Evalvid-RA: trace driven simulation of rate adaptive MPEG-4 VBR video

Due to the increasing deployment of conversational real-time applications like VoIP and videoconferencing, the Internet is today facing new challenges. Low end-to-end delay is a vital QoS requirement for these applications, and the best effort Internet architecture does not support this natively. The delay and packet loss statistics are directly coupled to the aggregated traffic characteristics when link utilization is close to saturation. In order to investigate the behavior and quality of such applications under heavy network load, it is therefore necessary to create genuine traffic patterns. Trace files of real compressed video and audio are text files containing the number of bytes per video and audio frame. These can serve as material to construct mathematical traffic models. They can also serve as traffic generators in network simulators since they determine the packet sizes and their time schedule. However, to inspect perceived quality, the compressed binary content is needed to ensure decoding of received media. The EvalVid streaming video tool-set enables this using a sophisticated reassembly engine. Nevertheless, there has been a lack of research solutions for rate adaptive media content. The Internet community fears a congestion collapse if the usage of non-adaptive media content continues to grow. This paper presents a solution named Evalvid-RA for the simulation of true rate adaptive video. The solution generates real rate adaptive MPEG-4 streaming traffic, using the quantizer scale for adjusting the sending rate. A feedback based VBR rate controller is used at simulation time, supporting TFRC and a proprietary congestion control system named P-AQM. Example ns-2 simulations of TFRC and P-AQM demonstrate Evalvid-RA’s capabilities in performing close-to-true rate adaptive codec operation with low complexity to enable the simulation of large networks with many adaptive media sources on a single computer.     

Scan-based volume animation driven by locally adaptive articulated registrations

This paper describes a complete system to create anatomically accurate example-based volume deformation and animation of articulated body regions, starting from multiple in vivo volume scans of a specific individual. In order to solve the correspondence problem across volume scans, a template volume is registered to each sample. The wide range of pose variations is first approximated by volume blend deformation (VBD), providing proper initialization of the articulated subject in different poses. A novel registration method is presented to efficiently reduce the computation cost while avoiding strong local minima inherent in complex articulated body volume registration. The algorithm highly constrains the degrees of freedom and search space involved in the nonlinear optimization, using hierarchical volume structures and locally constrained deformation based on the biharmonic clamped spline. Our registration step establishes a correspondence across scans, allowing a data-driven deformation approach in the volume domain. The results provide an occlusion-free person-specific 3D human body model, asymptotically accurate inner tissue deformations, and realistic volume animation of articulated movements driven by standard joint control estimated from the actual skeleton. Our approach also addresses the practical issues arising in using scans from living subjects. The robustness of our algorithms is tested by their applications on the hand, probably the most complex articulated region in the body, and the knee, a frequent subject area for medical imaging due to injuries.     

实例驱动的自适应本体学习

针对知识管理中本体构建存在的问题,将聚类算法与ODP（Open Directory Project）目录有机结合,给出了一种基于知识资源元数据的自适应本体学习方法。根据元数据对文档进行聚类形成本体概念,将生成的概念分别映射到ODP中确定概念间的层次关系,生成初始本体;根据内聚性和相关性的变化进行自适应本体学习,实现本体更新和概念丰富,以及时跟踪知识的变化。提出的自适应本体学习方法能够很好地反映研究领域的演变过程和发展趋势,满足知识型组织进行知识管理和研究人员共享知识的需求。实验结果表明了方法的有效性。     

A novel adaptive control for reaching movements of an anthropomorphic arm driven by pneumatic artificial muscles

Pneumatic artificial muscle is widely used since it has the advantage including simple structure, lightweight, force controllable, compliance and so on. In this paper, a two-link anthropomorphic arm is constructed by pneumatic artificial muscles for the upper-limb rehabilitation training. In order to assist impaired upper-limb patients to achieve various training, the anthropomorphic arm should realize flexible human reaching movements. Due to frictions and model uncertainties of the anthropomorphic arm system, an adaptive fuzzy backstepping control is proposed to ensure the stability and the adaptivity during the motion. The control method is proved by Lyapunov asymptotic stability and is verified by numerical simulations. Furthermore, experiments are performed and results demonstrate that the proposed control method is efficient and robust.     

双目标推动下群体行为的元胞自动机模拟

采用元胞自动机对自推动粒子改进模型进行模拟,在此基础上分别探讨无目标与双目标群体行为的演化特征。无目标条件下群体行为的元胞模拟结果显示低密度环境下大部分个体处于动态均衡,高密度环境下大部分个体处于静态均衡,中等密度下两种均衡均存在。基于双目标吸引力的群体行为模拟结果显示当智能体的理性程度较低时系统演化能够产生一定的集聚效应,处于吸引源以外的智能体与吸引源保持一定距离并呈湍流式运动,而当智能体具备小概率全局理性判断能力时,群体行为的演化结果为大部分智能体都聚集在吸引源附近。     

Non-linear adaptive robust control of electro-hydraulic systems driven by double-rod actuators

This paper studies the high performance robust motion control of electro-hydraulic servo-systems driven by double-rod hydraulic actuators. The dynamics of hydraulic systems are highly non-linear and the system may be subjected to non-smooth and discontinuous non-linearities due to directional change of valve opening, friction and valve overlap. Aside from the non-linear nature of hydraulic dynamics, hydraulic servosystems also have large extent of model uncertainties. To address these challenging issues, the recently proposed adaptive robust control (ARC) is applied and a discontinuous projection based ARC controller is constructed. The resulting controller is able to take into account the effect of the parameter variations of the inertia load and the cylinder hydraulic parameters as well as the uncertain non-linearities such as the uncompensated friction forces and external disturbances. Non-differentiability of the inherent non-linearities associated with hydraulic dynamics is carefully examined and addressing strategies are provided. Compared with previously proposed ARC controller, the controller in the paper has a more robust parameter adaptation process and may be more suitable for implementation. Finally, the controller guarantees a prescribed transient performance and final tracking accuracy in the presence of both parametric uncertainties and uncertain non-linearities while achieving asymptotic tracking in the presence of parametric uncertainties.     

Robust tracking control of an electrically driven robot: adaptive fuzzy logic approach

This paper is concerned with the robust tracking control of an electrically driven robot with the model uncertainties in the robot dynamics and the motor dynamics. The motors driving the joints of the robot are assumed to be equipped with only the joint position and the current measurement devices. Adaptive fuzzy logic and adaptive backstepping method are employed to provide the solution to the control problem. The suggested method does not require the measurement of the velocity nor the acceleration. Simulation results from a two-link electrically driven robot show the satisfactory performance of the proposed control scheme even in the presence of internal model uncertainties in both the robot and motor dynamics and external disturbances.     

Exemplar driven development of software product lines

The benefits of following a product line approach to develop similar software systems are well documented. Nevertheless, some case studies have revealed significant barriers to adopt such approach. In order to minimize the paradigm shift between conventional software engineering and software product line engineering, this paper presents a new development process where the products of a domain are made by analogy to an existing product. Furthermore, this paper discusses the capabilities and limitations of different techniques to implement the analogy relation and proposes a new language to overcome such limitations.     

变频泵控锚杆钻臂摆角动态滑模自适应控制

巷道支护锚杆/锚索安装过程中, 液压锚杆钻机钻臂通常人工控制, 定位精度低, 导致钻杆安装偏离设计位置, 引起设备故障和巷道坍塌. 因此, 设计一种基于动态切换函数的滑模自适应摆角控制器. 针对变频泵控液压锚杆钻臂旋转系统存在的诸多内外部干扰, 设计自适应律和动态滑模控制器, 有效降低抖振和抑制干扰. 联合仿真实验表明, 动态滑模自适应摆角控制能够有效克服诸多不确定性对系统的影响, 无超调的准确跟踪设定值, 满足煤炭安全规程中锚杆/锚索安装偏转角控制和巷道稳定支护的需求.     

协作态势驱动的自适应候选者协商维持模型

为提高云服务协作过程服务失效的替换成功率,提出一种云平台下协作态势驱动的自适应候选者协商维持模型,利用贝叶斯学习预测协商数据保留值,自适应提交协商议题,以维持与候选者的协商;通过对服务协作过程动态监测,动态优化服务候选集。实验结果表明,服务协商维持模型能适应协作过程变化,使服务协作具有良好的自适应性和健壮性。     

Generation of realistic saddle trajectories from captured horseback motion

Multibody System Dynamics - Hippotherapy, riding a horse in the context of rehabilitation, is a medical treatment that successfully has been employed in various fields, e.g. for improving...     

Robust interactive cutting based on an adaptive octree simulation mesh

We present an adaptive octree based approach for interactive cutting of deformable objects. Our technique relies on efficient refine- and node split-operations. These are sufficient to robustly represent cuts in the mechanical simulation mesh. A high-resolution surface embedded into the octree is employed to represent a cut visually. Model modification is performed in the rest state of the object, which is accomplished by back-transformation of the blade geometry. This results in an improved robustness of our approach. Further, an efficient update of the correspondences between simulation elements and surface vertices is proposed. The robustness and efficiency of our approach is underlined in test examples as well as by integrating it into a prototype surgical simulator.     

一种XML驱动的遥感产品生产并发数据流模型

通过分析现有遥感产品生产平台的并行策略与处理流程,结合现有的数据流模型,提出了一种XML驱动的遥感产品生产并发数据流模型,并给出该模型的文法以及并发性驱动原理。该模型通过适配XML驱动文件,有很好的拓展性。通过对模型并发性的分析,认为该模型在提高遥感产品生产效率、优化并行策略和可视化信息展示上有一定的优势。     

Parallel adaptive reservoir simulation

In oil-industry it is common use to simulate the exploitation of an oil-reservoir by means of some numerical method. Such a numerical method may use the concept of dynamical local grid refinement, in order to mark fronts of water and oil, which move through the reservoir. In this paper, we discuss a domain decomposition method, which may be used to parallelize reservoir simulation. The parallel algorithm and timing experiments on a hypercube-type parallel computer are considered.     

浮力驱动式水下滑翔机运动仿真

浮力驱动式水下滑翔机对我国海洋勘探和国防建设有着重要应用前景,根据水下滑翔机三维运动模型,以MATLAB/Simulink为平台完成了滑翔机建模和图形界面仿真工具的设计。并以此仿真软件进行算例计算。该仿真成本低廉,可广泛应用于一般的水下滑翔机设计方案验证。     

Dynamic simulation of product process

During 90’s Nokia utilized Concurrent Engineering (CE) process in mobile phone business successfully. Strong growing of the company, more complex technologies, maturing markets and changes in competition has increased the need to develop the product process of the company to keep its position as an agile, innovative and productive product developer. Dynamic simulation approach has been one of the activities among other product process re-engineering efforts in the company.This paper describes the approach and “Product Process Decision Simulation” (PPDS) solution as the first implemented application of the approach. A dynamic model of product development has been created and applied to manage product process complex dynamic behavior on system level in order to reduce product development cycle times, slippages and costs as well as improve perceived product quality. The key contribution of the simulation solution is to provoke facilitated discussion in order to gain shared understanding of interdependencies and dynamic causes and effects in product process.The implementation and frequent simulation workshops have started in June 2006 and about 500 R&D people have already participated.     

MTF driven adaptive multiscale bilateral filtering for pansharpening

The recently proposed Bilateral Filter Luminance Proportional (BFLP) method extracts the high-frequency details from panchromatic (Pan) image via a multiscale bilateral filter and adds them proportionally to the multispectral (MS) image. Although this approach seems similar to other multiresolution (MRA) based schemes such as Additive Wavelet proportional Luminance (AWLP) or Generalized Laplacian (GLP) methods, multiscale bilateral filter obtains the detail planes to be injected to MS image by the combination of two Gaussian kernels controlling the transfer of details and performing successively in spatial and range domains, thus it has two parameters to be defined, namely spatial and range parameters. Since the parameter determination step considerably affects the efficiency of the method, in this paper we propose a single parameter bilateral filter by approximating the Gaussian kernel with the bicubic kernel of à trous wavelet transform (ATWT) or modulation transfer function (MTF). Moreover, we adopt an adaptive injection scheme where the range parameter is determined adaptively so as to follow the statistics of the images to be fused. The pansharpening results are compared with ATWT-based methods, as well as some state-of-the-art methods and BFLP. The visual and quantitative comparisons for Système Pour l’Observation de la Terre 7 (SPOT 7) and Pléiades 1A images, field studies supported with UAV (Unmanned Aerial Vehicle) images and digitization results of the chosen areas in Istanbul Technical University (ITU) Maslak campus confirm the superiority of the proposed detail injection approach.     

Generation of singlet states with Rydberg blockade mechanism and driven by adiabatic passage

A single state is a special state that entangles multi-state quantum systems and plays a significant role in the field of quantum computation. In this paper, we propose a scheme to realize the generation of single states for Rydberg atoms, where one Rydberg atom is trapped in an optical potential and the others are trapped in an adjacent optical potential. Moreover, combining Rydberg blockade and adiabatic-passage technologies, an N-atom singlet state can be generated with the interaction of an N-dimensional Rydberg atom and an (\(N-1\))-atom singlet state. Compared to previous schemes, the advantage of our proposal is that an N-particle N-level singlet state with \(N\ge 3\) may be realized more simply.     

基于数据驱动的非线性网络系统自适应迭代学习控制

针对非线性网络控制系统中测量数据的量化及随机丢包问题,给出一种基于数据驱动的自适应迭代学习控制算法.该算法能够保证系统在数据量化、随机丢包以及不确定迭代学习长度等因素的影响下,经过有限次迭代后输出轨迹跟踪误差收敛到零;借助伪偏导线性化方法,将非线性系统转换为线形时变系统形式;在线性系统框架下利用前一批次的系统输出信息更...