Convolutional Neural Network (CNN) is a widely used deep learning framework and is applied in the field of face recognition achieving outstanding results. Macropixel Comparison Approach is a shallow mathematical approach that recognizes face by comparing original pixel blocks of face images. In this thesis, we are inspired by ideas of the currently popular deep neural network framework and introduce two features into the mathematical approach: deep overlap and weighted filter. The aim is exploring if the idea of deep learning could benefit mathematical method which might extends the scope of face recognition research. Results from our experiments show that the new proposed approach achives markedly better recognition rates than the original macropixel method.
The direct discharge of tannery waste and effluent could result in severe chromium (Cr) contamination in soils. This study focused on the remediation of Cr-contaminated soil via co-pyrolysis with rice straw. The influence of co-pyrolysis temperature, rice straw / soil mixing ratio and reaction time on Cr immobilization were investigated. Compared to untreated soil, the leachable Cr and total Cr(VI) in co-pyrolyzed soil were decreased by up to 95 % and 86 %, respectively. With increasing temperature and rice straw addition, the leachable Cr and total Cr(VI) were reduced. Reaction time did not show a significant effect on Cr immobilization. The time-varying desorption test indicated that the equilibrium amount of released Cr in various extractants was inhibited by co-pyrolysis. The Simple Bioaccessibility Extraction Test also showed that the bioaccessible Cr in the gastric phase was decreased after co-pyrolysis. The results suggested that co-pyrolysis was beneficial on Cr immobilization.
Local scour around piers and abutments is one of the main causes of the collapse of many bridges constructed inside rivers. Many researchers have conducted various studies to predict the maximum depth of a scour hole around bridge piers and abutments. However, most of them have been done in small-scale laboratory flumes and specifically for the open channel condition. Besides, most of the existing research on bridge piers uses uniform sediment which is not an appropriate representative of natural river systems. This can result in excessively conservative design values for scour in low risk or non-critical hydrologic conditions. The most severe cases of bridge pier scouring occur in cold regions when the surface of water turns into ice in which, an additional boundary layer is being added to the water surface, which leads to significant changes in the flow field and scour pattern around bridge piers. Ice cover also causes the maximum flow velocity to move closer to the channel bed.
Innovative technologies to combat environmental pollution are a significant part of sustainability research due to their increasing economic and environmental impact. The present biological process-based research study described herein was conducted in three phases. It investigated the effects of rhamnolipid-enhanced soil washing (phase 1), bioremediation treatment using indigenous microorganisms (phase 2), and the effect of four specific environmental and nutritional conditions (phase 3) on the biodegradation of petroleum hydrocarbons (PHC) in drill cuttings and petroleum-contaminated soil obtained from sites in northeastern British Columbia. For phase 1, maximum PHC reduction recorded for total petroleum hydrocarbon (TPH) and the petroleum hydrocarbon fractions- F2, F3 and F4 fractions was 58.5%, 48.4%, 63.5% and 59.8% respectively for petroleum-contaminated soil, and 76.8%, 85.4%, 71.3% and 76.9% respectively for drill cuttings. In phase 2, maximum PHC reduction of TPH, F2 and F3 fractions was 94.9%, 98.8% and 94.0% respectively for petroleum-contaminated soil and 82.6%, 94.9% and 59.5% respectively for drill cuttings following 50 days of rhamnolipid-mediated biodegradation treatment. Results from experiments conducted in phase 3 confirmed the importance of oxygen availability in biodegradation and indicated the inhibitory effects of excessive addition of biosurfactants and nutrients to hydrocarbon biodegradation treatments. Promising TPH degradation results were observed in conditions that normally slow down biodegradation. TPH degradation of 59.0%, 59.8% and 56.7% were observed in experiments conducted at an average temperature of ‒7.46 °C, and in waterlogged and air-tight conditions respectively. These results provide important insight on rhamnolipid-mediated biodegradation and indicate the high potential of rhamnolipid washing and bioremediation treatments as a combined approach to reduce PHC to levels within regulatory standards.
Westerly wind bursts (WWBs), usually occurring in the tropical Pacific region, play a vital role in El Niño–Southern Oscillation (ENSO). In this study, we use a hybrid coupled model (HCM) for the tropical Pacific Ocean-atmosphere system to investigate WWBs impact on ENSO. To achieve this goal, two experiments are performed: (a) first, the standard version of the HCM is integrated for years without prescribed WWBs events; and (b) second, the WWBs are added into the HCM (HCM-WWBs). Results show that HCM-WWBs can generate not only more realistic climatology of sea surface temperature (SST) in both spatial structure and temporal amplitudes, but also better ENSO features, than the HCM. In particular, the HCM-WWBs can capture the central Pacific (CP) ENSO events, which is absent in original HCM. Furthermore, the possible physical mechanisms responsible for these improvements by WWBs are discussed.
