With parallel and distributed computing entering the mainstream of computer science, it is important to ensure that parallel application codes are optimized to achieve the best possible performance. This thesis describes the design and implementation of CHITRA92, the second generation of a performance analysis system for parallel programs. CHITRA92 is unique in that it uses visualization techniques to analyze the dynamic activity of a program and produces a semi-Markov chain model of the program's behavior. This model can be parameterized to predict behavior of a program and identify the performance bottlenecks in the program. The important contributions of the CHITRA92 system are: • The dynamic activity of a program is represented through a program execution sequence (PES) and a set of program parameters. A PES description language has been defined to allow users to describe the structure of a PES state vector and instances of the state vector. • A PES is reduced to a semi-Markov chain model via a set of transformations. • Visualization is used to assist in selecting which transforms to apply to a PES. • The presence of periodic behavior in PES's can be identified using spectral analysis techniques. / Master of Science

Distributed computer systems are becoming increasingly prevalent, thanks to modern technology, and this leads to significant challenges for the software developers of these systems. In particular, in order to provide a certain service level agreement with users, the performance characteristics of the system are critical. However, developers today typically consider performance only in the later stages of development, when it may be too late to make major changes to the design. In this thesis, we propose a performance driven approach to development — based around tool support that allows developers to use performance modelling techniques, while still working at the level of program code. There are two central themes to the thesis. The first is to automatically relate performance models to program code. We define the Simple Imperative Remote Invocation Language (SIRIL), and provide a probabilistic semantics that interprets a program as a Markov chain. To make such an interpretation both computable and efficient, we develop an abstract interpretation of the semantics, from which we can derive a Performance Evaluation Process Algebra (PEPA) model of the system. This is based around abstracting the domain of variables to truncated multivariate normal measures. The second theme of the thesis is to analyse large performance models by means of compositional abstraction. We use two abstraction techniques based on aggregation of states — abstract Markov chains, and stochastic bounds — and apply both of them compositionally to PEPA models. This allows us to model check properties in the three-valued Continuous Stochastic Logic (CSL), on abstracted models. We have implemented an extension to the Eclipse plug-in for PEPA, which provides a graphical interface for specifying which states in the model to aggregate, and for performing the model checking.

Abstract The traditional industry of Taiwan boiler manufacturers¡¦ compensation system design is now facing the challenge of gradually improving working conditions and decreasing employees work hours to 84 hours (two week); in accordance with government regulations. These changes deeply affect organizations¡¦ development and cause a sense of uncertainty among employees. In addition, enterprises are becoming more concerned with improving employees¡¦ performance in order to enhance the performance of the organization as a whole. That is the reason to choose compensation system and performance as researching objective for this study. How does the compensation system affect performance? Which variables of compensation system may affect performance? This research refers to a cause and effect model of the organizational commitment to show the relationship between the compensation system, organizational commitment, performance, and how they influence each other. This study assumes that the compensation system affects performance via organizational commitment, which acts as the medium actor. Boiler manufacture industry employees are the object of this study; and there are 232 effective questionnaires in this survey. After statistic analysis, the study finds that: 1. The higher organizational commitment employees undertake, the higher performance they show; these two variables show positive correlation and influence. 2. The higher perceptions employees have toward the compensation system, the higher they expect to perform; these two variables show positive correlation and influence. 3. The higher perceptions employees have toward the compensation system, the higher commitment they undertake; these two variables show positive correlation and influence. 4. The compensation system either directly or indirectly affects performance via organizational commitment. 5. Using Structural Equation Modeling (SEM) to set up the integral pattern , and run on LISREL 8.2 to analyze data. The variable structure¡¦s appropriateness of this study is appropriate, and also able to prove that, organizational commitment is the medium factor between the compensation system and employee performance.

This research investigates ways to reduce the carbon dioxide emissions from the cement industry. Cement is one of the largest sources of man-made greenhouse gases, contributing ~5% of the global total. 40% of emissions from cement come from the fuel used in the process, while the electricity used contributes a further 5%. The focus of the research is to find operational changes that can reduce emissions without the need for large capital investment. Three cement plants in the UK were investigated using four different mathematical models based on real data from the plants. A new metric for assessing the environmental impact of the fuel mix of a plant was proposed, and evidence indicates that it may be a better predictor of environmental performance than the metrics currently used in industry. The research found that consistently improving this fuel metric to best-observed levels, as well as reducing the excess air ratio to industry-standard levels had the potential to reduce fuel consumption by up to 7%, and fuel derived CO2 emissions by up to 12%. Increasing use of biomass to best-observed levels had the potential to reduce the net fuel derived CO2 emissions by up to 20%. Comparing the proposed improvements to the historic range of plant performance showed that this level of performance is within the normal operating range of the plants. A reduction of 2-4% in electricity costs and electricity derived emissions was also possible from operational changes. These savings would reduce operating costs as well as emissions, and require little to no capital investment, meaning they could be implemented directly. If successfully implemented in the near future the total savings by 2050 would be on a similar scale to those expected from much more expensive technology changes, such as upgrading to new cement plants, or installing carbon capture and storage technology.