• Journal of People, Plants, and Environment
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• v.23 no.3
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• pp.347-362
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• 2020

Background and objective: It is difficult to conclusively determine the exact cause of tree defects since multiple causes are involved such as climate change, plantation, tree quality and planting time, construction, planting base, drainage, sunshine conditions, maintenance, and microclimate. The data related to landscaping construction defects are scattered or fragmented by companies and years, but not managed systematically by the defect information management system. Most of the earlier studies associated with tree defects in apartment complexes suggested defect rates after examining tree defects in the completed construction site and proposed fragmentary and subjective conclusions about the causes of defects observed in trees with high defect rates. It is proposed to continue to conduct studies on the establishment and analysis of systematic databases to identify the exact causes of tree defects and measures to improve, and the need to accumulate systematic data in the construction process where many defects arises. This study was conducted to reduce the defects of trees planted in apartment complexes. Methods: Main factors related to tree defects were subdivided based on the results of literature review and a defect investigation at the completion site, and tree history management items were selected and subdivided during the construction stage. Results: The criteria for the preparation of subdivided items were obtained, and the tree history management checklist was written for the site under actual construction and a systematic database was established. Items that are categorized based to the causes of defects include the location of nurseries, date, tree quality, site conditions, planting techniques, microclimates, and maintenance. Conclusion: This study suggested tree history management items based on the tree defects that can be identified at the construction stage and applied them to the selected study site, which differentiates this study from earlier studies. It will be necessary to conduct a comprehensive and objective time series analysis on tree defects that occur over time by continuously monitoring and collecting data after construction.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.563-570
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• 2022

Industrialized and modular construction is a growing construction technique that can transfer a large portion of the construction process to off-site fabrication yards. This method of construction often involves the fabrication, pre-assembly, and transportation of massive and long volumetric modules. The module weight keeps increasing as the modules become more complete (with infill) to minimize the work at the site and, as higher productivity can be achieved at the fabrication shop. Thus, a volumetric module delivery gets more challenging and risky. Despite its importance, past research paid relatively insufficient attention to the problem related to the lifting of heavy modules. This can be a complex and time-consuming problem with multiple lifting for transportation-and-installation operations both in fabrication yard and jobsite, and require complex crane operations (sometimes, more than one crane) due to crane load capacity and load balance/stability. This study investigates this problem by focusing on the structural perspective of lifting such long volumetric modules through simulation studies. Various scenarios of lifting a weighty module from the top using four lifting cables attached to crane hooks (either a single crane or double crane) are simulated in SAP software. The simulations account for various factors pertaining to structural indices, e.g., bending stress and deflection, to identify a proper method of module lifting from a structural point of view. The method can identify differences in structural indices allowing identification of structural efficiency and safety levels during lifting, which further allows the selection of the number of cranes and location of lifting points.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.2D
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• pp.225-231
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• 2006

On-line shopping allows consumers to order goods via internet and receive them at homes or workplaces. Emergence of online shopping industry has brought the changes in the structure of freight industry, in the location selection pattern of industrial clusters and in the consumer's travel pattern. This trend is likely to continue, especially in Korea, as the society sees increases in women's participation in workforce, in population of the elder and in production pattern of manufacturing individually customized goods. Despite on-line shopping's heavy influence on travel demand, no study on this particular topic has been done yet, and thus the effect of on-line shopping on travel demand has not been properly reflected on policy making process. This paper suggests the transportation strategy to cope with this change based on the analysis of the effect of on-line shopping on personal travel demand.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.1
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• pp.118-125
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• 2016

This study evaluates the performance of image to patient registration algorithm by using stereo vision and CT image for facial region surgical navigation. For the process of image to patient registration, feature extraction and 3D coordinate calculation are conducted, and then 3D CT image to 3D coordinate registration is conducted. Of the five combinations that can be generated by using three facial feature extraction methods and three registration methods on stereo vision image, this study evaluates the one with the highest registration accuracy. In addition, image to patient registration accuracy was compared by changing the facial rotation angle. As a result of the experiment, it turned out that when the facial rotation angle is within 20 degrees, registration using Active Appearance Model and Pseudo Inverse Matching has the highest accuracy, and when the facial rotation angle is over 20 degrees, registration using Speeded Up Robust Features and Iterative Closest Point has the highest accuracy. These results indicate that, Active Appearance Model and Pseudo Inverse Matching methods should be used in order to reduce registration error when the facial rotation angle is within 20 degrees, and Speeded Up Robust Features and Iterative Closest Point methods should be used when the facial rotation angle is over 20 degrees.

• Journal of Korean Association for Spatial Structures
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• v.8 no.3
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• pp.45-51
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• 2008

A single layer-latticed dome is advantageous for large span structures because it is very stiff despite the light weight of the structure itself. However, this structure becomes easily unstable during erection due to its large size. The Block method is popular with the large span structures. A partial block of the dome is fabricated on the ground and lifted by crane to a designated location of structures. The lifting point selection is very important to create a stable erection and to avoid buckling of members during the erection. The purpose of this study is to analyze the structural behaviors and buckling characteristics according to the lifting point of single-layer latticed domes with triangle network in order to take materials about the safe and economic erection. The conclusions are obtained as follow. 1) The buckling strength of the block part varies with the location of lifting points when it is erected. In case, the height of the dome is lower, the effort of buckling strength of the structure is higher. 2) In buckling strength, the effect of the lifting rope length is smaller than it of the lifting points change.

• Journal of the Korean Institute of Gas
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• v.22 no.2
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• pp.90-96
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• 2018

Design techniques for minimizing the damage caused by leakage of $H_2S$ gas, contained in natural gas and petroleum, have been widely studied abroad in chemical plants that purify and process natural gas and petroleum. However, there is no domestic engineering practice and regulation of $H_2S$. In accordance with the circumstances, this study proposes the quantitative criteria of process equipment to install $H_2S$ toxic gas detector as 500 ppm and explains the valid basis. The $H_2S$ gas dispersion radius up to IDLH 100 ppm is calculated by ALOHA under previous $H_2S$ gas leak accident scenario. The weather conditions of modeling include the conditions of Ulsan, Yeosu and Daesan, the three major petrochemical complexes in Korea. The long radius up to 100 ppm was derived in order of Ulsan, Daesan, Yeosu. For emergency safety the dispersion radius up to 100 ppm of the $H_2S$ gas obtained in this study should be extended to apply the additional $H_2S$ toxic gas detector, and local climate conditions should be considered.

• International Journal of Highway Engineering
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• v.7 no.4 s.26
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• pp.21-30
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• 2005

Traffic volume data have been used for the plan, the design, and the operation of highway. Since 1955, traffic survey has been nation- widely carried out at national highway and the regular survey in national highway has been conducted at the intersections of highways. However, it is critical issue to select the priority of the regular survey because it is almost impossible to conduct regular survey at all intersections of national highways. In this study, MCDM(Multiple Criteria Decision Making) using AHP(Analytic Hierarchy Process) was applied to decide the priority of the regular survey. The following standard variables for determining the priority was selected the highway plan variables[AADT, VKT, Peak Hourly Volume, Location of highway from Urban], the highway design variables[Volume(pcu), Directional Traffic Volume, Heavy Vehicle Rate], and the highway operation variables[Speed, Density, V/C]. The standard variables were quantified and normalized. Using the Eigen vector method, the weighted values of each hierarchy based on the pair-wise comparison values from the questionnaire survey were calculated. The selection of the priority of regular survey was dependent on the size of the product of the weighted values for each hierarchy and the normalized values for the standard variables. Finally, the priority of regular survey of the intersections of national highways was determined according to the order in the size of the product of two values.

• Journal of Environmental Policy
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• v.13 no.3
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• pp.43-73
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• 2014

Cities in Korea have rapidly urbanized and they are not well prepared for natural disasters which have been increased by climate change. In particular, they often struggle with urban flooding. Recently, green infrastructure has been emphasized as a critical strategy for flood mitigation in developed countries due to its capability to infiltrate water into the ground, provide the ability to absorb and store rainfall, and contribute to mitigating floods. However, in Korea, green infrastructure planning only focuses on esthetic functions or accessibility, and does not think how other functions such as flood mitigation, can be effectively realized. Based on this, we address this critical gap by suggesting the new green infrastructure planning framework for improving urban water cycle and maximizing flood mitigation capacity. This framework includes flood vulnerability assessment for identifying flood risk area and deciding suitable locations for green infrastructure. We propose the use of the combination of frequency ratio model and GIS for flood vulnerability assessment. The framework also includes the selection process of green infrastructure practices under local conditions such as geography, flood experience and finance. Finally, we applied this planning framework to the case study area, namely YeonJe-gu an Nam-gu in Busan. We expect this framework will be incorporated into green infrastructure spatial planning to provide effective decision making process regarding location and design of green infrastructure.

• Journal of the Institute of Convergence Signal Processing
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• v.23 no.4
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• pp.200-208
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• 2022

In this study, an automatic information collection system and geographic information construction algorithm for the transportation disadvantaged using electric mobility aids are implemented using an object recognition model. Recognizes objects that the disabled person encounters while moving, and acquires coordinate information. It provides an improved route selection map compared to the existing geographic information for the disabled. Data collection consists of a total of four layers including the HW layer. It collects image information and location information, transmits them to the server, recognizes, and extracts data necessary for geographic information generation through the process of classification. A driving experiment is conducted in an actual barrier-free zone, and during this process, it is confirmed how efficiently the algorithm for collecting actual data and generating geographic information is generated.The geographic information processing performance was confirmed to be 70.92 EA/s in the first round, 70.69 EA/s in the second round, and 70.98 EA/s in the third round, with an average of 70.86 EA/s in three experiments, and it took about 4 seconds to be reflected in the actual geographic information. From the experimental results, it was confirmed that the walking weak using electric mobility aids can drive safely using new geographic information provided faster than now.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.3
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• pp.149-159
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• 2018

The study is aimed at establishing basic data to identify the original forms of the garden in Unbo's House. Through interviews and related data comparison analysis the ideas and major events of the person involved in establishing a garden in Unbo's House. Also, derived the direct and indirect effects of these people on gardening. The results are as follows: First, Those directly related to garden in Unbo's House are representative figures of cultural heritage and traditional art in Korea. Based on their expertise and abundant experience in traditional spaces, they contributed greatly to the creation of Unbo's House as a traditional space. Unbo Kim, Gi-Chang who directly influenced Unbo's House gardening, which affected the site selection, location, and the installation of major garden plant plants and traditional landscaping facilities. Hyegok Choi, Soon-Woo recommended Wabon Kim, Dong-Hyun at the request of Kim Ki-Chang and was involved in the overall plan. Housing design, space design and design of major facilities such as pond were confirmed Wabon Kim Dong-Hyun. Second, Kim, Gi-Chang's wife Jeong, Rae-Hyun, who motived to construct a garden. Nosan Lee, Eun-Sang and Korean artist Lee, Seok-Ho were created a signboard and board of the Pillar to encourage simple life in paintings. The themes of the article motived image as creative. In addition, Kim, Hyeong-Sik and Kim, Wan who son of Unbo, has been with Unbo for a long time, watching and influencing garden changes in Unbo's House. Third, The main factors that influenced the garden by character are as follows. Unbo Kim, Ki-Chang had a thorough record-setting spirit and his longing for his mother and wife affected the selection of the site and setting the direction of the garden. His art world with the symbolic emphasis of traditional landscapes, including traditional facilities, and especially plant materials. Choi, Sun-Woo reflected his traditional consciousness and experience in the construction of Unbo's House. Kim, Dong-Hyun applied the basic framework of a traditional building based on Yeonkyongdang hall in Changdeokgung palace. He also reflected on the traditional landscaping design the facilities of ponds acquired through excavation of Donggung Palace and Wolji Pond, Gyeongju. Nosan Lee, Eun-Sang and Lee, Seok-Ho completed their unique place in Unbo's House. Kim, Hyung-Sik was involved in the process of changing, while Kim Wan ran the Unbo's House which he inherited from Kim, Ki-Chang.