• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.549-552
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• 2015

The galactic magnetic field (GMF) and the intergalactic magnetic field (IGMF) affect the propagation of ultra-high energy cosmic rays (UHECRs) from the source to us. Here we examine the influences of the GMF/IGFM and the dependence of their sky distribution on galactic latitude, b. We analyze the correlation between the arrival direction (AD) of UHECRs observed by the Pierre Auger Observatory and the large-scale structure of the universe in regions of sky divided by b. Specifically, we compare the AD distribution of observed UHECRs to that of mock UHECRs generated from a source model constructed with active galactic nuclei. Our source model has the smearing angle as a free parameter that reflects the deflection angle of UHECRs from the source. The results show that larger smearing angles are required for the observed distribution of UHECRs in lower galactic latitude regions. We obtain, for instance, a $1{\sigma}$ credible interval for smearing angle of $0^{\circ}{\leq}{\theta}_s{\leq}72^{\circ}$ at high galactic latitudes, $60^{\circ}$ < $\left|{b}\right|{\leq}90^{\circ}$, and of $75^{\circ}{\leq}{\theta}_s{\leq}180^{\circ}$, $-30^{\circ}{\leq}b{\leq}30^{\circ}$, at low galactic latitudes, respectively. The results show that the influence of the GMF is stronger than that of the IGMF. In addition, we can estimate the strength of GMFs by these values; if we assume that UHECRs would have heavier nuclei, the estimated strengths of GMF are consistent with the observational value of a few ${\mu}G$. More data from the future experiments may make UHECR astronomy possible.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.5
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• pp.41-54
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• 2018

A method to account a detention in a rice paddy field in hydrologic modeling was tested at plot and watershed scales. Hydrologic Simulation Program - Fortran (HSPF) and its one of surface runoff modeling method, i.e Surface-Ftable, were used to simulate a inundated condition in a rice paddy culture for a study plot and basins in Saemangeum watershed. Surface-Ftable in HSPF defines surface runoff ratio with respect to surface water depth in a pervious land segment, which can be implemented to the feature of water management in a rice paddy field. A Surface-Ftable for paddy fields in Saemangeum watershed was developed based on the study paddy field monitoring data from 2013 to 2014, and was applied to Jeonju-chun and Jeongeup-chun basins which comprise 12% and 22% of paddy fields in the basins, respectively. Four gaging stations were used to calibrate and validate the watershed models for the period of 2009 and 2013. Model performed 7.13% and 9.68% in PBIAS, and 0.94 and 0.90 in monthly NSE during model calibrations at Jeonju and Jeongeup stations, respectively, while the models were validated its applicability at Hyoja and Gongpyung stations. The comparison of results with and without considering detention effect of paddy fields confirmed the validity of the Surface-Ftable method in modeling watersheds containing rice paddy fields.

• Journal of Practical Engineering Education
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• v.16 no.3_spc
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• pp.309-325
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• 2024

The purpose of this study was to develop self-evaluation criteria for objective verification and performance analysis of LINC 3.0. To achieve this goal, evaluation indicators in the fields of human resources development and skill development and commercialization were developed and their validity was verified. We investigated previous evaluation-related studies and similar cases to construct an evaluation model and system and develop indicators. The validity of the developed evaluation indicators was secured through two round Delphi surveys. As a result of the research, LINC 3.0 evaluation indicators can be divided into the field of human resources development and skill development and commercialization. A total of 66 evaluation indicators were developed. CIPP in the field of human resources development was developed with 13 categories and 38 evaluation indicators, and CIPP in the field of skill development and commercialization was developed with 12 categories and 28 evaluation indicators. The significance of this study is that it suggests a way to increase the objective verification and validity of the university industry-academia cooperation model by developing self-evaluation indicators for the LINC 3.0 project. The evaluation indicators developed in the research need to be continuously upgraded based on field usability, and it is necessary to improve the quality and competitiveness of university education by sharing and spreading excellent affairs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.171-176
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• 2016

This paper proposes road safety facilities applying Hot-dip zinc-aluminum-magnesium alloy-coated steel sheets and coils to reduce the loss of function caused by the corrosion of steel in the service state. Vehicle crash simulations and full-scale crash tests were carried out to provide reliable information on evaluating the crash performance with the products of road safety facilities built with hot-dip zinc-aluminum-magnesium alloy-coated steel. From the results of the simulations and full-scale crash tests, the impact behaviors evaluated by the three-dimensional crash simulations considering the strain-rate dependency in a constitutive model were similar to those obtained from the full-scale crash test results. The full-scale crash test results met the crashworthiness evaluation criteria; hence, the proposed bridge barrier in this paper is ready for field applications.

• Journal of the Korea Society for Simulation
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• v.22 no.2
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• pp.63-71
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• 2013

Developing future weapons systems has become increasingly complicated and costly. There, modeling and simulation techniques have been highly interested in developing the defense systems. Modeling and simulation techniques provide a means to simulate military training, strategies, military doctrines, and weapons acquisition. In this paper, we proposed a small scale engagement scenario generation method for engagement M&S model. Generated scenario is one of critical factors in the field of commander training, operational analysis, and tactical evaluation. The objective of this paper is to develop a scenario generation method for small scale engagement using the FSA(Finite State Automata) and DFS(Depth First Search) algorithm. The proposed method is verified using a one-on-one combat engagement scenario between assault ship and reconnaissance ship. Also, we are visualized using Delta3D$^{TM}$.

• Journal of The Korean Association For Science Education
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• v.4 no.2
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• pp.57-63
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• 1984

An inquiry approach in teaching science has been advocated by many science educators for the past few decades, and most elementary and secondary science curricula have incorporated it in varying degrees. It has been proven in recent studies, however, that there exists considerable discrepancy between the expectation of outcomes of the inquiry approach and the actuality. This in part implies that there is a somewhat urgent need for the systematic evaluation of the approach in teaching science. The purpose of this study is to develop a comprehensive instrument for evaluating inquiry teaching approaches embedded in science curricular materials. To develop a more valid and reliable instrument a set of empirical data was used in the developmental procedure, and most of the previous studies regarding inquiry teaching method and inquiry evaluation were consulted. The inquiry evaluation method developed in this study, called the Scientific Inquiry Evaluation Inventory (SIEI), is composed of three parts: (1) analyzing and coding each science process task of inquiry activity; (2) evaluating each inquiry activity as a whole; and (3) evaluating each science laboratory curriculum as a whole. The first part of the instrument consists of twenty science process categories and thirty subcategories grouped into four sections: (1) gathering and organizing data; (2) interpreting and analyzing data; (3) synthesizing results and evaluation; and (4) hypothesizing and designing an experiment. The science process categories are arranged according to the level of difficulty, psychological level of thinking, degree of creativity demand, and the model of the process of scientific inquiry, which is also developed in the study. The second part of the instrument contains four evaluation scales of inquiry activity: (1) competition/cooperation scale; (2) discussion scale; (3) openness scale; and (4) inquiry scope scale. And the last part consists of three methods for evaluating a science laboratory curriculum as a whole: (1) inquiry pyramid; (2) inquiry index; and (3) difficulty index. The instrument is designed to be used by teachers, science curriculum developers and science education evaluators for the purpose of diagnosing the nature and appropriateness of scientific inquiry introduced in secondary science curricular materials, especailly in laboratory work and field work.

• The KIPS Transactions:PartD
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• v.16D no.4
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• pp.613-620
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• 2009

It is necessary to develop a system of judging whether or not the parts are defective easily at low cost, especially in a small scale factory which manufactures a large variety of products in small amounts. To develop such system, we require to recognize objects using human's cognitive ability under various circumstances. Human's high intelligence originates mostly from neocortex of human brain. The HTM theory, which is proposed by Jeff Hopkins, is one of the recent researches to model the operation principle of neocortex. In this paper we developed PRESM (Parts image REcognition System for small scale Manufacturing industry) system based on the HTM theory to judge badness of manufactured products. As a result of application to the real field of workplace environments we identified the superiority of our recognition system.

• Journal of Digital Convergence
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• v.19 no.11
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• pp.415-424
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• 2021

The purpose of the current study is to to examine the psychometric properties of the Subjective Agingwell Scale (SAS). Three hundred and forty two elders completed the SAS and the scales assessing subjective well-being, optimism, perceived control and adhering to healthy behavior. The 11-item SAS that displays good internal reliability and good fit to the three-factor model consisting of cognitive satisfaction, positive affect, and spiritual fullness. Correlational analyses with measures of subjective agingwell, subjective well-being, and optimism provide evidence for construct validity. Moreover, the results from hierarchical regression analyses show criterion-related validity of the SAS. This scale could be used in the field to measure and promote subjective agingwell.

• Journal of Radiation Protection and Research
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• v.48 no.1
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• pp.28-43
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• 2023

Background: High-fidelity meteorological data is a prerequisite for the realistic simulation of atmospheric dispersion of radioactive materials near nuclear power plants (NPPs). However, many meteorological models frequently overestimate near-surface wind speeds, failing to represent local meteorological conditions near NPPs. This study presents a new high-resolution (approximately 1 km) meteorological downscaling method for modeling short-range (< 100 km) atmospheric dispersion of accidental NPP plumes. Materials and Methods: Six considerations from literature reviews have been suggested for a new dynamic downscaling method. The dynamic downscaling method is developed based on the Weather Research and Forecasting (WRF) model version 3.6.1, applying high-resolution land-use and topography data. In addition, a new subgrid-scale topographic drag parameterization has been implemented for a realistic representation of the atmospheric surface-layer momentum transfer. Finally, a year-long simulation for the Kori and Wolsong NPPs, located in southeastern coastal areas, has been made for 2016 and evaluated against operational surface meteorological measurements and the NPPs' on-site weather stations. Results and Discussion: The new dynamic downscaling method can represent multiscale atmospheric motions from the synoptic to the boundary-layer scales and produce three-dimensional local meteorological fields near the NPPs with a 1.2 km grid resolution. Comparing the year-long simulation against the measurements showed a salient improvement in simulating near-surface wind fields by reducing the root mean square error of approximately 1 m/s. Furthermore, the improved wind field simulation led to a better agreement in the Eulerian estimate of the local atmospheric dispersion. The new subgrid-scale topographic drag parameterization was essential for improved performance, suggesting the importance of the subgrid-scale momentum interactions in the atmospheric surface layer. Conclusion: A new dynamic downscaling method has been developed to produce high-resolution local meteorological fields around the Kori and Wolsong NPPs, which can be used in short-range atmospheric dispersion modeling near the NPPs.

• Ocean and Polar Research
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• v.25 no.1
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• pp.63-74
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• 2003

The build-up of the heat field in shallow coastal water due to a point source has been investigated using an analytical solution of a time-integral form derived by extending the solutions by Holley(1969) and also presented in Harleman (1971). The uniform water depth is assumed with non-isotropic turbulent dispersion. The alongshore-flow is assumed to be uni-directional, spatially uniform and oscillatory. Due to the presence of the oscillatory alongshore-flow, the heat build-up occurs in an oscillatory manner, and the excess temperature thereby fluctuates in that course and even in the quasi-steady state. A series of calculations reveal that proper choices of the decay coefficient as well as dispersion coefficients are critical to the reliable prediction of the excess temperature field. The dispersion coefficients determine the absolute values of the excess temperature and characterize the shoreline profile, particularly within the tidal excursion distance, while the decay coefficient determines the absolute value of the excess temperature and the convergence rate to that of the quasi-steady state. Within the e-folding time scale $1/k_d$ (where $k_d$ is the heat decay coefficient), heat build-up occurs more than 90% of the quasi-steady state values in a region within a tidal excursion distance (L), while occurs increasingly less the farther we go to the downstream direction (about 80% at 1.25L, and 70% at 1.5L). Calculations with onshore and offshore discharges indicate that thermal spreading in the direction of the shoreline is reduced as the shoreline constraint which controls the lateral mixing is reduced. The importance of collecting long-term records of in situ meteorological conditions and clarifying the definition of the heat loss coefficient is addressed. Interactive use of analytical and numerical modeling is recommended as a desirable way to obtain a reliable estimate of the far-field excess temperature along with extensive field measurements.