Arhivă — Seria C

1

CALCUL DES PROPRIETES THERMOPHYSIQUES DES FLUIDES FRIGOPORTEURS DIPHASIQUES

Constantin IONESCU, Horia NECULA

Following the international regulations concerning the reduction of the use of ozone-depletion substances and gases with greenhouse effect, new solutions to replace this type of fluids are searched. One of these solutions is the use of the secondary cooling loops, which utilize a two-phase secondary refrigerant for the…

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2

CURRENT-MODE REFERENCES BASED ON MOS SUBTHRESHOLD OPERATION

Radu H. IACOB, Anca MANOLESCU

Subthreshold MOS operation, or weak inversion, is most often required by the low-power applications in modern electronics. Voltage and current references are among the circuits that can greatly benefit from operating the MOS devices in weak inversion. At the same time, the current-mode architectures for voltage and cur…

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3

ON SOME STATISTICAL INDICATORS OF THE TRAFFIC IN WIRELESS LOCAL AREA NETWORKS

ªerban Alex. STÃNêILÃ

In the last time, the protocol capacity of the wireless networks, for instance the throughput as allowed in a given wireless channel, plays an important role in the Internet applications. There are many theoretical models and variants to take into account the transmission delay due to collisions or to subsequent transm…

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4

QUALITY EVALUATION OF MULTIRESOLUTION REMOTE SENSING IMAGES FUSION

Liviu Florin ZORAN

With the availability of multisensor data in satellite remote sensing and computer vision fields, sensor fusion at the pixel or the so-called image, feature, and symbol level is a new research area. The aim of this paper was to study environmental changes of the Romanian Black Sea coastal zone using different image fus…

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5

GENERAL GUIDELINES FOR THE SECURITY OF A LARGE SCALE DATA CENTER DESIGN

Jalal FRIHAT, Florica MOLDOVEANU, Alin MOLDOVEANU

The security of a large scale data center is based on an effective security policy that defines the requirements to protect network resources from internal and external security threats and ensures data privacy and integrity. This paper summarizes the layered security principles and how they have been applied in the de…

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6

SYSTEM ANALYSIS FOR E-LEARNING GRIDS

O. B. ALABA, Ioana FÃGÃRêAN, Radu DOBRESCU, Sergiu ªt. ILIESCU

E-learning systems consist of complex activities and most of them have been designed based on client-server or peer to peer, and recently web services architecture. These systems have major drawback because of their limitations in scalability, availability, distribution of computing power and storage systems, as well a…

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7

REAL TIME ON-LINE ANALYTICAL PROCESSING FOR BUSINESS INTELLIGENCE

Guran MARIUS, Mehanna AREF, Hussein BILAL

The business needs to know what is happening right now, faster, in order to determine and influence what should happen next time. The goal of business intelligence (BI) systems is to capture (data, information, knowledge) and respond to business events and needs better, more informed, and faster, as decisions. To suppo…

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8

FRAMEWORK FOR DATA-INTENSIVE APPLICATIONS OPTIMIZATIONIN LARGE-SCALE DISTRIBUTED SYSTEMS

Cãtãlin CÎRSTOIU, Nicolae ÞÃPUª

In this work we argue that when dealing with data-intensive applications in large distributed systems it is important to go beyond the simple scheduling of application tasks that have to run, and to support at the framework level the process of dynamically changing the configuration of the underlying resources, based o…

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9

PARALLEL QUERY OPTIMIZATION: PIPELINED PARALLELISM SCHEDULING AND GOLDEN NUMBER

Carmen Elena ODUBêTEANU, Cãlin Aurel MUNTEANU

Pipelined parallelism scheduling problem is very important in the area of parallel query optimization. To model the problem it is used a POT (Pipelined Operator Tree), which is a tree whose nodes represent query operators that can be run in parallel and edges represent communication between adjacent operators; we must …

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10

METHODS OF ADJUSTING MPLS NETWORK POLICIES

Rãzvan RUGHINIª, Rãzvan DEACONESCU

This paper discusses adjustment strategies for MPLS networks, taking into account users demands. Recent developments in MPLS technology are used to propose a new method for analyzing network adjustments, on four dimensions: security, error recovery, Quality of Service and network integration - with a special focus on …

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11

INTRODUCING A NEW ORTHOGONAL SPATIAL TRANSFORM FOR SIGNIFICANT DATA SELECTION

Constantin Liviu CÎRSTOIU

A new orthogonal transform is introduced, with applications especially for picture data compression and for feature selection in pattern recognition. Starting from the Legendre Polynomials, we deduced an orthogonal matrix defining the new transform, that we called the “Discrete Legendre Transform” (DLT). For a first or…

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12

A FRAMEWORK FOR PERFORMANCE PREDICTION IN DISTRIBUTED SYSTEMS

Corina STRATAN, Valentin CRISTEA

In large scale distributed systems, the performance parameters of the various components change frequently, making resource management a challenging task. In this paper we present a performance prediction platform that can be used to improve the efficiency of resource management systems. The framework is integrated in …

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13

NEURAL AND NERVOUS REFLEX NETWORKS: A NEW APPROACH TO INTEGRATED CONTROL

Alexandru M. PANAIT, Alexandru M. MOREGA

Neural networks have always been regarded as an exotic solution to non-linear problems and often thought to be more effective as code implemented on a classical architecture machine, such as a Von Neumann machine or equivalent, or even given a controller class of their own, the “neural computer”. This work represents a…

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14

ADAPTIVE BACKSTEPPING CONTROLLER DESIGN FOR LINEAR INDUCTION MOTOR POSITION CONTROL

Ismail Khalil BOUSSERHANE, Abdelkrim BOUCHETA, Abdeldjebar HAZZAB, Benyounes MAZARI, Mustepha RAHLI, Mohammed Karim FELLAH

In this paper, the mover position control of a linear induction motor using an adaptive backstepping control design based on filed orientation is proposed. First, the indirect field oriented control LIM is derived. Then, a novel adaptive backstepping control design technique is investigated to achieve a position and fl…

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15

OPTIMAL METHOD FOR CONTROLLED SWITCHING CIRCUITS

Dan OLARU, Dan FLORICÃU

The power control, using switching circuits is a power saving solution, but generates some problems concerning the power quality. Harmonic filtering, reactive power minimization and damping transient regimes must be solved by the control strategy.\r\nThe paper gives a numerical solution, verified by simulation results,…

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16

THE INFLUENCE OF DRAG-REDUCING ADDITIVES ON CRUDE OIL EMULSIONS IN PIPELINE FLOW

Andreea CÃLIN

The present paper investigates two samples of crude oil – water emulsions, in presence of drag reduction surfactants, in order to determine the pressure loss in pipes, respectively to compute the Darcy coefficient, λ. The experiments are performed at constant flow rate and the corresponding pressure differences between…

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17

CONTRIBUTION ABOUT THE ELECTROHYDRODYNAMIC SPRAYING

Luciana NISIPARU, Radu CRAMARIUC

The original aspects achieved by the author about the electrohydrodynamic phenomena are presented. The equations that overrule the phenomena spraying of the liquids are presented (The Maxwell’s equations, the current density, the ohmic regime, the unipolar injection regime and the mechanic equations of particle motion)…

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