Volume 18, Number 1, 2015

 

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Ştefan POPESCU
Networks of Polarized Evolutionary Picture Processors
pp. 3–17

 

Abstract. We define a new bio-inspired computational model for deciding 2-dimensional languages similar to those presented in [2] and [3]. The novel factor being the communication protocol, which is based on the polarity associated with the symbols on the picture frame. This model can be viewed as a 2-dimensional extension of the one presented in [1].
We compare the class of languages accepted by these networks to other classes of 2-dimensional languages, namely the classes of Local Languages and Tiling Recognizable Languages [12].
We show that these networks can accept the complement of any local picture language and some picture languages that are not recognizable by tiling systems. We also show that these networks can recognize any input that contains a given sub-picture, provided that the sub-picture is made up of at most 3 rows or 3 columns. Read the pdf

 

 

 

 

 

 

 

 

 

 

 

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Marek SÝS, Zdeněk ŘÍHA, Vashek MATYÁŠ, Kinga MÁRTON, Alin SUCIU
On the Interpretation of Results from the NIST Statistical Test Suite
pp. 18–32

 

Abstract. NIST Statistical Test Suite is an important testing suite for randomness analysis often used for formal certifications or approvals. Documentation of the NIST STS gives some guidance on how to interpret results of the NIST STS but interpretation is not clear enough or it uses just approximated values. Moreover NIST considers data to be random if all tests are passed yet even truly random data shows a high probability (80%) of failing at least one NIST STS test. If data fail some tests the NIST STS recommends the analysis of different samples. We analysed 819200 sequences (100 GB of data) produced by a physical source of randomness (quantum random number generator) in order to interpret results computed without analysing any additional samples. The results indicate that data can be still considered random for the significance
level α = 0:01 if they fail less than 7 NIST STS tests, 7 tests of uniformity of p-values (100 sequences) or 10 tests of proportion of passing sequences. We have also defined a more accurate interval of acceptable proportions computed with a new constant (2.6 instead of 3) for which 1000 sequences can be considered random if they fail less than 7 tests of proportion. Read the pdf.

 

 

 

 

 

 

 

 

 

 

 

 

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Horia CUCU, Andi BUZO, Corneliu BURILEANU
The SpeeD Grammar-based ASR System for the Romanian Language
pp. 33– 53

Abstract. This paper describes the grammar-based automatic speech recognition system for the Romanian language developed by the Speech and Dialogue Research Group. The paper links to previous work for the issues related to large vocabulary speech recognition and focuses on the specific optimization work done for several closed-vocabulary, grammar-based speech recognition tasks.
Among the specific problems approached, of particular interest is the informal pronunciation modelling of Romanian two-digit numbers. The paper proposes solutions for within-word and cross-word pronunciation modelling of numbers and reports significant relative improvements of the speech recognition word error rates.
Read the pdf

 

 

 

 

 

 

 

 

 

 

 

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Lucian PETRICĂ, Laura VASILESCU, Ana ION, Octavian RADU
IxFIZZ: Integrated Functional and Fuzz Testing Framework based on Sulley and SPIN
pp. 54– 68

Abstract. Fuzzing has long been established as a way to automate negative testing of software components. While effective, existing fuzzing frameworks lack the necessary features to test stateful protocols in-depth. We propose using the modelling language Promela, and its interpreter SPIN, as an intuitive and generic way to describe protocol state machines, allowing the automatic generation of stateful fuzzing scripts for the popular Sulley fuzzing framework. Our approach involves the simulation of the Promela description in order for a set of valid protocol conversation sequences to be extracted. These sequences are then automatically modified by IxFIZZ, which inserts erroneous messages in the protocol conversation according to a set of heuristics. This approach also
enables automatic analysis of test results against the protocol model and a tight integration of fuzzing with existing test-driven methodologies. We evaluated IxFIZZ against Linphone, a popular multi-platform SIP phone, to demonstrate the effectiveness of this approach, and compared the results to PROTOS, an established fuzzing framework for stateful network protocols. Our results indicate that IxFIZZ is able to detect more defects in the target software. Read the pdf

 

 

 

 

 

 

 

 

 

 

 

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Ion CHIŢESCU, Răzvan-Cornel SFETCU, Oana COJOCARU
Approximation of Köthe-Bochner Spaces  in case X has a Schauder Basis
pp. 69– 78

Abstract. We consider Köthe-Bochner spaces  (X Banach space, ρ function norm) in case X has a Schauder basis. The canonical finite dimensional subspaces Y of X generate the Köthe-Bochner spaces , which approximate . Numerical computations in case X is a Lorentz sequence space are performed. We present a general computation and a special computation for a particular case, comparing the procedures and noticing that the special computation is more economic. Read the pdf.

 

 

 

 

 

 

 

 

 

 

 

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Andrei ZENE, Claudiu-Teodor CHIRAP,  Octavian CREŢ,  Lucia VĂCARIU
Efficient Hardware Implementation of Snapshotting Algorithms for NoC Applications
pp. 79– 92

 

Abstract. The NoC domain has known a big development lately, acquiring an ever growing importance in the context of hardware miniaturization. However at this point it is still hard to observe and / or debug what is going on inside the chip, be it for debugging purposes or for long-running processes like computational biology simulations which could gain a great improvement when ran on an FPGA chip. Therefore, this paper proposes hardware implementations of three of the most important snapshot algorithms: Lai-Yang, Li et al. and Mattern, which could be used in order to achieve observability on a long-running process physically implemented on an FPGA target. The setup is based on the layers architecture, making it easy to separate the snapshot algorithm from the application or the intercommunication network. The intercommunication network was generated using the CONNECT NoC generator and the snapshots are sent to a PC via UART for displaying. The algorithms were compared from three points of view: operating frequency, throughput and resource usage. Based on the obtained results, we show that the Mattern algorithm is the best candidate for an effective hardware implementation (both from the resource usage and speed points of view). Read the pdf

 

 

 

 

 

 

 

 

 

 

 

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Cornel MICLEA, Luminiţa AMARANDE, Marius Cristian CIOANGHER,
Ciprian Tiberiu MICLEA, Mădălina MIHĂILESCU, Cristina RADU,
Anişoara IVANOV
Nanostructured Titanium Doped Iron Oxide Photoelectrodes for Water Splitting
pp. 93– 105

 

Abstract. Water splitting by means of semiconducting photoelectrodes and solar light represents a promising alternative to conventional fossil fuel economy. In this process the photoactive electrode absorb sunlight directly thus initiating the photochemical reaction which create excess electrons in the conduction band of the semiconducting electrode. Titanium doped iron oxide seems to be a promising semiconducting material for photoelectrodes. Consequently, we investigated the effect of Ti doping on the structure, electrical and photoelectrochemical properties α-Fe2O3. The Ti doped α-Fe2O3 were prepared by a slightly modified mixed oxide route, consisting in a prolonged mixing of the raw materials in a high energy planetary ball mill until the particles decreased to the nanometric sizes. Optimum results were obtained for samples doped with 5 at. %  titanium and sintered at 1200°C.
Photocurrents as high as 8.4 mA/cm2, for illumination from a 300 W xenon lamp, were recorded for such samples. It is hoped that such photoelectrodes show promise for water splitting. Read the pdf