Foreword

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Andrei ALEXANDRU, Gabriel CIOBANU
Nominal Semantics of Mobility
pp. 171–214

Abstract. We present a nominal semantics of the π-calculus defined by a set of compact transition employing a nominal quantifier. We analyze the behavior of the π-calculus binding operators new and input, and several nominal properties of new and input are presented. A comparison of expressiveness between the nominal semantics of the π-calculus and other known semantics is made; the nominal semantics and the late semantics of the π-calculus have the same expressive power. Read the pdf

 

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Lucian PETRICĂ
A SIMD Approach to Thread Matching for Interleaved Multithreading
pp. 215–228

Abstract. Interleaved multithreading processors offer improved performance and power efficiency in a multithreading environment compared to standard CPUs by allowing multiple threads to share a single processing pipeline. However, resource contention is a natural result of such a system and can determine how well the overall thread group performs on the processor. Selecting threads which perform well together has proven to be a difficult problem to solve because it is computationally intensive and grows rapidly in complexity with the number of threads in a system. We propose a vector algorithm for this task which is able to significantly outperform a scalar implementation and which shows improved scaling characteristics. Read the pdf

 

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Mihai Daniel ILIE, Cristian NEGRESCU, Dumitru STANOMIR
An efficient 3D Visual Speech Synthesis Framework for Romanian Language Logopedics Use
pp. 229–245

Abstract. In this paper, we propose a 3D facial animation model for simulating visual speech production in the Romanian language. To our best knowledge, this is the first study dedicated to 3D visual speech synthesis for the Romanian language. The model is also capable to generate complex emotion activity for the virtual actors during the speech. Using a set of existing 3D key shapes representing various facial expressions, fluid animations describing facial activity during speech pronunciation are provided, taking into account several Romanian language coarticulation effects. A novel mathematical model for defining efficient viseme coarticulation functions is provided. The 3D tongue activity could be closely observed in real-time while different words are pronounced in Romanian. The framework proposed in this paper is designed for helping people with hearing disabilities learn how to articulate correctly in Romanian and also it works as a training-assistant for Romanian language lip-reading. The efficiency of our method was successfully proven by tests made on various logopedics specialists, deaf students and deaf lip-reading instructors from a special school for people with hearing disabilities in Bucharest, Romania. Read the pdf

 

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K. G. SUBRAMANIAN, P. WIEDERHOLD, Ibrahim VENKAT, Rosni ABDULLAH
Generative models for pictures tiled by triangles
pp. 246–265

Abstract. The problem of generation of triangle-tiled pictures that are two-dimensional figures tiled by isosceles right triangles of the same size, is investigated. Grammars called context-free triangle-tiled picture grammars (CF-ttPG) that generate such figures making use of context-free type rules, are proposed. The special case that all rules of such a grammar are regular, is studied. In the framework of membrane computing which is a biologically inspired computability model, generation of triangle-tiled pictures by rules of a CF-ttPG is considered. The picture language of rectangular hollow frames which cannot be generated by any CF-ttPG, can be generated by a specific type of P system with two membranes. Read the pdf

 

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Wenbo SHI, Yitao CHEN
An Efficient RSA-Based Remote User Authentication Scheme
pp. 266–276

Abstract. Password authentication has been adopted as one of the most commonly used solutions in network environment to protect resources from unauthorized access. Recently, Awasthi et al. proposed an efficient RSA-based remote user authentication scheme. In this paper, we will point out that Awasthi et al.'s scheme is vulnerable to a privileged insider attack, a password guessing attack and an impersonation attack. To improve the security, we also propose a new RSA-based remote user authentication scheme. The analysis shows our scheme could overcome the weaknesses in Awasthi et al.'s scheme and has better performance than their scheme. Read the pdf

 

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Octavian CREŢ, Tamás GYÖRFI, Alin SUCIU
Implementing True Random Number Generators Based on High Fanout Nets
pp. 277–298

Abstract. The main component of a true random number generator (TRNG) is its source of entropy. Field Programmable Gate Arrays (FPGAs) are emerging as a popular platform for implementing single-chip TRNGs. Most of the generators implemented in FPGAs exploit the jitter from ring oscillators as source of entropy. The present paper proposes a new method for implementing TRNGs in FPGAs based on high fanout circuits operating at high frequency. The advantage of this design is its solid source of entropy and its high throughput. The quality of the random number stream is further increased by applying post-processing functions. All the theoretical assumptions related to the analysis of the entropy source are validated by practical implementations and results. Read the pdf