Badlishah Ahmad

Simulation and analysis of LEACH for wireless sensor networks in agriculture

The challenges in deploying robust wireless sensor networks WSNs in agricultural environments are limited power supply and variability of wireless propagation channel that restrict performance. Proposed protocols do not meet the challenges for realistic simulation and evaluation of WSN for agricultural applications. The design of LEACH protocol is, for the most part, efficient for many applications. It achieves energy efficiency through a clustering technique with TDMA based MAC layer algorithms and data aggregation method. Analysis performed shows that LEACH uses simple radio propagation and energy models that are unrealistic. This paper focuses on the performance analysis of LEACH protocol for agricultural environments.

Subtractive Fuzzy Classifier Based Driver Distraction Levels Classification Using EEG

[Purpose] In earlier studies of driver distraction, researchers classified distraction into two levels (not distracted, and distracted). This study classified four levels of distraction (neutral, low, medium, high). [Subjects and Methods] Fifty Asian subjects (n=50, 43 males, 7 females), age range 20–35 years, who were free from any disease, participated in this study. Wireless EEG signals were recorded by 14 electrodes during four types of distraction stimuli (Global Position Systems (GPS), music player, short message service (SMS), and mental tasks). We derived the amplitude spectrum of three different frequency bands, theta, alpha, and beta of EEG. Then, based on fusion of discrete wavelet packet transforms and fast fourier transform yield, we extracted two features (power spectral density, spectral centroid frequency) of different wavelets (db4, db8, sym8, and coif5). Mean ± SD was calculated and analysis of variance (ANOVA) was performed. A fuzzy inference system classifier was applied to different wavelets using the two extracted features. [Results] The results indicate that the two features of sym8 posses highly significant discrimination across the four levels of distraction, and the best average accuracy achieved by the subtractive fuzzy classifier was 79.21% using the power spectral density feature extracted using the sym8 wavelet. [Conclusion] These findings suggest that EEG signals can be used to monitor distraction level intensity in order to alert drivers to high levels of distraction.

Fuzzy logic control based adaptive media playout design approach for video streaming

Adaptive media playout (AMP) control, common receiver-based technique, is proposed to adjust the playout rate based on the bit-rate fluctuation of network channels to avoid playout interruptions. Most AMP techniques found in the literature adjust playout frame rate based on the buffer fullness or the buffer fullness variation. However, choosing an appropriate threshold to adjust a playout frame rate is challenging due to fluctuation in the channels quality and its unpredictable video bitrate. In this research, a new AMP control, based on fuzzy logic control, is proposed as a solution to avoid video stream interruption and the challenge of choosing an appropriate threshold. The new Fuzzy Logic Adaptive Media Playout (FLAMP) control is designed based on buffer fullness and its variation. The FLAMP is expected to constrict the buffer outage probability and improve the video playback smoothness.

A hybrid chaos and neural network cipher encryption algorithm for compressed video signal transmission over wireless channel

In this paper, a hybrid framework of compressed and encrypted video signal transmission over wireless channel has been designed and implemented. Chaos theory property has been combined with artificial neural network to construct a cipher algorithm called a Chaotic Neural Network (CNN). This algorithm has been embedded and integrated inside MPEG-2 video codec standard to transform the plaintext (compressed video data) into an unintelligible form. The resultant compressed and encrypted bitstream has been transmitted from source to destination by using Orthogonal Frequency Division Multiplexing (OFDM) modulation technique. The effect of wireless channel condition has been investigated for both AWGN and Rayleigh fading channel. A video signal sample of size 176 × 144 (QCIF standard format) with rate of 30 frame per second has been used for test and simulate the overall system model framework performance. MATLAB software package has been used for system model framework implementation. The proposed framework is flexible and has ability to control output video quality, bit rate, and group of picture (GOP) number and their arrangement. Subjective and objective measurements have been used for overall system model performance evaluation. Results indicate high sensitivity behavior for both key and plaintext modification with high entropy result value.

SIGNIFICANCE OF THE ELECTROMYOGRAPHIC ANALYSIS OF THE UPPER LIMB MUSCLES OF CRICKET BOWLERS: RECOMMENDATIONS FROM STUDIES OF OVERHEAD-THROWING ATHLETES

The purpose of this study was twofold: (i) to review the existing literature on electromyographic (EMG) analysis of the upper limb muscles of present overhead-throwing (OT) athletes during throwing and of cricket bowlers (CBs) during cricket bowling (CB) and, (ii) to discuss the importance of and generate recommendations for the EMG assessment of the muscle activity of CBs with respect to previous studies of OT athletes. A literature search of the PubMed, Scopus and Google Scholar electronic databases was performed to identify relevant articles published up to December 2012. This search was performed to evaluate the following areas, (i) what are the upper limb muscles that should be evaluated during OT sports and cricket bowling? (ii) what types of EMG methodologies have been used? (iii) what are the anthropometric, performance and physical functional variables that are usually selected? and (iv) what recommendations can be made for the assessment of the muscle activity of CBs? The search identifies 32 publications on OT athletes and 4 on CBs. The results note the following conclusions: (i) there are relatively few CB-related papers that utilize EMG, particularly for the assessment of muscle activity and coordination, (ii) a total of 22 upper limb muscles were investigated using EMG (from both criteria), (iii) surface electrodes are used more frequently than needle electrodes, (iv) most of the article normalized and analyzed the EMG amplitudes than the frequency, and the data was more often analyzed through a descriptive statistical analysis and (v) the majority of the studies analyzed the right limb of physically normal (uninjured) males both the amateur and professional athletes that were 20 to 29 years of age. Finally, the published evidence on CBs is inadequate to validate a sound recommendation for the assessment of the muscles of CBs using EMG. However, the studies on OT athletes do provide guidelines that can be used to analyze CBs. The overall conclusion of this review show that, further studies are needed to evaluate the efficacy of EMG for the assessment of the upper limb muscle of CBs to ultimately identify and prevent injury which is still a matter of discussion in the sports medicine community.

Effects of anthropometric variables and electrode placement on the SEMG activity of the biceps brachii muscle during submaximal isometric contraction in arm wrestling.

Abstract Surface electromyography (SEMG) has been widely used to analyze the biceps brachii (BB) muscle during voluntary contraction, and the effect of the interelectrode distance has been studied. However, the effect of anthropometric variations and the placement of electrodes on the BB activity during arm wrestling (i.e., during isometric contraction at a submaximal intensity) has seldom been investigated. In this study, the BB strength throughout this type of static contraction was evaluated. The SEMG signals were recorded from three locations on the BB: the muscle belly (M), near proximal (P), and distal tendon (L) regions. Twenty subjects who participated in the experiment were divided into five groups (A, B, C, D, and E). The average SEMG, root mean square, and variability of the signal were calculated using the coefficient of variance. The results indicated that the M region was more active and exhibited increased signal consistency (10.91%) compared with the other two regions (P: 24.47% and L: 19.13%). Significant differences were observed between the L and P regions and between the M and P regions (p<0.05); however, there were no differences between the M and L regions (p>0.05). The increase in the SEMG value in groups B and C was significant (p<0.05), whereas groups A, D, and E did not exhibit a significant increase (p>0.05). In addition, muscle size was the strongest predictor of strength compared with body weight and height. The results suggest that the M region displays considerable SEMG effects and signal reliability. Furthermore, the SEMG measurements were found to correlate strongly with the strength of the contractions and the muscle size, and not with weight and height.

Synthesis of Finite Length Multi Level Sequences for Clutter Rejection in Radar

In radar systems the very low side-lobes that can be achieved with amplitude and phase modulated pulse trains make their use particularly attractive in systems requiring a large dynamic range. Moreover, the excellent self-clutter rejection performance is obtained without sacrificing the ability for the separation of close targets (no main lobe widening). The additional expense of encoding and decoding in amplitude and phase may be justified for radars that must cope with land clutter or operate in a dense-target environment. This paper presents a method for generating finite length multi-level sequences of large lengths that have low side-lobe energy in their autocorrelation function. It is shown that energy ratio of multilevel sequences that have low side lobe energy, is improved through the process of clipping. The proposed method generates sequences with low side lobe energy and large energy ratio of any desired length starting from sequences of smaller length.

A Congestion Control Optimal Model Design Perspectives of Non-safety Applications on Vehicular Ad Hoc Networks: A Survey of Requirements, Protocols, and Challenges

The issues of congestion control on non-safety applications in vehicular ad hoc networks (VANETs) have received considerable crucial attention in the field of intelligent transport systems (ITS). The critical challenges of ITS applications are in the events of intermittent connectivity and data collisions. Another challenge is the event-driven effect on both safety and non-safety applications that are critically relied on delay and reliability. So far, the development of protocol stacks for VANETs implies the WAVE protocol other IEEE 802.11p MAC protocol. Based on IEEE 802.11p MAC protocol standard in the 5.9 GHz band (other similar protocols such as C2C-CC for European and CALM from ISO) in which adopt of vehicle manufacturers of Information Communication Technology (ICT) to address the safety systems, emergency (breakdown, SOS), traffic control, environmental, navigational, and tracking. Little attention has been given to non-safety applications, for instance, chat, twitter, SMS, internet services, video-on-the-go, etc. Besides, roadside-vehicle communications (RVC) caters for information concerning repair notifications, remote diagnostics, context information, navigation information, and alerts system. In this survey, we present a framework that proposes a guideline and recommendation for the congestion control mechanism perspectives in VANETs. In particular, researches are centered on the investigation of the mobility model of congestion control algorithms. Finally, this survey contributes to appropriate knowledge and challenges in legacy congestion control of VANETs and toward the future research development.

Hybrid (OCDMA/WDM) system using EDFA for optical access networks

This paper represents the hybrid system performance compare to different bit rate with direct detection techniques. Implementation of EDFA in hybrid system which is increasing the fiber distance for subscriber requirement for high connectivity and speed data transmission. We have to used Modified Double Weight (MDW) code as signature code for flexible, scalable together enhance the performance and improve the security of the system. Proposed hybrid system provides high bandwidth for the immense users. The different detection techniques apply to increased capacity, accuracy and ability to operate simultaneously. The result shows that using EDFA provides 2.5×−10 BER at distance 6km where without EDFA 3.6×10−07. According to the analysis results, the proposed direct detection technique improves the signal quality with low optimum gain of the system. Thus, this system is considered as encouraging solution for the optical access network.

Dispersion flattened low loss hybrid octa-circular porous core fiber for THz wave guiding

This manuscript represents a hybrid type porous core photonic crystal fiber for THz propagation. The proposed fiber has showed excellent waveguide properties regarding Effective Material Loss (EML) and near zero flat dispersion. The reported EML is considerably low with a long range of near zero flat dispersion characteristics. The proposed hybrid design consists of a circular core with central air hole and octagonal cladding having only circular air holes. Different waveguide properties of the fiber have been reported for different core diameter and porosity of the core. The confinement loss, effective area, power fraction of the proposed fiber also has been reported. The waveguide has exhibited a low EML of 0.02623 cm−1 at 1THz frequency for 60% porosity and 350µm core diameter with 1.0-3.0 THz near zero flat dispersion of 0.4±0.0405 ps/THz/cm. The proposed porous fiber is efficient for broadband transmission of THz radiation.