Trustworthiness of Internet-based software

Recent years see an increasing concern over the trustworthiness of Inter- net-based software. By analyzing the trustworthiness of Internet-based software and the nature of the Internet applications, we point out that, on the one hand, due to the open- ness and dynamic nature of the Internet, the identity trustworthiness and the capability trustworthiness of the software are facing serious challenges; on the other hand, in order to ensure the trustworthiness of the whole system, emerging computing paradigms based on the collaboration of autonomous software need some impacts on the behavior of the software. Here we put forward a conceptual model for the trustworthiness of Inter- net-based software, and propose a trustworthy assurance framework for Internet-based virtual computing environment (iVCE). This framework deals with the trustworthy proper- ties of software on identity, capability and behavior in a combinated way. The authorization management in inter-domain computing environment, assurance on high availability of service and incentive mechanism for autonomic collaboration are taken as three core mechanisms of iVCE trustworthy assurance.     

An Image-Based Virtual Reality Prototype System

The most important goal of virtual reality is to create a virtual world computers where users are allowed to view the environment and control the virtual objects interactively.Traditionally,virtual reality systems use 3D computer graphics to model and render a virtual environment in real time.However,this approach usually requires laborious modeling and expensive special-purpose rendering hardware.Image-based rendering is a new approach in composing a virtual environment in which a set of panoramic images is used to compose the virtual environment and walking in the space is accomplished by “hopping”to different panoramic points.This paper introduces an experimental image-based VR system.The techniques utilized in the system,in particular the authoring and interactive control tools of the system,are described in detail.     

Integration of manufacturing services into virtual environments over the internet

Virtual reality (VR) is a rapidly developing technology that has a wide spectrum of industrial and commercial applications. Networked (distributed or shared) virtual environments (VE) are of growing interest to modern manufacturing industry; a dominating use of networked virtual manufacturing environments (VMEs) is on-line visualisation and collaborative control of 3D information. This has to be supported by real-time data transfer. To meet a broad range of common requirements for Internet-based VE communications, particularly for virtual manufacturing and collaborative design and control, this paper presents a networked virtual environment system that is designed to support networked virtual design and manufacturing. The system is implemented with manufacturing message specification (MMS) standards so as to integrate a range of manufacturing services into networked VEs over the Internet.     

Decrement delay with widest K-shortest paths Q-routing algorithm

During the last few years the Internet has grown tremendously and has penetrated all aspects of everyday life. Starting off as a purely academic research network, the Internet is now extensively used for education, for entertainment, and as a very promising and dynamic marketplace, and is envisioned as evolving into a vehicle of true collaboration and a multi-purpose working environment. Although the lnternet is based on a best-effort service model, the simplicity of its packet-switched design and the flexibility of its underlying packet forwarding regime （IP） accommodate millions of users while offering acceptable performance. At the same time, exciting new applications and networked services have emerged, putting greater demands on the network. In order to offer a better-than-best-effort Internet, new service models that offer applications performance guarantees have been proposed. While several of these proposals are in place, and many QOS-enabled networks are operating, there is still a lack of comprehension about the precise requirements new applications have in order to function with high or acceptable levels of quality. Furthermore, what is required is an understanding of how network-level QOS reflects on actual application utility and usability. In this work a proposal for routing which improves the delay factor and is based on the reinforcement learning is concerned. We use Q-learning as the reinforcement learning technique and introduce K-shortest idea into the learning process. The proposed algorithm is applied to two different topologies. The OPNET is used to evaluate the performance of the proposed algorithm. The algorithm evaluation is done for two traffic conditions, namely low load and high load.     

Gallbladder Removal Simulation for Laparoscopic Surgery Training: A Hybrid Modeling Method

Laparoscopic surgery has many advantages, but it is difficult for a surgeon to achieve the necessary surgical skills. Recently, virtual training simulations have been gaining interest because they can provide a safe and efficient learning environment for medical students and novice surgeons. In this paper, we present a hybrid modeling method for simulating gallbladder removal that uses both the boundary element method (BEM) and the finite element method (FEM). Each modeling method is applied according to the deformable properties of human organs: BEM for the liver and FEM for the gallbladder. Connective tissues between the liver and the gallbladder are also included in the surgical simulation. Deformations in the liver and the gallbladder models are transferred via connective tissue springs using a mass-spring method. Special effects and techniques are developed to achieve realistic simulations, and the software is integrated into a custom-designed haptic interface device. Various computer graphical techniques are also applied in the virtual gallbladder removal laparoscopic surgery training. The detailed techniques and the results of the simulations are described in this paper.     

A Strategy of Density-Based Partitioning for Scalability Problem in Network Self-management

A density-based partitioning strategy is proposed for large domain networks in order to deal with the scalability issue found in autonomic networks considering, as a scenario, the autonomic Quality of Service （QoS） management context. The approach adopted focus as on obtaining dense network partitions having more paths for a given vertices set in the domain. It is demonstrated that dense partitions improve autonomic processing scalability, for instance, reducing routing process complexity. The solution looks for a significant trade-off between partition autonomic algorithm execution time and path selection quality in large domains. Simulation scenarios for path selection execution time are presented and discussed. Authors argue that autonomic networks may benefit from the dense partition approach proposed by achieving scalable, efficient and near real-time support for autonomic management systems.     

Reflection and Refraction on Implicit Surfaces

Implicit surfaces are often used in computer graphics. They can be easily modeled and rendered, and many objects are composed of them in our daily life. In this paper, based on the concept of virtual objects, a novel method of real-time rendering is presented for reflection and refraction on implicit surface. The method is used to construct virtual objects from real objects quickly, and then render the virtual objects as if they were real objects except for one more step of merging their images with the real objects＇ images. Characteristics of implicit surfaces are used to compute virtual objects effectively and quickly. GPUs （Graphics Processing Units） are used to compute virtual vertices quickly and further accelerate the computing and rendering processes. As a result, realistic effects of reflections and refractions on implicit surfaces are rendered in real time.     

Integration Model of Eye-Gaze, Voice and Manual Response in Multimodal User Interface

This paper reports the utility of eye-gaze,voice and manual response in the design of multimodal user interface.A device-and application-independent user interface model(VisualMan)of 3D object selection and manipulation was developed and validated in a prototype interface based on a 3D cube manipulation task.The multimodal inpus are integrated in the prototype interface based on the priority of modalities and interaction context.The implications of the model for virtual reality interface are discussed and a virtual environment using the multimodal user interface model is proposed.     

A method for trust management in cloud computing: Data coloring by cloud watermarking

With the development of Internet technology and human computing, the computing environment has changed dramatically over the last three decades. Cloud computing emerges as a paradigm of Internet computing in which dynamical, scalable and often virtualized resources are provided as services. With virtualization technology, cloud computing offers diverse services (such as virtual computing, virtual storage, virtual bandwidth, etc.) for the public by means of multi-tenancy mode. Although users are enjoying the capabilities of super-computing and mass storage supplied by cloud computing, cloud security still remains as a hot spot problem, which is in essence the trust management between data owners and storage service providers. In this paper, we propose a data coloring method based on cloud watermarking to recognize and ensure mutual reputations. The experimental results show that the robustness of reverse cloud generator can guarantee users embedded social reputation identifications. Hence, our work provides a reference solution to the critical problem of cloud security.     

Flexibility analysis of a tracking control method for air-breathing hypersonic vehicles

This paper studies the flexibility of a tracking control method originally proposed by the authors for air-breathing hypersonic vehicles （AHVs）. The main feature of this method is to design the tracking controller without canceling but using aero-propulsive, as well as elevator-to-lift couplings. By introducing a virtual input, the tracking controller and external reference trajectories are simultaneously obtained by solving a system of linear algebraic equations. This system of linear algebraic equations is always solvable and the solution space of the corresponding homogeneous system is of dimension 3, which leads to much freedom in choosing or defining the free variables. The flexibility is reflected by the fact that the flight requirements of AHVs are involved in the definition of the free variables. Three case studies on different maneuvers, i.e., flight at constant dynamic pressure, flight at variant dynamic pressure and flight with fast climb rate are considered to verify the flexibility of this method. Simulation results show its effectiveness and flexibility.     

A Programming Language Approach to Internet-Based Virtual Computing Environment

There is an increasing need to build scalable distributed systems over the Internet infrastructure. However, the development of distributed scalable applications suffers from lack of a wide accepted virtual computing environment. Users have to take great efforts on the management and sharing of the involved resources over Internet, whose characteristics are intrinsic growth, autonomy and diversity. To deal with this challenge, Internet-based Virtual Computing Environment (iVCE) is proposed and developed to serve as a platform for distributed scalable applications over the open infrastructure, whose kernel mechanisms are on-demand aggregation and autonomic collaboration of resources. In this paper, we present a programming language for iVCE named Owlet. Owlet conforms with the conceptual model of iVCE, and exposes the iVCE to application developers. As an interaction language based on peer-to-peer content-based publish/subscribe scheme, Owlet abstracts the Internet as an environment for the roles to interact, and uses roles to build a relatively stable view of resources for the on-demand resource aggregation. It provides language constructs to use 1) distributed event driven rules to describe interaction protocols among different roles, 2) conversations to correlate events and rules into a common context, and 3) resource pooling to do fault tolerance and load balancing among networked nodes. We have implemented an Owlet compiler and its runtime environment according to the architecture of iVCE, and built several Owlet applications, including a peer-to-peer file sharing application. Experimental results show that, with iVCE, the separation of resource aggregation logic and business logic significantly eases the process of building scalable distributed applications.     

Embedded DHT overlays in virtual computing environments

With the rapid development of computing and networking technologies, people propose to build harmonious, trusted and transparent Internet-based virtual computing environments (iVCE). The overlay-based organization of dynamic Internet resources is an important approach for iVCE to realizing efficient resource sharing. DHT-based overlays are scalable, low-latency and highly available; however, the current DHT overlay (SKY) in iVCE cannot satisfy the trust requirements of Internet applications. To address this...     

VirtMan: design and implementation of a fast booting system for homogeneous virtual machines in iVCE

Internet-based virtual computing environment (iVCE) has been proposed to combine data centers and other kinds of computing resources on the Internet to provide efficient and economical services. Virtual machines (VMs) have been widely used in iVCE to isolate different users/jobs and ensure trustworthiness, but traditionally VMs require a long period of time for booting, which cannot meet the requirement of iVCE’s large-scale and highly dynamic applications. To address this problem, in this paper we design and implement VirtMan, a fast booting system for a large number of virtual machines in iVCE. VirtMan uses the Linux Small Computer System Interface (SCSI) target to remotely mount to the source image in a scalable hierarchy, and leverages the homogeneity of a set of VMs to transfer only necessary image data at runtime. We have implemented VirtMan both as a standalone system and for OpenStack. In our 100-server testbed, VirtMan boots up 1000 VMs (with a 15 GB image of Windows Server 2008) on 100 physical servers in less than 120 s, which is three orders of magnitude lower than current public clouds.     

一种基于聚类的虚拟计算环境资源聚合方法

作为面向互联网资源共享的虚拟计算环境的实例,iVCE(Internet based virtual computing environment) for Memory致力于解决广域分布的内存资源的共享与综合利用问题.由于内存资源的特殊性,传统的资源管理方法很难适用.以iVCE for Memory作为背景,提出一种基于聚类的虚拟计算环境资源聚合方法,有效降低了资源聚合的问题规模;借鉴物理学中的力场和势能理论,建立了实现资源聚合的基本模型和力场-势能模型以及相应的分布式算法;通过基于真实网络拓扑的模拟,对两种模型和算法分别进行了评估和验证.     

虚拟计算环境中基于资源池的资源聚合机制

虚拟计算环境中存在着极为丰富的资源,但由于其系统的动态性与自治性特点非常突出,系统服务质量很难得到保证。本文提出一种基于资源池的资源聚合方法,即根据应用需求将所需资源聚合成资源池,并以资源池的形式为用户提供服务,使得在任务执行过程中即使部分节点由于系统故障、超载等原因中途退出任务处理,用户的服务请求仍能得到处理和响应。此外,该方法结合负载均衡,优化了资源节点的选择与资源池的构建,从而有效地提高了系统服务质量。     

虚拟计算环境中的DHT拓扑构建技术研究综述

基于互联网的虚拟计算环境(iVCE)是一种新型网络计算平台.互联网资源的成长性、自治性和多样性等自然特性给iVCE中的资源共享带来巨大的挑战.DHT覆盖网(简称DHT)具有可扩展、延迟低、可靠性高等优点,是iVCE实现资源有效共享的重要途径之一.拓扑构建是DHT的基础性关键技术,实现了DHT的动态维护与消息路由等基本功能.本文首先概述传统DHT的拓扑构建技术,主要包括各种典型DHT的动态维护机制与消息路由算法、支持复杂查询的DHT索引构建技术,以及支持管理域匹配的DHT分组构建技术等;进而针对互联网资源的特点,综述在iVCE中DHT拓扑构建技术的最新研究进展.本文在最后对DHT拓扑构建技术的未来发展方向进行探讨.     

虚拟计算环境中的多机群协同调度算法

基于虚拟计算环境的核心机理,提出由自主调度单元、域调度共同体、元调度执行体为核心的多机群协同系统框架.剖析多机群任务并发运行性能模型,设计了多机群协同调度算法框架,提出最大空闲节点优先、最小网络拥塞优先、最小异构因子优先与最小异构空闲节点优先4种启发式资源选择策略.实验验证了协同调度模型与算法在任务集完成时间与系统平均利用率的测度上的有效性.     

虚拟计算环境下信任管理研究

可信保证体系是虚拟计算环境的基础组件.虚拟计算环境下信任管理具有不确定性和动态性特点,因此,虚拟计算环境下的可信保证体系应具备主观性、基于证据以及上下文相关性的特性.针对虚拟计算环境下虚拟共同体的服务选取以及自主元素的可信度计算的安全问题,提出了基于贝叶斯分析的信任模型.     

虚拟计算环境中的覆盖网技术

互联网资源的成长、自治和多样等特性给资源的有效聚合带来了巨大挑战.通过覆盖网动态组织互联网资源并支持资源的高效搜索,是虚拟计算环境中资源按需聚合的重要途径之一.文中概述了虚拟计算环境中覆盖网技术的研究进展.针对互联网资源的成长性和自治性等特点,阐述了基于Kautz图的高效覆盖网拓扑构造方法,进而给出了适用于任意正则图的通用覆盖网拓扑构造方法;针对互联网资源的多样性等特点,提出了支持分组的覆盖网拓扑构造方法;在此基础上,阐述了基于覆盖网的高效区间搜索技术,并对覆盖网拓扑的优化方法及其它复杂搜索技术进行探讨.