Search

This paper is devoted to the problem of pauses detection in English speech signals. The aim of the current study is to create a new method of speech pauses detection that has no drawbacks other algorithms suffer from. The analysis of it suggests the opportunity to use the graphical method in real-time applications. The article provides a new vision and a new solution of pauses detection problem. The result of the study - the graphical method - may be applied to real-time signal processing, text-to-speech synthesis or used to enrich knowledge about the specified problems. [ABSTRACT FROM AUTHOR]

A recursive graphical approach for the evaluation of two-body operator matrix elements is presented. This new approach is simpler as well as clearer compared to other approaches. [ABSTRACT FROM AUTHOR]

Abstract: A pulse test is one of the simplest identification tests. Here a simple graphical method that uses the integral of pulse response and identifies a first order plus time delay (FOPTD) model is proposed. It can be effectively applied to noisy pulse responses because the integral of the pulse response is used. It can also be applied to noisy step responses, improving the previously developed area method. [Copyright &y& Elsevier]

In this paper, we propose a method based on the surfaces enveloping theory developed as a vertical application in the CATIA graphical design environment. This method is created for profiling tools intended to generate cylindrical helical surfaces with constant pitch. The devised method is applicable for the profiling of disc tools which are bounded by a primary peripheral surface of revolution. A few examples for the determination of the tool's 3D primary peripheral surface are presented such as helical flutes of cutting tools, worms with wide pitches, and gear involute flanks. The results are presented in both graphical and tabular form for completeness. Screen snapshots of the CATIA-based vertical application are also shown. [ABSTRACT FROM AUTHOR]

Water system integration with regeneration recycling can reduce freshwater consumption and wastewater discharge to the maximum extent. In this paper, by analyzing the limiting composite curve of a single-contaminant water system, a method is proposed to construct the optimal water supply line for regeneration recycling. Accordingly the targets for regeneration recycling water systems are obtained. The targets in sequence are the minimum freshwater consumption (the minimum wastewater discharge), the minimum regenerated water flowrate, and the optimal regeneration concentration. The post-regeneration concentration is taken to be fixed in the sequential targeting procedure. The interactions of these targets are analyzed, and formulas for calculating these targets are proposed. The results show that for a single-contaminant regeneration recycling water system, the minimum freshwater consumption is determined by the shape of the limiting composite curve below the post-regeneration concentration. The optimal regeneration concentration is defined as the minimum regeneration concentration at the minimum freshwater consumption and the corresponding minimum regenerated water flowrate. The minimum regenerated water flowrate and the optimal regeneration concentration are both related to the geometrical features of the limiting composite curve of the water-using system and to the post-regeneration concentration. The optimal regeneration concentration has no direct relationship with the pinch concentration. [Copyright &y& Elsevier]

Background Currently, we are not aware of a method to assess graphically on one simple plot agreement between more than two observers making continuous measurements on the same subjects.Methods We aimed to develop a simple graphical method to assess agreement between multiple observers using continuous measurements. The Bland–Altman graphical method for assessing agreement between two observers using continuous measures was modified and extended to accommodate multiple observers. Mathematical formulae are derived and real data examples used to illustrate the proposed method.Results The examples show that the proposed graphical method of assessing agreement provides clinically useful information. This information includes estimates of the limits of agreement with the mean and a visual means for determining these limits over the range of measurements. In a data example that included five readers’ measurements of 40 lung lesions, the intra-class correlation (ICC) was 0.84 indicating readers can reliably measure the lesions. However, the estimated limits of agreement with the mean were −1.1 to 1.1 cm implying that the readers’ measurements can plausibly differ from the mean estimated tumour size by more than 1 cm. This is a clinically significant difference according to the study authors. In addition, a plot of the limits of agreement with the mean by mean tumour size shows heterogeneous agreement presumably due to the varying degrees of definition at the edge of the lesions.Conclusions The proposed graphical method of assessing agreement can be used alongside other measures such as ICC for reporting on reproducibility in studies of multiple observers making continuous measurements. [ABSTRACT FROM AUTHOR]

2 x n or m x 2 interval matrix games are considered, and a graphical method for solving such games is given. Intervalmatrix game is the interval generation of classicalmatrix games. Because of uncertainty in real-world applications, payoffs of a matrix game may not be a fixed number. Since the payoffs may vary within a range for fixed strategies, an interval-valued matrix can be used to model such uncertainties. In the literature, there are different approaches for the comparison of fuzzy numbers and interval numbers. In this work, the idea of acceptability index is used which is suggested by Sengupta et al.2001 and Sengupta and Pal2009, and in view of acceptability index, well-known graphical method for matrix games is adapted to interval matrix games. [ABSTRACT FROM AUTHOR]

The functional relationship between the relative operating characteristic (ROC) and the economic value (EV) graphical methods have been exploited to develop a hybrid procedure called the extended ROC (EROC) method. The EROC retains the appealing simplicity of the traditional ROC method and the ability of the EV method to provide evaluation of the performance of an ensemble climate prediction system (EPS) for a hypothetical end user defined by the cost–loss ratio (μ = C/L). An inequality defining the lower and upper theoretical bounds of μ has been derived. Outside these limits, the EPS yields no added benefits for end user μ relative to the use of climatological persistence as an alternative prediction system. In the traditional ROC graphical method, the ROC skill (ROCS) is often expressed in terms of the area between the ROC graph and the diagonal baseline passing through the origin with slope m = 1. Thus, ROCS = 2A - 1, where A is the area under the ROC graph. In the proposed EROC approach, a more general procedure is recommended based on the construction of user-specific baselines that do not necessarily pass through the origin and, in general, have slope m ≠ 1. The skill of a particular EPS computed from the EROC method is proportional to the corresponding estimated value based on the EV graphical method. Therefore, the EROC geometry conveys the same basic information as the EV method. The Semazzi–Mera skill score (SMSS) is proposed as a convenient and compact way of expressing the combined verification based on the ROC and EV methods. The ROCS estimate is a special case of the SMSS. The near-horizontal trail-like geometry sometimes exhibited by EV graphs is also examined. It is shown to occur when either the hit-rate or false-alarm term dominates in the formula for EV, unlike the more typical situation in which both terms are comparable in magnitude. [ABSTRACT FROM AUTHOR]

In this paper, we present a graphical method for selection of a good model among the several competitive models for the same data set. The proposed method not only selects the model but also tests the equal prediction accuracy of the models. The results of the proposed method are compared with that of the model selection using Friedman test. [ABSTRACT FROM AUTHOR]

Calculating the optimum replacement period of meters has always been a major concern for water utility managers. Its determination is time-consuming and requires multiple calculations. This note presents a graphical method to obtain, in a simple but accurate manner, the optimum replacement period of installed meters. For this purpose, a chart has been produced, in which the most influencing variables are considered. These variables include the degradation rate of the weighted error of the meters, the selling price of water, the acquisition and installation cost of the meters, the volume consumed by the users and the discount rate. The chart also allows for a quick sensitivity analysis of different options. For example, by plotting straight lines it is possible to determine by how much the optimum replacement frequency of a meter would change if it degrades at a different rate than expected or if the selling price of water increases. [ABSTRACT FROM AUTHOR]

A graphical method is presented for assessing the state of identifiability of the parameters in a linear structural equation model based on the associated directed graph. We do not restrict attention to recursive models. In the recent literature, methods based on graphical models have been presented as a useful tool for assessing the state of identifiability of the parameters of the model. This article proposes the graphical counterpart of the rank condition of the matrix of structural coefficients, which allows for checking of the identifiability through a simple graphical rule. This approach can be used to develop algorithms. [ABSTRACT FROM AUTHOR]

This paper presents a comparison of different fault-current mitigation techniques used for adding an extra transformer to an existing substation whose fault-current level is close to nominal. Emphasis is placed on evaluating the net increase in substation loading capability provided by each technique while taking into account apparatus and system planning constraints. Operation under unusual peak loading conditions is investigated in terms of maximizing the use of substation assets. A graphical method based on linear programming is introduced to simplify the comparison of the techniques studied based on conventional passive technologies. The main strengths of the method are its ability to assess all techniques with a single general formulation and its possible generalization to complex problems. This paper shows that the avoided cost for reconfiguring a network and balancing the loads on the substation transformers could potentially justify more expensive techniques. [ABSTRACT FROM AUTHOR]

In occupational epidemiology, exposure-response analyses play an important role in the evaluation of the etiologic relevance of chemical and physical exposures. The standardized mortality or morbidity ratio (SMR) has been commonly used in occupational cohort studies. Statistical approaches to evaluate exposure-response patterns using SMRs have mostly been limited to analyses in which the exposure under investigation is categorized. Here, a graphical method for evaluating exposure-response patterns is presented based on SMR estimates across moving exposure windows. This method is demonstrated using the results of two hypothetical cohort studies. The proposed approach may be useful for graphical exploration of exposure-response trends in situations where the number of observed cases is small. [ABSTRACT FROM AUTHOR]

The goal of the present study is to demonstrate the possibility to analyze and evaluate certain multiple integrals that give residues of Feynman amplitudes by means of graph-theoretical methods. The method is applied to calculate the "wheel with N spokes" family of "Feynman periods" in a massless scalar quantum field theory. All calculations are performed in position space. We show that this specific integration problem can be mapped to a problem of enumerating weighted paths on an associated graph with weighted edges and vertices. The problem can be further reduced to the known problem of enumerating 2-Motzkin paths with N-2 steps, which gives the Catalan number CN-1. Relevant decompositions of Catalan numbers are also derived. [ABSTRACT FROM AUTHOR]

The graphic parallel has been and remains an exceptional method of knowing, learning, researching and disseminating the urban and architectural form. Here we try to outline the principles governing its design and take a slight look at some of the milestones of its intense history, that deserves a thorough attention. [ABSTRACT FROM AUTHOR]

Highlights: [•] A new graphical analysis method is proposed and applied to study C–Q hysteresis loops. [•] The method enables to quantify base load and additional sediment contributions. [•] The variability of flood types, sediment flux and origin is analyzed over 31-years. [•] The complex floods produced>53% of sediments, supplied by base load (84%). [•] The simpler floods were the most frequent ones but produced less sediments. [Copyright &y& Elsevier]

Multinomial logit analysis is a statistical technique for relating a set of continuous or discrete independent variables to a categorical dependent variable, The availability of statistical software and the publication of review articles dealing with logit analysis has resulted in increasing applications of the model. These applications have been limited by a failure to deal adequately with the magnitudes of the parameters, restricting discussion almost entirely to the direction of effects and their statistical significance. This limitation is a consequence of the large number of parameters involved and the nonlinearity of the effects. To deal with this problem, a graphical method is proposed to represent the magnitudes and statistical significance of all effects in a multinomial logit analysis. This allows for a clear interpretation of the relative magnitudes of effects both within and across independent variables. The article concludes with an example to illustrate the technique. [ABSTRACT FROM AUTHOR]

Suggested here is a simple graphical method for studying the goodness of fit in Cox's regression model for survival data. The method is easy to use, as it does not require the estimation of alternative models and only involves quantities similar to those already appearing in the partial likelihood expression that is needed in the parameter estimation. The rationale behind the graphs is very intuitive: They make a direct comparison between observed and expected failure frequencies, as estimated from the model. In a correctly specified model one anticipates an approximate balance between such frequencies; otherwise there will typically be groups of individuals for which the expected frequencies are systematically too high or too low to match with the data, and this shows in the graphs introduced here. In the concrete applications of the method the individuals are stratified in a way that depends on what aspect of the model is being checked against data. There is always one graph for each stratum. Simulated and real data are used to illustrate the method. In the simulations two types of defect that can come up in a Cox's model are considered: (a) an influential covariate has been deleted from the model, and (b) a common baseline hazard for all individuals has been assumed in a case in which the individuals should be stratified according to baseline hazard. Serious defects in the model are relatively easy to detect from the diagnostic graphs. As concrete applications of the method, studied briefly are the fitting of Cox's model to the well-known Stanford heart transplant data and to a data set describing the survival of malignant melanoma patients after operation. The article concludes with some general observations concerning the randomness in the graphs. [ABSTRACT FROM AUTHOR]

A 3D graphical representation of DNA sequences, which has no circuit or degeneracy, is derived for mathematical denotation of DNA sequence. Based on this graphical representation, we propose a new sequence distance measure. We make use of the corresponding similarity matrix to construct a phylogenic tree by virtue of the fuzzy theory. The examination of phylogenic tree belong to eight species illustrates the utility of our approach. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006 [ABSTRACT FROM AUTHOR]

This paper presents procedures whereby the symbolization of Thornthwaite's climatic classification may be quickly and accurately determined by use of graphs and nomograms. Potential evapotranspiration adjusted for months and latitude of the station is accomplished graphically. Soil water storage, soil water deficiency, and soil water surplus are determined by the Thornthwaite accounting procedure and, once determined, the symbolization for the complete climatic designation of the station is obtained by further graphical means. [ABSTRACT FROM AUTHOR]

The 19th century graphic method of Eddy-Lévy is analyzed and proposed in an analytical form as an assessment tool for masonry domes. The method determines the neutral hoop that separates the upper part of the dome that behaves as a compressed membrane from and the bottom that behaves as independent arches, due to the presence of vertical cracks. This method allows determining a no-tension equilibrated solution, accounting for the natural behavior of masonry domes of fracturing along meridian planes. Six case studies were investigated, considering spherical and pointed dome, complete, with hole and with hole and lantern. A modified version has been studied to model the biaxial stress of upper part properly through the membrane theory, and compared to the solution obtained by a numeric discrete block model. Limit thickness-to-radius ratio was identified, and a parametric analysis was carried out to investigate the extension of meridian fracture varying dome shape and thickness. [ABSTRACT FROM PUBLISHER]

For a bivariate data set the dependence structure cannot only be measured globally, for example with the Bravais-Pearson correlation coefficient, but the dependence structure can also be analysed locally. In this article the exploration of dependencies in the tails of the bivariate distribution is discussed. For this a graphical method which is called a chi-plot and which was introduced by Fisher and Switzer is used. Examples with simulated data sets illustrate that the chi-plot is suitable for the exploration of dependencies. This graphical method is then used to examine stock-return pairs. The kind of tail-dependence between returns has consequences, for example, for the calculation of the value at risk and should be modelled carefully. The application of the chi-plot to various daily stock-return pairs shows that different dependence structures can be found. This graph can therefore be an interesting aid for the modelling of returns. [ABSTRACT FROM AUTHOR]

Provides information on a study that proposed a graphical method, motivated by Bissell's iterative test for assessing mean squares in saturated fractional designs. Methodology of the study; Results and discussion on the study.

This paper addresses the problem of determining the stabilizing proportional-integral-derivative controller regions for a general linear system with or without time delay in unity output feedback configuration. When such a problem is solved in the 3D space by a graphical method, it brings in the visualizing difficulties. This paper proposes a new method by projecting the stability boundary in the 3D to the parameterized stability boundary band in the 2D plane of (Kp,Ki) while Kd varies in an interval. The boundary band divides the plane to the regions for which simple and effective stability test is developed and the complete stabilizing regions in the 2D plane of (Kp,Ki) are determined for any given interval on Kd. The rules are presented to find conditionally stable band portions, within which the corresponding stabilizing sub-interval for Kd can be obtained from an analytical formula for the case of no band intersections and from the root locus on Kd for the case of the band intersections. Several examples are designed to cover different cases and illustrate the method. [ABSTRACT FROM AUTHOR]

Presents a method for plotting data and drawing an objective line on the probability plot. Formula for plotting probability; Techniques for drawing lines on probability plots; Description of plotting formula.

Industrialized closing systems appear as rational solutions in steel-structured construction. These closing systems, consisting of multi-layered panels, have been applied in projects where it is intended to obtain a high sound transmission loss without raising the cost and without using a lot of mass. However, acoustic isolation depends on several factors, including the type of connection between the panels, requiring a preliminary study of the acoustic performance of the closing system to prevent future interventions. This paper uses a simplified graphical method to evaluate the influence of the type of connection (line-line, line-punctual or punctual-punctual) of industrialized closing panels on the estimation of the sound transmission loss that occurs across the wall constituted by these panels. The panels are combined, forming multi-layered closings interleaved by a layer of air, either without or with a sound-absorbing material between them. The results show that it is necessary to check the effectiveness of each type of fastening of the closing systems because, for example, for the frequency range between 500 and 2,000 Hz, the sound transmission loss of a closing system consisting of cementitious plate with glass wool and line-punctual and punctual-punctual connections exceeds in 6.25% the sound transmission loss of the same system with line-line fastening. For a system composed of expanded polystyrene with glass wool, the sound transmission loss provided by line-line fastening exceeds in 7.0% the sound transmission loss of the same closing system with line-punctual and punctual-punctual fastenings. [ABSTRACT FROM AUTHOR]

A graphical procedure is given to evaluate the sample size for which confidence intervals of specified lengths, for the parameters of the multinomial distribution, are simultaneously verified at a given significance level. [ABSTRACT FROM AUTHOR]

Estimation of static noise margin (SNM) is believed to be most important step of static random access memory (SRAM) bitcell design. Moreover, the measurement of bitcell stability is a critical issue with scaling of complementary metal-oxide semiconductor (CMOS) technology. Available techniques to find SNM are time consuming and difficult to implement by circuit simulation tool, so there is need of alternate method that can estimate SNM easily. In this article, we present a new method of SNM calculation that is based on curve fitting technique. We calculated SNM of six transistor (6T) SRAM cell with proposed method and established graphical method by varying cell ratio. The correlation coefficient of SNM was 0.99 that indicate proposed technique may be substitution for SNM calculation over conventional graphical method. We believe that we have developed an innovative solution for stability estimation of SRAM bitcell in nanometer technology. [ABSTRACT FROM AUTHOR]

It is very well known that the use of a load-holding valve (LHV) in a hydraulic system introduces additional energy consumption. This article presented a simplified graphical method for analyzing the power requirements of hydraulic systems equipped with load-holding valves for overrunning load control. The method helps to understand the performance of load-holding valves during actuator movement. In addition, it allows visualization of the influence on the overall system consumption of the main parameters (pilot ratio, set pressure) and others such as flow rate, back pressure, and load force. The method is attractive because, with only the pressures at the three ports and the valve relief function curve, it is sufficient to evaluate the energy consumption and to define the power ratio as an index indicating the percentage of energy that is to be used to open the LHV valve. The method was applied to real cases, in particular to two types of lifting mobile machines. It was validated following several outdoor tests on two mobile machines where experimental data were obtained. During tests, both machines were equipped with a set of seven different performance LHV valves. The described method could be beneficial for hydraulic machine manufacturers engaged in designing lifting devices when selecting a suitable valve for energy efficiency applications, especially now that the trend towards electrification is a reality. [ABSTRACT FROM AUTHOR]

The article discusses tectonic stresses determined in the West Sakhalin terrain using different tectonophysical methods. The reconstruction of the stress field in coal fields in Sakhalin is implemented using the graphical method of orientation finding of stress axes in fractures and faults (at 16 observation points). The supplementary on-site tectonophysical studies made it possible to estimate the preferred orientation of the main slickensides of different kinematics and to reconstruct on this basis the local stress tensors at 53 observation points. The typical stress state of the West Sakhalin terrain is horizontal tension. [ABSTRACT FROM AUTHOR]

Peirce and Frege both distinguished between the propositional content of an assertion and the assertion of a propositional content, but with different notational means. We present a modification of Peirce’s graphical method of logic that can be used to reason about assertions in a manner similar to Peirce’s original method. We propose a new system of Assertive Graphs (AGs), which unlike the tradition that follows Frege involves no ad hoc sign of assertion. We show that axioms of intuitionistic logic can be derived from AGs, and argue that AGs analyse and represent assertions and illocutionary content in a way which is motivated both by its logical properties and its historical connection with the ideas that led to the development of the graphical method. [ABSTRACT FROM AUTHOR]

In column testing of reactive solute transport, the retardation factor and column Péclet number can be simultaneously calculated by the nonlinear regression of the observed breakthrough curve. Several alternative methods exist to determine the retardation factor, but alternate techniques for determining the Péclet number have not been proposed. This paper presents a graphical method to obtain the Péclet number with examples of the proposed method. The graphical method provides results that are quite consistent with the nonlinear regression technique; and is a reasonable alternative, depending on the scatter in the effluent data. [ABSTRACT FROM AUTHOR]

In this article we consider the problem of testing for parameter changes in ARIMA models based on the cusum test. The proposed test procedure is applicable to testing for the change from stationary models to non stationary models, and vice versa. The idea is to transform the time series via differencing to make the whole time series as a combination of stationary subseries. For this task, we propose a graphical method to identify the right order of differencing. Then the cusum test statistic proposed by Lee et al. (2003) is constructed based the differenced time series. Simulation study and real data analysis are provided for illustration. [ABSTRACT FROM AUTHOR]

In this paper, the stability criteria are used to graphically determine the startup of oscillation in a Smith chart. This approach is suitable for slightly unstable circuits near the resonated frequency. In practice, an available design of a microwave two-port oscillator is presented here. © 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 19: 144–149, 1998. [ABSTRACT FROM AUTHOR]

The spline smoothing approach to nonparametric regression is extended to cover the estimation of curves that branch at certain specified points in time. This extension is motivated and illustrated by data from an experiment on sunflowers. Apart from providing insight into this particular data-analytic problem, the work described demonstrates the power of the roughness penalty approach in coping with curve estimation of a nonstandard kind. Particularly in the context of certain experiments in horticulture and arboriculture, the experimental material may be treated identically to the control up to a certain known time part of the way through the experiment. To display and investigate the effect of treatments applied during growth it is of interest to estimate a branching curve. In the simplest case we want to study two growth curves that are common up to a certain known time and then diverge (or branch) after the application of a treatment to part of the experimental material. The spline-smoothing approach to nonparametric regression as discussed, for example, by Silverman (1985) can be extended to deal with branching curves by defining a roughness penalty that measures the local variation in all branches of the curve system. The usual residual sum of squares is penalized by the addition of a multiple of this roughness penalty, and the resulting penalized sum of squares can be minimized. The solution branching curve is made up of a number of cubic spline branches that fit together according to rules that are derived in the present article and that allow the curve system to be found by solving a set of sparse linear equations. A nonparametric approach to this curve estimation problem is virtually essential, because it is hard to contemplate extensions of the usual parametric growth curve models that allow for branching curves in any way that is not rather artificial.... [ABSTRACT FROM AUTHOR]

The article presents the discussion on indicating the limitations in application of maximum likelihood estimation (MLE). Topics include providing a short literature review on development of Anderson-Darling test as a model diagnostic tool for continuous probability distribution functions; and evaluation of the parameters of extreme value distributions such as graphical method, method of moments, order statistics approach, and maximum likelihood estimation (MLE).

The guidance conditions of modes with both real and imaginary transverse wave numbers inside a dielectric slab with negative permittivity and permeability are solved. We show that for real transverse wave numbers, cutoffs exist for all modes, unlike in conventional media where the first even mode is always propagating. In addition, we also show that guided modes exist for imaginary transverse wave numbers, with the power concentrated at the interfaces instead of having maxima inside the slab. A graphical method of determining the imaginary transverse wave numbers of the guided modes is introduced which clearly identifies the different conditions of propagation depending on the properties of the slab. In particular, propagation of guided waves inside less dense negative media is shown to be possible. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The calculation formula of BQ (basic quality) classification index in GB 50218- 1994 is modified in the revised Standard for Engineering Classification of Rock Mass ( GB/T 50218- 2014), but its two limiting conditions (saturated uniaxial compressive strength of rock and rock mass integrity coefficient) were not modified simultaneously. Through a large number of data studies, it is found that the calculation results are inconsistent with the qualitative and quantitative calculation results when the data are directly reduced by Rc and Kv, constraints. Therefore, the limited conditions are modified and analyzed based on simplified graphical method. According to the analysis results that are widely affected by Rc constraints, 54 sets of new data in the database are taken as samples, and a new calculation formula is established by regression analysis of the data reduced by Rc constraints. The revised limit conditions and new section calculation formula obtained are analyzed and demonstrated on the basis of actual engineering data. The results show that the revised limited conditions and the calculation formula proposed in this study improve the agreement between the qualitative classification and the quantitative classification, and a more accurate classification result is obtained. [ABSTRACT FROM AUTHOR]

Rheometry is widely used throughout the rubber industry to characterise the cure behaviour of rubber mixes. Industrial rheometers produce continuous traces or rheograms in which torque is plotted as a function of time as a rubber progressively cures. Rheograms in which a distinct maximum or steady-state value is obtained within a reasonable time present few problems when the main objective is to determine optimum vulcanisation times. Nevertheless, some rubber mixes display cure profiles that do not exhibit steady-state values within acceptable time scales; taking extremely long periods of time to do so. Running rheometers over prolonged periods in order to attain flat or steady state cures is neither productive nor economical. In such situations, it is desirable to develop a methodology whereby steady-state values can be estimated from short running times. Assuming that cure advances by way of first-order kinetics a graphical technique is introduced enabling the steady-state torque value to be estimated from short running times. The steady-state torque value obtained from the graphical procedure was compared with experimental values; poor agreement was found being within about 11%. Notwithstanding the poor agreement between the steady-state torque value observed experimentally and that predicted by the graphical method we nevertheless continue to recommend the use of the graphical technique. Our justification for the use of the graphical method is that the procedure provides reliable rate constants for the incipient stages of vulcanisation without having to determine full extents of cure. The rate constant determined by the graphical procedure was in good agreement with typical values reported in the literature thus affording credibility to our graphical methodology. As further confirmation as to the reliability of our technique, an analytical method introduced by Rigby was employed to verify the authenticity of our results. Comparison of our results with those ascertained from the analytical method showed reasonable agreement. In order to account for the significantly large difference between the graphically-estimated and experimental steady-state torque value, the ideal and simplistic assumption that curing proceeds by first order kinetics throughout the entire curing period was abandoned. Instead, it was assumed that the crosslinking process comprises two concomitant first-order curing reactions; notably normal and slow crosslinking reactions. The kinetic expression describing the two simultaneous vulcanisation reactions in terms of rheometry parameters is: Tt-Ta = (T∞,c-Ta)(1-e-kc(t-ti))+(T∞,sc-Ta)(1-e-kc(t-ti)) where Tt is the torque at time t; Ta is the minimum torque; ti is the induction time; T¥,c and T¥,sc are the steady-state torque values for the normal and slow crosslinking processes respectively; and, kc and ksc represent the first-order rate constants for the normal and slow crosslinking processes respectively. Excellent agreement was found between the experimental steady-state torque value and that predicted by the composite kinetic expression. [ABSTRACT FROM AUTHOR]

Via a graphical method, which codes tree diagrams composed of partitions, a novel power series expansion is derived for the reciprocal of the logarithmic function ln (1+ z), whose coefficients represent an infinite set of fractions. These numbers, which are called reciprocal logarithm numbers and are denoted by A k, converge to zero as k→∞. Several properties of the numbers are then obtained including recursion relations and their relationship with the Stirling numbers of the first kind. Also appearing here are several applications including a new representation for Euler’s constant known as Hurst’s formula and another for the logarithmic integral. From the properties of the A k it is found that a term of ζ(2) cannot be eliminated by the remaining terms in Hurst’s formula, thereby indicating that Euler’s constant is irrational. Finally, another power series expansion for the reciprocal of arctangent is developed by adapting the preceding material. [ABSTRACT FROM AUTHOR]

For the Tuvalu Island group in the western Pacific, a simple graphical method is proposed as a means of forecasting whether rainfall totals for the next 1, 2,…,6 months will be below average. The method is based on scatter plots where the points are color-coded as above- or below-average rainfall, with the plot axes being lag-1 and lag-2 NINO4 sea surface temperatures. Within the scatter plots there are reasonably clear data fields with higher frequencies of below-average rainfalls associated with cooler precursor NINO4 temperatures. These data fields are defined by subjectively emplaced separation lines which bifurcate the scatter plots into ''predictable'' and ''unpredictable'' fields. If two precursor NINO4 temperature values define a point located in a predictable field then a warning would be issued for below-average rainfall over the next n-month period, depending on the time scale of the scatter plot. A long rainfall record at Funafuti in Tuvalu indicates that success in predictable-field forecasting of below-average rainfalls would range between 68% for 1-month rainfall totals and 89% for 6-month totals. The forecasting success derives from persistence of cooler NINO4 sea surface temperatures which are associated with lower rainfalls in Tuvalu. However, many dry periods are also located in the unpredictable field and cannot be forecast by this method. [ABSTRACT FROM AUTHOR]

We present a graphical method that uses a statistical likelihood approach to summarize evidence and risk in fishery status evaluation. The graphical method is based on the surplus production model and shows the fishery status as regions and colors on graphs. Two fishery status graphs are used: one is based on the comparison between observed catch and catch at the fishing mortality level corresponding to maximum sustainable yield; the other one is based on the comparison between observed catch and catch at the surplus production level. The graphical statistical likelihood approach quantifies the strength of evidence in supporting different hypotheses of fishing status as regions in the status graphs. A simulated hypothetical fishery is given as an example. Results are graphically presented to show the exploitation status of the fishery, and they compare favorably with those from a composite risk assessment method. This graphical statistical likelihood approach may improve the communication of knowledge and evidence among scientists, fishery stakeholders, and management agencies and may provide a better understanding of current fishery status. [ABSTRACT FROM AUTHOR]

In 1833 John Herschel published a graphical method for determining the orbits of double stars. He argued that his method, which depended on human judgment rather than mathematical analysis, gave better results than computation, given the uncertainty in the data. Herschel found that astronomy and terrestrial physics were especially suitable for graphical treatment, and he expected that graphs would soon become important in all areas of science. He argued with William Whewell and James D. Forbes over the process of induction, over the application of probability, and over the moral content of science. Graphs entered into all these debates; but because they constituted a method, not a metaphysics, they were acceptable to most practicing scientists and became increasingly popular throughout the nineteenth century. [ABSTRACT FROM AUTHOR]

Illustrates a graphical method for meta-analysis of epidemiological research with dichotomous exposures and outcomes that complements other graphical and analytical approaches to meta-analysis. Definition of meta-analysis; Importance of graphical methods in meta-analysis; Applications.

In multivariate regression, a graphical diagnostic method of detecting observations that are influential in estimating regression coefficients is introduced. It is based on the principal components and their variances obtained from the covariance matrix of the probability distribution for the change in the estimator of the matrix of unknown regression coefficients due to a single-case deletion. As a result, each deletion statistic obtained in a form of matrix is transformed into a two-dimensional quantity. Its univariate version is also introduced in a little different way. No distributional form is assumed. For illustration, we provide a numerical example in which the graphical method introduced here is seen to be effective in getting information about influential observations. [ABSTRACT FROM AUTHOR]

This paper investigates how ground bounce noise (GBN) is generated by crosstalk noises for two parallel ground planes with a narrow open-stub line (NOSL) and adjacent signal traces in a multilayer package structure. A noise reduction scheme and design guidelines for preventing intense noises (GBN and coupled noise) are also proposed. A graphical method that is based on wave tracing is also developed to elucidate the generation of crosstalk noise by adjacent signal traces on an NOSL. The mechanism of generation of the GBN by crosstalk noise can be elucidated based on reflection theory, open-stub quarter-wavelength resonance, and parallel-plane resonance. The time-domain simulation results are analyzed using a 3-D full-wave simulator, Computer Simulation Technology. Using an additional shorting via at the connection between the NOSL and parallel ground planes, the proposed noise reduction scheme can significantly reduce the GBN and coupled noise. Moreover, guidelines for designing the test structure to minimize noise (GBN and coupled noise) are presented. Finally, the simulation and measurement results in the time domain are compared to validate the proposed analysis and noise reduction scheme. [ABSTRACT FROM AUTHOR]

Regions of the south-western Mediterranean basin were the focus of many studies since they have experienced a series of climate changes. The contribution of the North Atlantic Oscillation in precipitations is required to be analyzed with the aim to understand the possible hydrological changes. In this way, an analysis of precipitations along the coast of central Maghreb (Morocco, Algeria and Tunisia) was carried. The present analysis was performed using (1) The graphical method of information processing and (2) wavelet transform technique. Results can be summarized as the following. Results show a high drought observed in all studied regions since the med-eighties and a return of the wet period since year 2003. Moreover, we demonstrate significant links of precipitations with the North Atlantic Oscillation [ABSTRACT FROM AUTHOR]