IRAQI JOURNAL OF COMPUTERS, COMMUNICATIONS, CONTROL AND SYSTEMS ENGINEERING

Pneumatic servo systems are widely used in industrial applications
but they are expensive, so decreasing their cost contribute in decreasing
products manufacturing cost. In this research a pneumatic servo system (PSS)
was designed and implemented using cheap conventional directional control
valve (CDCV) instead of expensive servo or proportional valves. The CDCV
was driven using pulse width modulation (PWM) technique, which was
generated in the LabVIEW program and send to the CDCV via Arduino uno
microcontroller board. A fuzzy PI controller was designed and implemented to
overcome the nonlinearity inherent in air systems, resulting from air
compressibility and dry friction, and the nonlinearity resulting from the use of a
CDCV which is a digital valve. It is found that getting acceptable results
require using PWM technique with frequencies greater than 90 Hz. The results
showed that increasing the applied pressure leads to a significant decrease in
the rising time but accompanied with a noticeable increase in the ripple
amplitude. So, getting accepted results require choosing the applied pressure
experimentally to suit the applied load, since they are affected by the applied
load.

The use of Induction Motor (IM) has been increased becuase of it’s robust
construction , simple design , and low cost . This paper presents a methodology for the
application and performance of Fuzzy like PI Controller to set the frequency of Space
Vector Pulse-Width modualtion (SVPWM) Inverter applied to closed loop speed control of
IM. When the controller is used with current controller, the quadratic component of stator
current is estimated by the controller. Instead of using current controller, this paper
proposes estimating the frequency of stator voltage. The dyanamic modelling of the IM is
presented by dq axis theory. From the simulation results, the superiority of the suggested
controller can be observed in controlling the speed of the three-phase IM.

The recognition and classification of languages represent a vital factor in the
computer interaction. This paper presents Arabic Sign Language recognition, which is
represented as an appealing application. The work in this paper is based on three steps;
preprocessing, feature extraction and classification (Recognition). The statistical features
have been used than the physical features, while Multilayer feed-forward neural network
as classification methods. The recognition percent is 96.33% has been gained over-perform
the earlier works. The simulation has been made by using Matlab 2015b.

Orthogonal Frequency Division Multiplexing is one of the most
important multiple carrier modulation format, which has many applications in
wireless communication and optical communication. It is considered as an
excellent method for fast optical communication inferable from its high spectral
efficiency and its strength to path losses. Peak to average power ratio is
regarded as one of the main problems that are experienced by the optical
orthogonal frequency division multiplexing system, which directly affects the
characteristics of the system. The current paper proposes an efficient technique
to reduce Peak to Average Power Ratio by the modified Dursun’s method or the
so called modified discrete sliding norm transformer in coherent optical
orthogonal frequency division multiplexing system for the first time to the base
of our knowledge consequently. The proposed technique does not need to send
side information to the receiver; also, it does not degrade bandwidth. This
algorithm lessens Peak to Average Power Ratio in the optical coherent
Orthogonal Frequency Division Multiplexing system to about 4.15 dB at
complementary cumulative distribution function (CCDF) probability of 10-3 and
improves the system performance.

High data rate and bandwidth efficiency are the requirements of modern
wireless systems. Most studies introduce different ways to develop communication systems
to meet these requirements. The researches in the last few years focused on the chaotic
system as a chaotic modulation due to its nature. So that the performances of various
chaotic modulation schemes (Initial Condition Modulation (ICM) and Chaotic Shift Keying
(CSK)) in terms of bit error rate (BER), for different spreading factors are implemented in
this article and simulated using MATLAB 2016b simulation. The main objective of this
paper is to make a comparison of various chaotic modulation schemes under AWGN
channel and study the effect of the spreading factor (β) on the performance of different
chaotic modulation schemes, where the spreading factor (β) is the number of generated
chaotic 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 modulation
schemes. The results show that the spreading factor value of (100) achieves good
performance 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 a
little bit enhancement to the system, whilst the processing time will increase dramatically.

Face recognition is one of the most important research fields of the last
two decades. This is due to the actual use of this technology in automatic detection
and monitoring systems. Face attribute and features recognition from images is
still a challenge. In this paper, face image recognition is proposed upon local face
image rather than focusing on the whole image recognition by applying pre-
processing techniques and Viola-Jones method. Principal Component Analysis
(PCA) method is used in order to extract the needed features. Experiments show
satisfied and more accurate results achieved by the proposed system comparing to
the existing systems.

orthogonal frequency division multiplexing (OFDM) is emerging as
the leading technology for high data rates. The OFDM based on multicarrier
transmission that transforms a wideband channel into a group of thin-band
channels. The high peak to average power ratio (PAPR) considers the main
drawback factor in this system, so the companding technique modifies the
amplitude of OFDM signal to reduce this factor. The proposed A-law
companding technique has been implemented in intensity modulation/direct
detection optical orthogonal frequency division multiplexing (IM/DD-
OOFDM). The proposed companding scheme guarantees the improved
performance in terms of bit error rate (BER) and quality factor (QF) while
reducing PAPR effectively and efficiently by modifying the amplitude of the
transmitted signals. Our results confirm that the suggested scheme exhibits a
good ability to reduce PAPR and a good BER performance based on the use the
A 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 of
un-companded signal at best control factor used of A at 87.6, accordingly the
QF is 2.5 dB and the BER is 6.2×10-3 at a distance 900km without any
equalization technique or training sequence or any channel estimation.