32612296
Automating performance-related impact analysis through event based traceability
Current impact analysis techniques tend to focus on assessing the impact of change upon the system's functionality, whilst a consideration of performance related requirements is often deferred until after implementation. This tendency can lead to costly and time-consuming mistakes that frustrate customers and require frantic last-minute efforts to fix. This paper proposes a method for supporting performance-related impact analysis in a heterogeneous software engineering environment. An event-based approach is taken to establish dynamic traceability links, capable of propagating data values and commands between requirements and performance models. Quantitative values in performance related requirements are adjusted to reflect proposed changes, and impacted models are re-executed to measure the impact of the change. The resulting outputs are then automatically compared to relevant performance requirements and a system-wide report showing the impact of the proposed change upon performance is generated.
15614662
Towards increasing web application productivity
In this paper we present and discuss a template/meta-data based partial code generation system supporting web application development. Seamlessly incorporating the recent top-notch technologies, the framework maximally exploits the capabilities of the underlying implementation technologies. Our approach primarily benefits the framework and code developers. In addition, the complete separation of data model, navigation model, and presentation model reflects on a more general conceptual process that would decouple the technique and methodology from its underlying technology choices. The decoupling between the generated code and the code that is necessarily added later on through other development pathways than the generator deals with the incremental changes and adaptations of the models in the face of an operational system, therefore further enhances the extensibility, maintainability, and reusability of the generated applications.
1871945
Specifications in software prototyping
Abstract We explore the use of software specifications for software prototyping. This paper describes a process model for software prototyping, and shows how specifications can be used to support such a process via a cellular mobile phone switch example.
18643244
An Empirical Performance Study on PSIM
It is well known that errors caught in the early stages of system development life cycle greatly helped reduce the expense for later error fixing and mitigate risks and complications. Performance analysis is one of the methods to ensure satisfactory system performance that can avoid redesign and patch in the later stage of system development when performance problems emerge. Much work has been done to address such concerns collectively known as the 'performance engineering' problem. However, a comprehensive method is still needed to provide an end-to-end support for performance evaluation on software architecture design. Automated tools to support the method must be developed, and its validation must be carefully planned and conducted. In response to this need, we propose our approach, PSIM (performance simulation and modeling). PSIM is a performance simulation and modeling tool that integrated performance properties into software architecture specifications expressed in several major UML diagrams. PSIM models can be transformed into Colored GSPN (colored generalized stochastic Petri nets) via an automated tool. As a result, the Colored GSPN models can be simulated to perform model-based performance evaluation. In this paper PSIM is first briefly reviewed and illustrated through modeling a web-based electronic conferencing system, called M-Net, to derive performance metrics. We then conduct runtime performance testing to the implementation of M-Net and compare the simulation results against the runtime testing data. PSIM is shown to be effective in predicting system performance and in identifying system performance bottlenecks through this experimentation.
10317156
A research on Collaboration Net
We present research on computer-supported cooperative work by introducing an approach to the multimedia based net-centric conference environment-Collaboration Net. Some basic definitions of the distributed Web-based meeting are provided, and the properties of this kind of collaboration are given. We explain problems associated with the well-known yet old-fashioned parliamentary procedure, Robert's Rules of Order, which must be formally modeled and adapted to the modern net-centric virtual conference where time synchronism is hard to enforce. A prototype of our Web-browser based approach to developing the Collaboration Net is also briefly presented. Finally, research challenges in this area are highlighted.
17140893
An Aspect-Oriented Approach to Resource Composition in Petri net-based Software Architectural Models
Petri net has been widely used for modeling software systems due to its mathematical soundness and support of various tools. In many cases, performance-related analyses of Petri net for a software system need to consider the resource limitations caused by a specific platform. In terms of aspect-oriented approach, the interference of various resources scattered across a software system can be regarded as a specific concern that is only necessary during its performance-related analysis process. To capture the interactions of resources within the Petri net-based software architectural model, we propose an aspect-oriented resource composition model and the XML-based representation language called the resource extension markup language (ReML) for its description. In our approach, one or more resource composition models can be developed and described in ReML separately from the development of base software architectural models. Through the weaving process, a resource composition model can be applied to extend several Petri net-based software architectural models. The resource weaver generates an augmented Petri net used for analyzing performance characteristics of the extended software architectural model with resource interactions. Our aspect-oriented approach facilitates selecting an optimal or superior resource composition model for a software architectural model, and vice versa, which is illustrated using two exemplary server models
14075719
Receiver-based rate-distortion optimized interactive streaming for scalable bitstreams of light fields
The paper proposes a receiver-based rate-distortion optimized framework to stream interactively scalable bitstreams of light fields. Based on the desired viewpoints, the predicted future buffer state, the network characteristics, and the target transmission rate, the receiver customizes the data request in order to minimize the distortion in the frames to be rendered. Experimental results show that the proposed framework improves the rendering quality by 1.0-2.8 dB over a heuristic scheme at the same rate. Correspondingly, to achieve the same rendering quality the proposed framework reduces 25-35% of the rate over the heuristic scheme.
39549662
Categorical Data Visualization and Clustering Using Subjective Factors
Clustering is an important data mining problem. However, most earlier work on clustering focused on numeric attributes which have a natural ordering to their attribute values. Recently, clustering data with categorical attributes, whose attribute values do not have a natural ordering, has received more attention. A common issue in cluster analysis is that there is no single correct answer to the number of clusters, since cluster analysis involves human subjective judgement. Interactive visualization is one of the methods where users can decide a proper clustering parameters. In this paper, a new clustering approach called CDCS (Categorical Data Clustering with Subjective factors) is introduced, where a visualization tool for clustered categorical data is developed such that the result of adjusting parameters is instantly reflected. The experiment shows that CDCS generates high quality clusters compared to other typical algorithms.
17968637
Robust localization of multiple events in sensor networks
Localization of events is a canonical problem for sensor networks, especially for applications such as intrusion detection or neighborhood monitoring. We employ a general sensor model which models various types of sensor nodes. However, traditional triangulation method will be unsolvable when the sensor nodes are positioned on a line. To overcome such ill-conditioned cases, we can use MAP or MMSE methods to estimate event locations. Moreover, to locate multiple simultaneous events and overcome the ill-conditioned case when the sensor nodes are collinear, we need to solve a system of nonlinear equations. We propose a novel method which solves this system of nonlinear equations and multiple-event locations can be found. Experiments and error analysis of the method demonstrate the performance of our methods
9167410
Computing curricula 2001 how will it work for you?
In the fall of 1998, the ACM Education Board and the Educational Activities Board of the IEEE Computer Society appointed representatives to a joint task force to prepare Computing Curricula 2001 (CC2001), the next installment in a series of reports on the undergraduate computer science curriculum that began in 1968 and was then updated in 1978 and 1991. Interim reports on the initial planning of the curriculum were presented at the SIGCSE symposium and the IEEE Frontiers in Education Conference in both 1999 and 2000. The CC2001 Task Force released its first draft report at the 2000 SIGCSE conference and plans to release its penultimate draft at SIGCSE 2001. The purpose of this session is to describe how we expect the recommendations of the report to apply in practice. The panelists represent a range of institutions and can therefore speak to the questions that audience members from similar institutions might have.
15632441
Direction-Adaptive Discrete Wavelet Transform via Directional Lifting and Bandeletization
We propose an adaptive lifted discrete wavelet transform to locally adapt the filtering direction to the geometric flow in the image. The proposed approach refines previous directional lifting approaches to achieve superior compression performance with less demand for computation. Additionally, a bandeletization procedure is combined with directional lifting in a unified framework to further remove the correlation in the wavelet coefficients. Up to 2.8 dB improvement in PSNR over the conventional 2-D CDF 9/7 wavelet transform for natural images is reported. Significant improvement in subjective quality is also observed.