• Title/Summary/Keyword: Mesh construction

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A Study on the Development of Efficient Parking Management System using the GIS (GIS를 이용한 효율적 주차관리시스템 개발에 관한 연구)

  • Kim, Jae-Seok;Woo, Yong-Han;Lee, Sung-Jun
    • Journal of the Korean Society of Industry Convergence
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    • v.7 no.3
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    • pp.273-279
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    • 2004
  • There are several ways to solve parking problem in the downtown One of them is to manage parking efficiently, that is, to raise use-efficiency of parking place and to help drivers to select easily. When we manage the parking place m the block efficiently, It can prevent disproportion that some parking space is over capacity and the other parking one is under. It causes not only the disproportion of economic efficiency but also the congestion of local road. The precondition to manage parking efficiently is to analyse the parking characteristics. In this study we found out the characteristics of parking vehicles by analyzing the turnover per parking mesh and occupancy rate And we build up total D/B by collecting every information about parking space. We developed the Parking Management System by using GIS with D/B and digital map. The efficient Parking Management System is for convenience of drivers and efficient usage of parking space. And this system is also the basic study to be developed as the total Parking Management System by upgrading every information.

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Shrinkage movement analysis of reinforced concrete floors constructed in stages

  • Kwan, A.K.H.;Ng, P.L.
    • Computers and Concrete
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    • v.6 no.2
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    • pp.167-185
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    • 2009
  • Reinforced concrete floors constructed between movement restraints often crack seriously due to shrinkage after completion. One common mitigation measure is to construct the concrete floors in stages to allow part of the shrinkage movement to take place before completion. However, shrinkage movement analysis of concrete floors constructed in stages is quite cumbersome, as the structural configuration changes during construction, thus necessitating reanalysis of the partially completed structure at each stage. Herein, a finite element method for shrinkage movement analysis of concrete floors constructed in stages is developed. It analyses the whole structure, including the completed and uncompleted portions, at all stages. The same mesh is used all the time and therefore re-meshing and location matching are no longer necessary. This is achieved by giving negligibly small stiffness to the uncompleted portions, which in reality do not exist yet. In the analysis, the locked-in strains due to increase in elastic modulus as the concrete hardens and the creep of the hardened concrete are taken into account. Most important of all, this method would enable fully automatic shrinkage movement analysis for the purpose of construction control.

Construction of a artificial levee line in river zones using LiDAR Data (라이다 자료를 이용한 하천지역 인공 제방선 추출)

  • Choung, Yun-Jae;Park, Hyeon-Cheol;Jo, Myung-Hee
    • Proceedings of the Korea Water Resources Association Conference
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    • 2011.05a
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    • pp.185-185
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    • 2011
  • Mapping of artificial levee lines, one of major tasks in river zone mapping, is critical to prevention of river flood, protection of environments and eco systems in river zones. Thus, mapping of artificial levee lines is essential for management and development of river zones. Coastal mapping including river zone mapping has been historically carried out using surveying technologies. Photogrammetry, one of the surveying technologies, is recently used technology for national river zone mapping in Korea. Airborne laser scanning has been used in most advanced countries for coastal mapping due to its ability to penetrate shallow water and its high vertical accuracy. Due to these advantages, use of LiDAR data in coastal mapping is efficient for monitoring and predicting significant topographic change in river zones. This paper introduces a method for construction of a 3D artificial levee line using a set of LiDAR points that uses normal vectors. Multiple steps are involved in this method. First, a 2.5-dimensional Delaunay triangle mesh is generated based on three nearest-neighbor points in the LiDAR data. Second, a median filtering is applied to minimize noise. Third, edge selection algorithms are applied to extract break edges from a Delaunay triangle mesh using two normal vectors. In this research, two methods for edge selection algorithms using hypothesis testing are used to extract break edges. Fourth, intersection edges which are extracted using both methods at the same range are selected as the intersection edge group. Fifth, among intersection edge group, some linear feature edges which are not suitable to compose a levee line are removed as much as possible considering vertical distance, slope and connectivity of an edge. Sixth, with all line segments which are suitable to constitute a levee line, one river levee line segment is connected to another river levee line segment with the end points of both river levee line segments located nearest horizontally and vertically to each other. After linkage of all the river levee line segments, the initial river levee line is generated. Since the initial river levee line consists of the LiDAR points, the pattern of the initial river levee line is being zigzag along the river levee. Thus, for the last step, a algorithm for smoothing the initial river levee line is applied to fit the initial river levee line into the reference line, and the final 3D river levee line is constructed. After the algorithm is completed, the proposed algorithm is applied to construct the 3D river levee line in Zng-San levee nearby Ham-Ahn Bo in Nak-Dong river. Statistical results show that the constructed river levee line generated using a proposed method has high accuracy in comparison to the ground truth. This paper shows that use of LiDAR data for construction of the 3D river levee line for river zone mapping is useful and efficient; and, as a result, it can be replaced with ground surveying method for construction of the 3D river levee line.

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Evaluation on Removal Efficiency of Methylene Blue Using Nano-ZnO/Laponite/PVA Photocatalyzed Adsorption Ball (Nano-ZnO/Laponite/PVA 광촉매 흡착볼의 메틸렌블루 제거효율 평가)

  • Oh, Ju Hyun;Ahn, Hosang;Jang, Dae Gyu;Ahn, Chang Hyuk;Lee, Saeromi;Joo, Jin Chul
    • Journal of Korean Society of Environmental Engineers
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    • v.35 no.9
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    • pp.636-642
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    • 2013
  • In order to overcome drawbacks (i.e., filtration and recovery) of conventional powder type photocatalysts, nano-ZnO/Laponite/PVA (ZLP) photocatalyzed adsorption balls were developed by using in situ mixing of nanoscale ZnO as a photocatalyst, and Laponite as both adsorbent and supporting media in deionized water, followed by the poly vinyl alcohol polymerization with boric acid. The optimum mixing ratio of nano-ZnO:Laponite:PVA:deionized water was found to be 3:1:1:16 (by weight), and the mesh and film produced by PVA polymerization with boric acid might inhibit both swelling of Laponite and detachment of nanoscale ZnO from ZLP balls. Drying ZLP balls with microwave (600 watt) was found to produce ZLP balls with stable structure in water, and various sizes (55~500 ${\mu}m$) of pore were found to be distributed based on SEM and TEM results. In the initial period of reaction (i. e., 40 min), adsorption through ionic interaction between methylene blue and Laponite was the main removal mechanism. After the saturation of methylene blue to available adsorption sites for Laponite, the photocatalytic degradation of methylene blue occurred. The effective removal of methylene blue was attributed to adsorption and photocatalytic degradation. Based on the results from this study, synthesized ZLP photocatalyzed adsorption balls were expected to remove recalcitrant organic compounds effectively through both adsorption and photocatalytic degradation, and the risks of environmental receptors caused by detachment of nanoscale photocatalysts can be reduced.

Development of Work Clothing for the Construction Site (건설현장 근로자인 작업복 개발에 관한 연구)

  • Chang Sun-Ok;Choi Hei-Sun
    • Journal of the Korean Society of Clothing and Textiles
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    • v.30 no.7 s.155
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    • pp.1090-1102
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    • 2006
  • The purpose of this study is to develop an improved work clothing which is much safe, comfortable, mobility and convenient than what workers currently wear at construction site. The investigation has been conducted to evaluate current work clothing to grasp any problems, discomforts and damages related to the work clothing. For the best and accurate data, hands-on investigation and a short-interview have been performed at the construction site as well as formulating a questionnaire. The questionnaires was answered by 425 workers and safety manager of 13 different construction site. The result of the questionnaire enables us to design a sample work clothing, many pa π s such as material, pattern and design have been improved. To improve the amenity of heat, the surface of a material was used by $Aerocool^{\circledR}$ fiber which contains inside dryness function. In order to absorb perspiration on the back the armpits, mesh martial that is mixture of $Coolever^{TM}$ fiber and $Mirawave^{TM}$ fiber was used to absorb perspiration in an effective manner. And a sleeve's bottom part and trousers' bottom part's cover method have been changed. Sample work clothing was shorten at the side of upper garment up to 2cm and lengthen the length of the back by 3cm. To reduce the tightness around armpit more room was given in that area. Darts were added to the elbow, the hip, and the knees that also followed an ergonomic pattern. A sample work clothing evaluated an objective assessment and subjective assessment to compare to a current work clothing. Assessment group consists of seven subject groups and nine expert groups to evaluate external appearance and adaptability to the movements. In all aspects of the test, the result of evaluation process of the sample work clothing received more positive assessment than the current work clothing.

English Predicate Inversion: Towards Data-driven Learning

  • Kim, Jong-Bok;Kim, Jin-Young
    • Journal of English Language & Literature
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    • v.56 no.6
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    • pp.1047-1065
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    • 2010
  • English inversion constructions are not only hard for non-native speakers to learn but also difficult to teach mainly because of their intriguing grammatical and discourse properties. This paper addresses grammatical issues in learning or teaching the so-called 'predicate inversion (PI)' construction (e.g., Equally important in terms of forest depletion is the continuous logging of the forests). In particular, we chart the grammatical (distributional, syntactic, semantic, pragmatic) properties of the PI construction, and argue for adata-driven teaching for English grammar. To depart from the arm-chaired style of grammar teaching (relying on author-made simple sentences), our teaching method introduces a datadriven teaching. With total 25 university students in a grammar-related class, students together have analyzed the British Component of the International Corpus of English (ICE-GB), containing about one million words distributed across a variety of textual categories. We have identified total 290 PI sentences (206 from spoken and 87 from written texts). The preposed syntactic categories of the PI involve five main types: AdvP, PP, VP(ed/ing), NP, AP, and so, all of which function as the complement of the copula. In terms of discourse, we have observed, supporting Birner and Ward's (1998) observation that these preposed phrases represent more familiar information than the postposed subject. The corpus examples gave us the three possible types: The preposed element is discourse-old whereas the postposed one is discourse-new as in Putting wire mesh over a few bricks is a good idea. Both preposed and postposed elements can also be discourse new as in But a fly in the ointment is inflation. These two elements can also be discourse old as in Racing with him on the near-side is Rinus. The dominant occurrence of the PI in the spoken texts also supports the view that the balance (or scene-setting) in information structure is the main trigger for the use of the PI construction. After being exposed to the real data and in-depth syntactic as well as informationstructure analysis of the PI construction, it is proved that the class students have had a farmore clear understanding of the construction in question and have realized that grammar does not mean to live on by itself but tightly interacts with other important grammatical components such as information structure. The study directs us toward both a datadriven and interactive grammar teaching.

Study for the Grounding Resistance of the Mesh Grounding Electrode by Water Tank Model (수조모델을 이용한 메쉬접지극의 접지저항에 관한 연구)

  • Kim, Ju-Chan;Kim, Sung-Sam;Choi, Jong-Gyu;Lee, Chung-Sik;Koh, Hee-Seog
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.3
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    • pp.28-35
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    • 2006
  • Recently, a number of equipments related with electricity, electronics, and communication in the same building are needed to the grounding system for safety from unexpected accidents. When the faulted electric current flows into a certain grounding system, the potential rise in that system takes place and it might induce the potential rise to other grounding system. This potential interference was strongly affected by the surface potential, which was deeply related with the electrode shape. In this paper, the fundamental formula was deduced on the basis of surface potential of two grounding electrodes. Which corresponds to source of the potential interference and other grounding electrode, respectively. Therefore, the degree of potential interference in this mesh grounding electrode system was verified by the simple model simulation. In addition, in order to identify the difference between the grounding resistance in the realistic construction site and the expected value from the corresponding simulation, the experiment was performed with model on a reduced scale about the realistic grounding system. It consists of stainless steel hemisphere electrodes in a water tank. From this work, the grounding resistance in the mesh grounding electrode showed the good coincidence results between those. Consequently, it is confirmed that the grounding resistance in the mesh electrode is possible to be estimated by performing the experiment using the water tank model.

A Study on the Factors Affecting Vegetation Cover After Slope Revegetation - Focused on a JSB Method of Construction - (비탈면 녹화이후 식생피복에 영향을 미치는 요인에 관한 연구 - 자연생태복원 공법을 중심으로 -)

  • Kil, Sung-Ho;Lee, Dong-Kun;Cho, Min-Whan;Yang, Byung-E
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.14 no.5
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    • pp.127-136
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    • 2011
  • This study was conducted on the field application for a method which is currently used. Although the method was performed with experimental knowledge, this study attempted to approach scientific ways through thirty sets of test-bed and three times monitoring limited by control variations for three months. The factors on previous studies are slope location, slope degree, type (roadfill vs. roadcut), aspect, vegetation cover, species, thickness, vertical length, horizontal length, soil type, elevation, erosion, soil-moisture, soil-hardness, pH, and so on. However, the factors of a suitable and significant level are slope degree, type, aspect, thickness, soil-moisture, vertical length and horizontal length in slope revegetation. the results were as follows : As a result of survey on soil types based on the status before construction, the rate of vegetation cover with non-mesh construction in soil areas was better than the rate of vegetation cover with fiber meshes and wire meshes. The rate of vegetation cover with fiber meshes in weathered rocks was better than using wire meshes. The rate of vegetation cover with the wire meshes in blasted rocks was better than using fiber meshes. Also, the factors affecting the rate of vegetation cover presented the number of appearance species, soil-moisture, thickness. this result presented the more appearance species as a positive role, and the lower soil-moisture and the thicker soil as a negative role.

A Comparative Study on the Quality of Recycled Aggregate for Concrete by Crushing Method (파쇄 방법에 따른 콘크리트용 순환골재의 품질 비교 연구)

  • Choi, Won-Young;Lee, Sae-Hyun;Kim, Seoung-Hwan
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.5 no.2
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    • pp.121-129
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    • 2017
  • In this study, the quality of recycled aggregate for concrete was investigated as the number of recycled aggregate crushing cycles, grinder and crusher, peeling and crushing. First, the quality of density, absorption ratio and solid content was improved as the separation distance decreased and the number of crushing increased, depending on the number of crushing of recycled aggregate and the distance between mantle and cone cave. The quality of density, absorption ratio and solid content was improved as the wire mesh used in striking plate and the number of hammers increased, depending on the type of striking plate and the number of hammers.

Composite $G^{1}$ surface construction from 2D cross-sections (2차원 단면 데이터로부터 복합 $G^{1}$ 자유곡면 생성)

  • Park, Hyung-Jun;Na, Sang-Wook;Bae, Chae-Yeol
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2004.05a
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    • pp.44-47
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    • 2004
  • This paper proposes an approach for composite surface reconstruction from 2D serial cross-sections, where the number of contours varies from section to section. In a triangular surface-based approach taken in most reconstruction methods, a triangular $G^{1}$ surface is constructed by stitching triangular patches over a triangular net generated from the compiled contours. In the proposed approach, the resulting surface is a composite $G^{1}$ surface consisting of three kinds of surfaces: skinned, surface is first represented by a B-spline surface approximating the serial contours of the skinned region and then serial contours of the skinned region and then transformed into a mesh of rectangular Bezier patches. On branched and capped regions, triangular $G^{1}$ surfaces are constructed so that the connections between the triangular surfaces and their neighboring surfaces are $G^{1}$ continuous. Since each skinned region is represented by an approximated rectangular $G^{2}$ surface instead of an interpolated triangular $G^{1}$ surface, the proposed approach can provide more visually pleasing surfaces and realize more efficient data reduction than the triangular surface-based approach. Some experimental results demonstrate its usefulness and quality.

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