<p> This thesis presents a novel hybrid methodology using Recurrent Neural Network and Dynamic Time Warping to solve the mode estimation problem of a radar warning receiver (RWR). The RWR is an electronic support (ES) system with the primary objective to estimate the threat posed by an unfriendly (hostile) radar in an electronic warfare (EW) environment. One such radar is the multi-function radar (MFR), which employs complex signal architecture to perform multiple tasks. As the threat posed by the radar directly depends on its current mode of operation, it is vital to estimate and track the mode of the radar. The proposed method uses a recurrent neural network (echo state network and recurrent multi-layer perceptron) trained in a supervised manner, with the dynamic time warping algorithm as the post processor to estimate the mode of operation. A grid filter in Bayesian framework is then applied to the dynamic time warp estimate to provide an accurate posterior estimate of the operational mode of the MFR. This novel approach is tested on an EW scenario via simulation by employing a hypothetical MFR. Based on the simulation results, we conclude that the hybrid echo state network is more suitable than its recurrent multi-layer perceptron counterpart for the mode estimation problem of a RWR.</p> / Thesis / Master of Applied Science (MASc)

There are many methods for modelling the reliability of systems based on component failure data. This task becomes more complex as systems increase in size, or undertake missions that comprise multiple discrete modes of operation, or phases. Existing techniques require certain levels of expertise in the model generation and calculation processes, meaning that risk and reliability assessments of systems can often be expensive and time-consuming. This is exacerbated as system complexity increases. This thesis presents a novel method which generates reliability models for phasedmission systems, based on Petri nets, from simple input files. The process has been automated with a piece of software designed for engineers with little or no experience in the field of risk and reliability. The software can generate models for both repairable and non-repairable systems, allowing redundant components and maintenance cycles to be included in the model. Further, the software includes a simulator for the generated models. This allows a user with simple input files to perform automatic model generation and simulation with a single piece of software, yielding detailed failure data on components, phases, missions and the overall system. A system can also be simulated across multiple consecutive missions. To assess performance, the software is compared with an analytical approach and found to match within 5% in both the repairable and non-repairable cases. The software documented in this thesis could serve as an aid to engineers designing new systems to validate the reliability of the system. This would not require specialist consultants or additional software, ensuring that the analysis provides results in a timely and cost-effective manner.

<p><strong>Aim</strong>: Social Entrepreneurship (SE) has been widely spread as a global phenomenon, although many researches have been done, the concept is still hard to define. However, it has been proved that SE has a positive effect on alleviating the social problems. The aim of this research is by the means of comparing three prevalent social enterprise models and analyzing the crucial factor in the social value creation process, to find out an appropriate mode for the Chinese organizations to develop SE, with twofold value creation: social and economic.</p><p> </p><p><strong>Method</strong>: Three companies are chosen as case study: Gefle Chocolaterie, Göranssonska Fonder and Lenovo. Face-to-face interview and phone interview are used to collect the primary data, also some books and articles are applied as secondary data. The analysis model is social enterprise models, and strategic triangle model.</p><p> </p><p><strong>Result & Conclusions</strong>: We find some advantages and disadvantages of social enterprise models, and come to a result that for each case company, because of the difference between crucial factor of the social enterprise model, their strategic triangle model are different as well. There is no fixed social enterprise model for Chinese companies to practice SE, each kind of the model should be adjusted to the specific situation of the company, only in this way, best results can be achieved.</p><p> </p><p><strong>Suggestions for future research</strong>: The information we got from the interviewees may be limited to their point of view, also, bias may occur in the research due to authors’ academic point of view. On the other hand, this research was only based on qualitative data, and the empirical study, which was not enough, hence, more quantitative data is needed in the future study.</p><p> </p><p><strong>Contribution of the thesis</strong>: After the study, according to the size of the company, we list the potential models for each of them to develop SE. It is valuable and helpful for managers to capture the SE practice model and embed it into the company behaviour.</p>

Aim: Social Entrepreneurship (SE) has been widely spread as a global phenomenon, although many researches have been done, the concept is still hard to define. However, it has been proved that SE has a positive effect on alleviating the social problems. The aim of this research is by the means of comparing three prevalent social enterprise models and analyzing the crucial factor in the social value creation process, to find out an appropriate mode for the Chinese organizations to develop SE, with twofold value creation: social and economic.   Method: Three companies are chosen as case study: Gefle Chocolaterie, Göranssonska Fonder and Lenovo. Face-to-face interview and phone interview are used to collect the primary data, also some books and articles are applied as secondary data. The analysis model is social enterprise models, and strategic triangle model.   Result &amp; Conclusions: We find some advantages and disadvantages of social enterprise models, and come to a result that for each case company, because of the difference between crucial factor of the social enterprise model, their strategic triangle model are different as well. There is no fixed social enterprise model for Chinese companies to practice SE, each kind of the model should be adjusted to the specific situation of the company, only in this way, best results can be achieved.   Suggestions for future research: The information we got from the interviewees may be limited to their point of view, also, bias may occur in the research due to authors’ academic point of view. On the other hand, this research was only based on qualitative data, and the empirical study, which was not enough, hence, more quantitative data is needed in the future study.   Contribution of the thesis: After the study, according to the size of the company, we list the potential models for each of them to develop SE. It is valuable and helpful for managers to capture the SE practice model and embed it into the company behaviour.

Made available in DSpace on 2016-06-02T19:51:49Z (GMT). No. of bitstreams: 1 3634.pdf: 1481408 bytes, checksum: d561cb2e4ab6a3abae07e5e1e88e2b20 (MD5) Previous issue date: 2011-02-25 / Financiadora de Estudos e Projetos / The use of lean manufacturing principles and techniques has been increasing considerably in companies over the past couple of decades. The employment of such techniques prompts profound transformations on both the project and work organization of the company that chooses to employ them. By this approach, companies that embrace the lean manufacturing model gain flexibility, acquire new principles, and adopt new techniques which enhance their manufacturing process management as well as their workforce management, supported upon the motivation of the worker as he performs his activities, upon team-work, and stimulated by qualification and engagement at work. The objective of this study is to deepen the knowledge of how workmen develop strategies and regulate work activities in productive situations that are planned and managed through principles and techniques based upon the lean manufacturing concept. In order to more clearly analyze the theme studied, a case study was conducted in the assembly line of a company that incorporated the lean manufacturing model to manage its manufacturing process. Work was analyzed through the analysis of activity, based on the precepts of the Ergonomic Analysis of Work. The case study certified that many aspects of the traditional assembly line remain evident in the lean assembly line; however, a new language is employed, due to the new culture and the more flexible model of lean manufacturing. Within the work situations that were analyzed in the case study, it was possible to establish some relevant aspects in the nature of regulations in which their relation to the lean techniques influence the strategies and operational modes of the workers during the process. Despite the diminishment of regulated space which takes place due to the application of lean manufacturing techniques, the operators continue to regulate work activities and fulfil production goals. / A utilização dos princípios e técnicas do modelo de produção enxuta tem crescido consideravelmente nas empresas nas últimas décadas. A ampliação da adoção das técnicas da produção enxuta nas empresas resulta em profundas transformações sobre o projeto e a organização do trabalho. Para essa abordagem, as empresas que adotam a produção enxuta passam a ser mais flexíveis, a ter novos princípios e a adotar novas técnicas na gestão da produção e da força de trabalho, apoiados na motivação do operário na execução de suas atividades, no trabalho em equipe, estimulados pelas qualificações e engajamento no trabalho. Diante disso, a ergonomia considera que as mudanças dos espaços de regulação fazem com que os trabalhadores adotem estratégias e modos operatórios a fim de regular seu estado interno e atingir os resultados esperados pela organização Esse estudo teve por objetivo aprofundar os conhecimentos sobre como os trabalhadores desenvolvem estratégias e regulam a atividade de trabalho em situações produtivas projetadas e geridas nos princípios e técnicas baseados na produção enxuta. Para melhor problematizar o tema estudado, foi realizado um estudo de caso em uma linha de montagem de uma empresa que adotou a produção enxuta como maneira de gerir a sua produção. O trabalho foi analisado utilizando como método a análise da atividade, apoiada nos pressupostos da Análise Ergonômica do Trabalho. No estudo de caso foi constatado que muitos aspectos da linha de montagem tradicional continuam evidentes na linha de montagem enxuta, porém utilizando-se de uma nova linguagem, devido à nova cultura, mais flexível do modelo de produção enxuta. Dentro das situações do trabalho analisado no estudo de caso foi possível constatar alguns aspectos relevantes na natureza das regulações, cuja relação com as técnicas enxutas influenciam nas estratégias e modos operatórios dos trabalhadores, durante o processo. Apesar da diminuição dos espaços de regulação com a utilização das técnicas da produção enxuta, os operadores, ainda assim, continuam a regular a atividade de trabalho e atingir os objetivos de produção.

This thesis focuses on identifying acoustic noise generating components in piezoelectric blowers through transverse velocity measurements and the development of a numerical fluid model. Piezoelectric ceramics have proven useful for many industries and areas of research involving: high precision actuators, noise control, ultrasonic devices, and many other areas. As of late, a unique adaptation of piezoelectric ceramics is surfacing in the area of pumping and cooling. Air pumps that use these ceramics replace the traditional electric motor, resulting in lower power consumption, less moving parts, constant pressure gradients, lower overall weight, and a low profile. The current drawback of this application is the acoustic radiation produced by the blowers. Since these blowers are new to market, little research or development has been done to characterize the noise emissions. This thesis studies the acoustic emissions from the front face of a Murata piezoelectric blower. Jet noise and structural vibrations are two acoustic sources of interest that are studied in this research. A Direct Numerical Simulation (DNS) of the fluid flow through a Murata blower is developed to better identify noise generating mechanisms. The model solutions predict trends in sound pressure levels (SPL) of the jet noise and volumetric flow rates. Both the SPL and flow rate are shown to be functions of critical geometrical dimensions within the flow path of a Murata blower. Important dimensional components are identified as well as non-influential ones. Design guidelines are given to reduce noise emission from the front side of a blower and increase the volumetric flow rate. The results of this research have a direct impact on the piezoelectric blower industry and future blower designs.