2000), RA-STM, FA-STM, and TATM. The proposed model, TATM, better predicted the relationships of the shear stress-strain of shear reinforcement and the shear stress-shear track width than other truss models.