1,324 research outputs found
The Gerber-Shiu expected discounted penalty-reward function under an affine jump-diffusion model.
We provide a unified analytical treatment of first passage problems under an affine state-dependent jump-diffusion model (with drift and volatility depending linearly on the state). Our proposed model, that generalizes several previously studied cases, may be used for example for obtaining probabilities of ruin in the presence of interest rates under the rational investement strategies proposed by Berk & Green (2004)First passage problems; Risk process; Stochastic rates of interest; Ruin with interest; Affine jump-diffusion models; Penalty/reward functions at ruin;
Finite time ruin probabilities with one Laplace inversion.
In this work we present an explicit formula for the Laplace transform in time of the finite time ruin probabilities of a classical Levy model with phase-type claims. Our result generalizes the ultimate ruin probability formula of Asmussen and Rolski [IME 10 (1991) 259]—see also the analog queuing formula for the stationary waiting time of the M/Ph/1 queue in Neuts [Matrix-geometric Solutions in Stochastic Models: An Algorithmic Approach. Johns Hopkins University Press, Baltimore, MD, 1981]—and it considers the deficit at ruin as wellFinite-time ruin probability; Phase-type distribution; Deficit at ruin; Lundberg’s equation; Laplace transform;
On the valuation ofconstant barrier options under spectrally one-sided exponential L&evy models and Carr’s approximation for American puts.
This paper provides a general framework for pricing options with a constant barrier under spectrally one-sided exponential L&evy model, and uses it to implement ofCarr’s approximation for the value of the American put under this model. Simple analytic approximations for the exercise boundary and option value are obtained. c 2002 Elsevier Science B.V. All rights reservedAmerican options; Perpetual approximation; Spectrally negative exponential L&evy process;
Immigrant workers and language formation: Gulf Pidgin Arabic
Ever since the oil boom of the 1970s, Saudi Arabia and the countries
on the western coast of the Arab Gulf, i.e. Kuwait, the United Arab
Emirates, Oman, Bahrain, and Qatar, have been witnessing both a
significant increase in their non-national labour force and considerable
urbanization. Most of the immigrant workers come from South and
South-East Asia, with smaller number of expatriates from other
regions. The overwhelming majority of these foreign workers live
and work in the cities, which have thus become not only a meeting
place of speakers of a variety of languages, but also a linguistic laboratory
in which a new means of inter-ethnic communication, generally
known as Gulf Pidgin Arabic, has emerged in approximately the last
40 years. The present paper describes the main features of the phonology,
morphology, syntax, and vocabulary of this still under
researched pidgin. Also discussed are the various sources of these
features: the speakers’ first languages, the Foreigner Talk register of
Arabic, grammaticalization, Gulf Arabic, and English.Trabajadores inmigrantes y formación de la lengua: el pidgin del
Golfo Pérsico. Desde el boom del petróleo de los años setenta, Arabia
Saudí y los países de la costa oeste del Golfo Pérsico, i.e. Kuwait,
Emiratos Árabes Unidos, Omán, Baréin y Catar, han conocido un
aumento significativo tanto de la mano de obra inmigrante como de
la urbanización. La mayoría de los trabajadores inmigrantes viene
del sur y del sudeste de Asia, existiendo un pequeño número de
expatriados de otras regiones. La apabullante mayoría de estos trabajadores
extranjeros vive y trabaja en las ciudades, que se han convertido
no solamente en un lugar de encuentro para los hablantes de
distintas lenguas, sino también en un laboratorio lingüístico donde
un nuevo tipo de comunicación entre las diferentes etnias, generalmente
conocido como pidgin del Golfo Pérsico, ha aparecido en,
aproximadamente, los últimos cuarenta años. Este artículo describe
las características principales de la fonología, morfología, sintaxis y
léxico de este pidgin poco investigado. El trabajo también trata las diferentes fuentes de estas características: las lenguas maternas de los
hablantes, los registros del árabe como lengua extranjera, la gramaticalización,
el árabe del Golfo y el inglés
Diagnostic features of English-lexifier contact-languages: Grenada Creole English
This paper draws on both diachronic and synchronic data and presents the attestations in Grenada Creole English of the diagnostic features of English-lexifier pidgins and creoles proposed by Baker & Huber (2001). This is followed by a comparison of the distribution of these features in Grenada Creole English and in the seven Atlantic English-lexifier contact languages considered by Baker & Huber (2001), and the quantification of the affinities of Grenada Creole English with several Eastern Caribbean varieties: Antiguan, Bajan, Kittitian, the Creole of Trinidad and Tobago, and Vincentian. A number of selected diagnostic features recorded in Grenada Creole English are then discussed in terms of their provenance, their relevance to the Western – Eastern Caribbean creoles divide, and their classification
Immigrant workers and language formation: Gulf Pidgin Arabic
Ever since the oil boom of the 1970s, Saudi Arabia and the countries
on the western coast of the Arab Gulf, i.e. Kuwait, the United Arab
Emirates, Oman, Bahrain, and Qatar, have been witnessing both a
significant increase in their non-national labour force and considerable
urbanization. Most of the immigrant workers come from South and
South-East Asia, with smaller number of expatriates from other
regions. The overwhelming majority of these foreign workers live
and work in the cities, which have thus become not only a meeting
place of speakers of a variety of languages, but also a linguistic laboratory
in which a new means of inter-ethnic communication, generally
known as Gulf Pidgin Arabic, has emerged in approximately the last
40 years. The present paper describes the main features of the phonology,
morphology, syntax, and vocabulary of this still under
researched pidgin. Also discussed are the various sources of these
features: the speakers’ first languages, the Foreigner Talk register of
Arabic, grammaticalization, Gulf Arabic, and English.Trabajadores inmigrantes y formación de la lengua: el pidgin del
Golfo Pérsico. Desde el boom del petróleo de los años setenta, Arabia
Saudí y los países de la costa oeste del Golfo Pérsico, i.e. Kuwait,
Emiratos Árabes Unidos, Omán, Baréin y Catar, han conocido un
aumento significativo tanto de la mano de obra inmigrante como de
la urbanización. La mayoría de los trabajadores inmigrantes viene
del sur y del sudeste de Asia, existiendo un pequeño número de
expatriados de otras regiones. La apabullante mayoría de estos trabajadores
extranjeros vive y trabaja en las ciudades, que se han convertido
no solamente en un lugar de encuentro para los hablantes de
distintas lenguas, sino también en un laboratorio lingüístico donde
un nuevo tipo de comunicación entre las diferentes etnias, generalmente
conocido como pidgin del Golfo Pérsico, ha aparecido en,
aproximadamente, los últimos cuarenta años. Este artículo describe
las características principales de la fonología, morfología, sintaxis y
léxico de este pidgin poco investigado. El trabajo también trata las diferentes fuentes de estas características: las lenguas maternas de los
hablantes, los registros del árabe como lengua extranjera, la gramaticalización,
el árabe del Golfo y el inglés
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Task Feedback Effects on Conflict Monitoring and Executive Control: Relationship to Subclinical Measures of Depression
Emerging evidence suggests that depression is associated with executive dysfunction, particularly after committing errors or receiving negative performance feedback. To test this hypothesis, 57 participants performed two executive tasks known to elicit errors (the Simon and Stroop Tasks) during positive or negative performance feedback. Participants with elevated depressive symptoms (Beck Depression Inventory scores >= 13) were characterized by impaired posterror and postconflict performance adjustments, especially during emotionally negative task-related feedback. Additionally, for both tasks, depressive symptoms were inversely related to postconflict reaction time adjustments following negative, but not positive, feedback. These findings suggest that subclinical depression is associated with impairments in behavioral adjustments after internal (perceived failure) and external feedback about deficient task performance.Psycholog
Anxiety Shapes Amygdala-Prefrontal Dynamics During Movie Watching
Background:
A well-characterized amygdala–dorsomedial prefrontal circuit is thought to be crucial for threat vigilance during anxiety. However, engagement of this circuitry within relatively naturalistic paradigms remains unresolved. //
Methods:
Using an open functional magnetic resonance imaging dataset (Cambridge Centre for Ageing Neuroscience; n = 630), we sought to investigate whether anxiety correlates with dynamic connectivity between the amygdala and dorsomedial prefrontal cortex during movie watching. //
Results:
Using an intersubject representational similarity approach, we saw no effect of anxiety when comparing pairwise similarities of dynamic connectivity across the entire movie. However, preregistered analyses demonstrated a relationship between anxiety, amygdala-prefrontal dynamics, and anxiogenic features of the movie (canonical suspense ratings). Our results indicated that amygdala-prefrontal circuitry was modulated by suspense in low-anxiety individuals but was less sensitive to suspense in high-anxiety individuals. We suggest that this could also be related to slowed habituation or amplified anticipation. Moreover, a measure of threat-relevant attentional bias (accuracy/reaction time to fearful faces) demonstrated an association with connectivity and suspense. //
Conclusions:
Overall, this study demonstrated the presence of anxiety-relevant differences in connectivity during movie watching, varying with anxiogenic features of the movie. Mechanistically, exactly how and when these differences arise remains an opportunity for future research
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