• Title/Summary/Keyword: School structure

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Electrical Properties of Organic Materials as Low Dielectric Constant Materials

  • Oh Teresa;Kim Hong Bae;Kwon Hak Yong;Son Jae Gu
    • Journal of the Semiconductor & Display Technology
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    • v.4 no.3 s.12
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    • pp.5-9
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    • 2005
  • The bonding structure of organic materials such as fluorinated amorphous carbon films was classified into two types due to the chemical shifts. The electrical properties of fluorinated amorphous carbon films also showed very different effect of two types notwithstanding a very little difference. Fluorinated amorphous carbon films with the cross-link break-age structure existed large leakage current resulting from effect of the electron tunneling. Increasing the cation due to the electron-deficient group increased the barrier height of the films with the cross-link amorphous structure, therefore the electric characteristic of the final materials with low dielectric constant was also improved. The lowest dielectric constant is 2.3 at the sample with the cross-link amorphous structure.

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Feasibility study of bonding state detection of explosive composite structure based on nonlinear output frequency response functions

  • Si, Yue;Zhang, Zhou-Suo;Wang, Hong-fang;Yuan, Fei-Chen
    • Steel and Composite Structures
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    • v.24 no.4
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    • pp.391-397
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    • 2017
  • With the increasing application of explosive composite structure in many engineering fields, its interface bonding state detection is more and more significant to avoid catastrophic accidents. However, this task still faces challenges due to the complexity of the bonding interface. In this paper, the concept of nonlinear output frequency response functions (NOFRFs) is introduced to detect the bonding state of explosive composite structure. The NOFRFs can describe the nonlinear characteristics of nonlinear vibrating system. Because of the presence of the bonding interface, explosive composite structure itself is a nonlinear system; when bonding interface of the structure is damaged, its dynamic characteristics show enhanced nonlinear characteristic. Therefore, the NOFRFs-based detection index is proposed as indicator to detect the bonding state of explosive composite pipes. The experimental results verify the effectiveness of the detection approach.

Low Power SAD Processor Architecture for Motion Estimation of K264 (K264 Motion Estimation용 저전력 SAD 프로세서 설계)

  • Kim, Bee-Chul;Oh, Se-Man;Yoo, Hyeon-Joong;Jang, Young-Beom
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.263-264
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    • 2007
  • In this paper, an efficient SAD(Sum of Absolute Differences) processor structure for motion estimation of 0.264 is proposed. SAD processors are commonly used both in full search methods for motion estimation or in fast search methods for motion estimation. Proposed structure consists of SAD calculator block, combinator block, and minimum value calculator block. Especially, proposed structure is simplified by using Distributed Arithmetic for addition operation. The Verilog-HDL(Hard Description Language) coding and FPGA implementation results for the proposed structure show 39% and 32% gate count reduction comparison with those of the conventional structure, respectively. Due to its efficient processing scheme, the proposed SAD processor structure can be widely used in size dominant H.264 chip.

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An approach of seismic design for sheet pile retaining wall based on capacity spectrum method

  • Qu, Honglue;Li, Ruifeng;Hu, Huanguo;Jia, Hongyu;Zhang, Jianjing
    • Geomechanics and Engineering
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    • v.11 no.2
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    • pp.309-323
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    • 2016
  • As the forefront of structural design method, capacity spectrum method can be applied conveniently, and through this method, deformation demand of structure can be considered. However, there is no research for the seismic application in the structure of sheet pile retaining wall to report. Therefore, focusing on laterally loaded stabilizing sheet pile wall, which belongs to flexible cantilever retaining structure and meets the applying requirement of capacity spectrum method from seismic design of building structure, this paper studied an approach of seismic design of sheet pile wall based on capacity spectrum method. In the procedure, the interaction between soil and structure was simplified, and through Pushover analysis, seismic fortification standard was well associated with performance of retaining structure. In addition, by comparing the result of nonlinear time history analysis, it suggests that this approach is applicable.

Influence of external structure and internal stacking on wind load characteristics of large-span spherical shell structure

  • Xiaobing Liu;Anjie Chen;Qun Yang;Bin Feng;Xuedong Tian
    • Wind and Structures
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    • v.39 no.3
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    • pp.191-205
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    • 2024
  • To investigate the wind load characteristics of a large-span spherical shell structure, a rigid model pressure test was conducted in a wind tunnel laboratory. The study aimed to examine the impact of various external structures and internal stacking forms on the wind loads of a spherical shell structure in a practical engineering project. This project features two adjacent spherical structures, each spanning 130 m and standing 67 m tall. These two structures are connected by trestles and a transfer station. Variations in the shape factor and the integral force coefficient of the structure were compared and analyzed under different test cases. The results indicate that when two structures are arranged in series, with the adjacent structure positioned upstream, the shape factor of the structure is most affected, resulting in a significant reduction effect at the bottom of the windward surface. Compared to the external structure, the impact of various internal stacking forms on the shape factor of the structure is relatively weak. The adjacent structure significantly improves the wind resistance of the main structure. The integral force coefficient of the structure reaches its peak when internal stacking is full and is at its lowest when there is no internal stacking.

Soil-structure interaction and axial force effect in structural vibration

  • Gao, H.;Kwok, K.C.S.;Samali, B.
    • Structural Engineering and Mechanics
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    • v.5 no.1
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    • pp.1-19
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    • 1997
  • A numerical procedure for dynamic analysis of structures including lateral-torsional coupling, axial force effect and soil-structure interaction is presented in this study. A simple soil-structure system model has been designed for microcomputer applications capable of reflecting both kinematic and inertial soil-foundation interaction as well as the effect of this interaction on the superstructure response. A parametric study focusing on inertial soil-structure interaction is carried out through a simplified nine-degree of freedom building model with different foundation conditions. The inertial soil-structure interaction and axial force effects on a 20-storey building excited by an Australian earthquake is analysed through its top floor displacement time history and envelope values of structural maximum displacement and shear force.

A study for the extraction of DGS 4-port equivalent circuit and it's parameters (DGS 구조의 4-port 등가회로 및 파라미터에 대한 추출 방법에 대한 연구)

  • Son, Chang-Sin;Jeong, Myung-Sub;Choi, Wan-Seoung;Park, Jun-Seok;Lim, Jae-Bong;Choi, Hong-Goo
    • Proceedings of the KIEE Conference
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    • 2004.07c
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    • pp.2043-2045
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    • 2004
  • This thesis complemented the weak points that the existing theses did not represented a phase characteristic as the equivalent circuit by applying 4-port simulation to DGS (Defected Ground Structure) characteristic and an equivalent circuit, which are the transmission line structure that has the defect made in the ground surface. We used a distribute device and a lumped device, obtained the equivalent circuit by applying the structure of balun to a discontinuous part. An indicated DGS (Defected Ground structure) is a dumbbells-shaped single defect, we indicated satisfying a magnitude and phase characteristics by applying this equivalent circuit.

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Strain hardening behavior of linear polymer melts

  • Hong Joung Sook;Ahn Kyung Hyun;Lee Seung Jong
    • Korea-Australia Rheology Journal
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    • v.16 no.4
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    • pp.213-218
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    • 2004
  • Linear high-density polyethylene (PE) was controlled to induce strain-hardening behavior by introducing a small amount of second component with an anisotropic structure. In order to form an anisotropic structure in the PE matrix, the polymer was extruded through a twin-screw extruder, and the structure was controlled by varying the extrusion conditions. Depending on conditions, the second component formed a film, thread and droplet structure. If the second component was kept rigid, the morphology evolution could be delayed and the second component could maintain its film or thread structure without further relaxation. In par­ticular, the second component of the thread structure made a physical network and gave rise to remarkable strain hardening behavior under high extension. This study suggests a new method that induces strain hard­ening behavior by introducing a physically networked second component into the linear polymer melt. This result is anticipated to improve the processibility of linear polymers especially when extensional flow is dominant, and to contribute to our understanding of strain hardening behavior.

A Replica Molding Technique for Fabricating Liquid Crystal Displays with Wide Viewing Characteristics

  • Kim, Yeun-Tae;Hong, Jong-Ho;Choi, Yoon-Seuk;Lee, Sin-Doo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.371-373
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    • 2005
  • We demonstrated a replica molding technique for producing a self-formed multidomain structure displays (LCDs). The multidomain structure was naturally obtained on a replica mold film having periodic patterns which have two dimensional microgrooves. It was found that with the axially symmetric multidomain structure along the microgrooves exhibits excellent viewing characteristics.

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