Miracle-dz/UniFAR-FTUs huggingface dataset:
Predicting the Skilled Use of Hierarchical Menus With the Keystroke-Level Model

This article addresses a key question in the application of Card, Moran, and Newell's (1983) keystroke-level model to software in which users specify a command by working through a system of hierarchical menus. For example, to insert a row in Lotus 1-2-3®, the user makes three menu choices: W for worksheet, I for insert, and R for row. In the keystroke-level model, it is assumed that a time-consuming mental operation precedes each command. The question in the application of the keystroke-level model to hierarchical menu systems is whether the keystrokes WIR in the previous example constitute the execution of three commands and thus require three mental operations or whether WIR acts as a single command and requires only one mental operation. Data were collected from four highly experienced Lotus 1-2-3 users as they went about their day-to-day work. Strong evidence that only one mental operation is involved in choosing from a hierarchical menu system was obtained. We hypothesize that the discrepancy of our results from the data of others is due to the fact that our subjects were more experienced. The implications of our findings for the design of menus is discussed.
Minimization of Rational Word Functions

Rational functions from a free monoid into another are characterized by the finiteness of the index of some congruence naturally associated with the function. A sequential bimachine is constructed computing the function, which is completely canonical, and in some sense minimal. This generalizes the Nerode criterion and the minimal automaton of a rational language, and similar results for sequential functions.
Literate Specification: Using Design Rationale to Support Formal Methods in the Development of Human-Machine Interfaces

The design of safety-critical user interfaces is typically very different from that of many other applications. Reactor control systems and aircraft cockpits are complex and dynamic, open to input from many different users and devices. A number of formal notations, including Z and temporal logic, have been developed to address these problems. They provide precise and concise means of representing a potential design before designers incur the expense of implementation. Consequently, government bodies and commercial organizations have recommended that these techniques be used when tendering for their contracts. However, there are a number of limitations that restrict the use of mathematical specifications for interface development in large scale projects. In particular, formal notations cannot easily be used to coordinate the activities of human factors and systems engineering teams. This creates particular difficulties if some group members have only a limited understanding of discrete mathematics. A further problem is that the development of a safety-critical application may take many months, or even years, to complete. This creates difficulties because abstract mathematical specifications cannot be used easily by new members of a development team to understand past design decisions. To avoid these limitations I have developed a literate approach to interface specification. This technique uses a formal development language and a semiformal design rationale to support the design of safety-critical user interfaces.
Exploding the Myth of the Symmetrical/Asymmetrical Dichotomy: Public Relations Models in the New South Africa

An empirical study of practitioners in the newSouth Africa found no evidence that respondents grouped public relations practices according to principles of symmetry or asymmetry, thus rejecting the notion of symmetry as a normative public relations approach in international settings. Instead, South African practitioners developed their ownculture-specific models of practice basedonthe economic, social, and political realities of their country. These included the conflict-based Western Dialogic model rooted in dissensus, the Activist model promoting change in organizations, theUbuntu model favoring harmony and reconciliation in theworkplace, and the Oral Communication model focusing on the use of oral media in the communication process. Practitioners' demographic characteristics did not influence their use of public relations models, most probably because of the similarity of their public relations education, which seemed to emphasize a focus on the characteristics of an organization's publics in the communication process rather than on practitioners' individual propensities.
A Longitudinal Study of Work Characteristics and Health Complaints Among Insurance Employees in VDT Work

Employees using visual display terminals (VDI) in their work in the head office and branch offices of a Finnish insurance company were followed for 8 years. Their job satisfaction and health complaints were studied in relation to VDT-use characteristics and job demands and stressors. A total of 144 employees participated 3 times in a questionnaire survey: in 1985 before a major change was implemented m the data system used just after its implementation in 1987, and later after the gradual increase of VDT application and enlargement of the data system in 1993. Most of the employees were women (65%) in customer service work. The original group of 477 decreased to these 144 employees during the follow-up due to employees leaving the company, moving to other departments, retiring, and nonresponding. The dropouts did not differ considerably from the retainees in the central variables of the study. The follow-up results showed an increase in the daily amount of VDT work and a better mastering of VDT application.
Solving Linear Equations by Monte Carlo Simulation

A new Monte Carlo estimator for solving the matrix equation x=Hx+b is presented, and theoretical results comparing this estimator with the traditional terminal and collision estimators are given. We then make a detailed investigation of the average complexity of the Monte Carlo estimators when several popular random variable generation techniques are used, and we show that the average complexity can be as low as $C\Vert z\Vert _{1}n+N$, where n is the number of random walks generated, N is the size of the matrix H, z is the solution of an associated matrix equation, and C is a small constant. As a consequence of the complexity results, we observe how scaling of matrices, a well-known technique in deterministic methods, can increase the efficiency of the Monte Carlo method. One advantage of the Monte Carlo method is the efficiency at which it can be parallelized. The algorithms we discuss can provide fast and approximate solutions to systems of linear equations in massively parallel computing environments. Surprisingly, sequential (or adaptive) Monte Carlo methods can even be competitive in single-processor computing environments. We present numerical results and compare our Monte Carlo algorithms with Krylov subspace methods for some test matrices.
Prevention of radiocontrast nephropathy

Purpose of reviewThe vast numbers of radiocontrast procedures performed yearly paired with the increasing prevalence of renal insufficiency in the aging population has focused recent attention on radiocontrast nephropathy. No effective treatment exists for this iatrogenic disease: therefore prevention remains the key strategy. Several clinical investigations have been published over the past 2 years that address potential prophylaxis against contrast nephropathy. Recent findingsIso-osmolar non-ionic contrast media appear to have the least nephrotoxicity. Pooled data of published randomized controlled trials of pre-procedural intravenous hydration plus N-acetylcysteine versus placebo demonstrate that acute renal failure from contrast nephropathy is rare when these therapies are given several hours in advance. Strategies that employ fenoldopam and theophylline, however, do not appear to be effective. Urine alkalinization with intravenous sodium bicarbonate may be useful, especially in high-risk patients, but further investigation is needed. SummaryAvailable evidence indicates that several hours of intravenous pre-hydration is protective against contrast nephropathy and some studies suggest that oral N-acetylcysteine administration adds to this protection. Further research is needed, however, with agents that can be administered immediately prior to contrast administration. This is particularly important for diabetics with baseline kidney disease who require emergent contrast studies and are at high risk for acute renal failure. Abbreviations ARF: acute renal failure; GFR: glomerular filtration rate; MDRD formula: Modification of Diet in Renal Disease formula.
An Aggregation Multilevel Method Using Smooth Error Vectors

Many algebraic multilevel methods for solving linear systems assume that the slowly converging, algebraically smooth error is locally constant. This assumption is often not true and can lead to poor performance of the method. Other multilevel methods require a description of the algebraically smooth error via knowledge of the near-nullspace of the operator, but this information may not always be available. This paper presents an aggregation multilevel method for problems where the near-nullspace of the operator is not known. The method uses samples of low-energy error vectors to construct its interpolation operator. The basis vectors for an aggregate are computed via a singular value decomposition of the sample vectors locally over that aggregate. Compared to many other methods that automatically adjust to the near-nullspace, this method does not require that the element stiffness matrices are available.
Supportive care to family caregivers is not supportive enough: moving towards an equitable approach to dementia home care

SUMMARY The current relationship between family caregivers and home care providers needs to be reconceptualized from one that is nonsupportive and potentially exploitive, to one that fosters a collaborative, empowering relationship. I present my argument in three parts. First, I focus on the problem of the current complementary model of care, one in which home care workers supplement and compensate for the care provided by family caregivers. In effect, I outline how this model of dementia home care in Canada perpetuates an inequitable distribution of care between formal and familial caregivers. Here, I underscore the negative consequences of this complementary approach on the caregiver–provider relationship. In the second part, I call for a reappraisal of ‘supportive relationships’ between home support workers and caregivers, identifying underlying values and principles (e.g., quity) that I believe should inform home care practices and policies in the future. Finally, I propose some possible strategies th.
A Primal-Based Penalty Preconditioner for Elliptic Saddle Point Systems

A primal-based penalty preconditioner is presented for a linear set of equations arising from elliptic saddle point problems. We show that the eigenvalues of the preconditioned matrix are positive real and demonstrate that a variant of the preconditioner can be combined with the conjugate gradient algorithm. Our approach is motivated by two basic observations. First, the solution of a problem with constraints is often similar to the solution of a problem where the constraints are penalized. Second, certain methods of solution not available for a constrained problem are possible for its penalized counterpart so motivating a primal-based Schur complement approach. Numerical examples for elliptic two- and three-dimensional problems are presented that confirm theoretical results and demonstrate the effectiveness of the preconditioner.
An Introductory Guide to Disease Mapping

Two books reviewed in the August 8, 2001, issue of JAMA: The Journal of the American Medical Association (1, 2) deserve your consideration. The first, entitled Great Feuds in Medicine: Ten of the Liveliest Disputes Ever, chronicles famous controversies that have erupted in the medical field since the 17th century. Of particular interest to epidemiologists are likely to be the chapters “Semmelweis versus the Viennese Medical Establishment: Childbed Fever,” “Sabin versus Salk: The Polio Vaccine,” and “Gallo versus Montagnier: The AIDS War”; but other chapter titles are also intriguing. I was particularly attracted by the chapters entitled “Bernard versus Chemists, Physicians, and Antivivisectionists: Experimental Medicine” and “Pasteur versus Liebig, Pouchet, and Koch: Fermentation, Spontaneous Generation, and Germ Theory. ” The book is enthusiastically reviewed by Joe Vander Veer, Jr., of the College of Physicians of Philadelphia. The second is entitled A Piece of My Mind: A New Collection of Essays from JAMA: The Journal of the American Medical Association. I had overlooked this feature of JAMA until 1996, when I read a column about Gertrude Stein. When I wrote to the Editor, Roxanne K. Young, to congratulate her on this new feature of the journal, she responded in part as follows: “Hmmm. Well, as a matter of fact, the column has been published in JAMA since 1981. ” She also sent me a copy of the first volume of collected essays. After I had read them, I wrote to my dean, “They (the essays) provide an insight into the ‘morality’ of medical care which I find poignant and insightful. Maybe they would calm a bit of the ‘doctor bashing’ which, I have long felt, is too common in our students and faculty. ” This second volume is thoughtfully and favorably reviewed by Andrew D. Furlik of the Yale University School of Medicine. I intend to acquire (and read) both of these books.
Letter: more studies are needed to elucidate the impact of HBV/HCV coinfection on cirrhosis and its consequences

EDITORS, We read the article by Pol et al recently published in the Alimentary Pharmacology & Therapeutics with great interest. The authors performed a nested exposure-matched study to compare the characteristics of HBV/ HCV coinfected patients to those of HBVor HCV-monoinfected patients. They found that HCV coinfection adversely affects liver fibrosis in HBV patients, while decompensated cirrhosis is increased in coinfected patients as compared with HBVor HCV-monoinfected patients. The study is very interesting and important. Although these data provide more evidence about the impact of HBV/HCV coinfection on cirrhosis and its consequences, several issues are worthy of discussion. As the authors mentioned in the methods, they could not evaluate the fibrosis stage for all the patients by liver biopsy. Instead, they evaluated the liver fibrosis stage by liver biopsy with less than 6 months from entry in (n = 107), or using the most recent evaluation of liver stiffness (n = 345), Fibrotest or Fibrometer (n = 36), or both (n = 90). However, different non-invasive markers of fibrosis have different sensitivity and specificity in staging liver fibrosis. Furthermore, the author used Fibrotest values 0.58 and 0.75 and Fibroscan 9.5 and 14.5, respectively, as the cut-offs for advanced fibrosis (F3) and cirrhosis (F4). Although Fibrotest and Fibroscan have been widely evaluated in HBVor HCV-monoinfected patients, there are still lack of uniformly established and validated cut-offs for specific stages of fibrosis, especially for HBV/HCV coinfected patients. Thus, there might exists a potential misclassification of fibrosis stages in the study which would have significantly biased the results. In the study, the authors analysed the comorbidities such as arterial hypertension and diabetes among different groups. However, the coexistences with other comorbidities such as nonalcoholic fatty liver diseases were not described by the authors. Severe steatosis was significantly associated with increased fibrosis in both HBVand HCVinfected patients. In addition, the patients were also not evaluated for other confounding factors such as smoking, statin use and coffee intake. These factors have been demonstrated to affect the liver disease progression in HBVor HCV-monoinfected patients. Recently, several studies reported that statin use may decrease the decompensation rate in both HBVand HCV-related cirrhosis. Coffee consumption may also decrease liver stiffness which indicates less fibrosis and inflammation in HBVor HCV-monoinfected patients. Thus, the results would be more convincing if the authors had adjusted these confounding factors when they investigated the impact of HBV/ HCV coinfection on cirrhosis and its consequences. Hence, large-scaled prospective and longitudinal studies are warranted to determine whether HBV/HCV coinfection is really associated with more severe liver disease than HBVor HCV-monoinfection.
Combined Complex Ridgelet Shrinkage and Total Variation Minimization

A new algorithm for the characterization of engineering surface topographies with line singularities is proposed. It is based on thresholding complex ridgelet coefficients combined with total variation (TV) minimization. The discrete ridgelet transform is designed by first using a discrete Radon transform based on the nonequispaced fast Fourier transform (NFFT) and then applying a dual-tree complex wavelet transform (DT CWT). The NFFT-based approach of the Radon transform completely avoids linear interpolations of the Cartesian-to-polar grid and requires only O(n2 log n) arithmetic operations for n by n arrays, while its inverse preserves the good reconstruction quality of the filtered backprojection. The DT CWT in the second step of the ridgelet transform provides approximate shift invariance on the projections of the Radon transform. After hard thresholding the ridgelet coefficients, they are restored using TV minimization to eliminate the pseudo-Gibbs artifacts near the discontinuities. Numerical experiments demonstrate the remarkable ability of the methodology to extract line scratches.
Dense Arrangements are Locally Very Dense. I

The Szemere´di-Trotter theorem [Combinatorica, 3 (1983), pp. 381-392] gives a bound on the maximum number of incidences between points and lines on the Euclidean plane. In particular it says that $n$ lines and $n$ points determine $O(n^{4/3})$ incidences. Let us suppose that an arrangement of $n$ lines and $n$ points defines $cn^{4/3}$ incidences, for a given positive $c$. It is widely believed that such arrangements have special structure, but no results are known in this direction. Here we show that for any natural number, $k$, one can find $k$ points of the arrangement in general position such that any pair of them is incident to a line from the arrangement, provided by $n\geq n_0(k)$. In a subsequent paper we will establish a similar statement for hyperplanes.
A Regression Equation for the Parallel Analysis Criterion in Principal Components Analysis: Mean and 95th Percentile Eigenvalues.

Monte Carlo research increasingly seems to favor the use of parallel analysis as a method for determining the "correct" number of factors in factor analysis or components in principal components analysis. We present a regression equation for predicting parallel analysis values used to decide the number of principal components to retain. This equation is appropriate for predicting criterion mean eigenvalues and was derived from random data sets containing between 5 and 50 variables and between 50 and 500 subjects. This relatively simple equation is more accurate for predicting mean eigenvalues from random data matrices with unities in the diagonals than a previously published equation. Moreover, given that the parallel analysis decision rule may be too dependent on chance, our equation is also used to predict the 95th percentile point in distributions of eigenvalues generated from random data matrices. Multiple correlations for all analyses were at least . 95. Regression weights for predicting the first 33 mean and 95th percentile eigenvalues are given in easy-to-use tables.
Stress factors and mental health adjustment of Filipino domestic workers in Hong Kong

males principally in the shipping industry; females principally as domestic workers. Although there are many local languages in The Philippines, English is widely spoken, reflecting a long period of contact with the United States, including colonial administration from 1898 to 1942, and US naval and military bases from 1945 to 1991. Filipinos’ facility in English language, and their knowledge of western cultural institutions, have made them a particularly adaptable group of contract workers. ’ Although migration in the form of contract labour can have psychological costs, there are few studies of Filipinos in this respect. The available studies are from psychiatric sources, suggesting that
Linear Problems Related to Asymptotic Stability of Solitons of the Generalized KdV Equations

This paper is concerned with the classification of global and uniformly localized solutions of linear problems related to the dynamics of the generalized Korteweg–de Vries equations in a neighborhood of solitons. In this context, we give a simpler and more general proof of a classification result introduced by Martel and Merle [J. Math. Pures Appl. , 79 (2000), pp. 339–425], [Arch. Ration. Mech. Anal. , 157 (2001), pp. 219–254]. We also consider the case of a nonlinear equation similar to the Korteweg–de Vries equation which was introduced by Peregrine [J. Fluid Mechanics, 27 (1967), pp. 815–827] and Benjamin, Bona, and Mahony [Philos. Trans. Roy. Soc. London Ser. , 272 (1972), pp. 47–78].
On the Temperature-Jump Problem in Rarefied Gas Dynamics: The Effect of the Cercignani-Lampis Boundary Condition

An analytical version of the discrete‐ordinates method (the ADO method) is used to establish a solution to the temperature‐jump problem in the rarefied gas dynamics field. Kinetic models derived from the linearized Boltzmann equation are used to formulate the problem in the one gas case and for a binary gas mixture. The gas‐surface interaction is described by the Cercignani–Lampis kernel, which is written in terms of two accommodation coefficients. The solution is found to be very accurate and fast. Numerical results are presented not only for the temperature‐jump coefficient but also for the density and temperature profiles. In particular, the effect of both accommodation coefficients on the temperature‐jump coefficient is analyzed.
Fans' Judgments About the 1994-95 Major League Baseball Players' Strike.

In this study, we used a multilevel analysis to examine how strike tactics influenced fans' support of the 1994-95 Major League Baseball player's strike. Strike tactics were discounted ticket prices for season games, replacement players in games, and picket lines of striking players. Tactics were varied within judgment scenarios (i.e., baseball game announcements) and fans' responses to scenarios were used as within-person variables to estimate tactic influences. Fans' perceptions of themselves (e.g., extent of fanship) and the strike situation (e.g., extent to which the dispute was perceived as a labor dispute) were used as between-person variables to predict individual differences in tactic influences. Results indicated that more replacement players has a positive influence on support for the strike and higher discounted prices had a negative influence on strike support. The influences of replacement players on judgments was not associated with individual differences, whereas the influence of discounted prices on judgments did show such differences. The findings were used to discuss implications for winning support from consumers in a professional entertainment workers' strike.
Differential Games with Asymmetric Information

We investigate a two-player zero-sum differential game in which the players have asymmetric information on the random terminal payoff. We prove that the game has a value and characterize this value in terms of dual solutions of some Hamilton-Jacobi equation. We also explain how to adapt the results to differential games where the initial position is random.