A model of continuous-time insider trading in which a risk-neutral in-sider possesses two imperfect correlated signals of a risky asset is studied.By conditional expectation theory and filtering theory,we first establ...A model of continuous-time insider trading in which a risk-neutral in-sider possesses two imperfect correlated signals of a risky asset is studied.By conditional expectation theory and filtering theory,we first establish three lemmas:normal corre-lation,equivalent pricing and equivalent profit,which can guarantee to turn our model into a model with insider knowing full information.Then we investigate the impact of the two correlated signals on the market equilibrium consisting of optimal insider trading strategy and semi-strong pricing rule.It shows that in the equilibrium,(1)the market depth is constant over time;(2)if the two noisy signals are not linerly correlated,then all private information of the insider is incorporated into prices in the end while the whole information on the asset value can not incorporated into prices in the end;(3)if the two noisy signals are linear correlated such that the insider can infer the whole information of the asset value,then our model turns into a model with insider knowing full information;(4)if the two noisy signals are the same then the total ex ant profit of the insider is increasing with the noise decreasing,while down to O as the noise going up to infinity;(5)if the two noisy signals are not linear correlated then with one noisy signal fixed,the total ex ante profit of the insider is single-peaked with a unique minimum with respect to the other noisy signal value,and furthermore as the noisy value going to O it gets its maximum,the profit in the case that the real value is observed.展开更多
Wavefield separation of multicomponent seismic data to image subsurface structures can be realized in either the space domain or the wavenumber domain. However, as the particle velocity components used in the wavenumb...Wavefield separation of multicomponent seismic data to image subsurface structures can be realized in either the space domain or the wavenumber domain. However, as the particle velocity components used in the wavenumber-domain wavefield separation are not defined at the same grid point with the staggered-grid finite-difference method for elastic wavefield simulation, we propose the wavenumber-domain interpolation method to estimate the required values at the common grid points prior to the wavenumber-domain true-amplitude wavefield separation. Moreover, numerical experiments show that the wavenumber-domain interpolation method has high interpolation accuracy and the trueamplitude wavefield separation method shows good amplitude preservation. The application of the proposed methodology to elastic reverse-time migration can obtain good amplitudepreserved images even in the case of some velocity error.展开更多
By using measures of Markov type, we proved that under the finite intersection property, multifractal decomposition still hold for a large class of recursive fractals which allow appropriate overlapping.
The effect of temperature on the life history characteristics of amictic females (AF), unfertilized mictic females (UMF) and fertilized mictic females (FMF) in Brachionus calyciflorus was studied with replicated indiv...The effect of temperature on the life history characteristics of amictic females (AF), unfertilized mictic females (UMF) and fertilized mictic females (FMF) in Brachionus calyciflorus was studied with replicated individual cultures at 20℃,25℃ and 30℃, and with algae Scenedesmus obliquus for their food. There were highly significant effects of both temperature and female type, independently and interactively, on the duration of juvenile and post-reproduction periods, and the number of eggs produced by the rotifer per life cycle. Among all the temperature-female type combinations, all the juvenile periods of FMF, and the post-reproduction periods of UMF and FMF at 20℃, were the longest, and the number of eggs produced by an UMF at 30℃ was the highest. There were highly significant effects of both temperature and female type on the duration of the reproduction period, but no clear correlation was observed between temperature and female type. The reproduction period of AF was longer than that of UMF and FMF. Only temperature influenced significantly the mean life-span of the three types of females. The duration of juvenile, reproduction and post-reproduction periods as well as the life-span of the three types of females were all reduced very significantly with rise of temperature, but the rates of reduction varied with female type. Among the three types of females, the number of eggs produced per life cycle by an UMF was the highest, and that of a FMF was the lowest. A significant relationship between the number of eggs produced per life cycle and temperature was observed only in the UMF.展开更多
It is noted that any variation in operating conditions has a considerable effect on the tire/road interaction. Furthermore,choosing a range of proper values for carcass stiffness is very essential for both tire safety...It is noted that any variation in operating conditions has a considerable effect on the tire/road interaction. Furthermore,choosing a range of proper values for carcass stiffness is very essential for both tire safety and effective driving action. In this work,an elaborated 3D model fully compliant with the geometrical size of radial tire 185/60 R15 is worked up, for evaluating the effects of components properties and working conditions on deformation and stress/strain fields created inside the tire. For the simulation, the tire structure is assumed to be composed of tread, carcass ply, and bead. The mechanical behavior of rubber as main component of tire is described by Mooney-Rivlin material model. The comparison of the obtained results and laboratory tests demonstrates the validity and high accuracy of analysis.展开更多
In order to investigate the effect of the use of battery electric vehicles on traffic dynamics,the valid paths of electric battery vehicles are defined and a check-based method is proposed to obtain them.Then,assuming...In order to investigate the effect of the use of battery electric vehicles on traffic dynamics,the valid paths of electric battery vehicles are defined and a check-based method is proposed to obtain them.Then,assuming that travelers only focus on their past travel experience,a day-to-day traffic assignment model is established based on reinforcement learning and bounded rationality.In the proposed model,the Bush-Mosteller model,a reinforcement learning model,is modified to calculate path choice probability according to bounded rationality.The modified model updates the path choice probability only if the gap between expected travel time and perceived travel time is beyond the cognitive threshold.Numerical experiments validate the effectiveness of the model and show that traffic flows can converge to the equilibrium in any case of cognitive thresholds and penetration rates of battery electric vehicles.The cognitive threshold has a positive influence on the variation of traffic flows while it has a negative influence on the differences between traffic flows.The adaptation of battery electric vehicles leads to the poor performance of the traffic system.展开更多
The systematical and scalable frameworks were provided for estimating the blocking probabilities under asynchronous traffic in optical burst switching(OBS) nodes with limited wavelength conversion capability(LWCC) . T...The systematical and scalable frameworks were provided for estimating the blocking probabilities under asynchronous traffic in optical burst switching(OBS) nodes with limited wavelength conversion capability(LWCC) . The relevant system architectures of limited range and limited number of wavelength converters(WCs) deployed by a share-per-fiber(SPF) mode were developed,and the novel theoretical analysis of node blocking probability was derived by combining the calculation of discouraged arrival rate in a birth-death process and two-dimensional Markov chain model of SPF. The simulation results on single node performance verify the accuracy and effectiveness of the analysis models. Under most scenarios,it is difficult to distinguish the plots generated by the analysis and simulation. As the conversion degree increases,the accuracy of the analysis model worsens slightly. However,the utmost error on burst loss probability is far less than one order of magnitude and hence,still allows for an accurate estimate. Some results are of actual significance to the construction of next-generation commercial OBS backbones.展开更多
The recently improved finite order BFT Hamiltonian embedding method is applied to the two dimensional chiral bosons in non-commutative space. It is then systematically converted to a first class constraint model. Perf...The recently improved finite order BFT Hamiltonian embedding method is applied to the two dimensional chiral bosons in non-commutative space. It is then systematically converted to a first class constraint model. Performing the momentum integrations, the corresponding fully gauge symmetry Lagrangian as well as its partition function in phase space are obtained.展开更多
The nonadiabatic dynamics of methyl nitrate(CH_(3)ONO_(2))is studied with the on-the-fy trajectory surface hopping dynamics at the ADC(2)level.The results confirmed the existence of the ultrafast nonadiabatic decay to...The nonadiabatic dynamics of methyl nitrate(CH_(3)ONO_(2))is studied with the on-the-fy trajectory surface hopping dynamics at the ADC(2)level.The results confirmed the existence of the ultrafast nonadiabatic decay to the electronic ground state.When the dynamics starts from S_(1) and S_(2),the photoproducts are CH_(3)O+NO_(2),consistent with previous results obtained from the experimental studies and theoretical dynamics simulations at more accurate XMS-CASPT2 level.The photolysis products are CH_(3)O+NO_(2) at the ADC(2)level when the dynamics starts from S3,while different photolysis products were obtained in previous experimental and theoretical works.These results demonstrate that the ADC(2)method may still be useful for treating the photolysis mechanism of CH_(3)ONO_(2) at the long-wavelength UV excitation,while great caution should be paid due to its inaccurate performance in the description of the photolysis dynamics at the short-wavelength UV excitation.This gives valuable information to access the accuracy when other alkyl nitrates are treated at the ADC(2)level.展开更多
The IASB stated that in the review of the conceptual framework, if measurement uncertainty is very high, a measurement basis different from fair value may provide more appropriate information. Level 3 fair value measu...The IASB stated that in the review of the conceptual framework, if measurement uncertainty is very high, a measurement basis different from fair value may provide more appropriate information. Level 3 fair value measurements are inappropriate for areas (called "Level 4" by the author) in which models are not formulated and that have material uncertainty in measurement. The purpose of this paper is to elucidate "measurement uncertainty", which impacts "faithful representation" in fair value measurement, from the perspective of "verifiability". To do so, it will employ a conceptual examination of the limits of Level 3 fair value measurement based on IFRS 13 (Fair Value Measurement). While taking into consideration recent discussions on reviewing conceptual framework, the author will reorganize the conceptual categories of verifiability (i.e., clarification of the "reasonable verifiability" categories) to underpin the fact that material uncertainties in measurement have obstructed constructing faithful representation. In addition, the author will discuss the problem that the dichotomy of direct and indirect found in IASB is not accurate enough to fully understand the concept of verifiability. In this context, the author will also suggest that the concept of verifiability, reorganized through "reasonable verifiability", can satisfy the requirements for constructing faithful representation.展开更多
A number of research studies have dealt with the relationship between diversity and effectiveness of corporate boards. The present paper makes an attempt to provide an international perspective on diversity and effect...A number of research studies have dealt with the relationship between diversity and effectiveness of corporate boards. The present paper makes an attempt to provide an international perspective on diversity and effectiveness of corporate boards and examines such relationship in detail in the case of India. The paper presents the theory relating to diversity and board effectiveness with particular reference to women on boards. The position of diversity as related to the boards of National Stock Exchange (NSE) listed 511 companies and the 245 state-owned enterprises (SOEs) by the Government of India (GoI) is reflected in the paper. It then examines gender diversity specifically in the case of India and Singapore. Drawing from the evidence of diversity in the case of global companies, it offers the rationale for making boards global in composition and character. The paper highlights an interestiiag issue: whether the boards should have younger or veteran members? This follows a discussion on diversity of boards in terms of skills, age, and personalities. Finally, the paper makes suggestions for balance boards to enhance their effectiveness and brings out lessons for the corporate organizations to promote diversity of their boards.展开更多
In the Greater Casablanca, road transport is the second largest emissions source of gaseous pollutants and particles after the industry [ 1 ]. The emitters are mobile and include different categories of vehicles in ci...In the Greater Casablanca, road transport is the second largest emissions source of gaseous pollutants and particles after the industry [ 1 ]. The emitters are mobile and include different categories of vehicles in circulation, in the road network of the region [2]. Air emissions from road transport considered in this study are the exhaust emissions from combustion of fuel during vehicle movement. This is mainly SO2 (sulfur dioxide), NOx (nitrogen oxides), CO (carbon monoxide), CO2 (carbon dioxide), SP (suspended particulate) [3], VOC (volatile organic compounds), benzene, lead Pb and cadmium. These emissions depend mainly on the technology of the vehicle (type, fuel, engine size, and age), the vehicle speed, the engine temperature and ambient temperature [4].展开更多
The authors propose a new "three-layer" conceptual model for the air-sea exchange of organic gases, which includes a dynamic surface microlayer with photochemical and biological processes. A parameterization...The authors propose a new "three-layer" conceptual model for the air-sea exchange of organic gases, which includes a dynamic surface microlayer with photochemical and biological processes. A parameterization of this three-layer model is presented, which was used to calculate the air-sea fluxes of acetone over the Pacific Ocean. The air-sea fluxes of acetone calculated by the three-layer model are in the same direction but possess half the magnitude of the fluxes calculated by the traditional two-layer model in the absence of photochemical and biological processes. However, photochemical and biological processes impacting acetone in the microlayer can greatly vary the calculated fluxes in the three-layer model, even reversing their direction under favorable conditions. Our model may help explain the discrepancies between measured and calculated acetone fluxes in previous studies. More measurements are needed to validate our conceptual model and provide constraints on the model parameters.展开更多
Traffic sector presents a major contributor to air pollution in Palestine. This has been maximized as Israeli closure of major roads resulted in major congestion in most of Palestinian cities in West Bank, which cause...Traffic sector presents a major contributor to air pollution in Palestine. This has been maximized as Israeli closure of major roads resulted in major congestion in most of Palestinian cities in West Bank, which causes high emissions of exhaust gases, such as carbon monoxide (CO). nitrogen oxides (NOx). particulate matters (PM), volatile organic compounds (VOCs) and sulphur dioxide (SO2). In order that traffic induced pollution can be assessed in Palestine. in this paper, an approach is presented by which the traffic emissions can be estimated relying on the emission factors as input together with vehicle types, annual traveled distance, etc.. The outcomes cover the emission from the various types of vehicles in West Bank.展开更多
Infinitesimal prolongation theorem is extended from sequences to nets based on κ-saturated nonstandard model. As its an application, a main property about topology of uniform convergence is proved. The proof is much ...Infinitesimal prolongation theorem is extended from sequences to nets based on κ-saturated nonstandard model. As its an application, a main property about topology of uniform convergence is proved. The proof is much simpler than it was, meanwhile the nonstandard characteristics of convergence with respect to u.c. topology is given.展开更多
This preliminary study investigates the relationship between lexical richness and communicative effectiveness in placement essays for graduate students whose first language (L1) is Chinese. Lexical richness is measure...This preliminary study investigates the relationship between lexical richness and communicative effectiveness in placement essays for graduate students whose first language (L1) is Chinese. Lexical richness is measured with Nation's web-based vocabulary profiler (Cobb, undated) software, and communicative effectiveness is scored by multiple raters. The structure of the study, lexical data compile review, results analysis, and teaching implications will be discussed. The study indicates that lexical richness needs to be taken into account in scoring the quality of writing. However, further investigation and analysis still need to be developed and discussed on the ongoing study.展开更多
We give a new proof of Wu's theorem on vortex sheets by using WI'p estimate for the elliptic equation of divergence form with partially BMO coitlcients and Lp boundedness of commutators of Calder6n- Zygmund operators.
The recently proposed weak form quadrature element method (QEM) is applied to flexural and vibrational analysis of thin plates The integrals involved in the variational description of a thin plate are evaluated by a...The recently proposed weak form quadrature element method (QEM) is applied to flexural and vibrational analysis of thin plates The integrals involved in the variational description of a thin plate are evaluated by an efficient numerical scheme and the par- tial derivatives at the integration sampling points are then approximated using differential quadrature analogs. Neither the grid pattern nor the number of nodes is fixed, being adjustable according to convergence need. The C~ continuity conditions char- acterizing the thin plate theory are discussed and the robustness of the weak form quadrature element for thin plates against shape distortion is examined. Examples are presented and comparisons with analytical solutions and the results of the finite element method are made to demonstrate the convergence and computational efficiency of the weak form quadrature element method. It is shown that the present formulation is applicable to thin plates with varying thickness as well as uniform plates.展开更多
The self-affine measure μM,D associated with an expanding matrix M ∈ Mn(Z) and a finite digit set D ? Znis uniquely determined by the self-affine identity with equal weight. The set of orthogonal exponential functio...The self-affine measure μM,D associated with an expanding matrix M ∈ Mn(Z) and a finite digit set D ? Znis uniquely determined by the self-affine identity with equal weight. The set of orthogonal exponential functions E(Λ) := {e2πiλ,x : λ∈Λ} in the Hilbert space L2(μM,D) is simply called μM,D-orthogonal exponentials. We consider in this paper the finiteness of μM,D-orthogonality. A necessary and sufficient condition is obtained for the set E(Λ) to be a finite μM,D-orthogonal exponentials. The research here is closely connected with the non-spectrality of self-affine measures.展开更多
文摘A model of continuous-time insider trading in which a risk-neutral in-sider possesses two imperfect correlated signals of a risky asset is studied.By conditional expectation theory and filtering theory,we first establish three lemmas:normal corre-lation,equivalent pricing and equivalent profit,which can guarantee to turn our model into a model with insider knowing full information.Then we investigate the impact of the two correlated signals on the market equilibrium consisting of optimal insider trading strategy and semi-strong pricing rule.It shows that in the equilibrium,(1)the market depth is constant over time;(2)if the two noisy signals are not linerly correlated,then all private information of the insider is incorporated into prices in the end while the whole information on the asset value can not incorporated into prices in the end;(3)if the two noisy signals are linear correlated such that the insider can infer the whole information of the asset value,then our model turns into a model with insider knowing full information;(4)if the two noisy signals are the same then the total ex ant profit of the insider is increasing with the noise decreasing,while down to O as the noise going up to infinity;(5)if the two noisy signals are not linear correlated then with one noisy signal fixed,the total ex ante profit of the insider is single-peaked with a unique minimum with respect to the other noisy signal value,and furthermore as the noisy value going to O it gets its maximum,the profit in the case that the real value is observed.
基金supported by the National Science Foundation of China(No.41174100)the Large-scale Oil and Gas Field and Coalbed Methane Development Major Projects(No.2011ZX05019-008-08)the China National Petroleum Corporation(No.2014A-3609)
文摘Wavefield separation of multicomponent seismic data to image subsurface structures can be realized in either the space domain or the wavenumber domain. However, as the particle velocity components used in the wavenumber-domain wavefield separation are not defined at the same grid point with the staggered-grid finite-difference method for elastic wavefield simulation, we propose the wavenumber-domain interpolation method to estimate the required values at the common grid points prior to the wavenumber-domain true-amplitude wavefield separation. Moreover, numerical experiments show that the wavenumber-domain interpolation method has high interpolation accuracy and the trueamplitude wavefield separation method shows good amplitude preservation. The application of the proposed methodology to elastic reverse-time migration can obtain good amplitudepreserved images even in the case of some velocity error.
文摘By using measures of Markov type, we proved that under the finite intersection property, multifractal decomposition still hold for a large class of recursive fractals which allow appropriate overlapping.
基金NSFC (No .3 9870 15 8) ,NaturalScienceFoundationofAnhuiProvince (No .10 0 3 3 0 No .0 42 416)andtheExcellentYouthFoundation (No .0 40 43 0 5 0 )
文摘The effect of temperature on the life history characteristics of amictic females (AF), unfertilized mictic females (UMF) and fertilized mictic females (FMF) in Brachionus calyciflorus was studied with replicated individual cultures at 20℃,25℃ and 30℃, and with algae Scenedesmus obliquus for their food. There were highly significant effects of both temperature and female type, independently and interactively, on the duration of juvenile and post-reproduction periods, and the number of eggs produced by the rotifer per life cycle. Among all the temperature-female type combinations, all the juvenile periods of FMF, and the post-reproduction periods of UMF and FMF at 20℃, were the longest, and the number of eggs produced by an UMF at 30℃ was the highest. There were highly significant effects of both temperature and female type on the duration of the reproduction period, but no clear correlation was observed between temperature and female type. The reproduction period of AF was longer than that of UMF and FMF. Only temperature influenced significantly the mean life-span of the three types of females. The duration of juvenile, reproduction and post-reproduction periods as well as the life-span of the three types of females were all reduced very significantly with rise of temperature, but the rates of reduction varied with female type. Among the three types of females, the number of eggs produced per life cycle by an UMF was the highest, and that of a FMF was the lowest. A significant relationship between the number of eggs produced per life cycle and temperature was observed only in the UMF.
文摘It is noted that any variation in operating conditions has a considerable effect on the tire/road interaction. Furthermore,choosing a range of proper values for carcass stiffness is very essential for both tire safety and effective driving action. In this work,an elaborated 3D model fully compliant with the geometrical size of radial tire 185/60 R15 is worked up, for evaluating the effects of components properties and working conditions on deformation and stress/strain fields created inside the tire. For the simulation, the tire structure is assumed to be composed of tread, carcass ply, and bead. The mechanical behavior of rubber as main component of tire is described by Mooney-Rivlin material model. The comparison of the obtained results and laboratory tests demonstrates the validity and high accuracy of analysis.
基金The National Natural Science Foundation of China(No.51478110)Postgraduate Research & Practice Innovation Program of Jiangsu Province(No.KYCX18_0139)
文摘In order to investigate the effect of the use of battery electric vehicles on traffic dynamics,the valid paths of electric battery vehicles are defined and a check-based method is proposed to obtain them.Then,assuming that travelers only focus on their past travel experience,a day-to-day traffic assignment model is established based on reinforcement learning and bounded rationality.In the proposed model,the Bush-Mosteller model,a reinforcement learning model,is modified to calculate path choice probability according to bounded rationality.The modified model updates the path choice probability only if the gap between expected travel time and perceived travel time is beyond the cognitive threshold.Numerical experiments validate the effectiveness of the model and show that traffic flows can converge to the equilibrium in any case of cognitive thresholds and penetration rates of battery electric vehicles.The cognitive threshold has a positive influence on the variation of traffic flows while it has a negative influence on the differences between traffic flows.The adaptation of battery electric vehicles leads to the poor performance of the traffic system.
基金Project(60632010) supported by the National Natural Science Foundation of China
文摘The systematical and scalable frameworks were provided for estimating the blocking probabilities under asynchronous traffic in optical burst switching(OBS) nodes with limited wavelength conversion capability(LWCC) . The relevant system architectures of limited range and limited number of wavelength converters(WCs) deployed by a share-per-fiber(SPF) mode were developed,and the novel theoretical analysis of node blocking probability was derived by combining the calculation of discouraged arrival rate in a birth-death process and two-dimensional Markov chain model of SPF. The simulation results on single node performance verify the accuracy and effectiveness of the analysis models. Under most scenarios,it is difficult to distinguish the plots generated by the analysis and simulation. As the conversion degree increases,the accuracy of the analysis model worsens slightly. However,the utmost error on burst loss probability is far less than one order of magnitude and hence,still allows for an accurate estimate. Some results are of actual significance to the construction of next-generation commercial OBS backbones.
文摘The recently improved finite order BFT Hamiltonian embedding method is applied to the two dimensional chiral bosons in non-commutative space. It is then systematically converted to a first class constraint model. Performing the momentum integrations, the corresponding fully gauge symmetry Lagrangian as well as its partition function in phase space are obtained.
基金supported by the National Natural Science Foundation of China(No.21933011,No.21873112)。
文摘The nonadiabatic dynamics of methyl nitrate(CH_(3)ONO_(2))is studied with the on-the-fy trajectory surface hopping dynamics at the ADC(2)level.The results confirmed the existence of the ultrafast nonadiabatic decay to the electronic ground state.When the dynamics starts from S_(1) and S_(2),the photoproducts are CH_(3)O+NO_(2),consistent with previous results obtained from the experimental studies and theoretical dynamics simulations at more accurate XMS-CASPT2 level.The photolysis products are CH_(3)O+NO_(2) at the ADC(2)level when the dynamics starts from S3,while different photolysis products were obtained in previous experimental and theoretical works.These results demonstrate that the ADC(2)method may still be useful for treating the photolysis mechanism of CH_(3)ONO_(2) at the long-wavelength UV excitation,while great caution should be paid due to its inaccurate performance in the description of the photolysis dynamics at the short-wavelength UV excitation.This gives valuable information to access the accuracy when other alkyl nitrates are treated at the ADC(2)level.
文摘The IASB stated that in the review of the conceptual framework, if measurement uncertainty is very high, a measurement basis different from fair value may provide more appropriate information. Level 3 fair value measurements are inappropriate for areas (called "Level 4" by the author) in which models are not formulated and that have material uncertainty in measurement. The purpose of this paper is to elucidate "measurement uncertainty", which impacts "faithful representation" in fair value measurement, from the perspective of "verifiability". To do so, it will employ a conceptual examination of the limits of Level 3 fair value measurement based on IFRS 13 (Fair Value Measurement). While taking into consideration recent discussions on reviewing conceptual framework, the author will reorganize the conceptual categories of verifiability (i.e., clarification of the "reasonable verifiability" categories) to underpin the fact that material uncertainties in measurement have obstructed constructing faithful representation. In addition, the author will discuss the problem that the dichotomy of direct and indirect found in IASB is not accurate enough to fully understand the concept of verifiability. In this context, the author will also suggest that the concept of verifiability, reorganized through "reasonable verifiability", can satisfy the requirements for constructing faithful representation.
文摘A number of research studies have dealt with the relationship between diversity and effectiveness of corporate boards. The present paper makes an attempt to provide an international perspective on diversity and effectiveness of corporate boards and examines such relationship in detail in the case of India. The paper presents the theory relating to diversity and board effectiveness with particular reference to women on boards. The position of diversity as related to the boards of National Stock Exchange (NSE) listed 511 companies and the 245 state-owned enterprises (SOEs) by the Government of India (GoI) is reflected in the paper. It then examines gender diversity specifically in the case of India and Singapore. Drawing from the evidence of diversity in the case of global companies, it offers the rationale for making boards global in composition and character. The paper highlights an interestiiag issue: whether the boards should have younger or veteran members? This follows a discussion on diversity of boards in terms of skills, age, and personalities. Finally, the paper makes suggestions for balance boards to enhance their effectiveness and brings out lessons for the corporate organizations to promote diversity of their boards.
文摘In the Greater Casablanca, road transport is the second largest emissions source of gaseous pollutants and particles after the industry [ 1 ]. The emitters are mobile and include different categories of vehicles in circulation, in the road network of the region [2]. Air emissions from road transport considered in this study are the exhaust emissions from combustion of fuel during vehicle movement. This is mainly SO2 (sulfur dioxide), NOx (nitrogen oxides), CO (carbon monoxide), CO2 (carbon dioxide), SP (suspended particulate) [3], VOC (volatile organic compounds), benzene, lead Pb and cadmium. These emissions depend mainly on the technology of the vehicle (type, fuel, engine size, and age), the vehicle speed, the engine temperature and ambient temperature [4].
基金funded by the National Natural Science Foundation of China (Grant No. 41222035)
文摘The authors propose a new "three-layer" conceptual model for the air-sea exchange of organic gases, which includes a dynamic surface microlayer with photochemical and biological processes. A parameterization of this three-layer model is presented, which was used to calculate the air-sea fluxes of acetone over the Pacific Ocean. The air-sea fluxes of acetone calculated by the three-layer model are in the same direction but possess half the magnitude of the fluxes calculated by the traditional two-layer model in the absence of photochemical and biological processes. However, photochemical and biological processes impacting acetone in the microlayer can greatly vary the calculated fluxes in the three-layer model, even reversing their direction under favorable conditions. Our model may help explain the discrepancies between measured and calculated acetone fluxes in previous studies. More measurements are needed to validate our conceptual model and provide constraints on the model parameters.
文摘Traffic sector presents a major contributor to air pollution in Palestine. This has been maximized as Israeli closure of major roads resulted in major congestion in most of Palestinian cities in West Bank, which causes high emissions of exhaust gases, such as carbon monoxide (CO). nitrogen oxides (NOx). particulate matters (PM), volatile organic compounds (VOCs) and sulphur dioxide (SO2). In order that traffic induced pollution can be assessed in Palestine. in this paper, an approach is presented by which the traffic emissions can be estimated relying on the emission factors as input together with vehicle types, annual traveled distance, etc.. The outcomes cover the emission from the various types of vehicles in West Bank.
基金Supported by the Speaial Science Foundation of the Edneational Committee of Shaanxi Province(oojk207).
文摘Infinitesimal prolongation theorem is extended from sequences to nets based on κ-saturated nonstandard model. As its an application, a main property about topology of uniform convergence is proved. The proof is much simpler than it was, meanwhile the nonstandard characteristics of convergence with respect to u.c. topology is given.
文摘This preliminary study investigates the relationship between lexical richness and communicative effectiveness in placement essays for graduate students whose first language (L1) is Chinese. Lexical richness is measured with Nation's web-based vocabulary profiler (Cobb, undated) software, and communicative effectiveness is scored by multiple raters. The structure of the study, lexical data compile review, results analysis, and teaching implications will be discussed. The study indicates that lexical richness needs to be taken into account in scoring the quality of writing. However, further investigation and analysis still need to be developed and discussed on the ongoing study.
基金supported by National Natural Science Foundation of China (Grant Nos.10990013 and 11071007)
文摘We give a new proof of Wu's theorem on vortex sheets by using WI'p estimate for the elliptic equation of divergence form with partially BMO coitlcients and Lp boundedness of commutators of Calder6n- Zygmund operators.
基金supported by the National Natural Science Foundation of China (Grant Nos.51178247 and 50778104)the National High Technology Research and Development Program of China (Grant No.2009AA04Z401)
文摘The recently proposed weak form quadrature element method (QEM) is applied to flexural and vibrational analysis of thin plates The integrals involved in the variational description of a thin plate are evaluated by an efficient numerical scheme and the par- tial derivatives at the integration sampling points are then approximated using differential quadrature analogs. Neither the grid pattern nor the number of nodes is fixed, being adjustable according to convergence need. The C~ continuity conditions char- acterizing the thin plate theory are discussed and the robustness of the weak form quadrature element for thin plates against shape distortion is examined. Examples are presented and comparisons with analytical solutions and the results of the finite element method are made to demonstrate the convergence and computational efficiency of the weak form quadrature element method. It is shown that the present formulation is applicable to thin plates with varying thickness as well as uniform plates.
基金supported by National Natural Science Foundation of China(Grant No.11171201)the Fundamental Research Fund for the Central University(Grant No.GK201401004)
文摘The self-affine measure μM,D associated with an expanding matrix M ∈ Mn(Z) and a finite digit set D ? Znis uniquely determined by the self-affine identity with equal weight. The set of orthogonal exponential functions E(Λ) := {e2πiλ,x : λ∈Λ} in the Hilbert space L2(μM,D) is simply called μM,D-orthogonal exponentials. We consider in this paper the finiteness of μM,D-orthogonality. A necessary and sufficient condition is obtained for the set E(Λ) to be a finite μM,D-orthogonal exponentials. The research here is closely connected with the non-spectrality of self-affine measures.