Browsing Electrical Engineering by Publication Date

Now showing items 41-60 of 2495

    • Power system frequency estimation based on simulated annealing: A variable frequency model 

      Soliman, S.A.; Alammari, R.A.; Mantaway, A.H.; El-Hawary, M.E. ( Sharif University of Technology , 2004 , Article)
      This paper presents a new technique for measuring power system frequency, rate of change of frequency and the voltage amplitude and phase angle using the Simulated Annealing (SA) based optimization algorithm. The algorithm ...

    • On-line estimation of transformer model parameters 

      Soliman, S.A.; Alammari, R.A.; Mostafa, M.A. ( IEEE , 2004 , Conference Paper)
      The conventional method for determining the parameters of the transformer is to performing the open and short-circuited tests. The method is only suitable for off-line application. This paper presents an alternative approach ...

    • A Novel Resolver-to-360° Linearized Converter 

      Benammar, Mohieddine; Ben-Brahim, Lazhar; Alhamadi, Mohd A. ( IEEE , 2004 , Article)
      A novel and simple resolver-to-dc converter is presented. It is shown that by appropriate processing of the sine and cosine resolver signals, the proposed converter may produce an output voltage proportional to the shaft ...

    • Average outage duration of multihop communication systems with regenerative relays 

      Yang L.; Hasna , Mazen; Alouini M.-S. ( IEEE , 2005 , Article)
      Closed-form expressions for the average outage duration (AOD) of multihop regenerative communication systems over generalized fading channels are presented. Both noise-limited and interference-limited systems are studied. ...

    • On the capacity of cooperative diversity systems with adaptive modulation 

      Hasna , Mazen ( IEEE , 2005 , Conference Paper)
      In recent years, cooperative diversity systems have gained increased attention in the literature as a new way of combating the effect of signal fading. In this paper, we investigate the performance of these systems when ...

    • Precise, wide-range approximations to arc sine function suitable for analog implementation in sensors and instrumentation applications 

      Benammar, M. ( IEEE , 2005 , Article)
      This paper presents four newly developed algebraic approximations of the inverse sine function, defined for the full [-1,+1] input range. These approximations contain few terms, and have numerical coefficients with low ...

    • A high precision resolver-to-DC converter 

      Benammar, Mohieddine; Ben-Brahim, Lazhar; Alhamadi, Mohd A. ( IEEE , 2005 , Article)
      A newly developed resolver converter, providing a pseudolinear voltage proportional to the shaft angle, is presented. This converter is based on a new concept involving the absolute values of the demodulated sine and cosine ...

    • Channel assignment of microcellular mobile radio networks 

      Abdel-Naby M.; Nofal M.; Khames S.; El-Khoby H.; Hasna , Mazen ( Institute of Electrical and Electronics Engineers Inc. , 2006 , Conference Paper)
      This paper addresses the analytical and simulation modeling of non overlapping microcells with both non-prioritized and prioritized handover schemes. The network performance is analyzed in terms of the analytical results ...

    • A novel converter for sinusoidal encoders 

      Benammar, Mohieddine; Ben-brahim, Lazhar; Alhamadi, Mohd A.; El-Naimi, Mohamed ( IEEE , 2006 , Conference Paper)
      The paper presents a novel and low cost method for determining the angle from sine and cosine signals generated by angular position sensors such as resolvers and sinusoidal encoders. The proposed scheme is based upon the ...

    • A neutral point voltage balancing method for multi-level GTO inverters 

      Ben-Brahim, Lazhar ( IEEE , 2006 , Conference Paper)
      The balancing problem of the DC-link capacitor voltage is inherent in the NPC inverter. It is extremely important to keep the upper and lower DC-link capacitor voltages balanced to guarantee the three level operation of ...

    • Power quality analysis based on fuzzy estimation algorithm: Voltage flicker measurements 

      Al-Kandari, A.M.; Soliman, S.A.; Alammari, R.A. ( Elsevier , 2006 , Article)
      This paper presents a method based on fuzzy linear estimation for voltage flicker measurements. The proposed algorithm uses the digitized samples of the voltage signal at the location where the power quality standards are ...

    • A novel multilevel carrier-based PWM-control method for GTO inverter in low index modulation region 

      Ben-Brahim, Lazhar; Tadakuma, Susumu ( IEEE , 2006 , Article)
      Gate turn offs (GTOs) have an inherent minimum ON-OFF time, which is needed for their safe operation. For GTO-based three-level or neutral-point-clamped (NPC) inverters, this minimum ON-OFF pulsewidth limitation results ...

    • Research in undergraduate education at Qatar University: EE department experience 

      Hasna , Mazen ( IEEE , 2007 , Conference Paper)
      This paper presents the research efforts taking place at Qatar University, the only national university in Qatar. Being a teaching institute, conducting research faces many challenges. The paper focuses on the experience ...

    • Power loading algorithms for SEC diversity schemes 

      Halwani H.A.; Hasna , Mazen; Alouini M.-S. ( IEEE , 2007 , Conference Paper)
      Switch and Examine Combing (SEC) diversity scheme is one of the simplest diversity schemes to combat fading. When the power used for probing the channels in this scheme is fixed, it can be higher than what is actually ...

    • A novel amplitude-to-phase converter for sine/cosine position transducers 

      Benammar, M. ( Taylor and Francis Group , 2007 , Article)
      Resolvers and various other types of sine/cosine encoders are used for both angular and linear position sensing. These devices provide analogue signals in the form of the sine and the cosine of an angle related to the ...

    • A new angle determination method for resolvers 

      Ben-Brahim, Lazhar; Benammar, Mohieddine; Alhamadi, Mohd; Al-Emadi, Nasser; Al-Hitmi, Mohammed ( IEEE , 2008 , Conference Paper)
      A new low cost method for converting the amplitudes of the sine/cosine signals generated by the resolver into a measure of the angle of its shaft. The new method operates without lookup tables (LUT), and takes advantage ...

    • A novel method for estimating the angle from analog co-sinusoidal quadrature signals 

      Benammar, Mohieddine; Ben-brahim, Lazhar; Alhamadi, Mohd A.; Al-Naemi, Mohamed ( Elsevier , 2008 , Article)
      The paper presents a new low cost and accurate method for determining the angle from sine and cosine signals produced by resolvers and sinusoidal encoders. In the proposed scheme, multiple phase-shifted sinusoids (PSS) are ...

    • Effects of Post and Early Selection on SEC Based Transmit Diversity Systems with Linear Power Loading 

      Hasna, M.O.; Yang, Hong-Chuan; Alouini, Mohamed-Slim ( IEEE , 2008 , Conference Paper)
      Switch and examine combing (SEC) diversity scheme provides a lowest-complexity closed-loop transmit diversity solution. Furthermore, by probing sequentially available branches with different power loading levels, the SEC ...

    • Comparison of relaying strategies for cooperative diversity systems with adaptive modulation 

      Choi, Seyeong; Alouini, M.-S.; Yang, Hong-Chuan; Hasna, M.O. ( IEEE , 2009 , Conference Paper)
      In this paper, we propose several relay selection schemes for cooperative diversity systems with adaptive transmission. The proposed schemes are based on dual-hop relaying with multiple relays. We analyze the performance ...

    • Performance of relay-assisted soft handover 

      Tourki K.; Alouini M.-S.; Hasna , Mazen ( IEEE , 2009 , Conference Paper)
      This paper examines the effect of relay-assisted soft handover on the performance of the uplink communication in the third generation mobile networks. We focus on users which are traveling over two cell boundaries in a ...