Software Performance

Experimental performance evaluation of heat pump-based steam supply system T Kaida, I Sakuraba, K Hashimoto et al. -Fluid-Structure interaction analysis and performance evaluation of a membrane blade M. Saeedi, R. Wüchner and K.-U. Bletzinger -Optimization and performance evaluation for nutrient removal from palm oil mill effluent wastewater using microalgae Raheek I Ibrahim, Z H Wong and A W Mohammad -This content was downloaded from IP address 168.151.1.23 on 24/09

Describes an automatic optical system that is attached to a slit lamp in order to provide automatic keratometry at low cost. The system consists of projecting a light ring as a target onto the patient's cornea as well as analysis of the deformation of the target in order to obtain the radius of curvature and the axis of the associated astigmatism. The reflected image of the target is displayed on a PC monitor, while dedicated software performs the analysis of the image, which provides the corneal keratometry

An implemented system for on-line analysis of multiple distributed data streams is presented. The system is conceptually universal since it does not rely on any particular platform feature and uses format adaptors to translate data streams into its own standard format. The system is as powerful as possible (from a theoretical standpoint) but still efficient enough for on-line analysis thanks to its novel rule-based language (RUSSEL) which is specifically designed for efficient processing of sequential unstructured data streams. The generic concepts are applied to security audit trail analysis. The resulting system provides powerful network security monitoring and sophisticated tools for intrusion/anomaly detection. The rule-based and command languages are described as well as the distributed architecture and the implementation. Performance measurements are reported, showing the effectiveness of the approach

System evolution depends greatly on the ability of a maintainer to locate source code that is specific to feature implementation. Existing feature location techniques require either exercising several features of the system, or rely heavily on domain experts to guide the feature location process. In this paper, we present a novel approach for feature location that combines static and dynamic analysis techniques. An execution trace is generated by exercising the feature under study (dynamic analysis). A component dependency graph (static analysis) is used to rank the components invoked in the trace according to their relevance to the feature. Our ranking technique is based on the impact of a component modification on the rest of the system. The proposed approach is automatic to a large extent relieving users from any decision that would otherwise require extensive domain knowledge of the system. A case study is presented to support and evaluate the applicability of our approach.

At Drexel University, instrumentation and measurement of the Reconfigurable Distribution Automation and Control Laboratory include hardware and software instruments which together form an automated measurement and control system. This system contains special features that were included to enable meter placement and network reconfiguration studies. This paper presents an outline of the measurement and control system for the general laboratory and then focuses on the capabilities purposely added for the meter placement and network reconfiguration studies.

Validation is one of the software engineering disciplines that help build quality into software. The major objective of software validation process is to determine that the software performs its intended functions correctly and provide information about its quality and reliability. This paper identifies general measures for the specific goals and its specific practices of Validation Process Area (PA) in Capability Maturity Model Integration (CMMI). CMMI is developed by Software Engineering Institute (SEI). CMMI is a framework for improvement and assessment of a software development process. CMMI needs a measurement program that is practical. The method we used to define the measures is to apply the Goal Question Metrics (GQM) paradigm to the specific goals and its specific practices of Validation Process Area in CMMI.

For real time embedded systems software performance is one of the most important quality attributes. Controlling and predicting the software performance in software is associated with a number of chal- lenges. One of the challenges is to tailor the established and rather gen- eral performance activities to the needs and available opportunities of a specific organization. This study presents a qualitative methodology for tailoring process activities to a specific organization. The proposed methodology is used in case study performed in a large company that develops embedded platforms. A number of suggestions for modification and addition of process activities has been brought forward as a result of the study. The result can further be summarized as SPE in embed- ded platform development holds more opportunities for reuse, but also requires more focus on external stakeholders, continual training and co- ordination between projects.

Validation is one of the software engineering disciplines that help build quality into software. The major objective of software validation process is to determine that the software performs its intended functions correctly and provide information about its quality and reliability. This paper identifies general measures for the specific goals and its specific practices of Validation Process Area (PA) in Capability Maturity Model Integration (CMMI). CMMI is developed by Software Engineering Institute (SEI). CMMI is a framework for improvement and assessment of a software development process. CMMI needs a measurement program that is practical. The method we used to define the measures is to apply the Goal Question Metrics (GQM) paradigm to the specific goals and its specific practices of Validation Process Area in CMMI.

S e p t e m b e r / O c t o b e r 2 0 0 3 I E E E S O F T W A R E 1 0 3 BOOKSHELF cal inference principles, and various optimizing techniques from operations research. Otherwise, Quality Software Project Management is an excellent reference for both new and seasoned software program managers. Robert C. Larrabee works for ARINC Engineering LLC. Contact him at [email protected].

In this paper we describe an automatic system for car parks payment based on Near Field Communication technology. This system has been projected and developed as part of the SIESTA project, a research project financed by the Tuscany region in Italy, to study innovative services for tourists visiting cities of art. The developed system allows users to use their own mobile phone both as an electronic ticket to enter and exit the parking and as an electronic wallet to pay automatically for it. To fully implement this system, four applicative protocols have been developed: two protocols manage the entrance and the exit operations for close parks, while the other two manage the interaction of the user with the kiosk, enabling respectively the load of the money on the phone and the cash payment. The underlying structure of the system foresees the presence of the corresponding softwares performing the protocol operations and interacting directly with the NFC memory of the phone for the read/write tasks, and of a database collecting all the information concerning the presence and the payment of the users.

Cesare A / i~~i , l e s s~n d r~ Ferrero, and Vincenzo Piuri rtificial intelligence technologies are now attractive tools to enhance and improve the efficiency, the capability, and the features f instrumentation in application areas related to measurement, system identification, and control. These techniques exploit the omputational capabilities of modern computing systems (in particular, of microprocessor and DSP-based systems) to manipulate the sampled input signals and extract the desired measurements. i The aim of the paper is to introduce the basic concepts of artificial intelligence techniques and present a survey of those applications related to instrumentation and measurement for which such paradigms have proven to be effechve. In particular, we focus on artificial neural networks, fuzzy logic, and expert systems. The common idea shared by artificial mtelligence technologies is to process and analyze available data and u pviovi information intelligently in order to attain low, medium, and high abstraction levels in the measurement process, enhance the quality and the consistency of measurements, and create new and advanced instruments. The introduction of new techniques in measurement science has usually been directed toward enhancing the quality of measurement procedures and instrument features, in order to create advanced solutions for known applications and to provide suitable tools for new ones. Research and industrial activities in the mstrumentation and measurement fields have traditionally been concerned with the design of, and experimentation with, new sensors, new materials, new technologies, and new methods to analyze data, process signals and images, and identify and control systems.

Early performance validation allows software developers to address performance issues since the first phases of software life cycle, when crucial decisions on the software system are taken. However, the lack of completely automated methodologies and the need of special skills for early software performance modelling and analysis prevent their introduction in real industrial context. The availability of such automation should facilitate the application of these methodologies on industrial products without delaying the software development process. Goal of this paper is to report our experience in the modelling and analysis of performance requirements of a real telecommunication system at the design level.

In this paper we describe UML-Ψ, a software performance evaluation tool based on process-oriented simulation. The tool can be used to evaluate performances of software systems described as annotated UML diagrams. UML-Ψ transforms the software model into a performance model based on process-oriented simulation, executes the performance model and collects results. Performance results are inserted into the software model as tagged values associated to the relevant UML elements.

Gesellschaft für Informatik e.V. (GI) publishes this series in order to make available to a broad public recent findings in informatics (i.e. computer science and information systems), to document conferences that are organized in cooperation with GI and to publish the annual GI Award dissertation.

Results of a case study in maintenance of an object-oriented software application are presented. A software en-gineer replaced a text-based user interface with a graph-ical user interface (GUI) based on the Microsoft Founda-tion Classes, adapted the application for ...

This paper describes the MESH block ciphers, whose designs are based on the same group operations as the IDEA cipher, but with a number of novel features: flexible block sizes in steps of 32 bits (the block size of IDEA is fixed at 64 bits); larger MA-boxes; distinct key-mixing layers for odd and even rounds; and new key schedule algorithms that achieve fast avalanche and avoid the weak keys of IDEA. The software performance of MESH ciphers are estimated to be better or comparable to that of triple-DES. A number of attacks, such as truncated and impossible differentials, linear and Demirci's attack, shows that more resources are required on the MESH ciphers than for IDEA, and indicates that both ciphers seem to have a large margin of security.

This paper reports on a modest study which relates seven different software complexity metrics to the experience of maintenance activities performed on a medium size software system. Three different versions of the system that evolved over a period of three years were analyzed in this study. A major revision of the system, while still in its design phase, was also analyzed.

Distributed Constraint Optimization (DCOP) is an elegant formalism relevant to many areas in multiagent systems, yet complete algorithms have not been pursued for real world applications due to perceived complexity. To capably capture a rich class of complex problem domains, we introduce the Distributed Multi-Event Scheduling (DiMES) framework and design congruent DCOP formulations with binary constraints which are proven to yield the optimal solution. To approach real-world efficiency requirements, we obtain immense speedups by improving communication structure and precomputing best case bounds. Heuristics for generating better communication structures and calculating bound in a distributed manner are provided and tested on systematically developed domains for meeting scheduling and sensor networks, exemplifying the viability of complete algorithms.

Purpose -The primary purpose of this paper is to present a comprehensive strategy for performance, reliability and scalability (PSR) testing of multi-tier web applications. Design/methodology/approach -The strategy for PSR testing is presented primarily through examination of the intangible knowledge base in the PSR testing field. The paper also draws on relevant recent work conducted in the area of software performance evaluation. Findings -The study revealed that appropriate testing procedures are critical for the success of web-based multi-tier applications. However, there was little academic work that collectively focused on PSR testing issues. This paper provides step-by-step testing procedures to ensure that web-based applications are functioning well to meet user demands. Research limitations/implications -Given the rapid changes in technology and business environments, more applied research will be needed in the area of PSR testing to ensure the successful functioning of web-based applications. For future studies, structured interviews or case-study methods could be employed to present the views of online companies. Originality/value -This paper provides a comprehensive strategy and the suggested steps for managers and technical personnel to ensure that the multi-tier, web-based applications are effective, scalable and reliable.

One of the very important aspects of software quality is software testing. Software testing consumes 30%-50% of the most software projects. Testing should not only be performed for the quality or development process requirement but due to the fact that testing needs to ...

The Space Shuttle orbit flight control system, which operates during all exo-atmospheric flight phases, has successfully met operational requirements. Many design integration and operational issues that required resolution during development and testing provide an experience base that will benefit the development of future space systems, particularly the Space Station. To this end, the applicable Shuttle and Space Station hardwarelsoftware is reviewed with some perspective provided on how current design groundrules were derived and how issues that affected the Shuttle orbit control system design are a pathway for the Space Station. Some of the most significant lessons learned from the Shuttle are summarized, with a discussion of the effect of performance and design of hardware, including the data processing system, on software structures and usage procedures. Crew interface issues and important results from man-in-the-loop tests are summarized. Problems resulting from trying to meet difficult orbital operational objectives, including some sophisticated payload operations are characterized. Several proposed Shuttle flight control design improvements, developed in response to some of the lessons learned so far, are identified. Potential application of the Shuttle design lessons and new control technologies to the Space Station are discussed.

This paper is an empirical study of the random and sequential I/O performance of Windows 2000™ using the NT File System. It continues the work done by Riedel, et. al. in their 1997 paper exploring sequential IO performance under Windows NT 4.0™. This paper explores the performance and overhead of today's Intel Pentium III™ based memory and IO subsystems, including the processor bus, the PCI bus, the disk controllers, the SCSI and IDE buses, and the disk media. It also examines the performance available from IDE RAID, a relatively new technology built from inexpensive IDE disks. Network IO performance is briefly covered. We describe how to achieve good throughput, and discuss the major bottlenecks. While Riedel's model of software performance remains largely unchanged, increases in hardware performance have made the 32bit, 33MHz PCI bus the dominant bottleneck reaching saturation with three disks.

Validation is one of the software engineering disciplines that help build quality into software. The major objective of software validation process is to determine that the software performs its intended functions correctly and provide information about its quality and reliability. This paper identifies general measures for the specific goals and its specific practices of Validation Process Area (PA) in Capability Maturity Model Integration (CMMI). CMMI is developed by Software Engineering Institute (SEI). CMMI is a framework for improvement and assessment of a software development process. CMMI needs a measurement program that is practical. The method we used to define the measures is to apply the Goal Question Metrics (GQM) paradigm to the specific goals and its specific practices of Validation Process Area in CMMI.

This paper presents a new proposed message digest algorithm 0). Many of its characteristics (applications domain, performance and implementation structure) are similar to those of MDCfamily of hash functions. The proposed algorithm takes as input a message of arbitrary length and produces as output a 128/160-bit fugerprint or message digest. New features of the proposed algorithm include the heavy use of data-dependent rotations, and the inclusion of integer multiplication as an additional primitive operation. These proposed features are expected to provide high security level with enhancement in throughput. The proposed algorithm is intended for digital signature applications, where a large fde must be compressed in a secure manner before being signed (encrypted) with a private secret key under a public-key cryptosystem. The proposed algorithm is designed to be quite fast on 32-bit machines. In addition, it does not require any large substitution tables, so that the algorithm can be coded quite compactly. We describe the general characteristics, architecture and implementation, and give a complete specifcation for MD-160/128. Several test vectors are used for inspecting the validity of the proposed algorithm. Also, we compare the software performance of several MDCbased algorithms, which is of independent interest. Simulation results show that the throughput of the proposed MD-128 is about 76.4 Mbitlsec while in RIPEMD-128 is about 69.8 Mbitlsec.

As semiconductor technology scales into the deep submicron regime the occurrence of transient or soft errors will increase. This will require new approaches to error detection. Software checking approaches are attractive because they require little hardware modification and can be easily adjusted to fit different reliability and performance requirements. Unfortunately, software checking adds a significant performance overhead.

Underspecified performance requirements can cause performance issues in a software system. However, a complete, upfront analysis of a software system is difficult, and usually not desirable. We propose an evolutionary model for performance requirements specifications and corresponding validation testing. The principles of the model can be integrated into agile development methods. Using this approach, the performance requirements and test cases can be specified incrementally, without big upfront analysis. We also provide a post hoc examination of a development effort at IBM that had a high focus on performance requirements. The examination indicates that our evolutionary model can be used to specify performance requirements such that the level of detail is commensurate with the nature of the project.

The Europa Jupiter System Mission (EJSM) has been prioritized as the next Outer Planets Flagship Mission that would be devoted to exploring the emergence of habitable worlds around gas giants. This joint NASA and ESA endeavor would focus on the Galilean moons Europa and Ganymede but would also investigate Io, Callisto, and the Jupiter system as a whole. The NASA-contributed Jupiter Europa Orbiter (JEO) and the ESA-contributed Jupiter Ganymede Orbiter (JGO) would be launched on separate launch vehicles in 2020. Here we focus on JEO. After 2-3 years of performing science in the Jovian system, JEO would orbit Europa and would operate in a high radiation environment. The life-limiting radiation environment complicates hardware and software performance as well as operations strategy. These challenges would require the Europa science goals to be met in an efficient duration of 9 months. To maximize the science while in orbit at Europa, JEO needs to develop strategies to make the system easily operable and robust to radiation degradation. In addition to radiation tolerant hardware and software designs along with robust margins, the project has already been considering operability features in its baseline design for JEO. Operability is the combination of aspects of a system that make it simple and inexpensive to operate, robust to changing system behavior, responsive to modified goals, and adaptive to deviations in expected environments or operating conditions. For JEO, being robust and flexible to meet science goals in the face of a harsh environment is paramount. The mission must be designed to have multiple means of meeting critical science goals; accommodate operation in the face of radiation-based noise, degradation and failure; and be flexible to changing science goals based upon discoveries. As a result, JEO has kept science goals and operability in mind for all system design processes and trade studies. The most stringent and driving operational requirements and con- - straints for the JEO concept are encountered during Europa Science orbit phase. Some of the key operability issues incorporated from the earliest concept studies include: (1) Make the flight and ground systems operable and survivable for a high intensity, rapid turn-around operations environment in Europa orbit in the presence of radiation based anomalies. (2) Use modern system engineering methods to model the system behavior as early as possible to balance mission scope with system capability, complexity, risk, and cost. Systems design based on behavior models allows for accommodation of changing behaviors in operating the systems. (3) Use lessons learned from previous applicable missions to guide design philosophy and trade studies specifically for operability issues. In this paper, we discuss the key flight system design trades, operations scenarios and lessons learned developed in recent JEO mission studies.

This work presents Jaca, a fault injection tool that aims to validate Java applications. Jaca injects high-level software faults by affecting attributes and methods of an object's public interface. Jaca is source-code independent: instrumentation needed for injection and monitoring purposes are introduced at bytecode level during load-time. Jaca's usefulness is shown in a case study used to validate a third-parties component. The case study consists of an OODBMS named Ozone as a component and a performance benchmark, Wisconsin OO7, which uses the OODBMS' stored objects.

We use mean value analysis models to compare representative hardware and software cache coherence schemes for a large-scale shared-memory system. Our goal is to identify the workloads for which either of the schemes is significantly better. Our methodology improves upon previous analytical studies and complements previous simulation studies by developing a common high-level workload model that is used to derive separate sets of lowlevel workload parameters for the two schemes. This approach allows an equitable comparison of the two schemes for a specific workload.

Over the last decade, a lot of research has been directed toward integrating performance analysis into the software development process. Traditional software development methods focus on software correctness, introducing performance issues later in the development process. This approach does not take into account the fact that performance problems may require considerable changes in design, for example, at the software architecture level, or even worse at the requirement analysis level. Several approaches were proposed in order to address early software performance analysis. Although some of them have been successfully applied, we are still far from seeing performance analysis integrated into ordinary software development. In this paper, we present a comprehensive review of recent research in the field of model-based performance prediction at software development time in order to assess the maturity of the field and point out promising research directions.

In the year 2000 the telecommunication market entered a very deep recession. In the current marketplace the service providers must improve network management to reduce operation costs. ATM network service providers offered mainly permanent virtual circuit connections to customers in the last years, but recently there is an increasing interest to offer switched virtual circuit (SVC) connections to end users. The SVC is based on the use of signalling protocols. Our paper focuses on the performance of call processing in ATM networks. Based on a series of measurement results that have a wide generality among ATM switches, we have built up a node-model to design large ATM signalling networks. The paper shows that a cascaded network is a good estimator for the signalling performance of an arbitrary network. In addition, it is shown that the call density of the network is an important network parameter, which is closely related to the maximum networ-level call arrival rate. The case studies are extended from homogeneous networks to hybrid networks. The simulation study was carried out based on the simulation software called ACCEPT, developed by the author and his colleague I. Moldován,

This paper presents the ALIZE/SpkDet open source software packages for text independent speaker recognition. This software is based on the well-known UBM/GMM approach. It includes also the latest speaker recognition developments such as Latent Factor Analysis (LFA) and unsupervised adaptation. Discriminant classifiers such as SVM supervectors are also provided, linked with the Nuisance Attribute Projection (NAP). The software performance is demonstrated within the framework of the NIST'06 SRE evaluation campaign. Several other applications like speaker diarization, embedded speaker recognition, password dependent speaker recognition and pathological voice assessment are also presented.

Distributed or parallel software with synchronous communication via rendezvous is found in client-server systems and in proposed open distributed systems, in implementation environments such as Ada, V, remote procedure call systems, in transputer systems, and in specification techniques such as CSP, CCS and LOTOS. The delays induced by rendezvous can cause serious performance problems, which are not easy to estimate using conventional models which focus on hardware contention, or on a restricted view of the parallelism which ignores implementation constraints. Stochastic rendezvous networks are queueing networks of a new type which have been proposed as a modelling framework for these systems. They incorporate the two key phenomena of included service and a second phase of service. This paper extends the model to also incorporate different services or entries associated with each task. Approximations to arrival-instant probabilities are employed with a mean-value analysis framework, to give approximate performance estimates. The method has been applied to moderately large industrial software systems

Existing advanced and powerful techniques for optimizing litz-wire winding designs are complex and usually require using multiple expensive software packages. A new CAD tool has been created to make advanced litz-wire design methods available to any designer through an easy-to-use web interface. The software performs two-dimensional field simulations and returns designs optimized considering cost and loss. It is shown that simple fullbobbin designs, compared to optimized choices, can result in much higher loss with almost no cost advantage or much higher cost with almost no loss advantage, whereas the optimization results provide a full range of choices providing the lowest loss at any given cost or the lowest cost at any given loss.

We consider what aspects of software performance can be validated during the early stages of development, before the system is fully implemented, and how this can be approached. There are mature and successful methods available for immediate use, but there are also difficult aspects that need further research. Ease of use and integration of performance engineering with software development are important examples. This paper describes issues in early performance validation, methods, successes and difficulties, and conclusions.

Weaves are networks of concurrently executing tool fragments that communicate by passing objects. Intended as an engineering medium for systems characterized by streams of data, weaves occupy a computational niche midway between heavyweight parallel processes and fine-grain dataflow. Weaves are distinguished from other data flow styles by their emphasis on instrumentation, continuous observability, and dynamic rearrangement: (1) Basic low-overhead instrumentation is inserted automatically. (2 )Executing weaves can be observed at any time by means of sophisticated analysis agents, without degrading the performance of the weave. (3) Weaves can be dynamically snipped and spliced without interrupting the data flow; this permits novel forms of experimentation and analysis.

BIOSOPE cruise covered an oceanographic transect through the centre of the South Pacific Gyre (SPG) from the Marquesas archipelago to the Peru-Chile upwelling (PCU). Water samples from 6 depths in the euphotic zone were collected at 20 stations. The concentrations of suspended calcite particles, coccolithophores cells and detached coccoliths were estimated together with size and weight using an automatic polarizing microscope, a digital camera, and a collection of softwares performing morphometry and pattern recognition. Some of these softwares are new and described here for the first time. The coccolithophores standing stocks were usually low and reached maxima west of the PCU. The coccoliths of Emiliania huxleyi, Gephyrocapsa spp. and Crenalithus spp. (Order Isochrysidales) represented more than 30% of all the suspended calcite particles detected in the size range 0.1-46 µm (22% of PIC in term of calcite weight). These species grew preferentially in the Chlorophyll maximum zone. In the SPG their maximum cell concentrations were recorded between depth of 150 and 200 m, which is unusually deep for these taxa. The weight of coccoliths and coccospheres were correlated to their size. Large and heavy coccoliths and coccospheres were found in regions with relatively high fertility in the Marquises Island and in the PCU. Small and light coccoliths and coccospheres were found west of the PCU. This distribution is strongly related to ocean chemistry in particular to alkalinity and to carbonate ions concentration. The biotic (coccolithophores production) influence on calcification is mainly driven at the local scale (depth) whereas the abiotic (carbonate chemistry) plays its most important role at the regional (horizontal) level. Here 94% of the variability of coccolith and coccosphere weight can be explained by a change in 7 environmental variables.