• Title/Summary/Keyword: Pre-Form Design

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A SMA-based morphing flap: conceptual and advanced design

  • Ameduri, Salvatore;Concilio, Antonio;Pecora, Rosario
    • Smart Structures and Systems
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    • v.16 no.3
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    • pp.555-577
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    • 2015
  • In the work at hand, the development of a morphing flap, actuated through shape memory alloy load bearing elements, is described. Moving from aerodynamic specifications, prescribing the morphed shape enhancing the aerodynamic efficiency of the flap, a suitable actuation architecture was identified, able to affect the curvature. Each rib of the flap was split into three elastic elements, namely "cells", connected each others in serial way and providing the bending stiffness to the structure. The edges of each cell are linked to SMA elements, whose contraction induces rotation onto the cell itself with an increase of the local curvature of the flap airfoil. The cells are made of two metallic plates crossing each others to form a characteristic "X" configuration; a good flexibility and an acceptable stress concentration level was obtained non connecting the plates onto the crossing zone. After identifying the main design parameters of the structure (i.e. plates relative angle, thickness and depth, SMA length, cross section and connections to the cell) an optimization was performed, with the scope of enhancing the achievable rotation of the cell, its ability in absorbing the external aerodynamic loads and, at the same time, containing the stress level and the weight. The conceptual scheme of the architecture was then reinterpreted in view of a practical realization of the prototype. Implementation issues (SMA - cells connection and cells relative rotation to compensate the impressed inflection assuring the SMA pre-load) were considered. Through a detailed FE model the prototype morphing performance were investigated in presence of the most severe load conditions.

A load-bearing structural element with energy dissipation capability under harmonic excitation

  • Pontecorvo, Michael E.;Barbarino, Silvestro;Gandhi, Farhan S.;Bland, Scott;Snyder, Robert;Kudva, Jay;White, Edward V.
    • Advances in aircraft and spacecraft science
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    • v.2 no.3
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    • pp.345-365
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    • 2015
  • This paper focuses on the design, fabrication, testing and analysis of a novel load-bearing element with energy dissipation capability. A single element comprises two von-Mises trusses (VMTs), which are sandwiched between two plates and connected to dashpots that stroke as the VMTs cycle between stable equilibrium states. The elements can be assembled in-plane to form a large plate-like structure or stacked with different properties in each layer for improved load-adaptability. Also introduced in the elements are pre-loaded springs (PLSs) that provide high initial stiffness and allow the element to carry a static load even when the VMTs cannot under harmonic disturbance input. Simulations of the system behavior using the Simscape environment show good overall correlation with test data. Good energy dissipation capability is observed over a frequency range from 0.1 Hz to 2 Hz. The test and simulation results show that a two layer prototype, having one soft VMT layer and one stiff VMT layer, can provide good energy dissipation over a decade of variation in harmonic load amplitude, while retaining the ability to carry static load due to the PLSs. The paper discusses how system design parameter changes affect the static load capability and the hysteresis behavior.

Seismic behavior enhancement of frame structure considering parameter sensitivity of self-centering braces

  • Xu, Longhe;Xie, Xingsi;Yan, Xintong;Li, Zhongxian
    • Structural Engineering and Mechanics
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    • v.71 no.1
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    • pp.45-56
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    • 2019
  • A modified mechanical model of pre-pressed spring self-centering energy dissipation (PS-SCED) brace is proposed, and the hysteresis band is distinguished by the indication of relevant state variables. The MDOF frame system equipped with the braces is formulated in an incremental form of linear acceleration method. A multi-objective genetic algorithm (GA) based brace parameter optimization method is developed to obtain an optimal solution from the primary design scheme. Parameter sensitivities derived by the direct differentiation method are used to modify the change rate of parameters in the GA operator. A case study is conducted on a steel braced frame to illustrate the effect of brace parameters on node displacements, and validate the feasibility of the modified mechanical model. The optimization results and computational process information are compared among three cases of different strategies of parameter change as well. The accuracy is also verified by the calculation results of finite element model. This work can help the applications of PS-SCED brace optimization related to parameter sensitivity, and fulfill the systematic design procedure of PS-SCED brace-structure system with completed and prospective consequences.

The Design Charts for Soil Nailing Slopes Through Limit Equilibrium Method (한계평형해석을 사용한 Soil Nailing보강사면의 설계도표의 제안)

  • Kim, Hak-Moon;Jang, Kyung-Jun;Seo, Jin-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.10
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    • pp.2794-2802
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    • 2009
  • Soil nailing method is widely used in reinforcing slopes and excavating earth. The analysis of nail-reinforced slopes, generally require complicated computer programs. The purpose of this paper is suggest, Soil stability Chart for nailed slopes which are very useful for pre-design, rapidly design, and final check. Three slope types, three nail lengths and three nail angles are selected for the stability analysis by using limit equilibrium method form Bishop and French. From the above results, this study propose the reinforced design charts for examine the necessity of reinforcement can be examined. The suggested stability chart and Taylor's Slope Stability Chart, showed similar safety factors. This Soil Nailing design charts can provide the solutions for necessity of reinforcement, economical of nail's length ratio and installation angle as well.

The Influence of Landscape Painting Concepts on Garden Design Principles in East-Asia - Focused on the Relationship between Chinese Painting Theory and Garden Theory - (동양그림의 경관관이 작정원리에 미친 영향 - 중국화론과 원림론의 관계를 중심으로 -)

  • Kim, Han-Bai
    • Journal of the Korean Institute of Landscape Architecture
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    • v.37 no.6
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    • pp.85-95
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    • 2010
  • East-Asian intellectual societies in the pre-modem age sustained a holistic system of poem-calligraphy-painting trinity until the coming of Western modernism. Therefore, it has been insisted that the principles of traditional landscape gardening were greatly influenced by those of landscape painting and related literature. This study examined those influences closely to discover the essence of traditional Asian landscape architecture through a comparative study between Chinese landscape painting theory and landscape gardening theory within the dual categories of 'contents(value and meaning)' and 'form(view and spatial structure)'. The most important theme of landscape painting theory in contents category was 'Chi and its Vitality(氣韻生動)'. The matching theme in landscape design field was 'Feng-Shui(風水)' and 'Yi-Jin'g(意境)'. The most important theme of landscape painting theory in formal category was 'the Three Ru1es of Perspective(三遠法)'. And the matching theme of landscape design theory was 'Yindi(因地)' and 'Jie-Jing(借景)'. The most important theme of landscape painting theory in formal category was 'the Three Rules of Perspective(三遠法)'. And the matching theme of landscape design theory was 'Yindi(因地)' and 'Jie-Jing(借景)'. It was found that themes and various principles of both fields were closely inter-related and have much in common in their representation of contents and form. In the close relationship with main art genres like this, the landscape gardening could have been recognized as one of the genres of fine art.

PreSPI: Protein-Protein Interaction Prediction Service System (PreSPI: 단백질 상호작용 예측 서비스 시스템)

  • Han Dong-Soo;Kim Hong-Soog;Jang Woo-Hyuk;Lee Sung-Doke
    • Journal of KIISE:Computing Practices and Letters
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    • v.11 no.6
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    • pp.503-513
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    • 2005
  • With the recognition of the importance of computational approach for protein-protein interaction prediction, many techniques have been developed to computationally predict protein-protein interactions. However, few techniques are actually implemented and announced in service form for general users to readily access and use the techniques. In this paper, we design and implement a protein interaction prediction service system based on the domain combination based protein-protein interaction prediction technique, which is known to show superior accuracy to other conventional computational protein-protein interaction prediction methods. In the prediction accuracy test of the method, high sensitivity($77\%$) and specificity($95\%$) are achieved for test protein pairs containing common domains with teaming sets of proteins in a Yeast. The stability of the method is also manifested through the testing over DIP CORE, HMS-PCI, and TAP data. Performance, openness and flexibility are the major design goals and they are achieved by adopting parallel execution techniques, web Services standards, and layered architecture respectively. In this paper, several representative user interfaces of the system are also introduced with comprehensive usage guides.

20세기말 패션 디자인에 나타난 신표현주의적 이미지에 관한 연구

  • 이효진
    • Journal of the Korean Society of Costume
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    • v.40
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    • pp.5-23
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    • 1998
  • The main purpose of this study was intended to analyze the image of N대-Expressionism represented in the late of 20th century fashion design. By the late 1960s and the early 1970s. the prevailing notion of modernity, which had pushed the limits of art beyond previous boundaries, had begun to lose its urgency. Critics called the new pluralistic era which the West was entering Post-Modern. Furthermore, the predominance of America and the New York scene is diminishing, and artistic leadership is now international. Post-Modernism dialectcally made denial of Modernism as likely as New Image Painting and Decorative Pattern Painting Art in 1970's and it was availed as a dialectcal means for the pre-diction of new comings that would be appeared at painting art in 1980's. New Image Painting has been called as Neo-Expressionism. The N대-Expressionists selected human's feature because appeared flankly, directly irregular agitation in the visual effect and they believed human's destructive and amputate body was cruelty. So they express it on the surface canvas. Under the these background, the image of Neo-Expressionism was represented in the late of 20th century fashion design such as the upside-down image of human feature, the image as ameditation on German myth and history, culture, the ecletic image is made of use a mixture of material. The properties of composition, line, color, texture, and form, common to all plastic art, are now more readily recognized and historically valued in every work. That is, individuality, humanity, and the human condition have been at the core of most Western art and Fashion design. Especially Fashion design has been one of the principal instruments used to examine our nature and to promote the notion of growth, self-understanding, and change.

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Implementation of an Arduino Compatible Modular Kit for Educational Purpose (모듈 기반 교육용 아두이노 호환 키트 제작)

  • Heo, Gyeongyong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.23 no.5
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    • pp.547-554
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    • 2019
  • With the curriculum revision in 2015, informatics for secondary high schools was designated as mandatory. As a result, there is an increasing interest in programming in elementary and junior high schools as well as in universities. Arduino is one of the famous tools for programming education, and the usefulness of it has been proven through various case studies. However, existing Arduino-based kits have hardware-dependent drawbacks such as complicated wiring, poor scalability, etc. To overcome these problems, we proposed a kit design, which has a module-based structure, can be extended through one common interface, and can be used for learning at various levels. In this paper, we describe the implementation details of FRUTO kit and a software to use it, which satisfies the proposed design criteria. FRUTO kit has been determined in its current form through several design changes, and is under pre-test before launching.

A Community-Based Integrated Preventive Program of Depression and Its Effectiveness in Caring for Vulnerable Elderly (취약계층 노인의 우울예방을 위한 지역사회기반의 통합프로그램 개발 및 효과검증)

  • Ahn, Yang-Heui
    • Research in Community and Public Health Nursing
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    • v.14 no.2
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    • pp.287-298
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    • 2003
  • The purpose of the study was to develop an integrated prevention program to strengthen elders self-care capability and to examine its effectiveness on their psychological condition. This study used one group pre- and post-test design. Subjects were 85 elderly residents (over 65 years of age) who lived alone, and received free basic medical care and social welfare services in a rural community in Korea. Subject eligibility criteria for this study were to an elders who 1) is not currently taking any anti-depressant medication 2) is able to communicate, and 3) agrees to participate in this study. The integrated program was composed of horticulture, reminiscence, and friendship activities. Twelve sessions were provided for 12 weeks in community-based partnerships to achieve better outcomes. The intervention was case-managed by a public health nurse and aided by six volunteers. The main outcome variable was depression, which was assessed by using 15 items selected from the Geriatric Depression Scale-short form Korean version. Socio-demographic characteristics, functional status, and satisfaction with social support were used as covariates. Results showed that there was a significant intervention effect at post-intervention time point compared to pre-intervention time point(E.S. 0.94). Multiple linear regression analysis showed significant interaction effects between intervention and satisfaction with social support. These findings must be interpreted within the context that an effects of an integrated program could be more synergistically increased when social support factor is considered in the program. A community-based integrated prevention program of depression is effective for vulnerable rural elderly. It is suggested that randomized controlled trials within community setting for better methodological strength as well as multi-level outcomes on community need to be conducted in future.

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Design and Implementation of Advanced Web Log Preprocess Algorithm for Rule based Web IDS (룰 기반 웹 IDS 시스템을 위한 효율적인 웹 로그 전처리 기법 설계 및 구현)

  • Lee, Hyung-Woo
    • Journal of Internet Computing and Services
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    • v.9 no.5
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    • pp.23-34
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    • 2008
  • The number of web service user is increasing steadily as web-based service is offered in various form. But, web service has a vulnerability such as SQL Injection, Parameter Injection and DoS attack. Therefore, it is required for us to develop Web IDS system and additionally to offer Rule-base intrusion detection/response mechanism against those attacks. However, existing Web IDS system didn't correspond properly on recent web attack mechanism because they didn't including suitable pre-processing procedure on huge web log data. Therfore, we propose an efficient web log pre-processing mechanism for enhancing rule based detection and improving the performance of web IDS base attack response system. Proposed algorithm provides both a field unit parsing and a duplicated string elimination procedure on web log data. And it is also possible for us to construct improved web IDS system.

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