The objective of this study was to investigate the growth performance, feed conversion efficiency and other production traits of beef cattle performance tested on the farm. Performance testing records (collected from 2000 to 2004), of 444 bulls comprising of six breeds [viz. Aberdeen Angus (n = 42), Beefmaster (n = 135), Bonsmara (n = 97), Drakensberger (n = 64), Nguni (n = 50) and Simbra (n = 56)] from the eastern Free State, Veld Bull Club (VBC) were obtained and analysed. Bulls were performance tested on the farm (Poortije in Vrede district) for 205 days (16.53 s.d.) and finished-off in a feedlot for 100 days. Upon the completion of the entire test period, the bulls were auctioned. Traits studied were: average daily gain (ADG), Kleiber ratio (KR) and veld feed conversion ratio (VFCR), body conditions score (BCS), muscling score (MS), temperament score (TS), tick count (TC), scrotum circumference (SC) and selling price (SP). An analysis of variance with the General Linear Model (GLM) was used to determine the significance within a breed between years, between breeds within a year, the interaction of year x breed, and breeders (breed x year) for all the dependent variables. Aberdeen Angus bulls showed a significant difference for all traits analysed except for SC and SP. Beefmasters did not only differ in BCS and TS. Bonsmaras differed in all traits analysed except for FWT, SC and SP. Unlike the other breeds, the Drakensberger had more traits that they showed no significant differences viz. IWT, FWT, MS, TS and SP. The Nguni showed significant difference in all traits analysed except for IWT, TS and SC. Finally, the Simbra also did not differ significantly in five of the eleven traits measured viz. FWT, MS, TC, SC and SP. According to these results, there is a significant variation within beef cattle breeds on rangeland in certain performance and other production traits such those measured in this study. This suggests that, although selection for desirable traits within-breed may be slow, the within-breed selection and exploitation has a role to play in improving long-term herd functional efficiency. During the feedlotting period, none of the breeds showed a significant difference in ADG, suggesting that, given a favourable environment, each animal will have an equal opportunity to perform at its optimum genetic potential. This further implies that in a production environment where feed resource is not the limiting factor, higher production efficiency may well be accomplished by each animal. / Dissertation (MSc(Agric): Animal Production Management)--University of Pretoria, 2008. / Animal and Wildlife Sciences / MSc(Agric) / unrestricted

Please read the abstract in the section 00front of this document / Dissertation (M Eng (Chemical Engineering))--University of Pretoria, 2005. / Chemical Engineering / unrestricted

Detecting performance issues in software systems is desirable and sometimes critical. In this thesis, a new tool is presented for the purpose of testing performance at a smaller scale. This tool, JFRNG, is implemented as an extension to the Java testing framework TestNG with the purpose of allowing developers to test the performance of Java code in unit and integration tests. The thesis also contains a study of the current methods and approaches to automating the process of detecting performance issues.  An evaluation of JFRNG is performed both in terms of performance and usability, where the tool is compared to JfrUnit, a similar tool that targets the JUnit framework. A usability survey took place during the usability evaluation where professional Java developers gave their opinions on the clarity of the code that is produced by JFRNG and JfrUnit. The survey participants found the code produced by JFRNG to be easier to read and understand and also rated JFRNG slightly higher on a number of specific aspects related to the clarity of the code. The added performance overhead that was observed for JFRNG during the performance evaluation is on par with JfrUnit and does add some run time for tests, suggesting that developers should be mindful when selecting tests that should utilize JFRNG. The functionality is relatively extensive, allowing developers to collect and test for a large number of metrics related to the tested code. Finally, the thesis is concluded with some suggestions for future work, such as integrating more complex methods for detecting performance regressions based on collected metrics.

An investor wants to maximize return at the cost of as little risk as possible and theBlack-Litterman model can help see that this condition is met. This thesis willinvestigate whether a portfolio created by using modern portfolio theory can beat thebenchmark index in terms of risk-adjusted return during a five year backtest period(2013-2017). Harry Markowitz provides the mean variance optimization frameworkwhile the practical Black-Litterman model adds the opportunity to tweak performancewith views on stock returns. The method for producing views for the Black-Littermanmodel can vary a lot and is what makes this thesis, for all that we know, unique. Theviews in our model stem from regression on the summed up earnings per share forthe last four quarters multiplied by the corresponding historical price earnings ratioand the historical stock price. The regressions provide data on how over orundervalued the stocks are. Backtesting our modified Black-Litterman model yieldsimpressive results in terms of risk-adjusted return and we encourage other studentsof the financial market to further investigate the performance of our modified portfolio.However most of the results are not statistically significant on a 5% significance leveldue to the need for more data points. This method is purely quantitative and can befully replicated to yield the same results for any interested investor.

International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / During engine and airfield performance testing it is often necessary to acquire weather data at the airfield where the test is being conducted. The airborne data acquisition system (DAS) acquires data associated with flight parameters. A separate system records airport weather conditions. Many times the separate system is an Automated Terminal Information Service (ATIS) or the ground crew relaying wind speed, wind direction and temperature from a weather station. To improve this system, the weather station is designed to acquire and store the data in memory. Utilizing a second DAS that is remote to the airborne DAS poses several problems. First, it is undesirable to have many different data acquisition systems from which to process data. The problem then develops into one of integrating the ground weather DAS with the existing airborne DAS. Other problems of system integrity, compatibility and FCC licensing exist. Complete system integration while maintaining integrity and compatibility is overcome by controlling signal format, flow and timing and is discussed in detail. Further discussion of the issue of transmission is overcome by a technique called spread-spectrum and is used in accordance with FCC rules and regulations.

This thesis is focused on ways of defining the requirements for performance testing software, both in practice (based on survey) as well as in theory. The aim of this thesis is to analyze ways of defining performance requirements, which are actually used on IT projects. In order to achieve this goal it is necessary to define concepts of performance testing, implement and evaluate the survey of the using ways of defining performance requirements in practice and then analyze ways of defining performance requirements in terms of their applicability to different types of IT projects. The contribution of this thesis is the comprehensive introduction performance testing software issues and mainly insight into ways of defining performance requirements used in practice and problems associated with them, through the survey, which was implemented and evaluated by myself. The conclusions resulting from this survey summarize which ways of defining performance requirements are applied to specific types of IT projects, which of these ways worked and which problems in certain cases that occur in practice. The thesis is divided into theoretical and practical part. The theoretical part explains the basic concepts associated with performance testing software. In this part, there is also described the methodology of defining performance requirements according to Tom Gilb. The practical part is focused on the realization and evaluation of survey of the using ways of defining performance requirements in practice and on the analysis ways of defining performance requirements with respect to certain types of projects.

The need for performance testing is growing, and many companies are moving toward automated performance testing. Telia uses HP Performance Center for performance testing and wants to explore the market for new performance testing tools. The study compares two performance testing tools: HP Performance Center and BlazeMeter.The study is based on several criteria, which are cost, usability, functionality, efficiency and agile performance testing. The report contains information about the literature review that led to the creation of the framework and interview questions. The purpose of the report is to inform the reader about which tool has better usability, functionality, efficiency and costs and which tool can be used in agile performance testing. / Behovet för prestandatestning växer och många företag går också mot automatiserad prestandatestning. Telia använder i dagsläge Performance Center för prestandatestning, de vill utforska marknaden för nya prestanda testverktyg. Studien går ut från att utvärdera två perstanda testverktyg som är BlazeMeter och HP Performance Center. Studien mellan BlazeMeter och Performance Center byggs på flera kriterier som är kostnad, användbarhet, funktionalitet, effektivitet och agil prestanda testning. Rapporten innehåller information om litteraturstudien, hur ramverket skapas och intervju frågorna som baseras på ramverket. Syftet med rapporten är att ge läsaren information om vilket verktyg som har bättre användbarhet, funktionalitet, effektivitet och verktyget som kan användas i agil prestanda testning.

With the development of service digitalization and the increased adoption of web services, modern large-scale software systems often need to support a large volume of concurrent transactions. Therefore, performance testing focused on evaluating the performance of systems under workload has gained greater attention in current software development. Although there are many performance testing tools available for providing assistance in load generation, there is a lack of a systematic evaluation process to provide guidance and parameters for tool selection for a specific domain. Focusing on business operations as the specific domain and the Nasdaq Central Securities Depository (NCSD) system as an example of large-scale software systems, this thesis explores opportunities and challenges of existing open- source performance testing tools as measured by usability and feasibility metrics. The thesis presents an approach to evaluate performance testing tools concerning requirements from the business domain and the system under test. This approach consists of a user study conducted with four quality assurance experts discussing general performance metrics and specific analytical needs. The outcome of the user study provided the assessment metrics for a comparative experimental evaluation of three open-source performance testing tools (JMeter, Locust, and Gatling) with a realistic test scenario. These three tools were evaluated in terms of their affordance and limitations in presenting analytical details of performance metrics, efficiency of load generation, and ability to implement realistic load models. The research shows that the user study with potential tool users provided a clear direction when evaluating the usability of the three tools. Additionally, the realistic test case was sufficient to reveal each tool’s capability to achieve the same scale of performance as the Nasdaq’s in-house testing tool OMEXUS and provide additional value with realistic simulation of user population and user behavior during performance testing with regard to the specified requirements. / Med utvecklingen av tjänste-digitalisering och ökad användning av webbtjänster behöver moderna storskaliga mjukvarusystem ofta stödja en stor mängd samtidiga transaktioner. Prestandatestning med fokus på att utvärdera prestanda för system under arbetsbelastning har därför fått större uppmärksamhet i den aktuella programvaru utvecklingen. Även om det finns många verktyg för prestandatestning tillgängliga för att ge hjälp i belastnings generering, saknas det en systematisk utvärderingsprocess för att ge vägledning och parametrar för verktygsval för en viss domän. Med fokus på affärsverksamhet som den specifika domänen och Nasdaq Central Securities Depository (NCSD) -systemet, som ett exempel på storskaliga mjukvarusystem, utforskar denna avhandling möjligheter och utmaningar med befintliga verktyg för prestandatestning med öppen källkod mätt med användbarhets- och genomförbarhet mått. Avhandlingen presenterar ett tillvägagångssätt för att utvärdera prestandatestverktyg avseende krav från företagsdomänen och det system som testas. Detta tillvägagångssätt består av en användarstudie utförd med fyra kvalitetssäkringsexperter som diskuterar allmänna prestandamått och specifika analytiska behov. Resultatet av användarstudien gav bedömningsmåtten för en jämförande experimentell utvärdering av tre verktyg för prestandatestning med öppen källkod (JMeter, Locust och Gatling) med ett realistiskt testscenario. Dessa tre verktyg utvärderades i termer av deras överkomlighet och begränsningar när det gäller att presentera analytiska detaljer om prestandamått, effektiviteten i lastgenereringen och förmågan att implementera realistiska belastningsmodeller. Forskningen visar att användarstudien med potentiella verktygsanvändare gav en tydlig riktning vid utvärdering av användbarheten av de tre verktygen. Dessutom var det realistiska testfallet tillräckligt för att avslöja varje verktygs förmåga att uppnå samma skala av prestanda som Nasdaqs interna testverktyg OMEXUS och ge ytterligare värde med realistisk simulering av användarpopulation och användarbeteende under prestandatestning med avseende på de angivna kraven.

International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The performance testing of underseas weapons involves many of the same challenges as for other “smart” systems. Data sets on the order of GigaBytes must be extracted, processed, analyzed, and stored. A few KiloBytes of significant information must be efficiently identified and accessed for analysis out of the great mass of data. Data from various sources must be time correlated and fused together to allow full analysis of the complex interactions which lead to a given test result. The fact that the various sources all use different formats and medias just adds to the fun. Testing of underseas weapons also involves some unique problems. Since real time data transmission is not practical; the vast bulk of the test data is recorded and then recovered with the vehicle at the end of the test. Acoustics are relied on for identification and ranging. As systems continue to get smarter; the rates, capacities, and “smarts” of the equipment and software used to process test data must similarly increase. The NUWES telemetry capabilities developed to test and analyze underseas weapons could be of use on other government related projects. “Key words: Telemetry, data processing, data analysis, undersea weapons, smart weapons, torpedoes, performance testing.”

Positron Emission Tomography (PET) is an imaging technique that uses biologically relevant molecules labelled with positron emitting radioisotopes to measure regional tissue function in living organisms. To maximise the detection efficiency, data are acquired in 3D, that is, all possible detector combinations in a scanner without inter-ring shielding (septa). The gain in sensitivity afforded by 3D PET is offset by the increase in random coincidences, scattered coincidences and deadtime. These problems must be overcome for the gain in sensitivity to be fully realised. The aim of this research project was to investigate strategies to increase the signal to noise ratio of the 3D PET data. Additional side shielding, both in neuro and body scanning, has been implemented and assessed. Large gains were achieved using the neuro shields in experimental and clinical studies. The potential of the body shields was tested in experimental and in-vivo studies which showed that they were scan dependent. For example, no gain was found for a cardiac blood flow (H2 IS0) study. A model-based scatter correction was assessed by companng compartment ratios within the 'Utah' phantom with radioactivity outside the field of view, with and without neuroshielding. Recovered ratios were within 6% of their actual values. The integration time was reduced in an effort to decrease the system deadtime. A peak increase of 150/0 in noise equivalent count rate was measured for a uniform cylinder inside the field of view. A random coincidence variance reduction technique was implemented and assessed to reduce the noise contained in the delayed window random coincidence estimate. The algorithm was evaluated using phantoms and tested on clinical data. A mean 16% reduction in coefficient of variation was measured for a C15O torso study.