Lighting Energy Use Research Articles

Improving lighting energy efficiency through user response

Technological advances have increased the energy performance of integrated daylighting and lighting systems to unprecedented levels. The shift to LED technologies, innovative shadings, and advanced lighting and shading controls promises a dramatic reduction in energy use for lighting. Work will continue to save more energy with technological solutions, but additional savings can be attained by understanding the complexity of human behaviour and by designing systems in such a way that they can accommodate energy-saving behaviour. This article reviews behaviour aimed at saving energy used for lighting. Four categories of behaviour are identified, concerning extent and speed of dimming, heuristics, design of the interface, and information/feedback strategies. The review suggests that lighting use can be halved by introducing simple strategies to existing and future systems, but the energy saving potential comes with low ecological validity. A multidisciplinary approach is required to increase the robustness of findings.

A new tool and workflow for the simulation of the non-image forming effects of light

Other than supporting vision, light plays an important role in regulating human circadian rhythms through its non-image-forming (NIF) effects. Simulating potential NIF stimulation from daylight indoors, however, is a challenging task, requiring the continuous evaluation of luminous exposures at the eye, which are affected by changing sky's spectral power distributions at a location, time of day and year, and estimation of the sky patches’ contributions at a viewing position, which dynamically vary through a space. Existing multi-channel NIF simulations tools use measured or pre-computed spectral sky data. Yet, these are difficult to obtain with flexible spatio-temporal resolution. To address this challenge, and dynamically estimate a range of NIF metrics, we developed a tool and workflow based on 17 original Python-scripted Grasshopper components. This paper illustrates the design and development of the tool and workflow, also presenting an example of practical application to evaluate the yearly variations of potential NIF stimulation from an interior position or under an unobstructed sky. This is the first step to propose more robust building design and modelling concepts, beyond conventional visual comfort issues, and to adequately balance lighting energy use with occupants’ comprehensive needs, while connecting daylighting and electric lighting systems and controls within integrated solutions.

Field validation of data-driven BSDF and peak extraction models for light-scattering fabric shades

Shading and daylighting systems affect cooling, heating, and lighting energy use by modulating solar radiation through the building façade. Characterizing shading systems holistically and accurately helps designers and engineers evaluate shading systems to achieve energy and non-energy performance goals. These complex fenestration systems can be modeled using Bidirectional Scattering Distribution Functions (BSDF), which map incident radiation to hemispherical distributions of outgoing radiation. Data-driven, tabulated BSDFs are derived from interpolated goniophotometer measured data, then sampled during the raytracing calculation. A peak extraction (PE) algorithm was developed to circumvent limits in BSDF angular resolution, where the specular peak is extracted during simulation by evaluating the BSDF in the through direction and surrounding region. The objective of this study was to validate this measurement and modeling workflow using field monitored data from a full scale testbed with eleven installed fabrics of different weaves, openness factors, and colors and assess the accuracy of the workflow under different adaptation and contrast conditions. Test conditions were limited to clear sky conditions with the sun in the field of view. Results showed that, for tensor tree datasets, vertical illuminance, solar luminance (2.5° apex), and daylight glare probability (DGP) were predicted to within a mean bias error (MBE) error of −456 lx (−12.3%), −3.46e5 (−38.4%), and −0.042 (−7.8%) when full PE occurred. With a binary classification of glare/ no glare, DGP was predicted accurately with a true positive rate of 0.98 and true negative rate of 1.0 using tensor tree data and less accurately with Klems BSDF data, particularly for cases of no glare. The workflow may be of insufficient accuracy to distinguish borderline performance between fabrics using the four-point glare scale, particularly under low adaptation, high contrast daylit conditions. Errors were due to reductions in peak shape and intensity across the BSDF interpolation and data reduction workflow. Future work is needed to better preserve measurement fidelity during interpolation and sampling, which in turn will improve PE performance.

Adaptive Responses of Common and Hybrid Bermudagrasses to Shade Stress Associated With Changes in Morphology, Photosynthesis, and Secondary Metabolites.

Alteration of ploidy in one particular plant species often influences their environmental adaptation. Warm-season bermudagrass is widely used as forage, turfgrass, and ground-cover plant for ecological remediation, but exhibits low shade tolerance. Adaptive responses to shade stress between triploid hybrid bermudagrass cultivars [“Tifdwarf” (TD), “Tifsport” (TS), and “Tifway” (TW)] and tetraploid common bermudagrass cultivar “Chuanxi” (CX) were studied based on changes in phenotype, photosynthesis, and secondary metabolites in leaves and stems. Shade stress (250 luminance, 30 days) significantly decreased stem diameter and stem internode length, but did not affect the leaf width of four cultivars. Leaf length of CX, TD, or TW showed no change in response to shade stress, whereas shade stress significantly elongated the leaf length of TS. The CX and the TS exhibited significantly higher total chlorophyll (Chl), Chl a, carotenoid contents, photosynthetic parameters [PSII photochemical efficiency (Fv/Fm), transpiration rate, and stomatal conductance] in leaves than the TW and the TD under shade stress. The CX also showed a significantly higher performance index on absorption basis (PIABS) in leaf and net photosynthetic rate (Pn) in leaf and stem than the other three cultivars under shade stress. In addition, the TS maintained higher proantho cyanidims content than the TW and the TD after 30 days of shade stress. Current results showed that tetraploid CX exhibited significantly higher shade tolerance than triploid TD, TS, and TW mainly by maintaining higher effective photosynthetic leaf area, photosynthetic performance of PSI and PSII (Pn and Fv/Fm), and photosynthetic pigments as well as lower Chl a/b ratio for absorption, transformation, and efficient use of light energy under shade stress. For differential responses to shade stress among three triploid cultivars, an increase in leaf length and maintenance of higher Fv/Fm, gas exchange, water use efficiency, carotenoid, and proanthocyanidin contents in leaves could be better morphological and physiological adaptations of TS to shade than other hybrid cultivars (TD and TW).

Oriented Nanoarchitectonics of Bacteriorhodopsin for Enhancing ATP Generation in a FoF1‐ATPase‐Based Assembly System

AbstractEnergy conversion plays an important role in the metabolism of photosynthetic organisms. Improving energy transformation by promoting a proton gradient has been a great challenge for a long time. In the present study, we realize a directional proton migration through the construction of oriented bacteriorhodopsin (BR) microcapsules coated by FoF1‐ATPase molecular motors through layer‐by‐layer (LBL) assembly. The changes in the conformation of BR under illumination lead to proton transfer in a radial direction, which generates a higher proton gradient to drive the synthesis of adenosine triphosphate (ATP) by FoF1‐ATPase. Furthermore, to promote the photosynthetic activity, optically matched quantum dots were introduced into the artificial coassembly system of BR and FoF1‐ATPase. Such a design creates a new path for the use of light energy.

Oriented Nanoarchitectonics of Bacteriorhodopsin for Enhancing ATP Generation in a Fo F1 -ATPase-Based Assembly System.

Energy conversion plays an important role in the metabolism of photosynthetic organisms. Improving energy transformation by promoting a proton gradient has been a great challenge for a long time. In the present study, we realize a directional proton migration through the construction of oriented bacteriorhodopsin (BR) microcapsules coated by Fo F1 -ATPase molecular motors through layer-by-layer (LBL) assembly. The changes in the conformation of BR under illumination lead to proton transfer in a radial direction, which generates a higher proton gradient to drive the synthesis of adenosine triphosphate (ATP) by Fo F1 -ATPase. Furthermore, to promote the photosynthetic activity, optically matched quantum dots were introduced into the artificial coassembly system of BR and Fo F1 -ATPase. Such a design creates a new path for the use of light energy.

Epigenetic and Physiological Responses to Varying Root-Zone Temperatures in Greenhouse Rocket.

Greenhouse production of baby leaf vegetables grown in hydroponic floating trays has become extremely popular in recent years. Rocket (Eruca sativa Mill.) can grow in temperatures varying between 10 and 20 °C; nevertheless, a root-zone temperature (RZT) range of 18–23 °C is considered optimal for high productivity, photosynthesis, and production of metabolites. Maintaining such temperatures in winter raises production costs and prevents sustainability. In this study, we tested the impact of lower RZT on plants’ status and recorded their responses while providing energy for heating using photovoltaic solar panels. We used three hydroponic tanks for cultivation; a non-heated (control) tank (12 °C) and two heated tanks; a solar panel-powered one (16 °C) and a public grid-powered one (22 °C). Methylation-sensitive amplified polymorphisms (MSAP) analysis of global methylation profiles and chlorophyll fluorescence analysis were employed to assess methylation and physiology levels of rocket leaves. We found that there is demethylation at 16 °C RZT in comparison to 22 °C RZT. Reduction of temperature at 12 °C did not reduce methylation levels further but rather increased them. Furthermore, at 16 °C, the effective quantum yield of photosystem II (PSII) photochemistry (ΦPSII) was significantly higher, with a higher PSII electron transport rate (ETR) and a significantly decreased non-regulated energy loss (ΦΝO), suggesting a better light energy use by rocket plants with higher photosynthetic performance. ΦPSII was significantly negatively correlated with DNA methylation levels. Our results show that at 16 °C RZT, where plants grow efficiently without being affected by the cold, DNA methylation and photosynthesis apparatus systems are altered. These findings corroborate previous results where hydroponic production of rocket at RZT of 16 °C is accompanied by sufficient yield showing that rocket can effectively grow in suboptimal yet sustainable root-zone temperatures.

Impacts of Courtyard Envelope Design on Energy Performance in the Hot Summer–Cold Winter Region of China

This paper aims to investigate the effects of courtyard envelope design on the energy performance of office buildings in the hot summer–cold winter region of China. Two types of courtyard buildings were simulated with 200 energy models by changing the following variables: window–wall ratio (south, north, east, and west walls), window U-value, wall U-value, solar heat gain coefficient, and orientation. The treed Gaussian process (TGP) sensitivity analysis method was employed to quantify the contributions of parameters related to courtyard design that result in the changes of annual cooling, heating, lighting, and total energy consumption. The results show that the courtyard envelope design has a significant effect on the energy consumption in this case study. The most influential factor affecting annual cooling energy consumption and the annual total energy consumption is the orientation, which is responsible for 37% and 81%, respectively, in two layouts to annual cooling energy use. The corresponding proportion increased to 45% and 86% in terms of the total energy consumption. The most influential factor influencing annual heating energy use is the window U-value, which explained nearly 60% of the changes to the heating energy use. The effect of the solar heat gain coefficient in two kinds of layouts is as high as 82% and 79% for lighting energy use in this case study. Due to the different courtyard forms, the magnitude of the effect of the parameters on energy consumption and the main trend of the effect is slightly different.

The Emergence and Evolution of the Ecosphere

The ecosphere is a natural construction, the development of which fundamentally differs from the way the other planets in our solar system evolved. Life emerged consequently to the connection between non-living factors and macromolecules – complex carbon-based compounds. Living beings had the capacity of creating a new type of informational pattern, which soon assumed the coordination of major processes at the planetary level, and the non-living components – the atmosphere, the hydrosphere and the lithosphere – were substantially modified by the biosphere. Our approach regarding thr evolution of life is an ecological one; emphasis is put on the interrelations between the living and the non-living worlds: the emergence of metabolism, interspecific relations, the use of multiple energy sources; the emergence of life generated biogeochemical cycles and evolutionary processes characterized by self-control, self-organization and self-improvement. A special role was played by the transition from the use of chemical energy to the use of light energy, with the release of oxygen, which, owing to oxidative reactions, became the main element in the global development of most energetic processes. Life progressed from self-reproducing organic macromolecules to protoorganisms, then single-celled organisms (prokaryotes) and finally eukaryotic organisms emerged. In time, they populated all environments: the marine, the brackish, the freshwater, the terrestrial and the underground one. Living beings created two planetary covers: the biosphere and the pedosphere. The interconnection of the biosphere with the non-living covers (the atmosphere, the hydrosphere, the lithosphere and the pedosphere) resulted in the emergence of the ecosphere.

中国陆地植被净初级生产力估算模型优化与分析——基于中国生态系统研究网络数据

PDF HTML阅读 XML下载 导出引用 引用提醒 中国陆地植被净初级生产力估算模型优化与分析——基于中国生态系统研究网络数据 DOI: 10.5846/stxb202011263031 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划项目（2016YFC0500201，2016YFC0502102-02）和国家自然科学基金（41771464，31761143018-2） Optimization of net primary productivity estimation model for terrestrial vegetation in China based on CERN data Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:该研究基于中国生态系统研究网络（CERN）数据对传统CASA模型进行优化，对比两叶模型与优化CASA模型在站点尺度和像元尺度对于8个典型生态站点的植被净初级生产力（NPP）估算精度，选择在像元尺度表现更好的优化CASA模型，结合中国土地覆被数据（ChinaCover）开展2000-2019年中国陆地植被NPP监测与分析。研究结果表明：（1）基于FY2D PAR的优化方案能够有效避免空间插值导致的不确定性问题，显著提高了PAR估算精度；（2）在站点尺度上，两叶模型用于估算典型森林、草地生态系统的NPP表现更好，而在像元尺度上优化CASA模型估算精度更高；（3）在全国尺度上，优化了最大光能利用率、水分胁迫系数以及光合有效辐射计算方法的CASA模型能够较好地模拟中国陆地植被NPP，近20年中国陆地植被NPP变化范围为2.703-2.882 PgC/a，在空间上呈西北低东南高的格局，在时间上呈现波动中缓慢增加的趋势。 Abstract:In this study, we optimized the traditional Carnegie-Ames-Stanford Approach (CASA) model based on China Ecosystem Research Network (CERN) datasets, and compared the estimation accuracy of the two-leaf model and the optimized CASA model at the site scale and pixel scale at eight CERN sites covering major ecosystem types. The optimized CASA model with better performance at the pixel scale combined with China Land Cover Data (ChinaCover) were employed for mapping and monitoring the spatio-temporal changes of terrestrial vegetation net primary production (NPP) in China from 2000 to 2019. The results show that:(1) the optimization for model input parameter of photosynthetically active radiation based on FY2D PAR can effectively avoid the uncertainty caused by the spatial interpolation, and significantly improve the accuracy of PAR estimation; (2) The two-leaf model shows higher NPP estimation accuracy at the site scale, while the optimized CASA model performs better for the NPP estimation at the pixel scale; (3) At the national scale, the CASA model with optimized maximum light energy use efficiency, water stress coefficient and photosynthetically active radiation can better simulate China's terrestrial vegetation NPP. The estimated total NPP in Chinese terrestrial vegetation ranges from 2.703 PgC/a to 2.882 PgC/a in the past 20 years and indicates a fluctuated and slow increasing trend. The spatial distribution of the NPP in China shows a general pattern of gradually increasing from northwest to southeast. 参考文献 相似文献 引证文献

Solar Controller with Automatic Search Technology for the Maximum Power Point with Autonomy Display

In our work, we have been interested in conducting technological research on the use of photovoltaic energy for lighting. In fact, we have produced a stand-alone photovoltaic system with automatic search for the maximum power point, consisting of a photovoltaic module, a solar regulator, a storage battery and a digital control by microcontroller. The solar field is connected to the input of the regulator and the battery to its output. When the battery voltage is lower than the regulation voltage, the controller operates the photovoltaic generator at maximum power Pmpp and transfers this power to the output. In addition to the protection function, this regulator ensures tracking of the maximum power point (MPPT) and allows the photovoltaic generator to deliver its power whatever the variation of climatic conditions (sunshine and temperature). The main role of the solar regulator is the continuous monitoring of the state of charge of the battery to ensure its protection against overcharging and excessive discharging, the coupling and decoupling of the user as well as its maintenance. The principle of operation is based on controlling a DC-DC converter by a rectangular “PWM” signal generated by a PIC16F874 microcontroller which also controls the entire system. The results of simulation after realization were presented to illustrate the operation of the regulator by curves.

Factors Influencing the Use of Solar Energy Technology in a Local Township of Blantyre City, Malawi

Challenges with access to electricity are global but becoming increasingly high in Malawi where more than 96% of the electricity is produced from hydro generation. Energy sources for electricity production can be renewable or non-renewable. Due to many challenges facing hydropower production such as water levels, debris in the inlet ponds, etc., renewable energy sources that produce clean energy such as solar power are becoming common. However, despite such opportunities, access to electricity whether renewable (solar) or non-renewable (hydro production) to many people in urban areas in Malawi is still a challenge. A household survey was carried out involving 100 households aimed to establish factors that influence the use of solar energy technology in Machinjiri, one of the townships in the city of Blantyre, in southern Malawi. Only 32% of the households have access to solar energy. Results indicated that the level of education attained has an influence on the peoples’ choices to use solar technology. In this regard, respondents with basic primary school certificate reported 8% while those with college education reported 32% and those with higher education, Malawi School Certificate of Education (MSCE) reported 52% use of solar energy for lighting. Some of the reasons for not using solar energy include: low production during winter (55%), not durable (23%), no knowledge (18%) and others mention combined reasons (4%). Only a few people use solar energy for lighting. Therefore, there is a need for the government and non-governmental organizations to continue sensitizing people on the importance of using renewable energy such as solar energy. Furthermore, the government should create deliberate conditions to make solar energy equipment affordable to many Malawians with low incomes.

Influence of the sowing period and denesityon yield and yield components of three semi -winter wheat varieties

Three semi-winter wheat varieties Zhoumai 18, Zhoumai 22 and Bainong 207 were selected as materials for this study to study quality seeds and reliable methods capable of supporting the dominant wheat cultivation technology in southern Huanghuai. In our experiments, each variety was used in six sowing times and seven planting densities. The results showed that: (1) varieties had significant effects on yield and yield components. The yield among different varieties in the order of high and low was Bainong 207 >Zhoumai 22 >Zhoumai 18; suitable sowing date from October 1 to October 22, and the density is 300 ~ 525 × 104 plant·hm-2. (2) The interaction of the date and planting density affects the yield and its constituent factors.The best combination of sowing date and density for Zhoumai 18 and Bainong 207 were 450×104 plant·hm-2 on October 8, and the yields were 10829.0 kg·hm-2 and 11891.7 kg·hm-2, respectively, and Zhoumai 22 is 450 × 104 plant·hm-2 on October 15 and the yield is 10792.5kg·hm-2. It can be seen that the best sowing date is October 8~15, and the seeding density is 450 × 104 plant·hm-2. All three varieties showed that the spikes was higher during the high-density and the suitable sowing date treatment (October 8~15, 525~675 × 104 plant·hm-2), and the grain number per spike was higher when the density was suitable (300-525 ×104 plant·hm-2), the thousand-grain weight is higher in the low-density treatment (225~300 × 104 plant·hm-2). (3) There are significant differences in the percentage of tiller among different varieties. The order of the three varieties is Bainong 207 >Zhoumai 18 >Zhoumai 22. With the postponement of the sowing date and the increase of the sowing density, the population tiller number (PTN) increased, and the percentage of earring-tiller gradually decreased. In summary, the appropriate sowing date and density can make the yield and its constituent factors make full use of light energy and water which build a reasonable population structure, and increase yield.

PENYULUHAN PENGGUNAAN LAMPU OTOMATIS BAGI MASYARAKAT

The need for electrical energy for lighting for the community is an important thing. However, people tend to pay less attention to the savings in the use of electrical energy for lighting in the house, both at night and during the day. When leaving the house empty, in general, the porch light is on all day and night. This is a common thing for the community, but they unconsciously waste the use of electrical energy which will cause an increase in electricity bill bills. To increase knowledge for the community about the importance of saving electrical energy, in this community service counselling will be carried out on saving electrical energy by using automatic, energy-saving lamps. Counselling is done by visiting people's homes to explain the benefits of saving electricity for them. Then distribute and install energy-saving lamps with light sensors. With this service, the community has been able to understand well the benefits of saving electrical energy for them. The use of energy-saving lamps with light sensors can help people to save on the use of electrical energy. With this counselling, the community can save electrical energy for lighting, where the porch light will turn on automatically in the afternoon and will turn off automatically in the morning

Development of a light control system using an optical aerial information transmission system

The inefficiency of the use of electric energy for indoor lighting is shown. The necessity of modernization of lighting control systems in the workplace area is justified. The method of automatic control and adjustment of illumination of workplaces and zones where it is necessary is offered. A control system has been developed, which is integrated into the air optical information transmission system (Internet). The simulation of the system operation is carried out, its parameters are calculated. The main characteristics are measured.

Nitrogen supplement attenuates drought stress for non‐leguminous hybrid plant fescue and does not affect nitrogen‐fixing alfalfa

AbstractThis work focuses on the investigation of forage crops hybrid fescue and legume alfalfa response to drought at different levels of nitrogen fertilization. Plants were grown in pots filled with a mixture of field soil, perlite and fine sand with three (N0, N60 and N90 kg/ha) levels of nitrogen fertilization in a greenhouse. Drought stress was applied by withholding watering for 1 week, after which plants were left for a recovery period of 1 week. In most cases, the morphological indices of alfalfa did not differ significantly between the treatments. In contrast, the above‐ground biomass of fescue grown under well‐watered conditions was largely enhanced by N addition. The main trend of JIP test parameters was that nitrogen fertilizer did not have a significant effect on alfalfa. Contrarily, additional nitrogen content increased energy fluxes (such as absorption, trapping, electron transport, reduction of end acceptors) and density of reaction centres not only in well‐watered but also in drought‐affected fescue plants. An increase in nitrogen fertilizers increased content of pigments and flavonoids in fescue leaves. In conclusion, the stress tolerance index of hybrid fescue increased along with the increase in N content due to more efficient use of light energy and increased antioxidative capacity, all of which led to significantly higher production of above‐ground biomass at higher N levels and drought stress.

Effects of tubular daylight guidance systems on the daylighting performance and energy savings in office buildings under different climate zones

Over the recent years, the energy use of artificial lighting has been gradually increasing in office buildings. Tubular daylight guidance system (TDGS) is an innovative daylighting technology, which is used to transport daylight into the core of a building. In this study, the effects of the tube radius of TDGSs, window-to-wall ratio (WWR), and window orientation on the indoor illuminance, artificial lighting electricity consumption, and heating/cooling loads of an office room are investigated for the five climate zones in China by both numerical simulations and experiments. The model is developed using Radiance and Ecotect, and its feasibility is validated by comparing the simulated indoor illuminance distributions with the field measurements. The results demonstrate that the increase in the tube radius and the decrease in the WWR and the utilization of a north-facing window can improve the daylighting performance and energy savings of the TDGSs. In general, the TDGSs can reduce the artificial lighting electricity consumption and heating load while increasing the cooling load of the office room. Due to the implementation of TDGSs, the maximum potential energy savings (on the lighting energy use and the heating/cooling energy use) are 27.6% in Kunming (moderate climate), 13.5% in Chengdu (hot summer and cold winter), 10.6% in Guangzhou (hot summer and warm winter), 10.3% in Beijing (cold), and 5.0% in Harbin (severe cold).

Comparison of control strategies for HCPV sun tracking

This paper presents a comparison between five control strategies for HCPV sun tracking that comprise open-loop by means of Solar Equations, closed-loop by Sun position feedback (using an electro-optical sensor and a DC power sensor), and pointing ahead of the Sun. The performance of the control strategies is tested under a fully calibrated sun-tracker conditions and not-calibrated conditions to expose the problematic of the high accuracy sun pointing. When the sun-tracker is calibrated, all control strategies perform in a very similar way in terms of efficiency of use of available light energy, with the exception that one of the control strategies does not need prior calibration. The measured loss in efficiency when the sun-tracker is not calibrated precisely is approximately equal to 6%.

Versatile gadolinium(III)-phthalocyaninate photoagent for MR/PA imaging-guided parallel photocavitation and photodynamic oxidation at single-laser irradiation

Current light-mediated photodynamic therapy (PDT) is far underutilized in clinical cancer treatment due to its low pharmacological effect. We herein proposed a new gadolinium(III)-phthalocyanine (GdPc)-enabled phototherapeutics, photoacoustic/dynamic therapy (PADT), towards in vivo solid tumors via parallel-produced photocavitation and photodynamic oxidation with excitation by a single pulsed laser. We demonstrated that pulsed irradiation of GdPc could simultaneously produce an intense acoustic effect and a high-level 1O2 quantum yield to afford mitochondrial damage and initiate programmed cell death. Under the guidance of magnetic resonance/photoacoustic dual-modal imaging, the mechanical oxygen-independent destruction of acoustic cavitation and the chemical damage of 1O2 were validated to afford combinatorial inhibition of tumors under either normal or hypoxic conditions after the agent delivered into the cancer cells by a pH-sensitive nanomicelle. The single-laser initiated PADT using GdPc as a versatile photoagent maximizes the use of light energy to minimize the dose requirement of oxygen and agent towards high therapeutic efficacy, surpassing dramatically over conventional PDT.

A data-driven method to minimize sensor use for dynamic shading control

Dynamic facade systems are a promising strategy to balance the benefits and drawbacks of daylight penetration through the window in a built environment. A well-operated shading system should allow for sufficient daylight access while preventing glare in response to changing weather conditions. The dynamic shading system can also help with making use of daylight to reduce the lighting energy use when integrated with electric lighting control. This paper presented a data-driven approach to control the automated shading system. The control method allows the system to be responsive to outdoor weather conditions. With data from offline daylight simulation using typical meteorological year weather, three machine learning classification algorithms were applied to train predictive models for online shading control. The proposed method was validated using a climate-based simulation. It was found that all models had a satisfying prediction performance, with an accuracy of 0.85 to 0.92. The shading control could maintain the work plane illuminance for 97% to 99% of the time during the year. It was also associated with a potential of reducing electric lighting energy use by 40% to 43% compared to that of on/off lighting control.