Showing papers on "Binary number published in 2009"
TL;DR: This work shows how correlated binary spike trains can be simulated by means of a latent multivariate gaussian model, which naturally extends to correlations over time and offers an elegant way to model correlated neural spike counts with arbitrary marginal distributions.
Abstract: Spike trains recorded from populations of neurons can exhibit substantial pairwise correlations between neurons and rich temporal structure. Thus, for the realistic simulation and analysis of neural systems, it is essential to have efficient methods for generating artificial spike trains with specified correlation structure. Here we show how correlated binary spike trains can be simulated by means of a latent multivariate gaussian model. Sampling from the model is computationally very efficient and, in particular, feasible even for large populations of neurons. The entropy of the model is close to the theoretical maximum for a wide range of parameters. In addition, this framework naturally extends to correlations over time and offers an elegant way to model correlated neural spike counts with arbitrary marginal distributions.
207 citations
TL;DR: Two pseudorandom binary sequence generators, based on logistic chaotic maps intended for stream cipher applications, are proposed, which possess high linear complexity and very good statistical properties.
Abstract: Two pseudorandom binary sequence generators, based on logistic chaotic maps intended for stream cipher applications, are proposed. The first is based on a single one-dimensional logistic map which exhibits random, noise-like properties at given certain parameter values, and the second is based on a combination of two logistic maps. The encryption step proposed in both algorithms consists of a simple bitwise XOR operation of the plaintext binary sequence with the keystream binary sequence to produce the ciphertext binary sequence. A threshold function is applied to convert the floating-point iterates into binary form. Experimental results show that the produced sequences possess high linear complexity and very good statistical properties. The systems are put forward for security evaluation by the cryptographic committees.
204 citations
TL;DR: This work proposes here a general method predicting, for the first time, the evolution of structural transitions and selectivity upon adsorption of gas mixtures in flexible nanoporous solids.
Abstract: Among the numerous applications of metal−organic frameworks (MOFs), a topical class of nanoporous materials, adsorptive separation is gaining considerable attention. Some of the most exciting candidates for gas separation processes exhibit structural transitions, such as breathing and gate opening. While predictive analytical methods are crucial in separation science and have been widely used for rigid nanoporous solids, a lack exists for materials that exhibit flexibility. We propose here a general method predicting, for the first time, the evolution of structural transitions and selectivity upon adsorption of gas mixtures in flexible nanoporous solids.
149 citations
15 May 2009
TL;DR: A layered approach is designed to address many of the real-world problems that an inexpensive lane detection system would encounter and shows good performance when tested on real- world data that contains fluctuating illumination and a variety of traffic conditions.
Abstract: A layered approach is designed to address many of the real-world problems that an inexpensive lane detection system would encounter. A region of interest is first extracted from the image followed by an enhancement procedure to manipulate the shape of the lane markers. The extracted region is then converted to binary using an adaptive threshold. A model based line detection system hypothesizes lane position. Finally, an iterated matched filtering scheme estimates the final lane position. The developed system shows good performance when tested on real-world data that contains fluctuating illumination and a variety of traffic conditions.
93 citations
TL;DR: The findings suggest that the current hard binary fraction near the half-mass radius is a good indicator of the hard primordial binary fraction, but the relationship between the true binary fraction and the fraction of main-sequence stars in binaries is nonlinear and rather complicated.
Abstract: Using our recently improved Monte Carlo evolution code, we study the evolution of the binary fraction in globular clusters. In agreement with previous N-body simulations, we find generally that the hard binary fraction in the core tends to increase with time over a range of initial cluster central densities for initial binary fractions 90%. The dominant processes driving the evolution of the core binary fraction are mass segregation of binaries into the cluster core and preferential destruction of binaries there. On a global scale, these effects and the preferential tidal stripping of single stars tend to roughly balance, leading to overall cluster binary fractions that are roughly constant with time. Our findings suggest that the current hard binary fraction near the half-mass radius is a good indicator of the hard primordial binary fraction. However, the relationship between the true binary fraction and the fraction of main-sequence stars in binaries (which is typically what observers measure) is nonlinear and rather complicated. We also consider the importance of soft binaries, which not only modify the evolution of the binary fraction, but can also drastically change the evolution of the cluster as a whole. Finally, we briefly describe the recent addition of single and binary stellar evolution to our cluster evolution code.
82 citations
TL;DR: In this paper, power density spectra (PDS) of X-ray flux variability in binary systems where the accretion flow is truncated by the magnetosphere was studied.
Abstract: We study power density spectra (PDS) of X-ray flux variability in binary systems where the accretion flow is truncated by the magnetosphere. PDS of accreting X-ray pulsars where the neutron star is close to the corotation with the accretion disk at the magnetospheric boundary, have a distinct break/cutoff at the neutron star spin frequency. This break can naturally be explained in the "perturbation propagation" model, which assumes that at any given radius in the accretion disk stochastic perturbations are introduced to the flow with frequencies characteristic for this radius. These perturbations are then advected to the region of main energy release leading to a self-similar variability of X-ray flux P~f^{-1...-1.5}. The break in the PDS is then a natural manifestation of the transition from the disk to magnetospheric flow at the frequency characteristic for the accretion disk truncation radius (magnetospheric radius). The proximity of the PDS break frequency to the spin frequency in corotating pulsars strongly suggests that the typical variability time scale in accretion disks is close to the Keplerian one. In transient accreting X-ray pulsars characterized by large variations of the mass accretion rate during outbursts, the PDS break frequency follows the variations of the X-ray flux, reflecting the change of the magnetosphere size with the accretion rate. Above the break frequency the PDS steepens to ~f^{-2} law which holds over a broad frequency range. These results suggest that strong f^{-1...-1.5} aperiodic variability which is ubiquitous in accretion disks is not characteristic for magnetospheric flows.
76 citations
TL;DR: New algorithms and properties are presented in this paper which are used in a software implementation of the IEEE 754R decimal floatingpoint arithmetic, with emphasis on using binary operations efficiently.
Abstract: The IEEE Standard 754-1985 for binary floating-point arithmetic [19] was revised [20], and an important addition is the definition of decimal floating-point arithmetic [8], [24]. This is intended mainly to provide a robust reliable framework for financial applications that are often subject to legal requirements concerning rounding and precision of the results, because the binary floating-point arithmetic may introduce small but unacceptable errors. Using binary floating-point calculations to emulate decimal calculations in order to correct this issue has led to the existence of numerous proprietary software packages, each with its own characteristics and capabilities. The IEEE 754R decimal arithmetic should unify the ways decimal floating-point calculations are carried out on various platforms. New algorithms and properties are presented in this paper, which are used in a software implementation of the IEEE 754R decimal floating-point arithmetic, with emphasis on using binary operations efficiently. The focus is on rounding techniques for decimal values stored in binary format, but algorithms are outlined for the more important or interesting operations of addition, multiplication, and division, including the case of nonhomogeneous operands, as well as conversions between binary and decimal floating-point formats. Performance results are included for a wider range of operations, showing promise that our approach is viable for applications that require decimal floating-point calculations. This paper extends an earlier publication [6].
72 citations
06 Nov 2009
TL;DR: In this paper, an algebraic model that describes the operation of binary Switched-Capacitor Converters (SCC) was developed and generalized to any radix case.
Abstract: An algebraic model that describes the operation of binary Switched-Capacitor Converters (SCC) was developed and generalized to any radix case. The proposed approach reduces the power loss by increasing the number of target voltages. In the binary case, the flying capacitors are automatically kept charged to binary weighted voltages and consequently, the resolution of the possible target voltages is binary. The paper presents the underlining theory of the proposed SCC and two new control methods to regulate the output voltage. It is shown that the theoretical formulation of the new number systems can describe many SCC circuits on the market and can help design new SCC with a larger number of target voltages. The theoretical results were verified for the binary case by simulation and experimentally. Excellent agreement was found between the theory and experimental results. The down side of the proposed SCC schemes is the relatively large number of switches which makes the approach more suitable for low power applications.
71 citations
TL;DR: The authors compare the performance of simple markets, combinatorial markets, call markets, and a market maker, isolated individuals who report to a scoring rule, and two ways to combine those individual reports into a group prediction.
Abstract: While a simple information market lets one trade on the probability of each value of a single variable, a full combinatorial information market lets one trade on any combination of values of a set of variables, including any conditional or joint probability. In laboratory experiments, we compare the accuracy of simple markets, two kinds of combinatorial markets, a call market and a market maker, isolated individuals who report to a scoring rule, and two ways to combine those individual reports into a group prediction. We consider two environments with asymmetric information on sparsely correlated binary variables, one with three subjects and three variables, and the other with six subjects and eight variables (thus 256 states).
70 citations
TL;DR: In this article, the authors investigate the characteristics of fast random bit generation using chaotic semiconductor lasers and show that chaotic laser devices can be fast and reliable sources of physical entropy for computing and communication applications.
Abstract: We investigate the characteristics of fast random bit generation using chaotic semiconductor lasers. The optical amplitudes of two lasers with chaotic oscillations induced by optical feedback are each sampled at a fixed rate to extract binary bit sequences which are then combined by an exclusive-OR operation to obtain a single random bit sequence. Bit sequences generated at rate of 1 Giga bit per second are verified to pass statistical tests of randomness. We describe the dependence of randomness on laser parameters, in particular the injection current, the external cavity length and the feedback strength. The results provide clear empirical guidelines for tuning the chaotic laser parameters to achieve random bit sequences. This study shows that chaotic laser devices can be fast and reliable sources of physical entropy for computing and communication applications.
59 citations
TL;DR: In this paper, a multi-wavelength study of the black hole X-ray binary V404 Cyg in quiescence is presented, focusing upon the spectral energy distribution (SED).
Abstract: We present a multiwavelength study of the black hole X-ray binary V404 Cyg in quiescence, focusing upon the spectral energy distribution (SED). Radio, optical, UV, and X-ray coverage is simultaneous. We supplement the SED with additional non-simultaneous data in the optical through infrared where necessary. The compiled SED is the most complete available for this, the X-ray and radio brightest quiescent black hole system. We find no need for a substantial contribution from accretion light from the near-UV to the near-IR, and in particular the weak UV emission constrains published spectral models for V404 Cyg. We confirm that no plausible companion spectrum and interstellar extinction can fully explain the mid-IR, however, and an IR excess from a jet or cool disc appears to be required. The X-ray spectrum is consistent with a Gamma~2 power-law as found by all other studies to date. There is no evidence for any variation in the hardness over a range of a factor of 10 in luminosity. The radio flux is consistent with a flat spectrum (in f(nu)). The break frequency between a flat and optically thin spectrum most likely occurs in the mid or far-IR, but is not strongly constrained by these data. We find the radio to be substantially variable but with no clear correlation with X-ray variability.
TL;DR: Novel designs of certain all-optical circuits that can be used for realizing multi-valued logic functions are presented and Polarization encoded all-Optical quaternary (4-valued) R–S flip-flop is proposed and described.
11 Feb 2009
TL;DR: DHV is an efficient code consistency maintenance protocol to ensure that every node in a network will eventually have the same code, based on the simple observation that if two code versions are different, their corresponding version numbers often differ in only a few least significant bits of their binary representation.
Abstract: Ensuring that every sensor node has the same code version is challenging in dynamic, unreliable multi-hop sensor networks. When nodes have different code versions, the network may not behave as intended, wasting time and energy. We propose and evaluate DHV, an efficient code consistency maintenance protocol to ensure that every node in a network will eventually have the same code. DHV is based on the simple observation that if two code versions are different, their corresponding version numbers often differ in only a few least significant bits of their binary representation. DHV allows nodes to carefully select and transmit only necessary bit level information to detect a newer code version in the network. DHV can detect and identify version differences in O (1) messages and latency compared to the logarithmic scale of current protocols. Simulations and experiments on a real MicaZ testbed show that DHV reduces the number of messages by 50%, converges in half the time, and reduces the number of bits transmitted by 40-60% compared to DIP, the state-of-the-art protocol.
TL;DR: The idea is to polarize two adjacent Booth encoded digits to directly form an RB partial product to avoid the hard multiple of high-radix Booth encoding without incurring any correction vector, which leads to lower encoding and decoding complexity than the recently proposed RB Booth encoder.
Abstract: The use of redundant binary (RB) arithmetic in the design of high-speed digital multipliers is beneficial due to its high modularity and carry-free addition. To reduce the number of partial products, a high-radix-modified Booth encoding algorithm is desired. However, its use is hampered by the complexity of generating the hard multiples and the overheads resulting from negative multiples and normal binary (NB) to RB number conversion. This paper proposes a new RB Booth encoding scheme to circumvent these problems. The idea is to polarize two adjacent Booth encoded digits to directly form an RB partial product to avoid the hard multiple of high-radix Booth encoding without incurring any correction vector. The proposed method leads to lower encoding and decoding complexity than the recently proposed RB Booth encoder. Synthesis results using Artisan TSMC 0.18-mum standard-cell library show that the RB multipliers designed with our proposed Booth encoding algorithm exhibit on average 14% higher speed and 17% less energy-delay product than the existing multiplication algorithms for a gamut of power-of-two word lengths from 8 to 64 b.
TL;DR: It is shown that under the ideal case the increase in throughput resulting from the proposed multilevel FO-CDMA system is proportional to the number of classes or power levels in use, and a closed-form relation for the upper bound on the probability of error is obtained.
Abstract: In this paper we introduce and propose novel signaling methods and receiver structures based on advanced binary optical logic gates for fiber-optic code division multiple access (FO-CDMA) systems using all-optical signal processing. In the proposed system the users of the network are categorized into multiple classes. Users of each class transmit at the same power level but different from the levels of the other classes' users. Using a combination of optical OR, AND and XNOR logic gates for the receiver structure we show that such a network not only takes the full advantages of all-optical signal processing but also demonstrates a considerable throughput efficiency when compared to ordinary FO-CDMA systems. The proposed receiver structure mitigates the effect of interfering users from the other classes by rejecting some specified power level combinations from the other classes. The depth of interference cancellation is a function of the corresponding number of power levels and the number of stages applied to the optical logic gates in use. In our analysis we choose the generalized form of optical orthogonal codes (OOC), i.e., OOCs with cross-correlation value greater than one, as the signature sequence. We begin by emphasizing on two-level systems, that is, when the users can select one out of two power levels for signal transmission. However, for multilevel FO-CDMA we obtain a closed-form relation for the upper bound on the probability of error.We will show that under the ideal case the increase in throughput resulting from the proposed multilevel system is proportional to the number of classes or power levels in use. Our analytical results are compared to the results of an extensive system simulation. The numerical closeness between, the analytical and system simulation, indicates the accuracy with which we have modeled mathematically our proposed signaling using advanced binary optical logic gates in FO-CDMA.
29 Jun 2009
TL;DR: Preliminary results of experiments with finding efficient circuits (over binary bases) using SAT-solvers using MOD-functions are reported and upper bounds for functions with constant number of inputs as well as general upper bounds that were found automatically are presented.
Abstract: In this paper we report preliminary results of experiments with finding efficient circuits (over binary bases) using SAT-solvers. We present upper bounds for functions with constant number of inputs as well as general upper bounds that were found automatically. We focus mainly on MOD-functions. Besides theoretical interest, these functions are also interesting from a practical point of view as they are the core of the residue number system. In particular, we present a circuit of size 3n + c over the full binary basis computing ${\rm MOD}_3^n$.
TL;DR: A modular synthesis method to realize a reversible BCD-full adder (BCD-FA) and subtractor circuit using genetic algorithm and don't care concept is proposed and a binary to BCD converter is presented.
Abstract: Reversible logic and binary coded decimal (BCD) arithmetic are two concerning subjects of hardware. This paper proposes a modular synthesis method to realize a reversible BCD-full adder (BCD-FA) and subtractor circuit. We propose three approaches to design and optimize all parts of a BCD-FA circuit using genetic algorithm and don't care concept. Our first approach is based on the Hafiz's work, and the second one is based on the whole BCD-FA circuit design. In the third approach, a binary to BCD converter is presented. Optimizations are done in terms of number of gates, number of garbage inputs/outputs, and the quantum cost of the circuit. We present four designs for BCD-FA with four different goals: minimum garbage inputs/outputs, minimum quantum cost, minimum number of gates, and optimum circuit in terms of all the above parameters.
11 Dec 2009
TL;DR: An improved Binary PSO is proposed which changes the formula of its probability mapping and the formulas of bit obtaining value to intensify the local exploration of binary PSO.
Abstract: In this paper, the binary Particle Swarm Optimization (PSO) is analyzed with bit change rate and velocity expected value, which results is that binary PSO is more and more stochastic, has the powerful ability of global search, but cannot converge to the optimal particle of swarm. So the Binary PSO is lack of local exploration which instructs the improvement of BPSO. Based on the analysis, an improved Binary PSO is proposed which changes the formula of its probability mapping and the formula of bit obtaining value. The new formulas are favorable of particle’ s convergence to the optimal particle and to intensify the local exploration of binary PSO. With 0/1 knapsack problem, the experiment conducted in this paper shows that the improved binary PSO is outperformed to original binary PSO.
01 Jan 2009
TL;DR: This paper provides a concise introduction to targeted maximum likelihood estimation (TMLE) of causal effect parameters and implements a basic version of TMLE that can be used to estimate the effect of a binary point treatment on a continuous or binary outcome.
Abstract: This paper provides a concise introduction to targeted maximum likelihood estimation (TMLE) of causal effect parameters. The interested analyst should gain sufficient understanding of TMLE from this introductory tutorial to be able to apply the method in practice. A program written in R is provided. This program implements a basic version of TMLE that can be used to estimate the effect of a binary point treatment on a continuous or binary outcome. Targeted Maximum Likelihood Estimation: A Gentle Introduction Susan Gruber and Mark J. van der Laan Division of Biostatistics, University of California, Berkeley sgruber@berkeley.edu, laan@berkeley.edu
TL;DR: In this paper, the authors studied the relation of radio emission to X-ray spectral and variability properties for a large sample of black hole Xray binary systems and found no strong evidence against the originally proposed model, confirming and extending some aspects of it with a much larger sample.
Abstract: In this paper we study the relation of radio emission to X-ray spectral and variability properties for a large sample of black hole X-ray binary systems. This is done to test, refine and extend -- notably into the timing properties -- the previously published `unified model' for the coupling of accretion and ejection in such sources. In 14 outbursts from 11 different sources we find that in every case the peak radio flux, on occasion directly resolved into discrete relativistic ejections, is associated with the bright hard to soft state transition near the peak of the outburst. We also note the association of the radio flaring with periods of X-ray flaring during this transition in most, but not all, of the systems. In the soft state, radio emission is in nearly all cases either undetectable or optically thin, consistent with the suppression of the core jet in these states and `relic' radio emission from interactions of previously ejected material and the ambient medium. However, these data cannot rule out an intermittent, optically thin, jet in the soft state. In attempting to associate X-ray timing properties with the ejection events we find a close, but not exact, correspondence between phases of very low integrated X-ray variability and such ejections. In summary we find no strong evidence against the originally proposed model, confirming and extending some aspects of it with a much larger sample, but note that several aspects remain poorly tested. (ABRIDGED)
TL;DR: A polarization encoded all-optical scheme for a binary-(radix = 2)-to-quaternary (radx = 4) encoder and a quaternary-to-binary decoder is proposed and described, which is simple, practical and useful for future all- optical information processing.
Abstract: A polarization encoded all-optical scheme for a binary-(radix = 2)-to-quaternary (radix = 4) encoder and a quaternary-to-binary decoder is proposed and described. The performance of the proposed circuit is verified through numerical calculation. In this all-optical scheme, the numbers are represented by different discrete polarized states of light. The model is simple, practical and useful for future all-optical information processing.
TL;DR: All-optical scheme for the conversion of binary to quaternary number and vice versa have been proposed and described and Simulation has also been done.
Abstract: To achieve the inherent parallelism in optics a suitable number system and efficient encoding/decoding scheme for handling the data are very much essential. Binary number is accepted as the best representing number system in almost all types of existing electronic computers. But, binary number (0 and 1) is insufficient in respect to the demand of the coming generation. Multi-valued logic (with radix >2) can be viewed as an alternative approach to solve many problems in transmission, storage and processing of large amount of information in digital signal processing. Here, in this paper all-optical scheme for the conversion of binary to quaternary number and vice versa have been proposed and described. Simulation has also been done. In this all-optical scheme the numbers are represented by different discrete polarized state of light.
TL;DR: In this paper, a family of lower bounds for the sum capacity of code-division multiple access (CDMA) channels assuming binary inputs and binary signature codes in the presence of additive noise with an arbitrary distribution was derived.
Abstract: In this paper, we obtain a family of lower bounds for the sum capacity of code-division multiple-access (CDMA) channels assuming binary inputs and binary signature codes in the presence of additive noise with an arbitrary distribution. The envelope of this family gives a relatively tight lower bound in terms of the number of users, spreading gain, and the noise distribution. The derivation methods for the noiseless and the noisy channels are different but when the noise variance goes to zero, the noisy channel bound approaches the noiseless case. The behavior of the lower bound shows that for small noise power, the number of users can be much more than the spreading gain without any significant loss of information (overloaded CDMA). A conjectured upper bound is also derived under the usual assumption that the users send out equally likely binary bits in the presence of additive noise with an arbitrary distribution. As the noise level increases, and/or, the ratio of the number of users and the spreading gain increases, the conjectured upper bound approaches the lower bound. We have also derived asymptotic limits of our bounds that can be compared to a formula that Tanaka obtained using techniques from statistical physics; his bound is close to that of our conjectured upper bound for large scale systems.
TL;DR: This paper presents an analytical solution for the case where no material is deposited ahead of the front and numerical solutions and scaling arguments for more general cases.
Abstract: Phase-separation fronts leave in their wakes morphologies that are substantially different from the morphologies formed in homogeneous phase separation. In this paper we focus on fronts in binary mixtures that are enslaved phase-separation fronts, i.e., fronts that follow in the wake of a control-parameter front. In the one-dimensional case, which is the focus of this paper, the formed morphology is deceptively simple: alternating domains of a regular size. However, determining the size of these domains as a function of the front speed and other system parameters is a nontrivial problem. We present an analytical solution for the case where no material is deposited ahead of the front and numerical solutions and scaling arguments for more general cases. Through these enslaved phase-separation fronts large domains can be formed that are practically unattainable in homogeneous one-dimensional phase separation.
TL;DR: Two bounded cost algorithms that solve multivalued consensus using binary consensus instances, where [email protected]?
07 Jul 2009
TL;DR: The synthesis results show that hardware sharing is feasible and has a reasonable impact on area, latency, and delay, and the critical path delay of a combined multiplier has a negligible increase over a standalone DFP multiplier.
Abstract: In this paper, we describe the first hardware design of a combined binary and decimal floating-point multiplier, based on specifications in the IEEE 754-2008 Floating-point Standard. The multiplier design operates on either (1) 64-bit binary encoded decimal floating-point (DFP) numbers or (2) 64-bit binary floating-point (BFP) numbers. It returns properly rounded results for the rounding modes specified in IEEE 754-2008. The design shares the following hardware resources between the two floating-point datatypes: a 54-bit by 54-bit binary multiplier, portions of the operand encoding/decoding, a 54-bit right shifter, exponent calculation logic, and rounding logic. Our synthesis results show that hardware sharing is feasible and has a reasonable impact on area, latency, and delay. The combined BFP and DFP multiplier occupies only 58% of the total area that would be required by separate BFP and DFP units. Furthermore, the critical path delay of a combined multiplier has a negligible increase over a standalone DFP multiplier, without increasing the number of cycles to perform either BFP or DFP multiplication.
TL;DR: This paper researches DAC codeword distribution over interval [0, 1] for equiprobable binary sources for equipped binary sources to verify theoretical analyses.
Abstract: Distributed Arithmetic Coding (DAC) is an effective implementation of Slepian-Wolf coding, especially for short data blocks. However, the properties of DAC codewords have not yet been studied so far. This paper researches DAC codeword distribution over interval [0, 1] for equiprobable binary sources. Some simulation results are given to verify theoretical analyses.
TL;DR: In this paper, quasi-simultaneous, multi-frequency Very Large Array observations at 4.8, 8.4, and 22.5 GHz of a sample of 13 Wolf-Rayet (WR) stars are presented, aimed at disentangling the nature of their radio emission and the possible detection of a nonthermal behavior in close binary systems.
Abstract: We present quasi-simultaneous, multi-frequency Very Large Array observations at 4.8, 8.4, and 22.5 GHz of a sample of 13 Wolf-Rayet (WR) stars, aimed at disentangling the nature of their radio emission and the possible detection of a non-thermal behavior in close binary systems. We detected 12 stars from our sample, for which we derived spectral information and estimated their mass-loss rates. From our data, we identified four thermal sources (WR 89, 113, 138, and 141), and three sources with a composite spectrum (similar contribution of thermal and non-thermal emission; WR 8, 98, and 156). On the other hand, from the comparison with previous observations, we confirm the non-thermal spectrum of one (WR 105), and also found evidence of a composite spectrum for WR 79a, 98a, 104, and 133. Finally, we discuss the possible scenarios to explain the nature of the emission for the observed objects.
TL;DR: An efficient and robust technique for observability checking in power system state estimation based on Gaussian elimination and binary arithmetic is provided and no rounding error, numerical instability or zero identification problems occur.
Abstract: An efficient and robust technique for observability checking in power system state estimation based on Gaussian elimination and binary arithmetic is provided. Since the proposed technique uses binary arithmetic, no rounding error, numerical instability or zero identification problems occur. In some cases, the technique may not identify all observable state variables, requiring an additional numerical analysis over a matrix of dimension that is highly reduced. An illustrative example of small size and a realistic case study are used to demonstrate the features of the proposed technique. Adequate conclusions are finally drawn.
30 Aug 2009
TL;DR: This paper uses a modified version of Yao's algorithm to go back from the popular double base chain representation to a more general double base system, and proposes for the first time a binary/Zeckendorf representation for integers, providing interesting results.
Abstract: In this paper we propose to take one step back in the use of double base number systems for elliptic curve point scalar multiplication. Using a modified version of Yao's algorithm, we go back from the popular double base chain representation to a more general double base system. Instead of representing an integer k as $\sum^n_{i=1}2^{b_i}3^{t_i}$ where (b i ) and (t i ) are two decreasing sequences, we only set a maximum value for both of them. Then, we analyze the efficiency of our new method using different bases and optimal parameters. In particular, we propose for the first time a binary/Zeckendorf representation for integers, providing interesting results. Finally, we provide a comprehensive comparison to state-of-the-art methods, including a large variety of curve shapes and latest point addition formulae speed-ups.