• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.3
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• pp.272-278
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• 2015

This paper studied various parameter extraction methods using pitch information of speech for the development of the emotion recognition system. For this purpose, pitch parameters were extracted from korean speech database containing various emotions using stochastical information and numerical analysis techniques. GMM based emotion recognition system were used to compare the performance of pitch parameters. Sequential feature selection method were used to select the parameters showing the best emotion recognition performance. Experimental results of recognizing four emotions showed 63.5% recognition rate using the combination of 15 parameters out of 56 pitch parameters. Experimental results of detecting the presence of emotion showed 80.3% recognition rate using the combination of 14 parameters.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.4
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• pp.317-325
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• 2007

Purpose: Biological parameters can be quantified using dynamic PET data with compartment modeling and Nonlinear Least Square (NLS) estimation. However, the generation of parametric images using the NLS is not appropriate because of the initial value problem and excessive computation time. In irreversible model, Patlak graphical analysis (PGA) has been commonly used as an alternative to the NLS method. In PGA, however, the start time ($t^*$, time where linear phase starts) has to be determined. In this study, we suggest a new Multiple Linear Analysis for irreversible radiotracer (MLAIR) to estimate fluoride bone influx rate (Ki). Methods: $[^{18}F]Fluoride$ dynamic PET scans was acquired for 60 min in three normal mini-pigs. The plasma input curve was derived using blood sampling from the femoral artery. Tissue time-activity curves were measured by drawing region of interests (ROls) on the femur head, vertebra, and muscle. Parametric images of Ki were generated using MLAIR and PGA methods. Result: In ROI analysis, estimated Ki values using MLAIR and PGA method was slightly higher than those of NLS, but the results of MLAIR and PGA were equivalent. Patlak slopes (Ki) were changed with different $t^*$ in low uptake region. Compared with PGA, the quality of parametric image was considerably improved using new method. Conclusion: The results showed that the MLAIR was efficient and robust method for the generation of Ki parametric image from $[^{18}F]Fluoride$ PET. It will be also a good alternative to PGA for the radiotracers with irreversible three compartment model.

• Information and Communications Magazine
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• v.20 no.4
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• pp.49-55
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• 2003

• Journal of Korean Society for Quality Management
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• v.36 no.4
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• pp.29-36
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• 2008

최근 자동차 경량화를 위한 부단한 노력이 진행되고 있다. 이 목적에서, HSS (high strength steel)는 전통적인 연강 (mild steel)의 대안으로 널리 사용되고 있다. 본 연구의 목적은 판금의 형단조에 있어서의 공구와 공정설계를 위하여 HSS의 스프링백(springback)을 정확히 예측하기 위한 성공적인 방법론을 추구하고자 함이다. 연구를 위하여 먼저 스프링백의 개념과 그의 측정치들을 설명했으며 U-draw bending 시험을 수행하였다. 시험 결과 및 선정된 파라메터들 중심의 수행평가기준에 근거하여, 주어진 파라메터 조합들을 중심으로 유한요소 해석을 수행하였다. 직교배열을 통하여 스프링백에 대한 인자 효과들을 포괄적으로 분석하였으며 최적 인자 조합들을 도출하였다. 이 과정에서 직교배열상의 한 조합 전체의 데이터가 가용하지 않는 문제가 수반되었으며, 반복적으로 signal-to-noise 비(ratio)를 개선해가는 기법을 적용하여 해결하였다.

• The Journal of the Acoustical Society of Korea
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• v.32 no.2
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• pp.167-173
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• 2013

This work examines classification of diphthongs, as part of a distinctive feature-based speech recognition system. Acoustic measurements related to the vocal tract and the voice source are examined, and analysis of variance (ANOVA) results show that vowel duration, energy trajectory, and formant variation are significant. A balanced error rate of 17.8% is obtained for 2-way diphthong classification on the TIMIT database, and error rates of 32.9%, 29.9%, and 20.2% are obtained for /aw/, /ay/, and /oy/, for 4-way classification, respectively. Adding the acoustic features to widely used Mel-frequency cepstral coefficients also improves classification.

• Journal of Broadcast Engineering
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• v.7 no.4
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• pp.335-344
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• 2002

A sub-picture slice structure is proposed which can perform the region-of-interest coding effectively, where the subjective quality can be improved by coding the region-of-interest in higher quality than the background region. In addition, the bit allocation mechanism is Proposed where the interval between quantization parameters of the foreground and background region is fixed. And the method to reduce the boundary effect between the foreground and background region is proposed. The foreground region is better protected to the network channel error than the background region. which results in the overall subjective quality improvement in the error prone environments.

• The Journal of the Acoustical Society of Korea
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• v.15 no.4
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• pp.50-57
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• 1996

In this paper, we proposed the method of optimal wavelet selection and wavelet expansion of AR(autoregressive) parameters by selected wavelet using F-test. A cost function is introduced as a wavelet selection method. Using this cost function, wavelets (D4 to D20) are tested to the synthesized signal. With this selected wavelet, we get the wavelet coefficients of AR parameters to both synthesized signal and real speech signal. To evaluate the proposed method, this wavelet based algorithm is compared with the Kalman filering algorithm. As a results, the proposed method shows a better performance by about 5-10dB than the Kalman filter.

• The Journal of the Korea Contents Association
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• v.10 no.4
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• pp.106-114
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• 2010

Mesh parameterization is the process of finding one-to-one mapping between an input mesh and a parametric domain. It has been considered as a fundamental tool for digital geometric processing which is required to develop several applications of digital geometries. In this paper, we propose a novel 3D volume parameterization by means that a harmonic mapping is established between a 3D volume mesh and a unit solid cube. To do that, we firstly partition the boundary of the given 3D volume mesh into the six different rectangular patches whose adjacencies are topologically identical to those of a surface cube. Based on the partitioning result, we compute the boundary condition as a precondition for computing a volume mesh parameterization. Finally, the volume mesh parameterization with a low-distortion can be accomplished by performing a harmonic mapping, which minimizes the harmonic energy, with satisfying the boundary condition. Experimental results show that our method is efficient enough to compute 3D volume mesh parameterization for several models, each of whose topology is identical to a solid sphere.

• Journal of Energy Engineering
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• v.9 no.4
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• pp.372-378
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• 2000

확산 모형은 원래 연속적인 확산과정을 개발하기 위하여 도입되었으나, 기본적인 확산 모형은 많은 제약과 가정을 내포하고 있다. 본 논문은 잘못된 추정의 가능성을 줄이기 위해 많은 제약하에서 유용한 데이터가 별로 많지 않은 상태에서의 파라메터 추정을 시도하였으며, DSM 프로그램의 효과를 예측하기 위하여 피이드 백 방법과 비선형 최소자승법에 의한 파라메터를 추정하였다. 또한 DSM에 많은 영향을 끼치는 광고효과를 반영하기 위하여 본 연구에서는 마케팅 변수에 의존하는 수정된 확산모델을 이용하여 수요관리의 모니터링 시스템을 연구하였다. 본 논문에서는 고효율 조명기기에 의한 사례 연구를 통하여 DSM 효과에 의한 전력수요 변화를 추정하였으며, 우리나라 처럼 축적된 자료의 양이 적은 상황에서 초반 추정 오류의 가능성을 줄일 수 있는 방안을 제시하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.3
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• pp.93-98
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• 2005

Silicon bipolar transistors (Si-BJT) are widely used in the telecommunication system such as short range wireless control and wireless indoor voice communication system. New modeling method for the internal current source model of Si-BJT is proposed. The proposed method based on new thermal resistance extraction method and new analytical expressions for the current source parameters of Si-BJT. The proposed method can directly extract the model parameters without any optimization procedure which is adopted in the conventional modeling method. The proposed method is applied to 5 finger $0.4\times20[{\mu}m^2]$ and the model shows good prediction of the measured data in $3[\%]$ of errors proving the validity of this method.