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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Layout-generator för sifferseriell tvåportsadaptor / Layout generator for digit serial two-port adaptor

Almquist, Tobias January 2002 (has links)
Vid sifferseriell aritmetik används ett antal parallella bitar för varje siffra. För att jämföra prestanda och effektförbrukning i förhållande till antalet bitar behövde Institutionen för systemteknik (ISY) en layout-generator för att enkelt kunna generera layout för en sifferseriell tvåportsadaptor. Layouten skulle göras i 0.18 mikrometer process. Antalet inkommande databitar och antalet koefficientbitar skulle vara variabelt. Stor vikt lades vid planeringen av layouten för att genereringen av adaptorn skulle fungera smidigt oberoende av de variabla parametrarna. Kod skrevs för att koppla samman layout-instanserna och för att förenkla adaptorn. / Digit serial arithmetics uses a number of parallel bits in each digit. To compare performance and power consumption relative the number of bits, the Department of Electric Engineering (ISY) needed a layout generator to generate layout for a digit serial two-port adaptor. The layout should be done in 0.18 micrometer process. The number of bits of the incoming data and the number of bits of the coefficient should be variable. Great concern was put in the planning of the layout to make the generation of the adaptor work well independent of the parameters. Code was written to connect the layout instances and to simplify the adaptor.
192

Design and Implementation of a Low-Power Random Access Memory Generator / Design och implementering av en lågeffekts-RAM-generator

Capello, Deborah January 2003 (has links)
In this thesis, a Static Random Access Memory generator has been designed and implemented. The tool can generate memories of different sizes. The number of words that can be stored can be chosen among powers of 2 and the number of bits per word can be up to 48. The focus of the thesis was to find an adequate structure for the generated memories depending on the size, and develop a memory generator that implements the structures, which has been thoroughly done. The single circuits used in the generated memories can be substituted with better circuits as well as adapted to other processes. All circuits apart from a block decoder circuit have been developed. The memory generator was not supposed to automatically produce a complete layout, and some manual interventions on the memories generated by the tool are necessary. The tool requires to be developed further to minimise this manual intervention on the generated memories. The complete memories generated have not been tested because of their complexity, but tests on circuits as well as many parts of the memories have been carried out. During the thesis work, a large amount of tasks had to be carried out and a lot of issues had to be dealt with, which has been a problem. The tool used for the implementation has powerful features for both analog and digital electronic design, but has stability problems with large designs, which has been a big obstacle in this work.
193

Integration of Combined Heat and Power Generators into Small Buildings - A Transient Analysis Approach

DeBruyn, Adrian Bryan January 2006 (has links)
Small combined heat and power generators have the potential to reduce energy consumption and greenhouse gas emissions of residential buildings. Recently, much attention has been given to these units. To date, the majority of studies in this field have concentrated on the steady operational performance of a specific generator type, and the available computer models have largely been theoretical in nature. <br /><br /> The main goal of this study was to evaluate the performance of the latest combined heat and power generators, when integrated into Canadian residential homes. A fair comparison of four 1 kW (electrical) units was made. The combined heat and power units studied were based on PEM fuel cell, solid oxide fuel cell, Stirling Engine, and internal combustion engine energy converters. <br /><br /> This study utilized recent test data in an attempt to evaluate the most efficient method of integrating the combined heat and power units into residential houses. Start-up, shut down, and load change transients were incorporated into the simulations. The impact of load variations due to building thermal envelope differences and varying building heating system equipment was evaluated. The simulations were evaluated using TRNSYS software. The building heat demands were determined with eQuest hourly building simulation software. <br /><br /> All of the combined heat and power units under study were capable of providing a net annual benefit with respect to global energy and greenhouse gas emissions. The fuel cells offer the highest integrated performance, followed closely by the internal combustion engine and lastly the Stirling engine. Annual global energy savings up to 20%, and greenhouse gas savings up to 5. 5 tonnes per year can be achieved compared to the best conventional high efficiency appliances. <br /><br /> Heat demand influences performance greatly. As the thermal output of the generator unit approaches half of the average building thermal demand, the system design becomes critical. The system design is also critical when integrating with a forced air furnace. Only the PEM fuel cell unit produces clear global energy and emissions benefits when operating in the summertime.
194

Modeling the Intersegmental Coordination of Heart Motor Neurons in the Medicinal Leech

Garcia, Paul Anthony 12 July 2004 (has links)
We constructed a model of the coordination of segmental heart motor neurons driving blood circulation in leeches. The heart motor neuron models were conductance-based; conductances of voltage-gated and synaptic currents were adjusted to match the firing pattern of heart motor neurons from the living system. Each motor neuron receives a specific pattern of inhibitory input from rhythmic premotor heart interneurons and translates this spatiotemporal pattern into the fictive heartbeat motor pattern. The temporal pattern of synaptic input to the model was derived from extracellularly recorded spikes of the premotor heart interneurons. We focused on determining the components necessary to produce side-to-side asymmetry in the motor pattern: motor neurons on one side fire nearly in synchrony (synchronous coordination), while on the other they fire in a rear-to-front progression (peristaltic coordination). The model reproduces the general trends in phasing and was used to investigate the effective contribution of several synaptic and cellular properties of the motor neurons. The spatial and temporal pattern of premotor synaptic input, the electrical coupling between the segmental motor neurons, intra-burst, short-term synaptic plasticity of the synaptic inputs, and the axonal conduction delays all were integrated with the intrinsic membrane properties to influence intersegmental phasing.
195

Design and Analysis of a Steady-Voltage Piezoelectric Transducer

Tsou, Teng-chieh 23 March 2010 (has links)
As micro-electromechanical systems (MEMS) and smart technologies have been more matured, applications for wider fields are more available. Piezoelectric materials have the property of electromechanical energy conversion, which can convert vibration energy into electrical energy. In this paper, a general concept of the piezoelectric energy conversion is first given. Then, a simple modeling design and analysis for a special transverse mode of the piezoelectric generator called mode 31 is presented. With regard to analytical method, the piezoelectric equivalent circuit model is able to illustrate the important parameters that influence the process how the piezoelectric element generates electrical energy. We may adjust unimorph voltage by controlling the deflection of cantilever beam. And the output power is taken as the indicated parameters for the generator. The energy conversion efficiency of the generator depends on the operation frequency. By using this way, the piezoelectric power generator may be widely applied to environment with both low-frequency and high-frequency vibration range.
196

The Event-table-driven Control Program Generator of Microprocessor-based Environment

Lian, Guo-sen 27 July 2011 (has links)
In the field of automatic control, using a microprocessor application system to monitor and control an automatic system is quite common and its usage rate are still increasing. Microprocessor can support complex processes scheduling, and accurately control on time and position. However, even a highly professional programmer still needs a lot of time to maintain the control programs running on this kind of control system. The advent of the programmable logic controller (PLC), which consists of CPU, data memory, digital and analog I/O port, and power module provides an alternative for designing an automatic system. It¡¦s used in the field of industrial control widely. Compared to the microprocessor-based control systems, the PLC-based control systems have the advantage of providing a development environment for easily programming and maintaining. However, the high cost, poor signal processing ability, and the restriction on the function of device are the major drawbacks of PLC. To solve the problems described above, this paper taking the advantages from the PLC-based microprocessor-based control systems proposes a PLC-like development environment for creating a microprocessor- based control system. To accomplish this goal, according to the object- oriented concept, this paper classified the device in a microprocessor into four categories, GPIO, ADC, Timer and Serial-com. And also provides an interface window for users to set and access device register. In addition, this paper provides a set of user customizable task module tools to easily establish a PLC-like based system. Then system developers can write a program via a simple event-table-driven way, and build up the operating procedures according to the approach of sequential multitasking. Our research result make the building of microprocessor-based system can be clearly divided in to three stages, microprocessor manufacturer, advance user, and generally user which not only makes the development of product easier and faster but also meets the time-to-market demands. In the future, some advanced technologies can be added into this automatic controller development tools to make it smarter and more automatic. For example, the environment can support the developed technology for multi-thread and multi-core microprocessor to analysis and establish Instruction trace, and adjust the load balancing automatically. Or it can integrate the graphical programming allows users to program simpler and more intuitive.
197

Study on the Electromagnetic Type of the Wave Power Conversion System

Tsai, Chih-Hsuan 30 August 2011 (has links)
The wave power converstion system nowadays nearly all have to depend on the converstion of mechanical energy.This way frequently causes unnecessary loss to the power.The costs of maintenance will also be high about the way. Therefore,we bring up a new wave power converstion system according to Faraday's Law.This way is no need to have the turbine.It can be catch the induced current from the generator directly. We use three different types of the PVC tubes as the model of the magnetic field and put into the round magnet.The motion of the round magnet will cause the change of the magnetic field to product the induced current.We install the magnet with the tube on a platform and combine them to be a structure.Different tubes, structure period and structure displasement will cause different effect of the generator.We apply to the data of experiments to find the relationship of the generator, structure period and structure displacement.We also use the neural network to build the model of the relationship. Finally, it will be the basis on the design of the real model in the future.
198

Optimization of a Steady-Voltage Piezoelectric Transducer

Tsai, Chi-Chang 23 September 2011 (has links)
Mechanical energy exists all over the place in our living, and vibration is the most common way of mechanical performance. Micro-electromechanical systems, the application which integrate techniques and combine different field of research, make it possible to convert vibration into electrical energy by using piezoelectric materials; moreover, it become a small piezoelectric power generator. The thesis set up an equivalent circuit model based on the principle of piezoelectric and cantilever mechanics for experimenting the model¡¦s exactness; consequently, model shows that resonant frequency has no effect on generate electricity when amplitude was fixed. The thesis attempts to change the shape of unimorph for enhancing its power generation. By using different sharp of unimorph, the experiment demonstrate that power generation have direct ratio with frequency at amplitude of 5mm. Moreover, different shapes of the unimorph at frequency of 16Hz have different power output; the disparity among power output might up to 1.78 times.
199

Design and fabrication of in-plane micro-generator using low temperature co-fire ceramics

Chen, Yong-Jheng 05 September 2012 (has links)
This study focuses on the design, fabrication, test and application of in-plane rotary electromagnetic micro-generator to obtain a high power output. The micro-generator comprises multilayer planar low temperature co-fired ceramics (LTCC) Ag micro-coil and multipole hard magnet of Nd/Fe/B. Finite element simulations have been carried out to observe electromagnetic information. The study also establishes analytical solutions for the micro-generator to predict the induced voltage. Three different configurations of planar micro-coils investigated, which are sector-shaped, circle-shaped, and square-shaped micro-coils. A prototype of the micro-generator is as small as 9¡Ñ9¡Ñ1 mm3 in volume size. The experimental results show that the micro-generator with sector-shaped micro-coil has the highest power output of 1.89 mW, and the effective value of the induced voltage of 205.7 mV at 13,325 rpm is achieved. In application, this study designed and fabricated a planar rotary electromagnetic energy harvester with a low rotary speed for use in bicycle dynamos. Finite element analysis and the Taguchi method were used to design this dynamo system. LTCC technology was applied to fabricate Ag planar multilayer coils with 20 layers. A 28-pole magnet Nd/Fe/B with an outer diameter of 50 mm and a thickness of 2 mm was also sintered and magnetized. This harvester system was approximately 50¡Ñ50¡Ñ3 mm3 in volume. The experimentally induced voltages for 20-layer coils were 1.539 V at the rotary speeds of 300 rpm. The power output was 0.788 mW with an external resistance load of 740 £[, and the efficiency was 26.62%. This harvester is capable of powering a minimum of 200 light emitted diodes (LEDs) (forward voltage (VF) <2.2 V and 20 mA) using a rotary speed of 250 rpm, and can be used for bicycle dynamo lighting.
200

Component-based Application Generator : A Designing Methodology for Application Construction

Wang, Chen-Yi 05 July 2004 (has links)
Component-based software is finally taking off in a big way and component-based application generators have been championed because they can be used to shorten a system¡¦s development cycle and therefore lower its development costs. Component-based application generators are standardardized building blocks that can be used to assemble, rather that develop, information systems (IS). This paper presents a component-based application generator in the restaurant food ordering setting and a requirement modeling methodology for IS construction based on the generator presented. A prototype was assembled using the generator and methodology presented to illustrate the concepts and application. With this approach, system developers or end users can more easily build, modify and maintain their applications.

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