共查询到20条相似文献，搜索用时 15 毫秒
1.
China is the largest solar water heater producer and market in the world. Despite the fast growth and an installed capacity that accounts for the majority of the global gross, China＇s per capita solar hot water capacity is still very low, implying a huge margin of market potential; and the recognition of the industry in the global market is handicapped by the scattered scale of production and inconsistent product quality. To ensure continued growth of China＇s solar water heating （SWH） industry, Chinese Government has established a series of national SWH standards, three national testing centers, and a certification program to lay the foundation for the development of the Golden Sun product labeling system. China General Certification Center （CGC） developed the Golden Sun product certification and labeling system on a pass/fail basis evaluating with established criteria. The system was designed to help manufacturers acclimate to explicit consistent requirements and to identify and fix the deficiencies in the design and execution of the program itself. Timely revision and integration of the national standards are recommended to accommodate the test procedures and requirements to new technologies and the evolving SWH ,market. Strict implementation of the Golden Sun certification and labeling system are suggested to avail improving the quality control and forging internationally reputable brands of Chinese solar water heating products. 相似文献
2.
Battery models are of great importance to develop portable computing systems, for whether the design of low power hardware architecture or the design of battery-aware scheduling policies. In this paper, we present a physically justified iterative computing method to illustrate the discharge, recovery and charge process of Li/Li-ion batteries. The discharge and recovery processes correspond well to an existing accurate analytical battery model： R-V-W＇s analytical model, and thus interpret this model algorithmically. Our method can also extend R-V-W＇s model easily to accommodate the charge process, The work will help the system designers to grasp the characteristics of R-V-W＇s battery model and also, enable to predict the battery behavior in the charge process in a uniform way as the discharge process and the recovery process. Experiments are performed to show the accuracy of the extended model by comparing the predicted charge times with those derived from the DUALFOIL simulations. Various profiles with different combinations of battery modes were tested, The experimental results show that the extended battery model preserves high accuracy in predicting the charge behavior. 相似文献
3.
The standardized IEEE ,802. II distributed coordination function （ DCF） provides a contention-based distributed channel access mechanism for mobile stations to share the wireless medium. However, when stations are mobile or portable units, power consumption becomes a primary issue since terminals are usually battery driven. This paper proposes an analytical model that calculates the energy efficiency of both the basic and the RTS/CTS access mechanisms of the IEEE 802. II protocol. The model is validated with simulation results using NS-2 simulation package. The effects of the network size, the average packet length, the initial contention window and maximum backoff stages on the energy efficiency of both access mechanisms are also investigated. Results show that the basic scheme has low energy efficiency at large packet length and large network size, and depends strongly on the number of stations and the backoff procedure parameters. Conversely, the RTS/CTS mechanism provides higher energy efficiency when the network size is large, and is more robust to variations in the backoff procedure parameters. 相似文献
4.
The local-world （LW） evolving network model shows a transition for the degree distribution between the exponential and power-law distributions, depending on the LW size. Cascading failures under intentional attacks in LW network models with different LW sizes were investigated using the cascading failures load model. We found that the LW size has a significant impact on the network＇s robustness against deliberate attacks. It is much easier to trigger cascading failures in LW evolving networks with a larger LW size. Therefore, to avoid cascading failures in real networks with local preferential attachment such as the Internet, the World Trade Web and the multi-agent system, the LW size should be as small as possible. 相似文献
5.
Financing constraints and corporate investment： an empirical analysis of china＇s manufacturing firms
KONG Yu WEI Feng 《重庆大学学报(英文版)》2005,4(3):170-174
With the measurement of dividend payout ratio, logistic regression index value and the firm size financing constraints, this paper investigated the investment behavior of China＇s manufacturing firms over the period from 1998 to 2003, and the relationship between financing constraints and corporate investment using the OLS regression method. The empirical evidence shows that there are certain extent financing constraints in China＇s manufacturing firms, but the results are different with different variables to measure the financing constraints. 相似文献
6.
Oyelami Olufemi Moses 《美中教育评论》2008,5(11):22-27
More recent motivational research focuses on the identification of effective techniques for enhancing instructional design and meeting the needs of diverse student populations （Wlodkowski R. J., 1981）. Learning-motivation researchers are applying some of the same theories and concepts found to be effective in industry to the development of motivational models that enhance the teaching-learning environment. One of such models is the Attention Relevance Confidence Satisfaction （ARCS） model of motivational design developed by John M. Keller （Small Ruth V., 2007）. The continuous improvement in handheld devices technologies has led to a new learning paradigm called mobile learning which involves the delivery of learning contents to learners utilizing mobile computing devices. Handheld devices, however, have constraints which limit their use for effective learning. Towards improving the effectiveness of mobile learning is a new mobile learning model proposed by Shih on which instructional designs for mobile learning can be based to facilitate mobile learning design and to achieve better mobile learning outcomes （Yushin E. Shih ＆ Dennis Mills, 2007）. Shih＇s model is based on Graphical User Interface （GUI）. This paper presents an enhanced Shih＇s model for effective mobile learning outcome in a university environment by making provision for instructional design to include online library search for both e-books and audio books using collaborative filtering algorithm to aid the search and posting and reading of testimonials about positive mobile learning outcomes so as to encourage other mobile learners. It also incorporates the use of Voice User Interface （VUI） to access the learning portal in order to overcome mobile devices interface limitations in addition to Graphical User Interface （GUI） proposed by Shih, so as to cater for the learning needs of the blind and the visually impaired. 相似文献
7.
Yong Jiang 《美中教育评论》2005,2(11):65-74
The purpose of this study was to explore the influencing and effective models of Chinese early childhood teachers＇ job satisfaction. Using a questionnaire of 317 teachers from 21 kindergartens in Shanghai, China, the present study established the influencing and effective structure model of teachers＇ job satisfaction. The results demonstrated that organizational climate and teachers＇ involvement in curriculum reform are the direct factors to affect teachers＇ job satisfaction, which is the important intermediate variable to influence on teachers＇ professional commitment, autonomy and burnout. It is also concluded that organizational climate improves teachers＇ professional commitment. What＇s more, involving in curriculum reform not only facilitates teachers＇ autonomy but also declines teachers＇ burnout. 相似文献
8.
The flooding distance is an important parameter in the design and evaluation of a routing protocol,which is related not only to the delay time in the route discovery,but also to the stability and reliability of the route.In this paper, the average flooding distance (AFD) for a mobile ad hoc network (MANET) in a random graph model was given based on the dynamic source routing (DSR) protocol.The influence of spatial reuse on the AFD was also studied.Compared with that in the model without the spatial reuse,the AFD in the model with the spatial reuse has much smaller value,when the connetivity probability between nodes in the network is small and when the number of reused times is large.This means that the route discovery with the spatial reuse is much more effective. 相似文献
9.
Sajid Sheikh Muhammad Muhammad Aurangzeb Imtiaz Tarique 《美中教育评论》2009,6(8):62-67
In this paper, the growth of the telecommunication sector in Pakistan and consequent development in the related professional education is studied. The widening gap between the telecommunication industry and associated education sector is identified. The higher educational programs in Pakistan have grown very rapidly to meet the needs of the explosive growth in the telecommunications＇ engineering sector but this growth is not in synchronization with the requirements of the industry due to non-existence of collaboration and co-operation between the two. The professional education in telecommunication in Pakistan and the higher educational degree programs are very precisely focused on producing quality graduates with refined technical and mathematical skills While the telecom sector in Pakistan is in principle a service provider and a consumer market that mainly requires engineers for operation and maintenance related activities. As such the skills imparted by the education sector are rarely utilized, which results in dissatisfaction among the telecommunications＇ engineers. A survey of both the telecommunication sector and the academia has been conducted along with detailed discussions to explore the reasons for this ever-increasing gap, ways and means to arrest this trend and future course of action for the academia and the telecom sector to develop. A study related to other emerging technical fields like computer science has also been made for the comparison. On the basis of this extensive exercise outlined above, measures have been suggested to bridge the gap between the education and the industrial needs of the telecom sector. By adopting these measures not only our education sector will become more beneficial to the industry, but the industry would also get the advantage of immense potential of young graduates and the academic research. 相似文献
10.
Eric C. K. Cheng 《美中教育评论》2011,(1):33-45
This paper aims to validate a theoretical model for developing teacher collective learning by using a quasi-experimental design, and explores the management strategies that would provide a school administrator practical steps to effectively promote collective learning in the school organization. Twenty aided secondary schools in Hong Kong were selected by cluster sampling, and 777 teachers took part in the questionnaire survey. A structural equation model was applied to identify the interrelationship of the 5 disciplines of Senge＇s （1990） learning organization model. Results showed that personal mastery and systems thinking are individual and collective level predictors respectively for teacher collective learning. Building a mental model and shared vision in a sequential order predict systems thinking. Management strategies in cultural, policy and leadership domains are recommended to school administrators who wish to promote teacher collective learning as a means of coping with the changes generated by the curriculum reform in Hong Kong. 相似文献
11.
The growth and evolution of the knowledge network in supply chain can be characterized by dynamic growth clustering and non-homogeneous degree distribution.The networks with the above characteristics are also known as scale-free networks.In this paper,the knowledge network model in supply chain is established,in which the preferential attachment mechanism based on the node strength is adopted to simulate the growth and evolution of the network.The nodes in the network have a certain preference in the choice of a knowledge partner.On the basis of the network model,the robustness of the three network models based on different preferential attachment strategies is investigated.The robustness is also referred to as tolerances when the nodes are subjected to random destruction and malicious damage.The simulation results of this study show that the improved network has higher connectivity and stability. 相似文献
12.
More and more enterprises are outsourcing activities that are neither cost efficient if done in-house nor central to their businesses. Most of the studies in outsourcing decision making focus on vendor selection. However, little research has been done about location selection, which is also a critical step in offshore service outsourcing. The purpose of this paper is to offer a new method to deal with the destination selection problem in China. We employed the additive SE-DEA model to overcome the drawbacks of traditional DEA and SE-DEA methods, and calculated the relative efficiency of 20 service outsourcing model cities （excluding Xiamen）. Based on two years of longitudinal study, we made a comparison of the 20 cities. Finally we classified the model cities by combining them with the service outsourcing ability dimension and also gave some selection suggestions and development suggestions for outsourcers＇ outsourcing service and the model cities, respectively. 相似文献
13.
Lucia Buttaro 《美中教育评论》2010,(1):62-75
This paper examines theoretical frameworks with which to study newly-immigrated mothers from China and calls for the need to make Chinese mothers become knowers and agents of knowledge. Although there are black and Chicana feminist epistemologies, currently there is no comparable discourse in the study of Chinese feminist epistemology, particularly on newly-immigrated Chinese mothers in the USA. By examining Chinese mothers＇ experiences immigrating to the United States and educating their children in the transnational context, the paper agrees that both endarkened feminist epistemology and transnational feminism cannot fully interpret and address newly-immigrated Chinese mothers＇ experiences. Drawing the research data directly from Chinese mothers, the paper describes different challenges Chinese mothers faced in immigrating and their children＇s education due to various factors, such as language, historical and cultural roots, to highlight Chinese mothers＇ various experiences in immigration and their children＇s education in the transnational context. 相似文献
14.
In order to research the feasibility of artificial neural network (ANN) in the research of eutrophication of the Bohai Bay in China, an ANN model simulating chlorophyll a, b and c concentrations, concerning temperature, dissolved oxygen, salinity, pH value, chemical oxygen demand (COD), PO43-, NO2-and NO3-factors in the Bohai Bay was presented and validated. After experiencing and training by Matlab, the model′s validation mean square error (MSE) performance is 0.009 985 02. R-squared between estimated and observed concentrations of chlorophyll a, b and c are 0.965 7, 0.998 7 and 0.970 7 respectively, indicating that the estimated value agrees with the observed value well, and the model can be used in the prediction of eutrophication of the Bohai Sea. In order to study the influence of model input factors on chlorophyll concentration (i.e. model outputs), hypothetical scenarios were introduced to show model output responses to variations in input factors. The limitation of temperature, salinity and phosphate that induce red tide in the Bohai Bay was also presented. 相似文献
15.
Companies use many different marketing strategies in order to make their products known and place their corporate images and brandings in the market. Besides, nowadays, being on the Intemet is a must for every company striving for success. The development and implementation of Web 2.0 or social web are threatening the basis of the ways of mixing with other people. A company devoted to open and distance learning, such as Master-D Corporation, a clear example of how a proper and planned use of the different possibilities offered by the Web 2.0, based on blogs, allows a company to achieve bigger market shares and brand positioning following the win-win principle. Blogs are, undoubtedly, channels of communication that prove the power of attraction of good information. These changes are affecting everybody and, in particular, companies and institutions related to people＇s education, teaching and training for their inclusion in society and labor market. This essay brings up some reflections in two ways： The first one deals with some reasons why education is also related to the concept of ＂company＂; and the second one deals with how these changes generated by Web 2.0 are affecting some training companies, represented in this case by Master-D, 相似文献
16.
Among complex network models, the hierarchical network model is the one most close to such real networks as world trade web, metabolic network, WWW, actor network, and so on. It has not only the property of power-law degree distribution, but also the scaling clustering coefficient property which Barabási-Albert （BA） model does not have. BA model is a model of network growth based on growth and preferential attachment, showing the scale-free degree distribution property. In this paper, we study the evolution of cooperation on a hierarchical network model, adopting the prisoner＇s dilemma （PD） game and snowdrift game （SG） as metaphors of the interplay between connected nodes. BA model provides a unifying framework for the emergence of cooperation. But interestingly, we found that on hierarchical model, there is no sign of cooperation for PD game, while the frequency of cooperation decreases as the common benefit decreases for SG. By comparing the scaling clustering coefficient properties of the hierarchical network model with that of BA model, we found that the former amplifies the effect of hubs. Considering different performances of PD game and SG on complex network, we also found that common benefit leads to cooperation in the evolution. Thus our study may shed light on the emergence of cooperation in both natural and social environments. 相似文献
17.
With the development of the world economy. The booming MNC has become a more and more important factor to impel the global economy in the 21 century,and with the further development of the national reform,more and more prestigious MNCs have watched out China automobile market and regarded it as their long-term investment target.Therefore.the marketing stratagem of AUDI car in China was cited as a car case to make a research on the marketing stratagem of MNC in China automobile market in my paper. I use the Porter's five forces model to analyze the AUDI car in Chinese market. 相似文献
18.
Algorithm for Delay-Constrained Minimal Cost Group Multicasting 总被引：1，自引：0，他引：1
Group multicast routing algorithms satisfying quality of service requirements of real-time applications are essential for high-speed networks. A heuristic algorithm was presented for group multicast routing with bandwidth and delay constrained. A new metric was designed as a function of available bandwidth and delay of link, And source-specific routing trees for each member were generated in the algorithm by using the metric, which satisfy member＇s bandwidth and end-to-end delay requirements. Simulations over random network were carried out to compare the performance of the proposed algorithm with that from literature. Experimental results show that the algorithm performs better in terms of network cost and ability in constructing feasible multicast trees for group members. Moreover,the algorithm can avoid link blocking and enhance the network behavior efficiently. 相似文献
19.
GARCH-M （generalized autoregressive conditional heteroskedasticity in the mean） model is used to analyse the volatility clustering phenomenon in mobile communication network traffic. Normal distribution, t distribution and generalized Pareto distribution assumptions are adopted respectively to simulate the random component in the model. The demonstration of the quantile of network traffic series indicates that common GARCH-M model can partially deal with the “fat tail” problem. However, the “ fat tail” characteristic of the random component directly affects the accuracy of the calculation. Even t distribution is based on the assumption for all the data. On the other hand, extreme value theory, which only concentrates on the tail distribution, can provide more accurate result for high quantiles. The best result is obtained based on the generalized Pareto distribution assumption for the random component in the GARCH-M model. 相似文献
20.
康俊民 《语数外学习(初中版)》2008,(7):89-92
Where is China？
Mike has a new toy bus. He wants to playwith it in school, but it＇s time for class and he hasto go to the classroom. It＇s ten twenty now. MrClark comes into the classroom of Class Four. Heputs up a map on the blackboard in his geographyclass. He wants to tell his students about China.＂China is one of the most famous countries,＂theteacher says, ＂Look! It＇s here. The Chinese aregood people and they＇re our friends.＂ Now Mr Clarksees that all his students are looking at the map, butMike is looking in his desk. 相似文献