The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Circular microphone arrays facilitate spatial processing and analysis of sound fields in applications where the sound field sources are primarily expected from the azimuthal directions. The operating frequency bandwidth of the array depends on the array aperture and on the number of microphones. At high frequencies, spatial aliasing generates side-lobes in the array beam pattern, which limits array...
In this paper, we apply statistical mechanics methods to the problem of detection of multiple primary wireless sources by a wireless sensor network. We assume that the location of the primary sources is known, but that the channel connecting them to the sensors is random. The sensor network tries to detect which sources are emitting by employing a belief propagation algorithm. We use the Replica approach...
In Content-centric Networking (CCN), in-network caching can enhance content delivery at a global scale without requiring special infrastructure. In this paper, we propose a lifetime-based greedy caching approach (LBGC) which involves both caching decision and cache replacement. Contents are preferred to be stored in nodes with high betweenness centrality, and only expired cache items can be replaced...
Most non-sinusoidal power theories have been developed from theoretical techniques, as well as relying on hypothetical and experimental networks to highlight the advantages of each. The drawback of the power theories is that no single one has been universally accepted as a benchmark for other developments. This paper will however show this weakness by means of evaluating two power theories in the...
Level set method for topology optimization are by now sophisticated and used in a wide variety of research areas. Level set method with mesh requires finite element analysis that is often complex and time consuming due to large sparse coefficient matrix of equations. This paper presents EBE-CG method to parallel compute large sparse linear equations for level set method based on normal conjugate gradient...
This paper presents an equation-based phase noise optimization technique for MOS LC-VCOs in contrast with feedback-based optimization architectures. The proposed technique relies on a simplified equation relating the bias current to the oscillation amplitude and the equivalent tank losses. The applied technique takes also into account the tank losses dependency on frequency setting in wideband LC-VCOs...
We improve the best previously-known lower bound on the size of largest homometric sets in sparse diameter-two graphs. Along with the proof, we provide a method for constructing the desired homometric sets. We also study outerplanar graphs and show how to construct homometric sets in a given outerplanar graph of the size at least clogn, where n is the number of vertices in the graph, and c a positive...
When linear programming is used to decode low-density parity-check (LDPC) codes, the outcome is a codeword or a pseudocodeword that contains fractional symbol values. It is possible to make pseudocodewords infeasible and increase the performance of linear programming decoders by generating redundant parity check equations. In this paper, redundant parity check equations that can eliminate pseudocodewords...
We study a multi-class time-sharing discipline with relative priorities known as Discriminatory Processor Sharing (DPS), which provides a natural framework to model service differentiation in systems. The analysis of DPS is extremely challenging and analytical results are scarce. We develop closed-form approximations for the mean conditional and unconditional sojourn times. The main benefits of the...
We present an analytical framework to investigate the interplay between a communication graph and an overlay of social relationships. Particularly, we focus on geographical distance as the key element that interrelates the concept of routing in a communication network with interaction patterns on the social graph. Through this regime, we attempt to identify classes of social relationships that let...
RFID technology has been widely adopted in a variety of applications from logistics to access control. Many applications gain benefits from knowing the exact position of an RFID-tagged object. Existing localization algorithms in wireless network, however, can hardly be directly employed due to tag's limited capabilities in terms of energy and memory. For example, the RSS based methods are vulnerable...
It is well known that resistive grid structures yield exponentially decreasing spatial impulse response yielding a spatial frequency response similar to that of a Gaussian filter, hence used as smoothing filters. In this paper it is shown that although the grid structure can be modeled with a recurrence (difference) equation this equation is not recursively computable but the output image can be obtained...
The analysis of the system behavior under influence of the noise of the order parameter has been performed within the nonlinear model of the shear melting. Time dependencies of the order parameter has been calculated and the situation with low intensity of the order parameter noise has been investigated in detail. The distinctive feature of the obtained dependencies is a power-law density distribution...
Search for improving accuracy of the vibratory gyro by reducing influence of manufacturing imperfections has resulted in differential mode of operation. This operation mode allowed us to drive frequency mismatch as close to null as possible. It has also allowed compensating for the damping cross-coupling by arrangement in essence two opposite directed sensing axes in one ring-like resonator. These...
Following the wide use of cloud services, the volume of data stored in the data center has experienced a dramatically growth which makes real-time information retrieval much more difficult than before. Furthermore, text information is usually encrypted before being outsourced to data centers in order to protect users' data privacy. Current techniques to search on encrypted data do not perform well...
Distributed storage plays a crucial role in the current cloud computing framework. After the theoretical bound for distributed storage was derived by the pioneer work of the regenerating code, Reed-Solomon code based regenerating codes were developed. The RS code based minimum storage regeneration code (RS-MSR) and the RS code based minimum bandwidth regeneration code (RS-MBR) can achieve the theoretical...
Two-port networks are normally used for oscillator or feedback amplifier synthesis by aggregation in four possible configurations. To define the oscillation frequency or stability margins a return ratio should be used. A technique is developed to define the analytic relation for the return ratio of an oscillator in frequency domain. Its application requires the knowledge of the equivalent load impedance...
Recently, the results of experiment, in which electron flow passing through the array of double-helix DNA molecules become spin-polarized, were reported [1]. In the present work we propose the physical model capable of explaining the spin-polarization effect. The main idea is that the action of elliptic-symmetry parabolic potential (with two different stiffness constants) formed by the array of DNA...
Lightning current is an important parameter that has to be considered. The different behaviour of lightning current depends on the way the lightning strikes either as a direct or indirect lightning strike. In this paper the modelling of the current as a result of a direct strike of lightning on a tall structure is considered. A few of up-to-date on current models, current functions, reflection factors,...
In a pervasive networking scenario like the Cyber-Physical World convergence, personal mobile devices must assist their users in analysing data available in both the physical and the virtual world, to help them discovering the features of the environment where they move. Mobile Social Networking applications are an example of Cyber-Physical applications, supporting users in their interactions in both...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.