• 한국소음진동공학회논문집
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• 제15권12호
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• pp.1408-1415
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• 2005

Active vibration control of smart hull structure using Macro Fiber Composite (MFC) actuator is performed. Finite element modeling is used to obtain governing equations of motion and boundary effects of end-capped smart hull structure. Equivalent interdigitated electrode model is developed to obtain piezoelectric couplings of MFC actuator. Modal analysis is conducted to investigate the dynamic characteristics of the hull structure, and compared to the results of experimental investigation. MFC actuators are attached where the maximum control performance can be obtained. Active controller based on Linear Quadratic Gaussian (LQG) theory is designed to suppress vibration of smart hull structure. It is observed that closed loop damping can be improved with suitable weighting factors in the developed LQG controller and structural vibration is controlled effectively.

• 한국통신학회논문지
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• 제23권7호
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• pp.1689-1698
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• 1998

본 논문에서는 잡음환경하에서의 과도기형태 신호의 매개변수를 효율적으로 추정하기 위한 새로운 방법을 제안한다. 이 방법은 선형예측모델을 토대로 하여 확장된 차수를 갖는 자기상관유사행렬의 truncated singular value decomposition을 이용한다. 제안된 자기상관유사행렬의 우수성을 보여주기 위하여 감쇄계수가 같은 경우와 감쇄계수가 다른 경우에 대하여 각각 일반적인 데이터 행렬방법과 통계적 성능을 비교분석하였다. 시뮬레이션 결과 데이터 행렬 방법보다 자기상관유사행렬 방법의 통계적 성능이 보다 우수함을 알 수 있었다. 이러한 결과는 부가된 백색잡음의 자기상관지연값이 클 경우에 잡음의 영향이 어느정도 줄어든다는 성질로 부터 기인한다.

• 한국음향학회지
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• 제21권4호
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• pp.156-156
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• 2002

We apply independent component analysis (ICA) for extracting an optimal basis to the problem of finding efficient features for representing speech signals of a given speaker The speech segments are assumed to be generated by a linear combination of the basis functions, thus the distribution of speech segments of a speaker is modeled by adapting the basis functions so that each source component is statistically independent. The learned basis functions are oriented and localized in both space and frequency, bearing a resemblance to Gabor wavelets. These features are speaker dependent characteristics and to assess their efficiency we performed speaker identification experiments and compared our results with the conventional Fourier-basis. Our results show that the proposed method is more efficient than the conventional Fourier-based features in that they can obtain a higher speaker identification rate.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.217-222
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• 2005

Active vibration control of smart hull structure using Macro Fiber Composite (MFC) actuator is performed. Finite element modeling is used to obtain governing equations of motion and boundary effects of end-capped smart hull structure. Equivalent interdigitated electrode model is developed to obtain piezoelectric couplings of MFC actuator. Modal analysis is conducted to investigate the dynamic characteristics of the hull structure, and compared to the results of experimental investigation. MFC actuators are attached where the maximum control performance can be obtained. Active controller based on Linear Quadratic Gaussian (LQG) theory is designed to suppress vibration of smart hull structure. It is observed that closed loop damping can be improved with suitable weighting factors in the developed LQG controller and structural vibration is controlled effectively.

• International journal of advanced smart convergence
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• 제4권1호
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• pp.45-53
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• 2015

This paper is proposed mathematical load modelling based on system identification approach of energy consumption of residential air conditioning. Due to air conditioning is one of the significant equipment which consumes high energy and cause the peak load of power system especially in the summer time. The demand response is one of the solutions to decrease the load consumption and cutting peak load to avoid the reservation of power supply from power plant. In order to operate this solution, mathematical modelling of air conditioning which explains the behaviour is essential tool. The four type of linear model is selected for explanation the behaviour of this system. In order to obtain model, the experimental setup are performed by collecting input and output data every minute of 9,385 BTU/h air-conditioning split type with $25^{\circ}C$ thermostat setting of one sample house. The input data are composed of solar radiation ($W/m^2$) and ambient temperature ($^{\circ}C$). The output data are power and energy consumption of air conditioning. Both data are divided into two groups follow as training data and validation data for getting the exact model. The model is also verified with the other similar type of air condition by feed solar radiation and ambient temperature input data and compare the output energy consumption data. The best model in term of accuracy and model order is output error model with 70.78% accuracy and $17^{th}$ order. The model order reduction technique is used to reduce order of model to seven order for less complexity, then Kalman filtering technique is applied for remove white Gaussian noise for improve accuracy of model to be 72.66%. The obtained model can be also used for electrical load forecasting and designs the optimal size of renewable energy such photovoltaic system for supply the air conditioning.

• 한국지리정보학회지
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• 제14권3호
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• pp.174-187
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• 2011

항공 LiDAR 측량으로 토석류 발생 전 후의 지형자료를 취득하는 경우 토석류로 인하여 유출된 토사량을 알 수 있다. 그러나 토석류 발생지를 미리 예측하여 촬영하기가 힘들고, 토석류 발생 지역의 과거 항공 LiDAR 자료는 존재가능성이 낮아 토석류 발생이전 지형자료를 이용하는 것은 어렵다. 따라서 본 연구에서는 토석류 발생지역의 토사량 추정을 위해 발생전 지형을 복원하고, 토사유출의 공간적 범위를 파악할 수 있는 지형복원기법을 개발하였다. 지형복원기법은 토석류 발생지역에서 추출한 선형 및 비선형 횡단면을 가우시안혼합모델로 수식화하고 중심점 추정방법과 근사정확도로 근사결과를 평가하여 토석류 발생이전의 지형을 복원한다. 지형복원기법은 토석류 발생 전 후의 항공 LiDAR 자료를 이용하여 두 가지 방법으로 검증하였다. 먼저 토석류 발생구간에서 추출한 각 횡단면을 지형복원하여 발생전 항공 LiDAR 자료와 비교하였다. 또한 토석류 발생지역에 지형복원기법을 적용한 뒤 지형자료를 제작하여 토석류 발생전 항공 LiDAR DEM과 비교하여 검증하였다. 지형복원기법의 검증한 결과 전반적으로 근사정확도가 0.5m에 가까운 높은 정확도를 나타냈다.

• 대한기계학회논문집
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• 제17권5호
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• pp.1123-1131
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• 1993

본 논문에서는 비행체의 사이드슬립(sideslip)의 변화를 최소로 하면서 롤(roll) 및 요(yaw) 운동을 제어하는 것을 제어목표로 하여, 입출력 갯수가 같은 정방(square)시스템과 입출력 갯수가 다른 비정방(nonsquare)시스템에 대하여 LQG/LTR 및 비례 재어기를 각각 설계하여 그 성능을 비교분석한다.

• 전기학회논문지
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• 제57권11호
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• pp.2108-2116
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• 2008

The paper concerns Fuzzy C-Means clustering based Radial Basis Function neural networks (FCM-RBFNN) and the optimization of the network is carried out by means of Particle Swarm Optimization(PSO). FCM-RBFNN is the extended architecture of Radial Basis Function Neural Network(RBFNN). In the proposed network, the membership functions of the premise part of fuzzy rules do not assume any explicit functional forms such as Gaussian, ellipsoidal, triangular, etc., so its resulting fitness values directly rely on the computation of the relevant distance between data points by means of FCM. Also, as the consequent part of fuzzy rules extracted by the FCM - RBFNN model, the order of four types of polynomials can be considered such as constant, linear, quadratic and modified quadratic. Weighted Least Square Estimator(WLSE) are used to estimates the coefficients of polynomial. Since the performance of FCM-RBFNN is affected by some parameters of FCM-RBFNN such as a specific subset of input variables, fuzzification coefficient of FCM, the number of rules and the order of polynomials of consequent part of fuzzy rule, we need the structural as well as parametric optimization of the network. In this study, the PSO is exploited to carry out the structural as well as parametric optimization of FCM-RBFNN. Moreover The proposed model is demonstrated with the use of numerical example and gas furnace data set.

• 말소리와 음성과학
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• 제7권1호
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• pp.3-10
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• 2015

In this paper, different frequency scales in cepstral feature extraction are evaluated for the text-independent speaker recognition. To this end, mel-frequency cepstral coefficients (MFCCs), linear frequency cepstral coefficients (LFCCs), and bilinear warped frequency cepstral coefficients (BWFCCs) are applied to the speaker recognition experiment. In addition, the spectro-temporal features extracted by the cepstral-time matrix (CTM) are examined as an alternative to the delta and delta-delta features. Experiments on the NIST speaker recognition evaluation (SRE) 2004 task are carried out using the Gaussian mixture model-universal background model (GMM-UBM) method and the joint factor analysis (JFA) method, both based on the ALIZE 3.0 toolkit. Experimental results using both the methods show that BWFCC with appropriate warping factor yields better performance than MFCC and LFCC. It is also shown that the feature set including the spectro-temporal information based on the CTM outperforms the conventional feature set including the delta and delta-delta features.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
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• pp.70-75
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• 1998

The comparison of Topex/Poseidon sea surface heights and Tide Gauge sea levels was studied in the South Indian Ocean after Topex/Poseidon mission of about 3 years (11- 121 cycles) from January 1993 through December 1995. The user's handbook (AVISO) for sea surface height data process was used in this study Topex/Poseidon sea suface heights ($\zeta$$^{T/P}$), satellite data at the point which is very closed to Tide Gauge station, were chosen in the same latitude of Tide Gauge station. These data were re-sampled by a linear interpolation with the interval of about 10 days, and were filtered by the gaussian filter with a 60 day-window. Tide Gauge sea levels ($\zeta$$^{Argos}$, $\zeta$$^{In-situ}$ and $\zeta$$^{Model}$), were also treated with the same method as satellite data. The main conclusions obtained from the root-mean-square and correlation coefficient were as follows: 1) to Produce Tide Gauge sea levels from bottom pressure, in-situ data of METEO-FRANCE showed very good values against to the model data of ECMWF and 2) to compare Topex/Poseidon sea surface heights of Tide Gauge sea levels, the results of the open sea areas were better than those of the coast and island areas.