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Octavian PASTRAVANU, Mihaela Hanako MATCOVSCHI, Mihail VOICU
Invariant-Set-Based Analysis and Design – A Survey of Some Noticeable Contributions
pp. 425–439

Abstract. Invariant-set-based techniques represent a research direction in systems engineering emerged during the last two decades. The authors of the current paper have brought some noticeable contributions to the development of this direction. The exposition of our results is connected to the international evolution of the field. Our material offers an overview structured at two levels:
1. Present framework – results available for invariant sets with general shapes described by arbitrary HÄolder p-norms: (i) Types of dynamical systems and invariant sets under consideration; (ii) Invariance and stability; (iii) Invariance criteria for nonlinear systems; (iv) Invariance criteria for linear systems (time-variant, time-invariant, positive, with interval type uncertainties); (v) Linear synthesis based on invariant sets; (vi) Comparison methods for invariant sets.
2. Researches prefiguring the present framework – results for invariant sets with rectangular shapes (i) Linear time-invariant systems; (ii) Linear systems with interval-type uncertainties; (iii) Linear synthesis; (iv) Nonlinear systems.

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Petru CAŞCAVAL, Radu SILION, Doina CAŞCAVAL
A BIST Logic Design for MarchS3C Memory Test BIST Implementation
pp. 440–454

Abstract. A logic design for a possible built-in self-testing implementation of a march test able to detect all static simple three-cell coupling faults in n × 1 random-access memories (RAMs) is presented. Single-array single bit and multiple-array single bit test architectures have been considered. The memory test (MarchS3C [1]) needs 66n operations and is able to detect all realistic simple (i.e. not linked) static three-cell coupling faults that have been shown to exist in real designs, namely: state coupling faults, transition coupling faults, write disturb coupling faults, read destructive coupling faults, deceptive read destructive coupling faults, and incorrect read coupling faults. To reduce the length of the test, only the coupling faults between physically adjacent memory cells have been considered. The test assumes that the storage cells are arranged
in a rectangular grid and that the mapping from logical addresses to physical cell locations is known completely.

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Ioan TOMESCU, Ruxandra MARINESCU-GHEMECI, Gabriela MIHAI
On Dense Graphs Having Minimum Randić Index
pp. 455–465

Abstract. In this paper all graphs G of order n and minimum degree δ(G) = k having minimum Randić index R(G) are determined for k ≥ [n/2]. Each extremal graph is the join between a regular graph of order n – s and a complete graph of order s (where for n even and for n odd). This yields an alternative proof in the case of dense graphs to that proposed by Li, Liu and Liu [5] who very recently solved a long-standing conjecture on Randić index. Also, the minimum value of this index in the class of graphs of order n and δ(G) = k is determined for k ≥ (n–1)/2.

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Monica DASCĂLU, Gheorghe ŞTEFAN, Adrian ZAFIU
Multi-level Simulator for Artificial Societies
pp. 466–484

Abstract. The simulator presented in this paper is used for human society modelling in order to understand its specific phenomena and to predict the future evolution of large human collectivities. The present paper presents also some new and original artificial society experiments, highlighting how the artificial societies model allows collective significant behaviors to appear through simple individual rules. The artificial society concept basically consists of a „cellular” landscape that contains different resources and a population of agents grouped in social categories which have economical and political activities. The experiments were related to the real conditions of our country. This simulator create a proper environment in order to identify the causes and mechanism which influence the economical, social and political phenomena evolution from the human society: production of goods, trade, diseases' spreading / the efficiency of the immunizing methods, the impact of information in different welfare and cultural conditions of population, voting mechanisms.

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Cristian ANDRIESEI, Liviu GORAS, Farid TEMCAMANI, Bruno DELACRESSONIÈRE
Wide Tuning Range Active RF Bandpass Filter with MOS Varactors
pp. 485–495

Abstract. The paper presents an improved tuning method implemented for a differential active inductor based RF bandpass filter. Derived from a previous designed transistor-only second order filter topology, independent frequency and quality factor tuning are demonstrated in 0.18 μm CMOS technology. The circuit has been basically designed for a maximum frequency of 2.4 GHz, high enough to cover the main wireless standards, has small power consumption and can exhibit very high Q values. A wide frequency tuning range is obtained by using MOS varactors. The circuit absorbs 1 mW from a 1.8 V supply at 2.4 GHz central frequency.

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Teodora IGNAT, Roberto MUNOZ, Irina KLEPS, Mihaela MIU, Isabel OBIETA, Monica SIMION
SERS-Active Substrate Based on Macroporous Silicon
pp. 496–503

Abstract. Novel architectures with nanometric are very promising as building blocks for future nanotechnological applications. Metallic substrates with ordered morphology have been shown to be very effective for surface-enhanced Raman scattering (SERS). The sensitivity of detection is increased by several orders of magnitude by using this technique. In this paper we investigate SERS on thermal evaporated gold layer / porous silicon substrate comparatively to a PVD-gold layer/flat silicon substrate.

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Cristian RAVARIU, Ala BONDARCIUC, Florina RAVARIU, Elena MANEA, Cecilia PODARU
A first experimental model for a characterisation biodevice with epinephrine solution
pp. 504–513

Abstract. The electrical properties of the chemical mediators at synapses level could be investigated in vitro, with some test biodevices. One of neurotransmitters, like epinephrine, placed on an insulator support and contacted with metal electrodes, provides a Biomaterials On Insulators - BOI-type, test architecture. The test device is inspired from the pseudo-MOS technique, frequently used in the Silicon On Insulator characterisation. The DC regime study allows some polarography experiments. A behavior like a Field Effect Transistor was also investigated in DC regime, biasing a third terminal – the gate and monitoring the drain-source current. A dependence of the current – gate voltage is expected. It is still linear, emphasizing none inversion layer of the ionic charge. The AC regime measurements of the BOI device provided some conductometry
results like resistivity. The current is a variable of time due to the oxidation / reduction rate at the electrode surface. This parameter is extracted from the switch regime of the biodevice.