This paper focuses on exporting relational data into extensible markup language (XML). First, the characteristics of both relational schemas represented by E-R diagrams and XML document type definitions (DTDs) are an...This paper focuses on exporting relational data into extensible markup language (XML). First, the characteristics of both relational schemas represented by E-R diagrams and XML document type definitions (DTDs) are analyzed. Secondly, the corresponding mapping rules are proposed. At last an algorithm based on edge tables is presented. There are two key points in the algorithm. One is that the edge table is used to store the information of the relational dictionary, and this brings about the efficiency of the algorithm. The other is that structural information can be obtained from the resulting DTDs and other applications can optimize their query processes using the structural information.展开更多
The small-cell technology is promising for spectral-efficiency enhancement. However, it usually requires a huge amount of energy consumption. In this paper, queue state information and channel state information are jo...The small-cell technology is promising for spectral-efficiency enhancement. However, it usually requires a huge amount of energy consumption. In this paper, queue state information and channel state information are jointly utilized to minimize the time average of overall energy consumption for a multi-carrier small-cell network, where the inter-cell interference is an intractable problem. Based on the Lyapunov optimization theory, the problem could be solved by dynamically optimizing the problem of user assignment, carrier allocation and power allocation in each time slot. As the optimization problem is NP-hard, we propose a heuristic iteration algorithm to solve it. Numerical results verify that the heuristic algorithm offers an approximate performance as the brute-force algorithm. Moreover, it could bring down the overall energy consumption to different degrees according to the variation of traffic load. Meanwhile, it could achieve the same sum rate as the algorithm which focuses on maximizing system sum rate.展开更多
Switch policy is essential for small cells to properly serve variable number of users in an energy efficient way.However,frequently switching small cell base stations(SBSs) may increase the network operating cost,espe...Switch policy is essential for small cells to properly serve variable number of users in an energy efficient way.However,frequently switching small cell base stations(SBSs) may increase the network operating cost,especially when there is an nonnegligible start-up energy cost.To this end,by observing the variety of user number,we focus on the design of a switch policy which minimize the cumulative energy consumption.A given user transmission rate is guaranteed and the capability of SBSs are limited as well.According to the knowledge on user number variety,we classify the energy consumption problem into two cases.In complete information case,to minimize the cumulative energy consumption,an offline solution is proposed according to critical segments.A heuristic algorithm for incomplete information case(HAIIC) is proposed by tracking the difference of cumulative energy consumption.The upper bound of the Energy Consumption Ratio(ECR) for HAIIC is derived as well.In addition,a practical Q-learning based probabilistic policy is proposed.Simulation results show that the proposed HAIIC algorithm is able to save energy efficiently.展开更多
This paper focuses on solving the delay constrained least cost routing problem, and propose a simple, distributed heuristic solution, called distributed recursive delay constrained least cost (DR DCLC) unicast routing...This paper focuses on solving the delay constrained least cost routing problem, and propose a simple, distributed heuristic solution, called distributed recursive delay constrained least cost (DR DCLC) unicast routing algorithm. DR DCLC only requires local information to find the near optimal solution. The correctness of DR DCLC is proued by showing that it is always capable of constructing a loop free delay constrained path within finite time, if such a path exists. Simulation is also used to compare DR DCLC to the optimal DCLC algorithm and other algorithms.展开更多
A novel software tool for optimization and synthesis of RF CMOS polyhase filters(PPFs),PPFOPTIMA,is developed.In the optimization engine,genetic algorithm is adopted to avoid local optima.Experiments on PPFOPTIMA demo...A novel software tool for optimization and synthesis of RF CMOS polyhase filters(PPFs),PPFOPTIMA,is developed.In the optimization engine,genetic algorithm is adopted to avoid local optima.Experiments on PPFOPTIMA demonstrate that it is an efficient design aid for design and optimization of RF CMOS PPFs.展开更多
With the challenges brought by the expansion of network scale,as well as the diversity of the equipments and the complexity of network protocols,many self-configurable systems have been proposed combining formal speci...With the challenges brought by the expansion of network scale,as well as the diversity of the equipments and the complexity of network protocols,many self-configurable systems have been proposed combining formal specification and model finding techniques.In this paper,we pay more attention to formal specifications of network information,i.e.,exploring principles and algorithm to map network information(topology,devices and status,etc.) to Alloy specifications.We first model network information in relational form,which is easy to realize because of the structured feature of network information in nature.Then we map the relational data to Alloy specifications according to our novel data mapping principles and algorithm.Based on the transition of relational data,it is possible to automatically map network information to Alloy specifications.We evaluate our data mapping principles and algorithm by applying them to a practical application scenario.The results illustrate that we can find a model for the task within a tolerant time interval,which implies that our novel approach can convert relational data to Alloy specifications correctly and efficiently.展开更多
It has been shown that the deployment of device-to-device(D2D) communication in cellular systems can provide better support for local services. However, improper design of the hybrid system may cause severe interferen...It has been shown that the deployment of device-to-device(D2D) communication in cellular systems can provide better support for local services. However, improper design of the hybrid system may cause severe interference between cellular and D2D links. In this paper, we consider transceiver design for the system employing multiple antennas to mitigate the interference. The precoder and decoder matrices are optimized in terms of sum mean squared error(MSE) and capacity, respectively. For the MSE minimization problem, we present an alternative transceiver optimization algorithm. While for the non-convex capacity maximization problem, we decompose the primal problem into a sequence of standard convex quadratic programs for efficient optimization. The evaluation of our proposed algorithms for performance enhancement of the entire D2D integrated cellular system is carried out through simulations.展开更多
Today,backbone networks deploy a large number of devices and links.This is mainly due to both redundancy purposes for network service reliability,and resource over-dimensioning for maintaining quality of service durin...Today,backbone networks deploy a large number of devices and links.This is mainly due to both redundancy purposes for network service reliability,and resource over-dimensioning for maintaining quality of service during rush hours.Unfortunately,current routers do not have power management primitives,and have constant energy consumption independent of their actual workloads.How to implement a low power and multi-stage switch forwarding for IP lookup is a challenge in high-performance green routers design.A forwarding information base multi-stage mapping routing lookup architecture is presented,and the dynamic routing table mapping algorithm is designed to determine the optimal strides for building tree bitmap tries which lead the worst-case power consumption of the IP lookup engine to be minimized.Experimental results show that the application of reallife routing tables demonstrates that the proposed method could reduce power consumption of routing lookup by 30%.展开更多
Due to the encephalic tissues are highly irregular, three-dimensional (3D) modeling of brain always leads to compli- cated computing. In this paper, we explore an efficient method for brain surface reconstruction fr...Due to the encephalic tissues are highly irregular, three-dimensional (3D) modeling of brain always leads to compli- cated computing. In this paper, we explore an efficient method for brain surface reconstruction from magnetic reso- nance (MR) images of head, which is helpful to surgery planning and tumor localization. A heuristic algorithm is pro- posed foi" surface triangle mesh generation with preserved features, and the diagonal length is regarded as the heuristic information to optimize the shape of triangle. The experimental results show that our approach not only reduces the computational complexity, but also completes 3D visualization with good quality.展开更多
This paper introduces several algorithms for signal estimation using binary-valued outputsensing.The main idea is derived from the empirical measure approach for quantized identification,which has been shown to be con...This paper introduces several algorithms for signal estimation using binary-valued outputsensing.The main idea is derived from the empirical measure approach for quantized identification,which has been shown to be convergent and asymptotically efficient when the unknown parametersare constants.Signal estimation under binary-valued observations must take into consideration oftime varying variables.Typical empirical measure based algorithms are modified with exponentialweighting and threshold adaptation to accommodate time-varying natures of the signals.Without anyinformation on signal generators,the authors establish estimation algorithms,interaction between noisereduction by averaging and signal tracking,convergence rates,and asymptotic efficiency.A thresholdadaptation algorithm is introduced.Its convergence and convergence rates are analyzed by using theODE method for stochastic approximation problems.展开更多
文摘This paper focuses on exporting relational data into extensible markup language (XML). First, the characteristics of both relational schemas represented by E-R diagrams and XML document type definitions (DTDs) are analyzed. Secondly, the corresponding mapping rules are proposed. At last an algorithm based on edge tables is presented. There are two key points in the algorithm. One is that the edge table is used to store the information of the relational dictionary, and this brings about the efficiency of the algorithm. The other is that structural information can be obtained from the resulting DTDs and other applications can optimize their query processes using the structural information.
基金partially supported by National Basic Research Program of China (2013CB329002)National Natural Science Foundation of China (61631013)+6 种基金The National High Technology Research and Development Program of China(2014AA01A703)Science Fund for Creative Research Groups of NSFC (61321061)National Major Project (2017ZX03001011)International Science and Technology Cooperation Program (2014DFT10320)National Science Foundation of China (61701457 \& 61771286)Tsinghua-Qualcomm Joint Research ProgramHuawei Innovation Research Program
文摘The small-cell technology is promising for spectral-efficiency enhancement. However, it usually requires a huge amount of energy consumption. In this paper, queue state information and channel state information are jointly utilized to minimize the time average of overall energy consumption for a multi-carrier small-cell network, where the inter-cell interference is an intractable problem. Based on the Lyapunov optimization theory, the problem could be solved by dynamically optimizing the problem of user assignment, carrier allocation and power allocation in each time slot. As the optimization problem is NP-hard, we propose a heuristic iteration algorithm to solve it. Numerical results verify that the heuristic algorithm offers an approximate performance as the brute-force algorithm. Moreover, it could bring down the overall energy consumption to different degrees according to the variation of traffic load. Meanwhile, it could achieve the same sum rate as the algorithm which focuses on maximizing system sum rate.
基金partially supported by National Key Project of China under Grants No. 2013ZX03001007-004National Natural Science Foundation of China under Grants No. 61102052,61325012,61271219,91438115 and 61221001
文摘Switch policy is essential for small cells to properly serve variable number of users in an energy efficient way.However,frequently switching small cell base stations(SBSs) may increase the network operating cost,especially when there is an nonnegligible start-up energy cost.To this end,by observing the variety of user number,we focus on the design of a switch policy which minimize the cumulative energy consumption.A given user transmission rate is guaranteed and the capability of SBSs are limited as well.According to the knowledge on user number variety,we classify the energy consumption problem into two cases.In complete information case,to minimize the cumulative energy consumption,an offline solution is proposed according to critical segments.A heuristic algorithm for incomplete information case(HAIIC) is proposed by tracking the difference of cumulative energy consumption.The upper bound of the Energy Consumption Ratio(ECR) for HAIIC is derived as well.In addition,a practical Q-learning based probabilistic policy is proposed.Simulation results show that the proposed HAIIC algorithm is able to save energy efficiently.
文摘This paper focuses on solving the delay constrained least cost routing problem, and propose a simple, distributed heuristic solution, called distributed recursive delay constrained least cost (DR DCLC) unicast routing algorithm. DR DCLC only requires local information to find the near optimal solution. The correctness of DR DCLC is proued by showing that it is always capable of constructing a loop free delay constrained path within finite time, if such a path exists. Simulation is also used to compare DR DCLC to the optimal DCLC algorithm and other algorithms.
文摘A novel software tool for optimization and synthesis of RF CMOS polyhase filters(PPFs),PPFOPTIMA,is developed.In the optimization engine,genetic algorithm is adopted to avoid local optima.Experiments on PPFOPTIMA demonstrate that it is an efficient design aid for design and optimization of RF CMOS PPFs.
基金supported by the National Science Foundation for Distinguished Young Scholars of China under Grant No.61225012 and No.71325002the Specialized Research Fund of the Doctoral Program of Higher Education for the Priority Development Areas under Grant No.20120042130003the Liaoning BaiQianWan Talents Program under Grant No.2013921068
文摘With the challenges brought by the expansion of network scale,as well as the diversity of the equipments and the complexity of network protocols,many self-configurable systems have been proposed combining formal specification and model finding techniques.In this paper,we pay more attention to formal specifications of network information,i.e.,exploring principles and algorithm to map network information(topology,devices and status,etc.) to Alloy specifications.We first model network information in relational form,which is easy to realize because of the structured feature of network information in nature.Then we map the relational data to Alloy specifications according to our novel data mapping principles and algorithm.Based on the transition of relational data,it is possible to automatically map network information to Alloy specifications.We evaluate our data mapping principles and algorithm by applying them to a practical application scenario.The results illustrate that we can find a model for the task within a tolerant time interval,which implies that our novel approach can convert relational data to Alloy specifications correctly and efficiently.
基金supportedin part by Science and Technology Project of State Grid Corporation of China(SGIT0000KJJS1500008)Science and Technology Project of State Grid Corporation of China:“Research and Application of Distributed Energy Resource Public Information Service Platform based on Multisource Data Fusion and Mobile Internet Technologies”Science and Technology Project of State Grid Corporation of China:“Research on communication access technology for the integration, protection, and acquisition of multiple new energy resources”
文摘It has been shown that the deployment of device-to-device(D2D) communication in cellular systems can provide better support for local services. However, improper design of the hybrid system may cause severe interference between cellular and D2D links. In this paper, we consider transceiver design for the system employing multiple antennas to mitigate the interference. The precoder and decoder matrices are optimized in terms of sum mean squared error(MSE) and capacity, respectively. For the MSE minimization problem, we present an alternative transceiver optimization algorithm. While for the non-convex capacity maximization problem, we decompose the primal problem into a sequence of standard convex quadratic programs for efficient optimization. The evaluation of our proposed algorithms for performance enhancement of the entire D2D integrated cellular system is carried out through simulations.
基金Supported by the National High Technology Research and Development Programme of China(No.2008AA01A323,2009AA01A334)the National Basic Research Program of China(No.2007CB307102)
文摘Today,backbone networks deploy a large number of devices and links.This is mainly due to both redundancy purposes for network service reliability,and resource over-dimensioning for maintaining quality of service during rush hours.Unfortunately,current routers do not have power management primitives,and have constant energy consumption independent of their actual workloads.How to implement a low power and multi-stage switch forwarding for IP lookup is a challenge in high-performance green routers design.A forwarding information base multi-stage mapping routing lookup architecture is presented,and the dynamic routing table mapping algorithm is designed to determine the optimal strides for building tree bitmap tries which lead the worst-case power consumption of the IP lookup engine to be minimized.Experimental results show that the application of reallife routing tables demonstrates that the proposed method could reduce power consumption of routing lookup by 30%.
基金supported by the National Natural Science Foundation of China(No.61202169)
文摘Due to the encephalic tissues are highly irregular, three-dimensional (3D) modeling of brain always leads to compli- cated computing. In this paper, we explore an efficient method for brain surface reconstruction from magnetic reso- nance (MR) images of head, which is helpful to surgery planning and tumor localization. A heuristic algorithm is pro- posed foi" surface triangle mesh generation with preserved features, and the diagonal length is regarded as the heuristic information to optimize the shape of triangle. The experimental results show that our approach not only reduces the computational complexity, but also completes 3D visualization with good quality.
基金supported in part by the National Science Foundation under ECS-0329597 and DMS-0624849in part by the Air Force Office of Scientific Research under FA9550-10-1-0210+2 种基金supported by the National Science Foundation under DMS-0907753 and DMS-0624849in part by the Air Force Office of Scientific Research under FA9550-10-1-0210supported in part by a research grant from the Australian Research Council
文摘This paper introduces several algorithms for signal estimation using binary-valued outputsensing.The main idea is derived from the empirical measure approach for quantized identification,which has been shown to be convergent and asymptotically efficient when the unknown parametersare constants.Signal estimation under binary-valued observations must take into consideration oftime varying variables.Typical empirical measure based algorithms are modified with exponentialweighting and threshold adaptation to accommodate time-varying natures of the signals.Without anyinformation on signal generators,the authors establish estimation algorithms,interaction between noisereduction by averaging and signal tracking,convergence rates,and asymptotic efficiency.A thresholdadaptation algorithm is introduced.Its convergence and convergence rates are analyzed by using theODE method for stochastic approximation problems.