• Annual Conference of KIPS
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• 2017.04a
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• pp.1160-1162
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• 2017

자연광은 시시각각 변화하며 광 특성의 변화는 계절별 시간별 일주기리듬을 갖는다. 이러한 자연광의 리듬은 인간의 감성 또는 수면-각성 패턴과 같은 생체리듬에 영향을 미친다. 인간의 생체리듬은 멜라토닌에 의해 조절되며 특히, 수면-각성주기를 일정한 수면패턴으로 유지하게 한다. 이에 본 논문에서는 자연광의 하루 주기변화에 따라 조명의 단파장 영역 중 446nm~477nm의 비율을 제어하여 심부 체온의 변화를 통해 수면패턴을 분석한다. 분석결과, 자연광의 일몰시간과 유사한 시점에서 446nm~477nm의 비율을 최소로 제어 하였을 때 수면에 긍정적인 영향을 미치는 것을 확인하였다.

• Journal of Internet Computing and Services
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• v.24 no.2
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• pp.19-26
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• 2023

Humans have adapted and evolved to natural light. However, as humans stay in indoor longer in modern times, the problem of biorhythm disturbance has been induced. To solve this problem, research is being conducted on lighting that reproduces the correlated color temperature(CCT) of natural light that varies from sunrise to sunset. In order to reproduce the CCT of natural light, multiple LED light sources with different CCTs are used to produce lighting, and then a control index DB is constructed by measuring and collecting the light characteristics of the combination of input currents for each light source in hundreds to thousands of steps, and then using it to control the lighting through the light characteristic matching method. The problem with this control method is that the more detailed the steps of the combination of input currents, the more time and economic costs are incurred. In this paper, an LED lighting control method that applies interpolation and combination calculation based on the minimum spectral power distribution information for each light source is proposed to reproduce the CCT of natural light. First, five minimum SPD information for each channel was measured and collected for the LED lighting, which consisted of light source channels with different CCTs and implemented input current control function of a 256-steps for each channel. Interpolation calculation was performed to generate SPD of 256 steps for each channel for the minimum SPD information, and SPD for all control combinations of LED lighting was generated through combination calculation of SPD for each channel. Illuminance and CCT were calculated through the generated SPD, a control index DB was constructed, and the CCT of natural light was reproduced through a matching technique. In the performance evaluation, the CCT for natural light was provided within the range of an average error rate of 0.18% while meeting the recommended indoor illumination standard.

• Annual Conference of KIPS
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• 2017.04a
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• pp.454-456
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• 2017

인간은 오랜 시간 자연광에 순응하며 진화해왔고 자연광과 유사한 환경에서 보다 능률적인 작업과 편안한 휴식을 갖는다. 자연광의 광 특성은 색온도, 단파장, 조도 및 휘도 등으로 분류되며 광 특성에 따라 인간에게 미치는 영향과 효과가 달라진다. 이에 본 논문에서는 자연광의 광 특성을 고려하여 사용자의 건강과 감성, 조명의 에너지 효율 등 다양한 목적에 따라 최적의 조명서비스를 제공할 수 있는 통합제어시스템을 구현하였다.

• Annual Conference of KIPS
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• 2012.11a
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• pp.1307-1310
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• 2012

최근 도시화가 급격히 진행되면서 도심 공간의 효율적인 이용을 위하여 지하공간의 개발이 새로운 대안으로 주목 받고 있다. 지하공간은 일반적으로 건축 구조상 자연채광의 유입이 불가능한 구조로서 지하 거주자의 심리적, 환경적 문제를 초래하므로 이의 활성화를 위해서는 공간의 질적 제고가 선행되어야 한다. 빛과 조명은 공간의 질을 결정하는 중요한 요소로서 거주자를 위해 건강하고 편안한 환경을 제공하기 위해서는 거주자의 생체리듬과 부합하는 자연광과 유사한 광 환경(색온도, 조도) 서비스를 제공해야 한다. 본 논문은 지하공간을 대상으로 인공조명의 광 환경을 시간의 흐름에 따라 변화하는 자연의 빛과 유사하게 서비스하기 위한 LED제어시스템을 개발한다.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06d
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• pp.462-464
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• 2012

최근 건물 내 에너지 소비량의 30%를 점유하고 있는 조명 에너지 절감을 위해 자연광을 이용하여 인공조명의 의존도를 낮추고 에너지 사용을 최소화하기 위한 다양한 연구가 진행되고 있다. 이에 본 논문에서는 조명 에너지 소비 절감 및 재실자의 작업 능률 향상을 위해 조명시뮬레이션 소프트웨어인 Relux를 이용하여 소규모 사무 공간을 3D로 모델링하고, 이를 기준으로 시간대별 자연광의 유입량에 따라 조명장치를 점멸제어, 조광제어, 스텝제어의 다양한 제어방법을 적용하여 반복적인 시뮬레이션 과정을 통해 각 제어방법에 따른 에너지 절감률을 비교 및 분석하였다. 분석 결과 조광제어가 60.5%로 가장 높은 에너지 절감률을 보였다.

• Journal of the Korea Computer Industry Society
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• v.10 no.4
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• pp.153-158
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• 2009

This paper designed for natural lighting environment implementation with mixed color and white LED equipment. Lighting LED equipment Have a lot of advantage than traditional commercial lighting equipment. Such as high energy conversion efficiency and easy dimming control performance. This paper proposed LED lighting equipment with color sensor acquisition system can make best lighting environment for Human various kinds necessary.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.217-222
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• 2004

사진 측광은 일시에 대량의 데이터를 얻을 수 있으므로 시간에 따라 빛이 변화하는 주광의 측정 수단으로 이용될 수 있다. 이를 위하여 자연광 아래에서 디지털 이미지와 휘도 측정치의 보정실험을 행하였으나 청공광과 백색시료를 제외한 나머지 시료에 대해서는 그리 만족스러운 결과를 가져오지 못하였다. 앞으로 Videophotometry를 실현하기 위해서는 피 계측면의 분광 반사특성에 의한 계측치의 오차를 제거하기 위한 CCD 소자의 시감도 보정, 시야를 정확하게 재현하기 위한 광학적 연구, 인간의 시각 특성에 부합하는 측정 휘도의 보정 등에 대한 연구가 이루어져야 할 것이다.

• Korean Chemical Engineering Research
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• v.49 no.5
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• pp.505-509
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• 2011

Visible light-activated photocatalysts (based on doped titania) are the subject of intensive current research due to the promise they offer in relation to solar powered systems for photocatalysis, hybrid systems for $CO_2$ conversion and hydrogen production from water. Current synthetic methodologies suffer from one or more serious shortcomings, which seriously hinder practical application. These include high cost, irreproducibility, difficulty in controlling the dopant level and unsuitability for scale up. In this review new reproducible and controllable methods (developed by Lambert group, Cambridge University) allowing the synthesis of practical quantities of efficient, visible light active anion (e.g. N, C and B) doped $TiO_2$ photocatalysts are summarized.

• Journal of Internet Computing and Services
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• v.25 no.4
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• pp.65-72
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• 2024

To faithfully represent the intention of the work in the exhibition space, lighting that provides high color reproduction like natural light is required. Thus, many lighting technologies have been introduced to improve CRI, but most of them only evaluated the general color rendering index (CRI Ra), which considers eight pastel colors. Natural light provides excellent color rendering performance for all colors, including red and blue, expressed by color rendering index of R9 and R12, but most artificial lighting has the problem that color rendering performance such as R9 and R12 is significantly lower than that of natural light. Recently, lighting technology that provides CRI at the level of natural light is required to realistically express the colors of works including primary colors but related research is very insufficient. Therefore this paper proposes exhibition hall lighting that fulfills CRI with a focus on CRI Ra, R9, and R12 based on the characteristics of natural light. First reinforcement wavelength bands for improving R9 and R12 are selected through analysis of the actual measurement SPD of natural and artificial lighting. Afterward virtual SPDs with a peak wavelength within the reinforcement wavelength band are created and then SPD combination conditions that satisfy CRI Ra≥95, R9, and R12≥90 are derived through combination simulation with a commercial LED light source. Through this, after specifying two types of light sources with 405,630nm peak wavelength that had the greatest impact on the improvement of R9 and R12, the exhibition hall lighting applied with two W/C White LEDs is designed and a control Index DB of the lighting is constructed. Afterward experiments with the proposed method showed that it was possible to achieve high CRI at the level of natural light with average CRI Ra 96.5, R9 96.2, and R12 94.0 under the conditions of illuminance (300-1,000 Lux) and color temperature (3,000-5,000K).

• Journal of the Korean Geophysical Society
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• v.4 no.2
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• pp.87-93
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• 2001

The roof tiles excavated from the mountain fortress at Namsan-ri Seocheon-gun in Chungnam province were dated by using SAR protocol, Sample preparation was done with the quartz exclusion method. The paleodoses from 6 kinds of roof tiles were obtained from OSL measurements and the does rates of the soil around the excavated roof tiles and the tile themselves were measured from ICP/MS and ICP/AES with the conversion table. From the evaluated paleodose and the dose rate, the age of the roof tiles were determined to be from(733 ± 50)AD to (1160 ± 50)AD and the error was less than 10%.