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Showing papers by "Tilburg University published in 1990"


Journal ArticleDOI
TL;DR: The English form of the Cancer Locus of Control Scale provides a valid measure of perceptions of control of cancer patients and is a useful method of assessing these important psychological responses.
Abstract: The English form of the Cancer Locus of Control Scale was administered to an heterogeneous sample of 68 cancer patients. A principal components analysis confirmed the three subscales described in the original Dutch form, however, with five items excluded. Correlations with other measures indicated that high internal control over the course of the illness was associated with a tendency to adopt an attitude toward cancer of 'fighting spirit' whereas high internal control over the cause of the illness was associated with an 'anxious preoccupation' about cancer. No specific relationship was found between scale scores and either depression and anxiety or the tendency to be emotionally controlled. It was concluded that the scale provides a valid measure of perceptions of control of cancer patients and is a useful method of assessing these important psychological responses.

124 citations


Journal ArticleDOI
TL;DR: In this paper, the authors present 41 educational heterogamy tables for 23 industrial nations after World War II and find that the relative chances of educational heterophamy are more equal than the relative chance of heterophy.
Abstract: This article presents 41 educational heterogamy tables for 23 industrial nations after World War II. Countries differ in gross heterogamy rates and relative chances of heterogamy. Evidence is found in favour of a trend towards higher gross rates of heterogamy and towards more equal relative chances of heterogamy. Hypotheses on effects of economic and political factors are tested. The contribution these factors make to the explanation of relative heterogamy is smaller than found in studies on intergenerational mobility. Between countries more equal relative father-to-son occupational mobility chances go together with more equal relative chances of educational heterogamy. Within countries relative mobility chances are more equal than relative chances of heterogamy. All in all Lipset and Zetterberg's notion of general societal openness is confirmed, whereas Bourdieu's notion tblt mobilit~ d heterogamy are compensatory strategi~ · of reproduction is not upheld.

122 citations


Journal ArticleDOI
TL;DR: In this article, a latent class model is described in which the latent classes are ordered imposing inequality constraints on item response and cumulative response probabilities from subsequent latent classes, and an algorithm to obtain the maximum likelihood estimates of the model parameters is proposed and is applied to a real data set.
Abstract: In this paper a latent class model is described in which the latent classes are ordered imposing inequality constraints on item response and cumulative response probabilities from subsequent latent classes. These inequality constraints are derived from the basic assumption that, when the latent classes may be ordered from low to high along the latent continuum, the probability of a ‘positive’ response should increase monotonically as one moves along this continuum. An algorithm to obtain the maximum likelihood estimates of the model parameters is proposed and is applied to a real data set.

112 citations


Journal ArticleDOI
TL;DR: In this paper, a multi-period version of the Spence job market signaling model is analyzed, where workers cannot commit to an education choice and firms make wage offers at any point in time.
Abstract: This paper analyzes a multiperiod version of the Spence Job Market Signalling Model in which workers cannot commit to an education choice and firms make wage offers at any point in time. The dynamic competition combined with the incomplete information yield a multiplicity of sequential equilibria, including ones that sustain implicit collusion, even though the length of the game is finite. Emphasis is placed on equilibria that satisfy the "independence of never weak best response" criterion of Kohlberg and Mertens (1986). It is shown that in the limit, as the time between offers tends to zero, any such equilibrium results (in expectation) in the unique stable outcome of the static Spence model.

100 citations


Journal ArticleDOI
01 Sep 1990-Headache
TL;DR: The Contingent Negative Variation (CNV) is an event-related slow potential as mentioned in this paper, which is recorded in healthy volunteers (n = 8) and in patients suffering from migraine without (n= 12) or with (n. = 5) foreperiods in a forewarned reaction time task.
Abstract: The Contingent Negative Variation (CNV) is an event-related slow potential. It was recorded in healthy volunteers (n = 8) and in patients suffering from migraine without (n = 12) or with (n = 5) aura, during one (CNV1) and three second (CNV3) foreperiods in a forewarned reaction time task. CNV1 was recorded at the vertex while CNV3 was recorded at multiple electrode sites to assess topographical differences. Seven out of twelve migraine patients without aura had increased CNV1 amplitudes. CNV3 amplitudes were increased as well, but only at electrode positions C3 and C4 and not at Fz. CNV3, which allows for analysis of both an early and a late CNV component, could improve the discrimination of migraine without aura beyond that of CNV1. In migraine with aura all CNV parameters were at control levels, confirming previous results. The data obtained are discussed in terms of arousal, activation and stress and the "biobehavioral model of migraine" (Welch, 1986).

98 citations


Journal ArticleDOI
TL;DR: Results from Lagrangian duality for convex programs, the length-width inequality, and Dilworth's Theorem for directed acyclic graphs are used to obtain a strong relationship between optimal solutions of this problem and its dual.
Abstract: Consider the following resource allocation problem on a directed acyclic graph the precedence graph. Each vertex has a known work load, and a fixed amount of total resource is available. The time required to process a vertex is inversely proportional to the amount of the resource allocated to it. The time to complete all of the work is the length of time to complete a longest chain in the graph. The problem of finding an allocation which minimizes the time required to complete all of the work subject to the limited resource availability can be formulated as a separable convex programming problem. We use results from Lagrangian duality for convex programs, the length-width inequality, and Dilworth's Theorem for directed acyclic graphs, to obtain a strong relationship between optimal solutions of this problem and its dual. This allows us to obtain closed-form solutions for certain special classes of graphs, and leads to a generalization of the LYM Property for partially ordered sets. The computational complexity of the general problem is an open question. However, the ellipsoid method yields a fully-polynomial approximation scheme, and some light can be shed on the associated decision problem. The results of this paper are shown to extend to resource allocation problems on perfect graphs.

97 citations


Journal ArticleDOI
TL;DR: A fast computational method to compute the average costs under a given ( n, N )-policy is presented, based on a well-known embedding technique and a heuristic based on this computational method, is presented by which the optimal values of n and N can be determined.

63 citations


Posted Content
TL;DR: In this article, the pros and cons of institutionalized constraints limiting the freedom of national budgetary policies within an Economic and Monetary Union (EMU) in Europe are discussed. And the desirability of constraints on budgetary policy is related to the arrangements for EMU-wide monetary policy, the credibility of a no-bailout clause among member states, and progress in the area of supply-side policies.
Abstract: This paper reviews the pros and cons of institutionalized constraints limiting the freedom of national budgetary policies within an Economic and Monetary Union (EMU) in Europe. The issue is approached from three angles: the influence of EMU on (i) budget discipline; (ii) intergenerational equity and intertemporal efficiency; and (iii) macroeconomic stabilization. The desirability of constraints on budgetary policy is related to the arrangements for EMU-wide monetary policy, the credibility of a no-bailout clause among member states, and progress in the area of supply-side policies.

63 citations


Posted Content
TL;DR: In this article, a multi-item inventory system with joint replenishment costs is studied for constant deterministic demand, and two different types of strategies are distinguished: direct grouping strategies and indirect grouping strategies.
Abstract: Multi-item inventory systems with joint replenishment costs are studied for constant deterministic demand. Two different types of strategies are distinguished: direct grouping strategies and indirect grouping strategies. For these types of strategies different heuristics are reviewed. The performances of the strategies is measured as the percentage cost savings of a joint replenishment strategy relative to an independent strategy. These performances are quantified through simulation. The input-output behaviour of several simulation experiments is summarized by regression analysis.

60 citations


Journal ArticleDOI
Marno Verbeek1
TL;DR: In this paper, the authors present a transformation to eliminate the fixed individual effects and show that the corresponding marginal maximum likelihood estimator is computationally feasible and can be used to estimate the remaining parameters consistently even if number of time periods is finite.

58 citations


Journal ArticleDOI
TL;DR: It is shown that for the first problem the algorithm presented generates undominated allocations and the algorithm provides us with bounds to check how close the allocation generated is to the optimal allocation.

Journal ArticleDOI
TL;DR: It was found that the seven health habits did not constitute a homogeneous operationalization of a construct “positive lifestyle” and neuroticism and hostility discriminated best between the groups with poor or good health behaviors.
Abstract: Four hundred and fifty-five males and 523 females from a community sample participated in a study on the relationship between seven health practices (sleeping; breakfasting; snacking; being at good weight; smoking; alcohol consumption and physical activity) and seven personality factors (Neuroticism; Social Inadequacy; Rigidity; Hostility; Self-sufficiency; Dominance and Self-esteem). It was found that the seven health habits did not constitute a homogeneous operationalization of a construct “positive lifestyle.” The intercorrelations between the different health practices were typically low. The results of MANOVAs and subsequent ANOVAs revealed small, but statistically significant differences between subjects reporting positive and those reporting poor health habits. The failure to find significant interactions with sex indicated that the results for males and females were generally similar. Neuroticism and hostility discriminated best between the groups with poor or good health behaviors. This ...

Journal ArticleDOI
TL;DR: It is derived sufficient conditions for coherency which are related to regularity properties of the demand system; these conditions appear to be ‘almost necessary’ for regularity.

Posted Content
01 Jan 1990
TL;DR: In this article, a simplicial variable dimension restart algorithm for the stationary point problem or variational inequality problem on a polytope is proposed, where a linear programming pivot step is used to follow a linear piece of the path and replacement steps are used to find an approximate stationary point.
Abstract: A simplicial variable dimension restart algorithm for the stationary point problem or variational inequality problem on a polytope is proposed. Given a polytope C in (R-openface) n and a continuous function f : C (rightarrow) (R-openface) n , find a point (bigcirc) in C such that f ( (bigcirc) ) · (bigcirc) (ge) f ( (bigcirc) ) · x for any point x in C . Starting from an arbitrary point v in C , the algorithm generates a piecewise linear path of points in C . This path is followed by alternating linear programming pivot steps to follow a linear piece of the path and replacement steps in a simplicial subdivision of C . Within a finite number of function evaluations and linear programming pivot steps the algorithm finds an approximate stationary point. The algorithm leaves the starting point v along a ray pointing to one of the vertices w of C . The vertex w is obtained from the optimum solution of the linear programming problem maximize f ( v ) · x subject to x (in) C . (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.)

Posted Content
TL;DR: In this article, a survey of strategic issues in the statistical design and analysis of experiments with deterministic and random simulation models is presented, including validation, what-if analysis, optimization, and so on.
Abstract: This tutorial gives a survey of strategic issues in the statistical design and analysis of experiments with deterministic and random simulation models. These issues concern validation, what-if analysis, optimization, and so on. The analysis uses regression models and least-squares algorithms. The design uses classical experimental designs such as 2k−p factorials, which are more efficient than one at a time designs are. Moreover, classical designs make it possible to estimate interactions among inputs to the simulation. Simulation models may be optimized through response surface methodology, which combines steepest ascent with regression analysis and experimental design. If there are very many inputs, then special techniques such as group screening and sequential bifurcation are useful. Several applications are discussed. (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.)

Journal ArticleDOI
TL;DR: In this paper, the authors consider the estimation of time-dependent parameters in linear models from panel data, cross-sections, or both, and determine the fraction of individuals that should be reinterviewed each period in order to minimize the variance of the most efficient estimator of linear combinations of the parameters.

Journal ArticleDOI
J.P.C. Blanc1
TL;DR: In this article, an iterative numerical technique for the evaluation of queue length distributions is applied to multi-queue systems with one server and cyclic service discipline with Bernoulli schedules.
Abstract: An iterative numerical technique for the evaluation of queue length distributions is applied to multi-queue systems with one server and cyclic service discipline with Bernoulli schedules. The technique is based on power-series expansions of the state probabilities as functions of the load of the system. The convergence of the series is accelerated by applying a modified form of the epsilon algorithm. Attention is paid to economic use of memory space. The technique is based on power-series expansions of the state probabilities as functions of one parameter (the traffic intensity) of the systems. The coefficients of these power series can be recursively calculated for a large class of multi-queue models. The coefficients of the power-series expansions of the moments of the queue length distributions follow directly from those of the state probabillities. In most instances a bilinear transformation ensures convergence of the power series over the whole range of traffic intensities for which the system is stable. We have introduced in Blanc (2,3) extrapolations of the coefficients of the power series in order to accelerate the convergence of the series. One of these extrapolations will be combined with the epsilon algorithm (cf. Brezinski (6), Wynn (13)) in the present paper. The advantages of the present technique are that quantities are calculated iteratively, that it is relatively easy to compute additional terms of the power series in order to increase accuracy, that algorithms for accelerating the convergence of sequences can be applied, and that, once the coefficients of the

Journal ArticleDOI
TL;DR: In this paper, the authors discuss the implications of wait unemployment in a two-sector model with a dual labour market, where primary sector firms pay efficiency wages; the wage rate in the secondary sector is determined by labour supply and demand.

Journal ArticleDOI
TL;DR: In this article, the analysis of waiting times in polling systems in which the stations are polled according to a general service-order table is discussed and an extension of the principle of work conservation to systems with nonzero switchover times leads to an exact expression for a weighted sum of the mean waiting times at the various queues.
Abstract: The analysis of waiting times in polling systems in which the stations are polled according to a general service-order table is discussed. Such systems can be used to represent token-bus local area networks in which the routing of the token is fixed. Stations are given higher priority by being listed more frequently in the table, or by receiving service according to the exhaustive service discipline. The polling system is modeled by a single-server multiqueue system in discrete time. Nonzero switchover times between the queues are assumed. An extension of the principle of work conservation to systems with nonzero switchover times leads to an exact expression for a weighted sum of the mean waiting times at the various queues. By using a limiting procedure, the discrete-time results are translated to continuous-time results. The special case of polling in a star network is discussed and compared to polling in a corresponding network with strictly cyclic service order. >

Posted Content
J.P.C. Blanc1
TL;DR: The power-series algorithm as mentioned in this paper provides a means for the numerical analysis of polling systems with a moderate number of stations, for a wide variety of access protocols, including Coxian service and switching time distributions, with infinite buffers, and with a Bernoulli schedule for each visit to a station.
Abstract: Polling systems are widely used to model communication networks with several classes of messages, a single transmission channel and a collision-free access prolocol. However, they can only be analysed exactly for some special service disciplines. The power-series algorithm provides a means for the numerical analysis of polling systems with a moderate number of stations, for a wide variety of access protocols. This paper contains a general description of the power-series algorithm, with emphasis on the application to a general class of polling systems with Poisson arrival streams, with Coxian service and switching time distributions, with infinite buffers, with a fixed periodic visit order, and with a Bernoulli schedule for each visit to a station. The applicability and the complexity of the algorithm are discussed for several more service disciplines for polling systems.

Journal ArticleDOI
TL;DR: The creation of a transnational European model of management should be rooted in the values and behaviour of a European way of life as discussed by the authors, since there are both convergent and divergent forces and tendencies at work.

Journal ArticleDOI
TL;DR: In this article, the parameter identification of multivariate AR (1) models and of univariate ARMA (2,1) and AR (2) models is discussed, where the variables in the model are observed every mth period where m is some integer greater than unity.
Abstract: . We discuss the parameter identification of multivariate AR (1) models and of univariate ARMA (2,1) and AR (2) models if the variables in the model are observed every mth period where m is some integer greater than unity. The results indicate that the models will often not be globally identified even if they are locally identified and that the likelihood function can have a large number of local maxima.

Journal ArticleDOI
TL;DR: A heuristic for operational production planning in a chemical processing environment, characterized by a single bottleneck machine, fixed batch sizes, sequence-dependent setup times, as well as production and storage capacity constraints, is developed.

Journal ArticleDOI
TL;DR: In this article, a three-state hazard model is used to predict individual probabilities of participation in the labour force, of unemployment and employment, and to calculate expected lengths of stay in each of these labour market states as a function of personal characteristics and relevant demand conditions.
Abstract: Using data from a set of retrospective questions from a Dutch national sample on individual labour market experiences in the period 1980–85, a three-state hazard model is estimated. Transitions are analysed between three labour market states: employment, unemployment and the out-of-the labour force, as well as between jobs (job mobility). Allowance is made for time-varying exogenous variables and for duration dependence. The estimated transition rates allow us to predict individual probabilities of participation in the labour force, of unemployment and employment, and to calculate expected lengths of stay in each of these labour market states as a function of personal characteristics and relevant demand conditions.

Journal ArticleDOI
TL;DR: In this paper, the authors report on a study of indicators of well-being, including objective indicators, global, affective and socio-economic indicators, and conclude that these indicators contribute significantly to the prediction of happiness.
Abstract: The paper reports on a study of indicators of well-being, including objective indicators of well-being, global, affective indicators of well-being, and indicators of socio-economic well-being. Socioeconomic well-being is (narrowly) defined as that part of the individual's universal well-being which is strongly related to money and material means. It was hypothesized that these 3 classes of indicators of well-being have different meanings for the various groups of people on social security. Therefore, data were collected from a Dutch, nationally representative sample of 3 categories of individuals drawing benefits, namely: people receiving social benefits; unemployed, and disabled people, and a group of people in work. Hypotheses were tested regarding the following issues: The results indicate that, for the groups mentioned above, material aspects of well-being may be distinguished from immaterial aspects of well-being, and that indicators of socio-economic well-being contribute significantly to the prediction of happiness. Furthermore, these indicators discriminate best between people having employment and categories of individuals drawing benefits. It is concluded that a socio-economic version of well-being may be highly relevant when studying the quality of life of people on social security.

Journal ArticleDOI
TL;DR: It appeared that the direction of drawing a horizontal line is the only variable that differentiates well between handedness groups, and it was argued that the handedness of individual subjects cannot safely be determined from these measures.

Journal ArticleDOI
TL;DR: In this article, the authors present a formalism to describe economic dynamics in a qualitative way, which is a modification of an existing algorithm for qualitative simulation as proposed by Kuipers, and demonstrate that the framework of qualitative dynamics can clarify economic reasoning without using any quantative data.

Book ChapterDOI
01 Jan 1990
TL;DR: In this paper, a market entry game with information transmission and equilibrium refinements is illustrated by means of variations on a simple market entry (EM) game, which is similar to the one we consider in this paper.
Abstract: Recent developments in noncooperative game theory (especially those dealing with information transmission and equilibrium refinements) are illustrated by means of variations on a simple market entry game.

Journal ArticleDOI
TL;DR: In this article, the effects of a free internal market for the decision-making process are analyzed and it is shown that if some country tries to obtain a comparative advantage in attracting capital by lowering its benefit rate, the reaction of other countries may increase the coverage of their social insurance systems.

Posted Content
TL;DR: In this article, the impact of the construction of the cohorts on the bias in the standard fixed effects estimator was analyzed under which conditions this is a valid approach and the results showed that the effects of ignoring the fact that only a synthetic panel is available will be small if the cohort sizes are sufficiently large (100, 200 individuals) and if the true means within each cohort exhibit sufficient time variation.
Abstract: If repeated observations on the same individuals are not available it is not possible to capture unobserved individual characteristics in a linear model by using the standard fixed effects estimator. If large numbers of observations are available in each period one can use cohorts of individuals with common characteristics to achieve the same goal, as shown by Deaton (1985). It is tempting to analyze the observations on cohort averages as if they are observations on individuals which are observed in consecutive time periods. In this paper we analyze under which conditions this is a valid approach. Moreover, we consider the impact of the construction of the cohorts on the bias in the standard fixed effects estimator. Our results show that the effects of ignoring the fact that only a synthetic panel is available will be small if the cohort sizes are sufficiently large (100, 200 individuals) and if the true means within each cohort exhibit sufficient time variation.