• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.3
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• pp.143-149
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• 2019

In this study, a U-shape composite beam was developed to be effectively used for a steel parking lot which is 8m or lower in height. When the U-shape composite beam was applied to a steel parking lot, essential considerations were story-height and long-span. In addition, due to the mixed structural system with reinforced concrete and steel material, the U-shape composite beam needed to have a structural integrity and reliable performance over demand capacity. The main objective of this study was to investigate the performance of the structure consisting of the reinforced concrete (RC) slab and U-shape beam. A U-shape composite beam generally used at a parking lot served as a control specimen. Four specimens were tested under four-point bending. To calculate theoretical values, strain gauges were attached to rebar, steel plate, and concrete surface in the middle of the specimens. As the results, initial yielding strength of the control specimen occurred at the bottom of the U-shaped steel. After yielding, the specimen reached the maximum strength and the RC slab concrete was finally failed by concrete crush due to compressive stress. The structural performance such as flexural strength and ductility of the specimen with the increased beam depth was significantly improved in comparison with the control specimen. Furthermore, the design of the U-shape composite beam with the consideration of flexural strength and ductility was effective since the structural performance by a negative loading was relatively decreased but the ductile behavior was evidently improved.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3A
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• pp.341-347
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• 2008

Among coating systems used for steel bridge coatings on highway such as red lead-pigmented alkyd, chlorinated rubber, waterborne inorganic zinc, inorganic zinc/epoxy/urethane and inorganic zinc/epoxy/fluororesin, evaluation of deterioration degree and prediction of lifetime through regression analysis were carried out for coating systems widely used and grossly degraded. For evaluation of deterioration degree, 75 bridges on highway were selected, and evaluations were carried out according to point offering method regulated by Guideline of maintenance coating for steel bridges used in Korea Expressway Corporation. Lifetime prediction results showed 13.0~13.3 years for the whole nation, 11.8 years for urban and industrial region in the metropolitan area, 13.2 years for rural region except the metropolitan area, 13.5~13.7 years for chlorinated rubber coating systems, and 12.86 years for red lead-pigmented alkyd systems. For prediction of the rest life of coating, we tried to execute parallel translations of standard deterioration curve to current life and deterioration degree for both x and y axes, and it was thought that parallel translation for x axis corresponded to deterioration aspects in actual environment. Maximum and minimum equations were derived from standard deterioration equation by adding and subtracting error values deduced in regression analysis to/from each coefficient in order to establish maintenance coating criteria for overall steel bridges on highway. Whole domain was divided into 8 parts in order to predict the rest life of coating and optimum time of maintenance coating, and maintenance coating criteria for each 8 domains were presented.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.3
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• pp.9-20
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• 2008

The government is planning to link a small park with the soon to be ready subway line 9 as a part of Seoul's policy, "The standard or plan for making a water-friendly space by water use" (2007). However, the specified concepts and instructions of the small parks need further work. Therefore, the policy is expected to expand to neighboring small parks near the subway station, but these are not supported by research or data which suggests the needs or actual user behavior and utilization of small parks. our country added the specified concept of small parks and theme parks to the classification of urban parks in the Urban Park Act Revision (2005.3.31), but the concept of small parks is not clearly settled in the law in the scopes of its function, scale, promotion nor particularly defined plans for small park projects. This study examines as small park near a subway station. The characteristics of there region and users vary from the characteristics of the station and region. In the "directions for concrete standards under the types of urban parks and green zones" (2007.2) the types of small parks are classified by "regional characteristics" and "user characteristics". Therefore, this study classifies the subject of neighboring small parks near subway stations as the neighborhood and small urban parks according to the Urban Park Act. The study was paralleled with observation and questionnaires on the analysis of the neighborhood and small urban parks. The actual conditions of park utilization and user behavioral characteristics were deducted by observation, while the questionnaire determined actual user utilization, importance and satisfaction level as well as the small park environment. This study largely focused on three aspects: park facility, design of this sentence isn't even complete. The second aspect isn't finished and the third isn't here.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.561-569
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• 2020

This study was done to develop indicators for cities that can be used in the long term and in a sustainable manner. Activation indicators were developed to improve the resilience in the downtown area of Seo-gu, Incheon. Preliminary indicators were derived from prior studies on similar indicators of resilience for urban regeneration, and an expert opinion survey was conducted to analyze the suitability and importance of the indicators. Activation indicators were established for improving urban resilience in six areas: population stability, social inclusion, industrial diversity, local productivity, environmental sustainability, and social-based convenience. From 60 preliminary indicators, 42 indicators were selected through the expert opinion surveys for securing an economically active population, establishing a living infrastructure, improving the settlement environment, and upgrading industry to reflect the characteristics of the West, including industrial complexes. It was found that diversification is necessary. Further study is still necessary to improve the objectivity of the indicators and calculate a resilience index. The significance of this study is that it looks at quantitative indicators, complements other studies on regional decline diagnosis, and presents realistic alternatives suitable for domestic situations based on the concept of resilience.

• Journal of the Korean Regional Science Association
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• v.37 no.2
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• pp.63-82
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• 2021

This study aims to explore how manufacturing start-up activities from 2000 to 2018 have changed spatially and to predict changes in distribution patterns of future start-up activities. For the analysis, the Census on Establishments microdata from 2000 to 2018 were used, and the manufacturing industry was classified into four detailed industrial groups according to the 40 manufacturing standards presented by the Korea Institute for Industrial Economics and Trade's ISTANS. According to the results, start-up activities in industries that require high technology levels are concentrated in southern Gyeonggi region, and other start-up activities are concentrated outside of the metropolitan area. When the distribution change from 2018 to 2036, extending the trend from 2000 to 2018, it was confirmed that there was a high possibility of a rise in the hierarchy in the future in regions adjacent to regions where start-up activities occur. This study aimed to provide implications for regional policies related to fostering start-ups and creating jobs by dynamically analyzing the location pattern of manufacturing start-ups, which is a major source of job creation.

• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.561-580
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• 2021

This study analyses the historical and cultural streets at Pinggang Road in the city of Suzhou, by understanding the development and conservation of the area, and uses the following ways to investigate its development, re-organization, and current state. This paper comprehensively compares, collates and investigates 4 different historical and cultural areas in Insadong and Samcheong-dong in South Korea, and South Luogu Lane in China. From initial research and analysis, this paper gathers the cultural, economic, and societal perspectives as non-physical measures, and spatial structure, road structure, and building maintenance as physical factor framework. It is significant in that it can provide an evaluation model for the preservation and regeneration of historical and cultural streets by presenting the viewpoint of complex development of non-physical and physical elements in Pyeonggang-ro. In addition, it is necessary to conduct optimization and specific research on insufficient areas, such as maintenance and development of programs and signature systems for visitors, and continuous development of historical and cultural network platforms by combining on-site surveys. Basic data should be provided for reference on the street.

• Journal of Software Assessment and Valuation
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• v.16 no.2
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• pp.99-107
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• 2020

An underground integrated map is being built for underground safety management and is being updated periodically. The map update proceeds with the procedure of deleting all previously stored objects and saving newly entered objects. However, even unchanged objects are repeatedly stored, deleted, and stored. That causes the delay of the update time. In this study, in order to shorten the update time of the integrated map, an updated object and an unupdated object are separated, and only updated objects are reflected in the underground integrated map, and a system implementing this technology is described. For the updated object, an object comparison method using the center point of the object is used, and a quad tree is used to improve the search speed. The types of updated objects are classified into addition and deletion using the shape of the object, and change using its attributes. The proposed system consists of update object detection, extraction, conversion, storage, and history management modules. This system has the advantage of being able to update the integrated map about four times faster than the existing method based on the data used in the experiment, and has the advantage that it can be applied to both ground and underground facilities.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.2
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• pp.89-100
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• 2021

This study evaluated the degree of interaction between the people and the environment using perceived naturalness measure. The seventh-grade index of Hemeroby was divided into subclasses of land cover according to degrees of human influence. The grade was standardized for each indicator to evaluate the current state of urban parks in Seoul by applying probability density function and weight. User evaluation was conducted on six distinctive parks selected. In the results, three implications were found between spatial evaluation according to the perceived naturalness. First, park users evaluated highly for the spaces such as broad-leaved forest, coniferous forest and mixed forest evaluated highly in the Hemeroby grade index. Park users generally recognized that various types of trees in the area had high naturalness. The density of trees is one of the factors in perceived naturalness. Second, water spaces were highly evaluated for naturalness in the Hemeroby grade index. However, the perceived naturalness of water spaces such as inland wetlands, pond and reservoir evaluated in various ways depending on environmental conditions around the park. Third, perceived naturalness is easily evaluated through vertical landscape elements such as trees rather than horizontal landscapes such as grassland. The perceived naturalness is similar to the naturalness evaluation using land cover. However the study found the perceived naturalness for a specific space was different from the Hemeroby index. Perceived naturalness by the user includes the content that the individual sees, hears, and experiences. Park users are usually structuring naturalness through evaluating the value of urban green spaces based on personal perception. Therefore there is no absolute standard criterion for evaluating the naturalness of urban green spaces. A deeper study is needed that considers user bundles or user groups with conflicting interests on the perceived naturalness in urban parks. These studies will be essential data on the direction of naturalness urban park service should provide.

• Journal of the Korean GEO-environmental Society
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• v.17 no.3
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• pp.21-26
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• 2016

Soil particle shape analysis was conducted with sands from Jumujun, Korea and Ras Al Khair, Saudi Arabia. Two hundred times enlarged digital images of the particles of those two sands were obtained with an optical microscope. The resolution of the digital images was $640{\times}320$. By conducting digital image processing, the coordinates of the soil particle boundary were extracted. After mapping those coordinates to the complex space, Fourier transformation was performed and the coefficients of each trigonometry term were computed. The coefficients reflect the shape characteristics of the sand grains and are invariant to translation. To evaluate the shape itself excluding the size of the soil particle, the coefficient was normalized by the equivalent radius of soil particle; this is called Fourier descriptor. After analyzing the Fourier descriptors, it was found that the major characteristics of Jumunjin and Ras Al Khair sands were elongation and asymmetry. Furthermore, it was found that the particle shapes reflect the self-similar, fractal nature of the textural features. The effects of resolution on soil particle shape analysis was also studied. Regarding this, it was found that the significant Fourier descriptors were not significantly affected by the image resolution investigated in this study, but the descriptors associated with textural features were affected.

• Analytical Science and Technology
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• v.7 no.3
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• pp.329-338
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• 1994

The retention behaviors of natural gas components were studied on a single column by gas chromatography. The dead time, $t_0$ was obtained by using extrapolation of homologous series to determine capacity factors. The plots of retention data for homologous series and carbon number at different temperatures were shown to converge into a single point, which point was determined as a dead time. The results of the effect of temperature on the column efficiency for n-butane exhibited the plate number, N incerased with temperature, but the resolution among the fast eluted components decreased. The adsorption enthalpy (${\Delta}H^0{_{ads}}$) for each component on 28% DC 200 stationary phase was determined, and in order to investigate the retention behaviors of natural gas components the regression analysis of log $t_R$, log k' and log ${\alpha}$ vs. van der Waals volume(Vw), molecular connectivity index(X) and hydrophobic fragmental constant(f) were carred out. Good correlation was found between log k' vs. Vw, and log k' vs. f. The correlations between the physical properties of natural gas and the physical parameters were investigated by the linear regression analysis. The relationships between Vw vs. molecular weight and heating value(${\Delta}H_{comb}$), X vs. boiling point, and f vs. molecular weight, boiling point and heating value exhibited the high correlation coefficient more than 0.99. Using the regression equation between the heating value of natural gas and Vw the predicted heating values from $C_6$ to $C_{10}$ showed good agreement with those reported in the literature within 0.2% relative error.