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Solid-State Smart Circuit Breaker with Self-Resetting and Early Overload Detection for Residential Applications
No full textIn this thesis a solid-state smart breaker for 15A residential circuits is designed and tested. Having an embedded controller and being solid state allows for a plurality of features that would be impossible for a normal breaker. The primary novel feature explored here is a self-resetting that uses early overload detection to minimize the potential for damage when powering back on. Safe self-resetting would be especially useful for those with disabilities who may struggle to access and reset a breaker. The breaker is designed to be an easy, drop-in replacement for the existing Siemens QP-style breaker and can operate independently. The breaker measures power usage and quality and can have its parameters configured on the fly from an external controller. This is to allow an IoT-enabled master controller to add remote control and monitoring in the future. Thermal and electrical tests show the breaker meets or exceeds the requirements for standard 15A breakers in North America and was capable of early overload detection during self-resetting
Design and Analysis of an Isolated Resonant Pulsed DC-DC Buck-Boost Converter
No full textThis thesis entails the design, modeling, simulation, construction, and analysis of a new isolated DC-DC buck-boost converter with Zero-Current-Switching (ZCS) operation, continuous input current, and a low-side switch to simplify driving requirements. The proposed converter was designed to regulate a 5V output from an input range of 15V-18V, at a rated output power of 20W, and a switching frequency range of 90kHz-500kHz. Software simulations are performed to develop a mathematical model that describes the converter’s modes of operation, as well as the current and voltage waveforms of the resonant power components. Results from hardware experimentation confirm that the converter effectively provides the desired 5V output voltage at different loads and input voltage values. Furthermore, the converter operating at nominal input voltage and full load conditions yields an efficiency of 59.88% and a peak-to-peak input voltage ripple of 2.91%. Hardware results also verify the ZCS property of the proposed converter, but the output voltage peak-to-peak ripple exceeds the expected performance due to the presence of voltage overshoot. Potential solutions to the ripple issue are discussed and evaluated along with recommendations for future improvements. Overall, the results of the study demonstrate the potential of the proposed converter as an isolated alternative to the conventional buck-boost converter
A Heuristic Approach to Portrait Segmentation and Its Application to Synthetic Bokeh Generation
Get PDFSegmentation of portrait images is an important technique used to separate the foreground and background of an image. This separation of layers is useful for selectively applying post-processing techniques to enhance the quality of the image, such as blurring the background. Automatic portrait segmentation is a complex process that can be completed with a high degree of accuracy using deep learning with neural networks, but training and inference are often very computationally expensive. This thesis aims to take a heuristic approach to portrait segmentation by combining classical image processing and computer vision techniques into a solution that can be run on lower-cost hardware. This allows a simple smartphone to emulate the visually pleasing bokeh background blur effect seen in photos taken on DSLR cameras. This thesis implements a human segmentation workflow that sequentially addresses three key areas: facial skin, hair, and the torso. After a binary mask has been generated, a Gaussian kernel is applied to the background region to introduce the blur. AiSegment.com\u27s Human Matting Dataset and neural network output are used to evaluate the performance of the workflow, where the Intersection over Union (IoU) between masks is calculated. Across 40 test images, the percentage of images with an IoU greater than 0.75 (considered passing) was found to be 87.5% with an average IoU among passing results of 0.8619 and an average processing speed of 0.4263 seconds per image on the faster M1 Pro processor tested. These results show that the heuristic approach is a viable solution
Optimizing Biofungicide Use In Managing Winegrape Powdery Mildew On The Central Coast Of California
Get PDFGrapevine powdery mildew caused by the fungal pathogen Erysiphe necator is a persistent threat to wine grape production in California. While synthetic fungicides remain the primary management strategy, increasing concerns over pesticide resistance, environmental impact, and regulatory restrictions have driven interest in biofungicides as a sustainable alternative. However, their efficacy is inconsistent, requiring research into optimized application strategies, integration with synthetic fungicides, and their effects on disease suppression, grape yield, and fruit quality.
This two-year study (2023–2024) was conducted at two vineyard sites, Trestle Vineyard in the San Luis Obispo Coast AVA and a commercial vineyard in the Arroyo Grande Valley AVA. In each experimental trial, 14 treatments were tested, which included three biofungicides applied alone at three different intervals, weekly, biweekly, and based on powdery mildew risk assessment index (RAI), and in rotation with synthetic fungicides, a grower standard, and a non-treated control. The treatments were assessed by disease incidence and severity, grape yield, juice chemistry (Brix, pH, titratable acidity), and economic profit.
Field trials were conducted using a randomized complete block design, and the tested biofungicides contained the active ingredients extract of Reynoutria sachalinensis, Streptomyces lydicus Strain WYEC 108, and Bacillus subtilis Strain QST 713. Disease pressure was monitored using RAI, and an economic analysis was conducted to assess treatment viability based on input costs, application expenses, and revenue differences.
Results demonstrated that treatments with biofungicide-synthetic rotations provided disease suppression comparable to synthetic-only programs, particularly when applied at optimized intervals. Standalone biofungicide treatments exhibited variable efficacy, with greater disease suppression under moderate disease pressure but reduced effectiveness under high-pressure conditions. At Trestle Vineyard, refinements in application timing and a typical disease progression led to improved control in 2024 compared to 2023. In Arroyo Grande Valley, biofungicides performed better under moderate disease pressure but declined in effectiveness when disease pressure intensified, emphasizing the role of environmental conditions in treatment success.
Beyond disease suppression, biofungicide applications indirectly influenced grape chemistry, as improved disease control correlated with higher yield and balanced juice composition. Diseased clusters exhibited elevated °Brix and pH, suggesting stress-induced ripening, whereas healthier clusters maintained a more desirable sugar-acid balance, which is crucial for wine quality.
Economic analysis confirmed that integrated biofungicide-synthetic programs consistently provided strong disease control and financial returns, reinforcing their potential as sustainable tools for powdery mildew management. This study highlighted the importance of strategic application timing, environmental conditions, and disease pressure in optimizing biofungicide efficacy. By demonstrating that biofungicides can effectively contribute to disease management when integrated with synthetic programs, these findings support efforts to reduce synthetic fungicide reliance while maintaining vineyard productivity and fruit quality