• 제목/요약/키워드: spatial problem

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A Study on the Mathematical Programming Approach to the Subway Routing Problem (지하철 차량운용 문제에 대한 수리적 해법에 관한 연구)

  • Kim, Kyung-Min;Hong, Soon-Heum
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.1731-1737
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    • 2007
  • This paper considers subway routing problem. Given a schedule of train to be routed by a railway stock, the routing problem determines a sequence of trains while satisfying turnaround time and maintenance restrictions. Generally, the solution of routing problem is generated from set partition formulation solved by column generation method, a typical integer programming approach for train-set. However, we find the characteristics of metropolitan subway which has a simple rail network, a few end stations and 13 departure-arrival patterns. We reflect a turn-around constraint due to spatial limitations has no existence in conventional railroad. Our objective is to minimize the number of daily train-sets. In this paper, we develop two basic techniques that solve the subway routing problem in a reasonable time. In first stage, we formulate the routing problem as a Min-cost-flow problem. Then, in the second stage, we attempt to normalize the distance covered to each routes and reduce the travel distance using our heuristic approach. Applied to the current daily timetable, we could find the subway routings, which is an approximately 14% improvement on the number of train-sets reducing 15% of maximum traveling distance and 8% of the standard deviation.

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A Pixel-based Assessment of Urban Quality of Life (도시의 삶의 질을 평가하기 위한 화소기반 기법)

  • Jun, Byong-Woon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.3
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    • pp.146-155
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    • 2006
  • A handful of previous studies have attempted to integrate socioeconomic data and remotely sensed data for urban quality of life assessment with their spatial dimension in a zonal unit. However, such a zone-based approach not only has the unrealistic assumption that all attributes of a zone are uniformly spatially distributed throughout the zone, but also has resulted in serious methodological difficulties such as the modifiable areal unit problem and the incompatibility problem with environmental data. An alternative to the zone-based approach can be a pixel-based approach which gets its spatial dimension through a pixel. This paper proposes a pixel-based approach to linking remotely sensed data with socioeconomic data in GIS for urban quality of life assessment. The pixel-based approach uses dasymetric mapping and spatial interpolation to spatially disaggregate socioeconomic data and integrates remotely sensed data with spatially disaggregated socioeconomic data for the quality of life assessment. This approach was implemented and compared with a zone-based approach using a case study of Fulton County, Georgia. Results indicate that the pixel-based approach allows for the calculation of a microscale indicator in the urban quality of life assessment and facilitates efficient data integration and visualization in the assessment although it costs an intermediate step with more processing time such as the disaggregation of zonal data. The results also demonstrate that the pixel-based approach opens up the potential for the development of new database and increased analytical capabilities in urban analysis.

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The Influence of Market in Agricultural Spatial Organization (농업공간조직에서 시장의 영향)

  • Lee, Sang-Yool
    • Journal of the Korean association of regional geographers
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    • v.3 no.2
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    • pp.151-162
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    • 1997
  • Although modern versions of the traditional Von $Th{\ddot{u}}nen$ theory have contributed to a description of spatial organization in agriculture, they did not incorporate the market mechanism as an integral part of location theory. This deficiency has been indicated and new mathematical structure has been proposed elsewhere by the author. The closed model, which simultaneously considered a basic principle of supply and demand, exposed a computational complexity. Based on the problem, this study attempts to extend market mechanism in order to consider the influence of city (market) size in agricultural location theory. To theoretically explore the economic relationship in a location theory, this study simplifies agricultural activity as just two activities in one-dimensional spatial economy. The problem has been solved by equating total supply and demand of agricultural products, and then by determining each agricultural price from the relationship. All of the mathematical problems have been arranged in matrix form. First, the traditional model and closed model have been compared by quantitative comparative statics which provides the sensitivity test for each model. The results have shown that the traditional model shows a relatively excessive change in land use, besides the deficiency of a constant agricultural price. Second, the effects of the size of market town and its population increase were examined, using the closed model. In this case, the price of agricultural product is increased, and the land use is extended outward. This proves that locational rent is related to the expansion of land use. Third, environmental uncertainty was associated with the closed model, in order to further consider the difference of farmers attitude in strategic perspective. In this study, two extreme attitudes, which reflects the maximum average expected returns and the maximum guaranteed returns, were examined in their land use and their effects on the prices of agricultural products. It was shown that the two farmers attitudes can be interconnected with location theory. Due to the exogenous data, the differences in the area of land use and total quantities of agricultural products were not clearly shown in this study. However, it was shown that the land use pattern is very different. That is, maximum guaranteed return model reveals a mixed land use pattern around the market town. Basically, this study shows some spatial and economic implications related to Von $Th{\ddot{u}}nen$ model.

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A Study on the Spatial Distribution of the Vacant Houses and their Accessibility : Focused on the Vacant Houses in Okcheon-gun, Chungcheongbuk-do (빈집 공간분포 특성 및 접근성에 관한 연구 : 충청북도 옥천군 빈집을 중심으로)

  • Lee, Jong-Soo;Kim, Sun-Duck
    • The Journal of the Korea Contents Association
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    • v.21 no.12
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    • pp.791-802
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    • 2021
  • In Korea, the cities continue to deteriorate, while the vacant houses in the small local towns emerge as a serious social problem. Despite the vacant houses emerge as a serious social problem in the small local towns as well as in the large cities, the basic researches into them are yet to be conducted on a full scale. Thus, in order to know about the spatial distribution of the vacant houses, this study conducted the square analysis and the kernel density analysis. As a result, it was confirmed that the vacant houses in Okcheon-gun had certain crowding forms and characteristics at the level of statistical significance. Next, in order to examine the distribution of the vacant houses in terms of the accessibility to the living SOC facilities, the GIS network analysis was performed, focusing on the major facilities and road networks. As a result, it was found that the better the accessibility to the living SOC facilities such as medical and well-being was, the ratio of the vacant houses was lower. In contrast, it was found that the accessibility to the obligatory facilities such as public administration and educational facilities did not have any important effects on the distribution of the vacant houses. All in all, through this study, the spatial distribution of the vacant houses in the small local town and their accessibility to the major SOC facilities could be analyzed.

The Acquisition of Geo-spatial Information by Using Aerial Photo Images in Urban Area (항공사진 영상을 이용한 도심지역의 지형공간정보 취득)

  • 이현직;김정일;황창섭
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.21 no.1
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    • pp.27-36
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    • 2003
  • Generally, the latest acquisition method of geo-spatial informations in urban area is executed by generation of digital elevation model (DEM) and digital ortho image by digital photogrammetry method which is used large scale photo image. However, the biggest problem of this method is coarse accuracy of DEM which is automatically generated by digital photogrammetry workstation system. The coarse accuracy of DEM caused geo-spatial information in urban area to reduce of accuracy. Therefore, this study is purposed to increase of DEM accuracy which is applied to method terrain classification in urban area. As the results of this study, the proposed method of this study which is increased to accuracy of DEM by classification of terrain is better than accuracy of DEM which is automatically generated by digital photogrammetry workstaion system. And, the edge detection method which is proposed by this study is established to capability of 3D digital mapping in urban area.

Spatial Information Data Construction and Data Mining Analysis for Topography Investigation of Land Characteristics (토지특성 고저조사를 위한 공간정보 데이터 구축과 데이터 마이닝 분석)

  • Choi, Jin Ho;Kim, Jun Hyun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.37 no.6
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    • pp.507-516
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    • 2019
  • The investigation of land characteristics is an important task for the calculation of officially land prices and standard comparison table of land price. Therefore, it should be done objectively and consistently. However, the current investigation system is mainly done by researcher's subjective judgment. Therefore, the objectivity and consistency of this investigation is not guaranteed and questionable. In this study, we first defined the problem by analyzing the current land topography investigation method. In addition, in order to investigate the land topography, the geometry of the parcel is quantified by spatial information and applied to the decision tree based method(C4.5) to produce the final result. This study intended to extract the parcel characteristics data of the topographic by the use of spatial information and to apply the information to the C4.5, there by suggesting a method for addressing the problems. The findings showed approximately 93.5% between the results of topography classification estimated with rules learned by C4.5.

Adjustment of A Simplified Satellite-Based Algorithm for Gross Primary Production Estimation Over Korea

  • Pi, Kyoung-Jin;Han, Kyung-Soo;Kim, In-Hwan;Lee, Tae-Yoon;Jo, Jae-Il
    • Korean Journal of Remote Sensing
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    • v.29 no.3
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    • pp.275-291
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    • 2013
  • Monitoring the global Gross Primary Pproduction (GPP) is relevant to understanding the global carbon cycle and evaluating the effects of interannual climate variation on food and fiber production. GPP, the flux of carbon into ecosystems via photosynthetic assimilation, is an important variable in the global carbon cycle and a key process in land surface-atmosphere interactions. The Moderate-resolution Imaging Spectroradiometer (MODIS) is one of the primary global monitoring sensors. MODIS GPP has some of the problems that have been proven in several studies. Therefore this study was to solve the regional mismatch that occurs when using the MODIS GPP global product over Korea. To solve this problem, we estimated each of the GPP component variables separately to improve the GPP estimates. We compared our GPP estimates with validation GPP data to assess their accuracy. For all sites, the correlation was close with high significance ($R^2=0.8164$, $RMSE=0.6126g{\cdot}C{\cdot}m^{-2}{\cdot}d^{-1}$, $bias=-0.0271g{\cdot}C{\cdot}m^{-2}{\cdot}d^{-1}$). We also compared our results to those of other models. The component variables tended to be either over- or under-estimated when compared to those in other studies over the Korean peninsula, although the estimated GPP was better. The results of this study will likely improve carbon cycle modeling by capturing finer patterns with an integrated method of remote sensing.

A STUDY ON EXTRACTING THE SURFACE TEMPERATURE USING THERMAL INFRARED OF ASTER IMAGES IN URBAN AREA

  • Jo Myung-Hee;Kim Hyung-Sub;Kim Sung-Jae;Yu Seong-Ok
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.717-720
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    • 2005
  • Recently as large sized urban development and the city ward drifting of population are caused, the urban surface temperature is raised very seriously and rapidly. These artificial developments have destroyed the inner and outer landscapes such as topography and have changed complex local climate such as a sudden rise in temperature, the change of wind field and air pollution. In order to clarify this problem visually, the studies on extracting the thermal infrared and the characteristic analysis of local climate in urban area had been performed by using the sixth band of Landsat TM and ETM+. However, there is a need to alternate Landsat TM and ETM+ because these satellite images are not applied any more. Therefore, in this paper it is proposed to use 2 Aster image (2004.4.17 daily 2b03, 2004.10.10 night 2b03) of EOS AM and to extract the surface temperature. Also, the pattern of surface temperature in urban area and the application possibility in local climate study are proposed by verifying the correlation with A WS data. Also, IKONOS image was used to figure out the artificial development area in visual.

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An ICA-Based Subspace Scanning Algorithm to Enhance Spatial Resolution of EEG/MEG Source Localization (뇌파/뇌자도 전류원 국지화의 공간분해능 향상을 위한 독립성분분석 기반의 부분공간 탐색 알고리즘)

  • Jung, Young-Jin;Kwon, Ki-Woon;Im, Chang-Hwan
    • Journal of Biomedical Engineering Research
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    • v.31 no.6
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    • pp.456-463
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    • 2010
  • In the present study, we proposed a new subspace scanning algorithm to enhance the spatial resolution of electroencephalography (EEG) and magnetoencephalography(MEG) source localization. Subspace scanning algorithms, represented by the multiple signal classification (MUSIC) algorithm and the first principal vector (FINE) algorithm, have been widely used to localize asynchronous multiple dipolar sources in human cerebral cortex. The conventional MUSIC algorithm used principal component analysis (PCA) to extract the noise vector subspace, thereby having difficulty in discriminating two or more closely-spaced cortical sources. The FINE algorithm addressed the problem by using only a part of the noise vector subspace, but there was no golden rule to determine the number of noise vectors. In the present work, we estimated a non-orthogonal signal vector set using independent component analysis (ICA) instead of using PCA and performed the source scanning process in the signal vector subspace, not in the noise vector subspace. Realistic 2D and 3D computer simulations, which compared the spatial resolutions of various algorithms under different noise levels, showed that the proposed ICA-MUSIC algorithm has the highest spatial resolution, suggesting that it can be a useful tool for practical EEG/MEG source localization.

A Study on Surveillance System in Korea's National and Public Museum - Focussed on Indirect Surveillance System in Conjunction with Spatial Structure of Museums - (국내 국, 공립 뮤지엄 감시체계에 관한 연구 - 공간구조에 의한 간접감시체계를 중심으로 -)

  • Moon, Jung-Mook
    • Korean Institute of Interior Design Journal
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    • v.20 no.2
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    • pp.176-183
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    • 2011
  • Modern museums that started from 17th century in Europe have played a role of storage for collections of the upper class as a form of private museum. Since 18th century the publicity has been more emphasized in the society of Europe and there became a public museum that serves as a institution for social education. In addition to this, the mass production that began with the Industrial Revolution relieved the working hour of the public and they started to spend their more time for visiting museums to have social education. In korea there constructed a lot of public museums after economic development and people experienced the social education and the cultural events. However, there raised questions on security issue regarding relic because of growing number of visitors to the museums. Due to this, the museums asked a surveillance system for their relic. But the museums don't have enough research on this nor understanding the current situation. Because the relic in museums of history has a money value, the anti-theft system is more focussed. In addition to the direct surveillance system with staff or closed-circuit television(CCTV), the indirected system with visitor's mutual surveillance in conjunction with spatial structure has to be researched. This study is to understand the relationship between surveillance system and spatial structure with reference to korea's national and public museum of history. With the results of the research, the study provides a planning guideline to the museum architecture to prevent security problem.