• Title/Summary/Keyword: LWM

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Reconstruction of Linear Cyclic Codes (미지의 선형 순회부호에 대한 복원기법)

  • Chung, Ha-Bong;Jang, Hwan-Seok;Cho, Won-Chan;Park, Cheal-Sun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.10C
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    • pp.605-613
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    • 2011
  • In most digital communication systems over the noisy channel, some form of forward error correction scheme is employed for reliable communications. If one wants to recover the transmitted message without any knowledge of the error correcting codes employed, it is of utmost importance to figure out and reconstruct the error correcting codes. In this paper, we propose two algorithms of reconstructing linear cyclic codes from the corrupted received bit sequence, one for general linear binary cyclic codes and the other for Reed-Solomon codes. For two algorithms, we ran computer simulations and the performances are shown to be superior to those with the conventional LWM method.

Defect Detection in Laser Welding Using Multidimensional Discretization and Event-Codification (Multidimensional Discretization과 Event-Codification 기법을 이용한 레이저 용접 불량 검출)

  • Baek, Su Jeong;Oh, Rocku;Kim, Duck Young
    • Journal of the Korean Society for Precision Engineering
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    • v.32 no.11
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    • pp.989-995
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    • 2015
  • In the literature, various stochastic anomaly detection methods, such as limit checking and PCA-based approaches, have been applied to weld defect detection. However, it is still a challenge to identify meaningful defect patterns from very limited sensor signals of laser welding, characterized by intermittent, discontinuous, very short, and non-stationary random signals. In order to effectively analyze the physical characteristics of laser weld signals: plasma intensity, weld pool temperature, and back reflection, we first transform the raw data of laser weld signals into the form of event logs. This is done by multidimensional discretization and event-codification, after which the event logs are decoded to extract weld defect patterns by $Na{\ddot{i}}ve$ Bayes classifier. The performance of the proposed method is examined in comparison with the commercial solution of PRECITEC's LWM$^{TM}$ and the most recent PCA-based detection method. The results show higher performance of the proposed method in terms of sensitivity (1.00) and specificity (0.98).

Lightweight Energy IoT Standard Protocol and Test Certification Procedure (에너지 IoT 표준 프로토콜 경량화 및 시험인증절차에 관한 연구)

  • Park, Myunghye;Kim, Younghyun;Myoung, Nogil;Kang, Sukyung;Eun, Changsoo
    • KEPCO Journal on Electric Power and Energy
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    • v.6 no.2
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    • pp.129-135
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    • 2020
  • The standardization of e-IoT (energy Internet of Things) communication and service, which is the energy field of energy, is to define the standard model and to demonstrate the practical model in order to take the lead and occupy the market where new market is created with the latest technology. In particular, detailed technical specifications are defined for developing a framework for IoT technology, the foundation technology of the 4th Industrial Revolution, securing interoperability through standardization, and operating a standard platform. In this paper, we propose a method for e-IoT standard protocol lightening and test certification procedure. The proposed method provides a product implementation method that can solve the problem of low power issue of e-IoT product in the future.

Low Rate VLC Receiver Design Using NCP302 Voltage Detector for IoT/IoL Connected Smart Homes

  • Lee, Beomhee;Mariappan, Vinayagam;Khudaybergenov, Timur;Han, Jungdo;Cha, Jaesang
    • International journal of advanced smart convergence
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    • v.7 no.4
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    • pp.50-56
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    • 2018
  • The Internet of Things (IoT) and Visible Light Communication (VLC) is opening up new services in lighting industry by integrating sensory network features in addition to standard illumination functionality. In this progressive developments, the next generation lighting devices for smart homes are capable to sense the environmental conditions and transfer the captured data through lights to gateway controller to access remotely. The smart home environmental sensor information's are few kbps only so VLC systems need to built-in with low rate light connectivity to transfer data to the gateway. To provide error free communication, the quality of a received light signal is important to be considered when designing an VLC receiver. Therefore, this paper proposes the design of robust low rate IoL receiver design using NCP302 voltage detector for micro controller to adapt the IoT/IoL front end module for system integration. To evaluate the proposed system performance, the Arduino UNO based IoT/IoL controller designed with lighting, sensors and lights connectivity interfaces. The experimental result shows that the robust interference rejection is feasible on proposed VOL receiver and possible to have an error-free communication up to 10 kbps at a low SNR using OOK modulation.