• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국정보통신학회 2017년도 춘계학술대회
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• pp.744-746
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• 2017

The maximum number of fiber spans is induced in disoersion-managed optical links with the non-midway optical phase conjugator (OPC) for the compensation of the distorted WDM signals due to the group velocity dispersion (GVD) are evaluated and compared.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국정보통신학회 2018년도 추계학술대회
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• pp.477-479
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• 2018

This study was carried out to utilize LSTM(Long Short-Term Memory) technique which is one kind of artificial neural network. Among the 27 types of motion data released by the UTD(University of Texas at Dallas), 3-axis acceleration and angular velocity data were applied to the basic LSTM and Deep Residual Bidir-LSTM techniques to classify the behavior.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제11권1호
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• pp.1-15
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• 1986

Optic flow is 2D velocity projected on the image plane of 3D velocity of a moving surface element. In this paper, we survey techniques computing optic flows from an image time sequence of moving objects and techniques determining 3D velocities and surface structures of the moving objects from the optic flows determined.

• Journal of the Korea Society of Computer and Information
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• 제23권2호
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• pp.17-26
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• 2018

In this paper, we propose a gait type classification method based on pressure sensor which reflects various terrain and velocity variations. In order to obtain stable gait classification performance, we divide the whole gait data into several steps by detecting the swing phase, and normalize each step. Then, we extract robust features for both topographic variation and speed variation by using the Null-LDA(Null-Space Linear Discriminant Analysis) method. The experimental results show that the proposed method gives a good performance of gait type classification even though there is a change in the gait velocity and the terrain.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제27권3A호
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• pp.240-248
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• 2002

This paper presents a new motion-based segmentation algorithm of moving objects in image sequences. The procedure toward complete segmentation consists of two steps: pixel labeling and motion segmentation. In the first step, we assign a label to each pixel according to magnitude of velocity vector. And velocity vector is generated by optical flow. And, in the second step, we have modeled motion field as a markov random field for noise canceling and make a segmentation of motion through energy minimization. We have demonstrated the efficiency of the presented method through experimental results.

• Journal of the Korean Society of Safety
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• 제23권6호
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• pp.34-37
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• 2008

The composite materials are widely used in the many applications of industry as well as aerospace field because of their high specific stiffness and strength which benefits the material and provides potential energy savings. However, composite materials also have a low property about external applied impact. In this paper, impact tests were conducted on different sample types(glass, carbon and kevlar composite) to obtain information such as absorbed energy and composite deformation using an instrumented impact test machine (DYNATUP 8250). 3 type samples were compared to experimental results. The data from impact test provided valuable information between the different type samples by wet lay up. This paper shows results of that kevlar composite has larger absorption energy and deformation than others.

• Journal of information and communication convergence engineering
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• 제2권3호
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• pp.177-181
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• 2004

In this paper, we suggest an Iris recognition system with an excellent recognition rate and confidence as an alternative biometric recognition technique that solves the limit in an existing individual discrimination. For its implementation, we extracted coefficients feature values with the wavelet transformation mainly used in the signal processing, and we used neural network to see a recognition rate. However, Scale Conjugate Gradient of nonlinear optimum method mainly used in neural network is not suitable to solve the optimum problem for its slow velocity of convergence. So we intended to enhance the recognition rate by using Levenberg-Marquardt Back-propagation which supplements existing Scale Conjugate Gradient for an implementation of the iris recognition system. We improved convergence velocity, efficiency, and stability by changing properly the size according to both convergence rate of solution and variation rate of variable vector with the implementation of an applied algorithm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국정보통신학회 2017년도 추계학술대회
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• pp.671-673
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• 2017

The maximum number of fiber spans is induced in disoersion-managed optical links with the non-midway optical phase conjugator (OPC) for the compensation of the distorted WDM signals due to the group velocity dispersion (GVD) are evaluated and compared.

• Annual Conference of KIPS
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• 한국정보처리학회 2013년도 추계학술발표대회
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• pp.259-261
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• 2013

금융 IT와 같은 분야에서는 빅데이터의 큰 특징 중 하나인 Velocity의 개선이 가장 큰 문제이다. 이는 산업의 특성상 승자가 시장을 독식하는 구조로 0.1 초라도 빠른 시스템 속도를 확보하면 시장 경쟁력이 매우 크기 때문이다. 비단 금융 IT 뿐만 아니라 다른 산업들도 최근 보다 빠른 속도의 데이터 처리에 매우 민감하게 반응하는 환경으로 변화하고 있으므로 이에 대한 솔루션이 필요하며 본 연구에서는 폭증스트림의 고속처리를 위한 Low-Latency에 대한 다양한 실험과 환경 구축을 통해 빅데이터의 Velocity 문제를 해결할 수 있는 방안을 제시한다.

• The Journal of the Acoustical Society of Korea
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• 제42권4호
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• pp.320-328
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• 2023

Underwater active target detection is vital for defense systems, requiring accurate detection and estimation of distance and velocity. Sequential transmission is necessary at each beam angle, but divided pulse length leads to range ambiguity. Multi-frequency transmission results in time-bandwidth product losses when bandwidth is divided. To overcome these problem, we propose a novel method using Generalized Sinusoidal Frequency Modulation (GSFM) for rapid target detection, enabling low-correlation pulses between subpulses without bandwidth division. The proposed method allows for rapid updates of the distance and velocity of target by employing GSFM with minimized pulse length. To evaluate our method, we simulated an underwater environment with reverberation. In the simulation, a linear frequency modulation of 0.05 s caused an average distance estimation error of 50 % and a velocity estimation error of 103 % due to limited frequency band. In contrast, GSFM accurately and quickly tracked targets with distance and velocity estimation errors of 10 % and 14 %, respectively, even with pulses of the same length. Furthermore, GSFM provided approximate azimuth information by transmitting highly orthogonal subpulses for each azimuth.