• Title/Summary/Keyword: Cushion

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Ductility Capacity for Concrete Filled Steel Circular Tubes Reinforced by Carbon Fiber Sheets(CFSs) (탄소섬유쉬트로 보강된 콘크리트충전 원형강관기둥의 연성능력)

  • Park, Jai-Woo;Hong, Young-Kyun;Choi, Sung-Mo
    • Journal of Korean Society of Steel Construction
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    • v.22 no.2
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    • pp.185-195
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    • 2010
  • This paper presents the experiment results for a CFT column confined by carbon fiber sheets(CFSs) under an axial load. Nine specimens were constructed and axial compression tests were conducted. The main experiment parameters were diameter-thickness ratio(D/t), reinforcing CFSa, and the attachment of a cushion gap between surface of steel tube and CFSs. The load-displacement curves of the specimens were obtained from the compression tests. Finally, it was concluded that the CFT column with a gap had grater ductility capacity improvement that the CFT column confined by CFSs.

The effects of special metallic dampers on the seismic behavior of a vulnerable RC frame

  • Ozkaynak, Hasan
    • Structural Engineering and Mechanics
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    • v.61 no.4
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    • pp.483-496
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    • 2017
  • Earthquake excitations may induce important amount of seismic energy into structures. Current design philosophy mainly deals with the plastic deformations of replaceable energy dissipating devices rather than damages accumulated on structural members. Since earthquake damage is substantially concentrated on these devices they could be replaced after severe earthquakes. In this study, the efficiency of steel cushion (SC) on seismic improvement of a vulnerable reinforced concrete (RC) frame is determined by means of several numerical simulations. The cyclic shear behaviors of SCs were determined by performing quasi-static tests. The test results were the main basis of the theoretical model of SCs which were used in the numerical analysis. These analyses were performed on three types of RC frames namely bare frame (BF), full-braced frame (F-BF) and semi-braced frame (S-BF). According to analysis results; implementation of SCs has considerable effects in reducing the storey shear forces and storey drifts. Moreover plastic energy demands of structural elements were reduced which indicates a significant improvement in seismic behavior of the RC frame preventing damage accumulation on structural elements. Full-braced frame having SCs with the thickness of 25 mm has better performance than semi-braced frame interms of energy dissipation. However, global energy dissipation demand of S-BF and F-BF having SCs with the thickness of 18 mm are almost similar.

Drivability of Offshore Pile Foundation at Ieodo Ocean Research Station (이어도 해양과학기지 말뚝기초의 항타 관입성 연구)

  • Shim, Jae-Seol;Yoon, Gil-Lim;Lee, Seung-Jun
    • Ocean and Polar Research
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    • v.25 no.spc3
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    • pp.373-384
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    • 2003
  • When pile foundation is constructed by dynamic method, it is desirable to perform monitoring of drivability with pile penetration. Dynamic pile monitoring yields information regarding driving hammer, cushion, pile and soil behaviour that can be used to confirm the assumptions of wave equation analysis. In this study, dynamic monitoring of the steel pipe pile was performed with Pile Driving Analyser (PDA). The PDA utilizes the wave propagation theory to compute numerous variables which describe the conditions of the hammer-pile-soil system in real-time and following each hammer impact. This approach allows immediate field verification of hammer performance, driving efficiency, and estimation of pile bearing capacity. A series of PDA test were performed at the Ieodo Ocean Research Station (IORS) located in southeast of Marado, a southernmost small island south of Jeju Island. The drilling core sediments of Ieodo subsoil are composed of mud and sand, showing lamination and wavy or lenticular bedding, which were often bioturbated. This paper summarizes the results of PDA tests which were applied in measurement and estimation of large diameter open ended steel pipe pile driven by steam hammer, Vulcan-560 and MRBS-4600, at the marine sediments.

A Development of Living Cultural Products Design Using Symbol of a Maritime Mokpo City (해양 목포시의 상징 모티브를 이용한 생활문화상품 디자인개발)

  • Park, Mi-Ryung;Park, Hea-Ryung
    • Journal of the Korea Fashion and Costume Design Association
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    • v.12 no.4
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    • pp.103-114
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    • 2010
  • This study aims to examine current status of cultural products in Mokpo city and their problems and develop cultural products design suitable to this situation. Cultural products in Mokpo sold here are made from China and have lower quality or traditional crafts and folkcrafts which can be purchased anywhere in Korea and they are not enough to show identity or image of Mokpo city. So I mixed the logos of 'mokpo city' and 'national maritime museum' based on main motive of 'modern Korean ship and shipbuilding tools' held by 'National Maritime Museum' and 'Goebukseon (turtle ship)' and 'Hanseon' which are suitable to the image of maritime culture as cultural products advocated by Mokpo city and developed one design style for print. This design is applied to T-shirts, necktie, cap, cushion and mug. Silk print, transfer print and needlework techniques are applied to each item and the whole cultural products have design of set concept. It is a case of applying modern product marketing technique to our cultural products not a design for only one item, is aimed to recreate spiritual and cultural value that a region has as daily goods to be used by general consumers and show the chance and possibility to complement shortcomings of existing cultural products and develop traditional culture having locality.

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Effects of the Support Surface Condition on Muscle Activity of Trunk Muscles during Balance Exercises in Patients with Stroke

  • Jung, Kyoung-Sim;Kim, Yong-Su;In, Tae-Sung
    • The Journal of Korean Physical Therapy
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    • v.27 no.4
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    • pp.196-200
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    • 2015
  • Purpose: The purpose of this study was to examine the muscle activity of the trunk muscles during balance exercises on a stable and unstable surface in patients with stroke. Methods: Thirteen subjects (8 males, 5 females) with stroke were enrolled in the study. Muscle activity was recorded using surface EMG electrodes from the affected side of the erector spinae, external oblique, and internal oblique muscles. The exercise was performed under three conditions. For the first condition for balance exercise, subjects were instructed to sit on an exercise mat with legs extended. The second condition was to sit with legs extended, with a balance pad under their buttocks. The third condition was to sit with legs extended, have a balance pad under the buttocks and a balance cushion under the lower legs. Results: This study showed significant differences in EMG activities during both arm lifting exercise and weight shifting exercise between conditions. This study showed that the EMG activities of the erector spinae, external oblique, and internal oblique muscles were significantly higher when the trunk exercise was performed using the balance pad with balance ball than when using the stable surface. Conclusion: In conclusion, performing balance exercises using an unstable surface is a useful method for facilitating trunk-muscle strength and hence trunk stability.

Effective Broadcasting and Caching Technique for Video on Demand over Wireless Network

  • Alomari, Saleh Ali;Sumari, Putra
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.3
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    • pp.919-940
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    • 2012
  • Video on Demand (VOD) is a multimedia service which allows a remote user to select and then view video at his convenience at any time he wants, which makes the VOD become an important technology for many applications. Numerous periodic VOD broadcasting protocols have been proposed to support a large number of receivers. Broadcasting is an efficient transmission scheme to provide on-demand service for very popular movies. This paper proposes a new broadcasting scheme called Popularity Cushion Staggered Broadcasting (PCSB). The proposed scheme improves the Periodic Broadcasting (PB) protocols in the latest mobile VOD system, which is called MobiVoD system. It also, reduces the maximum waiting time of the mobile node, by partitioning the $1^{st}$ segment of the whole video and storing it in the Local Media Forwarder (LMF) exactly in the Pool of RAM (PoR), and then transmitting them when the mobile nodes miss the $1^{st}$ broadcasted segment. The results show that the PCSB is more efficient and better than the all types of broadcasting and caching techniques in the MobiVoD system. Furthermore, these results exhibits that system performance is stable under high dynamics of the system and the viewer's waiting time are less than the previous system.

A Study of A Nonlinear Viscoelastic Model for Elastomeric Bushing in Automotive Suspension System (I) -Axial Mode- (차량현가장치용 일래스토메릭 부시으이 비선형점탄성 모델연구 (I) -축 방향 모드-)

  • 이성범
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.5
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    • pp.154-161
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    • 1999
  • An elastomeric bushing is a device used in automotive suspension systems to cushion the force transmitted from the wheel to the frame of the vehicle. A bushing is an elastomeric hollow cylinder which is bonded to a solid metal shaft at its inner surface and a metal sleeve at its outer suface. The relation between the force applied to the shaft or sleeve and their relative deformation is nolinear and exhibits features of viscoelasticity. Numerical solutions of the boundary value problem represent the exact bushing response for use in the method for determining the force relaxation function of the bushing. The new nonlinear viscoelastic bushing model, which is called Pipkin-Rogers model, is proposed and it is shown that the predictions of the proposed force-displacement relation are in very good agreement with the exact results. This new bushing model is thus very suitable for use in multi-body dynamics codes. The success of the present study for axial mode response suggests that the same approach be applied to other modes, such as torsional or radial modes.

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A Study on the Compressional Properties of Acrylic Carpet (Acrylic Carpet의 압축특성에 관한 연구)

  • Sung Su Kwang;Koo Kyung Ock
    • Journal of the Korean Society of Clothing and Textiles
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    • v.11 no.2 s.24
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    • pp.13-21
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    • 1987
  • Nowadays, the amount used carpets are on the increase, according to the improvement of life-style. The pleasantness of carpet is caused by the properties of pile, because the most carpets are made pile fabric. For that reason, a study on the compressional properties of carpet is very important issue. This study has been carried out to investigate the differences of compressional properties in various acrylic carpets which were Cut, Tufted, Jacquard and Shag. Each acrylic carpets was transformed to 4, 6, 8 mm of pile height, as results of transformation, we could get the pressure-thickness curve and pressure-deformation curve. The results are summarized as follows. 1. Rate of compression increases, compressive resistance and compressive elasticity decr-eases, as pile height increases. 2. Regardless of pile height, compressive elasticity reached the limit in recovery period at about 10 minutes. 3. Work of compression increases, as pile height increases. 4. Work of compression decreases, as apparent density increases. 5, Cut-type carpet has the best cushion.

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A Study on Symbolic Meaning of Woman's Body and Clothes in Fashion Works of Vivienne Westwood (Vivienne Westwood 작품에 나타난 여성 인체와 복식 상징성 연구)

  • Yun, Ji-Young
    • Journal of the Korean Society of Clothing and Textiles
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    • v.33 no.3
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    • pp.379-390
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    • 2009
  • This Study is a research on symbolic meaning and artist's will of Vivienne Westwood's works which provide a new vision on woman's body and clothes. For the literary research, this study investigates theories of human's body which are phenomenal body of Merleau-Ponty's, the relations between power and body of M. Foucault's, cultural and social body of E. Goffman's and habitus of p, Bourdieu's. For the case research, Vivienne Westwood's collections are classified into each item which exaggerating and distorting woman's body such as Mini-Crini, corset, bustle cushion, bum-pad, farthingale and tailoring suits. Also she puts man's clothes item such as codpiece into woman's body. Through all of these design, she wants to reinterpret the woman's body and self-identity. Vivienne Westwood dose not leave the past just as a historic trace but recreates with her way of creation. Westwood has presented the satire which leads the parody of past in her unique ways of thinking and interpretation which mix the ideology of the past and the presents. Those make her look back the history and culture and express her esteem for self-identity of woman. Vivienne Westwood's works express woman's power and freedom in modem society.

Study on Settlement Calculation of the Long-Short Pile Composite Foundation

  • XU, Xin;Kwag, Yunehyeong;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.7
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    • pp.13-18
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    • 2013
  • As a new foundation treatment technology, long-short pile composite's design theory is still in primary phase, and there are no explicit settlement calculation methods in active codes. So it is necessary to study the working mechanism and the methods of settlement calculation. In this paper, the mechanics of long-short pile composite foundation are fully discussed. Meanwhile, based on the shear deformation method, the Mylonakis & Gazetas models about mutual action between two piles and the one between pile and soil are introduced, Considering the performance of cushion, the flexible factors of mutual actions are provided. Then the settlement calculation of long-short pile composite foundation which can consider the mutual actions between pile, soil and cap is deduced, and the correlated program is also developed. Finally, an engineering example is discussed with the method. A comparison shows that calculated results and measured data from a field test pile are in a good agreement, indicating that the presented approach is feasible and applicable in engineering practice.