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[IEEE 2018 IEEE 3rd International Conference on Image, Vision and Computing (ICIVC) - Chongqing (2018.6.27-2018.6.29)] 2018 IEEE 3rd International Conference on Image, Vision and Computing (ICIVC) - Improved Differential Evolution with Parameter Adaption Based on Population Diversity
摘要： The differential evolution algorithm is an important branch of the bionic intelligent computation, which uses the Darwinian population's evolutionary principle: survival of the fittest and survival of the fittest. Due to the simple implement and few parameters, many researchers have invested into the study of the algorithm and proposed a large number of differential evolution variants. For the existing differential evolution algorithm, once the size of the population is determined, the size of the search range is fixed. Based on the global diversity of population, we focus on controlling the value of the search parameters p. In the proposal, after normalizing the population diversity, each individual will select its unique search scope according to the diversity conditions. Therefore, the proposed method can balance between the global search and the local search. According to our extensive experimental results on various benchmark functions, the proposed method outperform other compared advanced algorithms.
关键词： population diversity,SHADE,differential evolution
更新于2025-09-23 15:22:29
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Photovoltaic panels as shading resources for livestock
摘要： Based on our search, we believe that this is the first paper to evaluate the use of photovoltaic panels as shade resources for livestock. Photovoltaic panels can provide artificial shades to protect livestock against intense solar radiation while serving as a clean energy source, reducing CO2 emission, and providing an additional source of income to farmers. These benefits foster sustainable livestock farming practices. In this study, we (1) determined livestock shade preference for photovoltaic panels and the classical 80%-blockage cloth material, and (2) quantified the reduction in radiant heat load provided by these shade structures. To determine the shade preference, the behavior of five Corriedale lambs and six Corriedale ewes were observed in a paddock with two shade structures (one with photovoltaic panels and another with an 80%-blockage cloth). The following behavioral activities were determined using the instantaneous scan sampling method each 10-min from 07:00h to 17:00h: grazing, ruminating, idling, lying, standing, under the sun, under the shade from photovoltaic panels, and under the shade from cloth. To correlate animal behavior with environmental conditions and to quantify the reduction in radiant heat load provided by these shade structures, the following meteorological variables were recorded: solar radiation (total and short-wave), air temperature, relative humidity, wind speed, and black-globe temperature (in the shades and in the sun). We observed that the animals spent less than 1% of their time under the shade from cloth compared to 38% under the shade from photovoltaic panels and 61% exposed to the sun. Sheep preference for shade projected by photovoltaic panels might be explained by the reduced radiant heat load (approximately lower by 40 W m-2) compared to that from the cloth. When the intensity of solar radiation increased from 250 to 850 W m-2, the time the animals spent outside the shades decreased from 96.7 ± 3.6 % to 30.2 ± 6.3 %, which was coupled with a similar increase in the time spent in the shade from photovoltaic panels (from 13.0 ± 3.3 % to 69.3 ± 6.2 %). For the same increase in solar radiation, the energy generated (integrated over 5-min) by the photovoltaic panels increased from 38.8 ± 5.9 to 197.9 ± 3.8 kWh. Over a period of one year, an electric energy of 5.19 MWh (monthly average of 432.33 kWh) was generated and 2.77 tons of CO2 were not emitted to the atmosphere. In economic terms, the electric energy generated in one year was equivalent to a saving of $740.
关键词： photovoltaic panel,tropical conditions,livestock,shade,solar irradiance
更新于2025-09-23 15:19:57
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Comparison of accuracies of an intraoral spectrophotometer and conventional visual method for shade matching using two shade guide systems
摘要： Background and Objectives: This in vitro study compared the shade matching abilities of an intraoral spectrophotometer and the conventional visual method using two shade guides. The results of previous investigations between color perceived by human observers and color assessed by instruments have been inconclusive. The objectives were to determine accuracies and interrater agreement of both methods and effectiveness of two shade guides with either method. Methods: In the visual method, 10 examiners with normal color vision matched target control shade tabs taken from the two shade guides (VITAPAN Classical? and VITAPAN 3D Master?) with other full sets of the respective shade guides. Each tab was matched 3 times to determine repeatability of visual examiners. The spectrophotometric shade matching was performed by two independent examiners using an intraoral spectrophotometer (VITA Easyshade?) with five repetitions for each tab. Results: Results revealed that visual method had greater accuracy than the spectrophotometer. The spectrophotometer; however, exhibited significantly better interrater agreement as compared to the visual method. While VITAPAN Classical shade guide was more accurate with the spectrophotometer, VITAPAN 3D Master shade guide proved better with visual method. Conclusion: This in vitro study clearly delineates the advantages and limitations of both methods. There were significant differences between the methods with the visual method producing more accurate results than the spectrophotometric method. The spectrophotometer showed far better interrater agreement scores irrespective of the shade guide used. Even though visual shade matching is subjective, it is not inferior and should not be underrated. Judicious combination of both techniques is imperative to attain a successful and esthetic outcome.
关键词： spectrophotometer,shade guide,Accuracy,dental shade matching,repeatability
更新于2025-09-19 17:15:36
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A High Performance Shade-Tolerant MPPT Based on Current-Mode Control
摘要： This paper proposes a high performance shade-tolerant maximum power point tracking (STMPPT) technique for DC-DC converter stage of photovoltaic (PV) applications. The average current-mode control (ACMC) is utilized to regulate the PV array current using two feedback control loops. The current-mode control is a superior scheme in control of DC-DC power electronic converters. The proposed STMPPT technique operates in two modes. The ACMC with the perturb and observe (P&O) MPPT algorithm functions in a local MPPT (LMPPT) mode under normal irradiance condition. When the PV array is likely to be partially shaded, a global MPPT (GMPPT) subroutine effectively scans the PV profile to optimize the PV system operation. This is achieved by implementing simple innovations to the ACMC-based P&O algorithm. The innovations benefit from useful observations of I-V characteristics. The idea behind using the I-V characteristics is to significantly reduce the search space, make the algorithm independent of shading conditions and PV array configuration, and inherently recognize the occurrence of partial shading conditions (PSCs). The proposed STMPPT technique enables very fast and reliable tracking of global maximum power point (GMPP). In addition, it can stably work under dynamic environmental change without losing correct sense of tracking direction. Its simplicity and independency would offer a viable solution for PV converter products. Simulation and experimental performance assessments are presented under different operating conditions that could happen in outdoor PV installations.
关键词： perturb and observe algorithm,partial shading condition,Photovoltaic system,current-mode control,shade-tolerant maximum power point tracking
更新于2025-09-19 17:15:36
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Performance enhancement of Hybrid interconnected Solar Photovoltaic array using shade dispersion Magic Square Puzzle Pattern technique under partial shading conditions
摘要： During Partial Shading (PS) condition, Solar Photovoltaic (SPV) array exhibits multiple peaks in both Power-voltage and Current-voltage characteristics, leading to Mismatch Power Losses (MPL). Overcoming the losses, enhancing power and performance improvement of SPV array during PS conditions is a challenging task. MPL due to PS condition, not only depend on the shaded area, but also on SPV array Interconnections and Shading Patterns. The present investigation aims to enhance the output power of SPV array subjected to PS conditions. Studies are initially performed on eight combinations of SPV array test panel interconnections. Results obtained imply improved performance of the ‘Proposed New Reconfigured Hybrid interconnected array’ under four defined different typical partial shading conditions. Also, performance of ‘Proposed New Hybrid interconnected array’ with ‘Shade Dispersion Magic Square Puzzle Pattern’ technique applied is shown to be superior, compared with either SUDUKO or ODD-EVEN shade dispersion technique.
关键词： Shade Dispersion Magic Square Puzzle Pattern (SDMSPP),Solar Photovoltaic (SPV),Hybrid Interconnections,Partial Shading (PS),Power Enhancement
更新于2025-09-16 10:30:52
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An Improved Particle Swarm Optimization Algorithm Suitable for Photovoltaic Power Tracking Under Partial Shading Conditions
摘要： The partial shading of a photovoltaic array repeatedly occurs in the natural environment, which can cause a failure of a conventional maximum power point tracking (MPPT) algorithm. In this paper, the convergence conditions of the standard particle swarm optimization (PSO) algorithm are deduced by the functional analysis, and then the influence of the random variables and inertia factor of the algorithm on the trajectory in the particle swarm optimization is analyzed. Based on the analysis results, an improved particle swarm optimization (IPSO) algorithm, which adopts both global and local modes to locate the maximum power point, is proposed. Compared to the standard PSO algorithm, in the improved PSO algorithm, many random and interfered variables are removed, and the structure is optimized significantly. The proposed algorithm is first simulated in MATLAB to ensure its capability. The feasibility of the approach is validated through physical implementation and experimentation. Results demonstrate that the proposed algorithm has the capability to track the global maximum power point within 3.3 s with an accuracy of 99%. Compared with five recently developed Global MPPT algorithms, the proposed IPSO algorithm achieved better performance in the maximum power tracking in the partial shading conditions.
关键词： partial shade,particle swarm optimization,Maximum power point tracking,photovoltaic array
更新于2025-09-11 14:15:04
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Proof of concept for a novel and smart shade resilient photovoltaic module
摘要： In this study, the performance of a shade resilient smart module is studied under a dynamic shading pattern. A smart module architecture is developed to mitigate the non-linear shading effect on the module performance. Partial shading decreases the output current of the shaded cells and affects the unshaded cells’ output power. After distributing the module cells into small groups, based on a least square support vector machine optimisation method, DC–DC buck converters compensate the decreased current levels, by adjusting the output current and voltage level from any individual group of cells. The system is simulated in the MATLAB Simulink environment, and the output results are presented. Results show that the module performs efficiently and output power of the unshaded groups of cells never decreased because of the effect of shading on the other groups. Additionally, the maximum output power is harvested from all groups simultaneously. Prototype hardware is designed and built to implement the proof of concept. The real-time results of hardware testing show that the smart module performs as expected and mitigates partially shaded conditions by extracting maximum power from each group, regardless of other groups shading condition.
关键词： least square support vector machine,dynamic shading pattern,MATLAB Simulink,shade resilient photovoltaic module,DC–DC buck converters
更新于2025-09-11 14:15:04
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Performance enhancement by shade dispersion of Solar Photo-Voltaic array under continuous dynamic partial shading conditions
摘要： Partial shading adversely affects the output parameters of the Solar Photo-Voltaic (SPV) array because it causes shading of some panels and at the same time, other panels in the array remain unshaded. This also hinders the performance of SPV Array by causing multiple peaks in the voltage-power characteristics and abrupt changes in the row current. In this work, conventional Total Cross-Tied (TCT) panels are reconfigured based on the Arrow Sudoku (AS) puzzle pattern. This reconfiguration minimizes the mismatch of current between the rows. The physical locations of shaded and unshaded panels are changed in this reconfiguration technique, without altering their electrical connections. This reconfiguration can dodge the requirement of complex maximum power point tracking algorithms. The performance of the proposed approach is investigated in terms of maximum output power, mismatch power loss and utility factor. A comprehensive analysis of the proposed reconfiguration for different continuous dynamic partial shading conditions like top to bottom, diagonal and left to right shading, proves its efficacy. The outperforming nature of the proposed approach with respect to the existing state-of-art approaches for all cases of the partial shading conditions provides apparent evidences in support of its utility.
关键词： Arrow Sudoku (AS),Partial Shading,Shade dispersion,Array configurations,Power generation
更新于2025-09-10 09:29:36
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The Effect of Light Intensity and Temperature on Flowering and Morphology of Potted Red Firespike
摘要： Red ?respike (Odontonema strictum) is a tropical ?owering plant that was selected as a potential ?owering potted plant for its attractive red ?oral spikes. The objective of this study was to evaluate how light intensity, photoperiod, and temperature affect the growth and ?owering of ?respike. In Experiment 1, plants were grown under 0%, 45%, or 65% shade and two photoperiod conditions; long-day (LD = ≥14 h) and short-day (SD = 9 h), for 16 weeks. Plants grown under 45% shade + LD were tallest at 35.9 cm, while plants grown under 65% shade + SD were shortest at 22.8 cm. During the ?nishing stage, the number of in?orescences increased when plants were grown under 45% shade + SD, 45% shade + LD, and no shade, with 6, 7, and 9 in?orescences, respectively. In addition, the ?rst open ?ower was observed in the 0% shade group (control) 92 days after starting the experiment. The time to ?rst open ?ower increased when the plants were grown under 65% shade, either under SD or LD. In Experiment 2, plants were grown in controlled environment growth chambers with average daily temperatures of 15, 25, or 35 ?C and an irradiance of 200 μmol·m?2·s?1 for 9 h per day. Plants grown at 25 ?C were the tallest and had the largest leaf area. Plants grown at 15 and 35 ?C had 28% and 22% less leaf area, respectively. The average number of in?orescences in plants grown at 25 ?C was 1.6, while no in?orescence development was observed in plants grown at 15 or 35 ?C by the termination of the experiment. There were no differences between plant growth index or branch number in response to temperature. Under the experimental conditions tested, the most rapid and uniform ?owering of ?respike occurred when plants were grown under no shade or at 25 ?C.
关键词： shade,irradiance,Odontonema strictum,photoperiod,short-day
更新于2025-09-04 15:30:14