• Title/Summary/Keyword: structural connection

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Structural Performance on the Self-centering Connections with Different Conditions of PT Strands (긴장재 적용조건에 따른 셀프센터링 접합부의 구조성능에 관한 연구)

  • Jung, Mi Jin;Yoon, Sung Kee
    • Journal of Korean Society of Steel Construction
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    • v.29 no.1
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    • pp.73-80
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    • 2017
  • In this study, cyclic loading analysis was conducted in order to understand the behavior of self-centering connections based on the number of PT(posttensioning) strands and initial posttensioning force. The initial posttensioning force needs to be above the yield moment of an angle for obtaining noticeable self-centering effect and it is proper that decompression moment ratio needs to be below 0.35 to minimize the residual displacement of major elements. As the number of PT strands increased, self-centering capacity also improved since initial posttensiong force in each PT strand has been decreased. It is also appropriate that initial posttensiong force needs to be less than or equal to 75% of yield strength of PT strands.

The Relationships between Mother's Child caring Behavior and Child behavioral Problems (어머니의 자녀양육행동이 아동행동문제에 미치는 영향)

  • Moon, Young-Sook;Han, Jin-Sook
    • Korean Parent-Child Health Journal
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    • v.5 no.2
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    • pp.161-176
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    • 2002
  • Among the causes of childhood behavioral problems - that is, physiological, psychological, and environmental factors -, the common element of non-organic psychological and environmental factors is influences from the parents. Roles of mother who does the biggest emotional exchange with the child after birth may have substantial association with the childhood behavioral problems. In this connection, the present explanatory study was conducted for the purpose of understanding the causal structural relationship in which mother's child caring behaviors affect child behavioral problems. The data collection period was July 2 - 7, 2001. The subject was 4th, 5th, 6th graders' mothers in 4 elementary schools located in Daejoen city and 299 surveys were used in the analysis. As for the tools used in this study to assess the mother's child caring Behavior Scale by Park, Seong-Yeon and Yi, Sook (1990) was used to measure the mother's behaviors. The child behavioral problems were measured with the Korean-Child Behavior Checklist (K-CBCL), standardized into the Korean version by O, Gyung-Ja, Yi, Hye-Ryon, Hong, Gang-Eui, and Ha, Eun-Hye. For the data processing, the frequency and the percentage were calculated, and the analyses of variance, correlation were carried out. The result of this study is summarized as follows: First, the examination of the effect of mother's general characteristics on the mother's caring behavior shows that significant differences are made by the active participation (p=0.020) in the occupation, affection(p=0.000), authority control(p=0.013), achievement(p=0.030), active participation(p=0.032) in the education level, consistency regulation(p=0.007) in the religion. Second, the examination of the effect of mother's caring behaviors on the child behavioral problems shows that significant differences are made by some child behavioral problems in the affection, achievement, consistency regulation, authority control, over protection caring behaviors. Third, as for the correlation between mother's child caring behavior and child behavioral problems, a significant correlation is revealed between the negative child caring behavior and child behavioral problems.

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Flip Chip Assembly Using Anisotropic Conductive Adhesives with Enhanced Thermal Conductivity

  • Yim, Myung-Jin;Kim, Hyoung-Joon;Paik, Kyung-Wook
    • Journal of the Microelectronics and Packaging Society
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    • v.12 no.1 s.34
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    • pp.9-16
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    • 2005
  • This paper presents the development of new anisotropic conductive adhesives with enhanced thermal conductivity for the wide use of adhesive flip chip technology with improved reliability under high current density condition. The continuing downscaling of structural profiles and increase in inter-connection density in flip chip packaging using ACAs has given rise to reliability problem under high current density. In detail, as the bump size is reduced, the current density through bump is also increased. This increased current density also causes new failure mechanism such as interface degradation due to inter-metallic compound formation and adhesive swelling due to high current stressing, especially in high current density interconnection, in which high junction temperature enhances such failure mechanism. Therefore, it is necessary for the ACA to become thermal transfer medium to improve the lifetime of ACA flip chip joint under high current stressing condition. We developed thermally conductive ACA of 0.63 W/m$\cdot$K thermal conductivity using the formulation incorporating $5 {\mu}m$ Ni and $0.2{\mu}m$ SiC-filled epoxy-bated binder system to achieve acceptable viscosity, curing property, and other thermo-mechanical properties such as low CTE and high modulus. The current carrying capability of ACA flip chip joints was improved up to 6.7 A by use of thermally conductive ACA compared to conventional ACA. Electrical reliability of thermally conductive ACA flip chip joint under current stressing condition was also improved showing stable electrical conductivity of flip chip joints. The high current carrying capability and improved electrical reliability of thermally conductive ACA flip chip joint under current stressing test is mainly due to the effective heat dissipation by thermally conductive adhesive around Au stud bumps/ACA/PCB pads structure.

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The Effect of Anchorage of Reinforcement in Slab-Column Connection (슬래브-기둥 접합부에서 전단보강체에 정창성능에 따른 영향)

  • Choi, Huyn-Ki;Kim, Jun-Seo;Lee, Moon-Sung;Choi, Chang-Sik
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.185-188
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    • 2008
  • Flat plate system has structural weakness such as punching shear. Punching shear resistance can be increase by using a lager column section and effective depth, higer concrete compressive strength, and more flexural reinforcement ratio. But using a shear reinforcement is most economical, enable, workable solution in flat plate. The slab with thickness smaller than 250mm can not perform effectively due to insufficient development length of shear reinforcement in the slab. In case of proposed reinforcements, since the shear reinforcements were installed between the top bar and the bottom bar, shear elements generated slip failure before they reached yield. strength. effect of anchorage strength were effective anchorage length, concrete strength, diameter of shear element and anchorage detail. considering effect of slab thickness and concrete strength, formula of K factor propose in thin flat plate slab. by considering effect of anchorage length and concrete strength, strength of shear reinforcement will be computed correctly in thin flat plate slab.

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Performance of the CDMA Receiver with PN Sequence Orthogonal Reception Process (PN 부호의 직교 수신 방식을 이용한 CDMA 수신기 성능)

  • Hyun, Kwang-Min;Yoon, Dong-Weon;Park, Sang-Kyu
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.4A
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    • pp.200-207
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    • 2003
  • This paper proposes a CDMA receiver structure with time-shifted m-sequence orthogonal reception process, and analyzes the output SNR performance and the characteristics of the orthogonal receiver. This structure can be simply implemented with the converntional receiver adding an additional integrator path in parallel and an adder sums the conventional path and the new path output signals. The structure provides to reference user signal not only increment of signal component but also perfect orthogonal characteristic, canceling the accumulated cross-correlated value out to zero between the reference user and other user signals. Hence, the proposed structure can be applied for channel impulse response measurement, and used for multi-user interference signal cancellation and channel capacity increment by flexible structural inter-working operation of the added path, connection or disconnection, to conventional receiver structure.

Improved Transmission of UHSC Column Loads by Puddling of Fiber Reinforced UHSC (강섬유 보강 초고강도 콘크리트의 확대 타설을 통한 기둥 하중 전달 성능 향상)

  • Lee, Joo-Ha;Yang, Jun-Mo;Lee, Seung-Hoon;Yoon, Young-Soo
    • Journal of the Korea Concrete Institute
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    • v.19 no.2
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    • pp.209-216
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    • 2007
  • This study reports on the structural characteristics of slab-column connections using fiber-reinforced ultra-high-strength concrete (UHSC). Compression tests were performed on two slab-column and four isolated column specimens. In the column load tests, slab loads were also applied on the slab-column specimens so that the actual confinement condition at the slab-column joint was considered. The main parameter investigated was the "puddling" of fiber-reinforced UHSC. This paper also investigates the effects of some parameters, such as confinement of slab concrete, steel fibers, and concrete strength of the joint, related to the ability of the slab-column specimens and isolated column specimens without the surrounding slab to transmit axial loads from the UHSC columns through slab-column connections. Furthermore, the ACI Code (2005) and the CSA Standard (2004) are compared to the experimental results. The beneficial effects of the puddling of fiber-reinforced UHSC on the transmission of column loads through slab-column connections are demonstrated.

A Study on the Effect of the Cyclic Hardening by Fatigue in Structural Mild Steel (구조용(構造用) 연강재(軟鋼材)에 대한 피로경화(疲勞硬化)의 영향(影響)에 관한 연구(硏究))

  • Chang, Dong Il;Yong, Hwan Sun;Hwang, Yoon Koog
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.2 no.4
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    • pp.23-32
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    • 1982
  • In order to obtain the necessary data for the safety maintenance, repair, and reinforcement of steel structures, experiment was carried out to examine the mechanical capacity and toughness variation for steel with service history and without. In this paper, hardening and embrittlement by fatigue accumulation, and the decrease of toughness was examined and weld that was commonly used as the connection method of steel structure was also examined. It was found that hardening and embrittlement have more effect on the decrease of toughness than the increase of strength. Such a tendency was also similary state in case of weld. And it was found that, in the weld of steel with service history and without, embrittlement was observed at normal temperature.

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Design and Optimization of Intelligent Service Robot Suspension System Using Dynamic Model (동역학 모델을 활용한 서비스용 지능형 로봇의 현가 시스템 설계 및 최적화)

  • Choi, Seong-Hoon;Park, Tae-Won;Lee, Soo-Ho;Jung, Sung-Pil;Jun, Kab-Jin;Yun, Ji-Won
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.8
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    • pp.1023-1028
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    • 2010
  • Recently, an intelligent service robot is being developed for use in guiding and providing information to visitors about the building at public institutions. The intelligent robot has a sensor at the bottom to recognize its location. Four wheels, which are arranged in the form of a lozenge, support the robot. This robot cannot be operated on uneven ground because its driving parts are attached to its main body that contains the important internal components. Continuous impact with the ground can change the precise positions of the components and weaken the connection between each structural part. In this paper, the design of the suspension system for such a robot is described. The dynamic model of the robot is created, and the driving characteristics of the robot with the designed suspension system are simulated. Additionally, the suspension system is optimized to reduce the impact for the robot components.

The Meaning of Anthony Browne's Picture Book 'Gorilla' : Mainly about the Semiology of A.J. Greimas (앤서니 브라운 그림책 '고릴라' 의미연구:그레마스 기호학을 중심으로)

  • Kim, Young-Su
    • The Journal of the Korea Contents Association
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    • v.10 no.2
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    • pp.176-183
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    • 2010
  • Picture book is the artistic format to develop forms an organic relationship with text and illustration. Not only meaning which the text and illustration deliver from the picture book but understand the symbolic meaning can discover new enjoyment of reading picture book. Sees the text and illustration of the picture book at one unit which is put in indivisible relationship and analyzing in semeiology provides the viewpoint which is important in picture book comprehension. The Greimas's theory of signification leads and understands the interaction of the text and illustration of world-famous author Anthony Browne's picture book 'Gorilla'. In addition, analysing the structural connection with text and visual expression it approaches the integrated meaning of a story from a new point of view. From the researches of existing interpreted the Hanna and relationship of dad was simple being lonely but this research sees which there exists not only paternal love but also heterosexuality between Hanna and dad and could newly be interpreted with the viewpoint where heal the discord is principal.

Stability Analysis of Shear-Flexible and Semi-Rigid Plane Frames (전단변형효과를 고려한 부분강절 평면뼈대구조의 안정성 해석)

  • Min, Byoung Cheol;Min, Dong Ju;Jung, Myung Rag;Kim, Moon Young
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.1A
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    • pp.9-18
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    • 2011
  • Generally the connection of structural members is assumed as hinge, rigid and semi-rigid connections. The exact tangent stiffness matrix of a semi-rigid frame element is newly derived using the stability functions considering shear deformations. Also, linearized elastic- and geometric-stiffness matrices of shear deformable semi-rigid frame are newly proposed. For the exact stiffness matrix, an accurate displacement field is introduced by equilibrium equation for beam-column under the bending and the axial forces. Also, stability functions considering sway deformation and force-displacement relations with elastic rotational spring on ends are defined. In order to illustrate the accuracy of this study, various numerical examples are presented and compared with other researcher's results. Lastly, shear deformation and semi-rigid effects on buckling behaviors of structure are parametrically investigated.