Spelling suggestions: "subject:"ehe lll"" "subject:"ehe 3ll""
261 |
STATISTICAL ANALYSIS OF INJURY DATA AND THE CONCEPTUAL DESIGN OF A ROLLOVER PROTECTIVE STRUCTURE FOR AN ALL-TERRAIN VEHICLEParvathareddy, Bhavana 01 January 2005 (has links)
The rising statistics of fatal and non-fatal injuries involving an all-terrain vehicle has called for an analysis of the accumulated data from the past years. The analysis has led to the conclusion that in the past years, the fatal and non-fatal injuries have been rising rapidly in spite of the consent decrees which were brought into effect from 1988-1998 by the consumer product safety commission. A necessity to provide increased safety while riding an all-terrain vehicle is recognized. Rollover protective structures which were used with successful results in curbing the injuries on agricultural tractors have been identified as having a potential to serve the purpose. A conceptual design of an automatically deployable rollover protective structure has been dealt with, in the thesis.
|
262 |
On-ship Power Management and Voyage Planning InteractionFrisk, Mikael January 2015 (has links)
Voyage planning methods have advanced significantly in recent years to take advantage of the increasingly available computing power. With the aid of detailed weather predictions it is now possible to decide a route that is optimized with respect to some criterion. With the introduction of so called All Electric Ships; ships with diesel electric propulsion, varying the power production in order to adjust the propulsion has become easier. Incorporating a power management system with the voyage planning software on a ship allows for different techniques to reduce fuel consumption. In this thesis, three different approaches are developed, compared and combined. The first method handles the task of how to optimally share a load demand across a set of generators. The second is performing power production scheduling with respect to engine efficiencies, and finally in the third the potential in energy storage integration with the power management system is investigated. From the results, it is argued that the largest potential lies in the first approach where large fuel savings can be made without any large risk. The second approach shows potential for fuel reduction but this however is found to be heavily dependent on weather predictions and accuracy of the used models. Regarding energy storage it is found that while it is not economically feasible to increase the fuel efficiency, energy storage can be used to handle load transients and fulfil power redundancy requirements.
|
263 |
Education for All in Sri Lanka : ICT4D Hubs for Region-Wide Dissemination of Blended LearningMozelius, Peter January 2014 (has links)
ICT4D, here defined as the use of Information and Communication Technologies (ICT) in developing regions, can be seen as one of the most powerful and cost efficient ways to improve the standard of living in the developing world. Many regions in Asia have shown a rapid but heterogeneous development where information technology had a drastic impact on development but often with the problems related to ICT4D 1.0: lack of sustainability and lack of scalability. This study analysed the Sri Lankan infrastructure for region-wide dissemination of blended learning in the 21st century based on the exploration of some selected ICT4D hubs and educational initiatives. The overall aim of the research was to observe, describe and analyse how the selected ICT4D initiatives and the creation of ICT4D hubs in Sri Lanka might support region-wide dissemination of blended learning and local development. A longitudinal case study has been the overall approach where a number of embedded thematic units were explored in long-term fieldwork conducted between 2006 and 2012. Data has been collected from a combination of observations, interviews, group discussions, surveys and document analysis. Findings showed that several of the studied ICT4D hubs have contributed to the general development but the country’s internal digital divide has in fact grown, as urban growth has been so much faster than the growth in rural areas, leaving the country with geographic as well as socio-economic gaps. Some of the former war zones have definitely been left behind and there is a need for further support of the Eastern and Northern regions of the island. Sri Lanka has had an outcome that must be classified as better than average compared to other developing regions with increased opportunities for education and with some ICT4D hubs as multipurpose meeting points. Contributing factors to the successful development are the high literacy rate, the chain of ICT4D projects rolled out in the right order and a committed implementation of educational eServices. On the other hand there were other, more negative findings indicating that sustainability, knowledge sharing and inter-project cooperation and coordination have often failed. The identified strength in the Sri Lankan model, which can be recommended for other parts of the world as well, is the way top-down management of infrastructure sometimes is combined with bottom-up grass-root activities. Other recommendations, that also are global, are to extend existing ICT4D hubs and upgrade them to more intelligent, autonomous and multi-service ICT4D routers that could also handle the future need for eServices in the fields of eHealth, eFarming and eGovernance.
|
264 |
Vanadium Redox Flow Battery : Sizing of VRB in electrified heavy construction equipmentZimmerman, Nathan January 2014 (has links)
In an effort to reduce global emissions by electrifying vehicles and machines with internal combustion engines has led to the development of batteries that are more powerful and efficient than the common lead acid battery. One of the most popular batteries being used for such an installation is lithium ion, but due to its short effective usable lifetime, charging time, and costs has driven researcher to other technologies to replace it. Vanadium redox flow batteries have come into the spotlight recently as a means of replacing rechargeable batteries in electric vehicles and has previously be used mainly to store energy for load leveling. It possesses many qualities that would be beneficial to electrify vehicles. The battery has the ability for power and energy to be sized independently which is not dissimilar to internal combustion vehicles. It also has the potential for a tolerance to low discharges, fast response time, and can quickly be refueled by replacing the electrolyte; just like is done when a car refuels at the gas station. The purpose of the study is to determine the possibility of using vanadium redox flow batteries to power heavy construction equipment, a wheel loader, with a finite amount of space available for implementation. A model has been designed in MATLAB to determine how long the battery could last under typically applications for the wheel loader which needs a peak power of 200 kW. From the volume available it has been determined that the battery can be installed with an energy capacity of 148 kWh. The results of the model show that vanadium redox flow batteries can be used to power a wheel loader but due to the limiting energy density and cell components it remains to be impractical.
|
265 |
The design of an all-digital VCO-based ADC in a 65nm CMOS technologyThangamani, Manivannan, Prabaharan, Allen Arun January 2014 (has links)
This thesis explores the study and design of an all-digital VCO-based ADC in a 65 nm CMOS technology. As the CMOS process enters the deep submicron region, the voltage-domain-based ADCs begins to suffer in improving their performance due to the use of complex analog components. A promising solution to improve the performance of an ADC is to employ as many as possible digital components in a time-domain-based ADC, where it uses the time resolution of an analog signal rather than the voltage resolution. In comparison, as the CMOS process scales down, the time resolution of an analog signal has found superior than the voltage resolution of an analog signal. In recent years, such time-domain-based ADCs have been taken an immense interest due to its inherent features and their design reasons. In this thesis work, the VCO-based ADC design, falls under the category of time-based ADCs which consists of a VCO and an appropriate digital processing circuitry. The employed VCO is used to convert a voltage-based signal into a time signal and thereby it also acts as a time-based quantizer. Then the resulting quantized-time signal is converted into a digital signal by an appropriate digital technique. After different architecture exploration, a conventional VCO-based ADC architecture is implemented in a high-level model to understand the characteristic behaviour of this time-based ADC and then a comprehensive functional schematic-level is designed in reference with the implemented behavioural model using cadence design environment. The performance has been verified using the mixed-levels, of transistor and behavioural-levels due to the greater simulation time of the implemented design. ADC’s dynamic performance has been evaluated using various experiments and simulations. Overall, the simulation experiments showed that the design was found to reach an ENOB of 4.9-bit at 572 MHz speed of sample per second, when a 120 MHz analog signal is applied. The achieved peak performance of the design was a SNR of 40 dB, SFDR of 34 dB and an SNDR of 31 dB over a 120 MHz BW at a 1 V supply voltage. Without any complex building blocks, this VCO-based all-digital ADC design provided a key feature of inherent noise shaping property and also found to be well compatible at the deep submicron region.
|
266 |
Strong-Coupling Quantum Dynamics in a Structured Photonic Band Gap: Enabling On-chip All-optical ComputingMa, Xun Jr. 17 December 2012 (has links)
In this thesis, we demonstrate a new type of resonant, nonlinear, light-matter interaction facilitated by the unique electromagnetic vacuum density-of-state (DOS) structure of Photonic Band Gap (PBG) materials. Strong light localization inside PBG waveguides allows extremely strong coupling between laser fields and embedded two-level quantum dots (QD). The resulting Mollow splitting is large enough to traverse the precipitous DOS jump created by a waveguide mode cutoff. This allows the QD Bloch vector to sense the non-smoothness of the vacuum structure and evolve in novel ways that are forbidden in free space. These unusual strong-coupling effects are described using a "vacuum structure term" of the Bloch equation, combined with field-dependent relaxation rates experienced by the QD Bloch vector. This leads to alternation between coherent evolution and enhanced relaxation. As a result, dynamic high-contrast switching of QD populations can be realized with a single beam of picosecond pulses. During enhanced relaxation to a slightly inverted steady state at the pulse peak, the Bloch vector rapidly switches from anti-parallel to parallel alignment with the pulse torque vector. This then leads to a highly inverted state through subsequent coherent "adiabatic following" near the pulse tail, providing a robust mechanism for picosecond, femto-Joule all-optical switching. The simultaneous input of a second, weaker (signal) driving beam at a different frequency on top of the stronger (holding) beam enables rich modulation effects and unprecedented coherent control over the QD population. This occurs through resonant coupling of the signal pulse with the Mollow sideband transitions created by the holding pulse, leading to either augmentation or negation of the final QD population achieved by the holding pulse alone. This effect is applied to ultrafast all-optical logic AND, OR and NOT gates in the presence of significant (0.1 THz) nonradiative dephasing and (about 1%) inhomogeneous broadening. Further numerical studies of pulse evolutions inside the proposed devices demonstrate satisfactory population contrast within a PBG waveguide length of about 10 micro meter. These results provide the building blocks for low-power, ultrafast, multi-wavelength channel, on-chip, all-optical computing.
|
267 |
Strong-Coupling Quantum Dynamics in a Structured Photonic Band Gap: Enabling On-chip All-optical ComputingMa, Xun Jr. 17 December 2012 (has links)
In this thesis, we demonstrate a new type of resonant, nonlinear, light-matter interaction facilitated by the unique electromagnetic vacuum density-of-state (DOS) structure of Photonic Band Gap (PBG) materials. Strong light localization inside PBG waveguides allows extremely strong coupling between laser fields and embedded two-level quantum dots (QD). The resulting Mollow splitting is large enough to traverse the precipitous DOS jump created by a waveguide mode cutoff. This allows the QD Bloch vector to sense the non-smoothness of the vacuum structure and evolve in novel ways that are forbidden in free space. These unusual strong-coupling effects are described using a "vacuum structure term" of the Bloch equation, combined with field-dependent relaxation rates experienced by the QD Bloch vector. This leads to alternation between coherent evolution and enhanced relaxation. As a result, dynamic high-contrast switching of QD populations can be realized with a single beam of picosecond pulses. During enhanced relaxation to a slightly inverted steady state at the pulse peak, the Bloch vector rapidly switches from anti-parallel to parallel alignment with the pulse torque vector. This then leads to a highly inverted state through subsequent coherent "adiabatic following" near the pulse tail, providing a robust mechanism for picosecond, femto-Joule all-optical switching. The simultaneous input of a second, weaker (signal) driving beam at a different frequency on top of the stronger (holding) beam enables rich modulation effects and unprecedented coherent control over the QD population. This occurs through resonant coupling of the signal pulse with the Mollow sideband transitions created by the holding pulse, leading to either augmentation or negation of the final QD population achieved by the holding pulse alone. This effect is applied to ultrafast all-optical logic AND, OR and NOT gates in the presence of significant (0.1 THz) nonradiative dephasing and (about 1%) inhomogeneous broadening. Further numerical studies of pulse evolutions inside the proposed devices demonstrate satisfactory population contrast within a PBG waveguide length of about 10 micro meter. These results provide the building blocks for low-power, ultrafast, multi-wavelength channel, on-chip, all-optical computing.
|
268 |
Blocking Performance Of Class Of Service Differentiation In Survivable All& / #8208 / optical NetworksTuran, Bilgehan 01 January 2005 (has links) (PDF)
This thesis evaluates the performance of service differentiation with different
class of services namely protection, reservation and the best effort services on
the NxN meshed torus and the ring topology, which are established as
survivable all& / #8208 / optical WDM networks. Blocking probabilities are measured
as performance criteria and the effects of different number of wavelengths,
different type of services and different topology size with wavelength
selective lightpath allocation schemes are investigated by simulations with
respect to increasing load on the topologies.
|
269 |
Achieving A Pedestrian Oriented Transportation System In AnkaraYasdag, Serkan 01 May 2006 (has links) (PDF)
After World War II, automobile use expanded rapidly in the developed countries. As a result, travel pattern changed entirely and automobile has become the dominant form of transport in cities. As a result, the city has been shaped and sized in response to automobile needs. Such increase caused traffic problems in the Central Business Districts and surrounding areas. The problems of traffic congestion and pedestrian circulation have become an important issue in the whole city. As traffic problems have grown in developed cities, they had to be engaged in managing travel demand of people in order to provide mobility and access with reference to the advancing principles of sustainability. In this scope, this study shows the need of travel demand management to create a sustainable transport system. As a case, this study will evaluate the transport problems of Ankara and the place of the city in the urban transport policy process. At this point, transport problems and the transformation of road network and their impacts on the city will be examined in four periods. As a conclusion, urban transportation strategies needed for creating a sustainable transport system are overviewed for the city of Ankara.
|
270 |
About free-will : In search for a philosophical and theistic understanding of free-willLi, Oliver January 2013 (has links)
No description available.
|
Page generated in 0.1911 seconds