Showing papers by "Brigham Young University published in 2003"
TL;DR: Fine particulate air pollution is a risk factor for cause-specific cardiovascular disease mortality via mechanisms that likely include pulmonary and systemic inflammation, accelerated atherosclerosis, and altered cardiac autonomic function.
Abstract: Background— Epidemiologic studies have linked long-term exposure to fine particulate matter air pollution (PM) to broad cause-of-death mortality. Associations with specific cardiopulmonary diseases might be useful in exploring potential mechanistic pathways linking exposure and mortality. Methods and Results— General pathophysiological pathways linking long-term PM exposure with mortality and expected patterns of PM mortality with specific causes of death were proposed a priori. Vital status, risk factor, and cause-of-death data, collected by the American Cancer Society as part of the Cancer Prevention II study, were linked with air pollution data from United States metropolitan areas. Cox Proportional Hazard regression models were used to estimate PM-mortality associations with specific causes of death. Long-term PM exposures were most strongly associated with mortality attributable to ischemic heart disease, dysrhythmias, heart failure, and cardiac arrest. For these cardiovascular causes of death, a 10-...
2,530 citations
TL;DR: In this paper, the authors investigate the relationship between supplier trust in the buyer and transaction costs and information sharing in a sample of 344 supplier-automaker exchange relationships in the United States, Japan, and Korea.
Abstract: In this paper we investigate the relationship between supplier trust in the buyer and transaction costs and information sharing in a sample of 344 supplier-automaker exchange relationships in the United States, Japan, and Korea. Our findings indicate that perceived trustworthiness reduces transaction costs and is correlated with greater information sharing in supplier-buyer relationships. Moreover, the findings suggest that the value created for transactors, in terms of lower transaction costs, may be substantial. In particular, we found that the least-trusted automaker spent significantly more of its face-to-face interaction time with suppliers on contracting and haggling when compared to the most trusted automaker. This translated into procurement (transaction) costs that were five times higher for the least trusted automaker. Finally, we argue that trust is unique as a governance mechanism because it not only minimizes transaction costs, but also has a mutually causal relationship with information sharing, which also creates value in the exchange relationship. Other governance mechanisms (e.g., contracts, financial hostages) are necessary costs incurred to prevent opportunistic behavior, but do not create value beyond transaction cost minimization. Our findings provide empirical evidence that trustworthiness lowers transaction costs and may be an important source of competitive advantage.
1,444 citations
TL;DR: The onset of the Asian financial crisis in Malaysia reduced the expected value of government subsidies to politically connected firms, accounting for roughly 9% of the estimated $60 billion loss in their market value from July 1997 to August 1998.
1,187 citations
TL;DR: The association between religiousness and depressive symptoms was examined with meta-analytic methods across 147 independent investigations, indicating that greater religiousness is mildly associated with fewer symptoms.
Abstract: The association between religiousness and depressive symptoms was examined with meta-analytic methods across 147 independent investigations (N 98,975). Across all studies, the correlation between religiousness and depressive symptoms was –.096, indicating that greater religiousness is mildly associated with fewer symptoms. The results were not moderated by gender, age, or ethnicity, but the religiousness– depression association was stronger in studies involving people who were undergoing stress due to recent life events. The results were also moderated by the type of measure of religiousness used in the study, with extrinsic religious orientation and negative religious coping (e.g., avoiding difficulties through religious activities, blaming God for difficulties) associated with higher levels of depressive symptoms, the opposite direction of the overall findings.
1,076 citations
01 Dec 2003
TL;DR: Hardware results demonstrate the effectiveness of the proposed formation control strategies, which injects interrobot damping via passivity techniques and accounts for actuator saturation.
Abstract: This paper presents a behavior-based approach to formation maneuvers for groups of mobile robots. Complex formation maneuvers are decomposed into a sequence of maneuvers between formation patterns. The paper presents three formation control strategies. The first strategy uses relative position information configured in a bidirectional ring topology to maintain the formation. The second strategy injects interrobot damping via passivity techniques. The third strategy accounts for actuator saturation. Hardware results demonstrate the effectiveness of the proposed control strategies.
1,045 citations
TL;DR: In this paper, the grain structure, dislocation density and second phase particles in various regions including the dynamically recrystallized zone (DXZ), thermo-mechanically affected zone (TMAZ), and heat-affected zone (HAZ) of a friction stir weld aluminum alloy 7050-T651 were investigated and compared with the unaffected base metal.
934 citations
01 Jul 2003
TL;DR: A generalization of non-uniform B-spline surfaces called T-splines, which are C2 (in the absence of multiple knots), and T-NURCCs (Non-Uniform Rational Catmull-Clark Surfaces with T-junctions) are a superset of both T- Splines and Catm Mull-Clark surfaces, which can handle any NURBS or CatmULL-Clark model as special cases.
Abstract: This paper presents a generalization of non-uniform B-spline surfaces called T-splines. T-spline control grids permit T-junctions, so lines of control points need not traverse the entire control grid. T-splines support many valuable operations within a consistent framework, such as local refinement, and the merging of several B-spline surfaces that have different knot vectors into a single gap-free model. The paper focuses on T-splines of degree three, which are C2 (in the absence of multiple knots). T-NURCCs (Non-Uniform Rational Catmull-Clark Surfaces with T-junctions) are a superset of both T-splines and Catmull-Clark surfaces. Thus, a modeling program for T-NURCCs can handle any NURBS or Catmull-Clark model as special cases. T-NURCCs enable true local refinement of a Catmull-Clark-type control grid: individual control points can be inserted only where they are needed to provide additional control, or to create a smoother tessellation, and such insertions do not alter the limit surface. T-NURCCs use stationary refinement rules and are C2 except at extraordinary points and features.
849 citations
TL;DR: In this article, the authors examined the impact of HR practices and organisational commitment on the operating performance and profitability of business units using a predictive design with a sample of 50 autonomous business units within the same corporation.
Abstract: This article examines the impact of HR practices and organisational commitment on the operating performance and profitability of business units. Using a predictive design with a sample of 50 autonomous business units within the same corporation, the article reveals that both organisational commitment and HR practices are significantly related to operational measures of performance, as well as operating expenses and pre-tax profits.
797 citations
TL;DR: Nine methods for delimiting species boundaries are reviewed by summarizing the relevant biological properties of species amenable to empirical evaluation, the classes of data required and some of the strengths and limitations of each.
Abstract: The literature about species concepts might be larger than that about any other subject in evolutionary biology, but the issue of empirically testing species boundaries has been given little attention relative to seemingly endless debates over what species are. The practical issue of delimiting species boundaries is nevertheless of central importance to many areas of evolutionary biology. The number of recently described methods for delimiting species suggests renewed interest in the topic, and some methods are explicitly quantitative. Here, we review nine of these methods by summarizing the relevant biological properties of species amenable to empirical evaluation, the classes of data required and some of the strengths and limitations of each.
654 citations
TL;DR: In this article, the authors describe why there is a dearth of research using family as a variable in the mainstream management literature and the focus of this article is to describe (1) why there are no studies that use family variables in the management literature.
Abstract: Few studies in the mainstream management literature have included the family as a variable. The focus of this article is to describe (1) why there is a dearth of research using family as a variable...
553 citations
12 Jan 2003
TL;DR: An interactive machine-learning (IML) model that allows users to train, classify/view and correct the classifications and the Crayons tool embodies the notions of interactive machine learning is proposed.
Abstract: Perceptual user interfaces (PUIs) are an important part of ubiquitous computing. Creating such interfaces is difficult because of the image and signal processing knowledge required for creating classifiers. We propose an interactive machine-learning (IML) model that allows users to train, classify/view and correct the classifications. The concept and implementation details of IML are discussed and contrasted with classical machine learning models. Evaluations of two algorithms are also presented. We also briefly describe Image Processing with Crayons (Crayons), which is a tool for creating new camera-based interfaces using a simple painting metaphor. The Crayons tool embodies our notions of interactive machine learning
TL;DR: The authors suggest that issuing debt can credibly commit an entrepreneur to propping, even though creditors can never take possession of any underlying collateral, which helps to explain why emerging markets with weak institutions sometimes grow rapidly and why they are also subject to frequent economic and financial crises.
TL;DR: In this paper, the authors recommend the inclusion of ideological currency in the psychological contract perspective in order to broaden the range of employee-organization exchanges that the perspective can accommodate, and develop a model that articulates the conditions under which the breach and violation of ideology-infused psychological contracts will likely occur.
Abstract: We recommend the inclusion of “ideological currency” in the psychological contract perspective in order to broaden the range of employee-organization exchanges that the perspective can accommodate. We differentiate ideological currency from other forms of exchange currency and develop a model that articulates the conditions under which the breach and violation of ideology-infused psychological contracts will likely occur. We conclude by considering the opportunities and challenges implied by the inclusion of ideology in the psychological contract.
TL;DR: In this article, the authors compared how three work venues (traditional office, n =4316, virtual office and home office) may influence aspects of work (job performance, job motivation, job retention, workload success, and career opportunity) and personal/family life.
TL;DR: It may be time for clinicians routinely and formally to monitor patient treatment response and a meta-analytic review of three large-scale studies suggests that formally monitoring patient progress has a significant impact on clients who show a poor initial response to treatment.
Abstract: Empirically supported psychotherapies, treatment guidelines, best practices, and treatment manuals are methods proposed to enhance treatment outcomes in routine practice. Patient-focused research systems provide a compatible and contrasting methodology. Such systems monitor and feed back information about a patient's progress during psychotherapy for the purpose of enhancing outcomes. A meta-analytic review of three large-scale studies is summarized and suggests that formally monitoring patient progress has a significant impact on clients who show a poor initial response to treatment. Implementation of this feedback system reduced deterioration by 4% to 8% and increased positive outcomes. Our interpretation of these results suggests that it may be time for clinicians routinely and formally to monitor patient treatment response.
TL;DR: Seven patients with bilateral damage thought to be limited primarily to the hippocampal region were impaired on three standard tests of recognition memory and were impaired to a similar extent at Remembering and Knowing, measures of the two processes thought to support recognition performance.
TL;DR: In this article, a U.S. national probability sample of on-line heads of households was used to provide a lifestyle perspective of who is using the Internet to shop, who does not shop, and why.
Abstract: This study examines the lifestyle characteristics of on-line households. By means of a U.S. national probability sample of on-line heads of households, this descriptive research is the first of its kind to provide a lifestyle perspective of who is using the Internet to shop, who does not shop, and why. It is hypothesized and shown that, compared with on-line nonshoppers, on-line shoppers are younger, wealthier, better educated, have higher computer literacy, spend more time on their computer, spend more time on the Internet, find on-line shopping to be easier and more entertaining, and are more fearful of financial loss from on-line shopping. The study further hypothesizes that on-line shoppers, and on-line nonshoppers, are heterogeneous groups comprised of particular market segments having unique Internet-related lifestyles. Four on-line shopper segments and four on-line nonshopper segments are identified. Each segment is profiled and its marketing implications discussed. © 2003 Wiley Periodicals, Inc.
TL;DR: Empirical results on a large (20,000-instance) speech recognition task and on 26 other learning tasks demonstrate that convergence can be reached significantly faster using on-line training than batch training, with no apparent difference in accuracy.
TL;DR: Stick insects (order Phasmatodea) diversified as wingless insects and that wings were derived secondarily, perhaps on many occasions are shown, suggesting that wing developmental pathways are conserved in wingless phasmids and that ‘re-evolution' of wings has had an unrecognized role in insect diversification.
Abstract: The evolution of wings was the central adaptation allowing insects to escape predators, exploit scattered resources, and disperse into new niches, resulting in radiations into vast numbers of species1. Despite the presumed evolutionary advantages associated with full-sized wings (macroptery), nearly all pterygote (winged) orders have many partially winged (brachypterous) or wingless (apterous) lineages, and some entire orders are secondarily wingless (for example, fleas, lice, grylloblattids and mantophasmatids), with about 5% of extant pterygote species being flightless2,3. Thousands of independent transitions from a winged form to winglessness have occurred during the course of insect evolution; however, an evolutionary reversal from a flightless to a volant form has never been demonstrated clearly for any pterygote lineage. Such a reversal is considered highly unlikely because complex interactions between nerves, muscles, sclerites and wing foils are required to accommodate flight4. Here we show that stick insects (order Phasmatodea) diversified as wingless insects and that wings were derived secondarily, perhaps on many occasions. These results suggest that wing developmental pathways are conserved in wingless phasmids, and that ‘re-evolution’ of wings has had an unrecognized role in insect diversification.
TL;DR: The data reveal that mammalian herbivores eating identical diets can have hair δ15N values that differ by as much as 3.6‰, which suggests that interspecific physiological differences can lead to larger shifts in δ 15N values than a shift in trophic level.
Abstract: Nitrogen isotope analysis is a common technique for investigating dietary behaviour in modern and archaeological populations. One of its primary uses is to provide trophic level information. This application is possible because of a ∼3‰ enrichment in 15N along each step in the food chain, resulting in carnivores having higher δ15N values than herbivores, which in turn have higher δ15N values than plants. Much variation has also been observed within a trophic level, although the reasons for this are poorly understood. Here we present the results of a controlled feeding study designed to test the effects of gut anatomy and dietary protein levels on hair δ15N values within a trophic level. The data reveal that mammalian herbivores eating identical diets can have hair δ15N values that differ by as much as 3.6‰. This is particularly striking as it suggests that interspecific physiological differences can lead to larger shifts in δ15N values than a shift in trophic level. We also found that diet-hair fractionation was 2.3‰ greater when herbivores were fed high-protein (19%) diets than when they were fed low-protein (9%) diets. The primary nitrogen losses in mammalian herbivores are 15N-depleted urine and 15N-enriched faeces. We reason that an increase in the ratio of urinary to faecal nitrogen efflux leads to greater diet-hair fractionation on the high-protein diet. Copyright © 2003 John Wiley & Sons, Ltd.
Journal Article•
TL;DR: In this article, the authors provide decision makers with 32 trends that affect distance learning and thus enable them to plan accordingly, including students and enrollment, faculty members, academics, technology, the economy, and distance learning.
Abstract: Recent issues in this journal and other prominent distancelearning journals have established the need for administrators to be informed and prepared with strategic plans equal to foreseeable challenges. This article provides decision makers with 32 trends that affect distance learning and thus enable them to plan accordingly. The trends are organized into categories as they pertain to students and enrollment, faculty members, academics, technology, the economy, and distance learning. All the trends were identified during an extensive review of current literature in the field Informed Planning Recent issues in this journal and other prominent distancelearning journals have established the need for administrators to be informed and prepared with strategic plans equal to foreseeable challenges. This article provides decision makers with 32 trends that affect distance learning and thus enable them to plan accordingly. The trends are organized into categories as they pertain to students and enrollment, faculty members, academics, technology, the economy, and distance learning. All the trends were identified during an extensive review of current literature in the field. In a recent issue of Distance Learning Administration, Beaudoin (2003) stressed the importance for institutional leaders “to be informed and enlightened enough to ask fundamental questions that could well influence their institution’s future viability” (p. 1). Example questions included “How many faculty will we be needed in ten years? Will the notion of classrooms survive? Is the present structure of the institution viable? Will teachers and students need to meet on campus anymore? [and] Can the
TL;DR: In this paper, the authors examined the performance of a thermal-relaxation calorimeter that operates in the temperature range of 1.8-395 K. The accuracy of the PPMS specific heat data is determined by comparing data measured on copper and synthetic sapphire samples with standard literature values.
TL;DR: The authors investigated whether market participants perceive pro forma earnings to be more informative and more persistent than GAAP operating income by analyzing a sample of 1,149 actual pro-forma press releases.
Abstract: This study investigates whether market participants perceive pro forma earnings to be more informative and more persistent than GAAP operating income by analyzing a sample of 1,149 actual pro forma press releases. We find that pro forma announcers report frequent GAAP losses and are mostly concentrated in the service and high-tech industries. Our analyses of short-window abnormal returns and revisions in analyst' one-quarter-ahead earnings forecasts indicate that pro forma earnings are more informative and more permanent than GAAP operating earnings. Our evidence suggests that market participants believe pro forma earnings are more representative of "core earnings" than GAAP operating income.
TL;DR: This article investigated whether market participants perceive pro forma earnings to be more informative and more persistent than GAAP operating income by analyzing a sample of 1,149 actual pro-forma press releases.
TL;DR: The results show that the hippocampal region supports semantic memory as well as episodic memory and that its role in the acquisition and storage of semantic knowledge is time limited.
TL;DR: An experimental measurement platform capable of providing the narrowband channel transfer matrix for wireless communications scenarios is presented and a discussion of the relationship between multipath richness and path loss, as well as their joint role in determining channel capacity is discussed.
Abstract: Detailed performance assessment of space-time coding algorithms in realistic channels is critically dependent upon accurate knowledge of the wireless channel spatial characteristics. This paper presents an experimental measurement platform capable of providing the narrowband channel transfer matrix for wireless communications scenarios. The system is used to directly measure key multiple-input-multiple-output parameters in an indoor environment at 2.45 GHz. Linear antenna arrays of different sizes and construction with up to ten elements at transmit and receive are utilized in the measurement campaign. This data is analyzed to reveal channel properties such as transfer matrix element statistical distributions and temporal and spatial correlation. Additionally, the impact of parameters such as antenna element polarization, directivity, and array size on channel capacity are highlighted. The paper concludes with a discussion of the relationship between multipath richness and path loss, as well as their joint role in determining channel capacity.
TL;DR: Evidence that the ‘Kronecker’ model underestimates the channel capacity of an 8×8 multiple input, multiple output (MIMO) system in indoor non-line-of-sight (NLOS) scenarios is presented.
Abstract: Evidence that the ‘Kronecker’ model underestimates the channel capacity of an 8×8 multiple input, multiple output (MIMO) system in indoor non-line-of-sight (NLOS) scenarios is presented. Moreover, the model does not render the multipath structure correctly, which is the cause for the systematic capacity mismatch.
TL;DR: This paper shows how to model the information flow of a negotiation for use in analyzing strategy interoperation, and develops the theory for black-box propositional credentials as well as credentials with internal structure and for access control policies whose contents are (respectively are not) sensitive.
Abstract: Business and military partners, companies and their customers, and other closely cooperating parties may have a compelling need to conduct sensitive interactions on line, such as accessing each other's local services and other local resources. Automated trust negotiation is an approach to establishing trust between parties so that such interactions can take place, through the use of access control policies that specify what combinations of digital credentials a stranger must disclose to gain access to a local resource. A party can use many different strategies to negotiate trust, offering tradeoffs between the length of the negotiation, the amount of extraneous information disclosed, and the computational effort expended. To preserve parties' autonomy, each party should ideally be able to choose its negotiation strategy independently, while still being guaranteed that negotiations will succeed whenever possible---that the two parties' strategies will interoperate. In this paper we provide the formal underpinnings for that goal, by formalizing the concepts of negotiation protocols, strategies, and interoperation. We show how to model the information flow of a negotiation for use in analyzing strategy interoperation. We also present two large sets of strategies whose members all interoperate with one another, and show that these sets contain many practical strategies. We develop the theory for black-box propositional credentials as well as credentials with internal structure, and for access control policies whose contents are (respectively are not) sensitive. We also discuss how these results fit into TrustBuilder, our prototype system for trust negotiation.
TL;DR: In this paper, the authors examined data collected on 1841 clients seen by 91 therapists over a 2.5-year period in a University Counseling Center and found that therapists whose clients showed the fastest rate of improvement had an average rate of change 10 times greater than the mean for the sample.
Abstract: Improving the effects of psychotherapy has been accomplished through a variety of methods. One infrequently used method involves profiling patient outcomes within therapist in order to find the empirically supported psychotherapist. This study examined data collected on 1841 clients seen by 91 therapists over a 2.5-year period in a University Counseling Center. Clients were given the Outcome Questionnaire-45 (OQ-45) on a weekly basis. After analysing data to see if general therapist traits (i.e. theoretical orientation, type of training) accounted for differences in clients' rate of improvement, data were then analysed again using Hierarchical Linear Modeling (HLM), to compare individual therapists to see if there were significant differences in the overall outcome and speed of client improvement. There was a significant amount of variation among therapists' clients' rates of improvement. The therapists whose clients showed the fastest rate of improvement had an average rate of change 10 times greater than the mean for the sample. The therapists whose clients showed the slowest rate of improvement actually showed an average increase in symptoms among their clients. Use of this information for improving quality of patient outcomes is discussed. Copyright © 2003 John Wiley & Sons, Ltd.
TL;DR: It is suggested that premarital prevention programs are generally effective in producing immediate and short-term gains in interpersonal skills and overall relationship quality and that these improvements are significantly better than nonintervention couples in these areas.
Abstract: We present a comprehensive, meta-analytic review and critical evaluation of outcome research pertaining to the effectiveness of premarital prevention programs. Results revealed that the mean effect size for premarital programs was .80, which means that the average person who participated in a premarital prevention program was significantly better off afterwards than 79% of people who did not participate. Stated differently, the average participant in a premarital program tends to experience about a 30% increase in measures of outcome success. Our findings suggest that premarital prevention programs are generally effective in producing immediate and short-term gains in interpersonal skills and overall relationship quality and that these improvements are significantly better than nonintervention couples in these areas. However, because of a lack of extended follow-up research, conclusions about long-term effectiveness remain elusive. We propose implications for future research, education, and policy.