11,028 research outputs found

    Real-time Spatial Detection and Tracking of Resources in a Construction Environment

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    Construction accidents with heavy equipment and bad decision making can be based on poor knowledge of the site environment and in both cases may lead to work interruptions and costly delays. Supporting the construction environment with real-time generated three-dimensional (3D) models can help preventing accidents as well as support management by modeling infrastructure assets in 3D. Such models can be integrated in the path planning of construction equipment operations for obstacle avoidance or in a 4D model that simulates construction processes. Detecting and guiding resources, such as personnel, machines and materials in and to the right place on time requires methods and technologies supplying information in real-time. This paper presents research in real-time 3D laser scanning and modeling using high range frame update rate scanning technology. Existing and emerging sensors and techniques in three-dimensional modeling are explained. The presented research successfully developed computational models and algorithms for the real-time detection, tracking, and three-dimensional modeling of static and dynamic construction resources, such as workforce, machines, equipment, and materials based on a 3D video range camera. In particular, the proposed algorithm for rapidly modeling three-dimensional scenes is explained. Laboratory and outdoor field experiments that were conducted to validate the algorithm’s performance and results are discussed

    Encouraging sustainable development in a coastal community: New Hanover County, North Carolina's exceptional design zoning district

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    While New Hanover County is the second smallest county in North Carolina, it is also the second most densely populated with approximately 850 people per square mile. Nestled between the Cape Fear River and Atlantic Ocean with surrounding barrier island beach communities, the County’s geographic location provides a prime vacation destination, as well as an ideal location for residents who wish to live at the water’s edge. Wilmington is the largest city in the County with a population just under 200,000. Most of the Wilmington metropolitan area is developed, creating intense development pressures for the remaining undeveloped land in the unincorporated County. In order to provide development opportunities for mixed use or high density projects within unincorporated New Hanover County where appropriate urban features are in place to support such projects without the negative effects of urban sprawl, County Planning Staff recently developed an Exceptional Design Zoning District (EDZD). Largely based on the LEED for Neighborhood Development program, the EDZD standards were scaled to fit the unique conditions of the County with the goal of encouraging sustainable development while providing density incentives to entice the use of the voluntary district. The incentive for the voluntary zoning district is increased density in areas where the density may not be allowed under normal circumstances. The rationale behind allowing for higher density projects is that development can be concentrated in areas where appropriate urban features are in place to support such projects, and the tendency toward urban sprawl can be minimized. With water quality being of high importance, it is perceived that higher density development will better protect water quality then lower density projects. (PDF contains 4 pages

    Simulation of evacuation processes using a bionics-inspired cellular automaton model for pedestrian dynamics

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    We present simulations of evacuation processes using a recently introduced cellular automaton model for pedestrian dynamics. This model applies a bionics approach to describe the interaction between the pedestrians using ideas from chemotaxis. Here we study a rather simple situation, namely the evacuation from a large room with one or two doors. It is shown that the variation of the model parameters allows to describe different types of behaviour, from regular to panic. We find a non-monotonic dependence of the evacuation times on the coupling constants. These times depend on the strength of the herding behaviour, with minimal evacuation times for some intermediate values of the couplings, i.e. a proper combination of herding and use of knowledge about the shortest way to the exit.Comment: 19 pages, 13 pictures, accepted for publication in Physica

    An Archaeological and Geomorphological Investigation of Northrup Park, Boerne, Kendall County, Texas

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    The Center for Archaeological Research (CAR) of The University of Texas at San Antonio contracted with the city of Boerne, Texas, to conduct a pedestrian survey with limited shovel and backhoe testing of 103 acres of raw land planned for development as a city park in south Kendall County. The purpose of the survey was to identify archaeological sites visible on the surface and areas with potential for buried sites. Seven prehistoric sites were found and recorded. A plan of avoidance was recommended for all sites; however, the proposed construction plan could not be altered to accommodate both the needs of the city and the avoidance of all the archaeological sites. Therefore, with the concurrence of the Texas Historical Commission, 41KE141, 41KE142, 41KE143, 41KE144, 41KE145, and 41KE147 were 100-percent surface collected, and additional shovel tests were excavated in all but 41KE143. As the shovel tests revealed no cultural material , CAR recommends the Boerne be allowed to proceed with development of the park as planned. Site 41KE146 will not be impacted by the current project as planned; however, CAR recommends that further testing be conducted at the site prior to any future construction activities within the site boundaries

    Interstate 74 Quad Cities Corridor Study Scott County, Iowa and Rock Island County, Illinois Project Number IM-74-1(122)0-13-82 FHWA-IOWA-EIS-09-01-F, February 2009

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    The Federal Highway Administration (FHWA) and the Iowa and Illinois Departments of Transportation (Iowa DOT and IDOT) have identified the Selected Alternative for improving Interstate 74 (I-74) from its southern terminus at Avenue of the Cities (23rd Avenue) in Moline, Illinois to its northern terminus one mile north of the I-74 interchange with 53rd Street in Davenport, Iowa. The Selected Alternative identified and discussed in this Record of Decision is the preferred alternative identified in the Final Environmental Impact Statement (FEIS). The purpose of the proposed improvements is to improve capacity, travel reliability, and safety along I-74 between its termini, and provide consistency with local land use planning goals. The need for the proposed improvements to the I-74 corridor is based on a combination of factors related to providing better transportation service and sustaining economic development

    Anti-collision systems in tunneling to improve effectiveness and safety in a system-quality approach: A review of the state of the art

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    Tunnelling and underground construction operations are often characterized by critical safety issues mainly due to poor visibility and blind spots around large vehicles and equipment. This can lead to collisions between vehicles or between vehicles and pedestrians or structural elements, causing accidents and fatalities. To improve the OS&H conditions, it is important to investigate the possible introduction of innovative techniques and technologies to reduce the occurrences and consequences of shared spaces (spaces used by both vehicles and pedestrians). For this reason, research was conducted to investigate the possible use of different technologies of anti-collision systems in tunnelling operations. First, to achieve this goal, an extensive review of the literature was carried out in accordance with the PRISMA statement to select the current techniques and technologies used by general anti-collision systems in civil and mining construction sites. Then, the operating principles, the relative advantages and disadvantages, combinations, and costs were examined for each of these. Eight types of systems and many examples of applications of anti-collision systems in underground environments were identified as a result of the analysis of the literature. Generally, it was noted that the anti-collision techniques available have found limited application in the excavation sites of underground civil works up to the present day, though the improvement in terms of safety and efficiency would be considerable
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