• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.1
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• pp.70-76
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• 2002

In this paper, we proposed a personal identification algorithm using the iris region which has discriminant features. First, we acquired the eye image with the black and white CCD camera and extracted the iris region by using a circular edge detector which minimizes the search space for real center and radius of the iris. And then, we localized the iris region into several circles and extracted the features by filtering signals on the perimeters of circles with one dimensional Gabor filter We identified a person by comparing ,correlation values of input signals with the registered signals. We also decided threshold value minimizing average error rate for FRR(Type I)error rate and FAR(Type II)error rate. Experimental results show that proposed algorithm has average error rate less than 5.2%.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.788-792
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• 2004

In this study, the performance of the DPRMs is evaluated and the measurement precision for the pile driving is presented. The DPRMs is a visual-measurement system for the pile rebound and the penetration movement using a high speed line-scan camera. But the measurement errors of the DPRMs are caused by the strong impact for the pile driving. Therefore, the DPRMs should guarantee its measurement values for the pile driving. For this reason, the performance of the DPRMs by the vibration signal analysis is studied. It is found from this study that the measurement values of the DPRMs are reliable.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.01a
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• pp.59-61
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• 2014

본 논문에서는 단일의 카메라로부터 획득한 영상에 있는 동공 중심을 실시간으로 검출하는 알고리즘을 제안한다. 제안하는 방법은 원에서 현의 수직이등분선은 그 원의 중심을 지난다는 사실을 이용하여 동공의 현을 찾고 동공 중심을 계산하는 것이다. 먼저 VPF(Variance Projection Function)을 이용해 일차적으로 동공 중심을 탐지한다. 탐지된 중심점을 기준으로 원을 탐색하여 정확한 동공 중심점을 찾는다. 실험을 통하여 제안한 방법은 높은 검출율과 처리시간 관점에서 우수함을 보인다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.12 s.243
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• pp.1653-1659
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• 2005

In this study, the performance of a DPRMs is evaluated and the measurement precision for the pile driving is presented. The DPRMs is a visual-measurement system for the pile rebound and the penetration movement using a high speed line-scan camera. The DPRMs generates the measurement deviation. It is caused by the strong impact for the pile driving. To reduce it, the vibration signal analysis about the pile driving is performed. As a result, it is confirmed that the tilting frequency of a camera-tripod structure corresponding to excitation frequency range of the ground is under 40Hz. Through the structure modification, the camera-tripod structure is redesigned to the model being free itself from the excitation frequency range of the ground. By the verification testing about the improvement effects, it is inspected that the tilting and measurement deviation of the redesigned DPRMs are reduced.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.5 s.110
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• pp.514-520
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• 2006

In this study, the performance of a digital pile rebounding and penetration monitoring system (DPRMS) is evaluated and the measurement precision of the DPRMS is improved. The DPRMS is a high speed line-scanning camera system to measure the rebound and penetration of a pile in a construction work. A main problem in the DPRMS is a measurement error, which is caused by a shock or vibration due to a hammer impact. The measurement error is investigated by analyzing vibration signals of the DPRMS during the impact. Moreover, the frequency response functions of the DPRMS are also analyzed. As a result, it is found that the tripod height has an influence on the DPRMS performance and a shorter tripod is better. One more founding in this study is that the DPRMS should be placed with a appropriate distance from a pile for improving the measurement precision.

• KIISE Transactions on Computing Practices
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• v.21 no.3
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• pp.239-246
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• 2015

QR(Quick Response) Code has been developed to provide greater storage capacity and more functionality compared to 1D bar codes. With the emergence of increasingly mobile devices equipped with cameras such as smart-phones and tablets, QR codes have become very popular and more important in mobile businesses. Typically, most QR codes are used as a URL link for redirecting users to webpages. However, the URL based QR codes are required to be connected over the internet and to be run a server. This can incur unnecessary traffics in the Internet. Furthermore, it is not suitable for the country lagging behind others in its network infrastructure. In this paper, we propose a server-less ${\mu}$-webpage to provide mobile web services and be optimized for the capabilities and limitations of QR Code. We have implemented the ${\mu}$-webpage in Android, and the results showed that the proposed mechanism can provide web-services without requiring extra servers or incurring mobile traffic data compared to the URL-based QR Codes.

• Korean Journal of Remote Sensing
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• v.37 no.5_1
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• pp.1111-1124
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• 2021

Mudflats are crucial for understanding the ecological structure and biological function of coastal ecosystem because of its high primary production by microalgae. There have been many studies on measuring primary productivity of tidal flats for the estimation of organic carbon abundance, but it is relatively recent that optical remote sensing technique, particularly hyperspectral sensing, was used for it. This study investigates hyperspectral sensing of chlorophyll concentration on a tidal flat surface, which is a key variable in deriving primary productivity. The study site is a mudflat in Geunso bay, South Korea and field campaigns were conducted at ebb tide in April and June 2021. Hyperspectral reflectance of the mudflat surfaces was measured with two types of hyperspectral sensors; TriOS RAMSES (directionalsensor) and the Specim-IQ (camera sensor), and Normal Differenced Vegetation Index (NDVI) and Contiuum Removal Depth (CRD) were used to estimate Chl-a from the optical measurements. The validation performed against independent field measurements of Chl-a showed that both CRD and NDVI can retrieve surface Chl-a with R² around 0.7 for the Chl-a range of 0~150 mg/m² tested in this study.