• International Journal of Fluid Machinery and Systems
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• v.9 no.2
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• pp.150-158
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• 2016

In this paper, a new framework that works the automatic execution with less design cycle time and human intervention bottlenecks is introduced to optimize the vortex shedder design by numerical integration method. This framework is based on iSIGHT combined with the pre-processor GAMBIT, and flow analysis software FLUENT. Two vortex shedders, circular with slit and triangular- semi circular cylinder, are employed as the designed models to be optimized, and DOE driver is used for optimization. According to the essential properties of a vortex shedder, it has found that the best diameters are 30mm for circular cylinder with slit and 30 to 35 mm for tri-semi cylinder. For slit ratio, 0.1 and 0.15 are the optimized values for circular with slit and tri-semi cylinder respectively. And it is found that these optimal results generated by DOE automated design cycle are in well agreement with the experiment.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.11 no.3
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• pp.106-113
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• 1997

In uninterruptible power supply(UPS), a high speed phase control is usually required to compensate transients in the output voltage at the instant of transfer from the ac line to the inverter when the ac line fails or backs to the ac line in case of the inverter fails. To overcome this problem, this paper pre¬sents the closed digital phase-locked loop(DPLL) techniques designed by full software with TMS320C31 digital signal processor and describes the functional operation of the proposed DPLL. Fi¬nally, the performance of the proposed DPLL is shown and discussed through simulation and experiment.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.05a
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• pp.1-5
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• 2002

The purpose of this paper is developing a speech recognition module in a wheelchair for the sake of convenience. of the disability. For this system, we used TMS320C32 as a main processor; eliminated noise by applying Winer filler while considering characteristics of noise environment in pre-processing stage, and; extracted 12 feature patterns per france using LPC&Cepstrum. Then, we implemented the hybrid form combining DTW (Dynamic Time Warping), which is generally used for isolated words in the conventional algorithms, in the recognition Part, and NN (Neural network) to prevent any error of recognition. In this research, we achieved a recognition rate of more than 96% on isolated words when DTW and Hybrid forms were individually experimented in noise environment

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.2 no.2
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• pp.133-138
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• 2002

In this paper, we propose an integrated GUI environment of parallel fuzzy inference system fur pattern classification of remote sensing data. In this, as 4 fuzzy variables in condition part and 104 fuzzy rules are used, a real time and parallel approach is required. For frost fuzzy computation, we use the scan line conversion algorithm to convert lines of each fuzzy linguistic term to the closest integer pixels. We design 4 fuzzy processor unit to be operated in parallel by using FPGA. As a GUI environment, PCI transmission, image data pre-processing, integer pixel mapping and fuzzy membership tuning are considered. This system can be used in a pattern classification system requiring a rapid inference time in a real-time.

• Journal of Oral Medicine and Pain
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• v.14 no.1
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• pp.67-80
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• 1989

The author studied the changes of muscle activity with Bioelectric processor Model EM2(Myotronics Corp., USA) before and after occlusal stabilization splint therapy. For this study, 15 temporomandibular disorders patients and 15 students without any temporomandibular disorders symptoms were selected, for experimental group and control group, respectively. Experimental group were treated with occlusal stabilization splint and checked about electromyographic activity before and after therapy. Electromyographic levels were measured in both groups at the following mandibular position, i.e., physiologic rest, tapping, light biting, hard open without pain, open with pain, right excursion and ipsilateral biting, left excursion and ipsilateral biting, protrusion, protrusive biting, edge biting and physiologic rest after movement. The obtained results were as follows : 1. In experimental group, post-treatment mean values of muscle activity were lower than pretreatment values. 2. In general, the pre-treatment mean values of muscle activity in experimental group were higher than those of control group. 3. In experimental group, no statistically significant difference appeared between affected and unaffected side. 4. The mean value of muscle activity in physiologic rest position after each movement check was lower than that before each movement check.

• Journal of applied mathematics & informatics
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• v.29 no.5_6
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• pp.1337-1349
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• 2011

So far as a solution of the given consistent linear system is concerned many numerical methods - both mathematically non-iterative as well as iterative - have been reported in the literature over the last couple of centuries. Most of these methods consider all the equations including linearly dependent ones in the system and obtain a solution whenever it exists. Since linearly dependent equations do not add any new information to a system concerning a solution we have proposed an algorithm that identifies them and prunes them in the process of solving the system. The pruning process does not involve row/column interchanges as in the case of Gauss reduction with partial/complete pivoting. We demonstrate here that the use of pruning as an inbuilt part of our solution process reduces computational and storage complexities and also computational error.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.2
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• pp.579-603
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• 2018

In this paper we propose a QoS-enhanced intelligent stochastic optimal fair real-time packet scheduler, QUEST, for 4G LTE traffic in routers. The objective of this research is to maximize the system QoS subject to the constraint that the processor utilization is kept nearly at 100 percent. The QUEST has following unique advantages. First, it solves the challenging problem of starvation for low priority process - buffered streaming video and TCP based; second, it solves the major bottleneck of the scheduler Earliest Deadline First's failure at heavy loads. Finally, QUEST offers the benefit of arbitrarily pre-programming the process utilization ratio.Three classes of multimedia 4G LTE QCI traffic, conversational voice, live streaming video, buffered streaming video and TCP based applications have been considered. We analyse two most important QoS metrics, packet loss rate (PLR) and mean waiting time. All claims are supported by discrete event and Monte Carlo simulations. The simulation results show that the QUEST scheduler outperforms current state-of-the-art benchmark schedulers. The proposed scheduler offers 37 percent improvement in PLR and 23 percent improvement in mean waiting time over the best competing current scheduler Accuracy-aware EDF.

• Journal of Broadcast Engineering
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• v.9 no.1
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• pp.9-16
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• 2004

In this paper, we present a speech enhancement method as a pre-processor for voice commander under car environment. For the friendly and safe use of voice commander in a running car, non-stationary audio signals such as music and non-candidate speech should be reduced. Ow technique is a two microphone-based one. It consists of two parts Blind Source Separation (BSS) and Kalman filtering. Firstly, BSS is operated as a spatial filter to deal with non-stationary signals and then car noise is reduced by kalman filtering as a temporal filter. Algorithm Performance is tested for speech recognition. And the results show that our two microphone-based technique can be a good candidate to a voice commander.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.1
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• pp.58-65
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• 2007

The method of 3D sound realization using 2 speakers provides two advantages: cheap and easy to build. In the case, crosstalk between 2 speakers has to be eliminated. To calculate and remove the effect of the crosstalk it is essential to find a rotation angle of human head correctly. In the paper, we suggest an algorithm to find the head angle of 2 channel system. We first detect a face area of the given image using Haar-like feature. After that, the eve detection using pre-processor and morphology method. Finally, we calculate the face rotation angle with the face andi the eye location. As a result of the experiment on various face images, the proposed method improves the efficiency much better than the conventional methods.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.361-363
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• 2005

본 논문에서는 MPEG-4 Version2 Audio 표준에 근거하여 낮은 연산부담을 갖는 독자적인 엘고리즘을 적용한 MPEG-4 BSAC Audio 디코더를 개발하였다. 개발된 BSAC 디코더는 32bit RISC 구조를 갖는 Intel Xscale Processor 기반 시스템에 최적화하여 구현 및 평가를 수행하였다. 수행속도 증가 및 연산 정밀도 향상을 위해 각 기능 블록별 기능 및 구현 원리 연구와 32 bit 연산 구조를 파악하여, 이를 고정소수점 연산 구조로 구현함으로써 성능을 향상시켰다. 유한비트에 따른 오차 영향을 최소화하기 위해 데이터의 표현 범위에 대한 연구를 통해 근사한 오차를 최소화 하여 연산 정밀도를 향상 시키고자 하였다. 비선형 양자화기 및 filter bank 등 상대적으로 높은 연산 부담을 갖는 기능 블록은 Table look-up, 보간법, 지수연산 제거, pre/post scrambling 기법 등을 적용하여 최적화 하였다. 최종적으로 개발된 BSAC 디코더는 32 bit 연산 구조의 X-scale 프로세서를 탑재한 Development Board와 WindowsCE OS로 구성된 타겟 system에 이식하여 performance 평가하였으며, 높은 연산 정밀도 및 다른 수행속도를 확인할 수 있었다. 주관적인 청각 평가에서도 MPEG-4 reference 디코더와의 음원의 차이가 거의 없음을 확인하였다.