16943053
Towards an indoor location system using RF signal strength in IEEE 802.11 networks
Location is one of the most important contexts used in pervasive computing environments. GPS systems are intensely used to detect the location information; they mainly work in outdoor environment. Applications call for precise, easy-to-build, and easy-to-use indoor location systems. This paper presents our work to implement an indoor location determination system for Microsoft-Windows-based platforms using a preexisting IEEE 802.11 wireless network. The location is determined from radio signal strength information collected from multiple base stations at different physical locations. Our experiments show a high accuracy rate of this approach.
447865
Middleware support for embedded software with multiple QoS properties for ubiquitous computing environments
Ubiquitous application software usually has multiple QoS requirements, such as situation-awareness, real-time, and security, which make the application software development complicated. In this paper, an approach to supporting multiple QoS properties in application software using middleware is presented. Our reconfigurable context-sensitive middleware (RCSM), which provides situation-awareness support to the application software, is expanded to support more QoS by using aspect-oriented software development techniques. In the expanded RCSM, each QoS is processed through a set of aspect components. The application developers specify the QoS requirements in a specification file, which is in turn compiled to configure the corresponding aspect components. Being associated with certain application objects, the QoS aspect components enforce the QoS requirements according to the specification during run-time. In this paper, security, in addition to situation-awareness, is used as an example to illustrate our approach.
13186882
Distributed constraint satisfaction, restricted recombination, and genetic protocols
In this paper, we present four genetic protocols for solving randomly generated distributed constraint satisfaction problems. These genetic protocols are based on an evolutionary paradigm known as a society of hill-climbers (SoHC) and are thus referred to as genetic SoHCs (GSoHCs). The difference between the SoHC and the GSoHCs is that each of the GSoHCs use a distributed restricted recombination operator. We compare the SoHC and GSoHC protocols on a test suite of 400 randomly generated distributed constraint satisfaction problems (DisCSPs) that are composed of asymmetric constraints (referred to as DisACSPs). In a second experiment, we compare the best performing GSoHC and the SoHC on an additional 1100 randomly generated DisACSPs in order to compare their performances across the phase transition. Our results show that all of the GSoHCs dramatically outperform the SoHC protocol even at the phase transition where, on average, the most difficult DisACSPs reside.
18364887
An approach to enhancing mobile applications with situation-awareness capabilities
In ubiquitous computing environments, mobile applications reside in devices that move arbitrarily and communicate with each other through wireless means. They are presented with fast changing situations, such as the location variation, service availability change, and resource fluctuation. Under these circumstances, situation-awareness is a desirable feature for mobile applications. Being situation-aware, a mobile application is capable of detecting situation changes and responding to it on-the-fly without bothering the user all the times. This paper presents an approach to enhancing mobile applications with situation-aware capabilities using middleware service.
1622745
Replication-based efficient data delivery scheme (red) for delay/fault-tolerant mobile sensor network (DFT-MSN)
The delay/fault-tolerant mobile sensor network (DFT-MSN) has been proposed recently for pervasive information gathering. DFT-MSN distinguishes itself from conventional sensor networks by several unique characteristics such as sensor mobility, loose connectivity, and delay/fault tolerability. The mainstream approaches for sensor networking/communication cannot be applied in DFT-MSN directly. In this paper we propose a replication-based efficient data delivery (RED) scheme based on erasure coding technology tailored for DFT-MSN. RED consists of two key components for data transmission and message management, respectively. The former makes decision on when and where to transmit data messages according to the delivery probability. The latter decides the optimal erasure coding parameters (including the number of data blocks and the needed redundancy) based on its current delivery probability, in order to achieve the desired data delivery ratio while minimizing overhead at the same time. Extensive simulation has been carried out for performance evaluation. Compared with other approaches, the proposed RED data delivery scheme achieves high message delivery ratio with low transmission overhead and data management complexity
2273352
Near-Linear Time Approximation Algorithms for Curve Simplification
AbstractWe consider the problem of approximating a polygonal
 curve P under a given error criterion by another
 polygonal curve P’ whose vertices are a
 subset of the vertices of P. The goal is to minimize
 the number of vertices of P’ while ensuring that the
 error between P’ and P is below a certain threshold.
 We consider two different error measures: 
 Hausdorff and Frechet. For both error criteria, we present
 near-linear time approximation algorithms that, given a
 parameter ε > 0, compute a simplified polygonal
 curve P’ whose error is less than ε and
 size at most the size of an optimal simplified
 polygonal curve with error ε/2. We consider
 monotone curves in ℝ2 in the case of the Hausdorff error measure
 under the uniform distance metric
 and arbitrary curves in any dimension for the Frechet error measure
 under Lp metrics. 
 We present
 experimental results demonstrating that our algorithms
 are simple and fast, and produce close to optimal
 simplifications in practice.
39368933
Improved QIM Strategies for Gaussian Watermarking
This paper revisits the problem of watermarking a Gaussian host, where the embedder and attacker are subject to mean-squared distortion constraints. The worst (nonadditive) attack and unconstrained capacity have been identified in previous work. Here we constrain the encoding function to lie in a given family of encoding functions — such as spread-spectrum or fixed-dimensional Quantization Index Modulation (QIM), with or without time-sharing, with or without external dithering. This gives rise to the notion of constrained capacity. Several such families are considered in this paper, and the one that is best under the worst attack is identified for each admissible value of the watermark-to-noise ratio (WNR) and the noise-to-host ratio (NHR). With suitable improvements, even scalar QIM can outperform any (improved) spread-spectrum scheme, for any value of WNR and NHR. The remaining gap to unconstrained capacity can be bridged using higher-dimensional lattice QIM.
19562173
Web-service-agents-based family wealth management system
The roiling financial markets, constantly changing tax law and increasing complexity of planning transaction increase the demand of aggregated family wealth management (FWM) services. However, current trend of developing such advisory systems is mainly focusing on financial or investment side. In addition, these existing systems lack of flexibility and are hard to be integrated with other organizational information systems, such as CRM systems. In this paper, a novel architecture of Web-service-agents-based FWM systems has been proposed. Multiple intelligent agents are wrapped as Web services and can communicate with each other via Web service protocols. On the one hand, these agents can collaborate with each other and provide comprehensive FWM advices. On the other hand, each service can work independently to achieve its own tasks. A prototype system for supporting financial advice is also presented to demonstrate the advances of the proposed Webservice- agents-based FWM system architecture.
9393238
Detecting Tables in HTML Documents
Table is a commonly used presentation scheme for describing relational information. Table understanding on the web has many potential applications including web mining, knowledge management, and web content summarization and delivery to narrow-bandwidth devices. Although in HTML documents tables are generally marked as ?table? elements, a ?table? element does not necessarily indicate the presence of a genuine relational table. Thus the important first step in table understanding in the web domain is the detection of the genuine tables. In our earlier work we designed a basic rule-based algorithm to detect genuine tables in major news and corporate home pages as part of a web content filtering system. In this paper we investigate a machine learning based approach that is trainable and thus can be automatically generalized to including any domain. Various features reflecting the layout as well as content characteristics of tables are explored. The system is tested on a large database which consists of 1, 393 HTML files collected from hundreds of different web sites from various domains and contains over 10,000 leaf ?table? elements. Experiments were conducted using the cross validation method. The machine learning based approach outperformed the rule-based system and achieved an F-measure of 95.88%.