• 한국안전학회지
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• 제30권2호
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• pp.48-55
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• 2015

The number of collapse accidents relevant to form support since 2003 is 30 on the basis of statistical data from Ministry of Employment and Labor,. Total number of casualty was 138 (47 for deaths and 91 for injuries). The accident severity rate was high because the 4.6 casualties per one accident were occurred averagely although the incident rate was relatively low. Especially, one of form support members, the pipe supports have not been equipped adequately so that the accidents could have happened. In this regard, this study performed buckling test related to the effect of horizontal connection and slope in the single pipe which is one of typical pipe supports. The buckling load, which was estimated from the single pipe with the horizontal connectors theoretically and experimentally, was increased as more than 2 times compared to the buckling load obtained from the pipe supports without the connector. The buckling load was reduced as more than 26%, 34% slope of the single pipe comparing with 5% and 10% slope, respectively. Thus, the purpose of this study is to provide the guideline for installation and the maintenance of the pipe supports legally and institutionally to prevent the collapse accidents of the pipe supports.

• 대한조선학회지
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• 제12권1호
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• pp.23-30
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• 1975

Because of the simplicity in analysis and design of steel structure, the connections of members are assumed either as perfectly hinged or rigidly fixed. However, a more economical design would result if the effect of restraint in connections were included in analyzing frame structure. From this point of view, stiffness matrices for member with bracketed connections are presented in the form of the stiffness matrices for member with variable moment of inertia, modified by a correction matrix, whose elements are functions of fixity factors of the connections. To obtain fixity factors, the displacements and stress distribution of bracketed connections are investigated by using of the degital computer program, which have been developed to make computing time shorten and the round off errors smaller. The relationship of moments and slip angle in bracketed connections are presented in the form of curves, which can be used in establishing a stiffness matrices for member with bracketed connections.

• 대한수학회논문집
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• 제16권4호
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• pp.637-648
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• 2001

An n-dimensional ME-manifold ME $X_{n}$ is a general-ized Riemannian manifold connected by the ME-connection which is both Einstein and of the form (2.13). The purpose of this paper is to study the properties of the ME-curvature tensors, the con-tracted ME-curvature tensors and the field equations in ME $X_{n}$)n)

• 한국공간구조학회지
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• 제16권1호
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• pp.13-17
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• 2016

• 한국공간구조학회지
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• 제11권3호
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• pp.5-11
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• 2011

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2151-2154
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• 2003

Internet is deeply rooted in everyday life and many things are performed using internet in real-world, therefore internet users increased because of convenience. Also internet accident is on the increase rapidly. The security vendor developed security system to protect network and system from intruder. Many hackings can be prevented and detected by using these security solutions. However, the new hacking methods and tools that can detour or defeat these solutions have been emerging and even script kids using these methods and tools can easily hack the systems. In consequence, system has gone through various difficulties. So, Necessity of intruder trace-back technology is increased gradually. Trace-back technology is tracing back a malicious hacker to his real location. trace-back technology is largely divided into TCP connection trace-back and IP packet trace-back to trace spoofed IP of form denial-of-service attacks. TCP connection trace-back technology that autonomously traces back the real location of hacker who attacks system using stepping stone at real time. In this paper, We will describe watermark trace-back system using TCP hijacking technique to supplement difficult problem of connection maintenance happened at watermark insertion. Through proposed result, we may search attacker's real location which attempt attack through multiple connection by real time.

• 구강회복응용과학지
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• 제21권2호
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• pp.113-132
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• 2005

The purpose of this study was to assess the stress-induced pattern at the supporting bone, the implant fixture, the abutment and the abutment screw according to a friction-fit joint (Astra; Model 1) or slip- fit joint (Frialit-2; Model 2) in the internal connection system under vertical and inclined loading using finite element analysis. In conclusion, in the internal connection system of the implant and the abutment connection methods, the stress-induced pattern at the supporting bone, the implant fixture, the abutment and the abutment screw according to the abutment connection form had difference among them, and the stress distribution pattern usually had a widely distributed tendency along the inner surface of the implant fixture contacting the abutment post. The magnitude of the stress distributed in the supporting bone, the implant fixture, the abutment and the abutment screw was higher in the friction-fit joint than in the slip-fit joint. But it is considered that the further study is necessary about how this difference in the magnitude of the stress have an effect on the practical clinic.

• 전기학회논문지
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• 제64권1호
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• pp.72-77
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• 2015

When connecting 6 lead wires from stator windings to the terminals of 3 phase induction motors for Y or ${\triangle}$ connection, it is feared that the polarities of windings could be reversed each other if the wire tags are lost or erased, resulting in inadmissibly high current to motors in case of starting. To protect motors against such situations, some test procedures are necessary during wire connection which need to be easy ways to electricians without particular tools except a general multi-tester and with less time-consuming in the field. This study focuses on a test measure to satisfy these requirements which is able to provide them a convenient procedure for winding polarity discrimination considering the field condition. Here, the proposed measure utilizes the residual magnetism of the rotor and checks the indication of voltage or current at windings which are induced by the residual flux of rotor when rotating it by hands with 3 stator windings connected in the form of I connection. Principle characteristics and experiment results for this method are analyzed in the view of the effectiveness and applicability for the winding polarity discrimination.

• International Journal of Concrete Structures and Materials
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• 제9권1호
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• pp.61-67
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• 2015

The concept of horizontal shear connection utilization on wood-concrete beams intends to be an alternative connection detail for composite wood-concrete decks. The volume of sawn-wood is over three times more expensive than concrete, in Brazil. In order to be competitive in the Brazilian market we need a composite deck with the least amount of wood and a simple and inexpensive connection detail. This research project uses medium to high density tropical hardwoods managed from the Brazilian Amazon region and construction steel rods. The beams studied are composed of a bottom layer of staggered wood boards and a top layer of concrete. The wood members are laterally nailed together to form a wide beam, and horizontal rebar connectors are installed before the concrete layer is applied on top. Two sets of wood-concrete layered beams with horizontal rebar connectors (6 and 8) were tested in third-point loading flexural bending. The initial results reveal medium composite efficiency for the beams tested. An improvement on the previously conceived connection detail (set with six connectors) for the composite wood-concrete structural floor system was achieved by the set with eight connectors. The new layout of the horizontal rebar connectors added higher composite efficiency for the beams tested. Further analysis with advanced rigorous numerical Finite Element Modeling is suggested to optimize the connection parameters. Composite wood-concrete decks can attend a large demand for pedestrian bridges, as well as residential and commercial slabs in the Brazilian Amazon.

• 구강회복응용과학지
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• 제22권1호
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• pp.55-74
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• 2006

The external contour of an implant can have significant effects on the load transfer characteristics and may result in different bone failure rates for different implant system. The purpose of this study was to investigate the effects of crest module shape and occlusal load direction on bone failure modes of five commercially available dental implant systems. Five different implant systems with internal connection; ITI (Model 1), Astra (Model 2), Bicon (Model 3), Friadent (Model 4), and Paragon (Model 5), comparable in size, but different in thread profile and cest module shapes, were compared using the finite element method. Conclusively, in the internal connection system of the implant-abutment connection methods, the stress-induced pattern at the supporting bone according to the abutment connection form had differenence among them, and implants with narrowing crestal module cross-sections at the top of the cortical bone created more favorable load transfer characteristics in this region. But it is considered that the future study is necessary about how this difference in the magnitude of the stress have an effect on the practical clinic.