• 한국인터넷방송통신학회논문지
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• 제13권2호
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• pp.157-163
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• 2013

본 논문에서는 조명이 없는 야간 및 악천후 등 가시영상 카메라를 이용하여 사람 영역을 추정하기 힘든 환경에서의 대안으로 열화상 카메라를 이용한 사람검출 방법을 제안한다. 일반적인 열화상에서 사람은 주변 배경에 비해 밝게 표현되는 특징을 이용하여, 밝기 히스토그램 상의 사람의 열화상의 신뢰 구간을 계산해 1차적으로 사람 영역을 추정한 뒤, 가우시안 필터링 및 레이블링을 통해 불필요한 잡음을 제거한다. 그 이후에 Self-occlusion 등에 의해 분리된 사람 영역을 각 blob별 무게중심 및 분포정보를 이용하여 하나의 객체 영역을 추정한다. 최종적으로 추정 영역에 대한 가로와 세로의 비율 및 크기 정보와 주성분분석(PCA; principal component analysis)를 이용하여 추정된 영역에 대하여 사람인지 여부를 결정한다. 실험결과를 통하여, 제안된 방법은 가시영상에서 검출하기 힘든 환경들에 대하여 좋은 성능을 나타내는 것을 알 수 있었다.

• 대한치과기공학회지
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• 제33권2호
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• pp.129-136
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• 2011

Purpose: The purpose of this study was to investigate the transmittance differences of zirconium core due to thickness within the visible light spectrum. Methods: 36 specimens were divided into 3 groups (0.6mm, 0.8mm, 1.0mm) which have each 12 specimens. The size of specimens was 10mm high and 10mm wide. The transmittance of specimens are measured by spectrophotometer Model Cary 500 that can measure infrared-ray, visible wave and ultraviolet-ray. Results: The results shows that there was no significant difference between specimen's thickness and transmittance. Conclusion: The individual's color perception is personal and there are numerous factors that influence on it. In general, human eye can perceive the color of thing only within visible light spectrum but in this experiment through spectrophotometer there was no big difference between specimen's thickness and transmittance. To sum up, The most important factors were a layed porcelain structure and its thickness rather than core thickness in the porcelain crown.

• 한국위성정보통신학회논문지
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• 제7권3호
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• pp.41-46
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• 2012

LED 기반 가시광 통신 시스템은 RF통신과 달리 인체에 무해하며, 주파수 허가를 받을 필요가 없고, 보안 특성이 우수하며, 넓은 가시광 대역을 사용할 수 있는 시스템이다. 하지만 LED 발광을 조명과 광 데이터 전송으로 동시에 사용하기 위해 깜박거림 방지와 밝기 조절 기능의 구현이 요구되는데 이때 code rate의 열화가 발생한다. 따라서 고속 멀티미디어 데이터 전송을 위해 본 논문에서 가시광 통신 시스템에서 적용 가능한 line coding기법 Symbolic-PPM(Pulse Position Modulation)을 제안하고 기존의 VPPM(Variable Pulse Position Modulation) 기법과 비교하여 깜박거림 방지 및 밝기 조절 기능을 구현 한 상태에서 고속 데이터 전송을 위한 전송 효율 증가 효과를 모의실험을 통하여 검증하였다.

• 조명전기설비학회논문지
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• 제27권10호
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• pp.1-8
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• 2013

Wireless Visible Light Communication is the technology that enables communication using LED illumination Infrastructure instead of existing illumination such as incandescent lamp or fluorescent light. Because VLC uses light for communication, it has no problem of frequency permission and is harmless to human body. It is also possible to check the communication through eye. So VLC can be used as a supplement to the Radio Frequency communication, Infrared in indoor environment. So far, researchers on the LED Visible light communication have focused on the increasing transmission speed, transmission distance, modulation method. However, there is few research of main factors that influence on system performance. System performance has been mainly predicted through simulation. In this paper, I recognized that these factors such as outside light noise, obstacle, LED panel position or emitted angle have a great impact on wireless communication system. So I experimented VLC system by changing distance and position to discover location suitable for BER regulation.

• 로봇학회논문지
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• 제11권4호
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• pp.277-284
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• 2016

A new prediction scheme has been proposed for the robust teleoperation in a non-visible environment. The positioning error caused by the time delay in the non-visible environment has been compensated for by the Smith predictor and the sensory data have been estimated by the Grey model. The Smith predictor is effective for the compensation of the positioning error caused by the time delay with a precise system model. Therefore the dynamic model of a mobile robot has been used in this research. To minimize the unstable and erroneous states caused by the time delay, the estimated sensor data have been sent to the operator. Through simulations, the possibility of compensating the errors caused by the time delay has been verified using the Smith predictor. Also the estimation reliability of the measurement data has been demonstrated. Robust teleoperations in a non-visible environment have been performed with a mobile robot to avoid the obstacles effective to go to the target position by the proposed prediction scheme which combines the Smith predictor and the Grey model. Even though the human operator is involved in the teleoperation loop, the compensation effects have been clearly demonstrated.

• 전자공학회논문지B
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• 제30B권12호
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• pp.67-72
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• 1993

An adaptive block truncation coding(BTC) using human visual system(HVS) is proposed. To reduce visible blocking effect at sensitive area in HVS. a new category classification coefficient is proposed. The categroy classification coefficient was derived by combining the modified HVS and standard deviation. By computer simulations, we showed that the proposed method reduced blocking effect at low bit rate coding more than the conventional Hui's method.

• 분석과학
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• 제33권1호
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• pp.42-48
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• 2020

Bromate is a disinfection by-product generated mainly from the oxidation of bromide during the ozonation and disinfection process in order to remove pathogenic microorganism of drinking water, and classified as a possible human carcinogen by International Agency for Research of Cancer (IARC) and World Health Organization (WHO). For the purpose of determining the trace level concentration of bromate, several sensitive techniques are applied mostly based on suppressed conductivity detection and UV/Visible detection after postcolumn reaction (PCR). In this study, the suppressed conductivity detection method and the PCR-UV/Visible detection method through the triiodide reaction were compared to analyze the trace bromate in water samples and estimated for the availability of these analytical methods. In addtion, the state-of-the-art techniques was applied for the determination of trace level bromate in various water matrices, i.e., soft drinking water, hard drinking water, mineral water, swimming pool water, and raw water. In comparison of two analytical methods, it was found that the conductivity detection had the suitable advantage to simultaneously analyze bromate and inorganic anions, however, the bromate might not be precisely quantified due to the matrix effect especially by chloride ion. On the other hand, the trace bromate was analyzed effectively by the method of PCR-UV/Visible detection through triiodide reaction to satisfactorily minimize the matrix interference of chloride ion in various water samples, showing the good linearity and reproducibility. Furthermore, the method detection limit (MDL) and recovery were 0.161 ㎍/L and 101.0-108.1 %, respectively, with a better availability compared to conductivity detection.

• 한국전자통신학회논문지
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• 제17권5호
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• pp.995-1002
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• 2022

위성항법시스템은 전지구에서 어디에서나 위성신호만 수신하면 수신기의 위치와 시간 정보를 획득할 수 있는 편리한 시스템이다. 하지만 항법신호는 오차를 포함하고 있고 신호의 수신 상태에 따라 수신기의 위치 오차가 발생한다. 또한, 위성들의 기하학적 배치에도 위치 오차는 영향을 받는다. 그러므로 가시위성의 개수와 상태에 따라 수신기의 위치 성능은 변화한다. 특히, 위성이 뜨거나 지는 시각에는 해당 위성의 신호 상태가 좋지 않으며 도심지에서 건물 등의 장애물로 인해 신호가 차단되는 경우에는 수신기의 위치가 변화하여 나타난다. 본 논문에서는 보정량을 추정하여 수신기가 측정한 의사거리에 반영하는 기법과 가시위성을 조정하는 기법을 이용하여 위성항법 성능을 향상하는 방법을 제안하였다. 제안된 기법을 가시위성의 개수가 빈번하게 변화하는 환경에 적용하여 위성항법 시스템의 성능향상을 검증하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1478-1481
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• 2007

This paper introduced a measurement method for image sticking based on human vision perception. Existing image sticking quantification method is mostly different from visible level by human perception. It takes a long time to measure image sticking which is degraded by time due to using a spot photometer, therefore many test samples could not be evaluated in a given short period of time in mass production line. However, the new measurement method in this paper is possible to evaluate a large quantity of samples in fast and high correlation with human perceptual level of image sticking.

• 혜화의학회지
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• 제20권1호
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• pp.25-37
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• 2011

It fuses into culture of the East and the West in use of color ; colors of five direction, which had been from the Five Phase Theory in East Asia. Formative ability of color fields in a formative early Oriental Medicine history as well. Color is a very important factor and a necessary step of visible diagnosis. As a human's body is maintained and alive under the control of spirit and spirit is stored by five viscera, so spirit expresses the change of five viscera and is reflected by color. Visible diagnosis consists of spirit, appearance, Qi and color and movement. The purpose of each visible diagnosis is that we would know states of essence, Qi and spirit in patient's body. To ancient Asia people 'to see' was a kind of insight to the object as a whole. Similarily the activity of seeing the human body was the integral part of making diagnosis of a patient. This was the cause that there was suggested the discussion of the Five color theory in Oriental Medicine as a counterpart to that of the 'Goethe for Zur Farbenlehrer'. The inspection of Oriental Medicine was not a simple gazing of the eye as a sense organ, but the total insight to the internal state of the patient. For that reason, the eye－perception in early Chinese medicine was the reading the signs of the internal body which had have not the visual form but the flux of the internal life.