3 research outputs found

    Fuzzy model reference adaptive controller for position control of a DC linear actuator motor in a robotic vehicle driver

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    This paper presents the controller development for DC linear actuator motors that are used to control the throttle and brake pedals of a passenger car with automatic transmission. The Fuzzy Model Reference Adaptive Control (Fuzzy MRAC) system allows the vehicle to follow speed vs. time profiles of driving cycles by dynamically adjusting the position of the driver pedals in a vehicle. The designed controller was implemented to a virtual vehicle model to determine the required position of the linear pedal actuators over a standard driving cycle. The driving- cycle simulation was conducted using Matlab Simulink and the performance of the controller was analyzed based on overshoot, rise time, settling time and mean square error whereas the robustness test was carried out via set-point tracking method. The result shows 19.79 s rise time, 0.1619% overshoot, 32.65 s settling time and 0.0041 mean square error. The results have proven Fuzzy MRAC to be a viable option for use in highly dynamic systems such as automotive standard driving cycle controllers

    Quality of service (QoS) analysis frameworkn for text to speech (TTS) services

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    Quality of service (QoS) evaluations is significant and necessary for text to speech web service applications. Text to speech media conversion quality measurements has general and specific mechanisms for its functional and nonfunctional requirements. The main objective of this thesis is to introduce QoS framework which is able to evaluate and analyze the perceived quality of services (QoS) for text to speech (TTS) web services. To achieve this goal, the framework combines two main mechanisms for measuring the speech quality. General quality attributes measure the response time of TTS services, specific quality attributes measure intelligibility and naturalness through subjective quality measurements, which are mapped onto mean opinion score (MOS). Twenty individuals participated the experiment to test the speech quality by comparing three services fromtexttospeech.com, Natural Reader and Yakitome. Aggregate scores has been used to calculate the combination of general and specific nonfunctional QoS on TTS Web services. The result shown better scale for quality estimation, service1 (Fromtexttospeech) 47.84% is suitable TTS service provider where service2 and service3 (NaturalReader and Yakitome) are close 31.62 and 21.53% respectively and less preferred for listening tests to assess synthesized speech. It is essential to consider the user’s perspective when evaluating the quality of services for media conversion services such as text to speech (TTS) to enhance the user experience

    Broker-based service-oriented content adaptation framework

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    Electronic documents are becoming increasingly rich in content and varied in format and structure. At the same time, user preferences vary towards the contents and their devices are getting increasingly varied in capabilities. This mismatch between rich contents and user preferences along with the end device capability presents a challenge in providing ubiquitous access to these contents. Content adaptation is primarily used to bridge the mismatch by providing users with contents that is tailored to the given contexts e.g., device capability, preferences, or network bandwidth. Existing content adaptation systems employing these approaches such as client-side, server-side or proxy-side adaptation, operate in isolation, often encounter limited adaptation functionality, get overload if too many concurrent users and open to single point of failure, thus limiting the scope and scale of their services. To move beyond these shortcomings, this thesis establishes the basis for developing content adaptation solutions that are efficient and scalable. It presents a framework to enable content adaptation to be consumed as Web services provided by third-party service providers, which is termed as “service-oriented content adaptation”. Towards this perspective, this thesis addresses five key issues – how to enable content adaptation as services (serviceoriented framework); how to locate services in the network (service discovery protocol); how to select best possible services (path determination); how to provide quality assurance (service level agreement (SLA) framework); and how to negotiate quality of service (QoS negotiation). Specifically, we have: (i) identified the key research challenges for service-oriented content adaptation, along with a systematic understanding of the content adaptation research spectrum, captured in a taxonomy of content adaptation systems; (ii) developed an architectural framework that provides the basis for enabling content adaptation as Web services, providing the facilities to serve clients’ content adaptation requests through the client-side brokering; (iii) developed a service discovery protocol, by taking into account the searching space, searching time, match type of the services and physical location of the service providers; (iv) developed a mechanism to choose the best possible combination of services to serve a given content adaptation request, considering QoS levels offered; (v) developed an architectural framework that provides the basis for managing quality through the conceptualization of service level agreement; and (vi) introduced a strategy for QoS negotiation between multiple brokers and service providers, by taking into account the incoming requests and server utilization and, thus requiring the basis of determining serving priority and negotiating new QoS levels. The performance of the proposed solutions are compared with other competitive solutions and shown to be substantially better
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