• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.3
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• pp.111-119
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• 1987

Scale effects of stability, run-up, run-down and reflection of layered coastal structures are investigated through the experiments with 7 kinds of hydraulic scale models. The occurrence mechanism and the control method of scale effects are also discussed. As a result, it is found that the similarity of permeability of inner layers plays an important role in the occurrence of scale effects, which has been neglected in the most of conventional model tests. To assure the best scale effects for permeable coastal structures, control of Reynolds numbers of the porous media flow in each layer is recommended. It is also found that Reynolds numbers in revetment, filter, and core layer must be greater than $2{\times}10^4$, $3{\times}10^3$, and $1{\times}10^3$, respectively.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.10a
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• pp.40-41
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• 2009

In general, ships are towed to keep the safe operations in harbor or channel by tug boats. Due to increase in ocean traffic, many accidents are happened in harbor or channel in these days. Therefore it is necessary to predict manoeuvrability of tug-barge system, and to assure the safety of that system. Turg-barge system is composed of tug boat, barge, and towing cable, connecting both ships. Manoeuvring equations of tug-barge system are suggested, and the scopes of model tests are discussed to establish the mathematical models for tug boats in this paper.

• Journal of Korea Water Resources Association
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• v.44 no.5
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• pp.339-350
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• 2011

This study developed a climate informed Bayesian nonstationary frequency model which allows us to forecast seasonal summer rainfall at Nakdong River. We constructed a 37-year summer rainfall data set from 10 weather stations within Nakdong river basin, and two climate indices from sea surface temperature (SST) and outgoing longwave radiation (OLR) were derived through correlation analysis. The selected SST and OLR have been widely acknowledged as a climate driver for summer rainfall. The developed model was applied first to the 2010-year summer rainfall (888.1 mm) in order to assure ourself. We demonstrated model performance by comparing posterior distributions. It was confirmed that the proposed model is able to produce a reasonable forecast. The forecasted value is about 858.2 mm, and the difference between forecast and observation is about 30 mm. As the second case study, 2011-year summer rainfall forecast was made using an observed winter SSTs and an assumed 50% value of OLRs. The forecasted value is 967.7 mm and associated exceedance probability over average summer rainfall 680 mm is 92.9%. In addition, 50-year return period for summer rainfall was projected through the nonstationary frequency model. An exceedance probability over 1,400 mm corresponding to the 50-year return level is about 73.7%.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.4
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• pp.347-354
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• 2001

SCR (Selective Catalytic Reduction) process is presently considered as one of the most effective techniques for removing nitric oxides from exhaust gases. In this study, based on the conceptually designed SCR reactor of 500 MW coal fired power plant. a reduced scale (1/20) SCR reactor model was made to analyze the flow pattern in front of catalyst layer according to the guide vane's design factors such as the number, interval, and angle of vanes. The results of the test were compared to those numerical simulation in order to assure the reliability of two methods. On the basis of our study. the critical Reynolds number (2.0$\times$ 10$^{5}$ ) was proposed for ensuring the similarity between the reduced scale model and the prototype of SCR reactor. Optimum design parameters of guide vanes were determined as follows, 4 vanes, the first vane angle of 93$^{\circ}$, and the vane intervals of 0.85 S/n, 1.05 S/n, 1.1 S/n, 1.0S/n, 1.0S/n (S: the distance of duct, n: the number of guide vanes). The excellent agreement between the results of the numerical simulation and the reduced scale model provides the validation of two methods for prediction of flow through SCR reactor.

• Journal of Ocean Engineering and Technology
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• v.13 no.2 s.32
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• pp.138-146
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• 1999

The viscous flow around a ship hull is calculated by the use of RANS(Reynolds-averaged Navier-Stokes) solver. Reynolds stresses are midelled by using the k-${epsilon}$ turbulence model and the law is applied near the body. Body fitted corrdinates are introduced for the treatment of the complex boundary of the ship hull form and the governing equations in the physical domain transformed into ones in the computational domain. The transformed equations are numerically solved by an employment of FVM(Finite Volume Method). SIMPLE(Semi-Implicit Pressure Linked Equation) method is adopted in the calculation of pressure and the solution of the sidcretized equation is obtained by the line-by-line method with the use of TDMA(Tri-Diagonal Matrix Algorithme). To assure the proprietty of this computing method, HSVA tanker and Dyne hull are calculated ar both model and ship scale Reynolds number. Their reaults of pressure distributions on fore and aft body, axial velocity contours and transverse velocity velocity vectors and viscous resistance coefficients are compared with other's experiments and calculations.

• Journal of KIISE:Software and Applications
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• v.37 no.3
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• pp.222-232
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• 2010

The purpose of this investigation was to help university professors for making their systematic design of instruction easily and scientifically. To increase of learner's studying ability, the systemic instructional design is imperative. But most of university professors could not get proper experiences to know develop instructional design system, specially to develop web-based system. This new system made it possible to select the proper instructional methods and the media type suitable for the corresponding data. And also every professor who is involved to know this system, can put informations for the target learners, learning contents and learning objectives, and present the proper media types and the many different conditions in the process of the each instructional design process. Finally, the results of the learner's study will be effective and professors showed their positive opinions for the using of the system.

• The Journal of the Korea Contents Association
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• v.10 no.3
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• pp.423-435
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• 2010

The number of professionals in the science and engineering fields decreases all over the world. Especially in Korea, the declining rate of both the laborable and economically active population, aging of the population at the fastest level, and the declining birth rate make it tougher to secure the core brains of the future. After speculation of all programs above, some common factors have been derived and every program appeared to have the support for each level of inducing, caring, and utilizing. And the means of support could be categorized into the financial, legal, and social aspects. Lastly, a logical tool called Systems Thinking has been applied to the FLS Conditions and the Brain Internalization Process to assure the efficacy and applicability of the models. This is to minimize any de facto side effects by analyzing all 'feedback loops' stemming from the models. And the 'causal loop diagrams' have been utilized to come with the complementary measures. Such series of verification could convince the virtue of the models. Governments and universities can make use of the FLS Conditions and the Brain Internalization Process so the policies or plans about the foreign brains can be built in a uniformized and consistent framework. I hope, as a result, the international competency of Korea to induce and utilize the foreign brains be raised with the constant and standardized formality.

• Korea journal of population studies
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• v.23 no.2
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• pp.143-166
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• 2000

This paper attempts to explore the relation between health care availability and child mortality among ethnic groups with different cultural traditions of sex preference. Micro-data from the 1990 Census of China for Yanbian and Xishuangbanna Prefectures are used. Based on the analysis of data for Koreans, Hans, and Dais in these prefectures, a new model explaining the relation between sex preference, health care. and differentials in child mortality is proposed in this paper. In societies, where health care is easily available, the level of child mortality is not likely to be a function of sex preference. In societies where there is little availability of health care, members of ethnic groups with strong sex preference do whatever possible to assure survival of their children of the preferred sex. But actions to assure survival of children of the sex not preferred by their parents depend on the costs involved and other considerations. Therefore, the level of child mortality for the preferred sex is likely to be substantially lower than that of the not-preferred sex. However, as availability of health care improves and the cost of obtaining health care becomes lower, survival of children of the not-preferred sex are likely to improve. It is generally agreed that Koreans and Hans show strong son preference, while Dais have cultural traditions of daughter preference. In Yanbian, where virtually all children receive health care whenever it is needed, Korean females and Han females show lower child mortality than their male counterparts, although the difference is not found to be significant for Koreans. In Xishuangbanna, where there is little availability of health care, Dai males show markedly higher child mortality than Dai females, and Han females have higher child mortality than Han males. However, small improvements in the availability of health care in Xishuangbanna translate into substantial improvements in survival of male children for Dais, and survival of female children for Hans.

• Journal of the Korean GEO-environmental Society
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• v.8 no.5
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• pp.39-46
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• 2007

In this study, the centrifuge tests were performed to investigate the lateral flow behavior and stability of the ground improved by SCP. The centrifuge tests were fulfilled in the case of the back of abutment filled by EPS (case 1) and soil (case 2), and the potentiometer was installed on the abutment and embankment to measure the vertical and horizontal displacement at the top of abutment. As a result, the vertical displacement measured at the back of abutment was maximum 2.1 m, which was about 12% if compared with the height of embankment. In the case of the back of abutment filled by soil, the vertical and horizontal displacement measured at the top of abutment was 10 cm and 1.1 m, respectively, which exceeded the allowable horizontal displacement. On the other hand, in the case of the back of abutment filled by EPS, the vertical displacement of abutment did nor occur and the horizontal displacement was 1.4 cm. Therefore, the effect of SCP improvement with EPS method adopted to prevent the lateral flow and assure the stability of embankment on the soft ground was far superior.

• Journal of Korea Technology Innovation Society
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• v.19 no.2
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• pp.254-279
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• 2016

Recently, with the conversion towards knowledge-based economy era, the importance of the evaluation for patent valuation has been growing rapidly because technology transactions are increasing with the purpose of practically utilizing R&D outcomes such as technology commercialization and technology transfer. Nevertheless, there is a lack of research on determinants of patent valuation by analyzing technology transactions due to the difficulty of collecting data in practice. Hence, to suggest quantitative determinants for the patent valuation which could be applied to scoring methods, 15 patent valuation models domestically and overseas are analysed in order to assure the objectiveness for subjective results from qualitative methods such as expert surveys, comparison assessment, etc. Through this analysis, the important 6 common determinants are drawn and patent information is matched which can be used as proxy variables of individual determinant factors by advanced researches. In addition, to validate whether the model proposed has a statistically meaningful effect, total 517 technology transactions are collected from both public and private technology transaction offices and analysed by multiple regression analysis, which led to significant patent determinant factors in deciding its value. As a result, it is herein presented that patent connectivity(number of literature cited) and commercialization stage in market influence significantly on patent valuation. The meaning of this study is in that it suggests the significant quantitative determinants of patent valuation based on the technology transactions data in practice, and if research results by industry are systematically verified through seamless collection of transaction data and their monitoring, we would propose the customized patent valuation model by industry which is applicable for both strategic planning of patent registration and achievement assessment of research projects (with representative patents).