• 제목/요약/키워드: Convergence Characteristics

검색결과 5,523건 처리시간 0.03초

GMA용접에서 용접전류와 아크 길이의 동특성에 관한 연구 (A Study on Dynamic Characteristics of Welding Current and Arc Length At GMAW)

  • 이태영
    • 한국산업융합학회 논문집
    • /
    • 제14권1호
    • /
    • pp.15-21
    • /
    • 2011
  • Welding variables and conditions in gas metal arc welding (GMAW) effect on the quality and productivity of the weld, extensive research efforts have been made to analyze the effect of the welding variables and conditions. In this study dynamic behavior of GMAW system is investigated using the characteristics of the power supply, wire and welding arc. Characteristic equation of wire is modified to include the effect of droplets attached at the electrode tip. The dynamic characteristics of arc length, current, voltage with respect to the step, ramp inputs of CTWD was simulated. From results of simulation, some predictions about dynamic characteristics of GMAW and welding process are available. The proposed simulator and results appear to be utilized to determine the proper welding conditions, to be improved by considering power supply dynamic characteristics.

내열성 세라믹스 재료의 분광복사특성 (Spectral Radiative Characteristics of Heat Resisting Ceramics Materials)

  • 상희선
    • 한국산업융합학회 논문집
    • /
    • 제4권1호
    • /
    • pp.35-40
    • /
    • 2001
  • A spectral measurement system for reflection and transmission properties by using an optical fiber and an ellipsoidal mirror was newly developed. The hemispherical reflectance and transmittance spectra of several heating resisting ceramics materials were measured from visible to middle infrared region. The directional characteristics of reflection and transmission were also investigated in consideration of the absorptance. The measured data were analyzed by using a four flux model of radiation transfer, The radiation properties could be estimated by the obtained scattering and absorption coefficient spectra.

  • PDF

Hydro Dynamic Model을 이용한 CMOS의 파괴특성의 Transient Simulation해석 (Transient Simulation of CMOS Breakdown characteristics based on Hydro Dynamic Model)

  • 최원철
    • 한국산업융합학회 논문집
    • /
    • 제5권1호
    • /
    • pp.39-43
    • /
    • 2002
  • In present much CMOS devices used in VLSI circuit and Logic circuit. With increasing a number of device in VLSI, the confidence becomes more serious. This paper describe the mechanism of breakdown on CMOS, especially n-MOS, based on Hydro Dynamic model with device self-heating. Additionally, illustrate the CMOS latch-up characteristics on simplified device structure on this paper.

  • PDF

Relation between Certainty and Uncertainty with Fuzzy Entropy and Similarity Measure

  • Lee, Sanghyuk;Zhai, Yujia
    • 한국융합학회논문지
    • /
    • 제5권4호
    • /
    • pp.155-161
    • /
    • 2014
  • We survey the relation of fuzzy entropy measure and similarity measure. Each measure represents features of data uncertainty and certainty between comparative data group. With the help of one-to-one correspondence characteristics, distance measure and similarity measure have been expressed by the complementary characteristics. We construct similarity measure using distance measure, and verification of usefulness is proved. Furthermore analysis of similarity measure from fuzzy entropy measure is also discussed.

다관절 다단의 햅틱장치 제어에 관한 연구 (A study on control of the Haptic Device use for Robot Arm)

  • 박인만;김덕수;박정만
    • 한국산업융합학회 논문집
    • /
    • 제18권1호
    • /
    • pp.61-66
    • /
    • 2015
  • Force feedback control is investigated for improving the quality of the haptic feedback in virtual reality applications. We proposed method for control of the haptic device using universal serial bus. and evaluated the characteristics with experimental set.

공과대학 융합교육 형태 연구 (A Study of Convergence Education Type for the College of Engineering)

  • 김연희;변호승;홍철호;한정수
    • 공학교육연구
    • /
    • 제19권4호
    • /
    • pp.60-71
    • /
    • 2016
  • Due to the development of science and technology, diversity of fusion technologies has become a major concern. Especially the application of the convergence education became necessary in the curriculum of engineering department. The purpose of this paper is to extract characteristics of convergence education among engineering majors and to present a model of applicable convergence education. The researchers collected studies of past 15 years in domestic and international journals in related themes. Academic research information systems, DBpia, e-article, Academic Search Complete were used for keyword searches. 43 Korean papers and 25 international papers were analyzed for the study. The results showed that the convergence education models for college of engineering can be classified into the three types: the cooperative convergence, multidisciplinary convergence, and transdisciplinary convergence. Based on the results, a convergence education model is suggested for the schools of engineering in Korea.

Convergence Behavior of the filtered-x LMS Algorithm for Active Noise Caneller

  • Lee, Kang-Seung
    • The Journal of the Acoustical Society of Korea
    • /
    • 제17권2E호
    • /
    • pp.10-15
    • /
    • 1998
  • Application of the Filtered-X LMS adaptive filter to active noise cancellation requires to estimate the transfer characteristics between the output and the error signal of the adaptive canceler. In this paper, we derive an adaptive cancellation algorithm and analyze is convergence behavior when the acoustic noise is assumed to consist of multiple sinusoids. The results of the convergence analysis of the Filtered-X LMS algorithm indicate that the effects of parameter estimation inaccuracy on the convergence behavior of the algorithm are characterize by two distinct components : Phase estimation error and estimated magnitude. In particular, the convergence of the Filtered-X LMS algorithm is show to be strongly affected by the accuracy of the phase response estimate. Simulation results of the algorithm are presented which support the theoretical convergence analysis.

  • PDF

Pressure Control Organic Vapor Deposition Methods for Fabricating Organic Thin-Film Transistors

  • Ahn, SeongDeok;Kang, Seong Youl;Oh, Ji Young;Suh, Kyung Soo;Cho, Kyoung Ik;Koo, Jae Bon
    • ETRI Journal
    • /
    • 제34권6호
    • /
    • pp.970-973
    • /
    • 2012
  • In this letter, we report on the development progress of a pressure control organic vapor deposition (PCOVD) technology used to design and build a large area deposition system. We also investigate the growth characteristics of a pentacene thin film by PCOVD. Using the PCOVD method, the mobility and on/off current ratio of an organic thin-film transistor (OTFT) on a plastic substrate are $0.1cm^2/Vs$ and $10^6$, respectively. The developed OTFT can be applied to a flexible display on a plastic substrate.

The Trends of IT Convergence in Korea

  • 이성열
    • 한국산업정보학회논문지
    • /
    • 제17권7호
    • /
    • pp.101-110
    • /
    • 2012
  • These days, the environment of IT development goes through converging with various industries and technologies. Also, it accelerates to pioneer new markets and develop new technologies. This trend becomes one of the most important factors to explore new national growth engines in Korea. Thus, this research examines current trends of IT convergence in Korea. The strategic characteristics of IT convergence in overseas are briefly explained for comparing purpose. The governmental strategies or efforts regarding the IT convergence have been surveyed. Some example convergences of LG, Samsung, and POSCO as major IT industries in Korea have been introduced. It also identifies several buzz concepts in this field. The study aims to provide an insight about the activities that are happening in the field of IT convergence in Korea. Finally, the findings through the research have been summarized.

QAM 시스템에 선택적으로 NCMA를 적용한 블라인드 등화 알고리즘의 수렴속도 개선 (Convergence Rate Improvement of the Blind Equalization Algorithm for QAM System using Selective NCMA)

  • 강윤석;안상식
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 1999년도 추계종합학술대회 논문집
    • /
    • pp.43-46
    • /
    • 1999
  • Blind equalizers recover the transmitted data using signal's statistical characteristics only. Because of its computational simplicity and fast convergence rate, CMA is widely used in practice. Blind equalizers, however, converge much slowly than conventional equalizers which use the training signals. In order to improve the convergence rate, many modified blind equalization algorithms have been proposed. Among those, Normalized CMA (NCMA) was applied to increase the convergence rate by using the large step size. Unfortunately it can only be applied for the constant modulus signal constellation scheme. this paper, we propose the Selective NCMA (SNCMA) that improve the convergence rate of blind equalization algorithms by using NCMA for non-constant modulus signalling method such as QAM constellation. We achieved fast start-up convergence rate and reduced steady-state residual error.

  • PDF