• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.316-321
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• 2007

The casualties due to slope failures such as landslide, rock fall, debris flow etc. are about 24% in total casualties caused by natural disasters for the last 10 years. And these slope failures are focused in the season in which typhoon and torrential rain take place. Not much attention, however, have been put into landslide mitigation research. Meanwhile, USN(Ubiquitous Sensor Network) forms the self-organization network, and transfers the information among sensor nodes that have computing technology ability. Accordingly, USN is embossed a social point technology. The objective of this paper is to develop a prototype system for slope failure monitoring using USN technology. For this we develop module that collects and change slope movement data measured by two tiltermeter and a tension wire, store transferred data in database. Also we develop application program that can easily analyze the data. We apply the prototype system to a test site at KICT for testing and analyzing the system's performance.

• Journal of Korean Society for Geospatial Information Science
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• v.12 no.1 s.28
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• pp.63-68
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• 2004

Since 20th century, the rapid growth in economy development and ill-advisable construction of infrastructure which causing injury of nature has generated an El Nino phenomenon problems. For this reason, establishment of heritage preservation plan is being required to prevent damages of important cultural assets from natural disaster. In this study, we obtained both 3D-dxf and VRML-wrl(which support 3D image) files from stone pagodas(stone cultural heritages) by using the digital photogrammetric program. Then database are formed by these two files with other attribute informations. And we made existing cultural heritages management information data format to be unified using JAVA, HTML, and Cosmo Player. Thus, we could construct the web-server for Cultural Heritages Management Information System to contribute not only effective management but also ease of use for expert or amateur user in using of cultural assets informations. And, in virtual reality system, we could make texture presented like as actual texture by using the VRML program.

• Journal of Korean Society of Steel Construction
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• v.15 no.6 s.67
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• pp.661-672
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• 2003

The advanced analysis and optimal design of semi-rigid frame were presented. Advanced analysis can predict the combined nonlinear effects of connection, geometry, and material on the behavior and strength of semi-rigid frames. The Kishi-Chen power model was used to describe the nonlinear behavior of semi-rigid connections. Geometric nonlinearity was determined using stability functions. On the other hand, material nonlinearity was determined using the Column Research Council (CRC) tangent modulus and parabolic function. The direct search method proposed by Choi and Kim was used as optimization technique. The member with the largest unit value evaluated using the LRFD interaction equation was replaced one by one with an adjacent larger member selected from the database. The objective function was assumed as the weight of steel frame, with the constraint functions accounting for load-carrying capacities, deflections. inter-story drifts, and ductility requirement. Member sizes determined by the proposed method were compared with those derived using the conventional LRFD method.

• Korean Journal of Remote Sensing
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• v.24 no.2
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• pp.153-164
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• 2008

According to the economic growth, many highways are constructed for increasing need of better life style. Especially roads and roadside facilities are used for accident prevention and offering mobility for drivers. For these purpose, roads and roadside facilities should be well maintained and managed. Now, many roads and roadside facilities are constructed in many areas. Because of traditional surveying method requires much time and surveying efforts, we designed and developed mobile mapping system for highway maintenance and management purpose using multi sensors. We tested our mobile mapping system and data management process. Using developed database, road managers can easily check the information of facility conditions, positions, and attributes. We are expecting low cost and efficient road maintenance process by using our system.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.3
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• pp.503-509
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• 2019

Order-revealing encryption which enables a range query over encrypted data is attracting attention as one of the important security technologies in industry such as IoT, smart manufacturing, and cloud computing. In 2015, an ideally-secure order-revealing encryption whose ciphertexts reveal no additional information beyond the order of the underlying plaintexts has been proposed. However, their construction is too inefficient for practical use and some security analysis of multilinear maps, which their construction relies on, have been proposed. Recently, more practical schemes have been proposed, focusing on achieving practically usable efficiency rather than the ideal security. In this paper, we propose a more storage-efficient order-revealing encryption scheme than the Lewi et al.'s scheme most recently published by presenting an idea that can generate shorter ciphertexts without any security loss.

• Journal of the Korean GEO-environmental Society
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• v.20 no.2
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• pp.5-18
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• 2019

In this study, it was conducted a broad-area landslide analysis for the entire area of Kyungsangbuk-do Province based on spatially-distributed wetness index and root reinforcement infinity slope stability theory. Specifically, digital map, soil map and forest map were used to extract topological and geological parameters, and to build spatially-distributed database at $10m{\times}10m$ resolution. Infinity flow direction method was used for rain catchment area to produce spatially-distributed wetness index. The safety level that indicates risk of a broad-area landslide was classified into four groups. The result showed that areas with a high estimated risk of a landslide coincided with areas that recently went through an actual landslide, including Bonghwa and Gimcheon, and unstable areas were clustered around mountainous areas. A comparison between the estimation result and the records of actual landslide showed that the analysis model is effective for estimating a risk of a broad-area landslide based on accumulation of reasonable parameters.

• Tunnel and Underground Space
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• v.28 no.6
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• pp.569-583
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• 2018

The purpose of this study is to identify the collapse characteristics by analyzing various factors causing collapse based on field survey and existing data on rock slopes occurring in the construction of roads and industrial complexes in Gyeongsangnam - do area. In the case of the slope where the slope has been directly surveyed, the analysis of the collapse characteristics can be used for the prediction and prevention of slope failure through the continuous collection of the slope data, database construction, management and analysis. The evaluation items used in the collapse characteristics of slope were selected among the items that can be regarded as objective evaluation items among the overlapping factors by comparing the evaluation items frequently used for the evaluation of the existing slope stability among various factors. The type of destruction of the rock slope depends on the type of carcass of the bedrock, such as planar fracture, wedge fracture, onho fracture, and conduction fracture, which are different from each other. And the slope stability analysis should be performed accordingly.

• Korean Journal of Construction Engineering and Management
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• v.20 no.3
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• pp.86-96
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• 2019

The research efforts to modernize Hanok (Korean traditional housing) have been performed to improve the quality and cost-effectiveness through application of modern building methods and materials, and to disseminate it in various forms of sizes and facilities. In this study, in order to identify the variations of modernized Hanok, data from seven test-bed projects are analyzed based on the building work-section, element, method, and material. The data were standardized and managed through the modernized Hanok classification system (Hanclass) to facilitate systematic comparisons of the test-bed projects by the variation of building method and it's cost impact. Identified factors of the variation in terms of building methods were then itemized and quantified in terms of building cost. Findings of this study indicate that the timber structure is the most critical area for future variation for improving the quality and cost-effectiveness. The results of this study will be also used to systemize the Hanok database for further studies.

• Journal of the Korea Institute of Building Construction
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• v.22 no.1
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• pp.115-123
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• 2022

Statistics on the occurrence of fires in residential facilities over the past 10 years, show that approximately 40% are fires in apartment buildings. To prevent the spread of fire and support evacuation in apartment housing, the fire resistance performance and performance design of fire doors are becoming more important. This study established a database using 395 quality inspection reports from 2016 to 2020, which passed the fire performance test, and derived the fire door performance-influencing factors through an analysis of the structure (12 elements) of the fire door. As a result, the effect of core material, adhesive, hinge type, blowing agent, etc. was confirmed in 287 pass cases. On the other hand, it was confirmed that the occurrence of flames and crevices in the 108 cases of failure were the major failure factors in the fire door fire resistance test. Fire doors are composed of composite materials to prevent failure of fire resistance performance, and efficient design and quality control are required through standardization of components.

• Korean Journal of Construction Engineering and Management
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• v.24 no.5
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• pp.35-43
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• 2023

Along with the increase in Multi-unit housing defect disputes, the importance of defect management is also increased. However, previous studies have mostly focused on the Multi-unit housing's 'common part'. In addition, there is a lack of research on the system for the 'management office', which is a part of the subject of defect management. These resulted in the lack of defect management capability of the management office and the deterioration of management quality. Therefore, this paper proposes a machine learning-based defect data management system for management offices. The goal is to solve the inconvenience of management by using Optical Character Recognition (OCR) and Natural Language Processing (NLP) modules. This system converts handwritten defect information into online text via OCR. By using the language model, the defect information is regenerated along with the form specified by the user. Eventually, the generated text is stored in a database and statistical analysis is performed. Through this chain of system, management office is expected to improve its defect management capabilities and support decision-making.