• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.5
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• pp.83-91
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• 2015

With varying conditions of concrete surface, induced chloride contents are changed and this is a key parameter for steel corrosion and service life in RC (Reinforced Concrete) structures. Many surface enhancement techniques using impregnation have been developed, however the evaluation techniques for chloride behavior through doubly layered media and time-dependent diffusion are rarely proposed. This paper presents an analysis technique considering double-layer concrete and time-dependent diffusion behavior, and the results are compared with those from the previous test results through reverse analysis. The chloride profiles from the surface-impregnated concrete exposed to atmospheric, tidal, submerged zone for 2 years are adopted. Furthermore surface chloride contents and diffusion coefficients are obtained, and are compared with those from Life365. Through consideration of time effect, the relative error decreases from 0.28 to 0.20 in atmospheric, 0.29 to 0.11 in tidal, and 0.54 to 0.40 in submerged zone, respectively, which shows more reasonable results. Utilizing the diffusion coefficients from Life365, relative errors increases and it needs deeper penetration depth (e) and lower diffusion coefficient ratio ($D_1/D_2$) due to higher diffusion coefficient.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3B
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• pp.301-310
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• 2006

Typically, we needs enormous national budget for the flood control project and so the project usually has big influence on the national economy. Therefore, the reliable estimation of flood damage is the key issue for the economic analysis of the flood control project. This study aims to provide a GIS based technique for distributed flood damage estimation. We consider two aspects of engineering and economic sides, which are the inundation analysis and MD-FDA (Multi-Dimensional Flood Damage Analysis), for the flood damage assessment. We propose the analysis framework and data processing using GIS for assessing flood damages. The proposed methodology is applied to the flood control channel project for flood disaster prevention in Mokgamcheon/Dorimcheon streams and this study presents the detailed GIS database and the assessment results of flood damages. This study may have the worth in improving practical usability of MD-FDA and also providing research direction for combining economic side with the engineering aspect. Also this distributed technique will help decision-making in evaluating the feasibility of flood damage reduction programs for structural and nonstructural measures.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.1
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• pp.35-44
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• 2020

The growing use of public blockchain-based virtual cryptocurrency calls for secure management of blockchain account information managed through cryptocurrency wallet programs. The previously proposed wallet program has high security in terms of managing an account's private key, but low security in managing an account's recovery phrase. Therefore, in this paper, we propose a safe management system of blockchain account recovery string based on the new user authentication method using the user's mobile device information and OTP technique to overcome the problem of the existing account recovery string management method. It also conducts an analysis of the proposed blockchain account recovery string management system based on the expected behavior scenario.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.231.1-231.1
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• 2015

Surface energy, being an important material parameter to control its interactions with the other surfaces plays a key role in bio-related application. Carbon films are found very promising due to their characteristics such as wear and corrosion resistant, high hardness, inert, low resistivity and biocompatibility. The present work deals with the deposition of carbon films using unbalanced facing target magnetron sputtering technique. The discharge characteristics were studied using optical emission spectroscopy and correlated with the film properties. Surface energy was investigated through contact angle measurement. The ID/IG ratio as calculated from Raman spectroscopy data increases with the increase in power density due to the higher number of sp2 clusters embedded in the amorphous matrix. The deposited films were smooth and homogeneous as observed by Atomic force microscopy having RMS roughness in the range of 1.74 to 2.25 nm. It is observed that electrical resistivity and surface energy varies in direct proportionality with operating pressure and has inverse relation with power density. The surface energy results clearly exhibited that these films can have promising applications in cell cultivation.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.616-621
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• 2006

Recently, the researches based on vision about user attention and action awareness are being pushed actively for human computer interaction. Among them, various applications of tabletop display system are developed more in accordance with touch sensing technique, co-located and collaborative work. Formerly, although supported only one user, support multi-user at present. Therefore, collaborative work and interaction of four elements (human, computer, displayed objects, physical objects) that is ultimate goal of tabletop display are realizable. Generally, tabletop display system designs according to four key aspects. 1)multi-touch interaction using bare hands. 2)implementation of collaborative work, simultaneous user interaction. 3)direct touch interaction. 4)use of physical objects as an interaction tool. In this paper, we describe a critical analysis of the state-of-the-art in advanced multi-touch sensing techniques for tabletop display system according to the four methods: vision based method, non-vision based method, top-down projection system and rear projection system. And we also discuss some problems and practical applications in the research field.

• Journal of the Korea Institute of Building Construction
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• v.15 no.1
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• pp.99-105
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• 2015

The building structure has an decisive influence on the environment as it takes over one third part in the energy consumption and greenhouse gas emissions of whole world. Accordingly, every country makes the reduction of greenhouse gas emission compulsory pursuant to Kyoto Protocol of 1997, and Korea government makes an announcement for the improvement of building energy performance in 2014. In this study, the key technology of Energy Saving Environmental-Friendly Building is sorted into 3rd categories, and the analysis of patent trend for patent documents published in Korea, USA, Japan and Europe is carried out. The purpose of this study is to solve the problem of current technology that it cannot show the detailed situation of technique and development strategy of R&D, and to provide a systematic approach for R&D strategy and an exact technology development direction.

• Korean Journal of Construction Engineering and Management
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• v.5 no.6 s.22
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• pp.235-244
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• 2004

The effective management of major construction resources is the key to the success in high-rise residential building construction projects. It is even more important and challenging as well especially in CBD(central business district) area under tight project duration since little leeway in interface between construction trades, severe constraints in staging n and heavy demands for lifting among construction resources. In order to meet high demands among major construction resources, highly effective construction resource management information system is required This research develops and provides a system which selects and disseminates these information from each phase of procurement transportation, lift-up and storage for major construction resources This research applies the Kanban system, well recognized material information system technique in automobile manufacturing industry, in concrete work processes. It develops concrete procurement information system utilizing VSM(Value Stream Mapping) and also applies the model in actual super-high rise residential building construction project in order to analyze the benefit of the research model.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1223-1227
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• 2005

Fine microgroove is the key component to fabricate micro-grating, micro-grating lens and so on. Conventional groove fabrication methods such as etching and lithography have some problems in efficiency and surface integrity. This study deals with the creation of ultra-precision micro grooves using non-rotational diamond tool and CNC machining center. The shaping type machining method proposed in the study allows to produce V-shaped grooves of $40\mu{m}$ in depth with enough dimensional accuracy and surface. For the analysis of machining characteristics in micro V-grooving, three components of cutting forces and AE signal are measured and processed. Experimental results showed that large amplitude of cutting forces and AE appeared at the beginning of every cutting path, and cutting forces had a linear relation with the cross-sectional area of uncut chip thickness. From the results of this study, proposed micro V-grooving technique could be successfully applied to forming the precise optical parts like prism patterns on light guide panel of TFT-LCD.

• Journal of Korea Water Resources Association
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• v.51 no.2
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• pp.131-140
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• 2018

Precipitation is a key variable to enhance the understanding of water cycle system and secure and manage the water resources efficiently. In this study, we evaluated the feasibility of GPM precipitation datasets through comparison with the 92 ASOS sites in South Korea during 2015. Additionally, three merging techniques (i.e., Geographical Differential Analysis, Geographical Ratio Analysis, Conditional Merging) were applied to improve accuracy of precipitation by fusing the advantages from point and satellite-based datasets. The results of this study are as follows. 1) GPM dataset indicated slightly overestimation with compared ASOS dataset, especially high uncertainties in summer season. 2) Validation of three merging techniques through jackniffe cross-validation showed that uncertainty were decreased as the spatial resolution increased. Especially, conditional merging showed the best performance among three methods.

• Korean Institute of Interior Design Journal
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• v.24 no.1
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• pp.3-11
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• 2015

I paid attention to the fact that surrealism emerging in early 20th century has been resurfacing in the 21st century. It may be because of the increasing interest on the space showing the surrealistic features as people in these days prefer the experimental and dramatic space beyond repetitive daily life. I tried to identify the expressive characteristics in the interior space adopting the depaysement technique among a variety of expression techniques of surrealism. To this end, this paper selected 10 interior design projects by Fabio Novembre and Marcel Wanders since 2000s. As the methodology, chapter 2 examined the theories to identify the expression targets and approaches of depaysement around the art paintings. Next, the standard for case analysis in this paper was established by investigating the existing theses related to interior and space design with depaysement as the key word. The expressive characteristics of depaysement identified from the existing researches were classified into morphological, figurative, material and space program. Those programs were developed as the classification system in this paper. Chapter 3 described the design background and features of Fabio Novembre and Marcel Wanders. On the basis of the features and analysis framework identified in chapter 2 and 3, chapter 4 analyzed the features of depaysement observed in the works by both designers. The conclusion was presented in chapter 5. For the expressive characteristics of depaysement observed in the space by both designers, Novembre created optical illusion using distortion or overlap on the morphological aspect. Wanders showed mainly the feature of changing the scale. In accordance with the analysis on expression principles, the features including spatial continuity, ambiguity of border, visual amusement and uncertainty were differentiated in all spaces.