A bivalency proof of the lower bound for uniform consensus

Bivalency argument is a widely-used technique that employs forward induction to show impossibility results and lower bounds related to consensus. However, for a synchronous distributed system of n processes with up to t potential and f actual crash failures, applying bivalency argument to prove the lower bound for reaching uniform consensus is still an open problem. In this paper, we address this problem by presenting a bivalency proof that the lower bound for reaching uniform consensus is (f+2)-rounds where 0?f?t−2.     

Effect of Rare Earths on Electronic Structure of (110) Twin Martensite Boundary for Ni2MnGa Alloy

The doping effect of rare earth elements (Tb and Sm) on the electronic structure of (110) martensitic twin boundary in Ni2MnGa alloys was investigated by using ab initio method within the DFT and the supercell implementation. The calculated results show that the atomic relaxation lowers the boundary energy and the segregation energy. Sm seems easier to segregate to the boundary and has a greater doping effect compared with Tb due to its lower segregation energy and bigger bonder order with neighboring atoms. Tb makes a greater contribution to the magnetic properties of the twin boundary than Sm.     

Data Consistency for Cooperative Caching in Mobile Environments

The trend toward wireless communications and advances in mobile technologies are increasing consumer demand for ubiquitous access to Internet-based information and services. A 3D framework provides a basis for designing, analyzing, and evaluating strategies to address data consistency issues in mobile wireless environments. A proposed relay-peer-based cache consistency protocol offers a generic and flexible method for carrying out cache invalidation     

城镇土地估价多媒体信息系统研究

随着我国土地使用制度改革的深入和地产市场的逐步培育、完善、土地估价以及地价信息的管理和利用显得越来越重要了。该文介绍了将城镇土地估价、地价信息管理与先进的计算机技术有机结合，研制开发多功能可视化城镇土地估价多媒体信息系统的设计思想和实现方法。该系统的使用将大大提高土地估价和地价信息管理的科学化和自动化水平。     

Multicast protection scheme based on Hamiltonian cycle in fault-tolerant optical mesh networks

The increase of multimedia service requirements results in the growing popularity of the multicast in Wavelength-Division Multiplexing (WDM) optical mesh networks. Multicast fault tolerance in WDM optical mesh networks is an important issue because failures caused by the traffic carried in WDM optical mesh networks may lead to huge data loss. Previous works have proposed multicast protection algorithms to address the single-fiber link failure dominant in current optical mesh networks. However, these existing algorithms are all mainly based on path protection or segment protection, which may lead to long restoration times and complicated protection switching procedures. This paper therefore proposes a new heuristic algorithm, called Enhanced Multicast Hamiltonian Cycle Protection (EMHCP), in which all working light-trees of multicast demands can be protected by a Hamiltonian cycle in the network. For each multicast demand, EMHCP computes a least-cost light-tree based on the presented link-cost function that considers load balancing and proper straddling link selection so that backup wavelengths on the Hamiltonian cycle can be reduced. Simulation results show that EMHCP can obtain significant performance improvement compared with the conventional algorithm.     

Estimation of intracellular phosphate content in plant cell cultures using an extended Kalman filter

Phosphate is an essential nutrient that is usually taken up by plant cells rapidly and stored intracellularly. Currently, there is no convenient means for on-line sensing of the intracellular phosphate content in cultured plant cells. In this study, a state estimator for this important parameter in batch plant cell cultures was developed using extended Kalman filter (EKF) methodology. A non-linear kinetic model was constructed to describe the dynamics of intracellular phosphate uptake and utilization. For intracellular phosphate estimation, this model was found to be most sensitive to three parameters: the maximum specific growth rate (mu(max)), the maximum phosphate uptake rate (nu(max)), and the yield coefficient on oxygen (y(o)). The EKF algorithm coupled with the kinetic model and on-line oxygen uptake rate (r(o)) measurement was used successfully to track the intracellular phosphate content under different initial phosphate concentrations. The state estimator could also accurately predict the biomass concentration. When mu(max), nu(max), and y(o) were included in the state vector, tracking of intracellular phosphate was only slightly affected. The estimation system was found very stable as long as the measurement errors of the initial states, the r(o) measurement error, and the system error were respectively within 30%, 30%, and 50%. With a r(o) measurement interval as long as 12 h, accurate tracking of the intracellular phosphate content could still be attained using a discrete EKF. Apparently, the slow r(o) dynamics in plant cell cultures allows the use of a long measurement interval. Considering the difficulties encountered in the on-line sensing of intracellular phosphate using the chemical or nuclear magnetic resonance (NMR) methods, the EKF method coupled with simple on-line oxygen uptake rate measurement provides a promising means for sensing this important culture parameter on-line.     

SFD505型双宫自动缫丝机工艺探索

分析SFD505型双宫自动缫丝机与双宫立缫机在工艺要求上的主要不同点;采用单因素试验方法,重点讨论缫丝汤温、小(竹或)转速、喷水量与双宫丝纤度值之间的关系,并求出回归方程式。     

一种新型双感应八侧向测井仪结构研究

文章阐述了一种新型双感应八侧向测井仪的结构设计及其技术难点.通过强度和稳定性校核确定了探头电子部件外壳及电子线路绝缘外壳的结构.通过分析传统方法的不足,确定了一种压力平衡补偿装置的新型结构.     

纳秒级d－T聚变反应的16．7MeVγ测量

ｄ－Ｔ聚变反应产生的１６７ＭｅＶγ射线很弱，必须从很强的γ、中于混合场中筛选出来，故要求探测系统有高的信噪比，快的时间响应和宽的动态范围。利用高能γ与介质相互作用的康普顿效应及其定量对应关系，由扇形聚焦磁场一次偏转，用ＣＯ２气体切连科夫探测器（ＧＣＤ）探测电子束，或由扇形聚焦磁场（ＳＣＤ）二次偏转，用有机玻璃切连科夫探测器测电子束。仔细考虑了探测装置的辐射屏蔽和探测系统的电磁屏蔽。分别在“闪光－１”装置、ＤＨＪ－２５回旋加速器和２ＭＶ直线加速器上对探测装置进行了模拟检验实验和标定实验。在实际测试中，首次获得了纳秒级ｄ－Ｔ聚变反应产生的１６７ＭｅＶγ波形。