• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.1
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• pp.59-67
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• 2005

This paper proposes method for determining exterior orientation parameters (EOPs) from the RPC mathematical camera model of the satellite image. SPOT satellite stereo pair is pre-tested using the proposed method. As results that, geopositioning errors are similar with those of the original EOPs. Differences between EOPs determined from the RPC and original EOPs were small. IKONOS Geo-level stereo pair is tested by the proposed method. Results of this method are compared with those of the RPC block adjustment method which have been verified in reported studies. Consequently, the proposed method showed accuracy similar to the RPC block adjustment method. The digital elevation models (DEMs) of sample area acquired by the two method almost did not have a difference.

• The Korean Journal of Applied Statistics
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• v.24 no.4
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• pp.575-586
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• 2011

In this paper, we study an asymptotic behavior of the finite-time ruin probability of the compound Poisson model in the case that the initial surplus is large. To compare an exact ruin probability with an approximate one, we place the focus on the exact calculation for the ruin probability when the claim size distribution is regularly varying tailed (i.e. exponential claims and inverse Gaussian claims). We estimate an adjustment coefficient in these examples and show the relationship between the adjustment coefficient and the safety premium. The illustration study shows that as the safety premium increases so does the adjustment coefficient. Larger safety premium means lower "long-term risk", which only stands to reason since higher safety premium means a faster rate of safety premium income to offset claims.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.142-142
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• 2022

Adjusting weather radar data is a prerequisite for its use in various hydrological studies. Effect of spatial variables are considered to adjust weather radar data in many of these researches. The existence of diverse topography in South Korea has increased the importance of analyzing these variables. In this study, some spatial variable like slope, elevation, aspect, distance from the sea, plan and profile curvature was considered. To investigate different topographic conditions, tried to use three radar station of Gwanaksan, Gwangdeoksan and Gudeoksan which are located in northwest, north and southeast of South Korea, respectively. To form the suitable fuzzy model and create the best membership functions of variables, ANFIS-PSO model was applied. After optimizing the model, the correlation coefficient and sensitivity of adjusted Quantitative Precipitation Estimation (QPE) based on spatial variables was calculated to find how variables work in adjusted QPE process. The results showed that the variable of elevation causes the most change in rainfall and consequently in the adjustment of radar data in model. Accordingly, the sensitivity ratio calculated for variables shows that with increasing rainfall duration, the effects of these variables on rainfall adjustment increase. The approach of this study, due to the simplicity and accuracy of this method, can be used to adjust the weather radar data and other required models.

• ETRI Journal
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• v.37 no.5
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• pp.845-855
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• 2015

To enable the coexistence of Licensed Assisted Access (LAA) and Wi-Fi in 5 GHz unlicensed bands, a new channel access mechanism is proposed. Accounting for the fairness between LAA and Wi-Fi, the proposed mechanism finds the optimal transmission time ratio by adaptively adjusting the transmission durations for LAA and Wi-Fi. In addition, we propose a new analytical model for the distributed coordination function of IEEE 802.11 through some modifications of conventional analytical models for saturation and non-saturation loads. By computing the activity ratio of Wi-Fi, the proposed analytical model is able to control the time ratio between LAA and Wi-Fi, which is required for practical implementation of the proposed access mechanism. Through numerical simulations, the proposed channel access mechanism is compared with conventional methods in terms of throughput and utility.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.10a
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• pp.13-18
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• 2004

In this study, a new method is proposed generating 3D wire-frames of building using the lowest level topology, points, which are input by human operators. Through the procedure, it is possible to make prediction occlusion points and generate the topology automatically among points, lines, surfaces from buildings. In order to adjust the error of initial values which are input manually, the least squares adjustment for model-image fitting is carried out using the edge information of aerial imagery. And also, model fitting procedure is done making all surfaces plane of buildings by the least squares adjustment. As a result of those procedure, 3D building models are refined similar to real figures of buildings.

• Communications for Statistical Applications and Methods
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• v.25 no.6
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• pp.577-590
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• 2018

Employing the covariance adjustment technique, we show that in the system of two seemingly unrelated multivariate regressions the estimator of regression coefficients can be expressed as a matrix power series, and conclude that the matrix series only has a unique simpler form. In the case that the covariance matrix of the system is unknown, we define a two-stage estimator for the regression coefficients which is shown to be unique and unbiased. Numerical simulations are also presented to illustrate its superiority over the ordinary least square estimator. Also, as an example we apply our results to the seemingly unrelated growth curve models.

• Journal of radiological science and technology
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• v.44 no.6
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• pp.591-597
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• 2021

In the present study, we developed virtual reality education contents for radiation generator on radiation education field. The radiation generator was divided by module and even the X-ray exposure part was manufactured in detail for designing 3D models. The mechanical details of the X-ray exposure part, the function of adjusting field size of the X-ray, the function of moving the exposure part, and the demonstrating the principle of the X-ray tube were applied. For developing VR contents, the Unreal Engine was used. To evaluate the usefulness of virtual reality content, we used t-test by SPSS. The group used the simulator showed significantly higher levels of understanding of X-ray generation, X-ray irradiation unit composition, irradiation field size adjustment, irradiation unit position adjustment, and overall composition and function. We believe that this VR contents will be used well with radiation safe environment.

• The Journal of Society for e-Business Studies
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• v.4 no.3
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• pp.63-76
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• 1999

Internet-based electronic trade has been growing fast. But most users are not yet familiar with the system and find it very difficult to purchase and sell the products in the cyber market place. To handle these problems, agent-based virtual market place system has been proposed where agents instead of individuals participate in trading of goods. Most of the proposed models have been in the two general categories. The first is the direct transaction among sellers and buyers, and the second is the agent-based transaction. However, the transaction is not fair and the best deal can't be guaranteed for both models. In this paper, we propose a new broker based synchronous transaction algorithm which is fair to both parties and guarantees the best deal. Our algorithm is implemented using Visual C++ and the experimental results show that our method is better than the two traditional transaction models in every performance metrics, Number of transactions are increased up to 21% and price adjustment is up to 280% better for some transactions.

• Korean Journal of Social Welfare
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• v.55
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• pp.255-281
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• 2003

This study sought to explore factors affecting the adjustment of children living in shelters for battered women. Specifically, the impact of domestic violence on children's internal and external adjustment was examined using data from two samples: children who were exposed to marital violence and those who did not have violent experience. Likewise, this study identified the variables that distinguished the "resilient" children from the maladjusted group. The pathways by which protective factors considerably affected children's adjustment were also investigated. A total of 72 children in a women's shelter and their mothers and 76 children in nonviolent homes and their mothers were considered. ANOVA, logistic regression models, and path analysis were employed to process the data. Results revealed that children of battered women demonstrated a high frequency of aggressive and delinquent behaviors and had poor academic achievement and depressive mood compared to children coming from nonviolent homes. Likewise, children who were exposed to marital violence and were physically abused themselves were more likely show aggressive or delinquent behaviors compared to those who only witnessed marital violence. In addition, social support was found to be a protective factor in academic achievement. Predictors of delinquent behavior included the mother's education and income as well as the children's age and social support. Factors related to children's self-esteem included the social support and the mother's self-esteem. Moreover, woman battering has a direct effect on children's adjustment as well as indirect effect through children's academic achievement and self-esteem. Finally, woman battering indirectly affected children's academic achievement through the mother's depression or the child's social support. Based on these findings, practical implications of enhancing children's adjustment were discussed.

• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.794-807
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• 2021

The purpose of this study is to examine the effect of family poverty on the school adjustment of multi-cultural adolescents in Korea. For this purpose, the 7th data of Multi-cultural Adolescents Panel Study(MAPS) was used and the OLS multiple regression models ware applied. to the analyses. From the result of the OLS model analyses, we found out that family poverty affect significantly on the school adjustment of multi-cultural adolescents. Especially, family poverty has the significant negative(-) effects on academic achievement and friend relationships. These results of this study show that family poverty is an important factor influencing the school adjustment of multi-cultural adolescents. And they confirm that family poverty during period of the adolescent has an important meaning and influence on the aspect of school adjustment as to the multi-cultural adolescents. Implications of this study may be that policy attentions are necessary to not only multi-cultural characteristics but also family background such as poverty in oder to improve the school adjustment of the multi-cultural adolescents. In addition, results of this study suggest that more special support and interventions are requested to the multi-cultural adolescents from poverty families who are suffering dual difficulties such as multi-cultural problems and poverty problem.