Teaching assessment is one of the most important components of college English teaching. The traditional assessment system over emphasizes the summative assessment, which used examinations as the main assessment metho...Teaching assessment is one of the most important components of college English teaching. The traditional assessment system over emphasizes the summative assessment, which used examinations as the main assessment method. Formative assessment focuses on the process assessment during the practice of teaching. It is integrated in the teaching and learning process and cannot be separated as evaluation. The formative assessment aims to confirm the students' potential, develop their ability in study and strengthen the students' confidence and the spirit of cooperation. It is also a method intended to generate feedback on performance to improve and accelerate teaching and learning effectively. Based on some theories, this paper states the importance of the application of formative assessment in college oral English teaching. It also introduces some principles and measures to apply this assessment. The reasonable and effective application can promote college oral English teaching.展开更多
In order to analyze and test the component-based web application and decide when to stop the testing process, the concept of coverage criteria and test requirement reduction approach are proposed. First, four adequacy...In order to analyze and test the component-based web application and decide when to stop the testing process, the concept of coverage criteria and test requirement reduction approach are proposed. First, four adequacy criteria are defined and subsumption relationships among them are proved. Then, a translation algorithm is presented to transfer the test model into a web application decision-to-decision graph(WADDGraph)which is used to reduce testing requirements. Finally, different sets of test requirements can be generated from WADDGraph by analyzing subsumption and equivalence relationships among edges based on different coverage criteria, and testers can select different test requirements according to different testing environments. The case study indicates that coverage criteria follow linear subsumption relationships in real web applications. Test requirements can be reduced more than 55% on average based on different coverage criteria and the size of test requirements increases with the increase in the complexity of the coverage criteria.展开更多
MC CDMA is a thriving topic in recent years. Multiuser interference is also very severe as in DS CDMA. ML method is the best multiuser detection, but it has a computational complexity exponentially increased with th...MC CDMA is a thriving topic in recent years. Multiuser interference is also very severe as in DS CDMA. ML method is the best multiuser detection, but it has a computational complexity exponentially increased with the number of users. Mean field annealing and chaotic neural network are two promising optimum techniques. This paper applies them into the ML detection, comparison of the two methods is made.展开更多
This paper considers the problem of time varying congestion pricing to determine optimal time-varying tolls at peak periods for a queuing network with the interactions between buses and private cars.Through the combin...This paper considers the problem of time varying congestion pricing to determine optimal time-varying tolls at peak periods for a queuing network with the interactions between buses and private cars.Through the combined applications of the space-time expanded network(STEN) and the conventional network equilibrium modeling techniques,a multi-class,multi-mode and multi-criteria traffic network equilibrium model is developed.Travelers of different classes have distinctive value of times(VOTs),and travelers from the same class perceive their travel disutility or generalized costs on a route according to different weights of travel time and travel costs.Moreover,the symmetric cost function model is extended to deal with the interactions between buses and private cars.It is found that there exists a uniform(anonymous) link toll pattern which can drive a multi-class,multi-mode and multi-criteria user equilibrium flow pattern to a system optimum when the system's objective function is measured in terms of money.It is also found that the marginal cost pricing models with a symmetric travel cost function do not reflect the interactions between traffic flows of different road sections,and the obtained congestion pricing toll is smaller than the real value.展开更多
The mechanism of mine water inrushes in coal mines in China differs considerably from that in other countries.In China, most water inrushes occur from floor strata, where the water-inrush sources are karstic limestone...The mechanism of mine water inrushes in coal mines in China differs considerably from that in other countries.In China, most water inrushes occur from floor strata, where the water-inrush sources are karstic limestone aquifers.Our study describes the mechanism of mine water inrushes through a fault in the mine floor using principles of strata mechanics and the path of water inrush from an aquifer to the working face.A criterion to judge whether a ground water inrush will occur through a fault or not is also described, together with a case history of water inflow in the Feicheng coalfield, China.展开更多
The practical application of semiconductor-based high-efficiency white-light sources, also known as light-emitting diodes, or LEDs, is a recent development of Japanese engineering. This development could be a game-cha...The practical application of semiconductor-based high-efficiency white-light sources, also known as light-emitting diodes, or LEDs, is a recent development of Japanese engineering. This development could be a game-changer for lighting worldwide, given that current power consumption for lighting accounts for 16% of the total electricity consumption in Japan.展开更多
Hyperbole is a very common rhetorical device which is widely used both in English and Chinese. In order to express his/her strong feelings and also to make his/her language more powerful, the writer/speaker exaggerate...Hyperbole is a very common rhetorical device which is widely used both in English and Chinese. In order to express his/her strong feelings and also to make his/her language more powerful, the writer/speaker exaggerates things on purpose. Yet in spite of the over-truth expression, employment of hyperbole does not affect the conversation flow between parties. Through an analysis of hyperbole from the perspective of pragrnatics, this article tries to explain the pragmatic functions of hyperbole.展开更多
Equipment selection for industrial process usually requires the extensive participation of industrial experts and technologists, which causes a serious waste of resources. This work presents an equipment selection kno...Equipment selection for industrial process usually requires the extensive participation of industrial experts and technologists, which causes a serious waste of resources. This work presents an equipment selection knowledge base system for industrial styrene process(S-ESKBS) based on the ontology technology. This structure includes a low-level knowledge base and a top-level interactive application. As the core part of the S-ESKBS, the low-level knowledge base consists of the equipment selection ontology library, equipment selection rule set and Pellet inference engine. The top-level interactive application is implemented using S-ESKBS, including the parsing storage layer, inference query layer and client application layer. Case studies for the industrial styrene process equipment selection of an analytical column and an alkylation reactor are demonstrated to show the characteristics and implementability of the S-ESKBS.展开更多
For a long time, it has been generally believed that spin-spin interactions can only exist in a theory where Lorentz symmetry is gauged, and a theory with spin-spin interactions is not perturbatively renormalizable. B...For a long time, it has been generally believed that spin-spin interactions can only exist in a theory where Lorentz symmetry is gauged, and a theory with spin-spin interactions is not perturbatively renormalizable. But this is not true. By studying the motion of a spinning particle in gravitational field, it is found that there exist spin-spin interactions in gauge theory of gravity. Its mechanism is that a spinning particle will generate gravitomagnetic field in space-time, and this gravitomagnetic field will interact with the spin of another particle, which will cause spin-spin interactions. So, spin-spin interactions are transmitted by gravitational field. The form of spin-spin interactions in post Newtonian approximations is deduced. This result can also be deduced from the Papapetrou equation. This kind of interaction will not affect the renormalizability of the theory. The spin-spin interactions will violate the weak equivalence principle, and the violation effects are detectable. An experiment is proposed to detect the effects of the violation of the weak equivalence principle.展开更多
The presented iterative multiuser detection technique was based on joint deregularized and box-constrained solution to quadratic optimization with iterations similar to that used in the nonstationary Tikhonov iterated...The presented iterative multiuser detection technique was based on joint deregularized and box-constrained solution to quadratic optimization with iterations similar to that used in the nonstationary Tikhonov iterated algorithm.The deregularization maximized the energy of the solution,which was opposite to the Tikhonov regularization where the energy was minimized.However,combined with box-constraints,the deregularization forced the solution to be close to the binary set.It further exploited the box-constrained dichotomous coordinate descent algorithm and adapted it to the nonstationary iterative Tikhonov regularization to present an efficient detector.As a result,the worst-case and average complexity are reduced down as K2.8 and K2.5 floating point operation per second,respectively.The development improves the "efficient frontier" in multiuser detection,which is illustrated by simulation results.In addition,most operations in the detector are additions and bit-shifts.This makes the proposed technique attractive for fixed-point hardware implementation.展开更多
Two dimensional irregular polygons packing problem is very difficult to be solved in traditional optimal way.Simulated annealing(SA)algorithm is a stochastic optimization technique that can be used to solve packing pr...Two dimensional irregular polygons packing problem is very difficult to be solved in traditional optimal way.Simulated annealing(SA)algorithm is a stochastic optimization technique that can be used to solve packing problems.The whole process of SA is introduced firstly in this paper. An extended neighborhood searching method in SA is mainly analyzed. A general module of SA algorithm is given and used to lay out the irregular polygons. The judgment of intersection and other constrains of irregular polygons are analyzed. Then an example that was used in the paper of Stefan Jakobs is listed.Results show that this SA algorithm shortens the computation time and improves the solution.展开更多
In distributed systems independent agents need to interact with each other to accomplish their task. Modern peer-to-peer computing technologies always concern with enabling interaction among agents and help them coope...In distributed systems independent agents need to interact with each other to accomplish their task. Modern peer-to-peer computing technologies always concern with enabling interaction among agents and help them cooperate with each other. But in fact, access control should also be considered to limit interaction to make it harmless. This paper proposed a proxy based rule regulated interaction (PBRRI) model. Role based access control is introduced for security concerns. Regulation rules are enforced in a distributed manner so that PBRRI can be applied to the open distributed systems such as Internet.展开更多
Fuzzy association rules (FARs) can be powerful in assessing regional soil quality, a critical step prior to land planning and utilization; however, traditional FARs mined from soil quality database, ignoring the impor...Fuzzy association rules (FARs) can be powerful in assessing regional soil quality, a critical step prior to land planning and utilization; however, traditional FARs mined from soil quality database, ignoring the importance variability of the rules, can be redundant and far from optimal. In this study, we developed a method applying different weights to traditional FARs to improve accuracy of soil quality assessment. After the FARs for soil quality assessment were mined, redundant rules were eliminated according to whether the rules were significant or not in reducing the complexity of the soil quality assessment models and in improving the comprehensibility of FARs. The global weights, each representing the importance of a FAR in soil quality assessment, were then introduced and refined using a gradient descent optimization method. This method was applied to the assessment of soil resources conditions in Guangdong Province, China. The new approach had an accuracy of 87%, when 15 rules were mined, as compared with 76% from the traditional approach. The accuracy increased to 96% when 32 rules were mined, in contrast to 88% from the traditional approach. These results demonstrated an improved comprehensibility of FARs and a high accuracy of the proposed method.展开更多
In order to evaluate the feasibility of safe mining close to the contact zone under reduced security coal pillar conditions at a coal mine in eastern China, the interaction mechanism of the interface between deep buri...In order to evaluate the feasibility of safe mining close to the contact zone under reduced security coal pillar conditions at a coal mine in eastern China, the interaction mechanism of the interface between deep buried sand and a paleo-weathered rock mass was investigated in the laboratory by direct shear testing. A DRS-1 high pressure soil shear testing machine and orthogonal design method were used in the direct shear tests. Variance and range methods were applied to analyze the sensitivity of each factor that has an influence on the mechanical characters of the interface. The test results show that the normal pressure is the main influencing factor for mechanical characteristics of the interface, while the lithological characters and roughness are minor factors; the shear stress against shear displacement curve for the interface shows an overall hyperbola relationship, no obvious peak stress and dilatancy was observed.When the normal pressure is 6 MPa, the shear strengths of interfaces with different roughness are basically the same, and when the normal pressure is more than 8 MPa, the larger the roughness of the interface, the larger will be the shear strength; the shear strength has a better linear relationship with the normal pressure, which can be described by a linear Mohr–Coulomb criterion.展开更多
Based on the rough set theory which is a powerful tool in dealing with vagueness and uncertainty, an algorithm to mine association rules in incomplete information systems was presented and the support and confidence w...Based on the rough set theory which is a powerful tool in dealing with vagueness and uncertainty, an algorithm to mine association rules in incomplete information systems was presented and the support and confidence were redefined. The algorithm can mine the association rules with decision attributes directly without processing missing values. Using the incomplete dataset Mushroom from UCI machine learning repository, the new algorithm was compared with the classical association rules mining algorithm based on Apriori from the number of rules extracted, testing accuracy and execution time. The experiment results show that the new algorithm has advantages of short execution time and high accuracy.展开更多
Linear failure criterion is widely used in calculation of earth pressure acting on shallow tunnels. However, experimental evidence shows that nonlinear failure criterion is able to represent fairly well the failure of...Linear failure criterion is widely used in calculation of earth pressure acting on shallow tunnels. However, experimental evidence shows that nonlinear failure criterion is able to represent fairly well the failure of almost all types of rocks, A nonlinear Hock-Brown failure criterion is employed to estimate the supporting pressures of shallow tunnels in limit analysis framework. Two failure mechanisms are proposed for calculating the work rate of extemal force and the internal energy dissipation. A tangential line to the nonlinear failure criterion is used to formulate the supporting pressure problem as a nonlinear programming problem. The objective function formulated in this way is minimized with respect to the failure mechanism and the location of tangency point. In order to assess the validity, the supporting pressures for the proposed failure mechanisms are calculated and compared with each other, and the present results are compared with previously published solutions when the nonlinear criterion is reduced to linear criterion. The agreement supports the validity of the proposed failure mechanisms. An experiment is conducted to investigate the influences of the nonlinear criterion on collapse shape and supporting pressures of shallow tunnels.展开更多
Binuclear transition metal carbonyl clusters serve as the simplest models in understand- ing metal-metal and ligand bonding that are important organometallic chemistry catalysis. Binuclear first row transition metal c...Binuclear transition metal carbonyl clusters serve as the simplest models in understand- ing metal-metal and ligand bonding that are important organometallic chemistry catalysis. Binuclear first row transition metal carbonyl ions are produced via a pulsed laser vaporiza- tion/supersonic expansion cluster ion source in the gas phase. These ions are studied by mass-selected infrared photodissociation spectroscopy in the carbonyl stretching frequency region. Density functional theory calculations have been performed on the geometric struc- tures and vibrational spectra of the carbonyl ions. Their geometric and electronic structures are determined by comparison of the experimental IR spectra with the simulated spectra. The structure and the metM-metal and metal-CO bonding of both saturated and unsaturated homonuclear as well as heteronuclear carbonyl cluster cations and anions are discussed.展开更多
The national musicology was introduced into China from the western countries, so the Chinese scholars need to continue to absorb and draw lessons from the advanced western national musicological theories, and should c...The national musicology was introduced into China from the western countries, so the Chinese scholars need to continue to absorb and draw lessons from the advanced western national musicological theories, and should carry out the innovation base on the "used doctrine". According to China's national conditions and the characteristics of the cultures, improve the research methodology of the national musicology, so that the national musicology can have the Chinese characteristics. The national musicology is an independent basic discipline in the university education. In China, the music education and research work in colleges and universities has an important role in the inheritance and development of the national music. In this paper, combined with the present situations of the music education in colleges and universities, from the perspectives of the education and the research, the author expounds the ideas of the development trends of the national musicology in the music education in colleges and universities.展开更多
In this paper,the criteria set related to the priority preorders of water resources projects is introduced.A fuzzy multiple criteria group decision-making model is established,which incorporates quantitative analysis,...In this paper,the criteria set related to the priority preorders of water resources projects is introduced.A fuzzy multiple criteria group decision-making model is established,which incorporates quantitative analysis,judgments,experience and preferences of decision-makers.The model is used in practice to determine the priority preorders of five water resources projects,and the results show that the best choice can supply more new employment,domestic water and irrigation water,and has better quality.展开更多
The objective of improving the state accounting system is to build a state accounting system based on a single and complete database which is applied uniformly across all public authorities and agencies from central t...The objective of improving the state accounting system is to build a state accounting system based on a single and complete database which is applied uniformly across all public authorities and agencies from central to local. Such an accounting system must ensure a reliable and smooth flow of information among all the entities that take part in the preparation, allocation, execution, and finalization of the state budget. In order to improve the quality of financial information, to harmonize, and to develop accounting profession globally, the trend of international economic integration requires the standardization of accounting legislative framework among countries and first of all, the harmonization and unification of the preparation, presentation, and disclosure of financial information. Financial statements of each business in the private sector and financial statements of the government in the public sector in different countries should be transparent and presented in accordance with the accounting standards and principles and in line with international practices so that the financial information will be able to be compared and evaluated. Therefore, financial statements of each entity in the public sector and the consolidated financial statements of public sector entities issued by the government in different countries must be prepared and presented in a unified form to suit the international public sector accounting standards. Accordingly, with the application of the interview method in research, the main objective of this article is to focus on searching for the bases and consideration for the application of international public sector accounting standards in Vietnam in current conditions. This article consists of eight sections: (1) what are international public sector accounting standards? (2) accounting entities of the public sector; (3) the limitations of current public sector accounting in Vietnam; (4) financial information to meet the requirements of state management and to comply with international practices; (5) the advantages of applying international public sector accounting standards in Vietnam; (6) the difficulties and challenges of applying international public sector accounting standards in Vietnam; (7) learning experiences from other countries; and (8) conclusion.展开更多
文摘Teaching assessment is one of the most important components of college English teaching. The traditional assessment system over emphasizes the summative assessment, which used examinations as the main assessment method. Formative assessment focuses on the process assessment during the practice of teaching. It is integrated in the teaching and learning process and cannot be separated as evaluation. The formative assessment aims to confirm the students' potential, develop their ability in study and strengthen the students' confidence and the spirit of cooperation. It is also a method intended to generate feedback on performance to improve and accelerate teaching and learning effectively. Based on some theories, this paper states the importance of the application of formative assessment in college oral English teaching. It also introduces some principles and measures to apply this assessment. The reasonable and effective application can promote college oral English teaching.
基金The National Natural Science Foundation of China(No.90818027,60873050)the National High Technology Research andDevelopment Program of China (863 Program) (No.2009AA01Z147)+2 种基金Opening Foundation of State Key Laboratory Software Engineering in Wu-han University(No.SKLSE20080717)Opening Foundation of State KeyLaboratory for Novel Software Technology in Nanjing University(No.ZZ-KT2008F12)the Key Laboratory Foundation of Shanghai Municipal Science and Technology Commission (No.09DZ2272600)
文摘In order to analyze and test the component-based web application and decide when to stop the testing process, the concept of coverage criteria and test requirement reduction approach are proposed. First, four adequacy criteria are defined and subsumption relationships among them are proved. Then, a translation algorithm is presented to transfer the test model into a web application decision-to-decision graph(WADDGraph)which is used to reduce testing requirements. Finally, different sets of test requirements can be generated from WADDGraph by analyzing subsumption and equivalence relationships among edges based on different coverage criteria, and testers can select different test requirements according to different testing environments. The case study indicates that coverage criteria follow linear subsumption relationships in real web applications. Test requirements can be reduced more than 55% on average based on different coverage criteria and the size of test requirements increases with the increase in the complexity of the coverage criteria.
文摘MC CDMA is a thriving topic in recent years. Multiuser interference is also very severe as in DS CDMA. ML method is the best multiuser detection, but it has a computational complexity exponentially increased with the number of users. Mean field annealing and chaotic neural network are two promising optimum techniques. This paper applies them into the ML detection, comparison of the two methods is made.
基金The National High Technology Research and Development Program of China (863 Program) (No. 2007AA11Z202)the National Key Technology R & D Program of China during the 11th Five-Year Plan Period(No. 2006BAJ18B03)the Fundamental Research Funds for the Central Universities (No. DUT10RC(3) 112)
文摘This paper considers the problem of time varying congestion pricing to determine optimal time-varying tolls at peak periods for a queuing network with the interactions between buses and private cars.Through the combined applications of the space-time expanded network(STEN) and the conventional network equilibrium modeling techniques,a multi-class,multi-mode and multi-criteria traffic network equilibrium model is developed.Travelers of different classes have distinctive value of times(VOTs),and travelers from the same class perceive their travel disutility or generalized costs on a route according to different weights of travel time and travel costs.Moreover,the symmetric cost function model is extended to deal with the interactions between buses and private cars.It is found that there exists a uniform(anonymous) link toll pattern which can drive a multi-class,multi-mode and multi-criteria user equilibrium flow pattern to a system optimum when the system's objective function is measured in terms of money.It is also found that the marginal cost pricing models with a symmetric travel cost function do not reflect the interactions between traffic flows of different road sections,and the obtained congestion pricing toll is smaller than the real value.
基金Projects Y2007F46 supported by the Natural Science Foundation of Shandong Province20070424005 by the Doctor Disciplines Special Scientific Researc Foundation of the Ministry of Education+1 种基金108158 by the Key Project of the Ministry of Education of China50539080 by the National Natural Scienc Foundation of China
文摘The mechanism of mine water inrushes in coal mines in China differs considerably from that in other countries.In China, most water inrushes occur from floor strata, where the water-inrush sources are karstic limestone aquifers.Our study describes the mechanism of mine water inrushes through a fault in the mine floor using principles of strata mechanics and the path of water inrush from an aquifer to the working face.A criterion to judge whether a ground water inrush will occur through a fault or not is also described, together with a case history of water inflow in the Feicheng coalfield, China.
文摘The practical application of semiconductor-based high-efficiency white-light sources, also known as light-emitting diodes, or LEDs, is a recent development of Japanese engineering. This development could be a game-changer for lighting worldwide, given that current power consumption for lighting accounts for 16% of the total electricity consumption in Japan.
文摘Hyperbole is a very common rhetorical device which is widely used both in English and Chinese. In order to express his/her strong feelings and also to make his/her language more powerful, the writer/speaker exaggerates things on purpose. Yet in spite of the over-truth expression, employment of hyperbole does not affect the conversation flow between parties. Through an analysis of hyperbole from the perspective of pragrnatics, this article tries to explain the pragmatic functions of hyperbole.
基金Supported by the National Science Foundation China(61422303)National Key Technology R&D Program(2015BAF22B02)the Development Fund for Shanghai Talents
文摘Equipment selection for industrial process usually requires the extensive participation of industrial experts and technologists, which causes a serious waste of resources. This work presents an equipment selection knowledge base system for industrial styrene process(S-ESKBS) based on the ontology technology. This structure includes a low-level knowledge base and a top-level interactive application. As the core part of the S-ESKBS, the low-level knowledge base consists of the equipment selection ontology library, equipment selection rule set and Pellet inference engine. The top-level interactive application is implemented using S-ESKBS, including the parsing storage layer, inference query layer and client application layer. Case studies for the industrial styrene process equipment selection of an analytical column and an alkylation reactor are demonstrated to show the characteristics and implementability of the S-ESKBS.
文摘For a long time, it has been generally believed that spin-spin interactions can only exist in a theory where Lorentz symmetry is gauged, and a theory with spin-spin interactions is not perturbatively renormalizable. But this is not true. By studying the motion of a spinning particle in gravitational field, it is found that there exist spin-spin interactions in gauge theory of gravity. Its mechanism is that a spinning particle will generate gravitomagnetic field in space-time, and this gravitomagnetic field will interact with the spin of another particle, which will cause spin-spin interactions. So, spin-spin interactions are transmitted by gravitational field. The form of spin-spin interactions in post Newtonian approximations is deduced. This result can also be deduced from the Papapetrou equation. This kind of interaction will not affect the renormalizability of the theory. The spin-spin interactions will violate the weak equivalence principle, and the violation effects are detectable. An experiment is proposed to detect the effects of the violation of the weak equivalence principle.
文摘The presented iterative multiuser detection technique was based on joint deregularized and box-constrained solution to quadratic optimization with iterations similar to that used in the nonstationary Tikhonov iterated algorithm.The deregularization maximized the energy of the solution,which was opposite to the Tikhonov regularization where the energy was minimized.However,combined with box-constraints,the deregularization forced the solution to be close to the binary set.It further exploited the box-constrained dichotomous coordinate descent algorithm and adapted it to the nonstationary iterative Tikhonov regularization to present an efficient detector.As a result,the worst-case and average complexity are reduced down as K2.8 and K2.5 floating point operation per second,respectively.The development improves the "efficient frontier" in multiuser detection,which is illustrated by simulation results.In addition,most operations in the detector are additions and bit-shifts.This makes the proposed technique attractive for fixed-point hardware implementation.
文摘Two dimensional irregular polygons packing problem is very difficult to be solved in traditional optimal way.Simulated annealing(SA)algorithm is a stochastic optimization technique that can be used to solve packing problems.The whole process of SA is introduced firstly in this paper. An extended neighborhood searching method in SA is mainly analyzed. A general module of SA algorithm is given and used to lay out the irregular polygons. The judgment of intersection and other constrains of irregular polygons are analyzed. Then an example that was used in the paper of Stefan Jakobs is listed.Results show that this SA algorithm shortens the computation time and improves the solution.
文摘In distributed systems independent agents need to interact with each other to accomplish their task. Modern peer-to-peer computing technologies always concern with enabling interaction among agents and help them cooperate with each other. But in fact, access control should also be considered to limit interaction to make it harmless. This paper proposed a proxy based rule regulated interaction (PBRRI) model. Role based access control is introduced for security concerns. Regulation rules are enforced in a distributed manner so that PBRRI can be applied to the open distributed systems such as Internet.
基金Supported by the National Natural Science Foundation of China (Nos.40671145 and 60573115)the Provincial Natural Science Foundation of Guangdong,China (Nos.04300504 and 05006623)
文摘Fuzzy association rules (FARs) can be powerful in assessing regional soil quality, a critical step prior to land planning and utilization; however, traditional FARs mined from soil quality database, ignoring the importance variability of the rules, can be redundant and far from optimal. In this study, we developed a method applying different weights to traditional FARs to improve accuracy of soil quality assessment. After the FARs for soil quality assessment were mined, redundant rules were eliminated according to whether the rules were significant or not in reducing the complexity of the soil quality assessment models and in improving the comprehensibility of FARs. The global weights, each representing the importance of a FAR in soil quality assessment, were then introduced and refined using a gradient descent optimization method. This method was applied to the assessment of soil resources conditions in Guangdong Province, China. The new approach had an accuracy of 87%, when 15 rules were mined, as compared with 76% from the traditional approach. The accuracy increased to 96% when 32 rules were mined, in contrast to 88% from the traditional approach. These results demonstrated an improved comprehensibility of FARs and a high accuracy of the proposed method.
基金the National Natural Science Foundation of China(Nos.41172290 and40572160)
文摘In order to evaluate the feasibility of safe mining close to the contact zone under reduced security coal pillar conditions at a coal mine in eastern China, the interaction mechanism of the interface between deep buried sand and a paleo-weathered rock mass was investigated in the laboratory by direct shear testing. A DRS-1 high pressure soil shear testing machine and orthogonal design method were used in the direct shear tests. Variance and range methods were applied to analyze the sensitivity of each factor that has an influence on the mechanical characters of the interface. The test results show that the normal pressure is the main influencing factor for mechanical characteristics of the interface, while the lithological characters and roughness are minor factors; the shear stress against shear displacement curve for the interface shows an overall hyperbola relationship, no obvious peak stress and dilatancy was observed.When the normal pressure is 6 MPa, the shear strengths of interfaces with different roughness are basically the same, and when the normal pressure is more than 8 MPa, the larger the roughness of the interface, the larger will be the shear strength; the shear strength has a better linear relationship with the normal pressure, which can be described by a linear Mohr–Coulomb criterion.
基金Projects(10871031, 60474070) supported by the National Natural Science Foundation of ChinaProject(07A001) supported by the Scientific Research Fund of Hunan Provincial Education Department, China
文摘Based on the rough set theory which is a powerful tool in dealing with vagueness and uncertainty, an algorithm to mine association rules in incomplete information systems was presented and the support and confidence were redefined. The algorithm can mine the association rules with decision attributes directly without processing missing values. Using the incomplete dataset Mushroom from UCI machine learning repository, the new algorithm was compared with the classical association rules mining algorithm based on Apriori from the number of rules extracted, testing accuracy and execution time. The experiment results show that the new algorithm has advantages of short execution time and high accuracy.
基金Foundation item: Project(2013CB036004) supported by the National Basic Research Program of China Project(51178468) supported by the National Natural Science Foundation of China
文摘Linear failure criterion is widely used in calculation of earth pressure acting on shallow tunnels. However, experimental evidence shows that nonlinear failure criterion is able to represent fairly well the failure of almost all types of rocks, A nonlinear Hock-Brown failure criterion is employed to estimate the supporting pressures of shallow tunnels in limit analysis framework. Two failure mechanisms are proposed for calculating the work rate of extemal force and the internal energy dissipation. A tangential line to the nonlinear failure criterion is used to formulate the supporting pressure problem as a nonlinear programming problem. The objective function formulated in this way is minimized with respect to the failure mechanism and the location of tangency point. In order to assess the validity, the supporting pressures for the proposed failure mechanisms are calculated and compared with each other, and the present results are compared with previously published solutions when the nonlinear criterion is reduced to linear criterion. The agreement supports the validity of the proposed failure mechanisms. An experiment is conducted to investigate the influences of the nonlinear criterion on collapse shape and supporting pressures of shallow tunnels.
基金supported by the National Natural Science Foundation of China(No.21688102,No.21573047and No.21273045)
文摘Binuclear transition metal carbonyl clusters serve as the simplest models in understand- ing metal-metal and ligand bonding that are important organometallic chemistry catalysis. Binuclear first row transition metal carbonyl ions are produced via a pulsed laser vaporiza- tion/supersonic expansion cluster ion source in the gas phase. These ions are studied by mass-selected infrared photodissociation spectroscopy in the carbonyl stretching frequency region. Density functional theory calculations have been performed on the geometric struc- tures and vibrational spectra of the carbonyl ions. Their geometric and electronic structures are determined by comparison of the experimental IR spectra with the simulated spectra. The structure and the metM-metal and metal-CO bonding of both saturated and unsaturated homonuclear as well as heteronuclear carbonyl cluster cations and anions are discussed.
文摘The national musicology was introduced into China from the western countries, so the Chinese scholars need to continue to absorb and draw lessons from the advanced western national musicological theories, and should carry out the innovation base on the "used doctrine". According to China's national conditions and the characteristics of the cultures, improve the research methodology of the national musicology, so that the national musicology can have the Chinese characteristics. The national musicology is an independent basic discipline in the university education. In China, the music education and research work in colleges and universities has an important role in the inheritance and development of the national music. In this paper, combined with the present situations of the music education in colleges and universities, from the perspectives of the education and the research, the author expounds the ideas of the development trends of the national musicology in the music education in colleges and universities.
文摘In this paper,the criteria set related to the priority preorders of water resources projects is introduced.A fuzzy multiple criteria group decision-making model is established,which incorporates quantitative analysis,judgments,experience and preferences of decision-makers.The model is used in practice to determine the priority preorders of five water resources projects,and the results show that the best choice can supply more new employment,domestic water and irrigation water,and has better quality.
文摘The objective of improving the state accounting system is to build a state accounting system based on a single and complete database which is applied uniformly across all public authorities and agencies from central to local. Such an accounting system must ensure a reliable and smooth flow of information among all the entities that take part in the preparation, allocation, execution, and finalization of the state budget. In order to improve the quality of financial information, to harmonize, and to develop accounting profession globally, the trend of international economic integration requires the standardization of accounting legislative framework among countries and first of all, the harmonization and unification of the preparation, presentation, and disclosure of financial information. Financial statements of each business in the private sector and financial statements of the government in the public sector in different countries should be transparent and presented in accordance with the accounting standards and principles and in line with international practices so that the financial information will be able to be compared and evaluated. Therefore, financial statements of each entity in the public sector and the consolidated financial statements of public sector entities issued by the government in different countries must be prepared and presented in a unified form to suit the international public sector accounting standards. Accordingly, with the application of the interview method in research, the main objective of this article is to focus on searching for the bases and consideration for the application of international public sector accounting standards in Vietnam in current conditions. This article consists of eight sections: (1) what are international public sector accounting standards? (2) accounting entities of the public sector; (3) the limitations of current public sector accounting in Vietnam; (4) financial information to meet the requirements of state management and to comply with international practices; (5) the advantages of applying international public sector accounting standards in Vietnam; (6) the difficulties and challenges of applying international public sector accounting standards in Vietnam; (7) learning experiences from other countries; and (8) conclusion.