• Title/Summary/Keyword: water accessibility

Search Result 101, Processing Time 0.034 seconds

An integral based fuzzy approach to evaluate waste materials for concrete

  • Onat, Onur;Celik, Erkan
    • Smart Structures and Systems
    • /
    • v.19 no.3
    • /
    • pp.323-333
    • /
    • 2017
  • Waste materials in concrete have been considered as one of the most important issues by the authorities, policy makers and researchers to maintain engineering serviceability in terms of economy, durability and sustainability. Therefore, evaluation and selection of waste materials with respect to multi criteria decision making (MCDM) for the construction industry has been gained importance for recovery and reuse. In this paper, Choquet integral based fuzzy approach is proposed for evaluating the most suitable waste materials with respect to compressive strength, tensile strength, flexural strength, compactness, toughness (resistivity for dynamic loads), water absorption and accessibility. On conclusion, waste tyre and silica fume were determined as the most suitable waste materials for concrete production. The obtained results are recommended to assist the authorities on configuring well designed strategies for construction industry with disposal materials.

Survey of Farmer Informationization State and Needs for Knowledge based Agricultural Information System (지식기반 농업정보시스템 구축을 위한 농민 정보화 실태 및 지식수요 조사)

  • Kim, Hong-Yeon;Jung, Nam-Su;Jang, Woo-Suk;Oh, Tae-Suk;Lim, Chang-Su
    • Journal of Korean Society of Rural Planning
    • /
    • v.16 no.4
    • /
    • pp.139-145
    • /
    • 2010
  • Agricultural information was discussed for suggesting tasks and solutions of knowledge based information system. States of agricultural information systems in rural development administration were described and problems and tasks were summarized in knowledge needs survey of farmers who have to decide many alternatives for farming. Hard to access information are soil state, disease and insect pest. Important information in agriculture are water, soil fertility, soil physical property, and accessibility from main road. In conclusion, knowledge based agricultural information system can be developed based on surveyed needs.

Regional Scale Satellite Data Sets for Agricultural, Hydrological and Environmental Applications in Zambia

  • Ngoma, Solomon
    • Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
    • /
    • 2001.06a
    • /
    • pp.43-48
    • /
    • 2001
  • Many applications in the areas of agricultural, hydrological and environmental resource management require data over very large areas and with a high imaging frequency - monitoring crop growth, water stress, seasonal wetland flooding and natural vegetation development. This precludes the use of fine resolution data (Landsat, Spot) on the grounds of cost, accessibility and low imaging frequency. Meteorological satellites have the potential to fill this need, given their very wide spatial coverage, and high repeat imaging. The Remote Sensing Unit (RSU) at the Zambia Meteorological Department routinely receives, processes and archives imagery from both Meteosat and NOAA AVHRR satellites. Here I wish to present some examples of applications of these data sets that arise from the RSU work - relationships between rainfall and vegetation development as assessed by satellite, derived information and seasonal patterns of flooding in the Barotse floodplain and the Kafue flats. I also wish to outline ways in which a more widespread use of this data by the Zambian institutions canbe achieved.

  • PDF

Discharge header design inside a reactor pool for flow stability in a research reactor

  • Yoon, Hyungi;Choi, Yongseok;Seo, Kyoungwoo;Kim, Seonghoon
    • Nuclear Engineering and Technology
    • /
    • v.52 no.10
    • /
    • pp.2204-2220
    • /
    • 2020
  • An open-pool type research reactor is designed and operated considering the accessibility around the pool top area to enhance the reactor utilization. The reactor structure assembly is placed at the bottom of the pool and filled with water as a primary coolant for the core cooling and radiation shielding. Most radioactive materials are generated from the fuel assemblies in the reactor core and circulated with the primary coolant. If the primary coolant goes up to the pool surface, the radiation level increases around the working area near the top of the pool. Hence, the hot water layer is designed and formed at the upper part of the pool to suppress the rising of the primary coolant to the pool surface. The temperature gradient is established from the hot water layer to the primary coolant. As this temperature gradient suppresses the circulation of the primary coolant at the upper region of the pool, the radioactive primary coolant rising up directly to the pool surface is minimized. Water mixing between these layers is reduced because the hot water layer is formed above the primary coolant with a higher temperature. The radiation level above the pool surface area is maintained as low as reasonably achievable since the radioactive materials in the primary coolant are trapped under the hot water layer. The key to maintaining the stable hot water layer and keeping the radiation level low on the pool surface is to have a stable flow of the primary coolant. In the research reactor with a downward core flow, the primary coolant is dumped into the reactor pool and goes to the reactor core through the flow guide structure. Flow fields of the primary coolant at the lower region of the reactor pool are largely affected by the dumped primary coolant. Simple, circular, and duct type discharge headers are designed to control the flow fields and make the primary coolant flow stable in the reactor pool. In this research, flow fields of the primary coolant and hot water layer are numerically simulated in the reactor pool. The heat transfer rate, temperature, and velocity fields are taken into consideration to determine the formation of the stable hot water layer and primary coolant flow. The bulk Richardson number is used to evaluate the stability of the flow field. A duct type discharge header is finally chosen to dump the primary coolant into the reactor pool. The bulk Richardson number should be higher than 2.7 and the temperature of the hot water layer should be 1 ℃ higher than the temperature of the primary coolant to maintain the stability of the stratified thermal layer.

A Study on the Validation of Vector Data Model for River-Geospatial Information and Building Its Portal System (하천공간정보의 벡터데이터 모델 검증 및 포털 구축에 관한 연구)

  • Shin, Hyung-Jin;Chae, Hyo-Sok;Hwang, Eui-Ho
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.17 no.2
    • /
    • pp.95-106
    • /
    • 2014
  • In this study, the applicability of a standard vector model was evaluated using RIMGIS vector data and a portal based river-geospatial information web service system was developed using XML and JSON based data linkage between the server and the client. The RIMGIS vector data including points, lines, and polygons were converted to the Geospatial Data Model(GDM) developed in this study and were validated by layers. After the conversion, it was identified that the attribute data of a shape file remained without loss. The GeoServer GDB(GeoDataBase) that manages a DB in the portal was developed as a management module. The XML-based Geography Markup Language(GML) standards of OGC was used for accessing to and managing vector layers and encoding spatial data. The separation of data content and expression in the GML allowed the different expressions of the same data, convenient data revision and update, and enhancing the expandability. In the future, it is necessary to improve the access, exchange, and storage of river-geospatial information through the user's customized services and Internet accessibility.

Influence of Foraging Behaviors of Shorebirds on Habitat use in Rice Fields During Spring Migration (봄철 논습지에 도래하는 도요물떼새류의 취식 행동에 따른 서식지 이용 특성 연구)

  • Nam, Hyung-Kyu;Choi, Seung-Hye;Yoo, Jeong-Chil
    • Korean Journal of Environmental Agriculture
    • /
    • v.34 no.3
    • /
    • pp.178-185
    • /
    • 2015
  • BACKGROUND: The coexisting shorebirds often use various foraging strategies, including feeding methods and habitat use, which are the likely mechanisms to explain the variation of morphological and behavior traits. We studied the foraging behaviors of four shorebirds to define how species separate according to habitat structures in rice fields of western-central Korea during their northward migration. METHODS AND RESULTS: The studied species were Long-toed Stints (Calidris subminuta), Wood Sandpipers (Tringa glareola), Common Greenshanks (Tringa nebularia), and Black-tailed Godwits (Limosa limosa), which were commonly observed in rice fields and represented by a wide range of morphological traits. Habitats were categorized into three types ("plowed with water", "shallow water level after harrowing", and "deep water level after harrowing") according to the irrigation intensity and soil manipulation of the farming practices. Long-toed Stints mainly foraged in the "plowed with water", where they used both visual and tactile searching methods. Wood Sandpipers and Common Greenshanks were frequently observed in "shallow water level after harrowing" They spent a considerable amount of time using a visual searching method. Black-tailed Godwits were selectively attracted to "deep water level after harrowing" and used tactile cues as their predominant feeding technique. CONCLUSION: This study demonstrates that the water levels related in soil manipulation and irrigation intensity influence the accessibility to foraging sites and the detectability of prey for shorebirds species.

The Conceptual Design of Semi-submersible Type Mobile Harbor Using Axiomatic Design Principles (공리설계를 이용한 반잠수식 모바일하버의 개념설계)

  • Lee, Joo-Hee;Yoon, Seong-Jin;Chung, Hyun;Lee, Phill-Seung
    • Korean Journal of Computational Design and Engineering
    • /
    • v.15 no.3
    • /
    • pp.189-203
    • /
    • 2010
  • The axiomatic design principles are applied to the conceptual design of semi-submersible type mobile harbor (B1). The process of how the design of mobile harbor is elaborated, evaluated and improved from the very beginning is presented in this paper. The concept of mobile harbor is a functional harbor, which can move to a container ship anchoring out of ports in the deep water to load/unload containers on sea and transfer them to their destination ports. This floating system will innovate the maritime transport and distribution since it will greatly enhance the accessibility of super-sized container ships to existing harbors and harbors without enough infrastructures. Designing a mobile system which can perform the functions of traditional harbors on the floating system requires innovative ideas as well as rigorous validations of each sub systems. In order to enhance the chance of design success, we try to satisfy the design axioms in early stage of conceptual design. We use the zigzagging process for defining Functional Requirements (FR)-Design Parameters (DP) hierarchy due to the complexity of the system. In other words, we decomposed the complexity of the design by FR-DP hierarchy and reduced coupled design logically and systematically. This paper shows applicability of the axiomatic design principles to the field of ocean systems engineering.

A Study on the Ecological Aspects of Stream in Rural Village (농촌마을 소하천의 구간별 특성에 관한 연구 - 농촌 주거지역 소하천의 구조,수질,식생을 중심으로 -)

  • 이춘석;라순애
    • Journal of Korean Society of Rural Planning
    • /
    • v.3 no.1
    • /
    • pp.23-32
    • /
    • 1997
  • The purpose of this study is to analyze structural and ecological characteristics of streams in rural village. The methods used in this study were measuring the section and surveying the vegetation of the stream at three points(upstream, inner village, downstream ) of 10 rural villages. The major findings of this study can be summarized as follows : 1) The average width of streams is 9 m, and the height of banks 3.1 m. the downstreams are the widest(average 10 m), and the inner-villages are the narrowest (average 8 m), and the slopes of basin are 7.33 %, 2.67 %, 1.39 % at upstream, inner-village, downstream respectively. 2) The downstreams are more contaminated than upstreams due to the sewage from the residents, especially livestock wastewater. 3) The dominant species in the streams are Persicaria thunbergii H. Gross (average Cover 17.76 %) and cumulus japonicas Sieb et. Zucc (average Cover 7.75 % ). 4) The average area covered by vegetation is 53.31 % the downstreams are covered 65.7 %, but inner-village area covered by vegetation is 46.6 %. 5) The problem found in this study are severe water contamination, poor accessibility to stream and poor vegetation of inner-village area, etc.

  • PDF

Using habitat suitability model for the wild boar (Sus scrofa Linnaeus) to select wildlife passage sites in extensively disturbed temperate forests

  • Rho, Paikho
    • Journal of Ecology and Environment
    • /
    • v.38 no.2
    • /
    • pp.163-173
    • /
    • 2015
  • The occurrence of wild boars (Sus scrofa Linnaeus) and reports of wildlife-vehicle conflicts (i.e., road-kill) involving them have increased in natural forest regions of Korea. In the past few decades, many wildlife passages have been constructed to reduce vehicle collisions involving wildlife species. However, few studies have assessed the habitat suitability of target wildlife species when locating the construction sites of wildlife passages. Target species rarely use wildlife passages if built in an inappropriate location. Therefore, a quantitative habitat model is required to find suitable sites for wildlife passages that can connect the fragmented forest patches of wildlife habitats in Korea. In this study, the wild boar was selected as the target species, and six environmental variables (percentage of Quercus forest, slope aspect, distance to roads, water accessibility, forest stand age and density) were measured. The habitat model for wild boars was developed with a Delphi survey, and habitat suitability maps were delineated for the provinces of Gangwon-do and Jeollanam-do. In this study, 298 and 64 boars were observed in Gangwon-do and Jeollanam-do, respectively. Observations of wild boars derived from the second nationwide natural environmental survey were used to evaluate the habitat model. Habitat suitability maps that superimposed existing road networks suggested that wild boar habitats were severely fragmented in both provinces, particularly in Gangwon-do. To connect the fragmented habitats and prevent wildlife-vehicle collisions, this study proposes 11 and 5 wildlife passage sites in Gangwon-do and Jeollanam-do, respectively.

Research on the Design Guidelines and Implementations of Barrier-free Space for Children - Focused on the Common Spaces of the Outpatient Clinics in Pediatric Rehabilitation Hospitals - (어린이를 고려한 무장애공간 계획기준 및 적용실태 연구 - 어린이 재활병원의 외래부 공용공간을 중심으로 -)

  • Cho, Min-Jung
    • Korean Institute of Interior Design Journal
    • /
    • v.25 no.4
    • /
    • pp.113-124
    • /
    • 2016
  • This research examines domestic and oversea's barrier-free design guidelines provided exclusively for children and their implementations in the common spaces of the outpatient clinics in two pediatric rehabilitation hospitals in Seoul. Based on literature review, a checklist was developed to compare various barrier-free design guidelines in consideration of children's accessibility in space. In addition, four spatial areas in the outpatient clinics of the two hospitals were investigated based on the checklist. As a result, the domestic and Japanese guidelines were aiming primarily to all user groups regardless of ages. Whereas in other oversea's guidelines, a number of barrier-free design standards exclusive for children were found in the facility items such as handrail, sink, urine, toilet, water fountain, chair, table, shelve, and so on, throughout the indoor waiting and sanitary spaces. Concerning implementations, most of the items in the indoor passage, waiting, and sanitary spaces of the two hospitals were not sufficiently facilitated enough to meet with the barrier-free design standards exclusive for children. As such, it is recommended to review and improve the current domestic barrier-free design guideline to accommodate various physical and spatial needs of children in all age groups and regardless of disability types, in the design of a pediatric rehabilitation hospital in the future.