Documents disponibles écrits par cet auteur

Buyer uncertainty and two-part pricing / I. P. L. Png in Management science, Vol. 56 N° 2 (Fevrier 2010) 

Public ISBD [article]  in Management science > Vol. 56 N° 2 (Fevrier 2010) . - pp. 334-342 Titre : Buyer uncertainty and two-part pricing : Theory and applications Type de document : texte imprimé Auteurs : I. P. L. Png, Auteur ; Hao Wang, Auteur Année de publication : 2010 Article en page(s) : pp. 334-342 Note générale : Management Langues : Anglais (eng) Mots-clés : Pricing  Demand  uncertainty  Insurance  Risk  aversion Index. décimale : 658 Organisation des entreprises. Techniques du commerce Résumé : We consider two-part pricing of a service offered to risk-averse buyers subject to demand uncertainty. Buyers subscribe to the contract before resolution of the uncertainty. Sellers set two-part prices that trade off between insuring buyers against the uncertainty and the ex post deadweight loss from inefficient usage. If marginal and total benefits from the service are positively correlated (a sufficient condition is that the uncertainty not directly affect the buyer benefit), the usage charge should be set above the marginal cost of the service. If marginal and total benefits are negatively correlated, the usage charge should be set below the marginal cost. These results apply whether the seller has market power or is subject to competition. The difference between the profit-maximizing usage charge and marginal cost increases with buyer risk aversion. Our results can be extended to the case of the seller being more risk averse than the buyers. We discuss applications to pricing of beach and ski resorts, lines of credit, utility computing, and government services. DEWEY : 658 ISSN : 0025-1909 En ligne : http://mansci.journal.informs.org/content/56/2.toc [article] Buyer uncertainty and two-part pricing : Theory and applications [texte imprimé] / I. P. L. Png, Auteur ; Hao Wang, Auteur . - 2010 . - pp. 334-342. Management Langues : Anglais (eng) in Management science > Vol. 56 N° 2 (Fevrier 2010) . - pp. 334-342 Mots-clés : Pricing  Demand  uncertainty  Insurance  Risk  aversion Index. décimale : 658 Organisation des entreprises. Techniques du commerce Résumé : We consider two-part pricing of a service offered to risk-averse buyers subject to demand uncertainty. Buyers subscribe to the contract before resolution of the uncertainty. Sellers set two-part prices that trade off between insuring buyers against the uncertainty and the ex post deadweight loss from inefficient usage. If marginal and total benefits from the service are positively correlated (a sufficient condition is that the uncertainty not directly affect the buyer benefit), the usage charge should be set above the marginal cost of the service. If marginal and total benefits are negatively correlated, the usage charge should be set below the marginal cost. These results apply whether the seller has market power or is subject to competition. The difference between the profit-maximizing usage charge and marginal cost increases with buyer risk aversion. Our results can be extended to the case of the seller being more risk averse than the buyers. We discuss applications to pricing of beach and ski resorts, lines of credit, utility computing, and government services. DEWEY : 658 ISSN : 0025-1909 En ligne : http://mansci.journal.informs.org/content/56/2.toc

Enrichment and purification of total flavonoid C - glycosides from abrus mollis extracts with macroporous resins / Huibin Du in Industrial & engineering chemistry research, Vol. 51 N° 21 (Mai 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7349-7354 Titre : Enrichment and purification of total flavonoid C - glycosides from abrus mollis extracts with macroporous resins Type de document : texte imprimé Auteurs : Huibin Du, Auteur ; Hao Wang, Auteur ; Jia Yu, Auteur Année de publication : 2012 Article en page(s) : pp. 7349-7354 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Macroporosity  Extract  Purification Résumé : In the present study, the performance and separation characteristics of six macroporous resins for the enrichment and purification of total flavonoid C-glycosides (vicenin-2, 1; isoschaftoside, 2; schaftoside, 3) from Abrus mollis extracts have been evaluated. The adsorption and desorption properties of total flavonoid C-glycosides were studied on macroporous resins, including HPD-100, HPD-450, AB-8, HPD-600, DA-201, and HPD-417. According to the results, HPD-100 resin showed the best adsorption and desorption capacity for these three flavonoid C-glycosides among six resins. Adsorption isotherms were constructed on HPD-100 resin and fitted well to the Langmuir (R2 > 0.99) and Freundlich (R2 > 0.89, 0.1 < 1/n < 0.5) models. After the treatment with gradient elution on HPD-100 resin packed chromatography column, the contents of the flavonoid C-glycosides (1, 2, and 3) increased from 2.05, 2.90, and 2.30% in the extracts to 14.3, 21.9, and 15.1%, respectively, in the product. The recoveries of compounds 1, 2, and 3 were 83.8, 90.3, and 78.7%, respectively. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948475 [article] Enrichment and purification of total flavonoid C - glycosides from abrus mollis extracts with macroporous resins [texte imprimé] / Huibin Du, Auteur ; Hao Wang, Auteur ; Jia Yu, Auteur . - 2012 . - pp. 7349-7354. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7349-7354 Mots-clés : Macroporosity  Extract  Purification Résumé : In the present study, the performance and separation characteristics of six macroporous resins for the enrichment and purification of total flavonoid C-glycosides (vicenin-2, 1; isoschaftoside, 2; schaftoside, 3) from Abrus mollis extracts have been evaluated. The adsorption and desorption properties of total flavonoid C-glycosides were studied on macroporous resins, including HPD-100, HPD-450, AB-8, HPD-600, DA-201, and HPD-417. According to the results, HPD-100 resin showed the best adsorption and desorption capacity for these three flavonoid C-glycosides among six resins. Adsorption isotherms were constructed on HPD-100 resin and fitted well to the Langmuir (R2 > 0.99) and Freundlich (R2 > 0.89, 0.1 < 1/n < 0.5) models. After the treatment with gradient elution on HPD-100 resin packed chromatography column, the contents of the flavonoid C-glycosides (1, 2, and 3) increased from 2.05, 2.90, and 2.30% in the extracts to 14.3, 21.9, and 15.1%, respectively, in the product. The recoveries of compounds 1, 2, and 3 were 83.8, 90.3, and 78.7%, respectively. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948475

Importance of nonlinear anisotropic modeling of granular base for predicting maximum viscoelastic pavement responses under moving vehicular loading / Hao Wang in Journal of engineering mechanics, Vol. 139 N° 1 (Janvier 2013) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 139 N° 1 (Janvier 2013) . - pp.29–38. Titre : Importance of nonlinear anisotropic modeling of granular base for predicting maximum viscoelastic pavement responses under moving vehicular loading Type de document : texte imprimé Auteurs : Hao Wang, Auteur ; Al-Qadi, Imad, Auteur Année de publication : 2013 Article en page(s) : pp.29–38. Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Nonlinear  analysis  Pavement  response  Cross  anisotropic  Viscoelastic  asphalt  layer  Granular  base  modulus  Moving  load,  Finite-element  model Résumé : This paper explains the importance of using a nonlinear anisotropic three-dimensional (3D) finite-element (FE) pavement model to simulate the granular base layer and predict viscoelastic pavement responses under moving vehicular loading. The FE model was built using the general-purpose FE software ABAQUS, and a user material subroutine was developed to implement the constitutive model of granular material using a modified Newton-Raphson approach with secant stiffness. The FE model utilizes implicit dynamic analysis and simulates the vehicular loading as a moving load with 3D contact stresses at the tire-pavement interface. The analysis results indicate that it is important to consider the viscoelastic nature of the asphalt layer and the moving load for accurately capturing the nonlinear granular base modulus in the mechanistic pavement model. The modulus distribution in the granular base layer is affected not only by wheel load and pavement structure (such as asphalt layer thickness and subgrade support) but also by temperature and vehicle speed because of the viscoelastic behavior of the asphalt surface layer. Excluding the cross-anisotropic stress-dependent behavior of the granular base layer could cause significant error in predicting fatigue cracking and rutting potential in thin asphalt pavements. In addition, the model results captured the trends of field measurements at different loading and temperature conditions. ISSN : 0733-9399 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29EM.1943-7889.0000465 [article] Importance of nonlinear anisotropic modeling of granular base for predicting maximum viscoelastic pavement responses under moving vehicular loading [texte imprimé] / Hao Wang, Auteur ; Al-Qadi, Imad, Auteur . - 2013 . - pp.29–38. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 139 N° 1 (Janvier 2013) . - pp.29–38. Mots-clés : Nonlinear  analysis  Pavement  response  Cross  anisotropic  Viscoelastic  asphalt  layer  Granular  base  modulus  Moving  load,  Finite-element  model Résumé : This paper explains the importance of using a nonlinear anisotropic three-dimensional (3D) finite-element (FE) pavement model to simulate the granular base layer and predict viscoelastic pavement responses under moving vehicular loading. The FE model was built using the general-purpose FE software ABAQUS, and a user material subroutine was developed to implement the constitutive model of granular material using a modified Newton-Raphson approach with secant stiffness. The FE model utilizes implicit dynamic analysis and simulates the vehicular loading as a moving load with 3D contact stresses at the tire-pavement interface. The analysis results indicate that it is important to consider the viscoelastic nature of the asphalt layer and the moving load for accurately capturing the nonlinear granular base modulus in the mechanistic pavement model. The modulus distribution in the granular base layer is affected not only by wheel load and pavement structure (such as asphalt layer thickness and subgrade support) but also by temperature and vehicle speed because of the viscoelastic behavior of the asphalt surface layer. Excluding the cross-anisotropic stress-dependent behavior of the granular base layer could cause significant error in predicting fatigue cracking and rutting potential in thin asphalt pavements. In addition, the model results captured the trends of field measurements at different loading and temperature conditions. ISSN : 0733-9399 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29EM.1943-7889.0000465