Gain scheduling via linear fractional transformations

A linear finite-dimensional plant with rational state-space parameter dependence is controlled using a parameter-dependent controller. The parameters are known to take on values in a unit ball, and are known in real time. The goal of control is to stabilize the parameter-dependent closed-loop system, and provide disturbance/error attenuation as measured in induced l₂ norms. The approach taken uses the optimally scaled small-gain theorem, and solves the control synthesis problem by reformulating the existence conditions into a finite-dimensional convex optimization.     

Virtual network embedding: ensuring correctness and optimality by construction using model transformation and integer linear programming techniques

Software and Systems Modeling - Virtualization technology allows service providers to operate data centers in a cost-effective and scalable manner. The data center network (substrate network) and...     

Experiences building a communication‐oriented JavaOS

Mobile code makes it easier to maintain, debug, update, and customize a system. Active networks are one of the more interesting applications of mobile code: code is injected into the nodes of a network to customize the network's functionality, such as routing, and to add new features, such as special‐purpose congestion control and filtering algorithms. The challenge is to develop a communication‐oriented platform for such systems. We refer to mobile code targeted at low‐level, communication‐oriented systems like active networks as liquid software, the key distinction being that liquid software is focused on the efficient transfer of data, not high‐performance computation. To this end, we have designed and implemented Joust, which consists of a complete re‐implementation of the Java virtual machine (including both the runtime system and a just‐in‐time compiler), running on the Scout operating system (a configurable, communication‐oriented OS). The result is a configurable, high‐performance platform for running liquid software. We present the results of implementing two different applications of liquid software on Joust, including a prototype architecture for active networks. Copyright © 2000 John Wiley & Sons, Ltd.     

The experience of enchantment in human–computer interaction

Improving user experience is becoming something of a rallying call in human–computer interaction but experience is not a unitary thing. There are varieties of experiences, good and bad, and we need to characterise these varieties if we are to improve user experience. In this paper we argue that enchantment is a useful concept to facilitate closer relationships between people and technology. But enchantment is a complex concept in need of some clarification. So we explore how enchantment has been used in the discussions of technology and examine experiences of film and cell phones to see how enchantment with technology is possible. Based on these cases, we identify the sensibilities that help designers design for enchantment, including the specific sensuousness of a thing, senses of play, paradox and openness, and the potential for transformation. We use these to analyse digital jewellery in order to suggest how it can be made more enchanting. We conclude by relating enchantment to varieties of experience.An earlier version of this paper was presented at Chi’2004 Fringe.     

Visualising Errors in Animal Pedigree Genotype Data

Genetic analysis of a breeding animal population involves determining the inheritance pattern of genotypes for multiple genetic markers across the individuals in the population pedigree structure. However, experimental pedigree genotype data invariably contains errors in both the pedigree structure and in the associated individual genotypes, introducing inconsistencies into the dataset, rendering them useless for further analysis. The resolution of these errors requires consideration of genotype inheritance patterns in the context of the pedigree structure. Existing pedigree visualisations are typically more suited to human pedigrees and are less suitable for large complex animal pedigrees which may exhibit cross generational inbreeding. Similarly, table‐based viewers of genotype marker data can highlight where errors become apparent but lack the functionality and interactive visual feedback to allow users to locate the origin of errors within the pedigree. In this paper, we detail a design study steered by biologists who work with pedigree data, and describe successive iterations through approaches and prototypes for viewing genotyping errors in the context of a displayed pedigree. We describe how each approach performs with real pedigree genotype data and why eventually we deemed them unsuitable. Finally, a novel prototype visualisation for pedigrees, which we term the ‘sandwich view’, is detailed and we demonstrate how the approach effectively communicates errors in the pedigree context, supporting the biologist in the error identification task.     

2009年度12期读者推选IT企业品牌排行榜

2009年度第12期IT品牌评选活动得到众多热心读者的踊跃参与,包括全国各地的业界专家、设计院、系统集成商以及用户等专业人士。此次评选活动,共收到读者们的评选意见回馈表1026份,根据品牌认知、成功案例、价格定位、质量维护、服务支持等多项指标,评选出了十大IT品牌包括综合布线十大产品品牌,以及本次新增加的布线新锐品牌。