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