• Title/Summary/Keyword: roof systems

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Fatigue experiments on steel cold-formed panels under a dynamic load protocol

  • Garcia-Palencia, Antonio J.;Godoy, Luis A.
    • Structural Engineering and Mechanics
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    • v.46 no.3
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    • pp.387-402
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    • 2013
  • A dynamic load protocol has been used to experimentally simulate fatigue behavior in cold-formed metal panels with screwed connections under wind loading. The specific protocol adopted is an adaptation of SIDGERS, originally developed for non-metallic membranes, which is composed of levels each under increasing load values. A total of 19 tests were performed on 3.35 m long by 0.91 m wide panels, identified as Type B-wide rib and Type E, both with screw connections at the edge and at the center, thus conforming two-span specimens. In some configurations the panels were fixed at the valleys, whereas crest-fixed connections were also investigated. Reinforcing the connections by means of washers was also investigated to evaluate their efficiency in improving fatigue capacity. The experimental results show maximum load capacities in improved connections with washers of approximately twice of those with classical connections.

Supervisory control of reheating furnace

  • Kim, Young-Il;Min, Kwang-Gi;Nam, In-Sik;Chang, Kun-Soo
    • 제어로봇시스템학회:학술대회논문집
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    • 1995.10a
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    • pp.538-541
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    • 1995
  • In steel works, reheating furnace is an essential part of a rod mill plant and it treats various types of billets continuously. Although getting an optimal setting for a single billet is simple, control setting for whole groups of billets is a difficult task. In this work, we studied a detail mathematical model and optimal control setting of reheating furnace. As the mathematical model of each billet is a partial differential equation, on-line control is almost impossible for the whole billets charged into the furnace. Therefore, we tried to provide a guideline for optimal setting value of the roof(index) temperature for the target billets which account for about 20% of the charged billets.

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Decision of SSI Network dimension for Safety based ODLM(LDT) installation (안전성 기반 ODLM(LDT) 설치를 위한 SSI 네트워크 규모 결정)

  • Min, Geun-Hong;Lee, Jong-Woo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.5
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    • pp.797-802
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    • 2008
  • High Speed Rail Train Control System consists of CTC, IXL and ATC. IXL and ATC perform train control and command via interchanging relevant information between a signal room and CTC. However, it is proved that IXL and ATC are attributed to train delay error since those systems are highly sensitive to trackside conditions. Especially, network error on IXL blocks transmitting signal information to adjacent signal room so that its effects give rise to system overall problems. In order to figure out the measures for which minimizing the occurrence rate of train delay error due to HSR TCS, This paper is performed analysis on communication network structure, the length of SSI network roof and SSI-TFM distance by examining and analyzing the error cases related to IXL in a network aspect.

Investigation of In-Cylinder Phenomena in a SI Engine (가솔린 엔진의 연소실내 현상 연구)

  • Kim, K.S.
    • Journal of ILASS-Korea
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    • v.3 no.1
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    • pp.10-18
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    • 1998
  • To investigate the in-cylinder phenomena in a SI engine with 3 valves and pent-roof type combustion chamber, flow fields, fuel distributions, and flame propagations were measured in a single c!'tinder visualized engine. Flow fields were visualized by PTV system during the intake and compression process. Fuel distributions were measured by PLIF at the various engine conditions including the cold and hot engine conditions and the effect of air-shrouded injector on the fuel distribution was investigated also. In addition, flame propagation patterns were characterized.

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A Study on the Bifurcation Characteristics of Hybrid Cable Domes under Axisymmetric Load (축대칭 하중을 받는 Hybrid 케이블 돔의 Bifurcation 특성에 관한 연구)

  • 김승덕;백인성;김형석
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.277-284
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    • 2003
  • One of important problem, in large space structure, is to overcome the self-weight of roof structure. This problem can be solved with using tension members effectively. Thus the rapid progress of hybrid structure, that makes effective use of the means of settling, has a good effect on realizing the large space. These systems of hybrid structure have the advantages of light weight and its own internal redundancy, but are occurred unstable phenomenon such as bifurcation or snap-through buckling, when the load level is come to the critical point. Among the hybrid structure, cable dome is shown the strong nonlinearity of unstable phenomenon in accordance with the external force. Therefore, the purpose of this study is to analyze and verify comparatively the unstable phenomenon of the Geiger and Flower type cable dome structures under axismmetric load.

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Calatrava's Morphogenetic Mechanism Based on Methodological Hypothesis; Analogy and Analysis (칼라트라바의 방법론적 전제에 의한 형태구성 메커니즘)

  • Park, Sun-Woo;Choi, Sun-Young;Park, Chan-Soo;Choi, Chui-Kyung
    • Proceeding of KASS Symposium
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    • 2006.05a
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    • pp.142-152
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    • 2006
  • The purpose of this study is to explore an inquisitive and innovative approach to structure and form, Calatrava's morphogenetic mechanism and to trace the ideas behind his working methods and his theoretical preoccupations. The bridges and buildings of S. Calatrava possess a breathtaking rhythm and of them some are designed to expand and contract like living organisms. The analogy Calatrava has used as a creative tool to mutate human bodies into arcing roof forms and bridge suspensions is introduced to illustrate the morphogenetic process. At the same time, the analysis used developing how to design frame structures foldable with brilliant mathematical solution is also investigated. Consequently, the potentialities of Calatrava's morphogenetic mechanism to invent new systems are generated by methodological hypothesis; analysis and analogy.

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Optimum design of PV system used by parameter design method (파라미터 설계방식을 이용한 PV시스템의 최적설계)

  • Jeong, B.H.;Choi, Y.O.;Choi, M.H.;Lee, K.Y.;Baek, H.L.;Cho, G.B.
    • Proceedings of the KIPE Conference
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    • 2007.07a
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    • pp.64-66
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    • 2007
  • Photovoltaic power systems convert sunlight directly into electricity. A residential PV power system enables a homeowner to generate some or all of their daily electrical energy demand on their own roof, exchanging daytime excess power for future energy needs In this paper, It was suggested that new design method for PV system installation for the purpose of system efficiency improvement. and according to loss parameter compensation method, designed for the PV system and investigated through the simulation practically.

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Behavior and Hysteresis Characteristics of Traditional Timber Framers under Lateral Load (전통 문화재 목조 프레임의 횡하중에 대한 거동 및 이력특성)

  • 이필성
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1999.10a
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    • pp.396-403
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    • 1999
  • This experimental study investigates the hysterestic behavior of traditional timber frames subjected to lateral loads. Prototype frames for this study were selected from one of typical national treasures for timber structures in Korea. For simplicity roof structures and braket systems were excluded from specimens and the joint behavior of beam-to-column system were presumed to have crucial effect on their global behavior. The experimental observation showed stiffness degradation and slip after experiencing initial yield and the first cycle at a new larger displacement due to inherent gaps in traditional timber connection and gradual indentation of interfaces, The cyclic behaviors of all specimens were similar to those os modern timber frames with bolt and nail connections. Additional structural members such as an upper beam and clay-filled wall increased the initial stiffness strength and energy dissipation. It is expected that collapse of Korean traditional timber frames under lateral load is mainly caused from P-$\Delta$ effects rather than local member failure.

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A Synthetic Method for Generating Texture Patterns Similar to a Selected Original Texture Image

  • Shinji, Ohyama;Hong, Keum-Shik
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.35.5-35
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    • 2001
  • The purpose of the study is to develop a synthetic method for generating arbitrary number of not the same but similar texture images. The method includes processes to extract basic shape elements from texture images originating in actual objects, to select them to reappear the image features and to arrange them in a image plane. The authors have already proposed the shape-pass type filter bank assuming that the sensual impression mainly depends on minute shapes existing in the texture images. By use of nine basic shape elements, namely black/white-roof, black/white-line, black/white-snake, black/white-pepper, and cliff, natural texture images originating in actual objects have been characterized by feature vectors in a nine dimensional space. To generate arbitrary number of similar texture images, minute shape pieces ...

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Ministry of Taxation Tower in Baku, Azerbaijan: Turning Away from Prescriptive Limitations

  • Choi, Hi Sun;Ihtiyar, Onur;Sundholm, Nickolaus
    • International Journal of High-Rise Buildings
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    • v.9 no.4
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    • pp.377-386
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    • 2020
  • Beginning a few decades ago, Baku, the capital city of Azerbaijan, has experienced a dramatic construction boom that is revitalizing its skyline. The expansive growth looks to uphold the historic past of Baku as a focal point within the Caspian Sea Region while also evoking aspirations for a city of the future. With superstructure complete and interiors progressing, the Ministry of Taxation (MOT) tower is the latest addition to the city, with its stacked cubes twisting above a multi-level podium at the base. Each cube is separated by column-free green roof terraces, creating unique parametric reveals of the developing surroundings. Aside from MOT's stunning shape, its geolocation resulted in unusually high wind loads coupled with high seismic hazards for a tower of its height. In addition, limitations on possible structural systems required stepping away from a typical prescriptive code-based approach into one that utilized Performance-Based Design (PBD) methods. This paper presents the numerous structural challenges and innovations that allowed the design of a new icon to be realized.