• 제목/요약/키워드: Spatial Variables

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The Effects of Using Cane on Hemiplegic Gait of Strock Patients (뇌졸증으로 인한 편마비 보행의 시간적 공간적 요소 분석: 지팡이가 보행에 미치는 영향)

  • Lee hyun-ok;Kim byung-jo
    • The Journal of Korean Physical Therapy
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    • v.15 no.4
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    • pp.372-383
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    • 2003
  • The purpose of this study was to assess of cane use on the hemiplegic gait of strock patients in temporal and spatial variables. Subjects were thirteen including 8 men and 5 women. They could walk independently without cane, To compare the effect of walking with and without a cane, temporal and spatial variables was measured using GAITRite. Cane walking demonstrated increased stance time on the affected side, and swing time, step length on the sound side were increased, and base of support was decreased. In conclusion, hemiplegic gait pattern of strock patients were improved with cane than those not using a cane.

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Comparative Study of Bursting Force Equations for Post-Tensioned Anchorage Zones (포스트텐션 정착구역에서의 파열력 산정식 비교 분석)

  • Kim, Min Sook;Yoon, Chi Ho;Lee, Young Hak
    • Journal of Korean Association for Spatial Structures
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    • v.17 no.4
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    • pp.69-76
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    • 2017
  • For evaluating equations of bursting force in different codes, comparative study of the formulas was conducted. Because the equations does not consider variables such as shape of anchorages, angle of tendons, and eccentricity, a relation between the bursting forces and the variables has to be analyzed. In this paper, therefore, a comparative analysis of bursting forces computed by equations in the codes and finite element analysis was performed. As a result, it could be figured out that bursting force equations in the local zone were determined by coefficient k.

Seismic Characteristics Evaluation According to Construction and Configuration Types of Fortress Structure (성곽구조물의 축조 및 구성형식에 따른 내진특성평가)

  • Kim, Ho-Soo;Yoo, Jun;Kim, So-Yeon;Kim, Jin-Wan
    • Journal of Korean Association for Spatial Structures
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    • v.17 no.2
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    • pp.63-70
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    • 2017
  • In Korea, the occurrence frequency of earthquakes has recently increased, compared with the past. So, the various damages for cultural properties due to earthquake can be expected, and especially fortress structure is vulnerable to earthquake. Therefore, the resonable seismic characteristics evaluation is required to secure the safety for fortress structure with the various construction and configuration types. Also, we should consider the various applied load conditions as design variables. To this end, this study classifies fortress structures according to the construction and configuration types, and then applies the discrete element method to model and analyze fortress structures. Finally, the seismic characteristics is evaluated through slip condition due to the analysis results considering the various design variables.

Development of a Consistent General Order Nodal Method for Solving the Three-Dimensional, Multigroup, Static Neutron Diffusion Equation

  • Kim, H.D.
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05a
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    • pp.34-39
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    • 1996
  • A consistent general order nodal method for solving the 3-D neutron diffusion equation in (x-y-z) geometry has ben derived by using a weighted integral technique and expanding the spatial variables by the Legendre orthogonal series function. The equation set derived can be converted into any order nodal schemes. It forms a compact system for general order of nodal moments. The method utilizes the analytic solutions of the transverse-integrated quasi -one dimensional equations and a consistent expansion for the spatial variables so that it renders the use of an approximation for the transverse leakages no necessary. Thus, we can expect extremely accurate solutions and the solution would converge exactly when the mesh width is decreased or the approximation order is increased since the equation set is consistent mathematically.

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Zero-Stress Member Selection for Sizing Optimization of Truss Structures (트러스 구조물 사이즈 최적화를 위한 무응력 부재의 선택)

  • Lee, Seunghye;Lee, Jonghyun;Lee, Kihak;Lee, Jaehong
    • Journal of Korean Association for Spatial Structures
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    • v.21 no.1
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    • pp.61-70
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    • 2021
  • This paper describes a novel zero-stress member selecting method for sizing optimization of truss structures. When a sizing optimization method with static constraints is implemented, the member stresses are affected sensitively with changing the variables. However, because some truss members are unaffected by specific loading cases, zero-stress states are experienced by the elements. The zero-stress members could affect the computational cost and time of sizing optimization processes. Feature selection approaches can be then used to eliminate the zero-stress member from the whole variables prior to the process of optimization. Several numerical truss examples are tested using the proposed methods.

Optimization of spatial truss towers based on Rao algorithms

  • Grzywinski, Maksym
    • Structural Engineering and Mechanics
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    • v.81 no.3
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    • pp.367-378
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    • 2022
  • In this study, combined size and shape optimization of spatial truss tower structures are presented by using new optimization algorithms named Rao-1, and Rao-2. The nodal displacements, allowable stress and buckling for compressive members are taken into account as structural constraints for truss towers. The discrete and continuous design variables are used as design variables for size and shape optimization. To show the efficiency of the proposed optimization algorithm, 25-bar, and 39-bar 3D truss towers are solved for combined size and shape optimization. The 72-bar, and 160-bar 3D truss towers are solved only by size optimization. The optimal results obtained from this study are compared to those given in the literature to illustrate the efficiency and robustness of the proposed algorithm. The structural analysis and the optimization process are coded in MATLAB programming.

An Empirical Study on the Correlation between TOD Planning Elements and Subway Ridership in Busan Metropolitan City (부산시 역세권 TOD계획요소의 공간특성과 지하철 이용객 수의 상관성에 관한 실증연구)

  • Choi, Don-Jeong;Suh, Yong-Cheol
    • Journal of the Korean Association of Geographic Information Studies
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    • v.17 no.3
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    • pp.147-159
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    • 2014
  • Public transportation ridership and walkability of urban district can be enhanced through high quality of TOD(Transit Oriented Development) elements. Generally, TOD have been evaluated several physical components such as the diversity of land use pattern, accessibility of public transportation and aspects of urban design around the station area. Especially, Spatial characteristics of TOD planning elements have many potential dependent when considering the characteristics of Rail Station-Influenced Area Development which is performing around subway station. Therefore, researchers should be considering the variation of spatial properties for planning elements according the set of spatial area and their socioeconomic factors. However, existing many cases related TOD does not consider about this point. In this paper, the changes of TOD characteristics were analyzed by different spatial units surrounding subway station in Busan Metropolitan City. Multiple Regression Analysis was performed for an investigation of effective spatial unit of TOD planning elements in this area using subway ridership data. In addition, the application validity of socioeconomic variables was examined through a comparative analysis of regression results with the multiple regression that implied only physical TOD elements. As the result, the variation of spatial properties for TOD planning elements according to the set of spatial unit was found. Furthermore, the specific spatial unit to applicable TOD elements in this area was derived. And the multiple regression model which added socioeconomic variables was derived more improved estimate results than the multiple regression model that implied only physical TOD elements.

Spatial Econometrics Analysis of Fire Occurrence According to Type of Facilities (시설물 유형에 따른 화재 발생의 공간 계량 분석)

  • Seo, Min Song;Yoo, Hwan Hee
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.37 no.3
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    • pp.129-141
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    • 2019
  • In recent years, fast growing cities in Korea are showing signs of being vulnerable to more disasters as their population and facilities increase and intensify. In particular, fire is one of the most common disasters in Korea's cities, along with traffic accidents. Therefore, in this study, we analyze what type of factors affect the fire that threatens urban people. Fire data were acquired for 10 years, from 2007 to 2017, in Jinju, Korea. Spatial distribution pattern of fire occurrence in Jinju was assessed through the spatial autocorrelation analysis. First, spatial autocorrelation analysis was carried out to grasp the spatial distribution pattern of fire occurrence in Jinju city. In addition, correlation and multiple regression analysis were used to confirm spatial dependency and abnormality among factors. Based on this, OLS (Ordinary Least Square) regression analysis was performed using space weighting considering fire location and spatial location of each facility. As a result, First, LISA (Local Indicator of Spatial Association) analysis of the occurrence of fire in Jinju shows that the most central commercial area are fire department, industrial area, and residential area. Second, the OLS regression model was analyzed by applying spatial weighting, focusing on the most derived factors of multiple regression analysis, by integrating population and social variables and physical variables. As a result, the second kind of neighborhood living facility showed the highest correlation with the fire occurrence, followed by the following in the order of single house, sales facility, first type of neighborhood living facility, and number of households. The results of this study are expected to be useful for analyzing the fire occurrence factors of each facility in urban areas and establishing fire safety measures.

The Relationship between Residential Distribution of Immigrants and Crime in South Korea

  • Park, Yoonhwan
    • Journal of Distribution Science
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    • v.16 no.7
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    • pp.47-56
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    • 2018
  • Purpose - This study aims to not only investigate spatial pattern of immigrants' residence and crime occurrences in South Korea, but shed light on how geographic distribution of immigrants and immigrant segregation affect crime rates. Research design, data, and methodology - Th unit of analysis is Si-Gun-Gu municipal level entities of South Korea. The crime data was obtained by Korea National Police Agency and two major types(violence and property) of crime were measured. Most demographic, social, and economic variables were derived from Korean Census Data in 2015. In order to examine spatial patterns of immigrants' distribution and crime rates in South Korea, the present study utilized GIS mapping technique and Exploratory Spatial Data Analysis(ESDA) tools. The causal linkage was investigated by a series of regression models using STATA. Results - Spatial inequality between urban metropolitan vs rural areas was visualized by mapping. Assuming large Moran's I value, spatial autocorrelation appeared to be quite strong. Several neighborhood characteristics such as residential stability and economic prosperity were found to be important factors leading to crime rate change. Residential distribution and segregation for immigrants were negatively significant in the regression models. Conclusions - Unlike the traditional arguments of social disorganization theory, immigrant segregation appeared to reduce violent crime rate and the high proportion of immigrants also turned out to be a crime prevention factor.

Spatial Interpolation of Meteorologic Variables in Vietnam using the Kriging Method

  • Nguyen, Xuan Thanh;Nguyen, Ba Tung;Do, Khac Phong;Bui, Quang Hung;Nguyen, Thi Nhat Thanh;Vuong, Van Quynh;Le, Thanh Ha
    • Journal of Information Processing Systems
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    • v.11 no.1
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    • pp.134-147
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    • 2015
  • This paper presents the applications of Kriging spatial interpolation methods for meteorologic variables, including temperature and relative humidity, in regions of Vietnam. Three types of interpolation methods are used, which are as follows: Ordinary Kriging, Universal Kriging, and Universal Kriging plus Digital Elevation model correction. The input meteorologic data was collected from 98 ground weather stations throughout Vietnam and the outputs were interpolated temperature and relative humidity gridded fields, along with their error maps. The experimental results showed that Universal Kriging plus the digital elevation model correction method outperformed the two other methods when applied to temperature. The interpolation effectiveness of Ordinary Kriging and Universal Kriging were almost the same when applied to both temperature and relative humidity.