2009年8月8日至8月11日,第二届国际光子与光电子学会议(POEM:Potonics and OptoelectronicsMeetings 2009)在华中科技大学召开。在光存储与新型存储技术(OSNS:Optical Storage and NewStorage Technologies)分会上,来自学术界的众多相...2009年8月8日至8月11日,第二届国际光子与光电子学会议(POEM:Potonics and OptoelectronicsMeetings 2009)在华中科技大学召开。在光存储与新型存储技术(OSNS:Optical Storage and NewStorage Technologies)分会上,来自学术界的众多相关人士,回顾了近年来光存储技术的发展,同时也进一步探索了当前各种数据存储技术的发展前景。展开更多
针对海洋传感网(Ocean Sensor Networks,OSNs)中采用非协同算法单一循环地对多个水面目标节点依次定位导致的定位效率低、定位精度差等问题,提出一种基于有效集的再优化协同定位(Active Set Method based Re-Estimation Cooperative Loc...针对海洋传感网(Ocean Sensor Networks,OSNs)中采用非协同算法单一循环地对多个水面目标节点依次定位导致的定位效率低、定位精度差等问题,提出一种基于有效集的再优化协同定位(Active Set Method based Re-Estimation Cooperative Localization,ASM-RECL)算法。研究将原定位的非凸非线性问题转化为基于交替非负约束最小二乘(Alternative Nonnegative Constrained Least Squares,ANCLS)的优化问题,利用有效集法(Active Set Method,ASM)通过内外循环寻求优化问题的可行解。但ASM算法易陷入局部最优,为进一步提升解的质量,改进定位精度,基于ASM得出的可行解,应用一阶泰勒级数线性展开再次构造优化方程,最小化定位误差。此外,研究还推导得到基于协同定位的克劳美罗下界(Cooperative Localization-based Cramer-Rao Low Bound,CRLB-CL),以此作为评价标准评估提出的定位算法的有效性。仿真实验表明,在不同的条件下,ASM-RECL的定位精度较高于其他算法。展开更多
在线社交网络(Online Social Networks, OSNs)数据量庞大,如何以低成本采样获取具有代表性的子图成为当前一个研究热点。现有的大部分采样算法仅仅体现在样本列表的无偏特性上,很多情况下,其采样样本构造的诱导子图难以代表原图结构。...在线社交网络(Online Social Networks, OSNs)数据量庞大,如何以低成本采样获取具有代表性的子图成为当前一个研究热点。现有的大部分采样算法仅仅体现在样本列表的无偏特性上,很多情况下,其采样样本构造的诱导子图难以代表原图结构。本文对各种类型的OSN提出了一种新的采样方法,该算法在原有的随机游走算法基础上重新计算了采样跳转概率,修正采样诱导子图的偏差,使其能够更出色地代表原图。同时,本文的采样算法通过计算权重的方式采集邻接节点,省去了自循环过程,从而大幅度提高了采样效率。实验结果表明,本论文提出的采样算法在度分布、聚类系数、传递性、同配性各个方面综合对比,采样获取的子图更加接近原图的属性结构。最后,该算法在大多数情况下,其性能与表现均优于现有采样算法。展开更多
We investigate the structural and thermodynamic properties of OsN2 by a plane-wave pseudopotential density functional theory method. The obtained lattice constant, bulk modulus and cell volume per unit formula are con...We investigate the structural and thermodynamic properties of OsN2 by a plane-wave pseudopotential density functional theory method. The obtained lattice constant, bulk modulus and cell volume per unit formula are consistent with the available theoretical data. Moreover, the pressure-induced phase transition of OsN2 from pyrite structure to fluorite structure has been obtained. It is found that the transition pressure of OsN2 at zero temperature is 67.2 GPa. The bulk modulus B as well as other thermodynamic quantities of fluorite OsN2 （including the Griineisen constant γ and thermal expansion α） on temperatures and pressures have also been obtained.展开更多
The structure and magnetic properties of Osn （n=11～22） clusters are systematically studied by using density functional theory （DFT）. For each size, the average binding energy per atom, the second-order difference...The structure and magnetic properties of Osn （n=11～22） clusters are systematically studied by using density functional theory （DFT）. For each size, the average binding energy per atom, the second-order differences of total energies and the highest occupied molecular orbital （HOMO）–the lowest unoccupied molecular orbital （LUMO） gaps are calculated to analyze the stability of the cluster. The structures of Os14 and Os18 clusters are based on a close-packed hexagonal structure, and they have maximum stabilities, so n=14, 18 are the magic numbers. The 5d electrons play a dominant role in the chemical reaction of Osn clusters. The magnetic moments of Osn clusters are quenched around n=12, and when n=18～22 the value approximates to zero, due to the difference of electron transfer.展开更多
An efficient synthesis and screening of twenty one osteostatin(OSN) analogues were achieved by using pooling strategy. Three analogues were found to retain almost the same activity of inhibiting bone resorption in rat...An efficient synthesis and screening of twenty one osteostatin(OSN) analogues were achieved by using pooling strategy. Three analogues were found to retain almost the same activity of inhibiting bone resorption in rat as that of OSN. Therefore, it is possible to develop partially modified OSN surrogate with higher enzymic stability.展开更多
Different domains of computing systems require higher level of focus towards specific quality factors like privacy, integrity, flexibility, usability etc. Moreover, certain quality factors help in each other’s existe...Different domains of computing systems require higher level of focus towards specific quality factors like privacy, integrity, flexibility, usability etc. Moreover, certain quality factors help in each other’s existence while others oppose each other significantly. Usability of software applications is one factor that reduces security and privacy up to a substantial level. This paper examines the differences between usability factors and aspects related to security and privacy. A clear understanding of gaps between these two opposing factors has been presented in this paper. In addition, an account of efforts carried out to bridge these gaps has also been presented. We have divided these efforts into the categories of guidelines, frameworks and use of technology. The fields of e-banking and social networks have been considered specifically for identification of gaps in these particular fields.展开更多
The Usage of Online social network is increasing day by day where a large number of users publicly access their friend’s link and post any message on the wall. OSN enables different user’s to use the services with a...The Usage of Online social network is increasing day by day where a large number of users publicly access their friend’s link and post any message on the wall. OSN enables different user’s to use the services with a security of using these messages on the user’s wall. Hence various techniques are implemented for the filtering of these wall messages, but there are still various issues and challenges found during the usage of these techniques used in OSN. Here in this paper various issues and challenges from various techniques are discussed and hence on the basis of various issues a new and efficient technique is implemented in future.展开更多
文摘2009年8月8日至8月11日,第二届国际光子与光电子学会议(POEM:Potonics and OptoelectronicsMeetings 2009)在华中科技大学召开。在光存储与新型存储技术(OSNS:Optical Storage and NewStorage Technologies)分会上,来自学术界的众多相关人士,回顾了近年来光存储技术的发展,同时也进一步探索了当前各种数据存储技术的发展前景。
文摘针对海洋传感网(Ocean Sensor Networks,OSNs)中采用非协同算法单一循环地对多个水面目标节点依次定位导致的定位效率低、定位精度差等问题,提出一种基于有效集的再优化协同定位(Active Set Method based Re-Estimation Cooperative Localization,ASM-RECL)算法。研究将原定位的非凸非线性问题转化为基于交替非负约束最小二乘(Alternative Nonnegative Constrained Least Squares,ANCLS)的优化问题,利用有效集法(Active Set Method,ASM)通过内外循环寻求优化问题的可行解。但ASM算法易陷入局部最优,为进一步提升解的质量,改进定位精度,基于ASM得出的可行解,应用一阶泰勒级数线性展开再次构造优化方程,最小化定位误差。此外,研究还推导得到基于协同定位的克劳美罗下界(Cooperative Localization-based Cramer-Rao Low Bound,CRLB-CL),以此作为评价标准评估提出的定位算法的有效性。仿真实验表明,在不同的条件下,ASM-RECL的定位精度较高于其他算法。
文摘在线社交网络(Online Social Networks, OSNs)数据量庞大,如何以低成本采样获取具有代表性的子图成为当前一个研究热点。现有的大部分采样算法仅仅体现在样本列表的无偏特性上,很多情况下,其采样样本构造的诱导子图难以代表原图结构。本文对各种类型的OSN提出了一种新的采样方法,该算法在原有的随机游走算法基础上重新计算了采样跳转概率,修正采样诱导子图的偏差,使其能够更出色地代表原图。同时,本文的采样算法通过计算权重的方式采集邻接节点,省去了自循环过程,从而大幅度提高了采样效率。实验结果表明,本论文提出的采样算法在度分布、聚类系数、传递性、同配性各个方面综合对比,采样获取的子图更加接近原图的属性结构。最后,该算法在大多数情况下,其性能与表现均优于现有采样算法。
基金supported by the National Natural Science Foundation of China (Grant No. 10776022)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20090181110080)
文摘We investigate the structural and thermodynamic properties of OsN2 by a plane-wave pseudopotential density functional theory method. The obtained lattice constant, bulk modulus and cell volume per unit formula are consistent with the available theoretical data. Moreover, the pressure-induced phase transition of OsN2 from pyrite structure to fluorite structure has been obtained. It is found that the transition pressure of OsN2 at zero temperature is 67.2 GPa. The bulk modulus B as well as other thermodynamic quantities of fluorite OsN2 （including the Griineisen constant γ and thermal expansion α） on temperatures and pressures have also been obtained.
基金Project supported by the National Natural Science Foundation of China(Grant No.51072072)
文摘The structure and magnetic properties of Osn （n=11～22） clusters are systematically studied by using density functional theory （DFT）. For each size, the average binding energy per atom, the second-order differences of total energies and the highest occupied molecular orbital （HOMO）–the lowest unoccupied molecular orbital （LUMO） gaps are calculated to analyze the stability of the cluster. The structures of Os14 and Os18 clusters are based on a close-packed hexagonal structure, and they have maximum stabilities, so n=14, 18 are the magic numbers. The 5d electrons play a dominant role in the chemical reaction of Osn clusters. The magnetic moments of Osn clusters are quenched around n=12, and when n=18～22 the value approximates to zero, due to the difference of electron transfer.
文摘An efficient synthesis and screening of twenty one osteostatin(OSN) analogues were achieved by using pooling strategy. Three analogues were found to retain almost the same activity of inhibiting bone resorption in rat as that of OSN. Therefore, it is possible to develop partially modified OSN surrogate with higher enzymic stability.
文摘Different domains of computing systems require higher level of focus towards specific quality factors like privacy, integrity, flexibility, usability etc. Moreover, certain quality factors help in each other’s existence while others oppose each other significantly. Usability of software applications is one factor that reduces security and privacy up to a substantial level. This paper examines the differences between usability factors and aspects related to security and privacy. A clear understanding of gaps between these two opposing factors has been presented in this paper. In addition, an account of efforts carried out to bridge these gaps has also been presented. We have divided these efforts into the categories of guidelines, frameworks and use of technology. The fields of e-banking and social networks have been considered specifically for identification of gaps in these particular fields.
文摘The Usage of Online social network is increasing day by day where a large number of users publicly access their friend’s link and post any message on the wall. OSN enables different user’s to use the services with a security of using these messages on the user’s wall. Hence various techniques are implemented for the filtering of these wall messages, but there are still various issues and challenges found during the usage of these techniques used in OSN. Here in this paper various issues and challenges from various techniques are discussed and hence on the basis of various issues a new and efficient technique is implemented in future.
