Shading Function Research Articles

Theoretical and numerical simulation to control the wideband three-dimensional interfering noise by the broadband constant beam pattern method for a spherical array

The broadband constant beam pattern (CBP) spherical array synthesis theory is applied to suppress or to cancel wideband three-dimensional interfering noise sources by implanting zeros in the array's original synthesized shading function. This modified array angular shading function can be expanded by a series of spherical harmonics that will converge to the beam pattern in the far-field such that the created nulls are in the wideband interfering noise source directions per the CBP theory where the ratio of the spherical array radius to the operating frequency wavelength is large. The simulated numerical examples given for this wideband noise source suppression method demonstrate that a broadband CBP performance is maintained for the spherical array with a Legendre polynomial shading function, the classic Dolph–Chebyshev shading function, or a combination. With the CBP design, one set of the real shading functions works for all frequencies in the array's operating band to cancel or to suppress three-dimensional wideband interfering noise sources.

Evaluasi Fungsional Dan Estetika Pohon Pada Lanskap Jalan Uluwatu I, Jimbaran

Functional and Aesthetic Evaluation of Trees in the Road Landscape of Uluwatu I, Jimbaran Street. Uluwatu I, Jimbaran street must have a road landscape that can provide comfort and create high beauty forroad users to support tourism infrastructure on Uluwatu I, Jimbaran street. Therefore, this study aims toevaluate the functional and aesthetic value of road landscape trees. The method used is the observationmethod. There are two aspects of tree function that are assessed, namely the shade function and the pollutioncontrol function. In the assessment of all aspects of tree function, segment 2 received the highest percentageof assessment (64.6%). Each function has an average fulfillment of 54.1% for the shading function and 51.5%for the pollution control function, which is included in the medium category. For aesthetic value, in landscapephotos of similar tree groups there are only two landscape photos that fall into the category of high aestheticvalue, namely landscape photos 3 (segment 1) and landscape photos 7 (segment 4). In the mixed tree grouplandscape photo, there is only one landscape photo that is included in the high aesthetic value category, namely landscape photo 8 (segment 4). Therefore, intensive care is needed for young trees, so that tree height, branch height above the ground and maximum canopy shape can reach the ideal value. Adding a layer of plants, also adding tree planting to create a road landscape with high functional and aesthetic value.

Retractable roof module with photovoltaic panel as small solar power plant

The use of building-integrated photovoltaic (PV) systems in the form of retractable roofs is an alternative option to existing installations without tracking systems (NT) or horizontal single-axis tracking systems (HSAT). This paper presents a retractable roofing module intended for the installation of PV panels. The main objective of this study is to identify modern solutions for these systems in terms of geometry and kinematics, which would allow the displacement of the roof slopes to follow the trajectory of the Sun during the day. This study is based on the parametric modelling and virtual prototyping of engineering objects. A moveable roof module is obtained, which, in addition to its function of shading and protection from rainfall, serves as a small movable solar power plant. The structure of the roof module is based on the construction of a mechanism comprising three revolute kinematic pairs and one prismatic kinematic pair, whose movement is strictly defined. The roof comprised three moving slopes of the same length. One of the slopes is designed for the installation of a PV panel; it moves according to the Sun to obtain maximum energy gains. For an adopted PV panel length of 1.0a, the maximum roof covering space is 2.69a. An analysis of the natural lighting for the panel following the Sun was performed, and the angle of inclination with respect to the horizontal plane was determined. The inclination of the panel ranges from +80º to –75º. In the case analysed, the HSAT delivers approximately 16% more energy than the NT system. The adaptation of retractable roofs with PV panels enables the optimal use of space around buildings, which are occupied by fixed or moveable installations with PV panels.

Multirate Shading with Piecewise Interpolatory Approximation

AbstractEvaluating shading functions on geometry surfaces dominates the rendering computation. A high‐quality but time‐consuming estimate is usually achieved with a dense sampling rate for pixels or sub‐pixels. In this paper, we leverage sparsely sampled points on vertices of dynamically‐generated subdivision surfaces to approximate the ground‐truth shading signal by piecewise linear reconstruction. To control the introduced interpolation error at runtime, we analytically derive an L∞ error bound and compute the optimal subdivision surfaces based on a user‐specified error threshold. We apply our analysis on multiple shading functions including Lambertian, Blinn‐Phong, Microfacet BRDF and also extend it to handle textures, yielding easy‐to‐compute formulas. To validate our derivation, we design a forward multirate shading algorithm powered by hardware tessellator that moves shading computation at pixels to the vertices of subdivision triangles on the fly. We show our approach significantly reduces the sampling rates on various test cases, reaching a speedup ratio of 134% ~ 283% compared to dense per‐pixel shading in current graphics hardware.

Ecosystem services from coffee agroforestry in Central America: estimation using the CAF2021 model

The goal of sustainable coffee production requires multiple functions from agroforestry systems. Many are difficult to quantify and data are lacking, hampering the choice of shade tree species and agronomic management. Process-based modelling may help quantify ecosystem services and disservices. We introduce and apply coffee agroforestry model CAF2021 (https://doi.org/10.5281/zenodo.5862195). The model allows for complex systems with up to three shade tree species. It simulates coffee yield, timber and fruit production by shade trees, soil loss in erosion, C-sequestration, N-fixation, -emission and -leaching. To calibrate the model, we used multivariate data from 32 different treatments applied in two long-term coffee agroforestry experiments in Costa Rica and Nicaragua. Without any further calibration, the model was then applied to agroforestry systems on 89 farms in Costa Rica and 79 in Guatemala where yields had been reported previously in farmer interviews. Despite wide variation in environmental and agronomic conditions, the model explained 36% of yield variation in Costa Rica but only 15% in Guatemala. Model analysis quantified trade-offs between yield and other ecosystem services as a function of fertilisation and shading.

Theoretical and numerical simulation to control the wideband interfering noise by the broadband constant beam pattern method for a cylindrical array.

The broadband azimuthal constant beam pattern (CBP) cylindrical array synthesis theory is applied to suppress or to cancel wideband interfering directional noise sources on this plane by implanting zeros in the array's original synthesized shading function. This modified array shading function can be expanded by Fourier cosine and sine series, which are converged to the beam pattern in the far-field such that the created nulls (or reduced-response beam sidelobes) are in the wideband interfering noise source directions per the CBP theory for the large ratio of the cylindrical array radius to the operating frequency wavelength. The simulated numerical examples given for this wideband noise source suppression method for modified Legendre polynomial, classic Dolph-Chebyshev, and Taylor shading functions maintain a broadband CBP performance in the azimuthal plane for a cylindrical array. With the CBP design, one set of the real shading functions works for all frequencies in the array's operating band to cancel or to suppress wideband interfering noise sources.

AUTOMATIC TEXTURE MAPPING METHOD FOR 3D MODELS TO CIRCUMVENT OCCLUSION THROUGH 3D SPATIAL THROUGH-VIEW RELATIONSHIPS BETWEEN IMAGES,MODELS, AND POINT CLOUDS

Abstract. Photorealistic 3D models play an important role in various applications related to smart cities. Texture mapping plays a crucial role as the last step of 3D reconstruction. The texture of the model directly reflects the visualization and realism of the model. In complex city scenes, objects often have varying degrees of occlusion from one another. Traditional methods to circumvent occlusion by image or model data are not very effective. In this paper, we propose an automatic texture mapping method for 3D models to circumvent occlusion through 3D spatial through-view relationships between images, models, and point clouds. First of all, calculate the density and voxel resolution of the point clouds, the point clouds here can be either dense matching point clouds or laser point clouds. Voxelization is based on point clouds, voxels generated by voxelization can reflect the spatial location of the point clouds. Secondly, to determine whether there is an occlusion of voxels between the image and the model vertices based on the spatial through-view relationship between the image, the model, and the voxels, and filter out the unobstructed images. Finally, by optimizing the data items of the Markov random field, the shading function is added to the original data items for evaluating the shading condition, based on which the most suitable image is selected for texture mapping of a triangular surface of the model. Loop computation to complete the unobstructed texture mapping of the entire model. In this paper, the public test datasets released by the International Society for Photogrammetry and Remote Sensing (ISPRS) and several urban area datasets collected by ourselves are incorporated to test the performance of the proposed method. Both qualitative and quantitative cross-sectional comparisons with existing texture mapping algorithms are conducted and presented. Experimental results indicate that our method can effectively circumvent occlusion for automated texture mapping, and generate 3D models with fewer obstructed textures, which largely improves the visual quality and realism of the models.

Energy-saving performance of respiration-type double-layer glass curtain wall system in different climate zones of China: Experiment and simulation

The development of energy-saving technologies for buildings is an important means of achieving carbon neutrality. The respiration-type double-layer glass curtain wall (RDGCW) is a kind of enclosure structure with natural air circulation and a shading function. The RDGCW provides energy saving, and it is being widely promoted and used in China. However, there is still a lack of relevant research on the energy-saving effects and operating strategies of the RDGCW throughout the year. In response, this paper describes experimental evaluation and numerical simulation. First, the energy-saving effects in an office building using an RDGCW in Tianjin during the winter were studied experimentally, and the real-time temperature changes in the RDGCW and the room were measured with high accuracy under different operating strategies. Second, because the temperature distribution and energy consumption in a room is affected by the air flow in the RDGCW and by outdoor meteorological parameters in a complex manner, this investigation developed a coupled model on the basis of TRNSYS and CONTAM. The simulation results were in good agreement with the experimental results. Third, the verified model was used to evaluate the annual energy-saving effects of the RDGCW under dynamic outdoor meteorological conditions in Tianjin. When the optimal operating strategy was adopted, the energy-saving effect of the RDGCW in comparison with single skin façade (SSF) reached 32.8% under summer conditions and 38.3% under winter conditions. Finally, the RDGCW system in typical cities (Changchun, Shanghai, Guangzhou, Kunming and Tianjin) in five climate zones in China was simulated for the whole year. Under the optimal strategy, the RDGCW achieved good energy-saving effects. The energy saving was 27.7–49.2% in summer and 25.6–46% in winter, in comparison with SSF.

The value of the shading function of urban trees: A replacement cost approach

Cooling is one of the most important benefits of street trees, yet city planners lack estimates of the value of this benefit. Estimation of the value of the cooling effect could help to strengthen the case for investment in a tree cover as a part of the urban infrastructure for climate change adaptation. This article aims to address this research gap by presenting a novel application of a replacement cost method using the costs of parasols for estimating the value of shade provided by urban trees. Using the method, we calculated the net present value of the shade from a generic tree and used these estimates in a case study in Prague, Czech Republic. The results showed that the costs of tree planting and maintenance were higher than the estimated shading benefits in the short term (20–30 years), but the situation reversed when the tree life expectancy increased (> 40 years). Street trees are hence a long-term investment in terms of microclimate regulation. The proposed approach can assist city planners with an assessment of microclimate regulation by urban trees as it can be easily applied with local data, and can complement other methods to show the wider benefits of urban trees.

Optimization of Thickness Uniformity Distribution on a Large-Aperture Concave Reflective Mirror and Shadow Mask Design in a Planetary Rotation System

Improving the spatial resolution of remote sensing satellites has long been a challenge in the field of optical designing. Although the use of large-aperture reflective mirrors significantly improves the resolution of optical systems, controlling the film thickness uniformity remains an issue. The planetary rotation system (PRS) has received significant attention owing to the excellent uniformity of the coating applied to the large-aperture reflective mirror. However, the development of the PRS remains hindered by a lack of research on its properties and the design method of the shadow mask. To address this, we performed a theoretical analysis of the distribution of film thickness and uniformity in the PRS, which is impacted by parameters of geometric configuration in the vacuum chamber. We present a film thickness expression based on Knudsen’s law and the geometric configuration of the vacuum chamber that incorporates an additional shading function. Moreover, the variation of uniformity in the standard and counter PRSs was elucidated by changing the location of the evaporation source. Finally, a fixed-position shadow mask, which was obtained by theoretical design, allows the nonuniformity of the concave reflective mirror (with a 700 mm aperture) to reduce from 2.43% to 0.7%, highlighting the importance of initial shape design.

Numerical simulation and verification of adaptive shading modules with buckling as the driver for functionality

In conventional design paradigm, buckling of slender structural members is seen as a route toward failure and measures are taken to avoid its onset. In recent years, a new challenging approach is emerging where the mechanical instability of slender elements is utilised to achieve novel modes of functionality. Adapting such framework, the flexural-torsional buckling of frame geometries can be exploited as driver to change the shape of slender structural frames to fulfil specific function of shading. This study is concerned with numerical simulation of novel developed systems in which outof-plane buckling of members of a frame is judiciously harnessed to construct adaptive shading modules. Advanced numerical simulations are conducted using Abaqus software to gain better understanding of the factors that affect the behaviour and performance of the proposed solutions. Building on the gained insight a comprehensive search strategy is devised for finding optimum solutions for the governing material, geometrical, and actuation parameters. Within the constructed search space, nonlinear buckling analyses are carried out to determine the resultant shading area, and to quantify the influence of the governing parameters.

Assessment of solar shading performance of courtyard houses in desert climate of Kashan, Iran

ABSTRACT This paper concentrates on the effect of courtyard parameters on the shading function of courtyard houses in hot desert climates; BWh based on Köppen climate classification. The ultimate goal is to optimize the designing pattern for a courtyard regarding orientation, dimensions, and proportions, to enhance the shading performance and improve outdoor thermal comfort. For this purpose, 10 historical courtyard houses were selected with geometrical properties and different orientations from the hot desert climate of Kashan in Iran. The three-dimensional numerical model was applied, by Design Builder, to simulate sunlit and shaded areas. A field measurement was conducted on the shading performance of Borujerdi courtyard house in Kashan. A validation study was performed on the numerical model using the physical data and a close agreement was achieved. The shading index that was previously suggested by authors was employed based on hourly average temperature to investigate the correlations between the index and courtyard’s orientation and geometrical properties. Results illustrate that the courtyard’s design alternatives, particularly length-to-width ratio and height, have influential impacts on shading performance. Finally, some design recommendations for courtyard houses in hot desert regions were extracted to enhance the shading performance and increase the thermal comfort.

Morphogenetic, physiological, and productive of forage peanut responses to shading

Abstract: The objective of this work was to evaluate the morphogenetic, structural, physiological, and productive traits of forage peanut (Arachis pintoi) subjected to different levels of artificial shading in the field. The 'Amarillo MG-100' forage peanut was planted in April 2015, and the evaluations were carried out from May 2017 to April 2018. The treatments were: 0, 30, 45, and 75% of artificial shading. There was no significant effect of shading on the morphogenetic traits of forage peanut. Shading increased final leaf length and canopy height and decreased the leaf area index and number of stolons. Photosynthesis, transpiration rate, stomatal conductance, chlorophyll b, and leaf temperature increased quadratically as a function of shading. There was a linear positive effect on the growing cycle length and a quadratic effect on the production of dry matter mass, with the maximum at 30% shade. Forage peanut harvested at 95% light interception (11-cm height) shows adaptation to shading up to 45%, with increased leaf size, canopy height, photosynthetic rate, stomatal conductance, transpiration rate, and chlorophyll b. In addition, plants at 30% shading show a higher yield than those growing under full sun.

Evaluation of photosynthetic photon flux in lettuce cultivation at different shading levels

ABSTRACT Protected cultivation has grown in Brazil. Generally, greenhouses are covered with transparent plastic film and shading screen. The plastic, over time, loses its transparency due to pollution residues, dust and other debris. The loss of transparency reduces lightness, photosynthesis and leads to losses of productivity and product quality. The losses are not always detectable by the farmer. Additionally, internal shading screens are used to reduce heating transmission to the ground. The objective of this study was to evaluate the impact of shading on lettuce crop productivity and to determine the optimum shading to reach the highest productivity. Plots were set up inside and outside the greenhouse, with four shading levels with black screens (0, 35, 50 and 75%). The treatments were converted to real shading from the photosynthetic photon flux measurement. The results of fresh and dry phytomass were treated and analyzed by regression as a function of the real shading. In ambient conditions of photosynthetic photon fluxes around 1000 μmol m-2 s-1, reaching up to 2000 μmol m-2 s-1 at some hours of the day, typical of tropical environment, lettuce may support a shading of up to 50% without risk of productivity reduction; under these conditions, shading between 20 and 35% is beneficial, and can guarantee its maximum productivity in lettuce cultivation. It is recommended that the lettuce producer in protected cultivation monitors the shelf life of the plastic, avoiding that the shading exceeds 50%. In order to compare shading experiments, one should use the incident photon flux (FFI) for the whole crop cycle, indicating the minimum limit value of FFI = 600 mol m-2 cycle-1 for the crispy lettuce at an average temperature close to 21oC.

Adaptive responses of the embryos of birds and reptiles to spatial and temporal variations in nest temperatures.

Natural nests of egg-laying birds and reptiles exhibit substantial thermal variation, at a range of spatial and temporal scales. Rates and trajectories of embryonic development are highly sensitive to temperature, favouring an ability of embryos to respond adaptively (i.e. match their developmental biology to local thermal regimes). Spatially, thermal variation can be significant within a single nest (top to bottom), among adjacent nests (as a function of shading, nest depth etc.), across populations that inhabit areas with different weather conditions, and across species that differ in climates occupied and/or nest characteristics. Thermal regimes also vary temporally, in ways that generate differences among nests within a single population (e.g. due to seasonal timing of laying), among populations and across species. Anthropogenic activities (e.g. habitat clearing, climate change) add to this spatial and temporal diversity in thermal regimes. We review published literature on embryonic adaptations to spatio-temporal heterogeneity in nest temperatures. Although relatively few taxa have been studied in detail, and proximate mechanisms remain unclear, our review identifies many cases in which natural selection appears to have fine-tuned embryogenesis to match local thermal regimes. Developmental rates have been reported to differ between uppermost versus lower eggs within a single nest, between eggs laid early versus late in the season, and between populations from cooler versus warmer climates. We identify gaps in our understanding of thermal adaptations of early (embryonic) phases of the life history, and suggest fruitful opportunities for future research.

The effect of urbanization gradients and forest types on microclimatic regulation by trees, in association with climate, tree sizes and species compositions in Harbin city, northeastern China

Rapid urbanization and climate change require stronger microclimatic regulation by urban trees, and maximizing their cooling, humidifying, and shading functions requires an exact understanding of the underlying mechanisms affected by climatic conditions and the forest characteristics. By measuring different aspects of microclimate regulation by urban trees in 165 plots in Harbin city and measuring climatic conditions, tree size, and compositional differences, we define changes in patterns along various urban-rural gradients (ring-road development and urban history) and for different forest types and decoupling the complex associations among them. We found that the horizontal cooling (1.7 °C to 4.0 °C) was larger than the vertical cooling (−1.71 °C to 0.33 °C) and soil cooling (0.28 °C to 2.17 °C); The humidifying effect (ΔRH) ranged from −0.34% to 7.30%, and total radiation intercepted (ΔE) ranged from 11.07 kLux to 45.95 kLux. We also found higher under-branch height, larger canopy, and higher percentage of Ulmaceae, but lower percentage of Salicaceae in more urbanized regions. The relative importance of tree compositions and size on microclimatic regulation was shown using redundancy analysis (RDA), and RDA variation partitioning showed that tree sizes explained 24.7% of the variations in the microclimate regulations, and tree composition and their interactions with climatic conditions explained 9.5% and 25.4% of the variations, respectively. Our findings reveal that maximizing microclimatic regulation by urban forests in northeastern China could possibly be achieved through specific-function-oriented afforestation and an increase conservation of large existing trees, and the data in this paper could favor policy decision of urban forest manager and local administration of urban green infrastructure.

Inventory of Indonesian native montane trees for environmental support and space ornaments in Cibodas Botanical Garden

Nowadays, many urban outskirts which are commonly characterized by natural environment have changed into built environment including in the mountainous zones. In many cases, however, the use of plant species as recommended by policy makers for restoring the urban outskirts does not match with the local environmental settings that often causes failure in achieving the desired healthy environment. The objective of this study was to select and carry out inventory of suitable trees for improving the environmental settings in mountainous zone. Trees selection was conducted by gradual screening procedure, based on the plant collection in Cibodas Botanical Garden, specifically for Indonesian native trees. Tree inventory was performed based on core ecosystem functions such as shading function, soil adsorption capacity and aesthetic value. The results indicated that at least 125 trees species are suitable for shading function, such as Dipterocarpus cornutus, Castanopsis spp. and Cinnamomum spp. For soil adsorption capacity, 211 species were recorded, such as Canarium hirsutum, Magnolia spp. and Litsea spp., and for the aesthetic values, there were 237 recorded species, such as Garcinia spp., Lithocarpus spp. and Ficus spp. Certain trees have more than one function, such as Agathis dammara which is suitable for all functions, or Elaeocarpus spp. which is appropriate for soil adsorption and aesthetic function. These results are expected to be used as initial reference for tree selection within the framework of restoration of local mountain environment quality.

39.3: The LCD Technology Development and Application with an Improved Black Photo Spacer Structure

A novel Black Photo Spacer (BPS) structure is demonstrated in this present work. The black BPS material supports the substitution of black matix (BM) to realize shading function. Thus the BPS technology can integrate BM into PS process, which saves the material, mask, machine and time cost. In order to improve stability, we use full tone mask design. Different height (ΔH) of Main PS and Sub PS are generated by color filter stacking. Polymer film on array (PFA) is used to reduce the excessive primary height between Main PS and Sub PS. In addition, all the patterns included color filter, BM and PS are on array side, which can effectively avoid the backlight leakage and enhance contrast ratio (CR). More discussions of the designs, process and optical performances about 1‐tone BPS such as Data line BM less (DBS) are demonstrated in this paper, and a 28 inch demon with this BPS technology is shown at the end.

The design of broadband constant beamwidth and constant beam pattern transducers

The broadband constant beamwidth (CBT) and the constant beam pattern (CBP) transducers attracted much attentions, because of their main lobes or even the whole beam patterns (CBP case) are independent of frequencies. For a spherical (or hemispherical) design, the far field angular beam patterns are the same as the normal directional radial particle velocity, or shading, distribution on the surface of the spherical transducer, if the ka product for the wave number and the sphere radius is greater than one, per spherical Hankel function asymptotic approximation to the solution of the Helmholtz wave equation. Any arbitrary velocity shading functions can be expanded by series of Legendre polynomials for optimization beamwidth and sidelobe levels. This paper introduced a new transducer or array design, where the methodology by CBP is employed, while the geometry of CBT spherical cap is applied, such that the shading functions are no longer confined by only one Legendre polynomial P(cos(θ)) of the CBT case. Here, the shading examples by various Legendre polynomials of P(z0*cos(θ)) and the classic Dolph-Chebyshev T(z1*cos(θ)) of different orders have been successfully simulated, where the z0 and the z1 are the design control parameters of the beams.

Analysis of Selected Photovoltaic Panels Operating Parameters as a Function of Partial Shading and Intensity of Reflected Radiation

Abstract Due to expansion of utilisation of photovoltaics in ordinary households, the question arises how this phenomenon affects the electric power of photovoltaic modules. The article deals with the electric power analysis of photovoltaic modules as a function of two very important factors. The first examined factor was partial shading, and the second factor was the intensity of reflected radiation. In order to determine the dependence of module power on the aforementioned parameters, a measurement system under laboratory conditions has been prepared. For identification of the reflected radiation effect on the power of the photovoltaic module, a series of measurements was performed on 7 different surfaces with the same radiation source. It is evident from obtained experimental result that the ratio of reflected irradiation on the solar module power is 1.29%. By simulation of partial shading of photovoltaic module, the decrease of 86.15% in its output power was identified.