• Title/Summary/Keyword: gap joint

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Application of the Vision Sensor for Weld Seam Tracking System in Large Vessel Fabrication

  • Park, Sang-Gu;Lee, Jee-Hyung;Ryu, Sang-Hyun
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.56.3-56
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    • 2002
  • For the weld quality improvement and the convenient operation of machines, laser vision system can be used to track weld seams on pressure vessels. There are many bad conditions to the weld grooves such as cutting error, gap variation of weld joint, and offset error of center line caused by misalignment. We developed a laser vision seam tracking system which consists of a laser vision sensor, a two axis positioning mechanism and a user interface program running on the Windows system. It was found that our system worked well for U, V and X shaped grooves. We used an industrial PC as the system controller to secure immunity to electrical noise and dust. We introduce here a simple and...

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Nonlinear Finite Element Analysis for the Precast Concrete Large Panel Subassemblage subjected to Horizontal Force (수평하중을 받는 프리캐스트 콘크리트 대형 판넬 부분구조의 비선형 해석)

  • 박병순;서수연;이원호;이리형
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1993.10a
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    • pp.157-162
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    • 1993
  • During earthquakes, the joints provide a principal means for energy dissipation, and these are also responsible for introducing a nonlinear behavior to the overall building system, while large panels remain in the elastic range. In analysis for the precast concrete large panel system, it is difficult to make a general analysis for their behavior because of differences in joint details. Therefore, in case of presence of vertical joints, it is more difficult because of the interaction between the horizontal joints and vertical joints, In this study, a nonlinear finite element analysis is performed using the gap element, friction element, and concrete material model, and the results are compared with the experimental results.

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A Fuzzy Controller Design for Compensating Backlash at Robot Joint (로봇 관절의 백래쉬 보상을 위한 퍼지 제어기 설계)

  • Ahn, Won-Ki;Kim, Byung-Yoon;Kim, Jin-Hwan;Huh, Uk-Youl
    • Proceedings of the KIEE Conference
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    • 2006.04a
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    • pp.192-194
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    • 2006
  • Backlash between meshing gear teeth causes impact, tracking error and undesired vibrations. It is usually minimized by precision gear, spring-loaded anti-backlash gears and precise mechanical adjustment. Although these techniques can help to reduce the backlash gap, its cost is relatively high and performance is limited. And the classic controller is insufficient to control the dynamic system with nonlinearity. For these reason, a fuzzy controller is proposed to compensate the backlash effect at a robot system. The input variables are position error and change in error. The output variable can be defined by input voltage of motor. The performance of a fuzzy controller is verified by comparing with a PID controller. The results show that the undesired vibration is suppressed. And then diminishing the position error is observed.

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Dynamic Behaviour of Pile Foundation with Scour (세굴을 고려한 말뚝기초의 동적 거동분석)

  • 김정환;허택영;박용명
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.55-62
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    • 2003
  • This study considered the effect of scour depth on the behaviour of pile foundation of bridge structure under seismic excitation. The numerical model was composed of the superstructure, pile foundation and soil. The superstructure and pile was modeled by beam elements and soil was by spring elements. The pile head and concrete footing was considered as hinge and rigid connected situation, respectively. A toro-gap element was used to model the expansion joint of superstructure. Nonlinear dynamic analysis was carried out on the constructed model. It was acknowledged that the steel pile become to yield after the scour depth reached about 2.0m.

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The Plural Subject Account of Group Beliefs Using Grounding Concept

  • Koo, Ja-Rok
    • Journal of the Korea Society of Computer and Information
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    • v.20 no.11
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    • pp.17-23
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    • 2015
  • In this paper, we propose a plural subject account of group beliefs using grounding concept, which bridges the gap between the two main approaches of ACLs, the mentalistic accounts and the social commitment accounts. The key idea of this Gilbert's plural subject account of group beliefs is to extend the grounding logic into the common ground framework for the semantics of ACLs which is fully verifiable, fully formalized and easily applicable. Thus, we formalize the proper group belief concept using common ground framework and we define the semantics of the primitive speech acts of FIPA-ACL such as inform, request and confirm as case studies. Also, we illustrate our framework on an e-commerce agent purchase negotiation and compare this proposed framework with two traditional semantics for ACLs.

Quasi-Static Test of Precast Concrete Large Panel Subassemblage (P.C 대형판넬 부분구조물의 Quasi-Static 실험연구)

  • Choi, Jeong-Su;Lee, Han-Seon;Kim, U;Hong, Gap-Pyo
    • Proceedings of the Korea Concrete Institute Conference
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    • 1990.10a
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    • pp.73-78
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    • 1990
  • Large panel building systems are composed of vertical wall panels which support horizontal roof and floor panels to form a box like structure. The simplecity of the connections, which makes precast concrete economically viable, causes a lack of continuity in stiffness, strength and ductility. This precast concrete large panel systems typically have weak connection regions. Three types of 2-story full-scale precast concrete subassemblages were tested under reversed cyclic loading. The seismic resistance capacity and failure mode of each system are compared in connection with the characteristics of joint connection details.

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A Study on Evaluation of Combat Effectiveness in WMA-EA based on C2 Model (C2모델 기반 전장아키텍처의 전투효과 평가방안)

  • Park, Yang-Soo;Jung, Chan-Ki
    • Journal of the Korea Institute of Military Science and Technology
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    • v.13 no.4
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    • pp.619-626
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    • 2010
  • ROK Joint Chiefs of Staff in developing an WMA-EA(Warfighting Mission Area-Enterprise Architecture) tries to create the practical buildup requirements of military power through precise requirements and operational capabilities based on the architectures. However, it is difficult to verify the effectiveness of target architectures and do efficient requirement planning because we cannot know the gap of quantitative combat effectiveness between current and target WMA-EAs. This study presents an evaluation method of combat effectiveness and focuses on combat's positive effects in WMA-EAs. The method proposed is based on C2 model which is appropriate for the evaluation of combat effectiveness in architectures. We verify the effectiveness of the proposed method through a case study of an anti-ship warfare architecture.

Dot Idea (.IDEA): A New Concept for an Incubation Program and Open Innovation Based on User Needs

  • Maldaner, Luis Felipe;Simon, Luisa;Aranha, Carlos Eduardo de Souza
    • World Technopolis Review
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    • v.7 no.2
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    • pp.82-96
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    • 2018
  • This paper discussed the application process of the Dot Idea program. The Dot Idea program is an incubation and open innovation program co-created by Unitec, an incubator at Tecnosinos Tech Park, and an SAP innovation team. The main objective of this study was to cover an existing gap in the literature regarding the practical application of an open innovation methodology. Many companies seek interaction with external parties to enable advancement toward identified innovation opportunities. Technology clusters, parks, and incubators have played an important role in promoting connections and interaction. Consequently, the Dot Idea program emerged as a result of a joint effort to create a program using a design science research methodology aiming to foster new businesses and strengthen Brazil and Latin America as a hub to develop new solutions for traditional organizations. In regards to lessons learned, the Dot.health trial had some success but also experienced difficulties; these related to the relationships between startups and a hospital's internal teams, and startups' needs to be funded from the beginning in order to be fully dedicated to a project.

POOL MONITORING IN GMAW

  • Absi Alfaro, S.C.;de Carvallio, G.C.;Motta, J.M.
    • Proceedings of the KWS Conference
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    • 2002.10a
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    • pp.307-313
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    • 2002
  • This paper describes a weld pool monitoring technique, which is based on the weld pool image analysis. The proposed image analysis algorithm uses machine vision techniques to extract geometrical information from the weld pool image such as maximum weld pool width, gap width and misalignment between the joint longitudinal axis and the welding wire. These can be related to the welding parameters (welding voltage and current, wire feed speed and standoff) to produce control actions necessary to ensure that the required weld quality will be achieved. The experiments have shown that the algorithm is able to produce good estimates of the weld pool geometry; however, the adjustment of the camera parameters affects the image quality and, consequently, has a great influence over the estimation.

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Weld Quality Assessment Method for Short-Circuit Mode in GMAW

  • Kim, J.M.;Yoo, C.D.
    • International Journal of Korean Welding Society
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    • v.1 no.2
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    • pp.1-6
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    • 2001
  • A weld quality assessment method is proposed in this work, which can be applied to the short-circuit mode in GMAW. Information about the welding signal trajectory, distribution of the signal duration at each sub-regions and short-circuit frequency is used to evaluate the weld quality. The weighted penalty, which is determined experimentally, is imposed for each abnormal signal. Performance of the proposed method is compared with the Simpson's method under the conditions of shielding gas reduction, workpiece surface contamination and joint gap in the butt and fillet welds. Although the proposed method predicts the weld quality with reasonable accuracy, further modification and extension to other metal transfer modes are needed as a further study.

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