• Title/Summary/Keyword: Neighborhood-Based

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Multi-Exchange Neighborhood Search Heuristics for the Multi-Source Capacitated Facility Location Problem

  • Chyu, Chiuh-Cheng;Chang, Wei-Shung
    • Industrial Engineering and Management Systems
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    • v.8 no.1
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    • pp.29-36
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    • 2009
  • We present two local-search based metaheuristics for the multi-source capacitated facility location problem. In such a problem, each customer's demand can be supplied by one or more facilities. The problem is NP-hard and the number of locations in the optimal solution is unknown. To keep the search process effective, the proposed methods adopt the following features: (1) a multi-exchange neighborhood structure, (2) a tabu list that keeps track of recently visited solutions, and (3) a multi-start to enhance the diversified search paths. The transportation simplex method is applied in an efficient manner to obtain the optimal solutions to neighbors of the current solution under the algorithm framework. Two in-and-out selection rules are also proposed in the algorithms with the purpose of finding promising solutions in a short computational time. Our computational results for some of the benchmark instances, as well as some instances generated using a method in the literature, have demonstrated the effectiveness of this approach.

Railway sleeper crack recognition based on edge detection and CNN

  • Wang, Gang;Xiang, Jiawei
    • Smart Structures and Systems
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    • v.28 no.6
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    • pp.779-789
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    • 2021
  • Cracks in railway sleeper are an inevitable condition and has a significant influence on the safety of railway system. Although the technology of railway sleeper condition monitoring using machine learning (ML) models has been widely applied, the crack recognition accuracy is still in need of improvement. In this paper, a two-stage method using edge detection and convolutional neural network (CNN) is proposed to reduce the burden of computing for detecting cracks in railway sleepers with high accuracy. In the first stage, the edge detection is carried out by using the 3×3 neighborhood range algorithm to find out the possible crack areas, and a series of mathematical morphology operations are further used to eliminate the influence of noise targets to the edge detection results. In the second stage, a CNN model is employed to classify the results of edge detection. Through the analysis of abundant images of sleepers with cracks, it is proved that the cracks detected by the neighborhood range algorithm are superior to those detected by Sobel and Canny algorithms, which can be classified by proposed CNN model with high accuracy.

Reduction of Block Overlap in Motion Estimation

  • Cho, Seongsoo;Shrestha, Bhanu;Lee, Jongsup
    • International Journal of Internet, Broadcasting and Communication
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    • v.6 no.2
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    • pp.10-12
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    • 2014
  • This work is based on the motion estimation to handle the ill-posed nature. The algorithm used in this study that performs the motion estimation for overlapped block is used to calculate with using pixel of neighborhood block with higher correlation and present block by considering the correlation level of neighborhood block. The proposed method shows in a significant improvement in the quality of the mothion field when comparing the conventional methods.

Setting Development Priorities of Undeveloped Neighborhood Parks in the Downtown of Cheongju City using a Park Development Pressure Index (공원조성 압력지수를 이용한 공원개발 우선순위 선정 - 청주시 도심 미개발근린공원을 대상으로 -)

  • Ban, Yong-Un;Lee, Tae-Ho
    • Journal of the Korean Institute of Landscape Architecture
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    • v.37 no.4
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    • pp.1-11
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    • 2009
  • This study was intended to set development priorities for five undeveloped neighborhood parks scattered throughout the downtown area of Cheongju City using a PDPI(Park Development Pressure Index). In order to calculate the PDPI, this study employed an additive integration method. The PDPI was graded from 1 to 5, based on the evaluation scores in accordance with nine indicators selected through literature reviews and interviews with public officials. The indicators have been classified into three categories: physical environment, utilization possibility, and facility distribution. The indicators are as follows: 1) 'altitude and inclination' and 'NDVI' as physical environment indicators; 2) 'ratio of residential area', 'forecasted utility population', 'undeveloped period', 'redevelopment near parks', 'ratio of area divided by main streets', reflecting utilization possibility; and 3) 'Distance between Neighborhood Parks' and 'Distribution of alternative facilities' as facility distribution. The following results were found: 1) three neighborhood parks including 'Sagic 2', 'Sachen', and 'Dangsan' were ranked in the first grade of PDPI; and, 2) one neighborhood park 'Samsungdang' was ranked in the fifth grade of PDPI. The above results mean that among undeveloped neighborhood parks, three have been exposed to extremely strong park development pressure, and that while two neighborhood parks have had strong exposure to park development pressure due to potential users according to their close location to Sagic Ro, an east-west main axis of Cheongju City, one neighborhood park has had weak exposure to development pressure because of the close location to 'Chuungbuk National University' and a lack of residential areas, showing a low possibility for development.

Analysis of Child-Friendly Environment in a Neighborhood Park in Child-Friendly City - Focused on the Moraetmal Neighborhood Park of Seongbuk-gu - (아동친화도시 근린공원의 아동친화환경 분석 - 성북구 모랫말 근린공원을 중심으로 -)

  • Choi, Jin-Ho;Kim, Ah-Yeon
    • Journal of the Korean Institute of Landscape Architecture
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    • v.47 no.6
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    • pp.87-102
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    • 2019
  • Since the Child Friendly Cities Initiative(CFCI), a UNICEF-led initiative, was first introduced to Seongbuk-gu in 2013, more than half of the districts of Seoul are making efforts to achieve the accreditation of the Child Friendly City(CFC). At this point, when an initiative is transformed from a special policy of a few districts into a general policy of many local governments, we need to examine and check on how friendly urban parks are to children. This study focused on neighborhood parks that tend to be less friendly to children as compared to children's parks and looked into the current status, because neighborhood parks are also well used by users of all ages including children. The evaluation criteria was developed based on the review of domestic and international guidelines of child friendly parks and neighborhood parks. Futhermore, field studies, user questionnaire, and a participatory design workshop were introduced to analyze the status of child-friendly environment of neighborhood parks. Findings are as follows. First, vague definitions of child cause the inconsistency of child-related policies. Second, Neighborhood parks are not conceived as a public space for children. Third, the consideration of youth is relatively low. Fourth, adjacent area of a park turns out not to be child friendly as well.

Development and Effectiveness Analysis of Workshop Program for Child Safety Map Making (아동안전지도 제작을 위한 워크숍 프로그램 개발 및 효과분석)

  • Son, Dong-Pil;Lee, Kyung-Hwan;Chae, Han-Hee
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.35 no.7
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    • pp.109-117
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    • 2019
  • Recently, child safety map making education has attracted attention as a way to reduce crimes against children. In Korea, the Ministry of Gender Equality and Family organized a child safety map making education program in 2011. The program's manual was revised in 2013 and the Ministry implemented it as a project to promote the rights of women and children. Child safety map making education aims to raise a child's understanding of their neighborhood, to have voluntary control and normal consciousness as a local inhabitant, to be aware of wrong behavior and crime, and to be part of creating a safe urban environment. However, when compared to educational programs in other major developed countries, the child safety map making education program in Korea currently does not improve a child's awareness of their surroundings. In this workshop study, we proposed and ran a new program to improve children's awareness of their environment based on the active participation of children in the existing safety map educational program. The workshop was held for 4 weeks for 48 students from 5th and 6th grade at Osan Daeho Elementary School. We analyzed this new program's effects with the following results. First, an analysis of the effects of the program on children's recognition of safe and dangerous spaces revealed that their understanding of these spaces increased by 30.4% after the workshop. The safety-related factor in the mind map key concept increased from 0.94 to 4.94, indicating that the children's perception of neighborhood risk and safety factors improved. Second, the analysis of the effects of the program on the children's coping ability in dangerous situations showed that their understanding of how to deal with dangerous situations increased by 11.3%. The children's understanding of facilities they could ask for help, such as police boxes and child safety guard houses, improved by 17.9%. Third, analysis of the effects of child safety map making education on children's understanding of their neighborhood, their perception of responsibility in the neighborhood, and their neighborhood attachment showed that these levels of children's understanding of the neighborhood improved by 6.0% after the workshop.

Derivation of Inequality Areas in Spatial Accessibility to Support the Establishment of Neighborhood Unit Plan (생활권계획 수립지원을 위한 공간적 접근성 불평등 지역 분석)

  • Ho-Yong Kim;JiSook Kim
    • Journal of the Korean Association of Geographic Information Studies
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    • v.27 no.3
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    • pp.99-114
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    • 2024
  • Recently, the concept of neighborhood unit plan has been receiving attention due to expectations of balanced development and sustainable development through resolving regional gaps and reflecting regional characteristics. Accessibility to essential living facilities that can support daily life is considered an important factor in neighborhood unit plan. Therefore, this study analyzed accessibility from facilities based on the living facilities and access range set in the neighborhood unit plan, and analyzed spatial accessibility inequality in connection with the neighborhood unit plan and spatial clustering. As a result of analyzing accessibility in Busan Metropolitan City, various accessibility ranges were found depending on the facility. In addition, as a result of analyzing in connection with spatial clustering, regional inequality was found, such as hotspot areas in Gangdong, old downtown, Dongrae, and Haeundae, and coldspot areas in Gangseo and Gijang, and spatial inequality was found in which hotspots and coldspots exist simultaneously within the same neighborhood unit. Considering these spatial characteristics, detailed planning and policy establishment are necessary for facilities lacking in small-size neighborhood units, and the results of the analysis are expected to be meaningful in realizing the urban policy of balanced development that has been recently promoted.

Crime Mapping Based on Experts' and Residents' Assessments of Neighborhood Environment

  • Kim, Jaecheol
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.4
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    • pp.213-220
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    • 2017
  • This study examines the limitations of existing crime mapping that relies mainly on reported crime data, suggests a crime mapping method based on experts' and users' assessments of a neighborhood environment as an alternative approach, and conducts a case study on a real-world site by applying the suggested approach. According to the results of the case analysis, while the areas adjoining arterial roads with heavy pedestrian traffic were shown as high crime risk areas in the crime map based on actual reported crime data, the areas adjoining local roads with low pedestrian traffic were high-risk areas in the crime risk area map based on experts' and residents' evaluations. This study makes a contribution to the field in that it demonstrates the detailed application process of crime risk area mapping according experts' and residents' evaluations, compares the results with those of an existing crime map, and finally shows that the former can function as a complement to the latter.

Spatial Impacts of Brownfield Redevelopments on Neighborhood Housing Turnover and Stability - Case Study of Cuyahoga County, Ohio in the US - (브라운필드 재개발이 주변 지역 주택소유회전 및 주거 안정성에 미치는 공간적 파급효과 - 미국 오하이오주 쿠야호가 카운티를 중심으로 -)

  • Woo, Ayoung
    • Journal of KIBIM
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    • v.10 no.3
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    • pp.54-62
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    • 2020
  • There is growing consensus among planners and policymakers that brownfield remediation has positive impacts on neighborhoods in terms of housing prices, public health, and environmental quality. However, there is a limited understanding of how brownfield redevelopments spatially affect neighborhood housing turnover and stability. This paper addresses the spatial impacts of brownfield redevelopments on neighboring housing turnover in Cuyahoga County, Ohio. This study examines housing turnover before and after the remediation of brownfield sites countywide and in housing submarkets stratified by household income. Based on housing sales data between 1996 and 2007, the extended Cox Hazard model with the difference-in-difference approach is employed to clarify the causal relationships between brownfield redevelopments and neighboring housing turnover. Additionally, along with the results of the previous study examining impacts of brownfield remediation on nearby housing prices, this paper estimates the change of neighborhood stability due to brownfield redevelopments based on both attributes of housing prices and turnovers.