• Journal of Korean Society of Disaster and Security
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• v.15 no.1
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• pp.1-12
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• 2022

An automatic optimization technique is used to estimate the optimal parameters of the hydrologic model, and different hydrologic response results can be provided depending on objective functions. In this study, the parameters of the event-based rainfall-runoff model were estimated using various objective functions, the reproducibility of the hydrograph according to the objective functions was evaluated, and appropriate objective functions were proposed. As the rainfall-runoff model, the storage function model(SFM), which is a lumped hydrologic model used for runoff simulation in the current Korean flood forecasting system, was selected. In order to evaluate the reproducibility of the hydrograph for each objective function, 9 rainfall events were selected for the Cheoncheon basin, which is the upstream basin of Yongdam Dam, and widely-used 7 objective functions were selected for parameter estimation of the SFM for each rainfall event. Then, the reproducibility of the simulated hydrograph using the optimal parameter sets based on the different objective functions was analyzed. As a result, RMSE, NSE, and RSR, which include the error square term in the objective function, showed the highest accuracy for all rainfall events except for Event 7. In addition, in the case of PBIAS and VE, which include an error term compared to the observed flow, it also showed relatively stable reproducibility of the hydrograph. However, in the case of MIA, which adjusts parameters sensitive to high flow and low flow simultaneously, the hydrograph reproducibility performance was found to be very low.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.40-47
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• 2003

The main purpose of Construction Management(CM) is the improvement of efficiency and effectiveness of the project with construction methodologies systematically and technically. This pilot project Dong Myeong Service Area and Gas Station project among 5 projects designated and supervised by Ministry of Construction and transportation(MOCT), is to reduce cost, to maintain and control schedule, to keep proper quality, Claim and Risk through Partnering, Design Review, Constructability, Value Engineering and Project Management Information System(PMIS) and so on. Major factors of CM Plan are introduction of the phased and classified Construction Management Services from initiation of project to completion and adaptation of CM technologies and guide the implementation methodologies of the CM Pilot Project in CM construction market.

• Journal of Digital Convergence
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• v.16 no.3
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• pp.543-552
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• 2018

The purpose of this study is to provide basic data for the improvement of the tournament operating environment and effective tournament operation. For the factor analysis, exploratory factor analysis was conducted. Based on this, in order to conduct hierarchical analysis, we've produced and distributed the questionnaire to expert group. And after, with collected data, AHP (Analytical Hierarchy Process) technique was used to analyze relative importance and determinants. As a result, operational factors showed the highest priority among the components of evaluation. And next prior factors are satisfaction of participants, environmental factors and etc. In order to stabilize the operation of the tournament, priority shall be securing the budget. And it is necessary to understand the desire of participants and shall consider characteristics and level of the tournament. In future studies, it will be necessary to make a comparative study through expert group in order to secure the fitness.

• Journal of Korean Society of Transportation
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• v.30 no.1
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• pp.19-30
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• 2012

The majority of daily travel demands concentrate at particular time-periods, which causes the difficulties in the travel demand analysis and the corresponding benefit estimation. Thus, it is necessary to consider time-specific traffic characteristics to yield more reliable results. Traditionally, na$\ddot{i}$ve, heuristic, and statistical approaches have been applied to address the peak-hour ratio. In this study, a hybrid clustering model which is one of the statistical methods is applied to calculate the peak-hour ratio and its duration. The 2009 national 24-hour traffic data provided by the Korea institute of Construction Technology are used. The analysis is conducted dividing vehicle types into passenger cars and trucks. For the verification for the usefulness of the methodology, the toll collection system data by the Korea Express Corporation are collected. The result of the research shows lower errors during the off-peak hours and night times and increasing error ratios as the travel distance increases. Since the method proposed can reduce the arbitrariness of analysts and can accommodate the statistical significance test, the model could be considered as a more robust and stable methodology. It is hoped that the result of this paper could contribute to the enhancement of the reliability for the travel demand analysis.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.5
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• pp.101-109
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• 2014

In order to save costs and enhance quality in construction without damaging the environment, the VE/LCC analysis method is increasingly used. This study was carried out to conduct a value analysis for the ecological restoration of a slope considering life cycle cost and performance. The construction conditions were classified into three types(A, B, C) according to the condition of each base. Three construction methods for slope ecological restoration were selected by each condition. Eventually, a value analysis was conducted for total nine conditions by analyzing the life cycle cost and performance. The gradient of slope and base of Condition 1 were below 1:1.2 and general soil, while condition 2 and 3 were below 1:1.0(reaping rock) and below 1:0.7(soft rock, blasted rock), respectively. A value analysis was conducted based on the value estimated via life cycle cost and performance analysis. The result showed that the B construction method had the highest value in Condition 1 as it showed 108.4, while A and C showed 90.3 and 45.8, respectively. When it comes to Condition 2, Construction Method A indicated the highest value as it showed 89.1(B: 47.5, C: 47.0). In Condition 3, Construction Method A(89.1) was the highest, while B and C showed 55.4 and 40.2, respectively. Based on the result of this study, in order to make a reasonable decision that can enhance quality and reduce costs in slope ecological restoration, the slope ecological restoration method must be reviewed in consideration of life cycle cost and performance.

• Journal of Practical Engineering Education
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• v.5 no.2
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• pp.101-107
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• 2013

Clickers that are personal response systems are a technology used to promote active learning and most research on the benefits of using clickers has shown that students become engaged and enjoy using them. But, existing clickers consisting of hardware devices and aggregation software provide simple response and aggregation function and it costs a lot. In this paper, in order to resolve the limitation of the existing clickers, we've designed and implemented the Smart Clicker consisting of a smartphone application for students and a web application & a MFC program for professors. Students can answer professor's questions with O/X or numbers or text and even ask questions with text messaging by using Smart Clicker in the classroom. Professors can see students' answers or questions immediately and check up students' response participation rate on the web page. Besides, the Smart Clicker will help professors actively engage students during the entire class period and gauge their level of understanding of the material being presented, and provide prompt feedback to student questions. As a result, we expect that quality of education will be increased.

• Journal of Broadcast Engineering
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• v.23 no.1
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• pp.45-52
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• 2018

The virtual reality (VR) cartoon is a format of VR contents that leverage the characteristics of webtoons that provides the simple story line and graphical storytelling tools to strategically surmount limitations of VR contents design. The VR cartoon enables people to experience the imaginary three-dimensional space in the webtoon as a real space by the transformation of webtoon contents through VR prototyping. The VR cartoon successfully presents focused environment where people can readily pay attention to the contents without notable motion sickness. People have been familiar with the storytelling strategy in the context of published cartoons and webtoons, likely we've understood the narrative of a movie through the continuous scenes projected in the screen. Indeed, it has been recognized as a popular toolset of communication, where visual images are sequentially delivered by replacing multiple planar spaces to tell a story narrative. While there are discrete panels with the time and space resolution in the graphical cartoons, people can distill a commit closure based on their past experiences. This is a typical "grammar" of the cartoon, which can be extrapolated to the VR cartoon that provides a seminal storytelling strategy. In this article, we review how the storytelling strategy in webtoons has been transformed into that in VR cartoons, and analyze the key components of VR cartoons. We envision that our research can potentially create keystones to produce variety of new VR contents by reflecting various narrative media including cartoon as a 'sequential art'.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.3 no.4
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• pp.59-88
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• 2008

For the success of the DMB market to meet consumers' demands for Ubiquitous Media and strengthen the nation's competitiveness, it's inevitable for us to activate DMB advertising as of main profit source for DMB Media, and to develop various types of DMB advertising which are linked to the profit model. So I'd like to look over the various types of DMB advertising which are suitable for DMB features as one of the efforts to activate DMB advertising. First of all, I've figured out what kinds of advertising are available for new media and which related technologies are required for DMB media. Through this research, I could find out what features of new media such as cable broadcasting, Internet and Mobile have become the source of developing various types of advertising and how to a great part to activate new media advertising markets by making the best use of their media features. This research also shows that DMB advertising has the high potential to be developed in various and effective types and kinds of advertising with its media feature and technological feature. This research observing DMB advertising cases showed that DMB advertising can be divided into 6 types such as forms, purposes, techniques, advertising positions, the use of LBS(Location Based Service), coupons and it could be developed into various kinds of DMB advertising dependent on each type. On the other hands, it would be great to have continual researches and follow-ups for various types of DMB advertising and the verification of the effectiveness for DMB advertising by performing potential DMB advertising.

• Journal of KIISE:Databases
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• v.36 no.2
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• pp.73-83
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• 2009

In this paper we propose an object similarity matching method based on shape characteristics of an object in an image. The proposed method extracts edge points from edges of objects and generates a log polar histogram with respect to each edge point to represent the relative placement of extracted points. It performs the matching in such a way that it compares polar histograms of two edge points sequentially along with edges of objects, and uses a well-known k-NN(nearest neighbor) approach to retrieve similar objects from a database. To verify the proposed method, we've compared it to an existing Shape-Context method. Experimental results reveal that our method is more accurate in object matching than the existing method, showing that when k=5, the precision of our method is 0.75-0.90 while that of the existing one is 0.37, and when k=10, the precision of our method is 0.61-0.80 while that of the existing one is 0.31. In the experiment of rotational transformation, our method is also more robust compared to the existing one, showing that the precision of our method is 0.69 while that of the existing one is 0.30.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2B
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• pp.121-135
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• 2010

This study is to assess the effect of potential future climate change on the inflow of agricultural reservoir and its impact to downstream streamflow by reservoir operation for paddy irrigation water supply using the SLURP. Before the future analysis, the SLURP model was calibrated using the 6 years daily streamflow records (1998-200398 and validated using 3 years streamflow data (2004-200698 for a 366.5 $km^2$ watershed including two agricultural reservoirs (Geumgwang8 and Gosam98located in Anseongcheon watershed. The calibration and validation results showed that the model was able to simulate the daily streamflow well considering the reservoir operation for paddy irrigation and flood discharge, with a coefficient of determination and Nash-Sutcliffe efficiency ranging from s 7 to s 9 and 0.5 to s 8 respectively. Then, the future potential climate change impact was assessed using the future wthe fu data was downscaled by nge impFactor method throuih bias-correction, the future land uses wtre predicted by modified CA-Markov technique, and the future ve potentiacovfu information was predicted and considered by the linear regression bpowten mecthly NDVI from NOAA AVHRR ima ps and mecthly mean temperature. The future (2020s, 2050s and 2e 0s) reservoir inflow, the temporal changes of reservoir storaimpand its impact to downstream streamflow watershed wtre analyzed for the A2 and B2 climate change scenarios based on a base year (2005). At an annual temporal scale, the reservoir inflow and storaimpchange oue, anagricultural reservoir wtre projected to big decrease innautumnnunder all possiblmpcombinations of conditions. The future streamflow, soossmoosture and grounwater recharge decreased slightly, whtre as the evapotransporation was projected to increase largely for all possiblmpcombinations of the conditions. At last, this study was analysed contribution of weather, vegetation and land use change to assess which factor biggest impact on agricultural reservoir and stream watershed. As a result, weather change biggest impact on agricultural reservoir inflow, storage, streamflow, evapotranspiration, soil moisture and groundwater recharge.