转移法色交换

将图Ｇ的着色由一种变为中一种，通常用Ｋｅｍｐｅ法以交换。但是，对于某些情况，用此法无效。针对这个问题，本文提出了一种转移法色交换，它适用于平面图着色，方法直观，清晰且有效。     

PPREM: Privacy Preserving REvocation Mechanism for Vehicular Ad Hoc Networks

One of the critical security issues of Vehicular Ad Hoc Networks (VANETs) is the revocation of misbehaving vehicles. While essential, revocation checking can leak potentially sensitive information. Road Side Units (RSUs) receiving the certificate status queries could infer the identity of the vehicles posing the query. An important loss of privacy results from the RSUs ability to tie the checking vehicle with the query's target. We propose a Privacy Preserving Revocation mechanism (PPREM) based on a universal one-way accumulator. PPREM provides explicit, concise, authenticated and unforgeable information about the revocation status of each certificate while preserving the users' privacy.     

Model checking response times in Networked Automation Systems using jitter bounds

Response time (RT) of Networked Automation Systems (NAS) is affected by timing imperfections induced due to the network, computing and hardware components. Guaranteeing RT in the presence of such timing imperfections is essential for building dependable NAS, and to avoid costly upgrades after deployment in industries.This investigation proposes a methodology and work-flow that combines modelling, simulation, verification, experiments, and software tools to verify the RT of the NAS during the design, rather than after deployment. The RT evaluation work-flow has three phases: model building, modelling and verification. During the model building phase component reaction times are specified and their timing performance is measured by combining experiments with simulation. During the modelling phase, component based mathematical models that capture the network architecture and inter-connection are proposed. Composition of the component models gives the NAS model required for studying the RT performance on system level. Finally, in the verification step, the NAS formal models are abstracted as UPPAAL timed automata with their timing interfaces. To model timing interfaces, the action patterns, and their timing wrapper are proposed. The formal model of high level of abstraction is used to verify the total response time of the NAS where the reactions to be verified are specified using a subset of timed computation tree logic (TCTL) in UPPAAL model checker. The proposed approach is illustrated on an industrial steam boiler deployment.     

Modeling deterministic echo state network with loop reservoir

Echo state network (ESN),which efficiently models nonlinear dynamic systems,has been proposed as a special form of recurrent neural network.However,most of the proposed ESNs consist of complex reservoi...     

Study of hybrid optical burst networks

We propose the hybrid optical burst switching (HOBS), and investigate the HOBS-based ring topology with numerical simulation. Results indicate that the packet loss ratio in HOBS is much less than that in optical burst switching(OBS) and its performance depends on some parameters such as the packet proportion, the electronic buffer size and the processing speed in the node. __________ Translated from Journal on Communications, 2005, 26(11): 7–11 (in Chinese)     

An approximation method of origin–destination flow traffic from link load counts

Traffic matrix (TM) is a key input of traffic engineering and network management. However, it is significantly difficult to attain TM directly, and so TM estimation is so far an interesting topic. Though many methods of TM estimation are proposed, TM is generally unavailable in the large-scale IP backbone networks and is difficult to be estimated accurately. This paper proposes a novel method of TM estimation in large-scale IP backbone networks, which is based on the generalized regression neural network (GRNN), called GRNN TM estimation (GRNNTME) method. Firstly, building on top of GRNN, we present a multi-input and multi-output model of large-scale TM estimation. Because of the powerful capability of learning and generalizing of GRNN, the output of our model can sufficiently capture the spatio-temporal correlations of TM. This ensures that the estimation of TM can accurately be attained. And then GRNNTME uses the procedure of data posttreating further to make the output of our model closer to real value. Finally, we use the real data from the Abilene Network to validate GRNNTME. Simulation results show that GRNNTME can perform well the accurate and fast estimation of TM, track its dynamics, and holds the stronger robustness and lower estimation errors.     

TD-SCDMA上行增强系统中的负载控制

研究了TD-SCDMA上行增强系统中的负载控制策略,提出了一种基于小区间干扰的离散式负载控制算法.该算法通过限制本小区用户造成的邻小区干扰水平,可以有效平衡系统负载,提高系统资源利用率,从而达到提高系统吞吐量,保证用户服务质量的目的.仿真结果表明,该算法能够提供较好的系统性能.     

LTE-Hi高阶星座调制性能研究

在室内/热点区域场景下,由于终端与基站之间信道质量良好,因此可以考虑引入高阶星座调制以提高频谱效率。基于一种MCS/TBS/CQI配置,对多种Small Cell场景进行引入256QAM的系统级仿真,并通过仿真结果来对比在不同场景中,引入256QAM和采用原有调制方式对用户吞吐量、频谱效率等多项指标的影响。仿真结果初步表明,在Small Cell scenario 3稀疏场景下,引入256QAM后将对系统产生较大增益。     

DIV： Dynamic Integrity Validation Framework for Detecting Compromises on Virtual Machine Based Cloud Services in Real Time

with the increasing popularity of cloud services,attacks on the cloud infrastructure also increase dramatically.Especially,how to monitor the integrity of cloud execution environments is still a difficult task.In this paper,a real-time dynamic integrity validation（DIV） framework is proposed to monitor the integrity of virtual machine based execution environments in the cloud.DIV can detect the integrity of the whole architecture stack from the cloud servers up to the VM OS by extending the current trusted chain into virtual machine＇s architecture stack.DIV introduces a trusted third party（TTP） to collect the integrity information and detect remotely the integrity violations on VMs periodically to avoid the heavy involvement of cloud tenants and unnecessary information leakage of the cloud providers.To evaluate the effectiveness and efficiency of DIV framework,a prototype on KVM/QEMU is implemented,and extensive analysis and experimental evaluation are performed.Experimental results show that the DIV can efficiently validate the integrity of files and loaded programs in real-time,with minor performance overhead.