• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.5
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• pp.83-99
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• 2021

With the advent of the fourth industrial revolution, studies on driving management and driving strategies of autonomous vehicles are emerging. While obtaining microscopic traffic data on vehicles is essential for such research, we also see that conventional traffic data collection methods cannot collect the driving behavior of individual vehicles. In this study, UAV videos were used to collect traffic data from the viewpoint of the aerial base that is microscopic. To overcome the limitations of the related research in the literature, the micro-traffic data were estimated using the multiple object tracking of deep learning and an image registration technique. As a result, the speed obtained error rates of MAE 3.49 km/h, RMSE 4.43 km/h, and MAPE 5.18 km/h, and the traffic obtained a precision of 98.07% and a recall of 97.86%.

• Journal of Korean Association for Spatial Structures
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• v.7 no.3 s.25
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• pp.79-86
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• 2007

Recently, as steel structures become higher and more long-spanned, construction of high-strength steels is increasing gradually. Application of high-strength steel can be possible to make a more light and economic steel structures by reducing thickness and space. To apply a high-strength steel to structure, criteria of high-strength steel for buckling is required. However, current specification is not sufficient for criteria of high-strength steels. In this paper, buckling behavior of high-strength steel truss columns with box sections is investigated by using three-dimensional elastic-plastic finite deformation analysis program. The criteria equation for allowable compressive stress of high-strength steel truss columns with box sections is proposed and confirmed the applicability. It is reasonable form analytical results that formulated equations after finding the upper limit of allowable axial direction compression stresses of high-strength steel truss columns. And new equation is suitable to buckling design of high-strength steel truss columns.

• Journal of Korean Association for Spatial Structures
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• v.12 no.2
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• pp.109-118
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• 2012

Few paper deal with the dynamic bucking under the load with periodic characteristics, and the behavior under periodic excitation is expected the different behavior against STEP excitation. A space frame structure has high stiffness with a structure resisting external forces in steric conformation. According to many structural conditions, structural stability problems in the space frame are determined and considered very important. This study seeks to understand the space frame collapse mechanism using the 2-free nodes truss model in order to examine static structural instability characteristics of the latticed dome. According to geometrical shape, the star dome, parallel lamella dome and three way grid dome were selected as models. The models were examined for characteristics of instability behavior according to rise-span ratio(${\mu}$) and shape imperfection.

• Journal of Industrial Convergence
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• v.21 no.4
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• pp.13-22
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• 2023

Due to COVID-19, organizations are rapidly changing the way they work by providing telecommuting and flexible work, and by expanding Smart Work spaces. In a Smart Work situation, workers have improved their job autonomy to choose their work methods, hours, and places. However, previous studies do not reflect the Smart Work situation and there are limitations to still using the previous job autonomy concept and measurements. To overcome these problems, this study derived job autonomy types such as methods, scheduling, criteria, time, and place applicable to Smart Work environments and verified that the five types of job autonomy have a statistically significant positive effect on Smart Workers' creative behavior. This study is meaningful in that it categorized job autonomy into five types applicable to Smart Work by adding temporal and spatial flexibility to the traditional job autonomy concept such as method, scheduling, and criteria autonomy and provided the basis for subdividing and evaluating the operation performance of Smart Work through multi-dimensional job autonomy verification.

• Asia Marketing Journal
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• v.15 no.1
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• pp.107-128
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• 2013

When Korea's retail industry was liberalized, new store formats such as large discount stores and Super Supermarket(SSMs) have grown. New types of business have borne significant influence on traditional market. Traditional markets have been in gradual decline since they fail to meet to consumer's purchasing behavior. The South Korean government has been making sustained efforts to revitalize the modernization of traditional markets since 2004. This research is conducted to analyze how changes in the distribution of different types of distributors influence the consumer's purchasing behaviors depending on the changes in the market environment. The purpose of this research is to present a policy to invigorate consumer-oriented traditional markets by analyzing the consumption behavior among major retail channels at a point when competition among retail channels is becoming intensified. In order to examine the effect of the spatial competitive landscape among major retail channels on consumption behavior, an empirical analysis was conducted with 613 consumers in 6 cities nationwide, using the multiple regression model. This research identified three main areas of factors. The analysis result indicates that the physical factor (time required to go to the traditional market), socioeconomic factors (the number of vehicles owned and average monthly income), and competitive factors (intensity of competition in spatial locations and average monthly spending in supermarkets) have significant influence on consumption patterns of consumers. The findings present that the Korean government should go ahead with policies aimed to revitalize traditional markets, keeping in mind the factors that influence the consumption patterns of customers based on these results. We propose that the policy supporting traditional markets need to be a customized-strategy, considering traditional market's characteristic.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.6
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• pp.281-287
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• 2001

In order to obtain guidelines for design and operation of a new plasma source by a magnetic neutral loop discharge(NLD), the electron behavior was studied experimentally and numerically. Experimentally, the magnetic field gradient was changed over a wide range, and it was found that there existed an optimum value for efficient plasma production. Analyses of the electron behavior were performed using a model that included effects of a three dimensional electromagnetic field configuration considering the spatial decay of the electric field, and the limitation to the motion of electron caused by the existence of walls and thus electron loss at wall surfaces. These three dimensional factors were found to explain the existence of the optimum magnetic field gradient. It was shown that the L dependence of the plasma production efficiency was firstly decided by the finite decay length of the electric field strength, which was further modified by electron elastic collisions with neutral atoms which drove the electron to walls. The latter effect tends to reduce the optimum value of L.

• Environmental Engineering Research
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• v.13 no.3
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• pp.107-111
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• 2008

Water quality contamination issues are of critical concern to human health, whilst pesticide release generated from irrigated land should be considered for protecting natural habitats and human health. This paper suggests new method for evaluation and analysis using the GIS technique based on integrated spatial modeling framework. The pesticide use on irrigated land is a subset of the larger spectrum of industrial chemicals used in modern society. The behavior of a pesticide is affected by the natural affinity of the chemical for one of four environmental compartments; solid matter, liquid, gaseous form, and biota. However, the major movements are a physical transport over the ground surface by rainfall-runoff and irrigation-runoff. The irrigated water carries out with the transporting sediments and makes contaminated water by pesticide. This paper focuses on risk impact identification and assessment using GIS technique. Also, generated data on pesticide residues on farmland and surface water through GIS simulation will be reflected to environmental research programs. Finally, this study indicates that GIS application is a beneficial tool for spatial pesticide impact analysis as well as environmental risk assessment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5608-5618
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• 2015

This study conducted a spatial characterization of the public space using the pattern language of Christopher Alexander. It is the place which the city offers the human various experience. Urban public space has played an important role in flourishing public life through history. It has been a place for communication, cultural events, commercial exchange recreation, etc. among people in the city. But today, various behavior in public space and public life are declined. One of the reason in neglecting the user's need when urban space are planned and managed. This study examined the role and types of urban public space through literature survey and found the reason for its decline. For this public space spatial characteristics and indicators by FGI(Focus Group Interview) derived through. After those, case study was examined Jongro in Seoul and analyzed the spatial characteristics of the urban public space in a pattern language. Consequently, this study presents suitable a space structure direction of the public space and do for rather abundant a city space furtherance.

• Journal of Korean Association for Spatial Structures
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• v.8 no.1
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• pp.41-48
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• 2008

Spatial structure is an appropriate shape that resists external force only with in-plane forte by reducing the influence of bending moment, and it maximizes the effectiveness of structure system. the spatial structure should be analyzed by nonlinear analysis regardless static and dynamic analysis because it accompanys large deflection for member. To analyze the spatial structure geometrical and material nonlinearity should be considered in the analysis. In this paper, a geometrically nonlinear finite element model for plane truss structures is developed, and material nonlinearity is also included in the analysis. Arc-length method is used to solve the nonlinear finite element model. It is found that the present analysis predicts accurate nonlinear behavior of plane truss.

• Journal of the Economic Geographical Society of Korea
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• v.10 no.1
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• pp.44-63
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• 2007

The purpose of this study is to propose mining processes in the large trip-transaction database of the Metropolitan Seoul area and to analyze the spatial characteristics of travel behavior. For the purpose. this study introduces a mining algorithm developed for exploring trip patterns from the large trip-transaction database produced every day by transit users in the Metropolitan Seoul area. The algorithm computes trip chains of transit users by using the bus routes and a graph of the subway stops in the Seoul subway network. We explore the transfer frequency of the transit users in their trip chains in a day transaction database of three different years. We find the number of transit users who transfer to other bus or subway is increasing yearly. From the trip chains of the large trip-transaction database, trip patterns are mined to analyze how transit users travel in the public transportation system. The mining algorithm is a kind of level-wise approaches to find frequent trip patterns. The resulting frequent patterns are illustrated to show top-ranked subway stations and bus stops in their supports. From the outputs, we explore the travel patterns of three different time zones in a day. We obtain sufficient differences in the spatial structures in the travel patterns of origin and destination depending on time zones. In order to examine the changes in the travel patterns along time, we apply the algorithm to one day data per year since 2004. The results are visualized by utilizing GIS, and then the spatial characteristics of travel patterns are analyzed. The spatial distribution of trip origins and destinations shows the sharp distinction among time zones.