37 research outputs found

    Optimal Rooftop Photovoltaic System Placement To Minimize Monthly Used Energy Costs For Households In Vietnam’s Cities And Towns

    Get PDF
    This study presents a strategy to stop paying monthly used energy costs for households in Vietnam’s cities and towns. To get there, the total energy cost acquired from the utility grid must equal the total extra energy supplied to the grid. In addition to the power consumption reduction from the grid for household cus- tomers, the extra energy produced by the rooftop photo- voltaic system (RPV) is sold back to the grid. This mechanism has effectively freed up the monthly en- ergy bill for individual customers. However, the op- timal rated power of the rooftop photovoltaic system (RPV) must first be determined. Two meta-heuristic algorithms, including the Coati optimization algorithm (COA) and the Osprey optimization algorithm (OOA), are implemented to solve the problem. The results obtained by the two algorithms are compared using different criteria. Through these comparisons, OOA completely outperforms COA regarding solution qual- ity and stabilization. For instance, OOA is the only method to reach the best optimal rated power of the RPV. Moreover, OOA is also more effective than COA with 50.17% on mean cost, 11.49% on maximum cost, and 17.06% on standard deviation. By using the solu- tion found by OOA, RPV not only fulfills the house- hold’s needs but also reduces the electric energy cost to zero. While evaluating a five-year operation period, the household can get the benefit of $3,635.64. So, using the RPV is very effective for reaching both economic and environmental benefits

    Finding optimal reactive power dispatch solutions by using a novel improved stochastic fractal search optimization algorithm

    Get PDF
    In this paper, a novel improved Stochastic Fractal Search optimization algorithm (ISFSOA) is proposed for finding effective solutions of a complex optimal reactive power dispatch (ORPD) problem with consideration of all constraints in transmission power network. Three different objectives consisting of total power loss (TPL), total voltage deviation (TVD) and voltage stabilization enhancement index are independently optimized by running the proposed ISFSOA and standard Stochastic Fractal Search optimization algorithm (SFSOA). The potential search of the proposed ISFSOA can be highly improved since diffusion process of SFSOA is modified. Compared to SFSOA, the proposed method can explore large search zones and exploit local search zones effectively based on the comparison of solution quality. One standard IEEE 30-bus system with three study cases is employed for testing the proposed method and compared to other so far applied methods. For each study case, the proposed method together with SFSOA are run fifty run and three main results consisting of the best, mean and standard deviation fitness function are compared. The indication is that the proposed method can find more promising solutions for the three cases and its search ability is always more stable than those of SFSOA. The comparison with other methods also give the same evaluation that the proposed method can be superior to almost all compared methods. As a result, it can conclude that the proposed modification is really appropriate for SFSOA in dealing with ORPD problem and the method can be used for other engineering optimization problems

    A hierarchical architecture for increasing efficiency of large photovoltaic plants under non-homogeneous solar irradiation

    Get PDF
    Under non-homogeneous solar irradiation, photovoltaic (PV) panels receive different solar irradiance, resulting in a decrease in efficiency of the PV generation system. There are a few technical options to fix this issue that goes under the name of mismatch. One of these is the reconfiguration of the PV generation system, namely changing the connections of the PV panels from the initial configuration to the optimal one. Such technique has been widely considered for small systems, due to the excessive number of required switches. In this paper, the authors propose a new method for increasing the efficiency of large PV systems under non-homogeneous solar irradiation using Series-Parallel (SP) topology. In the first part of the paper, the authors propose a method containing two key points: a switching matrix to change the connection of PV panels based on SP topology and the proof that the SP-based reconfiguration method can increase the efficiency of the photovoltaic system up to 50%. In the second part, the authors propose the extension of the method proposed in the first part to improve the efficiency of large solar generation systems by means of a two-levels architecture to minimize the cost of fabrication of the switching matrix

    EmbryosFormer: Deformable Transformer and Collaborative Encoding-Decoding for Embryos Stage Development Classification

    Full text link
    The timing of cell divisions in early embryos during the In-Vitro Fertilization (IVF) process is a key predictor of embryo viability. However, observing cell divisions in Time-Lapse Monitoring (TLM) is a time-consuming process and highly depends on experts. In this paper, we propose EmbryosFormer, a computational model to automatically detect and classify cell divisions from original time-lapse images. Our proposed network is designed as an encoder-decoder deformable transformer with collaborative heads. The transformer contracting path predicts per-image labels and is optimized by a classification head. The transformer expanding path models the temporal coherency between embryo images to ensure monotonic non-decreasing constraint and is optimized by a segmentation head. Both contracting and expanding paths are synergetically learned by a collaboration head. We have benchmarked our proposed EmbryosFormer on two datasets: a public dataset with mouse embryos with 8-cell stage and an in-house dataset with human embryos with 4-cell stage. Source code: https://github.com/UARK-AICV/Embryos.Comment: Accepted at WACV 202

    Validation of Mesocyclops (Copepoda) and community participation as an effective combination for Dengue control in Northern Vietnam

    Get PDF
    The “Programme Meso-Vietnam” was implemented in Vietnam from October 2007 to December 2010 to reduce dengue and dengue hemorrhagic fever incidence and to improve the quality of life in the four project communes. This dengue control project was based on biological control using Mesocyclops, a larvivorous micro-crustacean, as well as on the establishment of a strong community involvement to educate the population on dengue transmission and to reduce Aedes breeding by removal of containers. During three years, a network of collaborators was responsible for introducing Mesocyclops in all the containers defined as key breeding-sites, and regular activities such as community training workshops, school programmes, clean-up campaigns and health promotion through IEC programmess were performed. To make this programme sustainable, local leadership has been strengthened as well. The use of these larvivorous micro-crustaceans as a biological control strategy against dengue over the medium and long term, when combined with community participation and effective health promotion, demonstrated a significant reduction in dengue vector populations and dengue cases.  In Vietnam, this study reconfirms that there is an ecological alternative to systematic use of insecticides to control dengue vector population. (Abstract word count: 186)Le " Programme Meso-Vietnam " a été mis en œuvre au Vietnam entre octobre 2007 et décembre 2010. Ce programme vise à réduire l'incidence de la dengue et de la fièvre hémorragique de la dengue et à améliorer la qualité de vie dans les quatre communes sélectionnées pour le projet. Ce projet de lutte contre la dengue était basé sur un contrôle biologique assuré par des Mésocyclopes, micro-crustacés larvivores, et sur l'établissement d'une forte implication de la communauté pour éduquer la population sur la transmission de la dengue et pour réduire la reproduction des moustiques Aedes par élimination des conteneurs leur servant de site de ponte. Pendant trois ans, un réseau de collaborateurs a été chargé d'introduire des Mésocyclopes dans tous les conteneurs définis comme des sites de reproduction clés, et des activités régulières telles que des ateliers de formation communautaires, des programmes scolaires, des campagnes de nettoyage et des activités de promotion de la santé via les programmes IEC ont été mises en place. En outre, pour assurer la pérennité de ce programme, le leadership local a été renforcé. L'utilisation de ces micro-crustacés larvivores comme stratégie de contrôle biologique de la dengue à moyen et long terme, associée à une participation communautaire et à une promotion efficace de la santé, a permis d'aboutir à une réduction significative des populations vecteurs de la dengue et des cas de dengue. Au Vietnam, cette étude confirme une fois de plus qu'il existe une alternative écologique à l'utilisation systématique d'insecticides pour lutter contre les vecteurs de la dengue.El “Programa Meso-Vietnam” se implementó en Vietnam desde octubre de 2007 hasta diciembre de 2010 para reducir la incidencia del dengue y la fiebre hemorrágica del dengue y para mejorar la calidad de vida en los cuatro municipios del proyecto. Este proyecto de control del dengue se basaba en el control biológico usando Mesocyclops, un microcrustáceo larvívoro, así como en el establecimiento de una fuerte implicación comunitaria para educar a la población sobre la transmisión del dengue y para reducir la cría de Aedes mediante la eliminación de recipientes. Durante tres años, una red de colaboradores fue responsable de la introducción de Mesocyclops en todos los recipientes definidos como sitios clave para la cría, y se realizaron actividades regulares tales como talleres de formación comunitaria, programas escolares, campañas de limpieza y promoción de la salud a través de programas de IEC. Para hacer sostenible este programa, también se reforzó el liderazgo local. El uso de estos microcrustáceos larvívoros como estrategia de control biológico contra el dengue a medio y largo plazo demostró una reducción significativa de las poblaciones de vectores del dengue y los casos de dengue cuando se combinaba con la participación comunitaria y la promoción eficaz de la salud. En Vietnam, este estudio vuelve a confirmar que existe una alternativa ecológica al uso sistemático de insecticidas para controlar la población de vectores del dengue

    Did COVID-19 challenge the volatility of the sustainable stock market? An examination of Asian market

    Get PDF
    The coronavirus outbreak at the end of 2019 hit many aspects of the financial sector, especially the stock market. This research examines the impacts of the COVID-19 pandemic, exchange rates, gold price, and the Brent oil price on the volatility of the Sustainable Stock Market in Asia. A quantitative research method is applied using average monthly panel data from March 2020 to April 2022, covering the COVID-19 pandemic period. We employed panel regressions and applied Feasible Generalized Least Square (FGLS) in the analysis, which also serves as a robustness check. This study contributes to the literature by examining the variables significantly impacting sustainable investing, particularly in the sustainable stock market. Empirical results find that COVID-19, gold price and the exchange rate have negatively affected sustainable stock market volatility, while the Brent oil price has a positive impact on the volatility of the sustainable stock market. This study's recommendations infer that both investors and managers should consider the increase of COVID-19 cases and frequency-varying exchange rates to the USD on the Asian sustainable stock market volatility

    Efficacy of Adding Oral Simvastatin to Topical Therapy for Treatment of Psoriasis: The Vietnamese Experience

    Get PDF
    BACKGROUND: Psoriasis, the prevalence of which ranges from 2% to 3% of the general population, has been recently recognised as not only a chronic inflammatory skin disorder but also an immunometabolic systemic disease. Dyslipidemia is one of the most important comorbidities of psoriasis. Statins, frequently used as anti-hyperlipidemic agents, may be beneficial in the treatment of several autoimmune diseases, including psoriasis, due to their anti-inflammatory and immunomodulatory characteristics. Hence, we hypothesised that using this medication was not only beneficial for reducing hyperlipidemia but also improving psoriatic conditions. AIM: We conducted a study to determine the prevalence of dyslipidemia in psoriatic patients as well as whether the addition of statins (simvastatin prescribed forms) to standard topical antipsoriatic treatment can improve skin lesions in psoriatic patients. METHODS: A group of 128 psoriatic patients and 128 healthy controls who were matched with the patients regarding ethnicity, age, and sex were enrolled, and their lipid concentrations were determined. Furthermore, sixty patients were randomly selected from the former group and divided into two treatment subgroups to evaluate the effect of statins on the severity of psoriasis using the PASI score. RESULTS: We found that the rate of dyslipidemia in the patient group was significantly higher than in the healthy group (53.9% versus 21.9%, p < 0.001), particularly the triglyceride concentration (1.86 ± 1.17 versus 1.43 ± 0.79 mg/dL, p < 0.001). Also, the PASI score reduction in the simvastatin-treated subgroup was significantly different from that in the placebo-treated one after eight weeks of therapy (8.63 ± 4.78 versus 5.34 ± 3.59, p < 0.01). CONCLUSION: This study showed that simvastatin might play a role in controlling hyperlipidemia and in turn decrease the PASI score in psoriatic patients

    TextANIMAR: Text-based 3D Animal Fine-Grained Retrieval

    Full text link
    3D object retrieval is an important yet challenging task, which has drawn more and more attention in recent years. While existing approaches have made strides in addressing this issue, they are often limited to restricted settings such as image and sketch queries, which are often unfriendly interactions for common users. In order to overcome these limitations, this paper presents a novel SHREC challenge track focusing on text-based fine-grained retrieval of 3D animal models. Unlike previous SHREC challenge tracks, the proposed task is considerably more challenging, requiring participants to develop innovative approaches to tackle the problem of text-based retrieval. Despite the increased difficulty, we believe that this task has the potential to drive useful applications in practice and facilitate more intuitive interactions with 3D objects. Five groups participated in our competition, submitting a total of 114 runs. While the results obtained in our competition are satisfactory, we note that the challenges presented by this task are far from being fully solved. As such, we provide insights into potential areas for future research and improvements. We believe that we can help push the boundaries of 3D object retrieval and facilitate more user-friendly interactions via vision-language technologies.Comment: arXiv admin note: text overlap with arXiv:2304.0573

    Adaptive Controller of the Major Functions for Controlling a Drive System with Elastic Couplings

    No full text
    In any drive system, there are always couplings between the motor and the load. Since the hardness of these couplings is finite, they have elastic properties, causing unwanted vibration and negatively affecting system quality. When the couplings are springs with nonlinear characteristics, control is particularly difficult because it is very difficult or impossible to define the parameters of the controlled object. To solve these difficulties, this article proposes an adaptive controller of the major functions for controlling a drive system with nonlinear elastic couplings of unidentified parameters. For the proposed control system, we measure the response speed of the object, use a Luenberger observer to estimate the state variables of the system, and use an adaptive controller to control the system. The experimental results demonstrate that the control object can be controlled without knowing the parameters: the control quality of the system is very good, close to that of a system with a hard coupling, there is no vibration or overshoot, and the transition time is small

    Wprowadzenie nowej aplikacji do symulacji i optymalizacji długoterminowego planowania produkcji w kamieniołomach wapienia

    No full text
    Long-term limestone quarry production planning is essential to maintain the supply to the cement plant. In which, quarry planners usually attempt to fulfil the complicated calculations, which ensure a consistent supply of raw materials to the cement plant while guaranteeing technical and operational parameters in mining. Traditionally, the calculations are done on a spreadsheet or by trial and error procedure resulting in high additive cost and an increase in product variability. Modern quarry management relies on block models and mathematical algorithms integrated into the software to optimize the long-term limestone quarry production planning. However, this method is potentially sensitive to geological uncertainty in block modelling, resulting in the deviation of the supply production of raw materials. The need for mining intelligently raw material is, therefore, crucial and an increasing issue in the cement industry. In this research, a new simulation and optimization software application called Quarrier is introduced, allowing quarry planners to address the conflicting requirements of long-term limestone quarry production planning while forecasting and mitigating the effects of geological uncertainty on the supply of raw materials for the cement plant. The benefits of this software are demonstrated through a limestone quarry in Vietnam.Długoterminowe planowanie produkcji w kamieniołomie wapienia ma zasadnicze znaczenie dla utrzymania dostaw do cementowni. W którym planiści kamieniołomów zazwyczaj starają się wykonywać skomplikowane obliczenia, które zapewniają stałe dostawy surowców do cementowni przy jednoczesnym zagwarantowaniu parametrów techniczno-eksploatacyjnych w górnictwie. Tradycyjnie obliczenia są wykonywane manualnie lub metodą prób, co skutkuje wysokimi kosztami dodatków i zwiększeniem zmienności produktu. Nowoczesne zarządzanie kamieniołomami opiera się na modelach blokowych i algorytmach matematycznych zintegrowanych z oprogramowaniem w celu optymalizacji długoterminowego planowania produkcji w kamieniołomie. Jednak metoda ta jest potencjalnie wrażliwa na niepewność geologiczną w modelowaniu bloków, co skutkuje odchyleniem w zakresie dostaw surowców do produkcji. Potrzeba inteligentnego wydobywania surowca jest zatem kluczowym i rosnącym problemem w przemyśle cementowym. W ramach tych badań wprowadzono nową aplikację do symulacji i optymalizacji o nazwie Quarrier, umożliwiającą planistom kamieniołomów sprostanie sprzecznym wymaganiom długoterminowego planowania produkcji kamieniołomu wapienia, jednocześnie prognozując i łagodząc skutki niepewności geologicznej na dostawy surowców do cementu. roślina. Korzyści płynące z tego oprogramowania są widoczne w kamieniołomie wapienia w Wietnamie
    corecore