scholarly journals Classifying Descents According to Equivalence mod k

10.37236/1090 ◽  
2006 ◽  
Vol 13 (1) ◽  
Author(s):  
Sergey Kitaev ◽  
Jeffrey Remmel
Keyword(s):  
Current Paper ◽  
Open Problems ◽  
Type Formula ◽  
New Statistics ◽  
Permutation Statistic

In an earlier paper the authors refine the well-known permutation statistic "descent" by fixing parity of (exactly) one of the descent's numbers. In the current paper, we generalize the results of that earlier paper by studying descents according to whether the first or the second element in a descent pair is divisible by $k$ for some $k\geq 2$. We provide either an explicit or an inclusion-exclusion type formula for the distribution of the new statistics. Based on our results we obtain combinatorial proofs of a number of remarkable identities. We also provide bijective proofs of some of our results and state a number of open problems.

Invariant Curves and Focal Points in a Lyness Iterative Process

2003 ◽  
Vol 13 (07) ◽  
pp. 1841-1852 ◽  
Author(s):  
L. Gardini ◽  
G. I. Bischi ◽  
C. Mira
Keyword(s):  
Dynamic Behavior ◽  
Iterative Process ◽  
Focal Points ◽  
Invariant Curves ◽  
Open Problems ◽  
Type Formula ◽  
Iterated Maps

We investigate the properties of recurrence of the type [Formula: see text], known as Lyness iterations from [Lyness, 1942, 1945, 1961] and recently analyzed by several authors in the case a > 0, see e.g. [Kocic et al., 1993; Csornyei & Laczkovich, 2000]. We reconsider Lyness recurrences at the light of some recent results on iterated maps with denominator, given in [Bischi et al., 1999a], where new kinds of singularities, such as focal points and prefocal curves, have been defined. In this paper, in particular, we give an answer to one of the open problems proposed in [Kocic & Ladas, 1993, pp. 141] concerning the dynamic behavior of Lyness recurrences for a < 0. We also give some new results in the case a > 0, and we improve a previous result on Lyness "periodic recurrences".

Zero Marking of Past Tense in Child African American English

2014 ◽  
Vol 21 (4) ◽  
pp. 173-181 ◽  
Author(s):  
Ryan Lee ◽  
Janna B. Oetting
Keyword(s):  
African American ◽  
American English ◽  
African American English ◽  
Current Paper ◽  
Past Tense ◽  
Typically Developing ◽  
Grammatical Function

Zero marking of the simple past is often listed as a common feature of child African American English (AAE). In the current paper, we review the literature and present new data to help clinicians better understand zero marking of the simple past in child AAE. Specifically, we provide information to support the following statements: (a) By six years of age, the simple past is infrequently zero marked by typically developing AAE-speaking children; (b) There are important differences between the simple past and participle morphemes that affect AAE-speaking children's marking options; and (c) In addition to a verb's grammatical function, its phonetic properties help determine whether an AAE-speaking child will produce a zero marked form.

Ethical Issues Relevant to the Assessment of Suicide Risk in Nonclinical Research Settings

Crisis ◽  
2012 ◽  
Vol 33 (1) ◽  
pp. 54-59 ◽  
Author(s):  
Carolyn M. Wilson ◽  
Bruce K. Christensen
Keyword(s):  
Undergraduate Students ◽  
Suicide Risk ◽  
Ethical Issues ◽  
Current Paper ◽  
Self Report ◽  
Ethical Guidelines ◽  
Schizotypal Personality ◽  
Increased Risk ◽  
Genetic Features ◽  
Conducting Research

Background: Our laboratory recently confronted this issue while conducting research with undergraduate students at the University of Waterloo (UW). Although our main objective was to examine cognitive and genetic features of individuals with schizotypal personality disorder (SPD), the study protocol also entailed the completion of various self-report measures to identify participants deemed at increased risk for suicide. Aims and Methods: This paper seeks to review and discuss the relevant ethical guidelines and legislation that bear upon a psychologist’s obligation to further assess and intervene when research participants reveal that they are at increased risk for suicide. Results and Conclusions: In the current paper we argue that psychologists are ethically impelled to assess and appropriately intervene in cases of suicide risk, even when such risk is revealed within a research context. We also discuss how any such obligation may potentially be modulated by the research participant’s expectations of the role of a psychologist, within such a context. Although the focus of the current paper is on the ethical obligations of psychologists, specifically those practicing within Canada, the relevance of this paper extends to all regulated health professionals conducting research in nonclinical settings.

The Persnickety Pervasiveness of Rating Enhancement in Personality Assessment

2020 ◽  
pp. 1-13
Author(s):  
Alicia A. Stachowski ◽  
John T. Kulas
Keyword(s):  
Response Bias ◽  
Personality Assessment ◽  
Current Paper ◽  
Psychological Measurement ◽  
Shared Sets ◽  
Self Reports ◽  
Original Target ◽  
Target Profile ◽  
Do So ◽  
Normative Influences

Abstract. The current paper explores whether self and observer reports of personality are properly viewed through a contrasting lens (as opposed to a more consonant framework). Specifically, we challenge the assumption that self-reports are more susceptible to certain forms of response bias than are informant reports. We do so by examining whether selves and observers are similarly or differently drawn to socially desirable and/or normative influences in personality assessment. Targets rated their own personalities and recommended another person to also do so along shared sets of items diversely contaminated with socially desirable content. The recommended informant then invited a third individual to additionally make ratings of the original target. Profile correlations, analysis of variances (ANOVAs), and simple patterns of agreement/disagreement consistently converged on a strong normative effect paralleling item desirability, with all three rater types exhibiting a tendency to reject socially undesirable descriptors while also endorsing desirable indicators. These tendencies were, in fact, more prominent for informants than they were for self-raters. In their entirety, our results provide a note of caution regarding the strategy of using non-self informants as a comforting comparative benchmark within psychological measurement applications.

Attachment Anxiety Mitigates the Well-Being Costs of Object Attachment

2021 ◽  
Vol 42 (1) ◽  
pp. 41-56
Author(s):  
Lucas A. Keefer ◽  
Zachary K. Rothschild
Keyword(s):  
Past Research ◽  
Well Being ◽  
Attachment Anxiety ◽  
Current Paper ◽  
Personality Research ◽  
Psychological Correlates ◽  
State Study ◽  
Object Attachment ◽  
Diary Methods ◽  
State Variation

Abstract. Clinical and personality research consistently demonstrates that people can form unhealthy and problematic attachments to material possessions. To better understand this tendency, the current paper extends past research demonstrating that anxieties about other people motivate these attachments. These findings suggest that although object attachment generally correlates with poorer well-being, it may attenuate well-being deficits associated with insecurity about close relationships. The current paper presents two studies using converging correlational ( N = 394) and diary methods ( N = 413) to test whether object attachments’ association with poorer well-being is moderated by relationship uncertainties. We find that both trait (Study 1) and state (Study 2) insecurities about others eliminated, and in some cases reversed, the negative psychological correlates of object attachment. These effects, however, were only observed when focusing on between-person variation in both studies; within-person analysis demonstrated that state variation in object attachment predicted better psychological well-being. These results highlight a need for more nuanced studies of object attachment and well-being.

Introducing the new statistics in the classroom.

2019 ◽  
Vol 5 (2) ◽  
pp. 162-168
Author(s):  
Christopher J. Normile ◽  
Emily K. Bloesch ◽  
Christopher C. Davoli ◽  
Kyle C. Scherr
Keyword(s):  
New Statistics

An Evaluation of Colour-to-Greyscale Image Conversion by Linear Anisotropic Diffusion and Manual Colour Grading

2019 ◽  
Vol 2019 (1) ◽  
pp. 69-74
Author(s):  
Aldo Barba ◽  
Ivar Farup ◽  
Marius Pedersen
Keyword(s):  
Anisotropic Diffusion ◽  
Motion Pictures ◽  
Current Paper ◽  
Original Image ◽  
Colour Image ◽  
Image Conversion ◽  
Significant Difference ◽  
Greyscale Image

In the paper "Colour-to-Greyscale Image Conversion by Linear Anisotropic Diffusion of Perceptual Colour Metrics", Farup et al. presented an algorithm to convert colour images to greyscale. The algorithm produces greyscale reproductions that preserve detail derived from local colour differences in the original colour image. Such detail is extracted by using linear anisotropic diffusion to build a greyscale reproduction from a gradient of the original image that is in turn calculated using Riemannised colour metrics. The purpose of the current paper is to re-evaluate one of the psychometric experiments for these two methods (CIELAB L* and anisotropic Δ99) by using a flipping method to compare their resulting images instead of the side by side method used in the original evaluation. In addition to testing the two selected algorithms, a third greyscale reproduction was manually created (colour graded) using a colour correction software commonly used to process motion pictures. Results of the psychometric experiment found that when comparing images using the flipping method, there was a statistically significant difference between the anisotropic Δ99 and CIELAB L* conversions that favored the anisotropic method. The comparison between Δ99 conversion and the manually colour graded image also showed a statistically significant difference between them, in this case favoring the colour graded version.

Topics in Quaternion Linear Algebra

2014 ◽  
Author(s):  
Leiba Rodman
Keyword(s):  
Linear Algebra ◽  
Complex Analysis ◽  
Dimensional Space ◽  
Applied Mathematics ◽  
Three Dimensional ◽  
Number System ◽  
Graduate Course ◽  
Open Problems ◽  
Unpublished Research ◽  
Reference Tool

Quaternions are a number system that has become increasingly useful for representing the rotations of objects in three-dimensional space and has important applications in theoretical and applied mathematics, physics, computer science, and engineering. This is the first book to provide a systematic, accessible, and self-contained exposition of quaternion linear algebra. It features previously unpublished research results with complete proofs and many open problems at various levels, as well as more than 200 exercises to facilitate use by students and instructors. Applications presented in the book include numerical ranges, invariant semidefinite subspaces, differential equations with symmetries, and matrix equations. Designed for researchers and students across a variety of disciplines, the book can be read by anyone with a background in linear algebra, rudimentary complex analysis, and some multivariable calculus. Instructors will find it useful as a complementary text for undergraduate linear algebra courses or as a basis for a graduate course in linear algebra. The open problems can serve as research projects for undergraduates, topics for graduate students, or problems to be tackled by professional research mathematicians. The book is also an invaluable reference tool for researchers in fields where techniques based on quaternion analysis are used.

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