Showing papers on "Binary number published in 2008"

Design of regular (2,d/sub c/)-LDPC codes over GF(q) using their binary images

Abstract: In this paper, a method to design regular (2, dc)- LDPC codes over GF(q) with both good waterfall and error floor properties is presented, based on the algebraic properties of their binary image. First, the algebraic properties of rows of the parity check matrix H associated with a code are characterized and optimized to improve the waterfall. Then the algebraic properties of cycles and stopping sets associated with the underlying Tanner graph are studied and linked to the global binary minimum distance of the code. Finally, simulations are presented to illustrate the excellent performance of the designed codes.

Design of Regular (2,d c )-LDPC Codes over GF(q )U sing Their Binary Images

Abstract: In this paper, a method to design regular (2,dc)- LDPC codes over GF(q) with both good waterfall and error floor properties is presented, based on the algebraic properties of their binary image. First, the algebraic properties of rows of the parity check matrix H associated with a code are characterized and optimized to improve the waterfall. Then the algebraic properties of cycles and stopping sets associated with the underlying Tanner graph are studied and linked to the global binary minimum distance of the code. Finally, simulations are presented to illustrate the excellent performance of the designed codes. Index Terms—Channel coding, error correction coding, non- binary LDPC codes, iterative decoding, binary image.

The evolution of the multiplicity of embedded protostars. ii. binary separation distribution and analysis

Abstract: We present the Class I protostellar binary separation distribution based on the data tabulated in a companion paper. We verify the excess of Class I binary stars over solar-type main-sequence stars in the separation range from 500 AU to 4500 AU. Although our sources are in nearby star-forming regions distributed across the entire sky (including Orion), none of our objects are in a high stellar density environment. A log-normal function, used by previous authors to fit the main-sequence and T Tauri binary separation distributions, poorly fits our data, and we determine that a log-uniform function is a better fit. Our observations show that the binary separation distribution changes significantly during the Class I phase, and that the binary frequency at separations greater than 1000 AU declines steadily with respect to spectral index. Despite these changes, the binary frequency remains constant until the end of the Class I phase, when it drops sharply. We propose a scenario to account for the changes in the Class I binary separation distribution. This scenario postulates that a large number of companions with a separation greater than ~1000 AU were ejected during the Class 0 phase, but remain gravitationally bound due to the significant mass of the Class I envelope. As the envelope dissipates, these companions become unbound and the binary frequency at wide separations declines. Circumstellar and circumbinary disks are expected to play an important role in the orbital evolution at closer separations. This scenario predicts that a large number of Class 0 objects should be non-hierarchical multiple systems, and that many Class I young stellar objects (YSOs) with a widely separated companion should also have a very close companion. We also find that Class I protostars are not dynamically pristine, but have experienced dynamical evolution before they are visible as Class I objects. Our analysis shows that the Class I binary frequency and the binary separation distribution strongly depend on the star-forming environment.

Modeling disjunctive constraints with a logarithmic number of binary variables and constraints

Abstract: Many combinatorial constraints over continuous variables such as SOS1 and SOS2 constraints can be interpreted as disjunctive constraints that restrict the variables to lie in the union of m specially structured polyhedra. Known mixed integer binary formulations for these constraints have a number of binary variables and extra constraints that is linear in m. We give sufficient conditions for constructing formulations for these constraints with a number of binary variables and extra constraints that is logarithmic in m. Using these conditions we introduce the first mixed integer binary formulations for SOS1 and SOS2 constraints that use a number of binary variables and extra constraints that is logarithmic in the number of continuous variables. We also introduce the first mixed integer binary formulations for piecewise linear functions of one and two variables that use a number of binary variables and extra constraints that is logarithmic in the number of linear pieces of the functions. We prove that the new formulations for piecewise linear functions have favorable tightness properties and present computational results showing that they can significantly outperform other mixed integer binary formulations.

The Evolution of the Multiplicity of Embedded Protostars II: Binary Separation Distribution & Analysis

Abstract: We present the Class I protostellar binary separation distribution based on the data tabulated in the companion paper. We verify the excess of Class I binary stars over solar-type main-sequence stars, especially at separations beyond 500 AU. Although our sources are in nearby star forming regions distributed across the entire sky (including Orion), none of our objects are in a high stellar density environment. The binary separation distribution changes significantly during the Class I phase, and the binary frequency at separations greater than 1000 AU declines steadily with respect to spectral index. Despite these changes, the binary frequency remains constant until the end of the Class I phase, when it drops sharply. We propose a scenario to account for the changes in the Class I binary separation distribution. This scenario postulates that companions with a separation greater than ~1000 AU were ejected during the Class 0 phase, but remain gravitationally bound due to the mass of the envelope. As the envelope dissipates, these companions become unbound and the binary frequency at wide separations declines. This scenario predicts that a large number of Class 0 objects should be non-hierarchical multiple systems, and that many Class I YSOs with a widely separated companion should also have a very close companion. We also find that Class I protostars are not dynamically pristine, and have experienced dynamical evolution before they are visible as Class I objects. For the first time, evidence is presented showing that the Class I binary frequency and the binary separation distribution strongly depend on the star forming environment. The reason for this dependence remains unclear.

Non Binary and Precoded Faster Than Nyquist Signaling

Abstract: Faster than Nyquist (FTN) signaling is an important method of narrowband coding. The concept is extended here to non binary signal constellations; these are much more bandwidth efficient than binary ones. A powerful method of finding the minimum distance for binary and non binary FTN is presented. Preceding FTN transmissions with short linear filters proves to be an effective way to gain distance. A Shannon limit to bit error rate is derived that applies for FTN. Tests of an M-algorithm receiver are performed and compared to this limit.

Method and apparatus for context adaptive binary arithmetic coding and decoding

Abstract: A method of and apparatus for context adaptive binary arithmetic coding and decoding of a significance map indicating the position of a coefficient that is not zero in a residual block are provided. According to the method and apparatus, a subdivided context is selected according to whether or not a coefficient of a previous residual block corresponding to a coefficient of a current residual block, and binary arithmetic coding is performed according to the selected context, thereby improving the performance of context-based binary arithmetic coding.

The evolution of the binary population in globular clusters: a full analytical computation

Abstract: I present a simplified analytical model that simulates the evolution of the binary population in a dynamically evolving globular cluster. A number of simulations have been run spanning a wide range in initial cluster and environmental conditions by taking into account the main mechanisms of formation and destruction of binary systems. Following this approach, I investigate the evolution of the fraction, the radial distribution, the distribution of mass ratios and periods of the binary population. According to these simulations, the fraction of surviving binaries appears to be dominated by the processes of binary ionization and evaporation. In particular, the frequency of binary systems changes by a factor of 1-5 depending on the initial conditions and on the assumed initial distribution of periods. The comparison with the existing estimates of binary fractions in Galactic globular clusters suggests that significant variations in the initial binary content could exist among the analysed globular cluster. This model has been also used to explain the observed discrepancy found between the most recent N-body and Monte Carlo simulations in the literature.

Tight Bounds on the Capacity of Binary Input random CDMA Systems

Abstract: We consider multiple access communication on a binary input additive white Gaussian noise channel using randomly spread code division. For a general class of symmetric distributions for spreading coefficients, in the limit of a large number of users, we prove an upper bound on the capacity, which matches a formula that Tanaka obtained by using the replica method. We also show concentration of various relevant quantities including mutual information, capacity and free energy. The mathematical methods are quite general and allow us to discuss extensions to other multiuser scenarios.

Restricted Full Three-Body Problem : Application to Binary System 1999 KW4

Abstract: DOI: 10.2514/1.30937 The motion of a satellite in the gravitational field of a binary system is investigated. The two bodies of the binary systemaremodeledas asphere andatriaxialellipsoid andthesatelliteisassumed tohavenoinfluenceonthemotion of the two primaries. The case of relative equilibria in the full two-body problem is assumed. In earlier papers, we looked at equilibrium solutions in the restricted full three-body problem, especially for L4;5. In the present work, we investigate energy constraints on the motion of the spacecraft using zero-velocity curves, collinear Lagrangian points, and the Jacobi constant for varying parameters of the system. We study transit and nontransit trajectories between the components. The methods are applied in the study of the binary asteroid system 1999 KW4, and some results are shown.

Topological Repairing of 3D Digital Images

Abstract: We present here a new randomized algorithm for repairing the topology of objects represented by 3D binary digital images. By "repairing the topology", we mean a systematic way of modifying a given binary image in order to produce a similar binary image which is guaranteed to be well-composed. A 3D binary digital image is said to be well-composed if, and only if, the square faces shared by background and foreground voxels form a 2D manifold. Well-composed images enjoy some special properties which can make such images very desirable in practical applications. For instance, well-known algorithms for extracting surfaces from and thinning binary images can be simplified and optimized for speed if the input image is assumed to be well-composed. Furthermore, some algorithms for computing surface curvature and extracting adaptive triangulated surfaces, directly from the binary data, can only be applied to well-composed images. Finally, we introduce an extension of the aforementioned algorithm to repairing 3D digital multivalued images. Such an algorithm finds application in repairing segmented images resulting from multi-object segmentations of other 3D digital multivalued images.

Speeding up chemical database searches using a proximity filter based on the logical exclusive or.

Abstract: In many large chemoinformatics database systems, molecules are represented by long binary fingerprint vectors whose components record the presence or absence in the molecular graphs of particular functional groups or combinatorial features, such as labeled paths or labeled trees. To speed up database searches, we propose to store with each fingerprint a small header vector containing primarily the result of applying the logical exclusive OR (XOR) operator to the fingerprint vector after modulo wrapping to a smaller number of bits, such as 128 bits. From the XOR headers of two molecules, tight bounds on the intersection and union of their fingerprint vectors can be rapidly obtained, yielding tight bounds on derived similarity measures, such as the Tanimoto measure. During a database search, every time these bounds are unfavorable, the corresponding molecule can be rapidly discarded with no need for further inspection. We derive probabilistic models that allow us to estimate precisely the behavior of the XO...

Terahertz optical asymmetric demultiplexer based tree-net architecture for all-optical conversion scheme from binary to its other 2n radix based form

Abstract: To exploit the parallelism of optics in data processing, a suitable number system and an efficient encoding/decoding scheme for handling the data are very essential. In the field of optical computing and parallel information processing, several number systems like binary, quaternary, octal, hexadecimal, etc. have been used for different arithmetic and algebraic operations. Here, we have proposed an all-optical conversion scheme from its binary to its other 2n radix based form with the help of terahertz optical asymmetric demultiplexer (TOAD) based tree-net architecture.

Decimal multiplication using compact BCD multiplier

Abstract: Decimal multiplication is an integral part of financial, commercial, and internet-based computations. The basic building block of a decimal multiplier is a single digit multiplier. It accepts two Binary Coded Decimal (BCD) inputs and gives a product in the range [0, 81] represented by two BCD digits. A novel design for single digit decimal multiplication that reduces the critical path delay and area is proposed in this research. Out of the possible 256 combinations for the 8-bit input, only hundred combinations are valid BCD inputs. In the hundred valid combinations only four combinations require 4 times 4 multiplication, 64 combinations need 3 times 3 multiplication, and the remaining 32 combinations use either 3 times 4 or 4 times 3 multiplication. The proposed design makes use of this property. This design leads to more regular VLSI implementation, and does not require special registers for storing easy multiples. This is a fully parallel multiplier utilizing only combinational logic, and is extended to a Hex/Decimal multiplier that gives either a decimal output or a binary output. The accumulation of partial products generated using single digit multipliers is done by an array of multi-operand BCD adders for an (n-digit times n-digit) multiplication.

Microlensing Detections of Planets in Binary Stellar Systems

Abstract: We demonstrate that microlensing can be used for detecting planets in binary stellar systems. This is possible because in the geometry of planetary binary systems, in which the planet orbits one of the binary components and the other binary star is located at a large distance, both planet and secondary companion produce perturbations in a common region around the planet-hosting binary star, and thus the signatures of both planet and binary companion can be detected in the light curves of high-magnification lensing events. We find that identifying planets in binary systems is optimized when the secondary is located within a certain range that depends on the type of the planet. The proposed method can detect planets with masses down to one-tenth of the Jupiter mass in binaries with separations 100 AU. These ranges of planet masses and binary separations are not covered by other methods, and thus microlensing would be able to make the planetary binary sample richer.

On the spectral gap of the kac walk and other binary collision processes

Abstract: We give a new and elementary computation of the spectral gap of the Kac walk on S N. The result is obtained as a by-product of a more general obser- vation which allows to reduce the analysis of the spectral gap of an N-component system to that of the same system for N = 3. The method applies to a number of random "binary collision" processes with complete-graph structure, including non-homogeneous examples such as exclusion and colored exclusion processes with site disorder.

Searching for gravitational waves from binary systems in non-stationary data

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A New Residue to Binary Converter Based on Mixed-Radix Conversion

Abstract: In this paper, an efficient design of the residue to binary converter for the new moduli set {2n-1, 2n, 22n+1-1} based on mixed-radix conversion (MRC) is presented. The moduli set {2n-1, 2n, 22n+1-1} is obtained by enhancing one of the moduli of the recently introduced moduli set {2n-1, 2n, 22n+1-1}. The proposed moduli set includes well-formed moduli which can result in efficient residue to binary conversion as well as binary to residue conversion. The presented residue to binary converter is adder based and requires less conversion time and lower hardware cost, compared to the residue to binary converters for a moduli set with similar dynamic range.

Novel High-Speed Architecture for 32-Bit Binary Coded Decimal (BCD) Multiplier

Abstract: With the increasing prominence of commercial, financial and Internet-based applications that process data in decimal format, there is a renewed interest in providing hardware support to handle such data. In this paper, novel efficient parallel architectures for 32-digit binary coded decimal (BCD) multipliers are proposed using novel binary counters, BCD full adders and binary to BCD converters. These binary counters have been designed and used to add the partial products generated during multiplication using a partial product reduction tree. The proposed architecture focuses on using efficient binary architectures to compute BCD products without the loss of accuracy. The existing and proposed architectures have been simulated and compared (both qualitatively and quantitatively) and the results have been mentioned.

A novel image encryption scheme based on chaotic maps

Abstract: In this paper, a novel image encryption scheme based on chaotic maps is proposed. By combining XOR operations and circular bit shift operation, the security of this encryption algorithm is enhanced effectively. Two chaotic maps are adopted in the proposed scheme. One creates a binary stream for XOR operation, and the other creates some random numbers which are used to determine the circular bit shift. First the pixel values of the plain-image are modified randomly by the classical chaotic masking technique, namely XOR operation from the first block to the last block, and then the modified image is encrypted by the circular bit shit operation from the last block to the first block in the inverse order. The security of the proposed encryption scheme is detailed analyzed, and the experimental results show that the algorithm has a high security performance and a good efficiency.

N-bin arithmetic coding for context adaptive binary arithmetic coding

Abstract: A method of context adaptive binary arithmetic coding and decoding groups a plurality N binary symbols in corresponding syntax elements and divides a range into 2 N subranges based upon corresponding contexts. The invention encodes data by selecting an offset determined by the probability states of the context of the N binary symbols. Decoding is similar with the place of the coded offset within the 2 N subranges determining the syntax decoding. When the total number of binary symbols to be coded does not equal an integral multiple of N, the invention codes dummy binary symbols at the end of a grouping of a plurality N binary symbols. Probability state updates occur only following every N binary symbols.

Construction of pseudorandom binary lattices by using the multiplicative inverse

Abstract: In an earlier work Hubert and the authors of this paper introduced and studied the notion of pseudorandomness of binary lattices. Later in another paper the authors gave a construction for a large family of “good” binary lattices by using the quadratic characters of finite fields. Here, a further large family of “good” binary lattices is constructed by using finite fields and the notion of multiplicative inverse.

Adaptive binary signature design for code-division multiplexing

Abstract: When data symbols modulate a signature waveform to move across a channel in the presence of disturbance, the signature that maximizes the signal-to-interference-plus-noise ratio (SINR) at the output of the maximum-SINR filter is the smallest-eigenvalue eigenvector of the disturbance autocovariance matrix. In digital communication systems the signature alphabet is finite and digital signature optimization is NP-hard. In this paper, we present a formal search procedure of cost, upon eigenvector decomposition, log-linear in the signature code length that returns the maximum-SINR binary signature vector near arcs of least SINR decrease from the real maximum SINR solution in the Euclidean vector space. The quality of the proposed adaptive binary designs is measured against the theoretical upper bound of the complex/real eigenvector maximizer.

A Binary Differential Evolution Algorithm For Transmission And Voltage Constrained Unit Commitment

Abstract: The paper proposes a binary version of the differential evolution algorithm and then solves the transmission and voltage constrained unit commitment using it. The proposed algorithm uses binary coding of the selection variables and implementing OR/XOR/NOT type Boolean logics on variable strings. The inclusion of the ramp rate, transmission/voltage constraints ensure the feasibility of the schedule. The solution algorithm has been found to be capable of finding the optimum/near optimum solution.