• Title/Summary/Keyword: the area of a circle

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Determination Grid Cell for Estimation of Radar Relationship (레이더 관계식 산정을 위한 격자망 크기 결정)

  • Lee, Won-Ho;Kim, Jin-Geuk
    • Journal of The Korean Society of Agricultural Engineers
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    • v.48 no.5
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    • pp.3-15
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    • 2006
  • The purpose of the study is to determine grid cell of radar relationship, and to promote the radar data on hydrology field. The study region is the Chungjudam basin with a drainage area of $6,648km^{2}$ located within the 260 km circle under the DWSR-88C C-band umbrella(Kwanak Mt Radar). Grid cell was produced to extract radar reflectivity and rainfall data of the same time and point using Arc-view software package. The grid cell size is to estimate mean correlation coefficient for $1km{\times}1km,\;2km{\times}2km,\;3km{\times}3km$ grid. The result of mean correlation coefficient showed good result(0.57) for the $1km{\times}1km$ grid cell. The 32 rainfall stations Z-R relationship was estimated in Chungjudam basin.

The Characteristic of Wind Pressure of Low-rise Building Located Behind a Circle Wind Fence (원형방풍팬스 후면에 있는 저층건물의 풍압특성)

  • Jeon, Jong-Gil;You, Jang-Youl;You, Ki-Pyo;Kim, Young-Moon
    • Proceeding of KASS Symposium
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    • 2006.05a
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    • pp.102-109
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    • 2006
  • The effects of wind fence on the pressure characteristics around low-rise building model were investigated experimentally. Flow characteristics of turbulences behind wind fence were measured using hot-wire anemometer. The wind fence characterize by varying the porosity of 0 %, 40 % and the distances from the wind fence from 1 H to 6 H with maintaining the uniform flow velocity of 6 m/s. We investigated the overall characterization of the low-rise building by measuring pressure seventy four on model. The effects of porosity fences varied with the porosity of the fence and measurement locations(1H-6H). The 0% porosity proved to be effective for the protection area of 4H to 6H, but the 40% porosity proved to be effective for the protection area of 1H to 6H. The low-rise building of front face was found to be best wind fence for decreasing the mean, maximum and minimum pressure fluctuation.

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Development of Weight Type Rounded Snow Plate (중량식 원형 적설판 개발에 관한 연구)

  • Lee, Bu-Yong;Kim, Hyun-Chul
    • Atmosphere
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    • v.19 no.1
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    • pp.1-8
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    • 2009
  • We need water equivalent unit data of snowfall for the purpose of forecast and hydrology related research area. This study developed new method of automatic recording snowfall as weight unit with circle type plate using stain-gauge loadcell. Field test of instrument carried out at Daegwallyeong Obs. Station from 20 to 23 Jan. 2008 during heavy snowfall. There is 74.2cm snow depth and 54.6mm precipitation by Daegwallyeong Obs. Station. But the instrument of this study recorded 71.0mm of precipitation amount. Because of different observation method can cause more 15.4mm than Daegwallyeong Obs. Station. But this study gives the possibility of observation of new snow fall measurement under freezing conditions of snow. From the observation data the density of snowfall calculated from 0.09 to $1015g/cm_3$ from the observation period. And have a good relations between manual observation and automatic observation data from this study instrument with slope of 1.35 to 1.39.

Characteristics of Wound Contraction according to the Shape and Antomical Regions of the Wound in Porcine Model (돼지모델에서 상처의 모양과 부위에 따른 상처수축의 특성)

  • Chu, Ho-Jun;Son, Dae-Gu;Kwon, Sun-Young;Kim, Jun-Hyung;Han, Ki-Hwan
    • Archives of Plastic Surgery
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    • v.38 no.5
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    • pp.576-584
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    • 2011
  • Purpose: The shape and location, the amount of the wound and the characteristics of the remaining tissues are known to influence wound contraction. The previous studies using small animals have not been an appropriate model because the wound healing mechanisms and skin structures are different from those of the human. The purpose of this study is to evaluate wound contraction according to the shape and location of the wound using a $Micropig^{(R)}$. Methods: Four $Micropigs^{(R)}$ (Medikinetics, Pyeongtaek, Korea) that were 10 months of age weighed 25 kg were used. Full thickness skin defects were made by clearing all the tissues above the fascial layer in the shape of square, a regular triangle and a circle of 9 $cm^2$ each on the back around the spine. Eight wounds were created on the back of each pig, 50 mm apart from each other. The randomly chosen wound shapes included 11 squares, 11 regular triangles, and 10 circles. Wound dressing was done every other day with polyurethane foam. The wound size was measured using a Visitrak $Digital^{(R)}$ (Smith & Nephew, Hull, UK) on every other day after surgery from day 2 to day 28. A biopsy was performed on day 3, and 1, 2, 3 and 4 weeks to investigate the degree of acute and chronic inflammation, the number of microvesssel and myofibroblast density using H & E stain and immunohistochemistry. The wound contraction rate was calculated to figure out the differences among each of the shapes and the locations. Results: The ultimate shape of the circle wound was oval, and that of the regular triangle and square were stellate. The maximum contraction rate was obtained on 8 to 10 days for all the shapes, which corresponds with the immunohistochemical finding that myofibroblast increases in the earlier 2 weeks whereas it decreases in the later 2 weeks. Epithelialization was seen in the wound margin on day 7 and afterwards. The final wound contraction rates were highest for the regular triangle shapes; however, there were no statistically significant differences. The wound contraction rates by locations showed statistically significant differences. The wound in the cephalic area presented more contractions than that of the wounds in the caudal area. Conclusion: The location of a wound is more important factor than the wound shape in wound contraction.

민자사업의 사업관리 사례분석

  • Lee Kwan-Young;Kim Se-Jong
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2004.11a
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    • pp.13-19
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    • 2004
  • In most PFI(Private Finance Initiative) projects in Korea, the project management are in charge of the Special Purpose Company(SPC) established for carrying out the project. This paper is a case study about an owner CM executed by the organizations and staffs of SPC itself. : Seoulbeltway (Ilsan $\~$ Toegaewon) Private Investment Project. In time management area, the SfC was the leader of project management throughout the life circle - plan, design, permit, construction, operation and maintenance - beyond the schedule manager's role. In cost management area, the methods of reducing the total costs by VE, new technologies, etc. has been needed assuming the construction risks were subject to SPC.

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A Study on the Village Groves in Chinan-Gun Region, Korea (진안지역 마을 숲에 관한 연구)

  • Park, Jae-Chul
    • Journal of Korean Society of Rural Planning
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    • v.5 no.1 s.9
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    • pp.56-65
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    • 1999
  • The purpose of this study was to identify remained real state of the village groves in human settlement circle. That was practiced in case of Chinan-Gun region which traditional elements had well been conserved. 33 village groves were found by site survey, reference and interview in Chinan-Gun region. 31 of 51 village groves were clarified as complementing village grove by classification of grove character. It was identified through survey that many were partially destructed by development and human overuse. The results of this study showed general, socio-behavioral characteristics, characteristics of forest state and vegetation structure of village groves in Chinan-Gun region. Length, area, form, type, motive, location, relationship of those were analyzed to identify general characteristics. Facilities, human behavior and ownership of those were analyzed to identify socio-behavioral characteristics. Principal dominant species and appearing rate, height, width, density of those, species diversity of groves were analyzed to identify forest state and vegetation structure. Interrelation between each factor were analyzed and comparative review with previous studies was achieved.

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Exploring the 4th Industrial Revolution Technology from the Landscape Industry Perspective (조경산업 관점에서 4차 산업혁명 기술의 탐색)

  • Choi, Ja-Ho;Suh, Joo-Hwan
    • Journal of the Korean Institute of Landscape Architecture
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    • v.47 no.2
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    • pp.59-75
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    • 2019
  • This study was carried out to explore the 4th Industrial Revolution technology from the perspective of the landscape industry to provide the basic data necessary to increase the virtuous circle value. The 4th Industrial Revolution, the characteristics of the landscape industry and urban regeneration were considered and the methodology was established and studied including the technical classification system suitable for systematic research, which was selected as a framework. First, the 4th Industrial Revolution technology based on digital data was selected, which could be utilized to increase the value of the virtuous circle for the landscape industry. From 'Element Technology Level', and 'Core Technology' such as the Internet of Things, Cloud Computing, Big Data, Artificial Intelligence, Robot, 'Peripheral Technology', Virtual or Augmented Reality, Drones, 3D 4D Printing, and 3D Scanning were highlighted as the 4th Industrial Revolution technology. It has been shown that it is possible to increase the value of the virtuous circle when applied at the 'Trend Level', in particular to the landscape industry. The 'System Level' was analyzed as a general-purpose technology, and based on the platform, the level of element technology(computers, and smart devices) was systematically interconnected, and illuminated with the 4th Industrial Revolution technology based on digital data. The application of the 'Trend Level' specific to the landscape industry has been shown to be an effective technology for increasing the virtuous circle values. It is possible to realize all synergistic effects and implementation of the proposed method at the trend level applying the element technology level. Smart gardens, smart parks, etc. have been analyzed to the level they should pursue. It was judged that Smart City, Smart Home, Smart Farm, and Precision Agriculture, Smart Tourism, and Smart Health Care could be highly linked through the collaboration among technologies in adjacent areas at the Trend Level. Additionally, various utilization measures of related technology applied at the Trend Level were highlighted in the process of urban regeneration, public service space creation, maintenance, and public service. In other words, with the realization of ubiquitous computing, Hyper-Connectivity, Hyper-Reality, Hyper-Intelligence, and Hyper-Convergence were proposed, reflecting the basic characteristics of digital technology in the landscape industry can be achieved. It was analyzed that the landscaping industry was effectively accommodating and coordinating with the needs of new characters, education and consulting, as well as existing tasks, even when participating in urban regeneration projects. In particular, it has been shown that the overall landscapig area is effective in increasing the virtuous circle value when it systems the related technology at the trend level by linking maintenance with strategic bridgehead. This is because the industrial structure is effective in distributing data and information produced from various channels. Subsequent research, such as demonstrating the fusion of the 4th Industrial Revolution technology based on the use of digital data in creation, maintenance, and service of actual landscape space is necessary.

Virtual Force(VF)-based Disaster Monitoring Network Using Multiple UAVs (대규모 공중무인기를 이용한 가상력 기반 재난 감시 네트워크)

  • Chun, Jeongmyong;Yoon, Seokhoon;Kim, Daeyoung
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.4
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    • pp.97-108
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    • 2016
  • In this paper, we consider a cooperative monitoring network, which consists of a large number of UAVs, in order to promptly detect event in a disaster area. A command center may not be able to control each UAV individually due to resource constraints. Therefore, UAVs need to autonomously construct a mobile monitoring network in order to maximize monitoring coverage and to adapt the network formation according to environment changes in the disaster area. To that end, we propose multiple UAVs-based cooperative monitoring schemes that uses virtual forces. In this monitoring scheme, an effective monitoring is enabled by extending monitoring coverage using each UAV's circle movements. The UAVs-based monitoring network can also be splitted or merged in order to increase the monitoring effectiveness. Through simulations, we show that the proposed scheme can effectively monitor a large area and achieve a high event detection ratio.

Estimation Carbon Storage of Urban Street trees Using UAV Imagery and SfM Technique (UAV 영상과 SfM 기술을 이용한 가로수의 탄소저장량 추정)

  • Kim, Da-Seul;Lee, Dong-Kun;Heo, Han-Kyul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.22 no.6
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    • pp.1-14
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    • 2019
  • Carbon storage is one of the regulating ecosystem services provided by urban street trees. It is important that evaluating the economic value of ecosystem services accurately. The carbon storage of street trees was calculated by measuring the morphological parameter on the field. As the method is labor-intensive and time-consuming for the macro-scale research, remote sensing has been more widely used. The airborne Light Detection And Ranging (LiDAR) is used in obtaining the point clouds data of a densely planted area and extracting individual trees for the carbon storage estimation. However, the LiDAR has limitations such as high cost and complicated operations. In addition, trees change over time they need to be frequently. Therefore, Structure from Motion (SfM) photogrammetry with unmanned Aerial Vehicle (UAV) is a more suitable method for obtaining point clouds data. In this paper, a UAV loaded with a digital camera was employed to take oblique aerial images for generating point cloud of street trees. We extracted the diameter of breast height (DBH) from generated point cloud data to calculate the carbon storage. We compared DBH calculated from UAV data and measured data from the field in the selected area. The calculated DBH was used to estimate the carbon storage of street trees in the study area using a regression model. The results demonstrate the feasibility and effectiveness of applying UAV imagery and SfM technique to the carbon storage estimation of street trees. The technique can contribute to efficiently building inventories of the carbon storage of street trees in urban areas.

Flexible Formation Algorithm for Multiple UAV Using the Packing (패킹을 이용한 다수 무인기의 유동적 대형 형성 알고리즘)

  • Kim, Hyo-Jung;Kim, Jeong-Hun;Kim, Moon-Jung;Ryoo, Chang-Kyung
    • Journal of Advanced Navigation Technology
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    • v.25 no.3
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    • pp.211-216
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    • 2021
  • Multiple UAV System has been used for various purposes such as reconnaissance, networking and aerial photography. In such systems, it is essential to form and maintain the formation of multiple UAVs. This paper proposes the algorithm that produces an autonomous distributed control for each vehicle for a flexible formation. This command is a repulsive force in the form of the second-order system by the nearest UAV or mission area. The algorithm uses the relative position/speed through sensing and communication for calculating the command without external intervention. The command allows each UAV to follow the reference distance and fill the mission area as densely as possible without overlapping. We determine the reference distance via optimization technique solving the packing problem. The mission area comprises the desired formation outline and can be set flexibly depending on the mission. Numerical simulation is carried out to verify the performance of the proposed algorithm under a complex and flexible environment. The formation is formed in 26.94 seconds and has a packing density of 71.91%.