With the explosive growth of variable renewable energy,the balance between the supply and demand of the power grid is faced with new challenges.Based on the development experience from typical countries and the state ...With the explosive growth of variable renewable energy,the balance between the supply and demand of the power grid is faced with new challenges.Based on the development experience from typical countries and the state quo in China,this paper further analyzes the system architecture and development trend of demand response under the background of Energy Internet.Five dimensions are considered:Energy Internet platform,demand response application scenarios,system architecture,information technology system construction,and demand response development trend.The results show that the application of the Energy Internet platform can effectively solve the problems of data acquisition and processing,“terminal-edge-network-cloud”cooperation of demand response,etc.The system architecture of the demand response platform that supports user resource management,user information access,control instruction receiving,control strategy issuing,and response process monitoring is proposed in this paper.It is also helpful to provide a feasible technical choice for expanding the application services of Energy Internet towards government and society.展开更多
This paper examines the mutual displacement of functional elements (FE) of risky technical systems (RTS). To this group of systems belong transport systems, technical systems operating in heavy regimes, energy and...This paper examines the mutual displacement of functional elements (FE) of risky technical systems (RTS). To this group of systems belong transport systems, technical systems operating in heavy regimes, energy and power systems, building structures. etc. A unit of mutual displacement of the functional elements of RTS is introduced, as well as a definition of the deformator of the system. The value of the deformator of a sample system is determined.展开更多
There are two phases in the development of China's high-speed railway after the1990s:the research and experiment phase during the Eighth and the Tenth Five-Year Plan periods;the construction and operation phase du...There are two phases in the development of China's high-speed railway after the1990s:the research and experiment phase during the Eighth and the Tenth Five-Year Plan periods;the construction and operation phase during the Eleventh and the Thirteenth Five-Year Plan periods.This paper regards the Beijing-Shanghai High-Speed Railway as the corner stone in the development of high-speed railway subgrade system,and proposes suggestions and solutions to the problems which may reduce the service life of subgrade.These solutions and methods can be referred to in future railway projects.展开更多
Elevation is one of many components that influence agriculture, and this in turn affects the level of both inputs and outputs of farmers. This article focuses on the productivity and technical efficiency of 100 cocoa ...Elevation is one of many components that influence agriculture, and this in turn affects the level of both inputs and outputs of farmers. This article focuses on the productivity and technical efficiency of 100 cocoa farms using cross-sectional data from areas ranging from 190 to 1021 m above sea level which were classified as low, medium, and high elevation in Davao City, considered as the chocolate capital of the Philippines. Using stochastic frontier analysis, the results showed that the cost of inputs per ha and the number of cocoa trees per ha significantly increase yield. Farms at high elevations were less technically efficient, as this entails lower temperatures and increased rainfall, and cocoa farming in those areas and conditions can be more challenging, especially with changes in farming practices, terrain, and distance to markets. Other significant variables were age of cocoa farms, married farmers, and age of the farmers. Older farms may be more developed, farmers who are married benefit from their spouses being able to readily contribute as farm labor, and lastly, older farmers' inefficiency may likely stem from nonadaptation of newer farming practices. With an average technical efficiency of 0.61, 0.63, and 0.26 in low, medium, and high elevation areas, respectively, farmers therefore have an incentive to improve farm practices and consider topographical variations found in high elevation areas. Recommendations for the improvement of technical efficiency of cocoa farms are better connectivity to markets, enhancing farm practices, and continuation and improvement of government programs on cocoa with an added emphasis on research. For farmers in high elevation areas, mitigating solutions such as sustainable agriculture practices and ecolabelling are key to improving efficiency and minimizing the potential negative impact on upland farming systems. Moreover, such adaptation measures may also contribute to sustainability of cocoa farming in high elevation areas.展开更多
Sea launch has the characteristics of flexible launching points, high landing area safety, and good economy. In recent years, it has become one of the important launch methods. Since 2019, China has carried out a tota...Sea launch has the characteristics of flexible launching points, high landing area safety, and good economy. In recent years, it has become one of the important launch methods. Since 2019, China has carried out a total of 11 successful sea launches. The Gravity-1(YL-1) sea launch system consists of a launch vehicle system and a sea launch platform. The sea launch program includes roll on/roll off boarding, sea mooring, sea maneuvering, anchoring and positioning, system testing, and formal launch. Through the maiden flight of YL-1, the design and manufacturing technology of large tonnage dedicated launch ship, launch vehicle vertical transfer and roll on/roll off boarding technology, anti-shake technology for sea launch, simple inflatable flexible insulation protective cover technology, and remote wireless measurement and control technology have been fully verified.展开更多
We presented Mathematical apparatus of the choice of optimum parameters of technical, technological systems and materials on the basis of vector optimization. We have considered the formulation and solution of three t...We presented Mathematical apparatus of the choice of optimum parameters of technical, technological systems and materials on the basis of vector optimization. We have considered the formulation and solution of three types of tasks presented below. First, the problem of selecting the optimal parameters of technical systems depending on the functional characteristics of the system. Secondly, the problem of selecting the optimal parameters of the process depending on the technological characteristics of the process. Third, the problem of choosing the optimal structure of the material depending on the functional characteristics of this material. The statement of all problems is made in the form of vector problems of mathematical (nonlinear) programming. The theory and the principle of optimality of the solution of vector tasks it is explained in work of https://rdcu.be/bhZ8i. The implementation of the methodology is shown on a numerical example of the choice of optimum parameters of the technical, technological systems and materials. On the basis of mathematical methods of solution of vector problems we developed the software in the MATLAB system. The numerical example includes: input data (requirement specification) for modeling;transformation of mathematical models with uncertainty to the model under certainty;acceptance of an optimal solution with equivalent criteria (the solution of numerical model);acceptance of an optimal solution with the given priority of criterion.展开更多
China's coastal zone is a region with a highly developed economy that contrasts clearly with the slow paced regular investigation on its natural environment,which cannot keep pace with the requirement of economic ...China's coastal zone is a region with a highly developed economy that contrasts clearly with the slow paced regular investigation on its natural environment,which cannot keep pace with the requirement of economic development and modern management.Laying a theoretical foundation for the modern management of China's costal zone is aimed at. This research focuses on the following processing and analyzing technologies for coastal zone high-resolution remote sensing data: organization and management of large amounts of high-resolution remote sensing data, quick and precise spatial positioning system,algorithms for image fusion in feature level and coastal zone feature extraction. They will form a technical foundation of the system. And, if combined with other research results such as coastal zone remote sensing classification system and its mapping subsystem, an advanced technical frame for remote sensing investigation of coastal zone resource will be constructed.展开更多
This study provides estimates of smallholder household's production efficiency and its determinants, and separately analyses the technical efficiency of dairy technology adopting and non-adopting farmers using data f...This study provides estimates of smallholder household's production efficiency and its determinants, and separately analyses the technical efficiency of dairy technology adopting and non-adopting farmers using data from Ethiopia. Cobb-Douglas stochastic frontier production function was modeled in the context of local level agricultural innovation systems framework and estimated using 2011 milk production data on 304 dairy farmers. Results show that the mean level of technical efficiency among the sampled farmers was about 26%. This result suggests that there is room for significant increases of production through reallocation of existing resources. Despite significant variation among farmers, these results also indicate only 19% of farmers have mean efficiency scores (_〉 50%), implying a need to focus on creating innovation capacity that pushes the production frontier outward in the dairy production system. It is also revealed that individual farm households' efficiency varied widely across dairy technology adoption status, gender and districts. The significant gamma (g) statistic, of 0.9985 in the analysis indicates that about 99.85% variation in the output of milk production would be attributed to technical inefficiency effects (those under farmer's control) while only 0.0015% would be due to random effects, i.e., beyond the farmers control and hence calling for a focus on efficiency enhancing investments. Education, farm size, extension visit and off-farm income opportunity were found to be efficiency enhancing. The study recommends that different components of an agricultural innovation system have to interact to improve the innovation capacity of different actors and thereby improve the estimated technical inefficiencies.展开更多
This study examines the technical efficiency(TE) differences among typical cropping systems of smallholder farmers in the purple-soiled hilly region of southwestern China.Household-,plot-,and crop-level data and commu...This study examines the technical efficiency(TE) differences among typical cropping systems of smallholder farmers in the purple-soiled hilly region of southwestern China.Household-,plot-,and crop-level data and community surveys were conducted to explore TE levels and determinants of typical cropping systems by using a translog stochastic frontier production function.Results indicate significant difference in TE and its determinants among cropping systems.The mean TEs of the rice cropping system(R),the rice-rape cropping system(RR),the rice-rape-potato cropping system(RRP),and the oil cropping system(O) are0.86,0.90,0.84,and 0.85,respectively,which are over 1.17 times higher than those of the maize-sweet potato-other crop cropping system(MSO) and the maize-sweet potato-wheat cropping system(MSW) at0.78 and 0.69,respectively.Moreover,Technical inefficiency(TIE) of different cropping systems is significantly affected by characteristics of the household as well as plot.However,the impact of land quality,mechanical cultivation conditions,crop structure,farming system,farm radius,household type,cultivated land area per capita,and annual household income per capitalon TIE vary by cropping system.Additionally,output elasticity of land,labor,and capital,as a group,is greater than the one of agricultural machinery and irrigation.Finally,when household-owned effective agricultural labor is at full farming capacity,optimal plot sizes for the R,RR,RRP,MSO,MSW,and 0 cropping systems are 1.12hm^2,0.35 hm^2,0.25 hm^2,2.82 hm^2,1.87 hm^2,and 1.17hm^2,respectively.展开更多
Continuous efforts are underway to reduce carbon emissions worldwide in response to global climate change.Water electrolysis technology,in conjunction with renewable energy,is considered the most feasible hydrogen pro...Continuous efforts are underway to reduce carbon emissions worldwide in response to global climate change.Water electrolysis technology,in conjunction with renewable energy,is considered the most feasible hydrogen production technology based on the viable possibility of large-scale hydrogen production and the zero-carbon-emission nature of the process.However,for hydrogen produced via water electrolysis systems to be utilized in various fields in practice,the unit cost of hydrogen production must be reduced to$1/kg H_(2).To achieve this unit cost,technical targets for water electrolysis have been suggested regarding components in the system.In this paper,the types of water electrolysis systems and the limitations of water electrolysis system components are explained.We suggest guideline with recent trend for achieving this technical target and insights for the potential utilization of water electrolysis technology.展开更多
Technical stability:allowing quantitative estimation of trajectory behavior of a dynamical system over a given time interval was considered. Based on a differential comparison principle and a basic monotonicity condit...Technical stability:allowing quantitative estimation of trajectory behavior of a dynamical system over a given time interval was considered. Based on a differential comparison principle and a basic monotonicity condition, technical stability relative to certain prescribed state constraint sets of a class of nonlinear time-varying systems with small parameters was analyzed by means of vector Liapunov function method. Explicit criteria of technical stability are established in terms of coefficients of the system under consideration. Conditions under which the technical stability of the system can be derived from its reduced linear time-varying (LTV) system were further examined, as well as a condition for linearization approach to technical stability of general nonlinear systems. Also, a simple algebraic condition of exponential asymptotic stability of LTV systems is presented. Two illustrative examples are given to demonstrate the availability of the presently proposed method.展开更多
To construct the Agricultural Scientific and Technical Information Core Metadata (ASTICM) standard and its expanding principles, and to develop a register system based on ASTICM, the policy and methods of DC (Dubli...To construct the Agricultural Scientific and Technical Information Core Metadata (ASTICM) standard and its expanding principles, and to develop a register system based on ASTICM, the policy and methods of DC (Dublin Core) and SDBCM (Scientific Database Core Metadata) were studied. The construction of ASTICM has started from the proposed elements of the DCMI (Dublin Core Metadata Initiative), and has expanded the DC and SDBCM with related expanding principles. ASTICM finally includes 75 metadata elements, five expanded principles, and seven application profile creation methods. According to the requirement analysis of a large number of users of agricultural information, a register system based on ASTICM was developed. The ASTICM standard framework and its register system supported the search, sharing, integration exchange and other applications, effectively.展开更多
The study was conducted with the aim of exploring the barriers to the adoption of BOT contract systems for infrastructural development of technical universities in Ghana. In an empirical questionnaire survey with prof...The study was conducted with the aim of exploring the barriers to the adoption of BOT contract systems for infrastructural development of technical universities in Ghana. In an empirical questionnaire survey with professionals and experts in the construction and education sector, the respondents were invited to rate their perception on the barriers to the adoption of the BOT contracts systems. An interview session to satisfy ways of adopting the BOT contracts for infrastructural development in technical universities was conducted with selected professionals. The study revealed that the major barriers to the adoption of the BOT contract system are: delays in approval, corruption, reliability and credit worthiness of entities and expropriation. The study suggested that detailed policy or framework for implementing BOT contracts;proper planning by technical universities;and adequate protection for lenders is required for successful BOT implementation. Therefore there is a need to explore this concept, using adequate policy initiatives, proper measures and support from government to improve on the proper implementation of the BOT contracts in Technical Universities in Ghana.展开更多
The objective of this research was to calculate the technical efficiency and its determinants in seasonal milk production of dual-purpose cattle system farms of El Salvador (DPCS). Seasons were classified as rainy ...The objective of this research was to calculate the technical efficiency and its determinants in seasonal milk production of dual-purpose cattle system farms of El Salvador (DPCS). Seasons were classified as rainy (May-October) and dry (November-April). The stochastic production frontier model through the Cobb-Douglas specification was used to provide the technical efficiency score and its determinants for the production data of the 2009 rainy season and the 2010 dry season of the DPCS farms from South East El Salvador. The results showed that the mean technical efficiency was 14% higher for the dry season than for the rainy season. Moreover, more farms obtained higher efficiency scores in the dry season. In the rainy season, milk production was attributed to labor and farmland, whereas in the dry season, it was attributed to the decrease of herd size. Therefore, we suggest adopting strategies such as increased cow productivity and improved feed quality to increase the overall technical efficiency of DPCS farms.展开更多
The given article deals with the development of analytical model of request service process by multichannel technical system with unreliable, repaired and reconfigured service facilities. It is assumed that the system...The given article deals with the development of analytical model of request service process by multichannel technical system with unreliable, repaired and reconfigured service facilities. It is assumed that the system is functioning in service mode of random length random request flows. The system considers the existence of time redundancy for afterservice of calls, the service of which is interrupted with refusal, non-depreciating the performed part of the task. Special probability functions are introduced which on the basis of probability reasoning allow to make the systems of integral equations describing the dynamics of request service process.展开更多
Delivering IPTV services entails a complex integration of a variety of industries as well as the support of network,computer,and image processing technologies. That is to say,the IPTV architecture should carry a myria...Delivering IPTV services entails a complex integration of a variety of industries as well as the support of network,computer,and image processing technologies. That is to say,the IPTV architecture should carry a myriad of services and technologies. In light of current telecom/TV status,the IPTV architecture can be set up on the convergence of the three networks to deliver comprehensive services and make Live TV,TV on Demand (TVOD),and Time-shifted TV services accessible on one platform. It also supports local and cross-regional user and service certification,provides EPG and smooth TV images and guarantees secured content as well.展开更多
High-level of technical skills and tactical behaviour are key factors for an optimal performance in soccer games. About the most used and innovative training methods, the small-sided games (SSGs) seem to be a worthy...High-level of technical skills and tactical behaviour are key factors for an optimal performance in soccer games. About the most used and innovative training methods, the small-sided games (SSGs) seem to be a worthy and valid methodology to train simultaneously many skills by reproducing several conditions of a real match. Accordingly, the aim of this study was to conduct a systematic review of the available literature to lead an improved understanding in the usefulness of SSGs for improving technical skills in soccer. To ensure a rigorous and reliable approach, the review was performed according to PRISMA (Preferred Reporting Items for Systematic review and Meta-analyses) guidelines. 1031 records were initially identified, but only 26 studies were further included in the review. Moreover, other two studies were added after a check of the bibliography of two major reviews. So, each of these studies was analysed according to the aforementioned guidelines and using inclusion criteria related to SSG and training in soccer. The current analysis provided several indications and recommendations for coaches and trainers of soccer teams in order to improve several technical skills by means of the use of SSGs. Furthermore, several evidences for using SSGs in school environment are also provided.展开更多
The security system for police technical and tactical training in public security colleges in China is mainly composed of seven security guarantee systems: management organization, safety education, laws and regulatio...The security system for police technical and tactical training in public security colleges in China is mainly composed of seven security guarantee systems: management organization, safety education, laws and regulations, training control, site equipment, safety supervision and emergency plan, scienti??cally and rationally constructing a security system in relevant public security colleges. This paper has carried out a comprehensive research on Hebei Vocational College of Public Security Police, and provided corresponding safety theory and guarantee for the security protection of the college during the police training period.展开更多
Intangible cultural heritage has a rich connotation of unique thinking way, ethical imaginationand cultural awareness, which is an important sign of national spiritual culture. Possessing the specialvalues of professi...Intangible cultural heritage has a rich connotation of unique thinking way, ethical imaginationand cultural awareness, which is an important sign of national spiritual culture. Possessing the specialvalues of professionalism, permanency, security and openness, with the advantages museums play acentral role in inheriting and rescuing our intangible cultural heritage. Museums have a lot of technicalmeans for museums to protect and inherit intangible cultural heritage, such as scientific research,preservation of material carrier, museum publications, displays on intangible cultural heritage, estab-lishing thematic museums. In intangible cultural heritage, agricultural heritage is the most importantpart. The core content of which is the ideas and methods of harmony between mankind and environ-ment. There is a variety of practices on the protection by China National Agricultural Museum.展开更多
Constructive research of a market-oriented industry's system of technical standardization by redefining those technical standards is the basis of innovation. Through considering and implementing innovation of the ...Constructive research of a market-oriented industry's system of technical standardization by redefining those technical standards is the basis of innovation. Through considering and implementing innovation of the industry's standards, rapid development and standardization of the industry can be achieved.展开更多
基金supported by the Fundamental Research Funds for the Central Universities(2019QN066).
文摘With the explosive growth of variable renewable energy,the balance between the supply and demand of the power grid is faced with new challenges.Based on the development experience from typical countries and the state quo in China,this paper further analyzes the system architecture and development trend of demand response under the background of Energy Internet.Five dimensions are considered:Energy Internet platform,demand response application scenarios,system architecture,information technology system construction,and demand response development trend.The results show that the application of the Energy Internet platform can effectively solve the problems of data acquisition and processing,“terminal-edge-network-cloud”cooperation of demand response,etc.The system architecture of the demand response platform that supports user resource management,user information access,control instruction receiving,control strategy issuing,and response process monitoring is proposed in this paper.It is also helpful to provide a feasible technical choice for expanding the application services of Energy Internet towards government and society.
文摘This paper examines the mutual displacement of functional elements (FE) of risky technical systems (RTS). To this group of systems belong transport systems, technical systems operating in heavy regimes, energy and power systems, building structures. etc. A unit of mutual displacement of the functional elements of RTS is introduced, as well as a definition of the deformator of the system. The value of the deformator of a sample system is determined.
文摘There are two phases in the development of China's high-speed railway after the1990s:the research and experiment phase during the Eighth and the Tenth Five-Year Plan periods;the construction and operation phase during the Eleventh and the Thirteenth Five-Year Plan periods.This paper regards the Beijing-Shanghai High-Speed Railway as the corner stone in the development of high-speed railway subgrade system,and proposes suggestions and solutions to the problems which may reduce the service life of subgrade.These solutions and methods can be referred to in future railway projects.
文摘Elevation is one of many components that influence agriculture, and this in turn affects the level of both inputs and outputs of farmers. This article focuses on the productivity and technical efficiency of 100 cocoa farms using cross-sectional data from areas ranging from 190 to 1021 m above sea level which were classified as low, medium, and high elevation in Davao City, considered as the chocolate capital of the Philippines. Using stochastic frontier analysis, the results showed that the cost of inputs per ha and the number of cocoa trees per ha significantly increase yield. Farms at high elevations were less technically efficient, as this entails lower temperatures and increased rainfall, and cocoa farming in those areas and conditions can be more challenging, especially with changes in farming practices, terrain, and distance to markets. Other significant variables were age of cocoa farms, married farmers, and age of the farmers. Older farms may be more developed, farmers who are married benefit from their spouses being able to readily contribute as farm labor, and lastly, older farmers' inefficiency may likely stem from nonadaptation of newer farming practices. With an average technical efficiency of 0.61, 0.63, and 0.26 in low, medium, and high elevation areas, respectively, farmers therefore have an incentive to improve farm practices and consider topographical variations found in high elevation areas. Recommendations for the improvement of technical efficiency of cocoa farms are better connectivity to markets, enhancing farm practices, and continuation and improvement of government programs on cocoa with an added emphasis on research. For farmers in high elevation areas, mitigating solutions such as sustainable agriculture practices and ecolabelling are key to improving efficiency and minimizing the potential negative impact on upland farming systems. Moreover, such adaptation measures may also contribute to sustainability of cocoa farming in high elevation areas.
文摘Sea launch has the characteristics of flexible launching points, high landing area safety, and good economy. In recent years, it has become one of the important launch methods. Since 2019, China has carried out a total of 11 successful sea launches. The Gravity-1(YL-1) sea launch system consists of a launch vehicle system and a sea launch platform. The sea launch program includes roll on/roll off boarding, sea mooring, sea maneuvering, anchoring and positioning, system testing, and formal launch. Through the maiden flight of YL-1, the design and manufacturing technology of large tonnage dedicated launch ship, launch vehicle vertical transfer and roll on/roll off boarding technology, anti-shake technology for sea launch, simple inflatable flexible insulation protective cover technology, and remote wireless measurement and control technology have been fully verified.
文摘We presented Mathematical apparatus of the choice of optimum parameters of technical, technological systems and materials on the basis of vector optimization. We have considered the formulation and solution of three types of tasks presented below. First, the problem of selecting the optimal parameters of technical systems depending on the functional characteristics of the system. Secondly, the problem of selecting the optimal parameters of the process depending on the technological characteristics of the process. Third, the problem of choosing the optimal structure of the material depending on the functional characteristics of this material. The statement of all problems is made in the form of vector problems of mathematical (nonlinear) programming. The theory and the principle of optimality of the solution of vector tasks it is explained in work of https://rdcu.be/bhZ8i. The implementation of the methodology is shown on a numerical example of the choice of optimum parameters of the technical, technological systems and materials. On the basis of mathematical methods of solution of vector problems we developed the software in the MATLAB system. The numerical example includes: input data (requirement specification) for modeling;transformation of mathematical models with uncertainty to the model under certainty;acceptance of an optimal solution with equivalent criteria (the solution of numerical model);acceptance of an optimal solution with the given priority of criterion.
基金the"863"Marine Monitor of Hi-tech Research and Development Program of China under contract No.2003AA604040.
文摘China's coastal zone is a region with a highly developed economy that contrasts clearly with the slow paced regular investigation on its natural environment,which cannot keep pace with the requirement of economic development and modern management.Laying a theoretical foundation for the modern management of China's costal zone is aimed at. This research focuses on the following processing and analyzing technologies for coastal zone high-resolution remote sensing data: organization and management of large amounts of high-resolution remote sensing data, quick and precise spatial positioning system,algorithms for image fusion in feature level and coastal zone feature extraction. They will form a technical foundation of the system. And, if combined with other research results such as coastal zone remote sensing classification system and its mapping subsystem, an advanced technical frame for remote sensing investigation of coastal zone resource will be constructed.
文摘This study provides estimates of smallholder household's production efficiency and its determinants, and separately analyses the technical efficiency of dairy technology adopting and non-adopting farmers using data from Ethiopia. Cobb-Douglas stochastic frontier production function was modeled in the context of local level agricultural innovation systems framework and estimated using 2011 milk production data on 304 dairy farmers. Results show that the mean level of technical efficiency among the sampled farmers was about 26%. This result suggests that there is room for significant increases of production through reallocation of existing resources. Despite significant variation among farmers, these results also indicate only 19% of farmers have mean efficiency scores (_〉 50%), implying a need to focus on creating innovation capacity that pushes the production frontier outward in the dairy production system. It is also revealed that individual farm households' efficiency varied widely across dairy technology adoption status, gender and districts. The significant gamma (g) statistic, of 0.9985 in the analysis indicates that about 99.85% variation in the output of milk production would be attributed to technical inefficiency effects (those under farmer's control) while only 0.0015% would be due to random effects, i.e., beyond the farmers control and hence calling for a focus on efficiency enhancing investments. Education, farm size, extension visit and off-farm income opportunity were found to be efficiency enhancing. The study recommends that different components of an agricultural innovation system have to interact to improve the innovation capacity of different actors and thereby improve the estimated technical inefficiencies.
基金the support of the National Natural Science Foundation of China (Grant No.41501104)the National Key Technology R&D Program of China (Grant Nos.2013BAJ11B02,2013BAJ11B02-03)+1 种基金the Basic and Frontier Research Project of Chongqing Science &Technology Commission (Grant No.cstc2015jcyj A80025)the Science and technology research project of Chongqing Education Committee (Grant No.KJ1500336)
文摘This study examines the technical efficiency(TE) differences among typical cropping systems of smallholder farmers in the purple-soiled hilly region of southwestern China.Household-,plot-,and crop-level data and community surveys were conducted to explore TE levels and determinants of typical cropping systems by using a translog stochastic frontier production function.Results indicate significant difference in TE and its determinants among cropping systems.The mean TEs of the rice cropping system(R),the rice-rape cropping system(RR),the rice-rape-potato cropping system(RRP),and the oil cropping system(O) are0.86,0.90,0.84,and 0.85,respectively,which are over 1.17 times higher than those of the maize-sweet potato-other crop cropping system(MSO) and the maize-sweet potato-wheat cropping system(MSW) at0.78 and 0.69,respectively.Moreover,Technical inefficiency(TIE) of different cropping systems is significantly affected by characteristics of the household as well as plot.However,the impact of land quality,mechanical cultivation conditions,crop structure,farming system,farm radius,household type,cultivated land area per capita,and annual household income per capitalon TIE vary by cropping system.Additionally,output elasticity of land,labor,and capital,as a group,is greater than the one of agricultural machinery and irrigation.Finally,when household-owned effective agricultural labor is at full farming capacity,optimal plot sizes for the R,RR,RRP,MSO,MSW,and 0 cropping systems are 1.12hm^2,0.35 hm^2,0.25 hm^2,2.82 hm^2,1.87 hm^2,and 1.17hm^2,respectively.
基金supported by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)grant from the Ministry of Trade,Industry&Energy,Republic of Korea(No.20213030040590)the National R&D Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(NRF-2021K1A4A8A01079455)。
文摘Continuous efforts are underway to reduce carbon emissions worldwide in response to global climate change.Water electrolysis technology,in conjunction with renewable energy,is considered the most feasible hydrogen production technology based on the viable possibility of large-scale hydrogen production and the zero-carbon-emission nature of the process.However,for hydrogen produced via water electrolysis systems to be utilized in various fields in practice,the unit cost of hydrogen production must be reduced to$1/kg H_(2).To achieve this unit cost,technical targets for water electrolysis have been suggested regarding components in the system.In this paper,the types of water electrolysis systems and the limitations of water electrolysis system components are explained.We suggest guideline with recent trend for achieving this technical target and insights for the potential utilization of water electrolysis technology.
文摘Technical stability:allowing quantitative estimation of trajectory behavior of a dynamical system over a given time interval was considered. Based on a differential comparison principle and a basic monotonicity condition, technical stability relative to certain prescribed state constraint sets of a class of nonlinear time-varying systems with small parameters was analyzed by means of vector Liapunov function method. Explicit criteria of technical stability are established in terms of coefficients of the system under consideration. Conditions under which the technical stability of the system can be derived from its reduced linear time-varying (LTV) system were further examined, as well as a condition for linearization approach to technical stability of general nonlinear systems. Also, a simple algebraic condition of exponential asymptotic stability of LTV systems is presented. Two illustrative examples are given to demonstrate the availability of the presently proposed method.
文摘To construct the Agricultural Scientific and Technical Information Core Metadata (ASTICM) standard and its expanding principles, and to develop a register system based on ASTICM, the policy and methods of DC (Dublin Core) and SDBCM (Scientific Database Core Metadata) were studied. The construction of ASTICM has started from the proposed elements of the DCMI (Dublin Core Metadata Initiative), and has expanded the DC and SDBCM with related expanding principles. ASTICM finally includes 75 metadata elements, five expanded principles, and seven application profile creation methods. According to the requirement analysis of a large number of users of agricultural information, a register system based on ASTICM was developed. The ASTICM standard framework and its register system supported the search, sharing, integration exchange and other applications, effectively.
文摘The study was conducted with the aim of exploring the barriers to the adoption of BOT contract systems for infrastructural development of technical universities in Ghana. In an empirical questionnaire survey with professionals and experts in the construction and education sector, the respondents were invited to rate their perception on the barriers to the adoption of the BOT contracts systems. An interview session to satisfy ways of adopting the BOT contracts for infrastructural development in technical universities was conducted with selected professionals. The study revealed that the major barriers to the adoption of the BOT contract system are: delays in approval, corruption, reliability and credit worthiness of entities and expropriation. The study suggested that detailed policy or framework for implementing BOT contracts;proper planning by technical universities;and adequate protection for lenders is required for successful BOT implementation. Therefore there is a need to explore this concept, using adequate policy initiatives, proper measures and support from government to improve on the proper implementation of the BOT contracts in Technical Universities in Ghana.
文摘The objective of this research was to calculate the technical efficiency and its determinants in seasonal milk production of dual-purpose cattle system farms of El Salvador (DPCS). Seasons were classified as rainy (May-October) and dry (November-April). The stochastic production frontier model through the Cobb-Douglas specification was used to provide the technical efficiency score and its determinants for the production data of the 2009 rainy season and the 2010 dry season of the DPCS farms from South East El Salvador. The results showed that the mean technical efficiency was 14% higher for the dry season than for the rainy season. Moreover, more farms obtained higher efficiency scores in the dry season. In the rainy season, milk production was attributed to labor and farmland, whereas in the dry season, it was attributed to the decrease of herd size. Therefore, we suggest adopting strategies such as increased cow productivity and improved feed quality to increase the overall technical efficiency of DPCS farms.
文摘The given article deals with the development of analytical model of request service process by multichannel technical system with unreliable, repaired and reconfigured service facilities. It is assumed that the system is functioning in service mode of random length random request flows. The system considers the existence of time redundancy for afterservice of calls, the service of which is interrupted with refusal, non-depreciating the performed part of the task. Special probability functions are introduced which on the basis of probability reasoning allow to make the systems of integral equations describing the dynamics of request service process.
文摘Delivering IPTV services entails a complex integration of a variety of industries as well as the support of network,computer,and image processing technologies. That is to say,the IPTV architecture should carry a myriad of services and technologies. In light of current telecom/TV status,the IPTV architecture can be set up on the convergence of the three networks to deliver comprehensive services and make Live TV,TV on Demand (TVOD),and Time-shifted TV services accessible on one platform. It also supports local and cross-regional user and service certification,provides EPG and smooth TV images and guarantees secured content as well.
文摘High-level of technical skills and tactical behaviour are key factors for an optimal performance in soccer games. About the most used and innovative training methods, the small-sided games (SSGs) seem to be a worthy and valid methodology to train simultaneously many skills by reproducing several conditions of a real match. Accordingly, the aim of this study was to conduct a systematic review of the available literature to lead an improved understanding in the usefulness of SSGs for improving technical skills in soccer. To ensure a rigorous and reliable approach, the review was performed according to PRISMA (Preferred Reporting Items for Systematic review and Meta-analyses) guidelines. 1031 records were initially identified, but only 26 studies were further included in the review. Moreover, other two studies were added after a check of the bibliography of two major reviews. So, each of these studies was analysed according to the aforementioned guidelines and using inclusion criteria related to SSG and training in soccer. The current analysis provided several indications and recommendations for coaches and trainers of soccer teams in order to improve several technical skills by means of the use of SSGs. Furthermore, several evidences for using SSGs in school environment are also provided.
文摘The security system for police technical and tactical training in public security colleges in China is mainly composed of seven security guarantee systems: management organization, safety education, laws and regulations, training control, site equipment, safety supervision and emergency plan, scienti??cally and rationally constructing a security system in relevant public security colleges. This paper has carried out a comprehensive research on Hebei Vocational College of Public Security Police, and provided corresponding safety theory and guarantee for the security protection of the college during the police training period.
文摘Intangible cultural heritage has a rich connotation of unique thinking way, ethical imaginationand cultural awareness, which is an important sign of national spiritual culture. Possessing the specialvalues of professionalism, permanency, security and openness, with the advantages museums play acentral role in inheriting and rescuing our intangible cultural heritage. Museums have a lot of technicalmeans for museums to protect and inherit intangible cultural heritage, such as scientific research,preservation of material carrier, museum publications, displays on intangible cultural heritage, estab-lishing thematic museums. In intangible cultural heritage, agricultural heritage is the most importantpart. The core content of which is the ideas and methods of harmony between mankind and environ-ment. There is a variety of practices on the protection by China National Agricultural Museum.
文摘Constructive research of a market-oriented industry's system of technical standardization by redefining those technical standards is the basis of innovation. Through considering and implementing innovation of the industry's standards, rapid development and standardization of the industry can be achieved.