Virtual private networks: What,why, when,where and how

In the last few months, I have been asked by many major customer sites to help them with a Virtual Private Network (VPN) implementation strategy. My first question is if they know what a VPN is. The answer, when the fog around the issue gets cleared up, is usually “no”. But, they have been reading about them and feel a need to implement a strategy or get left behind in the technology curve that eludes us all. Sigh.     

MobiCache: Cellular traffic offloading leveraging cooperative caching in mobile social networks

Offloading cellular traffic through mobile social networks has arisen as a promising way for relieving cellular networks. Prior studies mainly focused on caching data in a number of pre-selected helpers. However, such a strategy would fail when mobile users enter and leave the target area over time. In this paper, we examine the research decisions and design tradeoffs that arise when offloading cellular traffic in such a dynamic area of interest, referred to as a MobiArea, and we design an offloading framework, MobiCache, for maximizing cellular operators’ revenues and minimizing the overhead imposed on mobile devices. On the user side, we propose a content floating-based cooperative caching strategy that caches data in geographical floating circles, instead of selected helpers in previous studies, to cope with the dynamics. A geographical routing scheme is designed for delivering data and queries towards floating circles. We also develop a cache replacement scheme to improve caching cost-effectiveness inside floating circles. On the operator side, query history and feedback are maintained for cellular operators to optimize framework parameters that maximize their revenues. Extensive trace-driven simulations show that, compared with a state-of-the-art scheme, MobiCache offloads up to 52% more traffic with 15% shorter delay and 6% less forwarding cost.     

Virtual learning environment to predict withdrawal by leveraging deep learning

The current evolution in multidisciplinary learning analytics research poses significant challenges for the exploitation of behavior analysis by fusing data streams toward advanced decision-making. The identification of students that are at risk of withdrawals in higher education is connected to numerous educational policies, to enhance their competencies and skills through timely interventions by academia. Predicting student performance is a vital decision-making problem including data from various environment modules that can be fused into a homogenous vector to ascertain decision-making. This research study exploits a temporal sequential classification problem to predict early withdrawal of students, by tapping the power of actionable smart data in the form of students' interactional activities with the online educational system, using the freely available Open University Learning Analytics data set by employing deep long short-term memory (LSTM) model. The deployed LSTM model outperforms baseline logistic regression and artificial neural networks by 10.31% and 6.48% respectively with 97.25% learning accuracy, 92.79% precision, and 85.92% recall.     

Pervasive community care platform: Ambient Intelligence leveraging sensor networks and mobile agents

Several powerful trends are contributing to an aging of much of the world's population, especially in economically developed countries. To mitigate the negative effects of rapidly ageing populations, societies must act early to plan for the welfare, medical care and residential arrangements of their senior citizens, and for the manpower and associated training needed to execute these plans. This paper describes the development of an Ambient Intelligent Community Care Platform (AICCP), which creates an environment of Ambient Intelligence through the use of sensor network and mobile agent (MA) technologies. The AICCP allows caregivers to quickly and accurately locate their charges; access, update and share critical treatment and wellness data; and automatically archive all records. The AICCP presented in this paper is expected to enable caregivers and communities to offer pervasive, accurate and context-aware care services.     

Virtual Networking and the Internet

Examining the issues of economics, network predictability, and security helps IS managers decide when to consider the Internet a transmission mechanism for replacing private network and public packet-network applications, the types of applications best suited for virtual networking on the Internet, and the safeguards necessary for protecting organizational data that travels on it.     

Virtual database technology: transforming the Internet into adatabase

Much of the world's data lies outside relational databases-scattered across Web sites, file systems, nonrelational databases, and legacy applications. These data sources differ in the way they organize data, in the vocabulary they use, and in their data-access or query mechanisms. These differences make it difficult to combine data from multiple sources. Virtual database (VDB) technology makes external data sources act as an extension of an enterprise's relational database system. Using VDB technology, applications can make powerful queries of data scattered over a variety of sources. The VDB gathers, structures, and integrates the data from these sources, and gives the application programmer the appearance of a single, unified RDBMS     

Social networks on the Internet

The rapid development and expansion of the Internet and the social–based services comprised by the common Web 2.0 idea provokes the creation of the new area of research interests, i.e. social networks on the Internet called also virtual or online communities. Social networks can be either maintained and presented by social networking sites like MySpace, LinkedIn or indirectly extracted from the data about user interaction, activities or achievements such as emails, chats, blogs, homepages connected by hyperlinks, commented photos in multimedia sharing system, etc. A social network is the set of human beings or rather their digital representations that refer to the registered users who are linked by relationships extracted from the data about their activities, common communication or direct links gathered in the internet–based systems. Both digital representations named in the paper internet identities as well as their relationships can be characterized in many different ways. Such diversity yields for building a comprehensive and coherent view onto the concept of internet–based social networks. This survey provides in–depth analysis and classification of social networks existing on the Internet together with studies on selected examples of different virtual communities.     

Internet上的虚拟仪器

本文介绍了新一代虚拟仪器具有的网络功能,着重论述了实现Internet上的测量系统的软件基础－DataSocket,并举例说明如何用虚拟仪器构建Internet上的测量和自动化系统。     

The latest in virtual private networks: part I

Virtual private networks (VPNs) are discrete network entities configured and operated over a shared network infrastructure. An intranet is a VPN in which all the sites (the customer locations that are part of a VPN) belong to a single organization. An extranet is a VPN with two or more organizations wishing to share (some) information. In the business world, VPNs let corporate locations share information over the Internet. VPN technology is being extended to the home office, providing telecommuters with the networking security and performance commensurate with that available at the office. Service providers are looking at their geographic footprints and their network routing expertise to create and deliver new revenue-generating VPN services. Looking ahead, these provider-provisioned and managed VPNs are intended to emulate whatever local- or wide-area network connectivity customers desire.     

Survey on leveraging pre-trained generative adversarial networks for image editing and restoration

Generative adversarial networks(GANs) have drawn enormous attention due to their simple yet efective training mechanism and superior image generation quality. With the ability to generate photorealistic high-resolution(e.g., 1024 × 1024) images, recent GAN models have greatly narrowed the gaps between the generated images and the real ones. Therefore, many recent studies show emerging interest to take advantage of pre-trained GAN models by exploiting the well-disentangled latent space and the le...     

On private computation in incomplete networks

Suppose that some parties are connected by an incomplete network of reliable and private channels. The parties cooperate to execute some protocol. However, the parties are curious—after the protocol terminates each party tries to learn information from the communication it heard. We say that a function can be computed privately in a network if there is a protocol in which each processor learns only the information implied by its input and the output of the function (in the information theoretic sense). The question we address in this paper is what functions can be privately computed in a given incomplete network. Every function can be privately computed in two-connected networks with at least three parties. Thus, the question is interesting only for non two-connected networks. Generalizing results of (Bläser et al. in J. Cryptol, 19(3): 341–357, 2006), we characterize the functions that can be computed privately in simple networks—networks with one separating vertex and no leaves. We then deal with private computations in arbitrary non two-connected networks: we reduce this question to private computations of related functions on trees, and give some sufficient conditions and necessary conditions on the functions that can be privately computed on trees.     

基于INTERNET的虚拟现实技术

网络虚拟现实技术代表着未来计算机的发展方向,有着广阔的应用前景。本文概述了虚拟现实的三要素、关键技术及其应用,着重介绍了基于Ｉｎｔｅｒｎｅｔ虚拟现实的Ｗｅｂ技术。最后介绍了一种用于Ｗｅｂ上的虚拟现实建模语言ＶＲＭＬ。     

SWAP: leveraging the Web to manage workflow

Many organizations are beginning to discover what workflow vendors already know-namely, that the real value of the Web lies not just in its documents and resources, but also in the activities surrounding them. Collaborative work involves not only handoff and routing of data between humans, but the coordination of activities among them and with automated agents as well. Workflow engines typically ensure that the information ends up on the right desktop along with the tools to accomplish a slated task. It is difficult to synchronize work and activity tracking within a technically diverse organization. Tools and formats typically differ among workgroups, as do skill levels and understanding among individual participants in a process. Browser-based user interfaces offer a mechanism to easily access distributed information and hand off documents and data over the Web, but at the expense of being able to effectively manage and track work activities. Web protocols provide no inherent support for automated change notification, handoff of control, or initiation of human- and computer-executed activities. In essence, there is no standard way for service requests to trigger a workflow process and monitor it across platforms and between organizations     

Virtual Society: Collaboration in 3D Spaces on the Internet

The Virtual Society (VS) project is a long term research initiativethat is investigating the evolution of the futureelectronic society. Our vision for this electronic societyis a shared 3D virtual world where users, from homes and offices, canexplore, interact and work. Our first implementation of aninfrastructure to support our investigation is known asCommunityPlace and has been developed to support large-scale shared 3D spaces onthe Internet using the Virtual Reality Modeling Language (VRML). Obviously, such an ambitious project cutsacross many different domains. In this paper we outline thegoals of the Virtual Society project, discuss the architecture andimplementation of CommunityPlace with particular emphasis on Internetrelated technologies such as VRML and present our views on the role ofVRML and the Internet to support large-scale shared 3D spaces.     

Virtual private network bandwidth management with traffic prediction

Dynamic link resizing is an attractive approach for resource management in virtual private networks (VPNs) serving modern real-time and multimedia traffic. In this paper, we assess the use of linear traffic predictors to dynamically resize the bandwidth of VPN links. We present the results of performance comparisons of three predictors: Gaussian, auto-regressive moving average (ARMA) and fractional auto-regressive integrated moving average (fARIMA). The comparisons are based on the mean packet delay, the variance of the packet delay, and the buffer requirements. Guided by our performance tests, we propose and evaluate a new predictor for link resizing: linear predictor with dynamic error compensation (L-PREDEC). Our performance tests show that L-PREDEC works better than Gaussian, ARMA and fARIMA in terms of the three metrics listed above. The benefit of L-PREDEC over the Gaussian predictor is demonstrated in two configurations: a common queue with aggregate link resizing and multiple queues with separate link resizing. In both configurations, L-PREDEC has consistently achieved better multiplexing gain and higher bandwidth utilization than its Gaussian counterpart.     

On virtual private networks security design issues

The concept of virtual private networks (VPNs) provides an economical and efficient solution on communicating private information securely over public network infrastructure.In this paper, we discuss two issues on the design of VPN. We first propose the VPN services, the mandatory VPN operations for each VPN service and the design on VPN protocol stack.Afterwards, we propose a list of protocol modules to be used to support the VPN operations and co-relate the mandatory VPN operations to the appropriate VPN protocols. We then propose the design of VPN software that provides guarantees on security, connectivity and quality of service. We also discuss the message processing sequence by the VPN software.