• 제목/요약/키워드: Adaptive Mechanism

검색결과 585건 처리시간 0.026초

Posterior density estimation for structural parameters using improved differential evolution adaptive Metropolis algorithm

  • Zhou, Jin;Mita, Akira;Mei, Liu
    • Smart Structures and Systems
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    • 제15권3호
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    • pp.735-749
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    • 2015
  • The major difficulty of using Bayesian probabilistic inference for system identification is to obtain the posterior probability density of parameters conditioned by the measured response. The posterior density of structural parameters indicates how plausible each model is when considering the uncertainty of prediction errors. The Markov chain Monte Carlo (MCMC) method is a widespread medium for posterior inference but its convergence is often slow. The differential evolution adaptive Metropolis-Hasting (DREAM) algorithm boasts a population-based mechanism, which nms multiple different Markov chains simultaneously, and a global optimum exploration ability. This paper proposes an improved differential evolution adaptive Metropolis-Hasting algorithm (IDREAM) strategy to estimate the posterior density of structural parameters. The main benefit of IDREAM is its efficient MCMC simulation through its use of the adaptive Metropolis (AM) method with a mutation strategy for ensuring quick convergence and robust solutions. Its effectiveness was demonstrated in simulations on identifying the structural parameters with limited output data and noise polluted measurements.

DSP를 이용한 고장허용을 갖는 신뢰 적응 필터 설계 (Design of Reliable Adaptive Fitter with Fault Tolerance Using DSP)

  • 유동완;이전우;서보혁
    • 대한전기학회논문지:시스템및제어부문D
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    • 제50권1호
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    • pp.8-13
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    • 2001
  • LMS algorithm has been used for plant identifier and noise cancellation. This algorithm has been researched for performance enhancement of filtering. The design and development of a reliable system has been becoming a key issue in industry field because the reliability of a system is considered as an important factor to perform the system's function successfully. And the computing with reliability and fault tolerance is a important factor in the case of aviation, system communication, and nuclear plant. This paper presents design of reliable adaptive filter with fault tolerance. Generally, redundancy is used for reliability. In this case it needs computing or circuit for voting mechanism, or fault detection. Therefore it has simple computing, and practicality for application. And in this paper, reliability of adaptive filter is analyzed. The effectiveness of the proposed adaptive filter is demonstrated to the case studies of plant identifier and noise cancellation by using DSP.

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MRAS Based Speed Estimator for Sensorless Vector Control of a Linear Induction Motor with Improved Adaptation Mechanisms

  • Holakooie, Mohammad Hosein;Taheri, Asghar;Sharifian, Mohammad Bagher Bannae
    • Journal of Power Electronics
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    • 제15권5호
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    • pp.1274-1285
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    • 2015
  • This paper deals with model reference adaptive system (MRAS) speed estimators based on a secondary flux for linear induction motors (LIMs). The operation of these estimators significantly depends on an adaptation mechanism. Fixed-gain PI controller is the most common adaptation mechanism that may fail to estimate the speed correctly in different conditions, such as variation in machine parameters and noisy environment. Two adaptation mechanisms are proposed to improve LIM drive system performance, particularly at very low speed. The first adaptation mechanism is based on fuzzy theory, and the second is obtained from an LIM mechanical model. Compared with a conventional PI controller, the proposed adaptation mechanisms have low sensitivity to both variations of machine parameters and noise. The optimum parameters of adaptation mechanisms are tuned using an offline method through chaotic optimization algorithm (COA) because no design criterion is given to provide these values. The efficiency of MRAS speed estimator is validated by both numerical simulation and real-time hardware-in-the-loop (HIL) implementations. Results indicate that the proposed adaptation mechanisms improve performance of MRAS speed estimator.

농림수산식품분야 정보처리를 위한 적응하는 분기히스토리 길이를 갖는 분기예측 메커니즘 (A Branch Prediction Mechanism With Adaptive Branch History Length for FAFF Information Processing)

  • 고광현;조영일
    • 현장농수산연구지
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    • 제13권1호
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    • pp.3-17
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    • 2011
  • Pipelines of processor have been growing deeper and issue widths wider over the years. If this trend continues, branch misprediction penalty will become very high. Branch misprediction is the single most significant performance limiter for improving processor performance using deeper pipelining. Therefore, more accurate branch predictor becomes an essential part of modem processors for FAFF(Food, Agriculture, Forestry, Fisheries)Information Processing. In this paper, we propose a branch prediction mechanism, using variable length history, which predicts using a bank having higher prediction accuracy among predictions from five banks. Bank 0 is a bimodal predictor which is indexed with the 12 least significant bits of the branch PC. Banks 1,2,3 and 4 are predictors which are indexed with different global history bits and the branch PC. In simulation results, the proposed mechanism outperforms gshare predictors using fixed history length of 12 and 13, up to 6.34% in prediction accuracy. Furthermore, the proposed mechanism outperforms gshare predictors using best history lengths for benchmarks, up to 2.3% in prediction accuracy.

인터넷 차별 서비스 망에서 적응적 연결 수락 제어 메커니즘 (Adaptive Admission Control Mechanism in Differentiated Services Network)

  • 이준화;양미정;이우섭;김상하
    • 대한전자공학회논문지TC
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    • 제40권12호
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    • pp.83-93
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    • 2003
  • IP 망에서의 차별 서비스 구조는 품질 보장 서비스를 위해 대역폭 브로커를 기반으로 QoS프로비저닝의 제어 및 관리를 수행한다. 그러나, 이러한 대역폭 브로커는 모든 입구 에지 노드로 유입되는 호의 연결 수락 제어를 위해 중앙 집중형 자원 관리를 수행함에 따라 확장성 면에서 큰 단점을 갖는다. 본 논문에서는 대역폭 브로커를 갖는 차별 서비스 구조에서 확장성을 높이고 유입되는 호의 상태를 반영한 적응적 연결 수락 제어 메커니즘을 제안하고자 한다. 이를 위해 대역폭 브로커의 기능을 입구 에지 노드와 분리해서 자원 관리 및 프로비저닝을 대역폭 브로커에서 수행하고, 입구 에지 노드에서는 연결 수락 제어를 담당한다. 입구 에지 노드에서는 연결 수락제어를 위해 각 에지 노드간 패스 개념을 도입하고, 패스 단위로 할당된 대역 기반으로 연결 수락 제어를 수행한다. 패스 별 할당 대역량은 유입되는 트래픽에 따라 적응적으로 변화하게 되며 이는 대역록 브로커와의 통신을 최소화하면서 대역 자원의 효율적인 사용을 가능케 한다. 본 논문에서는 이러한 적응적 연결 수락 메커니즘을 제안하고 성능 분석을 통한 효율성 및 확장성의 개선을 제시하고자 한다.

컨텐츠 및 모델의 효과적 관리를 위한 메타-지식 생성 메커니즘 연구 (A Study on Production Mechanism of Meta-Knowledge for Effectively Managing Contents and Models)

  • 김철수
    • 정보처리학회논문지B
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    • 제8B권5호
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    • pp.441-446
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    • 2001
  • 글로벌 네트워크 시대에는 전세계적으로 흩어져 있는 수많은 컨텐츠가 실시간으로 위한 생활의 스며들 것이며 그로 인해 많은 변화를 줄 것이다. 아울러 컨텐츠 및 다양한 모델 제공 업체들의 환경은 급속하게 변화 할 것이다. 인터넷이나 무선 인터넷으로 컨텐츠나 모델들을 적시에 활용할 수 있는 점은 기업측면에서 의사결정 프로세스를 변화시키며, 공급체인 상에서 많은 기업들이 자신들의 의사결정에 필요로 하는 정보나 모델을 짧은 시간에 탄력적으로 제공 받을 수 있어서 기업이 환경변화에 대한 높은 대응력을 갖출수 있게 한다. 이 논문은 컨텐츠와 모델을 필요로 하는 기업들에게 효과적이면서 효율적으로 제공하기 위한 메타지식의 생성 메커니즘을 제안하는 것이다. 그리고 본 논문에서 제안한 메커니즘을 통해서 실험결과를 얻었으며, 그 결과를 가지고 이 논문에서 제시한 탄력적인 컨텐츠나 모델 제공 이론이 인터넷이나 모바일 네트워크에서 요약된 모델 제공과 트래픽 감소 측면에서 매우 우수함을 보이고 있다.

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HomePlug AV 네트워크에서의 성능 향상을 위한 적응적 Contention Window 조절 방식 (Adaptive Contention Window Mechanism for Enhancing Throughput in HomePlug AV Networks)

  • 윤성국;윤정균;김병승;박세웅
    • 한국통신학회논문지
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    • 제33권5B호
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    • pp.318-325
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    • 2008
  • HomePlug AV(HPAV)는 댁내에 깔려있는 전력선을 이용하여 데이터 전송뿐만 아니라 음향과 영상까지 전송을 목표로 HomePlug Alliance에서 제정한 표준이다. 이 표준은 TDMA와 CSMA/CA 기술을 혼합하여 사용하는 MAC 기술을 사용한다. HPAV의 CSMA/CA 프로토콜은 Contention Window(CW)와 Deferral Counter(DC)라는 두 가지 주요한 변수를 가지고 HPAV 네트워크를 제어한다. 본 논문에서는 CW와 DC가 성능에 미치는 영향을 여러 각도에서 조명하였고 이를 기반으로 HPAV MAC의 수율을 높이기 위한 적응적 CW 조절 방식을 제안한다. 여러 실험을 통해 얻은 결과 CW가 DC 보다 수율에 더 민감한 성질을 가지고 있어서 제안하는 방식은 DC는 표준에 정의된 기본값을 사용하고 CW만을 조정한다. 제안하는 방식은 네트워크가 과부하가 걸려있다면 CW를 두 배로 늘려주고 네트워크의 부하가 적으면 CW를 반으로 줄여주는 단순한 방식을 이용함으로 복잡도를 낮춰 구현이 가능하다는 장점이 있다. 모의실험과 수리분석을 통해 제안하는 방식이 여러 다양한 환경에서 좋은 성능을 보이는 것을 확인할 수 있다.

The Mediating Effect of Empathy on the Relationship between Cultural Intelligence and Intercultural Adaptation in Intercultural Service Encounters

  • KONG, Lan Lan;MA, Zhi Qiang;JI, Sung Ho;LI, Jin
    • The Journal of Asian Finance, Economics and Business
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    • 제7권2호
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    • pp.169-180
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    • 2020
  • Globalization has led to a dramatic increase in intercultural service encounters between services providers and customers from diverse cultural backgrounds. This paper explores the causal relationship between service employees‟ cultural intelligence and adaptive sales behavior in intercultural service encounters, and the mediating effect of cognitive and emotional empathy on this relationship. A quantitative survey methodology was utilized to collect data on 341 salespeople at duty-free shops located on Jeju Island, Korea. Data analysis was conducted using SPSS 18 and Amos 18. The results show that cultural intelligence has a significant impact on cognitive empathy, emotional empathy, and adaptive sales behavior. Cognitive empathy has a positive impact on adaptive sales behavior, whereas the relationship between emotional empathy and adaptive sales behavior is not significant. Additionally, cognitive empathy mediates the relationship of cultural intelligence and adaptive sales behavior. This study has useful managerial implications for employee selection, training, and development in service firms engaged in intercultural service encounters. This study extends prior research on intercultural service encounters by exploring the direct impact of cultural intelligence on intercultural adaptation and the mediating effect of empathy, suggesting the presence of a cognitive mechanism that plays a key role in the impact of cultural intelligence on adaptive sales behavior.

아버지의 거친신체놀이, 유아의 정서표현성과 적응적 정서조절의 관계: 아버지 놀이참여태도의 조절된 매개효과 (The Relationship among a Father's Rough-and-Tough Play, Child's Emotional Expressiveness and Adaptive Emotional Regulation: The Moderated Mediation Effect of a Father's Play Participation Attitud)

  • 오지현
    • 한국보육지원학회지
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    • 제19권1호
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    • pp.23-41
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    • 2023
  • Objective: The purpose of this study is to explain in detail the factors of the father's play interaction that predict children's adaptive emotional regulation. This study examined the moderated mediation effect of a father's rough-and-tough play toward a child's emotional expressiveness and the father's play participation attitude on the child's adaptive emotional regulation. Methods: The study participants included 309 fathers of children aged from 3 to 5 years. Data were analyzed using models of the PROCESS Macro. Results: As a result of this research, the relationship of the father's rough-and-tough play with the child's adaptive emotional regulation was that this was indeed mediated by the child's negative emotional expressiveness. Additionally, the father's responsive and fun play attitude moderated the relationship between the father's rough-and-tough play and the child's adaptive emotional regulation. Further, the father's responsive and fun play attitude according to level had a moderated mediation effect. Conclusion/Implications: These results are meaningful in that they derives a mechanism for why and how a father's rough-and-tough play affects children's adaptive emotional regulation.

Adaptive Cross-Device Gait Recognition Using a Mobile Accelerometer

  • Hoang, Thang;Nguyen, Thuc;Luong, Chuyen;Do, Son;Choi, Deokjai
    • Journal of Information Processing Systems
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    • 제9권2호
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    • pp.333-348
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    • 2013
  • Mobile authentication/identification has grown into a priority issue nowadays because of its existing outdated mechanisms, such as PINs or passwords. In this paper, we introduce gait recognition by using a mobile accelerometer as not only effective but also as an implicit identification model. Unlike previous works, the gait recognition only performs well with a particular mobile specification (e.g., a fixed sampling rate). Our work focuses on constructing a unique adaptive mechanism that could be independently deployed with the specification of mobile devices. To do this, the impact of the sampling rate on the preprocessing steps, such as noise elimination, data segmentation, and feature extraction, is examined in depth. Moreover, the degrees of agreement between the gait features that were extracted from two different mobiles, including both the Average Error Rate (AER) and Intra-class Correlation Coefficients (ICC), are assessed to evaluate the possibility of constructing a device-independent mechanism. We achieved the classification accuracy approximately $91.33{\pm}0.67%$ for both devices, which showed that it is feasible and reliable to construct adaptive cross-device gait recognition on a mobile phone.