• 제목/요약/키워드: Sources of variation

검색결과 609건 처리시간 0.025초

STS 강의 $O_2$ 및 Al함량이 용접용입량에 미치는 영향 (Effect of $O_2$ and Al Coantent on the Weld Penetration)

  • 김희봉;김정호;이창희
    • Journal of Welding and Joining
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    • 제15권3호
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    • pp.65-78
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    • 1997
  • The effect of $O_2$and Al contents and the variation of welding parameters such as arc currents, welding speed on the weld penetration was investigated. Examination of weld penetration using GTAW was accomplished in the ferritic STS410L and austenitic STS304. Good penetration could be controlled by the variation of $O_2$ and Al contents in STS304. However, influences of $O_2$ and Al contents on the ferritic STS410L are far less than those on the austenitic STS304. Welding parameters should be considered first before controlling $O_2$ and Al contents for a good penetration in ferritic STS410L. In the simulation study under the stationary heat sources, the results of simulation and experiment have a similar tendency.

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System-On-Panel을 위한 Poly-Si TFT Vth보상 전류원 (Vth Compensation Current Source with Poly-Si TFT for System-On-Panel)

  • 홍문표;정주영
    • 대한전자공학회논문지SD
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    • 제43권10호
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    • pp.61-67
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    • 2006
  • 본 논문에서는 Poly-Si의 불규칙한 Grain boundary 분포로 인해 발생하는 문턱전압의 변화에 대해서도 일정한 전류를 흘려줄 수 있는 전류원을 제안하였다. 기존의 문턱전압 보상 전류원에 비해 넓은 입력전압 범위에서도 포화영역의 특성이 매우 향상되었으며 문턱전압의 변화에 따른 전류의 오차를 감소시킬 수 있었다. 마지막으로 HSPICE 시뮬레이션 과정을 통해 Poly-Si TFT의 특성곡선과 제안된 전류원의 특성곡선을 비교하였으며 각각의 입력전압에 대한 문턱전압의 변화에 따른 출력전류의 상대오차를 측정하였다.

Efficient Multi-Touch Detection Algorithm for Large Touch Screen Panels

  • Mohamed, Mohamed G.A.;Cho, Tae-Won;Kim, HyungWon
    • IEIE Transactions on Smart Processing and Computing
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    • 제3권4호
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    • pp.246-250
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    • 2014
  • Large mutual capacitance touch screen panels (TSP) are susceptible to display and ambient noise. This paper presents a multi-touch detection algorithm using an efficient noise compensation technique for large mutual capacitance TSPs. The sources of noise are presented and analyzed. The algorithm includes the steps to overcome each source of noise. The algorithm begins with a calibration technique to overcome the TSP mutual capacitance variation. The algorithm also overcomes the shadow effect of a hand close to TSP and mutual capacitance variation by dynamic threshold calculations. Time and space filters are also used to filter out ambient noise. The experimental results were used to determine the system parameters to achieve the best performance.

품질비용 산정에 의한 지속적 개선 방법 사례 연구 (A Case Study of Continuous Improvement Methodology by Calculated Quality-Cost)

  • 이강인;한석만
    • 품질경영학회지
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    • 제33권3호
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    • pp.19-30
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    • 2005
  • Recently many organization to become survival in changing marketplace, they must commit to implementing tools, systems, and quality management techniques. In this paper we develop process method of Team's problem-solving to reduce in failure costs. This paper suggest the step process how to measure quality cost reasonably that works in all types organizations. Or what is continuous improvement? Continuous improvement can be described as the continuous reduction of variation. Variation has many sources(machines, methods, materials, measurements, people, and environments) and cause(special & common in organization). As quality cost are not the answer to every organization financial, or quality-related problem, it's real results are designing & implementing quality cost system might be the answer.

통계적 공정 제어에 전문가 시스템의 적용에 관한 연구 (Applying an Expert System to Statistical Process Control)

  • 윤건상;김훈모;최문규
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1995년도 추계학술대회 논문집
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    • pp.411-414
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    • 1995
  • Statistical Process Control (SPC) is a set of methodologies for signaling the presence of undesired sources of variation in manufacturing processes. Expert System in SPC can serve as a valuable tool to automate the analysis and interpretation of control charts. In this paper we put forward a method of successful application of Expert System to SPC in manufacturing process.

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An Adaptive Photon Mapping in the Use of Automatic Differentiation

  • Namae, Takuya;Makino, Mitsunori
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 ITC-CSCC -2
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    • pp.991-994
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    • 2002
  • Photon mapping is an efficient global illumination technique for realistic image synthesis that has been developed in computer graphics. In this paper, an adaptive photon mapping in the use of automatic differentiation is proposed. Since the automatic differentiation is used when photons emit from the light sources through the scene, we can check the variation of surrounding shape. Therefore, we can decrease the number of photons and generate an image in relatively low computational cost.

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승용차의 조타륜 쉬미에 대한 실험적 고찰 (Experimental Analysis for Steering Wheel Shimmy in Passenger Vehicle)

  • 배병국;허필정;유병규
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 추계학술대회논문집 I
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    • pp.439-443
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    • 2001
  • The steering wheel vibrations such as shimmy, brake judder and shake are affected by the vibration characters of steering and suspension. For the analysis of shimmy, nonuniformities of tire can be considered the major sources. This study investigates unbalances and uniformities of tire in which the lateral force variation is highly correlated with shimmy. The hardness of suspension bushes can be modified to change the dynamic behavior of suspension that is effective to reduce the sensitivity of shimmy.

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Pattern Formations with Turing and Hopf Oscillating Pattern in a Discrete Reaction-Diffusion System

  • 이일희;조웅인
    • Bulletin of the Korean Chemical Society
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    • 제21권12호
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    • pp.1213-1216
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    • 2000
  • Localized structures with fronts connecting a Turing patterns and Hopf oscillations are found in discrete reaction-diffusion system. The Chorite-Iodide-Malonic Acid (CIMA) reaction model is used for a reaction scheme. Localized structures in discrete reaction-diffusion system have more diverse and interesting features than ones in continuous system. Various localized structures can be obtained when a single perturbation is applied with variation of coupling strength of two intermediates. Roles of perturbations are not so simple that perturbations are sources of both Turing patterns and Hopf oscillating domains, and spatial distribution of them is determined by strength of a perturbation applied initially.

통신로 특성변화에 대한 적응성 부여 방법 (Adaption Method for Channel Charateristics Variation)

  • 이종헌;진용옥
    • 전자공학회논문지A
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    • 제29A권3호
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    • pp.1-7
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    • 1992
  • This paper discusses the self-adaptive equalization technique which has adaptibility to channel characteristics varation without training sequence. The criterion function used in this paper is based on the concept of cumulant matching. This function can be applied to nonminimum phase channel, and we can verify the fact that if the constrained condition is satisfied. this criterion has no local optimum. As the adaption algorithm, the normalized gradient-searching technique is used. Simulations verify the performance of our method in case of 8PAM, 8PSK(CCITT V.27), 16QAM(CCITT V.29) sources and three type nonminimum phase channels.

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Feature engineering with Wavelet transform for Transient detection in KMTNet Supernova Project

  • Lee, Jae-Joon
    • 천문학회보
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    • 제42권2호
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    • pp.64.3-64.3
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    • 2017
  • For the detection of transient sources in optical wide field surveys like KMTNet Supernova Project, difference imaging technique is commonly used. As this method produces a fair amount of false positives, it is also common to utilize machine learning algorithms to screen likely true positives. While deep learning methods such as a convolutional neural network has been successfully applied recently, its application can be limited if the size of the training sample is small. I will discuss a variation of more conventional method that adopts the wavelet transform for feature engineering and its performance.

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