• Title/Summary/Keyword: Roll minimization

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Vibration Behavior of a Rotating Brush Roll in Contact with a Solid Roll (강체롤과 접촉 회전하는 브러시롤의 진동 현상)

  • 허주호
    • Journal of KSNVE
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    • v.7 no.3
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    • pp.499-509
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    • 1997
  • During the process of oxide removal from work rolls in sheet metal manufacture, filamentary brushes frequently exhibit a bouncing or chatter behavior. The dynamics of this phenomenon is investigated through the development of expressions for the non-linear contact stiffness between the brush and the roll. With formulation of simple structural models, the time responses in the presence and absence of friction under random excitation are investigated. Possible solutions for the minimization or avoidance of this bouncing or chatter problem are also suggested.

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MINIMIZATION OF PARENT ROLL TRIM LOSS FOR THE PAPER INDUSTRY

  • Bae, Hee-Man
    • Journal of the Korean Operations Research and Management Science Society
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    • v.3 no.2
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    • pp.95-108
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    • 1978
  • This paper discusses an application of mathematical programming techniques in the paper industry in determining optimal parent roll widths. Parent rolls are made from the reels produced at wide paper machines by slitting them to more manageable widths. The problem is finding a set of the slitting patterns that will minimize the trim loss involved in the sheeting operation. Two programming models, one linear and one mixed integer linear, are presented in this paper. Also presented are the computational experience, the model sensitivity, and the comparison of the optimal solutions with the simulated operational data.

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Improvement of Roll Profile Prediction Model in Hot Strip Rolling (열간압연 공정에서 롤 프로파일 예측모델 향상)

  • Chung, J.S.;You, J.;Park, H.D.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2007.05a
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    • pp.229-232
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    • 2007
  • In hot strip rolling, the work roll profile is one of the main factors in predicting and correcting the strip profile. Various studies concerning the wear profile and the thermal crown of work roll have been performed, and the results of these studies have shown that the work roll profile must be predicted accurately so as to efficiently control the strip qualities such as thickness, crown, flatness, and camber. Therefore, a precise prediction model of roll profile is called for in a perfect shape control system. In this paper, a genetic algorithm was applied to improve on the roll profile prediction model in hot strip rolling. In this approach, the optimal design problem is formulated on the basis of a numerical model so as to cover the diverse design variables and objective functions. A genetic algorithm was adopted for conducting design iteration for optimization to determine the coefficient of the numerical model for minimization of errors in the result of the calculated value and the measured data. A comparative analysis showed a satisfactory conformity between them..

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Improvement of Roll Profile Prediction Model in Hot Strip Rolling (열간압연 공정에서 롤 프로파일 예측모델 향상)

  • Chung, J.S.;You, J.;Park, H.D.
    • Transactions of Materials Processing
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    • v.16 no.4 s.94
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    • pp.250-253
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    • 2007
  • In hot strip rolling, the work roll profile is one of the main factors in predicting and correcting the strip profile. Various studies concerning the wear profile and the thermal crown of work roll have been performed, and the results of these studies have shown that the work roll profile must be predicted accurately so as to efficiently control the strip qualities such as thickness, crown, flatness, and camber. Therefore, a precise prediction model of roll profile is called for in a perfect shape control system. In this paper, a genetic algorithm was applied to improve on the roll profile prediction model in hot strip rolling. In this approach, the optimal design problem is formulated on the basis of a numerical model so as to cover the diverse design variables and objective functions. A genetic algorithm was adopted for conducting design iteration for optimization to determine the coefficient of the numerical model for minimization of errors in the result of the calculated value and the measured data. A comparative analysis showed a satisfactory conformity between them.

Optimization of Printing Conditions Using Design Experiments for Minimization of Resistances of Electrodes in Roll-to-roll Gravure Printing Process (롤투롤 그라비어 방식의 인쇄 전극 저항 최소화를 위한 실험계획법 적용 인쇄 공정 조건 최적화)

  • Lee, Sang Yoon;Kim, Cheol;Kim, Chung Hwan
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.26 no.4
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    • pp.351-356
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    • 2017
  • The resistance of printed patterns for electrodes fabricated using printing technology should be minimized. This parameter depends on the pattern width and thickness; however, from the viewpoint of printability, the printed patterns should be printed at the designed width. The resistance of the printed patterns as well as printability is affected by various printing conditions. In this paper, the printing condition is optimized to minimize the resistance of electrodes printed by the roll-to-roll gravure method. This is done by considering the spread ratio of pattern width as a parameter of printability using design experiments. The drying temperature, dryer fan speed, and printing speed are selected as effective factors for the experiment objective. The optimized conditions are obtained and reproducibility test using these demonstrates that the optimized conditions can produce low-resistance electrodes for printability of the pattern width.

Development of Nano Convergence Films Using a Roll-to-Roll Coating System

  • Hwang, Joong Kook;Chang, Sang-Mok;Shin, Hoon-Kyu
    • Transactions on Electrical and Electronic Materials
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    • v.17 no.3
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    • pp.168-171
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    • 2016
  • There has been growing interest and rapid development in transparent electrode films, which are flexible and light and used in mobile, simple information, and electronic devices, and based on recent advancements in nano technology, information technology, and display technology. In particular, studies on developing such films with both high conductivity and high transmittance of visible rays are highly in demand for commercialization. In this study, transparent electrode films were developed for IT using micro patterns that show sheet resistance less than 10 Ω/□, adhesive strength more than 98%, and light transmittance more than 90%. The results of applying a surface emission gradient minimization (Honey Comb) technology to the films was the verification of the sheet resistance, adhesive strength, and light transmittance satisfying the target level of this study through Imprinting and Remolding processes.

Development of cutting length control systems for crop loss minimization of head end in wire rolling process (선재압연공정에서의 선단부 crop loss최소화를 위한 절사량 제어시스템 개발)

  • 이상호;손붕호
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1493-1495
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    • 1997
  • Cropping of head and tail ends of rod in wire Rolling Process is required to aviod roll damage, and prevent cobbles. In order to reduce the crop loss, the new crop control system for rotary shear of Wire rolling Process has been developed. Performance shows the developed system cut precisely within setting length. As a result, it is expected to increase the yield ratio of products about 0.2 percent and stabilize the operantional condition.

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Process Design of Electric Steel by a Multiple Objective Optimization (다중 목적함수 최적화기법을 이용한 전기강판 생산 공정설계)

  • 정제숙;변상민;김홍준;황상부
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1997.10a
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    • pp.153-157
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    • 1997
  • The investigation deals with the process design in cold rolling mill of electric plant. In this study, multiple objective optimization is conducted by a genetic algorithm, where the fitness values are evaluated on the basis of one - dimensional model of flat rolling. The approach is applied to the determination of the process conditions which are optimal with regard to minimization of roll power and maximization of productivity.

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The Fuzzy Steering Control Using a Slope Direction Estimation Method for Small Unmanned Ground Vehicle (경사방향 추정 기법을 이용한 소형로봇의 퍼지 조향 제어)

  • Lee, Sang Hoon;Huh, Jin Wook;Kang, Sincheon;Lee, Myung Chun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.6
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    • pp.721-728
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    • 2012
  • The tracked SUGVs(Small Unmanned Ground Vehicles) are frequently operated in the narrow slope such as stairs and trails. But due to the nature of the tracked vehicle which is steered using friction between the track and the ground and the limited field of view of driving cameras mounted on the lower position, it is not easy for SUGVs to trace narrow slopes. To properly trace inclined narrows, it is very important for SUGVs to keep it's heading direction to the slope. As a matter of factor, no roll value control of a SUGV can makes it's heading being located in the direction of the slope in general terrains. But, the problem is that we cannot directly control roll motion for SUGV. Instead we can control yaw motion. In this paper, a new slope driving method that enables the vehicle trace the narrow slopes with IMU sensor usually mounted in the SUGV is suggested which including an estimation technique of the desired yaw angle corresponding to zero roll angle. In addition, a fuzzy steering controller robust to changes in driving speed and the stair geometry is designed to simulate narrow slope driving with the suggested method. It is shown that the suggested method is quite effective through the simulation.

Output feedback, decentralized controller design for an active suspension system using 7 DOF full car model (7 자유도 차량 모델과 출력 되먹임을 이용한 자동차 능동 현가장치 설계에 관한 연구)

  • 노태수;정길도;홍동표
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.871-875
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    • 1996
  • The Output feedback linear quadratic regulator control is applied to the design of active suspension system using 7 DOF full car model. The performance index reflects the vehicle vertical movement, pitch and roll motion, and minimization of suspension stroke displacements in the rattle space. The elements of gain matrix are approximately decoupled so that each suspension requires only local information to generate the control force. The simulation results indicates that the output feedback LQ controller is more effective than purely passive or full state feedback active LQ controllers in following the road profile at the low frequency range and suppressing the road disturbance at the high frequency ranges.

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