• Journal of information and communication convergence engineering
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• v.8 no.4
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• pp.370-376
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• 2010

Ensemble learning is a method for improving the performance of classification and prediction algorithms. However, its performance can be degraded due to multicollinearity problem where multiple classifiers of an ensemble are highly correlated with. This paper proposes genetic algorithm-based optimization techniques of SVM ensemble to solve multicollinearity problem. Empirical results with bankruptcy prediction on Korea firms indicate that the proposed optimization techniques can improve the performance of SVM ensemble.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2763-2765
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• 2003

Generally, we made use of PID control for torque control, speed control and stability, Hence, dynamic characteristic of DC motor has been studied for stable drive and accurate speed control by many engineers. But, in this paper, we applied genetic algorithm to current control for robust control and stability In conclusion, we prove that current control of genetic algorithm can be high efficiency.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.1
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• pp.102-110
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• 2017

In this paper, we have implemented an real-time adaptive feedback cancellation(AFC) algorithm that can be applied to multi-channel digital hearing aid. Multichannel digital hearing aid typically use the FFT filterbank based Wide Dynamic Range Compression(WDRC) algorithm to compensate for hearing loss. The implemented real-time acoustic feedback cancellation algorithm has one integrated structure using the same FFT filter bank with WDRC, which can be beneficial in terms of computation affecting the hearing aid battery life. In addition, when the AFC fails to operate due to nonlinear input and output, the reduction gain is applied to improve robustness in practical environment. The implemented algorithm can be further improved by adding various signal processing algorithm such as speech enhancement.

• IE interfaces
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• v.17 no.spc
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• pp.111-121
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• 2004

In this paper, we propose an urgency and efficiency based wireless packet scheduling (UEPS) algorithm that is able to schedule real time (RT) and non-real time (NRT) traffics at the same time. The proposed UEPS algorithm is designed to support wireless downlink packet scheduling in the OFDMA system which is a strong candidate wireless system for the next generation mobile communications. The UEPS algorithm uses the time-utility function as a scheduling urgency factor and the relative status of the current channel to the average one as an efficiency indicator of radio resource usage. The design goal of the UEPS algorithm is to maximize throughput of NRT traffics with satisfying QoS requirements of RT traffics. The simulation study shows that the proposed UEPS algorithm is able to give better throughput performance than existing wireless packet scheduling algorithms such as proportional fair (PF) and modified-largest weighted delay first (M-LWDF) while satisfying QoS requirements of RT traffics such as the average delay and the packet loss rate under various traffic loads.

• Journal of Advanced Navigation Technology
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• v.22 no.6
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• pp.557-565
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• 2018

For GNSS navigation in urban environment, a novel short delay multipath mitigation algorithm is proposed in this paper. This algorithm detects which satellite's signal is the multipath signal by using the constraint that GNSS receiver is equipped in a ground vehicle, then estimate new position after separating the measurement of that satellite. A criterion for detecting and validating the multipath signal depends on the performance grade of the GNSS receiver and the dynamics of the vehicle. In order to evaluate the proposed algorithm, the real data had been collected at the multipath environment of 4 scenarios. By post-processing the real data with both of the multipath mitigation algorithm in the receiver and the proposed algorithm, it can be checked that the position errors were less than 5 meters except the case that the number of visible satellite is lower than 5.

• Journal of Digital Convergence
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• v.17 no.1
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• pp.203-208
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• 2019

In this paper, we propose a real-time virtual model synchronization algorithm using object feature detection. The proposed algorithm may be useful to synchronize between real objects and their corresponding virtual models through object feature search in two-dimensional images. It consists of an algorithm to classify objects with colors individually, and an algorithm to analyze the orientation of objects with angles. We can synchronize the motion of the real object with the virtual model by providing the environment of moving the virtual object through the hand without specific controllers. The future research will include the algorithm to synchronize real object with unspecified shapes, colors, and directions to the corresponding virtual object.

• Atmosphere
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• v.31 no.5
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• pp.489-510
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• 2021

In this paper, we propose an algorithm for detecting convective initiation (CI) using GEO-KOMPSAT-2A/advanced meteorological imager data. The algorithm identifies clouds that are likely to grow into convective clouds with radar reflectivity greater than 35 dBZ within the next two hours. This algorithm is developed using statistical and qualitative analysis of cloud characteristics, such as atmospheric instability, cloud top height, and phase, for convective clouds that occurred on the Korean Peninsula from June to September 2019. The CI algorithm consists of four steps: 1) convective cloud mask, 2) cloud object clustering and tracking, 3) interest field tests, and 4) post-processing tests to remove non-convective objects. Validation, performed using 14 CI events that occurred in the summer of 2020 in Korean Peninsula, shows a total probability of detection of 0.89, false-alarm ratio of 0.46, and mean lead-time of 39 minutes. This algorithm can be useful warnings of rapidly developing convective clouds in future by providing information about CI that is otherwise difficult to predict from radar or a numerical prediction model. This CI information will be provided in short-term forecasts to help predict severe weather events such as localized torrential rainfall and hail.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.230-230
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• 2006

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.12C
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• pp.1075-1081
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• 2008

In this paper, we propose a code acquisition algorithm using optical orthogonal code (OOC) for optical code division multiple access (CDMA) systems. Generally, a good code acquisition algorithm offers short mean acquisition time (MAT). The conventional multiple-shift (MS) algorithm consists of two stages and has shorter MAT than that of well-known serial-search (SS) algorithm. This paper proposes a novel code acquisition algorithm called enhanced multiple-shift (EMS) algorithm. By using multiple thresholds, the proposed EMS algorithm provides shorter MAT compared with that of the MS algorithm. The simulation results show that the EMS algorithm presents shorter MAT compared with the MS algorithm in both single-user and multi-user environments.

• Journal of KIISE:Software and Applications
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• v.34 no.5
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• pp.397-406
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• 2007

The problem of finding an optimal alignment between sequence A and B can be solved by dynamic programming algorithm(DPA) efficiently. But, if the length of string was longer, the problem might not be solvable because it requires O(m*n) time and space complexity.(where, $m={\mid}A{\mid},\;n={\mid}B{\mid}$) For space, Hirschberg developed a linear space and quadratic time algorithm, so computer memory was no longer a limiting factor for long sequences. As computers's processor and memory become faster and larger, a method is needed to speed processing up, although which uses more space. For this purpose, we present an algorithm which will solve the problem in quadratic time and linear space. By using division method, It computes optimal alignment faster than LSA, although requires more memory. We generalized the algorithm about division problem for not being divided into integer and pruned additional space by entry/exit node concept. Through the proofness and experiment, we identified that our algorithm uses d*(m+n) space and a little more (m*n) time faster than LSA.