• Title/Summary/Keyword: Spatial Unit

Search Result 872, Processing Time 0.023 seconds

An Efficient Distributed Shared Memory System for Parallel GIS (병렬 GIS를 위한 효율적인 분산공유메모리 시스템)

  • Jeong, Sang-Hwa;Ryu, Gwang-Yeol;Go, Yun-Yeong;Gwak, Min-Seok
    • Journal of KIISE:Computing Practices and Letters
    • /
    • v.5 no.6
    • /
    • pp.700-707
    • /
    • 1999
  • 본 논문에서는 GIS 관련 연산을 실시간에 효율적으로 처리하기 위한 분산공유메모리 기반 병렬처리 시스템을 제안한다. 본 논문의 분산공유메모리 시스템은 메시지전달 방식의 분산메모리 MIMD 컴퓨터 상에 소프트웨어 기반 분산공유메모리 모듈을 탑재함으로써 구현되었다. 또한 GIS 연산의 기본이 되는 공간 객체를 공유의 기본 단위로 설정하고, GIS 데이타의 특성을 반영하여 읽기전용 공유데이타 타입을 추가하였으며, 네트워크 오버헤드를 줄이기 위하여 복수의 객체를 한번에 읽어오는 bulk access가 가능하도록 하였다. 본 시스템에서는 GIS 데이타의 효율적인 분배를 위하여 부하균등화 기법으로 guided self scheduling을 사용하였다. 실험결과 본 시스템은 네트워크 캐쉬의 효율적인 활용을 통하여 소프트웨어 기반 분산메모리 시스템의 오버헤드에도 불구하고 MPI 기반 메시지전달 방식에 비하여 향상된 성능을 얻을 수 있었다.Abstract In this paper, we propose a distributed shared memory(DSM) based parallel processing system to process GIS related computations efficiently in real time. The system is based on a software DSM module implemented on top of a distributed MIMD computer. In the DSM system, spatial object, which is a fundamental structure to represent GIS data, is used as a basic unit for sharing, and a read-only shared data type is added to reflect the characteristics of GIS data. In addition, a bulk access to multiple shared data is made possible to reduce the network overhead. A guided self scheduling method is devised for efficient load balancing in distributing GIS data to parallel processors. The experimental results show that the DSM system performs better than an MPI based message-passing system through the efficient utilization of network cache in spite of the system's software overhead.

Vegetation Types and Ecological Characteristics of Larix kaempferi Plantations in Baekdudaegan Protected Area, South Korea (백두대간 보호지역 일본잎갈나무림의 현존식생 유형과 생태적 특성)

  • Oh, Seung-Hwan;Kim, Jun-Soo;Cho, Joon-Hee;Cho, Hyun-Je
    • Journal of Korean Society of Forest Science
    • /
    • v.110 no.4
    • /
    • pp.530-542
    • /
    • 2021
  • To establish the basic unit for the ecological management of the Larix kaempferiplantations in the Baekdudaegan protected area, we classified the vegetation types using TWINSPAN and DCA ordination analysis based on the vegetation information collected from 119 plots and analyzed their spatial arrangement status. Vegetation types were classified into seven types, including Quercus mongolica-Rhododendron schlippenbachii type, Q. mongolica-Lespedeza maximowiczii type, Cornus controversa-Morus australis type, Q. mongolica-Carpinus cordata type, Lindera erythrocarpa-Rosa multiflora type, Q. serrata-Zanthoxylum schinifolium type, and Q. serrata-Sasa borealis type and they have usually reflected differences in the floristic composition according to latitude, elevation, establishment period, operation history, characteristics of the surrounding stands, and degree of disturbance. Furthermore, using the Jaccard coefficient to comparethe floristic composition similarity between Larix kaempferiplantations and surrounding potential natural vegetation (Q. mongolica and Q. serrata forests), although some differences depended on vegetation types, it was 0.21 on average with Q. mongolica forest and 0.32 with Q. serrata forest, indicating that the floristic composition was still heterogeneous.

Avulsion injuries: an update on radiologic findings

  • Choi, Changwon;Lee, Sun Joo;Choo, Hye Jung;Lee, In Sook;Kim, Sung Kwan
    • Journal of Yeungnam Medical Science
    • /
    • v.38 no.4
    • /
    • pp.289-307
    • /
    • 2021
  • Avulsion injuries result from the application of a tensile force to a musculoskeletal unit or ligament. Although injuries tend to occur more commonly in skeletally immature populations due to the weakness of their apophysis, adults may also be subject to avulsion fractures, particularly those with osteoporotic bones. The most common sites of avulsion injuries in adolescents and children are apophyses of the pelvis and knee. In adults, avulsion injuries commonly occur within the tendon due to underlying degeneration or tendinosis. However, any location can be involved in avulsion injuries. Radiography is the first imaging modality to diagnose avulsion injury, although advanced imaging modalities are occasionally required to identify subtle lesions or to fully delineate the extent of the injury. Ultrasonography has a high spatial resolution with a dynamic assessment potential and allows the comparison of a bone avulsion with the opposite side. Computed tomography is more sensitive for depicting a tiny osseous fragment located adjacent to the expected attachment site of a ligament, tendon, or capsule. Moreover, magnetic resonance imaging is the best imaging modality for the evaluation of soft tissue abnormalities, especially the affected muscles, tendons, and ligaments. Acute avulsion injuries usually manifest as avulsed bone fragments. In contrast, chronic injuries can easily mimic other disease processes, such as infections or neoplasms. Therefore, recognizing the vulnerable sites and characteristic imaging features of avulsion fractures would be helpful in ensuring accurate diagnosis and appropriate patient management. To this end, familiarity with musculoskeletal anatomy and mechanism of injury is necessary.

Development of Walkability Search System (보행친화도 검색 시스템 개발)

  • Kim, Eun Jung;An, Donghyeok
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
    • /
    • v.9 no.12
    • /
    • pp.987-997
    • /
    • 2019
  • Walk score, walkablity index of built environmental condition, has developed and used in everyday life in United States. The purpose of this study is to produce walk score in Seoul, and to develop computer-based walk score system for improving it's usage. This study covers city of Seoul, and the unit of spatial analysis is 100m × 100m grid cell. This study uses same methodology with walk score in US, the Geographic Information Systems(GIS) is used for calculating the values of walk score(N=58,062). This study implemented Java-based system that utilizes walk score dataset(latitude, longitude, and walk score). This system provided search functions including both lat/long-based and address-based options. Meanwhile, this system was designed to provide the closest value of walk score in dataset if location did not match the certain points in dataset. This study has significance to provide walk score system being easily available to all.

Evaluation of Applicability of APEX-Paddy Model based on Seasonal Forecast (계절예측 정보 기반 APEX-Paddy 모형 적용성 평가)

  • Cho, Jaepil;Choi, Soon-Kun;Hwang, Syewoon;Park, Jihoon
    • Journal of Korean Society of Rural Planning
    • /
    • v.24 no.4
    • /
    • pp.99-119
    • /
    • 2018
  • Unit load factor, which is used for the quantification of non-point pollution in watersheds, has the limitation that it does not reflect spatial characteristics of soil, topography and temporal change due to the interannual or seasonal variability of precipitation. Therefore, we developed the method to estimate a watershed-scale non-point pollutant load using seasonal forecast data that forecast changes of precipitation up to 6 months from present time for watershed-scale water quality management. To establish a preemptive countermeasure against non-point pollution sources, it is possible to consider the unstructured management plan which is possible over several months timescale. Notably, it is possible to apply various management methods such as control of sowing and irrigation timing, control of irrigation through water management, and control of fertilizer through fertilization management. In this study, APEX-Paddy model, which can consider the farming method in field scale, was applied to evaluate the applicability of seasonal forecast data. It was confirmed that the rainfall amount during the growing season is an essential factor in the non-point pollution pollutant load. The APEX-Paddy model for quantifying non-point pollution according to various farming methods in paddy fields simulated similarly the annual variation tendency of TN and TP pollutant loads in rice paddies but showed a tendency to underestimate load quantitatively.

A Study on the Common Space Characteristics of Early Housing by Hayakawa Kunihiko - Focusing on Labyrinth housing in Tokyo - (하야카와 쿠니히코 초기 공동주택의 공용공간 특성에 관한 연구 - 도쿄 라비린스(ラビリンス)를 중심으로 -)

  • Ki, Yu-Mi;Jun, Byung-Kweon;Kim, Kyoung-Yon
    • Journal of the Architectural Institute of Korea Planning & Design
    • /
    • v.35 no.1
    • /
    • pp.55-62
    • /
    • 2019
  • Hayakawa Kunihiko introduced community space as an open space in Housing in Japan for the first time. We can find the continuity of his architectural intent from his three works (Atrium, Steps, Labyrinth) during the early period of his Housing buildings, In particular, from Labyrinth, his intent was expanded to cities through 'Urban Void', seeking communication and harmony. Accordingly, based on the architectural overview and a field survey of Labyrinth, an analysis was conducted using Space Syntax to investigate whether the space of an inner courtyard is being used as a community space for neighbors who pass through the courtyard and whether the courtyard plays the role of 'Urban Void' as intended by the architect. For this investigation, according to VGA, the courtyard showed the role of great visual connectivity and integration and facilitated connections to the center of the entire space. On the other hand, according to J-Graph, the access stairway connected to each household from the courtyard helped secure privacy in the midst of common space. Step Depth noted that a hierarchy of space was formed to ensure visual privacy within each unit household in addition to privacy for each household.

A Study on Architectural Characteristics of the Newly Built Hanok in Seoul Since 2000 - Focused on the Kan Composition - (2000년 이후 서울의 신축한옥에서 보이는 건축적 특징 - 칸 구성을 중심으로 -)

  • Kim, SungHa;Jeon, BongHee
    • Journal of the Architectural Institute of Korea Planning & Design
    • /
    • v.35 no.9
    • /
    • pp.109-117
    • /
    • 2019
  • Since 'Hanok Expanse Support' has been started in Seoul, its target was expanded from renovation to new construction and from 'Hanok District' to all area in Seoul. The newly built hanok with Hanok Expanse Support had to follow the standards about the form of the hanok and adapt to modern lifestyle. However, the newly built hanok were planned with 'kan' since it retained the traditional wooden structure. So their composition of kan were considered to be influenced by the standards of each district and modern lifestyle. Therefore the aim of this study is to understand the architectural characteristics of newly built hanok in Seoul since 2000 focusing on the kan composition. Because of the differences in site conditions and the district unit plan, newly built hanok in Hanok District have more limited changes than Other District. However, kan is composed variously in horizontal and vertical ways to make the most space according to site conditions and most of the newly built hanok have opened courtyard rather than closed courtyard layout. With kan composition in various directions and kan added under the eaves, kan is highlighted in form. On the other hand, the composition of kan as an interior spatial element has changed and weakened because the lifestyle has changed compared to the traditional hanok and the 20th century urban hanok. Also the regular kan composition of Mom-chae and Nalgae-chae has changed. And kan is divided regardless to the wooden structure. Also, with the added kan under the eaves the main kan is dismantled inside. This paper indicates that although there is an undeniable premise that the case is restricted to hanok received Hanok Expanse Support on the condition of following the standards of the form of hanok, it is a part of the transitional changes that hanok is experiencing.

Derivation of Candidate Sites for a Tidal Current-Pumped Storage Hybrid Power Plant Using GIS-based Site Selection Analysis (GIS기반 적지분석을 통한 조류-양수 융합발전시스템 설치후보지 도출 연구)

  • LEE, Cholyoung;CHOI, Hyun-Woo;PARK, Jinsoon;KIM, Jihoon;PARK, Junseok
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.23 no.4
    • /
    • pp.184-207
    • /
    • 2020
  • This study aimed to determine candidate areas for tidal current-pumped storage hybrid power plants using GIS-based site selection analysis. The study area is the southwestern sea surrounding Jindo Island in South Korea. Factors to be considered for the site selection analysis were derived considering the design and installation characteristics of the hybrid power plant. Numerical simulation to predict tidal speed was performed using the MOHID(Modelo HIDrodin?mico) and the results were converted into spatial data. Subsequently, a GIS-based overlay analysis method proposed in this study was applied to derive the installation candidate area. A total of 10 regions were identified as candidate sites. Among them, it was determined that the power generator could be installed in relatively wide sea areas in Jindo, Seongnamdo, and Hajodo.

Analysis of Jeju Public Transit System Reorganization Effect Based on Accessibility of Public Transit Networks - Considering the Temporal Variability of Public Transit Travel Time - (대중교통 네트워크 중심의 접근성을 기준으로 한 제주도 대중교통 개편 효과 분석 - 대중교통 통행시간의 시간적 변동을 고려하여 -)

  • Sim, Jae-Woong;Cho, Gi-Hyoug
    • Journal of Korea Planning Association
    • /
    • v.54 no.6
    • /
    • pp.68-79
    • /
    • 2019
  • The purpose of this study is to propose a transit accessibility analysis method based on temporal variability of travel time. In this study, transit accessibility was defined in three levels (in transit route, spot and region unit) to present findings from different spatial scopes. Recently, Jeju special self-governing province reorganized bus system of the island. To compare transit accessibility before and after transit policy implementation, the reorganized bus system of Jeju special self-governing province was selected as a case study. This study used General Transit Feed Specification (GTFS) data format as storage public transit information, and calculated travel time using ArcGIS GTFS networks analysis tools. In the analysis of individual transit route level, we found the 3 types of accessibility changes which is increments, no significant changes and reductions and these results come from transit route change (number of transfer, distance change) rather than changes of vehicle interval. We found increases of inflow and outflow speed in most target spots and overall transit accessibility has been substantially improved in Jeju island. This study implies that accounting for temporal variability of travel time in accessibility analysis can result in more useful and sophisticated accessibility information in decision-making processes.

Catch Variations of Argentine Shortfin Squid Illex argentinus in the Southwest Atlantic (남서대서양 아르헨티나 짧은지느러미오징어(Illex argentinus)의 어획변동)

  • Ku, Jeong Eun;Choi, Seok-Gwan;An, Doo-Hae;Kim, Eunjung
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.53 no.6
    • /
    • pp.934-941
    • /
    • 2020
  • The spatial and temporal catch variations of Argentine shortfin squid Illex argentinus in the Southwest Atlantic Ocean (SWA) were analyzed using Korean squid-jigging fishery data collected through electronic reporting system (ERS) from 2016 to 2020. The ERS linked with GPS has been implemented for collecting fishing data from all Korean fishing vessels operating in international waters since November 2015. The fishing period of the Korean squid-jigging fishery in the SWA runs from early summer to autumn (December to June) in the Southern Hemisphere. The fishing ground was extended from 42°S to 48°S along the Patagonian continental shelf and slope, and the main fishing ground was formed around the Falkland Islands. The yearly catch per unit effort (CPUE) of I. argentinus fluctuated between 1.69 and 7.53 tons/day. In this study, during the fishing season, a south and westward shift on the fishing ground was observed indicating the feeding migration of the south Patagonian stock. The shift in monthly fishing centroids differed according to fishing season. The gradual southward shifts of fishing centroids were observed in the catch years (2017 and 2018), whereas unapparent shifts in fishing centroids were observed in the low catch years (2016 and 2019).