Cooperative communication can achieve spatial diversity gains,and consequently combats signal fading due to multipath propagation in wireless networks powerfully.A novel complex field network-coded cooperation（CFNCC...Cooperative communication can achieve spatial diversity gains,and consequently combats signal fading due to multipath propagation in wireless networks powerfully.A novel complex field network-coded cooperation（CFNCC） scheme based on multi-user detection for the multiple unicast transmission is proposed.Theoretic analysis and simulation results demonstrate that,compared with the conventional cooperation（CC） scheme and network-coded cooperation（NCC） scheme,CFNCC would obtain higher network throughput and consumes less time slots.Moreover,a further investigation is made for the symbol error probability（SEP） performance of CFNCC scheme,and SEPs of CFNCC scheme are compared with those of NCC scheme in various scenarios for different signal to noise ratio（SNR） values.展开更多
Both D-stability and finite L2-gain properties are studiedfor a class of uncertain discrete-time systems with timevaryingnetwork-induced delays. By using coordinate transformand delay partition, the D-stability and H...Both D-stability and finite L2-gain properties are studiedfor a class of uncertain discrete-time systems with timevaryingnetwork-induced delays. By using coordinate transformand delay partition, the D-stability and H∞ performance problemsfor such networked control systems （NCSs） are equivalentlytransferred into the corresponding problems for switching systemswith arbitrary switching. Then, a sufficient condition for the existenceof the robust D-stabilizing controllers is derived in termsof linear matrix inequality （LMI）, and the design method is alsopresented for the state feedback controllers which guarantee thatall the closed-loop poles remain inside the specified disk D（α,r）and the desired disturbance attenuation level. Finally, an illustrativeexample is given to demonstrate the effectiveness of the proposedresults.展开更多
Recent researches show that inter-session network coding could decrease the number of packets transmission and achieve higher throughput in wireless network compared with traditional forwarding mechanism. In most exis...Recent researches show that inter-session network coding could decrease the number of packets transmission and achieve higher throughput in wireless network compared with traditional forwarding mechanism. In most existing relay mechanisms based on inter-session network such as COPE, relay node demands to collect the messages from its neighbor nodes to get notice of which packets already overheard by them so as to determine whether there exists coding opportunity between or among forwarding packets. However, transmission overhead of this message collection and computing cost of opportunity determination will degrade the performance of these mechanisms. It is observed that coding opportunity at relay node is much more related with the local topology, and the opportunity of encoding three or more packets together is far less than that of encoding two packets together in wireless network with general density. Based on this, a new coding-aware routing mechanism, named TCAR, is proposed. TCAR ignores the oppommity of encoding three or more than three packets together. Each relay node maintains an encoding mapping table being established according to the result of its local topology detection, which can be used to calculate the path cost during routing setup phase, and determine that which two packets can be encoded together during the packets forwarding phase. In TCAR, instead of periodic messages collection, each relay nodes just need once local topology detection, and the encoding determination is much simpler than that of the former mechanisms. Simulation results show that compared with typical inter-session network coding mechanisms COPE and COPE-based routing, TCAR achieves 12% and 7% throughput gains, and keeps the minimum end to end delay.展开更多
To adjust the variance of source rate in linear broadcast networks, global encoding kernels should have corresponding dimensions to instruct the decoding process. The algorithm of constructing such global encoding ker...To adjust the variance of source rate in linear broadcast networks, global encoding kernels should have corresponding dimensions to instruct the decoding process. The algorithm of constructing such global encoding kernels is to adjust heterogeneous network to possible link failures. Linear algebra, graph theory and group theory are applied to construct one series of global encoding kernels which are applicable to all source rates. The effectiveness and existence of such global encoding kernels are proved. Based on 2 information flow, the algorithm of construction is explicitly given within polynomial time O（｜E｜ ｜T｜.ω^2max）, and the memory complexity of algorithm is O（｜E｜）. Both time and memory complexity of this algorithm proposed can be O（ωmax） less than those of algorithms in related works.展开更多
Laser assisted turning （LAT） is one of the advanced machining technologies, which uses laser power to heat the surface of a workpiece before the material is removed. It has several advantages of low manufacturing co...Laser assisted turning （LAT） is one of the advanced machining technologies, which uses laser power to heat the surface of a workpiece before the material is removed. It has several advantages of low manufacturing costs, high productivity and high qualities to machine difficult-to-cut materials such as silicon nitride, muUite, zirconia and Ni. A large part of studies on LAT have been focused on a round bar. With increasing demands for high quality products and high performance engineering system, the researches on LAT for clover and square section members are necessary. But, these workpieces are impossible to be machined on conventional CNC lathe and to generate NC code with current CAM softwares. As a basic research for combining LAT with a tilting index table type 5-axis machining center, i.e. laser assisted turn-mill, a new method is suggested to generate NC code that can process various types of clover and square section members through development of C＋＋ program.展开更多
A new combinational technology is proposed,which is feasible to apply physical-layer network coding（PNC） to wireless fading channels by employing the harmful interference strategically.The key step of PNC is that so...A new combinational technology is proposed,which is feasible to apply physical-layer network coding（PNC） to wireless fading channels by employing the harmful interference strategically.The key step of PNC is that sources broadcast signals simultaneously without orthogonal scheduling.Naturally,the signals overlap in the free space at the receivers.Since the signals from different sources are mutual independent,rooted on this rational assumption,an enhanced joint diagonalization separation named altering row diagonalization（ARD） algorithm is exploited to separate these signals by maximizing the cost function measuring independence among them.This ARD PNC（APNC） methodology provides an innovative way to implement signal-level network coding at the presence of interference and without any priori information about channels in fading environments.In conclusions,the proposed APNC performs well with higher bandwidth utility and lower error rate.展开更多
This paper investigates a signal difference-based dead- band H∞ control approach for networked control systems （NCSs） with limited resources. The effects of variable network-induced de- lays, sampling intervals and...This paper investigates a signal difference-based dead- band H∞ control approach for networked control systems （NCSs） with limited resources. The effects of variable network-induced de- lays, sampling intervals and data transmitting deadbands are con- sidered simultaneously and the model of the NCS is presented. A Lyapunov functional is adopted, which makes full use of the network characteristic information including the bounds of net- work delay （BND）, the bounds of sampling interval （BSI） and the bounds of transmission deadband （BTD）. In the meanwhile, the new H∞ performance analysis and controller design conditions for the NCSs are proposed, which describe the relationship of BND, BSI, BTD and the system＇s performance. Three examples are used to illustrate the advantages of the proposed methods. The results have shown that the proposed method not only effectively reduces the data traffic, but also guarantees the system asymptotically sta- ble and achieves the prescribed H∞ disturbance attenuation level.展开更多
目的研究中药复方桃红四物汤(Tao Hong Si Wu decoction,THSWD)治疗大脑中动脉闭塞(middle cerebral artery occlusion,MCAO)大鼠长链非编码RNA(long non-coding RNA,lncRNA)的表达,并确定THSWD治疗MCAO大鼠可能的分子机制。方法从对照...目的研究中药复方桃红四物汤(Tao Hong Si Wu decoction,THSWD)治疗大脑中动脉闭塞(middle cerebral artery occlusion,MCAO)大鼠长链非编码RNA(long non-coding RNA,lncRNA)的表达,并确定THSWD治疗MCAO大鼠可能的分子机制。方法从对照组、MCAO组和MCAO+THSWD组各获得3个大脑半球组织。采用RNA测序技术鉴定三组中的lncRNA基因表达。鉴定了THSWD调节的lncRNA基因,然后构建了THSWD调节的lncRNA-mRNA网络。通过MCODE插件鉴定lncRNA-mRNA网络的模块。基因本体(gene ontology,GO)和京都基因与基因组百科全书数据库(kyoto encyclopedia of genes and genomes,KEGG)用于分析富集的生物功能和信号通路。鉴定了THSWD调节的lncRNA的顺式和反式调控基因。采用逆转录实时定量聚合酶链式反应(RT-qPCR)验证lncRNA。分子对接用于验证lncRNA-mRNA网络靶点和通路相关蛋白结合能力。结果在MCAO大鼠中,THSWD共调节了302个lncRNA。生物信息学分析表明,一些核心lncRNA可能在THSWD治疗MCAO大鼠中发挥重要作用,此外,我们进一步发现THSWD可能也通过lncRNA-mRNA网络以及网络富集的补体和凝血级联反应等多通路治疗MCAO大鼠。分子对接结果表明,THSWD活性化合物没食子酸和苦杏仁苷与蛋白质靶点具有一定的结合能力。结论THSWD可以通过调节lncRNA保护MCAO大鼠脑损伤,为THSWD治疗缺血性中风提供了新见解。展开更多
Network coding is proved to have advantages in both wireline and wireless networks. Especially, appropriate network coding schemes are programmed for underlined networks. Considering the feature of strong node mobilit...Network coding is proved to have advantages in both wireline and wireless networks. Especially, appropriate network coding schemes are programmed for underlined networks. Considering the feature of strong node mobility in aviation communication networks, a hop-by-hop network coding algorithm based on ad hoc networks was proposed. Compared with COPE-like network coding algorithms, the proposed algorithm does not require overhearing from other nodes, which meets confidentiality requirements of aviation communication networks. Meanwhile, it does save resource consumption and promise less processing delay. To analyze the performance of the network coding algorithm in scalable networks with different traffic models, a typical network was built in a network simulator, through which receiving accuracy rate and receiving delay were both examined.The simulation results indicate that, by virtue of network coding, the proposed algorithm works well and improves performance significantly. More specifically, it has better performance in enhancing receiving accuracy rate and reducing receiving delay, as compared with any of the traditional networks without coding. It was applied to both symmetric and asymmetric traffic flows and, in particular, it achieves much better performance when the network scale becomes larger. Therefore, this algorithm has great potentials in large-scale multi-hop aviation communication networks.展开更多
基金supported by the National Natural Science Foundation of China(6104000561001126+5 种基金61271262)the China Postdoctoral Science Foundation Funded Project(201104916382012T50789)the Natural Science Foundation of Shannxi Province of China(2011JQ8036)the Special Fund for Basic Scientific Research of Central Colleges (CHD2012ZD005)the Research Fund of Zhejiang University of Technology(20100244)
文摘Cooperative communication can achieve spatial diversity gains,and consequently combats signal fading due to multipath propagation in wireless networks powerfully.A novel complex field network-coded cooperation（CFNCC） scheme based on multi-user detection for the multiple unicast transmission is proposed.Theoretic analysis and simulation results demonstrate that,compared with the conventional cooperation（CC） scheme and network-coded cooperation（NCC） scheme,CFNCC would obtain higher network throughput and consumes less time slots.Moreover,a further investigation is made for the symbol error probability（SEP） performance of CFNCC scheme,and SEPs of CFNCC scheme are compared with those of NCC scheme in various scenarios for different signal to noise ratio（SNR） values.
基金supported by the National Natural Science Foundation of China(61403344)
文摘Both D-stability and finite L2-gain properties are studiedfor a class of uncertain discrete-time systems with timevaryingnetwork-induced delays. By using coordinate transformand delay partition, the D-stability and H∞ performance problemsfor such networked control systems （NCSs） are equivalentlytransferred into the corresponding problems for switching systemswith arbitrary switching. Then, a sufficient condition for the existenceof the robust D-stabilizing controllers is derived in termsof linear matrix inequality （LMI）, and the design method is alsopresented for the state feedback controllers which guarantee thatall the closed-loop poles remain inside the specified disk D（α,r）and the desired disturbance attenuation level. Finally, an illustrativeexample is given to demonstrate the effectiveness of the proposedresults.
基金Projects(61173169,61106036)supported by the National Natural Science Foundation of ChinaProject(NCET-10-0798)Program for New Century Excellent Talents in University,China
文摘Recent researches show that inter-session network coding could decrease the number of packets transmission and achieve higher throughput in wireless network compared with traditional forwarding mechanism. In most existing relay mechanisms based on inter-session network such as COPE, relay node demands to collect the messages from its neighbor nodes to get notice of which packets already overheard by them so as to determine whether there exists coding opportunity between or among forwarding packets. However, transmission overhead of this message collection and computing cost of opportunity determination will degrade the performance of these mechanisms. It is observed that coding opportunity at relay node is much more related with the local topology, and the opportunity of encoding three or more packets together is far less than that of encoding two packets together in wireless network with general density. Based on this, a new coding-aware routing mechanism, named TCAR, is proposed. TCAR ignores the oppommity of encoding three or more than three packets together. Each relay node maintains an encoding mapping table being established according to the result of its local topology detection, which can be used to calculate the path cost during routing setup phase, and determine that which two packets can be encoded together during the packets forwarding phase. In TCAR, instead of periodic messages collection, each relay nodes just need once local topology detection, and the encoding determination is much simpler than that of the former mechanisms. Simulation results show that compared with typical inter-session network coding mechanisms COPE and COPE-based routing, TCAR achieves 12% and 7% throughput gains, and keeps the minimum end to end delay.
基金Project(60872005) supported by National Natural Science Foundation of China
文摘To adjust the variance of source rate in linear broadcast networks, global encoding kernels should have corresponding dimensions to instruct the decoding process. The algorithm of constructing such global encoding kernels is to adjust heterogeneous network to possible link failures. Linear algebra, graph theory and group theory are applied to construct one series of global encoding kernels which are applicable to all source rates. The effectiveness and existence of such global encoding kernels are proved. Based on 2 information flow, the algorithm of construction is explicitly given within polynomial time O（｜E｜ ｜T｜.ω^2max）, and the memory complexity of algorithm is O（｜E｜）. Both time and memory complexity of this algorithm proposed can be O（ωmax） less than those of algorithms in related works.
基金Project(2011-0017407)supported by the National Research Foundation of Korea(NRF)funded by Korea government(MEST)
文摘Laser assisted turning （LAT） is one of the advanced machining technologies, which uses laser power to heat the surface of a workpiece before the material is removed. It has several advantages of low manufacturing costs, high productivity and high qualities to machine difficult-to-cut materials such as silicon nitride, muUite, zirconia and Ni. A large part of studies on LAT have been focused on a round bar. With increasing demands for high quality products and high performance engineering system, the researches on LAT for clover and square section members are necessary. But, these workpieces are impossible to be machined on conventional CNC lathe and to generate NC code with current CAM softwares. As a basic research for combining LAT with a tilting index table type 5-axis machining center, i.e. laser assisted turn-mill, a new method is suggested to generate NC code that can process various types of clover and square section members through development of C＋＋ program.
基金supported by the National Natural Science Foundation of China(6120118361132002)
文摘A new combinational technology is proposed,which is feasible to apply physical-layer network coding（PNC） to wireless fading channels by employing the harmful interference strategically.The key step of PNC is that sources broadcast signals simultaneously without orthogonal scheduling.Naturally,the signals overlap in the free space at the receivers.Since the signals from different sources are mutual independent,rooted on this rational assumption,an enhanced joint diagonalization separation named altering row diagonalization（ARD） algorithm is exploited to separate these signals by maximizing the cost function measuring independence among them.This ARD PNC（APNC） methodology provides an innovative way to implement signal-level network coding at the presence of interference and without any priori information about channels in fading environments.In conclusions,the proposed APNC performs well with higher bandwidth utility and lower error rate.
基金supported by the National Natural Science Foundation of China(6110410661473195)+1 种基金the Natural Science Foundation of Liaoning Province(201202156)the Program for Liaoning Excellent Talents in University(LJQ2012100)
文摘This paper investigates a signal difference-based dead- band H∞ control approach for networked control systems （NCSs） with limited resources. The effects of variable network-induced de- lays, sampling intervals and data transmitting deadbands are con- sidered simultaneously and the model of the NCS is presented. A Lyapunov functional is adopted, which makes full use of the network characteristic information including the bounds of net- work delay （BND）, the bounds of sampling interval （BSI） and the bounds of transmission deadband （BTD）. In the meanwhile, the new H∞ performance analysis and controller design conditions for the NCSs are proposed, which describe the relationship of BND, BSI, BTD and the system＇s performance. Three examples are used to illustrate the advantages of the proposed methods. The results have shown that the proposed method not only effectively reduces the data traffic, but also guarantees the system asymptotically sta- ble and achieves the prescribed H∞ disturbance attenuation level.
文摘目的研究中药复方桃红四物汤(Tao Hong Si Wu decoction,THSWD)治疗大脑中动脉闭塞(middle cerebral artery occlusion,MCAO)大鼠长链非编码RNA(long non-coding RNA,lncRNA)的表达,并确定THSWD治疗MCAO大鼠可能的分子机制。方法从对照组、MCAO组和MCAO+THSWD组各获得3个大脑半球组织。采用RNA测序技术鉴定三组中的lncRNA基因表达。鉴定了THSWD调节的lncRNA基因,然后构建了THSWD调节的lncRNA-mRNA网络。通过MCODE插件鉴定lncRNA-mRNA网络的模块。基因本体(gene ontology,GO)和京都基因与基因组百科全书数据库(kyoto encyclopedia of genes and genomes,KEGG)用于分析富集的生物功能和信号通路。鉴定了THSWD调节的lncRNA的顺式和反式调控基因。采用逆转录实时定量聚合酶链式反应(RT-qPCR)验证lncRNA。分子对接用于验证lncRNA-mRNA网络靶点和通路相关蛋白结合能力。结果在MCAO大鼠中,THSWD共调节了302个lncRNA。生物信息学分析表明,一些核心lncRNA可能在THSWD治疗MCAO大鼠中发挥重要作用,此外,我们进一步发现THSWD可能也通过lncRNA-mRNA网络以及网络富集的补体和凝血级联反应等多通路治疗MCAO大鼠。分子对接结果表明,THSWD活性化合物没食子酸和苦杏仁苷与蛋白质靶点具有一定的结合能力。结论THSWD可以通过调节lncRNA保护MCAO大鼠脑损伤,为THSWD治疗缺血性中风提供了新见解。
基金Project(61175110)supported by the National Natural Science Foundation of ChinaProject(2012CB316305)supported by National Basic Research Program of ChinaProject(2011ZX02101-004)supported by National S&T Major Projects of China
文摘Network coding is proved to have advantages in both wireline and wireless networks. Especially, appropriate network coding schemes are programmed for underlined networks. Considering the feature of strong node mobility in aviation communication networks, a hop-by-hop network coding algorithm based on ad hoc networks was proposed. Compared with COPE-like network coding algorithms, the proposed algorithm does not require overhearing from other nodes, which meets confidentiality requirements of aviation communication networks. Meanwhile, it does save resource consumption and promise less processing delay. To analyze the performance of the network coding algorithm in scalable networks with different traffic models, a typical network was built in a network simulator, through which receiving accuracy rate and receiving delay were both examined.The simulation results indicate that, by virtue of network coding, the proposed algorithm works well and improves performance significantly. More specifically, it has better performance in enhancing receiving accuracy rate and reducing receiving delay, as compared with any of the traditional networks without coding. It was applied to both symmetric and asymmetric traffic flows and, in particular, it achieves much better performance when the network scale becomes larger. Therefore, this algorithm has great potentials in large-scale multi-hop aviation communication networks.
基金Supported by National Natural Science Foundation of China 60404022, 60704009）, National Outstanding Youth Foundation 60525303）, and Natural Science Foundation of Hebei Province F2005000390, F2006000270）
文摘水声网络(underwater acoustic network,UAN)具有长传播时延、高误码率、半双工通信等特性,这些特性严重影响了UAN中数据的可靠传输。而在线喷泉码具有在线控制、编解码复杂度低、码率自适应等诸多优势,在线喷泉码适合于保障UAN中数据的可靠传输。针对递归与限制反馈的在线喷泉码(recursive OFC with limited feedback,ROFC-LF)存在不理想覆盖和4元环问题导致略高的开销和频繁的反馈,提出适用于UAN的基于优先级与可Zigzag解码的ROFC-LF(priority-based and zigzag-decodable ROFC-LF,P-ZROFC-LF)。P-ZROFC-LF在建立阶段选取具有最高优先级的原始包进行编码直至所有原始包均参与编码。同时,引入可Zigzag解码编码,将无用编码包进行移位异或转换为有用编码包来提高解码性能。通过随机图理论,分析P-ZROFC-LF所需编码包数与原始包数之间的关系。理论分析与仿真结果表明,与大部分在线喷泉码相比,P-ZROFC-LF显著提高了反馈和开销性能。其中P-ZROFC-LF相比于ROFC-LF的反馈和开销分别减少了18%和0.0176,更适用于UAN。
