• Journal of Information Display
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• 제13권4호
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• pp.159-166
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• 2012

In this paper, a display's emotional image quality can be primarily determined by designing the proper luminance level. Though displays with high luminance are preferred, too much light emission from a display may cause glare or visual fatigue to viewers. To find out the proper luminance level based on various video contents, this study was conducted with an OLED display with a real-black level and a wide color gamut, and with an LCD display with a high luminance level, to set the glare threshold under various conditions. The optimum luminance levels according to the display's loading ratio were found, and the maximum luminance that did not cause a glare in the test is proposed.

• 한국도로학회논문집
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• 제16권3호
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• pp.85-99
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• 2014

PURPOSES : This study has been performed with the objective to determine threshold zone luminance of adaptation luminance by target safety level in a vehicular traffic tunnel with design speed set at 100km/h. METHODS : The study made a miniature capable of portraying changes in luminance distribution within $2{\times}10^{\circ}$ conical field of view of the driver approaching to the tunnel for the test. Test conditions were set based on justifications for CIE 88-1990's threshold zone luminance used as a reference by domestic tunnel light standards (KS C 3703 : 2010). Luminance contrast of object background and object is 23%, object presentation duration is 0.5 seconds, and size of the object background is $7.3{\times}11.5m^2$ RESULTS : Threshold zone luminance was set within adaptation luminance of $100{\sim}3,000cd/m^2$. Adaptation luminance and threshold zone luminance based on 50%, 75% and 90% target safety level all showed a relatively high linear relationship. According to findings in the study, it is not appropriate to specify the relationship between adaptation luminance and threshold zone luminance as luminance ratio. Rather, direct utilization of the linear relationship gained from the study findings appears to be the better solution. CONCLUSIONS : Findings of this study may be used to determine operation of threshold zone luminance based on target safety level. However, a proper verification and validity of test results are required. Furthermore, a study to determine proper threshold zone luminance level considering target safety level reviewed in this study and various decision-making factors such as economic conditions in Korea and energy-related policies should be carried out in addition. Additional tests on adaptation luminance greater than $3,000cd/m^2$ will be performed, through which application scope of the test findings will be broadened.

• 한국도로학회논문집
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• 제17권1호
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• pp.129-142
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• 2015

PURPOSES : The purpose of this study is to suggest a basis for setting appropriate safety goals specifically related to the threshold zone luminance in a vehicular traffic tunnel. METHODS : In the test, drivers were divided into two groups. One group consisted of all drivers (average drivers) group with an age ratio of drivers holding domestic driver's license and driver group by age to produce threshold zone luminance in the tunnel. The threshold zone luminance produced as a result was used to analyze how it affects the safety level of each driver group and provide a basis for setting an appropriate safety criterion that can be used to determine threshold zone luminance. We used test equipment, test conditions, and ananalysis of threshold zone luminance identical to that reported by ChoandJung(2014) but the values of adaptation luminance in our analys is were expanded to range from100 to $10,000cd/m^2$. RESULTS : Adaptation luminance and threshold zone luminance are found to be related by a quadratic function. The threshold zone luminance needed by older drivers to ensure a certain safety level is significantly higher than that for drivers of other age brackets when adaptation luminance increases. 56% of older drivers are at an increased risk of an accident at the same luminance for which the safety level of average drivers is 75%. The safety level that can be achieved for older drivers increases to above 60% when threshold zone luminance level is set with the goal of attaining a safety level of more than 85% for average drivers. The safety level that can be attained for average drivers is above 90% when the threshold zone luminance is high enough to ensure over 75% in the safety level of older drivers. Results of this study are applicable to highways and others whose designed speed is 100 km/h. CONCLUSIONS : Threshold zone luminance determined on the basis of drivers having average visual ability is of limited value as a performance standard for ensuring the safety of older drivers. Hence, safety level for older drivers should be considered separately from safety levels for drivers with an average ability to avoid risk. Upward adjustment of older drivers' safety level in the process of determining appropriate threshold zone luminance in a vehicular traffic tunnel may bring both tangible and intangible benefit as a result of reducing accidents. However, there is an associated dollar cost arising from installing and operating lights. As a result, the economic impact of these trade-offs should also be considered.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권4호
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• pp.161-165
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• 2005

Need of a dimmer function becomes more important with increasing interest on a HDTV for home theater applications. In a conventional AC PDP, a possible method to reduce luminance of a whole Panel is to reduce a total number of sustain pulses and then to change the gray level. However, the reduction of the total sustain number causes the step of luminance to be rough. Moreover, it is impossible to control the luminance of the panel for a given gray level. In this paper, a simple and robust method is proposed to control linearly the luminance of whole panel by applying the asymmetric sustain pulses in the display period of the ADS driving scheme. As the range of luminance control by the proposed method is about $50\%$ for a given gray level. Moreover, it is experimentally verified that the proposed method shows similar dynamic margin performances compare with the conventional method.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.171-175
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• 2004

Need of a dimmer function becomes more important with increasing interest on a HDTV for home theater applications. In a conventional ac PDP, a possible method to reduce luminance of a whole panel is to reduce a total number of sustain pulses and then to change the gray level. However, the reduction of the total sustain number causes the step of luminance to be rough Moreover, it is impossible to control the luminance of the panel for a given gray level. In this paper, a simple and robust method is proposed to control linearly the luminance of whole panel by applying the asymmetric sustain pulses in the display period of the ADS driving scheme. As the range of luminance control by the proposed method is about 50% for a given gray level. Moreover, it is experimentally verified that the proposed method shows similar dynamic margin performances compare with the conventional method.

• 한국자기학회지
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• 제26권5호
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• pp.168-172
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• 2016

MRI 검사실의 최적환경을 목적으로 검사실 및 모니터의 휘도와 조도를 측정하였다. 대학병원(n = 6)의 MRI(n = 10)에서 휘도와 조도를 Unfors Xi Light Probe(Unfors Instruments AB, Billdal, Sweden)를 이용하여 측정하였다. 휘도는 black level과 white level을 조도는 모니터의 측면의 중앙에서 3회 반복하여 평균과 표준편차를 구하여 t-test를 이용하여 유의성 검정의 통계적 처리를 하였다. 모니터 휘도는 black level에서 평균 $1.78cd/m^2$, 표준편차 $0.85cd/m^2$이었고, white level에서는 평균 $43.58cd/m^2$, 표준편차 $13.19cd/m^2$로 측정되었다. MRI 검사실 조도는 최저값 30.5 lux, 최대값 601.3 lux, 평균 177.86 lux로 측정되었고, 휘도와 조도는 통계학적으로 유의한 차이가 있다(p < .05). MRI 모니터 및 검사실 휘도와 조도의 권고 기준을 참고하여 최적인 환경을 조성하도록 한다.

• 한국산업융합학회 논문집
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• 제1권2호
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• pp.55-64
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• 1998

This paper deals with the effects of fluorescent lamp description and luminance level on the occupant's brightness perception and other sensation in building interiors. The following experiments were conducted: the subjects compared on room lit by daylight fluorescent lamps with the other room lit by the different lamp description at equal luminance at equal luminance level. The degree of that effect decreased with a rise in luminace level. The brightness perception had high correlation with the visual clarity and no correlation with favorite sensation.

• 한국정보통신학회논문지
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• 제10권11호
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• pp.1946-1953
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• 2006

광도 요소의 워터마크 내장은 컬러 영상을 그레이 스케일 영상과 같은 변형에서 삽입한 소유권 정보의 추출을 보장하기 때문에 YCbCr와 같은 광도-색차 컬러 공간에서 색상의 광도 요소에 소유권 정보를 내장한다. 따라서 본 논문은 워터마크의 견고성과 비시각성에 중점을 두고, 멀티미디어 컨텐츠서비스의 장치와 성능을 고려한 컬러 영상의 워터 마크 내장, 추출 및 인증 알고리즘을 제안한다. 컬러 영상은 RGB 컬러 공간에서 YCbCr 컬러 공간으로 변형 한 다음 Y(Luminance), Cb(Color Differences) 및 Cr(Color Differences) 각 요소의 특성을 고려하여 웨이브릿 기반의 주파수 영역에서 다중 레벨(Multi-Level)의 워터마크를 내장하고 추출 및 인증한다. 실험 결과, JPEG 압축에 따른 견고성과 다중 레벨에 대한 워터마크의 비 시각성을 보장할 수 있었다

• 한국조명전기설비학회지:조명전기설비
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• 제9권3호
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• pp.59-66
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• 1995

In this study through a series of the experiments, 1) the preferable luminance values of the CRT screens, 2) the preferable luminance ratios between the CRT screens and its surrounding surfaces are determined. The results are evaluated by the level of satisfaction, and re-examined by the work performance (number of types, rate of errors) and the level of eye fatique (number of blinks, near point distance)

• 한국생활환경학회지
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• 제20권2호
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• pp.233-237
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• 2013

Daylighting affects the luminous environment and provides comfortable environment to the occupants. However, excessive daylighting might have negative influences on the visual comfort. Skylight, light intensity and distribution, and insolation could cause glare effects on the occupants. This study analyzed the effect of fenestration on the interior glare effects, and verified luminous environment adjustability through mock up test of conventional fenestration and 'Convergence Window System' by analyzation of luminance, luminance contrast, and glare effect. Consequently, room installed Convergence Window System was improved luminance contrast and PGSV Level.