20698705
Home health care support
We describe an ap@ication to interconnect health care providers and thew patients in the home. The application includes information services, symptom analy SIS, ~idance in the performance of procedures, emotmnal support, and communications among the health care providers, patients and caretakers.
6041360
Modeling timed user-interactions in multimedia documents
Interactive multimedia documents (or systems) can be characterized by active user participation and the diversity of multimedia information accessed at various levels of granularity. They need to support extensive user participation in selecting and tailoring the information and its presentation. Multimedia information fragments may vary from portions of video, pieces of audio, newspaper quotations or chapters of a book. Effectively managing the creation, evolution and complexity of multimedia documents formed by combining media fragments is an essential capability. We consider the hyperstory model of a multimedia document, where a document is structured hierarchically in three dimensions: time, space and asynchrony. The model provides a layered approach in structuring multimedia documents, thus reducing the complexities of large systems. The hyperstory model supports user interactions that are timed, and also supports preemptive resuming. Timed user interactions with the document are modeled with a newly introduced timed Petri-net (TPN*). TPN* is used to infer the behavior of the system. This paper describes TPN*'s modeling and analysis and its application to the hyperstory model.
8536996
Goal and scenario based domain requirements analysis environment
Identifying and representing domain requirements among products in a product family are crucial activities for a successful software reuse. The domain requirements should be not only identified based on the business goal, which drives marketing plan, product plan, and differences among products, but also represented as familiar notations in order to support developing a particular product in the product family. Thus, our proposal is to identify the domain requirements through goals and scenarios, and represent them as variable use cases for a product family. Especially, for identification of the domain requirements, we propose four abstraction levels of requirements in a product family, and goal and scenario modeling. For representation of them, variable use case model is suggested, and also the use case transfer rules are proposed so as to bridge the gap between the identification and representation activity. The paper illustrates the application of the approach within a supporting tool using the HIS (Home Integration System) example.
10669533
Optimal distribution tree for Internet streaming media
Internet radio and television stations require significant bandwidth to support delivery of high quality audio and video streams to a large number of receivers. IP multicast is an appropriate delivery model for these applications. However, widespread deployment of IP multicast on the Internet is unlikely in the near future. An alternative is to build a multicast tree in the application layer Previous studies have addressed tree construction in the application layer However most of them focus on reducing delay. Few systems have been designed to achieve a high throughput for bandwidth-intensive applications. In this paper we present a distributed algorithm to build an application-layer tree. We prove that our algorithm finds a tree such that the average incoming rate of receivers in the tree is maximized (under certain network model assumptions). We also describe protocols that implement the algorithm. For implementation on the Internet, there is a tradeoff between the overhead of available bandwidth measurements and fast convergence to the optimal tree. This tradeoff can be controlled by tuning some parameters in our protocols. Our protocols are also designed to maintain a small number, O(log n), of soft states per node to adapt to network changes and node failures.
1783266
Robustness in large-scale random networks
We consider the issue of protection in very large networks displaying randomness in topology. We employ random graph models to describe such networks, and obtain probabilistic bounds on several parameters related to reliability. In particular, we take the case of random regular networks for simplicity and consider the length of primary and backup paths in terms of the number of hops. First, for a randomly picked pair of nodes, we derive a lower bound on the average distance between the pair and discuss the tightness of the bound. In addition, noting that primary and protection paths form cycles, we obtain a lower bound on the average length of the shortest cycle around the pair. Finally, we show that the protected connections of a given maximum finite length are rare. We then generalize our network model so that different degrees are allowed according to some arbitrary distribution, and show that the second moment of degree over the first moment is an important shorthand for behavior of a network. Notably, we show that most of the results in regular networks carry over with minor modifications, which significantly broadens the scope of networks to which our approach applies. We present as an example the case of networks with a power-law degree distribution.
1475409
An ethnographic study of copy and paste programming practices in OOPL
Although programmers frequently copy and paste code when they develop software, implications of common copy and paste (C&P) usage patterns have not been studied previously. We have conducted an ethnographic study in order to understand programmers' C&P programming practices and discover opportunities to assist common C&P usage patterns. We observed programmers using an instrumented Eclipse IDE and then analyzed why and how they use C&P operations. Based on our analysis, we constructed a taxonomy of C&P usage patterns. This paper presents our taxonomy of C&P usage patterns and discusses our insights with examples drawn from our observations. From our insights, we propose a set of tools that both can reduce software maintenance problems incurred by C&P and can better support the intents of commonly used C&P scenarios.
33615174
PMEPR Reduction Algorithms for STBC-OFDM Signals
This paper evaluates the peak-to-mean envelope power ratio (PMEPR) performance in a space-time block coded (STBC) OFDM system using the selective mapping (SLM) and partial transmit sequence (PTS) approaches. The investigated SLM and PTS schemes for STBC-OFDM signals select the transmitted sequence with the lowest average PMEPR over all transmit antennas and retrieve the side information (SI) very accurately at the expense of a slight degradation of the PMEPR performance.