• 대한임베디드공학회논문지
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• 제6권5호
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• pp.311-317
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• 2011

The blind spot is an area where drivers visibility does not reach. When drivers change a lane to adjacent lane, they need to give an attention because of the blind spot. If drivers try to change lane without notice of vehicle approaching in the blind spot, it causes a reason to have a car accident. This paper proposes a night-time blind spot vehicle detection using cameras. At nighttime, head-lights are used as characteristics to detect vehicles. Candidates of headlight are selected by high luminance feature and then shape filter and kalman filter are employed to remove other noisy blobs having similar luminance to head-lights. In addition, vehicle position is estimated from detected head-light, using virtual center line represented by approximated the first order linear equation. Experiments show that proposed method has relatively high detection porformance in clear weather independent to the road types, but has not sufficient performance in rainy weather because of various ground reflectors.

• Archives of Reconstructive Microsurgery
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• 제17권1호
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• pp.19-27
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• 2008

Purpose: Microvascular reconstructive surgery has become an integral part of the treatment of head and neck cancer patients. This review of 121 free flaps for head and neck cancer patients performed over the last 11 years was done to evaluate circulatory crisis, salvage, and secondary reconstruction and to investigate which factors may contribute to these rates. Method: Nine emergent explorations among 121 head and neck reconstruction with free flaps were reviewed to analyze detection of vascular crisis, the time interval from detection of circulatory crisis to exploration, operation procedures and results, and secondary reconstructions. Emergent exploration was done with our protocol. Result: Nine free flaps exhibited signs of vascular problems between 1 day and 6 days postoperatively. The emergent exploration rate of this series was 7.4% (9/121). The salvage rate was 55.6% (5/9), giving an overall flap viability of 96.7% (117/121). In our study, preoperative radiation therapy, positive smoking history, alcohol consumption history, combined disease such as diabetes mellitus and hypertension, recipient vessels and types of vascular anastomosis were not related to the causes of circulatory crisis. The mean time interval between the onset of clinical recognition of impaired flap perfusion and re-exploration of the salvaged 5 flaps was 3.2 hours, that of failed 4 flaps was 11.25 hours. Conclusion: Despite high overall success rate, relatively low salvage rate may be attributed to late detection of circulatory crisis and in long time interval between detection and exploration. We conclude that early detection of circulatory crisis and expeditious re-exploration are a matter of great importance for the success of salvage operation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.155-156
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• 2007

This paper presents the vision-based camber and optimal cutting line detection algorithm for hot-rolling process. It is important to measure the camber of head and tail part of strips because many problems are caused by the camber in the hot-rolling process. The hot-rolling process has time constraints. The camber detection algorithm of head and tail parts requires fast and less complex for satisfying time constraints. The proposed algorithm consists of two parts: measurement of the camber in the head and tail part of strips and decision part of the optimal cutting line of hot-rolled strip. First, we obtain the camber value of the strip from the difference between the real center line and the center line of head, tail part. Second, the head and tail part of strips isn't suitable for strips connections. Therefore, the cutting process is needed in the hot-rolling process. The optimal cutting line is determined by the head and tail images obtained from cameras. The algorithm is applied into the vision system with two area cameras, Matrox image processing board and host PC for verification.

• 한국멀티미디어학회논문지
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• 제8권11호
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• pp.1421-1431
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• 2005

입체음향을 구현하는 방법은 두 가지가 있으며, 5.1 채널과 같은 서라운드 시스템(surround system)을 이용하는 방법과 2 채널의 바이노럴 시스템(binaural system)을 이용하는 방법이 있다. 바이노럴 시스템은 사람이 두 귀를 이용하여 음상을 정위하는 원리를 이용하는 방법이다. 일반적으로 라우더 스피커 시스템에서 각 채널사이에 발생하는 크로스토크(crosstalk)는 본래의 입체음향을 재생하기 위해서는 제거되어야만 한다. 이 문제를 해결하기 위해서는 머리의 움직임을 추정할 필요가 있다. 본 논문에서는 청취자의 머리 움직임을 제대로 추정하는 새로운 알고리즘을 제안한다. 제안하는 알고리즘은 얼굴과 눈의 영역 검출을 기본으로 한다. 얼굴 검출은 이미지의 밝기 값을 이용하고 눈 검출은 수학적 형태학(mathematical morphology)을 이용한다. 청취자의 머리가 움직일 때 얼굴 영역과 눈 사이의 경계선의 길이가 변한다. 이 정보를 이용하여 머리 움직임을 추정한다. 컴퓨터 시뮬레이션을 통해 제안하는 알고리즘이 +10오차 범위 내에서 머리의 움직임을 효율적으로 추정하는 것을 확인하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(4)
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• pp.25-28
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• 2000

Gaze detection is to find out the position on a monitor screen where a user is looking at, using the computer vision processing. This System can help the handicapped to use a computer, substitute a touch screen which is expensive, and navigate the virtual reality. There are basically two main types of the study of gaze detection. The first is to find out the location by face movement, and the second is by eye movement. In the gaze detection by eye movement, we find out the position with special devices, or the methode of image processing. In this paper, we detect not the iris but the pupil from the image captured by Head-Mounted Camera with infra-red light, and accurately locate the position where a user looking at by A(fine Transform.

• 한국압력기기공학회 논문집
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• 제10권1호
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• pp.15-19
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• 2014

A Failure or degradation of reactor upper head penetration is a recurring problem due to long term operation at nuclear power plants. And a flaw in the reactor upper head penetration has caused unplanned plant shutdown for repair as well as high economic impact on the plants. Consequently, a detection of flaws is of the utmost importance. Prior to the replacement of reactor upper head penetration, some utilities have repaired the flaws of reactor upper head penetration generated by overlay weld. Until now, only the base metal in reactor upper head penetration has been inspected according to 10 CFR 50.55a and ASME code case N-729-1. Accordingly, it is difficult to detect manufacturing defects and repair defects in overlay weld. This paper presents a case study on the application of Time of Flight Diffraction technique for reactor head penetration mockup with artificial flaws in overlay weld. This study offers a way to understand the flaws detected in reactor upper head penetration overlay weld.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권11호
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• pp.4644-4661
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• 2015

Wireless sensor networks are often organized in the form of clusters leading to the new framework of WSN called cluster or hierarchical WSN where each cluster head is responsible for its own cluster and its members. These hierarchical WSN are prone to various routing layer attacks such as Black hole, Gray hole, Sybil, Wormhole, Flooding etc. These routing layer attacks try to spoof, falsify or drop the packets during the packet routing process. They may even flood the network with unwanted data packets. If one cluster head is captured and made malicious, the entire cluster member nodes beneath the cluster get affected. On the other hand if the cluster member nodes are malicious, due to the broadcast wireless communication between all the source nodes it can disrupt the entire cluster functions. Thereby a scheme which can detect both the malicious cluster member and cluster head is the current need. Abnormal energy consumption of nodes is used to identify the malicious activity. To serve this purpose a learning based energy prediction algorithm is proposed. Thus a two level energy prediction based intrusion detection scheme to detect the malicious cluster head and cluster member is proposed and simulations were carried out using NS2-Mannasim framework. Simulation results achieved good detection ratio and less false positive.

• 대한임베디드공학회논문지
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• 제12권2호
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• pp.113-120
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• 2017

In this paper, we present a night-time vehicle detection method using CNN (Convolutional Neural Network) classification. The camera based night-time vehicle detection plays an important role on various advanced driver assistance systems (ADAS) such as automatic head-lamp control system. The method consists mainly of thresholding, labeling and classification steps. The classification step is implemented by existing CIFAR-10 model CNN. Through the simulations tested on real road video, we show that CNN classification is a good alternative for night-time vehicle detection.

• 대한두경부종양학회:학술대회논문집
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• 대한두경부종양학회 2004년도 제21차 학술대회
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• pp.241-243
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• 2004

• 한국압력기기공학회 논문집
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• 제11권2호
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• pp.1-5
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• 2015

A failure or degradation of reactor upper head penetration is a troublesome problem at Nuclear Power Plants. A flaw in the reactor upper head penetration can result in unplanned plant shutdown for repair, and cause serious economic losses on the plants. Consequently, a detection of flaws is a matter of more importance. Until now, only the base metal, not including J-groove weld, in reactor upper head penetration has been inspected in accordance with 10 CFR 50.55a and ASME code case N-729-1 requirements. Accordingly, it is rather difficult to detect manufacturing defects and repair defects in J-groove weld. This paper presents a case study on the application of Time of Flight Diffraction UT technique to examine the J-groove weld in reactor head penetration using reactor head penetration mockup with artificial flaws. We expect that this study result will offer a way to understand the non-destructive examination technology for J-groove weld in reactor upper head penetration.