• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.4
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• pp.248-255
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• 2003

This paper presents a fingerprint recognition algorithm using cross-correlation function. This algorithm consists of minutiae extraction, minutiae alignment and minutiae matching, where we propose a new minutiae alignment method. In our alignment method, the rotation angle between two fingerprints is obtained by using cross-correlation function of the minutia directions, thereafter the displacement is obtained from the rotated fingerprint. This alignment method is capable of finding rotation angle and displacement of two fingerprints without resorting to exhaustive search. Our fingerprint recognition algorithm has been tested on fingerprint images captured with inkless scanner. The experiment results show that 17.299% false rejection ratio(FRR) at 2.086% false acceptance ratio(FAR).

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.11
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• pp.904-911
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• 2007

A measurement technique fur void fraction has been proposed using a time-resolved two-phase PIV system and the bubble dynamics has been investigated in gas-liquid two-phase flows. For the three-dimensional evaluation of the bubble information, both the images from the front and side views are simultaneously recorded into a high speed CCD camera by reflecting the side view image on a $45^{\circ}$ oriented mirror to be juxtaposed with the front view image. Then, a stereo-matching technique is applied to calculate the void fraction, bubble size and shape. To obtain the rising bubble velocities, the 2-frame PTV method was adopted. The present technique is applied to freely rising bubby flows in stagnant liquid. The results show that the increase of bubble flow rate gives rise to the increase of bubble size and rising velocity at first. If it goes over a certain level, the rising velocity becomes constant and the horizontal velocity grows bigger instead due to the obstruction of other bubbles.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.302-302
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• 2008

다층 세라믹 기판은 내열성, 내마모성 및 우수한 전기적 특성으로 인하여 기존의 PCB의 대체품으로 많이 이용되며 그 수요가 점점 늘어가고 있는 추세이다. 이에 고집적 다층 세라믹 기판을 보다 다기능화, 고밀도화, 고성능화하기 위해서는 세라믹 층간 정밀도가 아주 중요한 요소로 부각되고 있으며, 무수촉 기판 소성기술을 이용한 층간 정밀도를 높이는 연구가 진행되어지고 있다. 그러나 무수축 기판에서 이러한 정밀도를 유지하기 위해서는 전극의 수축률을 기판의 수축율과 같은 0%에 가깝게 제어하여야 하며 이를 위해서 여러 가지 Frit을 이용하여 수축율을 제어를 시도되고 있다. Ag 전극은 낮은 비저항 우수한 접착성 등의 장점을 가지고 있을 뿐 아니라 가격이 저렴하여 전극재료로서 많은 연구가 이루어졌다. 특히 Infiltration법에 의한 무수축소성의 경우 Glass가 Ag paste로 Infiltration되어 Ag paste와 세라믹의 matching성 확보에 많은 문제가 발생하였다. 이에 본 실험에서는 제조된 Ag conductor paste 에 첨가되는 frit이 무수축 기판과의 매칭성에 어떠한 영향이 있는지에 대하여 고찰하였다. 시편의 준비는 frit이 첨가된 Ag paste를 기판에 screen printing 한 후 $900^{\circ}C$에서 소결한 것을 사용하였으며 Ag 전극의 미세구조를 관찰하고 전기적 특성과 미세구조와의 연관성에 관해 고찰하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.1709-1712
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• 2013

교통 신호등은 운전자 혹은 보행자들의 뚜렷한 시인성 확보를 위해 가능한 주위 배경과 구분되는 색상, 모양, 질감 등으로 구성하여 설치되어 있는 특징을 가지고 있다. 결국 기존 교통 신호등 검출 연구들에서는 대부분 교통 신호등의 색상과 모양을 기반으로 한 검출 연구가 주류를 이루고 있는 것이 사실이다. 하지만, 외부 날씨, 복잡한 시내, 다른 물체와의 겹침 등의 문제로 인해 색상 및 모양 기반의 교통 신호등, motion blur, 검출 오류가 증가 되고 있다. 따라서 본 연구에서는 입력 영상에서 색상정보를 배제하고 motion blur나 밝기 변화에 덜 민감하고 먼 거리에서도 뛰어난 시인성을 가진 spot light 검출을 통해 입력 영상에서 가장 밝은 교통표지판 후보 영역들을 검출한다. 그리고 교통 신호등의 특징인 가능한 원형을 유지하고 있으며 원형 외부 색상과 내부 색상이 현저하게 두드러지는 영역을 maximally stable extremal regions (MSER) 알고리즘을 사용하여 입력 영상에서 후보 영역을 선택한다. 마지막으로, 검출된 영역들에서 교통 신호등 영역을 검출하기 위해 템플릿 매칭 방법을 적용한다. 제안한 방법을 도로 상에서 실험한 결과, 평균 94% 이상의 검출율을 제시하였고, 특히 야간 시간대에 검출율이 비교적 높게 제시되었다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.1A
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• pp.122-131
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• 2000

In this paper, we propose a cell scheduling algorithm for input queueing ATM switch. The input queueing architecture is attractive for building an ultra-high speed ATM (Asynchronous Transfer Mode) switch. We proposea WMUCS (Weighted Matrix Unit Cell Scheduler) based on the MUCS which resolves HOL blocking and outputport contention. The MUCS algorithm selects an optimal set of entries as winning cells from traffic matrix (weightmatrix). Our WMUCS differs from the MUCS in generating weight matrices. This change solves the starvationproblem and it reduces the cell loss variance. The performance of the proposed algorithm is evaluated by thesimulation program written in C++. The simulation results show that the maximum throughput, the average celldelay, and the cell loss rate are significantly improved. We can see that the performance of WMUCS is excellentand the cost-effective implementation of the ATM switch using proposed cell scheduling algorithm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.894-897
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• 2008

The stress is an unavoidable result and a complex phenomenon in modem society. too, Human activity changes under control of the stress. The stress is a reaction to adrenalin or other stress hormones. It provides the power for fighting and the energy for going away from dangers. Because of the stress, our bodies increase the pulse, the blood pressure and the breath for more blood and more oxygen. So, in this research, we are measuring those which was increased by the stress. Also we will examine the change of HRV and APG on music. After that, in order to reduce the stress, we will design matching system that is based on the sense for music by using Zigbee.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5471-5478
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• 2012

In this paper, we propose a new short-circuit detecting method which can detect bad short-circuits, one of bad types occurring in PCB(Printed Circuit Board), by using SURF(Speeded-Up Robust Features) algorithm. The basic procedure in the proposed method sequentially consists of extracting features from both sample and inputted images by SURF, performing perspective transform by feature matching and matching results, extracting check areas of interest, binary coding and extracting short-circuits, and verifying results. The proposed method focuses on the robustness which can detect bad short-circuits even though the position and angle of PCB are not uniform and arbitrarily placed. Experimental results show that our method enables to detect bad short-circuits regardless of the location and angle of PCB placed variously and validate that the proposed method outperforms the conventional methods detecting bad short-circuits manually on the aspect of both the detection rate and time.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.10
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• pp.1114-1120
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• 2009

The conductivity of various electro-threads is analyzed, and the washable electro-thread embroidery UHF RFID tag antennas using the character shape without T-matching structure are designed by adding a T-matching structure. The RFID tag antenna using the electro-thread is easy to be embedded on a cloth as a wearable antenna because it is flexible and different from general copper inlay shape and tape type tag. The embroidery tag antennas are designed with the English alphabet 'F' and the Korea alphabet 'ㄹ' character. Those are easy to be applied to general clothes. The parameters of antennas are optimized and fabricated. The characteristics and the reading range patterns of the tag antennas are measured. The reading ranges of wet tags(tap water, sea water and soapy water) are tested and compared.

• Journal of KIISE:Information Networking
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• v.36 no.1
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• pp.50-56
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• 2009

This paper proposes a new algorithm of clustering similar nodes defined as nodes having similar characteristic values in pure P2P environment. To compare similarity between nodes, we introduce a fitness function whose return value depends only on the two nodes' characteristic values. The higher the return value is, the more similar the two nodes are. We propose a GORGFM algorithm newly in conjunction with the fitness function to recommend and exchange nodes' characteristic values for an interest group formation and maintenance. With the GORGFM algorithm, the interest groups are formed dynamically based on the similarity of users, and all nodes will highly satisfy with the information recommended and received from nodes of the interest group. To evaluate of performance of the GORGFM algorithm, we simulated a matching rate by the total number of nodes of network and the number of iterations of the algorithm to find similar nodes accurately. The result shows that the matching rate is highly accurate. The GORGFM algorithm proposed in this paper is highly flexible to be applied for any searching system on the web.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.4
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• pp.1285-1293
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• 2010

This study suggests the design and implementation of an e-mentoring system, which creates more than one role models to help adult learners of cyber university to improve their academic performance and to successfully complete their education. The benefits of this system are as following; First, automatic matching system is built in consideration of mutual requests between mentor and mentee. And the system enforces all participants to actively participate in the program by sharing ideas and to improve their academic performance with specific academic goals. Second, participants are rewarded at the end of the program for their performance by an evaluation system developed for assessing role models and participants' activities. Also, the system encourages best mentors to remain in the program and help adult learners to improve academic performance.