1,782 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

    K*{\Lambda}(1116) photoproduction and nucleon resonances

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    In this presentation, we report our recent studies on the Kβˆ—Ξ›(1116)K^*\Lambda(1116) photoproduction off the proton target, using the tree-level Born approximation, via the effective Lagrangian approach. In addition, we include the nine (three- or four-star confirmed) nucleon resonances below the threshold sthβ‰ˆ2008\sqrt{s}_\mathrm{th}\approx2008 MeV, to interpret the discrepancy between the experiment and previous theoretical studies, in the vicinity of the threshold region. From the numerical studies, we observe that the S11(1535)S_{11}(1535) and S11(1650)S_{11}(1650) play an important role for the cross-section enhancement near the sth\sqrt{s}_\mathrm{th}. It also turns out that, in order to reproduce the data, we have the vector coupling constants gKβˆ—S11(1535)Ξ›=(7.0∼9.0)g_{K^*S_{11}(1535)\Lambda}=(7.0\sim9.0) and gKβˆ—S11(1650)Ξ›=(5.0∼6.0)g_{K^*S_{11}(1650)\Lambda}=(5.0\sim6.0).Comment: 2 pages, 2 figures, talk given at International Conference on the structure of baryons, BARYONS'10, Dec. 7-11, 2010, Osaka, Japa

    Service-Learning in Language for Specific Purposes: A Case of Korean Language Practicum

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    While service-learning has been greatly acknowledged as an effective instructional tool in education for the past two decades, it has not been extensively applied to the Korean classroom and Language for Specific Purposes (LSP) settings as of yet. The practical challenges of community-involved service-learning for the less commonly taught language (LCTL) programs such as Korean are discussed. Moreover, community engagement through the campus community combined with the language teaching practicum is suggested for service-learning as an alternative to address the challenges. This study explores the curriculum design of a service-learning for a small language group and offers practical ideas on how to expose the students to campus communities, thereby providing them with cross-cultural insights and language practicum competence that extend beyond classroom language learning. The outcome supports that the campus community engagement effectively provides a hands-on opportunity for the students to practice not only their academics but also their leadership skills through the experience of designing their own service details in collaboration with their campus community partners

    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

    Selection of Elevation Models for Flood Inundation Map Generation in Small Urban Stream: Case Study of Anyang Stream

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    To reduce flood damages, the Ministry of Environment in Korea has provided a flood inundation map so that people can expediently identify flood-prone areas. However, the current flood inundation maps have been produced based on the DEM which makes it difficult to represent realistic situations due to the lack of reproduction of land surface conditions. This study aims to provide more accurate and detailed flood inundation maps for flooding events due to river overflow in small urban areas. In this study, flood inundation analysis is performed using the river analysis system, HEC-RAS 2D, with the DSM and the DEM of urban areas in the Anyang Stream Basin, Korea to examine the differences in terms of terrain data and flooded area. Finally, for urban areas with dense buildings and congested road networks, the flood inundation analysis based on DSM can represent a more realistic flood situation and create an appropriate flood inundation map

    Hydraulic and ecological changes under drainage gate operations with coupled model SCHISM-CoSiNE in Saemangeum basin, Korea

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    The drainage gates have been controlled for desalination under normal conditions and flood defense in  Saemangeum basin, Korea. Recently, it became an issue that the gates have been opened not to deteriorate water quality in the lake. It is, thus, necessary to precisely estimate the changes of water quality characteristics, especially DO, phosphate and nitrate, in the lake according to various gate operations. In this study, Semi-implicit Cross-scale Hydroscience Integrated System Model and Carbon, Silicate, Nitrogen Ecosystem model (SCHISM-CoSiNE) which is cable to simulate dynamic exchange such as gate operation conditions was utilized to obtain reliable and reasonable results including hydrodyanamic and environmental variables. For the verification, the measured data at 6 locations in Saemangeum basin was used to compare  incluidng temperatue and salintiy from 2016 and each relative error became small enough to show high accurary. Also, under various scenarios by changing the designated water surface elevation on flood seasons, this model has been applied to present the best designated water surface elevation in terms of both water quality and water supply in the Saemangeum basin. It becomes possbile to show reliable guidance for dynamic operations and environmental changes with this model as requested in near future

    A Score-Based Evaluation Model for Rehabilitation of Existing Pumped Storage Hydropower Plant Construction

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    As the proportion of new and renewable energy increases, power control demands are becoming more frequent due to variability in power generation. As a complementary means against this, the pumped storage hydropower plants (PSHP) are attracting attention as energy storage systems (ESS), but it has high construction costs. Therefore, this study aims to improve the economic feasibility by developing the evaluation model of the existing infrastructure into an upper/lower dam suitable for PSHP. The concept of upper dam capacity is newly defined, and the evaluation index is constructed using normalization. A new evaluation system is presented for five factors: environment, stability, energy, capacity, and economy. Finally, it is tested in the pilot area in Korea. Several candidates, including the PSHP in operation, are found to have been distributed with higher scores. These results will help to satisfy the selection of candidates during the preliminary feasibility study phase, and programming them will enable more accurate and rapid assessment

    Contribution of higher nucleon resonances to K*{\Lambda} photoproduction

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    We investigate K*{\Lambda}(1116) photoproduction off the proton and neutron targets in the effective Lagrangian method in the tree-level Born approximation. In addition to the K, K*, and {\kappa} exchanges which are the main contributions to the reaction, we consider the contributions from the higher nucleon resonances D13(2080) and the D15(2200). We find that the D13(2080) plays a crucial role in explaining the enhancement of the near-threshold production rate, which results in a good agreement with the experimental data for the proton targets, while the contribution of the D15(2200) is rather small. A similar conclusion is drawn for K* photoproduction off the neutron targets. In addition to the energy and angular dependence of the cross sections, we present the predictions on the photon-beam asymmetry.Comment: 12 pages, 19 figure
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