• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.1
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• pp.25-30
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• 2009

This experiment was conducted to evaluate the effect of direct seeding time on the yield and quality of whole crop rice at experimental field of Grassland and Forages Research Center, National Institute of Animal Science, RDA from 2005 to 2006. Whole crop rice variety, "Namil", was direct seeded at five different calender date (25 April, 10 May, 25 May, 4 June and transplanted at 25 May). The heading date was delayed at late seeding date. Crude protein (CP) was increased with delayed direct seeding date. The content of ADF (acid detergent fiber) and NDF(neutral detergent fiber) increased with delayed seeding date. The average TDN (total digestible nutrient) content was 61.5% and it also decreased with delayed direct seeding date. The highest DM (dry matter) yield was seeded at 25 April and transplanted at 25 May, 15,185 and 15,815 kg/ha, respectively. Although delayed direct seeding date decrease the DM yield, mid-May will be recommendable as proper direct seeding date.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.4
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• pp.48-54
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• 2020

Cracks in reinforced concrete structures are the most common type of damage and are used as important analytical data to understand the fracture behavior characteristics of structures. Currently, there is a problem that most of the crack investigation relies on visual inspection, therefore many researchers have proposed image analysis techniques to improve the problem. In this study, we proposed a crack evaluation method to be applied at an indoor experimental level using image analysis method. The image analysis technique using color is for distinguishing a boundary surface between objects existing in an image, and is a method for separating similar colors into one region based on a predefined color. In this study, to improve the accuracy of image analysis, blue paint was applied to the concrete surface and bending experiments were performed. The image analysis method was able to measure the crack width with superior accuracy compared to the crack diameter, and at the same time, it was also possible to analyze the deflection of the beam. Both the crack and deformation were able to confirm the accuracy similar to the existing measurement method, and it was found that the image analysis method was very excellent in terms of applicability.

• Elastomers and Composites
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• v.45 no.1
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• pp.51-57
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• 2010

Cellulose nanowhiskers (CNW) gamered increasing interest for their remarkable reinforcement of polymer composites. In this work, we were to produce cellulose whiskers from commercially available microcrystalline cellulose (MCC) by acid hydrolysis with sulfuric and hydrochloric acids. Electron microscopy found that each acid produced sililar cellulose crystals of diameters ranging from 20 to 30 nm and lengths ranging from 200 to 300 nm. Moreover, all samples showed remarkable flow birefringence through crossed polarization filters. Conductometric titration of CNW suspensions revealed that the sulfuric acid treated sample had a surface charge of between 140.00 mmol/kg and 197.78 mmol/kg due to sulfate groups, while that of the hydrochloric acid treated sample was undetectable. Thermogravimetric analysis showed that the thermal decomposition temperature and apparent activation energy (evaluated by Broido's method at different stages of thermal decomposition.) of H1-CNW - prepared by hydrolysis with hydrochloric acid - was higher than those of S1-CNW and S2-CNW - prepared by hydrolyzing MCC with sulfuric acid.

• Korean Journal of Construction Engineering and Management
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• v.14 no.3
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• pp.146-156
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• 2013

Recently, to reflect the various needs of customers in the apartment field, the customized apartment has emerged. From the point of the customer, customized apartments have the definite advantage of being able to guarantee more customer options. On the other hand, from the point of the project manager, there are significant risk factors, with increase of management factors, construction delays, etc. The reasons for this are, to date, the insufficient systematic analysis of the project, and the lack of experience of similar projects. This study provides the waste factors of each phase in a customized apartment project. A survey and interview are conducted to achieve the waste factors using MUDA methodology; a process of the project was analyzed; and a factor of each process was identified. Also, AHP(Analytic Hierarchy Process) are used, to evaluate the waste factors in project stages. The AHP results show that "Design change" and "Inappropriate intervention in construction process" ranked highly in the waste factors. The results of our research will provide a countermeasure that addresses waste factors in similar projects, and contributes to reducing the extra cost and time in new projects.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.4
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• pp.293-298
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• 2003

Livestock manure have been utilized as fertilizer, and trying to make resources natural circulation of organic materials. This experiment was carried out to investigate the effect of swine slurry on production and nutritive value of rye, and to determine optimal application level for 2 years from Oct. 2000 to May 2002 in the experimental field of Grassland and Forage Crops Division, National Livestock Research Institute. Summary of the results were as follows. The application of swine slurry 200% Plot showed the best regrowth after winter and lodging was severe in all plots except non-fertilized plot. Plant height was lower in lodging plots. The dry matter yield was not significantly difference between chemical fertilizer(CF) plot and swine slurry application plots, and swine slurry 100% + CF 50% plot showed the highest yield among manure application plots. The dry matter yield per input nitrogen was 80kg in CF, 81kg in swine slurry 100% application plot. Above the level, it was decreased severely by 41 ∼ 61kg. Conclusively, application to swine slurry 100% showed superior productivity considering the DM yield per input nitrogen, That level would be recommended to produce higher yield and to conserve environment.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.3
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• pp.422-427
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• 2010

Korean Game industry, especially MMORPG(Massively Multiplayer Online Game) has been rapidly expanding in these days. But As game industry is growing, lots of online game security incidents have also been increasing and getting prevailing. One of the most critical security incidents is 'Game Bots', which are programs to play MMORPG instead of human players. If player let the game bots play for them, they can get a lot of benefic game elements (experience points, items, etc.) without any effort, and it is considered unfair to other players. Plenty of game companies try to prevent bots, but it does not work well. In this paper, we propose a behavior pattern model for detecting bots. We analyzed behaviors of human players as well as bots and identified six game features to build the model to differentiate game bots from human players. Based on these features, we made a Naive Bayesian classifier to reasoning the game bot or not. To evaluated our method, we used 10 game bot data and 6 human Player data. As a result, we classify Game bot and human player with 88% accuracy.

• The Journal of the Korea Contents Association
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• v.19 no.10
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• pp.511-521
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• 2019

This study is designed to define the smart city as the platform for digital social innovation, and acquire the evaluation indicator for objectively diagnosing domestic cities from the perspective of the implementation process and capability of smart city and analyze its importance. Through prior studies and in-depth interview with experts, candidate groups for evaluation indicators were acquired and the conformance test(T-test) was conducted to finally select 16 detailed indicators in 4 fields. The importance of the evaluation item was found to be high in the policy and system, followed by innovation infrastructure, citizen's participation and infrastructure. The analysis of the 16 detailed indicators for importance showed that the willingness of conducting the smart city by the head of local government, construction of organization dedicated to the smart city have the highest importance. This may reflect the fact that in domestic cities, the smart city is sponsored by public organizations. The analysis of the importance of expert groups (local government and Private sector groups) found that both groups recognized that politics and systems are important factors but they varied in the recognition of importance in the innovation infrastructure and citizen's participation. This study has implication as the indicator for smart city from the perspective of digital social innovation can be acquired for use of the domestic cities and that it can give basic and objective data for the priority of policies on which the domestic smart cities shall focus.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.5
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• pp.263-270
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• 2021

In this study, a reliability-based design optimization of a 130-m class fixed-type offshore platform, to be installed in the North Sea, was carried out, while considering environmental, material, and manufacturing uncertainties to enhance its structural safety and economic aspects. For the reliability analysis, and reliability-based design optimization of the structural integrity, unity check values (defined as the ratio between working and allowable stress, for axial, bending, and shear stresses), of the members of the offshore platform were considered as constraints. Weight of the supporting jacket structure was minimized to reduce the manufacturing cost of the offshore platform. Statistical characteristics of uncertainties were defined based on observed and measured data references. Reliability analysis and reliability-based design optimization of a jacket-type offshore structure were computationally burdensome due to the large number of members; therefore, we suggested a method for variable screening, based on the importance of their output responses, to reduce the dimension of the problem. Furthermore, a deterministic design optimization was carried out prior to the reliability-based design optimization, to improve overall computational efficiency. Finally, the optimal design obtained was compared with the conventional rule-based offshore platform design in terms of safety and cost.

• Korean Journal of Construction Engineering and Management
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• v.20 no.1
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• pp.22-31
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• 2019

The application of BIM that can manage and integrate information generated during the entire life cycle of buildings in domestic and overseas construction projects is becoming active. When BIM is utilized in the construction phase, it can shorten the construction period, reduce the occurrence of reworks and improve collaboration capability. However, there are limitations in applying BIM to the construction phase due to the insufficient definition level of domestic BIM guidelines and inadequate design standards. In this regard, this study developed BIM model requirements checklist for the application of BIM in the construction phase. To develop the checklists, 21 domestic and overseas BIM guidelines, three public construction projects and four private construction projects to which construction BIM was applied, were analyzed. Based on the guidelines and cases, a total of 62 construction BIM model requirements (31 model objects and 31 attribute rules) and proposed construction BIM model requirement checklists by dividing the 61 requirements according to the requirement and purpose for utilization were identified. It is expected that the practical applications of the checklists proposed in this study will improve the level of BIM model in construction phase. In addition, this study has its significance as a basic research that can be used in the development of standardized guidelines for BIM model in construction phase from academic aspects.

• 재활복지
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• v.20 no.1
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• pp.131-150
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• 2016

This study aims to compare global policies on ICT accessibility and to suggest possible solutions that help to enhance ICT accessibility for socially disadvantaged groups. The results indicated that related laws and standards in Korea are relatively well established than Asian countries' whereas they need improvements when compared to the US or the UK. Particularly, in spite of rapid development in information communication technology industry, incorporating the definition of newly developed technologies into existing laws related to ICT accessibility seemed slow that caused reluctancy of related parties to address accessibility issues the new technologies create. In addition, Korean government seems less effortful to develop policies and standards apart from web and mobile application accessibility. In order to resolve the problems, firstly, the period or process of enacting and amending laws can be shorten. Next, a government affiliated research institute can be established to do research and develop ICT accessibility related to user scenarios so that effective policies and standards could be readily provided. Even though other possible solutions can be suggested, what is more important than that is that any interested parties should sustainably make efforts to provide equal opportunities for the underserved populations.