• Journal of Mechanical Science and Technology
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• v.20 no.4
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• pp.437-446
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• 2006

Laser vision inspection systems are becoming popular for automated inspection of manufactured components. The performance of such systems can be enhanced by improving accuracy of the hardware and robustness of the software used in the system. This paper presents a new approach for enhancing the capability of a laser vision system by applying hardware compensation and using efficient analysis software. A 3D geometrical model is developed to study and compensate for possible distortions in installation of gantry robot on which the vision system is mounted. Appropriate compensation is applied to the inspection data obtained from the laser vision system based on the parameters in 3D model. The present laser vision system is used for dimensional inspection of car chassis sub frame and lower arm assembly module. An algorithm based on simplex search techniques is used for analyzing the compensated inspection data. The details of 3D model, parameters used for compensation and the measurement data obtained from the system are presented in this paper. The details of search algorithm used for analyzing the measurement data and the results obtained are also presented in the paper. It is observed from the results that, by applying compensation and using appropriate algorithms for analyzing, the error in evaluation of the inspection data can be significantly minimized, thus reducing the risk of rejecting good parts.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1814-1821
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• 2012

As a new Korean grid code which includes LVRT requirement to wind farm of which capacity is greater than 20MW is activated in 2012, this paper developed the analytical model of the Korean LVRT for the simulation based feasibility study of the wind farm interconnection into power systems. The developed model of the LVRT is verified by applying it into the performance evaluation of the wind farm interconnected power systems and the effect of Korean LVRT is analyzed through case studies considering typical disturbances of power systems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.10
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• pp.4995-5014
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• 2018

As the area covered by the CPS grows wider, agencies such as public institutions and critical infrastructure are collectively measuring and evaluating information security capabilities. Currently, these methods of measuring information security are a concrete method of recommendation in related standards. However, the security controls used in these methods are lacking in connectivity, causing silo effect. In order to solve this problem, there has been an attempt to study the information security management system in terms of maturity. However, to the best of our knowledge, no research has considered the specific definitions of each level that measures organizational security maturity or specific methods and criteria for constructing such levels. This study developed an information security maturity model that can measure and manage the information security capability of critical infrastructure based on information provided by an expert critical infrastructure information protection group. The proposed model is simulated using the thermal power sector in critical infrastructure of the Republic of Korea to confirm the possibility of its application to the field and derive core security processes and goals that constitute infrastructure security maturity. The findings will be useful for future research or practical application of infrastructure ISMSs.

• Journal of Internet Computing and Services
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• v.20 no.5
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• pp.79-86
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• 2019

This paper is an overview of key elements of Korea National Open University's smart mobile learning system, and an attempt to evaluate its main services relative to the FRAME model and the Mobile Learning Development Model for distance learning in higher education. KNOU improved its system architecture to one based on xMOOC e-learning content delivery while also upgrading its PC-based online/mobile learning services to facilitate an easier and more convenient access to lectures and for better interactivity. From the users' viewpoint, the upgraded 'U-KNOU Campus' allows for a more integrated search capability coupled with better course recommendations and a customized notification service. Using the new system, the students can access not only the school- and peer-issued messages via online bulletin boards but also share information and pose questions to others including to the school faculty/officials and system administrators. Additionally, a new mobile payment method has been incorporated into the system so that the students can select and pay for additional courses from anywhere. In spite of these advances, the issue of device usability and content development remain; specifically U-KNOU Campus needs to improve its instructor-learner and learner-to-learner interactivity and mobile evaluation interface.

• Nuclear Engineering and Technology
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• v.53 no.12
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• pp.3930-3943
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• 2021

To improve the capability of the SAS4A code, which simulates the initiating phase of core disruptive accidents for MOX-fueled Sodium-cooled Fast Reactors (SFRs), the authors have investigated in detail the physical phenomena under unprotected loss-of-flow (ULOF) conditions in a previous paper (Kawada and Suzuki, 2020) [1]. As the conclusion of the last article, fuel stub motion, in which the residual fuel pellets would move toward the core central region after fuel pin disruption, was identified as one of the key phenomena to be appropriately simulated for the initiating phase of ULOF. In the present paper, based on the analysis of the experimental data, the behaviors related to the stub motion were evaluated and quantified by the author from scratch. A simple model describing fuel stub motion, which was not modeled in the previous SAS4A code, was newly proposed. The applicability of the proposed model was validated through a series of analyses for the CABRI experiments, by which the stub motion would be represented with reasonable conservativeness for the reactivity evaluation of disrupted core.

• Journal of Korea Water Resources Association
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• v.49 no.2
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• pp.165-175
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• 2016

In order to examine the applicability, the evaporation estimation approaches based on solar radiation are classified into 3 different model groups (Model groups A, B, and C) in this study. Each group is tested in the 6 study stations (Seoul, Daejeon, Jeonju, Busan, Mokpo, and Jeju). The model parameters of each model group are estimated and verified with measured pan evaporation data. The applicability of verified model groups are compared with results of Penman (1948) combination approach. Nash-Sutcliffe (N-S) efficiency coefficients greater than 0.663 in all study stations indicate satisfactory estimates of evaporation. On the other hand, in the model verification process, N-S efficiency coefficients greater than 0.526 in all study stations indicate also satisfactory estimates of evaporation. However, N-S efficiency coefficients in all study cases except Model groups B and C in Busan are less than those of Penman (1948) combination approach. Therefore, it is concluded in this study that the evaporation estimation approaches based on solar radiation have capability to replace Penman (1948) combination approach for the estimation of evaporation in case that some meteorological data (wind speed, relative humidity) are missing or not measured.

• Journal of Wetlands Research
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• v.16 no.2
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• pp.235-243
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• 2014

According to the "Safety Evaluation Detailed Instructions (Dam)", precise safety inspection is carried out for dams that exceed a certain scale. However, as the Hydrological Safety Evaluation from various evaluation standards is designed to evaluate the safety of existing dams considering PMF, the evaluation is much less applicable for most agricultural reservoirs. Therefore, the Hydrological Safety Guidelines for agricultural reservoirs are expected to be re-evaluated considering the diverse risk factors with the coefficient model and AHP in this study. The coefficient model has been developed by selecting the hydrological safety superordinate subordinate evaluation factors to reflect diverse risk factors of agricultural reservoirs. After calculating the sum of indicators score for each evaluation factors, validation procedures were performed for the questionnaire which a panel answered. The practical coefficient has eventually been estimated for the hydrological safety evaluation considering the diverse risk factors. The conclusions acquired based on the study done are that both most agricultural reservoirs were classified as flood defense capability is insufficient and agricultural reservoirs which meet embankment-freeboard standards considering PMF was overestimated.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.2
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• pp.137-147
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• 2012

GRS is an effective urban ecology restoration technique that can manage a variety of environmental functions such as ecological restoration, rainwater spill control and island heat effect from a low-impact development standpoint that can be utilized in new construction and retrofits. Recently, quantitative evaluation studies, both domestic and abroad, in the areas related to these functions, including near-earth surface climate phenomenon, heavy rainwater regulation, thermal environment of buildings, have been actively underway, and there is a trend to standardize in the form of technological standards. In particular, centered on the advanced European countries, studies of standardizing the specific insulation capability of buildings with green system that comprehensively includes the green roof, from the perspective of replacing the exterior materials of existing buildings, are in progress. The limitation of related studies in the difficulties associated with deriving results that reflect material characteristics of continuously evolving systems due in part to not having sufficiently considered the main components of green system, mechanisms of vegetation, soils. This study attempts to derive, through EnergyPlus, the effects that the vegetation-related indicators such as vegetation height, FCV, etc. have on building energy load, by interpreting vegetation and soil mechanisms through plant canopy model and using an ecological standard indicator LAI that represent the condition of plant growth. Through this, the interpretations that assume green roof system as simple heat insulation will be complemented and a more practical building energy performance evaluation method that reflects numerical methods for heat fluxes phenomena that occur between ecology restoration systems comprised of plants and soil and the ambient space.

• Journal of the Korea Convergence Society
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• v.12 no.10
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• pp.249-254
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• 2021

This study is about the class model that can demonstrate the modeling ability using the spatial perception capability on basic modeling required for jewelry design majors and the most important perspective method in jewelry design. The outputs were obtained by presenting the topics for creative activities to students after theoretical explaining how to present a spatial sense and presenting practical classes on basic shapes, stereoscopic shapes and perspective methods. While the existing basic molding classes were only practical classes, this study presented students with a class model that allows them to use creativity, basic perspective, and spatial sense together. And it was found out evaluation method that both students and professors can relate to each other through the intensive education effects and clear evaluation standards. I hope that this paper will continue to study more diverse materials and convergent class models.

• Korean Journal of Construction Engineering and Management
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• v.17 no.2
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• pp.118-126
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• 2016

International construction market have quantitatively increased and have reached up to 700 Bil. US$ through active effort of construction firms and government. In spite of this increase, substantiality issue has been constantly disputed due to qualitative problems such as lack of capability and technical shortage. To overcome these problems, many methods in performing quantitative growth and qualitative substantiality of overseas construction are being researched which showed that selection of subcontractors in general contractor is regarded as a very important success factor. However, it is difficult to make a reasonable decision for selecting the subcontractors due to the lack of evaluation standards and reliability. This study proposes an improved evaluation system through adjustment of the evaluation indicators using correlations analysis and multiple regression analysis with pre-qualification and performance evaluation of 121 firms in 6 countries.