Group testing is a method that can be used to estimate the prevalence of rare infectious diseases,which can effectively save time and reduce costs compared to the method of random sampling.However,previous literature ...Group testing is a method that can be used to estimate the prevalence of rare infectious diseases,which can effectively save time and reduce costs compared to the method of random sampling.However,previous literature only demonstrated the optimality of group testing strategy while estimating prevalence under some strong assumptions.This article weakens the assumption of misclassification rate in the previous literature,considers the misclassification rate of the infected samples as a differentiable function of the pool size,and explores some optimal properties of group testing for estimating prevalence in the presence of differential misclassification conforming to this assumption.This article theoretically demonstrates that the group testing strategy performs better than the sample by sample procedure in estimating disease prevalence when the total number of sample pools is given or the size of the test population is determined.Numerical simulation experiments were conducted to evaluate the performance of group tests in estimating prevalence in the presence of dilution effect.展开更多
This paper depicted the physiographic landscape features and natural vegetation situation of study area (the eastern Jilin Province), and expatiates the definition, basic characters and its development of Ecological L...This paper depicted the physiographic landscape features and natural vegetation situation of study area (the eastern Jilin Province), and expatiates the definition, basic characters and its development of Ecological Land Classification (ELC). Based on the combination of relief map, satellite photography for study area and vegetation inventory data of 480 sample sites, a 5-class and a 15-class ecological land type map was concluded according to 4 important factors including slope, aspect, vegetation and elevation. Ecological Classification System (ECS) is a method to identify, characterize, and map ecosystems. The Ecological Land Type (ELT) was examined and applied initially in eastern Jilin Province.展开更多
Eight kinds of phytoecdysteroids extracted from different parts of Ajuga multiflora Bunge (Labiatae) that were collected from different places at different time were tested for killing effects on the 2-instar larvae o...Eight kinds of phytoecdysteroids extracted from different parts of Ajuga multiflora Bunge (Labiatae) that were collected from different places at different time were tested for killing effects on the 2-instar larvae of Cryptorrhynchus lapathi L by adding them to the artificial diet of larvae. The experimental results indicated that adding 1-3-mL phytoecdysteroids to the artificial diet could lead 58%-100% of 2-instar larvae of C. lapathi to death within 24 days. The phytoecdysteroids extracted from the whole plant of A. multiflora which was collected before flowering time were much more effective than those extracted from the plants collected at flowering and after flowering periods, and the modified mortality rate of larvae reached 65.22%, 85.07%, and 98.11% at the dosage level of 1-mL, 2-mL, and 3-mL extracts, respectively. The extract made from root of A. multiflora plant was more effective in killing efficiency than those from stem and leaves, and the average death rates of larvae were up to 100%, 98.20% and 98.32% at dosage levels of 1-mL, 2-mL, and 3-mL extracts, respectively. The killing speed of the extracted phytoecdysteroids was slower than that of triflumuron, hexaflumuron or deltamethrin emulsifiable concentrate. The mortality rate of larvae is closely related to the feeding duration on the diets containing phytoecdysteroids. Feeding on the diets with addition of phytoecdysteroids for 16 days, more than 80% of treated 2-instar larvae of C. lapathi were led to death. The killing effect of the extracts was little affected by the growth areas of A. multiflora plant and the adding way to artificial diet.展开更多
Based on the conclusions of domestic and foreign research, we have analyzed the collapse-fall characteristics of overlying strata and the mechanism of aquifer-protective mining in shallow coal seam working faces at th...Based on the conclusions of domestic and foreign research, we have analyzed the collapse-fall characteristics of overlying strata and the mechanism of aquifer-protective mining in shallow coal seam working faces at the Shendong Mine. We have selected the height of the water-conducting fracture zone in overlying strata as a composite index and established the applicable conditions of aquifer-protective mining in shallow coal seams with a multi-factor synthetic-index classification method. From our calculations and analyses of variance, we used factors such as the overlying strata strength, mining disturbing factors and rock integrity as related factors of the composite index. We have classified the applicable conditions of aquifer-protective mining in shallow coal seams into seven types by comparing the result of the height of water-conducting fractured zones of long-wall and short-wall working faces with the thickness of the bedrock, the thickness of the weathered zone and the size of safety coal-rock pillars. As a result, we propose the preliminary classification system of aquifer-protective mining in shallow coal seams. It can provide a theoretical guidance for safe applications of aquifer-protective mining technology in shallow coal seams under similar conditions.展开更多
In this paper,we prove the Srivastava-Pint'er's addition theorems(see Applied Mathematic Lett.17(2004),375-380) by applying the another methods.We also provide some analoges of these addition theorems and dedu...In this paper,we prove the Srivastava-Pint'er's addition theorems(see Applied Mathematic Lett.17(2004),375-380) by applying the another methods.We also provide some analoges of these addition theorems and deduce the corresponding special cases.展开更多
Based on the massive data collected with a passive network monitoring equipment placed in China＇s backbone, we present a deep insight into the network backbone traffic and evaluate various ways for inproving traffic ...Based on the massive data collected with a passive network monitoring equipment placed in China＇s backbone, we present a deep insight into the network backbone traffic and evaluate various ways for inproving traffic classifying efficiency in this pa- per. In particular, the study has scrutinized the net- work traffic in terms of protocol types and signatures, flow length, and port distffoution, from which mean- ingful and interesting insights on the current Intemet of China from the perspective of both the packet and flow levels are derived. We show that the classifica- tion efficiency can be greatly irrproved by using the information of preferred ports of the network applica- tions. Quantitatively, we find two traffic duration thresholds, with which 40% of TCP flows and 70% of UDP flows can be excluded from classification pro- cessing while the in^act on classification accuracy is trivial, i.e., the classification accuracy can still reach a high level by saving 85% of the resources.展开更多
This paper addresses multi-resource fair allocation: a fundamental research topic in cloud computing. To improve resource utilization under well-studied fairness constraints, we propose a new allocation mechanism call...This paper addresses multi-resource fair allocation: a fundamental research topic in cloud computing. To improve resource utilization under well-studied fairness constraints, we propose a new allocation mechanism called Dominant Resource with Bottlenecked Fairness(DRBF), which generalizes Bottleneck-aware Allocation(BAA) to the settings of Dominant Resource Fairness(DRF). We classify users into different queues by their dominant resources. The goals are to ensure that users in the same queue receive allocations in proportion to their fair shares while users in different queues receive allocations that maximize resource utilization subject to well-studied fairness properties such as those in DRF. Under DRBF, no user 1) is worse off sharing resources than dividing resources equally among all users; 2) prefers the allocation of another user; 3) can improve their own allocation without reducing other users' allocations; and(4) can benefit by misreporting their resource demands. Experiments demonstrate that the proposed allocation policy performs better in terms of high resource utilization than does DRF.展开更多
In order to analyze changes in human settlement in Xuzhou city during the past 20 years, changes in land cover and vegetation were investigated based on multi-temporal remote sensing Landsat TM images. We developed a ...In order to analyze changes in human settlement in Xuzhou city during the past 20 years, changes in land cover and vegetation were investigated based on multi-temporal remote sensing Landsat TM images. We developed a hierarchical classifier system that uses different feature inputs for specific classes and conducted a classification post-processing approach to improve its accuracy. From our statistical analysis of changes in urban land cover from 1987 to 2007, we conclude that built-up land areas have obviously increased, while farmland has seen in a continuous loss due to urban growth and human activities. A NDVI difference approach was used to extract information on changes in vegetation. A false change information elimination approach was developed based on prior knowledge and statistical analysis. The areas of vegetation cover have been in continuous decline over the past 20 years, although some measures have been adopted to protect and maintain urban vegetation. Given the stability of underground coal exploitation since 1990s, urban growth has become the major driving force in vegetation loss, which is different from the vegetation change driven by coal exploitation mainly before 1990.展开更多
A new predictive model for evaluating the vibration of a sawing machine was developed using a new rock classification system. The predictors are machine parameters and a rock sawability index. The new rock classificat...A new predictive model for evaluating the vibration of a sawing machine was developed using a new rock classification system. The predictors are machine parameters and a rock sawability index. The new rock classification system includes four major parameters of the rock： uniaxial compressive strength, abrasiv- ity index, mean MoWs hardness, and Young＇s modulus. The FAHP approach was used when determining the weights of these parameters by six decision makers. Two groups of carbonate rocks were sawn using a fully-instrumented laboratory sawing rig at different feed rates and depths of cut. During the sawing trials system vibration was monitored as a measure of saw performance. Then, a new statistical model was obtained by multiple regression on the machining parameters and the rock sawability index. The model is very useful for the evaluation of the system vibration, and for selecting suitable machining parameters, from a limited set of mechanical properties.展开更多
As the risk of malware is sharply increasing in Android platform,Android malware detection has become an important research topic.Existing works have demonstrated that required permissions of Android applications are ...As the risk of malware is sharply increasing in Android platform,Android malware detection has become an important research topic.Existing works have demonstrated that required permissions of Android applications are valuable for malware analysis,but how to exploit those permission patterns for malware detection remains an open issue.In this paper,we introduce the contrasting permission patterns to characterize the essential differences between malwares and clean applications from the permission aspect Then a framework based on contrasting permission patterns is presented for Android malware detection.According to the proposed framework,an ensemble classifier,Enclamald,is further developed to detect whether an application is potentially malicious.Every contrasting permission pattern is acting as a weak classifier in Enclamald,and the weighted predictions of involved weak classifiers are aggregated to the final result.Experiments on real-world applications validate that the proposed Enclamald classifier outperforms commonly used classifiers for Android Malware Detection.展开更多
This paper introduces the Chinese"Dove"——A practical application system of bird-mimetic air vehicles developed for more than a decade by the Institute of Flight Vehicle Innovation of Northwest Polytechnic ...This paper introduces the Chinese"Dove"——A practical application system of bird-mimetic air vehicles developed for more than a decade by the Institute of Flight Vehicle Innovation of Northwest Polytechnic University(NWPU)in China.Firstly,the main components,flight capability and flight verification of the Chinese"Dove"are presented.Then,the methods for the aerodynamic simulation and wind tunnel experiments are put forward.Secondly,the design of high-lift and high-thrust flexible flapping wings,a series of flapping mechanisms,gust-resistance layout and micro flight control/navigation system are presented.Some future studies on the application system of bionic micro air vehicles are given,including observation of natural flight creatures,aerodynamics in flight,mechanical and new material driving systems,structural mechanics,flight mechanics,and the information perception and intelligent decision-making control,which are related to research of flight bioinformatic perception and brain science.Finally,some application examples of complex flapping movements,active/passive deformation of bird wings,new low-energy motion-driven system,bionic intelligent decision-making and control/navigation are discussed.展开更多
In limited feedback-based CloudRAN(C-RAN) systems,the inter-cluster and intra-cluster interference together with the quantification error can seriously deteriorates the system spectral efficiency.We,in this paper,prop...In limited feedback-based CloudRAN(C-RAN) systems,the inter-cluster and intra-cluster interference together with the quantification error can seriously deteriorates the system spectral efficiency.We,in this paper,propose an efficient three-phase framework and corresponding algorithms for dealing with this problem.Firstly,a greedy scheduling algorithm based on the lower bound of the ergodic rate is performed for generating an elementary cluster in the first phase.And then the elementary cluster is divided into many small clusters according to the following proposed algorithms based on the short term instantaneous information in the second phase.In the end,based on the limited feedback two zero-forcing(ZF) precoding strategies are adopted for reducing the intra-cluster interference in the third phase.The provided Monte Carlo simulations show the effectiveness of our proposed algorithms in the respect of system spectral efficiency and average user rate.展开更多
In order to discuss the effect of tectonic stress on the structural evolution of coal, given the importance attached to High-resolution Transmission Electron Microscopy (HTEM), we investigated several aspects of mater...In order to discuss the effect of tectonic stress on the structural evolution of coal, given the importance attached to High-resolution Transmission Electron Microscopy (HTEM), we investigated several aspects of material structures of high-rank Carboniferous period coal, located in the northern foreland basin of the Dabie orogenic belt in eastern China. High powered crystal lattice images of Bright Fields (BF) and Selected Area Diffraction patterns (SAD) of different types of metamorphism in coal were obtained. The results show that the Basic Structural Units (BSU) become increasingly more compact as a function of rising tem-perature and pressure. Under pressure, the local orientation of molecules is strengthened, the arrangement of BSU speeds up and the degree of order is clearly enhanced.展开更多
Nowadays,many steganographic tools have been developed,and secret messages can be imperceptibly transmitted through public networks.This paper concentrates on steganalysis against spatial least significant bit(LSB) ma...Nowadays,many steganographic tools have been developed,and secret messages can be imperceptibly transmitted through public networks.This paper concentrates on steganalysis against spatial least significant bit(LSB) matching,which is the prototype of many advanced information hiding methods.Many existing algorithms deal with steganalysis problems by using the dependencies between adjacent pixels.From another aspect,this paper calculates the differences among pixel pairs and proves that the histogram of difference values will be smoothed by stego noises.We calculate the difference histogram characteristic function(DHCF) and deduce that the moment of DHCFs(DHCFM) will be diminished after stego bits are hidden in the image.Accordingly,we compute the DHCFMs as the discriminative features.We calibrate the features by decreasing the influence of image content on them and train support vector machine classifiers based on the calibrated features.Experimental results demonstrate that the DHCFMs calculated with nonadjacent pixels are helpful to detect stego messages hidden by LSB matching.展开更多
The results of commercial application of two types of C_8 aromatics isomerization catalysts under different feed conditions were compared to gain an insight in the techno-economical basis for selecting proper technolo...The results of commercial application of two types of C_8 aromatics isomerization catalysts under different feed conditions were compared to gain an insight in the techno-economical basis for selecting proper technological route at the plant.The comparison reveals differences in every aspect of feed consumption,unit capacity,product output,product distribution,and unit process parameters depending upon which catalyst type is adopted by the integrated PX complex.The type of aromatics isomerization catalyst has its influence on the plant scale,the construction cost,the process unit capacity and the product cost,with the magnitude of its impact varying with changing feed conditions.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.72091212).
文摘Group testing is a method that can be used to estimate the prevalence of rare infectious diseases,which can effectively save time and reduce costs compared to the method of random sampling.However,previous literature only demonstrated the optimality of group testing strategy while estimating prevalence under some strong assumptions.This article weakens the assumption of misclassification rate in the previous literature,considers the misclassification rate of the infected samples as a differentiable function of the pool size,and explores some optimal properties of group testing for estimating prevalence in the presence of differential misclassification conforming to this assumption.This article theoretically demonstrates that the group testing strategy performs better than the sample by sample procedure in estimating disease prevalence when the total number of sample pools is given or the size of the test population is determined.Numerical simulation experiments were conducted to evaluate the performance of group tests in estimating prevalence in the presence of dilution effect.
基金supported by Chinese Academy of Sciences"100 people’project and the Open Research Station of Changbai Mountain Forest Ecosystem
文摘This paper depicted the physiographic landscape features and natural vegetation situation of study area (the eastern Jilin Province), and expatiates the definition, basic characters and its development of Ecological Land Classification (ELC). Based on the combination of relief map, satellite photography for study area and vegetation inventory data of 480 sample sites, a 5-class and a 15-class ecological land type map was concluded according to 4 important factors including slope, aspect, vegetation and elevation. Ecological Classification System (ECS) is a method to identify, characterize, and map ecosystems. The Ecological Land Type (ELT) was examined and applied initially in eastern Jilin Province.
基金This paper was supported by National Natural Science Foundation of China(39970620)the"TRAPOYT"
文摘Eight kinds of phytoecdysteroids extracted from different parts of Ajuga multiflora Bunge (Labiatae) that were collected from different places at different time were tested for killing effects on the 2-instar larvae of Cryptorrhynchus lapathi L by adding them to the artificial diet of larvae. The experimental results indicated that adding 1-3-mL phytoecdysteroids to the artificial diet could lead 58%-100% of 2-instar larvae of C. lapathi to death within 24 days. The phytoecdysteroids extracted from the whole plant of A. multiflora which was collected before flowering time were much more effective than those extracted from the plants collected at flowering and after flowering periods, and the modified mortality rate of larvae reached 65.22%, 85.07%, and 98.11% at the dosage level of 1-mL, 2-mL, and 3-mL extracts, respectively. The extract made from root of A. multiflora plant was more effective in killing efficiency than those from stem and leaves, and the average death rates of larvae were up to 100%, 98.20% and 98.32% at dosage levels of 1-mL, 2-mL, and 3-mL extracts, respectively. The killing speed of the extracted phytoecdysteroids was slower than that of triflumuron, hexaflumuron or deltamethrin emulsifiable concentrate. The mortality rate of larvae is closely related to the feeding duration on the diets containing phytoecdysteroids. Feeding on the diets with addition of phytoecdysteroids for 16 days, more than 80% of treated 2-instar larvae of C. lapathi were led to death. The killing effect of the extracts was little affected by the growth areas of A. multiflora plant and the adding way to artificial diet.
基金Financial support for this work, provided by the research fund of the North China Institute of Science and Technology (No.A09002)the National Natural Science Foundation of China (No.50834005)the National Basic Research Program of China (No.2007CB209402)
文摘Based on the conclusions of domestic and foreign research, we have analyzed the collapse-fall characteristics of overlying strata and the mechanism of aquifer-protective mining in shallow coal seam working faces at the Shendong Mine. We have selected the height of the water-conducting fracture zone in overlying strata as a composite index and established the applicable conditions of aquifer-protective mining in shallow coal seams with a multi-factor synthetic-index classification method. From our calculations and analyses of variance, we used factors such as the overlying strata strength, mining disturbing factors and rock integrity as related factors of the composite index. We have classified the applicable conditions of aquifer-protective mining in shallow coal seams into seven types by comparing the result of the height of water-conducting fractured zones of long-wall and short-wall working faces with the thickness of the bedrock, the thickness of the weathered zone and the size of safety coal-rock pillars. As a result, we propose the preliminary classification system of aquifer-protective mining in shallow coal seams. It can provide a theoretical guidance for safe applications of aquifer-protective mining technology in shallow coal seams under similar conditions.
基金Supported by the PCSIRT of Education of China(IRT0621)Supported by the Innovation Program of Shanghai Municipal Education Committee of China(08ZZ24)Supported by the Henan Innovation Project for University Prominent Research Talents of China(2007KYCX0021)
文摘In this paper,we prove the Srivastava-Pint'er's addition theorems(see Applied Mathematic Lett.17(2004),375-380) by applying the another methods.We also provide some analoges of these addition theorems and deduce the corresponding special cases.
基金This paper was partially supported by the National Natural Science Foundation of China under Crant No. 61072061111 Project of China under Crant No. B08004 the Fundamental Research Funds for the Central Universities under Grant No. 2009RC0122. References
文摘Based on the massive data collected with a passive network monitoring equipment placed in China＇s backbone, we present a deep insight into the network backbone traffic and evaluate various ways for inproving traffic classifying efficiency in this pa- per. In particular, the study has scrutinized the net- work traffic in terms of protocol types and signatures, flow length, and port distffoution, from which mean- ingful and interesting insights on the current Intemet of China from the perspective of both the packet and flow levels are derived. We show that the classifica- tion efficiency can be greatly irrproved by using the information of preferred ports of the network applica- tions. Quantitatively, we find two traffic duration thresholds, with which 40% of TCP flows and 70% of UDP flows can be excluded from classification pro- cessing while the in^act on classification accuracy is trivial, i.e., the classification accuracy can still reach a high level by saving 85% of the resources.
基金financial support of the Oversea Study Program of the Guangzhou Elite Project(GEP)supported by the National Natural Science Foundation of China under Grant 61471173Guangdong Science Technology Project(no:2017A010101027)
文摘This paper addresses multi-resource fair allocation: a fundamental research topic in cloud computing. To improve resource utilization under well-studied fairness constraints, we propose a new allocation mechanism called Dominant Resource with Bottlenecked Fairness(DRBF), which generalizes Bottleneck-aware Allocation(BAA) to the settings of Dominant Resource Fairness(DRF). We classify users into different queues by their dominant resources. The goals are to ensure that users in the same queue receive allocations in proportion to their fair shares while users in different queues receive allocations that maximize resource utilization subject to well-studied fairness properties such as those in DRF. Under DRBF, no user 1) is worse off sharing resources than dividing resources equally among all users; 2) prefers the allocation of another user; 3) can improve their own allocation without reducing other users' allocations; and(4) can benefit by misreporting their resource demands. Experiments demonstrate that the proposed allocation policy performs better in terms of high resource utilization than does DRF.
基金supported by the National High Technology Research and Developmemt Program of China (No2007AA12Z162)the Program for New Century Excellent Talents in University, Ministry of Education (NoNCET-06-0476)the Jiangsu Provincial 333 Engineering for High Level Talents(No.BK2006505)
文摘In order to analyze changes in human settlement in Xuzhou city during the past 20 years, changes in land cover and vegetation were investigated based on multi-temporal remote sensing Landsat TM images. We developed a hierarchical classifier system that uses different feature inputs for specific classes and conducted a classification post-processing approach to improve its accuracy. From our statistical analysis of changes in urban land cover from 1987 to 2007, we conclude that built-up land areas have obviously increased, while farmland has seen in a continuous loss due to urban growth and human activities. A NDVI difference approach was used to extract information on changes in vegetation. A false change information elimination approach was developed based on prior knowledge and statistical analysis. The areas of vegetation cover have been in continuous decline over the past 20 years, although some measures have been adopted to protect and maintain urban vegetation. Given the stability of underground coal exploitation since 1990s, urban growth has become the major driving force in vegetation loss, which is different from the vegetation change driven by coal exploitation mainly before 1990.
文摘A new predictive model for evaluating the vibration of a sawing machine was developed using a new rock classification system. The predictors are machine parameters and a rock sawability index. The new rock classification system includes four major parameters of the rock： uniaxial compressive strength, abrasiv- ity index, mean MoWs hardness, and Young＇s modulus. The FAHP approach was used when determining the weights of these parameters by six decision makers. Two groups of carbonate rocks were sawn using a fully-instrumented laboratory sawing rig at different feed rates and depths of cut. During the sawing trials system vibration was monitored as a measure of saw performance. Then, a new statistical model was obtained by multiple regression on the machining parameters and the rock sawability index. The model is very useful for the evaluation of the system vibration, and for selecting suitable machining parameters, from a limited set of mechanical properties.
基金This work was supported by Deakin Cyber Security Research Cluster National Natural Science Foundation of China under Grant Nos. 61304067 and 61202211 +1 种基金 Guangxi Key Laboratory of Trusted Software No. kx201325 the Fundamental Research Funds for the Central Universities under Grant No 31541311314.
文摘As the risk of malware is sharply increasing in Android platform,Android malware detection has become an important research topic.Existing works have demonstrated that required permissions of Android applications are valuable for malware analysis,but how to exploit those permission patterns for malware detection remains an open issue.In this paper,we introduce the contrasting permission patterns to characterize the essential differences between malwares and clean applications from the permission aspect Then a framework based on contrasting permission patterns is presented for Android malware detection.According to the proposed framework,an ensemble classifier,Enclamald,is further developed to detect whether an application is potentially malicious.Every contrasting permission pattern is acting as a weak classifier in Enclamald,and the weighted predictions of involved weak classifiers are aggregated to the final result.Experiments on real-world applications validate that the proposed Enclamald classifier outperforms commonly used classifiers for Android Malware Detection.
基金supported by the National Key Research and Development Program of China(No.2017YFB1300102)the National Natural Science Foundation of China(No.U1613227)。
文摘This paper introduces the Chinese"Dove"——A practical application system of bird-mimetic air vehicles developed for more than a decade by the Institute of Flight Vehicle Innovation of Northwest Polytechnic University(NWPU)in China.Firstly,the main components,flight capability and flight verification of the Chinese"Dove"are presented.Then,the methods for the aerodynamic simulation and wind tunnel experiments are put forward.Secondly,the design of high-lift and high-thrust flexible flapping wings,a series of flapping mechanisms,gust-resistance layout and micro flight control/navigation system are presented.Some future studies on the application system of bionic micro air vehicles are given,including observation of natural flight creatures,aerodynamics in flight,mechanical and new material driving systems,structural mechanics,flight mechanics,and the information perception and intelligent decision-making control,which are related to research of flight bioinformatic perception and brain science.Finally,some application examples of complex flapping movements,active/passive deformation of bird wings,new low-energy motion-driven system,bionic intelligent decision-making and control/navigation are discussed.
基金supported by the National Natural Science Foundation of China(NSFC) under Grant(No. 61461136001)
文摘In limited feedback-based CloudRAN(C-RAN) systems,the inter-cluster and intra-cluster interference together with the quantification error can seriously deteriorates the system spectral efficiency.We,in this paper,propose an efficient three-phase framework and corresponding algorithms for dealing with this problem.Firstly,a greedy scheduling algorithm based on the lower bound of the ergodic rate is performed for generating an elementary cluster in the first phase.And then the elementary cluster is divided into many small clusters according to the following proposed algorithms based on the short term instantaneous information in the second phase.In the end,based on the limited feedback two zero-forcing(ZF) precoding strategies are adopted for reducing the intra-cluster interference in the third phase.The provided Monte Carlo simulations show the effectiveness of our proposed algorithms in the respect of system spectral efficiency and average user rate.
基金support for this work, provided by the National Natural Science Foundation of China (No40872105)the Scientific Research Foundation of the North China Institute of Science Technology (NoA08002)
文摘In order to discuss the effect of tectonic stress on the structural evolution of coal, given the importance attached to High-resolution Transmission Electron Microscopy (HTEM), we investigated several aspects of material structures of high-rank Carboniferous period coal, located in the northern foreland basin of the Dabie orogenic belt in eastern China. High powered crystal lattice images of Bright Fields (BF) and Selected Area Diffraction patterns (SAD) of different types of metamorphism in coal were obtained. The results show that the Basic Structural Units (BSU) become increasingly more compact as a function of rising tem-perature and pressure. Under pressure, the local orientation of molecules is strengthened, the arrangement of BSU speeds up and the degree of order is clearly enhanced.
基金supported by the NSFC(61173141,61362032,U1536206, 61232016,U1405254,61373133,61502242,61572258)BK20150925+4 种基金the Natural Science Foundation of Jiangxi Province, China(20151BAB207003)the Fund of Jiangsu Engineering Center of Network Monitoring(KJR1402)the Fund of MOE Internet Innovation Platform(KJRP1403)the CICAEET fundthe PAPD fund
文摘Nowadays,many steganographic tools have been developed,and secret messages can be imperceptibly transmitted through public networks.This paper concentrates on steganalysis against spatial least significant bit(LSB) matching,which is the prototype of many advanced information hiding methods.Many existing algorithms deal with steganalysis problems by using the dependencies between adjacent pixels.From another aspect,this paper calculates the differences among pixel pairs and proves that the histogram of difference values will be smoothed by stego noises.We calculate the difference histogram characteristic function(DHCF) and deduce that the moment of DHCFs(DHCFM) will be diminished after stego bits are hidden in the image.Accordingly,we compute the DHCFMs as the discriminative features.We calibrate the features by decreasing the influence of image content on them and train support vector machine classifiers based on the calibrated features.Experimental results demonstrate that the DHCFMs calculated with nonadjacent pixels are helpful to detect stego messages hidden by LSB matching.
文摘The results of commercial application of two types of C_8 aromatics isomerization catalysts under different feed conditions were compared to gain an insight in the techno-economical basis for selecting proper technological route at the plant.The comparison reveals differences in every aspect of feed consumption,unit capacity,product output,product distribution,and unit process parameters depending upon which catalyst type is adopted by the integrated PX complex.The type of aromatics isomerization catalyst has its influence on the plant scale,the construction cost,the process unit capacity and the product cost,with the magnitude of its impact varying with changing feed conditions.
