Types Of Multipliers Research Articles

Mean cycle slip time of first-order phase-lockedloop withlimiter phase detector

The mean cycle slip time of a first-order phase-locked loop with sinusoidal limiter phase detector is evaluated to account for the dependence of the loop noise spectrum on the phase error. It is shown that neglecting this dependence leads to a considerable underestimation of the mean cycle slip time. Numerical results superior to those for the multiplier type phase detector are reported.

Application of the channel electron multiplier to the unipole mass spectrometer

The performance of a channel multiplier, type KPE, applied to the ion detection system of the unipole mass spectrometer was tested. It was found that this type of multiplier is fully useful in ion spectrometer systems in the pressure range 10 −4–10 −12 torr. The amplification characteristic of the ion current vs the pressure of gases reveals a good linearity. The shape of the characteristic indicates that amplification of the electron multiplier for the mixture is dependent only on the amount and kinetic energy of the ions. All three measurement series were taken with the electron multiplier used in the analogue mode of operation.

Design of a C-testable booth multiplier using a realistic fault model

A Booth multiplier is the most widely used type of multiplier. In this article, the testability issues involved in its design are discussed. In contrast to previous work, the fault model includes not only node stuck-at faults, but also transistor stuck-open and stuck-close faults. Moreover, as a result of adopting a hierarchical testability approach, the designed Booth multiplier turns out to be fully C-testable. To achieve this C-testability, only three additional controllable inputs are required, which results in a negligible area and delay overhead.

Internal estimations for one-and two-parameter exponential distributions under multiple type-II censoring

In this article, there methods are proposed to give the lower confidence bounds for the parameters in one-and two-parameter exponential distributions with multiply Type II censored data. The accuracy of the approximate methods are compared both theoretically and numerically. The problem of significance testing for the threshold parameter is also addressed.

TESTS FOR FRACTIONAL INTEGRATION:A MONTE CARLO INVESTIGATION

Abstract. The performance of the Geweke‐Porter‐Hudak (GPH) test, the modified rescaled range (MRR) test and two Lagrange multiplier (LM) type tests for fractional integration in small samples is examined using Monte Carlo methods. Both the GPH and MRR tests are found to be robust to moderate autoregressive moving‐average components, autoregressive conditional heteroskedasticity effects and shifts in the variance. However, these two tests are sensitive to large autoregressive moving‐average components and shifts in the mean. It is also found that the LM tests are sensitive to deviations from the null hypothesis. As an illustration, the GPH test is applied to two economic data series.

POWER OF THE NEURAL NETWORK LINEARITY TEST

Abstract. Recently, a new linearity test for time series was introduced based on concepts from the theory of neural networks. Lee et al. have already studied the power properties of this test and they are further investigated here. They are compared by simulation with those of a Lagrange multiplier (LM) type test that we derive from the same single‐hidden‐layer neural network model. The auxiliary regression of our LM type test is a simple cubic ‘dual’ of the Volterra expansion of the original series, and the power of the test appears superior overall to that of the other test.

Realization of monolithic variable gyrators and their application to active filters

AbstractWith the development of IC and LSI technology, it is strongly desired that integration of the analog filter be realized. This paper proposes a method to construct the differential input voltage‐controlled current source (VCCS) and the differential input, differential output VCCS, using the conventional current multiplier type VCCS. The features of the proposed construction is that the VCCS characteristics can be varied by the control current and the transconductance is not affected by the absolute accuracy of the resistances as long as their relative accuracy is maintained.A method also is presented in which the conventional LC filter is simulated using the gyrators composed of the proposed circuits. Then, by adding a resistor‐controlled current source circuit, a circuit construction also is presented whose control current can be determined by an external resistor so that the characteristics of more than one VCCS can be controlled.To verify the effectiveness of the proposed method, the third‐order elliptic filter with a 0.25‐dB ripple is designed. As a result of computer simulation, it is verified that the characteristics change little by the ambient temperature of ‐10 to 60°C and that the cut‐off frequency changes little for ±12.5 percent variation of the supply voltage. Thus, it is shown that the analog filter can be integrated without using the tuning system which has often been employed.

Testing exogeneity in overidentified models

In this paper we analyse the consequences of model overidentification on testing exogeneity, when maximum likelihood techniques for estimation and inference are used. This situation is viewed as a particular case of the more general problem of considering how restrictions on nuisance parameters could help in making inference on the parameters of interest. At first a general model is considered. A suitable likelihood function factorization is used which allows a simple derivation of the information matrix and others tools useful for building up joint tests of exogeneity and overidentifying restrictions both of Wald and Lagrange Multiplier type. The asymptotic local power of the exogeneity test in the justidentified model is compared with that in the overidentified one, when we assume that the latter is the true model. Then the pseudo-likelihood framework is used to derive the consequences of working with a model where overidentifying restrictions are erroneously imposed. The inconsistency introduced by imposing false restrictions is analysed and the consequences of the misspecification on the exogeneity test are carefully examined.

Automatic synthesis of testable VLSI cellular array multipliers

Abstract We present an application‐specific computer‐aided design (ASCAD) tool that aids the design of easily testable bit‐level cellular array multipliers, including bit‐serial, bit‐parallel, and block multipliers. The tool, based on a nonlinear space‐time transformation algorithm and bit‐level cellular array architectures, is a very high‐level one. A multiplier designer only needs to specify (1) the multiplicand and the multiplier word lengths, (2) the throughput range, and (3) the multiplier type. The tool then generates a VLSI circuit layout for the multiplier which meets the designer's specifications, and the circuit is guaranteed to be functionally correct. Our ASCAD tool thus eliminates the design and verification costs associated with manual design. Because it is application‐specific, the tool itself is very easy to implement.

Time Variations in the Risk of Cancer Following Irradiation in Childhood

The Japanese atomic bomb survivors and three other cohorts of children exposed to radiation are analyzed, and evidence is found for a reduction in the radiation-induced relative risk of cancers other than leukemia with time following exposure. Multiplicative adjustments to the excess risk either of the form exp[-delta.(time since exposure)] or of the form [time since exposure] gamma give equivalent goodness of fit. Using the former type of adjustment an annual overall reduction of 6.9-8.6% in excess relative risk is indicated (depending on the year after which this reduction might take effect). Using the second type of multiplier an adjustment to the excess relative risk varying between [time after exposure]-2.0 and [time after exposure]-3.2 fits best overall. All these reductions are statistically significant at the 5% level. There is no significant variation by cohort, by sex, by cancer type, or by age at exposure group in the degree of annual reduction in excess relative risk. Although time-adjusted relative and absolute risk models give equivalently good fits within each cohort, there is significant variation between cohorts in the degree of increase of risk with time in the absolute risk formulation, in contrast to the lack of such heterogeneity for the relative risk formulation. It is shown that if the range of observed reductions in relative risk is assumed to operate 40 or more years after exposure in the youngest age groups, the calculated UK population risks would be reduced by 30-45% compared to those based on a constant relative risk model.

Feedback compensated synchronous and multiplier type phase sensitive detectors

A feedback technique for phase sensitive detection (PSD) is developed, which is suitable for both synchronous and multiplier modes of implementation. The feedback-compensated PSD straightaway provides a DC output proportional to the amplitude of the measurand. The technique is very useful in a noisy environment where post-processing of the in-phase and quadrature components would otherwise deteriorate the stability, accuracy, and sensitivity. Quantitative comparison of the extent of compensation obtained experimentally with that estimated by PC-simulation indicates good agreement. >

A generalized harmonic map equation for micromagnetics (abstract)

Static micromagnetic configurations are determined by minimizing the sum of anisotropy, demagnetization, exchange, and external interaction energies subject to the constraint that the magnitude of the magnetization vector is constant throughout a sample. If this constraint is not explicitly imposed in a numerical or analytical investigation, a Lagrange multiplier type of term must be appended to the energy functional. In a region R, two candidates are λ∫R(1 − ‖m(r)‖2)2 dV and ∫Rλ(r)(1 − ‖m(r)‖2)dV. The first expression is a Higgs or penalty term in the terminology of physicists and numerical analysts. The penalty parameter λ is given a physical meaning through the Ginsburg–Landau theory.1 The second expression is avoided by physicists and numerical analysts since the scalar Lagrange multiplier λ(r) represents an unwelcomed proliferation of variables. Following the theory of harmonic maps, the scalar Lagrange multiplier field is eliminated in this paper and a generalized harmonic map equation for micromagnetics is obtained. This equation has no extraneous phenomenological constants and enables one to ignore the original constraint in numerical solutions. It also provides a means for tying together results concerning singularities of harmonic maps2 with Block point phenomena believed to exist in VBL memories. This, in turn, enables one to make general inferences about the energetics of Bloch points which are not possible through purely topological investigations or simulations involving specific geometries.<ks>

An MOS four-quadrant analog multiplier using simple two-input squaring circuits with source followers

An MOS four-quadrant analog multiplier is described. It is based on the square-law dependence of the MOS-transistor drain current on the gate-to-source voltage in the saturation region. One input is applied to the gate directly while the other input is applied to the source through a source-follower buffer stage. The circuit is realized with only 12 MOS transistors and two resistors. The circuit has been fabricated using a metal-gate NMOS process which has separate p-wells to eliminate the substrate bias effect. The multiplier achieves less than 0.45% nonlinearity when the input voltage range is 40% of the supply voltages, and it achieves a -3-dB bandwidth of 30 MHz. The total harmonic distortion is less than 0.6%. The power consumption and chip size are 8 mW and 1.2 mm/sup 2/, respectively. The second-order effects for this type of multiplier are considered in detail.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The design of a testable parallel multiplier

A scheme for an easily testable multiplier and the corresponding test generation procedures are presented. To provide 100% controllability of the summand-counter, the summand-generator is modified. The modified summand-generator can be implemented with little hardware overhead. Since the summands are 100% controllable, the summand-counter can be constructed with the minimum number of adder cells. The multiplier is not C-testable, but can be tested with a small numbers of test vectors, i.e. 3n+60 vectors. It requires only one extra input, whereas C-testable multipliers usually require at least four or five extra inputs and more adder cells along with extra circuitry. Using the modified summand-generator, other types of multipliers can be easily constructed to be testable with only one extra input. Test sets for these multipliers can be obtained using the same test generation approach.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

On the maximum likelihood estimation of the location and scale parameters of exponential distribution based on multiply Type II censored samples

The maximum likelihood (ML) estimation of the location and scale parameters of an exponential distribution based on singly and doubly censored samples is given. When the sample is multiply censored (some middle observations being censored), however, the ML method does not admit explicit solutions. In this case we present a simple approximation to the likelihood equation and derive explicit estimators which are linear functions of order statistics. Finally, we present some examples to illustrate this method of estimation.

Estimating the Immigration Multiplier: An Analysis of Recent Korean and Filipino Immigration to the United States

"This article explores the effect of 'chaining' through the petitioning of relatives on the demand for future immigrant visas [to the United States]. The data for the study come from a 1986 survey of 3,911 respondents from the Philippines and the Republic of Korea who were interviewed in Manila and Seoul just after they had received their U.S. immigrant visas. Analyses are conducted to derive different types of multipliers that may be used in estimating the effects of chain migration.... The empirical results for the Philippines and Korea indicate that the potential for future immigration through the family reunification entitlements of the immigration law is lower than has previously been suggested." This is a revised version of a paper originally presented at the 1987 Annual Meeting of the Population Association of America (see Population Index, Vol. 53, No. 3, Fall 1987, p. 385).

Measuring inter-industry impacts of producing and processing agricultural products

This study develops and analyzes a conceptual model of inter-industry economic flows for state economies with attention focused on the role of producing and processing of agricultural products in the overall economy. Three types of multipliers—impact, interim, and total multipliers—are estimated. These multipliers describe the initial, intermediate, and ultimate responses of the overall economy to changes in food and farm sectors.

Input — Output Multipliers When Data are Incomplete or Unreliable

A general class of estimation procedures for input — output multipliers is introduced which is flexible enough to cope with all possible sets of information within the input — output framework. The class of procedures is general in the sense that multipliers derived from updated input — output tables, as well as some of the existing shortcut multiplier formulae, are included as borderline cases. Furthermore, the procedures are general in the sense that different types of multipliers (output multipliers, employment multipliers, final demand multipliers, etc) are dealt with simultaneously. It is also demonstrated how these estimation procedures could be supplemented by calculating deterministic intervals for the true but unknown results.

A trial construction of a secondary electron multiplier with ring-shaped dynodes

A box-grid type of secondary electron multiplier with ring-shaped dynodes has been constructed. In this multiplier, since the area of the later dynode becomes larger, output current shows no saturation by the space-charge effect at high current (70 μA).

A new type of position-sensitive electron multiplier

A new type of position-sensitive electron multiplier is under development. The results of a first prototype are presented. The status and the construction of two other prototypes are described. A straightforward application of such a device is to monitor very-low-energy antiprotons ejected from LEAR under high-vacuum conditions.