MOSAIC: Declarative platform for dynamic overlay composition

Overlay networks create new networking services using nodes that communicate using pre-existing networks. They are often optimized for specific applications and targeted at niche vertical domains, but lack interoperability with which their functionalities can be shared. Mosaic is a declarative platform for constructing new overlay networks from multiple existing overlays, each possessing a subset of the desired new network’s characteristics.This paper focuses on the design and implementation of Mosaic: composition and deployment of control and/or data plane functions of different overlay networks, dynamic compositions of overlay networks to meet changing application needs and network conditions, and seamless support for legacy applications. Mosaic overlays are specified using Mozlog, a new declarative language for expressing overlay properties independently from their particular implementation or underlying network.Mosaic is validated experimentally using compositions specified in Mozlog in order to create new overlay networks with compositions of their functions: the i3 indirection overlay that supports mobility, the resilient overlay network (RON) overlay for robust routing, and the Chord distributed hash table for scalable lookups. Mosaic uses runtime composition to simultaneously deliver application-aware mobility, NAT traversal and reliability. We further demonstrate Mosaic’s dynamic composition capabilities by Chord switching its underlay from IP to RON at runtime.Mosaic’s benefits are obtained at a low performance cost, as demonstrated by measurements on both a local cluster environment and the PlanetLab global testbed.     

一种在旋转量很小情形下的图像镶嵌技术

1简介真实世界是一个丰富的信息源，而视觉信息又是其中最重要的信息．通常，我们能够获取现实世界的一序列图像．然而，把这些图像合成全维场景对我们更重要．图像镶嵌技术的目的就是把一序列真实世界的图像合成一个单一的，更大的，更复杂的全维场景（Panorama）[1]．它是一种表示真实世界的有效方法．通常真实世界的序列图像有很大程度的重叠．通过图像镶嵌技术，我们可以剔除冗余信息，压缩信息存储量，从而更加有效地表示信息．自然，更重要的是通过图像镶嵌技术，我们可以更加客观形象地认识和理解真实世界．有许多方法已经用于图像…     

一种改进的快速图像拼接方法

为了提高图像拼接的速度,提出了一种快速的图像拼接方法.首先在SUSAN角点检测算法检测出图像角点的基础上,采用图像分块和邻近角点剔除的方法来保证图像角点分布均匀并且避免出现角点聚簇现象,利于提高拼接的精度.其次,利用灰度相关性进行特征角点的匹配并消除伪匹配.然后采用改进的RANSAC算法快速地估计变换矩阵,该算法中采用预检测的方法快速抛弃那些不是候选模型的临时模型,加快了算法的速度.最后进行颜色融合,生成无缝拼接图像.实验结果表明,该方法在得到较高精度的情况下,大大减少了运算量,提高了图像拼接的速度.     

A probabilistic modeling of MOSAIC learning

Humans can generate accurate and appropriate motor commands in various, and even uncertain, environments. MOSAIC (MOdular Selection And Identification for Control) was originally proposed to describe this human ability, but this model is hard to analyze mathematically because of its emphasis on biological plausibility. In this article, we present an alternative and probabilistic model of MOSAIC (p-MOSAIC) as a mixture of normal distributions and an online EM-based learning method for its predictors and controllers. A theoretical consideration shows that the learning rule of p-MOSAIC corresponds to that of MOSAIC except for some points which are mostly related to the learning of controllers. The results of experiments using synthetic datasets demonstrate some practical advantages of p-MOSAIC. One is that the learning rule of p-MOSAIC stabilizes the estimation of “responsibility.” Another is that p-MOSAIC realizes more accurate control and robust parameter learning in comparison to the original MOSAIC, especially in noisy environments, due to the direct incorporation of the noises into the model. This work was presented in part at the 12th International Symposium on Artificial Life and Robotics, Oita, Japan, January 25–27, 2007     

图像拼接技术在军事监控系统中的应用

在军事监控系统中,通过植入图像拼接技术,能展现更广阔、完整的监控场景.本文针对不同监控摄像头的监控图像,提出了一种基于SIFT(Scale Invariant Feature Transform)特征匹配的监控图像自动拼接方法.实验结果表明.该方法能适应户外复杂军事监控环境,为军事监控系统提供全方位监控场景.     

Tools for multiple-CPU environments

A brief overview precedes ten separate tool reviews. Five of the tools address the problems of performance analysis, testing, and debugging in a multiple-CPU environment. The first set of tools-Graspin PPSE, and Integral-supports this activity by providing specification or design languages for concurrent applications. The next pair of tools-Pie and Total-supports the development of multiple-CPU software by representing the software's behavior in a parallel or concurrent environment. The next set of five tools is aimed at the problem of serial-to-parallel conversions. The first three tools-E/SP, Mimdizer, and PRETS-recapture the design of the original source code and display it in a graphical form for analysis. The remaining tools-Pat and Aspar-support direct source-to-source transformations. These ten tools are representative of current approaches being taken to address the problem of multiple-CPU computing     

Message-passing environments for metacomputing

In this paper, we present the three libraries PACX-MPI, PLUS, and PVMPI that provide message-passing between different high-performance computers in metacomputing environments. Each library supports the development and execution of distributed metacomputer applications.

The PACX-MPI approach offers a transparent interface for the communication between two or more MPI environments. PVAMPI allows the user spawning parallel processes under the MPI environment. The PLUS protocol bridges the gap between vendor-specific (e.g., MPL, NX, and PARIX) and vendor-independent message-passing environments (e.g., PVM and MPI). Moreover, it offers the ability to create and control processes at application runtime.     

Video mosaics for virtual environments

As computer-based video becomes ubiquitous with the expansion of transmission, storage, and manipulation capabilities, it will offer a rich source of imagery for computer graphics applications. This article looks at one way to use video as a new source of high-resolution, photorealistic imagery for these applications. If you walked through an environment, such as a building interior, and filmed a video sequence of what you saw you could subsequently register and composite the video images together into large mosaics of the scene. In this way, you can achieve an essentially unlimited resolution. Furthermore, since you can acquire the images using any optical technology, you can reconstruct any scene regardless of its range or scale. Video mosaics can be used in many different applications, including the creation of virtual reality environments, computer-game settings, and movie special effects. I present algorithms that align images and composite scenes of increasing complexity-beginning with simple planar scenes and progressing to panoramic scenes and, finally, to scenes with depth variation. I begin with a review of basic imaging equations and conclude with some novel applications of the virtual environments created using the algorithms presented     

Access-control language for multidomain environments

The XML role-based access control (X-RBAC) specification language addresses multidomain environments' policy-specification needs. X-RBAC is based on an extension of the widely accepted US National Institute of Standards and Technology role-based access-control (RBAC) model. In addition to allowing specification of RBAC policies and facilitating specification of timing constraints on roles and access requirements, X-RBAC provides a framework for specifying mediation policies in a multidomain environment where RBAC policies have been employed.     

Face recognition for smart environments

Smart environments, wearable computers, and ubiquitous computing in general are the coming “fourth generation” of computing and information technology. But that technology will be a stillbirth without new interfaces for interaction, minus a keyboard or mouse. To win wide consumer acceptance, these interactions must be friendly and personalized; the next generation interfaces must recognize people in their immediate environment and, at a minimum, know who they are. In this article, the authors discuss face recognition technology, how it works, problems to be overcome, current technologies, and future developments and possible applications. Twenty years ago, the problem of face recognition was considered among the most difficult in artificial intelligence and computer vision. Today, however, there are several companies that sell commercial face recognition software that is capable of high-accuracy recognition with databases of more than 1,000 people. The authors describe the face recognition technology used, explaining the algorithms for face recognition as well as novel applications, such as behavior monitoring that assesses emotions based on facial expressions     

Certifying software for high-assurance environments

It does not make sense to grant carte blanche high-assurance certificates to product that may be used across multiple platforms and in multiple environments. We should bind software certification to a product's known environment and operational profile. The author proposes three techniques for verifying high assurance: desirable-behavior testing, abnormal testing, and fault injection. Each uses the product's operational profile to detect software-related anomalies that might allow a catastrophic event     

Work environments for employee creativity

Innovative organisations need creative employees who generate new ideas for product or process innovation. This paper presents a conceptual framework for the effect of personal, social-organisational and physical factors on employee creativity. Based on this framework, an instrument to analyse the extent to which the work environment enhances creativity is developed. This instrument was applied to a sample of 409 employees and support was found for the hypothesis that a creative work environment enhances creative performance. This paper illustrates how the instrument can be used in companies to select and implement improvements. STATEMENT OF RELEVANCE: The ergonomics discipline addresses the work environment mainly for improving health and safety and sometimes productivity and quality. This paper opens a new area for ergonomics: designing work environments for enhancing employee creativity in order to strengthen an organisation's capability for product and process innovation and, consequently, its competitiveness.     

Radiosity redistribution for dynamic environments

The radiosity algorithm is extended to dynamic environments, providing global-illumination simulations to scenes that are modified interactively. The illumination effects introduced by a change in position, shape, or attributes of any object in the scene are computed very rapidly by redistributing the energy already exchanged between objects. Corrections are made by shooting positive and negative energy, accounting for increased illumination and the creation of shadows. Object coherence is used to minimize computation, and progressive-refinement techniques are used to accelerate convergence. The extended algorithm yields excellent approximations to the exact solutions at interactive speeds     

Speculative optimizations for interpreting environments

Most constrained systems use interpreters to run mobile programs written in Java. Such interpreters are designed to minimize resource usage and often do not allow mobile code in the devices to be changed. For this reason, runtime optimization is typically not supported, even though it is completely feasible. In this paper, we propose optimistic optimization as a concept for improving application performance in restricted interpreter environments. In an optimistic optimization, a mobile program is restructured speculatively during code generation. This requires that it is possible to undo such optimizations, at runtime, if an incorrect use is detected or the set of available classes has changed when compared with compile time. Experimental results show that interpreted applications using optimistic optimizations tend to run faster when compared with their conventionally optimized counterparts. Compared with standard load elimination, reductions in runtimes of up to 9% for optimistic load elimination and up to 23% for the combined optimization were achieved. Whereas an average performance improvement of 1.87% for optimistic load elimination and 3.7% for the combined optimization could be realized. Copyright © 2013 John Wiley & Sons, Ltd.     

Architecting multimedia environments for teaching

Thus far, developers have created only partial solutions for using computational equipment in education. Research must focus more effort on developing architectures capable of combining technologies that target the classroom and that allow specifying "what" rather than "how" tasks should be done. The difficult task of architecting multimedia environments for teaching must start with a needs analysis. The most challenging task involves warranting reliability on the one hand, while accommodating opportunities for innovation on the other. Thus, we propose building a reliable, ubiquitous, adaptable, and easy-to-use technology-integrating black box. Placing this system atop a service-oriented component model implemented on a platform-independent layer such as a virtual machine provide the adaptability developers need. Loosely coupled components accommodate a nonmonolithic approach and ease reuse. By reusing and enhancing components, the system become increasingly reliable, while a building-block architecture keep it manageable.     

Strategies for integrating CASE environments

An experimental information-system environment, called DAIDA (development assistance for integrated database applications), developed as part of the European Community's ESPRIT program is described. DAIDA goes beyond traditional knowledge-based techniques for CASE by addressing three important dimensions of integration in a process-oriented model: how to handle dependencies among development stages, how to manage the evolving relationship among systems and their technical and social environments, and how to integrate development tasks-from both development in the small, in which the focus is the content of actions and results, and development in the large, which is concerned with object and process management and the collaboration of people involved in developing and using systems. This threefold integration strategy is discussed, along with the DAIDA architecture and a development example. The ConceptBase process information repository, which is used to define the process-oriented integration model, is also discussed     

Telerobotic manipulator for hazardous environments

The Center for Engineering Design at the University of Utah, in collaboration with Sarcos Research Corporation and others, recently developed the Dextrous Teleoperation System (DTS). The DTS is a master/slave 10 degree of freedom (dof) arm that includes a 3 dof dextrous end effector. The system has demonstrated a number of significant remote manipulation capabilities. This article discusses design considerations, features, and capabilities of the slave Dextrous Arm. An earlier article discussed potential applications, general features, and system capabilities of the DTS. Subsequent articles will discuss the master and control systems.     

Standards for moderate thermal environments

Recently two Draft International Standards dealing with specifications of the conditions for thermal comfort (ISO DIS 7730) and measurement procedures (ISO DIS 7726) have been approved by the International Stadardisation Organisation (ISO). The American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) has made a standard with similar requirements for the thermal environment (ASHRAE, 1981). To verify the requirements, measurements of different thermal parameters have to be performed. Guidelines as to how and where to measure are also given in the standards. The present paper deals mainly with the requirements and measurements that are relevant for moderate thermal environments in places of residence, offices, hospitals and light industry. For evaluation of very hot or very cold surroundings, other methods are required. Only measurements of parameters that influence the perception of the thermal surroundings are included.     

Virtual environments for engineering applications

Virtual reality (VR), provides the user with an ego-centred human-computer interaction environment by presenting the data as a computer-generated 3D virtual environment. This enables the user to be immersed in this world via user position tracking devices and to interact with the data objects in the world in intuitive ways. This paper describes a selection of VR simulations for engineering applications implemented in CLRC which demonstrate the potential of VR interaction techniques to offer quicker and possibly better understanding of spatial relationships and temporal patterns inherent in large data sets. Two of the case studies have been implemented to support engineers communicate and review their designs with scientists, managers and manufacturers and to plan their assembly and maintenance work in hazardous physical environments. The other two applications are visualisation case studies based on data sets generated by computational engineering simulations. The case studies are real world applications, involving end-users of large or complex data sets. Insight gained into the user interaction requirements through the implementation and user comments is guiding ongoing research and development activity and this is discussed briefly.