• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.23 no.6
• /
• pp.31-39
• /
• 2009

This paper proposes an ultrasonic sensor based intelligent automatic door system which improves the performance of conventional door systems by adding more intelligent functions such that it offers more convenience to passersby and reduces power loss. The conventional automatic door systems employed passive and active infrared sensors for detecting objects and human bodies. But, they have problems such as power loss in door closing, not sensing fast approaching objects, and safety. The proposed automatic door system with ultrasonic sensors prevents unnecessary door closings to save the power and senses fast approaching objects to open the door at proper time, and improves safety. Thus, the proposed system improves the performance of the conventional systems in terms of operation, economy, and safety.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.22 no.6
• /
• pp.1-6
• /
• 2008

In this paper describes the process of designing a protection circuit against an open or short electronic ballast. An open electronic ballast creates high voltages in a regular period, which a lies voltage stress on switching devices. On the other hand, a shorted output generates excessive current, causing problems such as heat generation in the ballast and reduced lifespan of semiconductor devices. This study proposes a protection circuit consisting of TTL and passive devices to resolve the problems. The proposed protection circuit offers the benefits of low cost and high reliability. The proposed circuit was connected to an actual ballast to demonstrate its applicability.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.8
• /
• pp.1918-1924
• /
• 2010

This In this paper, we propose an efficient algorithm for motion estimation of the image sequences with luminance fluctuation. For such sequences, conventional motion estimation methods based on the difference of pixel values usually produce the erroneous motion information. The proposed algorithm defines the luminance fluctuation as a linear model with gain and offset parameter, and extracts motion information using gradient and phase of the corresponding local region within consecutive frames. Therefor the method is robust to the luminance change of the frames. We test our algorithm for the ground truth sequence with artificially added luminance change and motion, and real sequences corrupted by the flicker. The results shows that the proposed algorithm outperforms the conventional methods.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2019.07a
• /
• pp.241-242
• /
• 2019

4차 산업 혁명에 맞춰 빠르게 발전하고 1990년대부터 등장하기 시작했던 '인텔리전트 빌딩'이 다시 주목을 받고 있다. 센서와 컴퓨터가 내장된 사물들이 인터넷으로 연결되어 각종 서비스를 제공하여 환경을 변화시키고 삶이 편해지고 있다. 그럼에도 불구하고 편리함을 추구하는 기존 기술 들은 대기업들이 주를 이루어 관리를 하게 되고 있고 유지 보수비용이 많이 들어 스마트 기기에 능숙하지 않은 부분도 있어 본 논문은 보다 기존의 IOT 기술보다 유지 보수비용의 절감과 손쉬운 접근방식을 제공한다. 본 논문인 '구글 어시스턴트를 이용한 스마트 홈 제어'는 집 전체를 제어하여 조명, 냉난방, 환기 등을 조절하고 무단 침입자를 감지하며 경고음을 알려주는 것이다. 예를 들어 집 주인이 외출을 하였는데 가스렌지의 불을 안 끄고 나왔거나 조명을 안 끄고 나왔는데 집을 다시 들어가기 어려운 상황일 때 핸드폰으로 버튼 하나만 누르면 제어가 된다. 본 논문의 목적은 집안의 화재나 전기 요금절감을 위하고 편리한 삶을 추구하고자 개발 되었다.

• Journal of Korea Society of Industrial Information Systems
• /
• v.16 no.4
• /
• pp.87-98
• /
• 2011

Detecting a moving object from videos and tracking it are basic and necessary preprocessing steps in many video systems like object recognition, context aware, and intelligent visual surveillance. In this paper, we propose a method that is able to detect a moving object quickly and accurately in a condition that background and light change in a real time. Furthermore, our system detects strongly an object in a condition that the target object is covered with other objects. For effective detection, effective Eigen-space and FCM are combined and employed, and a CONDENSATION algorithm is used to trace a detected object strongly. First, training data collected from a background image are linear-transformed using Principal Component Analysis (PCA). Second, an Eigen-background is organized from selected principal components having excellent discrimination ability on an object and a background. Next, an object is detected with FCM that uses a convolution result of the Eigen-vector of previous steps and the input image. Finally, an object is tracked by using coordinates of an detected object as an input value of condensation algorithm. Images including various moving objects in a same time are collected and used as training data to realize our system that is able to be adapted to change of light and background in a fixed camera. The result of test shows that the proposed method detects an object strongly in a condition having a change of light and a background, and partial movement of an object.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.22 no.3
• /
• pp.73-87
• /
• 2023

Furnishing traffic safety information can contribute to providing hazard warnings to drivers, thereby avoiding crashes. A smart road lighting platform that instantly recognizes road conditions using various sensors and provides appropriate traffic safety information has therefore been developed. This study analyzes the short-term traffic safety improvement effects of the smart road lighting's tunnel traffic safety information service using surrogate safety measures (SSM). Individual driving behavior was investigated by applying the vehicle trajectory data collected with RADAR in the Anin Avalanche 1 and 2 tunnel sections in Gangneung. Comparing accumulated speeding, speed variation, time-to-collision, and deceleration rate to avoid the crash before and after providing traffic safety information, all SSMs showed significant improvement, indicating that the tunnel traffic safety information service is beneficial in improving traffic safety. Analyzing potential crash risk in the subdivided tunnel and access road sections revealed that providing traffic safety information reduced the probability of traffic accidents in most segments. The results of this study will be valuable for analyzing the short-term quantitative effects of traffic safety information services.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.9 no.1
• /
• pp.9-18
• /
• 2010

Our country has so large mountain area that the tunnel construction is inevitable and the need of incident detection that provides safe management of tunnels is increasing. In this paper, we suggest a tunnel incident detection system using computer vision techniques, which can detect the incidents in a tunnel and provides the information to the tunnel administrative office in order to help safe tunnel operation. The suggested system enhances the processing speed by using simple processing algorithm such as image subtraction, and ensures the accuracy of the system by focused on the incident detection itself rather than its classification. The system is also cost effective because the video data from 4 cameras can be simultaneously analyzed in a single PC-based system. Our system can be easily extended because the PC-based analyzer can be increased according to the number of cameras in a tunnel. Also our web-based structure is useful to connect the other remotely located tunnel incident systems to obtain interoperability between tunnels. Through the experiments the system has successfully detected the incidents in real time including dropped luggage, stoped car, traffic congestion, man walker or bicycle, smoke or fire, reverse driving, etc.

• Journal of Broadcast Engineering
• /
• v.13 no.3
• /
• pp.339-349
• /
• 2008

We present a novel method to estimate the light source direction and relight a face texture image of a single 3D model under arbitrary unknown illumination conditions. We create a virtual irradiance sphere to detect the light source direction from a given illuminated texture image using both normal vector mapping and weighted bilinear interpolation. We then induce a relighting equation with estimated ambient and diffuse coefficients. We provide the result of a series of experiments on light source estimation, relighting and face recognition to show the efficiency and accuracy of the proposed method in restoring the shading and shadows areas of a face texture image. Our approach for face relighting can be used for not only illuminant invariant face recognition applications but also reducing visual load and Improving visual performance in tasks using 3D displays.

• Journal of the Korea Computer Graphics Society
• /
• v.26 no.3
• /
• pp.87-97
• /
• 2020

In this paper, we propose a novel neural relighting that infers a relighted rendering image based on the user-guided specular highlight map. The proposed network utilizes a pre-trained neural renderer as a backbone network learned from the rendered image of a 3D scene with various lighting conditions. We jointly optimize a 3D light position and its associated relighted image by back-propagation, so that the difference between the base image and the relighted image is similar to the user-guided specular highlight map. The proposed method has the advantage of being able to explicitly infer the 3D lighting position, while providing the artists' preferred 2D screen-space interface. The performance of the proposed network was measured under the conditions that can establish ground truths, and the average error rate of light position estimations is 0.11, with the normalized 3D scene size.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.416-417
• /
• 2013

최근 질화물계 발광다이오드(light emitting diode, LED) 소자는 핸드폰, 스마트 TV 등의 디스플레이 분야와 실내외조명, 감성조명, 특수조명 등의 조명분야에 그 응용분야가 급속히 확대되고 있다. 이러한 LED 소자는 에너지 절감과 친환경에 장점을 가지고, 가까운 미래에 조명시장을 대체할 것으로 예상된다. 이를 만족하기 위해서는 현재보다 더 높은 효율을 갖는 LED 개발이 요구되어지고 있는 상황이다. 일반적으로 질화물계 LED 소자의 효율은 내부양자 효율, 광추출 효율 등으로 나타낼 수 있다. 내부 양자효율은 성장된 결정의 질의 개선 및 다층의 이종접합 또는 다중양자우물 구조와 같이 활성층의 캐리어 농도를 높이는 접합구조로 설계되어 80% 이상의 효율을 나타낸다. 그러나 광추출 효율은 이에 미치지 못하고 있다. 이는 반도체 재료의 높은 굴절률로 인하여 빛이 외부로 탈출하지 못하고 내부로 반사되거나 물질 안에서 흡수가 일어나기 때문이다. 따라서 이러한 문제를 해결하기 위해 많은 연구 그룹들은, 표면에 패턴 형성하여 빛의 전반사를 줄여 그 효율을 올리는 연구결과를 보고하고 있다. 대표적인 방법으로는 wet etching, 전자빔 리소그라피, 나노임프린트 리소그라피, 레이저 홀로 리그라피, 나노스피어 리소그라피 등이 사용되고 있다. 이 중, 나노스피어 리소그라피는 폴리스틸렌 혹은 실리카 등과 같은 나노 크기의 bead를 사용하여 반도체 기판 표면에 단일층으로 고르게 코팅한 마스크로 사용하여 패턴을 주는 방법이다. 이 방법의 장점으로는 대면적에 균일한 패턴을 형성할 수 있고, 공정비용이 저렴하여 양산하기에 적합하다는 특징이 있다. 나노스피어 리소그라피를 통해서 표면에 생성된 패턴 모양의 각도에 따라서, 식각되는 깊이에 변화에 따라 실험한 결과들은 있지만, 아직까지 크기가 다른 나노입자들의 마스크 이용하여 형성된 패턴 밀도에 따른 광 추출 효과에 대한 연구가 많이 미흡하다. 따라서 본 연구에서는 다양한 크기의 실리카로 패턴을 형성시켜 패턴 밀도에 대한 광추출 효율의 효과에 대해서 조사하였다. 실험 방법으론, DI, 에탄올, TEOS, 암모니아의 순서대로 그 혼합 비율을 조정하여 100, 250, 500 nm 크기의 나노입자를 합성하였고 이것을 질화물계 LED의 표면 위에 단일층으로 스핀코팅 방법을 통해 코팅을 하였다. 그 후 ICP-RIE 방법으로 필라 패턴을 형성하였는데, 그 결과 100 nm SiO2 입자를 이용한 경우 $4.5{\times}10^9$/$cm^2$, 250 nm의 경우 $1.4{\times}10^9$/$cm^2$, 500 nm의 경우 $0.4{\times}10^9$/$cm^2$의 패턴의 밀도를 보여주었다(Fig. 1). 패턴의 밀도에 따라 전계광학적 특성을 확인하여 보았는데, 그 결과는 평평한 표면과 비교하였을 때 100 nm에서 383%, 250 nm에서는 320%, 500 nm에서는 244% 상승하는 결과를 보여주었다(Fig. 2). 이번 실험을 통해서 LED의 광추출 효율은 표면 모양과 깊이 뿐 아니라 밀도가 커질수록 그 효율이 올라간다는 사실을 알 수 있었다.