• Title/Summary/Keyword: Thermal compensation

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The Study on Residual Stress of Laser Weldment for the Heterogeneous Materials (이종재료의 레이저용접에서 잔류응력 평가)

  • 오세헌;민택기
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.13 no.3
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    • pp.119-125
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    • 2004
  • Generally, it is used the compensation spring to compensate the inaccuracy of screen image induced by thermal deformation in CRT monitor. Its mechanism is bi-metallic system made of heterogeneous metals and these is bonded by laser welding. But laser welding induces the non-uniform temperature distribution and locally residual stress is yielded by these temperature deviation. This paper studies residual stress of laser weldment using FEA and hole drilling method. The results are followed. In the case of heterogeneous materials weldment, higher residual stress induced in the weldment region of SUS 304 which have larger CTE than Ni 36 and residual stress on the middle of specimen is higher by 10.9% than that of its surface Measured residual stress of SUS 304 yield 481MPa and that of Ni 36 is 140.5MPa in the vicinity of the welding region. And the residual distribution is very similar in comparison with FEA result.

Key Technology Analysis for Machining Process Optimization and Automation (가공공정 최적화 및 무인화를 위한 요소기술 분석 연구)

  • Kim, Dong-Hoon;Song, Jun-Yeob
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.2
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    • pp.179-184
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    • 2013
  • In this article, we introduce the study case of technology that can automatically compensate the errors of these factors of a machine during processing on the machine tool's CNC(Computerized Numerical Controller) in real time. The biggest factors that lower the machining accuracy are thermal deformation and chatter vibration. This study is related to the detection and compensation of thermal deformation and chatter vibration that can compensate for faster and produce processed goods with more precision by autonomous compensation. In addition, this study is related to the active control of vibration during machining, monitoring of cutting force and auto recognition of machining axes origin. Thus, we attempt to introduce the related contents of the development we have made in this article.

Response Time Compensation of LCD with Integrated Thermal Sensor

  • Lee, Ki-Chan;Park, Yun-Jae;Ahn, Ik-Hyun;Choi, Kyung-Uk;Moon, Seung-Hwan
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.825-828
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    • 2007
  • This paper presents a thermally adaptive driving (TAD) technology for response time compensation of LCD with integrated sensor. The TAD is comprised of analog sensor signal conditioning and a digital feedback algorithm. Utilizing with a digital feedback system, TAD reduces response time of nearly 50% over the temperature range $0^{\circ}C-60^{\circ}C$.

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Mathatical Analysis for Efficiency of Power Factor Correction System Using IP3003 (타려식 형광등 안정기용 구동 반도체 IP3102의 온도 보상 설계법)

  • Joo, Sung-Juni;Chang, Cheon-Seop
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2007.05a
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    • pp.152-156
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    • 2007
  • We introduce the IP3102 which is developed by Interpion Semiconductor co. LTD. for the CFL ballaster. The IP3102 has thermal compensation function. In this paper, we present the temperature compensation design technique and its implementation in the IP3102. The experimental results is also presented in this paper.

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Small Camera Module for TEC-less Uncooled Thermal Image (TEC-less 비냉각 열영상 검출기용 소형카메라 모듈 개발)

  • Kim, Jong-Ho
    • IEMEK Journal of Embedded Systems and Applications
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    • v.12 no.2
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    • pp.97-103
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    • 2017
  • Thermal imaging is mainly used in military equipment required for night observation. In particular, technologies of uncooled thermal imaging detectors are being developed as applied to low-cost night observation system. Many system integrators require different specifications of the uncooled thermal imaging camera but their development time is short. In this approach, EOSYSTEM has developed a small size, TEC-less uncooled thermal imaging camera module with $32{\times}32mm$ size and low power consumption. Both domestic detector and import detector are applied to the EOSYSTEM's thermal imaging camera module. The camera module contains efficient infrared image processing algorithms including : Temperature compensation non-uniformity correction, Bad/Dead pixel replacement, Column noise removal, Contrast/Edge enhancement algorithms providing stable and low residual non-uniformity infrared image.

Characteristics Analysis and Compensation of Thermal Deformation for Machine Tools with respect to Operating Conditions (작업조건에 따른 공작기계의 열변형 특성 해석 보정)

  • 이재종;최대봉;박현구;곽성조
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.10 no.4
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    • pp.70-75
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    • 2001
  • In metal cutting, the machining accuracy is more affected by thermal errors than by geometric errors. This paper models of the thermal errors for error analysis and develops on-the-machine measurement system by which the volumetric error are measured and compensated. The thermal error is modeled by means of angularity errors of a column and thermal drift error of the spindel unit which are measured by the touch probe unit with a star type styluses, a designed spherical ball arti-fact, and five gap sensors. In order to analyze the thermal characteristics under several operating conditions, experiments performed with the touch probe unit and five gap sensors on the vertical and horizontal machining centers.

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A Study on the Problem-Solving Method and Thermal Efficiency Properties at the Time of High Expansion Realization in a 4-Cycle Diesel Engine (4사이클 디젤기관에서 고팽창 실현 시 문제점 해결방안과 열효율 특성에 대한 연구)

  • Jang, Tae-Ik
    • Journal of Advanced Marine Engineering and Technology
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    • v.33 no.6
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    • pp.835-842
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    • 2009
  • The present thesis carried out a research on a compression pressure's reduction phenomenon and its countermeasure according to the thermal efficiency improvement method by a Miller method in 4-cycle low speed diesel engine. In case of retardation of intake valve closing time in a engine, the theoretical heat efficiency shows a remarkably reducing trend when a compression ratio is not compensated. Accordingly, the thermal efficiency showed an increasing trend in case of compensating the compression ratio. Especially, it could be understood that the theoretical heat efficiency at near ABDC $100^{\circ}$ of intake valve closing time in case of compensation of the compression ratio was improved by around 25.1%, and the mean effective pressure was also increased by around 18.6%. Also, as the retardation of intake valve closing time increases, air quantity becomes insufficient due to a backflow phenomenon of intake air and thus thermal efficiency was decreased in a high load operation domain. The solving method of this problem is possible by supercharge. Therefore, in order to improve thermal efficiency by retardation of ntake valve closing time, the thermal efficiency improvement according to low compression is possible when there are a compensation device of a compression ratio and a supercharge device. This is a problem-solving method of low compression and high expansion cycle.

Novel Process to Improve Defect Problems for Thermal Nanoimprint Lithography (열 나노임프린트 리소그래피를 위한 패턴의 결함 향상에 관한 실험적 연구)

  • Park, Hyung-Seok;Shin, Ho-Hyun;Seo, Sang-Won;Sung, Man-Young
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.55 no.5
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    • pp.223-230
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    • 2006
  • The reliability of imprint patterns molded by stamps for industrial application of nanoimprint lithography (NIL), is an important issue. Usually, defects can be produced by incomplete filling of negative patterns and the shrinkage phenomenon of polymers in conventional NIL. In this paper, the patterns that undergo a varied temperature or varied pressure period during the thermal NIL process have been investigated, with the goal of resolving the shrinkage and defective filling problems of polymers. The effects on the formation of polymer patterns in several profiles of imprint processes are also studied. Consequently, it is observed that more precise patterns are formed by the varied temperature (VT-NIL) or varied pressure (VP-NIL). The NIL (VT-NIL or VP-NIL) process has a free space compensation effect on the polymers in stamp cavities. From the results of the experiments, the polymer's filling capability can be improved. The VT-NIL is merged with the VP-NIL for the better filling property. The patterns that have been imprinted in the merged NIL are compared with the results of conventional NIL. In this study, the improvement in the reliability for results of thermal NIL has been achieved.