976 resultados para Industrial electronics


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A large percentage of Vanier College's technology students do not attain their College degrees within the scheduled three years of their program. A closer investigation of the problem revealed that in many of these cases these students had completed all of their program professional courses but they had not completed all of the required English and/or Humanities courses. Fortunately, most of these students do extend their stay at the college for the one or more semesters required for graduation, although some choose to go on into the workforce without returning to complete the missing English and/or Humanities and without their College Degrees. The purpose of this research was to discover if there was any significant measure of association between a student's family linguistic background, family cultural background, high school average, and/or College English Placement Test results and his or her likelihood of succeeding in his or her English and/or Humanities courses within the scheduled three years of the program. Because of both demographic differences between 'hard' and 'soft' technologies, including student population, more specifically gender ratios and student average ages in specific programs; and program differences, including program writing requirements and types of practical skill activities required; in order to have a more uniform sample, the research was limited to the hard technologies where students work hands-on with hardware and/or computers and tend to have overall low research and writing requirements. Based on a review of current literature and observations made in one of the hard technology programs at Vanier College, eight research questions were developed. These questions were designed to examine different aspects of success in the English and Humanities courses such as failure and completion rates and the number of courses remaining after the end of the fifth semester and as well examine how the students assessed their ability to communicate in English. The eight research questions were broken down into a total of 54 hypotheses. The high number of hypotheses was required to address a total of seven independent variables: primary home language, high school language of instruction, student's place of birth (Canada, Not-Canada), student's parents' place of birth (Both-born-in-Canada, Not-both-born-in-Canada), high school averages and English placement level (as a result of the College English Entry Test); and eleven dependent variables: number of English completed, number of English failed, whether all English were completed by the end of the 5th semester (yes, no), number of Humanities courses completed, number of Humanities courses failed, whether all the Humanities courses were completed by the end of the 5th semester (yes, no), the total number of English and Humanities courses left, and the students' assessments of their ability to speak, read and write in English. The data required to address the hypotheses were collected from two sources, from the students themselves and from the College. Fifth and sixth semester students from Building Engineering Systems, Computer and Digital Systems, Computer Science and Industrial Electronics Technology Programs were surveyed to collect personal information including family cultural and linguistic history and current language usages, high school language of instruction, perceived fluency in speaking, reading and writing in English and perceived difficulty in completing English and Humanities courses. The College was able to provide current academic information on each of the students, including copies of college program planners and transcripts, and high school transcripts for students who attended a high school in Quebec. Quantitative analyses were done on the data using the SPSS statistical analysis program. Of the fifty-four hypotheses analysed, in fourteen cases the results supported the research hypotheses, in the forty other cases the null hypotheses had to be accepted. One of the findings was that there was a strong significant association between a student's primary home language and place of birth and his or her perception of his or her ability to communicate in English (speak, read, and write) signifying that both students whose primary home language was not English and students who were not born in Canada, considered themselves, on average, to be weaker in these skills than did students whose primary home language was English. Although this finding was noteworthy, the two most significant findings were the association found between a student's English entry placement level and the number of English courses failed and the association between the parents' place of birth and the student's likelihood of succeeding in both his or her English and Humanities courses. According to the research results, the mean number of English courses failed, on average, by students placed in the lowest entry level of College English was significantly different from the number of English courses failed by students placed in any of the other entry level English courses. In this sample students who were placed in the lowest entry level of College English failed, on average, at least three times as many English courses as those placed in any of the other English entry level courses. These results are significant enough that they will be brought to the attention of the appropriate College administration. The results of this research also appeared to indicate that the most significant determining factor in a student's likelihood of completing his or her English and Humanities courses is his or her parents' place of birth (both-born-in-Canada or not-both-born-in-Canada). Students who had at least one parent who was not born in Canada, would, on average, fail a significantly higher number of English courses, be significantly more likely to still have at least one English course left to complete by the end of the 5th semester, fail a significantly higher number of Humanities courses, be significantly more likely to still have at least one Humanities course to complete by the end of the 5th semester and have significantly more combined English and Humanities courses to complete at the end of their 5th semester than students with both parents born in Canada. This strong association between students' parents' place of birth and their likelihood of succeeding in their English and Humanities courses within the three years of their program appears to indicate that acculturation may be a more significant factor than either language or high school averages, for which no significant association was found for any of the English and Humanities related dependent variables. Although the sample size for this research was only 60 students and more research needs to be conducted in this area, to see if these results are supported with other groups within the College, these results are still significant. If the College can identify, at admission, the students who will be more likely to have difficulty in completing their English and Humanities courses, the College will now have the opportunity to intercede during or before the first semester, and offer these students the support they require in order to increase their chances of success in their education, whether it be classes or courses designed to meet their specific needs, special mentoring, tutoring or other forms of support. With the necessary support, the identified students will have a greater opportunity of successfully completing their programs within the scheduled three years, while at the same time the College will have improved its capacity to meeting the needs of its students.

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In this study of workers of the two industrial units, it has been found that the women workers are more committed to the organization than the men workers. The organizational commitment has been a popular research topic among organizational sociologists, industrial psychologists and labour relations specialists. Much of the early research was directed on organizational commitment of men workers and studies on organizational commitment of women workers were less when compared to that of men workers. The results of this study is partially supported by the findings of Aranya and Jacobson (1975) who found that parental responsibility is linked with maintaining stable patterns of employment.

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Mode of access: Internet.

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Most high-power ultrasound applications are driven by two-level inverters. However, the broad spectral content of the two-level pulse results in undesired harmonics that can decrease the performance of the system significantly. On the other hand, it is crucial to excite the piezoelectric devices at their main resonant frequency in order to have maximum energy conversion. Therefore a high-quality, low-distorted power signal is needed to excite the high-power piezoelectric transducer at its resonant frequency. This study proposes an efficient approach to develop the performance of high-power ultrasonic applications using multilevel inverters along with a frequency estimation algorithm. In this method, the resonant frequencies are estimated based on relative minimums of the piezoelectric impedance frequency response. The algorithm follows the resonant frequency variation and adapts the multilevel inverter reference frequency to drive an ultrasound transducer at high power. Extensive simulation and experimental results indicate the effectiveness of the proposed approach.

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The main contribution of this project was to investigate power electronics technology in designing and developing high frequency high power converters for industrial applications. Therefore, the research was conducted at two levels; first at system level which mainly encapsulated the circuit topology and control scheme and second at application level which involves with real-world applications. Pursuing these objectives, varied topologies have been developed and proposed within this research. The main aim was to resolving solid-state switches limited power rating and operating speed while increasing the system flexibility considering the application characteristics. The developed new power converter configurations were applied to pulsed power and high power ultrasound applications for experimental validation.

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Biodiesel run engines are gaining popularity since the last few years as a viable alternative to conventional petro-diesel based engines. In biodiesel exhaust the content of volatile organic compounds, oil mist, and mass of particulate matter is considerably lower. However, the concentration of oxides of nitrogen (NOx) is relatively higher. In this paper the biodiesel exhaust from a stationary engine is treated under controlled laboratory conditions for removal of NOx using dielectric barrier discharge plasma in cascade with adsorbents prepared from abundantly available industrial waste byproducts like red mud and copper slag. Results were compared with gamma-alumina, a commercial adsorbent. Two different dielectric barrier discharge (DBD) reactors were tested for their effectiveness under Repetitive pulses /AC energization. NOx removal as high as 80% was achieved with pulse energized reactors when cascaded with red mud as adsorbent.

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From its origins in the US electronics sector in the 1970s, technology roadmapping has been adapted (and adopted) widely, for many different innovation, strategy and policy applications. Communication is commonly cited as one of the key benefi ts of roadmapping, particularly in terms of the process that brings different organizational perspectives together, with the roadmap providing a common visual 'language'. There is signifi cant demand for methods that are agile, in the sense of being rapid, flexible and effective to apply, focused on strategic decisions and actions. 'Fast-start' roadmapping workshop techniques enable key stakeholders to address strategic issues efficiently using the visual structure of roadmaps to capture, discuss, prioritize, explore and communicate. This paper presents the learning from a set of five diverse applications of the fast-start approach in the Basque Country, which demonstrate the agility of the technique.

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Power electronic modules distinguish themselves from other modules by their high power operation. These modules are used extensively in high power application markets such as aerospace, automotive, industrial and traction and drives. This paper discusses typical packaging technologies for power electronics modules. It also discusses the latest results from a UK research project investigating the physics-of-failure approach to reliability analysis and predictions for power modules. An integrated design enviroment for incorporating of affects of uncertainty into the design environment was outlined.

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One of the most prominent industrial applications of heat transfer science and engineering has been electronics thermal control. Driven by the relentless increase in spatial density of microelectronic devices, integrated circuit chip powers have risen by a factor of 100 over the past twenty years, with a somewhat smaller increase in heat flux. The traditional approaches using natural convection and forced-air cooling are becoming less viable as power levels increase. This paper provides a high-level overview of the thermal management problem from the perspective of a practitioner, as well as speculation on the prospects for electronics thermal engineering in years to come.

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This work presents a simplified architecture of a neurofuzzy controller for general purpose applications that tries to minimize the processing used in the several stages of hazy modeling of systems. The basic procedures of fuzzification and defuzzification are simplified to the maximum while the inference procedures are computed in a private way. The simplified architecture allows a fast and easy configuration of the neurofuzzy controller and the structuring rules that define the control actions is automatic. Th controller's Limits and performance are standardized and the control actions are previously calculated. For application, the industrial systems of fluid flow control will be considered.

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Recently in most of the industrial automation process an ever increasing degree of automation has been observed. This increasing is motivated by the higher requirement of systems with great performance in terms of quality of products/services generated, productivity, efficiency and low costs in the design, realization and maintenance. This trend in the growth of complex automation systems is rapidly spreading over automated manufacturing systems (AMS), where the integration of the mechanical and electronic technology, typical of the Mechatronics, is merging with other technologies such as Informatics and the communication networks. An AMS is a very complex system that can be thought constituted by a set of flexible working stations, one or more transportation systems. To understand how this machine are important in our society let considerate that every day most of us use bottles of water or soda, buy product in box like food or cigarets and so on. Another important consideration from its complexity derive from the fact that the the consortium of machine producers has estimated around 350 types of manufacturing machine. A large number of manufacturing machine industry are presented in Italy and notably packaging machine industry,in particular a great concentration of this kind of industry is located in Bologna area; for this reason the Bologna area is called “packaging valley”. Usually, the various parts of the AMS interact among them in a concurrent and asynchronous way, and coordinate the parts of the machine to obtain a desiderated overall behaviour is an hard task. Often, this is the case in large scale systems, organized in a modular and distributed manner. Even if the success of a modern AMS from a functional and behavioural point of view is still to attribute to the design choices operated in the definition of the mechanical structure and electrical electronic architecture, the system that governs the control of the plant is becoming crucial, because of the large number of duties associated to it. Apart from the activity inherent to the automation of themachine cycles, the supervisory system is called to perform other main functions such as: emulating the behaviour of traditional mechanical members thus allowing a drastic constructive simplification of the machine and a crucial functional flexibility; dynamically adapting the control strategies according to the different productive needs and to the different operational scenarios; obtaining a high quality of the final product through the verification of the correctness of the processing; addressing the operator devoted to themachine to promptly and carefully take the actions devoted to establish or restore the optimal operating conditions; managing in real time information on diagnostics, as a support of the maintenance operations of the machine. The kind of facilities that designers can directly find on themarket, in terms of software component libraries provides in fact an adequate support as regard the implementation of either top-level or bottom-level functionalities, typically pertaining to the domains of user-friendly HMIs, closed-loop regulation and motion control, fieldbus-based interconnection of remote smart devices. What is still lacking is a reference framework comprising a comprehensive set of highly reusable logic control components that, focussing on the cross-cutting functionalities characterizing the automation domain, may help the designers in the process of modelling and structuring their applications according to the specific needs. Historically, the design and verification process for complex automated industrial systems is performed in empirical way, without a clear distinction between functional and technological-implementation concepts and without a systematic method to organically deal with the complete system. Traditionally, in the field of analog and digital control design and verification through formal and simulation tools have been adopted since a long time ago, at least for multivariable and/or nonlinear controllers for complex time-driven dynamics as in the fields of vehicles, aircrafts, robots, electric drives and complex power electronics equipments. Moving to the field of logic control, typical for industrial manufacturing automation, the design and verification process is approached in a completely different way, usually very “unstructured”. No clear distinction between functions and implementations, between functional architectures and technological architectures and platforms is considered. Probably this difference is due to the different “dynamical framework”of logic control with respect to analog/digital control. As a matter of facts, in logic control discrete-events dynamics replace time-driven dynamics; hence most of the formal and mathematical tools of analog/digital control cannot be directly migrated to logic control to enlighten the distinction between functions and implementations. In addition, in the common view of application technicians, logic control design is strictly connected to the adopted implementation technology (relays in the past, software nowadays), leading again to a deep confusion among functional view and technological view. In Industrial automation software engineering, concepts as modularity, encapsulation, composability and reusability are strongly emphasized and profitably realized in the so-calledobject-oriented methodologies. Industrial automation is receiving lately this approach, as testified by some IEC standards IEC 611313, IEC 61499 which have been considered in commercial products only recently. On the other hand, in the scientific and technical literature many contributions have been already proposed to establish a suitable modelling framework for industrial automation. During last years it was possible to note a considerable growth in the exploitation of innovative concepts and technologies from ICT world in industrial automation systems. For what concerns the logic control design, Model Based Design (MBD) is being imported in industrial automation from software engineering field. Another key-point in industrial automated systems is the growth of requirements in terms of availability, reliability and safety for technological systems. In other words, the control system should not only deal with the nominal behaviour, but should also deal with other important duties, such as diagnosis and faults isolations, recovery and safety management. Indeed, together with high performance, in complex systems fault occurrences increase. This is a consequence of the fact that, as it typically occurs in reliable mechatronic systems, in complex systems such as AMS, together with reliable mechanical elements, an increasing number of electronic devices are also present, that are more vulnerable by their own nature. The diagnosis problem and the faults isolation in a generic dynamical system consists in the design of an elaboration unit that, appropriately processing the inputs and outputs of the dynamical system, is also capable of detecting incipient faults on the plant devices, reconfiguring the control system so as to guarantee satisfactory performance. The designer should be able to formally verify the product, certifying that, in its final implementation, it will perform itsrequired function guarantying the desired level of reliability and safety; the next step is that of preventing faults and eventually reconfiguring the control system so that faults are tolerated. On this topic an important improvement to formal verification of logic control, fault diagnosis and fault tolerant control results derive from Discrete Event Systems theory. The aimof this work is to define a design pattern and a control architecture to help the designer of control logic in industrial automated systems. The work starts with a brief discussion on main characteristics and description of industrial automated systems on Chapter 1. In Chapter 2 a survey on the state of the software engineering paradigm applied to industrial automation is discussed. Chapter 3 presentes a architecture for industrial automated systems based on the new concept of Generalized Actuator showing its benefits, while in Chapter 4 this architecture is refined using a novel entity, the Generalized Device in order to have a better reusability and modularity of the control logic. In Chapter 5 a new approach will be present based on Discrete Event Systems for the problemof software formal verification and an active fault tolerant control architecture using online diagnostic. Finally conclusive remarks and some ideas on new directions to explore are given. In Appendix A are briefly reported some concepts and results about Discrete Event Systems which should help the reader in understanding some crucial points in chapter 5; while in Appendix B an overview on the experimental testbed of the Laboratory of Automation of University of Bologna, is reported to validated the approach presented in chapter 3, chapter 4 and chapter 5. In Appendix C some components model used in chapter 5 for formal verification are reported.