• Title/Summary/Keyword: cross-connection

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The Psychiatrist and the Revolutionary: Frantz Fanon's Critique of Colonial Discourse

  • Rasmussen, Kim Su;Sorensen, Eli Park
    • Cross-Cultural Studies
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    • v.24
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    • pp.5-18
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    • 2011
  • This article offers a reflection on Frantz Fanon's diagnosis and analysis of French colonialism in Algeria. We will attempt to demonstrate that there is a concrete and clear connection between Fanon as the psychiatrist diagnosing the devastating effects of the French colonial system, and his subsequent political involvement in the Algerian revolution. This is not to say that each part does not contain valuable insights in their own rights, but rather to stress that without being read together, as a whole, one would miss a significant element in the understanding of the importance Fanon's thought subsequently came to play in the emancipation struggles of the colonized worldwide. Furthermore, we argue that it is crucial to understand the intimate connection between Fanon's psychiatric work, his diagnosis of colonial mental disorders, as well as diagnosis of the colonial system as such, and then his political engagement, in order to understand the particular context in which he favourably discusses the use of violence in the name of fighting against the oppressive system of colonialism. Above all, we argue that Fanon's critique of colonialism continues to spark controversy because it still represents the most powerful and incisive analysis of, as well as answer to, the troubled relationship between the blessed and the wretched of the earth.

Free vibrations of a two-cable network inter-supported by cross-links extended to ground

  • Zhou, H.J.;Wu, Y.H.;Li, L.X.;Sun, L.M.;Xing, F.
    • Smart Structures and Systems
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    • v.23 no.6
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    • pp.653-667
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    • 2019
  • Using cross-ties to connect cables together when forming a cable network is regarded as an efficient method of mitigating cable vibrations. Cross-ties have been extended and fixed on bridge decks or towers in some engineering applications. However, the dynamics of this kind of system need to be further studied, and the effects of extending cross-links to bridge decks/towers on the modal response of the system should be assessed in detail. In this paper, a system of two cables connected by an inter-supported cross-link with another lower cross-link extended to the ground is proposed and analyzed. The characteristic equation of the system is derived, and some limiting solutions in closed form of the system are derived. Roots of cable system with special configurations are also discussed, attention being given to the case when the two cables are identical. A predictable mode behavior was found when the stiffness of inter-connection cross-link and the cross-link extended to the ground were the same. The vector of mode energy distribution and the degree of mode localization index are proposed so as to distinguish global and local modes. The change of mode behaviors is further discussed in the case when the two cables are not identical. Effects of cross-link stiffness, cross-link location, mass-tension ratio, cable length ratio and frequency ratio on $1^{st}$ mode frequency and mode shape are addressed.

Free Vibration Analysis of Composite H-Type Cross-section Beams (복합재료 H형 단면 보의 자유진동 해석)

  • Kim, Sung-Kyun;Song, Oh-Seop
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.5
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    • pp.492-501
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    • 2010
  • Equations of motion of thin-walled composite H-type cross-section beams incorporating a number of nonclassical effects of transverse shear and primary and secondary warping, and anisotropy of constituent materials are derived. The vibrational characteristics of a composite thin-walled beam exhibiting the circumferentially asymmetric stiffness system(CAS) and the circumferentially uniform stiffness system(CUS) are exploited in connection with the bending-transverse shear coupling and the bending-twist coupling resulting from directional properties of fiber reinforced composite materials.

Nonlinear System Modeling Using a Neural Networks (비선형 시스템의 신경회로망을 이용한 모델링 기법)

  • Chong, Kil To;No, Tae-Soo;Hong, Dong-Pyo
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.12
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    • pp.22-29
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    • 1996
  • In this paper the nodes of the multilayer hidden layers have been modified for modeling the nonlinear systems. The structure of nodes in the hidden layers is built with the feedforward, the cross talk and the recurrent connections. The feedforward links are mapping the nonlinear function and the cross talks and the recurent links memorize the dynamics of the system. The cross talks are connected between the modes in the same hidden layers and the recurrent connection has self feedback, and these two connections receive one time delayed input signals. The simplified steam boiler and the analytic multi input multi output nonlinear system which contains process noise have been modeled using this neural networks.

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A Cognitive Study on the Usability of Cross-referencing link ad Multiple hierarchies (교차적 연결과 다계층구조의 유용성에 관한 인지적 연구 : 사이버쇼핑몰의 커스터머 인터페이스를 중심으로)

  • 이정원;김진우
    • Korean Journal of Cognitive Science
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    • v.10 no.1
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    • pp.25-43
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    • 1999
  • The focus of this study is on the elements of structure design that facilitate u user interaction with applications within cyberspace Structure design entails decisions regarding the optimal classification and hierarchical organization of information into s successively higher units. i.e .. the grouping of highly related information in the form of nodes of a site and the subsequent connection of nodes that are inter-related. The decisions are based on the designer's subjective classification framework. which is not always compatible with that of the user. We propose that the ensuing cognitive dissonance can be reduced via the employment of multiple hierarchies and cross-referencing links. Multiple hierarchies represent a single information space in terms of a number of single hierarchies. each of which represent a different perspective Cross-referencing refers to the inter-connection between the constituent hierarchies by providing a link to the alternate hierarchy for information that is most likely to be categorized in diverse manners by users with differing perspectives. In this study we conducted two empirical studies to gauge the effectiveness of multiple hierarchies and Cross-referencing links in the domain of cyber shopping malls. In the first phase. an experiment was conducted to determine how subjects classified given products with respect to two different perspectives for categorization. Experimental cyber malls were developed based on the results from the first phase to test the effectiveness of multiple hierarchies and cross-referencing links. Results show that the ease of navigation was higher for cyber malls that had implemented cross-referencing links are of greater value when used in conjunction with single hierarchical designs rather than multiple hierarchies. Users satisfaction with and ease of navigation was higher for cyber malls that had not implemented multiple hierarchies. This paper concludes with discussion of these results and their implications for designers of cyber malls.

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FIT OF FIXTURE/ABUTMENT/SCREW INTERFACES OF INTERNAL CONNECTION IMPLANT SYSTEM

  • Kim, Jin-Sup;Kim, Hee-Jung;Chung, Chae-Heon;Baek, Dae-Hwa
    • The Journal of Korean Academy of Prosthodontics
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    • v.43 no.3
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    • pp.338-351
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    • 2005
  • Statement of problem. Accurate fit between the implant components is important because the misfit of the implant components results in frequent screw loosening, irreversible screw fracture, plaque accumulation, poor soft tissue reaction, and destruction of osseointegration. Purpose. This study is to evaluate the machining accuracy and consistency of the implant fixture/ abutment/screw interfaces of the internal connection system by using a Stereoscopic Zoom microscope and FE-SEM(field emission scanning electron microscope) Materials and methods. The implant systems selected in this study were internal connection type implants from AVANA(Osstem^{\circledR}), Bioplant(Cowell-Medi^{\circledR}), Dio(DIO^{\circledR}), Neoplant(Neobiotech 􀋓), Implantium(Dentium􀋓)systems. Each group was acquired 2 fixtures at random. Two piece type abutment and one piece type abutment for use with each implant system were acquired. Screw were respectively used to hold a two piece type abutment to a implant fixture. The implant fixtures were perpendiculary mounted in acrylic resin block. Each two piece abutment was secured to the implant fixture by screw and one piece abutment also secured to the implant fixture. Abutment/fixture assembly were mounted in liquid unsaturated polyester. All samples were cross-sectioned with grinder-polisher unit. Finally all specimens were analysed the fit between implant fixture/abutment/screw interfaces Results and conclusions. 1. Implant fixture/abutment/screw connection interfaces of internal connection systems made in Korea were in good condition. 2. The results of the above study showed that materials and mechanical properties and quality of milling differed depending on their manufacturing companies.

Pull-off resistance of a screwless implant-abutment connection and surface evaluation after cyclic loading

  • Alevizakos, Vasilios;Mosch, Richard;Mitov, Gergo;Othman, Ahmed;See, Constantin von
    • The Journal of Advanced Prosthodontics
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    • v.13 no.3
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    • pp.152-159
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    • 2021
  • Purpose. The aim of this study was to investigate to what extent cyclic load affects the screwless implant-abutment connection for Morse taper dental implants. Materials and Methods. 16 implants (SICvantage max) and 16 abutments (Swiss Cross) were used. The screwless implant-abutment connection was subjected to 10,000 cycles of axial loading with a maximum force of 120 N. For the pull-off testing, before and after the same cyclic loading, the required force for disconnecting the remaining 6 implant-abutment connections was measured. The surface of 10 abutments was examined using a scanning electron microscope 120× before and after loading. Results. The pull-off test showed a significant decrease in the vertical force required to pull the abutment from the implant with mean 229.39 N ± 18.23 before loading, and 204.30 N ± 13.51 after loading (P<.01). Apart from the appearance of polished surface areas and slight signs of wear, no visible damages were found on the abutments. Conclusion. The deformation on the polished abutment surface might represent the result of micro movements within the implant-abutment connection during loading. Although there was a decrease of the pull-off force values after cyclic loading, this might not have a notable effect on the clinical performance.

An Experimental Study on the Bending Behaviour of Steel Grid Composite Deck (격자형 강합성 바닥판의 휨거동에 대한 실험적 연구)

  • Shin, Hyun Seop;Lee, Chin Hyung;Park, Ki Tae
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.4
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    • pp.175-184
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    • 2011
  • To take advantage of reduced on-site construction periods and minimize traffic impacts various types of steel grid composite deck have been developed since 1930's. Modular prefabricated unfilled grid decks permit a long-distance transportation and construction under unfavorable condition, for example, in mountainous regions due to its comparatively light-weighter structure than fully filled grid deck. In this study bending tests of unfilled grid decks for the deck member of various kinds of infrastructure are carried out, bending strength and behaviour of composite action are experimentally evaluated. In this bending test, design variables are considered, such as type of shear connection between steel grid and concrete slab, spacing between cross bars and thickness of concrete slab. Through test results bending strength and behaviour of composite action are evaluated, reference data for proper type of shear connection and other details of the deck, such as spacing between cross bars, are obtained.

Damping and frequency of twin-cables with a cross-link and a viscous damper

  • Zhou, H.J.;Yang, X.;Peng, Y.R.;Zhou, R.;Sun, L.M.;Xing, F.
    • Smart Structures and Systems
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    • v.23 no.6
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    • pp.669-682
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    • 2019
  • Vibration mitigation of cables or hangers is one of the crucial problems for cable supported bridges. Previous research focused on the behaviors of cable with dampers or crossties, which could help engineering community apply these mitigation devices more efficiently. However, less studies are available for hybrid applied cross-ties and dampers, especially lack of both analytical and experimental verifications. This paper studied damping and frequency of two parallel identical cables with a connection cross-tie and an attached damper. The characteristic equation of system was derived based on transfer matrix method. The complex characteristic equation was numerically solved to find the solutions. Effects of non-dimensional spring stiffness and location on the maximum cable damping, the corresponding optimum damper constant and the corresponding frequency of lower vibration mode were further addressed. System with twin small-scale cables with a cross-link and a viscous damper were tested. The damping and frequency from the test were very close to the analytical ones. The two branches of solutions: in-phase modes and the out-of-phase modes, were identified; and the two branches of solutions were different for damping and frequency behaviors.

Installation Standards of Urban Deep Road Tunnel Fire Safety Facilities (도심부 대심도 터널의 방재시설 설치 기준에 관한 연구(부산 승학터널 사례를 중심으로))

  • Lee, Soobeom;Kim, JeongHyun;Kim, Jungsik;Kim, Dohoon;Lim, Joonbum
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.41 no.6
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    • pp.727-736
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    • 2021
  • Road tunnel lengths are increasing. Some 1,300 tunnels with 1,102 km in length had been increased till 2019 from 2010. There are 64 tunnels over 3,000 m in length, with their total length adding up to 276.7 km. Safety facilities in the event of a tunnel fire are critical so as to prevent large-scale casualties. Standards for installing disaster prevention facilities are being proposed based on the guidelines of the Ministry of Land, Infrastructure and Transport, but they may be limited to deep underground tunnels. This study was undertaken to provide guidelines for the spacing of evacuation connection passages and the widths of evacuation connection doors. Evacuation with various spacing and widths was simulated in regards to evacuation time, which is the measure of safety, using the evacuation analysis simulation software EXODUS Ver.6.3 and the fire/smoke analysis software SMARTFIRE Ver.4.1. Evacuation connection gates with widths of 0.9 m and 1.2 m, and spacings of 150 m to 250 m, were set to every 20 m. In addition, longitudinal slopes of 6 % and 0 % were considered. It was determined to be safe when the evacuation completion time was shorter than the delay diffusion time. According to the simulation results, all occupants could complete evacuation before smoke spread regardless of the width of the evacuation connection door when the longitudinal slope was 6 % and the interval of evacuation connection passage was 150 m. When the evacuation connection passage spacing was 200 m and the evacuation connection gate width was 1.2 m, all occupants could evacuate when the longitudinal slope was 0 %. Due to difference in evacuation speed according to the longitudinal slope, the evacuation time with a 6 % slope was 114 seconds shorter (with the 190 m connection passage) than with a 0 % slope. A shorter spacing of evacuation connection passages may reduce the evacuation time, but this is difficult to implement in practice because of economic and structural limitations. If the width of the evacuation junction is 1.2 m, occupants could evacuate faster than with a 0.9 m width. When the width of a connection door is 1.2 m with appropriate connection passage spacing, it might provide a means to increase economic efficiency and resolve structural limitations while securing evacuation safety.