A case study is conducted to test and evaluate the implemented forecasting methodology and softwareapplication. The main objective is to determine whether it is possible to fit historical generation data to the proposed probability distributions commonly used to model solar irradiation. Furthermore, the case study aims to illustrate how the analysis results are also useful in assessing the performance of a solar plant for varying TOU structures. The historical generation data available at the time of this project is very limited. Therefore, this case study does not focus on the statisticalanalysis of the available data, but rather to test whether the forecasting methodology is successful in the TOU context. The case study is conducted for an operational solar plant which provides supplementary energy to a cold storage facility in the Western Cape province of South Africa. The energy supplied by the solar plant is used to mitigate the cold storage’s energy usage from the utility provider (Eskom) in order to reduce electricity expenses.
Lam and Shiu used DEA to analyse 30 Chinese thermal plants in different regions of the country over two years in their 2001 paper . They included total energy input, plant MW capacity and number of employees as inputs, while their only output was generated electrical energy. DEA results were analysed using a regression analysis, where the authors investigated the various effects of other variables. They concluded that their results showed no excess capacity, but found that environmental factors had significant effects on efficiency scores . Furthermore, they found plants that used diesel generators and larger units to be far less efficient . The authors cover the economic aspects of their findings in detail, describing the ability of the DEA method to "allow regulators to formulate policies on deregulation and privatization, and to determine the appropriate productivity factor when imposing price-cap regulation or yardstick competition on electric utilities ".
The developed software was tested for accuracy using data from real engine operation. The output from the software (compressure exit temperature and pressure, net power output, exhaust gas temperature and thermal efficiency) for the ideal cycle plant as may be expected do not match the field data closely. But using the real cycle by exploiying appropriate compressor and turbine isentropic efficiencies, combustor pressure loss, exhaust pressure loss and combustion efficiency, the output from the software closely matched the field data. Every gas turbine engine is basically defined by the PR. To create an engine model that can mimic a real engine, adaptation techniques are used , , but that is not within the scope of this work.
The specific fuel consumption, sfc (in kg/sMW) of the various engine cycles at a given temperature ratio at different pressure ratios is presented in Figure 12. The sfc of the simple cycle engine (sfc, SC) is less than the sfc of the inter-cooled plant (sfc, IC) and that of the reheat plant (sfc, RC) indicating that more fuel is burnt in both the intercooled plant and reheat plant to produce a unit quantity of power compared to the simple cycle plant. Thus, intercooled plant and reheat plant are not suitable stand-alone modifications to the simple cycle plant. The sfc of all the three plants reduces with pressure ratio, as the compressor exit temperature increases with pressure ratio hence less fuel is burnt to attain the set TET at higher pressure ratios.
In this paper the development and application process of web-based software ESPT (Engineering Students’ Performance Test) has been discussed. In previous researches, it is proved that there are number of factors like students’ individual characteristics, learning behaviour, previous educational background, family background, college environment etc. which influence directly or indirectly the students’ performance in their university examination. The influencing factors were identified by studying the previous work carried out by different researchers all over the world and also included some other relevant factors which were investigated by considering the opinions of the students and teaching faculties. Descriptive analysis and one way ANOVA technique were used for identifying the important influencing factors. Finally 22 influencing factors were identified as important by analyzing the results of statistical methods and discussion with the experts. These identified factors were further used to develop a mathematical model by using binary logistic regression method to predict students’ performance in university examination. Pass/fail result in university examination was used as performing factor. On the basis of this model, web-based software ESPT was developed and made freely available for the engineering students so that they can use and predict their performance in university examination in advance.
Relational Database Management Systems (RDMS) were and still are standard preferred solutions in the market of corporate information system, mainly because they are mature enough and their wide field of usability is determining factor for many types of software systems. They are building on top relational algebra, which give them solid mathematical background. Modern RDMS were also able to adapt themselves for the needs of current developer’s (e.g. there is no problem to work with documents in eXtensible Markup Language XML) RDMS can be used in today’s modern object objected applications but developers need to fight with connection of OO and relational worlds. Of course there are other data storage paradigms like Object Oriented Database Managements Systems (OODMS) or Document Oriented Database Management Systems (DODMS) but they are not established yet. It will be interesting to see how this field of informatics will evolve in future, however for now when we are developing OO application with RDMS system as a storage background, it is important to have layer which connect this two different approaches together and that is the case of ORM . The example of layered business application with ORM persistence layer is shown in the Fig. 2.
MPPT is a method that compensates for changing voltage and current characteristic of solar panel and maximum utilization of solar energy from panel. Maximum power point tracking, or MPPT, is the automatic adjustment of the load of a photovoltaic system to achieve the maximum possible power output. PV cells have a complex relationship between current, voltage, and output power, which produces a non-linear output. This output is expressed as the current-voltage characteristic of the PV cell. Constant fluctuations in external variables such as temperature, irradiance, and shading cause constant shifts of the I-V curve upwards and downwards. A change in temperature will have an inversely proportional effect on output voltage, and a change in irradiance will have a proportional affect on output current.
Abstract. The paper proposes to integrate performanceanalysis in the early phases of the model-driven development process for Software Product Lines (SPL). We start by adding generic performance annotations to the UML model representing the set of core reusable SPL assets. The annotations are generic and use the MARTE Profile recently adopted by OMG. A first model transformation realized in the Atlas Transformation Language (ATL), which is the focus of this paper, derives the UML model of a specific product with concrete MARTE performance annotations from the SPL model. A second transformation generates a Layered Queueing Network performance model for the given product by applying an existing transformation approach named PUMA, developed in previous work. The proposed technique is illustrated with an e-commerce case study that models the commonality and variability in both structural and behavioural SPL views. A product is derived and the performance of two design alternatives is compared.
The base model was developed and accepted by client. After acceptance the client placed different work orders. For every work order, customization of the base model was to be made as per the requirements. Timelines were set for each and every activity including requirements gathering, development and testing. A work plan was prepared at the beginning of the project wherein constraints were highlighted. To control the project there is need to compare actual performance with planned performance and taking corrective action to get the desired outcome when there are significant differences. By monitoring and measuring progress regularly, identifying variances from plan, and taking corrective action if required, project control ensures that project objectives are met.
Each string of PV power plant is composed of several photovoltaic modules in series. Within each module, its I-V characteristics are different, resulting in modules losses due to different internal resistance, short circuit current and electromotive force. This section focuses on the circuit model, calculation method and avoidance principle of modules loss.
In production, statistical process control is a technique based on collecting data from the output that the process produced, such as physical quality attributes like size, weight, or form, and measure variations. By comparing those measured variations with various other process parameters, root causes for variations become apparent. Eliminating root causes limits these variations. We iterate that until all variations encountered remain within tolerable limits. Such limits we call tolerance interval. Process results that lie outside of the tolerance interval we call defects. A defect therefore is a strange behavior of the process results that affects the customer or user. 1.3 The Metrics for Variance
Faculty of Science, University of Ilorin. The data was collected from eight departments in the faculty and it covers the performance of students measured by their Grade Point Average (GPA) and Cumulative Grade Point Average (CGPA) in both their first and final year between 2000-2006 academic sessions. It is of interest to determine the proportion of students that improved on their performance, dropped from the class of grade point which they started with and those that maintained their performance using psychometrics approach. Also, the strength of agreement that exist between the first and the final year was examined.
This paper presents an economic perspective of rooftop solar systems consisting of a 1kWp grid-connected photovoltaic (GC-PV) and an evacuated tube solar collector (ETC) water heater (1.37m2 unit) as a case study at Christchurch, New Zealand. The study considers the case that both systems are partially covering the energy demand of a one-family house. According to the average availability of solar radiation at Christchurch the expected year ac energy yield of the 1kWp GC-PV system has been found to be 1018 kWh/year and that of the solar thermal collector 851 kWh/year. Economic analysis has been carried out on the basis that PV electricity is fully used, either directly at user premises or by feeding the utility grid whereas the thermal energy made available by the solar collector is assisting the usual electrical water heating system to supply the necessary hot- water demand. The assumption made in this analysis is that the energy provided by the solar water heater is entirely replacing the otherwise used electricity for heating water. The final electrical energy demand after installing the solar system is then calculated. The presented analysis can be applied for larger capacities for commercial and industrial users considering that repetitive units of the here presented modules can be considered.
• Which performance losses are the most sig- nificant ones and which can actually be im- proved? In industrial practice the real evalua- tion of deviation is important (heat rate) (cost of deviation); using a correction curve to as- signing this value seems far from perfect. In the past the advantages of the present method were advertised as, for example, the possibil- ity of calculating how much it costs to operate a unit with parameters di fferent than the nom- inal ones. Even if by nominal parameters we mean optimal parameters (the best achievable), then by making direct use of the current method and correction curves we will obtain an ideal- ized (and thus fictional and practically nonexis- tent) solution. Theoretical assumptions of this method assume that the influence of each of the parameters can be treated individually and that it is possible to change each one of them to the reference value without changing the other pa- rameters. This is not possible in normal unit performance. It seems purposeful to search for a method which would at the same time iden- tify the losses (deviations) that can be reduced and the real influence of process parameters on the e ffectives of unit operation (taking into con- sideration real unit characteristics and thus, the reaction of automatic control systems).
Hydrological analysis evaluation is enhanced when conducting a multi-objective analysis. This study presents a unified framework for proper interpretation of statistical evaluation performance in a statistically rigorous way and for the evaluation of other effects such as bias, outliers and repeated data. As shown in this work, when the goodness-of-fit evaluation is based on a single indicator, the value is affected by other factors (outliers, model bias, repeated data). A comprehensive procedure for evaluating statistical evaluation performance is proposed and tested here that can serve as a useful guidance and less subjective tool for the hydrological analyst.
 K. Nishioka, N. Sakitani, Y. Uraok, T. Fuyuki “Analysis of multicrystalline silicon solar cells by modified 3-diode equivalent circuit model taking leakagecurrent through periphery into consideration” Graduate School of Materials Science, Japan Advanced Institute of Science and Technology, 1- 1 Asahidai, Nomi, Ishikawa, 923-1292, Japan,Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0101, Japan,2007
firstly identify the required competencies from university graduates as demanded by the labor market, and secondly to find out the mismatches that may exist between the current higher educational students receive and company demands; third, to look into minimizing the gap that exists between the current level of education of the graduates and the business need, as recognized by employer, so that higher education institutes can seek to reduce this lacuna through improvements to the curriculum. The objectives of the aforementioned study was done through mixed methods, using 4 in-depth interviews and questionnaires targeting 872 companies surveyed from a database of the 5000 main Spanish companies and respectively they have divided the competencies under vocational competencies and generic competencies (knowledge related skills, methodological skills, and interpersonal skills) and subsequently the results of the study showed that employers value the most in graduates are technical field specific knowledge as well as interpersonal skills. Furthermore Jusoh (2011) investigated in expectation gaps, job satisfaction, and organizational commitment of fresh graduates to reveal the difference between what fresh graduates expect and their experiences pertaining to the working environment, by using self-administered questionnaires. This study was in the view of graduates after employment. The data was collected from 128 graduates, and they were asked to indicate their preferences on organizational culture, leadership, communication, decision making, team working, motivation and development, the results indicate that significant expectation gap exists in all the areas surveyed. Focusing on both the graduates and employers' perspectives of the necessary level of skill that the graduates as employees must have, it was revealed that there is a disparity that explained the role that higher education plays in teaching the software needed
As a future step, the IMPACT tool can be further enhanced to make use of advanced features provided by MARTE like performanceanalysis contexts with varying workload distributions or resource platforms. The tool has been tested on a reasonable power development station only on small size simple case models. In order to validate its operation, the tool is still to be tested on more complex case studies to evaluate the performance information produced. More work also needs to be done in the area of results feedback. Reverse relational QVT transformations need to be executed to integrate the generated performance information back where they belong on the UML design and provide the user with more detailed feedback about the system’s performance profile.
The system has the ability of sustaining itself for a period of 25 to 30 years if operated as recommended. At a certain time, the system begins to save money and in turn generates income if connected to the grid. We have also learnt how the various components of this system function together and can eventually take up any PV contract anywhere without fear of failure. This photovoltaic system is therefore a great investment.