• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.505-508
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• 2006

Self-leveling mortar is walkable bottom mortar which can maintain the horizontality of self fluid and have the the quick-setting quality, the low-human-effort practicable material of high-quality bottom in construction. In accordance with more adhesive strength with bottom side and absorption control, Primer is used for purpose to prevent pin-hole occurrence by self leveling mortar application prior to construction. This study is composed measurement of absorption, adhesive strength. Used material is NP-40 as nonionic emulsifying agent, uses SA-210L as negative ion emulsifying agent, uses APS, SBS as ridical initiator. A result of test, in accordance with image of Primer, as low temperature and application frequency, indicates low absorption rate and adhesive strength, as solid powder and dryness time is increse, absorption rate and adhesive strength lowly shows figure.

• Journal of the Korea Society of Computer and Information
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• v.22 no.12
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• pp.95-100
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• 2017

In this paper, we propose a zone based ad hoc network construction scheme which support ad hoc path between nodes in local IoT networks consisting of IoT devices with the constrained feature, such as low power, the limited transmission rate and low computing capacity. Recently, the various routing protocols have been studied to support ad hoc networking of local IoT environments. This is, because basis RPL protocol is deigned to be used for the connecting service with Internet through gateway, ad hoc path between nodes in local IoT networks is not supported in basis RPL protocol. Thus, in this paper, the proposed routing scheme provides both ad hoc path and Infra path through gateway, supporting basis RPL protocol simultaneously. Through simulation, we show that the proposed routing scheme with zone based path selection scheme improves the performance of the success rate of end-to-end data transmission and the end-to-end delay, compared to basis RPL protocol.

• Korean Journal of Computational Design and Engineering
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• v.12 no.6
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• pp.413-421
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• 2007

3D rendering is becoming a common feature of mobile application programs with the rapid advance of mobile devices. Since the existing rendering engines do not provide triangulation functions, mobile 3D programs have focused on an efficient handling with pre-tessellated geometry. In addition, triangulation is comparatively expensive in computation, so it seems that the triangulation cannot be easily implemented on mobile devices with limited resources. Triangulation of 3D geometry is the essential process of visualization of 3D model data and many different triangulation methods have been reported. We developed a light and fast visualization process that involves constrained triangulation based on Voronoi diagram and applied it to a mobile computer application. In this paper, we applied kd-tree to the original incremental construction algorithm and produced new O(nlogn) incremental construction algorithm. And we show a simple and efficient constrained triangulation method based on Voronoi diagram. This paper also describes an implementation of mobile STEP data viewer as an application of our proposed algorithms.

• Journal of The Korean Digital Architecture Interior Association
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• v.3 no.2
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• pp.1-7
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• 2003

Remodeling has improved through many interests of people and governmental positive support. Accordingly, this study precedes definition and typology of remodeling. As well, it analyzed the type of remodeling preference group who asked consulting on internet following items and researched a special feature of construction case. - Area, Age, Size and Type of Building, Prospective Cost, Constructing Period, Range of Remodeling- Then, remodeling will have a big effect and be needed lasting evaluation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.7
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• pp.1092-1099
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• 2017

This paper proposes a novel way of vehicle detection and classification based on image features. There are two main processes in the proposed system, which are database construction and vehicle classification processes. In the database construction, there is a tight censorship for choosing appropriate images of the training set under the rigorous standard. These images are trained using Haar features for vehicle detection and histogram of oriented gradients extraction for vehicle classification based on the support vector machine. Additionally, in the vehicle detection and classification processes, the region of interest is reset using a number plate to reduce complexity. In the experimental results, the proposed system had the accuracy of 0.9776 and the $F_1$ score of 0.9327 for vehicle classification.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.159-162
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• 1993

A new approach using fuzzy dynamic programming is proposed for the flexible long-term generation mix under uncertain circumstances. A characteristic feature of the presented approach is that not only fuzziness in fuel and construction cost. load growth and reliability but also many constraints of generation mix can easily be taken into account by using fuzzy dynamic programming. The method can accommodate arbitrary shape of membership function as well as the operation of pump-generator. And so more realistic solution can be obtained. The effectiveness of the proposed approach is demonstrated by the best generation mix problem of KEPCO-system which contains nuclear, coal, LNG, oil and pump-generator hydro plant in multi-years.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.671-672
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• 2015

Due to harsh conditions of disaster areas, understanding of current feature of collapsed buildings, terrain, and other infrastructures is critical issue for disaster managers. However, because of difficulties in acquiring the geographical information of the disaster site such as large disaster site and limited capability of rescue workers, comprehensive site investigation of current location of survivors buried under the remains of the building is not an easy task for disaster managers. To overcome these circumstances of disaster site, this study makes use of an unmanned aerial vehicle, commonly known as a drone to effectively acquire current image data from the large disaster areas. The framework of 3D model reconstruction of disaster site using aerial imagery acquired by drones was also presented. The proposed methodology is expected to assist rescue workers and disaster managers in achieving a rapid and accurate identification of survivors under the collapsed building.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.351-358
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• 2024

In Japan, bridge inspections are mandated every five years. The inspection database for bridges under the jurisdiction of the Ministry of Land, Infrastructure, Transport, and Tourism enables the acquisition of damage progression data for each structural element. This study develops a methodology for predicting the deterioration of girder bridges, employing a novel approach where inspection drawings are processed using Optical Character Recognition (OCR) to extract element numbers and their spatial relationships, subsequently creating a comprehensive graph of these elements. A key feature of this prediction methodology is its ability to consider the adjacency relationships between different bridge members, made possible by the detailed analysis of drawing information and a Graph Transformer model. The research examines and compares the accuracy of predictions made with and without considering adjacency relationships, highlighting the effectiveness of incorporating detailed structural information in the predictive analysis of bridge deterioration.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.25
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• pp.3-40
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• 2005

Many Korean construction companies have been performing a variety of overseas construction projects since the 1970s. It is unfortunate that in many cases they have had to suffer big losses caused by errors and defects in the design and construction of the projects. In the author's opinion, however, there were losses that could have been avoided if they had understood better the feature and content of the particular construction contract. Few lawyers and scholars in Korea have been interested in the research and study of international construction contracts. This is mainly because they do not have access to practical sources outside of Korea for them to research and study since the contracts undertaken have been dealt with by law firms in other jurisdictions to which the disputes apply. This article is aiming primarily at the introduction of the issues which the practitioners are likely to confront in the process of reviewing and performing the international construction contract. In some cases solutions are sought about these issues based upon the FIDIC standard terms and conditions, the actual experience of practice, and UNIDROIT Principles, etc. It is reasonable to say that all the issues related to the international construction contract cannot be covered in a short article like this. The author wishes this article could induce subsequent studies on international construction contracts for further research. It has to be noted that from time to time Korean construction practices have been compared to the international ones for better understanding. This article mostly includes cases where the Korean construction companies go overseas for their projects, while there are some cases where foreign developers and financial investors participated in domestic projects in which international construction contracts forms were adopted. A few precedent domestic writings about international construction contracts seems to lack emphasis on the points that there are several standard construction contract forms and that they are different. The differences are mainly in accordance with who bears the design responsibility, how the owner has to make progress payments to the contractor and who the funding source for the project is. This article tries to make it clear that there are significant differences between the standard contract forms, e.g. a simple construction form, a design-build form and an EPC/turnkey form of contract. Again, the author hopes that this article can arouse the interest in the international construction contracts from both academic and practical fields, so that many subsequent advanced articles can help our construction industry become much more competitive in the world through awareness of the methods of procurement and administration of the contracts.

• Korean Journal of Construction Engineering and Management
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• v.11 no.3
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• pp.3-12
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• 2010

Recently, workers on construction sites can hardly understand their tasks and the process of the tasks because the construction projects are becoming large and complex. Due to the complexity, workers need a tool that can help them understand their works and some paper-based manuals exist to support them. However, the existing paperbased manuals are not actively used by workers due to the low credibility of information on the manual. In particular, paper-based manual can not be updated frequently because those manuals have to be manually updated by experts. Thus, the credibility of information is decreased and the decrease let the users distrust information of the paper-based manual. Therefore, this research analyzed the feature of wiki-based system and suggested an wiki-based IETM(Interactive Electronic Technical Manual) system model that can be modified by users, and then conducted a survey through a prototype based on urban regeneration project. The result of the survey indicated that wikibased IETM can improve the stakeholder communication by reinforcing the process of creating knowledge as well as knowledge itself.