Showing papers by "Tilburg University published in 1993"
TL;DR: In this article, the effects of increased environmental care on optimal technology choice and long-term growth are studied for an economy in which pollution is a side-product of physical capital used in production.
Abstract: The effects of increased environmental care on optimal technology choice and long-term growth are studied for an economy in which pollution is a side-product of physical capital used in production. First, it is shown that in case of a standard neoclassical production structure, the result is a less capital-intensive production process whereas the long-run growth rate is not affected. Next, we introduce assumptions of the endogenous growth literature. When there are constant returns to physical capital, an increase in abatement activities crowds out investment and lowers the endogenous growth rate. When human capital accumulation is the engine of growth, physical capital intensity declines and the endogenous optimal growth rate is unaffected by increased environmental care or is even higher, depending on whether or not pollution influences agents' ability to learn.
378 citations
TL;DR: Despite very different macroeconomic conditions, demographic structures and degrees of income inequality, favorable income changes among low-income families with children were widespread and strikingly similar across the eight countries in this paper.
Abstract: Despite very different macroeconomic conditions, demographic structures and degrees of income inequality, favorable income changes among low-income families with children were widespread and strikingly similar across the eight countries in our study. In most European countries, the combination of modest inequality and extensive mobility among the poor enabled virtually all families to avoid relative income deprivation at least occasionally. However, even substantial mobility among the poor in the Unites States could not elevate the living standards of one in seven white and two in five black families to a level that was half that enjoyed by a typical American family.
235 citations
TL;DR: It is concluded that the sensory and motor input to the cortex are subjected to a similar control mechanism, under frontal control, for the transmission of subcortical motor information to the cerebral cortex.
Abstract: In this paper the similarities in the structural and functional organization of motor preparation and attention are discussed. A crucial structure in this organization is the thalamus, a complex of sensory and motor nuclei that transmits information from subcortical origins to the cortex. For the most part, the thalamus is overlapped by the nucleus reticularis, which has a local inhibitory influence on the underlying nuclei. This serves as a gating mechanism for the transmission of sensory information to the cortex. Skinner and Yingling (1977) have provided arguments in favor of a frontal control in the gating of sensory information. The present paper extends their suggestions to the motor system: a similar gating mechanism for the transmission of subcortical motor information to the cortex is hypothesized, also under frontal control. Slow potentials recorded during motor preparation and attention for an upcoming stimulus show a different distribution over the scalp. These distributions are interpreted as an indication of which thalamic gates are open to transmit information to the cortex. Probe responses (spinal reflexes, evoked potentials, and the startle reflex) can also be used to investigate which thalamocortical gates are open under certain experimental conditions. It is concluded that the sensory and motor input to the cortex are subjected to a similar control mechanism. Language: en
203 citations
TL;DR: In this article, the authors investigate how the incentives for cost reduction in a differentiated industry depend upon the degree of product substitutability and show that when goods are imperfect substitutes, both Cournot and Bertrand competition result in underinvestment in the sense that a social planner would be willing to pay more for a given cost reduction than a profit-maximizing firm.
186 citations
TL;DR: In this paper, the authors investigated the content of thoughts and images which spider phobics report to have during a confrontation with a spider and investigated the frequency and strength of the subjective belief in the idea.
186 citations
TL;DR: In this article, the authors considered the problem of finding a positive definite solution of the matrix equation X + A ∗ X -1 A = Q in a special case of the discrete-time Riccati equation.
182 citations
TL;DR: This paper delineates mental load and stress as two related concepts that originate from different theoretical frameworks that may lead to different interpretations of experimental results, and, consequently, to different recommendations in applied situations.
Abstract: This paper delineates mental load and stress as two related concepts that originate from different theoretical frameworks. A proper distinction between the two concepts is important, not only for theory building, but because it may lead also to different interpretations of experimental results, and, consequently, to different recommendations in applied situations. High workload is regarded as an important but not a critical factor in the development of stress symptoms. It is quite possible to work hard in difficult and complex tasks, even under unfavourable conditions, without cognitive strain, psychosomatic complaints, or adverse physiological effects. High task demands can be met by mobilizing extra energy through mental effort. This 'trying harder' reaction is a normal and healthy coping strategy to adapt to situational demands. In contrast, stress is regarded as a state in which the equilibrium between cognitive and energetical processes is disturbed by ineffective energy mobilization and negative emotions. Stress typically is characterized by inefficient behaviour, overreactivity, and the incapacity to recover from work. Stress is regarded as a state in which the physiological system is disorganized, which results in decreased well-being, sleeping problems, psychosomatic complaints, and increased health risks.
163 citations
TL;DR: In this article, the question under which conditions on the real (square) matrix A the matrix equation X+ATX−1A=I has a real symmetric positive definite solution X is raised.
160 citations
TL;DR: For a class of games with perfectly coinciding interests modeled as asymmetric contests, where players are unsure of which role they will have, only meaningful communication is evolutionarily stable.
152 citations
TL;DR: Results are consistent with the notion that EMG amplitude of frontalis, corrugator, and orbicularis oris provides a sensitive index of the degree of exerted mental effort.
Abstract: In earlier studies, positive but inconsistent relationships have been reported between mental effort and electromyogram (EMG) amplitude in task-irrelevant limb muscles. In this study, we explored whether facial EMG activity would provide more consistent results. Tonic EMG activity of six different facial and jaw-elevator muscles was bilaterally recorded during a two-choice serial reaction task with paced presentation of auditory or visual signals. In Experiment 1, task load (signal presentation rate) was kept constant for 20 min at the level of the subject's maximal capacity. In Experiment 2, task load was increased in a stepwise fashion over six successive 2-min periods from sub- to supramaximal capacity levels. EMG amplitude and coherency between momentary bilateral amplitude fluctuations were measured. In Experiment 1, EMG amplitude of frontalis, corrugator supercilii, and orbicularis oris inferior showed a strong gradual increase throughout the task period, whereas taks performance remained fairly stable. Orbicularis oculi, zygomaticus major, and temporalis EMG showed a much smaller increase or no increase. In Experiment 2, the first three muscles showed a fairly consistent increase in EMG amplitude with increasing task load. Orbicularis oculi and zygomaticus major were not active until task load became supramaximal. Effects of stimulus modality or laterality were not found in any experiment. These results are consistent with the notion that EMG amplitude of frontalis, corrugator, and orbicularis oris provides a sensitive index of the degree of exerted mental effort.
147 citations
TL;DR: This paper put these ethnographic exhibits into the wider context of collecting, measuring, classifying, picturing, filing, and narrating of colonial Others during the heyday of colonialism, arguing that it is possible to have a wide range of seemingly divergent modes of dealing with the Other within one single analytic field.
Abstract: "To see is to know"-this motto was attached to the anthropological exhibits of the World's Columbian Exposition of 1893, one of the many world fairs during the era of imperialism and colonialism (Rydell 1984:44). At these gigantic exhibitions, staged by the principal colonial powers, the world was collected and displayed. Natives from a wide range of colonized cultures quickly became a standard part of most manifestations of this kind. Together with their artifacts, houses, and even complete villages, so-called savages or primitives were made available for visual inspection by millions of strolling and staring Western citizens. Comparable places of spectacle such as zoos, botanical gardens, circuses, temporary or permanent exhibitions staged by missionary societies and museums of natural history, all exhibited other races and/or other species and testified to the imperialism of 19th-century nation-states. In this article I will put these ethnographic exhibits into the wider context of the collecting, measuring, classifying, picturing, filing, and narrating of colonial Others during the heyday of colonialism. All these modes of dealing with the exotic, with colonial otherness, functioned in a context of European hegemony, testifying to the successful imperialist expansion of 19th-century nation-states and to the intricate connections that developed between scientific and political practices. Of course, I cannot bypass the historical changes and national differences in exhibitionary practices in the period under study-the last decades of the 19th and the first decades of the 20th century-but I will concentrate on the similarities, which in my view are predominant, arguing that it is possible to have a wide range of seemingly divergent modes of dealing with the Other within one single analytic field.
TL;DR: In this article, the first dorsal interosseus muscle contraction was recorded from the right hand and onsets were visually determined in the raw EMG, compared with the onsets produced by the automated methods on the rectified and low-pass filtered EMG.
Abstract: Many researchers have used off-line techniques for the automatic detection of electromyogram (EMG) onset. However, very little is known about the accuracy of these methods. In the present study, five such methods are evaluated and their accuracy is reported. Five subjects were asked to produce fast (ballistic) and slow (ramp) contractions with thumb and index finger of the right hand in a simple reaction time task. EMG was recorded from the first dorsal interosseus muscle, and onsets were visually determined in the raw EMG. These onsets were compared with the onsets produced by the automated methods on the rectified and low-pass filtered EMG. Four of the automated methods produced very reliable estimates of the visually determined onsets, at least when additional constraints upon the initial estimates were made. Studies using automated methods for EMG onset detection should report findings about their accuracy.
TL;DR: In this article, the authors show that Deaton's estimator is inconsistent if the number of time periods is small and propose an alternative estimator which does not suffer from a bias due to a small number of sampling periods.
21 Apr 1993
TL;DR: It is shown that using supervised learning techniques, based on a corpus of transcribed words, the same and even better performance can be achieved, without explicit modeling of linguistic knowledge.
Abstract: It is traditionally assumed that various sources of linguistic knowledge and their interaction should be formalised in order to be able to convert words into their phonemic representations with reasonable accuracy. We show that using supervised learning techniques, based on a corpus of transcribed words, the same and even better performance can be achieved, without explicit modeling of linguistic knowledge.In this paper we present two instances of this approach. A first model implements a variant of instance-based learning, in which a weighed similarity metric and a database of prototypical exemplars are used to predict new mappings. In the second model, grapheme-to-phoneme mappings are looked up in a compressed text-to-speech lexicon (table lookup) enriched with default mappings. We compare performance and accuracy of these approaches to a connectionist (backpropagation) approach and to the linguistic knowledge-based approach.
TL;DR: In this paper, the authors present several solvability concepts for linear differential-algebraic equations (DAEs) with constant coefficients on the positive time axis as well as for the associated singular systems, and investigate under which conditions these concepts are met.
TL;DR: In this paper, the authors considered the joint replenishment inventory problem for N items under constant demand and proposed a solution to find the global optimum within the class of cyclic strategies, however, the algorithm of Goyal does not always lead to the optimal cyclic strategy.
Abstract: This note considers the joint replenishment inventory problem for N items under constant demand. The frequently-used cyclic strategy (T; k1, …, k N ) is investigated: a family replenishment is made every T time units and item i is included in each k i th replenishment. Goyal proposed a solution to find the global optimum within the class of cyclic strategies. However, we will show that the algorithm of Goyal does not always lead to the optimal cyclic strategy. A simple correction is suggested.
11 Jul 1993
TL;DR: This work proposes an alternative approach which differs from the top-down approach in that it starts with an analysis of the tuples in the relation: a bottom-up approach.
Abstract: Data dependencies express the presence of structure in database relations, that can be utilised in the database design process. The discovery of data dependencies can be viewed as an induction process. Like in induction, we can distinguish between top-down approaches and bottom-up approaches. In top-down approach, dependencies are generated and then tested against the given relation. Since each test requires O(n2) comparisons, where n is the number of tuples in relation, this can be computationally costly. We propose an alternative approach which differs from the top-down approach in that it starts with an analysis of the tuples in the relation: a bottom-up approach.
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TL;DR: In this paper, an axiomatic characterization of the Nash equilibrium (NE) correspondence in terms of consistency, converse consistency and one-person rationality is given, and axiomatizations are given of the strong NE correspondence, the coalition-proof NE correspondence and the semi-strong NE.
Abstract: We start with giving an axiomatic characterization of the Nash equilibrium (NE) correspondence in terms of consistency, converse consistency and one-person rationality. Then axiomatizations are given of the strong NE correspondence, the coalition-proof NE correspondence and the semi-strong NE. In all these characterizations consistency and suitable variants of converse consistency play a role. Finally, the dominant NE correspondence is characterized. We also indicate how to generalize our results to Bayesian and extensive games. (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.) (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.) (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.) (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.) (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.)
TL;DR: In this article, the authors consider a possibly nonlinear regression model under any multivariate elliptical data density, and examine Bayesian posterior and predictive results, which are shown to be robust with respect to the specific choice of a sampling density within this elliptical class.
TL;DR: Results are consistent with the earlier evidence that learning a non-alphabetic orthography does not promote awareness of the segmental structure of utterances and confirm the conclusion drawn earlier from work with illiterate subjects that explicit instruction is more critical for the development of segmental representations of language than of representations of higher levels such as those of rhymes and syllables.
Abstract: The metaphonological abilities of two groups of bilingual Chinese adults residing in the Netherlands were examined. All subjects were able to read Chinese logograms, but those in the alphabetic group had, unlike those in the non-alphabetic group, also acquired some competence in reading Dutch. In Experiment 1, strong, significant differences between the two groups were obtained in the task of deleting the initial consonant of a Dutch spoken pseudo-word and also in a task consisting of segmenting a sentence into progressively smaller fragments, but there was no difference in a rhyme-nonrhyme classification task with pairs of Dutch words. In the latter task, the subjects in the two groups performed at a near-ceiling level. In Experiment 2, a significant difference was obtained again for the consonant-deletion task and no difference with an initial syllabic-vowel-deletion task, but the non-alphabetic subjects performed at a significantly lower level than the alphabetic subjects in the rhyme-judgement task. Taken together, these results are consistent with the earlier evidence that learning a non-alphabetic orthography does not promote awareness of the segmental structure of utterances. On the other hand, they confirm, for a population of Chinese readers, the conclusion drawn earlier from work with illiterate subjects that explicit instruction is more critical for the development of segmental representations of language than of representations of higher levels such as those of rhymes and syllables.
TL;DR: This article argued that the integration of natural resources into the framework of economic theory is a prerequisite for environmental policy and the Dutch abatement policy regarding acid rain is analysed in this respect.
TL;DR: In this paper, the kernel estimation method was used to develop a formula for the bandwidth that describes the sensitivity of the average derivative estimator, which tries out to undersmooth the density of the regression variable.
TL;DR: In this paper, the authors introduced a new autonomy scale that takes the criticism mentioned into account and connects with new insights into gender identity, and concluded that the scale is a valid and reliable instrument for measuring the new autonomy concept in various populations.
Abstract: The concept of autonomy has a long history, not only in psychology, but also in philosophy. In this article, the concept is discussed in relation to gender and mental health. The criticisms of several authors with regard to the classical psychological concept of autonomy are reviewed. Also, some recent theoretical developments which start from a psychoanalytical perspective are discussed. Then the reader is introduced to the construction of a new Autonomy scale that takes the criticism mentioned into account and connects with new insights into gender identity. Two studies are presented in which the structure of the scale, as well as it validity and reliability, is investigated. The Autonomy scale appears to measure consistently three aspects: Self-awareness, Sensitivity to Others, and Capacity for Managing New Situations. Reliability and validity are satisfactory. Furthermore, in a third study the factor structure found in Studies 1 and 2 was cross-validated in a more heterogeneous, adult sample. This cross-validation was also done across the sexes. It is concluded that the Autonomy scale is a valid and reliable instrument for measuring the new autonomy concept in various populations. Secondly, the scale seems to fill the gap that is left open by more classically oriented autonomy (and dependence) scales by measuring Sensitivity to Others, an important aspect of femininity and thus for female identity.
TL;DR: In this article, the authors provide definitions and conditions for two notions of left (right) invertibility of a general singular system in terms of their distributions, subspaces, and Rosenbrock's system matrix.
TL;DR: In this article, the authors present comparative results on poverty in seven countries and regions of the European Community: Belgium, The Netherlands, Luxembourg, Lorraine, Ireland, Catalonia and Greece.
Abstract: This paper presents comparative results on poverty in seven countries and regions of the European Community: Belgium, The Netherlands, Luxembourg, Lorraine, Ireland, Catalonia and Greece. The data are obtained from comparable socio-economic surveys in each country. Subjective as well as relative poverty lines are used. The results indicate that the subjective poverty lines are plausible in a comparative context, although the levels of the subjective standards are rather generous. The estimated equivalence scales are much flatter than the one recommended by the OECD. The extent of poverty is much greater in the “peripheral” EC-countries than in the “central” ones. Though similar factors are found to be associated with poverty in all countries, there are also important differences in the characteristics of the poor across countries. The impact of social security transfers on poverty appears to be much smaller in the southern countries Greece and Catalonia, than in the Benelux and Lorraine.
TL;DR: The decrease of the intermediate latency components towards the end of the foreperiod is discussed in terms of gating, while the increase in the long latency component is discussed with respect to a decrease in RT on trials where the fingers were stimulated just before the RS, pointing to the role of attentional mechanisms.
TL;DR: In this article, the authors explore how intergenerational and international distributional effects, in addition to intertemporal efficiency impacts, affect the macroeconomic consequences of investment-promoting policies.
TL;DR: A simple test of the Law of Initial Values is described and illustrated, and the reduction of variance from the pretest to the posttest is crucial in this test.
Abstract: The conceptualization and testing of the Law of Initial Values remains a controversial issue. We critically review common procedures to test the Law, and a simple test of the Law is described and illustrated. The reduction of variance from the pretest to the posttest is crucial in this test.
TL;DR: The negative effect of signal degradation on performance was aggravated by sleep loss and time-on-task, whereas KR improved performance, especially when signals were degraded.
Abstract: This study explores whether KR (knowledge of results) and reward compensate for the negative joint effects of sleep deprivation and signal degradation in a choice-reaction task. The negative effect of signal degradation on performance was aggravated by sleep loss and time-on-task, whereas KR improved performance, especially when signals were degraded. Reward changed the effects of time-on-task owing to lack of sleep. Performance was also improved by a brief task interruption after 30 minutes' work, with 5 more minutes to go. These results can be interpreted in terms of the performance model of Sanders (1983), which links energetic mechanisms to stages of information processing. A lack of energetic supply from the arousal mechanism to perceptual processing, induced by signal degradation, sleep deprivation, and time-on-task, was effectively counteracted by KR: KR enables the mobilization of effort to compensate for this lack of arousal. The relation between reward and KR is not yet clear. The interruption effect suggests that the influence of time-on-task is not due to loss of arousal, but causes a reallocation of resources by effort.
TL;DR: In this article, the authors give a survey on several well-known compromise values in cooperative game theory and its applications, including the τ-value for TU games, the Raiffa-Kalai-Smorodinsky solution for bargaining problems, and the compromise value for NTU games.
Abstract: The aim of this paper is to give a survey on several well-known compromise values in cooperative game theory and its applications. Special attention is paid to the τ-value for TU-games, the Raiffa-Kalai-Smorodinsky solution for bargaining problems, and the compromise value for NTU-games.