Taking absorptive capacity effects on research spillovers into consideration, this paper focuses on the R&D investment decisions and the output decisions of labor-managed firms. Based on the general model of the cost...Taking absorptive capacity effects on research spillovers into consideration, this paper focuses on the R&D investment decisions and the output decisions of labor-managed firms. Based on the general model of the cost-reducing R&D, the strategic interactions of output and R&D investment between labor-managed firms in a duopoly are analyzed. Moreover, the impact of absorptive capacity effects on optimal output in the production stage is discussed. In the R&D stage, the impacts of absorptive capacity effects on the equilibrium R&D investment in cooperative and non-cooperative R&D are analyzed. Finally, the R&D strategy of labor-managed firms is compared with the behavior of profit-maximizing firms. The results show that equilibrium R&D investment is always higher than that in the exogenous spillover rate, which is similar to the behavior of the profit-maximizing firms. However, unlike the profit-maximizing firms, the impact of the absorptive capacity that affects the relationship between the optimal output and its own(rival' s)R&D is shown to be dependent upon a return-to-scale of the production.展开更多
An improved internetworking approach is proposed to enhance the Internet connectivity which is deteriorated due to unidirectional links and blind rebroadcasting of gateway discovery packets for mobile ad hoc networks....An improved internetworking approach is proposed to enhance the Internet connectivity which is deteriorated due to unidirectional links and blind rebroadcasting of gateway discovery packets for mobile ad hoc networks. The hybrid gateway discovery scheme that combined the advantages of a proactive and reactive gateway discovery approach is used to achieve high connectivity while keeping overhead costs low. By exchanging ad hoc on-demand distance vector (AODV) hello packet which includes additional fields named symmetric neighbor list and asymmetric neighbor list, unidirectional links are removed from route computation and broadcast storm can also be relieved simultaneously. Performance results using ns-2 simulations, under varying numbers of unidirectional links and node speeds, show that this improved Internet connectivity approach can provide better performance than others.展开更多
As an important factor in evaluating service,QoS(Quality of Service) has drawn more and more concerns with the rapid increasing of Web services. However,due to the great volatility of services in Mobile Internet envir...As an important factor in evaluating service,QoS(Quality of Service) has drawn more and more concerns with the rapid increasing of Web services. However,due to the great volatility of services in Mobile Internet environments,such as internet of vehicles,Web services often do not work as announced and thus cause unacceptable problems. QoS prediction can avoid failure before it takes place,which is considered a more effective way to assure quality. However,Current QoS prediction approaches neither consider the highly dynamic of Web services,nor maintain good prediction performance all the time. Consequently we propose a novel Bayesian combinational model to predict QoS by continuously adjusting credit values of the basic models so as to keep good prediction accuracy. QoS attributes such as response time,throughput and reliability are used to validate the proposed model. Experimental results show that the model can provide stable prediction results in Mobile Internet environments.展开更多
Mountainous areas have been long recognized as particularly important for the planet and sustainable mountain development is a global priority. In order to improve the socioeconomic development perspectives of mountai...Mountainous areas have been long recognized as particularly important for the planet and sustainable mountain development is a global priority. In order to improve the socioeconomic development perspectives of mountain societies, efficient and well-targeted energy strategies should be formed. An important step towards this direction is adequate understanding of local conditions and specific features that affect energy sector. This procedure allows the inclusion of "locality" in energy planning and so, decentralized energy production is facilitated. The present study attempts to determine the particular energy identity of mountainous areas. Greece, which is the second most mountainous country in the EU, has been selected as a case study. Essential features of the mountainous space have been selected, namely altitude, inclination, remoteness, lack of productive activities, old buildings/vernacular architecture, in order to explore their interrelation with the energy sector. Based on literature review and research findings the interaction between mountainous character and energy is outlined. Therefore, a framework of the characteristics of mountain energy identity is composed, which can provide support to the formation of specialized energy policy for mountainous areas. Some of the main findings of the present study include the significantly increased energy loads of mountainous areas, the abundance of renewable energy potential in high – altitude areas, the vulnerability of mountain societies to energy poverty and the difficulties in sitting energy projects in the restricted usable space of mountains. Since the literature regarding mountains and energy is rather poor the present paper aspires to be a step towards highlighting the importance of energy issues for mountain areas and societies. By determining the features of mountain energy identity energy planning in high – altitude areas and so, helping make energy planning more effective, such research works can be parts of sustainable development strategies for mountainous areas.展开更多
The article presents results inducing pollution of the air which is through traffic automotive vehicles. of research of diesel engines working the exhaust gas smokiness against its in city agglomeration working genera...The article presents results inducing pollution of the air which is through traffic automotive vehicles. of research of diesel engines working the exhaust gas smokiness against its in city agglomeration working general pollution in two urban Also the study of the factors agglomerations with similar展开更多
With the rapid development of wireless transmission technologies and the proliferation of mobile terminals, the mobile Internet has experienced exponential growth in recent years. However, at the same time, it is also...With the rapid development of wireless transmission technologies and the proliferation of mobile terminals, the mobile Internet has experienced exponential growth in recent years. However, at the same time, it is also facing more challenges, particularly regarding bandwidth, address space, security, mobility, and energy. In this article, we analyse the five abovementioned challenges and then survey related technology trends. We also describe the progress of architecture research aimed at the future mobile Internet. We reach the conclusion that a single technology cannot solve all the problems of mobile Internet, and future research should focus more on how to make architectures and technologies work together more effectively.展开更多
This study draws on sociocultural theory to explore how adult EFL learners interact with each other in learning target form in collaborative task performance. It investigates the features of scaffolding in peer collab...This study draws on sociocultural theory to explore how adult EFL learners interact with each other in learning target form in collaborative task performance. It investigates the features of scaffolding in peer collaboration in which a group of four Chinese undergraduate students are engaged in a writing task in an English enhancement course at a university in Hong Kong. The study also examines how the scaffolding categories affect the learners' production of appropriate grammatical forms. The findings advocate the presence of the teacher (or tutor) to direct learners' attention to important form-meaning connections in L2 pedagogical group activities due to the limitations of peer interaction.展开更多
Flexible wearable sensors with excellent electric response and self-powered capability have become an appealing hotspot for personal healthcare and human-machine interfaces.Here,based on triboelectric nanogenerator(TE...Flexible wearable sensors with excellent electric response and self-powered capability have become an appealing hotspot for personal healthcare and human-machine interfaces.Here,based on triboelectric nanogenerator(TENG),a flexible self-powered tactile sensor composed of micro-frustum-arrays-structured polydimethylsiloxane(PDMS)film/copper(Cu)electrodes,and poly(vinylidenefluoride-trifluoroethylene)(P(VDF-TrFE))nanofibers has been demonstrated.The TENG-based self-powered tactile sensor can generate electrical signals through the contact-separation process of two triboelectric layers under external mechanical stimuli.Due to the uniform and controllable micro-frustum-arrays structure fabricated by micro-electro-mechanical system(MEMS)process and the P(VDF-TrFE)nanofibers fabricated by electrostatic spinning,the flexible PDMS-based sensor presents high sensitivity of 2.97 V kPa^-1,stability of 40,000 cycles(no significant decay),response time of 60 ms at 1 Hz,low detection pressure of a water drop(~4 Pa,35 mg)and good linearity of 0.99231 in low pressure region.Since the PDMS film presents ultra-flexibility and excellent-biocompatibility,the sensor can be comfortably attached on human body.Furthermore,the tactile sensor can recognize various types of human body movements by the corresponding electrical signals.Therefore,the as-prepared TENGs are potential on the prospects of gesture detection,health assessment,human-machine interfaces and so on.展开更多
Characteristics of wheel-rail dynamic interaction due to the rail corrugation in a high-speed railway are analyzed based on the theory of vehicle-track coupled dynamics in this paper.Influences of the corrugation wave...Characteristics of wheel-rail dynamic interaction due to the rail corrugation in a high-speed railway are analyzed based on the theory of vehicle-track coupled dynamics in this paper.Influences of the corrugation wavelength and depth on the wheel-rail dynamic performance are investigated.The results show that,under the excitation of a measured rail corrugation,the wheel-rail dynamic interaction of high-speed railway is enhanced obviously,and the high-frequency dynamic force between wheel and rail is generated,which has an obvious impact on the vibrations of the wheelset and rail,and little effect on the vibration of the frame and carbody.If the corrugation wavelength is shorter than the sensitive wavelength,the wheel-rail vertical force will increase with the growth of the corrugation wavelength,otherwise,it will decrease.However,the wheel-rail vertical force keeps increasing with the growth of corrugation depth.Furthermore,if the corrugation wavelength is shorter than the sensitive wavelength,the wheel-rail vertical force will increase with the decrease of the running speed,otherwise,it will decrease.It is also found that the critical wavelength of corrugation increases with the growth of the corrugation depth and the running speed,and the critical depth of corrugation is nonlinearly related to the sensitive wavelength.展开更多
基金The National Natural Science Foundation of China(No.70671024)Annual Research Results in Zhejiang Federation of Humanities and Social Sciences Circles(No.08N40)
文摘Taking absorptive capacity effects on research spillovers into consideration, this paper focuses on the R&D investment decisions and the output decisions of labor-managed firms. Based on the general model of the cost-reducing R&D, the strategic interactions of output and R&D investment between labor-managed firms in a duopoly are analyzed. Moreover, the impact of absorptive capacity effects on optimal output in the production stage is discussed. In the R&D stage, the impacts of absorptive capacity effects on the equilibrium R&D investment in cooperative and non-cooperative R&D are analyzed. Finally, the R&D strategy of labor-managed firms is compared with the behavior of profit-maximizing firms. The results show that equilibrium R&D investment is always higher than that in the exogenous spillover rate, which is similar to the behavior of the profit-maximizing firms. However, unlike the profit-maximizing firms, the impact of the absorptive capacity that affects the relationship between the optimal output and its own(rival' s)R&D is shown to be dependent upon a return-to-scale of the production.
基金The National Natural Science Foundation of China(No60362001)
文摘An improved internetworking approach is proposed to enhance the Internet connectivity which is deteriorated due to unidirectional links and blind rebroadcasting of gateway discovery packets for mobile ad hoc networks. The hybrid gateway discovery scheme that combined the advantages of a proactive and reactive gateway discovery approach is used to achieve high connectivity while keeping overhead costs low. By exchanging ad hoc on-demand distance vector (AODV) hello packet which includes additional fields named symmetric neighbor list and asymmetric neighbor list, unidirectional links are removed from route computation and broadcast storm can also be relieved simultaneously. Performance results using ns-2 simulations, under varying numbers of unidirectional links and node speeds, show that this improved Internet connectivity approach can provide better performance than others.
基金supported by National Natural Science Foundation of China (61572171,61202097,61202136)Research Fund for the Doctoral Program of Higher Education of China (20120094120009)+2 种基金Fundamental Research Funds for the Central Universities of China (B15020191)the national college students innovation training program (No.201511460012)by Jiangsu Province,and key special funds of efficient utilization of water resources (No.2016YFC0402710)
文摘As an important factor in evaluating service,QoS(Quality of Service) has drawn more and more concerns with the rapid increasing of Web services. However,due to the great volatility of services in Mobile Internet environments,such as internet of vehicles,Web services often do not work as announced and thus cause unacceptable problems. QoS prediction can avoid failure before it takes place,which is considered a more effective way to assure quality. However,Current QoS prediction approaches neither consider the highly dynamic of Web services,nor maintain good prediction performance all the time. Consequently we propose a novel Bayesian combinational model to predict QoS by continuously adjusting credit values of the basic models so as to keep good prediction accuracy. QoS attributes such as response time,throughput and reliability are used to validate the proposed model. Experimental results show that the model can provide stable prediction results in Mobile Internet environments.
文摘Mountainous areas have been long recognized as particularly important for the planet and sustainable mountain development is a global priority. In order to improve the socioeconomic development perspectives of mountain societies, efficient and well-targeted energy strategies should be formed. An important step towards this direction is adequate understanding of local conditions and specific features that affect energy sector. This procedure allows the inclusion of "locality" in energy planning and so, decentralized energy production is facilitated. The present study attempts to determine the particular energy identity of mountainous areas. Greece, which is the second most mountainous country in the EU, has been selected as a case study. Essential features of the mountainous space have been selected, namely altitude, inclination, remoteness, lack of productive activities, old buildings/vernacular architecture, in order to explore their interrelation with the energy sector. Based on literature review and research findings the interaction between mountainous character and energy is outlined. Therefore, a framework of the characteristics of mountain energy identity is composed, which can provide support to the formation of specialized energy policy for mountainous areas. Some of the main findings of the present study include the significantly increased energy loads of mountainous areas, the abundance of renewable energy potential in high – altitude areas, the vulnerability of mountain societies to energy poverty and the difficulties in sitting energy projects in the restricted usable space of mountains. Since the literature regarding mountains and energy is rather poor the present paper aspires to be a step towards highlighting the importance of energy issues for mountain areas and societies. By determining the features of mountain energy identity energy planning in high – altitude areas and so, helping make energy planning more effective, such research works can be parts of sustainable development strategies for mountainous areas.
文摘The article presents results inducing pollution of the air which is through traffic automotive vehicles. of research of diesel engines working the exhaust gas smokiness against its in city agglomeration working general pollution in two urban Also the study of the factors agglomerations with similar
基金supportedin part by Sub-project "Mobile Internet Architecture and Key Technology Research" of National Core Electronic Devices,High-end Generic Chips and Basic Software (CHBS) Project "Development Strategy and Planning ofMobile Internet System Hardware and Software Technology and Service" under Grant No.2012ZX01039003Sub-project "IPv6 Application and Demonstration of Mobile Internet inCampus Environment" of National Sci-Tech Major Special Item Project "IPv6 Applicationand Demonstration of Mobile Internet" under Grant No. 2012ZX03002015-003A New Network Architecture:Address Driven Network Architecture and Technology Research and Development under Grant No. CNGI-12-03-001
文摘With the rapid development of wireless transmission technologies and the proliferation of mobile terminals, the mobile Internet has experienced exponential growth in recent years. However, at the same time, it is also facing more challenges, particularly regarding bandwidth, address space, security, mobility, and energy. In this article, we analyse the five abovementioned challenges and then survey related technology trends. We also describe the progress of architecture research aimed at the future mobile Internet. We reach the conclusion that a single technology cannot solve all the problems of mobile Internet, and future research should focus more on how to make architectures and technologies work together more effectively.
基金supported by"the Fundamental Research Funds for the Central Universities"(Project No.:1022759454)"the National Funds for Social Science"(Project No.:10BYY088)
文摘This study draws on sociocultural theory to explore how adult EFL learners interact with each other in learning target form in collaborative task performance. It investigates the features of scaffolding in peer collaboration in which a group of four Chinese undergraduate students are engaged in a writing task in an English enhancement course at a university in Hong Kong. The study also examines how the scaffolding categories affect the learners' production of appropriate grammatical forms. The findings advocate the presence of the teacher (or tutor) to direct learners' attention to important form-meaning connections in L2 pedagogical group activities due to the limitations of peer interaction.
基金financially supported by the National Natural Science Foundation of China(51605449,51675493 and51705476)the National Key R&D Program of China(2018YFF0300605)+2 种基金Shanxi “1331 Project” Key Subject Construction(1331KSC)the Applied Fundamental Research Program of Shanxi Province(201601D021070)Zhangjiakou Science and Technology Research and Development Plan of Zhangjiakou City(1811009B-10)
文摘Flexible wearable sensors with excellent electric response and self-powered capability have become an appealing hotspot for personal healthcare and human-machine interfaces.Here,based on triboelectric nanogenerator(TENG),a flexible self-powered tactile sensor composed of micro-frustum-arrays-structured polydimethylsiloxane(PDMS)film/copper(Cu)electrodes,and poly(vinylidenefluoride-trifluoroethylene)(P(VDF-TrFE))nanofibers has been demonstrated.The TENG-based self-powered tactile sensor can generate electrical signals through the contact-separation process of two triboelectric layers under external mechanical stimuli.Due to the uniform and controllable micro-frustum-arrays structure fabricated by micro-electro-mechanical system(MEMS)process and the P(VDF-TrFE)nanofibers fabricated by electrostatic spinning,the flexible PDMS-based sensor presents high sensitivity of 2.97 V kPa^-1,stability of 40,000 cycles(no significant decay),response time of 60 ms at 1 Hz,low detection pressure of a water drop(~4 Pa,35 mg)and good linearity of 0.99231 in low pressure region.Since the PDMS film presents ultra-flexibility and excellent-biocompatibility,the sensor can be comfortably attached on human body.Furthermore,the tactile sensor can recognize various types of human body movements by the corresponding electrical signals.Therefore,the as-prepared TENGs are potential on the prospects of gesture detection,health assessment,human-machine interfaces and so on.
基金supported by the National Basic Research Program of China("973"Project)(Grant Nos.2013CB036206,2013CB036205)the National Natural Science Foundation of China(Grant No.61134002)
文摘Characteristics of wheel-rail dynamic interaction due to the rail corrugation in a high-speed railway are analyzed based on the theory of vehicle-track coupled dynamics in this paper.Influences of the corrugation wavelength and depth on the wheel-rail dynamic performance are investigated.The results show that,under the excitation of a measured rail corrugation,the wheel-rail dynamic interaction of high-speed railway is enhanced obviously,and the high-frequency dynamic force between wheel and rail is generated,which has an obvious impact on the vibrations of the wheelset and rail,and little effect on the vibration of the frame and carbody.If the corrugation wavelength is shorter than the sensitive wavelength,the wheel-rail vertical force will increase with the growth of the corrugation wavelength,otherwise,it will decrease.However,the wheel-rail vertical force keeps increasing with the growth of corrugation depth.Furthermore,if the corrugation wavelength is shorter than the sensitive wavelength,the wheel-rail vertical force will increase with the decrease of the running speed,otherwise,it will decrease.It is also found that the critical wavelength of corrugation increases with the growth of the corrugation depth and the running speed,and the critical depth of corrugation is nonlinearly related to the sensitive wavelength.