The flammability of electronic components in spacecraft environments Final report, 15 Mar. - 15 Oct. 1968

Mathematical model for combustion at zero gravity in spacecraft environment

Rotor Eddy-Current loss in permanent-magnet brushless AC machines

This paper analyzes rotor eddy-current loss in permanent-magnet brushless ac machines. It is shown that analytical or finite-element techniques published in literature for predicting rotor eddy-current loss using space harmonic based approaches may not yield correct results in each magnet segment when one magnet-pole is circumferentially segmented into more than two pieces. It is also shown that the eddy-current loss in each equally segmented piece may differ by a large margin, which implies that the temperature distribution in the magnets will be uneven and the risk of demagnetization has to be carefully assessed. The theoretical derivation is validated by time-stepped transient finite-element analysis

Rotor Position Estimation of a Pseudo Direct Drive PM machine using Extended Kalman Filter

The paper describes an improved method to control a Pseudo Direct Drive (PDD) permanent magnet machine with only one sensor on the low-speed rotor (LSR). Due to the magnetic coupling between the two rotors, the PDD machine exhibits low stiffness and non-linear torque transmission characteristics, and hence, the position of the high-speed rotor (HSR) cannot be determined using a simple gear ratio relationship. An extended kalman filter is proposed to accurately estimate the position of the HSR which is used to provide electronic commutation for the drive. The technique has been implemented on a prototype PDD subjected to various speed and load torque profiles

Influence of control structures and load parameters on performance of a pseudo direct drive

The paper describes an in-depth and systematic analysis of a pseudo direct drive permanent magnet machine in closed loop control. Due to the torque being transmitted from the high-speed rotor (HSR) to the low-speed rotor (LSR), through a relatively low stiffness magnetic gear with non-linear characteristics, speed oscillations appear in the drive output with a conventional proportional integral (PI) controller. Therefore two candidate controllers have been proposed as an alternative to the PI control and all controllers have been optimally tuned with a genetic algorithm against a defined criterion. Furthermore, closed loop models are established in the complex frequency domain to determine the system damping and the cause of the oscillations. Consequently, the best controller structure that improves the dynamic behaviour of the system in terms of speed tracking and disturbance rejection could be identified, based on the frequency domain analysis. Experimental results are presented to validate the analysis and the proposed control technique

Relationship Marketing and Supply Chain policy in Enhancing the Customer Value in the Telecommunication Sector

The purpose of this study was to investigate the effect of alignment of marketing strategies on the supply chain and organizational performance in the Telecommunication Sector. The purpose of this research is practical, and in terms of nature and method, it is a descriptive-survey research of correlation type. The communication creations became one of the huge projects in Iraq during the last few years, yet at the year 2005 these projects was manipulated by one or two firms, yet , there are now more than five firms working in this field, we can notice that the Iraqi customer has no loyalty toward any specific company or firm because of their reputation, moreover he/she is ready to abandon any firm in order to obtain low price services, which led to intense the marketing efforts by other firms win and keep the current customers in the Iraqi market. This situation forced the firms to reform working strategies to improve the competition advantage, From the above discussion, it will be clear that the research proposal for this study is to identify and verify the relationship between marketing and quality in the process of creating and delivering value to customers. And this was made through the use of the questionnaire, followed by analysis of the collected data and a conceptual framework based on the results. The researchers used questionnaires, and the total sample reached 1257 among the involved customers in the communication company in Iraq, and more specific in Baghdad the involved ages where between (18-40) years, %43 females, and %57 males. The authors have used 5 point Likert scale. The proposed hypothesis of the study: relationship marketing (perceived service quality, trust, customer satisfaction, the Corporate Image) has a positive effect on customer value.The result was a (perceived service quality, trust, customer satisfaction) has a positive effect on customer value, while the Corporate Image. Does not has a positive effect on customer value

The Impact of Knowledge Processes and Customer Relationship Management (CRM) on Services Quality along Supply Chain

This study summarizes a sample of the managers of the Iraqi cellular communications company with 84 employees. The company is a service organization responsible for providing integrated telecommunications services. As a management system that uses human, technical, material and financial resources, its size and value increase in line with technical progress. The demand for telecommunication services is increasing for several factors, the most important being the only means available to the majority and to the increase in population. The aim of this study is to develop and test a empirical model to link knowledge management processes and customer relationship management to the quality of services along supply chain. The problem of the study was formed through many mental and practical inquiries represented in the negotiation of the customer's knowledge and behavior, the importance of the horizon of customer relationship management, the level of its importance and its impact on the quality of services, the concept of quality of service, the level of its importance, the types of knowledge processes and their importance in the studied companies and their impact on Quality of services along supply chain. These questions were investigated later. The new study aimed at determining the relationship between the changes in the study in the company that was examined and the ability to apply it in all its parts and its ability to develop and use it to serve the customers in the examined organization. The study used the survey as a tool to collect the information that was diverted to be transferred because of statistical tools that were examined for results. The results and recommendations highlighted the reality and facts of the variables that the study addressed from the mental point of view and applied in the company's exams

Technology Management for Supply Chain in Sports Clubs Iraqi and Its Reflection on the Excellence Performance

This research seeks to spread the culture of total quality management among employees at all levels of management in sports clubs working in Iraq and the duration of their reflection on the creation of outstanding performance, and to explore any of the variables of TQM more influential performance excellence studies aims: Identify the latest trends in total quality management and the requirements for applying them in sports clubs to raise their performance within the sports sector Design/methodology/approach: The descriptive descriptive approach was used. The questionnaire was used to collect data in order to develop a reliable and correct measurement model for TQM variables and their distances. The hypotheses were tested using some statistical treatments. Findings : The study concluded the sample agreement that the distinct performance is directly affected by TQM and its dimensions (administrative leadership, continuous improvement, process improvement, relationship marketing). The model of measurement of these variables has been developed. Moreover, the results support the hypothesis of influence and correlation between the investigated variables . Practical implications:This study provides a useful measure of overall quality management and performance, helping managers and employees at the sports club levels to assess the current status of club performance. Managers may improve their performance programs more effectively and efficiently through their strategic approaches to competition. Originality / value: This study is committed to assisting the administrations working in the sports sector to address the challenge of increasing the performance of sports clubs through the management of total quality and its dimensions