192543
Performance Model Interchange Format: Semantic Validation
A Performance Model Interchange Format (PMIF) provides a mechanism whereby system model information may be transferred among queueing network model (QNM) based modeling tools. The PMIF allows diverse tools to exchange information and requires only that those tools provide importing/exporting mechanisms from/to the PMIF. The XML specification of the PMIF allows implementers to use widely available tools to parse the XML file, check the syntax, and simplify the translation to/from the XML format. Those tools, however, do not know the semantics of a QNM so they cannot check the XML to ensure that it contains a valid QNM. This paper presents the study of the validations needed to carry out such a semantic analysis, and the development of a semantic validation tool that can be used by any developer who wants to implement PMIF import/export mechanisms.
6961424
Designing High-Performance Distributed Applications Using Software Performance Engineering: A Tutorial
Summary This paper reviewed the purpose of SPE, the steps forapplying the SPE methods throughout the life cycle ofnew systems, the data requirements and illustrated aperformance walkthrough approach for gathering thedata. The software and system execution models forassessing the performance of alternatives weredescribed and their use throughout the life cycle wasreviewed.SPE is becoming increasingly popular for large,strategic systems to systematically manage theperformance. The models are relatively easy toconstruct and evaluate with the performance modelingtools available today. SPE’s current problems are notthe technical problems of constructing and evaluatingthe performance models. The chief barriers aremaking developers and managers aware of SPE’spotential, and persuading them to incorporate themethods into their development life cycle. References [HEID93] Ruth V. Heidel and George W. Dodson,(Editor), Special Issue on Client/Server Computing ,CMG Transactions, no. 82, 1993.[SMIT88a] Connie U. Smith, "Applying SynthesisPrinciples to Create Responsive Software Systems,"
2552665
From UML models to software performance results: an SPE process based on XML interchange formats
The SPE process uses multiple performance assessment tools depending on the state of the software and the amount of performance data available. This paper describes two XML based interchange formats that facilitate using a variety of performance tools in a plug-and-play manner thus enabling the use of the tool best suited to the analysis. The Software Performance Model Interchange Format (S-PMIF) is a common representation that is used to exchange information between (UML-based) software design tools and software performance engineering tools. On the other hand, the performance model interchange format (PMIF 2.0) is a common representation for system performance model data that can be used to move models among system performance modeling tools that use a queueing network model paradigm. This paper first defines an XML based S-PMIF based on an updated SPE meta-model Then it demonstrates the feasibility of using both the S-PMIF and the PMIF 2.0 to automatically translate an architecture description in UML into both a software performance model and a system performance model to study the performance characteristics of the architecture. This required the implementation of some extensions to the XPRIT software in order to export UML models into the S-PMIF and a new function in the SPEED software to import S-PMIF models, which are also described. The SPE process and an experimental proof of concept are presented.
25855174
General Principles for Performance Oriented Design
11071330
Performance Engineering of Software Systems
We may not be able to make you love reading, but performance engineering of software systems will lead you to love reading starting from now. Book is the window to open the new world. The world that you want is in the better stage and level. World will always guide you to even the prestige stage of the life. You know, this is some of how reading will give you the kindness. In this case, more books you read more knowledge you know, but it can mean also the bore is full.
28516165
Best Practices for Software Performance Engineering
Performance—responsiveness and scalability—is a make-or-break quality for software. Software Performance Engineering (SPE) provides a systematic, quantitative approach to constructing software systems that meet performance objectives.It prescribes ways to build performance into new systems rather than try to fix them later. Many companies suc- cessfully apply SPE and they attest to the financial, quality, customer satisfaction and other benefits of doing it right the first time. This paper describes 24 best practices for applying SPE to proactively managing the per- formance of new applications. They are vital for successful, proactive SPE efforts, and they are among the practices of world-class SPE organizations. They will help you to establish new SPE programs and fine tune existing efforts in line with practices used by the best software development projects.
17908956
Local Specification of Surface Subdivision Algorithms
Many polygon mesh algorithms operate in a local manner, yet are formally specified using global indexing schemes. This obscures the essence of these algorithms and makes their specification unnecessarily complex, especially if the mesh topology is modified dynamically. We address these problems by defining a set of local operations on polygon meshes represented by graph rotation systems. We also introduce the vv programming language, which makes it possible to express these operations in a machine-readable form. The usefulness of the vv language is illustrated by the application examples, in which we concentrate on subdivision algorithms for the geometric modeling of surfaces. The algorithms are specified as short, intuitive vv programs, directly executable by the corresponding modeling software.
36985476
Who Wins on eBay: An Analysis of Bidders and Their Bid Behaviours
Online auctioning is one of the more successful business innovations on the Web. The auction format at eBay, the leading online auctioneer, has some unique characteristics including a fixed closing time for the bids and the use of a proxy bidding system that that is capable of acting as a bidder's agent. These features, coupled with third party products such as sniping software, have introduced novel bidder behaviours that may not occur in more traditional auction formats. In an attempt to study these behaviours, we collected and analysed data from over 11,000 eBay auctions. This paper presents the results of the analyses including descriptive information about the auctions and the classification of bids and bidders based on bid timing, frequency and strategy employed. The different types of bidders and their success rates offer insights into the nature of bidder participation in eBay auctions. In addition, chi‐square analyses reveal significant differences among the bidding strategies with respect to auc...
32322570
Teaching teachers to teach with technology while encouraging students to look forward to college: a case study of learner-centered training
6341521
Rethinking classical internal forces for active contour models
The classical active contour model has two basic internal forces: tension and curvature. These forces are included to provide cohe sion, equal control point spacing, and locally smooth shape. These classical internal forces have undesirable attributes that are in conflict with these original desired characteristics. Tension evenly spaces the control points, but also causes the models to collapse in weak image gradients. Curvature produces locally smooth curvature, but it does so by forcing the model toward a straight line. The paper returns to the original active contour model motivations to reformulate these internal forces. The desired properties are achieved without the introduction of unwanted model behavior A new spacing force and a new constant change in curvature force are introduced and their performance characteristics are discussed. The paper includes experimental results that demonstrate the efficacy and performance of the proposed reformulations.
14452564
Eye Tracking Using Active Deformable Models
Developing a robust, non-intrusive, inexpensive eye tracker is quite a challenge in the computer vision field. This paper introduces a new eye tracking approach based on an enhanced formulation of the statistical pressure snakes. Using a head-mounted camera, to eliminate the effect of head movements, we can detect and track the eye pupil robustly. Experimental results on video sequences for normal and blinking eyes are presented with high accuracy.