67 research outputs found
The impact of website quality and online reviews on booking intention: The case for Algerian Hotels
The present study assess the effect of Algerian hotels website quality and online reviews, on the online booking intention with keyword research scores as an indicator. Thru the analysis of combined scores and ratios obtained from a content analysis to TripAdvisor Online Travel Agencies (OTA) to four Algerian hotels websites located in the city of Constantine. The results support theorical findings that website quality effects the online booking intention only for Marriott Hotel, However a divergence of results for local hotels is noticed, due to the poor use of their websites, which is measured by the lowest online reviews number on TripAdvisor compared with Google Travel platform. Moreover, the study supports the theorical findings that online reviews number and especially positive online reviews effect the hotel customer's online booking intention; where high keyword rates are expected for best reviewd hotels
Caractérisation des cris des nourrissons en vue du diagnostic précoce de différentes pathologies
Lâutilisation des signaux de cris dans le diagnostic se base sur les thĂ©ories qui ont Ă©tĂ© proposĂ©es par les diffĂ©rents chercheurs dans le domaine. Le principal objectif de leurs travaux Ă©tait lâanalyse spectrographique ainsi que la modĂ©lisation des signaux de cris. Ils ont dĂ©montrĂ© que les caractĂ©ristiques acoustiques des cris des nouveau-nĂ©s sont liĂ©es Ă des conditions mĂ©dicales particuliĂšres.
Cette thĂšse est destinĂ©e Ă contribuer Ă lâamĂ©lioration de la prĂ©cision de la reconnaissance des cris pathologiques par la combinaison de plusieurs paramĂštres acoustiques issus de l'analyse spectrographique et des paramĂštres qui qualifient les cordes et le conduit vocal. Car les caractĂ©ristiques acoustiques reprĂ©sentant le conduit vocal ont Ă©tĂ© largement utilisĂ©es pour la classification des cris, alors que les caractĂ©ristiques des cordes vocales pour la reconnaissance automatique des cris, ainsi que leurs techniques efficaces dâextraction nâont pas Ă©tĂ© exploitĂ©es.
Pour rĂ©pondre Ă cet objectif, nous avons procĂ©dĂ© en premier lieu Ă une caractĂ©risation qualitative des cris des nouveau-nĂ©s sains et malades en utilisant les caractĂ©ristiques qui ont Ă©tĂ© dĂ©finies dans la littĂ©rature et qui qualifient le comportement des cordes et du conduit vocal pendant le cri. Cette Ă©tape nous a permis dâidentifier les caractĂ©ristiques les plus importantes dans la diffĂ©renciation des cris pathologiques Ă©tudiĂ©s.
Pour lâextraction des caractĂ©ristiques sĂ©lectionnĂ©es, nous avons implĂ©mentĂ© des mĂ©thodes de mesures efficaces permettant de dĂ©passer la surestimation et la sous-estimation des caractĂ©ristiques. Lâapproche de quantification proposĂ©e et utilisĂ©e dans ce travail facilite lâanalyse automatique des cris et permet une utilisation efficace de ces caractĂ©ristiques dans le systĂšme de diagnostic. Nous avons procĂ©dĂ© aussi Ă des tests expĂ©rimentaux pour la validation de toutes les approches introduites dans cette thĂšse. Les rĂ©sultats sont satisfaisants et montrent une amĂ©lioration dans la reconnaissance des cris par pathologie.
Les travaux réalisés sont présentés dans cette thÚse sous forme de trois articles publiés dans différents journaux. Deux autres articles publiés dans des comptes rendus de conférences avec comité de lecture sont présentés en annexes
Traitement d'ignifugation du bois d'ingĂ©nierie par des revĂȘtements intumescents
Les produits du bois d'ingĂ©nierie sont susceptibles Ă la dĂ©faillance pendant leur exposition au feu Ă cause de la dĂ©gradation thermique des sections minces ou de la perte rapide de rĂ©sistance des adhĂ©sifs utilisĂ©s pour le collage, contre-collage ou l'aboutage. Plusieurs approches ont Ă©tĂ© dĂ©veloppĂ©es pour protĂ©ger les structures en bois combustibles contre le feu. L'application des peintures intumescentes est une mesure prĂ©ventive complĂ©mentaire Ă d'autres approches telle l'utilisation des gicleurs et les panneaux de gypse dans une approche intĂ©grĂ©e de protection. Sous l'effet de la chaleur, les revĂȘtements intumescents agissent comme des barriĂšres physiques qui empĂȘchent l'oxygĂšne d'atteindre le substrat et les produits inflammables de s'Ă©chapper. Ainsi, ils isolent les matĂ©riaux de l'effet de la chaleur. L'objectif gĂ©nĂ©ral de ce projet est d'Ă©valuer la performance des revĂȘtements ignifuges pour augmenter la protection des produits du bois d'ingĂ©nierie contre le feu. L'Ă©tude vise plus spĂ©cifiquement Ă l'identification des revĂȘtements intumescents commerciaux efficaces, l'Ă©laboration des procĂ©dures de contrĂŽle de qualitĂ© appropriĂ©es de ces revĂȘtements intumescents et l'Ă©valuation de leur comportement aux intempĂ©ries. Ă cet effet, quatre peintures intumescentes nommĂ©es ont Ă©tĂ© sĂ©lectionnĂ©es et appliquĂ©es sur les surfaces des panneaux L VL Ă trois niveaux de grammage (120g/m2 , 240g/m2 , 360g/m2 ). Afin d'amĂ©liorer leur comportement aux intempĂ©ries, une cinquiĂšme peinture a est Ă©galement appliquĂ© au-dessus des peintures intumescentes. Les masses rĂ©siduelles ainsi que les pics endothermiques des mĂ©langes (peintures/bois) obtenus Ă partir de l'analyse thermogravimĂ©trique (TGA) Ă 600°C et de l'analyse calorimĂ©trie diffĂ©rentielle (DSC) ont dĂ©montrĂ© que toutes les peintures intumescentes testĂ©es amĂ©liorent le comportement des panneaux L VL face au feu. Les revĂȘtements opaques confĂšrent aux panneaux L VL une meilleure protection que les revĂȘtements transparents. MalgrĂ© que les propriĂ©tĂ©s thermiques et le comportement vis-Ă -vis le feu montrent des amĂ©liorations substantielles, les corrĂ©lations entre les paramĂštres obtenus par les diffĂ©rents tests ne sont pas toujours fortement corrĂ©lĂ©s. Finalement, les rĂ©sultats des essais de vieillissement indiquent un bon comportement face aux intempĂ©ries des diffĂ©rentes peintures intumescentes. Cependant, les peintures opaques ont montrĂ© un meilleur excellent comportement face au vieillissement alors que celui des peintures transparentes a Ă©tĂ© plutĂŽt faible
Nodule detection in digital chest radiography: part of image background acting as pure noise
There are several factors that influence the radiologist's ability to detect a specific structure/lesion in a radiograph. Three factors that are commonly known to be of major importance are the signal itself, the system noise and the projected anatomy. The aim of this study was to determine to what extent the image background acts as pure noise for the detection of subtle lung nodules in five different regions of the chest. A receiver operating characteristic (ROC) study with five observers was conducted on two different sets of images, clinical chest X-ray images and images with a similar power spectrum as the clinical images but with a random phase spectrum, resulting in an image background containing pure noise. Simulated designer nodules with a full-width-at-fifth-maximum of 10 mm but with varying contrasts were added to the images. As a measure of the part of the image background that acts as pure noise, the ratio between the contrast needed to obtain an area under the ROC curve of 0.80 in the clinical images to that in the random-phase images was used. The ratio ranged from 0.40 (in the lateral pulmonary regions) to 0.83 (in the hilar regions) indicating that there was a large difference between different regions regarding to what extent the image background acted as pure noise; and that in the hilar regions the image background almost completely acted as pure noise for the detection of 10 mm nodule
Nodule detection in digital chest radiography: part of image background acting as pure noise
There are several factors that influence the radiologist's ability to detect a specific structure/lesion in a radiograph. Three factors that are commonly known to be of major importance are the signal itself, the system noise and the projected anatomy. The aim of this study was to determine to what extent the image background acts as pure noise for the detection of subtle lung nodules in five different regions of the chest. A receiver operating characteristic (ROC) study with five observers was conducted on two different sets of images, clinical chest X-ray images and images with a similar power spectrum as the clinical images but with a random phase spectrum, resulting in an image background containing pure noise. Simulated designer nodules with a full-width-at-fifth-maximum of 10 mm but with varying contrasts were added to the images. As a measure of the part of the image background that acts as pure noise, the ratio between the contrast needed to obtain an area under the ROC curve of 0.80 in the clinical images to that in the random-phase images was used. The ratio ranged from 0.40 (in the lateral pulmonary regions) to 0.83 (in the hilar regions) indicating that there was a large difference between different regions regarding to what extent the image background acted as pure noise. and that in the hilar regions the image background almost completely acted as pure noise for the detection of 10 turn nodules
Sex differences in adrenal cortex beta-catenin immunolocalization of the Saharan gerbil, Libyan jird (Meriones libycus, Lichtenstein, 1823)
Background: The adrenal cortex provides adequate steroidogenic responses to environmental changes. However, in desert rodents, the adrenocortical activity varies according to several factors especially sex, age, and seasonal variations. Herein, we examined the sex differences in the adrenal cortex activity and explored the involvement of sex hormones in the regulation of this function in Libyan jird Meriones libycus. Materials and methods: Twenty-four adults male and female animals weighing 109-110g were captured in the breeding season and equally assigned into control and gonadectomised groups. Animal euthanasia was performed 50 days after the gonadectomy. Adrenal gland was processed for structural and immunohistochemistry study of ÎČ-catenin, whereas plasma was used for cortisol assay. Results: The results showed that female adrenal gland weight was heavier than male and gonadectomy reduced this dimorphism. The adrenal cortex thickness was greater in the female than in the male, mainly due to significant development of the zona fasciculata. Females presented higher cell density in fasciculata and reticularis zones. The plasma cortisol was higher in females than in males. The immunolocalization of ÎČ-catenin showed that the expression was particularly glomerular in both sexes. However, in the female, the immunostaining was present in the zona reticularis while it was absent in the control male. Orchiectomy reduced zona glomerulosa cell density and induced hypertrophy of zona reticularis characterized by strong ÎČ-catenin immunoreactivity. However, ovariectomy leads to hyperplastic expansion and high ÎČ-catenin expression in the zona glomerulosa associated with zona fasciculata and reticularis hypoplasia distinguished by weak ÎČ-catenin immunostaining. Conclusions: Results indicated that sex hormones had a major role in the regulation of the Saharan gerbilâs adrenal homeostasis by modulating ÎČ-catenin signaling. Androgens seem to inhibit the Wnt ÎČ-catenin pathway and estrogens are activators of the adrenal inner zones
Capital Budgeting Sophistication and Performance
This thesis investigates the relationship between capital budgeting
sophistication and firm performance. Initially, the theoretical relationship is
analysed. The traditional financial view, predicting a positive relationship, is
presented as a starting point for the analysis. Other aspects, based on
contingency and behavioural theories, are then brought into the discussion.
These aspects shed light on the complexity of the relationship and question the
positive relationship advocated by traditional financial theory. In a second step,
a model is constructed in order to measure the relationship between capital
budgeting sophistication and performance empirically. The statistical model
used is the regression analysis. Based on theory, variables for capital budgeting
sophistication, and performance are constructed. Moreover, relevant
explanatory variables are defined. Three different definitions of capital
budgeting sophistication, ranging from simple to more complex, are used in
order to be able to measure whether the choice of variable affects the findings.
For the same reason three different performance measures are used. The final
step of this thesis is to test the model constructed empirically on the Swedish
market. Due to insufficient data the model is only partially tested. The results
obtained are mostly negative and insignificant. These findings do not support
traditional financial theory
Lois de Pareto et estimation de l'intervalle de prevision de la valeur extreme
SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
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