Sensing of DVB-T signals for white space cognitive radio systems

In cognitive radio networks, systems operating in digital television white spaces are particularly interesting for practical applications. In this paper, we consider single- antenna and multi-antenna spectrum sensing of real DVB-T signals under different channel conditions. Some of the most important algorithms are considered and compared, including energy detection, eigenvalue based techniques and methods exploiting OFDM signal knowledge. The obtained results show the algorithm performance and hierarchy in terms of ROC and detection probability under fixed false alarm rate, for different channel profiles in case of true DVB-T signals

A Novel System for Non-Invasive Method of Animal Tracking and Classification in Designated Area Using Intelligent Camera System

This paper proposed a novel system for non-invasive method of animal tracking and classification in designated area. The system is based on intelligent devices with cameras, which are situated in a designated area and a main computing unit (MCU) acting as a system master. Intelligent devices track animals and then send data to MCU to evaluation. The main purpose of this system is detection and classification of moving animals in a designated area and then creation of migration corridors of wild animals. In the intelligent devices, background subtraction method and CAMShift algorithm are used to detect and track animals in the scene. Then, visual descriptors are used to create representation of unknown objects. In order to achieve the best accuracy in classification, key frame extraction method is used to filtrate an object from detection module. Afterwards, Support Vector Machine is used to classify unknown moving animals

Sensing of DVB-T signals for white space cognitive radio systems

In cognitive radio networks, systems operating in digital television white spaces are particularly interesting for practical applications. In this paper, we consider single- antenna and multi-antenna spectrum sensing of real DVB-T signals under different channel conditions. Some of the most important algorithms are considered and compared, including energy detection, eigenvalue based techniques and methods exploiting OFDM signal knowledge. The obtained results show the algorithm performance and hierarchy in terms of ROC and detection probability under fixed false alarm rate, for different channel profiles in case of true DVB-T signal

Singlet-Singlet and Triplet-Triplet Energy Transfer in Polychromophoric Peptides

The photophysics of several bichromophoric dipeptide model compounds and two trichromophoric 15-residue peptides have been studied by a combination of absorption, fluorescence, phosphorescence and laser flash photolysis. Intramolecular singlet-singlet energy transfer (SSET) occurs efficiently within these systems. Trichromophore 14 undergoes intramolecular SSET from the central chromophore to the termini, kSSET = 5.8 x109 s-1 , with a five fold increase over 13, kSSET = 1.1 x 109 s-1 . Evaluation of SSET mechanisms via the Förster treatment and molecular modeling indicates that the dipole-induced dipole mechanism is sufficient to account for the observed SSET. However, given the close distances of the chromophores (~10 Å), an electron exchange mechanism can not be ruled out. Low-temperature phosphorescence in 1:1 methanol/ethanol and room-temperature laser flash photolysis in acetonitrile results indicate that intramolecular triplet-triplet energy transfer (TTET) is efficient in dipeptides 7,9-12 and proceeds with a rate constant of kTTET > 5 x 10 8 s-1. The occurrence of TTET in dipeptide 8, (biphenyl-naphthalene), could not be confirmed due to the fact that SSET from biphenyl to the naphthalene moiety was 26 times greater than kISC. Thus nearly all absorbed light was funneled directly the to the singlet manifold of the naphthalene moiety. TTET in the trichromophores could not be fully evaluated due to their low solubility. However, it is shown from 77°K experiments that kTTET is at least 2.2 x 102 and 2.6 x 102 s-1 for 13 and 14 respectively

The Rational Design and Synthesis of Ionophores and Fluoroionophores for the Selective Detection of Monovalent Cations

The rational design, synthesis and complexation characteristics of several monovalent cation-selective ligands are described. Molecular modeling employing a combination of dynamics, mechanics (AMBER94) and electrostatics was used to design ligands for the complexation of ammonium, potassium, sodium and lithium ions. A modular technique was used to synthesize an ammonium selective ionophore based on a cyclic depsipeptide structure (8). The ionophore was incorporated into a planar ion selective electrode (ISE) sensor format and the selectivity tested versus a range of metal cations. It was found that the membrane containing the polar plasticizer NPOE (nitrophenyloctylether) in the absence of ionic additive exhibited near-Nernstian behavior (slope = 60.1 mV/dec @ 37¢ªC) and possessed high selectivity for ammonium ion over lithium and the divalent cations, calcium and magnesium (logK = -7.3, -4.4, -7.1 for lithium, calcium and magnesium ions, respectively). The same membrane also exhibited sodium and potassium selectivity that was comparable to that reported for nonactin (logK = -2.1, -0.6 for sodium and potassium, respectively, compared to -2.4, -0.9 in the case of nonactin). N-(9-methylanthracene)-25,27-bis(1-propyloxy)calix[4]arene-azacrown-5 (10) was synthesized and tested as a fluoroionophore for the selective detection of potassium ions. Compound 10 acts as an ¡°off-on¡± fluorescent indicator for ion complexation as a result of photoinduced intramolecular electron transfer (PET). Studies demonstrate that 10 is selective for potassium over other alkali metal cations, with excellent selectivity over sodium and lithium (log K ¡Â -3.5) and moderate selectivity over rubidium and cesium (log K ~ -1). N-(9-methylanthracene)-25,27-bis(1-propyloxy)-4-tert-butylcalix[4]arene-azacrown-3 (11) was synthesized and tested as a fluoroionophore for the selective detection of lithium cations. When exposed to lithium ions in a 75:25 dichloromethane/THF solvent mixture, the molecule, which operates on PET, exhibited a >106-fold enhancement in fluorescence emission intensity. Selectivity studies demonstrated that 11 effectively discriminates against sodium and potassium ions log K ¡Â -3.8 and log K ¡Â -2.3. A fluorescent sodium optode based on a fluoroionophore consisting of aminorhodamine B covalently-linked through an amide bond to a calix[4]arene has also been developed (12). The optode, fashioned by incorporation of the fluoroionophore into a single component polymer matrix, operates on the basis of PET. The fluorescence intensity increased linearly with increasing sodium ion concentration in the range 0.01 M to 2.0 M, exhibiting a three-fold enhancement over this range. The optode provides selectivity for sodium ions compared to potassium ions that is sufficient for clinical determinations of sodium ion concentration

Verification criteria on the reliability of personal dosimetric services from x and gamma radiations

The paper presents the methods used by Working Group ENEA-EDP (Experts in Personal Dosimetry) to control the reliability of the Dosimetric Services operating in Italy and asking for the above controls on voluntary basis. Testing and irradiation test methods are explained as well as the evaluation criteria. The paper includes suggestions and guide-lines to gain the status of 'Reliable Service'. Technical equipment and operating procedures needed to pass the test are also illustrated

Classification of animals to determine the migration potential at the construction of new infrastructure

At the planning and construction of new infrastructures, the information about migration potential of animals in a target area is needed. This information will be used to design of migration corridors for wild animals. To determine the migration potential of animals based on distributed video camera system, new methods for object recognition and classification are developed. In general, an object recognition system consists of three steps, namely, the image feature extraction from the training database, training the classifier and evaluation of query image of object/animal. In this paper, an extraction of local key point by SIFT or SURF descriptors, bags of key points method in combination with SVM classifier and two hybrid key points detection methods are proposed in detail

Criteri per la verifica dell'affidabilit di un servizio di dosimetria individuale per radiazioni X e Gamma

SIGLEITItal

Spectrum sensing in the TV white spaces

Cognitive radio networks operating in the digital television white spaces are of particular interest for their practical applications. In this paper, we review several parametric and nonparametric test statistics commonly used in spectrum sensing. Both single-antenna as well as multiple antenna techniques are considered. For a selected subset of these techniques, an accurate performance assessment is carried out in the presence of a DVB-T primary signal generated using a software-defined realtime transmitter. Sensing performance is assessed both through Monte Carlo simulation and using a real software-defined radio implementation. Different channel profiles are considered. The obtained results show the performance of each algorithm in terms of detection probability under fixed false alarm rate and of Receiver Operating Curve (ROC). Moreover, these results permit to establish clear relationships between the considered algorithms in case of DVB-T primary signals