On Minimum Weight Binary Representation of Integers and Continued Fractions with Application to Computer Arithmetic

Data is represented and stored in a computer using groups of binary digits called words. This chapter begins by describing binary codes and how words are used to represent characters. It then concentrates on the representation of positive and negative integers and how binary arithmetic is performed within the machine. The chapter concludes with a discussion on the representation of real number and floating point arithmetic.

We argue that a compact right-associated binary number representation gives simpler operators and better efficiency than the leftassociated binary number representation proposed by den Hoed and investigated by Goldberg. This representation is then generalised to higher number-bases and it is argued that bases between 3 and 5can give higher efficiency than binary representation.

This paper illustrates a TI N-Spire .tns file created by the author for generating continued fraction representations of real numbers and doing arithmetic with them. The continued fraction representation provides an alternative to the decimal representation. The .tns file can be used as tool for studying continued fractions and their properties as well as introducing the ideas of a best rational approximation to a real number and exploring some elementary ideas in error analysis. While the paper is a review of some of the classical works on continued factions, it does not present the material in a theorem/proof style. It motivates the results by citing examples and noting some interesting properties that will need to be verified. Notations are given to the references where exact and complete proofs of these facts can be found. The type of investigations done in this paper are motivational and the style of presentation is designed to pique students and teachers curiosity about the subject. Another purpose of this paper is to show that by looking at alternative representations of something that seems to be well known, such as the real numbers, can lead to exciting new and useful outcomes and applications.

Leading Zero Count (LZC) plays a crucial role in arithmetic and logic operations (ALU) within digital circuits, both sequential and combinational. LZC refers to the process of determining the number of consecutive leading zeros in a binary number. Both combinational and sequential LZC circuits find extensive usage in digital signal processing tasks, where quick and accurate determination of leading zeros is essential for various operations like normalization, filtering and feature extraction. Furthermore, they are integral components in hardware implementation of algorithms for data compression and encryption, contributing to enhanced efficiency and performance. The design principles, implementation strategies and applications of leading zero count in both combinational and sequential settings, highlighting their significance in modern digital systems. The LZC system is simulated and synthesized using Xilinx ISE tool and implemented on Artix-7 FPGA.

A competitive neural model of small number detection

This is a bibliographical review that provides a brief glimpse into the beauty of continued fractions and how they can be very useful, both in obtaining good rational approximations of a given real number and in their representation as a continued fraction. Furthermore, it presents important properties, such as the relationship between quadratic irrationals and periodic continued fractions. On the other hand, with a view to a potential introduction of this topic in elementary education, a method for obtaining square root approximations through continued fractions is presented. Finally, using more advanced tools, we present an infinite continued fraction representation of the Euler number, which consequently implies the irrationality of e.

A thorough exposition of finite simple continued fractions is given. All rational numbers have such representations. Convergents to a simple continued fraction is studied and a handy algorithm is developed which helps to readily compute them. The uniqueness of a continued fraction representation is covered. The theory is naturally extended to infinite simple continued fractions including those for $\sqrt 2 $ and for $\pi $ as well as the general importance of finite continued fractions as approximations to real numbers. The chapter culminates in a robust discussion of Christiaan Huygens’ cogwheeled planetarium which utilized continued fractions.

We introduce a novel method for complex number representation. The proposed, redundant complex binary number system (RCBNS) is developed by combining a redundant binary number and a complex number in base (-1+j). Donald (1960) and Walter Penny (1964, 1965) represented complex numbers using base -j and (-1+j) in the classified algorithmic models. A redundant complex binary number system consists of both real and imaginary-radix number systems that form a redundant integer digit set. This system is formed by using complex radix of (-1+j) and a digit set of /spl alpha/=3, where /spl alpha/ assumes a value of -3, -2, -1, 0, 1, 2, 3. The arithmetic operations of complex numbers with this system treat the real and imaginary parts as one unit. The carry-free addition has the advantage of redundancy in number representation in the arithmetic operations. Results of the arithmetic operations are in the RCBNS form. The two methods for conversion from the RCBNS form to the standard binary number form have been presented. The RCBNS reduces the number of steps required to perform complex number arithmetic operations, thus enhancing the speed.

The subject of this paper is the current state of art in theory of continued fractions, intermediate fractions and their relation to the best rational approximations of the first and second kind. The paper provides an overview of the some well known and even some new properties of continued fractions, and the various terms associated with them. In addition to intermediate fractions, paper considers the fine intermediate fractions and gave some statements to position these fractions in the continued fraction representation of numbers.

Even though decimal arithmetic is pervasive in financial and commercial transactions, computers are still implementing almost all arithmetic calculations using binary arithmetic. As chip real estate becomes cheaper it is becoming likely that more computer manufacturers will provide processors with decimal arithmetic engines. Programming languages and databases are expanding the decimal data types available while there has been little change in the base hardware. As a result, each language and application is defining a different arithmetic and few have considered the efficiency of hardware implementations when setting requirements. We propose a decimal format which meets the requirements of existing standards for decimal arithmetic and is efficient for hardware implementation. We propose this specification in the hope that designers will consider providing decimal arithmetic in future microprocessors and that future decimal software specifications will consider hardware efficiencies.

Addition of two binary numbers is a fundamental operation in electronic circuits. Several integer adder architectures have been proposed. Their formal properties are well known, but the proofs are either incomplete or difficult to find. In this paper, we present a formal proof for the correctness of prefix adders. Both sequential and parallel algorithms are formalized and proved. In contrast to previous proofs using higher order functions and rewriting systems, our work is based on first order recursive equations, which are familiar to the computer arithmetic community and are therefore understandable by people working on VLSI circuit design. This study sets up a basis for further work on formal proofs of computer arithmetic algorithms.

We show in this paper how the Laplace transform θ* of the duration θ of an excursion by the occupation process {Λt} of an M/M/∞ system above a given threshold can be obtained by means of continued fraction analysis. The representation of θ* by a continued fraction is established and the [m−1/m] Padé approximants are computed by means of well known orthogonal polynomials, namely associated Charlier polynomials. It turns out that the continued fraction considered is an S fraction and as a consequence the Stieltjes transform of some spectral measure. Then, using classic asymptotic expansion properties of hypergeometric functions, the representation of the Laplace transform θ* by means of Kummer's function is obtained. This allows us to recover an earlier result obtained via complex analysis and the use of the strong Markov property satisfied by the occupation process {Λt}. The continued fraction representation enables us to further characterize the distribution of the random variable θ.

The statistical properties of double main sequence (MS) binaries are very important for binary evolution and binary population synthesis. To obtain these properties, we need to identify these MS binaries. In this paper, we have developed a method to differentiate single MS stars from double MS binaries from the Chinese Space Station Telescope (CSST) Survey with machine learning. This method is reliable and efficient to identify binaries with mass ratios between 0.20 and 0.80, which is independent of the mass ratio distribution. But the number of binaries identified with this method is not a good approximation to the number of binaries in the original sample due to the low detection efficiency of binaries with mass ratios smaller than 0.20 or larger than 0.80. Therefore, we have improved this point by using the detection efficiencies of our method and an empirical mass ratio distribution and then can infer the binary fraction in the sample. Once the CSST data are available, we can identify MS binaries with our trained multi-layer perceptron model and derive the binary fraction of the sample.

We applied special graphical technique to investigate the influence of side/end groups of macromolecules upon long range electron transfer. We show that in case of acyclic side/end groups the Green function may be cast in the form of continued fraction, similarly to the result of electron transfer in random media. The structure of continued fraction correlates exactly to the side/end graph's structure. The rules of graphical construction of Green functions (which are solutions of Schwinger–Dyson equations) are presented in concise form.

The representation of numbers is essential for the digital logic design. In this chapter, positional number systems (decimal, binary, octal, hexadecimal), BCD and Gray codes are presented together with the rules for the conversion between numbers encoded in different bases and the representations of negative numbers. Then, the rules for the arithmetic operations and the circuits that execute them are presented. The addition of binary number is examined with particular attention, since it is the operation at the basis of all computational circuits. Alphanumeric codes and the concept of parity for error detection complete the chapter.