• Title/Summary/Keyword: natural environments

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Target Object Detection Based on Robust Feature Extraction (강인한 특징 추출에 기반한 대상물체 검출)

  • Jang, Seok-Woo;Huh, Moon-Haeng
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.12
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    • pp.7302-7308
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    • 2014
  • Detecting target objects robustly in natural environments is a difficult problem in the computer vision and image processing areas. This paper suggests a method of robustly detecting target objects in the environments where reflection exists. The suggested algorithm first captures scenes with a stereo camera and extracts the line and corner features representing the target objects. This method then eliminates the reflected features among the extracted ones using a homographic transform. Subsequently, the method robustly detects the target objects by clustering only real features. The experimental results showed that the suggested algorithm effectively detects the target objects in reflection environments rather than existing algorithms.

How effective are artificial nests in attracting bees? A review

  • Rahimi, Ehsan;Barghjelveh, Shahindokht;Dong, Pinliang
    • Journal of Ecology and Environment
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    • v.45 no.3
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    • pp.152-162
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    • 2021
  • Background: Recent declines in bee populations, along with increasing demand for pollination services in urban, agricultural, and natural environments, have led to strategies to attract wild bees to these areas. One of these strategies is installing artificial nests adjacent to urban gardens and agricultural farms. Bee hotels and nest boxes are among the artificial nests used by gardeners and farmers to attract pollinators. In this paper, we reviewed 50 studies that reported the efficiency of nest boxes and bee hotels in attracting bees. We considered the maximum occupation rate (percentage) as the main index to evaluate the efficiency of artificial nests. Results: The maximum occupation rate of bee hotels was higher in farms (averaged 44.1%) than in forests (averaged 30.3%) and urban (averaged 38.3%) environments. In the case of nest boxes, most studies reported efficiencies of less than 20%, with an occupation rate of 16% and 5.5% on average in forest and urban environments respectively. However, our meta-analysis results showed that there was no significant relationship between the occupation rate of the nests and their installation place. Regression analysis also showed that the structural features of bee hotels (length and diameter) and nest boxes (volume and entrance size) did not affect their efficiency in attracting bees. Conclusion: Our data showed that the strategy of installing artificial nests to attract pollinators is successful only concerning bee hotels, and the use of nest boxes has not been very successful.

Assessment of Natural Environment - II. Based on the Plant Taxa of the Natural Parks and Ulleung island- (자연환경 평가 -II. 국내 자연공원과 울릉도의 식물군을 이용하여-)

  • 김철환;이희천
    • Korean Journal of Environmental Biology
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    • v.19 no.1
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    • pp.49-58
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    • 2001
  • This study aims to compare and analyze the environment of natural parks and Ulleung island using the plant taxa classified by five degrees based on their distributional ranges. The scores differentially given based on the importance of each degree; taxa belonging to the fifth degree are given to 20 scores each, fourth 10, third 5, second 3.3, and first 2.5, respectively. The total assessed scores were ranked as Mt. Halla, Seorak, Jiri, Deokyu, Is. Ulleung, Mt. Sobaek, Odae, Palgong, Chink, Taebaek, Songni, Juwang, Gaya, Duryun, Gaeryong, Bukhan, Naebyeon, Worak, Naejang, Cheongryang, Naeyeon, Myeongii, Jokye, Mudeung, Wolchul, Geumo, Juheul, Biseul, Hwangmae, Jangan, Seonun, Moak, Seonam, Chilgap, and Gibaek, in order, respectively. It is suggested that the natural environments assessing more than 1,000 of total scores such as Mt. Halla and Mt. Deokyu are regarded as the most excellent ones, and those between 700 to 1,000 of total scores such as Is. Ulleung and Mt. Odae are regarded as relatively excellent ones. Natural parks scored between 500 to 700 such as Mt. Palgong and Mt. Gaya are regarded as good ones and parks scored between 300 to 500 such as Mt. Duryun and Mt. Mudeung are regarded as normal ones. The area assessed less than 300 of total scores such as Mt. Wolchul and Mt. Gibaek are regarded as the most inferior ones. The total scores of the national parks are generally higher than those of the provincial and county parks. In addition, Ulleung island has a total of 882.9 scores. Therefore, according to the IUCN the Ulleung island should be included in the criterion of the preservative model of natural ecosystem, suggested by Ministry of Environment. At the same time, Ulleung island should be included to the superior model of natural scenery resources by its uniqueness of topography, geography and natural environments. Ulleung island is assessed as having relatively excellent natural environments as compared with other national parks, suggesting that the island should be designated as a new national park.

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Development of GRD Measurement Method using Natural Target in Imagery (영상 내 자연표적을 이용한 GRD 측정기법 개발)

  • Kim, Jae-In;Jeong, Jae-Hoon;Kim, Tae-Jung
    • Korean Journal of Remote Sensing
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    • v.26 no.5
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    • pp.527-536
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    • 2010
  • This paper reports a reliable GRD (Ground Resolved Distance) measurement method of using natural targets instead of the method using artificial targets. For this, we developed an edge profile extraction technique suitable for natural targets. We demonstrated the accuracy and stability of this technique firstly by comparing GRD values generated by this technique visually inspected GRD values for artificial targets taken in laboratory environments. We then demonstrated the feasibility of GRD estimation from natural targets by comparing GRD values from natural targets to those from artificial targets using satellite images containing both artificial and natural targets. The GRDs measured from the proposed method were similar to the values from visual inspection and the GRDs measured from the natural targets were similar to the values from artificial targets. These results support our proposed method is able to measure reliable GRD from natural targets.

Implementation of Background Scene in the Virtual Reality Ship Simulator (가상현실 선박 시뮬레이터의 배경 구현)

  • 임정빈
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.6 no.1
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    • pp.11-22
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    • 2000
  • The paper describes creation methods of background scenes to implement realistic virtual environments in the VRSS (Virtual Reality Ship Simulator). VRSS is next-generation system constructed with virtual tools in a virtual space. Thus, it could have many benefits compared to conventional ship simulators composed with heavy bridge mock-up system and wide visual presentations. In this work, we developed effective 3D object modeling techniques, and constructed virtual harbor scene by using 3D-Webmaster authoring tool. The virtual harbor was built with object-oriented 3D objects modeled to interact with user's action. With the immersion-type VR system, we created virtual harbor environments in a virtual space, and discussed on the naturalness of the scene with test results of SDMPA (Semantic Differential Method for Psychophysical Assessment) by 10 subjects. As the results of subject assessment, all of the participants could felt natural-like harbor. Therefore, we found that the proposed creation methods and procedures of background scene are enabling to fit to the full mission VRSS construction.

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Development of a Potential Centrality Evaluation Model for Rural villages ( II ) - Application of model by Survey of villages and Analysis using GIS - (농촌마을의 중심성 평가 모형의 개발 (II) - 자료조사 및 GIS분석을 통한 모형의 적용 -)

  • 김대식;정하우
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.44 no.1
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    • pp.81-92
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    • 2002
  • The purpose of this paper, the 2nd stage of this study. is to test the applicability of the potential centrality evaluation model (PCEM) to a case study area. To verify the practical applicabilities of the PCEM, an administrative area of Ucheon-myeon, Hoengseong-gun, Gangwon-do was selected as a study area. Full data on the human environments of total 72 villages within the study area were surveyed. Data on the natural environments were collected through GIS analysis from digital maps developed far this study. The highest PCI (Potential Centrality Index) score was shown at Uhang village of which one being 841 (total score being 1,000), the real single center village of the study area. The evaluation results on potential centeralities of all the villages in the study area would provide decision-makers with more precised information for selection of center villages for development project.

Effectiveness of strake installation for traffic signal structure fatigue mitigation

  • Wieghaus, Kyle T.;Hurlebaus, Stefan;Mander, John B.
    • Structural Monitoring and Maintenance
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    • v.1 no.4
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    • pp.393-409
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    • 2014
  • Across-wind response is often the cause of significant structural vibrations that in turn cause fatigue damage to welded and other connections. The efficacy of low-cost helical strakes to mitigate such adverse response is presented for a traffic signal structure. Field observations are made on a prototype structure in a natural wind environment without and with helical strakes installed on the cantilevered arm. Through continuous monitoring, the strakes were found to be effective in reducing across-wind response at wind speeds less than 10 m/s. Estimates of fatigue life are made for four different geographical locations and wind environments. Results for the class of traffic signal structure show that helical arm strakes are most effective in locations with benign wind environments where the average annual wind speed is not more than the vortex shedding wind speed, which for this investigation is 5 m/s. It is concluded that while strakes may be effective, it is not the panacea to mitigating connection fatigue at all locations.

A Study for Open Space System Establishment of Chonju City -Chiefly as Viewed the Concept of Specified Nodes & Corridors- (전주시 "오픈스페이스"체계 수립에 관한 연구: 특화된 결정점과 "코리도"개념의 도입을 중심으로-)

  • 최만봉;김재식
    • Journal of the Korean Institute of Landscape Architecture
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    • v.15 no.1
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    • pp.69-84
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    • 1987
  • According to the complexity and the pluralism of the modern cities, they are changing themselves into the multinoded and social - classless urban environments. The sudden drift of population to the cities is giving rise to the serious environmental problems, and the rapid increase of recreational needs among the citizen is changing the urban society into a leisure - oriented one. In order to coping with the abrupt change in the social and natural urban environments, the various fields of urban society should be co - ordinated. The study uses the green - city concept to get solves the incongruity of urban structure in Chonju City. The existing open space maps were drawn up by the various techniques such as the analysis of the topographic maps and collected data, the interpretation of the aero-photographs and the reconnaissance of site. The authors suggested the existing condition, and the problems and potentials of open space elements in Chonju City through the analysis of the existing condition maps. After synthesizing the contents of analysis, the 7u(hors established an exclusive open space system for Chonju City.

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METRO - A Free Ranging Mobile Robot with a Laser Range Finder (METRO - 레이저 거리계를 장착한 자율 이동로봇)

  • Cha, Young-Youp;Gweon, Dae-Gap
    • Journal of Institute of Control, Robotics and Systems
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    • v.2 no.3
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    • pp.200-208
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    • 1996
  • This paper describes the mechanism, guidance, sensor system, and navigation algorithm of METRO, a free ranging mobile robot. METRO is designed for use in structured surroundings or factory environments rather than unstructured natural environments. An overview of the physical configuration of the mobile robot is presented as well as a description of its sensor system, an omnidirectional laser range finder. Except for the global path planning algorithm, a guidance and a navigation algorithm with a local path planning algorithm are used to navigate the mobile robot. In METRO the computer support is divided into a supervisor with image processing and local path planning and a slave with motor control. The free ranging mobile robot is self-controlled and all processing being performed on board.

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A Study on the Vernacular Dwellings in Noksan area, Kinhae (김해녹산지역 전통주거의 조사연구)

  • KyungTaiSeo
    • Journal of the Korean housing association
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    • v.4 no.1
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    • pp.5-16
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    • 1993
  • This paper tries to find out the characteristics of the vernacular dwellings in Noksan area which has been a part of Kaya cultural realm. Through the analyses of its environments and several practical unit plans. The characteristic of the vernacular dwellings in thes arer are as below. The dwellings has been transfigured form [Omaksari] hut which is generally the smallest house form in Korea. The noticeable vernacular hut in this area is smallest 4-kan double-wing plan which is irregular 전 shape, but they call it single wing and 2-kan plan. Leed which can be obtained easily in thes area is used on roof and in wall. Timbers used in constrution are very slim or rather weak, but they were treated carafully. The chimney form in this area seems the results of minimizing of their being from the invasion of Japanese pirate, but also it seems an effective method of heat control. In conclusion, we cannot deny that the house form of this area seems affected by its exclusive natural and social environments.

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