Current Issue : July - September Volume : 2013 Issue Number : 3 Articles : 6 Articles
As the scale of integration goes on increasing, it is desirable to have efficient communication strategies for System on Chip (SoC). Network on Chip (NoC) is new paradigm shift from conventional bus based communication to on chip communication. It provides the features such as flexibility, scalability, low power consumption and better performance in comparision with traditional interconnect architecture. The most important part of Network on Chip (NoC) is router design which is responsible to transmit message form source point to destination point. Different packet switching techniques have been proposed for on chip router structure. This paper gives brief review of router structure for on chip communication...
This paper presents modelling results for H.26x video traffic generated by popular videoconference software applications. The analysis of videoconference data, that were measured during realistic point-point videoconference sessions, led us to the general conclusion that the traffic can be distinguished into two categories: unconstrained and constrained. In the unconstrained traffic, there is a direct relation between the encoder and the form of the frequency histogram of the frame-size sequence. Moreover, for this type of traffic, strong correlations between successive video frames can be found. On the other hand, where bandwidth constraints are imposed during the encoding process, the generated traffic appears to exhibit similar characteristics for all the examined encoders with the very low autocorrelation values being the most notable one. On the basis of these results, this study proposes methods to calculate the parameters of a widely adopted autoregressive model for both types of traffic....
In previous studies classification algorithms were employed successfully for the detection of unknown malicious code. Most of these studies extracted features based on byte n-gram patterns in order to represent the inspected files. In this study we represent the inspected files using MLI n-gram patterns which are extracted from the files after disassembly. The MLI n-gram patterns are used as features for the classification process. The classification process main goal is to detect unknown malware within a set of suspected files which will later be included in antivirus software as signatures. A rigorous evaluation was performed using a test collection comprising of more than 36,500 files, in which various settings of MLI n-gram patterns of various size representations and eight types of classifiers were evaluated. A typical problem of this domain is the imbalance problem in which the distribution of the classes in real life varies. It has been observed that class imbalance may produce an important deterioration of the performance achieved by existing learning and classification systems. This situation is often found in real-world data describing infrequent but important cases. We investigated the imbalance problem, referring to several real-life scenarios in which malicious files are expected to be about 15% of the total inspected files. Lastly, we present a chronological evaluation in which the frequent need for updating the training set was evaluated. Evaluation results indicate that the evaluated methodology achieves a level of accuracy higher. Which slightly improves the results in previous studies that use byte n-gram representation?...
The fast growing popularity of smartphones and tablets enables us to use various intelligent mobile applications. As many of\r\nthose applications require position information, smart mobile devices provide positioning methods such as Global Positioning\r\nSystem (GPS),WiFi-based positioning system (WPS), or Cell-ID-based positioning service. However, those positioning methods\r\nhave different characteristics of energy-efficiency, accuracy, and service availability. In this paper, we present an Energy-Efficient\r\nCollaborative and Opportunistic Positioning System (ECOPS) for heterogeneous mobile devices. ECOPS facilitates a collaborative\r\nenvironment where many mobile devices can opportunistically receive position information over energy-efficient and prevalent\r\nWiFi, broadcasted from a few other devices in the communication range. The position-broadcasting devices in ECOPS have\r\nsufficient battery power and up-to-date location information obtained fromaccurate but energy-inefficient GPS.Aposition receiver\r\nin ECOPS estimates its location using a combination of methods including received signal strength indicators and 2D trilateration.\r\nOur field experiments showthat ECOPS significantly reduces the total energy consumption of deviceswhile achieving an acceptable\r\nlevel of location accuracy. ECOPS can be especially useful for unique resource scarce, infrastructureless, and mission critical\r\nscenarios such as battlefields, border patrol, mountaineering expeditions, and disaster area assistance....
The effect of self-interference due to the increase of spatial correlation in a MIMO channel has become one of the limiting factors\r\ntowards the implementation of future network downlink transmissions. This paper aims to reduce the effect of self-interference\r\nin a downlink multiuser- (MU-) MIMO transmission by exploiting the available spatial and frequency diversity. The subcarrier\r\nallocation scheme can exploit the frequency diversity to determine the self-interference from the ESINR metric, while the spatial\r\ndiversity can be exploited by introducing the partial feedback scheme, which offers knowledge of the channel condition to the base\r\nstation and further reduces the effect before the allocation process takes place. The results have shown that the proposed downlink\r\ntransmission scheme offers robust bit error rate (BER) performance, even when simulated in a fully correlated channel, without\r\nimposing higher feedback requirements on the base controller....
This paper presents wireless sensing systems to increase safety and robustness in industrial process control, particularly in industrial machines for marble slab working. The process is performed by abrasive or cutting heads activated independently by the machine controller when the slab, transported on a conveyer belt, is under them. Current slab detection systems are based on electromechanical or optical devices at the machine entrance stage, suffering from deterioration and from the harsh environment. Slab displacement or break inside the machine due to the working stress may result in safety issues and damages to the conveyer belt due to incorrect driving of the working tools. The experimented contactless sensing techniques are based on four RFID and two capacitive sensing technologies and on customized hardware/software. The proposed solutions aim at overcoming some limitations of current state-of-the-art detection systems, allowing for reliable slab detection, outside and/or inside the machine, while maintaining low complexity and at the same time robustness to industrial harsh conditions. The proposed sensing devices may implement a wireless or wired sensor network feeding detection data to the machine controller. Data integrity check and process control algorithms have to be implemented for the safety and reliability of the overall industrial process....
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