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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]

Abstract: Following specification of all variables of interest as well as their interrelationships, the validity of an ecological model (or of any of its components) is often tested by analysis of variance (ANOVA)-based procedures, either through experimentation, ‘screening’ of predictors, or simulation. To this end, the linear model diagram (LMD) is introduced as a graphical method for the display of factor relationships in ANOVA balanced complete designs. As an analysis-oriented diagram, hence in contrast with layout-oriented diagrams useful for the allocation of experimental units to factor levels (or vice versa), the purpose of the LMD is to streamline specification of a design''s underlying linear model. This contains all available information about each observation and its correct specification is essential for computing reliable ANOVA error terms. In the LMD, factor relationships, especially higher order interactions in complex fully factorial or nested/factorial designs, are more effectively visualised than in the other existing analysis-oriented diagrams. Further, by assigning a unique label to a design, including those sharing an otherwise identical linear model, the LMD provides the ecologist with a graphic ‘shorthand’ that streamlines the statistical analysis of an experiment as well as may help clarify terminological inconsistencies. [Copyright &y& Elsevier]

Background: Commonly used methods to evaluate heart rate variability require extensive filtering of the registrations in order to exclude artefacts and ectopic beats. We developed and validated a novel graphical method for time-domain measurements of heart rate variability, the differential index, which does not require filtering and is simple to use. Methods: The 24-h ambulatory long-term electrocardiogram recordings from 120 patients with angina pectoris and 49 control subjects were computerised without any filtering process. Sample density histograms of differences in the RR interval for successive beats were constructed and the widths of the histograms were used to obtain the differential index. For comparison, the same registrations were analysed by conventional methods. Results: The differential index was most closely related (P<0.001) to conventional short-term time domain (e.g. percent of differences between adjacent normal RR intervals >50 ms, pNN50, r=0.81) and frequency-domain (e.g. high frequency power, r=0.84) components, but also to long-term time domain (e.g. standard deviation of all normal-to-normal RR intervals for all 5-min segments of the entire registration, SDNNIDX, r=0.72) and frequency-domain (e.g. low frequency power, r=0.64) components. Conclusion: The differential index method shows good agreement with established indices of heart rate variability. The insensitivity to recording artefacts and short-lasting disturbances of sinus rhythm make the differential index method particularly suited when data quality is imperfect. The simplicity of the method is valuable when large numbers of registrations are to be evaluated. [Copyright &y& Elsevier]

A graphical method to assess the size reduction by grinding is presented and illustrated with data collected from laboratory grinding tests and industrial grinding circuits. The method lies between the graphical comparison of size distributions and the population balance model. The method is easy to apply and provides a quick way to compare grinding mill performances under various operating conditions and processed ores. The application of the method to industrial mills shows that a grinding mill operation could present an invariant behaviour that can be exploited for simulation purposes. [ABSTRACT FROM AUTHOR]

A piecewise linear model which consists of the set of two linear ordinary differential equations with four parameters was derived to investigate the behavior of the water column oscillator simulating a safety system of an advanced reactor. The model shows various bifurcation. The behavior of the model can be discussed using the two-dimensional mapping function. When the system is governed by the two (or more)-dimensional mapping function, it is difficult to draw the map because the map has four dimensions, from two dimensions to two dimensions. In this study, therefore, a “two-dimensional graphical method” is proposed and the bifurcation of the two-dimensional system is visualized. [Copyright &y& Elsevier]

Water/gas partition coefficients have been determined for hydrocarbons and chlorinated derivatives of hydrocarbons. In this paper a graphical method based on a static headspace gas chromatography technique is described. This technique relies on the linear dependence of the phase volume ratio in the vial and the ratio of the concentration of the solute in two phases. The partition coefficients were determined at four temperatures ranging from 10 to 25 °C. The temperature dependence of the partition coefficients is described by the classical van’t Hoff equation. [Copyright &y& Elsevier]

Based on the nonlinear algorithmic theory, the R-SVM water source discrimination model and prediction method were established by using the piper qualitatively to compare the differences between the ionic components and R-type factor approximation indicator input dimensions. Taking the mine water samples of Zhaogezhuang Coal Mine as an example, according to the chemical composition analysis of the water samples from different monitoring points, six indexes of Na+, Ca2+, Mg2+, Cl–, SO42– and HCO3– were selected as the discrimination factors. According to the water characteristics of each aquifer and the actual needs of discrimination, the water inrush sources in the mining area were divided into four categories: The goaf water is class I, Ordovician carbonate is class II, Sandstone fracture water from the 13 coal system is class III, and Sandstone fracture water from the 12 coal system is class IV. Taking 56 typical water inrush samples as training samples, 11 groups for prediction samples, establish the input index as typical ion content, output as water source type, using SPSS statistics and MATLAB to realize the R-SVM water source discriminant analysis model, automatically establishing the mapping relationship between the water quality indexes and the evaluation standards, which can achieve the purpose of rapid and accurate discrimination of the water sample data. The results showed that the accuracy of the R-SVM model classification was 90.90% in the verification of the water source discrimination example of Zhaogezhuang mine and the coupled model has high accuracy, good applicability and discriminant ability, and has certain guiding significance for the prevention and control of water damage and the related field work. [ABSTRACT FROM AUTHOR]

Focuses on the graphical method for assessing the logistic regression. Discrepancy measurement of the Bayes marginal model plot (BMMP); Methodology of BMMP; Use of standard continuous data smoothers in BMMP.

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]

SUMMARY The problem of testing the equality of several variances arises in many areas. For testing the equality of variances, several tests are available in the literature which demonstrate only the statistical significance of the variances. In this paper, a graphical method is presented for testing the equality of variances. This method simultaneously demonstrates the statistical and engineering significance. Two examples are given to illustrate the proposed graphical method, and the conclusions obtained are compared with the existing tests. [ABSTRACT FROM AUTHOR]

Adsorption carbon capture technology has been considered as one of the most promising technologies to control the CO 2 level in the atmosphere. From the view of thermodynamics, the adsorbed-bulk gas phase equilibrium system should be well developed for accurately elaborating the mechanism of CO 2 adsorption. Since thermodynamic properties of the adsorbed CO 2 plays a significant role in the cyclic analysis of carbon capture technology, in this work, the Gibbs' thermodynamic graphical method was extended to the expression of thermodynamic properties of the adsorbed CO 2 as a specific case study. The 3-dimensional (3D) thermodynamic surface was established to determine the thermodynamic properties of the adsorbed CO 2 in the thermodynamic equilibrium state. The temperature and pressure were treated as the individual variables to calculate the thermodynamic properties of the adsorbed CO 2 , including the adsorption capacity, chemical potential, entropy, and internal energy. Finally, the internal energy-adsorption capacity-entropy 3D thermodynamic surface of the adsorbed CO 2 was obtained by the Gibbs' thermodynamic graphical method. The thermodynamic surface established in this work will contribute and/or accelerate the research of the actual adsorption thermodynamic cycle and new findings are encouraged to be updated to our database to enhance the development on thermodynamic characteristics of the adsorption technology. • Two individual variables are needed to determine the adsorbed CO 2 thermodynamic state. • Calculation of adsorbed CO 2 thermodynamic properties is summarized. • The 3-dimensional thermodynamic surface of the adsorbed CO 2 was established. [ABSTRACT FROM AUTHOR]

Presents information on a study which determines a graphical method of exploring the mean structure in longitudinal data analysis. How longitudinal data arises; Error structure; Range of representation.

The speech intelligibility index (SII) is interpreted as the proportion of total speech information available to the listener's ear for a given speech material. Consequently, SII varies in the range 0-1. A simple graphical method for determining SII for monaural listening at 1 m distance from a talker producing “average speech” (or PB-words) at normal speech effort is described. The speech area is visualized by 10 × 10 = 100 points in the audiogram form, each point contributing 0.01 to the SII. The SII thus equals 0.01 times the number of points in the audible range. A sensorineural hearing loss gives rise to an additional loss in speech recognition due to reduced frequency discrimination and time resolving ability. This suprathreshold deficit is corrected for, if the SII contribution in each frequency band is multiplied with a hearing threshold level dependent “desensitization factor”. The SII is related to the intelligibility of speech, and may be used to evaluate a hearing disability. [ABSTRACT FROM AUTHOR]

Continuous variable dichotomization is a popular technique used in the estimation of the effect of risk factors on health outcomes in multivariate regression settings. Researchers follow this practice in order to simplify data analysis, which it unquestionably does. However thresholds used to dichotomize those variables are usually ad-hoc, based on expert opinions, or mean, median or quantile splits and can add bias to the effect of the risk factors on specific outcomes and underestimate such effect. In this paper, we suggest the use of a semi-parametric method and visualization for improvement of the threshold selection in variable dichotomization while accounting for mixture distributions in the outcome of interest and adjusting for covariates. For clinicians, these empirically based thresholds of risk factors, if they exist, could be informative in terms of the highest or lowest point of a risk factor beyond which no additional impact on the outcome should be expected. [ABSTRACT FROM AUTHOR]

Chemical compositions of 80 vegetable oils were collected from literature and the properties of the obtainable biodiesel (methyl esters) have been predicted by empirical relationships. The purpose has been to check the viability of predicting if a biodiesel could meet the EN 14214 standards knowing only the fatty acid profile (FAP) of the parent oil. Two parameters were used in this investigation: (i) average number of carbon atoms in the fatty acid chains, (ii) average number of double bonds (CC) per molecule. Two new empirical relationships have been proposed to predict the viscosity and the cetane number of biodiesel from the two parameters. The range of values of the two parameters leading to biodiesel meeting the EN 14214 standard for viscosity, cetane number, iodine value, and cold filter plugging point have been graphically obtained by overlapping the corresponding level surfaces. Practical applications: This work provides biodiesel producers with indications of the quality of biodiesel without the need for analytical testing of the product (indeed, of the product itself). Only the fatty acid profile of the starting vegetable oil is required. The quality of biodiesel can be estimated by using a chart developed in this work, allowing to estimate, e.g. if the biodiesel meets the European standards. The work can be useful to rapidly screen oil seed crops in studies of genetic engineering that require high throughput. [ABSTRACT FROM AUTHOR]

Abstract: A systematic approach using the graphical representation of water use and its system-wide manipulation is proposed for minimising freshwater and wastewater generation for discontinuous water systems. Design interactions of time-dependant water reuse and implications of storage tank in the network design have been fully addressed, and a new targeting and design method has been proposed to provide guidelines for achieving minimum freshwater requirements and to design the configuration of water re-use networks. Design complexity associated with simultaneous consideration of concentration and time constraints has been effectively dealt with in the proposed design method, which clearly provides benefits by reducing water consumptions and maintaining sustainable water usage. [Copyright &y& Elsevier]

Background: Derivative based a-priori structural identifiability analyses of mathematical models can offer valuable insight into the identifiability of model parameters. However, these analyses are only capable of a binary confirmation of the mathematical distinction of parameters and a positive outcome can begin to lose relevance when measurement error is introduced. This article presents an integral based method that allows the observation of the identifiability of models with two-parameters in the presence of assay error. Methods: The method measures the distinction of the integral formulations of the parameter coefficients at the proposed sampling times. It can thus predict the susceptibility of the parameters to the effects of measurement error. The method is tested in-silico with Monte Carlo analyses of a number of insulin sensitivity test applications. Results: The method successfully captured the analogous nature of identifiability observed in Monte Carlo analyses of a number of cases including protocol alterations, parameter changes and differences in participant behaviour. However, due to the numerical nature of the analyses, prediction was not perfect in all cases. Conclusions: Thus although the current method has valuable and significant capabilities in terms of study or test protocol design, additional developments would further strengthen the predictive capability of the method. Finally, the method captures the experimental reality that sampling error and timing can negate assumed parameter identifiability and that identifiability is a continuous rather than discrete phenomenon. [ABSTRACT FROM AUTHOR]

A graphical method for the evaluation of series resistance (R[sub s]) has been proposed after solving the dark and illuminated current-voltage equations for junction solar cells. The design of an electronic circuit has been described to obtain ideal open and short circuit conditions and the measurement of R[sub s] has been reported for a few diffused junction silicon solar cells as a function of illumination level up to ∼ 2 sun. It has been found that the series resistance decreases sharply with intensity of incident radiations up to ∼ 1 sun and it saturates with further increase of intensity. [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]

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]

Describes a graphical method for displaying data collection events over time that may help to visualize the volume and patterns of data and assist the statistician in preparing for statistical analysis in the presence of missing data or nonuniform data collection. Use of the term Follow-Up PLOT (FU-PLOT) to describe a class of graphical techniques.

Presents a graphical method of diffusion equation to estimate the charge collection from an ion track. Charge-collection frequency; Computation of average arrival time; Application of mathematical theory to any geometry.

A procedure is described by which three-dimensional yield criteria and flow rules can be derived graphically by drawing envelopes. Using computer graphics, this provides the modeller with a simple, clear, precise and flexible method with which to generate data that can be compared with results obtained analytically or experimentally. As illustrative examples, yield surfaces are constructed in the constant-pressure plane in principal stress space using the Drucker-Prager and Frossard's dissipation functions, and two modified forms of Houlsby's dissipation function. For constant-volume flow these produce the Drucker-Prager, Mohr-Coulomb and Matsuoka-Nakai yield surfaces. Each is paired with both an isotropic and an anisotropic dilatancy rule. The direction of plastic flow at yield, consistent with the choice of dissipation function and dilatancy rule, can be determined from these constructions. One of the yield surfaces produced is compared with the results from true triaxial tests where the rate of dilatancy has been determined. An example of Rowe's stress-dilatancy plots is also produced. [ABSTRACT FROM AUTHOR]

• A new graphical method is introduced to investigate the change in Gibbs free energy. • A change in Gibbs free energy is used to study ferroelectric domain switching. • A new domain switching criterion considers the effect of the grain size is given. • Critical single-domain grain sizes are obtained by the graphical method. • There are different critical single-domain grain sizes for different loadings. A change in the system Gibbs free energy can be used as a criterion for spontaneous reactions, including the ferroelectric domain switching process. In this work, a new effective graphical method is introduced to investigate the change in the Gibbs free energy of a grain system and intuitively represent the domain switching state since its expression is too complex to study directly. A barium titanate crystal is considered as an example, and only 90∘ domain switching is involved. We can obtain two kinds of applications by virtue of the graphical method by controlling different variables in the change of the free energy: one application involves a new form of a ferroelectric domain switching criterion that considers the effect of the grain size, and the other application involves the critical single-domain grain size. For different loading methods, there will be different critical single-domain grain sizes in ferroelectrics. [ABSTRACT FROM AUTHOR]

This article approaches the problem of selecting significant principal components from a Bayesian model selection perspective. The resulting Bayes rule provides a simple graphical technique that can be used instead of (or together with) the popular scree plot to determine the number of significant components to retain. We study the theoretical properties of the new method and show, by examples and simulation, that it provides more clear-cut answers than the scree plot in many interesting situations. [ABSTRACT FROM AUTHOR]

Modification of native ecosystems through land use can affect the biophysical functioning of agroecosystems, with spatial arrangement (configuration) through time often determining the degree to which landscapes experience dysfunctional states. An improved understanding is needed of how spatial and temporal patterns in land use affect ecohydrological dysfunctions, such as how landscapes leak or fail to retain water and soil, at scales relevant to farm management. We develop and apply a Graphical LAndscape Map Survey method, or ‘GLAMS’, for measuring changes in landscape function based upon a 3D graphic of a hypothetical sub-catchment. GLAMS was applied within four Landcare Groups comprised of farmers from the Western Catchments of Southeast Queensland, Australia. The aim was to capture the behaviors of farmers who manage land use under natural variations in precipitation, especially extended dry periods, and with the associated risks from ecohydrologically dysfunctional or ‘leaky’ landscapes. GLAMS provided variable spatial and temporal resolution which allowed quantification of the land use responses for three different property sizes: (1) small, less than 100 ha; (2) medium, 100–500 ha; and (3) large, larger than 500 ha. Responses were quantified using Bayesian Belief Networks to provide probability estimates of the likelihood of a given action, taking place within a particular part of the landscape, considering both climatic and ecohydrological risks. The findings indicated that GLAMS was more intuitive to farmers than traditional question-based surveys, resulting in a low cost technique that is rapid to implement while providing spatially explicit information relevant to farm and catchment management. [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]

The ’T–Z plot’ method consists of plotting the throw of sedimentary horizons across a growth fault versus their depth in the hanging wall. This method has been initially developed for the analysis of growth fault kinematics from seismic data. A brief analytical examination of such plots shows that they can also provide valuable information about the evolution of fault topography. When growth is a continuous process, stages of topography creation (fault scarp) and filling (of the space available in the hanging-wall) are related to non-dynamic (draping, mud-prone pelagic settling) and dynamic (sand-prone, dynamically deposited) sedimentation, respectively. In this case, the T–Z plot analysis becomes a powerful tool to predict major lithological variations on seismic profiles in faulted settings. [Copyright &y& Elsevier]

Inherently safer design (ISD) concepts have been with us for over two decades since their elaboration by Kletz [Chem. Ind. 9 (1978) 124]. Interest has really taken off globally since the early nineties after several major mishaps occurred during the eighties (Bhopal, Mexico city, Piper-alfa, Philips Petroleum, to name a few). Academic and industrial research personnel have been actively involved into devising inherently safer ways of production. The regulatory bodies have also shown deep interest since ISD makes the production safer and hence their tasks easier. Research funding has also been forthcoming for new developments as well as for demonstration projects.A natural question that arises is as to how to measure ISD characteristics of a process? Several researchers have worked on this [Trans. IChemE, Process Safety Environ. Protect. B 71 (4) (1993) 252; Inherent safety in process plant design, Ph.D. Thesis, VTT Publication Number 384, Helsinki University of Technology, Espoo, Finland, 1999; Proceedings of the Mary Kay O’Connor Process Safety Center Symposium, 2001, p. 509]. Many of the proposed methods are very elegant, yet too involved for easy adoption by the industry which is scared of yet another safety analysis regime. In a recent survey [Trans. IChemE, Process Safety Environ. Prog. B 80 (2002) 115], companies desired a rather simple method to measure ISD. Simplification is also an important characteristic of ISD. It is therefore desirable to have a simple ISD measurement procedure.The ISD measurement procedure proposed in this paper can be used to differentiate between two or more processes for the same end product. The salient steps are: Consider each of the important parameters affecting the safety (e.g., temperature, pressure, toxicity, flammability, etc.) and the range of possible values these parameters can have for all the process routes under consideration for an end product. Plot these values for each step in each process route and compare. No addition of values for disparate hazards (temperature, pressure, inventory, toxicity, flammability, etc.) is being suggested to derive an overall ISD index value since that conceals the effects of different parameters. Further, addition of numbers with different units (°C for temperature, atm/bar for pressure, t for inventory, etc.) is inappropriate in scientific sense. The proposed approach has a major advantage of expanding consideration in future to incorporate economic, regulatory, pollution control and worker health aspects, as well as factors such as the experience one has or ‘the comfort level’ one feels with each of the processes under consideration. Additionally, it would also guide the designers and decision makers into affecting specific changes in the processes to reduce the unsafe features.We demonstrate our simple approach by using the example of six routes to make methyl methacrylate as documented by Edwards and Lawrence [Trans. IChemE, Process Safety Environ. Protect. B 71 (4) (1993) 252; Quantifying inherent safety of chemical process routes, Ph.D. Thesis, Loughborough University, Loughborough, UK, 1996] and show that the decision could well have been different if addition of disparate hazards had not been done. [Copyright &y& Elsevier]

Electros, ionization mass spectrometry (ESI-MS) is becoming important tool in the study of natural organic matter (NOM) at the molecular level.[SUP1] Ultrahigh-resolution ESI-M analyses of NOM often produce very complicated spectra; therefore, visual presentation and structural interpretations of the spectra are difficult. To meet this analytical challenge, we herein propose and demonstrate an approach using the van Krevelen diagram. With this approach, complicated mass spectra can be visualized in a way allows for (1) possible reaction pathways to be identification and presented, and (2) qualitative analyses on major classes of compounds that comprise ultrahighresolutiion spectra. The qualitative analyses are in a good agreement with results obtained from analyses by other analytical techniques. Additionally, the van Krevelen diagram can be expanded to a 3D plot by using peak intensities relative intensities as the z-axis. The 3D van Krevelen diagram allows for an evaluation of the relative significance of structurally related compounds. The 3D plot can also be a useful tool for compositional differentiation among samples. [ABSTRACT FROM AUTHOR]

In this paper, we consider a repair-time limit replacement problem with imperfect repair and discounting, and focus on the problem to determine the optimal repair-time limit which minimizes the expected total discounted cost over an infinite time horizon. Based upon a sophisticated graphical idea, we develop a nonparametric method to estimate the optimal repair-time limit from the empirical repair-time data. Numerical examples are devoted to estimate the optimal policy and to examine the asymptotic properties of the estimator. [Copyright &y& Elsevier]

introduces a method of aggregating intra-subject behavioral data strings into behavior-specific domains that, when pooled across subjects, can quantify complex interoorganism processes. Representation of the aggregation by a coordination index expressed as either interactant disparity or coherence.

A new simple graphical method is described for the determination of inhibition type and inhibition constants of an enzyme reaction without any replot. The method consists of plotting experimental data as ( V– v)/ v versus the inhibitor concentration at two or more concentrations of substrate, where V and v represent the maximal velocity and the velocity in the absence and presence of inhibitor with given concentrations of the substrate, respectively. Competitive inhibition gives straight lines that converge on the abscissa at a point where [I] = − K i. Uncompetitive inhibition gives parallel lines with the slope of 1/ K’ i. For mixed type inhibition, the intersection in the plot is given by [I] = − K i and ( V–v)/ v = − K i /K’ i in the third quadrant, and in the special case where K i = K’ i (noncompetitive inhibition) the intersections occur at the point where [I] = − K i and ( V– v)/ v = −1. The present method, the “quotient velocity plot,” provides a simple way of determining the inhibition constants of all types of inhibitors. [ABSTRACT FROM AUTHOR]

Abstract: Objective: We set out to develop a method for assessing the performance of clinical risk models over the spectrum of risks and to assess the performance of the EuroSCORE risk model used in cardiac surgery. Methods: We developed a graphical method for assessing the performance of clinical risk models over the spectrum of risks. To illustrate the technique, we analysed retrospective data concerning 9268 patients that underwent cardiac surgery and for whom both the additive EuroSCORE prediction of risk of morality and vital status at 30 days were available. Results: The graphical tool developed, called MADCAP (Mean Adjusted Deaths Compared Against Predictions), can be used to highlight systematic features of the performance of a clinical risk model. Its use in the current study indicates that the additive version of the EuroSCORE model seems to underestimate risk amongst low-risk cases (0% and 1%). Otherwise the score systematically favours risk avoiding behaviour as the risk model underestimates mortality for 2–6% prediction but not at 7% and above. Conclusion: The robustness of case-mix adjusted audit is dependent on the performance of the risk scoring system over the entire spectrum of risk. If we are to use risk adjustment of mortality rates when comparing outcomes obtained by different units or individual surgeons, it is essential that we continually review the performance of the risk adjustment method. The MADCAP method presented here provides a useful tool to this end. [Copyright &y& Elsevier]

• New method to assess the tail of extremes based on the mean excess function. • Easy to apply to large databases. • Precipitation global analysis (21,348 stations) shows 75.8% of records have sub-exponential tails. • Strong spatial variability of tail's heaviness is observed. Extremes are rare and unexpected. This limits observations and constrains our knowledge on their predictability and behavior. Graphical tools are among the many methods developed to study extremes. A major weakness is that they rely on visual-inspection inferences which are subjective and make applications to large datasets time-consuming and impractical. Here, we advance a graphical method, the so-called Mean Excess Function (MEF), into an algorithmic procedure. MEF investigates the mean value of a variable over threshold, and thus, focuses on extremes. We formulate precise and easy-to-apply statistical tests, based on the MEF, to assess if observed data can be described by exponential or heavier tails. As a real-world example, we apply our method in 21,348 daily precipitation records from all over the globe. Results show that the exponential-tail hypothesis is rejected in 75.8% of the records indicating that heavy-tail distributions (alternative hypothesis) can better describe rainfall extremes. The spatial variation of the tail heaviness reveals that heavy tails prevail in regions of Australia and Eurasia, with a "hot spot" found in central Russia and Kazakhstan. We deem this study offers a new diagnostic tool in assessing the behavior of extremes, easy to apply in large databases, and for any variable of interest. Our results on precipitation extremes reinforce past findings and further highlight that exponential tails should be used with caution. [ABSTRACT FROM AUTHOR]

A method is described for calculation of the equivalent circuit elements, R, L, C, G, for single dielectric transverse electromagnetic (TEM) transmission lines. The method utilizes the graphical solution of the Laplace equation in the cross-section of the line. As an example of application of the method, the calculations are carried through for a coaxial line of a square cross-section. [ABSTRACT FROM AUTHOR]

The article analyses a Cockcroft-Walton circuit by graphical model. Many kinds of condenser diode voltage multipliere have been proposed so far, but the design procedures have been discussed little. An effective method is proposed to analyze the behavior of the Cockcroft-Walton circuit. This method makes it possible to calculate the output voltage much more accurately than the conventional design formulas. The proposed method would be useful for various circuits other than the Cockcroft-Walton circuit.

Investigates two methods of sequential analysis which were applied to hypothetical observational data. What the two methods were; Indepth look at both of the methods; Discussion on the findings.

Describes a factorial method for the graphical representation of ecological data which was originally designed for the mapping of biological activity spectra of drugs. Multivariate Ratio Analysis (MRA); Advantage of MRA over other methods.

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]

Recognition and type classification can be performed on the reduced plots of village land for the decision-making on the village and land reduction. The village and construction land can represent the low use efficiency in the economically developed regions of China, particularly with the fast urbanization. It is a high demand for the amount reduction and quality improvement of construction land use. This study aims to explore the quantitative recognition and distinguish of the reduced plot of village land using ecological security patterns, in order to promote the regional ecological civilization construction, as well as regional green and sustainable development. Taking Miyun District of Beijing as an example, the evaluation index system was comprehensively constructed for the reduced plot of village land from three different dimensions of ecological security, spatial stability, and development suitability. A regional ecological security pattern was also established using multi-source data, such as land use, point of interest (POI) and socioeconomic statistics. The reduced plots were then determined after evaluation. Furthermore, 3D Rubik’s cube graphical method was used to classify the reduced plots. The results showed that: 1) The classification of habitat quality was featured by the outstanding regional aggregation and distribution characteristics. Specifically, the high-value areas were mainly distributed in the north and middle parts of the study area. The land use types were dominated by woodland, grassland, and water area. The low-value areas were mainly in the towns and relatively dense areas in the southwest. The ecological source area was 781.65 km2 after screening using the habitat quality assessment, accounting for 35.06% of the total study area. A total of 15 ecological corridors with a total length of 479.11 km were recognized via the minimum cumulative resistance model. As such, the ecological security pattern was formed in the Miyun District. 2) There was a great different comprehensive evaluation score for reduced plot of village land. Among them, the high terrain was in the northeast, while the low was in the southwest. The area of reduced plots was 789.84 hm² after a comprehensive evaluation. 3) The reduced plots of village land were divided into short-, mid- and long-term reduction areas. The short-term area consisted of three types, such as ecology-space, ecology-development, and spatial-development reduction. A total area of 565 plots covered an area of 213.34 hm² and accounted for 27.01% of the total reduced plots. Three types of reduced plots were the fundamentals action for the amount reduction and quality improvement. The reduction target needed to be prioritized for the reduction. The mid-term reduction area was composed of three types: ecological security, spatial stability, and development suitable reduction, with a total of 565 plots, covering 337.18 hm2 and accounting for 42.69% of the total reduction plots. The reduced plots in the mid-term reduction areas occupied a large proportion for the core reduction areas. Some measures should be taken for the plot reduction of villages. The long-term reduction area included one type of comprehensive reduced area, with a total of 209 plots, covering a total area of 239.32 hm² and accounting for 30.30% of the total reduced plots. Special attention should be paid to the economical and intensive use of this part of the reduced plot. A long-term reduction area was gradually recovered as the village land. Finally, some reduction measures were proposed, according to the different types of reduced plots. The findings can provide the scientific basis for the identification and classification of the reduced plots of village land in the ecological conservation areas, in order to serve the reduction of ecological conservation areas, ecological protection and regional sustainable development. [ABSTRACT FROM AUTHOR]

Background: This work aims at clinically validating a graphical tool developed for treatment plan assessment, named SPIDERplan, by comparing the plan choices based on its scoring with the radiation oncologists (RO) clinical preferences.Methods: SPIDERplan validation was performed for nasopharynx pathology in two steps. In the first step, three ROs from three Portuguese radiotherapy departments were asked to blindly evaluate and rank the dose distributions of twenty pairs of treatment plans. For plan ranking, the best plan from each pair was selected. For plan evaluation, the qualitative classification of 'Good', 'Admissible with minor deviations' and 'Not Admissible' were assigned to each plan. In the second step, SPIDERplan was applied to the same twenty patient cases. The tool was configured for two sets of structures groups: the local clinical set and the groups of structures suggested in international guidelines for nasopharynx cancer. Group weights, quantifying the importance of each group and incorporated in SPIDERplan, were defined according to RO clinical preferences and determined automatically by applying a mixed linear programming model for implicit elicitation of preferences. Intra- and inter-rater ROs plan selection and evaluation were assessed using Brennan-Prediger kappa coefficient.Results: Two-thirds of the plans were qualitatively evaluated by the ROs as 'Good'. Concerning intra- and inter-rater variabilities of plan selection, fair agreements were obtained for most of the ROs. For plan evaluation, substantial agreements were verified in most cases. The choice of the best plan made by SPIDERplan was identical for all sets of groups and, in most cases, agreed with RO plan selection. Differences between RO choice and SPIDERplan analysis only occurred in cases for which the score differences between the plans was very low. A score difference threshold of 0.005 was defined as the value below which two plans are considered of equivalent quality.Conclusion: Generally, SPIDERplan response successfully reproduced the ROs plan selection. SPIDERplan assessment performance can represent clinical preferences based either on manual or automatic group weight assignment. For nasopharynx cases, SPIDERplan was robust in terms of the definitions of structure groups, being able to support different configurations without losing accuracy. [ABSTRACT FROM AUTHOR]

The article discusses the findings of research which was conducted on 169 randomised trials of non-drug interventions in primary care which were published between 199 and 2003. Researchers wanted to find ways to make the results of trials, such as the ones they studied, more understandable and readable to researchers and readers of the studies. They found that it would be helpful to researchers and readers if the experiments and data from the trials were posted in graphs rather than simply in the written word.

The Bayesian approach is applied to estimation of the Weibull-power law process (WPLP) parameters as an alternative to the maximum likelihood (ML) method in the case when the number of events is small. For the process model considered we propose to apply the independent Jeffreys prior distribution and we argue that this is a useful choice. Comparisons were also made between the accuracy of the estimators obtained and those obtained by using other priors—informative and weakly informative. The investigations show that the Bayesian approach in many cases of a fairly broad collection of WPLP models can lead to the Bayes estimators that are more accurate than the corresponding ML ones, when the number of events is small. The problem of fitting the WPLP models, based on ML and Bayes estimators, to some real data is also considered. It is shown that the TTT-concept, used in the reliability theory, is not fully useful for the WPLP models, and it may be so for some other trend-renewal processes. In order to assess the accuracy of the fitting to the real data considered, two other graphical methods are introduced. [ABSTRACT FROM AUTHOR]

Wide-angle X-ray diffraction on large-scale laser facility is a well-established experimental method, which is used to study the shock response of single crystal materials by recording X-rays diffracted from numerous lattice planes. We present a three-dimensional graphical method for extracting physical understanding from the raw diffraction data in shocked experiments. This method advances beyond the previous iterative process by turning abstract diffraction theories in shock physics into mathematic issues, providing three-dimensional visualization and quick extraction of data characteristics. The capability and versatility of the method are exhibited by identifying lattice planes for single crystal samples with different orientations and quantitatively measuring the lattice compression and rotation under dynamic loading. [ABSTRACT FROM AUTHOR]