312 research outputs found

    Fade Lighting Control Method for Visual Comfort and Energy Saving

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    This study proposes a fade lighting control method to ensure the visual comfort of indoor occupants through gradual illuminance control while saving energy. The illuminance sensor measures the indoor illuminance and calculates the required illuminance for achieving a reference illuminance of 500 Lux. The control illuminance for each lighting is derived based on the required illuminance, and it is confirmed to fall within the threshold range of 20%. The illuminance values and time intervals for fade lighting control are calculated, ensuring that the amount of illuminance adjustment is divided by the size of the threshold range or less. In the performance evaluation, the proposed method (experimental group) was compared with the influence-based control method (control group). The result shows that this fade lighting control method minimizes the visual discomfort of occupants caused by sudden changes in lighting, and the same energy-saving of 11-42% is achieved as the control group

    The Control Method for Wavelength-Based CCT of Natural Light Using Warm/Cool White LED

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    Reproducing circadian patterns of natural light through lighting requires technology that can control correlated color temperature (CCT) and short wavelength ratio (SWR) simultaneously. This study proposes a method for controlling wavelength-based CCT of natural light using LED light sources. First, the spectral power distribution (SPD) of each channel of the test lighting (two-channel LED lighting with warm white and cool white) is identified through actual measurement. Next, CCT and SWR are calculated based on the additive mixing of SPD using the mixing ratio from the measured SPD. Finally, the regression equations for mixing ratio-CCT and mixing ratio-SWR are derived through regression analysis. These equations are then utilized to implement a wavelength-based CCT control algorithm. For performance and evaluation purposes, natural light reproduction experiments were conducted, achieving a mean error of 94.5K for CCT and 1.5% for SWR

    H2 pressure swing adsorption for IGCC power plant and techno-economic analysis of integrating PSA to IGCC with carbon capture

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    Carbon capture and sequestration technologies emerge as the effectual remediation processes to reduce CO2 emissions from coal power plants. Integrated gasification combined cycle (IGCC) is a representative technology for utilizing coal as feedstock and is consequently playing a more important role to cover the global energy demand. The IGCC produces H2-rich mixture at high pressures (30-35 bar) after capturing CO2. It is reported that the high purity H2 recovered from the IGCC process can be economically supplied to a hydrogen turbine or fuel cell. And a PSA process is a strong candidate to produce high purity H2 from the IGCC effluent gas. However, due to higher operating pressure than the present H2 PSA processes, reducing the operating costs and efficiency has emerged as one of the key issues. Please click Additional Files below to see the full abstract

    In vivo functional photoacoustic tomography of traumatic brain injury in rats

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    In this study, we demonstrate the potential of photoacoustic tomography for the study of traumatic brain injury (TBI) in rats in vivo. Based on spectroscopic photoacoustic tomography that can detect the absorption rates of oxy- and deoxy-hemoglobins, the blood oxygen saturation and total blood volume in TBI rat brains were visualized. Reproducible cerebral trauma was induced using a fluid percussion TBI device. The time courses of the hemodynamic response following the trauma initiation were imaged with multi-wavelength photoacoustic tomography with bandwidth-limited spatial resolution through the intact skin and skull. In the pilot set of experiments, trauma induced hematomas and blood oxygen saturation level changes were detected, a finding consistent with the known physiological responses to TBI. This new imaging method will be useful for future studies on TBI-related metabolic activities and the effects of therapeutic agents

    Geomagnetic field influences probabilistic abstract decision-making in humans

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    To resolve disputes or determine the order of things, people commonly use binary choices such as tossing a coin, even though it is obscure whether the empirical probability equals to the theoretical probability. The geomagnetic field (GMF) is broadly applied as a sensory cue for various movements in many organisms including humans, although our understanding is limited. Here we reveal a GMF-modulated probabilistic abstract decision-making in humans and the underlying mechanism, exploiting the zero-sum binary stone choice of Go game as a proof-of-principle. The large-scale data analyses of professional Go matches and in situ stone choice games showed that the empirical probabilities of the stone selections were remarkably different from the theoretical probability. In laboratory experiments, experimental probability in the decision-making was significantly influenced by GMF conditions and specific magnetic resonance frequency. Time series and stepwise systematic analyses pinpointed the intentionally uncontrollable decision-making as a primary modulating target. Notably, the continuum of GMF lines and anisotropic magnetic interplay between players were crucial to influence the magnetic field resonance-mediated abstract decision-making. Our findings provide unique insights into the impact of sensing GMF in decision-makings at tipping points and the quantum mechanical mechanism for manifesting the gap between theoretical and empirical probability in 3-dimensional living space.Comment: 32 pages, 5 figures, 4 supplementary figures, 2 supplementary tables, and separate 15 ancillary file

    In vivo functional photoacoustic tomography of traumatic brain injury in rats

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    In this study, we demonstrate the potential of photoacoustic tomography for the study of traumatic brain injury (TBI) in rats in vivo. Based on spectroscopic photoacoustic tomography that can detect the absorption rates of oxy- and deoxy-hemoglobins, the blood oxygen saturation and total blood volume in TBI rat brains were visualized. Reproducible cerebral trauma was induced using a fluid percussion TBI device. The time courses of the hemodynamic response following the trauma initiation were imaged with multi-wavelength photoacoustic tomography with bandwidth-limited spatial resolution through the intact skin and skull. In the pilot set of experiments, trauma induced hematomas and blood oxygen saturation level changes were detected, a finding consistent with the known physiological responses to TBI. This new imaging method will be useful for future studies on TBI-related metabolic activities and the effects of therapeutic agents

    A study on the development of a cost model based on the owner's decision making at the early stages of a construction project

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    Decision making at the early stages of a construction project has a significant impact on the project, and various scenarios created based on the owner's requirements should be considered for the decision making. At the early stages of a construction project, the information regarding the project is usually limited and uncertain. As such, it is difficult to plan and manage the project (especially cost planning). Thus, a cost model that could be varied according to the owner's requirements was developed. The cost model that was developed in this study is based on the case‐based reasoning (CBR) methodology. The model suggests cost estimation with the most similar historical case as a basis for the estimation. In this study, the optimization process was also conducted, using genetic algorithms that reflect the changes in the number of project characteristics and in the database of the model according to the owner's decision making. Two optimization parameters were established: (1) the minimum criteria for scoring attribute similarity (MCAS); and (2) the range of attribute weights (RAW). The cost model proposed in this study can help building owners and managers estimate the project budget at the business planning stage. Santruka Sprendimu priemimas ankstyvuoju statybos projekto etapu turi didele itaka projektui ir ivairiems scenarijams, remiantis savininko reikalavimais, kuriu turi būti laikomasi priimant sprendimus. Ankstyvaisiais statybos projekto etapais informacijos apie projekta paprastai yra nedaug ir ji nera patikima. Del to sudetinga planuoti ir taisyti projekta (ypač išlaidu planavima). Todel šio tyrimo metu buvo sukurtas kainos modelis, kuris galetu būti keičiamas atsižvelgiant i savininko poreikius. Kainos modelis, kuris buvo sukurtas šio tyrimo metu, remiasi atveju analize, pagrista argumentu metodika (angl. CBR). Modelis siūlo samatinius skaičiavimus su panašiausiais ankstesniais atvejais, kurie yra skaičiavimo pagrindas. Šio tyrimo metu procesas buvo optimizuotas naudojant genetinius algoritmus, rodančius projektu skaičiaus kitima tam tikro modelio duomenu bazeje pagal savininko priimamus sprendimus. Buvo nustatyti du optimizavimo parametrai: 1) minimalūs kriterijai veiksniu panašumui ivertinti (angl. MCAS); 2) veiksniu svoriu vertinimo intervalas (angl. RAW). Kainos modelis, pasiūlytas šiame tyrime, gali padeti pastatu savininkams ir valdytojams ivertinti projekto biudžeta verslo planavimo etape. First Published Online: 18 Oct 201
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