Accepted Papers

  • THE ROLE OF SECURITY IN DISTRIBUTED SYSTEMS
    Nojoom Al-Najem and Eman Harbi, King Saud University, KSA
    ABSTRACT

    Security is one of the leading things in developing and evaluating distributed systems. Developing a secure distributed system is a hard task without knowing sufficient related secure-based knowledge even for controlling and managing such system security. Therefore, this paper is dedicated to present the role of security in distributed systems. It intends to discuss the importance of security and its objectives in distributed systems. It also aims to review some of security risks and threats in distributed systems and then to provide some ways of implementing security in distributed systems.

  • PAPR REDUCTION USING COMBINATION OF PCM AND ADOPTIVE POWER REDUCTION TECHNIQUE
    KiranV1, Sudha K L2 and Vinila Nagarj3, 1 & 2Assistant Professor, Dept.ECE, RVCE, Bangalore and 3Professor, Dept.ECE, DSCE, Bangalore
    ABSTRACT

    Orthogonal Frequency Division Multiplexing has been adopted as standard from 4G because of the increased high bit rate transmission, bandwidth efficiency under frequency selective fading channel. Orthogonal Frequency Division Multiplexing has been adopted as standard from 4G, as a number of subcarriers used in OFDMincrease the data rate,it also increases the peak average power ratio.

    The increased PAPR introduces non-linearity through non-linear power amplifier in the system. It is unwanted and decreases the system throughput & efficiency. To meet the data rate demand OFDM system may drive number of subcarriers so it is required to alleviate the high PAPR that appears. In view of BER and additional side information many techniques have been developed.

    Pulse cancelling is one among the other power reduction techniques. This paper proposes a method which combines both PCM and adoptive power reduction technique which reduces the PAPR by maintaining BER.

  • CODEBOOK DESIGN STRATEGIES FOR MMO-OFDM DOWNLINK SYSTEMS WITH ZF-BF
    Najoua ACHOURA1 and Ridha BOUALLEGUE2, 1Department National Engineering School of Tunis, Innov’Com Laboratory, Tunisia and 2High School of Communication of Tunis, SUP’COM, Innov’Com Laboratory,Tunisia
    ABSTRACT

    Using the Channel State Information (CSI) at the transmitter is fundamental for the precoder design in Multi-user Multiple Input Single Output (MU-MISO-OFDM) systems. In Frequency Division Duplex (FDD) systems, CSI can be just available at the transmitter through a limited feedback channel [1], where we assume that each user quantizes its channel direction with a finite number of quantization bits. In this paper, we consider a scalar quantization (SQ) scheme of the Channel Direction Information (CDI). Although vector quantization (VQ) schemes [2], [3] still outperform this scalar scheme in terms of quantization error and Sum rate, the former scheme suffers from an exponential search complexity and high storage requirements at the receiver for high number of feedback bits.

  • FAULT DIAGNOSIS IN BRAKING SYSTEM OF MINE HOIST BASED ON THE MOMENT CHARACTERISTICS
    Li Juanjuan1, Wang Aiming1, Meng Guoying1, Xie Guangming2, Wang Shuai1, Jia Yifan1, 1School of Mechanical Electronic &Information Engineering, China University of Mining and Technology (Beijing) and 2College of Engineering, Peking University
    ABSTRACT

    Fault diagnosis method based on the moment characteristic of system pressure data is presented in this paper. Using AMESim simulation technology, three typical faults of the brake system are studied. After the moment and the percentile characteristics of the pressure curve of the hydraulic system are extracted and used as characteristic parameter, fault information is diagnosed effectively using the BP neural network. The problem that the signal is not synchronized and the characteristic parameters can not be obtained accurately are overcome. It provides some theoretical basis for the intelligent diagnosis and predictive maintenance of the high speed deep well hoist.