Computer mediated communication for social and academic purposes: Profiles of use and University students’ gratifications

The present study approaches the Internet as a social space, where university students make use of computer mediated communication (CMC) applications, i.e. e-mail, instant messaging and social network sites, in order to satisfy social and academic needs. We focus on university students, because they represent one of the most avid groups of CMC users and additionally, because they are expected to carry their perceptions of media with them into the work place and their social life. In order to investigate this issue, we conducted an empirical research using, as a target group, a sample of students from a specific Greek University. Grounded in the “uses and gratifications” perspective, we investigated the various profiles of CMC use by students along with (a) the students’ perceptions about social and academic usefulness of CMC applications, (b) the extent up to which these perceptions are correlated with students’ prior experience with the use of CMC applications, and (c) how both of these factors can predict the frequency of present use of CMC for social or academic purposes respectively. The results reveal that although these three CMC applications constitute “functional alternatives” (media that satisfy similar needs) they are different to the degree of their “functionality” for the gratification of social and academic needs. Furthermore, the degree of CMC use by students is not correlated with the years of CMC experience, but with the profile of use that students dynamically adopt according to their daily needs and preferences. The results provide evidence for the current CMC use by university students and can be useful for the implementation of further academic policies regarding CMC use in Higher Education settings.     

Nanoscale electrical characterization of ultrathin high-k dielectric MOS stacks: A conducting AFM study

Extreme scaling in both silicon and alternative channel CMOS has highlighted the importance of localized characterization on the nanometer scale. We have used a conductive-contact atomic force microscopy (C-AFM) technique in ultra high vacuum (UHV) conditions to analyze and compare intrinsic stack degradation mechanisms leading to breakdown (BD) for ultrathin high-k dielectric films of (4 nm) Hf_xSiO_y/SiO₂ on Si and (2 nm) ZrO₂/GeO₂ on Ge. Simultaneous nanoscale current–voltage I–V characteristics, topography, tunneling current and relative tip–surface contact interactions as normal and lateral force maps revealed localized injected charge dependence on electrical stress. It is shown that the charge can propagate laterally. Successive voltage scanning is related to the overall post-BD conductivity for pre- to post-BD degradation propagation. In contrast with SiO₂ interface, an increased GeO₂ interlayer reactivity yielding more active interface defects is suggested.     

Test pattern generation and partial-scan methodology for an asynchronous SoC interconnect

Asynchronous design offers a solution to the interconnect problems faced by system-on-chip (SoC) designers, but their adoption has been held back by a lack of methodology and support for post-fabrication testing. This paper first addresses the problem of testing C-elements, an important building block of asynchronous circuits. A simple method for generating test patterns is described which is shown to be applicable for a wide range of implementations. Based on the C-element testability, a partial scan technique was developed that achieves a test coverage of over 99.5% when applied to an asynchronous, network-on-chip, interconnect fabric. Test patterns are automatically generated by a custom program, given the interconnect topology. Area savings of at least 60% are noted, in comparison to standard, asynchronous, full-scan level-sensitive scan devices (LSSD) methods.     

Power management in the Amulet microprocessors

Amulet microprocessors are asynchronous (clockless) implementations of the ARM 32-bit RISC architecture. Their asynchronous control framework has positive benefits for low-power applications because it reduces activity to the minimum required to perform a task, whereas a clock inevitably incurs wasteful activity     

Fast 1V bootstrapped inverter suitable for standard CMOStechnologies

The authors propose a novel low-voltage bootstrapped inverter, designed in a standard high V_T 0.35 μm CMOS technology. To enhance the switching speed of a CMOS inverter at low-voltage operation, an NMOS device is used in the pull-up section. A bootstrapping scheme is used to avoid the V_TN reduction of the output swing     

Energy balanced data propagation in wireless sensor networks

We study the problem of energy-balanced data propagation in wireless sensor networks. The energy balance property guarantees that the average per sensor energy dissipation is the same for all sensors in the network, during the entire execution of the data propagation protocol. This property is important since it prolongs the network’:s lifetime by avoiding early energy depletion of sensors. We propose a new algorithm that in each step decides whether to propagate data one-hop towards the final destination (the sink), or to send data directly to the sink. This randomized choice balances the (cheap) one-hop transimssions with the direct transimissions to the sink, which are more expensive but “bypass” the sensors lying close to the sink. Note that, in most protocols, these close to the sink sensors tend to be overused and die out early. By a detailed analysis we precisely estimate the probabilities for each propagation choice in order to guarantee energy balance. The needed estimation can easily be performed by current sensors using simple to obtain information. Under some assumptions, we also derive a closed form for these probabilities. The fact (shown by our analysis) that direct (expensive) transmissions to the sink are needed only rarely, shows that our protocol, besides energy-balanced, is also energy efficient. This work has been partially supported by the IST/FET/GC Programme of the European Union under contract numbers IST-2001-33135 (CRESCCO) and 6FP 001907 (DELIS). A perliminary version of the work appeared in WMAN 2004 [11]. Charilaos Efthymiou graduated form the Computer Engineering and Informatics Department (CEID) of the University of Patras, Greece. He received his MSc from the same department with advisor in S. Nikoletseas. He currently continuous his Ph.D studies in CEID with advisor L. Kirousis. His research interest include Probabilistic Techniques and Random Graphs, Randomized Algorithms in Computationally Hard Problems, Stochastic Processes and its Applications to Computer Science. Dr. Sotiris Nikoletseas is currently a Senior Researcher and Managing Director of Research Unit 1 (“Foundations of Computer Science, Relevant Technologies and Applications”) at the Computer Technology Institute (CTI), Patras, Greece and also a Lecturer at the Computer Engineering and Informatics Department of Patras University, Greece. His research interests include Probabilistic Techniques and Random Graphs, Average Case Analysis of Graph Algorithms and Randomized Algorithms, Fundamental Issues in Parallel and Distributed Computing, Approximate Solutions to Computationally Hard Problems. He has published scientific articles in major international conferences and journals and has co-authored (with Paul Spirakis) a book on Probabilistic Techniques. He has been invited speaker in important international scientific events and Universities. He has been a referee for the Theoretical Computer Science (TCS) Journal and important international conferences (ESA, ICALP). He has participated in many EU funded R&D projects (ESPRIT/ALCOM-IT, ESPRIT/GEPPCOM). He currently participates in 6 Fifth Framework projects: ALCOM-FT, ASPIS, UNIVERSAL, EICSTES (IST), ARACNE, AMORE (IMPROVING). Jose Rolim is Full Professor at the Department of Computer Science of the University of Geneva where he leads the Theoretical Computer Science and Sensor Lab (TCSensor Lab). He received his Ph.D. degree in Computer Science at the University of California, Los Angeles working together with Prof. S. Greibach. He has published several articles on the areas of distributed systems, randomization and computational complexity and leads two major projects on the area of Power Aware Computing and Games and Complexity, financed by the Swiss National Science Foundation. Prof. Rolim participates in the editorial board of several journals and conferences and he is the Steering Committee Chair and General Chair of the IEEE Distributed Computing Conference in Sensor Systems.