Retargeting of existing FORTRAN program and development of parallel compilers

The software models used in implementing the parallelizing compiler for the B-HIVE multiprocessor system are described. The various models and strategies used in the compiler development are: flexible granularity model, which allows a compromise between two extreme granularity models; communication model, which is capable of precisely describing the interprocessor communication timings and patterns; loop type detection strategy, which identifies different types of loops; critical path with coloring scheme, which is a versatile scheduling strategy for any multicomputer with some associated communication costs; and loop allocation strategy, which realizes optimum overlapped operations between computation and communication of the system. Using these models, several sample routines of the AIR3D package are examined and tested. It may be noted that automatically generated codes are highly parallelized to provide the maximized degree of parallelism, obtaining the speedup up to a 28 to 32-processor system. A comparison of parallel codes for both the existing and proposed communication model, is performed and the corresponding expected speedup factors are obtained. The experimentation shows that the B-HIVE compiler produces more efficient codes than existing techniques. Work is progressing well in completing the final phase of the compiler. Numerous enhancements are needed to improve the capabilities of the parallelizing compiler

Analysis of Image Transmission using MIMO-Alamouti Space-Time Encoding

Rapid increase in requirements of high speed transmission of multi-media information resulted in development of MIMO systems. MIMO systems have emerged as the most efficient methodology for the high speed robust data transmission. In this paper, the performance of Alamouti Space-time block coded MIMO system is analysed using the metric of efficient image transmission over the Rayleigh fading channel. The transmitted image is modulated using M-PSK modulation technique, and its reconstructed version is plotted as an output function. Zero-forcing equalization is done for the detection of the original symbols from the received symbols which are influenced by the multipath fading and the channel noise. The results for image transmission using 2×1 and 2×2 Alamouti STBC are evaluated for different SNR values. The inverse relationship between the SNR and BER in the results depict that the high value of SNR and receiver antenna leads to enhanced system efficiency with reduced BER and distortion less recovery of image. It is very evident from the analysis of the received images that as we increase the SNR or the number of the antennas at the receiving side, the quality of the received image improves for the same channel environment. During the analysis, it is also found that increasing the number of bits forming one symbol in M-PSK modulation increase the BER which is undesirable. Thus, trade-off between the number of antenna, SNR and the M value of PSK is an essential requirement for achieving enhanced performance

Guest Editorial Artificial Intelligence and Deep Learning for Intelligent and Sustainable Traffic and Vehicle Management (VANETs)

Intelligence and sustainability are two essential drivers for the development of current and future Intelligent Transportation Systems. On one hand, the complexity of vehicular ecosystems and the inherently risk-prone circumstances under which pedestrian and vehicles coexist call for the endowment of intelligent functionalities in almost all systems and processes participating in such ecosystems. On the other hand, risk may be the most important objective to be guaranteed by the provision of intelligence in ITS, but it is not certainly the only one: when safety is assured, sustainability comes into play, seeking to convey intelligence to the distinct parts composing the ITS landscape with efficiency, minimum carbon footprint, wastage of resources or any other factor affected by the technological empowerment itself

Effective data routing using mobile sinks in disjoint mobile wireless sensor networks

In Mobile WSNs (MWSNs), disjoint clusters could be naturally formed in an unpredictable way that possess the nature of highly dynamic connected and disconnected schema. Many partitions of the network could happen in disjoint mobile wireless sensor networks (DMWSNs), and could last for a significant amount of time that can challenge current routing protocols in crisis-driven and geography-driven applications. We propose in this paper, two new centralized and distributed routing discovery protocols for DMWSN. In the centralized protocol, the static sink controls the motion of mobile sinks. In the distributed protocol, each mobile sink is responsible for collecting data in a specific region. In our work, the mobile sinks need to coordinate among themselves for communication with the base station (BS). The simulation results shows the advantage of our newly proposed protocols in terms of time delay, energy consumed, and the delivery ratio

QoSHVCP: hybrid vehicular communications protocol with QoS prioritization for safety applications

This paper introduces a hybrid communication paradigm for achieving seamless connectivity in Vehicular Ad hoc Networks (VANETs), wherein the connectivity is often affected by changes in the dynamic topology, vehicles' speed, as well as the traffic density. Our proposed technique named QoS-oriented Hybrid Vehicular Communications Protocol (QoSHVCP) exploits both existing network infrastructure through a Vehicle-to-Infrastructure (V2I), as well as a traditional Vehicle-to-Vehicle (V2V) connection that could satisfy Quality-of-Service requirements. QoSHVCP is based on a V2V-V2I protocol switching algorithm, executed in a distributed fashion by each vehicle and is based on the cost function for alternative paths each time it needs to transmit a message. We utilize time delay as a performance metric and present the delay propagation rates when vehicles are transmitting high priority messages via QoSHVCP. Simulation results indicate that simultaneous usage of preexisting network infrastructure along with intervehicular communication provide lower delays, while maintaining the level of user's performance. Our results show a great promise for their future use in VANETs