Graphical Analysis Techniques Research Articles

Dynamic interaction among price, quality, durability and the sales rate in a steady state environment: A theoretical analysis

This paper investigates the relationship among price, quality, product durability, quality durability and the sales rate for durable goods. The research builds on a dynamic model of sales reponse, developed by Narasimhan et al. [R. Narasimhan, S. Ghosh, D. Mendez, A dynamic model of product quality and pricing decisions on sales response, Decision Sciences 24 (5) (1993) 893–908]. First, the paper determines whether a stable relationship among price, quality, product durability, quality durability and the sales rate exists, by examining the equilibrium properties of the model. Second, the paper uses the derived equilibrium expressions to develop insights into the relationship among these variables. Third, the paper examines the necessary conditions for the price equilibrium level to be optimal, from the point of view of a profit-maximizing producer. Finally, the paper employs a graphical analysis technique to investigate the impact of increases in quality and quality durability on the optimum price level. Among many results, the paper shows the existence of a minimum quality level and a maximum price level for the sales rate to remain positive. The research also shows that an increase in quality durability (stemming, for instance, from increased advertising) commands an increase in price regardless of the product’s price elasticity of demand. Additionally, the paper establishes an explicit relationship between quality improvements and optimal prices. The practical relevance of the findings is discussed.

Rovibrational characterization of XΣ+2B11H+ by the extrapolation of photoselected high Rydberg series in B11H

Optical-optical-optical triple-resonance spectroscopy of (11)BH isolates high Rydberg states that form series converging to rotational state specific ionization potentials in the vibrational levels of (11)BH(+) from nu(+)=0 through 4. Limits defined by a comprehensive fit of these series to state-detailed thresholds yield rovibrational constants describing the X (2)Sigma(+) state of (11)BH(+). The data provide a first determination of the vibrational-rotational interaction parameter alpha(e)=0.4821 cm(-1) and a more accurate estimate of omega(e)=2526.58 cm(-1) together with the higher-order anharmonic terms omega(e)x(e)=61.98 cm(-1) and omega(e)y(e)=-1.989 cm(-1). The deperturbation and global fit of series to state-detailed limits also yield a precise value of the adiabatic ionization potential of (11)BH of 79 120.3+/-0.1 cm(-1), or 9.810 33+/-1x10(-5) eV. High precision is afforded here by the use of graphical analysis techniques, narrow-bandwidth laser systems, and an analysis of newly observed, high principal quantum number Rydberg states that conform well with Hund's case (d) electron-core coupling limit.

Theoretical development of a graphical analysis technique to optimize the particle size distribution of pigments in paints and coatings

The new analytical expression introduced in this study shows that a plot of the accumulated volume fraction of pigment particles vs. the square root of particle size should be a straight line for the theoretically preferred particle size distribution. This linear theoretical model was also found to be consistent with the experimentally developed linear model proposed by Kaeuffer. However, Kaeuffer proposed that his straight line went through the origin, but the analytical model developed in this paper has shown that this intercept is not zero. Thus, Kaeuffer’s experimental model is only partially correct.

Graphical phasor analysis of three-phase PWM converters

A graphical steady-state analysis technique based on the complex 0-sequence, forward-rotating, and backward-rotating (0fb) phasors is described for balanced three-phase PWM inverters, rectifiers and cycloconverters. The technique avoids the cumbersome algebra of the 0fb transformation, and the coupling between the subcircuits resulting from the real direct-axis/quadrature-axis (dq) transformation. Using symmetric and de-coupled subcircuits that are time-invariant under steady state, the graphical method makes the analysis of three-phase converters straightforward and insightful. In the paper, time-invariant transient models with respect to an arbitrary reference node are first derived for all three-phase converter components. Application of the component models to steady-state analysis is demonstrated for the buck-boost inverter. The steady-state equivalent circuits for the popular buck and boost inverters, rectifiers, and cycloconverters are given along with the steady-state values for their capacitor voltages and inductor currents.

NIST micronutrients measurement quality assurance program: characterizing individual participant measurement performance over time.

The mission of the Micronutrients Measurement Quality Assurance Program (M2QAP) at the National Institute of Standards and Technology is enhanced interlaboratory measurement comparability for fat-soluble vitamin-related measurands in human serum. We recently described improved tools for evaluating individual participant measurement performance in single interlaboratory comparison exercises; we here apply and extend these tools to the evaluation of participant performance over the entire 15-year history of the M2QAP. We describe and illustrate a set of interconnected graphical reporting tools for identifying long-term trends and single-exercise events. We document and discuss recurrent patterns we observe in the measurement performance characteristics for M2QAP participants. The graphical analysis techniques utilized may be applicable to other interlaboratory comparison programs.

Graphical analysis and operative technique of single-cut osteotomy for complex femur deformities

The correction of complex long bone deformities with concurrent bending, twisting and shortening is primarily based on complex preoperative planning. Up to now, wedge-shaped cortico-spongiose osteotomy has usually been performed. The single cut osteotomy requires more complex mathematical calculations and was therefore less frequently undertaken. In this paper, we present a graphical approach to define the plane of the single-cut osteotomy without any calculations. The resulting osteotomy allows a simultaneous correction of a deformation in the coronal and sagittal planes, as well as a coexisting torsional error. The advantages of this graphical approach are evident. Preoperative planning is significantly simplified and abbreviated as mathematical calculations are no longer needed. Furthermore, the precision by which the osteotomy plane is defined is not decreased by application of this method. However, the osteotomy should be done preoperatively in a model.

Spatial variability in the soil foodwebs in a contaminated grassland ecosystem

Spatial relationships among soil nematodes and soil microorganisms were investigated in a grassland ecosystem at the U.S. Army's Aberdeen Proving Ground, Maryland. This area was contaminated with a wide range of concentrations of heavy metals. The study quantified microbial biomass, the abundance of soil protozoa and nematode populations. Geostatistical techniques were used to evaluate cross-correlations among biotic and abiotic parameters and to determine spatial distributions of these parameters in soil. The graphical analysis technique displayed a surface in three-dimensional space, the topography of which was generated by an independent variable and the surface colored by a dependent variable. Both the visualization technique and the cross general relative semivariogram showed a negative correlation between the abundance of fungivore nematodes and fungal biomass, the abundance of bacterivore nematodes and bacterial biomass, and between the numbers of protozoa and microbial biomass in less-contaminated portions of the study site. Graphical analyses of the spatial distribution of soil biota showed that relationships among components of the soil foodweb were altered in the highly contaminated area compared to the less-contaminated local background area. This suggests that environmental conditions in the soil of the contaminated areas may have a detrimental effect on trophic interactions in the soil foodweb.

Vector competition analysis: a new approach for evaluating vegetation control methods in young black spruce plantations

This paper reports on a new graphical analysis technique that facilitates screening alternative strategies for crop management in programs of integrated vegetation management in young forest plantations. The responsiveness of black spruce seedlings to three vegetation management measures (herbicide application, fertilization and seedling nutrient loading) on two contrasting site types (Hardwood [ST 10] and Feathermoss [ST 4]) located in northern Ontario, were compared and evaluated using vector competition analysis. The approach is based on vector diagnosis and regression analysis that compare growth and nutritional interactions between crop and non-crop plants competing for the same growth resources. Response parameters are examined in a bivariate model depicting vectors of changing biomass production or nutrient uptake relative to competition-free treatments. Although herbicide application reduced non-crop vegetation on both sites, it accelerated tree growth and nutrient uptake only in the herb-rich Hardwood site, but had no effect on seedlings in the Feathermoss site. Fertilization stimulated vegetation growth in the competitive Hardwood site causing seedling suppression, but stimulated both tree and non-crop vegetation growth in the Feathermoss site because of weaker competition. Preplant nutrient loading improved seedling growth and nutrition reducing competition of neighboring weeds. Vector competition analysis facilitated interpretation of plant interactive relationships and identification of limiting factors. Advantages over traditional competition indices are that both growth and nutrition parameters, as well as crop and non-crop responses are quantitatively and systematically evaluated, and that simultaneous comparisons simplified screening of the most effective treatments and sites for possible vegetation control. Key words: Competition indices, treatment screening, nutrient loading, fertilization, herbicide

Two levels of spacing and limits to local population density for settled larvae of the ascidian Clavelina moluccensis: a nearest-neighbour analysis

Among sessile marine invertebrates, the dispersion patterns of settling larvae are likely to strongly affect the nature and strength of subsequent intraspecific interactions. We use a recently developed graphical analysis technique to examine in situ spacing among settled larvae of the colonial ascidian Clavelina moluccensis. Larvae were mapped at settlement each day for 1 month at the time of their release from adults. Experimental plots measuring 90×90 mm were located on naturally occurring bare patches of wood on pier pilings which were extensively encrusted with sponges and ascidians. An inclusive one-tailed nearest-neighbour analysis applied at the time of the maximum number of individuals per plot revealed consistent fine-scale regular spacing between settled larvae. Furthermore, a two-tailed goodness-of-fit analysis indicated two modes of spacing: one at about 4.5 mm and the other at around 9 mm. No contact between larvae was observed at settlement and the spatial regularity is interpreted as a response of settling larvae to water-borne cues released from settled individuals. The two modes of spacing indicate the possibility of kin recognition as has been demonstrated for bryozoans. Water-borne cues may also limit local population density, as those plots with a high density of settlers showed a much greater decrease in settlement rate over time than low-density plots. Our findings are consistent with the hypothesis that intraspecific competitive interactions shape the patterns of dispersion of these invertebrates on hard substrata in the field.

Multicompartmental study of fluorine-18 altanserin binding to brain 5HT2 receptors in humans using positron emission tomography

Serotoninergic type 2 (5HT2) receptors have been implicated in the regulation of many brain functions in humans and may play a role in several neurological and psychiatric diseases. Fluorine-18 altanserin has been proposed as a new radiotracer for the study of 5HT2 receptors by PET because of its high affinity for 5HT2 receptors (Ki: 0.13 nM) and its good specificity in in vitro studies. Dynamic PET studies were carried out in 12 healthy volunteers after intravenous injection of 0.1 mCi/kg [18F]altanserin. Ninety minutes after injection, we observed mainly cortical binding. Basal ganglia and cerebellum showed very low uptake and the frontal cortex to cerebellum ratio was about 3. To evaluate the quantitative distribution of this ligand in the brain, we used two different methods of data analysis: a four-compartment model was used to achieve quantitative evaluation of rate constants (K1 and k2 through k6) by non-linear regression, and a multiple-time graphical analysis technique for reversible binding was employed for the measurement of k1/k2 and k3/k4 ratios. Using both methods, we found significant differences in binding capacity (estimated by k3/k4 = Bmax/Kd) between regions, the values increasing as follows: occipital, limbic, parietal, frontal and temporal cortex. After correction of values obtained by the graphical method for the existence of non-specific binding, results generated by the two methods were consistent.

Computer-based multimedia in plastic surgery education.

Computer animation complements text explanation, image documentation, and graphic analysis techniques. It is compatible with the development of interactive multimedia science. Computer animation may emerge as a critical tool to assist in the efficient processing and analysis of greater volumes of educational data in plastic surgery training. At St. Louis University, we have continuously developed multimedia plastic surgery teaching materials with full-fidelity digital sound, three-dimensional computer graphics, and "picture-in-picture" video capabilities since 1987. We have used these materials, many of which are illustrated in this paper, for patient informed consent and the education of medical students and residents.

An analysis method for piecewise linear dynamical systems

A wide range of nonlinear dynamical systems contain abrupt changes in system behaviour and are often controlled using some kind of logic such as a rule-base. These changes in the system dynamics or controller actions make such systems intractable to conventional methods of systems analysis. By assuming all system nonlinearities can be represented as piecewise linear functions, a graphical analysis technique reminiscent of a phase portrait is developed for this class of systems and controllers. The state space of the system model is mapped into a directed node graph that captures the possible dynamic paths through the system. The paths found are directly related to the piecewise linear system functions or logic rules that created them. This node graph provides a graphical representation of the system that, like the phase portrait, captures the global dynamics of the system. The major difference is that the node graph generalises the phase portrait idea to systems of arbitrary dimensions.

A new approach to evaluating inter-laboratory testing precision

A new approach to the evaluation of inter-laboratory testing precision has been developed based upon the analysis of a large inter-laboratory testing program on Mooney viscosity. The new approach (based on demonstrated non-random or ‘biased’ inter-laboratory test differences) consists of : (1) the adoption of newly proposed ‘between-lab’ and ‘within-lab’ statistical parameters, h and k, as developed by ASTM Standard E-691 (a standard practice for evaluating precision) and (2) a number of special graphical analysis techniques that allow for an identification of the good, the intermediate and the poor laboratories on the basis of both their between-lab (precision), reproducibility, R, and their within-lab (precision), repeatability, r. The h parameter indicates how the deviation d, of an individual laboratory test result from a reference value (the overall average measured property), compares to the range of deviations for all laboratories and the k parameter is a ratio of the within-lab variation of any laboratory to the overall level of variation of all laboratories. The deviation values may be used to prepare Deviation Profiles that show how the various laboratories rank; negative to zero to positive ‘biases’ or deviations compared to the reference value. Analysis of the relationships of: (1) h and the standard deviation of h across all the test materials, (2) k and the standard deviation of k across the materials and (3) average h and average k for all materials, provide valuable information for the diagnosis of laboratory testing behavior. The INTERCAL concept, a procedure for using independently obtained calibration curves to correct for the biased between-lab differences, gives a substantial reduction in the between-lab reproducibility, R; provided that: (1) all laboratories have good within-lab precision or small r and (2) that testing proficiency is maintained in a stable condition over a period of time. A global Quality Testing concept has been proposed based on the ability of this new approach to classify laboratories into one of three grades: Grade A, laboratories that have good inherent agreement with each other and to reference values; Grade B, laboratories that may be corrected by INTERCAL to the same level of agreement as Grade A, and Grade C, laboratories that cannot be corrected by INTERCAL because of poor within-lab control and resulting high within-lab variation.

Computer File Format Standards

Summary The Pressure Transient Testing Technical Program Committee for the 1990 SPE Annual Technical Conference and Exhibition established a subcommittee in 1988 to investigate computer file standards for well-test data, type-curve libraries, and subroutine calls for program algorithms. This paper proposes a format standard for well-test data on floppy disks. The proposed format is adopted from the Canadian Well Logging Soc.’s (CWLS’s) Floppy Disk Committee for log data. The format, known as LAS (Log ASCII Standard), provides a data-file specification so that PC users have a flexible file format to store and retrieve large amounts of electronic instrument data from floppy disk quickly. Using this standard will give analysts direct access to the data they need for graphical analysis and computer-aided interpretation techniques. The LAS standard gives well-test service companies and operators a common floppy disk file structure to support the growing number of PC users who use PC-based pressure-transient analysis (PTA) programs.

Impairment and recovery profiles of sensory-motor function following stroke: Single-case graphical analysis techniques

Graphical analysis procedures have been developed to improve interpretation of sensory-motor tests from individual subjects following acute brain damage. The procedures have been applied to 11 unilateral stroke patients assessed serially over 12 months on a computerized quantitative sensory-motor test battery of which grip strength, arm speed, and tracking have been chosen for illustrative purposes. The results indicate that four graphs are necessary to fully demonstrate neurologic impairment and recovery of each sensory-motor function, although fewer graphs would be satisfactory in some applications. Such analyses have proven valuable in the display of serial performance of individual patients but demonstration of impairment and recovery is much more difficult than for group analyses.

A technique for assessing the severity of terrain shadowing in mobile satellite service

A graphical analysis technique is presented that produces an estimate of the severity of terrain shadowing of a particular geosynchronous satellite. The technique can be used to analyze the coverage provided by a new group of satellites capable of direct communication with mobile and transportable units. Application of the technique to a number of highways in Alaska is described.

LEARNER CHARACTERISTICS AND SECOND LANGUAGE ACQUISITION: A MULTIVARIATE STUDY OF ADULT IMMIGRANTS AND SOME THOUGHTS ON METHODOLOGY

The study examined the relationship between learner characteristics and achievement in French as a second language in a sample of 391 adult immigrants completing a 900‐hour course of classroom instruction in Montreal. A multivariate analysis of variance was used to assess the relative contribution of nine learner variables to individual differences in performance on an FSL achievement test. Teachers' evaluations of subjects as “good learners” or “poor learners” served as the dependent variable in a multivariate ANOVA comparing the two groups. Results of the various analyses indicated that subjects who have more schooling, a higher degree of nonverbal reasoning ability, make greater use of French outside the classroom, are more competent in English, and display a greater degree of field independence are more likely to benefit from formal language instruction. Higher levels of illiteracy and classroom anxiety, coupled with greater age, were related to learning difficulties. The paper underlines the importance of multivariate data analysis techniques and proposes the use of graphical data analysis techniques for researchers exploring multivariate data sets with small groups of subjects.

Parallel Local Operations for a New Distance Transformation of a Line Pattern and Their Applications

The distance transformation of a line pattern (DTLP) is proposed and its properties are studied in detail. DTLP is the transformation of a binary line pattern by which the value at each 1-pixel in an input pattern is changed into the distance measured along a line pattern from that pixel to the furthest edge point (type I DTLP) or to the nearest edge point (type II DTLP). Both types of DTLP are performed by iterative local parallel operations. DTLP is effectively used in the processing of line patterns, such as the elimination or extraction of branches having prespecified features, and the description of the structure of a line pattern. The transformation can also be applied to the texture analysis of line patterns. Several parallel operations for feature extraction related to line patterns based upon the DTLP are given. Experimental results are shown concerning the application of the DTLP to the processing of blood vessel images in chest radiograms and to the texture analysis of photomicrographs of metal pieces. Line pattern analysis based on the DTLP is distinguished from other line pattern processing methods, such as graphical network analysis techniques, in that a two-dimensional line pattern can be processed directly by parallel local operations; and properties based on length as well as topology are effectively used.

A Study to Determine the Characteristic Shapes of Helicopter Visual Approach Profiles

Prior to this study, the characteristic shape of visual approach profiles had not been formally documented. In this study, over 200 visual approaches were flown using different helicopter types, test subjects, and initial conditions, and the altitude and groundspeed profiles were measured by a precision tracking radar. The data from each approach were then processed, and the characteristic shape of the altitude, groundspeed, and deceleration profiles was determined for each set of initial conditions. These flight data were processed further using graphical analysis techniques and parameterization which, in turn, led to developing closed-form equations that accurately describe the characteristic groundspeed and deceleration profiles. Results from this study can be used to select instrument approach profiles, to develop instrument approach control laws, and to define the corresponding hardware requirements.

DDA

Graphical techniques are becoming more and more popular tools of applied statisticians and data analysts. This growing popularity is due both to the great intrinsic utility of graphic data displays and to the more widespread availability of graphic peripherals to computing systems. Since, however, graphical data analysis techniques are most valuable when used 1) interactively and 2) in conjunction with each other, rapidly shifting and expanding graphic display hardware and software technology has inhibited their full exploitation and utilization. The DDA language “workbench” attempts to minimize the amount of time which a statistician or data analyst must devote to language and machine-dependent considerations of graphical data analysis. This should enable him or her to concentrate on the development, investigation, and utilization of the graphical techniques themselves.