Reduction of Context Switches due to Task Synchronization in Uniprocessor and Multiprocessor Platform

The problem of frequent context switches in multitasking is a real scheduling overhead which wastes extra CPU cycles, memory and causes much delay in scheduling. This paper focuses on reducing the context switches that result due to blocking when jobs are required to synchronize. The Priority Ceiling Protocol (PCP) is used to synchronize the tasks in uniprocessor as well as multiprocessor platforms. The jobs are scheduled using Earliest Deadline First (EDF) policy. The simulation results show that the context switches are reduced by about 20% on an average using our technique of avoiding context switches due to blocking

A Connection Admission Control Framework for UMTS based Satellite Systems.An Adaptive Admission Control algorithm with pre-emption control mechanism for unicast and multicast communications in satellite UMTS.

In recent years, there has been an exponential growth in the use of multimedia applications. A satellite system offers great potential for multimedia applications with its ability to broadcast and multicast a large amount of data over a very large area as compared to a terrestrial system. However, the limited transmission capacity along with the dynamically varying channel conditions impedes the delivery of good quality multimedia service in a satellite system which has resulted in research efforts for deriving efficient radio resource management techniques. This issue is addressed in this thesis, where the main emphasis is to design a CAC framework which maximizes the utilization of the scarce radio resources available in the satellite and at the same time increases the performance of the system for a UMTS based satellite system supporting unicast and multicast traffic. The design of the system architecture for a UMTS based satellite system is presented. Based on this architecture, a CAC framework is designed consisting of three different functionalities: the admission control procedure, the retune procedure and the pre-emption procedure. The joint use of these functionalities is proposed to allow the performance of the system to be maintained under congestion. Different algorithms are proposed for different functionalities; an adaptive admission control algorithm, a greedy retune algorithm and three pre-emption algorithms (Greedy, SubSetSum, and Fuzzy). A MATLAB simulation model is developed to study the performance of the proposed CAC framework. A GUI is created to provide the user with the flexibility to configure the system settings before starting a simulation. The configuration settings allow the system to be analysed under different conditions. The performance of the system is measured under different simulation settings such as enabling and disabling of the two functionalities of the CAC framework; retune procedure and the pre-emption procedure. The simulation results indicate the CAC framework as a whole with all the functionalities performs better than the other simulation settings

Design and development of smart interoperable electric vehicle supply equipment for electric mobility

The transportation industry at present is moving towards electrification and the number of electric vehicles in the market increased with the different policies of the directorate. Consumers, who wish to contribute to green mobility are concerned about the limited availability of charging points due to high manufacturing costs and the interoperability issues related to smart charging. This work proposes an Internet of things-based low-cost, interoperable smart electric vehicle supply equipment for deploying in all charging stations. The device hardware is designed to monitor, analyze, and collect consumed energy by the vehicle and transfer this data to a connected network. The pre-defined messages associated with the firmware will help to record this data with a remote management server for further processing. The messages are defined in JavaScript Object Notation (JSON), which helps to overcome the interoperability issue. The device is smart because it can gather energy usage, detect device faults, and be intimate with the controller for a better operational environment. The associated management servers and mobile applications help to operate the smart device remotely and keep track of the usage statics. The developed low-cost, interoperable smart model is most suitable for two and three-wheeler vehicles

Dynamic Voltage Scaling With Reduced Frequency Switching And Preemptions

Dynamic Voltage Scaling is an innovative technique for reducing the power consumption of a processor by utilizing its hardware functionality. Dynamic Voltage Scaling processors are mainly focusing on power management. Such processors can be switch between discrete frequency and voltage levels. The main challenges of Dynamic Voltage Scaling are increased number of preemptions and frequency switching. A part of dynamic energy as well as CPU time is lost due to these processes. To limit such processes, an algorithm is proposed which reduces both unwanted frequency switching and preemptions

Technology demonstrator of a novel software defined radio-based aeronautical communications system

YesThis paper presents the architectural design, software implementation, the validation and flight trial results of an aeronautical communications system developed within the Seamless Aeronautical Networking through integration of Data links Radios and Antennas (SANDRA) project funded by the European 7th Framework Aeronautics and Transport Programme. Based on Software Defined Radio (SDR) techniques, an Integrated Modular Radio (IMR) platform was developed to accommodate several radio technologies. This can drastically reduce the size, weight and cost in avionics with respect to current radio systems implemented as standalone equipment. In addition, the modular approach ensures the possibility to dynamically reconfigure each radio element to operate on a specific type of radio link. A radio resource management (RRM) framework is developed in the IMR consisting of a communication manager for the resource allocation and management of the different radio links and a radio adaptation manager to ensure protocol convergence through IP. The IMR has been validated though flight trials held at Oberpfaffenhofen, Germany in June 2013. The results presented in the paper validate the flexibility and scalability of the IMR platform and demonstrate seamless service coverage across different airspace domains through interworking between the IMR and other components of the SANDRA network.European Commissio

Whole genome expression profiles of yeast RNA polymerase II core subunit, Rpb4, in stress and nonstress conditions

Organisms respond to environmental stress by adopting changes in gene expression at the transcriptional level. Rpb4, a nonessential subunit of the core RNA polymerase II has been proposed to play a role in non-stress-specific transcription and in the regulation of stress response in yeast. We find that in addition to the temperature sensitivity of the null mutant of Rpb4, diploid null mutants are also compromised in sporulation and show morphological changes associated with nitrogen starvation. Using whole genome expression analysis, we report here the effects of Rpb4 on expression of genes during normal growth and following heat shock and nutritional starvation. Our analysis shows that Rpb4 affects expression of a small yet significant fraction of the genome in both stress and normal conditions. We found that genes involved in galactose metabolism were dependent on the presence of Rpb4 irrespective of the environmental condition. Rpb4 was also found to affect the expression of several other genes specifically in conditions of nutritional starvation. The general defect in the absence of Rpb4 is in the expression of metabolic genes, especially those involved in carbon metabolism and energy generation. We report that various stresses are affected byRPB4 and that on overexpression the stress-specific activators can partially rescue the corresponding defects

Enhanced production of lupeol through elicitation in in vitro shoot cultures of snake grass (Clinacanthus nutans)

Clinacanthus nutans (Acanthaceae), generally known as ‘snake grass’, has diverse uses in customary system of herbal medicine. The species is endowed with various bioactive compounds exhibiting extensive pharmacological properties. The present investigation focused on elicitor-intervened in vitro shoot biomass cultivation and scale-up production of the anti-cancerous compound ‘lupeol’, one of the foremost constituents in this species. For the augmented production of lupeol, the shoot cultures were elicited with various concentrations of yeast extract (YE), chitosan and methyl jasmonate (MeJA). Maximum shoot biomass yield and production of lupeol was detected in MS medium supplemented with 1.0 mgl-1 BA and 400 mgl-1 YE. The petroleum ether extracts of selected samples upon TLC analysis proved Rf values corresponding to lupeol. HPTLC analysis revealed that the sample treated with YE displayed relatively higher amount (975.50 ng) of lupeol than the in vivo plant (713.69 ng). Hence the in vitro shoot culture system with elicitor (YE) treatment propose an appropriate method for the elevated synthesis of lupeol which can be scaled up via bio-reactor technology in doing so profiting the pharmaceutical appliances

Ec-A: A Task Allocation Algorithm for Energy Minimization in Multiprocessor Systems

With the necessity of increased processing capacity with less energy consumption; power aware multiprocessor system has gained more attention in the recent future. One of the additional challenges that is to be solved in a multi-processor system when compared to uni-processor system is job allocation. This paper presents a novel task dependent job allocation algorithm: Energy centric- Allocation (Ec-A) and Rate Monotonic (RM) scheduling to minimize energy consumption in a multiprocessor system. A simulation analysis is carried out to verify the performance increase with reduction in energy consumption and required number of processors in the system