Familiar Procedures Research Articles

On Tests of Trend in a Weakly Stationary Time Series

SYNOPTIC ABSTRACTAnalysis of a Time Series represented by an error model frequently leads to familiar procedures in regression analysis. The statistical models we consider are applicable if the underlying population which generates the data has a substantial change in trend at some point. We are interested in testing hypotheses if this change is significant. Two test statistics are introduced and their distributions are derived under the assumption of weak stationarity. It is proved that these tests are unbiased and their power functions are monotonic. With correlated residuals, the linear test statistic does not give a UMP test. It is shown that a certain quadratic test statistic gives a more powerful test.

Simultaneous Inference Using Finite Intersection Tests: A Better Mousetrap.

In the behavioral and social sciences researchers utilize classical simultaneous test procedures (STP) developed by Duncan (1947, 1955), Scheffe (1953), Tukey (1949, 1953), and Roy and Bose (1953), and others to analyze differences among means. In this article we bring to the attention of the applied researcher the obscure finite intersection test (FIT) procedure developed by P.K. Krishnaiah ( 1964, 1965a. 1965b. 1965c), compare the method with more familiar classical procedures, and illustrate how one may use the FIT procedure to analyze differences among all means for both univariate and multivariate experimental designs.

Automated static perimetry in the child: methodologic and practical problems

In a pediatric population, the use of computerized static perimetry is known as particularly difficult. The specific difficulties which may occur when testing young subjects are stability of fixation, ability to maintain concentration, resistance throughout the procedure, and reliability of the answers. It seems important to investigate and to develop appropriate strategies for the examination of children aged 8 years and younger according to their ability to undergo visual field evaluation using automated static perimetry. Eighty normal children aged 5 to 8 years old were evaluated using an Octopus 2000R perimeter, with a one-level strategy. Adaptation of the procedure were included. The analysis of answers and false-positive catch-trials showed that children as young as five years old did remarkably well regarding both the duration of the examination and the reliability of answers. Automated static perimetry examination can provide reliable results in children as young as five years old once a familiarization procedure has been conducted and if the duration of examination does not exceed the child's capacity to remain task focused.

Functional data analyses of lip motion

The vocal tract’s motion during speech is a complex patterning of the movement of many different articulators according to many different time functions. Central issues are the accurate description of the shape of the vocal tract and determining how each articulator contributes to this shape. Techniques are described that provide useful tools for describing multivariate functional data such as the measurement of speech movements. The choice of data analysis procedures has been motivated by the need to partition the articulator movement in various ways: movement start- and end-effects separated from shape effects, effects due to different syllables, and the splitting of within-sensor variation from between-sensor overall variation. The techniques of functional data analysis seem admirably suited to the analyses of phenomena such as these. Familiar multivariate procedures such as analysis of variance and principal components analysis have their functional counterparts, and these reveal in a way more suited to the data the important sources of variation in lip motion. Finally, it is found that the analyses of acceleration were especially revealing in considering the character of possible control mechanisms. [Work supported by NIH Grant DC-00594.]

Familiarization process in cardiorespiratory fitness testing for persons with mental retardation

The purpose of this article is to review the familiarization protocols and other factors used in laboratory and field testing studies implemented to measure the cardiorespiratory fitness of persons with mental retardation. Test selection issues, pretest familiarization procedures, and motivational strategies will be discussed. Little information is available to identify specific guidelines for familiarizing a subject with a specific protocol prior to cardiorespiratory fitness testing. The recommendations suggested in this article provide valuable and necessary information for researchers interested in the measurement of cardiorespiratory fitness of persons with mental retardation.

The Influence of Familiarity on Judgments of Treated Speech

Three groups of 10 naive listeners transcribed sentences produced by a dysarthric speaker. The first group (Control) transcribed sentences that the speaker read in her customary manner. A second group (Treatment) transcribed the same sentences; however, the speaker produced them while implementing a breath-group strategy that she had learned in speech treatment. A final group of listeners (Familiarization) also transcribed the sentences that were produced by the speaker as she implemented the breath-group strategy. However, this Familiarization group first listened to an audiotape of the speaker reading aloud a paragraph as they followed along with a written script. This was regarded as a familiarization procedure. Statistical analysis revealed that the Familiarization group outperformed the Treatment group, which in turn outperformed the Control group. Potential perceptual benefits resulting from the familiarization procedure are discussed, along with clinical implications.

The role of listener familiarity in the perception of dysarthric speech

he effects of two qualitatively different familiarization procedures on listeners' perceptions of speech produced by a Korean woman with moderate-severe spastic-ataxic dysarthria were investigated. Thirty listeners were randomly assigned to one of three listening conditions. Prior to this task, members of the two experimental listening groups were familiarized with a speech sample produced by the woman with dysarthria. Listeners assigned to the Paragraph group heard the speaker read a paragraph twice as they followed along with a script. Listeners assigned to the Word List group heard the speaker read the same words comprising the paragraph, but the words were presented in a random order. This list was heard twice, as the listeners followed along with a script. The Control group performed the transcription task without receiving prior exposure to the dysarthric speech. The 30 listeners then orthographically transcribed sentences produced by the dysarthric speaker. Results showed that listeners familiarized with this dysarthric person's speech pattern (Word List and Paragraph groups) performed significantly better on the sentence transcription task than listeners who were not familiarized (Control group). Although the Paragraph group did not significantly outperform the Word List group, as was predicted, a trend in that direction did exist.

Seismic withstand capability of high‐voltage switchgear equipment

AbstractThe usefulness of the best‐known earthquake scales is described; the response spectrum is of major value to the engineer as evidence of seismic withstand capability. It is derived from seismograms. Based on the response spectrum, the earthquake is characterized by means of testing and/or calculation. The selection of test signals and their effect on the test specimen are discussed; a proven test procedure is demonstrated. An overview of the familiar calculation procedures is also given. The calculation tool is, particularly for complex structures, the finite‐element method. A way of working out the structural data often missing from calculation is described.

Development of Exclusivity in Perceptually Based Categories of Young Infants

The exclusivity of perceptually defined categorical representations for natural animal categories in young infants was investigated. Previously, as well as in Experiment 1, evidence was obtained for a categorical representation for cats in 3- and 4-month-old infants that excluded dogs but included perceptually similar female lions after a number of different familiarization procedures. However, in Experiment 2 both dogs and female lions were found to be excluded when the initial familiarization with cats alone was followed by six pairings of familiar cats and novel lions intermingled with two added pairings of familiar cats. The present results indicate that a categorical representation can attain a high level of exclusivity during early infancy as a consequence of experience with exemplars of the contrasting categories that accents the perceptual similarities among members of a category and the perceptual differences among exemplars from different categories.

The Attribution and Discounting of Perceptual Fluency: Preliminary Tests of a Perceptual Fluency/Attributional Model of the Mere Exposure Effect

Bornstein and D'Agostino (1990, 1992) hypothesized that the mere exposure effect results from a combination of two processes. First, an increase in perceptual fluency is induced by repeated exposure to a stimulus. Second, subjects attribute perceptual fluency effects to liking for a stimulus based on contextual cues provided by the experimenter. This paper describes two experiments that test predictions derived from the perceptual fluency/attributional model. In Experiment 1, the availability of information that allowed subjects to attribute perceptual fluency effects to the stimulus familarization procedure resulted in lower evaluative ratings of stimuli in a typical subliminal mere exposure effect experiment. In Experiment 2, the introduction of information that discouraged subjects from attributing perceptual fluency effects to the stimulus familiarization procedure resulted in more positive evaluative ratings of stimuli in a supraliminal mere exposure effect experiment. The theoretical implications of these findings are discussed, and suggestions for future studies in this area are offered.

The Transsphenoethmoid Approach to the Sphenoid Sinus and Clivus

Surgical access to the sphenoid sinus and clivus for the resection of benign and malignant disease is difficult and is often associated with significant morbidity. The transsphenoethmoid approach, an extension of a familiar otolaryngological procedure, with or without a limited medial maxillectomy, allows access to this region with little morbidity and excellent cosmetic results. Since 1988, the transsphenoethmoid approach has been used in 15 patients at our institution for resection of primary and recurrent chordomas, chondrosarcomas, pituitary macroadenomas, repair of cerebrospinal fluid leaks, and drainage of petroclival cysts. In most instances, an ipsilateral approach is most satisfactory. When necessary, a contralateral transsphenoethmoid approach is used when the tumor is posterolateral to the internal carotid artery and as far lateral as the abducens nerve.

INEXPERIENCED AND ANXIOUS COMPUTER USERS: COPING WITH A COMPUTER-ADMINISTERED TEST OF ACADEMIC SKILLS

The objective of this study was to assess the degree to which the mode of administration of the computer-based Academic Skills Assessments of The Praxis Series: Professional Assessments for Beginning Teachers™ contributes to performance differences among test takers. To make this determination, inexperienced or anxious computer users were recruited to take the assessments. The degree to which test design and test familiarization procedures effectively minimized variation due to comfort and familiarity with computers was examined from three perspectives: the extent to which the availability of a personal, information-providing test center supervisor influenced test performances, beyond the help provided by a computerized test familiarization tutorial, the effect of within-test practice on later performance on a subsequent section of the test, and the relationship of computer-based test performance to attitudes toward computers and experience in using them. The conclusion was that performance on the tests is not unduly affected by computer administration.

The determination of convex bodies from the mean of random sections

Random sectioning of particles (compact sets in ℝ3 with interior points) is a familiar procedure in stereology where it is used to estimate particle quantities like volume or surface area from planar or linear sections (see, for example, the survey [23] or the book [20]). In the following, we study the problem whether the whole shape of a convex particle K can be estimated from random sections. If E is an IUR (isotropic, uniform, random) line or plane intersecting K then the intersection Xk = K ∩ E is a (k-dimensional, k = 1 or 2) random set. It is clear that the distribution of Xk determines K uniquely and that if E1,…, En are such flats, the most natural estimator for K would be the convex hull

Fuzzy differential inclusions as substitutes for stochastic differential equations in population biology

The familiar procedure of adding white noise to deterministic systems of equations may not be appropriate or even possible in some modelling problems arising in the biological sciences. Although some mathematical handle on indeterminant factors (i.e. noise) may be necessary, sometimes the probabilistic requirements involved cannot be rigorously verified for the data set in hand. As an alternative, we discuss here the modelling utility of fuzzy differential inclusions associated with given systems of nonlinear ODE's. We give concrete examples and give account of the conservative stochastic mechanics of E. Nelson applied to growth of a dimorphic clone, and its fuzzy differential inclusion analogue.

A comparative analysis of sequencing procedures for mixed-model assembly lines in a just-in-time production system

In this paper several procedures for sequencing products on a mixed-model assembly line in a just-in-time production system are statistically compared using simulation analysis. The procedures include two 'goal chasing' heuristics developed at Toyota that focus on constant component usage, an algorithm developed by Miltenberg designed to achieve uniform production rates for each model, a time spread method developed by the authors that smooths the work load at each assembly line station, and the familiar batch sequencing procedure frequently used in practice. These five sequencing procedures are evaluated according to four measures of assembly line inefficiency, work not completed, worker idleness, worker station time and a measure of variability in uniform component usage. The results provide assembly line managers with guidelines for selecting the most effective sequencing procedure for achieving their operational objectives.

Implementing the modified LH algorithm

The modified Lemke-Howson algorithm is a constructive procedure which enables us to compute equilibrium points of a bimatrix game. The algorithm as described by one of the authors is based on the original version invented by Lemke and Howson. However, it differs from this version with respect to several features. It works directly with the matrices defining the bimatrix game A and B. It has an easy and very direct geometrical interpretation; hence for small games we can follow the development of the algorithm geometrically. Finally, instead of being bilinear, the algorithm behaves rather like a piecewise linear program. This presentation closes a gap: although the algorithm has been described geometrically (and with a flow diagram), there has been no constructive procedure that can be implemented on a computer. This is provided by the present paper. We give all necessary proofs and computations in order to establish the following facts: There are two tableaus accompanying the proceeding of the algorithm. As the algorithm changes, moving alternatingly in the simplices of mixed strategies, so does the computational procedure alternatingly dealing with the two different tableaus. Each tableau contains six regions, depending on the various sequences of transitions the procedure has to perform. While this all is in marked difference to linear programming, there is also consolation: The well-known rectangle rule of linear programming can be modified easily (that is, there is a family of rectangle rules) so that changing the tableau alternatingly amounts to applying the appropriate rectangle rule. Thus, there is also close similarity to the familiar LP procedure. Thus, a complete description of the modified LH algorithm is provided that can immediately be implemented on any computer. In particular, we supply an APL program that, e.g., can be run on an IBM ® PC.

Utilization of ambulatory care studies: testing the assumptions

A linear regression procedure is usually used to estimate the effect of a set of predictors on utilization of ambulatory health care. The implicit assumptions embedded in the linear regression model have never been examined. Here, with utilization data of a sample of 48292 patients from the file of the Quebec National Health Plan, four implicit hypotheses embedded in the linear regression model are tested: (1) the transition from the state of utilization to the state of no utilization, and vice-versa, depends on the level of the transition rates, (2) the effect of independent variables depends on the transitions being predicted from or to the state of utilization, (3) the transition is time dependent, and (4) the system of transitions from one state to another is not at equilibrium. The analysis shows that the first three hypotheses cannot be rejected. Thus, the use of the familiar linear regression procedure in this study to estimate the effect of a set of factors on utilization would have yielded biased estimates.

Porcelain-metal pontics for removable partial dentures

A custom-made porcelain-fused-to-metal ring pontic for a removable partial denture may be color characterized and glazed by use of familiar procedures. The use of this type of pontic on removable partial dentures has the potential of superior esthetic results when replacing isolated maxillary anterior teeth.

Cross spectral analysis of nonstationary processes

Consideration is given to the generalization of stationary cross spectral analysis methods to a class of nonstationary processes, specifically, the class of semistationary finite energy processes possessing sample functions that are of finite energy almost surely. A new quantity called the time-frequency coherence (TFC) is defined, and it is demonstrated that its properties are analogous to those possessed by the stationary coherence function. The problem of estimating the TFC by using elements of L. Cohen's (1966) class of joint time-frequency representations is investigated. It is shown that the only admissible estimators are those based on the class of time-frequency smoothed periodograms. Thus, the familiar procedure of segmentation and (smoothed) short-time Fourier analysis cannot be improved upon (within the framework considered) by the use of the higher-resolution nonparametric time-frequency methods. Procedures for selection of the appropriate estimators and a possible application are suggested. >

From ‘TO POLY’ to generalized poly‐figures and their classification: a learning experience

A heuristic description of a personal learning experience in a LOGO micro‐world is given. The figures produced by the familiar POLY procedure are generalized, and an attempt is made to develop a workable definition and a useful classification. It depicts the gradual evolution of relevant mathematical concepts, and the part intuition played in this process. Moreover, it shows mathematics both as a process of discovery and creative work, illustrating the difference between the final product and the untidy processes used to arrive there.