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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.
211

Incorporating Spatial and Temporal Variation of Watershed Response in a GIS-based Hydrologic Model

Al-Smadi, Mohammad Ahmed 16 December 1998 (has links)
The hydrograph at the watershed outlet was simulated using the time-area curve concept implemented in a geographic information system (GIS). The goal of this study was to determine if hydrograph prediction accuracy would be improved by accounting for spatial and temporal variation of excess rainfall. Three models with different methods of estimating excess rainfall were developed: the Distributed Curve Number (DCN) model uses a CN for each cell, generating spatially distributed excess rainfall using the Soil Conservation Services curve number method (SCS, 1972); the Uniform Curve Number (UCN) model uses a single "average" CN for the whole watershed, thus generating a uniform excess rainfall; the Phi index model which uses the Phi-index method to generate uniform excess rainfall. With the aid of a GIS, the cumulative flow time to the watershed outlet is estimated for each cell in the watershed and the isochrones of equal travel time are developed. The time-area curve is developed in the form of an S curve. The spatially distributed 1-hr unit hydrograph is derived from the S curve as the difference between the S curve and its value lagged by 1-hr. The models used in this study describe the physical processes and flow mechanisms. They also reflect effects of watershed characteristics (slope, landuse, soil drainage potential) and excess rainfall intensity on the resulting hydrograph at the watershed outlet. Surface flow is divided into channel flow and overland flow based on the upstream drainage area. Flow is routed to the watershed outlet through a channel network derived from the watershed Digital Elevation Model (DEM). The models developed were tested against observed rainfall-runoff data from the 1153-ha Virginia Piedmont watershed (Owl Run). A total of 30 storms were simulated, with statistical comparison of peak flow rate, time to peak flow rate, and the hydrograph shape. The hydrograph shape was compared both visually and statistically. Results indicated that the two models which account for temporal variation in excess rainfall (DCN and UCN) predicted the output hydrograph much more accurately than the Phi model which lacks the ability to capture the temporal variation of excess rainfall. For this watershed, results showed that the spatial variability in excess rainfall which was accounted for by the DCN model did not improve the prediction accuracy over the UCN model which lacks that ability. However, a sensitivity analysis for the effect of the spatial distribution of the excess rainfall indicated that can be a significant effect of spatial distribution on the predicted hydrograph. / Master of Science
212

Economic evaluation of small wind generation ownership under different electricity pricing scenarios

Jose, Anita Ann January 1900 (has links)
Master of Science / Department of Electrical and Computer Engineering / Anil Pahwa / With the Smart Grid trend setting in, various techniques to make the existing grid smarter are being considered. The price of electricity is one of the major factors, which affects the electric utility as well as the numerous consumers connected to the grid. Therefore deciding the right price of electricity for the time of day would be an important decision to make. Consumers’ response to this change in price will impact peak demand as well as their own annual energy bill. Owning a small wind generator under the Critical Peak Pricing (CPP) and Time of Use (TOU) price-based demand response programs could be a viable option. Economic evaluation of owning a small wind generator under the two pricing schemes, namely Critical Peak Pricing (CPP) and Time of Use (TOU), is the main focus of this research. Analysis shows that adopting either of the pricing schemes will not change the annual energy bill for the consumer. Taking into account the installed cost of the turbine, it may not be significantly economical for a residential homeowner to own a small wind turbine with either of the pricing schemes in effect under the conditions assumed.
213

Transformerende leierskapvaardighede as 'n voorspeller van topprestasie

Van Jaarsveld, Barend Francois Fourie 07 1900 (has links)
Text in Afrikaans / Die doel van hierdie navorsing is om te bepaal tot watter mate waargenome leierskapvaardighede van die middelvlakbestuurders in 'n provinsiale hospitaal, 'n voorspeller is van topprestasie. Vanuit die literatuuroorsig word leierskapteoriee, die veranderende konteks van leierskap, leierskapstrategiee en -vaardighede bespreek. Die rasionaal vir topprestasie, visie in topprestasie-organisasies en die beginsels van topprestasie word ook bespreek. Die navorsingsontwerp is 'n beskrywende studie en maak gebruik van 'n gestratifiseerde ewekansige steekproef. Die leierskapvaardigheidsvraelys (Charlton, 1991) is vir die meet van die leierskapvaardighede gebruik en die PA VE-vraelys is gebruik vir die meet van die vlak van topprestasie in die organisasie-eenheid. Die resultate vertoon bemagtiging as die vemaamste voorspeller van topprestasie by die middelvlakbestuurders. Toekomstige navorsing kan temas insluit soos die rol en potensiaal van 'n gedeelde visie, volharding, en werkstevredenheid. Relevante sleutelwoorde is transformerende leierskapvaardighede, topprestasie, bemagtiging en middelvlakbestuurders. / The aim of this research is to determine to what extent perceived leadership competency of the middle level manager in a provincial hospital, is a predictor of peak performance. The literature highlights leadership theories, the changing context of leadership, leadership strategies and competencies. The rationale for peak performance, vision in peak performing organizations and the principles of peak performance are also discussed. The research design is a descriptive study which uses a stratified randomized sample. The leadership competence questionnaire (Charlton, 1991) is used to measure the leadership competencies. The PA VE questionnaire is used to measure the level of peak performance in the organizational unit. The results indicate empowerment as the most prominent predictor of peak performance of middle level managers. Future research may include the role and potential of a shared vision, determination and work satisfaction. Relevant keywords are transformational leadership competencies, peak performance, empowerment and middle level managers. / Industrial and Organisational Psychology / M.Com. (Bedryfsielkunde)
214

OPTIMIZED LOW BIT RATE PCM/FM TELEMETRY WITH WIDE IF BANDWIDTHS

Law, Eugene 10 1900 (has links)
International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / This paper will present the results of some experiments with non-coherent, single symbol detection of pulse code modulation (PCM)/frequency modulation (FM) where the receiver intermediate frequency (IF) bandwidth is much wider than the bit rate. The experiments involved varying the peak deviation and measuring the bit error probability (BEP) at various signal energy per bit to noise power spectral density ratios (E(b)/N(o)). The experiments showed that the optimum peak-to-peak deviation was about 0.7 to 0.8 times the –3 dB IF bandwidth and that the E(b)/N(o) required for a given BEP increased as the ratio of IF bandwidth to bit rate increased. Further, bi-phase-level/FM performed slightly better than non-return-to-zero-level (NRZ-L)/FM with an ac coupled RF signal generator and IF bandwidths much wider than the bit rate.
215

Incorporation of Departure Time Choice in a Mesoscopic Transportation Model for Stockholm

Kristoffersson, Ida January 2009 (has links)
<p>Travel demand management policies such as congestion charges encourage car-users to change among other things route, mode and departure time. Departure time may be especially affected by time-varying charges, since car-users can avoid high peak hour charges by travelling earlier or later, so called peak spreading effects. Conventional transport models do not include departure time choice as a response. For evaluation of time-varying congestion charges departure time choice is essential.</p><p>In this thesis a transport model called SILVESTER is implemented for Stockholm. It includes departure time, mode and route choice. Morning trips, commuting as well as other trips, are modelled and time is discretized into fifteen-minute time periods. This way peak spreading effects can be analysed. The implementation is made around an existing route choice model called CONTRAM, for which a Stockholm network already exists. The CONTRAM network has been in use for a long time in Stockholm and an origin-destination matrix calibrated against local traffic counts and travel times guarantee local credibility. On the demand side, an earlier developed departure time and mode choice model of mixed logit type is used. It was estimated on CONTRAM travel times to be consistent with the route choice model. The behavioural response under time-varying congestion charges was estimated from a hypothetical study conducted in Stockholm.</p><p>Paper I describes the implementation of SILVESTER. The paper shows model structure, how model run time was reduced and tests of convergence. As regards run time, a 75% cut down was achieved by reducing the number of origin-destination pairs while not changing travel time and distance distributions too much.</p><p>In Paper II car-users underlying preferred departure times are derived using a method called reverse engineering. This method derives preferred departure times that reproduce as well as possible the observed travel pattern of the base year. Reverse engineering has previously only been used on small example road networks. Paper II shows that application of reverse engineering to a real-life road network is possible and gives reasonable results.</p> / Silvester
216

Travel Adaptive Capacity Assessment Simulation (TACA Sim)

Watcharasukarn, Montira January 2010 (has links)
More than 95% of fuel used for personal transportation is petroleum-based (Environment and Development Division (EDD), 2005). The peak and decline of world oil production is producing price and uncertainty pressures that may cause significant travel behaviour change in the future. Current travel behaviour has developed during conditions of low cost fuel and government investment in private vehicle mobility. Current urban forms and land use have also been developed during a period of growth in vehicle travel demand. Research that explores the long term (permanent oil supply reduction period) implications of reduced fuel demand on private travel behaviour is needed. Local and national government investments in transport infrastructure and urban development will be used and require maintenance for decades. Research is needed to assess long-term mode choice and car travel demand as a function of urban form and demographic indicators. This type of travel behaviour adaptive potential should be relevant to transport planning decision making. Literature review shows that there are a few available long-term planning methods, models, or tools in transportation engineering for future oil depletion. Transportation engineers need information of how current travel demand patterns may change over the lifetime of infrastructure investments in response to oil supply depletion. Behaviour change data for long term future situations would be difficult to obtain using traditional survey methods because most people have never experienced oil depletion situations. This research proposes that immersing people into the situation of oil depletion through sharp price rise would be necessary to generate relevant behaviour change decisions. The thesis is that the long term behaviour change can be assessed by characterising current adaptive capacity. Adaptive capacity is defined in this thesis as the travel demand pattern with maximum fuel reduction without reducing participation in activities. The reasons why people might change travel demand to reduce fuel use is not part of the definition. This research also proposed that an immersive sim game environment could be used to prompt behaviour change decisions relating to fuel price shocks. Research into sim game surveys and travel behaviour surveys was used to inform the design of a Transport Adaptive Capacity Assessment (TACA) Sim survey tool. The TACA Sim survey was designed to assess capacity to adapt travel behaviour to reduce fuel use, and to characterise the potential for mode change. Participants experience the TACA Sim survey as a self assessment or transport energy audit. The survey provides a personal feel, focuses on the usual weekly activities, and provides feedback to participants about their fuel use and car dependence. Participants supply their normal travel activities over a week, and three weeks of sim play includes a steep fuel price rise while people are allowed to change their travel behaviour in response. The TACA Sim survey was evaluated through a case study of surveys of staff and students at the University of Canterbury. A second version of the TACA survey was developed that surveyed the one week of normal travel, but then probed adaptive capacity by asking a simple question after each travel activity was entered “Could you get to the activity another way?” The sim game travel adaptive capacity is compared with the available alternative adaptive behaviour for participants in a case study at the University of Canterbury. The results of the case study show that the participants responded well with the simulated situation. This reflects that the TACA Sim is successful in helping participants to perceive the situation of fuel price rise and think about their alternatives to car travel. Asking people “Could you get to the activity another way?” was found to effectively probe their adaptive capacity which agreed well with the virtual reality survey. The virtual reality survey yields more details of what people can do such as moving house, chaining trips, combining trips and buying a more efficient vehicle. The web-based TACA survey has been developed and deployed in two further research projects.
217

The Geographic Adaptive Potential of Freight Transportation and Production System in the Context of Fuel and Emission Constraints

Asuncion, Janice Sy January 2014 (has links)
Freight transportation is an integral element of various supply chains and has a complex and dynamical interrelationship with human economic activities. Modern logistical strategies paved way to the current supply chain organisation and logistics network design resulting in a more global economy and huge economies of scale. Recent trends of volatility of oil price have major implications in the movement of commodities across the supply chains. Likewise, climate change issues have presented urgent challenges in reducing carbon emissions for the transport and logistics sector. Pressure on the sector comes from both governments and consumers alike, demanding future sustainability as well as corporate environmental and social responsibility. The original contribution of this research is to investigate the system-wide dynamics of freight transportation and production in the context of supply chains. A theoretical framework called the ‘Geographic Adaptive Potential’ or GAP is built to understand how constraints in energy and emissions affect the production and distribution of commodities. The changes in the supply chain were investigated in four different components, namely a) the potential to shift to less energy and emissions intensive modes for long-haul freight, b) logistical strategies in the last leg of the chain or urban freight and c) local production and distribution, and d) the accessibility of potential customers to the markets. The design of the GAP components is in correspondence with the links of the supply chain. The analyses yielded an evaluation of the adaptive capacity of the freight transport and production system. For long-haul freight, a GIS-based model was created called the ‘New Zealand Intermodal Freight Network’ or NZIFN. It is an optimisation tool integrating the road, rail and shipping network of New Zealand and calculates that minimum time, operating costs, energy and emissions routes between 2 given locations. The case studies of Auckland to Wellington and Auckland to Christchurch distributions of non-perishable products established that even a marginal increase of rail and coastal shipping share produced around 10% reduction in both freight energy and greenhouse gas emissions. In the study of the last leg of the supply chain, the truck trip generation rates of different food stores were investigated. The strongest factors influencing the trip rates to a store are its size and product variation, the latter being a new parameter introduced in the dissertation. It is defined as the total number of brands for 6 chosen commodities commonly found in the stores. The trip rates together with the truck type and distance travelled were used to compute the freight energy usage of the stores. Results revealed that supermarkets consume the most energy for their delivery operations but relative to its physical size, they are more energy efficient than smaller stores. This is due to the utilisation of advanced logistical strategies such as freight consolidation and the effective use of distribution centres. The localised production chapter was explored in the context of Farmers’ markets and their difference with the conventional supermarket distribution system. Using a freight transport energy audit, the energy intensities of both systems were compared. The findings showed that Farmers’ markets were more energy-intensive than supermarkets owing to the low volumes of goods delivered to the market and the lack of freight consolidation effort in the system. The study on the active mode access of potential customers to both Farmers’ markets and supermarkets captured the interplay between freight and personal transport and is the final component of GAP. The results of the ArcGIS based model called ‘Active Mode Access’ or AMA demonstrated that both Farmers’ markets and supermarkets have the same level of accessibility for walking or biking customers. However, the calculations also showed that almost 87% of New Zealanders have no AMA to stores and are at risk for fuel price increase. Finally, the key result of this dissertation is the assessment that there is actually limited adaptive capacity of the freight transport and production system. This is due to network infrastructure and geographical constraints as well as commodity type and mode compatibility and other operational concerns. Due to these limitations, the GAP model assessed that reduction in energy and allowable emissions will ultimately reduce the amount of commodities moved in the system.
218

Rule-Based Approaches for Large Biological Datasets Analysis : A Suite of Tools and Methods

Kruczyk, Marcin January 2013 (has links)
This thesis is about new and improved computational methods to analyze complex biological data produced by advanced biotechnologies. Such data is not only very large but it also is characterized by very high numbers of features. Addressing these needs, we developed a set of methods and tools that are suitable to analyze large sets of data, including next generation sequencing data, and built transparent models that may be interpreted by researchers not necessarily expert in computing. We focused on brain related diseases. The first aim of the thesis was to employ the meta-server approach to finding peaks in ChIP-seq data. Taking existing peak finders we created an algorithm that produces consensus results better than any single peak finder. The second aim was to use supervised machine learning to identify features that are significant in predictive diagnosis of Alzheimer disease in patients with mild cognitive impairment. This experience led to a development of a better feature selection method for rough sets, a machine learning method.  The third aim was to deepen the understanding of the role that STAT3 transcription factor plays in gliomas. Interestingly, we found that STAT3 in addition to being an activator is also a repressor in certain glioma rat and human models. This was achieved by analyzing STAT3 binding sites in combination with epigenetic marks. STAT3 regulation was determined using expression data of untreated cells and cells after JAK2/STAT3 inhibition. The four papers constituting the thesis are preceded by an exposition of the biological, biotechnological and computational background that provides foundations for the papers. The overall results of this thesis are witness of the mutually beneficial relationship played by Bioinformatics in modern Life Sciences and Computer Science.
219

Perceived exertion relationships and prediction of peak oxygen uptake in able-bodied and paraplegic individuals

Al-Rahamneh, Harran Qoblan Mefleh January 2010 (has links)
Rating of Perceived Exertion (RPE) relates to how ‘hard’ or ‘easy’ an exercise feels. The Borg 6-20 RPE scale is the most widely used scale to estimate the overall, peripheral and central perception of effort. To date, there are a limited number of studies on the use and efficacy of perceived exertion in persons with spinal cord injury and/or disease. The findings from these studies are also equivocal. Therefore, the aims of this thesis were to assess: i) the relationship between the RPE and physical and physiological markers of exercise intensity during arm cranking exercise in able-bodied and individuals with spinal cord disease, ii) the efficacy of sub-maximal RPE values to predict peak oxygen uptake during arm cranking exercise in able-bodied and paraplegic individuals using different exercise protocols, iii) the scalar property of the RPE during arm cranking exercise in able-bodied and paraplegic individuals. To achieve these goals, the thesis has been broken down to a series of seven studies. In each of these studies, except study 6, a group of able-bodied and a group of paraplegic participants were recruited to asses these hypotheses. Paraplegic individuals had spinal cord injury with neurological levels at or below the sixth thoracic vertebra (T6) or flaccid paralysis as a result of poliomyelitis infection. These individuals were physically active and participated in sports like wheelchair basketball, weightlifting, wheelchair racing and table tennis at both professional and recreational levels. Able-bodied participants were healthy and free from pre-existing injuries and physically active but not arm-trained. There were strong relationships between the RPE and each of the physiological and physical indices of exercise intensity during arm cranking exercise regardless of group or gender. Peak oxygen uptake can be predicted with reasonable accuracy from sub-maximal oxygen uptake values elicited during a sub-maximal perceptually-guided, graded exercise test for paraplegic individuals but not for able-bodied participants. It has also been shown that peak oxygen uptake can be predicted from power output using the equation prescribed by the American College of Sports Medicine (ACSM, 2006). Furthermore, for able-bodied participants using estimation procedures, a passive process in which an individual is asked to rate how ‘hard’ or ‘easy’ an exercise feels, the ramp exercise test provided more accurate prediction of peak oxygen uptake compared to the graded exercise test. For paraplegic persons using estimation procedures, the graded exercise test provided more accurate prediction of peak oxygen uptake compared to the ramp exercise test. Finally, the scalar property of the RPE (i.e., similar proportions of time at a given RPE) was evident during arm cranking exercise regardless of group. In conclusion, the prediction of peak oxygen uptake from sub-maximal exercise tests would provide a safer environment of exercise testing. In addition, using a sub-maximal protocol would make peak oxygen uptake more available for sedentary and clinical population compared to the graded exercise test to volitional exhaustion. Prediction of peak oxygen uptake from power output using the ACSM equation would make the estimation of peak oxygen uptake more available for large groups of people. Similar proportions of time were observed at a given RPE regardless of group or exercise intensity. The early RPE responses will give an indicator for how long a participant is going to exercise. This has important implications for rehabilitation settings. Based on the RPE responses the tester or the observer can increase or decrease the work rate to enable the participant to exercise for the desired duration.
220

2D SPECTRAL SUBTRACTION FOR NOISE SUPPRESSION IN FINGERPRINT IMAGES

Dandu, Sai Venkata Satya Siva Kumar, Kadimisetti, Sujit January 2017 (has links)
Human fingerprints are rich in details called the minutiae, which can be used as identification marks for fingerprint verification. To get the details, the fingerprint capturing techniques are to be improved. Since when we the fingerprint is captured, the noise from outside adds to it. The goal of this thesis is to remove the noise present in the fingerprint image. To achieve a good quality fingerprint image, this noise has to be removed or suppressed and here it is done by using an algorithm or technique called ’Spectral Subtraction’, where the algorithm is based on subtraction of estimated noise spectrum from noisy signal spectrum. The performance of the algorithm is assessed by comparing the original fingerprint image and image obtained after spectral subtraction several parameters like PSNR, SSIM and also for different fingerprints on the database. Finally, performance matching was done using NIST matching software, and the obtained results were presented in the form of Receiver Operating Characteristics (ROC)graphs, using MATLAB, and the experimental results were presented.

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