• Title/Summary/Keyword: Skylines

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A Filter Lining Scheme for Efficient Skyline Computation

  • Kim, Ji-Hyun;Kim, Myung
    • Journal of Korea Multimedia Society
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    • v.14 no.12
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    • pp.1591-1600
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    • 2011
  • The skyline of a multidimensional data set is the maximal subset whose elements are not dominated by other elements of the set. Skyline computation is considered to be very useful for a decision making system that deals with multidimensional data analyses. Recently, a great deal of interests has been shown to improve the performance of skyline computation algorithms. In order to speedup, the number of comparisons between data elements should be reduced. In this paper, we propose a filter lining scheme to accomplish such objectives. The scheme divides the multidimensional data space into angle-based partitions, and places a filter for each partition, and then connects them together in order to establish the final filter line. The filter line can be used to eliminate data, that are not part of the skyline, from the original data set in the preprocessing stage. The filter line is adaptively improved during the data scanning stage. In addition, skylines are computed for each remaining data partition, and are then merged to form the final skyline. Our scheme is an improvement of the previously reported simple preprocessing scheme using simple filters. The performance of the scheme is shown by experiments.

On Efficient Processing of Continuous Reverse Skyline Queries in Wireless Sensor Networks

  • Yin, Bo;Zhou, Siwang;Zhang, Shiwen;Gu, Ke;Yu, Fei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.4
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    • pp.1931-1953
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    • 2017
  • The reverse skyline query plays an important role in information searching applications. This paper deals with continuous reverse skyline queries in sensor networks, which retrieves reverse skylines as well as the set of nodes that reported them for continuous sampling epochs. Designing an energy-efficient approach to answer continuous reverse skyline queries is non-trivial because the reverse skyline query is not decomposable and a huge number of unqualified nodes need to report their sensor readings. In this paper, we develop a new algorithm that avoids transmission of updates from nodes that cannot influence the reverse skyline. We propose a data mapping scheme to estimate sensor readings and determine their dominance relationships without having to know the true values. We also theoretically analyze the properties for reverse skyline computation, and propose efficient pruning techniques while guaranteeing the correctness of the answer. An extensive experimental evaluation demonstrates the efficiency of our approach.

A Basic Study for the Improvement Project of Housing Environment in the Cheju Island Region the Era of Globalization (지방화시대에 따른 제주지역의 주환경 개선 사업에 관한 기초 연구)

  • BongAeKim
    • Journal of the Korean housing association
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    • v.6 no.2
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    • pp.69-76
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    • 1995
  • Recent opening of the era of local government and management randers study tasks concerning the improvement of the housing conditions by improving the problems in the residential conditions of the cheju Island region so as to help improve the life qualities of this legion make the area as an international resort place, and thus develop the indentify in the heat of the people in this region. The suggestions based on the study for the improvement of housing environment are summarized as follows: (1) To improve the collective housing. housing construction plan shall b made in harmony with the skylines of the Hanra mountain alongside the East-West rides across the long diameter of the oval shape of the Island, which includes 1) the construction of housing complex in harmony with and taking advantage of the natural scene of the area. and 2) the construction of variable housing readjustable in accordance with each family structure of variable housings for multi-families, which are believed not to provide quality housing conditions. Shall be entrained. (2) Encouraging the construction of detached house : 1) construction of housings in which three generations can reside together according to the traditional family structure in the region. 2) construction of the pastoral housings. 3) construction of tenement housings partitioned for each two families. 4) development of sliver town in the rural area. (3) Using the construction mateials produced in the Cheju I land will help promote the development of identity in the heart of the people in this region.

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Visual Environmental Influence on an User's Psycho-physiological Health at Healthcare Facilities (시간적 환경이 의료시설 이용자의 건강에 미치는 정신생리학적 영향)

  • Kim Nam-Gil
    • Journal of the Korean housing association
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    • v.17 no.1
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    • pp.1-8
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    • 2006
  • The purpose of this study is to understand how visual factors of healthcare facilities would have an effect on psycho-physiological health of inpatients. First, visual factors of a ward, where inpatients mostly spend their time in a hospital, were extracted in order to find out how visual environment would affect inpatient's health. Then experimental samples were made and inpatients' reactions against them were analyzed. This study is composed of two approaches a questionnaire for psychological analysis and an electroencephalogram measurement for physiological analysis. The results of this experiment show that psycho-physiological health of subject's can be remarkably improved according to artificial arrangement of visual environment of a ward. Especially, they also show that insignificant changes of visual environment such as furnishing trees, flowerpots or framed pictures in a ward, where there is no view and completely closed, will be able to exert a range of positive effects on an subject's psycho-physiological health. In conclusion, further studies need to be delivered about indoor designs to positively bring in natural elements to a ward as well as visibility ratio of views and skylines from a ward.

Comparisons of the Assessment of Ecological Landscape Design and the Apartment Skylines (생태학적 조경설계 평가와 아파트 스카이라인의 비교)

  • Kwon, Sang-Zoon
    • Journal of the Korean Institute of Landscape Architecture
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    • v.31 no.1
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    • pp.90-100
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    • 2003
  • 본 연구는 건축고도제한에 의해 생태학적 조경설계는 어떻게 통제되며, 또한 생태학적 조경 설계가 무엇인가를 구명하는 것이다. 따라서 두 가지 다른 단지를 비교하여 건축물 스카이라인이 주변경관과 조화로운 심미적 설계를 가능하게 하는 영향에 관하여 고찰할 수 있다. 이 비교를 통하여 스카이라인 통제가 아파트단지 계획과 설계에서 생태학적 조경설계에 영향을 주는가를 검증하게 될 것이며, 스카이라인이 통제된 아파트단지가 조경시설 설계에 있어서 전체적, 역동적, 반응적, 직관적 접근을 할 때 상대적으로 우선성을 표출할 수 있을 것이다. 아파트단지 계획·설계에 있어 건물고도제한이 적절하게 검토되어 스카이라인의 통제를 더 강하게 할수록 아파트단지에서 만들어진 조경환경의 특성이 강조되고 강화한 경관이 더 조화롭게 된다는 점에서 경관에 유용하고 편익이 있다. 생태학적 조경설계의 평가사항은 자기 지속적, 자연적·문화적 정체성, 개연적 외관, 생태학적 접근으로 이뤄진다는 전제 아래 세부사항 18개 항목을 표출하였다. 또한 스카이라인 통제는 자연적 경관을 보전하고 수목이 단지의 안팎으로 자연스럽게 펼쳐지는 녹지 네트워크와 야생 동물 코리도를 획득하기 위하여 독특한 경관을 설계하고 개성적인 것으로 도출하여 조화로운 심미성을 이룩하는데 유용하다는 것을 계량적으로 표출하였다. 아파트단지의 경관에서 의미 있는 것은 다양한 접근으로 설계되고 건물 스카이라인 통제방법을 강화함으로써 관리되는 스카이라인의 실루엣이 다양하고 개성적 형태를 표출한다는 것을 보여준다. 결과적으로 스카이라인의 영향과 생태학적 조경설계가 계량적 요소에 의해 상대적으로 비교될 수 있으며, 생태학적 조경설계의 평가시설지표는 보다 세분화됨으로써 전체적인 설계요소의 강도에 영향을 줄 수 있다.

Bim-based Life Cycle Assessment of Embodied Energy and Environmental Impacts of High-rise Buildings: A Literature Review

  • Lijian Ma
    • International Journal of High-Rise Buildings
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    • v.12 no.2
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    • pp.163-168
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    • 2023
  • Today 55 percent of the population in the world lives in urban areas which is expected to increase to 68 percent by the year 2050. In the cities, high-rise buildings as symbols of the modern cityscape are dominating the skylines, but the data to demonstrate their embodied energy and environmental impacts are scarce, compared to low- or mid-rise buildings. Reducing the embodied energy and environmental impacts of buildings is critical as about 42 percent of primary energy use and 39 percent of the global greenhouse gas (GHG) emissions come from the building sector. However, it is an overlooked area in embodied energy and environmental impacts of high-rise buildings. Life cycle assessment (LCA) is a widely used tool to quantify the embodied energy and environmental impacts of the building sector. LCA combined with Building Information Modeling (BIM) can simplify data acquisition of the building as well as provide both tools with feedback. Several studies recognize that the integration of BIM and LCA can simplify data acquisition of the building as well as provide tools with feedback. This article provides an overview of literature on BIM-based of embodied energy and environmental impacts of high-rise buildings. It also compares with different LCA methodologies. Finally, major strategies to reduce embodied energy and environmental impacts of high-rise buildings, research limitations and trends in the field are covered.

A Study on the Changes and Influencing Factors fo Townscape in Korea since 1945 (解防後 韓國의 都市景觀 變遷 및 그 要因 硏究 - 서울을 중심으로 -)

  • 이경목
    • Journal of the Korean Institute of Landscape Architecture
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    • v.26 no.2
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    • pp.1-14
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    • 1998
  • The purpose of this study is to find out how the urban landscape of Korea, especially Seoul, changed during the last half century since 1945. The modernization of Korea, which had begun in 1960's after the chaotic period caused by Korean War, influenced the rapid growth of cities and the radical changes of its structures. But the Western-minded planning theories based on rationalism and positivism was directly applied in developing our traditional cities and consequently the modern urban landscape including urban pattern, architectural style, and commercial and residential landscape revealed disharmony, discrepancy and inconsistency in skylines, streetscape and so on. The findings are summarized as follows. 1. Because the urban structure and pattern changed in undesirable manner in terms of land use and traffic circulation, cities as a whole resulted in exclusive and heterogeneous landscape, and citizens lost their identity and felt alienated. 2. Because the architectural forms of important and monumental buildings which influenced the character of streetscape were not so successful in inventing contemporary Korean Style in true sense, we still have difficulty in creating the urban landscape of originality and legibility. 3. Because from the beginning of this era almost all highrise buildings were designed by modernism-oriented western architects, the commercial landscape of central cities did not evoke a sense of place, and after the introduction of postmodernism this tendency is ore striking even in everyday ordinary streetscape. 4. The newly formed residential landscape which was mainly composed of highly dense and highrise apartment, not only evolved very overwhelming and ugly visual impact but also exposed many social problems in living condition, neighboring and face-to-face contact. In conclusion, in ordr to define the 'Koreanness' of our urban landscape, we have to struggle to combine traditional architectural heritage and native townscape with Western shape, thought and theory, no matter how difficult it may be.

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Discriminant Analysis of Natural Landscape Features in National Parks between Korea and Scotland - Using Low-Level Functions of Content-Based Image Retrieval - (한국과 영국 사이의 국립공원 자연 경관 특색의 판별 분석 - 내용기반 영상검색의 저단계 기능 측면에서 -)

  • Lee, Duk-Jae
    • Korean Journal of Environment and Ecology
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    • v.22 no.3
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    • pp.289-300
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    • 2008
  • This study aims to discriminate differences in natural landscapes between the Cairngorms National Park in Scotland and the Jirisan National Park in Korea, using functions of content-based image retrieval such as texture, shape, and color. Digital photographs of each National Park were taken and selected. The low-level functions of photographic images were reduced to orthogonally rotated five factors. Based on the reduced factors, a linear decision boundary was obtained between Cairngorms landscapes and Jirisan landscapes. As a result, the discriminant function significantly delineated two groups, resulting in $x^2=63.40$ with df=5(p<0.001). Both the eigenvalue 2.417 and the value of wilks' lambda 0.29 supported that the most proportion of total variability came from the differences between the means of discriminant function of groups. It was estimated that four independent variables explained about 70.7% of total variance of dependent variable. The variable with the largest effect on landscapes was far region-related factor(r=1.07), followed by near region-related factor (r=0.90). A total of 90.7% of cross-validated grouped cases were correctly classified. It was interpreted that far distant regions, as well as near distant regions, had sufficient discrimination power for landscape classification between the Cairngorms National Park and the Jirisan National Park, so that landscape identity of the National Park over cultures was revealed by skylines in a most effective way. Relatively fewer factors making visual landscapes were effectively used to classify natural landscapes of the National Parks which had different semantics.

Research on the Visual Characteristics of a Representative View of the Skyline; - Referring to Landscape Assessment of Mt. Mudeung from Various Viewpoints - (도시 배후 산 지형 스카이라인 경관의 조망 특성과 경관 대표성 평가 - 시점 위치에 따른 무등산 조망경관 분석을 중심으로 -)

  • Cho, Tong-Buhm
    • Journal of the Korean Institute of Landscape Architecture
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    • v.35 no.6
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    • pp.84-96
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    • 2008
  • This research investigated the landscape characteristics of the skyline and the cognitive characteristics of Mt. Mudeung (1,186m) from various viewpoints. Mt. Mudeung, the representative landscape of Gwangju City, has been recognized as a natural landmark and theme of paintings. By analyzing the perspective from 32 points with a digital terrain model, some landscape indices of the skyline were derived and the relationships are discussed. Assessment of the semantic differential scale with 21 adjective variables and representativeness to 15 landscape photographs of the mountain were accomplished. 1. Through regression analysis of the skyline indices, significant relationships were found between them the angle from the visual axis and number of skyline jumps, the vertical angle fluctuation and number of jumps per degree, the visual depth fluctuation and vertical angle fluctuation of skyline, and between the vertical angle mean and number of jumps per degree. Meaningful relations were found between the number of jumps of skyline to number of jumps per degree and the angle from visual axis to visual distance. However, in the representative assessment no difference was found on the angle from visual axis of viewpoints. On the other hand, it seemed to relate representativeness with visual clarity based on visual distance. 2. We found 4 factors "familiarity", "fluctuation of skylines", "openness", and "feeling of texture" in the results of factor analysis of semantic differential assessment. When considering the results of assessment for representativeness, adjective words for familiarity and openness seemed to have a close assessment. Specifically, the research showed that the landscape representation was highly assessed in a view which could be seen from the higher parts to the lower part of hills. This result indicates that the management of viewpoints which could get a scene from intermediate to distant, and locating a high elevation is important. 3. In the picturesque expression of Mt. Mudeung, various impressions from the different points, a skyline based on the top of Mt. Mudeung and a mono structure by overlapping hills were common characteristics. These common characteristics were also partially found through the analysis of topographical landscape indices and landscape images. Therefore, the viewpoints for the representative landscape management should be selected in natural or open spaces.

Construction of the Regional Basemap for a Developing Country: Focused on the Bab Ezzouar Municipality in Algeria (개발도상국 지역분석용 베이스맵 구축방안: 알제리의 밥 에주아흐 지역을 중심으로)

  • Lee, Yong Jik;Choei, Nae Young
    • Journal of Korean Society for Geospatial Information Science
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    • v.23 no.1
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    • pp.89-99
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    • 2015
  • Recently, our construction industry is actively participating in numerous city planning projects in the third world countries. Considering the current depression of domestic real estate market, the emerging foreign demands could certainly provide substantial opportunities for the domestic industry to overcome the trough. For the field planners dealing with such foreign projects, though, the immediate problem is the lack of public statistics and geographic information to perform spatial analyses and/or prepare master plans. This study, in this context, tries to simulate a process to construct a digitized basemap of the case area, 'Bab Ezzouar,' in Algeria of Northern Africa. The area is a typical municipality that lacks the IT databases. To overcome the data shortage, the study uses the satellite map tiles so as to digitize the roads and building structures. It then estimates the block-wise populations based on the building image interpolation as well as the supplementary field survey data. The topographic TINs are also built by the SRTM (Shuttle Radar Topography Mission) digital elevation maps so that the three-dimensional configuration of the structures and terrains are rendered to check the urban scenery and skylines.