Psychological distress in health sciences college students and its relationship with academic engagement

Objective: To determine the prevalence of psychological distress and its relationship with academic engagement (absorption, dedication and vigor), sex and degree among students from four public universities. Method: A non-experimental,comparative correlational, quantitative investigation without intervention. Study population: 1840 nursing and physical therapy students. The data collection tool used was a questionnaire. Results: A 32.2% prevalence of psychological distress was found in the subjects; a correlation between vigor and psychological distress was found for all of the subjects and also for women. High absorption and dedication scores and low psychological distress scores predicted higher vigor scores. Conclusion: The risk of psychological distress is high, especially for women. Women seem to have a higher level of psychological distress than men. Vigor, energy and mental resilience positively influence psychological distress and can be a vehicle for better results during the learning and studying process.







A randomized concave programming method for choice network revenue management

Models incorporating more realistic models of customer behavior, as customers choosing froman offer set, have recently become popular in assortment optimization and revenue management.The dynamic program for these models is intractable and approximated by a deterministiclinear program called the CDLP which has an exponential number of columns. However, whenthe segment consideration sets overlap, the CDLP is difficult to solve. Column generationhas been proposed but finding an entering column has been shown to be NP-hard. In thispaper we propose a new approach called SDCP to solving CDLP based on segments and theirconsideration sets. SDCP is a relaxation of CDLP and hence forms a looser upper bound onthe dynamic program but coincides with CDLP for the case of non-overlapping segments. Ifthe number of elements in a consideration set for a segment is not very large (SDCP) can beapplied to any discrete-choice model of consumer behavior. We tighten the SDCP bound by(i) simulations, called the randomized concave programming (RCP) method, and (ii) by addingcuts to a recent compact formulation of the problem for a latent multinomial-choice model ofdemand (SBLP+). This latter approach turns out to be very effective, essentially obtainingCDLP value, and excellent revenue performance in simulations, even for overlapping segments.By formulating the problem as a separation problem, we give insight into why CDLP is easyfor the MNL with non-overlapping considerations sets and why generalizations of MNL posedifficulties. We perform numerical simulations to determine the revenue performance of all themethods on reference data sets in the literature.

A new compact linear programming formulation for choice network revenue management

The choice network revenue management model incorporates customer purchase behavioras a function of the offered products, and is the appropriate model for airline and hotel networkrevenue management, dynamic sales of bundles, and dynamic assortment optimization.The optimization problem is a stochastic dynamic program and is intractable. A certainty-equivalencerelaxation of the dynamic program, called the choice deterministic linear program(CDLP) is usually used to generate dyamic controls. Recently, a compact linear programmingformulation of this linear program was given for the multi-segment multinomial-logit (MNL)model of customer choice with non-overlapping consideration sets. Our objective is to obtaina tighter bound than this formulation while retaining the appealing properties of a compactlinear programming representation. To this end, it is natural to consider the affine relaxationof the dynamic program. We first show that the affine relaxation is NP-complete even for asingle-segment MNL model. Nevertheless, by analyzing the affine relaxation we derive a newcompact linear program that approximates the dynamic programming value function betterthan CDLP, provably between the CDLP value and the affine relaxation, and often comingclose to the latter in our numerical experiments. When the segment consideration sets overlap,we show that some strong equalities called product cuts developed for the CDLP remain validfor our new formulation. Finally we perform extensive numerical comparisons on the variousbounds to evaluate their performance.

Audit of Academic Building Revenue Bond Funds of Iowa State University of Science and Technology (Iowa State University) as of and for the year ended June 30, 2007

Audit of Academic Building Revenue Bond Funds of Iowa State University of Science and Technology (Iowa State University) as of and for the year ended June 30, 2007

An ASsessment of Relationship between Students' Perception of Social Studies and their Academic Performance in Colleges of Education in Kaduna State

The objective of this study was to find out the relationship between students’ perception of Social Studies and their academic performance in the subject in Colleges of Education in Kaduna State. The respondents of the study comprised NCE 2 and NCE 3 students of Social Studies at the Federal College of Education in Zaria and the Kaduna State College of Education in Gidan Waya. The data for the study was collected using a questionnaire with reliability coefficient of 0.87. The Pearson’s Product Moment Correlation Coefficient was used to test the hypotheses formulated for the study. The hypotheses were tested at 0.05 level of significance with df = 232. The findings were as follows: 1. The Social Studies students in colleges of education in Kaduna State do not record high academic performance in the subject. 2. Students’ perception of the Social Studies curriculum does affect their academic performance in the subject 3. Students’ perception of relevance of Social Studies education has no bearing on their academic performance in the subject. 4. Students’ perception of public attitude towards Social Studies has no impact on their academic performance in the subject. 5. Students’ general perception of Social Studies does not affect their academic performance in the subject. Based on these findings the following recommendations were proffered for Social Studies researchers and policy makers. a. There is need for further research in order to determine the actual cause of students’ failure to display high performance in Social Studies. b. The NCE Social Studies curriculum should be reviewed in terms of volume and difficulty.

When performance-approach goals predict academic achievement and when they do not: A social value approach

Research on achievement goal promotion at University has shown that performance-approach goals are perceived as a means to succeed at University (high social utility) but are not appreciated (low social desirability). We argue that such a paradox could explain why research has detected that performance-approach goals consistently predict academic grades. First-year psychology students answered a performance-approach goal scale with standard, social desirability and social utility instructions. Participants' grades were recorded at the end of the semester. Results showed that the relationship between performance-approach goals and grades was inhibited by the increase of these goals' social desirability and facilitated by the increase of their social utility, revealing that the predictive validity of performance-approach goals depend on social value.

On the throughput-WIP trade-off in queueing systems, diminishing returns and the threshold property: A linear programming approach

We present a new unifying framework for investigating throughput-WIP(Work-in-Process) optimal control problems in queueing systems,based on reformulating them as linear programming (LP) problems withspecial structure: We show that if a throughput-WIP performance pairin a stochastic system satisfies the Threshold Property we introducein this paper, then we can reformulate the problem of optimizing alinear objective of throughput-WIP performance as a (semi-infinite)LP problem over a polygon with special structure (a thresholdpolygon). The strong structural properties of such polygones explainthe optimality of threshold policies for optimizing linearperformance objectives: their vertices correspond to the performancepairs of threshold policies. We analyze in this framework theversatile input-output queueing intensity control model introduced byChen and Yao (1990), obtaining a variety of new results, including (a)an exact reformulation of the control problem as an LP problem over athreshold polygon; (b) an analytical characterization of the Min WIPfunction (giving the minimum WIP level required to attain a targetthroughput level); (c) an LP Value Decomposition Theorem that relatesthe objective value under an arbitrary policy with that of a giventhreshold policy (thus revealing the LP interpretation of Chen andYao's optimality conditions); (d) diminishing returns and invarianceproperties of throughput-WIP performance, which underlie thresholdoptimality; (e) a unified treatment of the time-discounted andtime-average cases.

Interconnection among academic journal platforms: Multilateral versus bilateral interconnection

Electronic academic journal websites provide new services of text and/or datamining and linking, indispensable for e¢ cient allocation of attention among abun-dant sources of scienti?c information. Fully realizing the bene?t of these servicesrequires interconnection among websites. Motivated by CrossRef, a multilateralcitation linking backbone, this paper performs a comparison between multilateralinterconnection through an open platform and bilateral interconnection, and ?ndsthat publishers are fully interconnected in the former regime while they can be par-tially interconnected in the latter regime for exclusion or di¤erentiation motives.Surprisingly, if partial interconnection arises for di¤erentiation motive, exclusion ofsmall publisher(s) occurs more often under multilateral interconnection. We also?nd that in the case of multilateral interconnection, a for-pro?t platform inducesless exclusion than an open platform. Various other extensions are analyzed.

Implementing TURF analysis through binary linear programming

This paper introduces the approach of using Total Unduplicated Reach and Frequency analysis (TURF) to design a product line through a binary linear programming model. This improves the efficiency of the search for the solution to the problem compared to the algorithms that have been used to date. The results obtained through our exact algorithm are presented, and this method shows to be extremely efficient both in obtaining optimal solutions and in computing time for very large instances of the problem at hand. Furthermore, the proposed technique enables the model to be improved in order to overcome the main drawbacks presented by TURF analysis in practice.

Report of the Academic Building Revenue Bond Funds of Iowa State University of Science and Technology as of and for the year ended June 30, 2008

Report of the Academic Building Revenue Bond Funds of Iowa State University of Science and Technology as of and for the year ended June 30, 2008

Restless bandits, linear programming relaxations and a primal-dual index heuristic

We develop a mathematical programming approach for the classicalPSPACE - hard restless bandit problem in stochastic optimization.We introduce a hierarchy of n (where n is the number of bandits)increasingly stronger linear programming relaxations, the lastof which is exact and corresponds to the (exponential size)formulation of the problem as a Markov decision chain, while theother relaxations provide bounds and are efficiently computed. Wealso propose a priority-index heuristic scheduling policy fromthe solution to the first-order relaxation, where the indices aredefined in terms of optimal dual variables. In this way wepropose a policy and a suboptimality guarantee. We report resultsof computational experiments that suggest that the proposedheuristic policy is nearly optimal. Moreover, the second-orderrelaxation is found to provide strong bounds on the optimalvalue.

One hundred issues of Revista Española de Financiación y Contabilidad (REFC)-insights into trends in the Spanish academic community

From the year of its foundation, until the foundation of Revista deContabilidad in 1997, REFC has been the only referred accounting journalin Spain. Published by the Spanish Association for Accounting and BusinessAdministration (AECA), this journal is at the heart of the emergence ofa distinctly Spanish academic accounting community.Our study is based on:1. An analysis of 100 issues of REFC covering the period from 1985 to 1999.2. A questionnaire to Spanish accounting academics on their perceptionsand experience of the journal.Key points emerging from this study include:a) A move away from interest in accounting concepts and rules, as wellas accounting history, and towards positive accounting theory, the impactof accounting information on capital markets, and financial analysis.b) The emergence of a small number of universities as the driving forcein Spanish accounting research.c) Spanish academics rate REFC highly compared to other Spanish journalsfor publication status, as a support for research, and as a support forteaching. A number of English language journals are rated more highly forboth publication status and as a support for teaching.

The pricing of academic journals: A two-sided market perspective

More and more academic journals adopt an open-access policy, by which articlesare accessible free of charge, while publication costs are recovered through authorfees. We study the consequences of this open access policy on a journal s qualitystandard. If the journal s objective was to maximize social welfare, open accesswould be optimal as long as the positive externalities generated by its diffusionexceed the marginal cost of distribution. However, we show that if an open accessjournal has a different objective (such as maximizing readers payoffs, the impactof the journal or its profit), it tends to choose a quality standard below the sociallyefficient level.