Amer Abed Mansour; Walaa Mousa Hashim; Abbas Abdul Wahab Muhammad
Volume 18, Issue 3 , December 2018, Page 1-11
Abstract
Pneumatic servo systems are widely used in industrial applicationsbut they are expensive, so decreasing their cost contribute in decreasingproducts manufacturing cost. In this research a pneumatic servo system (PSS)was designed and implemented using cheap conventional directional controlvalve (CDCV) ...
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Pneumatic servo systems are widely used in industrial applicationsbut they are expensive, so decreasing their cost contribute in decreasingproducts manufacturing cost. In this research a pneumatic servo system (PSS)was designed and implemented using cheap conventional directional controlvalve (CDCV) instead of expensive servo or proportional valves. The CDCVwas driven using pulse width modulation (PWM) technique, which wasgenerated in the LabVIEW program and send to the CDCV via Arduino unomicrocontroller board. A fuzzy PI controller was designed and implemented toovercome the nonlinearity inherent in air systems, resulting from aircompressibility and dry friction, and the nonlinearity resulting from the use of aCDCV which is a digital valve. It is found that getting acceptable resultsrequire using PWM technique with frequencies greater than 90 Hz. The resultsshowed that increasing the applied pressure leads to a significant decrease inthe rising time but accompanied with a noticeable increase in the rippleamplitude. So, getting accepted results require choosing the applied pressureexperimentally to suit the applied load, since they are affected by the appliedload.
Farazdaq R. Yaseen; Walaa H. Nasser
Volume 18, Issue 3 , December 2018, Page 12-25
Abstract
The use of Induction Motor (IM) has been increased becuase of it’s robustconstruction , simple design , and low cost . This paper presents a methodology for theapplication and performance of Fuzzy like PI Controller to set the frequency of SpaceVector Pulse-Width modualtion (SVPWM) Inverter applied ...
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The use of Induction Motor (IM) has been increased becuase of it’s robustconstruction , simple design , and low cost . This paper presents a methodology for theapplication and performance of Fuzzy like PI Controller to set the frequency of SpaceVector Pulse-Width modualtion (SVPWM) Inverter applied to closed loop speed control ofIM. When the controller is used with current controller, the quadratic component of statorcurrent is estimated by the controller. Instead of using current controller, this paperproposes estimating the frequency of stator voltage. The dyanamic modelling of the IM ispresented by dq axis theory. From the simulation results, the superiority of the suggestedcontroller can be observed in controlling the speed of the three-phase IM.
Jabbar Salman; Thamir Rashed Saeed; Alaa Hussein Ali
Volume 18, Issue 3 , December 2018, Page 26-32
Abstract
The recognition and classification of languages represent a vital factor in thecomputer interaction. This paper presents Arabic Sign Language recognition, which isrepresented as an appealing application. The work in this paper is based on three steps;preprocessing, feature extraction and classification ...
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The recognition and classification of languages represent a vital factor in thecomputer interaction. This paper presents Arabic Sign Language recognition, which isrepresented as an appealing application. The work in this paper is based on three steps;preprocessing, feature extraction and classification (Recognition). The statistical featureshave been used than the physical features, while Multilayer feed-forward neural networkas classification methods. The recognition percent is 96.33% has been gained over-performthe earlier works. The simulation has been made by using Matlab 2015b.
Liqaa A. Al-Hashime; Sinan M. Abdul Satar; Ghaida A. AL-Suhail
Volume 18, Issue 3 , December 2018, Page 33-42
Abstract
Orthogonal Frequency Division Multiplexing is one of the mostimportant multiple carrier modulation format, which has many applications inwireless communication and optical communication. It is considered as anexcellent method for fast optical communication inferable from its high spectralefficiency and ...
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Orthogonal Frequency Division Multiplexing is one of the mostimportant multiple carrier modulation format, which has many applications inwireless communication and optical communication. It is considered as anexcellent method for fast optical communication inferable from its high spectralefficiency and its strength to path losses. Peak to average power ratio isregarded as one of the main problems that are experienced by the opticalorthogonal frequency division multiplexing system, which directly affects thecharacteristics of the system. The current paper proposes an efficient techniqueto reduce Peak to Average Power Ratio by the modified Dursun’s method or theso called modified discrete sliding norm transformer in coherent opticalorthogonal frequency division multiplexing system for the first time to the baseof our knowledge consequently. The proposed technique does not need to sendside information to the receiver; also, it does not degrade bandwidth. Thisalgorithm lessens Peak to Average Power Ratio in the optical coherentOrthogonal Frequency Division Multiplexing system to about 4.15 dB atcomplementary cumulative distribution function (CCDF) probability of 10-3 andimproves the system performance.
Suha Irfan Abdulrahman; Atheer Alaa Sabri; Faez Fawwaz Shareef
Volume 18, Issue 3 , December 2018, Page 43-51
Abstract
High data rate and bandwidth efficiency are the requirements of modernwireless systems. Most studies introduce different ways to develop communication systemsto meet these requirements. The researches in the last few years focused on the chaoticsystem as a chaotic modulation due to its nature. So that ...
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High data rate and bandwidth efficiency are the requirements of modernwireless systems. Most studies introduce different ways to develop communication systemsto meet these requirements. The researches in the last few years focused on the chaoticsystem as a chaotic modulation due to its nature. So that the performances of variouschaotic modulation schemes (Initial Condition Modulation (ICM) and Chaotic Shift Keying(CSK)) in terms of bit error rate (BER), for different spreading factors are implemented inthis article and simulated using MATLAB 2016b simulation. The main objective of thispaper is to make a comparison of various chaotic modulation schemes under AWGNchannel and study the effect of the spreading factor (β) on the performance of differentchaotic modulation schemes, where the spreading factor (β) is the number of generatedchaotic signal samples during the bit period (Tb). Different values of spreading factor (12,16, 20, 40, 60, 80, and 100) samples are selected to implement various chaotic modulationschemes. The results show that the spreading factor value of (100) achieves goodperformance for all types of chaotic modulation schemes which are implemented here.Increasing the value of spreading factor over (100) such as (120, 140, and 180) will add alittle bit enhancement to the system, whilst the processing time will increase dramatically.
Suhad Ibrahim Mohammed; Noor Abdulmuttaleb Jaafar; Kilan Mohammed Hussien
Volume 18, Issue 3 , December 2018, Page 52-59
Abstract
Face recognition is one of the most important research fields of the lasttwo decades. This is due to the actual use of this technology in automatic detectionand monitoring systems. Face attribute and features recognition from images isstill a challenge. In this paper, face image recognition is proposed ...
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Face recognition is one of the most important research fields of the lasttwo decades. This is due to the actual use of this technology in automatic detectionand monitoring systems. Face attribute and features recognition from images isstill a challenge. In this paper, face image recognition is proposed upon local faceimage rather than focusing on the whole image recognition by applying preprocessingtechniques and Viola-Jones method. Principal Component Analysis(PCA) method is used in order to extract the needed features. Experiments showsatisfied and more accurate results achieved by the proposed system comparing tothe existing systems.
Ali n. Kareem; Sinan M. Abdul Satar; Mohammed A. Husein
Volume 18, Issue 3 , December 2018, Page 60-69
Abstract
orthogonal frequency division multiplexing (OFDM) is emerging asthe leading technology for high data rates. The OFDM based on multicarriertransmission that transforms a wideband channel into a group of thin-bandchannels. The high peak to average power ratio (PAPR) considers the maindrawback factor in ...
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orthogonal frequency division multiplexing (OFDM) is emerging asthe leading technology for high data rates. The OFDM based on multicarriertransmission that transforms a wideband channel into a group of thin-bandchannels. The high peak to average power ratio (PAPR) considers the maindrawback factor in this system, so the companding technique modifies theamplitude of OFDM signal to reduce this factor. The proposed A-lawcompanding technique has been implemented in intensity modulation/directdetection optical orthogonal frequency division multiplexing (IM/DDOOFDM).The proposed companding scheme guarantees the improvedperformance in terms of bit error rate (BER) and quality factor (QF) whilereducing PAPR effectively and efficiently by modifying the amplitude of thetransmitted signals. Our results confirm that the suggested scheme exhibits agood ability to reduce PAPR and a good BER performance based on the use theA factor. At the complementary cumulative distribution function (CCDF) of 10-3, the PAPR value of our proposed scheme is about 4.4 dB lower than those ofun-companded signal at best control factor used of A at 87.6, accordingly theQF is 2.5 dB and the BER is 6.2×10-3 at a distance 900km without anyequalization technique or training sequence or any channel estimation.